CONTINUOUS MOTION CASE PACKING APPARATUS AND METHOD

Abstract: A continuous motion apparatus (A) and method are disclosed where discrete, successive slugs of articles (15) are picked up by pick-up heads (22, 24) revolving in a vertical plane path, and are transferred over a linear transfer section (26) of that path to a case packing station (18). A vertical motion mechanism (20) lowers the pick-up heads at the case packing station (18) to gently place the slugs into indexed cases (28) in a reliable manner. The slugs, pick-up heads, and indexed cases are fed at the same predescribed intervals and at constant speeds. The slug feeder (B) includes a slug converyor (10) and a slug metering section (12). The size of the slug may be easily adjusted by providing an adjustable metering block (124) carried in the metering section which moves in and out of the conveyor path of the articles to meter the number of articles in a slug.

Description: CONTINUOUS MOπON CASE PACKING APPARATUS AND METHOD Background of the Invention The invention relates to an apparatus and method for packing articles into cases, and particularly, to the packing of articles into cases using an apparatus and method having a continuous motion in which successive slugs or groups of moving articles are continuously picked up and transferred into moving cases. In the art of case packing, large numbers of articles must be grouped and packaged rapidly by an apparatus that will function dependably without damage to the articles processed. Case packing apparatus has been generally categorized as either intermittent case packing or continuous case packing. Most recently, attention has been directed to continuous case packing in order to increase production. However, the continuous case packing has brought increased problems with handling the processed articles without damage. In the continuous case packing apparatus, articles conveyed in at least one row of articles are divided up into slugs or groups of articles which are fed to a pick-up position. The slugs of articles are picked up at the pick-up position by article grippers carried by an orbital handling conveyor. The slugs are transferred to a case loading position where the grippers release the slug of articles into a case. The articles can be released either simultaneously or sequentially as the case is conveyed beneath the slug of articles. Apparatus of this type may be either of the "drop packer" type or "placement packer type". In the drop packer type, the articles are allowed to drop at least a small distance into the case after release. In the placement packer type, the drop, if any, is minimal and the articles are essentially placed gently onto the bottom of the case. Various case packers, generally of the continuous motion type, using a vertical orbital conveyor are shown in U. S. Patent Nos. 5,212,930; 4,541,524; and 4,294,057. The first patent shows depositing the articles sequentially and individually, rather than as slugs, into partitioned cases without positively gripping the articles. The latter two patents use gripper devices to grip the articles. U. S. Patent No. 4,457,121 discloses a continuous motion bottle packer wherein a plurality of grids are mounted individually on spokes of a vertical wheel so that each grid moves through an article infeed position where groups of articles are fed into the grid without interrupting the forward speed. The wheel moves the grids and articles to a lower discharge position where the groups of articles are dropped into a case without interrupting the motion of the articles in the direction of a case conveyor which indexes the cases. While continuous, this bottle packer generally of the drop packer type wherein the bottles are dropped into the case through resilient fingers. Also, a control problem is created due to the necessity of varying the speed between the rotating grids and the linearly moving cases in order to coordinate reliable timing of the grid and the case at the case packing position for reliable insertion of the slug. Angular and horizontal accelerations of the articles and their contents are also encountered due to the rotary wheel motion during the transfer which may be detrimental to the article and/or contents. Continuous motion case packers are also known having a vertical rotating wheel which carries a plurality of arms which include two articulating links. A set of article grippers is carried on the ends of the articulating arms. The relative angular positions of the articulating links are controlled to place the article grippers over a slug of articles at a pick-up position, positively grip the slug, and lower the slug to a case packing position where moving cases are indexed with the moving gripper sets. However, during the angular descent from the pick¬ up position to the case packing position, both horizontal and vertical accelerations are encountered by the articles which are gripped only at their tops or necks. U.S. Patent no. 5,313,764 discloses a continuous motion case packer wherein the articles and cases are indexed and conveyed on parallel conveyors arranged one above the other. Steering bars which correspond to the bars of a parallelogram move a gripper set, in the same general direction as the article and case conveyance, between the pick-up and case packing positions. However, again, horizontal and vertical accelerations are produced on the pick-up head and the articles, and timing becomes a problem. Continuous case packers are also known in which a horizontal rotary carousel is used to move vertically reciprocating gripper sets in a horizontal plane. The reciprocating gripper sets pick up a slug of articles at one position and transfer the slug of articles to a second position where the gripper set is lowered to deposit the articles into a case. However, the disposition of the rotary carousel in a horizontal plane requires an inconvenient floor lay-out which also occupies a large amount of floor space. Typically, parallel conveyor arrangements are needed for the articles and the cases adding to the floor space problem. The path of the gripper sets between the slug pick-up position and the case packing position is also typically curved producing angular accelerations and forces on the articles, and the curved article path intersects the path of the conveyed case only for a brief interval. In various of the rotary carousel types, it is known to deposit the articles by lowering the articles, already gripped by the gripper set, through resilient fingers that guide the articles into partitioned cases. Case packers, generally of the intermittent type, are shown in U. S. Patent Nos. 3,553,932 and 3,505,787 which also disclose using combinations of a lifting head having suction cups and bottle grids having pockets for picking up containers and depositing them into cases. The containers and the cases are conveyed on parallel conveyors rather than in-line conveyors, and the transfer from the pick-up position to the case loading position is lateral, or transverse, to the flow of containers and cases. U. S. Patent No. 2,277,688 discloses another case packer using an arrangement of a gripper set and a bottle guide set to package the containers into a case. These type of case packers are generally non-continuous as compared to the continuous motion in-line transfer case packers described above where neither the flow of articles nor the flow of the cases is stopped during operation of the packer. Accordingly, an object of the invention is to provide an improved continuous motion case packing apparatus and method. Another object of the invention is to provide a continuous motion case packing apparatus and method in which slugs of articles are picked up, transferred, and deposited in a case in a reliable, continuous manner without damage to the articles or their contents. Another object of the invention is to provide a continuous motion case packing apparatus and method having a slug feeder which can be adjusted to change over the size of the slug in a quick and easy manner without the need of extensive machine down time and substitution and reassembling of mechanical parts. Another object of the invention is to provide a continuous motion case packing apparatus and method in which slugs of articles are picked up and transferred to a case packing station over a horizontal linear transfer path in which the horizontal speed of the slug is constant, and depositing into a case is done in a gentle vertical motion. Still another object of the invention is to provide a continuous motion case packing apparatus and method having a grid head which includes a matrix of grid finger chutes in which slugs of articles are picked up from overhead, and retained with positive locking within the chutes for transfer and deposit into a case in a reliable and continuous manner. Yet another object of the invention is to provide a continuous motion case packing apparatus and method in which a revolving carriage moves a plurality of transfer arms having sliding article pick-up heads in a vertical plane, closed curve path in a manner that the slugs of articles conveyed in the same plane are picked up, transferred, and deposited into indexed cases conveyed in the same plane in a reliable, continuous manner, and with a minimum amount of floor space. Summary of the Invention The above objectives are accomplished according to the present invention by providing a continuous motion apparatus and method for packing slugs of articles continuously fed at fixed intervals into indexed cases indexed and conveyed at the intervals. The slugs are continuously picked up by a unique carriage with reciprocating article pick-up heads spaced at the fixed intervals, and moved at a constant horizontal speed across a linear transfer section. The articles may be packed into partitioned or non-partitioned cases. The apparatus comprises a slug feeder which receives at least one row of articles and forms successive slugs containing a predetermined number of the articles which are continuously fed to a slug pick-up station where the slugs are continuously picked up for transfer to a case packing station. The revolving carriage carries a plurality of article transfer arms. A plurality of the article pick-up heads is carried by the transfer arms which reciprocate in a linear motion relative to the transfer arms for picking up the slugs at the slug pick-up station, and lowering the slugs at the case packing station for deposit into the indexed cases. The carriage carries the transfer arms and pick-up heads in a curved, vertical plane path which includes the linear transfer section between the slug pick-up station and the case packing station. An actuator is associated with the pick-up heads and has a first position in which a slug of articles is retained by the pick-up head at the slug pick-up station for transfer. The actuator has a second position in which the slug of articles is released for deposit into the case at the case packing station. A case indexing conveyor conveys the indexed cases to the case packing station for receiving the released slug in synchronization with the moving carriage and the slug feeder. Preferably, the pick-up heads include grid heads having a plurality of pivoting grid fingers which are arranged in corners or sides of a grid array corresponding to an array of the articles in the slug, and the cells in a partitioned case. The grid fingers define grid chutes having upper ends and lower ends, and the grid chutes receive the slug of articles. The grid chutes have an open position wherein the lower chute ends are open so that the articles are received into the chutes through the lower ends. The apparatus further includes a vertical motion mechanism for lowering the grid heads relative to the transfer arms over the slug of articles with the grid chutes in the open position. The grid fingers have a closed position for retaining articles in the chutes. The actuator acts upon the grid fingers to move the grid fingers to the open and the closed positions. The actuator includes a grid actuator mechanism for positively holding the grid fingers in the closed position to positively retain the articles in the grid head. The pick-up heads may also include gripper heads carried by the transfer arms for sliding movement on the transfer arms in linear alignment with the grid heads. The gripper heads have a plurality of article grippers arranged in a matrix corresponding to the grid chute and slug array, and the grippers are constructed and arranged to attach to an upper portion of the articles to lower the slug gently into the case. A gripper actuator actuates the grippers, and an actuator arm is carried on the gripper head which engages an abutment carried on the grid head at the case packing station for releasing the slug. The grippers include pivoting gripper jaws constructed and arranged to engage the articles to center the articles in the chutes of the grid head. The case indexing conveyor extends in longitudinal alignment with the slug feeder, and indexes the cases at prescribed intervals at which the slugs are fed by the slug feeder and the transfer arms are moved by the carriage. A synchronized drive for the case indexing conveyor, slug feed conveyor, and the carriage, feeds and conveys the slugs and the cases in unison at a constant horizontal speed for packing.The carriage moves the transfer arms in a closed cyclic path which includes a linear transfer section at least between the pick-up station and the case packing station and a curvilinear return path from the case packing station to the pick-up station. The carriage moves the transfer arms and pick-up heads at a generally constant horizontal speed across the linear transfer section to transfer the slug of articles from the slug pick-up station to the case packing station generally without horizontal acceleration of the articles. The carriage moves the transfer arms and pick-up heads at a generally constant horizontal speed along the linear transfer section to transfer the slug of articles from the slug pick-up station to the case packing station generally without horizontal acceleration of the articles. A vertical motion mechanism connects to the pick-up heads and guides the pick-up heads in a vertical motion so that the pick-up heads are lowered to the case packing station while the carriage moves the pick-up heads at the constant horizontal speed. In an advantageous form of the invention, the slug feeder includes a slug feed conveyor, a slug metering section, and spaced side rails defining at least one lane