GB2250495A

GB2250495A - Rotary conveyors

Info

Publication number: GB2250495A
Application number: GB9019646A
Authority: GB
Inventors: Robert Sincliar Hall
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-09-07
Filing date: 1990-09-07
Publication date: 1992-06-10
Anticipated expiration: 2010-09-07
Also published as: GB9019646D0; GB2250495B

Abstract

Conveying apparatus for feeding objects from one station to another for their processing, the apparatus comprises: a turntable 3, 4 rotatably mounted with respect to a frame 102 of the apparatus, a plurality of stations 20, 40, 50, 60, 70, 80 angularly arranged around the turntables, means 90 mounted on the turntable for holding objects and adapted for advance radial movement with respect to the turntable to an object transfer/processing position and withdrawal to an object transport position, means 110 mounted on the frame at the stations for advance and withdrawal of the object holding means and means 9 for indexing the turntable in rotation whereby objects being transported are angularly moved with the turntable from one station to another. <IMAGE>

Description

FEEDING APPARATUS The present invention relates to apparatus for feeding objects for their processing.

In many processes it is necessary to feed objects from one station to another. The apparatus of the present invention is improved apparatus for such purpose.

According to the invention there is provided apparatus for feeding objects from one station to another for their processing, the apparatus comprising: a turntable rotatably mounted with respect to a frame of the apparatus, means mounted on the turntable for holding objects and adapted for radial movement for advance to an object transfer/processing position and withdrawal to a transport position, means for indexing the turntable in rotation whereby the objects are moved from one station to another angularly arranged around the turntable, means mounted on the frame at the stations for advance and withdrawal of the holding means.

The advance/withdrawal means preferably comprises a linear actuator at each station. The actuator may advance the holding means by simple abutment. A spring return may be provided on the turntable. However in the preferred embodiment, the advance/withdrawal means includes means for positive withdrawal for the holding means. Conveniently this is provided by a permanent magnetic coupling effected on advance.

The positive withdrawal means is preferably adapted for disengagement from the holding means immediately before the end of its stroke. With the magnetic coupling, this is effected by limiting the return stroke of the holding means to be slightly less than that of the actuator. Means is preferably provided for retaining the holding means in their withdrawn position, conveniently in the form of a spring.

Preferably the holding means is adapted to be operated at a selected one of the stations and released at another.

This operation may be by means of a device fixed to the frame. In the preferred embodiment, the operating means is a switch on the turntable and the device is an actuator fixed on the frame. This arrangement and that of mounting the advance/withdrawal means on the frame provides that a single source of power only is required to be fed to the turntable, namely that for the holding means. Preferably the holding means has vacuum sucker(s) as its active element(s) for which the source of power to the turntable is a vacuum line. It should be noted that if the holding means is adapted for mechanical gripping of the objects, no source of power to the turntable is required.

Where the apparatus is for use in feeding nestable objects, the first or input station is a de-nest station.

The preferred embodiment is for processing expanded plastic material trays. For these, the de-nester comprises a pair of front blades which are controllably withdrawable from in front of a stack of trays and a pair of laterally acting gripping jaws for holding back subsequent trays when the front blades are withdrawn for transfer of the front tray to the turntable. Alternatively to the gripping jaws, a second pair of blades may be provided for controllably engaging in front of the second tray.

It is envisaged that one processing station may be provided downstream of the input station. More than one processing station may be provided where more than one processing step is required. Where processing on opposite sides of the objects is required, two turntables may be provided with a transfer station common to both.

To help understanding of the invention, a specific embodiment thereof will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic plan view of the apparatus of the invention, Figure 2 is a plan view on a larger scale of an in-feed station of the apparatus, Figure 3 is a side view of one of eight tray holders in the apparatus, Figure 4 is a plan view of a transfer station, Figure 5 is a plan view of a gluing station, Figure 6 is a side view of a pad application station, and Figure 7 is a plan view of an out-feed station.

Referring first to Figure 1, the apparatus there shown is for labelling expanded plastics material trays and applying absorbent pads inside the trays to suit them for containing meat. The apparatus comprises the following main units and associated stations: in-feed conveyor 1, de-nester 2 , de-nest/in-feed station 20, first turntable 3, label applicator 4, labelling station 40, second turntable 5, transfer station 50, adhesive sprayer 6, adhesive station 60, pad applicator 7, pad station 70, out-feed conveyor 8, out-feed station 80, turntable stepper motors 9, tray holders 90, tray advance/withdrawal actuators 110.

