This invention pertains to a strappino machine arranged to compress a load before strappinq the load, particularly but not exclusively a load compressible along orthogonal axes, as exemplified by but not limited to several bags containing compressible batts of fiberglass insulation or other insulation.

Background of the Invention

Various strapping and other packaginσ machines are known which compress a load along a single axis or along orthogonal axes, usually a vertical axis and a horizontal axis, before strappinq or otherwise packaging the load.

Such a packaqing machine, which is described for packaqing a group of fibrous mats in a paper sheet, is exemplified in Brown U.S. Patent No. 2,765,838. The machine disclosed in the Rrown patent has a compressing ram, which operates along a vertical axis, two sealinq plates, which operate along longitudinal, horizontal axes, and plural crossheads, which operate along transverse, horizontal axes.

A machine for packaging collapsed cartons by compressing such cartons along a vertical axis and strrpping them with steel straps is disclosed in Wilson et al. U.S. Patent No. 2,947,125. A machine for compressing a stack of paper bags along a vertical axis and for wrapping the stack with a paper sheet is disclosed in Lowe et al. U.S. Patent No. 3,030,750.

A variety of other machines for compressinq compressible bales, compressible batts, or similar

loads and for strapping or otherwise packaging such loads are disclosed in Merkel et al. U.S. Patent No. 3,475,879, Hullhorst et al. U.S. Patent No. 3,499,261, Fox U.S. Patent No. 3,585,925, Spaulding U.S. Patent No. 3,977,155, Wistinghausen et al. U.S. Patent No. 4,099,363, McCormick et al. U.S. Patent No. 4,343,131, and Smith, Jr., U.S. Patent No. 4,360,997. See, also, Pasic U.S. Patent No. 3,735,555. Although some of these machines and other known machines for similar purposes may be qenerally satisfactory to their users, there has been a need, to which this invention is addressed, for a strapping machine having improved features by which it is possible to compress a load not only alono a vertical axis but also along a longitudinal, horizontal axis, and also to confine the load along a transverse, horizontal axis while the load is compressed, before strapping the load. Summary of the Invention

This invention provides a novel combination in a strapping machine arranged to compress a compressible load, as exemplified by but not limited to several bags containing compressible batts of fiberglass insulation or other insulation, before strapping the load with one or more straps.

The strapping machine is similar to known machines in that the strappinq machine comprises a frame, a table supported by the frame, preferably a table comprising a plurality of parallel rollers which may be motor-driven, and which are arranged to convey such a load onto and from the table, and a platen mounted to the frame, above the table, for vertical movement of the platen toward _. and away from the table, between an upper limit and a lower limit.

Hydraulically actuated or other means are provided, which are actuatable selectively for elevating the platen to the upper limit or for lowering the platen toward the lower limit. According to a principal feature contemplated by this invention, one or more pairs of load-end formers are mounted between the table and platen, in engagement with the platen at least after the platen has been lowered partially, and are arranged for relative movement between the load-end formers and the platen and for relative movement of the load-end formers of each pair toward and away from each other, at any elevation of the platen between the upper and lower limits, even with the load-end formers of each pair in engagement with the platen. Such an arrangement wherein the load-end formers are in engagement with the platen is a unique feature provided by this invention.

Preferably, each load-end former of each pair comprises upper and lower portions arranged in a telescoping arrangement or otherwise for relative movement along a vertical axis, between an extended condition and a shortened condition. The upper portion of each- load-end former of each pair is in engagement with the platen at least after the platen has been lowered partially. Sprinq-loaded or other means are provided for biasing the upper and lower portions of such load-end former toward the extended condition. Also, the platen is arranged to impart relative movement of the upper and lower portions of each load-end former toward the shortened condition, as the platen is lowered with the load-end formers of each pair in engagement with the platen. Thus, each load-end former has an adjustable height, which is adjusted automatically upon vertical movement of the

platen toward or away from the table, as another unique feature provided by this invention. Preferably, as well, the upper end of each load-end means is provided with rollable means facilitating relative movement between such load-end former and the platen upon relative movement of the load-end formers of each pair toward or away from each other, with the load-end formers of each pair in engaqe ent with the platen. Moreover, hydraulically actuated or other means are provided, which are actuatable selectively for imparting relative movement of the load-end formers of each pair toward each other, at any elevation of the platen between the upper and lower limits, or for imparting relative movement of the load-end formers of each pair away from each other, at any elevation of the platen between the upper and lower limits. Therefore, if a compressible load is conveyed or otherwise placed onto the table, below the platen, between the load-end formers of each pair, the load can be endwise compressed alonq a longitudinal, horizontal axis, between the load-end formers of each pair, while the load is confined between the platen and the table. Moreover, the platen can be also used to compress the load along a vertical axis, between the platen and the table.

Preferably, as an important feature provided by this invention, a pair of load-confining doors are provided. Each load-confining door is mounted to the frame for selective movement between a closed position and an opened position. In the closed position, each load-confining door is disposed so as to confine one side of such a load being compressed between the load-end formers of each pair. In the opened position, each load-confining door is removed

so as to permit such a load to be placed onto or displaced from the table.

Preferably, each load-confining door is mounted pivotally to the frame at one edqe, namely the edge constituting its lower edoe when such load-confininq door is in its closed position. Hydraulically actuated or other means may be then provided, which are actuatable selectively for pivoting each load-confining door to its closed position or for pivoting such load-confininq door to its opened position.