for receiving the row of articles which extends through the slug conveyor and slug metering sections. The slug metering section includes a revolving flight bar mechanism which has a plurality of engaging flight bars which engage a last of the articles in a slug for conveying the slug of articles through the metering section to the slug pick-up station. The flight bars extend across the slug metering section and rise above a back article in a row of a first slug and a front article in a row of a second slug to tilt the front article rearward and separate the first and second slugs of articles. The slug feed conveyor has a first speed for feeding the articles at a first rate and a second speed for feeding the articles at a second rate which is slower than the first rate. The slug feed conveyor operates at the second speed at least momentarily as the flight bar engages the back articles which facilitates dividing of the articles in the row. A metering block is disposed in each lane. A metering distance is generally defined between the metering block and the flight bar which determines the number of articles in a row of the slug of articles. The metering block is carried by an adjustable carrier by which the metering distance between the metering block and the flight bar may be adjusted so that the number of articles in the row may be adjusted. A drive mechanism moves the metering block in cyclic motions in and out of a conveyance path of the articles in the slug metering section in synchronization with the revolving flight bar. The drive mechanism includes a cam plate carried on the carrier for guiding the metering block in the cyclic motions which include reciprocating horizontal and vertical motions, and a timing cam connected to the cam plate for timing and driving the metering block in the cyclic motions. The timing cam is driven by a drive shaft and the apparatus includes an adjustable coupling which secures the timing cam to the drive shaft by which the relative rotational position between the timing cam and drive shaft may be varied corresponding to the metering distance between the metering block and the flight bar. The slug metering section includes bottom skids carried centrally in the bottom of each lane between adjacent side rails for supporting the bottom of the articles in the lane. The metering block is associated with each skid and slides relative thereto. A plurality of spaced cantilevered pick-up blades are arranged in parallel alignment near an end of the metering section which constitute the slug pick-up station. Advantageously, the grid head includes a locking element associated with the grid fingers for positively maintaining the grid fingers in a chute open position wherein the fingers are vertically positioned near corners of the chutes defined by finger sides. A plurality of spacer bars are spaced across the grid head. The grid fingers are pivotally carried by the spacer bars at a pivot intermediate an upper finger portion of the fingers and a lower main body portion of the fingers. A locking grid is disposed above the upper portions of the fingers and carry the locking elements so that the locking elements engage the upper finger portions and maintain the fingers locked in the open chute position. The locking grid comprises a frame and a plurality of support bars which extend across the frame upon which the locking elements are carried. The locking elements have an apex portion which engages terminal ends of the upper finger portions of the grid fingers for urging the fingers into the chute open position. At least one biasing member urges the locking grid towards the grid head and urges the apex portion of the locking elements into contact with the upper portions of the fingers. Preferably, the grid actuator is provided in the form of an actuator linkage assembly for moving the fingers toward the center of the grid chutes, and an actuator arm which connects to the actuator linkage assembly. A first abutment is carried near the transfer arms in the linear transfer section. The actuator arm is constructed and arranged for engaging the first abutment to move the grid fingers and close the chutes after the grid fingers are received over the slug of articles at the pickup station. The actuator arm includes a fork which has first and second arms. The first arm is engaged by the first abutment to close the grid chutes. The second arm is engaged by a second abutment disposed along the linear transfer section to allow the fingers to move and open the grid chutes after the grid fingers have penetrated a desired distance into the case at the case packing station. The vertical motion mechanism includes guide bearings which are slidably carried by the transfer arms and a cam track which is carried by the frame. A cam roller is carried by the guide bearings which follows the cam track, and the grid heads are carried by the guide bearings for following the cam track. The reciprocating article gripper heads are carried by the transfer arms in alignment with the grid heads by bearing blocks. The gripper heads hold the articles in the slug in a positive manner in conjunction with the grid heads. In accordance with the invention, a method is also disclosed wherein articles are continuously packaged into cases. The method comprises continuously conveying the articles in at least one longitudinal row and continuously dividing the articles into separate, successive slugs of articles wherein the slugs contain a prescribed number of articles. The method further includes conveying the slugs of articles to a slug pick-up station. The slug of articles are picked up at the pick-up station by a linearly reciprocating pick-up head which is carried on a transfer arm. The transfer arm rotates in a vertical plane curved path which includes a linear transfer section between the pick-up station and a case packing station to continuously transfer the slugs. The pick-up head moves vertically in a linear motion to deposit the slug of articles into the case at the case packing station. In another aspect of the method, slugs of articles are continuously picked-up at the pick-up station by grid heads having a plurality of grid chutes arranged in a matrix corresponding to an array of the articles in the slug. The grids are continuously moved into a slug pick-up position directly above the slugs at the slug pick-up station. The grid heads are moved downwardly over the slugs of articles with a lower end of the chutes being open for receiving the articles with the chutes. The articles are retained in the chutes of the grid head while the grid heads are moved from the slug pick-up station to the case pick-up station. The slugs of articles are released from the grid chutes into the indexed cases at the case packing station. The method also contemplates providing a gripper head having a plurality of grippers for gripping the articles, and reciprocating the gripper head in linear alignment with movements of the grid heads. The articles are gripped with the gripper head as the grid chutes move downwardly over the slug for retaining the articles together with the grid head for transfer to the case packing station. In accordance with still further aspects of the invention, the articles are conveyed on a slug feed conveyor to a slug metering section. A first article is fed in the row against a metering device while engaging a last article in the row with a revolving abutment whereby the slug of articles is defined by a metering distance between the metering device and the abutment to fix the number of articles in the slugs. The metering device reciprocates out of contact with the first article so that the abutment may convey the slug away from the metering section to the slug pick-up station. One of the metering device or revolving abutment is mounted on an adjustable carrier so that the metering distance may be adjusted to vary the slug size. Preferably, metering device is mounted on a drive mechanism which moves the metering device in translational and reciprocating motions. The drive mechanism for the metering device is mounted on a oveable carrier so that the metering distance between the metering device and the bar may be adjusted to vary the number of articles in the slug. Description of the Drawings The construction designed to carry out the invention will hereinafter be described, together with other features thereof. The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown and wherein: Figure 1 is a perspective view illustrating a continuous motion case packing apparatus and method according to the invention; Figure 2A is a front elevation of a continuous motion case packing apparatus and method according to the invention; Figure 2B is a side elevation of an infeed end of a continuous motion case packing apparatus and method according to the invention illustrating a laner for feeding articles into longitudinal lanes formed by side rails wherein the laner is disposed above a lower case indexing conveyor and flap opening station; Figure 2C is a schematic elevation illustrating a continuous motion case packing apparatus and method according to the invention illustrating the relative positions of an article transfer arm having gripper and grid heads, a slug of articles, and indexed case prior to article pick-up; Figure 2D is a schematic elevation illustrating a continuous motion case packing apparatus and method according to the invention illustrating the relative positions of an article transfer arm having gripper and grid heads, a slug of articles, and indexed case prior to article pick-up; Figure 2E is a schematic elevation illustrating a continuous motion case packing apparatus and method according to the invention illustrating the relative positions of an article transfer arm having gripper and grid heads, a slug of articles, and indexed case at a slug pick-up station; Figure 2F is a schematic elevation illustrating a continuous motion case packing apparatus and method according to the invention illustrating the relative positions of an article transfer arm having gripper and grid heads, a slug of articles, and indexed case leaving the slug pick-up station; Figure 2G is a schematic elevation illustrating a continuous motion case packing apparatus and method according to the invention illustrating the relative positions of an article transfer arm having gripper and grid heads, a slug of articles, and indexed case at a case packing station; Figure 2H is a schematic elevation illustrating a continuous motion case packing apparatus and method according to the invention illustrating the relative positions of an article transfer arm having gripper and grid heads, a slug of articles, and indexed case after depositing the slug of articles in a case; Figure 21 is a schematic view of a vertical plane, curved path of the article transfer arm of Figures 2C-2H traveled during a complete cycle of the arm according to the invention; Figure 3A is a top plan view illustrating a continuous motion case packing apparatus and method according to the invention wherein a slug feeder, slug pick-up station, case packing station, and linear transfer section are illustrated; Figure 3B is a top plan view taken along line 3 of Figure 2B; Figure 4A is a sectional view taken along line 4A-4A of Figure 3A of the position of a metered slug of articles prior to reaching a slug pick-up station; Figure 4B is a sectional view taken along line 4B-4B of Figure 3A of a slug pick-up station according to the invention; Figure 4C is a sectional view taken along line 4C-4C of Figure 3A of a case packing station according to the invention; Figure 5 is a perspective view of an article transfer arm and a reciprocating grid head having a matrix of grid chutes which fit over a slug of articles to capture and retaining the articles for transfer and case packing in a continuous motion apparatus and method according to the invention; Figure 6 is a sectional view taken along lines 6-6 of Figure 5; Figure 7 is a sectional view taken along line 7-7 of Figure 5; Figure 8A is a sectional view of the grid head of Figure 5 illustrating open grid chutes according to the invention for being place over the tops of articles contained in a slug; Figure 8B is a sectional view taken across a slug pick¬ up station according to the invention wherein open grid chutes are received over the articles contained in the slug; Figure 8C is a sectional view taken across the slug pick-up station of Figure 8B wherein the grid chutes of the grid head are closed to retain the articles in the grid chutes for transfer to a case packing station; Figure 9 is a sectional view of gripper tubes having grippers for engaging necks of articles in a continuous motion case packing apparatus and method wherein the articles may be placement packed; Figure 10 is an enlarged, partial view of a grid head having a plurality of corner grid fingers defining grid chutes according to the invention for picking up articles and transferring articles in a continuous motion apparatus and method according to the invention for being deposited in a partitioned case and the like; Figure 10A is a sectional view taken along line 10A-10A of Figure 10 illustrating a grid chute having four corners formed by fixed corner fingers according to the invention whereby the chute may be maintained open for a reliable fit over a slug; Figure 11 is an enlarged partial section view illustrating the opening and closing of gripper elements on a gripper tube according to the invention for gripping the necks of articles conveyed on a continuous motion apparatus according to the invention; Figure 11A is an elevation illustrating an alternate embodiment for a gripper according to the invention; Figures 11B - HE illustrate another alternate embodiment for a gripper head according to the invention; Figure 12 is a perspective view of a slug feeder and a slug pick-up station according to the invention for use with a continuous motion case packing apparatus and method in accordance with the invention; Figure 13A is a front elevation of an adjustable metering and drive mechanism for varying the number of articles formed into a slug according to a slug feeder of the invention wherein a metering block is illustrated in a first reciprocating position; Figure 13B is a front elevation of an adjustable metering and drive mechanism the metering block is in a second reciprocating position; Figure 13C is a front elevation illustrating an adjustable metering and drive mechanism carrier for an adjustable metering device according to the invention wherein the metering block