The in-feed conveyor 1 is a dual track conveyor having two tracks 12,13, which are mounted together on cross-rails 14 for movement in the direction of arrows a into alignment of an active one of the tracks with the de-nester 2. Each track carries a tray driver 15 actuated by a rodless cylinder or the like for feeding trays T in the direction of arrow b. Whilst the trays are being fed on edge from the active track, further trays are loaded into the other track.

When the trays on the first track have all been fed, the tracks are moved bodily sideways for feeding of trays from the other track.

The de-nester 2 comprises a pair of fixed side plates 21, on which are mounted for lateral movement a respective pair of front blades 22. For holding back the front tray T1, the blades are movable by means of pneumatic actuators 23 into or out of the path of the trays, which are being fed on edge with the top surface of their bases first along the active one of the tracks 12,13. Also movably mounted on the side plates 21 are a pair of pad supports 24, carrying a respective pair of elastomeric pads 25. By means of actuators 26, these pads can be moved in to grip the edges of the trays between them. The pads are so positioned to grip the second and third trays T2,T3 behind the first tray T1.A central controller - not shown - controls the actuators 23,26 to operate out of phase with each other at appropriate points in each operating cycle of the apparatus to withdraw the front blades 22 from in front of the front tray T1, whilst the second and third trays T2,T3 are held by the pads 25. After transfer of the front tray to the first turntable 3, as described below, the front blades are re-inserted into the path of the trays and the pads withdrawn, allowing the trays to move forwards by one position.

Set at 900 around both the turntables 3,5 are four tray holders 90 per turntable. Each holder has a central column 91 fixed to its turntable with upper and lower guides 92 for rods 93 fixed to a support 94 carrying a pair of suckers 95.

The arrangement is such that the suckers 95 can be radially advanced, towards the de-nester 2 for instance at the in-feed station, and withdrawn. The rods carry springs 96 which normally retain the suckers in their withdrawn position. A vacuum connection tube 97 connects the suckers to a single rotary vacuum manifold 98 at a hub 99 of the turntable, with the interposition of a respective valve 100 in each tube 97. The valves 100 are mounted on the turntables and each have an operating finger 101 extending from opposite ends thereof for movement in the direction of arrows c. The fingers 101 of the four valves 100 are oriented tangentially to a radius r at which the valves are arranged at 900 spacings.At the in-feed station on a base plate 102 beneath the turntable 3 an actuator 103 with a cone 104 at the end of its rod is arranged perpendicularly to the line of the finger of the valve appropriate to the suckers 95 of the tray holder at the station. When at the in-feed station, a valve 100 is arranged transversely to the direction of tray fee; and the actuator 103 is offset from the axis b of tray feed. A similar actuator 105 is arranged beneath the turntable 3 at the transfer station 50 in line with the actuator 103. When the in-feed station holder is advanced - as described below - the actuator 103 is briefly actuated to act on the finger 101 of the valve with the cone 104 moving it sideways with respect to the cone's movement, thus applying vacuum to the suckers which thus grip the tray T1.Simultaneously, the actuator 105 acts on the finger 101 of the valve on the opposite side of the turntable for transfer of the tray held there to a holder 90 on the second turntable 5. The arrangement is such that opposite ends of the fingers 101 are acted at the in-feed and transfer stations 20,50 for switching the state of the valves.

Corresponding valves are carried underneath the second turntable; and corresponding actuators 103',105' are mounted beneath the second turntable 5, but set at 90 since the out-feed station 80 is 2700 of index feed from the transfer station 50.

Attached to the base plate 102 and extending radially from the hubs 99 of the turntables 3,5 towards the stations 20,40,50,60,70,80, are tray advance/withdrawal actuators 110 having lines of action d, there being three actuators for the turntable 3 and four actuators for the turntable 5. The actuators 110 are set at the mid-height of the supports 94 of the tray holders 90. At the distal ends of the rods 111 of the actuators are fixed permanent magnets 112. Shafts 113 fixed to the supports 94 extend through the central columns 91 of the holders towards the magnets and carry at their distal ends steel plates 114, which the magnets 112 can attract and stick to.At appropriate points in the apparatus's cycle, the actuators 110 are all activated to drive out the holders 90 and their suckers 95, except the one particular holder at the time returning mid-way between the transfer and in-feed stations. When the operations/transfers at the stations have been effected, the actuators 110 are withdrawn. With the magnets 112 stuck to the plates 114, the suckers 95 and their trays are withdrawn, until the supports abut the columns 91. The actuators 110 complete a small further stroke to disengage the magnets 112 from the plates 114. On subsequent indexing of the turntables 3,5 by the stepper motors 9, which are mounted beneath the base plate 102, the springs 96 hold the suckers 95 in their withdrawn position.

