GB2140374A - Container conveying apparatus - Google Patents

Abstract

Containers, particularly empty trays (30) for cigarettes, are directly transferred from a delivery conveyor (32) into a position (on platform 50) in which they are successively loaded. In a preferred arrangement the forward end of the delivery conveyor includes oversize coaxial rollers (44) which engage a leading tray and separate it from following trays on the conveyor. The delivery conveyor (32) (or rollers 44) and/or the leading tray (30B) on the conveyor may act as a guide for the tray (30A) being loaded. With some types of tray side clamps (64) are used to prevent interference between the leading tray (30B) and the tray (30A) being loaded. <IMAGE>

Description

SPECIFICATION Container conveying apparatus This invention relates to apparatus for conveying containers, particularly trays for rod-like articles of the tobacco industry.

In the production of rod-like articles such as cigarettes or cigarette filter rods it is common to load the articles into containers after production by a rod making machine. The containers may be stored for a short time or conveyed substantially immediately to a further processing machine, such as a packing machine. Usually the rod making machine is linked to a container loading apparatus (e.g.

Molins Mk16 TFU or VTF) and the packing machine is linked to a container unloading apparatus (e.g. Molins TU4N). Containers vary as to details and dimensions but generally comprise at least two sides, a base, and a back wall, which define a store area of rectangular cross-section for a stack of articles. Such containers are commonly referred to as trays.

Rod-like articles may be loaded into trays by movement either in a direction parallel to their lengths or in a direction transverse to their lengths. In either case tray loading apparatus includes means for moving empty trays into a loading position at which loading is started. In some cases the trays progressively moved, usually in a downwards direction, from an initial loading position to receive successive articles or batches of articles. In other cases the articles are loaded as one or more batches with the tray stationary in the loading position.

It has been common to deliver empty trays to a loading position by means of a conveyer which moves successive trays to a position from which a timing mechanism or other synchronised conveyor delivers trays into the loading position.

According to the one aspect of the invention apparatus for loading containers with rodlike articles of the tobacco industry comprises conveyor means for delivering successive empty containers towards a loading position at which they receive articles, wherein the conveyor means conveys a plurality of containers towards the loading position and at least partly conveys a container into said loading position. In a preferred arrangement the container is moved from the loading position in a direction which is different, preferably transverse, to that of the conveyor means, and part of the conveyor means and/or an empty container on the conveyor means acts as a guide for a container moving from the loading position.The conveyor means may include endless band means passing around at least one end pulley adjacent the loading position, and a further conveyor, e.g. a downwardly moving 5 platform, for moving the container away from the loading position.

The conveyor means may include means for separating slightly from the following containers a container being moved into the loading position. For example, the conveyor means may include commonly driven means which engages a leading container on the conveyor means adjacent the loading position and conveys it forward towards the loading position at a slightly higher speed than that of the main conveyor means. The driven means may disorientate slightly the leading container relative to the following container and/or to a container already in the loading position. In a preferred arrangement, in which the conveyor means comprises at least one endless band passing around an end pulley adjacent the loading position, at least one roller having an overall diameter slightly greater than the band passing around the end pulley is arranged substantially coaxially with said pulley.Such an arrangement may produce slight lifting as well as separation of a leading container and such lifting (which may also tilt the container slightly) can be of advantage in delivering the container into the loading position. The separation (and possibly also lifting/tilting) can avoid interlocking between the leading container on the conveyor means and the container in the loading position, especially if the latter is subsequently moved away in a transverse direction.

Preferably means are provided to detect containers at at least one location on the conveyor means and to control motion of the conveyor means accordingly. For example, the motion of the conveyor means may be inhibited if fewer than a predetermined number of containers is present on the conveyor means or if a container is not present at a predetermined position on the conveyor means.Alternatively, instead of inhibiting the motion of the conveyor means in such conditions, the conveyor means may continue to move when a container is in the loading position to move other containers towards the loading position; this is particularly useful when there are few containers on the conveyor means adjacent the loading position since the motion of the conveyor means urging containers towards the loading position can add support to the leading container on the conveyor means adjacent to the loading position, so that it can act as a guide for movement of the container at the loading position away from said position. Generally, loading of containers (and movement away from the loading position) is inhibited if at least one, and preferably at least two, containers are not present on the conveyor means adjacent the loading position.