is in a third reciprocating position below the level of support skids on which rows of articles are conveyed; Figure 13D is a schematic view of the cyclic, reciprocating path of the metering block of Figures 13A-13C; Figures 14A-14D are a series of elevational views illustrating the dividing of a continuous flow of articles into slugs of articles in the slug metering section according to the invention wherein the slug contains a prescribed number of articles; Figure 15 is a perspective view illustrating a synchronized drive arrangement for a continuous motion case packing apparatus and method according to the invention for synchronizing the drives of a revolving carriage and article transfer arms/pick-up heads, a slug feeder, and a case indexing conveyor so that article pick-up heads, indexed slugs of articles, and indexed cases are delivered in a synchronized manner at the same delivery rate for case packing; Figure 16 is a sectional view taken along line 16-16 of Figure 12; Figure 17 is a sectional view taken along line 17-17 of Figure 16; Figure 18 is a perspective view illustrating adjustable lanes and bottom support skids for a slug metering section according to the invention in order to adjust the widths and number of lanes in a slug feeder; Figure 19 is a view taken along line 19-19 of Figure 4A illustrating a continuous motion case packing apparatus and method according to the invention wherein only a reciprocating grid set, shown in a chute open position, is used on an article transfer arm as a drop packer according to the invention; Figure 20 is a view taken along line 20-20 of Figure 4B illustrating a continuous motion case packing apparatus and method according to the invention wherein only a reciprocating grid set, shown in a chute closed position for article pick-up, is used on an article transfer arm as a drop packer according to the invention; Figure 21 is a perspective view illustrating a flap unfolding station for continuously unfolding the flaps of indexed cases being continuously conveyed on a continuous motion case packing apparatus according to the invention; Figure 22 is a sectional view illustrating an adjustable slug metering section according to the invention; Figure 23 is a perspective view of corner grid fingers and orthogonal chute forming members which form four common corners of adjacent grid chutes according to the invention; and Figure 24 is a perspective view with parts separated of an adjustable timing cam coupling for an adjustable metering block mechanism according to the invention. Description of a Preferred Embodiment Referring now in more detail to the drawings, as can best be seen in Figure 1, an apparatus and method for packing articles into cases in a continuous motion is illustrated, designated generally as A. The apparatus includes a slug feeder, designated generally as B which includes a slug feed conveyor 10 and a slug metering section 12. Slug feeder B receives a continuous flow of articles which are conveyed in at least one longitudinal row from a laner section, designated generally as 14. Slug feeder B continuously forms slugs containing a predetermined number of articles, as metered by slug metering sections 12, and continuously feeds the slugs to a slug pick-up station, designated generally as 16. The slugs of articles are picked up at the pick-up station and transferred to a case packing station, designated generally as 18. A revolving carriage, designated generally as C, carries a plurality of article transfer arms 20. A plurality of article pick-up heads in the form of stacked grid heads and gripper heads, designated generally as 22, 24, respectively, are slidably carried on the transfer arms and reciprocate in a linear motion for picking up the slug of articles at pick-up station 16. As can best be seen in Figure 2A, revolving carriage C carries transfer arms 20 and the article pick-up heads in a curved path which includes a linear transfer section 26 which includes the illustrated horizontal distance between pick-up station 16 and case packing station 18 over which the pick-up heads are lowered vertically to gently deposit the articles into a case. For this purpose, a case indexing conveyor, designated generally as D, is disposed below the slug feeder and revolving transfer arms to provide a continuous flow of indexed cases 28 to the case packing station 18 where the articles are gently deposited into the case. For this purpose, as can best be seen in Figure 2A, an interval "L" is provided which spaces the continuous, successive slugs 15, transfer arms 20 and indexed cases 28 so that the case packing process occurs in a synchronized and continuous manner. It is also pointed out, and will be explained fully later, that the rate of delivery, or horizontal speed, of the slugs, transfer arms, and indexed cases is the same. The center-line in the direction of conveyance for article pick-up heads 22, 24, slugs 15, and indexed cases 28 lie in a common vertical plane within linear transfer section 26. The horizontal speed of transfer arms 20 and article pick-up heads over the linear transfer section is constant. This enables trie pick-up heads and cases to track one another accurately for article transfer and case packing. This also provides reliable insertion of the pick-up heads and release of the articles into the case since only a vertical motion is necessary due to the pick-up heads and cases being parallel and vertically aligned for a linear distance within the linear transfer section. The size of slug 15 is determined by the number of longitudinal rows 30 (Figure 3B) and the number of articles in the longitudinal row. In the example illustrated in the drawings, a slug the size of twelve articles is illustrated. This includes four longitudinal rows 30 containing three articles in a row. As determined by the slug metering section 12 (Figure 3A) . The size of the interval "L" in the illustrated embodiment may be 30 inches, for example. This provides sufficient space between successive slugs and indexed cases such that most standard slug and case sizes used in case packers may be accommodated. In particular, large cases with flaps folded to a horizontal position can be accommodated. Revolving Carriage and Article Transfer Arms Referring now in more detail to the revolving carriage and transfer arms, as can best be seen in Figure 5, each transfer arm 20 includes a steel beam 32 having chain connectors connected to the top and bottom of the beam designated generally as 34, 36. Top chain connector 34 includes a plate 34a affixed to beam 32 by any suitable means such as welding, and four legs 34b extending up from plate 34. Each leg 34b includes a roller 34c. Also affixed to plate 34a is a block 36 having a pair of link plates 36a, 36b attached to a carriage chain 38 as the two inside links. As can best be seen in Figure 4A, carriage C includes a front carriage plate 40 and a rear carriage plate 42, spaced apart from each other. Rollers 34c of transfer arm connector 34 ride on tracks 40a and 42a of the respective carriage plates. At the same time, carriage chain 38 moves the transfer arms along a curved path which will be described in conjunction with Figure 21. In addition, side rollers 34d carried by plate 34a roll against the interior sides of carriage plates 40, 42. There are eight transfer arms 20 and each arm includes an upper connector 34 attached to carriage chain 38. As can best be seen in Figures 2A and 3A, carriage chain 38 travels on two sprockets 44 which rotate on journals 44a carried on opposite ends of the front and rear carriage plates 40, 42. The drive for sprockets 44 will be explained in conjunction with Figure 15. Lower transfer arm connector 36 includes a plate 36a having a pair of bottom rollers 36b (Figure 5) . A pair of horizontal connector plates 36c are affixed to plate 36 and are engaged by a bar 46 π affixed to a lower transfer arm drive chain 48. Upper and lower chains 38, 48 are driven in the same direction and hold the opposing connector ends of transfer arms 20 in a fixed, vertical position as the chains run parallel and horizontal across the transfer section of the carriage (Figure 15) . In this position, transfer arms 20 will be connected between a lower run 38a of carriage chain 38 and an upper run 48a of bottom drive chain 48. Both ends of the transfer arm are thus positively conveyed during the pick-up, transfer, and depositing operations. This provides stability and reliability to these operations as the article pick-up heads reciprocate on the transfer arms. Carriage plates 40, 42 may be supported on any suitable frame which includes a pair of vertical standards 50a, 50b affixed to the carriage plates and bolted to a base or floor surface. Referring now to article pick-up heads 22, 24, it can be seen in Figure 4B that pick-up head 22 includes a grid head and pick-up head 24 includes a gripper head. While in the preferred embodiment, both heads 22,24 are slidably carried on the transfer arms, it is to be understood that the heads may also be used alone in certain applications. As can best be seen in Figures 5, 8A, 10, and 10A, grid head 22 includes a plurality of grid closing elements in the form of grid fingers 52 which form an array of grid chutes in a matrix corresponding to the three-by-four matrix of articles 13 in slug 15. The grid chutes, formed by four of the grid fingers, are designated generally as 54. It is preferred that there is a corner grid finger in each corner of the chute so that the finger surfaces 52c define a generally rectangular chute (Figure 23). Basically, grid head 22 may be a suitable grid head such as that shown in U. S. Patent No. 4,215,521, incorporated here by reference, with the below described modifications. It is also to be understood that grid fingers mounted on the sides of the chutes with suitable actuators, as are known in the art, may be used instead of the corner mounted fingers as illustrated. Typically, articles are lowered into such grid sets or heads from the tops of the grid fingers. In accordance with the present invention, the grid head is designed so that grid chutes 54 are open, and held open in a positive manner, so that the open grid chutes may be received over the articles, i.e. the articles enter 16 the grid head from the bottom of the grid. For this purpose, a locking head, designated generally as 56 is provided which includes a plurality of spaced support bars 56a having locking elements 58 carried on the bars (Figure 10) . Locking grid 56 includes a rectangular frame 60 by which support bars 56a are carried. Frame 60 is affixed to grid head 24 by means of adjustable brackets 62. A compression spring 64 is affixed between frame 60 and a frame 66 of grid head 64. This causes a downward force on frame 60 as shown by arrow 65. This urges an apex portion 58a of locking elements 58 into a recess formed by the four upper ends 52d of a set of fingers 52 which form adjacent corners of adjacent chutes. This urges each finger inwardly into the corner of the adjacent chutes whereby the four fingers defining each chute are held in a chute open position for fitting over the individual articles in the slug for pick-up (Figure 23) . In the typical grid set referred to above, a camming arm 70 is provided which opens and closes the fingers, which have perpendicular backsides 52a, 52b. Camming arms 70 engage a first backside of the fingers and include a cam 71 having converging surfaces 71a and 71b, which intersect at ninety degrees, to wedge behind a second, intersecting backside of the fingers as described in detail in the above referenced grid set patent. When the camming arm is vertical, the fingers are closed and the chute is open. When the camming arm is rotated ninety degrees or more (past center) , the fingers open from their corner positions into and towards a center line 54a of chutes 54 to close the chutes. The past center actuation of the finger mechanism provides a positive locking of the fingers in the chute closed position for retaining the articles. Grid fingers 52 pivot about a pivot defined by a retainer ring 72 which also affixes four of the fingers 52 to lateral spacer bars 74 which are spaced across the grid head (Figure 23) , all of which may be more fully seen in the above referenced patent. Each chute corner is formed by two perpendicular, chute forming surfaces so that the corner fingers are maintained truly vertical and correctly positioned for fitting over articles, as can best be seen in Figure 10A. First, camming bar 70 forms one surface for each finger. Second, there are bracing rings 73, surrounding and perpendicular to the camming bars 70, which form the second surface against which each finger is biased by locking elements 58 in the open chute position. In this position, as can best be seen in Figures 8A, 10, and 10A, a lower chute end 68 is provided which is open for receiving articles and which is closed for retaining articles. In accordance with the present application, as can best be seen in Figures 5 and 6, a grid head actuator is provided for opening and closing the grid elements or fingers 52, which includes camming arms 70 and cams 71, and a linkage bar 76 connected to the camming arms. Linkage bar 76 is connected to an actuator rod 76a which in turn is connected to an actuator post 76b by a slidable connector 76c. Actuator post 76b is rotatably journaled in connector plate 36a at a lower end and to connector plate 34a at an upper end so that it may swivel and actuate camming arms 70 to open and close grid chutes 54. This actuation takes place in response to a forked actuator 78 being engaged by certain programmed abutments. Forked arm 78 includes a first arm 78a and a second arm 78b. There is a first chute closing abutment 80 carried in the path of travel of transfer arm 20 and hence actuator arm 78a, and a second chute opening abutment 82 spaced downstream in the travel direction for engagement with second arm 78b. Both abutments may be adjusted to ensure the correct timing of the actuator in closing and opening of the grid chutes. A backup abutment may be provided for each (Figure 2C) for redundancy to assure operation. The first abutment 80 is shown adjustably mounted to rear carriage plate 42 and second abutment 82 is shown adjustably affixed to front carriage plate 40. The operation of the grid head and actuator will be described more fully hereinafter. Referring again to Figure 5, it can be seen that grid set 22 rests on a rack 84 having a pair of spaced arms 84a, 84b which are affixed to a bearing block 86, as can best be seen in Figure 