Packaging method and machine for loading bags of a web of interconnected bags

Abstract: A packaging machine and process for loading bags of a novel web (15) of side connected bags are disclosed. The web is fed through a bagger section (17) by a pair of grooved main transport belts (40,41) and a pair of lip transport belts (48,49) each disposed in the groove (51,52) of the associated main belt to trap bag lips (38,39) in the grooves. Adjustable belt spreaders (61,62) space reaches of the transport belts as they move through a load station (60) whereby to sequentially open the bags (25) into rectangular configurations. A closure section (19) in the form of a novel and improved heat sealer is releasably connectable to the bagger section (17). The sections are adjustable together between horizontal and vertical orientations. Processes of opening, closing and sealing side connected bags are also disclosed.

Description: This invention relates to packaging machinery and more particularly to a packaging machine and method of packaging which are especially well suited for loading relatively bulky and liquid products sequentially into bags of a novel, side interconnected, chain of bags. Background of the Invention U.S. Patent 4,969,310 issued November 13, 1990 to Hershey Lerner et al. under the title Packaging Machine and Method (the SP Patent) discloses a packaging machine which has enjoyed commercial success. One of the major advantages of the machine of the SP Patent resides in a novel conveyor belt mechanism for gripping upstanding lips of bags of a chain as they are transported along a path of travel and registered at a load station. The firmness with which the lips are gripped makes the machine highly suitable for packaging bulky products which are stuffed into the bags. While the machine of the SP Patent was an advance over the prior art, especially in terms of its lip gripping capability, even greater lip gripping capabilities, if achieved, would be useful in enabling packaging of additional products. While the machine was a definite advance over the art, as to any given bag size, it has a finite maximum stuffing pressure it can withstand without slippage. The length of a bag along the path of travel is limited, loading of a bag while it moves along the path of travel is not possible and the concurrent loading of two or more bags is not available. With the machine of the SP Patent there is an intermittent section which includes the loading station and a continuous section which includes a sealing station. The through-put of the machine is inherently less than could be achieved with a continuously operating loading section. One prior machine provides rectangular openings, the dimensions of the rectangular openings, both longitudinally and transversely, are limited both by the construction of the chain of bags being filled and by guide rods used to transport the bags. To the extent, that the packaging machine could be adjusted to vary the configuration of the rectangular opening, such available adjustment was extremely limited because it required substitution of a different set up guide rods. A problem has been experienced with prior art sealers having pairs of opposed belts to transport bags through a seal station. The problem is that too frequently due to weight of the products there is slippage of bags relative to the belts and sometimes of the bag fronts relative to the backs resulting in poor seal quality. Alternatively or additionally it is too often necessary to provide a conveyor or other support for bags as they are transported through the sealer station. It is known from US Patent 4939310 to provide a packaging machine for loading bags of a web of side connected bags comprising: a) a frame structure; b) a bag feed and preparation mechanism carried by the frame structure for pulling a web of side connected bags from a supply and feeding the web along an entrance to a path of travel; c) the feed and preparation mechanism including: i) a pair of main transport belts supported on the frame structure and delineating a load station section of the path of travel; ii) a spreading and folding structure aperture is used to spread and fold bag lips oppositely and respectively over the main transport belts (40, 41); d) a pair of further transport belts each associated with a different one of the main belts for coacting with of the associated main belt to trap such lips between the associated belts; e) a pair of oppositely rotatable sets of pulley structures carried by the frame structure, each of the sets coacting with a different and associated one of the main transport belts to move the belts from closely spaced relationship near the preparation mechanism, through the load station in spaced relationship and return to closely spaced relationship downstream from the load station; f) a transport belt spreader to spread and space reaches of the transport belts as said reaches of the transport belts move through the load station sequentially to open the bags into polygonal configurations as the bags traverse the load station. Summary of the Invention The present invention is characterised over the disclosure of US 4939310 in that the transport belt spreader comprises a pair of spaced apart rails along each of which in use run a respective main transport belt, 41), further transport belt (48, 49) and lip trapped therebetween. With the machine of the present invention, the described problems of the prior art and others are overcome and an enhanced range of available packaging sizes is achieved. In its preferred form the machine has two, independently moveable carriages which are selectively rigidly interconnected. One of these carriages supports a novel and improved bagging section, while the other supports a closure mechanism. The disclosed closure mechanism is a novel and improved sealing section. Because the machine has two separable carriages other closure carriages supporting other closure mechanisms such as bag ties and staples can readily be used. Each of the sections is rotatably mounted on its carriage, such that once coupled the two sections may be rotated together