LIDDING MACHINE AND METHOD

Abstract

A lidding machine with a conveyor 7 for conveying containers and a set of jaws 11 positioned at opposite sides respectively of the containers. The jaws move towards and each other over the conveyor and upwards away from the conveyor to lift one or more containers 22 off the conveyor and urge each container into contact with a lid 23 supported over the conveyor by a picking head 19 arranged to move on a rotating support 21 to transport lids between a lid magazine 16 and a position where lids and containers can be fitted together.

Claims

1. A lidding machine comprising: a conveyor for conveying containers; a set of jaws positioned at opposite sides respectively of the conveyor the jaws being arranged to move towards each other over the conveyor and upwards away from the conveyor thereby to lift one or more containers off the conveyor and urge the/or each container into contact with a respective lid positioned over the conveyor; a lid magazine for storing lids; a picking head for supporting one or more lids over the conveyor, the picking head being mounted to a picking head support, the picking head support being mounted for rotation about an axis substantially parallel to a direction of travel of the conveyor enabling the picking head to be moved between a first position where the picking head can pick one or more lids from the lid magazine and a second position where the picking head can support one or more lids above the conveyor enabling containers and lids to be urged together, wherein the picking head support rotates through less than 150 degrees in order to move the picking head between its first and second positions.

2. A lidding machine as claimed in claim 1 wherein opposed edges of each jaw comprise one or more recesses arranged to fit around part of a container to be handled by the machine.

3. A lidding machine as claimed in claim 1 wherein opposed edges of each jaw comprise part circular and/or part rectangular recesses.

4. A lidding machine as claimed in claim 1 wherein opposed edges of each jaw comprise one or more raised walls arranged to be received into a rim of a container to be handled by the machine.

5. A lidding machine as claimed in claim 1 wherein the jaws are substantial mirror opposites of each other.

6. A lidding machine as claimed in claim 1 wherein the jaws are each slidably mounted to each other or to a support enabling them to move towards and away from each other.

7. A lidding machine as claimed in claim 6 wherein the jaws or the support are/is mounted to a structure operative to raise and lower the jaws relative to the conveyor.

8. A lidding machine as claimed in claim 1 wherein the picking head comprises one or more formations for locating one or more lids.

9. A lidding machine as claimed in 1 wherein the picking head support rotates through less than 140 degrees in order to move the picking head between its first and second positions.

10. A lidding machine as claimed in claim 1 wherein the picking head is moveably mounted to the picking head support so that the picking head may move perpendicular to the axis of rotation of the picking head support.

11. A method of fixing a lid to a container comprising the steps of providing a lidding machine as claimed in any preceding claim, placing the container on the conveyor and causing the conveyor to move the container to a predetermined position between the jaws, causing the jaws to move towards each other, and causing the jaws to lift the container off the conveyor and urge it into contact with a lid supported above the conveyor.

12. A method as claimed in claim 11 where the lid and the container fit together mechanically.

13. A method as claimed in claim 11 further comprising: lowering the jaws to lower containers back onto the conveyor, moving the jaws away from each other and causing the conveyor to move the containers out of the machine.

14. A method as claimed in claim 11 further comprising the step of: picking a lid from a magazine with the picking head and moving the lid to a position above the conveyor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0037] In order that the invention may be more clearly understood one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

[0038] FIG. 1 is a perspective view from the front and above of a lidding machine;

[0039] FIG. 2 is a perspective view of the jaws of the machine, holding a single container;

[0040] FIG. 3 is a perspective view of the support structure for the jaws of the machine;

[0041] FIG. 4 is a perspective view of part of the picking head of the machine;

[0042] FIG. 5 is a front part cut away view of the machine with guards removed in a first state;

[0043] FIG. 6 is a right side part cut away view of the machine in a second state;

[0044] FIG. 7 is a right side part cut away view of the machine in a third state;

[0045] FIG. 8 is a part cut away perspective view from the front and above of the machine in the third state;

[0046] FIG. 9 is a right side part cut away view of the machine in a fourth state;

[0047] FIG. 10 is a front part cut away view of the machine with guards removed in a fifth state;

[0048] FIG. 11 is a right side part cut away view of the machine in the fifth state;

[0049] FIG. 12 is a right side part cut away view of the machine in a sixth state;

[0050] FIG. 13 is a right side part cut away view of the machine in a seventh state;

[0051] FIG. 14 is a front part cut away view of the machine with guards removed in an eighth state;

[0052] FIG. 15 is a right side part cut away view of the machine in the eighth state;

[0053] FIG. 16 is a right side part cut away view of the machine in a ninth state;

[0054] FIG. 17 is a front part cut away view of the machine with guards removed in a tenth state;

[0055] FIG. 18 is a right side part cut away view of the machine in the tenth state;

[0056] FIG. 19 is a right side part cut away view of the machine in an eleventh state;

[0057] FIG. 20 is a front part cut away view of the machine with guards removed in the eleventh state; and

[0058] FIG. 21 is a front part cut away view of the machine with guards removed in a twelfth state.