4B. Bearing block 86 includes a cam roller 86a which rides on a first cam track 88. Rack arm 84a is affixed to an opposite side of bearing block 86. By this means, grid head 22 slides and reciprocates linearly on transfer arm 20 in response to the shape of cam track 88. For this purpose, as can best be seen in Figure 6, bearing block 86 includes four corner bearings 86a affixed within the corners of a hollow interior 86b of bearing blocks 86. Transfer arm beam 32 slidably engages the bearings for relative sliding movement therebetween. Referring now to gripper head 24, it too is slidably carried on transfer arm beams 32. As can best be seen in Figure 4B, there is a second bearing block 90 disposed above bearing block 86 which slidably receives beam 32 in a similar construction described above with reference to bearing block 86. A rubber pad 92 is carried by a top perimeter of lower bearing block 86 to cushion the nesting of bearing block 90 on top of bearing block 86. So that the heads may be nested or stacked upon one another along their return path, and at various other stages of operation, rack arms 84a,84b are offset wide on bearing block 86 to accommodate bearing block 90 nesting within the arms. A horizontal arm 90a which is wider than bearing block 90 extends across the front of the bearing block and carries a pair of vertical bars 90b which support a back frame 94 which supports rack arms 94a, 94b. Gripper head 24 sits in rack 94 in direct alignment with grid head 22, as can best be seen in Figures 4A- 4C. The weights of the gripper head and grid head maintain them in their respective racks. Bearing block 90 includes a cam roller 90c which rides on a second cam track 96. Cam tracks 88 and 96 include plastic bushings affixed to the main frame of carriage C by means of aluminum contoured strips having the desired contour of the cam track. The plastic bushings extend part the aluminum retaining strip to engage the cam rollers of the bearing blocks. Referring now in more detail to gripper head 24, it can be seen that the gripper head includes a frame 98 which holds an array of gripper tubes 99 affixed thereto in a manner that can best be seen in Figure 11. Basically, gripper tubes 99 include attachment ends 99a affixed to frame plates 98a as shown. A gripper head actuator includes a reciprocating rod 99b carried within gripper tubes 99 is affixed to a beveled follower 99c having a downwardly and outwardly beveled edge 99d. Gripper elements 100 pivoted at 100a include upper arms 100b received within gripper tube 99. When actuator rod 99b is forced downwardly, beveled camming surface 99d forces ends 100b of the gripper elements inwardly to spread them apart to an open position shown in dotted lines at 102. When rods 99b are not actuated by downward force, a spring 104 urges gripper ends 100b away from each other with a sufficient force to lock opposing gripper jaws 106 about a neck 13a of article 13. Winged jaws 106 also provide a centering device for centering the articles in grid chutes 54 as will become apparent. It is noted that winged jaws 106 include a pair of downwardly and outwardly diverging wings 106a (Figure 4A) . A gripper actuator mechanism, designated generally as 108 includes a pivotal arm 108b which pivots about a pivot 108c. A fixed abutment 66a is shown attached to the frame 66 of grid head 22. Abutment 66a is affixed to a post 66b whose lower portion is attached to frame 66. When grid head 22 and gripper head 24 are in a nested, proximity position shown in dotted lines in Figure 11, abutment 66a urges actuator arm 108a to the horizontal dotted line position shown. This forces an actuator bar 108d downwardly to engage the upper ends of actuator rods 99d there to move actuator head 99c downwardly to pinch ends 100, 100b inwardly to open the grippers. Thus, the gripper jaws are open when the grid head and gripper head are in the proximity position shown in Figure 11. However, when the grid head and gripper head move apart so that abutment 66a comes off actuator arm 108b, arm 108b pivots to the full line position under the force of a spring 108e to return actuator bar 109d to the full line position whereupon spring 104 pushes ends 100b apart to close gripper jaws 106. The article pick-up and case packing operation of the gripper tube head will be described more fully below. Figure HA illustrates another embodiment for a gripper element may be had which includes a resilient gripper element 107 constructed from a polymeric material, or synthetic or natural rubber. The gripper element includes resilient jaws 107a and 107b having interior ledges 107c which grip underneath the article head and around the neck as shown. It is not necessary to open the jaws to receive the article, and to release the article only requires downward actuation of actuator rod 99b. While the head 24 is referred to as a "gripper" head and the gripper elements have been illustrated as mechanical and resilient gripper jaws, it is to be understood, of course, that any element which attaches to the articles such as suction, or otherwise, may be used on the ends of tubes 99. Figures 11B - HE illustrate another alternate embodiment for a gripper head 24' and grid finger head 22'. In this embodiment, it is not necessary to provide a separate positive actuator for opening and closing the grid fingers 52. Instead, the gripper element includes a profiled body which engages the fingers to move the fingers away from the center of the grid chute to the corners of the chutes, as done previously in the operation of grid head 22. Referring now in more detail to alternate embodiment, as can best be seen in Figures 11B - HE, gripper head frame 98 and actuator mechanism, designated generally as 108, are the same as disclosed previously. In the alternate embodiment, there is a gripper actuator tube 109a which moves through a gripper tube 109b when the actuator tube is engaged and moved downwardly by actuator bar 108d. When gripper tube 109a is moved downwardly, a roll pin 109c compresses a spring 109d which is seated on a seated 109n machined in the interior of gripper head tube 109b. As can best be seen in Figure HC, when actuator bar 108d is depressed pushing gripper tube 109a downwardly, a gripper finger actuator 109e is also pushed downward causing a surface 109m to engage finger abutments 1091 and move a pair of gripper fingers 109f apart. In this position, the gripper fingers are spread apart so that a bottle can be accessed for gripping, or released. It is noted that spring 109d is compressed so that when actuator bar 108d is raised back up, actuator tube 109a also moves upwardly under the force of the compressed spring against roll pin 109c. As actuator tube 109a moves upward under the force of the spring, gripper finger actuator 109e is also raised upwardly causing gripper fingers 109f to close around the neck of the bottle due to engagement of finger abutments 109J with a tapering surface 109L formed on gripper actuator 109e. As the gripper ends 109k of the gripper fingers move inwardly, they engage underneath a ridge which protrudes outwardly from the neck of the bottle. The V- force of the spring urging gripper tube 109a upwardly cams gripper ends 109k tightly against the neck of the bottle underneath the ridge. The bottles or other articles are positively gripped until actuator tube 109a is again forced downwardly by actuator bar 108d at the case packing station where it is desired to release the bottles. The tapering of surface 109L facilitates the gripping of different diameter bottle necks which can vary during packing operations. For example, if the diameter of the bottle neck were smaller than that illustrated in Figure HB, actuator tube 109a would move further upwards causing gripper ends 109k to move continuously further inwardly to grip the smaller diameter bottle neck. In the alternate embodiment of Figures HB and HC, it is noted that the gripper elements include a profiled body 109h. This profiled body engages the grid fingers 52 of modified grid head 22', as can best be seen in Figures 11D and HE. In this instance, it is no longer necessary to provide an actuator mechanism for moving the grid fingers to an open position for receiving the bottles and a closed position after receiving the bottles, as described in the previous embodiments. Instead, profiled body 109h engages the fingers on the downward decent of the gripper head through the grid head. The profiled bodies 109h move the fingers into their corner positions to allow gripping of the bottle necks, described in the previous paragraph. Upon gripping of the bottle necks, and raising of the gripper head, the articles are pulled through the grid fingers whereupon the grid fingers are allowed to close beneath the bottles under a spring force, as is typically used. For this purpose, the spring return grid head shown in U. S. Patent No. 4,215,521 may be utilized without the need of forked actuator 78 (Figure 5) . For this purpose, it will be noted that the profiled body of the gripper element has a diameter generally equal to the diameter of the base of the bottle which is being gripped and passed through the grid fingers. To accommodate different bottle diameters, the profiled body of the gripper elements may be replaced likewise. In this manner, as the gripper elements extend down into the grid fingers, and as the gripper fingers approach the ends of the grid fingers, the grid fingers, and grid X chutes defined thereby, are fully opened to the equivalent diameter of the bottles. Accordingly, after the bottles are gripped and pulled upwards through the grid fingers, the profiled bodies hold the grid fingers open until the bottles have passed well up into the fingers. The bottles are held above the pivot point of the grid fingers in the grid head. The same opening of the grid chutes occurs as the gripper tubes descend at the case packing station for slug release. Slug Feeder Slug feeder B will now be described referring to Figures 12, 13A-13D,14A-14D, and 16-18. First, it will be noted that a laner assembly 110 counts the articles and directs them to a longitudinal rows 30 in order to keep the rows filled (Figures 2B and 3B) . Any suitable laner assembly may be utilized such as that disclosed in U. S. Patent No. 4,723,649, incorporated by reference herein. Typically, a laner includes a pivoting guide chute 110a which swings back and forth across a conveyor to discharge a predetermined number of articles into parallel lanes in which the longitudinal rows or articles are formed. Articles may be fed to the pivoting chute either in single file, or scrambled. As pivoting chute 110a moves back and forth, the articles are conveyed through the chute into the lanes by an infeed conveyor 110b. The lanes are defined by spaced side rails 112a-112e. In the illustrated embodiment, there are five such side rails to define four lanes since the exemplary slug is three-by-four. However, it is to be understood that any number of lanes may be utilized in conventional packers depending on the application being made. At least one lane is needed such as in the packing of large, round containers of beverages and food. The spaced side rails extend through the slug feed conveyor 10 and the slug metering section 12, as can best be seen in Figure 3A. The lateral spacing between the side rails may be adjusted so that the number and width of the lanes may be adjusted. This may be done in a conventional manner by suspending the side rails from above on transverse bars spaced above the conveyors wherein removable spacers 113 are fitted over the bars to space the side rails to provide the desired spacing (Figure 12) . In accordance with the invention, a variable speed conveyor 114 is utilized in slug conveyor section 10. Any conventional conveyor belting may be utilized driven in an endless manner. A counter finger 115 may be provided for each lane to count the number of articles in the lane. In the event that an article is not counted, the laner may be directed to direct an additional article to that lane where the article is missing. Referring now to slug metering section 12, slug conveyor 114 terminates at the slug metering section (Figure 3A) and feeds articles to the slug metering section over a transition plate 116 (Figure 2A) . The articles then move over a support floor defined by a plurality of adjustable bottom skids 118 which are centered in the lanes. As can best be seen in Figures 17 and 18, the bottom skids are adjustable so that they may be made to correspond to the side rail spacing when adjusted. For this purpose, an adjustable skid mechanism includes transverse rods 120 (a drive shaft to be described later) which are provided removable spacer blocks 120a are fitted between adjacent bottom skids 118. The skids may be spring loaded to force them inwardly against the spacer blocks. Slug metering section B includes a revolving flight bar mechanism 122 which provides a revolving abutment in the form of flight bars 122a for separating the continuous stream of articles into discrete slugs. It will be noted that flight bars 122a are spaced at an interval "L" apart. The flight bars revolve upwards to divide the articles, and engage the last article 13c in a slug for conveying the slug of articles forward through the metering section (Figure 14D) . The flight bars are carried on an endless chain 122b driven by a drive sprocket 122c and various other idler sprockets 122d. Drive sprocket 122c is driven by a shaft 123 which in turn is driven by a drive sprocket 123a. Drive sprocket 123a is driven by a drive chain 123b in synchronism with the transfer arms 20 and index case conveyor chain 138, to be described in conjunction with Figure 15. As can best be seen in Figures 13A-13D, slug metering section B further includes an adjustable slug metering mechanism which includes a metering block 124 disposed in centrally in each 2< lane which moves in and out of the conveyance path of the articles in a cyclic manner to meter the number of articles in the slug. A metering distance dl, defined between metering block 124 and flight bar 122a, determines the number of articles in the row and the size of the slug (Figure 14D) . There is a drive mechanism 126 for driving slug metering block 124 in cyclic movements in and out of the conveyance path independent of the revolving flight bar mechanism. Drive mechanism 126 includes a cam plate 128 having a pair of drive cam slots 128a and cam pins 128b. There is a drive rod 128c (Figure 12) carried by cam plate 128 on which metering blocks 124 are carried. The