GB2147264A

GB2147264A - Label wrapping machines

Info

Publication number: GB2147264A
Application number: GB08326067A
Authority: GB
Inventors: Peter Edwin Butcher
Original assignee: Metal Box PLC
Current assignee: Crown Packaging UK Ltd
Priority date: 1983-09-29
Filing date: 1983-09-29
Publication date: 1985-05-09
Also published as: EP0135935B1; IT8422928A0; ZA847506B; GB8326067D0; ATE31690T1; DE3468394D1; IN162477B; EP0135935A3; IT1178525B; GR80488B; GB2147264B; EP0135935A2

Abstract

A label wrapping machine has a turntable (10) carrying a plurality of wrapping stations (14). A label feeding station (28) feeds labels having adhesive applied to one end only to the pair of gripper assemblies (22 and 20) of each wrapping station (14) as it passes. Downstream of the label feeding station (28) is a can feeding station (24) which feeds cans (8) to each wrapping station (14) as it passes. <??>Each wrapping station (14) has a rotatable circular platform (18) for receiving a said can (8) and a belt providing an operative run. In a first configuration the run is rectilinear and a central portion thereof urges a central portion of the label into contact with the can (8). <??>In a second configuration the operative run becomes circular and in so doing wraps itself and the label around the can. Rotation of the belt brings the overlapping portions of the label into contact with each other and since adhesive has already been applied to one of the portions of the label will be tightly secured on to the can. No adhesive lies between the can and the label. <IMAGE>

Description

1 GB 2 147 264 A 1

SPECIFICATION

Label wrapping machines The present invention relates to label wrapping 70 machines.

In previously proposed machines for applying la bels to cans of food and drink each can and label is brought into a label wrapping station. At the wrapping station an adhesive is applied either to the can or along a leading edge of the label and the leading edge of the label is then pressed against the can to secure the edge of the label to the can. The can is then rotated to enable the rest of the label to become wrapped around the can and adhesive is then applied to the trailing edge of the label to secure the trailing end of the label to the leading end in the region of overlap.

Because the label is adhesively secured to the can the subsequent removal of the label from the 85 can is a difficult operation.

In the wrapping machine embodying the present invention a label is wrapped around a can without being adhesively secured to the can. The label is then secured to itself in the region of the overlap so that the label is held tightly around the can.

The label can then subsequently be stripped from the can by for example employing an air jet stripping process.

According to one aspect of the invention there is 95 provided a wrapping machine comprising a plat form for carrying an elongate item to be wrapped, means for supporting a web to be applied to the item, and belt means having a run movable be tween a first configuration in which an intermedi- 100 ate portion thereof urges an intermediate portion of a web when supported by the support means into engagement with said item, and a second con figuration in which the run conforms to the outer surface of the item thereby to wrap the web around the item, and means for driving the belt means to effect rotation of the web and the item about the longitudinal axis of the item.

According to another aspect of the invention there is further provided a wrapping machine com- 110 prising a rotary turn table, a plurality of angularly spaced wrapping stations on the turntable, each wrapping station including a platform for support ing an item to be wrapped, web support means for supporting a length of web to be wrapped around 115 the item, and a wrapping belt assembly movable between a first position in which it urges an inter mediate portion of the web against said item when located on said platform and a second position in which the assembly urges the remainder of the web into engagement with the item to cause the leading and trailing end portions to adopt a prede termined overlapping relationship; a web feeding station located adjacent said turntable for present- ing a web to the web support means of each wrap- 125 ping station in turn as it passes the web feeding station; an item feeding station located downstream of said web feeding station, said item feeding station being arranged to deposit a said item on to a said platform of each web wrapping station 130 in turn as it passes; and a discharge station lo cated downstream of the item feeding station, said discharge station being arranged to engage and re move a wrapped item from each wrapping station during its passage therepast.

A label wrapping machine embodying the inven tion will now be described, by way of example and with reference to the accompanying diagrammatic drawings in which:

Figure 1 is a plan view of the machine; Figure 2 is a front elevation of a label support member; Figure 3 is a plan view of the label support member of Figure 2; Figure 4 is a plan view of the member of Figure 3 in more detail; Figure 5 is a plan view of an upstream gripper assembly; Figure 6 is a plan view of a downstream gripper assembly; Figure 7 is a front elevation of a wrapping sta tion; Figure 8 is a plan view of a wrapping belt as sembly of the wrapping station in the retracted state; Figure 9 is a plan view of the wrapping belt as sembly of Figure 8 in the engaged state; and Figure 10 is a fragmentary plan view of the wrapping belt assembly in more detail.