[0059] In what follows the terms the terms top, bottom, front, rear, left, right and like terms are used to refer to the lidding machine and its components in the orientation shown in the drawings, which is the orientation in which it is intended to be used, but should not be taken as otherwise limiting. Like reference numerals are used to denote like features throughout the drawings, which are not to scale.

[0060] Referring to the drawings, the lidding machine comprises a main body in the form of a cabinet 1 provided with castors 2 to facilitate movement and adjustable feet 3 for supporting the machine when in use. The cabinet houses a lidding station, generally 4, over which is a second cabinet 5 housing switchgear and programmable control apparatus.

[0061] A first, infeed, servo motor driven conveyor belt 6 is supported on the outside left side of the cabinet 1 and extends towards an opening in the left side of the cabinet 1. A sensor 6a is provided towards the end of the first conveyor 6 closest to the cabinet, operative to detect containers of the conveyor. A second, accumulation and outfeed, conveyor belt 7 extends from a position adjacent the end of the first conveyor 6 just outside the opening in the left hand side of the cabinet 1, through the lidding station 4 and out of an opening in the right hand side of the cabinet 1. The second conveyor extends only slightly out of the opening in the left hand side of the cabinet 1, but much further out of the opening in the right hand side of the cabinet so that about half of its length extends out of the right hand side of the cabinet 1. The second conveyer belt 7 is narrower than the first conveyor belt 6.

[0062] Removable guards 8, 9, supported on the cabinet 1, are fitted over the first 6 and second 7 conveyors where they extend outside the cabinet. A removable guard 10 is fitted over an opening in the front of the cabinet.

[0063] The lidding station 4 comprises a set of two of opposed jaws positioned above and at opposite sides respectively of the second conveyor belt 7. The jaws (best seen in FIG. 2) are formed from two elongate, generally rectangular, plates 11 each lying in substantially the same plane, substantially parallel to, but (when in a lowest position) slightly spaced above, the surface of the second conveyor belt 7. The opposed edges 12 of the plates 11 are shaped to conform to the edges of multiple spaced apart containers to be handled.

[0064] In the illustrated example the edges 12 define six substantially rectangular recesses with curved corners. The opposed sides of each recess extend substantially parallel to each other from the back of the recess over a little over half of their length and diverge slightly from each other over the remainder of their length. This the width of the recess narrows slightly from its opening. These recesses are suitable for accommodating containers with a substantially rectangular cross-section. The top surface of the plates 11 is substantially flat. A respective upstanding wall 12a is formed on the top of the plate adjacent part of the edge of each recess, extending adjacent the back of the recess and the part of the sidewalls which are substantially parallel, effectively forming an upward extension of the side 12 of the plate 11.

[0065] Of course the shape of the recesses may be varied according to the shape of the containers it is desired to handle. In another example the edges 12 of the plates are provided with recesses formed by curves of constant radius each extending through about 160 degrees. These are suitable for handling containers with a substantially circular cross-section of a similar radius.

[0066] The plates 11 are each mounted on a support structure best shown generally in FIG. 3. The support structure comprises a respective stand for each plate. Each stand comprises an upper substantially rectangular plate 13 which is slightly longer but narrower than the plate 11 it supports. The plates 11 forming the jaws are mounted on the upper plates 13 so that their opposed edges 12 overhang the edges of the upper plates 13. The stand plates 13 are supported by upright plates 14, one at each end and two spaced in between. The upright plates 14 are generally trapezoidal (or some other suitable shape) with upper and lower parallel edges and may define an aperture so as to reduce the mass of material required to form the plates. The upper edge has a cut out into which the stand plate 13 is received so that the opposed edges of the stand plates 13 at least lie flush with, or overhang, the inner edges of the upright plates 14. The upright plates are wider at the bottom than the top.