about a horizontal axis for product loading, by gravity and/or stuffing when in the vertical and by stuffing when in the horizontal. Advantageously the two sections may also be oriented in any one of a set of angular orientations between the horizontal and the vertical. A major feature of the present machine is that the loading section opens the bags into rectangular configurations. The transverse and longitudinal dimensions of such openings for any given bag size are relatively and readily adjustable over a wide range. The machine may be operated in either a continuous or an intermittent mode at the operator's selection. Both sections are operated in the same mode. A novel and improved mechanism for gripping upstanding lips of bags as they are transported through the load section utilizes conveyor belts of a type more fully described in a concurrently filed European application EP-A-0 825 116 of Hershey Lerner entitled Plastic Transport System (the Belt Patent). Gripping is achieved by coaction of the bags upstanding lips and unique belts such that belt clamping mechanisms are neither required or relied on. A pair of main transport belts are positioned on opposite sides of a path of web travel. In the preferred embodiment, each main belt has an upstanding lip contacting surface with a centrally located, transversely speaking, lip receiving recess preferably of arcuate cross-sectional configuration. A pair of lip transport belts of circular cross-section are respectively cammed into the main transport belt recesses to force bag lips into the recesses and fix the lips. There is essentially no limit to the length of the loading station and multiple numbers of open bags can be concurrently conveyed through the loading station. With a machine operating on a continuous basis and a synchronized product supply one is able to concurrently transfer a set of products into a like numbered set of bags as the bags and the conveyed products advance through the load station. Another advantage of an elongated load station is that one may position a series of vibrator feeders along the station thus, eliminating the need for a feed conveyor. Extremely high rates of packaging can be achieved. For example, it is possible to load and seal 130 25.4 cm (ten inch) bags per minute. Rates achieved are in excess of those achieved with virtually all, if not all, prior art machines including so called "form and fill" machines. Another feature of the invention is a novel and improved mechanism for breaking frangible interconnections between adjacent sides of successive bags. Assuming the machine to be in its gravity fed horizontal mode, this mechanism comprises a belt which is trained about spaced pulleys which are rotatable about respective horizontal axes. The belt has projecting pins. The belt pulleys are rotated to move the belt in synchronism with positioning of a chain of bags being fed to cause one of the pins to break the frangible bag interconnections each time a set of such interconnections is longitudinally aligned with the belt. Another feature is in a novel and improved mechanism for adjusting the width of the load station by varying the spacing between the pairs of main and lip transport belts. This adjustment, which is infinite between maximum and minimum limits, coupled with the novel and improved bag web, provides a wide range of available transverse and longitudinal dimensions of rectangular bag openings for any given chain of like sized interconnected bags. As loaded bags exit the load station the lead side edge is advanced and the trailing side edge of each bag is retarded to bring inside surfaces of the top portions of each bag back into surface to surface touching orientation for sealing. Oppositely directed jets of air are employed which are effective to reestablish the surface to surface orientation. At an exit from the bagging section of the machine, the main transport belts overlie exit belts which in turn overlie the closure section transport belts. As the bags are transferred to the closure section belts, a rotary knife cuts the bags near their tops such that the lip portions that have been carried by the main transport belts are cut off and become recyclable scrap. The elevation of the cutter relative to the heat sealer is adjustable. In order to prevent excessive heating of bags passing through the sealing section and the sealing section belts, the heat source for effecting the seals is shifted away from loaded bags and the belts when the machine is stopped and moved to a location adjacent the bags when the bags are moving. As the loaded bags pass through the seal section, a series of longitudinally aligned, juxtaposed and individually biased, pressure members act against one of the seal section conveyor belts. These pressure members bias the one belt against the bags and thence against the other belt to in turn bias the other belt against a backup element to maintain pressure on the bag tops as they are transported through the seal section. Advantageously, unlike a prior machine of similar construction, individual coil springs are used to bias the pressure members. The belts used in the seal section are special belts which are effective substantially to prevent any product weight induced slippage of the bags. The belts are also effective to resist relative longitudinal movement of the face and back of each bag. One provision to prevent this relative slippage is providing belts which have corrugated belt engaging surfaces with the corrugations of one belt interlocking with the corrugation of the other to produce a serpentine grip of the face and back of each bag. Further, the preferred belts are metal reinforced polyurethane to provide enhanced resistance to belt stretching. A glue and grit mixture may be applied to the surfaces of the sealer belts, further to inhibit bag slippage. A urethane coating is applied over the glue and grit to complete the improvements. The belts of the sealer section are driven by a stepper motor through a positive drive, so that the sealer stepper motor in synchronism with bagger stepper motor maintain belt and bag feed rates of travel that