The wrapping machine to be described is ar ranged to wrap labels (bearing transferable print) around cans having a receptive surface thereon.

Once each can has received a label (with the print ing on the label being in contact with the outer re ceptive surface of the can), the label and can are processed to effect the transfer of the print from the label to the can. Thereafter the label is stripped from the can to leave the can with the print thereon. To ensure all round printing and to facili tate stripping, it is important that there should be no adhesive between the label and the can.

The machine shown in Figure 1 includes a main turntable 10 rotatably supported on a main shaft 12. A motor and gear arrangement (not shown) is arranged to rotate the turntable in a counter clock wise sense about the shaft 12. A plurality of wrap ping stations 14 supported by the turntable 10 are equiangularly arranged about the axis of the shaft 12. Each wrapping station 14 includes a wrapping belt assembly 16, a circular can support platform 18, a can centring mandrel (not shown) and a pair of label gripper assemblies 20 and 22.

A can feeding station 24 is arranged to feed cans arriving from a feed conveyor 26 on to the turnta ble 10. The feeding station 24 is arranged to space the cans arriving on the conveyor 26 with a prede termined spacing and to transfer each can in turn on to a respective one of the platforms 18 on the turntable 10 where it is held by a mandrel 86 (Fig ure 7) as the turntable rotates beyond the feeding station 24.

A label feeding station 28 located upstream of the can feeding station 24 is arranged to supply la bels from a label stack support arrangement 30 to the label gripper assemblies 20 and 22 of each 2 GB 2 147 264 A 2 wrapping station 14 as they pass the label feeding station 28.

A can discharge station 32 located downstream of the can feeding station 24 is arranged to remove each can in turn from the turntable 10 and to transfer it from the turntable 10 to a discharge conveyor 34.

Each wrapping station is actuated during its passage from the can feeding station 24 to the can discharge station 32 to wrap a label around its cor75 responding can.

The can feeding station The cans 8 arriving on the feed conveyor 26 are randomly spaced. A can guide 36 located adjacent one edge of the conveyor 26 acts to effect alignment of the cans. A rotary scroll 38 located adjacent the other edge of the conveyor acts to provide a uniform spacing between the cans 8. The scroll has a helical groove 38a and as each can approaches the passage between the guide 36 and the scroll it can only enter the passage by engaging the groove 38a. In this manner a uniform spacing (corresponding to the pitch of the helical groove) is ensured. A rotary star wheel 40 is located at the downstream end of the passage between the scroll 38 and guide 36. The star wheel 40 has four equiangularly spaced recesses 40a. Both the star wheel 40 and the scroll 38 are driven through the same motor and gear arrangement (not shown) which acts to drive the turntable 10. The relative angular positions of the star wheel 40 and scroll 38 are so set that as each can emerges from the passage it will engage a corresponding recess 40a.

Each recess 40a of the star wheel 40 is provided with a plurality of vacuum openings (not shown). A vacuum system (not shown) and a series of valves (not shown) cause a vacuum to be switched ON in each recess 40a as the recess is engaged by a can 8 from the passage and to be switched OFF when each can 8 has been carried round by the star wheel 40 to a position directly above a support platform 18 of a corresponding wrapping station.

By this operation each can 8 is held in a corresponding recess 40a by the suction force of the vacuum, transferred away from the conveyor 26 towards the turntable 10, and released only when located directly above a corresponding support platform 8. Again because the turntable 10 and star wheel 40 are both driven by a common source the positioning of the recesses 40a relative to the support platforms 18 can be synchronised.

The label feeding station As shown in Figure 1 the label feeding station 28 includes a satellite turntable 42. Four arcuate label support members 44 are supported by respective support shafts 46 on the satellite turntable 42. The satellite turntable 42 is arranged to be rotated in a clockwise sense to cause each member 44 to pass the stack of labels in turn so as to pick up a label and present it to the gripper arrangements 20 and 22 of a corresponding wrapping station 14.

