Thickness adjustment and stabilizer bar system for a case erector

A case forming machine for erecting cases from knock down case form to an open form and move an opened case downward to a bottom forming station using a fixed and a moveable jaw system is improved by providing a plurality of radially spaced, concentric stabilizer bars fixed to the fixed jaw and arranged to form concentric segments of circles centered on the pivotal axis of the moveable jaw and having their bottom edges in a radial plane relative to the pivotal axis. Also provided is a micrometer type adjustment mechanism that is used for adjusting the gap between the fixed and moveable jaws when the jaws are in the parallel pick-up position.

FIELD OF INVENTION

The present invention relates to a carton or case erector for squaring and erecting a case. More particularly the present invention relates to an improved case stabilizer system capable of stabilizing different sized cases as they are being erected. The present invention also relates to an improved case thickness adjusting system for the erector

BACKGROUND OF THE PRESENT INVENTION

In the manufacture (erection and taping of flaps to produce a carton or case from a knocked down blank) the knocked down carton or case is first squared and then the bottom flaps folded into closed position. The squaring operation generally withdraws a single knocked down case blank from a magazine of such blanks held in face to face position, opens the blank from the knocked down condition into a squared condition wherein adjacent side walls of the case are generally mutually perpendicular and positions the squared blank into a bottom flap folding station. In the bottom flap folding station the minor flaps (generally the shorter flaps) one connected to each of the leading and trailing side panels of the case (oriented in the direction of travel of the case from the erecting station) are folded relative to their respective side panels and then the major flaps one connected to each of the remaining side wall (walls parallel to the direction of travel) are folded into underlining relation (outwardly exposed relation) to the minor flaps. The so erected case is then moved into a bottom closure station which may be a taping station where a tape or adhesive is applied along the bottom major flaps extending in the direction of travel of the case through the taping station to secure the major flaps in folded closed position and thereby the case in squared condition with the adjacent side panels mutually perpendicular. In this condition the top closing flaps are generally in open position so that the case may be filled and then the top flaps are closed and secured in closed position for example by taping or adhesive similar to the bottom taping operation to complete the erecting filling and closing cycle and the filed box is ready for shipment.

U.S. Pat. No. 4,553,954 issued Nov. 10 1985 to Sewell et al. describes the erector to which the present invention is a significant improvement and the disclosure of this patent is incorporated herein by reference. This patent teaches the use of relatively pivoting jaws a fixed jaw oriented perpendicular to the direction of travel of a case through the erector i.e. from a bottom erector station and a moveable jaw that pivots on a pivotal axis between a pick-up or gripping position with the moveable jaw substantially parallel to and spaced from the fixed jaw to a position perpendicular to the fixed jaw. These erectors normally are designed to erect case blanks having significantly different thicknesses so the erector is normally made so that the spacing between the moveable and fixed jaws in the parallel position is adjustable to accommodate knocked down case blanks of different thicknesses. This is accomplished in the prior art by moving the fixed jaw.

The jaws grip the top flaps extending from a pair of adjacent side panels of a case and open (square) the case by pivoting the moveable jaw on the pivotal axis. These jaws in their mutually perpendicular position (open or squaring position) then move the so opened (squared) case down into the bottom erecting station wherein bottom flaps are folded as above described.

In the prior art system a single substantially circular stabilizer bar is removably mounted on the fixed jaw and extends in an arc centered on the pivot axis or hinge point between the jaws and passes through suitable opening in the moveable jaw (to permit the relative movement of the moveable jaw between parallel (pick-up) and open (squaring) position). The stabilizer bar is positioned with its bottom edge in position to contact with to top edges of the other major and minor top flaps adjacent to the free corner (corner remote from the pivotal axis) of the case to keep the case in proper orientation i.e. stop the free corner of the case from moving upward as the case is moved into the bottom forming station. The stabilizer bar must be moveably mounted to accommodate different sized cases i.e. cases having their free corner spaced from the pivotal axis by significantly different lengths and the above described thickness adjustment (change in the space between the fixed and moveable jaws in the parallel pick-up or gripping position) to position the stabilizer bar in a position whereby it will pass through holes in the moveable jaw positioned between adjacent grippers.