[0067] The upright plates 14 of each stand are supported on sliding elongate generally rectangular plates 15 which extend substantially parallel to the upper stand plates 13. The sliding plates 15 are each movably mounted to rails 15a mounted on a platform 16 beneath the plates allowing the sliding plates 15 in a direction substantially transverse to the direction of the second conveyor 7. This enables the jaws to move towards and away from each other. Movement of the sliding plates 15 is effected by two servo motors or other suitable rotary actuators 16a mounted to the underside of the platform 16 one under the position of each sliding plate. Each motor 16a drives a shaft which extends through the platform 16. A bearing 16b is mounted to each shaft off its axis of rotation and a bearing 16b is slidably received into a parallel sided slot 15b formed in each plate 15 extending substantially perpendicularly to the direction of movement of the plate 15. Thus, rotation of the servomotors causes transverse movement of the plates. Of course other suitable actuators, such as linear actuators, could be provided to move the sliding plates 15 between outer and inner positions.

[0068] The platform 16 is mounted to move upwards and downwards relative to the second conveyor 7. Movement is effected by a servo motor 16c driving a crank disposed in a housing 16d beneath the platform 16. A connecting rod is mounted to the crank and the platform.

[0069] Thus, it will be appreciated that each plate 11 forming a jaw can be moved both transversely and vertically relative to the direction of the conveyors 6, 7.

[0070] The lidding station 4 further comprises a lid magazine for storing lids for containers and a picking head for picking lids from the magazine and presenting them to containers to which they are to be fitted.

[0071] The lid magazine is formed by a substantially rectangular plate 17 which forms a wall of the cabinet 1. Its long sides extend parallel to the direction of the conveyors 6, 7 and its short sides extend at an angle of about 45 degrees to the horizontal so that it extends partially over the lidding station 4. Six, spaced apart, substantially rectangular apertures with curved corners 17a extend through the plate 17. Four elongate rods 18 are positioned evenly around each aperture 17a and extend substantially perpendicularly from the outside surface of the plate 17. The rods 18 are intended to support stacks of lids over each aperture 17a. Another suitable structure could of course be employed to support lids over the apertures.

[0072] The picking head comprises an elongate substantially rectangular plate 19 (best shown in FIG. 4 on which are positioned six spaced apart upstanding substantially rectangular walls 19a with curved corners. The thickness of each wall reduces in a step, in both the inside and outside of the wall, close to its free edge, so that there is a relatively narrow free edge 19b to wall, surrounded on each side by a shoulder. Each wall surrounds a generally central, circular aperture through the plate to which is fitted a concertina tube 19c formed of a resilient rubber or similar material which extends just beyond the free edge of the wall and terminates in a plane generally parallel to the plane of the opening defined by the free edges of the wall. Air may be drawn thought the tubes 19c by a vacuum pump (not shown). The walls 19a are positioned to correspond to the apertures 17a in the lid magazine plate and to the recesses and surrounding walls 12a of the jaws.

[0073] The plate 19 is slidably mounted to a rotating support 21. The rotating support is operative to rotate about an axis extending above and parallel to a centre lie of the second conveyor 7 to move the plate 19 between a picking position in which it is substantially parallel to the plate 17 of the lid magazine and a placing position in which it is substantially parallel to the surface of the second conveyor 7. This involves rotation through about 135 degrees.

[0074] Movement of the rotating support 21 is effected by a rotary actuator 21a. Movement of the plate 19 radially relative to the support 21 is effected by a linear actuator 20, which may be implemented by a rotary actuator driving an eccentric or crank. Springs (not shown) are provided to form resilient stops which arrest movement of the plate as it is moved to its radially innermost position relative to the support 21. Any suitable type of spring or indeed another suitable resilient member or members may be used to provide the stop(s).

[0075] The control apparatus is programmed to cause the conveyor servo motors and actuators of the lidding station to operate automatically to place click or other mechanically fitted lids to containers by repeatedly performing the follow sequence of operations.

[0076] As shown in FIG. 5, open containers 22 are placed onto the first conveyor 7. In this example the containers have a generally rectangular base, four rectangular sides and four elongate triangular sides (one between each adjacent rectangular side) a point of each of which is positioned at a corner of the base. So the container is generally cuboidal with an increasing cross-sectional area from base to top, where a rim is formed for receiving a click-fit lid. Lids 23 are placed into the lid magazine. The lids are substantially rectangular with curved corners and an edge formation intended to fit over the rim of a container 22. In the opposite face of the lid (that which is exposed when the lid is fitted to a container) a generally rectangular channel is formed, with curved corners, sized to fit over the narrow part 19b of the walls on the plate 19 of the picking head.