metering blocks include a slot 124a which receives bottom skids 118 so that the metering blocks reciprocate in and out of the conveyance paths of articles supported on the skids centered in the lane (Figure 12) . Cam plate 128 is affixed to a drive plate 128c by means of two bolts 128d. Drive plate 128c includes a drive slot 128e which slides on at least one drive pin 128f. Finally, the drive mechanism gets its reciprocating drive from a timing cam wheel 130 having a timing cam slot 130a formed in the wheel. Referring to Figure 16, it can be seen that timing cam 130 is driven off of the same drive which drives flight bar chain 122b by means of a drive chain 131 connected to a drive sprocket 131a, idler sprocket 131b, and timing cam drive sprocket 130e affixed to drive shaft 120 which is also affixed to timing cam shaft 130f. Drive sprocket 131a is driven off of shaft 120 to which driven sprocket 122d of the revolving flight bar mechanism is attached. In an advantageous embodiment of the invention, the drive mechanism just described for metering blocks 124 is mounted on a movable carrier plate 132 which includes a gear rack 132a which meshes with a gear 132b that is rotatable by a handle 132c. Carrier plate 132 may be affixed to each side frame 12a and 12b of the slug metering section by spaced lock bolts with handles 132d extending through adjustment slots 132e. By loosening lock bolts I32d, the carrier plate may be shifted left and right to vary the distance dl between the metering block and the flight bars. In this manner, the size of the slug may be advantageously varied, or the metering section may be adjusted to handle different sized articles regardless of the slug size. This is a highly important advantage of the adjustable metering mechanism and slug metering section of the present invention. Previously, the changeover of slug size or container size required much time and effort in changing out the drive chain and other parts of the metering section to which divider fingers were fixed. When the distance dl between the metering block and flight bar is changed, the timing cam 130 must also be adjusted in its relative position to timing cam drive shaft 13Of. For this purpose, timing cam 130 is mounted on drive shaft 130f by an adjustable coupling, designated generally as 129, between the timing cam wheel and the shaft, as can best be seen in Figure 24. The timing cam wheel may be manually turned so that the relative positions of the timing cam slot 130a and a follower pin 130d may be adjusted and the timing of the metering blocks and their cyclic motion is correct for the new distance dl. It is noted that follower pin 130d is affixed to drive plate 128c and received in camming slot 130a. As illustrated, adjustable coupling 129 includes a female spline 129a formed in an end of shaft 130f, and a male spline 129b formed on the end of a stub shaft affixed to timing cam 130. There is an enlarged bore 129c formed in shaft 123 behind female splines 129a that receives the male splines 129b as a threaded rod 129d is threaded into a threaded hole 129e by manual rotation of knob 130b. In this condition, the timing cam 130 may be rotated relative to shaft 13Of to vary their relative positions. This sets the timing cam in the correct position for the new metering distance dl and slug size. This can be done by visually setting the cam wheel at the same position relative to pin 13Od or using indexing indicia when provided as illustrated. The threaded rod is then backed off bringing the male and female splines back into driving engagement with each other. Thus, it can be seen that the metering block is reciprocated under the drive of the timing cam which is driven in synchronism with the flight bar chain and entire packer. The cam plates include a straight cam slot and a vertically inclined cam slot. The meter block moves longitudinally when the cam pins are in the straight portion of the cam slots. This moves the metering block longitudinally. When the cams are in the angled 2β slots, the metered block slides up and down. The timing cam controls the timing of the meter block movement. The cyclic movement of metering block 124 will now be described by referring to Figures 13A-13C. In Figure 13A, the metering block is to the right and up, extending above the surface of the bottom skids to abut a front a first article 13a in the row of articles contained in the slug. In Figure 13B, metering block 124 is moved to the left and up. In Figure 13C the metering block is to the left and down, i.e it has dropped below the bottom skid 118. In the position of Figure 13B, the articles are conveyed past the metering block forward to the slug pick-up station 16 (Figure 12) . Prior to reaching the slug pick¬ up station, the articles are conveyed onto a support plate 133f making their entrance onto a plurality of pick-up blades 133a- 133e smooth. An article counter mechanism 133g may be utilized to shut down the packer in the event that certain conditions exist in the counting of articles. For example, if three articles are not counted in the correct position in the slug, that is an indication that a bottle may be lying down in the lane, or missing, which could cause a significant malfunction condition at the slug pick-up station, requiring packer shut down to be described in conjunction with Figure 15. Referring to Figures 14A-14D, the operation of the slug metering section will now be described. In Figure 14A, articles 13 are conveyed by the slug feed conveyor onto the bottom skids 118 of the slug metering section. Regardless of the number of lanes or rows, in each row, the first article in the slug is 13a, the second articles is 13b, and the last article is 13c. The first article in the next slug will be 13d. The articles continue to be fed at a desired speed by variable speed slug conveyor 114 onto the support skids. In Figure 14B, the metering biock is up and the flight bar begins to revolve up to divide the articles. The articles are still fed at speed which keeps the articles in contact and together as shown. In Figure 14C, metering block 124 is up and first article 13a engages metering block 124. At this time, as determined by distance dl, flight bar 122a rises underneath article 13d to divide the continuous flow of articles. It will be pointed out that as long as metering block 124 is up, articles 13 will be conveyed at a sufficiently fast speed by conveyor 114 to maintain the articles in contact, as shown. As metering block 124 begins to drop, as can best be seen in Figure 14D, slug feed conveyor 114 will momentarily slow down so that the slug 15 is quickly conveyed away by the revolving flight bar, leaving article 13d behind, and forming a separated slug of articles, with a gap between the next slug. It is important to note that a fast conveyor speed of conveyor 114 will keep articles 13 snugly against each other as long as metering block 124 is up. This enables flight bar 122a, which is above the bottom surface of the articles to lift up first article 13d in the second slug being formed and tilt it rearwardly to divide the articles into slugs. The relative speeds of the revolving flight bar, metering block, and slug conveyor may be controlled using any suitable arrangement, such as that shown in conjunction with Figure 15. Transition plate 116 facilitates transfer from the slug feed conveyor to the bottom skids. Case Indexing and Flap Opening As can best be seen in Figures 2 and 21, a case indexing station/conveyor D is disposed vertically below laner 14 and slug feeder B, and the conveyor continues through case packing station 18. Empty cases, with or without partitions are fed into and indexed at the station. The indexing conveyor includes a driven belt conveyor 136 having two spaced belt runs 136a, 136b with a center drive chain 138 which is separate and independent. Drive chain 138 carries a plurality of case engaging dogs 138a for conveying indexed cases to the case packing station. There is an indexing block 140 carried between the belt runs. The indexing block holds the cases until a first drive chain dog comes up in front of the case. The index block then releases the case. The case is conveyed up against the front dog and then a second, back dog comes up on the chain and engages the back of the case. The case is then held between the front and back dogs of the chain and conveyed through the case packing station. The cases are fed to belt conveyor 136 by a standard roller conveyor (not shown) . For details of a suitable « 3θ case indexing system, reference may be had to U. S. Patent No. 3,986,321, incorporated herein by reference. The indexed cases may be with or without flaps. If the indexed cases have flaps, a suitable flap opening station may be provided. For example, a flap opening station, designated generally as F, may be provided as shown in Figure 21. Flap opening station F may include a pair of suction heads 140a, 140b which pivot from a vertical to a horizontal position under the control of a suitable reciprocating drive arrangement shown to include a cam 141 which rocks 180 degrees and drives the suction head through a chain 141a. In the horizontal position, suction is applied and major flaps 142a, 142b of a case 142 are opened to a vertical position. Next, the case with major flaps held vertical is conveyed underneath a horizontal plow 144 having diverging wings and diverging sides. The diverging plow sides fold the vertical flaps over from the vertical position to a horizontal position. The horizontal flaps are engaged by guide wires 146 on both sides of the plow which hold the major flaps horizontal. Next, the case is conveyed underneath a suspended pivot finger 148 with a hook end 148a which engages a rear flap 142c, and folds it open to a horizontal position. Next, a rocker arm 150 having a freely pivoting pivot finger 150a reciprocates and engages a front minor flap 142d and opens it horizontal. Pivot finger 150a pivots freely in a counter-clockwise direction so that on the return stroke of the rock arm, the pivot finger returns to a home position in which it is generally vertical. After front minor flap 142d is folded horizontal, a reciprocating, horizontal wiper arm 152 pivots forward to wipe over the rear and front minor flaps to ensure they are horizontal before they enter a center angle arm 154 which holds the flaps horizontal. A middle guide wire 154a continues to hold the flaps horizontal as indexed cases move continuously through the conveying process. Outside guide wires 146 and center wire 154a hold the flaps open for case packing through the case packing station. A suitable drive and control arrangement may be provided for the above described flap opening elements as, for example, disclosed in U.S. Patent 4,587,792. As can best be seen in Figure 15, a synchronized drive arrangement is provided for driving carriage C, slug feeder B, and case indexing conveyor D in synchronization and at the same speed so that the article pick-up heads, slugs, and cases are conveyed in intervals "L" for accurate timing of slug pick up and deposit. There is an electric drive motor 160 which drives a system drive shaft 162 through a pulley 162a and clutch 164, which may be any suitable electromagnetic clutch for starting and stopping the case packer operation. Clutch 164 may be actuated and deactuated manually, and in response to a controller 165. There is an upper gear box 166 and a lower gear box 168 driven by drive shaft 162. Upper gear box 166 drives top carriage chain 38, and lower gear box 168 drives the lower carriage chain 48 through a drive sprocket 48a, and drives indexing conveyor chain 138 through a common drive shaft 170 and drive sprocket 172. Revolving flight bar mechanism 122 is driven through drive sprockets 123a and 122c, which are driven off of drive chain 123 and shaft 123 (Figure 12) . Drive chain 123 is driven off of a indexing conveyor chain and shaft 138, 170a in unison therewith, through a drive sprocket 138b. The drive for metering block mechanism 126 has been explained previously in conjunction with the slug feeder. Variable speed slug feed conveyor 114 is driven by a variable speed motor and controller H4a as described in the operation section below. A conventional safety clutch 172 is provided through which the slug feed conveyor and revolving flight bar are driven. If there is a bottle jam, safety clutch will sense this condition and kick out to stop the slug feeder instantly. A signal is also sent to controller 165 to stop the packer. All of the sprockets shown are affixed to the shafts in a conventional manner such as a spline or the like. It is also noted that a programmable limit switch (PLS) 174 may be provided for use with one example of a controller for the apparatus, and is driven off of shaft 170a and clutch 172. PLS 172 provides sequencing of several events over the cycle interval "L" in order that several control functions may be had as described above. The PLS is divided into 300 increments so that the interval "L" is divided into increments of 0.1 inches for the example where "L" is thirty inches. At prescribed increments, or ranges of increments, certain control functions may be looked at. For example, signals from photo cells (not shown) positioned to detect the correct position of an indexed case on conveyor 138 may be processed by controller 165 over a desired increment range to assure that the case will be in a correct position a the case packing station. Photo cells may also be positioned over the cases to look into the cells and detect whether all cells are empty, a flap is closed, or a case is missing. There should be a case every 30 inches or cycle of the PLS. In addition, the PLS is used to vary the speed of slug feed conveyor 114. That is, over a desired increment range, the conveyor is speeded up to keep articles in tight contact in the slug metering section while the metering block is up during slug formation, as described above. Afterwards, the conveyor is reduced in speed to that of the flight bar mechanism or slightly slower. Signals from the article count of sensor 117 in lanes 30 may be looked at over an increment range prior to the slug reaching the slug pick-up station. If three bottles are not counted in their correct position, known by the PLS, a signal is generated and sent to the controller. In the case of any of the above events, signals may be transmitted to controller 165 to deactuate clutch 164 and stop the packer. Controller may be any programmable controller or computer, the provision of a which would be well within the purview of a skilled