In the prior art machine wherein the stabilizer bar position required adjustment when significantly different sized boxes or cases were to be erected the spacing between the jaws in the parallel pick up position which also had to be changed when knocked down blanks for cases of significantly different thickness were to be erected, was adjusted by physically moving the fixed jaw. Movement of the fixed jaw requires unbolting the fixed jaw, moving it and bolting it back in position which also required in many cases that the separator bar that moves the lead blank down from the magazine (see U.S. Pat. No. 4,553,954) required adjustment to be properly positioned relative to the fixed jaw in its new position. These procedures required a significant amount of time and skill to ready the machine to process blanks of the new (different) thickness.

BRIEF DESCRIPTION OF THE PRESENT INVENTION

It is the main object of the present invention to provide an improved stabilizer system requiring no adjustment to accommodate different sized cases.

It is a further object of the present invention to provide a simplified and easier operated adjustment system for accommodating knocked down cases of different thicknesses.

Broadly the present invention relates to a case forming machine for erecting cases from knock down case form to an open form and move an opened case downward to a bottom forming station comprising a fixed jaw and a moveable jaw mounted for movement on a pivotal axis between a pick-up position wherein said fixed and moveable jaws are substantially parallel and an open squaring position wherein said fixed and moveable jaws are substantially perpendicular, a plurality of radially spaced, concentric stabilizer bars fixed adjacent to one end to said fixed jaw and arranged to form concentric segments of circles centered on said pivotal axis, passages through said moveable jaw positioned to permit said bars to pass through said moveable jaw as said moveable jaw is moved between said pick-up and open positions, said bars having their bottom edges in a radial plane relative to said pivotal axis.

Preferably an interconnecting bar interconnects said bars on the side of said moveable jaw remote from said fixed jaw.

Preferably said bars have essentially the same cross sectional shape and a width measured in a direction radial to said pivotal axis significantly less than the height of said bars measured parallel to said pivotal axis.

Preferably said moveable jaw is mounted on an adjustment mechanism that adjusts the position of said moveable jaw so that the gap between said moveable and said adjustable jaw in said parallel pick-up position is changed.

Broadly the present invention also relates to a case forming machine for erecting cases from knock down case form to an open form and move an opened case downward to a bottom forming station comprising a fixed jaw and a moveable jaw mounted for movement on a pivotal axis between a pick-up position wherein said fixed and moveable jaws are substantially parallel and an open squaring position wherein said fixed and moveable jaws are substantially perpendicular, the improvement comprising an adjustment mechanism having a mounting portion and an adjustment portion, said mounting portion mounted for pivotal movement on said pivotal axis and said adjustment portion being moveable relative to said mounting portion in a direction substantially parallel to said fixed jaw when said moveable jaw is in said open squaring position and means to move said adjusting portion relative to said mounting portion thereby adjusting the gap between said fixed and moveable jaws when said jaws are in said parallel pick-up position.

Preferably said means to move comprises a manually operable micrometer type adjustment system.

Preferably a stop damper mounted in a fixed position relative to the fixed jaw dampens movement of said moveable jaw as it approaches said open perpendicular position and stops said moveable jaw in said open perpendicular position.

Preferably a second stop damper mounted in a fixed position relative to the fixed jaw dampens movement of said moveable jaw as it approaches said parallel pick-up position and stops said moveable jaw in said parallel pick-up position.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1illustrates a typical application of the present invention and particularly showing the invention applied to an erector of type described in U.S. Pat. No. 4,553,954 referred to above and incorporated herein by reference.

