GB2256831A - Assembling carton divisions - Google Patents

Abstract

In apparatus for assembling carton divisions, first dividing shoots 72 are fed from a feeder unit 2 through a vertically indexable distributor 4 with their slots facing rearwardly, and are received in pickups 202 on a transversely indexable carriage to form shingled arrays, which arrays are than indexed through an insertion station 8 and are engaged with further dividing shoots fed from a feed or unit 10 with their slots facing forwardly. Sheet material on one side of the array slots is unconstrained, whilst material on the other side of the slots is constrained. Raised guide portions (234, Fig. 6d) are provided to displace the unconstrained material and open the array slots for engagement with the slots in the further sheets. <IMAGE>

Description

ASSEMBLING CARTON DIVISIONS This invention concerns improvements in apparatus and methods for assembling carton divisions.

In order to divide a case, carton or the like (hereinafter referred to as a 'carton') into a number of cells or compartments for reception of individual items, it is usual to provide within the carton two or more sets of dividing sheets assembled to form what is known as a division. The dividing sheets extend vertically within the carton and, with two sets, interengage each other at right angles, the sheets being interengaged by means of complementary slots extending to their top or bottom edges respectively.

Hitherto it has been usual to assemble such divisions using a machine which feeds an array of first dividing sheets, called machine axial- or A-pieces, beneath an insertion station. The A-pieces are held aligned in spaced parallel planes so as to occupy the relative positions which they will eventually adopt when the erected division is used in a carton. The A-piece slots are thereby aligned for insertion of transverse dividing sheets ('B-pieces') as the array is moved in steps beneath the insertion station.

To supply A-pieces to the insertion station, a number of A-piece hoppers are required, usually as many as the number of A-pieces in the division. With large numbers of A-pieces this can lead to a complex and bulky machine. Also, the assembled carton divisions are normally collapsed flat for convenient packaging and supply to subsequent users. This is an extra step in the production process, usually performed by the machine operator as the assembled divisions are removed from the machine. This requires some skill and dexterity in order to avoid inadvertent disassembly of the divisions or creasing of the sheets and can lead to delays in the production process. The above arrangement also requires very accurate positioning of the A- and B-pieces for correct insertion, as the A- and B-pieces have relatively narrow slot mouths.

The present invention aims to overcome the above disadvantages and in a first aspect provides apparatus for inserting a first sheet of material into a slot formed in the edge of a second sheet of material, wherein, in use, the slotted edge is supported so as to leave material on one side of the slot unconstrained whilst constraining the material to the other side of the slot; there being provided displacement means for cooperation with said unconstrained material to move it out of the plane of the second sheet and open the slot; and an inserter for engaging the first sheet of material with the opened slot. With the slots opened in this way, the need for accurate positioning is reduced.Preferably, the slotted edge of the second sheet is supported in a guide so as to be movable therealong generally in the plane of the second sheet, to leave said unconstrained material projecting from the guide. A succession of slots in the second sheet can thus be opened using the same guide. Preferably, the displacement means comprises a part of the guide which is offset from the plane of the second sheet. This is a particularly simple and effective arrangement, in which the displacement means requires no extra moving parts.

A second aspect of the invention provides division assembly apparatus comprising means to engage slots in a first set of dividing sheets with slots in a second set of dividing sheets which may be arranged to extend transversely of the first set in the erected division, wherein, during assembly, the sheets of the first set are laid parallel to one another at a spacing less than the distance between adjacent slots in the second sheet set, and offset so that the distance between slots in adjacent sheets of the first set corresponds to the distance between the slots of a given sheet of the second set for engagement of slots of the first sheet set with slots of the second sheet set, such that the division is assembled in an at least partially collapsed condition. Accordingly, the extra step of collapsing the assembled divisions can be eliminated.

The sheets of the first set may conveniently be delivered from a single hopper, although this is not essential to the above aspect of the invention.

