GB2059868A - Machine for covering boxes with a cardboard or foil blank - Google Patents

Abstract

A machine for sticking a cardboard or foil covering blank to a rectangular box(s) comprises a magazine for boxes (S), a magazine for blanks and means for feeding in synchronism a box (S) and a blank to a processing zone (I, II). In a first station (I) of the processing zone spray heads (30) spray glue onto the blank and a piston (Z7) lifts the box (S) and the blank located thereabove together between bars (9) which fold a pair of end strips of the blank against the sidewalls of the box (S). Pivotal jaws (12) fold marginal areas of the blank over the free end faces of the thus covered side walls of the box (S). A feed cylinder (Z2) pushes the box (S) with the blank attached thereto to a second station (II) where spray heads spray glue onto a further pair of end strips of the blank which are then folded over in a manner similar to the previously folded strips in station (I). Corner flaps of the blank are also folded at station (II). <IMAGE>

Description

SPECIFICATION Machine for covering boxes with a cardboard or foil blank The invention relates to a machine for covering boxes with a cardboard or foil blank and in particular for covering boxes having pairs of opposed parallel walls.

Hitherto, a great deal of manual work was necessary for coating or covering boxes, in particular boxes consisting of polystyrene foam, with blanks consisting of cardboard or foil, so that boxes of this type are very expensive.

The object of the invention is to provide a machine which operates at least semi-automatically for carrying out this work, in order to make it less expensive to produce such boxes.

The invention provides a machine for covering rectangular boxes, having a bottom, and side walls which extend parallel to each other in pairs, with a blank consisting of cardboard or foil, and having end strips for atachment to said side walls, characterised by the fact that one of two magazines is respectively provided for the boxes and for the blanks, from which magazines and boxes and the blanks are removed individually and that a processing zone operating in synchronism with the movement of a blank and a box is provided and adapted to join and sticking each of said boxes and to a respective one of said blanks.

With the machine according to the invention, the covering of boxes consisting in particular of polystyrene foam with pre-manufactured blanks consisting of cardboard or foil is largely or completely automated. It is only necessary to supply the two magazines with boxes and with blanks and in the machine a box is then supplied together with a blank and the two parts are connected together in the correct position after the application of an adhesive by the processing station operating in synchronism.

Further features of the invention will become apparent from the sub-claims, description and drawings.

The drawings show a box with the associated blank and one embodiment of the machine according to the invention: Figure 1 shows a pre-manufactured box consisting of polystyrene foam; Figure 2 shows a cardboard blank for covering the box according to Fig. 1; Figure 3 is a cut-away cross-section through a corner of the box according to Fig. 1 after being covered with a cardboard blank according to Fig. 2.

Figure 4 is a plan view of the machine according to the invention; Figure 5 is a section on line A-B-C-D of Fig. 4; Figure 6 is a section on line E-F of Fig. 4; and Figure 7 is a cross-section corresponding to the cut-away view shown in Fig. 6 of station I, to an enlarged scale.

The machine illustrated in detail in Figs. 4 to 7, serves to cover boxes consisting of polystyrene foam with a blank of thin cardboard. Fig. 1 shows a pre-manufactured box (S), which has a rectangular bottom (B) and two longitudinal walls (L1 and L2) projecting at right angles from the bottom B as well as two side walls K1 and K2 at right angles to the longitudinal walls and to the bottom. Fig.

2 shows a cardboard blank M, which consists of a central part and two end strips R1 and R2 intended for covering the longitudinal walls L1 and L2 of the box as well as two end strips R3 and R4 intended for covering the side walls K1 and K2 of the box, which are separated from the central part of the cardboard blank M by bending lines L shown in dot dash line. The end strips R1 to R4 in turn have narrow marginals areas N1 to N4, which are intended to bear against the free end faces of the side walls of the box S. For bending over these marginal areas N1 to N4, bending grooves P are prepared in the cardboard blank M.The end strips R1 and R2 are extended at their two narrow sides by flaps X, which are later folded inwards along the ends of the bending lines L so that the cardboard blank is closed at the corners after folding.

The box S has a mark a (Fig. 1), which characterises the correct position for introduction into the machine. A mark b is likewise provided on the cardboard blank M for correct introduction of the blank into the machine.

The cardboard may be coated with polyethylene or polypropylene on one or two sides. A hot-melt adhesive is used as the connecting material between the cardboard blank and the box, which adhesive is sprayed in the form of strips or beads in the machine. The position of two such strips is shown at c and d in Fig. 3.