Preferably, as another important feature contemplated by this invention and applicable when plural pairs of load-end formers are provided as mentioned above, one or more strapping heads and one or more strap chutes are carried by the platen. If one strapping head and one strap chute are carried by the platen, the strappinq head coacts with the strap chute. If more than one strappinq head and more than one strap chute are carried by the platen, each strapping head coacts with a respective one of the strap chutes.

Each strapping head is carried by the platen, above a load-compressing plane defined by the platen, and is arranged to feed a strap, tension the strap, sever the strap, and join the strap, so as to form a tensioned loop. It does not matter whether the strap, which usuolly is severed from a coil of strapping, is severed before or after the strap is joined.

Preferably, the strap is a polyester strap, e.g., a poly(ethylene terephthalate) strap, or a polypropylene strap, either type being joinable by friction welding, although a steel strap, which is joined by a metal seal or by a sealless (notched)

connβction, may be alternatively used. The strappinq heads may be accordingly selected from known types of strapping headB.

Each strap chute is arranged to guide a strap being fed by the strapping head coacting with such strap chute and to release the strap when the strap ie tensioned by the same strapping head. Each strap chute is aligned with a strap-handling zone defined between two adjacent pairs of the load-end formers.

Each strap chute includes two upper sections, two vertical sections, and a lower section. The upper sections are disposed above the load-compressing plane noted above and are spaced from each other so as to accommodate the strapping head coacting with such strap chute and being disposed between the upper sections. Each vertical section communicates at its upper end with a respective one of the upper sections, passes through a load-supporting plane, as defined by the table, and is adjacent to a respective end of the table. The lower section is disposed below the load-supporting plane, at any elevation of the platen between the upper and lower limits, and communicates at each of its opposite ends with the lower end of a respective one of the vertical sections.

The foregoing features may be advantageously combined in a strapping machine embodying the principal feature noted above. Consequently, the strapping machine is useful to strap a load compressible along orthogonal axes, as exemplified by but not limited to several bags containing compressible batts of fiberglass insulation. If the foregoing features are combined in such a machine, the machine may be advantageously employed to

co press such a load not only along a vertical axis but also along a longitudinal, horizontal axis, and also to confine the load alonq a transverse, horizontal axis while the load is compressed, whereupon the machine may be then used to strap the compressed load with one strap or with a plurality of parallel straps. Each strap passes through a strap-handling zone defined between two adjacent pairs of the load-end formers as such strap is tensioned by the strapping head handling such strap. These and other objects, features, and advantages of this invention are evident from the following description of a preferred embodiment of this invention with reference to the accompanying drawings.

Brief Description of the Drawings

FIGURE 1 is a simplified, fragmentary, perspective view of a strapping machine constitutinσ a preferred embodiment of this invention. An inlet conveyor, which is used to convev a compressible load into the strapping machine, is sugqested by a series of parallel rollers.

FIGURE 2 is a reduced, simplified, fragmentary, top plan view, which shows four baqs containing compressible batts of fiberqlass insulation, constituting an exemplarv load, and having been placed onto a table of the strapping machine. The inlet conveyor suggested in FIGURE 1 is shown, on which four bags for a next load are shown fragmentarily, as well as an outlet conveyor, which is used to convey a strapped load from the machine. Upper portions of the strapping machine have been omitted so as to reveal lower portions of the strapping machine.

FIGURE 3 is a similarly reduced, simplified, elevational view, which is taken from the lower riqht of the strapping machine as shown in FIGURE 1. The exemplary load shown in FIGURE 1 is shown as compressed along a vertical axis, as well as along a longitudinal, horizontal axis, i.e., endwise.

FIGURE 4 is a view similar to FIGURE 2 but taken after the exemplary load has been strapped with four parallel straps. A prior load, which has been strapped, is shown fragmentarily on the outlet conveyor. SucH bags for the next load are shown as having been advanced by th inlet conveyor.

FIGURE 5 is a greatly enlarged, more detailed but still somewhat simplified, fraq entary, elevational view, which also is taken from the lower right of the strappinq machine as shown in FIGURE 1.

FIGURE 6 is a similarly enlarged, elevational view, which is taken from the left end of the strapping machine as shown in FIGURE 5. FIGURE 7 is a similarly enlarged, fragmentary, top plan view of the strappinq machine as shown in FIGURES 5 and 6.

FIGURE 8 is a greatly enlarged, fraσ entarv, top plan view of a load-end former, of which the strapping machine comprises plural pairs.

FIGURE 9 is ^' a back elevational view of the load-end former shown in FIGURE 8.

FIGURE 10 is a side elevational view of the load-end former shown in FIGURES 8 and 9. Certain elements are shown in an extended condition, in phantom lines, and in a contracted condition, in full lines.

FIGURE 11 is a similarly enlarqed, fragmentary, top plan view of the load-end formers at one end of the strapping machine.

FIGURE 12 is a similarly enlarqed, fragmentary, elevational view of the load-end formers as shown in FIGURE 11.

FIGURE 13 is a similarly enlarqed, fragmentary detail of a given end of a load-confininσ door of the strapping machine.

FIGURE 14 is a similarly enlaroed, fragmentary detail, which is taken from the riqht side of the load-confininq door shown in FIGURE 1^. Certain elements are shown, in phantom lines, in changed positions.

FIGURE 15 is a view analogous to FIGURE 14 but taken at the opposite end of the load-confininq door. FIGURE 16 is a view analogous to FIGURE ] 3 but taken at the opposite end of the load-confininq door. Detailed Description of Preferred Embodiment

As shown in the drawinσs, a strappinσ machine 10 constitutes a preferred embodiment of this invention. The strapping machine 10 is shown as used to compress a compressible load along a vertical axis, as well as alonq a longitudinal, horizonta.1 axis, to confine the load along a transverse, horizontal axis while the load is compressed, and to strap the load with four parallel straps after the load has been compressed.

In FIGURES 2, 3, and A , an exemplary load 12 is shown which consists of four baqs 14, each containing one or more batts of fiberglass insulation. Such bags 14 are conveyed into the strapping machine 10 in which such bags 14 are compressed, confined, and strapped, whereupon the exemplary load 12 is conveyed from the strappinσ

machine 10. In FIGURES 2 and 4, four bags 16 are shown, for a later load like the exemplary load 12, as such bags 16 are conveyed toward the strapping machine 10. Such bags 16 are shown as farther from the strapping machine 10 in FIGURE 3 and as closer to the strapping machine 10 in FIGURE 4. In FIGURE 4, a prior load 18 is shown, which is like the exemplary load 12, as the prior load 18 is conveyed away from the strapping machine 10. An inlet conveyor 2n, which is used to convey the bags for each load toward and into the strapping machine 10, is sugqested by a series of parallel rollers 22, which mav be motor-driven. An outlet conveyor 24, which is used to convey each strapped load away from the strappinq machine 10, is suggested by a series of parallel rollers 26, which also may be motor-driven. Precise details of the conveyors 20, 24, are outside the scope of this invention.

The strapping machine 10 comprises a main frame 30, which includes two taller stanchions "* , a cross-beam 34 connecting the taller stanchions 32, two shorter stanchions 36, a cross-beam 3P connectinq the shorter stanchions 36, and various lonqitudinal elements connected between the taller stanchions ? and the shorter stanchions 36. A roller table 5n, which is supported by the frame 30, comprises a series of parallel rollers 52, which are journalled to the frame 50, and which are driven by a hydraulic motor (not shown) via a sprocket and chain drive (not shown) in a known manner. A plane defined by such rollers 52, which are tangent with the plane, is regarded as a load-supporting plane.

Each of the stanchions 32, 36, is sσuare in outer cross-section. Two sleeves 60, which are square in inner cross-section, are provided. Each of

-li¬ the sleeves 60 is mounted around a respective o e of the taller stanchions 32 for vertical movement of the sleeves 60 along such stanchions 32. Each of the sleeves 60 is guided by three upper rollers 62 and three lower rollers 64. The rollers 62, 64, which are carried by the sleeves 60, are arranqed to roll along respective outer walls of the taller stanchions 32, as shown. A platen 70 is mounted inteorally to the sleeves 60, via a cross-plate 72 connected integrally between the sleeves 60, so as to be thus cantilevered over the roller table 50. Because the sleeves 60 are mounted for vertical movement a onq the taller stanchions 3?, the platen 70 is arranoed for vertical movement, above the roller table ?π, between an upper limit and a lower limit.

Hydraulically actuated means, as provided bv a piston-cylinder mechanism 80, which has a cylinder 82 mounted to the cross-beam ^ and a piston (not shown) operating within the cylinder 82 and drivinq a piston rod 84 connected to the cross-plate 72, are actuatable selectively for elevatinq the platen 7n to its upper limit or for lowerinq the platen 70 toward its lower limit. The upper and lower limits of vertical movement of the platen 70 are defined by the stroke of the piston rod 84. It is contemplated bv this invention that protoelectric or other limit switches (not shown) may be also provided, so as to enable the upper limit, the lower limit, or both such limits to be selectively varied. Whether the platen 70 reaches its lower limit when the platen 70 is lowered depends upon on such factors as compressibility of the load and initial heiqht of the load. A plane defined by the platen ^ , where the platen 70 engages a load when the platen 70 is lowered, is regarded as a load-compressinq plane,

which is parallel with the load-supporting plane noted above.

Five pairs of load-end formers are provided, namely three wide pairs spaced from one another by a strap-handling zone of a suitable width (which is sufficient to allow a strap, as mentioned above, to pass through such zone without interference) and two narrow pairs, each spaced from one of the wide pairs by a strap-handling zone of a similar width. Thus, as shown in FIGURES 2 and 3, such pairs of load-end formers are constituted by a first pair 90 of narrow load-end formers comprising a load-end former 90a, which is closer to the cross-beam 34, and a load-end former 90b, which is closer to the cross-beam 38, a second pair 92 of wide load-end formers beino spaced by a first strap-handling zone Z, from the first pair 90 and comprising a load-end former 92a, which is spaced equally from the load-end former ^Oa, and a load-end former 92b, which is spaced equally from the load-end former 90a, a third pair 94 of wide load-end formers being spaced by a second strap-handling zone Z _? from the second pair 92 and co prisinq a load-end former 94a, which is spaced equally from the load-end former 92a_, and a load-end former 94b. , which is spaced equally from the load-end former 92ID, a fourth pair 96 of wide load-end formers be nq spaced by a third strap-handling zone Z^ from the third pair 94 and comprising a load-end former 96a, which is spaced equally from the load-end former 94a_, and a load-end former 96b, which is spaced equally from the load-end former 94b, and a fifth pair 98 of narrow load-end formers being spaced by a fourth strap-handling zone Z ₄ f _rθ m the fourth pair 96 and comprising a load-end former 98a., which is spaced equally from the load-end former 96a, and a load-end

former 98b, which is spaced equally from the load-end former 96 . As representative examples, the load-end formers 90a, 92a, 94 , 96a, 98a are shown in further detail in FIGURES 11 and 12. As a representative example of the narrower load-end formers, the load-end former 98a_ is shown in FIGURES 5, 6, 11, and 12, as comprising an upper tube 100, which is square in outer cross-section, a lower tube 102, which is square in inner cross-section, and which is telescoped around the upper tube ion for vertical movement of the upper tube 100 relative to the lower tube 102, an upper forming member in*, which is mounted to the upper tube 100 for conjoint movement with the upper tube 100 relative to the lower tube 102, a lower forming member 106, which is mounted to the lower tube 102, an upper forminq blade 108, which is mounted to the upper forming member 104, so as to extend upwardly and inwardly over the roller table 50, a lower forminq blade 110, which is mounted to the lower forming member 10>, so as to extend downwardly and inwardly over the roller table 50, against which the lower forminq blade 110 wipes when the load-end former 98a_ moves along the roller table 50, and means 11? for biasinα the upper tube 100, the upper forming member 104, and the upper forming blade 108 upwardly, toward an extended condition of the load-end former 98a, but allowinσ the upper tube 100, the upper forminσ member 104, and the upper forming blade 108 to be forcibly lowered, toward a shortened condition of the load-end former 98ci. The biasing means 112 comprise an upper flanqe 114, which is mounted rigidly to the upper tube 100, a lower flange 116, which is mounted riqidly to the lower tube 102, below the upper flange 114, a rod 118, which extends downwardly from the upper flange

100, through an aperture (not shown) in the lower flange 116, and which is threaded at its lower end (not shown) where a nut (not shown) is threaded thereon, and a coiled sprinq 124, which is piloted over the rod 118, between the upper flange 114 and the lower flange 116, and which biases the upper tube, via the upper flange 114, and the lower tube 102, via the lower flange 116, to the extended position of the load-end former 98a, as the extended position of the load-end former 98a is defined by engagement between the lower flanqe 116 and the nut threaded on the lower end of the rod 118. The shortened condition of the load-end former is defined by relative lengths of the tubes 100, 102, and is achieved before the coiled spring 124 is compressed fully. The upper tube 100 is provided, at its upper end 126, with a pair of rollers 1?8 for a purpose to be later described.

As a representative example of the wider load-end formers, the load-end former 94^ is shown in FIGURES 6 and 8 through 12 as comprisinα an UDDer tube 130, which is sσuare in outer cross-section, a lower tube 132, which is square in inner cross-section, and which is telescoped over the upper tube 130 for vertical movement of the upper tube 130 relative to the lower tube 132, an upper forminq member 134, which is mounted to the upper tube 100 for conjoint movement with the upper tube 130 relative to the lower tube 132, a lower forming member 136, which is mounted to the lower tube 132, an upper forming blade 138, which is mounted to the upper forming member 134, so as to extend upwardly and inwardly over the roller table 50, and a lower forming blade 140, which is mounted to the lower forming member 136, so as to extend downwardly and

inwardly over the roller table 50, against which the lower forming blade 140 wipes when the load-end former 94a moves along the roller table 50, and means 142 for biasing the upper tube 130, the upper forming member 134, and the upper forming blade 138 upwardly, toward an extended condition of the load-end former 94a, but allowing the upper tube 130, the upper forming member 134, and the upper forming blade 138 to be forcibly lowered, toward a shortened condition of the load-end former 94a _^ . The biasing means 14? comprise an upper flange 144, which is mounted rigidly to the upper tube 130, a lower flanqe 146, which is mounted rigidly to the lower tube 132, below the upper flange 144, a rod 148, which extends downwardly from the upper flange 130, throuqh an aperture in the lower flange 146, in which is threaded at its lower end 150 where a nut ϊ is threaded thereon, and a coiled spring 154, which is like the coiled spring 124, and which piloted over the rod 148, between the upper flange 144 and the lower flange 146, and which biases the upper tube 130, via the upper flange 144, and the lower tube 132, via the lower flange 146, to the extended position of the load-end former 96 , as the extended position of the load-end former 96a is defined by engagement between the lower flange 1* and the nut 152 threaded on the lower end 150 of the rod 148. The shortened condition of th* load-end former 96a is defined by relative lengths of the tubes 130, 132, and is achieved before the coiled spring 154 is compressed fully. The upper tube 130 is provided, at its upper end 156, with a pair of rollers 1 for a purpose to be later described.

As shown in FIGURES 11 and 12, each of the load-end formers of the wide pairs 92, 94, 96, is

provided (within a cavity defined by its upper forminq member) with upper and lower, transversely oriented, hydraulically actuated, piston-cylinder mechanisms, each driving a piston rod, which operates a transversely extending pin shiftable between an extended position and a withdrawn position. As a representative example, the load-end former 92a_ is provided with an upper, transversely oriented, hydraulically ^" actuated, piston-cylinder mechanism 170 and with a lower, transversely oriented, hydraulically actuated, piston-cylinder mechanism 172. The piston-cylirider mechanism 170 drives a piston rod 174, which operates a transversely extending pin 176 shiftable between an extended position and a withdrawn position. The pin 176 is shown in its withdrawn position in FIGURE 11. In its extended position, which also is indicated fin phantom lines) in FIGURE 11, the pin 176 bridges an upper portion of the first strap-handlinq zone Z, , which is defined between the load-end formers 90 and the load-end formers 92. The piston-cylinder mechanism 172 drives a piston rod 178, which operates a transversely extendinq pin (not shown) similar to the pin 176 and shiftable between an extended position (in which such pin is spaced beneath the pin 176 and bridges a lower portion of the first strap-handling zone Z ₁ ) and a withdrawn position. Similarly, the load-end former $>4ei is provided with an upper, transversely oriented, hydraulically actuated, piston-cylinder mechanism 182 drivinq a piston rod 184, which operates a similar pin 186, and with a lower, transversely oriented, hydraulically actuated, piston-cylinder mechanism 188 driving a piston rod 190, which similarly operates a similar pin (not shown) beneath the pin 186, such that the

pin 186 and the pin operated by the piston rod 190 bridge upper and lower portions of the second strap-handling zone Z ₂ , which is defined between the load-end formers 92 and the load-end formers 94, when each such pin is in its extended position.

Moreover, the load-end former 94a also is provided with an upper, transversely oriented, hydraulically actuated, piston-cylinder mechanism 194 driving a piston rod 196, which similarly operates a similar pin 198 opposite to the pin 176, and with a lower, transversely oriented, hydraulically actuated, piston-cylinder mechanism 200 drivino a piston rod 202, which similarly operates a similar pin (not shown) beneath the pin 198, such that the pin 198 and the pin operated by the piston rod 202 bridqe upper and lower portions of the third strap-handling zone Z3, which is defined between the load-end formers 94 and the load-end formers 96, when each such pin is in its extended position. Furthermore, the load-end former 9βa_ is provided with an upper, transversely oriented, hydraulically actuated, piston-cylinder mechanim 20fi drivinq a piston rod 208, which operates a similar pin 210, and with a lower, transverselv oriented, hydraulically actuated, piston-cvlinder mechanism 212 drivinq a piston rod 214, which operates a similar pin (not shown) beneath the pin 210, such that the pin 210 and the pin operated by the piston rod 214 bridge upper and lower portions of the fourth strap-handlinq zone Z _Δ , which is defined between the load-end formers 96 and the load-end formers 98, when each such pin is in its extended position. Similar pins (not shown) operated similarly and associated with the load-end formers 92b, 94b, 96b, bridqe upper and lower portions of the strap-handling zones , , z ₂ , z ₃ , Z ₄ when each

such pin is in its extended position. The various pins bridging upper and lower portions of the strap-handling zones Z,, z ₂ , z ₃ , Z,, receive straps being applied by the strapping machine 10, as such straps are tensioned, severed, and joined, so as to prevent such straps from cuttinq into a compressible load, such as the exemplary load 12. After such pins are withdrawn, such a load rebounds slightly, until such joined straps become tioht. Among other longitudinally extendinq elements of the main frame 30, two lower beams 220 are provided, as shown in FIGURES 5 and 6, each beam supporting 220 supporting a carriage rail 2?? on one side of the strapping machine 10. A carriaqe ?30 is provided, from which each of the lower tubes (e.σ., the lower tubes 100, 130) of the load-end formers 90 _j a, 9?a, 94a, 9*a, 98a, extends upwardly, for conjoint movement of such load-end formers with the carriage 230. The carriaqe ?30 is quided by the carriage rails 222, via rollers 232 (see FIGURE fi) journalled to each side of the carriage 230, for longitudinal movement of the carriaσe 230 alonq the carriage rails 222. A carriage 240 is provided, from which each of the lower tubes of the load-end formers 90b, 92b, 94b, 96b, 98b, extends upwardly, for conjoint movement of such load-end formers with the carriage 240. The carriage 240 is guided by the carriage rails 222, via rollers (not shown) similar to the rollers 232 and journalled to each side of the carriage 240, for longitudinal movement of the carriage 240 along the carriage rails 222.

A hydraulically actuated, short stroke, piston-cylinder mechanism 250 is provided, which drives a piston rod 252 linked mechanically to the carriage 230. Conjoint movement of the load-end

formers 90^, 92a, 94a, 96a, 98aι, toward and away from the load-end formers 90b, 92b, 94b, 96b, 98b, between a displaced condition (in which such load-end formers are displaced from where they are shown in FIGURES 1 and 5) in a normal positon (in which they are shown in FIGURES 1 and 5) is limited, in either direction, by the stroke of the piston rod 222.

A hydraulically actuated, lonq stroke, piston-cylinder mechanism 260 is provided, which drives a piston rod 242 linked mechanically to the carriaqe 240. Conjoint movement of the load-end formers 90b, 92b, 94b, ^Q 6b, 98b, toward and away from the load-end formers 9θ , 92∑Ϊ, 94a, 96a, <>Ba , between an operative condition (in which the load end formers 90b, 92b, 94b, 96b, 98b, are shown in FIGURE 1) and in inoperative condition (in which they are shown in FIGURE 5) is limited in either direction by the stroke of the piston rod 24?. it is contemplated by this invention to provide photoelectric or other limit switches (not shown) or other conventional means (not shown) for adjusting the stroke of the piston rod 242.

When a load is to be compressed between the load-end formers of each pair, the load-end formers 90a, 92 _j a, 94a, 96j3, 98a, are held in the normal condition (in which they are shown in FIGURES 1 and 5) and the load-end formers 90b, 92b, 94b, 96b, 98b, are moved conjointly toward the load-end formfc s 9 ti, 92^, 94a, 96^, 98 , from the inoperative condition (in which the load-end formers 90b, 9?b, 94b, 96b, 98b, are shown in FIGURE 5) toward the operative condition (in which they are shown in FIGURE 1) so as to compress the load between the load-end formers of each pair. Whether the load-end formers 90b, 9?b, 94b, 96b, 98b, reach the operative condition depends

upon such factors of compressibility of the load and initial length of the load.

After the compressed load has been strapped, the load-end formers 90b, 92b, 94b, <>6b, 98b, are moved conjointly to the inoperative condition, as suggested in FIGURE 4, whereupon the load-end formers 90a, 92a, 94a, 96a, 98a _^ , are moved conjointly to the displaced condition, so as to displace the strap load, and then are moved conjointly to the normal condition, so as to withdraw the lower forminq blades 110, etc., which might be otherwise pinched between the strap load and the roller table * .

As shown in FIGURE 6, a pair of load- confininq doors are provided. Each such door is mounted pivotally to the main frame 30 for selective movement of such door between a vertical, closed position, which is suqqested, for each such door, in FIGURE 2, and a horizontal, opened position. In its vertical, closed position, each such door is disposed so as to confine one side of a load beinq compressed between the load-end formers of each pair. In its horizontal, opened position, each door is removed so as to permit a load to be placed onto or displaced from the roller table 50. Thus, a load-confininq door 280 comprising longitudinal panels ^' (not shown) between end plates (not shown) is mounted pivotally to the main frame 30, at the inlet side of the strapping machine 10, for selective movement of such door 280 between a vertical, closed position (see FIGURE 5) and a horizontal, opened position. Such door 280 is mounted pivotally to a shelf (not shown) fixed to the main frame 30, by hinges (not shown) at each end of such door 280, at one edge of such door 280, namely the edge constituting its lower eδqe when such door 280 is in its vertical, closed position.

Also, a load-confining door 290 is mounted pivotally to the main frame 230, at the outlet side of the strappinq machine 10, for selective movement of such door 290 between the vertical, closed position, in which such door 290 is shown, in full lines, in FIGURE 13, and in phantom lines, in FIGURES 14 through 16, and a horizontal, opened position, in which such door 290 is shown, in full lines, in FIGURES 13 through 16. Such door 290 is mounted pivotally to a shelf 292 fixed to the main frame 30, by hinges 294 at each end of such door 290, at one edge of such door 290, namely the edσe constitutinq its lower edge when such door is in its vertical, closed position. As a representative example of the load-confining doors 280, 2.90, which are similar to each other, the load-confining door 290 at the outlet side of the strapping machine 10 is shown in FIGURES 13 through 16 as comprisinq two end plates 300, which are mounted pivotally to the shelf 292 by the hinqes 294, a cross-piece 302, which is mounted between the end plates 300, in close proximity to the hinqes 294, a load-confining panel 304, which is mounted to the cross-piece 302.and spaced from the end plates 30n, a cross-piece 306, which is mounted between the end plates 300 and spaced from the cross-piece 302, a load-confining panel 308, which is mounted to the cress-piece 308 and spaced from the end plates 300 and from the panel 304, a cross-piece 310, which is mounted between the end plates 300 and spaced from the cross-piece 306, and a load-confininq panel 312 mounted to the cross-piece 310 and spaced from the end plates 300 and from the panel 308. The load-confining door 280 is constructed similarly. Moreover, two parallel rollers 320 are jounalled to two end flanges 322, which are mounted

to the shelf 292, so as to lie respectively between the panels 304, 308, and between the panels 308, 312, thereby to extend the roller bed 50 at the outlet side of the strapping machine 10, when such door 290 is in its horizontal, opened position. The rollers 320 are powered by the hydraulic motor 324 via a sprocket and chain drive 326, as shown in FIGURE 14. Similarly driven rollers 328 (see FIGURES 2 throuqh 4) are associated similarly with the load-confininq door 280. Such rollers 328 extend the roller bed 50, at the inlet side of the strappinσ machine 10, when such door 280 is in it ^' s horizontal, opened position.

A hydraulically actuated, piston-cylinder mechanism 330 is provided at each end of the load-confining door 290. Such mechanisms 330 are arranged to be selectively and conjointly actuated for pivoting such door 290 to its vertical, closed position or to its horizontal, ooened position. A hydraulically actuated, piston-cvlinder mechanism 330 is provided at each end of the load-confininq door

280. A similar mechanism 332 is provided at each end of the load-confining door 290. Such mechanisms 330, 332, are arranged to be selectively and conjointly actuated for pivoting each of such doors 290, 280, to its vertical, closed position or to its horizontal, opened position.

Furthermore, the shelf 292 constitutes an integral part of a sub-frame 340, which is arranged to be rigidly fastened (in a selective one of plural positions of adjustment) to a structural member 342 constituting an integral part of the main frame 30, via a plurality of handle-actuated bolts 344, as shown, whereby the door 290 is reσarded as mounted pivotally to the main frame 230. The load-confininq door 280 is mounted similarly to the main frame 230.

When the load-confining door 280 is pivoted to its horizontal, opened position, a load can then be conveyed from the inlet conveyor 20, onto the roller table 50, via the rollers 22 of the inlet conveyor 20, the rollers 328 associated with the load-confininq door 280, and the rollers 52 of the roller table 50. When the load-con ininq door 29 is pivoted to its horizontal, opened position, a load can then be conveyed from the roller table 50, onto the outlet conveyor 24, via the rollers 52 of the roller table 50, the rollers 320 associated with the load-confining door 290, and the rollers ?6 of the outlet conveyor 24. When each of such doors 280, 290, is in its veritcal, closed position, such doors 280, 290, serve to align side surfaces (e.g., the baα ends, as shown) of a load placed onto the roller table 50 and to confine the load alonσ a transverse, horizontal axis, between such doors 280, 290, while the load is compressed between the platen 70 and the roller table 50 and between the load-end formers of each pair noted above.

As shown in FIGURE 7, four similar strappinα heads are carried by the platen 70, namely a first strapping head 350 associated with the first strap-handling zone Z^ _t a second strappinq head "* ^« i associated with the second strap-han line zone 7 a third strapping head 354 associated with the third strap-handling zone Z- and a fourth strappinq head 356 associated with the fourth strappinq zone Z.. Each strappinq head is a Signode™ Model MCD-500 strapping head available commercially from Signode Corporation, Glenview, Illinois, and desiqned to handle Tenax™ poly(ethylene terephthalate) strapping available commercially from Signode Corporation, supra, and to handle Contrax™

polypropylene strapping available commercially from Signode Corporation, supra. Each strappinq head is arranged to feed a strap, (as supplied to such strapping head from a strap dispenser) through a strap chute, which guides the strap around a load and back to such strapping head, and to tension the strap, sever the strap, and join the strap by a friction weld into a tensioned loop. Because of spatial considerations, the first strappinq head "*5 and the third strapping head 354 are arranqed to feed straps through the strap chutes associated therewith, in a counterclockwise sense, as viewed in FIGURE 5, and the second strapping head 352 and the fourth strapping head 356 are arranged to feed straps through the strap chutes associated therewith, in a clockwise sense, as viewed in FIGURE 5. Precise details of such strappinq heads are outside of the scope of this invention.

As shown in FIGURE 7, a first strap dispenser 360 is arranqed to supply strappinq (from which straps are to be thus severed) to the first strappinq head 350. Moreover, a second strap dispenser 362, a third strap dispenser 364, and a fourth strap dispenser 366 are arranqed to supply strapping respectively to the second strappinα head 352, the third strapping head 354, and the fourth strapping head 356. Each of the strap dispensers 360, 362, 364, 366, is a Signode™ Model DF1-12D strap dispenser, as available commercially from Signode Corporation, supra. Pulleys are arranσed, as shown, where needed to guide strappinq from the respective strap dispensers to the respective strapping heads. Precise details of the such strap dispensers and associated pulleys are outside the scope of this invention.

Each of the strapping heads 350, 352, 354, 356, is arranged to receive a strap from the associated one of the strap dispensers 360, 36?, 364, 366, to feed the strap through an associated strap chute described below, until the strap is fed back to the strapping head and to tension, sever, and join the strap with a friction weld, so as to form a tensioned loop. Signode Model MCD-500 strapping heads, as mentioned above, are arranged to sever the straps before joininq them with friction welds.

Each of the strappinq heads 350, 352, 354, 356, is provided with a strap accumulator of a known type, so as to accommodate any excess strap beinσ pulled from the associated strap disDenser into the strappinq head, namely a first strap accumulator 7 ^p _f which is associated with the first straopinσ head 350, a second strap accumulator 37?, which is associated with the second strappinq head 35?, a third strap accumulator 374, which is associated with the third strappinq head 354, and a fourth straD accumulator 376, which is associated with the fourth strapping head 356. Precise details of the strap accumulators are outside the scope of this invention. Strap accumulators are used conventionally in strapping machines.

As shown in FIGURES 1 and 7, four strap chutes are carried by the platen 70, each coactinq with a respective <ne of the strappinq heads noted above, and each being arranged to guide a strap beinq fed by the strapping head coacting therebetween and to release the strap when the strap is tensioned by the same strapping head. Each strap chute is aliened with a respective one of the strap-handlinq zones noted above.

Each strap chute includes two upper sections, two vertical sections, and a lower section, in a conventional arrangement for a strap chute. The upper sections are disposed above the load- compressing plane, as defined by the platen 70, and are spaced from each other so as to accommodate the strapping head coacting with such strap chute. The strapping head coacting with such strap chute Is disposed between the upper sections. Each vertical section communicates at its upper end with a respective one of the upper sections, passes t rouqh the load-support.inq plane, as defined by the roller table 50, and is adjacent to a respective end of the roller table 50. The lower section is disposed helow the load-supportinq plane, as defined by the roller table 50, at any elevation of the platen 7n between its upper and lower limits, and communicates at each of its opposite ends with the lower end of a respective one of the vertical sections. Except as disclosed herein, each strap chute conforms essentially to the strap chute disclosed in Urban et al. U.S. Patent No. 4,520,720, the disclosure of which is incorporated herein by reference.