Where a single hopper is used for delivery of the first set of sheets, such sheets may be fed to distribution means from which they successively exit in different predetermined offset planes.

According to a third aspect of the present invention, there is provided division assembly apparatus comprising means to engage the slots in a first set of dividing sheets with the slots in a second set of dividing sheets, wherein dividing sheets are fed from a single hopper to distribution means from which they successively exit in different predetermined offset planes, in order to form the first set. In this way there is no need to provide a multiplicity of A-piece hoppers.

Conveniently, the exit planes may be offset from one another by a spacing less than the distance between adjacent slots in the second sheet set, such that the division is again assembled in an at least partially collapsed condition, although this is not essential to this third aspect of the invention. The sheets of the first set are then transversely offset so that the distance between slots in adjacent sheets of the first set corresponds to the distance between the slots of given sheets of the second set, for engagement of the slots of the first sheet set with slots of the second sheet set.

Upon exit from the distribution means where present, the sheets of the first set may be engaged by a transfer carriage movable transversely of the distribution means to carry the first set to an insertion station for engagement with the second set of sheets. For engagement with the sheets of the first set, the carriage may be provided with sheet pick-ups mutually offset to correspond substantially with the exit planes of the distribution means, adjacent pick-ups being transversely offset so that their spacing substantially corresponds to the spacing between the slots of a given sheet the second set, and in use the carriage being moved in steps so as to engage sheets delivered from the distribution means in successive planes and carry them in shingled formation to the insertion station.

Advantageously, the slotted edges of the first set of sheets may be engaged in respective guide channels whilst they are carried to the insertion station, the guide channels each including an offset portion at the insertion station which bends each sheet as it passes therealong causing separation of the slot sides for insertion of and engagement with a said second sheet.

In either of the second or third aspects; the first set of sheets may be laid out in shingled formation for engagement with the second set, corresponding slots in adjacent sheets of the first set being offset from one another by the spacing of the slots in the second set. In this way, a division may be assembled substantially in the completely collapsed condition.

In its first aspect, the present invention also provides a method of inserting a first sheet of material into a slot formed in the edge of a second sheet of material, comprising the steps of: supporting the slotted edge so as to leave material on one side of the slot unconstrained whilst constraining material to the other side of the slot; displacing the unconstrained material out of the plane of the second sheet so as to open the slot; and, engaging the first sheet of material with the opened slot.

In its second aspect, the present invention also provides a method of assembling divisions by engagement of the slots in a first set of dividing sheets with the slots in a second set of dividing sheets which may be arranged to extend transversely of the first set in the erected division, wherein during assembly the sheets of the first set are laid parallel to one another at a spacing less than the distance between adjacent slots in the second sheet set, and offset so that the distance between slots in adjacent sheets of the first set corresponds to the distance between the slots of a given sheet of the second set such that the division is assembled in an at least partially collapsed condition.

Further, in its third aspect the present invention additionally provides a method of assembling divisions by engagement of the slots in a first set of dividing sheets with the slots in a second set of dividing sheets, wherein dividing sheets are fed from a single hopper to distribution means from which they successively exit in different predetermined offset planes, in order to form the first set.