The machine illustrated in Figs. 4 to 7 has a base or foundation 1 with four guide pillars 2a, 2b, 2c, 2d. Connected positively to these guide pillars are two upper guide rods 3a and 3c and two lower guide rods 3b and 3d.

These rods are arranged in pairs so that the guide rods 3a and 3b are located one above the other and between the guide pillars 2a and 2b, whereas the guide rods Sc and 3d are located between the guide pillars 2c and 2d and are likewise one above the other.

Mounted on the two upper guide rods 3a and Sc is a horizontal support beam 4a and on the two lower guide bars 3b and 3d is a horizontal support beam 4b. These support beams are able to move respectively with sliding members 41a, 41b along the associated guide rods 3a, Sc or 3b, 3d. Located on the lower support beam 4b are brackets 44 and 45 of U-shaped cross section and on the upper support beam 4a are brackets 46 and 47 likewise of U-shaped cross section. Guided in the lower brackets 44 and 45 are two feed cylinders Z7, Z9 operating as lifting cylinders and guide in the upper brackets 46 and 47 are pressing cylinders Z4 and Z5.The pistons of the two lifting cylinders Z7 and Z9 support lifting plates 44a, 45a. Pressing plates 46a, 47a are attached to the pistons of the two pressing cylinders Z4 and Z5.

Four horizontal cross members 5a to 5d are also attached to the guide pillars 2a to 2d.

The two cross members 5a and Sc are located one above the other and extend between the guide pillars 2a and 2d. The other two cross members 5b and 5d are located between the guide pillars 2b and 2c and are likewise one above the other. Furthermore, the two guide pillars 2a and 2b are connected by horizontal supports 6a and 6b, which are arranged so that the support 6a extends in a plane above the cross members 5a and 5b whereas the support 6b is located in a plane between the pairs of cross members 5a, 5b and 5c, 5d.

The machine contains a processing zone consisting of two stations I and il (Fig. 6). The lifting cylinder Z7 and the pressing cylinder Z4 belong to the first station I, which is shown to an enlarged scale in cut-away view in Fig. 7. Two support rails 7 are screwed to the two cross members Sc and 5d, which rails consist of two individual rails 7a and 7b (Fig.

7). A holder 29 for a spray head 30 is located on the outer side of each support rail 7 (Figs.

6 and 7). Two clamping supports 8 are attached to the two upper cross members 5a and 5b. The support rails 7 and clamping supports 8 can be adjusted laterally according to the size of the box S to be covered.

Clamping bars 9 are provided on the clamping supports 8. One of these clamping bars is able to move by approximately 1 to 2mm against the force of a spring 48. Clamping plates 10 are screwed to the top of the clamping supports 8. Angle joints 11 are also seated on the clamping supports 8, by which joints jaws 1 2 are mounted to move. The jaws 1 2 can be swung by means of operating cylinders Z8.

The jaw 1 2 illustrated in Fig. 7 is shown in full line in its operating position (moved inwards). The dot dash lines in Fig. 7 show the jaw 12 in the preliminary position. In this position of the jaw 12, a box S can be moved by means of the lifting plate 44a of the lifting cylinder Z7 upwards in the direction of the arrow shown. A guide rail 1 3 is located respectively laterally and above the spray heads 30.These two guide rails are suspended from the cross members 5a and 5b so that they are vertically and laterally adjustable, by means of cross pieces 1 3a and mounting supports 1 sub. The cardboard blanks M are inserted in these guide rails, so that a blank M is respectively located above a box S, which is supported by the support rails 7 and is turned with its bottom B upwards.

When the blank M is inserted in the two guide rails 1 5, two nozzles 30a and 30b of each of the two spray heads 30 are opened and spray adhesive onto the points of the end strips R1 and R2 indicated by c and d in Fig.

3, in which case the marginal areas N1 and N2 are also coated (cf Fig. 2). When the piston of the cylinder Z7 is extended, its lifting plate 44a engages in the box which is open on the underside, until it comes to bear against the bottom of the box. As the lifting plate 44a continues to move upwards, the box is raised, so that the outer side of the bottom of the box bears against the blank M, which is then entrained by the box as it is raised further. The end strips R1 and R2 are bent over in a downwards direction as soon as the box S with the cardboard blank M arrives between the clamping bars 9. During the upwards movement of the box, the jaws 1 2 are swung outwards, so that they do not come into contact with the cardboard blank.