artisan in the control art, having been taught the principles of the invention. Operation The operation of the apparatus for continuously packing articles into cases and method will now be described referring mainly to Figures 2C-2I and 4A-4C. First, referring to Figure 2C, it can be seen that first cam track 88 and bearing block 86; and second cam track 96 and bearing block 90 provide a vertical motion mechanism by which grid head 22 and gripper head 24, respectively, are caused to slide over transfer arms 20 in reciprocating linear movements to be described in reference to Figures 2C-2G. These movements will first be described by referring to Figure 2C, and locations 1 through 9 on the cam tracks and across the linear path of transfer arm 20 as it is carried by carriage C. At location l, grid head 22 and gripper head 24 are positioned directly above and in alignment with a slug 15, as can best be seen in Figure 2D. Both the grid chutes and the gripper jaws are open. The gripper jaws are open because gripper actuator arm 108a is still engaged by abutment 66a, as can best be seen in Figure 4A. However, as soon as grid head 22 begins its descent over cam track portion 88a, abutment 66a moves downwardly to release gripper actuator arm 108a causing the gripper jaws to close around the necks of articles 13. From locations 2-4, the grid set descends to its lower most position at slug pick-up station 16 (Figure 2E) . At slug pick-up station 16, the gripper jaws grip the articles. The articles 13 have entered the open ends of the grid chutes 54 and the grid fingers defining the chutes have descended a sufficient distance past the bottoms of cantilevered blades 133 to enclose articles 13. Between locations 4 and 5, grid actuator arm 78a engages abutment 80 moving all of the grid fingers toward the center of the chutes to close off the chutes and positively retain the articles in the chutes (Figure 4B) . Thus, it can be seen that the articles are picked-up positively at the pick-up station by both the grid head and gripper head. This redundancy provides a highly reliable and fail safe pick-up of the articles which is particularly advantageous for glass containers. At location 5, Figure 2F, both the grid head and the gripper head begin their descent to case packing station 18 over cam track portions 88c and 96b, respectively. At location 6, Figure 2G, grid set 22 and gripper head 24 are at the case packing position. The closed grid fingers of grid head 22 have penetrated into the case at their lowest point (Figure 4C) . In packing partitioned cases, the closed grid fingers easily enter the individual cells of the partitioned case due to their converging configuration. Obviously, the gripper tubes, grid chutes, slugs, and cells defined by the partitions in the cases are arranged in a corresponding matrix. After the grid fingers have reached their lowest point of travel into the case as defined by cam track portion 88d, second actuator arm 78b strikes second abutment 82 to open the grid chutes. This causes the grid fingers to move away from the center of the chute into the corners of the case cells, or against the chute forming surfaces 70, 73 against which the corner fingers are urged in the chute open position (Figure 10A) when cases without partitions are being packed. For purposes of clarity, the partitions have been omitted from Figure 4C. As the gripper head reaches its lowest point of descent somewhere near the end of cam track portion 96b, gripper actuator arm 108a is again engaged by abutment 66a causing the gripper jaws to open. At this point, bearing block 90 which carries gripper head 24 rests on top of bearing block 86 which carries grid head 24. The nested heads are now in a position to be lifted out of the case for their return trip back to slug pick-up station 16. This occurs between locations 8 and 9 over cam track portion 88e, Figure 2H, whereupon grid head 22 travels upwardly to begin its return trip. Referring to Figure 21, it can be seen that carriage C moves the transfer arm and pick-up heads in a closed, vertical plane curve 160 which includes a linear path 160, which also includes linear transfer section 126, and a curvilinear return path 162. The curvilinear return path may also be considered as including a portion of path 160 in excess of the linear transfer section. Thus, it can be seen that a advantageous construction can be had for a continuous case packing apparatus can be had according to the invention wherein articles may be positively held by article pick-up heads for reliable transfer from a slug pick-up position over a linear section in which no horizontal acceleration occurs, and a vertical descent for case packing is smooth and gentle. The continuous case packer and method may be used as a drop packer with only grid head 22 employed on transfer arm 20 as shown in Figures 19 and 20, or the apparatus may use gripper head 24 and operate more gently as a placement packer, or with both the gripper head and grid head for increase reliability during slug pick up, transfer, and packing. In Figures 19 and 20, the case packer operates the same as described previously, except that gripper head 24 has been removed from rack 94. Slug feeder B and adjustable metering mechanism 124, 126, 130 provide a quick and easy changeover to the packaging of different sizes of slugs without the time consuming replacing of parts and down time required by prior packers. The apparatus and method are thus highly versatile, and provide the 6 manufacturer/packer a high degree of flexibility in the articles being packaged on a given run, which has not been provided before by the prior apparatus. While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims. 3έ>

Claims: What is claimed is: 1. Apparatus for packing articles conveyed in at least one longitudinal row into cases in a continuous motion comprising: a slug feeder receiving said row of articles for forming a slug containing a predetermined number of said articles in said row and conveying said articles to a slug pick-up station; said slug pick-up station supporting said slug of articles in a position to be picked up for transfer to a case packing station; a revolving carriage which carries a plurality of article transfer arms; a plurality of article pick-up heads carried by said transfer arms which reciprocate in a linear motion relative to said transfer arms for picking up said slug of articles at said slug pick-up station; said carriage carrying said transfer arms and pick-up heads in a curved, vertical plane path which includes a linear transfer section between said slug pick-up station and said case packing station; an actuator associated with said pick-up heads having a first position in which a slug of articles is retained by said pick-up head at said slug pick-up station for transfer, and said actuator having a second position in which said slug of articles is released for deposit into said case at said case packing station; and a case indexing conveyor for conveying indexed cases to said case packing station for receiving said released slug in synchronization with said moving carriage and said slug feeder. 2. The apparatus of claim 1 wherein said pick-up heads include grid heads having a plurality of pivoting grid fingers arranged in a grid array corresponding to an array of said articles in said slug, said grid fingers defining grid chutes having upper ends and lower ends, and said grid chutes receive said slug of articles. 3. The apparatus of claim 2 wherein said grid chutes have an open position wherein said lower chute ends are open so that said articles are received into said chutes through said lower ends, and said apparatus includes a vertical motion mechanism for lowering said grid heads relative to said transfer arms over said slug of articles with said grid chutes in said open position. 4. The apparatus of claim 3 wherein said grid fingers have a closed position for retaining articles in said chutes, and said grid actuator acts upon said grid fingers to move said grid fingers to said open and said closed positions. 5. The apparatus of claim 4 wherein said actuator includes a grid actuator mechanism for positively holding said grid fingers in said closed position to positively retain the articles in said grid head. 6. The apparatus of claim 5 including a gripper head carried by said transfer arms together with said grid heads for sliding movement on said transfer arms in linear alignment with said grid heads, said gripper heads having a plurality of article grippers arranged in a matrix corresponding to said grid chute and slug array, and said grippers constructed and arranged to attach to an upper portion of said articles to lower said slug gently into said case. 7. The apparatus of claim 6 including a gripper actuator for actuating said grippers, and an actuator arm carried on gripper head which engages an abutment carried on said grid head at said case packing station for releasing said slug. 8. The apparatus of claim 6 wherein said grippers include pivoting gripper jaws constructed and arranged to engage said articles to center said articles in the chutes of the grid head. 9. The apparatus of claim 8 wherein said gripper jaws include outwardly tapered wings which engage and center said articles. 10. The apparatus of claim 1 wherein said case indexing conveyor extends in longitudinal alignment with said slug feeder, and indexes said cases at prescribed intervals at which said slugs are fed by said slug feeder and said transfer arms are moved by said carriage. 3a 11. The apparatus of claim 1 including a synchronized drive for said case indexing conveyor, slug feed conveyor, and said carriage for feeding and conveying said slugs and said cases in unison at a constant horizontal speed for packing. 12. The apparatus of claim 1 wherein said pick-up heads include a plurality of reciprocating article gripper heads carried by said transfer arms in alignment with said grid heads, and said gripper heads having an array of article grippers arranged in a matrix corresponding to said slug for gripping said articles in said slug. 13. The apparatus of claim 12 wherein said actuator includes a gripper actuator for actuating said grippers to grip said articles, and an abutment carried by said gripper head for actuating said gripper actuation when said gripper head and grid head are in proximity to each other. 14. The application of claim 1 wherein said slug feeder includes a slug feed conveyor, a slug metering section, and spaced side rails defining at least one lane for receiving said row of articles which extends through said slug conveyor and slug metering sections. 15. The apparatus of claim 14 wherein said slug metering section includes a revolving flight bar mechanism having a plurality of engaging flight bars which engage a last of said articles in a slug for conveying said slug of articles through said metering section to said slug pick-up station. 16. The apparatus of claim 15 wherein said flight bars extend across said slug metering section and rise above a back article in a row of a first slug and a front article in a row of a second slug to tilt said front article rearward and separate said first and second slugs of articles. 17. The apparatus of claim 16 wherein said slug feed conveyor has a first speed for feeding said articles at a first rate and a second speed for feeding said articles at a second rate which is slower than said first rate; and said slug feed conveyor operating at said second speed at least momentarily as said flight bar engages said back articles facilitating dividing of said articles in said row. 3=- 18. The apparatus of claim 15 including a metering block disposed in each lane, and wherein a distance generally defined between said metering block and said flight bar determines the number of articles in a row of said slug of articles. 19. The apparatus of claim 18 wherein said metering block and is carried by an adjustable carrier by which said distance between said metering block and said flight bar may be adjusted so that said number of articles in said row may be adjusted. 20. The apparatus of claim 19 including a drive mechanism for moving said metering block in cyclic motions in and out of a conveyance path of said articles in said slug metering section in synchronization with said revolving flight bar. 21. The apparatus of claim 20 wherein said drive mechanism includes a cam plate carried on said carrier for guiding said metering block is said cyclic motions which include reciprocating horizontal and vertical motions, and a timing cam connected to said cam plate for timing and driving of said metering block in said cyclic motions. 22. The apparatus of claim 21 wherein said timing cam is driven by a drive shaft and said apparatus includes an adjustable coupling securing said timing cam to said drive shaft by which the relative rotational position between said timing cam and drive shaft may be varied corresponding to said distance between said metering block and said flight bar. 23. The apparatus of claim 22 wherein said slug metering section includes bottom skids carried centrally in the bottom of each lane between adjacent side rails for supporting the bottom of said articles in the lane, and a metering block is associated with each skid and slides relative thereto. 24. The apparatus of claim 23 including an adjustable skid mechanism which carries said skids for lateral adjustment in slug metering section, and said adjustable skid mechanism includes transverse rods slidably carrying said skids, and removable spacer blocks carried by said rods to vary the center spacing of said skids between side rails. 4o 25. The apparatus of claim 14 including a plurality of spaced cantilevered pick-up blades arranged in parallel alignment near an end of said metering section which constitute said slug pick-up station. 