Thus, a first strap chute 390 is associated with the first strapping head 350 and is aligned with the first strap-handlinq zone Z, _r and a second strap chute 392 is associated with the second strapping head 352 and is aligned with the second strap-handling zone Z ₂ . Also, a third strap chute 394 is associated with the third strappinq head "^54 and is aligned with the third strap-handlinq zone ₃ , and a fourth strap chute 396 is associated with the fourth strappinq head 356 and is aliqned with the fourth strap-handling zone Z ₄ . The strap chutes 390, 392, 394, 396, are suggested in FIGURE 1, are

shown partially in FIGURE 7, but are omitted in FIGURE 6.

When four bags like the bags 14, for a load like the exemplary load 12, are Placed onto the inlet conveyor 20, the load-confinino door 280 on the inlet side of the strapping machine 10 is pivoted to its horizontal, opened position, whereby the rollers 328 associated with such door 280 extend the roller table 50 at the inlet side of the strapping machine in, and the load-confining door 290 on the outlet side of the strapping machine 10 is pivoted to its vertical, closed position. Such bags can be then conveyed onto the roller table, via the rollers 2? of the inlet conveyor 20, the rollers 3?8 extendinq the roller table 50, and the rollers 52 of the roller table *0, until such bags reach the load-confininq door 290, which aligns such bags and confines such bags at the outlet side of the strapping machine 10, whereupon the load-confining door 280 is pivoted to its vertical, closed position, whereby such door 280 confines such bags at the inlet side of the strapoinσ machine 10. It does not matter if such baσs hapϋen to be thus compressed alonq a transverse, horizontal axis, as confined between the load-confininσ doors 280, 290.

After such bags have been confined between the load-confininq doors 280, 290, the o aten 70 is lowered, along with the strapping heads and associated strap chutes carried by the platen 70, whereby each load-end former is engaged by the platen 70, at the rollers at the upper end of the upper tube of such load-end former, so as to be forcibly telescoped from its extended condition toward its contracted condition, whereby such bags are confined between the platen 70 and the roller table 50, and

whereby such bags can be also compressed alono a vertical axis, between the platen 70 and the roller table 50. Whether the platen 70 reaches its lower limit depends upon such factors as compressibility of such bags and initial height of such bags. Thus, such bags are confined along a transverse, horizontal axis, between two load-confining planes defined respectively by the load-confining doors 280, 290, and along a vertical axis, between the load-compressing plane defined by the platen 70 and the load-suppor ing plane defined by the roller table 50. Also, as mentioned above, such bags can he vertically compressed, between the platen 70 and the roller table 5n. After such bags have been confined between the load-confining doors 280, 290, and between the platen 70 and the roller table 50, such baqs can be endwise compressed alonq a lonqitudinal, horizontal axis, between the load-end formers of each pair, bv conjoint movement of the load-end formers 90b, 92b, 94b, 96b, 98b, toward the load-end formers 90a, 92a, 94a, 96a, 98^, each of which is in the normal condition. Relative movement between the load-end formers and the platen 70 is facilitated by the rollers 128, 158, etc., as provided at the upper ends of the upper tubes of the load-end formers. Next, after the pins 176, 186, 198, 210, and similar pins noted above have been shifted, each to its extended position, such bags are strapped with four parallel straps, by the strapping heads 350, 352, 354, 356, which coact with the strap chutes 390, 392, 394, 396, whereupon each of such pins is shifted to its withdrawn position. Since the strap chutes 390, 39?, 394, 396, are aligned respectively with the strap-handling zones Z _χ , z _? , ?,^ _t z , such

straps pass respectively through the strap-handlinq zones Z,, Z ₂ , Z ₃ , Z ₄ , as such straris are tensioned by the strapping heads 350, 352, 354, 356. • - After such bags have been strapped, so as to form a strapped load, the load-end formers 90b, 9?b, 94JD, 96b, 98b, are moved conjointly awav from the load-end formers 90a, 92b, 94b, 96b, 98b, which are moved conjointly from the normal condition to the displaced condition, then back to the normal condition, so as to separate the strapped load from the load-end formers 90a, 92a, 94a, 96a, 8 , while the strapped load remains confined as mentioned above. Next, the platen 70 is elevated, along with the strapping heads and associated strap chutes carried by the platen 70, so as to clear the strapped load.

After the platen 7n has been elevated, so as to clear the strapped load, the load-confininq door 290 at the outlet side of the strappinα machine 10 is pivoted to its horizontal, opened position, whereby the rollers 320 associated with such door 2 0 extend the roller table 50 at the outlet side of the strapping machine 10, whereupon the strapped load can be then conveyed from the roller table *n, onto the 5 outlet conveyor 24 via the rollers 52 of the roller table 50, the rollers 320 associated with such door 290, and the rollers 26 of the outlet conveyor 24. The load-confining door 280 at th_r inlet side of the strapping machine 10 may be simultaneously or 0 subsequently pivoted to its horizontal, opened position. After the strapped load has cleared the rollers 320 associated with the load-confininq door 290 at the outlet side of the strapping machine 10, such door 290 may be then pivoted to its vertical, 5 closed position.

These and other operations of the strappinq machine 10 may be advantaqeousl.v controlled bv a microprocessor, programmable controller, or other programmable means (not shown) which may be suitably programmed by a person skilled in the art.

Other enhancements and modifications mav be also made in the strappinq machine 10 without departing from the scope and spirit of this invention,