When the box is completely introduced between the clamping bars 9, the jaws 1 2 are swung inwards so that they engage below the box by their bent end section. Thus, the marginal areas N1 and N2 which were hitherto projecting vertically downwards are bent over and placed against the end face of the associated side wall of the box. The piston of the pressing cylinder Z4 is then extended so that its pressing plate 46a projecting on all sides beyond the box bears over its entire surface against the bottom of the box and presses the walls of the box against the jaw 1 2 by their end faces covered by the marginal areas N1 and N2 of the blank M.Several boxes are each stuck to a blank in succession in this way, so that a plurality of boxes are stacked one above the other in the station I and the stack is raised by the height of one box during one cycle.

A pusher member 14 conveys the uppermost box from station I to station II (Figs. 4 and 6). The pusher member 14 is controlled by a cylinder Z2 and supports lateral bearings 15, which slide on horizontal support rods 1 5a. Two guide members 1 6 are attached to the pusher member 14, which members 1 6 are each adjustable according to the length of the boxes (Fig. 4). An ejection bar 1 7 which can be adjusted horizontally and vertically is fixed in the bearings '15 (Figs. 4 and 5). The uppermost box is pushed from station I by means of the pusher member 14 on support rails 18 of station ll. A lateral guide bar 19 is screwed respectively to the support rails 18, which bar prevents the box from moving sideways. At the same time that a box is inserted, the uppermost finished covered box is ejected from station Il by means of the ejection bar 1 7 and the latter may then be discharged along a slide 49 (Fig. 6). The halffinished box pushed on the support rails 1 8 is moved forwards by the pusher member as far as the abutments 20, which consist of angle brackets and are attached to mounting supports (Figs. 4 and 6). The support rails 1 8 are attached to the support 6b so that they can be adjusted according to the size of the box.

Holders for spray heads 21 are attached to the outsides of the support rails 1 8. Clamping supports 22 with clamping bars 23 and clamping plates 24 are located in the region above the support rails 1 8. The clamping supports 22 are attached to the support 6a in such a manner that they can be adjusted. One of the clamping bars 23 is able to move sideways by approximately 1-2 mm due to spring force.

Adjustable jaws 25 are mounted on angle joints 11 a on the clamping supports 22, which jaws 25 are tilted by cylinders Z1 0.

This arrangement corresponds to the clamping supports 8, clamping bars 9 and clamping plates 10 of station I (Fig. 7).

Apart from the two stations I and 11, the machine contains a box magazine SM and a cardboard magazine KM for the cardboard blanks (Fig. 4). The box magazine SM has a bracket 26, which is attached to the cross member 5d. The bracket 26 is also supported by a foot 26a on the base (Fig. 5). A further foot can be attached to the base plate of the frame or to the foundation 1 (not shown).

Plates 27 with their edges 27a bent downwards are screwed to a central cross piece 26b of the bracket 26 so that a channel exists between the plates 27, the bottom of which channel is formed by the upperside of the cross piece 26b of the bracket. The piston of a cylinder Z1 is guided in this channel, by means of which cylinder a pusher member 50 is to be actuated. The plates 27 serve as box supports and have slots 27b, in which supports 28 of L-shaped cross section are guided by their feet 28a so that they are able to move laterally and are able to be fixed. The feet have longitudinal slots, so that the supports 28 are also able to move at right angles to the slots 27b. The lowermost blank of the blanks S is pushed from the magazine SM by means of the pusher member 50 on the support rails of the station I.

The cardboard magazine KM has a bracket 31 with two guide rods 32 attached by screwing and a threaded spindle 33 and is attached to the frame 1 and aligned. A lifting plate 35 is attached to a support 34, which is fitted by its outer bearings on the guide rods 32 and can be raised and lowered by means of the threaded spindle 33. A cylinder Z1 1 is provided for lifting the support 34 and the lifting plate 35 connected thereto, by which cylinder a ratchet wheel attached to the threaded spindle 33 is rotated stepwise. According to the number of teeth of the ratchet wheel and the pitch of the threaded spindle 33, the lifting plate 35, on which a pile of cardboard blanks M is located, is raised by a certain amount, which is adjusted according to the thickness of the cardboard.Vertical guide bars can be adjusted in the slots in the lifting plate 35, of which three bars 36a, 36b and 36c are shown in Fig. 4 and which serve for aligning the cardboard blanks M.