Preferably, in conditions where the conveyor means continues to run when there is a container in the loading position and where that container is subsequently moved in a direction which differs from that of the conveyor means, the conveyor means may be associated with intermittently operable means for restaining the leading empty container on the conveyor means adjacent the loading position. Such means may comprise opposed clamps which are operated to hold the leading container when the conveyor means is being moved but it is not required to move that container into the loading position.

According to another aspect of the invention apparatus for conveying containers for rod-like articles of the tobacco industry comprises a conveyor for moving a succession of containers towards a transfer position from which successive containers are moved away in a direction which differs from that of the conveyor, wherein the conveyor is arranged to move a plurality of containers towards the transfer position and at least partially to transfer a leading container into the transfer position. The transfer position could be a loading or unloading position for containers, loading or unloading taking place either in said position or during movement from said position.

Further conveyor means may be provided to move successive containers from said transfer position, preferably in a direction transverse to that of said conveyor means. The conveyor means may have commonly driven means for separating slightly a leading container just prior to transfer into the transfer position.

Means may be provided to restrain a leading container on the conveyor during movement of a container from the transfer position. Preferably the arrangement is such that a leading container on the conveyor means and/or the conveyor means itself acts as a guide for a container being moved from the transfer position.

According to a further aspect of the invention apparatus for conveying containers for rod-like articles of the tobacco industry, particularly in container loading or unloading apparatus, comprises conveyor means for delivering a succession of containers towards a transfer position, and means for receiving a container at said transfer position and for conveying said container in a direction which differs from the coveyance direction of said coveyor means, wherein the receiving means is arranged below the level of the coveyor means at said transfer position so that the container falls a short distance from the conveyor means to the receiving means. The transferred container is thereby moved to a different level on transfer and is therefore separated from containers remaining on the conveyor means so that interference with those containers may be avoided.In a preferred arrangement the conveyor means continues to convey containers after transfer of a container so that said remaining containers may be conveyed towards the transfer position and the leading remaining container and/or the conveyor means itself may act as a guide for a container on said receiving means.

Preferably the conveyor means comprises an endless band and the receiving means comprises a movable platform onto which the containers are deposited from the end of the band. The receiving means may move successive containers through a loading position (or towards an unloading position).

According to a still further aspect of the invention apparatus for conveying containers for rod-like articles of the tobacco industry.

particularly in container loading or unloading apparatus, comprises conveyor means for delivering a container towards the transfer position, and means for receiving a container at the transfer position and for conveying the container in a direction which differs from the conveyance direction in which the conveyor means delivers the container towards the transfer position, wherein the conveyor means is arranged to remain in engagement with a container as it is moved at or from the transfer position in a direction which differs from said conveyance direction. The conveyor means may engage and move the container in a different direction before the receiving means has received it and/or the conveyor means may act as a guide for the container as it is moved by the receiving means.

The invention will be further described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a side view of a tray filling apparatus, Figure 2 is a view of the tray filling apparatus in the direction of the arrow II in Fig. 1, and Figure 3 is a plan view of part of the apparatus of Fig. 1.

The tray filling apparatus includes a hopper 10 arranged to receive rod like articles as a multi-layer stream, e.g. from a rod-making machine. The hopper 10 has a front wall 12, side walls 14, 1 6 and a backplate 18. The hopper 10 contains a flow control mechanism 20 which extends across the width of the hopper between the side walls 14, 1 6 just above the otherwise open base 22 of the hopper. The flow control mechanism 20 comprises a series of agitators 24 and vanes 26 defining channels 28. The vanes 26 are supplied with suction so that flow of articles through the channels 28 may be controlled in a manner similar to that described with reference to British patent specification No.

1186348, to which reference is directed for further details. The hopper 10 and the feed of articles to it may be substantially the same as that disclosed in British patent specification No. 2124174A the disclosure of which is hereby incorporated herein. The hopper 10 may include a membrane 27 and a pivoted sensor 29 resting on the membrane. On each side of the hopper 10, spaced apart by a distance slightly less than the width of a tray is a pair of brushes 25.

Successive empty trays (generally designated by the reference number 30) are:delivered towards the hopper 10 on a pair of endless bands 32 passing around front and rear pulleys 34, 36 respectively. The position of the front pulleys 34 is adjustable toward and away from the hopper 10 and also vertically. The position of the rear pulleys 36 is vertically adjustable, so that the inclination of the bands 32 may be varied. The bands 32 run over support bars or plates 38. The front pulleys 34 are mounted on a drive shaft 40 which is drivingly connected to a motor 42.