26. Apparatus for continuously packing articles into cases which includes a slug feeder for receiving articles conveyed in at least one row for forming a slug of said articles containing a predetermined number of said articles in said row; and a slug pick-up station for supporting said slug of articles in a position to be picked up and transferred to a case packing station for being deposited in a partitioned case; said apparatus comprising: a plurality of transfer arms; a plurality of grid heads slidably carried by said transfer arms which reciprocate in a linear motion relative to said transfer arms for picking up said slug of articles at said slug pick-up station and for transferring said slug of articles to said case packing station; an array of pivotal grid fingers depending downwardly from said grid heads to define a matrix of grid chutes corresponding to a matrix of said articles in said slug which may be opened and closed; a vertical motion mechanism for lowering said grid heads over said slug of articles at said slug pick-up station with said chute ends extending below a bottom level of said slug of articles when said chutes are open; a carriage carried by a frame for moving said transfer arms between said slug pick-up station and said case packing station; a grid actuator having a first position in which said grid fingers are moved toward a center of said grid chutes for closing said grid chutes to retain said articles while said grid head is moved from said slug pick-up station to said case pick-up station; and said actuator having a second position in which said grid fingers are moved away from said center of said grid chutes to open said grid chutes so that said retained articles retained Λ \ pass through said grid chutes and are deposited in said case at said case packing station. 27. The apparatus of claim 26 wherein said grid head includes a locking element associated with said grid fingers for positively maintaining said grid fingers in a chute open position wherein said fingers are vertically positioned near corners of said chutes. 28. The apparatus of claim 27 including: a plurality of spacer bars spaced cross said grid head; said grid fingers being pivotally carried by said spacer bars in a manner that said grid fingers pivot relative to spacer bars at a pivot intermediate an upper body portion of said fingers and a lower main body portion of said fingers; and a locking grid disposed above said upper portions of said fingers which carry said locking elements so that said locking elements engage said upper finger portions and maintain said fingers locked in said open chute position. 29. The apparatus of claim 28 wherein said locking grid comprises: a frame; a plurality of support bars extending across said frame upon which said locking elements are carried; and said locking elements having an apex portion which engages terminal ends of said upper finger portions of said grid fingers for urging said fingers into said chute open position. 30. The apparatus of claim 29 including at least one biasing member urging said locking grid towards said grid head for urging said apex portion of said locking elements into contact with said upper portions of said fingers. 31. The apparatus of claim 26 wherein said grid actuator comprises an actuator linkage assembly for moving said fingers toward said center of said grid chutes; and an actuator arm connected to said actuator linkage assembly. 32. The apparatus of claim 31 including a first abutment carried near said transfer arms in said linear transfer section; and said actuator arm is constructed and arranged for engaging said first abutment to move said grid fingers and close 41 said chutes after said grid fingers are received over said slug of articles at said pickup station. 33. The apparatus of claim 32 wherein said actuator arm includes a fork having first and second arms; and said first arm is engaged by said first abutment to close said grid chutes, and said second arm is engaged by a second abutment disposed along said linear transfer section to allow said fingers to move and open said grid chutes after said grid fingers have penetrated a desired distance into said case at said case packing station. 34. The apparatus of claim 26 wherein said vertical motion mechanism includes guide bearings slidably carried by said transfer arms, a cam track carried by said frame, a cam roller carried by said guide bearings which follows said cam track, and said grid heads being carried by said guide bearings for following said cam track. 35. The apparatus of claim 26 including a plurality of reciprocating article gripper heads carried by said transfer arms in alignment with said grid heads, said gripper heads having an array of article grippers arranged in a matrix corresponding to said slug for holding said articles in said slug in a positive manner in conjunction with said grid heads. 36. Apparatus for continuously packing articles into cases which includes a slug feeder receiving articles in at least one row for forming successive slugs of articles containing a predetermined number of said articles in said row and continuously feeding said slugs to a slug pick-up station where said slugs are picked up and transferred to a case packing station, said apparatus comprising: a plurality of article transfer arms; a plurality of reciprocating article pick-up heads carried by said transfer arms which slide in a linear motion relative to said transfer arms for picking up said slug of articles at said slug pick-up station and for releasing said slug of articles for deposit into said case at said case packing station; said carriage continuously moving said transfer arms in a curved, vertical plane path to continuously move said pick- A3 up heads and articles from said slug pick-up station to said case packing station; and an actuator for actuating said pick-up head at said pick-up station so that said articles are securely gripped by said pick-up head for transfer, and said actuator actuating said pick-up head at said case packing station for releasing said articles so that said slug of articles is deposited into said case. 37. The apparatus of claim 36 wherein said article pick-up head includes: a grid head having an array of grid chutes arranged in a matrix corresponding to an array of said articles in said slug; said grid chutes having an open position in which said articles may be received within said chutes, and said chutes having a closed position in which said articles are retained within said chutes for transfer to said case packing stations; a vertical motion mechanism for lowering said grid head over said slug of articles at said slug pick-up station with said chutes in said open position; and a grid actuator having first position in which said grid chutes are closed at said pick-up station so that said articles are retained within said grid chutes for transfer, and said actuator having a second position in which said grid chutes are open at said case packing station for releasing said slug of articles into said case. 38. The apparatus of claim 37 including a plurality of reciprocating article gripper heads carried by said transfer arms in alignment with said grid heads, said gripper heads having an array of article grippers arranged in a matrix corresponding to said slug for positively holding said slug of articles in conjunction with said grid heads, and a gripper actuator for actuating said grippers to grip said articles, and an abutment carried by said gripper head for actuating said gripper actuation when said gripper head and grid head are in proximity to each other. 39. The apparatus of claim 37 wherein said grid head includes a locking element associated with said grid fingers for positively maintaining said grid fingers in a chute open position wherein said fingers are positioned near corners of said chutes. 40. The apparatus of claim 36 wherein said article pick-up heads include a plurality of reciprocating article gripper heads carried by said transfer arms, and said gripper heads have an array of article grippers arranged in a matrix corresponding to said slug for positively holding said slug of articles. 41. The apparatus of claim 36 wherein said carriage moves said transfer arms in a closed cyclic path which includes a linear transfer section at least between said pick-up station and said case packing station, and a curvilinear return path from said case packing station to said pick-up station. 42. The apparatus of claim 41 wherein said carriage moves said transfer arms and pick-up heads at a generally constant horizontal speed across said linear transfer section to transfer said slug of articles from said slug pick-up station to said case packing station generally without horizontal acceleration of said articles. 43. The apparatus of claim 42 including a case indexing conveyor disposed below said slug feeder for conveying indexed cases at the same interval at which said slugs are fed by said slug feeder, and including a synchronized drive system for driving said case indexing conveyor, said slug feeder, and said carriage for feeding and conveying said slugs and cases in unison at said constant horizontal speed for case packing. 44. Apparatus for continuously packing articles into cases which includes an infeed conveyor for feeding articles in at least one longitudinal row; said apparatus comprising: a slug feeder for receiving said row of articles and forming successive slugs of said articles containing a predetermined number of said articles; said slug feeder continuously feeding said slugs of articles along a slug feed axis to a slug pick-up station where said slug of articles are continuously picked up for transfer to a case packing station; a plurality of article transfer arms; 4S a plurality of reciprocating article pick-up heads carried by said transfer arms which slide in a linear motion relative to said transfer arms for picking up said slug of articles at said slug pick-up station; a revolving carriage moving said transfer arms and said pick-up heads along a pick-up head transfer axis and having a linear transfer path over which said slugs of articles are continuously transferred between said slug pick-up station and said case packing station; a case indexing conveyor for delivering indexed cases to said case packing station along a case conveyor axis; and said slug feeder axis, said pick-up head transfer axis, and said indexing case conveyor axis lying in a common vertical plane. 45. The apparatus of claim 44 including a synchronized drive for said case indexing conveyor, slug feed conveyor, and said carriage for feeding and conveying said slugs and said cases in unison at a constant horizontal speed for packing. 46. Apparatus for continuously packing articles into cases which includes a slug feeder for receiving said articles from conveyed in at least one row and forming a slug of said articles containing a predetermined number of said articles; and a slug pick-up station for supporting said slug of articles in a position to be picked up for transfer to a case packing station where said slug of articles is deposited into a case; said apparatus comprising: a plurality of article transfer arms; a plurality of reciprocating article pick-up heads carried by said transfer arms for picking up said slug of articles at said slug pick-up station; a carriage moving said transfer arms in a closed cyclic path which includes a linear transfer section at least between said pick-up station and said case packing station, and a curvilinear return path from said case packing station to said pick-up station; said carriage moving said transfer arms and pick-up heads at a generally constant horizontal speed along said linear transfer section to transfer said slug of articles from said slug pick-up station to said case packing station generally without horizontal acceleration of said articles; and a vertical motion mechanism connected to said pick-up heads for guiding said pick-up heads in a vertical motion so that said pick-up heads are lowered to said case packing station while said carriage moves said pick-up heads at said constant horizontal speed. 47. The apparatus of claim 46 wherein said article pick-up heads include: a plurality of grid heads slidably carried by said transfer arms which reciprocate in a linear motion relative to said transfer arms for picking up said slug of articles at said slug pick-up station and for transferring said slug of articles to said case packing station; and an array of pivotal grid fingers depending downwardly from said grid head to define a matrix of grid chutes corresponding to a matrix of said articles in said slug, and said slug of articles being received in said grid chutes during pick¬ up and transfer of said articles. 48. The apparatus of claim 47 including: a plurality of gripper heads having an array of article grippers arranged in a matrix corresponding to a matrix of said articles in said slug for gripping an upper portion of said articles; and said gripper heads being carried by said transfer arms for collinear reciprocation with said grid heads. 49. The apparatus of claim 47 including reciprocating guides carried by said transfer arms which slide in linear motion relative to said transfer arms, and said article pick-up heads being carried by said reciprocating guides for reciprocating linearly relative to said transfer arms. 50. The apparatus of claim 47 wherein said article pick-up heads include a plurality of gripper heads having an array of article grippers arranged in a matrix corresponding to a matrix of said articles in said slug for attaching to an upper portion of said articles. 51. The apparatus of claim 47 including an actuator having a first position for actuating said pick-up head at said pick-up station to retain said articles for transfer, and said actuator having a second position for actuating said pick-up head to release said slug of articles at said case packing station and deposit said articles into said case. 52. A grid head for use with apparatus for continuously packing articles into cases which includes a slug feeder for receiving said articles in at least one row and forming successive slugs of articles containing a predetermined number of said articles; a slug pick-up station for continuously receiving said slugs of articles for pick-up and transfer to a case packing station; a revolving carriage which carries a plurality of transfer arms between said slug pick-up station and said case packing station; a plurality of reciprocating grid heads carried by said transfer arms for picking up said slugs of articles at said slug pick-up station and transferring said slugs to said case packing station; said grid head comprising: an array of pivotal grid fingers depending downwardly from said grid head to define a matrix of grid chutes corresponding to a matrix of said articles in said slug; said grid chutes having lower chute ends through which said slug of articles enter and exit said grid chutes, and said grid chutes having an open position in which said grid chutes are lowered over said articles in said slug at said slug pick-up station; said grid chutes having a closed position in which said articles are retained within said chutes above said lower chute ends for transfer to said case packing station; a grid actuator having a first position in which said grid fingers move toward a center of said chutes for closing said grid chutes at said pick-up station so that said articles are retained within said grid chutes for transfer; and said grid actuator having a second position in which said grid fingers move away from said center of said chute for opening said grid chutes at said case packing station to release said slug of articles for deposit into said case. 3 53. The apparatus of claim 52 wherein said grid head includes a locking element associated with said grid fingers for positively maintaining said grid fingers in a chute open position. 