Located upstream of the stack 30 is an adhesive supplying roller 48. Adhesive is continuously supplied to the roller 48 and a doctor blade bO ensures that a film of even thickness is maintained on the roller 48. Adhesive removed by the blade is recir- culated back to the roller 48. The roller is rotated in a counterclockwise sense.

Each arcuate support member 44 (see Figure 2) has a plurality of longitudinally extending vacuum grooves 52 (a)-(d) in its outer surface. The grooves 52 (a)-(d) are connected to a source of vacuum (not shown) through a cam operated valve assembly (not shown).

Both the trailing and the leading edge of the member 44 is provided with a row of recesses 56 to provide access for gripping fingers to remove a label when supported by the member 44. The trailing edge of the member 44 is provided with a raised rib 54. The locus of each member 44 when rotated by the satellite turntable 42 is such that only the rib 54 comes into contact with the adhesive supplying roller 48. In this way each time the member 44 passes the roller 48 only the rib 54 will be coated with adhesive.

In Figure 3 the stack 30 of labels is in the form of a magazine 58 housing a supply of labels. A pair of pushers 60 and 61 connected to a torsion spring, reel, cable and pulley system (not shown) urge the labels to the front of the magazine. Each of the pushers 60 and 61 may be withdrawn independ- ently to allow reloading of labels on-the-run (Figure 3(a)). The foremost labels are held captive in the magazine 58 by wedge-shaped knives 64 which engage the upper and lower edges of the labels and by spring biassed fingers 66 which engage the leading and trailing edges of the foremost label (See Figure 4).

The shaft 46 is mounted on the satellite turntable both for oscillation about its own axis and for reciprocation in the radial direction (see Figure 3). A series of cams (not shown) controls this movement in such a manner that as the arcuate member 44 approaches the foremost label in the stack the leading edge engages the leading edge of the label. Thereafter the remainder of the member 44 is caused progressively to engage corresponding parts of the label until finally the trailing edge of the member 44 engages the trailing edge of the label. During this period vacuum is applied to the grooves so that a label is pulled from under the fingers 66 and over the knives 64 to cause corre- sponding cuts to appear in the upper and lower edges of the label.

With the transfer of the foremost label from the stack 30 to the member 44 now complete, the vac- uum is maintained and rotation of the satellite turntable continued to cause the label to be carried round to the main turntable 10 for presentation to the gripper assemblies 20 and 22. During the transfer of the label from the stack to 125 the member 44, the rib 54 will have been firmly urged into contact with the trailing edge of the label and in doing so will have coated the trailing edge with the adhesive picked up from the roller 48. 130 In order to avoid the transfer of a label into any 3_ GB 2 147 264 A 3 wrapping station which will contain no can, a sen sor is fitted adjacent to scroll 38 to detect any missing can in the helical groove 38a. Upon detec tion of a missing can, the sensor will send a signal which activates a pneumatic cylinder (not shown).

This cylinder causes the label magazine assembly to temporarily retract so that as the appropriate member 44 passes, no label is collected.

The gripper assemblies As shown in Figure 5 the upstream gripper as sembly 22 of each wrapping station includes an elongate anvil 70 and row of gripper fingers 72 mounted on a shaft 74. Oscillation of the fingers 72 about the shaft 74 moves the fingers into and out of contact with the anvil 70. A cam assembly (not shown) moves the fingers away from the anvil 70 into the locus of the approaching member 44. The fingers 72 are spaced by an amount corresponding to the spacing of the recesses 56 in the leading edge of the member 44 (see Figure 2). At the in stant that the leading edge of the label carried by the member 44 lies between the anvil 70 and the fingers 72, the cam assembly acts to move the fin gers 72 towards the anvil 70. The fingers 72 pass through the recesses 56 and clamp the leading edge of the label against the anvil 70.

Valves controlling the vacuum supply to the slots 52 (a)-M in the member 44 are closed in sequence to allow the label to be separated from the mem95 ber 44.

The downstream label gripper assembly 20 (see Figure 6) has an elongate anvil 78 and a plurality of gripper fingers 76 mounted on a shaft 80. Oscil lation of the fingers 76 about the shaft 80 moves the fingers into and out of contact with the anvil 78. A cam assembly (not shown) controls the movement of the fingers 76. As the member 44 starts to leave the corresponding wrapping station the assembly 20 approaches the trailing edge of the label until the fingers 76 and anvil 78 lie on op posite sides of the label. At this moment the cam assembly is operated to cause the fingers 76 to move towards the anvil 78. The fingers 76 are spaced apart by the same spacing as that between the recesses 56 in the trailing edge of the member 44 and so pass through the recesses 56 to clamp the trailing edge of the label on to the anvil 78.

At this stage the two gripper assemblies 20 and 22 respectively hold the trailing and leading edges of the label and so the label is now carried by the main turntable 10.

The wrapping station Each wrapping station includes a circular support platform 18 (see Figure 7) supported by a shaft 84.

The shaft 84 is supported by a bearing 82 for free rotation on the main turntable 10. A mandrel 86 is located above the platform 18. The mandrel 86 is carried by a shaft 88 which is freely rotatable in a bearing 90. A cam mechanism (not shown) acts to control the sliding of the shaft 88 through the bearing 90.

The mandrel 86 is frusto-conical. In operation when the star wheel 40 had deposited a can on to130 the support 18 the cam mechanism displaces the shaft 88 downwardly to cause the mandre. Lo enter the open top of the can 8. Because of the frustoconical shape of the mandrel, the can becomes properly centred on the platform 18 and is firmly held in this position until after the label has been wrapped around the can.

In this state the label which is held by the gripper assemblies 20 and 22 now lies between the wrapping belt assembly 16 and the can 8.

The wrapping belt assembly is more clearly shown in Figures 8 and 9. The assembly includes two L-shaped support plates 92 and 94 supported for pivotal movement about respective axes 96 and 98. Each support plate 92 and 94 carries three roll ers 100, 102 and 104, and 106, 108 and 110 respec tively. On the plate 92 the three rollers 100, 102 and 104 are located at the three corners of a trian gle with the roller 104 having an axis of rotation common with the axis of rotation of the plate 92. On the plate 94 the three rollers 106, 108 and 110 are located at the three corners of a triangle with the roller 110 having an axis of rotation common with the axis of rotation of the plate 94. The two plates 92 and 94 are located symmetrically on opposite sides of a line A- A joining the axis of rotation of the platform 18 and the axis of rotation of the turntable 10. A drive roller 112 has its axis of rotation also located on the same line A-A but at a position located radially inwardly of the two Lshaped plates 92 and 94.

An endless belt 114 extends around the seven rollers 96 to 112 in such a manner as to form two triangular loops on opposite sides of the line A-A.

A Jockey wheel 116 mounted on an L-shaped sup- port 118 is urged into engagement with the length of belt extending between the drive wheel 112 and roller 110 by biasing means (not shown) to main tain the belt taut. Further localised tension may be applied between rolls 96-102 and 108-110.

A pair of actuators 120 (only one shown) control the displacement of the plates 92 and 94 about their respective axes of rotation 96 and 98. An ad justable stop 122 limits the rotation of the plate 94 in a clockwise sense (as viewed in Figure 8) while a similar stop (not shown) limits the rotation of the plate 92 in an anticlockwise sense.

The drive for the drive roller 112 is derived from the same source as that for the main turntable 10.

A pair of stops 124 (see Figure 9) limit the extent of displacement of the actuators 120 and thereby the extent of anticlockwise and clockwise rotation of the plates 92 and 94 respectively.

In operation as each wrapping station ap proaches the star wheel 40, the L-shaped plates 92 and 94 are held in a retracted position, that is in a position in which the stretch of belt 114 extending between the rollers 106 and 100 is tangential to the radially inner side of the platform 18 (see Figure 8).

With the label held between the gripping assemblies 20 and 22 a can 8 is deposited on to the platform 18 by the star wheel 40. The mandrel 86 is then lowered to centre the can and cause the label to become trapped between the belt 114 and the can 8.

4 GB 2 147 264 A 4 At this point the actuators 120 are operated to pivot the two triangular loops of the belt towards one another. As each triangular loop of the belt progressively engages the label, the tension in the label will increase. A degree of "give" is provided by the gripper assembly 22 because the whole as sembly is pivotally supported for rotation about the axis of the shaft 74 but is spring biassed into one predetermined angular position. Once a suita ble tension has been reached, both gripper assem blies 20 and 22 act to release the label which then becomes progressively wrapped around the can with continued movement of the triangular loops.

The sides of the two loops engaging the can be come semicircular when they reach the positions shown in Figure 9. Fingers 126 (see Figure 10) as sociated with the roller 100 enter the overlap be tween the two edges of the label to ensure that the leading edge of the label lies below the adhesive coated trailing edge. However the fingers 126 may 85 not be essential.

At this point, the drive to the roller 112 is en gaged and the belt 114 driven to the rotate the can in a clockwise sense (as viewed in Figure 9). Dur ing this operation the overlapping end portions of the label are brought into contact and so become adhesively secured together. The drive is transmit ted from the belt through the label to the can and thence to the platform 18 and mandrel 86 both of which are free to rotate.

The drive to the roller 112 is only engaged for a length of time sufficient to ensure that the can is rotated a full 360. After this operation the two ac tuators 120 are operated to retract the two L shaped plates 92 and 94 to bring them back to the positions shown in Figure 8.

The whole label wrapping operation takes place while the turntable is rotating between the can feeding station 24 and the can discharge station 32.

The label wrapping station is shown in more de tail in Figure 10.

The can discharge station The can discharge station (see Figure 1) includes 110 a star wheel 140 having recesses 140a. Openings in the recesses 140a are coupled to a vacuum source (not shown). In operation as each can reaches the star wheel 140 the mandrel 86 (see -50 Figure 7) is retracted and the can engages a corre- 115 sponding recess 140a in the star wheel.

Valves are operated to create a vacuum and the can, then securely held by the star wheel 140 is carried away from the main turntable 10 on to a discharge conveyor 34. At this point the valves are closed to discontinue the vacuum in the recess 140a and so the can drops on to the conveyor 34 to be carried to a processing station (not shown).

At the processing station the printed matter is transferred from the label to the can. The can continues its journey to a label stripping machine (not shown) where the labels are stripped, e.g. using an air jet.

Furthermore it will be appreciated that because the only adhesive holding the label on the can is in 130 the region of the overlap there will be no interference with the transfer of the printed matter and the need for special solvents which might otherwise be needed to break the adhesive bond between the la- bel and the can is obviated.

The use of a belt to envelop the label and the can ensures that the label is tightly wrapped round the can and that when the overlapping end portions are brought into contact the tightness of the label is maintained. This is especially important when the label bears printed matter which is to be transferred to the exterior surface of the can.

While the machine described is for wrapping labels around cans it will be appreciated that the machine can also be used to provide any form of web wrapping, around bodies of generally uniform cross-section.

Claims

1. A wrapping machine comprising a platform for carrying an elongate item of uniform cross section to be wrapped, means for supporting a web to be applied to the item, and belt means having a run moveable between a first configuration in which an intermediate portion thereof urges an intermediate portion of a web when supported by the support means into engagement with said item, and a second configuration in which the run conforms to the outer surface of the item thereby to wrap the web around the item, and means for driving the belt means to effect rotation of the web and the item about the longitudinal axis of the item.

2. A machine according to Claim 1 wherein said run in said first configuration is rectilinear.

3. A machine according to Claim 1 or to Claim 2 wherein said belt means comprises an endless belt supported by a plurality of rollers, a first sup- port supporting a first group of said rollers, a sec- ond support for supporting a second group of said rollers, the first group of rollers constraining a portion of said belt along a first generally triangular path, the second group of rollers constraining another portion of the belt along a second generally triangular path, the two supports being pivotal between a first position in which one side of the first triangular path is colinear with one side of the second triangular path and a second position in which but for an interposed said item said two sides would be parallel to one another.

4. A machine according to Claim 3 including adjustable stop means for defining the limits of said pivotal movement of the two supports. 120

5. A machine according to Claim 3 or to Claim 4 including finger means carried by one said support, said finger means being positioned to extend between the leading and trailing end portions of a said web when the supports are in their second position whereby to guide one said portion under the other when the belt means is driven thereby to ensure the correct overlap between the leading and trailing end portions of the web.

6. A machine according to any preceeding claim wherein said platform means is supported GB 2 147 264 A 5 for free rotation and including a rotary mandrel spaced from the platform and moveable towards and away from the platform, the mandrel being of such configuration that when the platform sup- ports a said item and the mandrel is displaced towards the platform, the mandrel engages the item and locates said item in a predetermined position on the platform, thereafter said item, said mandrel and said platform being freely rotatable as a uni- tary assembly.

7. A machine according to any preceeding claim wherein said web supporting means cornprises a pair of gripper assemblies spaced apart in the direction of said run when in said first configu- ration, one said gripper assembly being arranged to grip a leading end portion of said web and the other gripper assembly being arranged to grip a trailing end portion of the web, and actuating means arranged to cause said gripper assemblies to release said web during displacement of said run from said first to said second configuration.

8. A machine according to Claim 7 wherein one of said gripper assemblies is mounted on a resiliently biassed support which is displaceable against the bias in response to tension applied to said web by said belt means.

9. A wrapping machine comprising a rotary turntable, a plurality of angularly spaced wrapping stations on the turntable, each wrapping station in cluding a platform for supporting an item to be wrapped, web support means for supporting a length of web to be wrapped around the item, and a wrapping belt assembly moveable between a first position in which it urges an intermediate por- tion of the web against said item when located on 100 said platform and a second position in which the assembly urges the remainder of the web into engagement with the item to cause the leading and trailing end portions to adopt a predetermined overlapping relationship; a web feeding station lo- 105 cated adjacent said turntable for presenting a web to the web support means of each wrapping station in turn as it passes the web feeding station; an item feeding station located downstream of said web feeding station, said item feeding station being arranged to deposit a said item on to a said platform of each web wrapping station in turn as it passes; and a discharge station located downstream of the item feeding station, said discharge station being arranged to engage and remove a wrapped item from each wrapping station during its passage therepast.

10. A machine according to Claim 9 wherein the wrapping belt assembly of each wrapping sta- tion comprises a belt having a run moveable between a first configuration in which, when the station is located adjacent the item feeding station, an intermediate portion of the run urges the intermediate portion of the web against said item and a second configuration in which while the wrapping station is moving between the item feeding and discharge stations the run is made progressively to conform to the shape of the item thereby to wrap the web around the item.

11. A machine according to Claim 9 orto Claim wherein the web feeding station comprises a satellite turntable carrying angularly spaced web selecting members, a magazine for said webs located adjacent the satellite turntable upstream of the turntable carrying the web wrapping stations and adhesive application means located adjacent the satellite turntable upstream of the magazine whereby as said satellite turntable is rotated each said member picks up adhesive from the adhesive application means, applies said adhesive to the trailing end portion of the foremost label in the magazine, extracts the foremost label from the magazine and transfers it to the web support means of an adjacent wrapping station. 80

12. A machine according to Claim 11 wherein each said member is arcuate and has a protruding rib located adjacent its downstream edge, said rib being the only portion of the member receiving adhesive from the adhesive application means. 85

13. A machine according to Claim 11 or to Claim 12 wherein each said member has a plurality of vacuum grooves which function sequentially.

14. A machine according to any one of Claims 9 to 13 wherein the item feeding station includes a rotary scroll for spacing said items by a predetermined spacing and a star wheel for engaging each said item and transferring it to the platform of an adjacent wrapping station.

15. A machine according to any one of Claims 9 to 14 wherein said discharge station includes a discharge conveyor and a star wheel, the star wheel being positioned to engage and remove a wrapped item from the platform of an adjacent wrapping station and to deposit it upon said discharge conveyor.

16. A machine according to Claim 14 or to Claim 15 wherein the or each star wheel has an associated vacuum assembly to secure said items to the wheel by suction forces.

17. A machine according to any preceeding claim wherein said items arranged to be wrapped are of circular cross-section and said webs to be wrapped around said items are labels.

18. A machine according to Claim 17 wherein said labels are arranged to carry transferable print.

19. A wrapping machine substantially as hereinbefore described with reference to any one of the accompanying drawings.

Printed in the UK for HMSO, D8B18935, 3185, 7102. Published by The Patent Office, 25 Southampton Buildings. London, WC2A lAY, from which copies may be obtained.