[0077] The first and second conveyors 6, 7 are operated by the control apparatus in dependence on information received from the sensor 6a associated with the first conveyor so that six containers 22 are advanced from the first conveyor 6 to the second conveyor so they are spaced apart on the second conveyor 7 in a predetermined way, each container being positioned between respective opposed recesses 12 in the jaws of the lidding station 4, as shown in FIG. 6. Operation of conveyors in this manner to position containers with a desired spacing is known and within the capability of a person of ordinary skill in the art and so is not described in further detail here. At this stage the platform 16 is in its lower position and the sliding plates 15 are at their outermost positions. As such, the opposed edges 12 of the jaws are each spaced laterally away from the edges of the second conveyor 7 and the lower surfaces of the jaws are closely spaced above the plane of the surface of the second conveyor. The plate 19 of the picking head lies substantially parallel to the plate 16 of the lid magazine, but at its radially innermost position.

[0078] Vacuum is now applied to the apertures through the tubes 19c on the plate 19 of the picking head and the actuator 20 operated to move the picking head radially outwards towards the plate 16 of the lid magazine as shown in FIG. 5. This causes the lowermost lids in the stacks on the magazine to be drawn onto the plate so that the narrow edge 19b of walls on the plate 19 is received into the corresponding channel in the lids, thus locating the lids in desired positions on the plate 19, as illustrated in FIG. 3 where a single lid 23 is shown in broken lines.

[0079] The linear actuator 20 is now operated to move the picking head radially inwards to the position shown in FIG. 9, carrying six individual lids 23 with it.

[0080] Next, the picking head is rotated through about 135 degrees by the rotary actuator 21 so that the plate 19 is substantially parallel with the surface of the second conveyor 7, as shown in FIGS. 10 and 11. The lids 23 retained on the picking head are each now positioned over a respective container 22 on the second conveyor 7.

[0081] The sliding plates 15 are now moved towards each other to their inner most positions, to the position shown in FIG. 12. In this position the opposed faces 12 of the jaws 11 are still spaced apart so that the edges of the jaws partially encircle the containers. The jaws are positioned close to the surface of the second conveyor 7 and therefore towards the bottom of the containers 22 where their dimensions are smallest and smaller than those of the recesses in the jaws. This allows for some tolerance in the positioning of the containers 22 on the second conveyor 7, whilst avoiding the jaws contacting the containers as they move together and thus potentially upsetting the containers or their contents. Although, were the jaws to contact the containers, the shape of the recesses in the jaws would assist in positioning the containers as the jaws close.

[0082] Next, the platform 16 actuator is operated to raise the platform 16. As the platform is raised the jaws 11 move upwards relative to the containers 22 until the containers are supported on the jaws with the upstanding walls 12a on the jaws received in the rim of the containers as shown in FIG. 13 and also FIG. 2 where a single container 22 is shown in broken lines. It will be noted that, owing to the gradually increasing dimensions of the containers from base to top, as the jaws are raised the containers will become positioned correctly between them if they are not already in this position on the second conveyor 7.

[0083] As the platform 16 continues to rise the jaws lift the containers 22 off the second conveyor and urge them into contact with the lids 23 on the picking head, as shown in FIGS. 14 and 15, fitting the lids onto the containers.

[0084] At this stage, the plate 19 of the picking head 4 is at its radially innermost position and it is the action of the vertical platform 16 actuator which urges the containers and lids together, also urging the plate 19 of the picking head against its resilient stops. The stops serve to limit the maximum force applied between the jaws and picking head, simplifying control of the actuators whilst avoiding damage of the containers and lids. Alternatively or additionally the platform 16 may be sprung.

[0085] The vacuum is now disconnected from the picking head, releasing the lids from the head, and the platform actuator lowered through the position shown in FIG. 16 to the position shown in FIGS. 17 and 18, placing the containers back onto the second conveyor 7.

[0086] The sliding plates 15 are now moved away from each other to their outermost positions to the position shown in FIGS. 19 and 20. The jaws are now clear of the containers and the second conveyor 7 is run to move the containers 22 with fitted lids 23 out of the lidding station through the opening on the right hand side of the machine.

[0087] The process can now be repeated.

[0088] It will be appreciated that some of the steps of the process described above may be performed simultaneously to achieve an overall reduction in cycle time. For example the picking head may pick lids and position these over the second conveyor as containers are advanced onto the conveyor. Open containers may also be introduced onto the second conveyor as the lidded containers are moved out of the lidding station.

[0089] Cycle time can also be saved by only lowering the platform sufficient for the raised walls 12a of the jaws 11 to pass under the rim of a container 22, rather than to their lowermost position, thus minimising the required stroke of the platform actuator.

[0090] For containers of different shapes the jaws can conveniently be set to approach the containers at a height above the point of greatest dimension of the container, when this lies below the container rim.

[0091] The above embodiment is are described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims.