GB2270291A

GB2270291A - Article conveying apparatus.

Info

Publication number: GB2270291A
Application number: GB9318460A
Authority: GB
Inventors: Malcolm John Charles; John Robert Sayer
Original assignee: Molins Ltd
Current assignee: Mpac Group PLC
Priority date: 1992-09-08
Filing date: 1993-09-06
Publication date: 1994-03-09
Anticipated expiration: 2013-09-06
Also published as: GB9218980D0; NL9301536A; GB9318460D0; GB2270291B

Abstract

A tip-back conveyor for packets comprises an endless chain (2) having a series of spaced pushers (6) pivoted to the chain and arranged to convey packets along an article path (20, 24). A stationary pin (28) lies adjacent the end of the operative run of the chain (2) such that it enters a forward facing slot (26) provided in each pusher (6) with the result that as the pusher leaves the operative run and passes around an end sprocket (4) the pusher is pivoted so that its forward movement along the packet path is arrested and it is withdrawn from the path. As the pin (28) is engaged at low speed and does not reach the end of the slot (26), the mechanism is quiet in operation. <IMAGE>

Description

Article Convevina Apparatus This invention relates to article conveying apparatus, particularly that including a pusher conveyor. Such conveyors typically comprise one or more pushers secured to an endless chain or belt and so disposed that the pusher or pushers can advance articles along a supporting surface. The conveyor normally has an operative run of the chain or belt extending parallel to the supporting surface, and at the end of the operative run the chain or belt travels around a supporting sprocket or pulley to a return run; as each pusher commences to travel around the sprocket or pulley it necessarily rubs across the surface of the article it has been pushing and with many articles this is undesirable.

For example, if the article is a group of cigarettes wrapped in foil, but not yet enclosed in a packet, a pusher moving across the surface of the enclosing foil can seriously disturb the formation of the group.

To avoid this undesirable effect, the type of pusher conveyor known as a "tip-back" conveyor has been used; each pusher of a tipback conveyor is movable relative to the chain or belt, being held in a fixed attitude relative to the chain or belt while traversing the operative run and then being moved back relative to the chain or belt on reaching the end of the operative run so that it is clear of the article when it starts to travel around the sprocket or pulley. Commonly each pusher is pivotally secured to the chain or belt so that it can be tilted to provide the desired backward movement (i.e. movement in the opposite direction to that of the chain or belt). An example of a tip-back conveyor is disclosed in British patent specification No. 789590.The conveyor described in this specification and other similar conveyors are relatively complex and expensive, and can be noisy in operation, particularly at higher speeds, e.g. where it is required to advance articles at a rate of 200 per minute or more, such as is common in cigarette packing machines.

According to the present invention article conveying apparatus comprises an endless conveyor carrying at least one pusher connected to the conveyor by a pivotal connection, means defining an article path along which an article is advanced by the pusher while it is on an operative run of the conveyor, abutment means adjacent the end of the operative run and arranged to engage engagement means associated with the pusher at a position spaced from said pivotal connection whereby movement of the pusher beyond the end of said operative run in a direction which differs from that of the operative run causes the pusher to be pivoted around said connection in such manner that the movement of the pusher along said article path is arrested and the pusher is subsequently withdrawn from said path.Preferably said abutment means and said engagement means are so arranged that initial contact between said respective means is made at a low closing speed and that the engagement means is subsequently accelerated by contact with the abutment means. The movement of the pusher generated by engagement of said abutment means is preferably such that it is reversed on said path so that prior to complete withdrawal from the path the pusher is no longer in contact with the article previously conveyed.

The abutment means is preferably stationary, and may for example comprise a pin or bolt. Preferably the abutment means cooperates with a surface of said pusher such that pivotal movement of the pusher is generated only when the pusher begins to move away from its operative run. Preferably the conveyor follows a path which diverges from said article path beyond the end of the operative run, e.g.

it begins to pass around a sprocket and/or pulley. Thus, the surface may extend parallel to the operative run, being moved with the pusher in a transverse direction and making operative contact with the abutment means when the pusher moves beyond the end of the operative run.

The surface may comprise one side of a slot (or recess), the abutment means for example comprising a pin which enters the slot while the pusher is on the operative run and which engages the surface and initiates rotation of the pusher about the pivotal connection prior to reaching the end of the slot. Preferably the slot (or recess) is of such length in relation to the path of the pusher that the pin does not reach the end of it, the movement of the pusher with the conveyor causing pivoting of the pusher with consequent reduction to zero of the speed of advancement of the pin into the slot before that occurs. Clearly, this can be beneficial in reducing noise of the mechanism.In a particularly convenient arrangement, wherein the operative run and article path are straight and parallel, the pin, slot and pivotal connection lie substantially on a straight line while the pusher is on said operative run, this straight line extending parallel to the operative run and path.

The pusher preferably comprises a first part for contacting articles and advancing them along the article path and a second part provided with said engagement means for engaging with the abutment means.

Preferably the pivotal connection is in said second part, and in a convenient arrangement the engagement means and pivotal connection may lie on a line which extends parallel to the operative run.

The invention will be further described, by way of example only, with reference to the accompanying diagrammatic drawing which shows an article conveying apparatus in part-sectional side elevation.