These and further optional features of the present invention are described below with reference to a preferred embodiment, illustrated in the drawings wherein Fig. 1 is a plan view of the apparatus showing its general layout; Fig. 2a is a side view of an A-piece feeder and hopper adjustment mechanism, shown partially in section; Fig. 2b is a plan view of the A-piece feeder and hopper adjustment mechanism of Fig. 2a; Fig. 3a is a rear view of a sucker mechanism for use with "A" and "B" piece hoppers; Fig. 3b is a side view of the mechanism of Fig. 3a; Figs. 4a and 4b are perspective views of the hopper, Apiece push rods and sucker mechanism, taken from the rear and above and from one side and above respectively; Fig. 5a is a rear view of a feed roller mechanism of the apparatus of Fig. 1;; Figs. 5b and 5c are views on arrows Vb and Vc in Fig. 5a respectively; Fig. 5d is a perspective view of the left-hand end of the mechanism shown in Fig. 5a taken generally along arrow Vc; Fig. 6a is a side view of an A-piece distribution and transfer mechanism, taken in the same direction as Fig. 5c; Fig. 6b is a view of a transfer carriage and its drive mechanisms, taken on line VIb-VIb of Fig. 6a and on a somewhat reduced scale; Fig. 6c is a detail perspective view of A-piece distribution slots and fixed transfer guides, with removable transfer guides and their spacers removed and seen from the rear of the apparatus; Fig. 6d is a detail perspective view of a removable transfer guide and its spacer; Fig. 7a is a plan view of a B-piece insertion mechanism; Fig. 7b is a view on arrow VIIb in Fig. 7a; and Fig. 8 is a perspective view of the insertion station, again looking towards the rear of the apparatus.

The division assembly apparatus shown in Fig. 1 comprises an A-piece feeder unit 2, an A-piece distribution unit 4, an A-piece transfer unit 6, a B-piece insertion station 8, a Bpiece feeder unit 10 and a division take-off device 12.

The A-piece feeder and hopper adjustment mechanism 14 shown in Figs. 2a and 2b form part of the A-piece feeder unit 2. The mechanism 14 includes a movable carriage 16 mounted to the machine frame 18 by grooved rollers 20 engaged with a pair of parallel guide tracks 22.

Also mounted to the frame 18 by a cage 24 is a nut 26 carried upon a threaded spindle 28. A bearing block 30 mounts spindle 28 to the carriage 16. A pair of thrust bearings 32, 34 provided on the spindle 28 co-operate with the bearing block 30 to prevent relative longitudinal movement between the spindle 28 and carriage 16. Spindle 28 is rotatable by a handle 36, to cause movement of the nut 26 therealong, and hence adjustment of the carriage 16 relative to the machine frame 18 in the direction of feed of the Apieces. Fixed to the carriage 16 is a crossmember 38 forming part of the A-piece hopper backstop. A-pieces are stacked flat in the A-piece hopper, with their slots facing rearwardly, parallel to the direction of feed. Thus handle 36 provides for adjustment of the hopper to accommodate variations in A-piece height.

Fixed to the carriage 16 is a further guide track 40, above which is mounted a rodless pneumatic actuator 42. A crosshead 44 is mounted to run along the guide track 40 on further grooved rollers 46. The rodless pneumatic actuator 42 is engaged with the crosshead 44 by a driving connection 48. The crosshead mounts two sets of four grooved guide rollers 50 (not shown in Fig. 2a), each set engaging guide tracks provided on a pair of A-piece push rods 52. A toothed belt 54 is attached to each push rod 52 at an anchorage point 56 and is trained around a pulley 58 mounted co-axially with one of the grooved rollers 50. The other end of each belt 54 is fixed to the carriage 16 at an anchorage point 60.A further toothed belt 62 is anchored to each push rod 52 at 64, trained around a pulley 66 mounted co-axially with another of the rollers 50 and anchored by its other end to the carriage 16 at 68. This arrangement of pulleys 58, 66 and belts 54, 62 ensures that as the crosshead 44 and its rollers 50 are moved backwards or forwards through a given distance by the actuator 42, the push rods 52 move backwards or forwards through twice this distance relative to the carriage 16.

Figs. 3a and 3b show a suction cup mechanism 70 for pulling A-pieces 72 from the base of a hopper 74 past detents 76 and onto upper surfaces 78 of the push rods 52.

The mechanism 70 is mounted on a support frame 80 which is advantageously movable with respect to the machine frame 18 by means of a second roller, guide track, pulley and belt arrangement (not shown) analogous to that previously described, such that as the hopper backstop is adjusted by means of the handle 36, suction cups 82 of the mechanism 70 always remain positioned a small distance in front of the centreline of the hopper. As the A-piece slots face rearwardly and usually extend as far as the A-piece centreline, this ensures that the suction cups always gain a purchase on unslotted A-piece material when connected to a source of vacuum. In the second roller, pulley etc.

arrangement, clearly the support frame 80 is analogous to the crosshead 44, carriage 16 to the push rods 52 and machine frame 18 to the carriage 16 respectively.