Mounted on a transverse support 37a, which is supported on the cross member 5a is a two-part swinging arm 37 (Fig. 4), to which a cylinder Z3 is attached. Mounted on the piston rod of the cylinder Z3 is a vacuumsuction head 38 with a vertically aligned actuating cylinder. The uppermost cardboard blank is raised from the stack by the vacuumsuction head 38. The piston rod of the cylinder Z3 is then extended so that the vacuumsuction head 38 arrives in the position illustrated in Fig. 4. At this time, the cardboard blank entrained is moved between two laterial inlet plates 39 forwards into the region of feed rollers. Two feed rollers 40 are arranged in an adjustable manner on a shaft 42, which is driven by a geared motor 42a.A further, likewise driven feed roller (not shown in the drawings) is arranged in the feed direction in front of the feed rollers 40 and centrally with respect to the latter. Located above this central feed roller is a pressure roller, which is pressed by a cylinder against the feed roller or the cardboard blank located thereon. The cardboard blank held in this way between the two rollers can then be conveyed further to the next feed rollers 40. Upper pressure rollers are likewise associated with these two driven feed rollers 40, which pressure rollers are spring-loaded in the direction of the feed rollers 40. The feed rollers convey the cardboard blank on the guide rails 1 3 to an end stop.

The machine can be controlled electro-pneumatically or electronically, in which case a fully automated or even a semi-automated control can be provided. Hydraulic cylinders may also be used in place of pneumatic cylinders.

One working cycle will be described hereafter.

The pusher member 50 of the cylinder Z1 introduces the lowermost box of the pile located in the box magazine SM into the station I of the machine. When introducing the boxes into the box magazine, attention must be paid to the fact that the bottoms B of the boxes are directed upwards. At the time of insertion, the respective box S rests with the end faces of its side walls on the two lower support rails 7 and it is guided on both sides by the guide bars 7a. The cardboard magazine KM is located on the opposite side of the machine from the box magazine SM. The cardboard blanks M are inserted in the cardboard magazine with their printed side uppermost and are stacked to a height of approximately 40-50 cm. The pile is held by the guide rods 36 in the position set.When inserting the pile, the swinging arm 37 is swung upwards, so that the cardboard magazine is freely accessible.

At the beginning of the operating cycle, the swinging arm is swung into the operating position (Fig. 4) and the uppermost cardboard blank is sucked by the vacuum-suction head 38, which is then rasied by approximately 2 cm by means of the vertical cylinder associated therewith. The cylinder Z3 is actuated so that its piston rod moves the suction head 38 with the cardboard blank engaged by suction between the two inlet plates 39. The card board blank is then held at such a height that it arrives between the front feed roller and the associated pressure roller. The vacuum in the suction head 38 is then discontinued and the piston of the cylinder Z3 is retracted. The pressure roller is then moved by a cylinder in the direction of the associated feed roller, so that the cardboard blank is held between the two rollers.Since the feed roller is driven, the cardboard blank is entrained frictionally and moved to the next feed rollers 40. In conjunction with their pressure rollers, these feed rollers convey the cardboard blank into the guide rails 13, which position the blank laterally (Figs. 4 and 7). A spring-loaded stop prevents the cardboard blank from being inserted too far. The blank is then located with its inner bending edges L exactly above the side edges of the previously inserted box S. A fork is provided in one of the inlet plates 39, which fork produces a vertical light barrier 43, which passes through the cardboard blank as it is drawn into the station I. The light barrier 43 then sends a signal to the adhesive spray heads 30 mounted on both sides of the support rail 7 (Figs. 6 and 7).The nozzles 30a and 30b of these spray heads are opened, as soon as the cardboard blank M enters the station I by its front edge. The nozzles then spray beads of adhesive from below onto the incoming cardboard blank, so that the end strips R1 and R2 are coated with a strip of adhesive over their entire length. At the time of each cycle, the lifting plate 35 of the cardboard magazine is raised with the pile of cardboard blanks by means of the threaded spindle 33 by the thickness of one cardboard blank.