54. The apparatus of claim 53 including: a plurality of spacer bars spaced cross said grid head; said grid fingers being carried by said spacer bars in a manner that said grid fingers pivot relative to spacer bars at a pivot intermediate an upper finger portion of said fingers and a main body portion of said fingers; and a locking grid disposed above said upper portions of said fingers which carry said locking elements so that said locking elements engage said upper finger portions and maintain said fingers locked in said open chute position. 55. The apparatus of claim 54 wherein said locking grid comprises: a frame; a plurality of support bars extending across said frame upon which said locking elements are carried; and said locking elements having an apex portion which engages terminal ends of said upper finger portions of said grid fingers for urging said fingers into said open position. 56. The apparatus of claim 55 including at least one biasing member urging said locking grid towards said grid head for urging said apex portion of said locking elements into contact with said terminal ends of said fingers. 57. A slug feeder for use with apparatus which continuously packs articles into cases which includes a laner for feeding articles in at least one longitudinal row defined by a lane, a lane infeed conveyor for conveying said row of articles; a carriage which carries a plurality of transfer arms; a plurality of article pick-up heads carried by said transfer arms for picking up a slug of articles at a slug pick-up station and for transferring said slug of articles to a case packing station; said slug feeder comprising: & a slug feeder for receiving said row of articles from said laner; a slug feed conveyor included in said slug feeder for receiving articles from said lane infeed conveyor in a continuous manner; a slug metering section included in said slug feeder continuously receiving articles from said slug feed conveyor for creating a slug of said articles containing a predetermined number of said articles; a revolving abutment mechanism carried in said slug metering section having a revolving abutment for engaging a last of said articles in each row of said slug; a slug metering block movably carried in said slug metering section which moves in and out of a path of conveyance of said articles in a cyclic manner independent of said revolving abutment; a metering distance defined between said metering block and said revolving abutment which determines the number of said articles in said row and the size of said slug; a drive mechanism for driving said slug metering block in said cyclic movements in and out of said article conveyance path; and a slug pick-up station continuously receiving said slugs of articles from said slug metering section for supporting said slug of articles for being picked up for transfer to said case packing station for being deposited in a case. 58. The apparatus of claim 57 wherein said slug feed conveyor includes a two-speed conveyor having a first speed for feeding said articles against said metering block, and said conveyor having a second speed for feeding said articles after said metering block has moved out of said article conveyance path, and said second speed momentarily feeds said articles at a slower rate than said first speed whereby said articles in said infeed are maintained in a contacting relation with each other and metering block during said first speed. 59. The apparatus of claim 58 wherein said metering block is carried by an adjustable carrier by which said metering distance between said metering block relative to said revolving <5o abutment may be adjusted to determine the number of articles in said row and said slug size. 60. The apparatus of claim 57 wherein said metering block is carried by an adjustable carrier by which said metering distance between said metering block and said revolving abutment may be adjusted to determine the number of articles in said row and said slug size. 61. The apparatus of claim 60 wherein said revolving abutment mechanism includes a plurality of flight bars which engage said last articles in said slugs for conveying said slugs through said metering section. 62. The apparatus of claim 61 wherein said flight bars extend across said slug metering section and rise to engage a back article in a row of a first slug and a front article in a row of a second slug to tilt said front article rearward and separate said first and second slugs of articles. 63. The apparatus of claim 60 wherein said drive mechanism includes a cam plate carried on said carrier for guiding said metering block is said cyclic motions which include reciprocating horizontal and vertical motions, and a timing cam connected to said cam plate for timing and driving of said metering block in said cyclic motions. 64. The apparatus of claim 63 wherein said timing cam is driven by a drive shaft and said apparatus includes an adjustable coupling securing said timing cam to said drive shaft by which the relative rotational position between said timing cam and drive shaft by be varied corresponding to said distance between said metering block and said abutment. 65. The apparatus of claim 57 wherein said slug pick- up station includes a plurality of spaced cantilevered pick-up blades arranged in longitudinal alignment with the skids which constitute said slug pick-up station. 66. The apparatus of claim 57 wherein said slug feeder includes spaced side rails defining at least one lane for receiving said row of articles which extends through said slug conveyor and slug metering sections, and an adjustable side rail assembly for adjusting the lateral spacing between said side rails so that the number and width of said lanes may be adjusted. S( 67. The apparatus of claim 57 wherein said slug metering section includes bottom skids carried in the bottom of each lane between adjacent side rails for supporting the bottom of said articles in the lane. 68. The apparatus of claim 67 including an adjustable skid mechanism which carries said skids for lateral adjustment in slug metering section, and said adjustable skid mechanism includes transverse rods slidably carrying said skids, and a removable spacer block carried by said rods to vary the center spacing of said skids between side rails. 69. The apparatus of claim 67 wherein said metering block is slidably carried relative to said skid in said lane, and including a drive mechanism for moving said metering block in horizontal and vertical motions independent of said abutment. 70. A method of continuously packaging articles into a case comprising: continuously conveying said articles in at least one longitudinal row; continuously dividing said articles into separate, successive slugs of articles wherein said slugs contain a prescribed number of articles; conveying said slugs of articles to a slug pick-up station; picking up said slug of articles at said pick-up station using a linearly reciprocating pick-up head carried on a transfer arm; rotating said transfer arm in a vertical plane curved path which includes a linear transfer section between said pick¬ up station and a case packing station to continuously transfer said slugs; and moving said pick-up head vertically in a linear motion to lower said slug of articles for deposit into said case at said case packing station. 71. A method of continuously packing articles into a case comprising: continuously conveying said articles in at least one longitudinal row; continuously dividing said articles into slugs of articles wherein said slugs contain a prescribed number of said articles; continuously conveying said slugs of articles to a slug pick-up station; moving a grid head having a plurality of grid chutes arranged in a matrix corresponding to an array of said articles in said slugs into a slug pick-up position directly above said slugs at said slug pick-up station; moving said grid head downwardly over said slug of articles with a lower end of said chutes being open for receiving said articles with said chutes; closing said chutes to retain said articles in said chutes of said grid head while moving said grid head from said slug pick-up station to a case pick-up station; and releasing said slug of articles from said grid chutes into said cases at said case packing station. 72. The method of claim 71 including providing a gripper head having a plurality of grippers for gripping said articles and reciprocating said gripper head in linear movements in alignment with said grid heads; and gripping said articles with said gripper head as said grid head moves downwardly over said slug for retaining said articles together with said grid head for transferring to said case packing station. 73. The method of claim 71 including packing said slugs into partitioned cases having cells defined by partitions within said cases, and providing said array of grid chutes in a matrix corresponding to said cells. 74. A method for continuously packing articles into a case including arranging said articles in at least one longitudinal row; dividing said articles into slugs of articles which contain a predetermined number of said articles; picking said slug of articles up at an article pick-up station and transferring said slug of articles to a case packing station where said slug of articles is deposited into said case; said method comprising: conveying said articles on a slug feed conveyor to a slug metering section; 6 feeding a first article in said row against a metering device while engaging a last article in said row with a revolving abutment whereby said slug of articles is defined by a metering distance between said metering device and said abutment to fix the number of articles between said metering device and said abutment; moving said metering device out of contact with said first article on engagement as said abutment conveys said slug away from said metering section to said slug pick-up station; and mounting one of said metering device or revolving abutment on an adjustable carrier so that said metering distance may be adjusted to vary the slug size. 75. The method of claim 74 including mounting said metering device on a drive mechanism which moves said metering device in transnational and reciprocating motions. 76. The method of claim 75 including mounting said drive mechanism for said metering device on a moveable carrier so that said metering distance between said metering device and said bar may be adjusted to vary the number of articles in said slug. 77. The apparatus of claim 6 wherein said indexed cases consist of partitioned cases having cells defined by partitions within said case, and said cells are arranged in a matrix corresponding to said array of grid chutes and grippers. 78. Apparatus for continuously packing articles into cases which includes a slug feeder for receiving articles conveyed in at least one row for forming a slug of said articles continuing a predetermined number of said articles in said row; and a slug pick-up station for supporting said slug of articles in a position to be picked up and transferred to a case packing station for being deposited in a partitioned case, said apparatus comprising: a plurality of grid heads slidably carried by said transfer arms which reciprocate in a linear motion relative to said transfer arms; an array of pivotal grid fingers depending downwardly from said grid heads to define a matrix of grid chutes corresponding to a matrix of said articles in said slug which may S4 be opened for receiving said articles through opened chutes and closed with said articles generally above lower ends of closed chutes; a gripper head carried by each said transfer arm together with said grid head for sliding movement on said transfer arm in linear alignment with said grid head, said gripper head having a plurality of article gripper elements arranged in a matrix corresponding to said grid chutes and slug array, said gripper elements constructed and arranged to attach to an upper portion of said articles to grip and transfer said slug and to lower said slug gently into said case; a vertical motion mechanism for lowering said grid heads and gripper heads to operative positions relative to said slug of articles at said slug pick-up and case packing stations; a carriage carried by a frame for moving said transfer arms between said slug pick-up and said case packing stations; and said gripper elements including profiled bodies which engage said grid fingers during lowering of said gripper heads to move said grid fingers to said open positions and provide said open chutes for passage of said articles therethrough at said pick-up and case packing stations. 79. The apparatus of claim 78 including a gripper actuator for actuating said gripper elements to grip and retain said articles while said gripper and grid heads are moved from said slug pick-up station to said case pick-up station; and said actuator actuating said gripper elements to release said articles so that said articles are deposited in said case at said case packing station. 80. the apparatus of claim 79 wherein said gripper actuator includes an actuator arm carried on gripper head which engages an abutment carried on said grid head at said pick-up and case packing stations for picking up and releasing said slug. 81. The apparatus of claim 78 wherein said gripper elements include pivoting gripper fingers constructed and arranged to engage said articles, said gripper elements including a gripper finger actuator which is biased in a finger closing direction, and said gripper finger actuator includes a tapering surface which continuously urges said gripper fingers progressively towards said article for gripping of articles with differently dimensioned gripping areas. (o

Inventors: HARTNESS THOMAS PATTERSON, HARTNESS, THOMAS, PATTERSON
Applicants: HARTNESS INT INC, HARTNESS INTERNATIONAL, INC.
Application year: 1995
Main classification: B65B5
IPC codes: B65B21