Frame 80 carries a bracket 84, 85 on which are mounted four grooved guide rollers 86 for a slide 88. Mounted to the slide is a yoke 90 supporting the suction cups 82. A double acting pneumatic actuator 92 is connected between bracket portion 85 and yoke 90, for moving the latter relative to frame 80, guided by rollers 86 and slide 88.

Figs. 4a and 4b show further details of the hopper 74 and A-piece push rods 52. The width of the hopper 74 can be adjusted to accommodate A-pieces of different lengths. For this purpose, the hopper sides 94 are fixed to sliding blocks 96 movable on guide rods 98 by threaded spindle 100 and nut 110 mechanisms. The threaded spindles 100 are rotatable by handles (not shown) similar to handle 36.

The push rods 52 are each provided with two A-piece pick-ups 112, 114. The pick-ups are provided with front faces 116 which make an acute angle with the upper surfaces 78 of the push rods 52. The rearwardly extending portion of the forward pick-ups 114 is gently tapered to blend smoothly with the push rod upper surface 78. Only this portion of the forward pick-ups 114 is visible in Fig. 4a. The rearward pick-ups 112 are not visible at all in this figure. In Fig.

4b both rearward pick-ups 112 can be seen, as well as the rear edge of one forward pick-up 114.

In use of the feeder unit 2, the suction cup mechanism 70 is used to extract an A-piece from the bottom of the hopper 74 and place it onto the push rod upper surfaces 78, with the push rods in their fully retracted position. The push rods are then extended so that the front faces 116 of the rear pick-ups 112 engage the rear edge extracted A-piece and carry it forwards along the feeder bed 117. Channels 120 are provided in the feeder bed 117 to accommodate the forward ends of the push rods 52. The push rods are then retracted again, with the A-piece held stationary on the feeder bed 117, so that it rides up the rearwardly tapered portions of the forward pick-ups 114 and drops into place in front of the forward pick-up front faces.A hold-down brush 118 having depending bristles, or a series of spring fingers, may be provided for retaining the A-piece in position as the push rods are withdrawn. When the first A-piece is engaged by the forward pick-ups 114, the rearward pick-ups are ready to engage the next A-piece extracted from the hopper. Extending the push rods again will carry the first A-piece forwards to the A-piece distribution unit 4, on the forward pick-ups 114, and will carry the next A-piece onto the feeder bed 117, on the rearward pick-ups 112. In this way the A-piece feeding cycle can be repeated.

Figs. 5a-5d show the A-piece distribution unit in greater detail. It comprises a pair of high speed feed rollers 122 journalled on forwardly extending support arms 124, pivotable on horizontal shafts 126. The lower roller 124 is driven by a motor 128 via a gearbox 130, pulleys 132, 134 and toothed belt 136. The upper roller is geared to counter-rotate with the lower roller by pinions 138, and is pressed against the lower roller by its own weight and with spring assistance.

The correct spacing between the rollers 122 is maintained by a pair of cams 140 rigidly interconnected with their mounting shaft 144 and co-operating with followers 142 journalled on a shaft 143 connecting the lower arms 124. Shaft 144 may be rotated in bushings within the upper arms 124 and is locked in its adjusted position by setscrews 146 (Fig. 5d).

Alternatively, a pair of spacers may be used, removably coupled to the shaft 144 by setscrews, a different pair of spacers being used with each card thickness.

A-pieces are fed to the nip of the rollers 122 by the forward pick-ups 114, with the support arms 124 in a horizontal neutral position. In order to form an A-piece array, successive A-pieces are directed through successive vertically spaced slots 148 of a distribution guide 150 (Fig.

5d), which is described below in greater detail with reference to Figs. 6a-d.

When the support arms 124 are in their neutral position, the roller nip is aligned for feeding A-pieces to the lowermost slot 148. In order to feed A-pieces to all the remaining slots (or as many as are required in forming a given array), the rollers must be indexed alternately between the neutral position for receiving an A-piece, and successive raised positions for delivering A-pieces to the slots 148.

The indexing means comprise a pair of cams 152 (Fig. 5a & Fig.

5c) rigidly mounted to a shaft 154 journalled in the machine frame 18. The cams co-operate with followers 156, journalled to the lower support arms 124. The shaft 154 is rotatable by a servo motor 158, gearbox 160, toothed belt 162 and pulleys 164, 166, to index the arms 124 and rollers 122 to their required positions. (The stepper motor has been omitted from Figs. 5a-c for clarity; the gearbox has also been omitted in Fig. 5c.) Figs. 6a-c show the distribution guide 150 and two transfer carriages 168 of the transfer unit 6. Each carriage 168 is provided with six grooved rollers 170 which run along guide tracks 172. The carriages 168 are moved along the guide tracks by servo motors 174, pulleys 176, 178, a toothed belt 180 running parallel to each guide track 172, and driving links 182 which connect each carriage 168 to its respective drive belt 180.Each carriage includes a pair of arms 184 mounted on pivot shafts 186. A pick-up support member 190 is mounted upon the other ends of the arms 184 by pivot shafts 192 which extend parallel to pivot shafts 186, so that arms 184 form a parallelogram linkage. A double-acting pneumatic actuator 194 is connected between a pivot point 196 on the carriage body and a link member 197, itself connected to pivot points 198 on the arms 184, for raising and lowering the support member 190 relative to the carriage body.

The support member 190 has an undercut slot 200 in its upper surface, in which A-piece pick-up assembly 201 including pick-ups 202 are secured by setscrews (not shown). The number of pick-ups 202 is equal to the number of A-piece slots 148 and when the support member 190 is raised, an A-piece retaining notch 204 in each pick-up 202 lies at the same height as a corresponding slot 148 for reception of A-pieces fed therethrough. The pitch spacing of the notches is adjusted by means of the pick-up setscrews to be equal to the A-piece cell dimension. To form the A-piece array, the lowermost A-piece is fed through its slot 148 by the feed rollers 122. At this stage the carriage is positioned on guide track 172 such that the notch 204 of the lowermost pick-up 202 lies about 10-15 mm to the left of the A-piece left-hand edge as it would be shown in Fig. 6b (looking towards the rear of the machine). In this position, the Apiece left-hand edge is supported adjacent a sloping surface 206 of the pick-up 202. The carriage 168 and its associated pick-ups 202 are then indexed along the guide track 172 (to the right in Fig. 6b) to bring the next pick-up 202 into the transverse position formerly occupied by the lowermost pick-up 202. This movement gathers the lowermost A-piece into its pick-up notch 204. Successive indexing movements of the carriage 168 will thus bring the remaining A-pieces successively fed through their slots into their pick-up notches 204. In this way a set of A-pieces is formed into a shingled array.

The two carriages 168 work in tandem; as one is being filled with A-pieces from the distribution unit 4, the other is at the B-piece insertion station 8, the pick-up support members of both carriages being raised at this time. When the carriage 168 adjacent the distribution unit 4 is full, assembly of a division is simultaneously completed at the insertion station 8. The assembled division can therefore be removed from its carriage, the support member 190 of this carriage lowered, and this carriage moved along its guide track 172 until it is adjacent the distribution unit 4.

Simultaneously the carriage just filled can be moved along its guide track 172 to the insertion station 8, allowing the support member of the carriage 168 just emptied to be raised when it reaches the distribution unit 4.

Fig. 6c shows parts of A-piece guides, which together with the carriages 168 comprise the A-piece transfer unit 6.

Fig. 6c is a view looking towards the rear of the machine.

The distribution slots 148 are formed between adjacent slats 208 and also between the lowermost slat 208 and the bed 210 of the transfer unit 6, and between the uppermost slat 208 and a frame member 212. The slats are separated by spacers 214.

The forward edges 216 of the spacers lie rearwardly of the slat 208 front faces, so that the distribution slots are continued longitudinally of the transfer unit 6 in front of the spacers 214 to form A-piece guide grooves 218. The corners 220 of the spacers 214 leading from the slots 148 into the guide grooves 218 are angled so that the A-pieces emerging through the slots 148, and carried to the left as shown in Fig. 6c by one or other of the transfer carriages 168, are guided smoothly, without jamming, into contact with a backstop 222. This backstop is adjustably mounted between the machine frame 18 and supporting struts 224 by clamping screws 226, so as to hold the A-pieces securely within the guide grooves 218.

The downstream ends of the slats 208 disposed towards the B-piece insertion station 8 include machined recesses 228 in their upper surfaces. The upstream ends 230 of removable guides 232 formed from sheet stainless steel (Fig. 6d) are fitted into the recesses 228. A recess 229 is formed in the transfer unit bed 210, to accommodate the lowest guide 232.

The other ends of the removable guides 232 are bent to form raised or offset portions 234 at the B-piece insertion station 8. The removable guides 232 are separated by spacers 236 (Fig. 6d) of lesser width and positioned so that the guide grooves 218 continue between the removable guides 232. The upstream end of each spacer 236 is provided with a tongue 238 for engagement with the downstream ends 240 of the spacers 214. The raised portions 234 of the removable guides 232 project beyond the removable spacers 236. Several sets of spacers 236 and guides 232 are provided, corresponding to the various A-piece cell dimensions in manufacture. The lengths of the guides 232 forming each set are chosen such that when the guides 232 are installed in their recesses 228, adjacent raised portions 234 are pitched apart by the A-piece cell dimension, the lower guide 232 projecting beyond the upper.

The downstream end portion of each guide 232 including the raised portion 234 is thus exposed. The guides 232 and spacers 236 are secured in position by clamps (not shown).

The B-piece feeder unit 10 is generally similar to the A-piece feeder unit 2, except that the B-pieces are placed in their hopper with their slotted edges forward. Where there is provided automatic adjustment of the suction cup mechanism support frame dependent on hopper backstop adjustment, it is ensured that the suction cups remain to the rear of the hopper centreline, rather than in front. The whole B-piece feeder unit 10 is also tilted about 5" downwardly in the direction of feed and at an angle of about 10 from side to side, whereas the A-piece feeder unit 2 is substantially level. Unit 10 feeds B-pieces parallel to and in the same direction as the A-pieces are fed by unit 2.The tilt from side to side substantially matches the height variation of corresponding slots in the shingled A-piece set, so that A- and B-pieces can be brought together in the correct orientation at the B-piece insertion station 8.

A further important difference between the A- and B-piece feeder units is that the push rods 242 of the B-piece feeder unit 10 lack forward pick-ups 114. Instead, for more accurate control and guidance of B-pieces at the insertion station 8, B-piece pawls 244 are provided as shown in Figs. 7a and 7b. The pawls 244 are mounted on pivot shafts 246 carried by a crosshead 248 slidable on guide rods 250 by linear bearings 252. A toothed belt 254 runs beneath each guide rod 250, trained about a servo motor driven pulley 256 at one end and a further pulley 258 at the other. The crosshead 248 is driven back and forth along the guide rods 250 by linkages 260 connecting it with the belts 254.