A packet conveyor in a cigarette packing machine comprises laterally-spaced endless chains 2 passing around laterally-spaced sprockets 4. (It will be understood that the chains 2 and sprockets 4 on one side only of the conveyor are shown in the drawing.) The sprockets 4 are arranged at the downstream end of the conveyor and the chains 2 extend around similar sprockets (not shown) at its upstream end. The chains 2 carry a number of pusher members 6, each of which is connected to the chains by a pivotal connection 8. The pusher members 6 comprise a base member 10, and an upstanding bracket 12 connected to the base member and carrying a pusher plate 14. The base member 10 comprises laterally-spaced side parts 16 which respectively run on laterally-spaced rails 18 extending parallel to the operative run of the conveyor.The bracket 12 is connected to a central part of the base member 10 and, on the operative run of the conveyor, passes through a slot in a packet support platform 20.

In use, the chains 2 move the pusher members 6 to the left along the operative run as viewed in the drawing. The support platform 20 ends upstream of the end of the operative run, leaving a gap 22 before a further platform 24. Packets advanced by the pusher members 6 are moved over the gap 22 and deposited on the platform 24 at the end of the operative run of the conveyor.

The leading end of one side part 16 of the pusher base member 10 has a slot 26 aligned with the pivotal connection 8. At the end of the operative run the slot 26 engages a pin 28 which is fixed to part of the frame (not shown) supporting the apparatus. As the pusher member 6 is moved around the sprockets 4 by the chains 2 the pin 28, by engagement with the slot 26, causes the pusher member 6 progressively to rotate around the pivotal connection 8 in a clockwise direction as viewed in the drawing. Note that the position and shape of the downstream ends of the rails 18 allow the side parts 16 of each pusher base member 10 to rotate after initial engagement of the slot 26 with the pin 28.The rotation of the pusher member 6 causes the forward movement of the pusher plate 14 over the platform 24 to be arrested and the plate to be subsequently retracted, the bracket 12 and plate 14 being withdrawn through the gap 22. A packet conveyed by the pusher member 6 is thus left stationary on the platform 24, without having the pusher plate 14 dragged across its rear face. The packets left on the platform 24 may be engaged by a further conveyor (not shown) or may be left in place to be pushed forward by the next packet advanced by the next pusher member 6 (i.e there may be a line of abutting packets on the platform 24, which line is intermittently advanced as each successive packet is delivered onto the platform by successive pusher members 6).

Rotation or tip-back of the pusher members 6 caused by engagement of the slot 26 with the pin 28 is completed during about 60 of rotation of the sprockets 4. The slot 26 is of such depth that the pin 28 never reaches its end. Further rotation of the sprockets 4 causes disengagement of the slot 26 and pin 28. Rotational position of the pusher members 6 relative to the chains 2 is subsequently controlled by engagement of the base side parts 16 and/or bracket 12 with fixed guide rails (not shown) extending along the return runs of the chains 2.

In order to assist in location of the pusher members 6, particularly so that the slot 26 engages cleanly with the pin 28, resilient means such as a leaf spring may be provided to act between the platform 20 and the base member 10 so as to maintain it in contact with the rails 18. The resilient means could be carried by the pusher member 26 or be fixed at an appropriate part of the underside of the platform 20.

Claims

1. Article conveying apparatus comprising an endless conveyor carrying at least one pusher connected to the conveyor by a pivotal connection, means defining an article path along which an article is advanced by the pusher while it is on an operative run of the conveyor, abutment means adjacent the end of the operative run and arranged to engage engagement means associated with the pusher at a position spaced from said pivotal connection whereby movement of the pusher beyond the end of said operative run in a direction which differs from that of the operative run causes the pusher to be pivoted around said connection in such manner that the movement of the pusher along said article path is arrested and the pusher is subsequently withdrawn from said path.

2. Apparatus as claimed in claim 1, wherein said abutment means and said engagement means are so arranged that initial contact between said respective means is made at a low closing speed and that the engagement means is subsequently accelerated by contact with the abutment means.

3. Apparatus as claimed in claim 1 or claim 2, wherein the abutment means is stationary and cooperates with a surface of said pusher such that pivotal movement of the pusher is generated only when the pusher begins to move away from its operative run.

4. Apparatus as claimed in claim 3, wherein the conveyor follows a path which diverges from said article path beyond the end of the operative run and said surface extends parallel to said path while said pusher is on said operative run.

5. Apparatus as claimed in claim 3 or claim 4, wherein said surface comprises one side of a slot and the abutment means comprises a member which enters the slot while the pusher is on the operative run and which engages the surface and initiates rotation of the pusher about the pivotal connection prior to reaching the end of the slot.

6. Apparatus as claimed in claim 5, wherein the slot is of such length in relation to the path of the pusher that said member does not reach the end of it, the movement of the pusher with the conveyor causing pivoting of the pusher with consequent reduction to zero of the speed of advancement of the member into the slot before that occurs.

7. Apparatus as claimed in claim 5 or claim 6, wherein the operative run of the conveyor and the article path are substantially straight and parallel, and said member, slot and pivotal connection lie substantially on a straight line while the pusher is on said operative run, said straight line extending parallel to the operative run and path.

8. Apparatus as claimed in any preceding claim, wherein the pusher comprises a first part for contacting articles and advancing them along the article path and a second part provided with said engagement means for engaging with the abutment means.

9. Apparatus as claimed in claim 8, wherein the pivotal connection is in said second part, and said connection and said engagement means lie on a straight line which extends parallel to the operative run of the conveyor.

10. Apparatus as claimed in any preceding claim, wherein the engagement means and the abutment means are so arranged that engagement of the abutment means causes movement of the pusher to be reversed on said path so that prior to complete withdrawal from the path the pusher is no longer in contact with the article previously conveyed.

11. Article conveying apparatus substantially as herein described with particular reference to the accompanying drawings.