By actuating the cylinder ;|7 Z7 (Fig. 7), the lifting plate 44a is moved upwards and thus the box S is raised, which thus entrains the cardboard blank M located thereabove. When the box is inserted between the clamping bars 9, the cardboard blank M located on the box is bent downwards along the two longitudinal edges of the box and pressed against the side faces. The beads of adhesive which were sprayed on are now able to produce an adhesive connection between the cardboard blank and the walls of the box, in which case heat may be applied if necessary. As a result of the laterally resilient mounting of one clamping bar 9, inaccuracies in the dimensions of the boxes can be compensated for.As soon as the box S has been inserted completely against the clamping bars 9, the two jaws 1 2 are swung out of their position shown in dot dash line in Fig. 7, so that they engage by a dimension of approximately 12mm below the side walls of the box. Thus, the jaws 1 2 bend the marginal areas N1 and N2 of the cardboard blank over by approximately 90 so that these marginal areas lie parallel to the end faces of the side walls of the box. The width of these marginal areas is generally chosen to correspond to the thickness of the walls of the box. As soon as the jaws 1 2 engage below the box, the pressing cylinder Z4 is actuated, whereof the pressing plate 46a moves downwards and presses against the bottom of the box inserted first.In this case, the marginal areas N1 and N2 of the cardboard blank resting on the jaws 1 2 are pressed onto the end faces of the side walls of the box and stuck to these end faces by means of the beads of adhesive. After the machine is first started up, a plurality of boxes are always located one above the other in station I, the number of which depends on the height of the box. The uppermost box is then pushed from station I by the pusher member 14 controlled by the cylinder Z2, on the support rails 18 of station II. In this case, the box is guided by the lateral guide bars 1 9 of the support rails 18 and pushed as far as the fixed stop 20 of station II. At the same time, the uppermost finished, covered box is ejected by means of the ejection bar 1 7 from this station.When the box is inserted into station II, beads of adhesive are sprayed by means of the spray heads 21 onto the two end strips R3 and R4 of the cardboard blank which are still free. As the box is inserted into station II, the four flaps X of the cardboard blank are bent over (Fig. 2), so that the covering is closed at the corners of the finished box.

At station II, the end strips R3 and R4 are connected to the associated side walls of the box in the same manner as the end strips R1 and R2 in station I.

A particular advantage of the machine according to the invention consists in that the boxes are completely covered on the outer side with the cardboard blanks which may be printed, so that even all the outer edges of the box are covered. The separate introduction of the premanufactured boxes and of the covering material facilitates an automatic operation for covering the box with a very high ejection capacity of the machine.

Claims (11)

1. A machine for covering rectangular boxes, having a bottom, and side walls which extend parallel to each other in pairs, with a blank consisting of cardboard or foil and having end strips for attachment to said side walls characterised by the fact that one of two magazines is respectively provided for the boxes and for the blanks, from which magazines the boxes and the blanks are removed individually and that a processing zone operating in synchronism with the movement of a blank and a box is prnvided and adapted to join and sticking each of said boxes and to a respective one of said blanks.

2. A machine according to claim 1, characterised by the fact that the processing zone contains feed cylinders and parallel clamping bars arranged in pairs, between which each box together with its blank is to be inserted by means of the feed cylinders, in which case end strips of a blank are bent over and pressed against the side walls of the respective box.

3. A machine according to claim 2, characterised by the fact that the processing zone consists of two stations cooperating in synchronism, each of which is adapted to apply two opposite end strips of a blank against the associated side walls of said respective box.

4. A machine according to claim 2 or 3, characterised by the fact that pistons of the feed cylinders are able to move vertically and each supports a lifting plate which lies parallel to the bottom of a box or boxes whilst located in said processing zone.

5. A machine according to one of claims 2 to 4, characterised by the fact that associated with each feed cylinder is a pressing cylinder operating in the opposite direction thereto, and which is located on the side of a box or pile of boxes located in the station remote from said associated feed cylinder, and a piston of which pressing cylinder can be extended towards the bottom of a box adjacent the latter.

6. A machine according to claim 3 or any claims dependent thereon, characterised by the fact that a transverse feed cylinder is provided for conveying a box from the first station to the second station.

7. A machine according to claim 6, characterised by the fact that connected to the transverse feed cylinder is an ejecting device, directed towards the box or an uppermost box at the second station.

8. A machine according to claim 6 or 7, characterised by the fact that the transverse feed cylinder has a horizontal feed direction.

9. A machine according to any one of claims 1 to 8, characterised by the fact that at least one spray head for the application of glue is provided in the processing zone for each of the end strips of the blank which strips project beyond the bottom of the box whilst said box is still unfolded.

1 0. A machine according to any one of claims 1 to 9, characterised by the fact that provided in the processing zone are swinging jaws arranged in pairs, which when swung inwardly engage marginal areas of the end strips extending below the box to be stuck, and thus bend over said marginal areas against free end faces of the walls of the box.

11. A machine for covering boxes substantially as hereinbefore described with reference to and as illustrated in Figs. 4 to 7 of the accompanying drawings.