With the pawls in their rearmost position 244' (shown in phantom in Figs. 7a and b), a B-piece is pushed forwardly onto the bed 262 of the B-piece feeder unit 10, by pick-ups 264 (equivalent to the rear pick-ups 112 of the A-piece feeder unit 2). The B-piece is pushed beneath the pawls 244, which fall into place behind it. The crosshead 248 can then be moved forwards to carry the B-piece along the bed 262 to the insertion station, where it enters the A-piece slots. Holddown brushes (266, 268 Fig. 8, not shown in Figs. 7a and 7b) may be provided, to keep the B-pieces flat against the bed 262. The brushes 266 are preferably adjustable and may be skewed relative to the feed direction, e.g. to compensate for the tilt of the feeder unit 10.

Alternatively, a pair of adjustable side guides (not shown) forming continuation of the B-piece hopper sides may be provided between which the B-pieces are guided to the insertion station.

Fig. 8 shows the B-piece insertion station. A hold-down brush 270 is provided at the forward end of the feeder bed 262, to press B-pieces towards the exposed ends of the removable guides 232. For assembly, an A-piece array is fed to the insertion station by one or other of the transfer carriages 168 until the material of the first A-piece cells lies over the exposed ends of the guides 232. In this position, the A-piece material to the left of the first set of corresponding slots as shown will be bent upwardly by the raised guide portions 234, the material to the right of each such slot still being held between adjacent guides 232. In this way the first set of corresponding A-piece slots is opened, and the first B-piece can now be fed beneath the hold-down brush 270 by the pawls 244, with its slots aligned with the opened A-piece slots.Pressure from the hold-down brush 270 also causes the B-piece slots to open, as the material to the right of each slot as shown rides up the raised portion 234 of the A-piece guides, whilst the material to the left is pushed into the depressions between adjacent raised portions 234. In this way the A- and B-piece slots are opened to be interengaged as the B-pieces are fed forwardly. When the first B-piece has been assembled with the first set of corresponding A-piece slots, the carriage- 168 can be used to index the assembly to the left by a distance equal to the A-piece cell dimension. The B-piece insertion cycle is then repeated to fill all the remaining sets of corresponding A-piece slots. It is not necessary for the uppermost guide 232a to be provided with a raised portion, as this guide merely has to hold down the material on the right of the uppermost A-piece slots.It does not have to bend any material upwardly.

The above described apparatus is particularly suited to the assembly of "LOKFAST" (RTM) divisions, whose slot mouths are provided with a lead-in chamfer on one side. It is particularly advantageous if the A- and B-pieces are loaded into their hoppers with their chamfers respectively lying on opposite sides of the slot centrelines. This maximises permissible positioning errors during assembly. The machine may utilise PLC circuitry, a suitable controller being the "System 7000" available from Parker Digiplan Ltd., 21 Balena Close, Poole, Dorset, BH17 7DX, United Kingdom.

The positions of all moving parts may be sensed by proximity switches, so that the controller can provide suitable interlocks and error diagnostics based on the sensed positions. The controller can also be programmed so as to calculate automatically the necessary motor increments of movement during each cycle, e.g. for the distribution means servo motor 158, the transfer carriage servo motors 174, and the B-piece feeder crosshead servo motors. It will be readily appreciated that it is only necessary to input the Aand B-piece cell dimensions and numbers of cells for the controller to perform these calculations.

The servo motors may be of the brushless'type, provided with integral position encoders. The "System 7000" control unit includes suitable feedback circuitry for use with such motors. Other control methods will be apparent, for example using stepper motors.

Claims (17)

1. Apparatus for inserting a first sheet of material into a slot formed in the edge of a second sheet of material, wherein, in use, the slotted edge is supported so as to leave material on one side of the slot unconstrained whilst constraining the material to the other side of the slot; there being provided displacement means for cooperation with said unconstrained material to move it out of the plane of the second sheet and open the slot; and an inserter for engaging the first sheet of material with the opened slot.

2. Apparatus as claimed in claim 1, wherein, in use, the slotted edge of the second sheet is supported in a guide so as to be movable therealong generally in the plane of the second sheet, to leave said unconstrained material projecting from the guide.

3. Apparatus as claimed in claim 2, wherein the displacement means comprises a part of the guide which is offset from the plane of the second sheet.

4. Division assembly apparatus comprising means to engage the slots in a first set of dividing sheets with the slots in a second set of dividing sheets which may be arranged to extend transversely of the first set in the erected division, wherein, during assembly, the sheets of the first set are laid parallel to one another at a spacing less than the distance between adjacent slots in the second sheet set and offset so that the distance between slots in adjacent sheets of the first set corresponds to the distance between the slots of a given sheet of the second set, for engagement of slots of the first sheet set with slots of the second sheet set, such that the division is assembled in an at least partially collapsed condition.

5. Apparatus as claimed in claim 4 wherein sheets are fed from a single hopper to distribution means from which they successively exit in different predetermined offset planes, in order to form the first set.

6. Division assembly apparatus comprising means to engage the slots in a first set of dividing sheets with the slots in a second set of dividing sheets, wherein dividing sheets are fed from a single hopper to distribution means from which they successively exit in different predetermined offset planes, in order to form the first set.

7. Apparatus as claimed in claim 6, wherein the planes are offset from one another by a spacing less than the distance between adjacent slots in the second sheet set, and the sheets of the first set are transversely offset so that the distance between slots in adjacent sheets of the first set corresponds to the distance between the sets of a given sheet of the second set, for engagement of slots of the first sheet set with slots of the second sheet set, such that the division is assembled in an at least partially collapsed condition.

8. Apparatus as claimed in any of claims 5 to 7 wherein upon exit from the distribution means the sheets of the first set are engaged by a transfer carriage movable transversely of the distribution means to carry the first set to an insertion station for engagement with the second set of sheets.

9. Apparatus as claimed in claim 8 wherein, for engagement with the sheets of the first set, the carriage is provided with sheet pick-ups mutually offset to correspond substantially with the exit planes of the distribution means, adjacent pick-ups being transversely offset by a distance substantially corresponding to the spacing between the slots of the second set of sheets, and in use the carriage is moved in steps so as to engage sheets delivered from the distribution means in successive planes and carry them in shingled formation to the insertion station.

10. Apparatus as claimed in claim 8 or 9 wherein the slotted edges of the first set of sheets are engaged in respective guide channels whilst they are carried to the insertion station, the guide channels each including an offset portion at the insertion station which bends each sheet as it passes therealong, causing separation of the slot sides for insertion of and engagement with a said second sheet.

11. Apparatus as claimed in any of claims 4 - 10 wherein the first set of sheets are laid out in a shingled formation for engagement with the second set, corresponding slots in adjacent sheets of the first set being offset from one another by the spacing of the slots in a given sheet of the second set.

12. Division assembly apparatus substantially as described with reference to or as shown in the drawings.

13. A method of assembling divisions by engagement of the slots in a first set of dividing sheets which may be arranged to extend transversely of the first set in the erected division, wherein during assembly the sheets of the first set are laid parallel to one another at a spacing less than the distance between adjacent slots in the second sheet set, and offset so that the distance between slots in adjacent sheets of the first set correspond to the distance between the slots of a given sheet of the second set, such that the division is assembled in an at least partially collapsed condition.

14. A method of assembling divisions by engagement of the slots in a first set of dividing sheets with the slots in a second set of dividing sheets, wherein dividing sheets are fed from a single hopper to distribution means from which they successively exit in different predetermined offset planes, in order to form the first set.

15. A method of inserting a first sheet of material into a slot formed in the edge of a second sheet of material, comprising the steps of: supporting the slotted edge so as to leave material on one side of the slot unconstrained whilst constraining material to the other side of the slot; displacing the unconstrained material out of the plane of the second sheet so as to open the slot; and engaging the first sheet of material with the opened slot.

16. A method of inserting a first sheet of material into a slot formed in the edge of a second sheet of material, substantially as described with reference to the drawings.

17. A method of assembling divisions substantially as described with reference to the drawings.