Also mounted on the shaft 40 for rotation with it is a pair of spaced rollers 44 each having an overall diameter which is somewhat greater than that of the bands 32 passing around the pulleys 34.

Tray sensors in the form of spaced switches 46, 48 are operated by trays 30 on the bands 32. The tray 30B is iightly clamped in position by a pair of side clamps 64 acting on opposite sides of the tray. As shown particularly in Fig. 3 each side clamp 64 comprises an element 66 pivotally mounted about a vertical spindle 68 and having a rubbercoated curved cam surface 70 which engages the side of the tray 30B. A piston rod 72 is pivotally connected to the element 66 and movable under fluid pressure acting on a piston in a cylinder 54.

The tray 30A is delivered from the bands 32 and envelopes the hopper 10 with its bottom only slightly below the base 22 of the hopper. One edge of the tray 30A operates a sensor in the form of a switch 58. The bottom of the tray 30A is supported on each side by a pair of platforms 50 each carried by a pair of chains 52. The chains 52 are arranged to be driven together by a motor 54. Each pair of chains 52 carries a second platform 56.

The positions of the platforms 50, 56 relative to the chains 52 are adjustable, so that each pair of platforms can be located at precisely the same level. One of the platforms 50 (or 56) operates a switch 60 when it is supporting a tray in the position of tray 30A and operates a further switch 62 when it has been moved downwards by the chains 52 a distance corresponding to the height of a tray.

A pair of endless bands 76 passing around pulleys 78 mounted on a drive shaft 80 drivingly connected to a motor 82 is spaced below the bands 32 by a distance exceeding the height of a tray 30.

In normal operation there are empty trays 30 substantially in abutment on the bands 32 from the hopper 10 back at least to the position of the tray 30G. The bands 32 are driven to convey the empty trays 30 placed on the bands towards the hopper 10. Trays 30 in the positions of trays 30F and 30C depress the switches 46 and 48 respectively.

When the switch 60 is operated, showing that the platforms 50 are in position to receive a tray, the bands 32 run to place the tray 30A in the position shown in Fig. 1. The rollers 44, having a diameter somewhat greater than the bands 32 passing around the front pulleys 34, have a higher peripheral speed than the speed of the bands 32. Hence, a tray on the bands 32 is accelerated as it is engaged by the rollers 44. The tray is also tilted back slightly: this effect is shown exaggerated in the case of the tray 30B in Fig. 1. After initial engagement by the rollers 44 the tray is further separated from the following trays by the higher speed of the rollers and, when its centre of gravity passes over the axis of the rollers, it tilts forward so that its front edge tips downward onto the platforms 50.Depending on the friction between the tray and the surface of the rollers 44, and also on the speed of the bands 32, the tray is driven and/or slides into the position of the tray 30A. When the tray 30A is fully in position around the hopper 10 the switch 58 is operated by one side of the tray and this causes the bands 32 to stop, i.e. the motor 42 is stopped and may be braked. Up to this point the following tray 30B also assists in driving the tray 30A into position. The brushes 25, which are optional, help to grip the tray 30A and maintain it upright around the hopper 10.

Instead of, or as well as, the brushes 25 outwardly-extending brushes could be attached to the hopper side walls 14, 1 6.

With the tray 30A in the position shown in the drawings (as sensed by the switches 58 and 60) the flow control means 20, which was previously closed, opens and the chains 52 are driven to lower the platforms 50 and tray 30A at a rate appropriate to the flow of rod-like articles through the channels 28 of the flow control means and the flow of articles into the hopper 10. Thus the motor 54 may be controlled in response to signals derived from the sensor 29 resting on the membrane 27 so that the quantity of articles in the hopper 10 (which is continuously receiving articles from the rod-making machine) remains within predetermined limits.Below the level of the hopper 10 there is a driven patter bar (not shown) which is reciprocated to gently tap successive layers of articles to the back of the tray (i.e. so that they are moved inwards by about the width of the backplate 18). As the tray 30A descends on the platforms 50 any tendency of the back of the tray to tilt away from the hopper 10 is countered by the close proximity of the forward surface of the rollers 44 and the leading edge of the tray 30B.

When the platforms 50 have lowered to the position at which the switch 62 is operated the tray 30A is substantially full and the flow control means 20 is closed. Further downward movement of the platforms 50 deposits the now full tray 30A on the bands 76, which convey it to a receiving position. Still further movement of the chains 52 places the platforms 50 in the position of the platforms 56 in Figure versa. One of the platforms 56 operates the switch 60 and the bands 32 are restarted so that the filling cycle for the tray 30B is started.

As long as there are trays on the bands 32 depressing the switches 46 and 48 the normal filling cycle continues as described. If the switch 46 is not depressed when the switch 58 is made the bands 32 continue to run until the switch 62 is made by the descending platform; the bands are then stopped. Thus, when the switch 46 is not depressed the bands 32 continue to run while a tray is being filled, so that any empty trays placed on the bands upstream of the switch 46 are moved to catch up trays already on the bands closer to the hopper 10.The leading tray 30B on the bands 32 is urged against the descending filling tray and helps to maintain the latter in contact with the backplate 1 8. The bands 32 are stopped as soon as switch 62 is made since otherwise there would be a risk that the leading tray 30B on the bands would move towards the hopper 10 before the platforms 50 or 56 were in position to receive it. The bands 32 will restart as soon as the switch 60 is made. If the switch 46 is not made at the time the switch 58 is made the bands 32 will continue to run until the switch 62 is made even if the switch 46 is subsequently made either by a tray being placed on it or by trays reaching it from an upstream position on the bands.

Irrespective of the condition of the switch 46, if the switches 48 and 58 are not depressed and the switch 60 is depressed (indicating that platforms 50 or 56 are waiting to receive a tray) the bands 32 will not run and an alarm will sound. This is because the absence of a tray in the position of the tray 30C implies that if a tray is present on the conveyor in the position of tray 30B it will not be backed up by a tray following its movement onto the hopper 10. In some circumstances this can lead to the tray tilting backwards during loading; it is therefore preferred to inhibit loading with this condition and the alarm is sounded to advise the operator to place further empty trays 30 on the bands 32.

Again irrespective of the condition of the switch 46, if the switch 48 opens during a filling cycle (implying that only two trays were present on the bands 32 adjacent the hopper 10 prior to the start of the cycle) the bands 32 will continue to run until the switch 62 is operates by the platform 50 or 56 carrying the tray being filled. Trays on the bands 32 upstream of the switch 48 may reach the switch 48 and operate it during the period in which the platforms 50 and 56 are moving between switches 60 and 62. If the switch 48 is operated before the switch 62 then the bands 32 continue to run for a sufficient period to allow a tray in the position of tray 30C to reach 5 the position of tray 30B even if the switch 62 is operated in the intervening time.

For some types of tray, particularly those having horizontally running ribs, there is a possibility of interlocking or other undesirable interference between the trays 30A and 30B as the tray 30A is lowered, especially in operating conditions when the bands 32 continue to run while the tray 30A is being lowered. In order to prevent such problems of interference the clamps 64 may be brought into operation so that the rubber surfaces 70 of the elements 66 grip the opposite sides of the tray 30B and prevent it being driven against the tray 30A by the moving bands 32. The cylinders 74 are operated to activate the clamps 64 when the stitches 58 and 60 are made and at least one of the switches 46 and 48 is not made. The clamps 64 are released when the switch 58 is unmade and the switch 62 is made.

Examples of dimensions and other operational factors which have been found to produce satisfactory results in apparatus similar to that shown in the drawings are given below.

The position of the drive shaft 40 was adjusted to give a minimum clearance of about 1 mm between the rear face of the tray 30A and the most forward part of the rollers 44. An adjustment facility to allow the rollers 44 to be horizontally spaced from the hopper backplate 18 by from 5mm to 25mm will accommodate the thickness of the back wall of all conventional trays. A clearance of about 1 mm ensures that the tray is fed fully over the hopper 10 and that the back of the descending tray is supported if necessary. Similarly, the height of the rollers 44 should be adjustable so that the gap between the internal bottom of the tray and the base 22 of the hopper 10 may be reduced to a minimum.

The diameter of the rollers 44 was about 4 to 4.5mm greater than the diameter of the bands 32 passing around the pulleys 34. This provided a separation for the leading tray of about 5 to 8mm from the following tray. It also had the advantage of-setting the tray 30B at a slight angle and created an additional overlap to minimise the risk of interlocking between the trays 30A and 30B.

It is considered desirable that the material of the surface of the rollers 44 should have sufficient friction to engage and pick up the tray from the bands 32 and achieve the necessary separation but that it should not, however, grip the tray so positively that the latter cannot slide forward fully onto the platforms 50 or 56 when the bands 32 are stopped. To some extent this is dependent on band speed: preferably this is greater than 2m./min. A suitable material for the surface of the rollers 44 was SKANDURA WB 2 polypropylene belting.

The level of the platforms 50 or 56 when in position to receive a tray from the bands 32 was about 6-8mm below the upper part of the separation rollers 44.

The platforms 50 and 56 may have cut-outs to ensure that they will always clear stationary trays on the bands 32. Typically the platforms 50, 56 projected about 3mm beyond the backplate 18 towards the rollers 44.

The bands 32 were set at a small angle, about 1 .5"-2" running down towards the hopper 10. This was found to aid the stability of trays, particularly those which had a centre of gravity in a plane in or adjacent the tray back.

The switch 46 was positioned to be operated by the third, fourth or fifth tray on the conveyor, i.e. the tray 30D, 30E or 30F.

For some trays the separation rollers 44 are unnecessary. In this case the front pulleys 34 serve to feed the trays onto the platforms 50, 56 and to support the back of a descending filling tray. Where there are no separation rollers 44 the dimensions between the pulleys 34 and the hopper 10 and platforms 50, 56 should be about the same as those previously quoted for corresponding dimensions with reference to the rollers 44. In operation the main difference is that there is no separation on the bands 32 and the trsy 308 is not tilted back.

Generally, conventional trays fall into one of three types: those with flat backs, those with vertical ribs on their backs, and those with horizontal ribs on their backs. Although it is not possible to generalise completely (since, for example, the dimensions of the ribs can have significant effect on the success or otherwise of a particular form of apparatus in dealing with a particular tray), trays with flat backs may usually be fed successfully without any separation rollers 44 or clamps 64, trays with vertical ribs are more likely to require the separation rollers 44, and trays with horizontal ribs will often require the clamps 64.Apparatus having separation rollers 44 and clamps 64 (as well as the facility for adjustment of dimensions as described above, particularly the distance of the separation rollers 44 from the hopper 10 and the platforms 50, 56) can deal with all conventional trays.

In some circumstances, when for example a tray type is unstable, it may be desirable to move the position of the switch 48 to that of the tray 30D, so that at least two waiting trays are required before a filling cycle can take place. In addition, it might be provided that irrespective of the positions of the switchs 46 and 48 the bands 32 do not continue to run during filling (since this may aggravate the problem caused by instability of the tray).

In these conditions it might be possible to dispense with clamps when using trays which would otherwise require them. Alternatively, the switch 58 may be arranged to operate somewhat earlier (e.g. by fitting it with a projecting arm) so that the bands 32 are stopped and/or the clamps 64 are operated earlier to provide increased separation between the trays 30A and 30B.

Claims (5)

1. Apparatus for loading containers with rod-like articles of the tobacco industry, comprising conveyor means for delivering successive empty containers towards a loading position at which they receive articles, wherein the conveyor means conveys a plurality of containers towards the loading position and at least partly conveys a container into said loading position.

2. Apparatus for conveying containers for rod-like articles of the tobacco industry, comprising a conveyor for moving a succession of containers towards a transfer position from which successive containers are moved away in a direction which differs from that of the conveyor, wherein the conveyor is arranged to move a plurality of containers towards the transfer position and at least partially to transfer leading container into the transfer position.

3. Apparatus for conveying containers for rod-like articles of the tobacco industry, particularly in container loading or unloading apparatus, comprising conveyor means for delivering a succession of containers towards a transfer position, and means for receiving a container at said transfer position and for conveying said container in a direction which differs from the conveyance direction of said conveyor means, wherein the receiving means is arranged below the level of the conveyor means at said transfer position so that the container falls a short distance from the conveyor means to the receiving means.

4. Apparatus for conveying containers for rod-like articles of the tobacco industry, particularly in container loading or unloading apparatus, comprising conveyor means for delivering a container towards a transfer position, and means for receiving a container at the transfer position and for conveying the container in a direction which differs from the conveyance direction in which the conveyor means delivers the container towards the transfer position, wherein the conveyor means is arranged to remain in engagement with a container as it is moved at or from the transfer position in a direction which differs from said conveyance direction.

5. Apparatus substantially as herein described, with particular reference to the act companying drawings.