are consistent throughout the length of path of bag travel. Lips of the bags which project from the seal section conveyor belts are heated by a contiguous heat tube sealer having an elongate opening adjacent the path of bag lip travel. Heated air and radiation emanating from this sealer effect heat seals of the upstanding lips to complete a series of packages. Because the machine sections are either both continuous or both intermittent during machine operation, successive bags passing through the closure section are juxtaposed rather than spaced. This juxtaposition provides improved sealing efficiency and sealer belt life. A web embodying the present invention is an elongate, flattened, thermoplastic tube having face and back sides which delineate the faces and backs of a set of side by side frangibly interconnected bags. The tube includes an elongate top section which is slit to form lips to be laid over and then fixed in the main transport belts. The top section is interconnected to the bags by face and back, longitudinally endless, lines of weakness which are separated from each side edge toward the center of each bag to the extent necessary to achieve the desired rectangular openings. The invention also encompasses a process of packaging which includes gripping the upstanding front and back lip portions between main and lip transport belts. The belts are then spread as they pass through a load station pulling bag openings into rectangular configurations as portions of bag tops are separated from the top section. After bag loading, top portions of the bag inner surfaces are returned to abutting engagement, a portion of the lip section is trimmed from the bags, and the bags are sealed or otherwise closed to complete packages. Accordingly, the objects of this invention are to provide novel and improved packaging machine, packaging materials and methods of forming packages. In the Drawings Figure 1 is a top plan view of the machine of the present invention; Figure 2 is a fragmentary top plan view of the bagger section of the machine of Figure 1 and on an enlarged scale with respect to Figure 1; Figure 3 is a foreshortened elevational view of the bagger section as seen from the plane indicated by the line 3-3 of Figure 1; Figure is a fragmentary perspective view showing an arrangement for flattening bags; Figures 5 and 6 are enlarged sectional views from the planes respectively indicated by the lines 5-5 and 6-6 of Figure 4 show the main and lip transport belts together with a fragmentary top portion of the bag as bag lips are folded over the main transport belts and then trapped in the grooves of the main belts; Figure 7 is an enlarged, fragmentary, sectional view of the transport belt spacing adjustment mechanism as seen from the plane indicated by the lines 7-7 of Figure 2; Figure 8 is an elevational view of a portion of the machine as seen from the plane indicated by the line 8-8 of Figure 1 showing a bag support conveyor underneath the loading and seal sections; Figure 9 is an elevational view of the seal section on an enlarged scale with respect to Figure 8; Figure 10 is an elevational view of the angular orientation maintenance mechanism on an enlarged scale with respect to other of the drawings and as seen from the plane indicated by the line 10-10 of Figure 8; Figure 11 is an enlarged sectional view of the sealer positioning mechanism and a bag support conveyor as seen from the plane indicated by the lines 11-11 of Figure 9; Figure 12 is a sectional view of a web guide as seen from the plane indicated by the line 12-12 of Figure 3; Figure 13 is a sectional view of the lip plow as seen from the plane indicated by the line 13-13 of Figure 3; Figure 14 is an enlarged plan view of a force application element and a fragmentary plan view of the sealer belts; Figure 15 is an enlarged fragmentary plan view of a transfer location between the bagger and the closure sections, including a knife for trimming the tops of loaded bags prior to closure; Figure 16 is a further enlarged sectional view of the structure of Figure 15 as seen from the plane indicated by the line 16-16 of Figure 15; Figure 17 is a still further enlarged view of the knife and its height adjustment mechanism as seen from the plane indicated by the line 17-17 of Figure 16; Figure 18 is a plan view of an alternate and preferred sealer for the closure section; and, Figure 19 is an elevational view of the sealer of Figure 18. Detailed Description of the Preferred Embodiment I. The Overall Machine Referring to Figures 1 and 2 a web of side connected bags 25 is provided. The web is fed from a supply shown schematically at 16 to a bagger section 17. The bagger section 17 is separably connected to a sealer section 19. The bagger and sealer sections respectively include wheeled support carriages 20, 21. The support carriages 20, 21 respectively include support frames for supporting bagging and sealing mechanisms. In the drawings the bagging and sealing mechanisms are shown in their vertical orientations for gravity loading. The machine will be described in such orientation it being recognized that, as described more fully in section IV, the mechanisms may be positioned in a horizontal orientation and at other angular orientations. II. The Web The web is an elongated flattened plastic tube, typically formed of polyethylene. The tube includes a top section 23 for feeding along a mandrel 24, Figure 2. The top section 23 is connected to the tops of a chain of side connected bags 25 by front and back lines of weakness in the form of perforations 27, 28. Frangible connections 30 connect, adjacent bag side edges, Figures 3 and 4. Each bag 25 includes a face 31 and a back 32 interconnected at a bottom 33 by a selected one of a fold or a seal. Side seals adjacent the interconnections 30 delineate the sides of the bags 25. The bag faces and backs 31, 32 are respectively connected to the top section 23 by the lines of weakness 27, 28, such that the top section 23 when the web is flattened itself is essentially a tube. III. The Bagger Section 17 A. A Bag Feed and Preparation Portion 35 The web is fed from the supply 16 into a bag feed and preparation portion 35 of the bagger section 17. The feed is over the mandrel 24 and past a slitter 36, Figure 1. The slitter 36 separates the top section 23 into opposed face and back lips. The feed through the bag feed and preparation portion 35 is caused by a pair of endless, oppositely rotating, main transport belts 40, 41 supported by oppositely rotating pulley sets 42, 43. The main belts 40, 41 are driven by a stepper motor 44, Figure 2 through toothed pulleys 42T, 43T of the sets 42, 43. Other of the pulleys 42S, 43S are spring biased to tension the belts. A plow 45 is provided and shown in Figure 3. For clarity of illustration the slitter and the plow have been omitted from Figure 1. The plow is positioned a short distance upstream from a roller cam 46. As the lips are drawn along by the main transport belts 41, 42, the lips 38, 39 are respectively folded over the top bag engaging surfaces 41S, 42S, of the main transport belts under the action of the plow 45 as depicted in Figure 5. Once the lips are folded over the tops of the main transport belts 41, 42, the roller cam 46 presses endless, lip transport and clamp belts 48, 49 into complemental grooves 51, 52 in the main transport belts 41, 40 respectively. Thus, the grooves 51, 52 function as bag clamping surfaces that are complemental with the clamping belts 48, 49. More specifically, the clamp belts are circular in cross section, while the grooves 51, 52 are segments of circles, slightly more than 180° in extent. The camming of the clamp belts into the grooves traps the lips 38, 39 between the clamp belts and the grooves. The lip clamping firmly secures the lips between the coacting belt pairs such that the lips, due to their coaction with the belts, are capable of resisting substantial stuffing forces as products are forced into the bags at a load station 60. Sections of the clamp belts which are not in the grooves 51, 52 are trained around a set of lip transport belt pulleys 50. A bag side separator mechanism 53 is provided at a bag connection breaking station. The separator mechanism 53 includes an endless belt 54 which is trained around a pair of spaced pulleys 55 to provide spans which, as shown in Figure 3, are vertical. The pulleys 55 are driven by a motor 57, Figure 2. As the belt is driven breaking pins 58 projecting from the belt 54 pass between adjacent sides of bags to break the frangible interconnections 30. Thus, as the bags depart the bag feed and preparation portion 35, they are separated from one another but remain connected to the lips 38, 39. B. The Load Station 60 The load station 60 includes a pair of parallel belt spreaders 61, 62. The belt spreaders are mirror images of one another. As is best seen in Figure 7, the belt spreaders respectively include channels 63, 64. The channels 63, 64 respectively guide the main transport belts 40,41, on either side of the load station 60. When the transport belts 40,41, are in the channels 63, 64, as is clearly seen in Figure 7, the bags 25 are stretched between the belts in a rectangular top opening configuration. A schematic showing of a supply funnel 66 is included in Figure 3. As suggested by that figure, the products to be packaged are deposited through the rectangular bag openings each time a bag is registered with the supply funnel at the load station. A space adjusting mechanism is provided. This mechanism includes a spaced pair of adjustment screws 68, 69, Figure 2. The adjustment screw 68, 69 are respectively centrally journaled by bearings 70, 71. The screws have oppositely threaded sections on either side of their bearings 70, 71 which threadably engage the belt spreaders 61, 62. Rotation of a crank 72 causes rotation of the adjustment screw 69. The screw 69 is connected to the screw 70 via belts or chains 73, which function to transmit rotation forces so that when the crank 72 is operated the screws 68, 69 are moved equally to drive the spreaders equally into an adjusted spacial, but still parallel, relationship. As the spreaders are movably adjusted toward and away from one another, the spring biased pulleys 42S, 43S maintain tension on the main transport belts 40, 41 while permitting relative movement of spans of the belts passing through the spreader channels 63, 64. Similarly, spring biased lip transport belt pulleys 50S maintain tension on the clamp belts 48, 49. The spring biased pulleys of both sets are the pulleys to the right as seen in Figure 2, i.e. the entrance end pulleys in the bag feed and preparation portion 35. The main transport pulley sets 42, 43 include two idler pulleys 75, 76 downstream from the load station 60. The idler pulleys 75, 76 are relatively closely spaced to return the main transport belts 40, 41 into substantially juxtaposed relationship following exit from the load station 60. C. Bag Stretching As loaded bags exit the load station, it is desirable to return upper portions of the bag faces and backs into juxtaposition. This stretching of the now loaded bags as they exit the load station is accomplished with jets of air from nozzles 110, 112 which respectively blow against the lead and trailing edges of the bag, thus stretching the bags from their rectangular orientation into a face to back juxtaposed relationship as the transport belts are returned to juxtaposition. D. A Transfer Location After loaded bags have exited the load station 60 and the face and back of each bag have been brought into juxtaposition, the loaded bags are transferred to the closure section 19 at a transfer location 114. Exit conveyors 115, 116 underlie the main transport belts 40, 41 at an exit end of the bagger section 7. Loaded bags are transferred from the main transport belts to the exit conveyors. The exit conveyors in turn transfer the loaded bags to closure section conveyor belts 118, 119. Referring to Figures 15-17, a rotary knife 120 is positioned a short distance downstream from the exit conveyors. The knife is rotatively mounted in an externally threaded support tube 121. The tube in turn is threadedly connected to a knife support frame section K. An adjustment lock 123 is slidably carried by the frame section K. When the lock 123 is in the position shown in solid lines in Figure 17, it engages a selected one of a plurality of recesses R in the perimeter of the support tube 121 to fix the knife in an adjusted height position. When the lock 123 is slid to the phantom line position of Figure 17, the tube 121 may be rotated to adjust the vertical location of the knife 120. The knife 120 is driven by a motor 122 to sever the bag lip portions 38, 39, leaving only closure parts of the lip portions for closure, in the disclosed arrangement, by heat sealing. The trimmed plastic scrap 124, Figure 8, from the severed lip portions is drawn from the machine with a conventional mechanism, not shown, and thereafter recycled. IV. The Closure Section 19 As is best seen in Figure 1, the novel and improved sealer includes a plurality of independently movable force application elements 125. One of the force elements is shown on an enlarged scale in Figure 14. The force elements 125 slidably engage the outer surface of a bag engaging run 126 of the belt of the conveyor 119. Springs 128 bias the elements 125 to clamp the bag faces and backs together against a coacting run 130 of the conveyor belt 118. A backup 132 slidably engages the coacting run 130 to resist the spring biased force of the application elements 125. A stepper motor 134, Figure 1, is drivingly connected to the closure section conveyor belts 118, 119 to operate in synchronism with the stepper motor 44 of the bagger section, either intermittently or continuously. As is best seen in Figures 9 and 11, a heater tube 135 is provided. A heat element 136, Figure 11, is positioned within the tube to provide heat to fuse upstanding bag lips when the heater tube 135 is in the position shown in solid lines in Figure 9. The heat transfer to the lips is effected by both radiation and convection through an elongate slot 135S in the bottom of the tube. The heater tube 135 is connected to a pair of supports 137, 138. When the bags 25 are vertical the heater tube 135 is suspended by the supports 137, 138. The supports in turn are pivotally connected to and supported by a pair of cranks 140, 142. The cranks 140, 142 are pivotally supported by a section of the frame of the sealer carriage 21. The cranks 140, 142 are interconnected by a rod 144 which in turn is driven by an air cylinder 145. The air cylinder 145 is interposed between the carriage frame and the rod 144. Reciprocation of the air cylinder is effective to move the heat tube between its seal position shown in solid lines and a storage position shown in phantom, Figure 9. When the conveyor belts 118, 119 are operating to transport bags through the closure section the sealer is down, while whenever the machine is stopped the sealer is shifted to its storage or phantom position of Figure 9. As is best seen in Figure 14, the adjacent runs 126, 130 of the sealer conveyor belts 118, 119 have surfaces that are corrugated and interfitting. These interfittings corrugations provide both enhanced bag gripping and holding power and resistance to relative longitudinal movement of the runs as well as the faces and backs of the bag. The gripping and holding power of the belts is further enhanced by coating the belts with a glue and sand slurry and applying a polyurethane coating over the slurry to further enhance the frictional grip of the belts on bags being transported. The combined effects of the belt corrugations and coating substantially prevent slippage of the bags due to weight in the bags. V. Section Interconnection and Adjustments A. Section Interconnection The bagger and closure sections 17,19 are physically interconnected when in use. In the disclosed arrangement this interconnection includes a pair of lock bars 150. The lock bars which are removably positioned in apertures 151,152 formed in bosses 154,155 respectively projecting from frames of the bagger and closure stations 17,19. B. Angular Positioning As has been indicated, the bagger and closure sections are adjustable to horizontal or vertical orientations as well as angular orientations between the horizontal and the vertical. The bagger section 17 is rotatably supported on a pair of trunions one of which is shown at 157 in Figure 3. As can best be seen in Figures 8 and 9, the sealer section 19 is rotatably supported on the carriage 21 by spaced trunions 170, 172. The trunions 157,170 & 172 are axially aligned. The end trunion 170, to the left as viewed in Figures 8 and 9, is associated with an angular position holder. The holder includes an apertured plate 174 secured to and forming part of the frame of the carriage 21, Figure 10. The plate 174 includes a set of apertures 175 spaced at 15° intervals to provide incremental angular adjustments of 15° each between the horizontal and vertical orientations of the machine. Each of the apertures 175 may be selectively aligned with an aperture in a sealing section plate 176. A pin in the form of a bolt 178 projects through aligned apertures to fix the sealer section and the interconnected bagger section in a selected angular orientation. VI. A Support Conveyor While there normally is no need for bottom support of the bags 25 as they pass through the bagger section 17, nonetheless a conventional support conveyor 160 may be provided, see Figure 3. More frequently a conveyor 162 will be provided under the closure section 19. In either event, suitable height adjustment and locking mechanisms 164 are provided to locate the conveyors 160,162 in appropriate position to support the weight of loaded bags being processed into packages. VII. The Preferred Sealer Referring to Figures 187 and 19 , the preferred sealer for the closure mechanism is disclosed. The sealer includes an air manifold 180 for receiving air from a blower 182. In an experimental prototype a 8.5 cubic metres (300 cubic foot) per minute variable pressure blower was used to determine optimized air flows and pressures. The manifold 180 has three pairs of oppositely disposed outlets 184, 185, 186. Each outlet is connected to an associated one of six flexible tubes 188. The tubes in turn are connected to pairs of oppositely disposed, T-shaped sealer units 190,191,192 to respectively connect them to the outlets 184,185,186. The T-shaped sealer units respectively include tubular legs 190L,191L,192L extending vertically downward from their respective connections to the flexible tubes 188 to horizontal air outlet sections 190H,191H,192H. The outlet sections are closely spaced, axially aligned, cylindrical tubes which collectively define a pair of elongate heater mechanisms disposed on opposite sides of an imaginary vertical plane through the loaded bag path of travel. Each horizontal outlet section includes an elongate slot for directing air flow originating with the blower 182 onto upstanding bag lips being sealed. Each of the sealer unit legs 191,192 houses an associated heater element of a type normally used in a toaster. Thus air flowing through the T--shaped units 191,192 is heated and the escaping hot air effects seals of the upstanding bag lips. Air flowing through the units 190 is not heated, but rather provides cooling air to accelerate solidification of the seals being formed. The T-shaped sealer units 190,191,192 are respectively connected to the rod 144 for raising and lowering upon actuation of the air cylinder 145 in the same manner and for the same purpose as described in connection with the embodiment of Figures 8 and 9. A further unique feature of the embodiment of Figures 18 and 19 is a vertical adjustment mechanism indicated generally at 194. The vertical adjustment 194 permits adjustment of the slope of the horizontal sections of the t-shaped units 190-192 such that the outlet from 191H is lower than that of 192H. This downward sloping of the heater mechanism in the direction of bag travel assures optimized location of the hot air being blown on the plastic. The location is optimized because as the plastic melts it sags lowering the optimum location for the direction of the hot air. Further the cooling air from the unit 190 is directed onto a now formed bead. VIII. Operation The carriages 20, 21 are independently wheeled to a desired location. The two are then physically interconnected by inserting the lock bars 150 into the apertures 151,152. Assuming the bagger and sealer are in a vertical orientation, the relative heights of the bagger and closure section conveyors are adjusted as is the height of the knife 120. If the angular orientation of the machines is to be adjusted, the bolt(s) 178 is(are) removed and the bagger and sealer section are rotated about the axis of the trunions 157,170, 172 to a desired orientation. Following this rotation the bolt(s) is(are) reinserted to fix the mechanism in its desired angular orientation. Next a web 15 of bags 25 is fed through the bagger and sealer by jogging the two. The transverse spacing of the main conveyor belts 40, 41 is adjusted by rotating the crank 72 until the load station 60 has the desired transverse dimension. A control, not shown, is set to provide a desired feed rate and a selected one of continuous or intermittent operation. Assuming continuous operation, the feed rate may be as high as 130 25.4 cm (ten inch) bags per minute. Once the machine is in operation, the top section 21 of the web 15 is fed along the mandrel 24 and slit by the slitter 36. This forms the lips 38, 39 which are folded over the main transport belts 41, 42 by the action of the plow 45. The lip clamp belts 48, 49 descend from the elevated and spring biased pulleys 50S, as shown in Figure 3. The roller cam 46 cams the clamp belts 48, 49 respectively into the transport belt recesses 51, 52 to provide very positive and firm support for the bags as they are further processed. As successive side connections 30 of the bags are registered with the bag side separator 53, the motor 55 is operated to drive the belt 54 and cause the breaker pins 58 to rupture the side connections 30. As adjacent runs of the transport belts 41, 42 progress downstream from the bag feed and preparation portion 35, the belts are spread under the action of the belt spreaders 61, 62. As the belts are spread, the lips 38, 39 cause the front and back faces 31, 32 adjacent the lead edge of each bag to separate from the lips 38, 39 by tearing a sufficient length of the perforations between them to allow the lead edge to become the mid point in a bag span between the belts as the bag passes longitudinally through the load station 60. Similarly, the perforations adjacent the trailing edge are torn as the trailing part of the bag is spread until the bag achieves a full rectangular opening as shown in Figure 4 in particular. Next a product is inserted into the rectangular bag as indicated schematically in Figure 3. While the schematic showing is of discrete fasteners, it should be recognized that this machine and system are well suited to packaging liquids and bulky products which must be stuffed into a bag, such as pantyhose and rectangular items, such as household sponges. After the product has been inserted, the adjacent runs of the main transport belts are brought back together and the loaded bag tops are spread longitudinally of the path of travel by opposed air streams from nozzles 110, 112. As is best seen in Figure 3, exit ones 50E of the lip belt pulley set are spaced from the main transport belt and rotatable about angular axes. Expressed more accurately, when the machine is in a vertical loading orientation, the pulleys 50E are above the main transport belt such that the lip transport belts are pulled from the grooves 51, 52. The now loaded bags pass through the transfer location onto the exit conveyors 115, 116 and thence to the seal station conveyors 118, 119. At this juncture the scrap 124 is severed from the loaded bags by the action of the knife 120. As the bags are advanced through the sealer section, the heater tube 135 is maintained in its lowered and solid line position of Figures 8, 9 and 11. If the machine is operated in its intermittent mode, the cylinder 145 is cycled in coordination with the starts and stops of the intermittently operated machine to shift the heater tube 135 between its solid line seal position and its storage position shown in phantom in the Figure 9.

Claims: A packaging machine for loading bags of a web of side connected bags comprising: a) a frame structure (17); b) a bag feed and preparation mechanism (16) carried by the frame structure for pulling a web of side connected bags from a supply and feeding the web along an entrance to a path of travel; c) the feed and preparation mechanism (16) including: i) a pair of main transport belts (40, 41) supported on the frame structure and delineating a load station section(60) of the path of travel; ii) a spreading and folding structure (45, 46) operative in use to spread and fold bag lips (38, 39, 45) oppositely and respectively over the main transport belts (40, 41); d) a pair of further transport belts (48, 49) each associated with a different one of the main belts (40, 41) for coacting with of the associated main belt (40, 41) to trap such lips between the associated belts; e) a pair of oppositely rotatable sets of pulley structures (43, 50) carried by the frame structure, each of the sets coacting with a different and associated one of the main transport belts to move the belts from closely spaced relationship near the preparation mechanism, through the load station in spaced relationship and return to closely spaced relationship downstream from the load station; f) a transport belt spreader (61, 62) to spread and space reaches of the transport belts as said reaches of the transport belts move through the load station sequentially to open the bags into polygonal configurations as the bags traverse the load station, characterised in that the transport belt spreader (61, 62) comprises a pair of spaced apart rails (61, 62: Fig. 2, Fig 7) along each of which in use run a respective main transport belt (40, 41), further transport belt (48, 49) and lip trapped therebetween. The machine of claim 1 characterised in that the polygonal configurations are substantially rectangular configuration. The machine of claim 1 or claim 2 further including a slitter (36) forming a part of the supply and preparation mechanism and positioned along the path upstream of the spreading structure. The machine of any of claims 1 to 3 further including a pair of opposed exit conveyors (115, 116) for grasping loaded bags as they pass from a portion of the path of travel delineated by the main transport belts and as the loaded bags are separated from a lip strip. The machine of claim 4 wherein each of the exit conveyors is in overlapping relationship with an associated one of the main transport belts (40, 41). The machine of any of the preceding claims wherein the belt spreaders comprise a spaced pair of elongate belt engaging guides (61, 62) and a space adjusting mechanism (68, 69, 70, 71, 72, 79) operably connected to the guides. The machine of claim 6 wherein the guides are elongate channels. The machine of claim 6 or claim 7 wherein the space adjusting mechanism comprises a pair of elongate screws (68, 69) each having a pair of oppositely threaded sections with one section of each screw threadedly engaging one guide and the other section of each screw threadedly engaging the other guide whereby on rotation of the screws the guides are selectively movable toward and away from one another. The machine of any of the preceding claims wherein the components denoted (b) to (f) are rotatively mounted as a unit to adjust the orientation of the load station. The machine of claim 9 wherein a position fixing mechanism (170) is interposed between the frame structure and the unit. The machine of claim 10 wherein the position fixing mechanism includes a pair of apertured plates (174, 176) journaled for relative rotation and a pin (178) for projection through a selectively aligned pair of apertures. The machine of any of the preceding claims, wherein the spreading and folding structure includes a pair of lip folding plows (45) for folding the spread lips (38, 39) oppositely and respectively over the main transport belts. The machine of any of the preceding claims, wherein the main transport belts (40, 41) are grooved (51, 52) and wherein the further transport belts (48, 49) are each associated with a different one of the main transport belts for disposition in the groove of the associated main belt (40, 41) to trap such lips in the grooves and thereby fix the lips in the grooves and a cam mechanism (46) is carried by the frame and positioned for camming the lip belts into their respective and associated grooves. The machine of any of the preceding claims, wherein the polygonal configurations are rectangles. The machine of claim 1; further comprising a closure support frame structure (21) supporting a closure mechanism (118, 119); an interconnecting mechanism (150, 151, 512) having one section carried by one of the said frame structure (20) and the closure frame structure (21) and another section carried by the other of said frame structure (20) and the closure frame structure (21); the sections having an interconnected position securing the structures (20, 21) together with the bagger and closure mechanism coactably positioned for loading and sealing bags to form packages; and, the sections having a disconnected position permitting independent movement of the structures (20, 21). The machine of claim 15 wherein the closure section includes a heat sealer. The machine of claim 15 or claim 16, wherein the frame structures (20, 21) are wheeled support carriages. The machine of any of claims 15 to 17 wherein the bagger and closure mechanism are rotatably mounted on the structures (20, 21) and moveable between relatively upright and angled positions. The machine of claim 18 wherein the angled position is a horizontal position. The machine of claim 18 wherein the relatively upright position is a vertical position. The machine of any of claims 18 to 20 wherein the closure mechanism and bagger are moveable to at least one intermediate position between the relatively upright and angled positions. The machine of any of claims 15 to 21 wherein a position fixing arrangement (174, 176, 178) is interposed between one of the frame structures (20, 21) and the selected one of the bagger and closure mechanism supported by the one frame structure. The combination of claim 22 wherein a position fixing arrangement includes a pair of apertured plates (174, 176) journaled for relative rotation and a pin (178) for projection through a selectively aligned pair of plate apertures (175). The machine of any of claims 1 to 23, further including a mechanism (53) for breaking frangible side connections between sides of adjacent bags in the web comprising: a) an endless belt (54); b) a further structure supporting the endless belt (54) including a drive (57) for advancing the endless belt (54) along a path when a set of such frangible connections is positioned at a location wherein such connections are broken; and, c) at least one connection breaker (58) projecting outwardly from the endless belt (54). The machine of claim 24 wherein there are a plurality of such breakers (58) and each such breaker is an elongated pin. The machine of claim 24 wherein a synchronizing means is operably connected to the drive for synchronizing the advancement of the belt with the positioning of such connection at the location. The machine of any of claims 1 to 26 further comprising a sealing machine for sealing loaded plastic bags to form packages comprising: a) the closure frame structure (21); b) a pair of opposed conveyor belts (118, 119) carried by the closure structure (21) and having complemental sealing reaches (126) establishing a path of travel for loaded bags through a seal station; c) a heater (135,136) supported by the closure structure (21) and positioned adjacent the path, the heater being adapted to fuse pairs of bag lips projecting from the complemental reaches with each fused pair of lips being a seal for a loaded bag; characterised by: d) the opposed conveyor belts (118, 119) including slippage prevention means for preventing relative longitudinal movement of bag faces and backs as such bags are moved along the path. The machine of claim 27 wherein a heater support (137, 138) is interposed between the closure structure (21) and the heater for moving the heater between a seal position near the path and a storage position spaced from the path. The machine of claim 28 wherein there is a conveyor drive and a control (145) connected to the conveyor drive and the heater support for causing the support to place the heater in its seal position when the conveyor drive is operating to move bags along the path and to cause the support to shift the heater to its storage position when conveyor drive operation is interrupted. The machine of any of claims 27 to 29 wherein the slippage prevention means comprises interlocking belt corrugations. The machine of any of claims 27 to 30 wherein the slippage prevention means further comprises an abrasive material adhered to bag engaging surfaces of the belts. A bag spreader for use in the load station of a bagging machine of the type wherein a chain (15) of side connected bags (25) are sequentially loaded at the load station (60), characterised in that the bag spreader comprises; a) a spaced pair of elongate elements (61, 62) defining belt supporting guides for supporting and positioning bag transporting belts (40, 41) along a path of travel through such load station; b) element space adjusting mechanism (68, 69) connected to said elements to adjust the spatial relationship of the elements within an adjustment range; c) the guides being rectilinear and parallel and sufficiently elongate along the path of travel to maintain sections of such transport belts in spaced parallel relationship thereby enabling the concurrent support of a plurality of bags in open and loadable condition is such load station. The spreader of claim 32, wherein the mechanism includes a pair of screws (68, 69) each having opposed, oppositely threaded end sections respectively threadedly connected to the elements whereby rotation of said screws in one direction will move the elements apart and rotation in the other direction will bring them together. The spreader of claim 33, further including a rotation force transmitter (73) interconnecting the screws. The spreader of claim 34, wherein the transmitter is an endless member. The spreader of any of claims 32 to 35 wherein the elements are channels. The spreader of any of claims 32 to 36 wherein the adjustment mechanism provides infinite adjustment within a finite adjustment range.

Inventors: LERNER HERSHEY, LERNER, HERSHEY
Applicants: AUTOMATED PACKAGING SYST INC, AUTOMATED PACKAGING SYSTEMS, INC.
Application year: 1997
Main classification: B65B43
IPC codes: B65B43