The erector and sealer10is provided with a magazine12containing knocked down box blanks which are extracted and squared by the mechanism14which include a moveable jaw16and a fixed jaw18. The moveable jaw16is pivoted by a suitable drive as represented and indicated by arrow21on pivotal axis or hinge20between a pick-up or gripping position wherein the jaws16and18are in opposed substantially parallel position (seeFIGS. 2,5and6) and a squaring or open position wherein the jaws are substantially mutually perpendicular as shown inFIGS. 1 and 4. The fixed and moveable jaws18and16carrying an open or squared case24(squared by movement of the jaw16to the perpendicular or squaring position) are then moved vertically by the elevator mechanism schematically indicated at22as indicated by the arrow26. The jaws in pick-up position (substantially parallel) receive a knocked down blank there between and engage and move same from the magazine as described in U.S. Pat. No. 4,553,954 and as indicated below. The jaws16and18are then opened to the position illustrated i.e. at a right angle to each other, to square the case24which is then moved downward as indicated by the arrow26into the bottom flap folding station28(see U.S. Pat. No. 4,553,954 and related improvements forming the subject matter of other about to be applied for patents).

The squared case24has a leading wall panel30(leading in the direction of movement of the case through the machine10from the bottom flap folding station28to and through the bottom sealing station50which in the illustrated arrangement is a tape applying station (as indicated by the arrow52)) to which are connected a leading bottom flap32and a leading top flap34(seeFIGS. 2 and 4). The case24has a corresponding trailing wall36with corresponding trailing bottom38and top40trailing flaps. The leading and trailing wall panels30and36are interconnected by a pair of opposed side wall panels42and44each with their bottom and top flaps46and48(the bottom flap46connected to side wall44is visible inFIG. 3). The shorter leading and trailing sides and flaps are generally referred to as minor side walls or flaps and the longer walls42and44and their respective bottom and top flaps46and48are generally called the major side walls or flaps. Generally but not necessarily the major walls and flaps are oriented parallel to the direction of travel52which as will be apparent is the direction of tape application in the illustrated bottom taper50so the major flaps are folded last and are exposed as the case24is moved into the bottom sealing station50which is shown as a taping station50and the tape is applied to these flaps46.

The folding station28is provided with conventional flap folding equipment for folding the leading flap and trailing flaps32and38to fold these flaps32and38to positions substantially perpendicular to their respective leading and trailing wall panels30and36as the case24is moved down in the direction of the arrows26. Next the major bottom flaps46are folded substantially perpendicular to their respective side wall panels42and44.

The squared case24with its bottom flaps32,38and46folded is then advanced into and through the bottom sealing station50by any suitable mechanism60(in the illustrated version a pusher mechanism (subject of U.S. application Ser. No. 10/981,455 filed concurrently herewith by Makar et al (WEX5) has been shown).

As above described in the prior art machines the most relevant of which (to Applicant's knowledge) is described in U.S. Pat. No. 4,553,954 a single movably mounted stabilizer bar was employed and was moved to the appropriate location when different sized cases were to be erected. This operation required tools and took the operator a significant amount of time to accomplish.

The present invention overcomes many of the shortcomings of the old system by fixing one end of each of a plurality (3in the illustrated embodiment shown inFIGS. 1 to 5) of stabilizer bars100,102and104(see particularlyFIGS. 2 and 3and4) mounted in fixed relation to the fixed jaw18as indicated at106,108and110respectively (seeFIG. 4). These bars100,102and104form quadrants of concentric circles as indicated by the radius r1, r2and r3respectively (seeFIG. 2) centered on the hinge or pivotal axis20about which the moveable jaw16is pivoted when moving between the substantially parallel pick up position (SeeFIG. 5) and the open or squaring position (seeFIGS. 1,2or4) wherein the jaws16and18are mutually perpendicular.

In the illustrated arrangement gripping pins or pin holders112such as those taught in U.S. Pat. No. 4,553,954 but preferably of the type forming the subject matter of application Ser. No. 10/981,455, filed concurrently herewith by Makar et al (WEX4) are positioned adjacent to and between the mountings106,108and110of the bars100,102and104to the jaw18. Similar gripping pins or pin holders114(seeFIG. 1) are provided on the jaw16but are positioned on the opposite side of their respective adjacent bar100,102or104as the pins112. The pins or pin holders112and114are positioned in staggered relationship so that when the jaws16and18are in the parallel pick-up or gripping position (seeFIGS. 2,5and6) the pins or pin holders112and114do not clash and interfere with the closing of the jaw16into the parallel pick-up position relative to the jaw18.

The bars100,102and104pass through suitably positioned holes116,118and120respectively through the jaw16(seeFIG. 2). In the illustrated arrangement a suitable bearing panel122with apertures corresponding to the holes116,118and120through which the bars100,102and104pass is provided. The bearing panel122is made from material that will facilitate relative movement should the bars100,102and/or104come in contact with the sides of the apertures.

In the preferred form of the invention a suitable reinforcing bar123interconnects the free ends124,126and128of the bars100,102and104respectively at the side of the jaw16remote from the jaw18to maintain the correct spacing between these free ends.

As illustrated inFIG. 3the bars100,102and104have essentially the same cross sectional shape and a width w measured in a direction radial to the pivotal axis20significantly less than the height h of said bars measured parallel to said pivotal axis20.

As is apparent inFIGS. 3 and 4the bottom edges132,134and136of the bars100,102and104are in a common radial plane140relative to the axis20and are positioned to engage the top edges of flaps34and48adjacent to the free corner138of the case24(corner remote from the hinge axis20) so that this corner138is positioned at the same level as the opposite corner of the case24when the case24is forced down into the bottom flap folding station28i.e. contact of the bottom flaps with elements of the station28cannot move the top edges of the flaps34and48forming the free corner138upward past the plane140defined by the bottom edges132,134and136which would distort the box or case24.

In theFIG. 4illustration the case24is relatively large and its free corner engages the largest radius bar100, it will be apparent that when smaller cases are being erected the smaller radius bar102or104will engage the free corner138of the small case and function in the same manner. Thus a plurality or range of box or case sizes may be erected without requiring modification of the equipment thereby significantly decreasing down time when the size of the case being erected is significantly changed.

FIGS. 5 and 6show the micrometer adjustment system generally indicated at200for changing the gap dimension g (seeFIG. 6) defining the gap between the two jaws16and18when in parallel pick-up position. This gap dimension g is adjusted by manipulating the gap adjustment micrometer type adjustment system200.

The system200includes a mounting and bumper plate202that is connected to and extends from the hinge having a pivotal axis20described above via a mounting block204. A mounting and adjustment bar206is mounted to slide through and be guided by a passage through the plate202and is connected to the moveable jaw16via the mounting plate208which supports the jaw16in cantilever fashion. The micrometer adjustment mechanism includes a treaded shaft210operated by threads in a corresponding threaded aperture in the block204so that turning the knob212moves the threaded shaft210relative to the block in micrometer type increments. The threaded shaft210is connected to an operating arm214extending from the block206so that movement of the arm214imparts like movement to the block206. The connection between the arm214and the treaded shaft210permits substantially free rotation of the shaft210while preventing relative axial movement between the shaft210and the arm214so that axial movement of the shaft210is applied to the arm214and thereby through the bar206and mounting plate208to the jaw16. Preferably a locking bolt extends from the block204through a suitable slot218in the bar206and is represented by its nut which is in the form of a hand lever216. Turning the hand lever nut216in one direction releases the bar for axial movement (gap adjustment) and adjustment of the gap g and turning of the lever216in the opposite direction forces the bar206against the block204and locks the bar206and thereby the jaw16in adjusted position.

Preferably a suitable damper and stop device250having a bumper252is mounted in fixed relationship to the fixed jaw18and is positioned to be engaged by a portion of the plate202on the side of the bar206remote from the block204. The bumper is mounted on a pneumatically biased shaft254which functions to dampen and aid in stopping the movement of the jaw16at the appropriate position. A similar damper may be provided to dampen and stop the movement of the jaw16as it moves into the parallel pick-up position. It will be apparent that the size of the passages116,118and120will be sufficient to accommodate any displacement of the jaw16by the adjustment mechanism200.

Having described the invention, modifications will be evident to those skilled in the art without departing from the scope of the invention as defined in the appended claims.