The label applicator 4 is a conventional equipment and will not be described in detail. It is of the type supplied by . It peels self-adhesive labels from a roll and blows one in the direction of arrows e onto the base of a tray presented opposite it on indexing of the tray to the labelling station. On arrival at the station, the tray is advanced, the label is applied and the tray is withdrawn.

When the tray is indexed to the transfer station 50, it is advanced from the first turntable 3 towards the second turntable 5 by its holder on the first turntable 3.

Simultaneously, a holder 90 on the second turntable 5 advances. The valve actuators 105,103' are activated together switching off the vacuum to the first turntable's suckers 95 and switching on the vacuum to the second turntable's suckers 95 via the respective valves 100. The tray is drawn the short distance between the respective suckers. Then the holder on the second turntable is withdrawn.

The tray is next indexed to the adhesive station 60 where the adhesive sprayer 6 sprays hot melt adhesive onto the top side of the base of the tray on its advance towards the sprayer. The latter is conventional, of the type supplied by At the pad station 70, a length 71 of absorbent pad material is fed down from a roll 72 by a drive 73 to be presented opposite the tray as it approaches. A rolling knife 74 is operated across the pad material to severe the length 71. Then an actuator 75 pushes forwards a support 76 on which the pad length 71 is held by vacuum. On application of the pad 71 against the adhesive for adherence of the pad to the tray, the vacuum is released and the support 76 withdrawn.

Finally the tray is indexed on to the out-feed station 80, where advance of it onto the out-feed conveyor 8 causes it to be caught and retained on the conveyor by lateral brushes 81. Successive trays arriving at the station push earlier ones along the conveyor. The trays are held upright by a friction held support 82 pushed in front of the trays.

It will be appreciated the actuation at appropriate times in the apparatus's cycle of all the actuators, the indexing stepper motors, the label applicator, the adhesive sprayer and the pad applicator are under control of the controller. Programming of this is within the ability of the man skilled in the art and will not be described.

The invention is not intended to be restricted to the details of the above described embodiment. For instance, apparatus of the invention may have only one turntable or indeed may conceivably have more than two. Further, different numbers of stations may be provided around the or each turntable. Optional features may be incorporated such as a detector of the presence of a tray at the adhesive station and/or other stations to enable operation of the adhesive spray and/or other equipments only in the presence of a tray at the station, to guard against misfeed of the trays. The actuator 103 may be arranged at the blank station between the transfer station and the in-feed station, to ensure that the suckers are fully operational when indexed to the in-feed station and there advanced to grip a tray. To ease withdrawal of the tray from the in-feed conveyor, air may be sucked from the region in front of the first tray T1.

Claims

CLAIMS:

1. Apparatus for feeding objects from one station to another for their processing, the apparatus comprising: a turntable rotatably mounted with respect to a frame of the apparatus, a plurality of stations angularly arranged around the turntable, means mounted on the turntable for holding objects and adapted for advance radial movement with respect to the turntable to an object transfer/processing position and withdrawal to an object transport position, means mounted on the frame at the stations for advance and withdrawal of the object holding means and means for indexing the turntable in rotation whereby objects being transported are angularly moved with the turntable from one station to another.

2. Feeding apparatus as claimed in claim 1, wherein the advance and withdrawal means comprises a linear actuator at each station.

3. Feeding apparatus as claimed in claim 2, wherein each linear actuator is adapted to advance the holding means by simple abutment.

4. Feeding apparatus as claimed in claim 3, wherein for withdrawing each holding means a respective return spring is provided on the turntable.

5. Feeding apparatus as claimed in claim 2, wherein the advance and withdrawal means includes means for positive withdrawal of the holding means.

6. Feeding apparatus as claimed in claim 5, wherein the positive withdrawal means is provided by a magnetic coupling, which engages on advance.

7. Feeding apparatus as claimed in claim 5, wherein the positive withdrawal means is preferably adapted for disengagement from the holding means immediately before the end of its stroke.

8. Feeding apparatus as claimed in claim 7, as appendant to claim 6, wherein disengagement of the magnetic coupling is effected by limiting the return stroke of the holding means to be slightly less than that of the actuators.

9. Feeding apparatus as claimed in any preceding claim, wherein means is provided for retaining the holding means in their withdrawn position

10. Feeding apparatus as claimed in claim 10, wherein the means for retaining the holding means is in the form of a spring.

11. Feeding apparatus as claimed in any preceding claim, wherein the holding means is adapted to be actuated at a selected one of the stations and released at another.

12. Feeding apparatus as claimed in claim 11, wherein a device fixed to the frame is provided for selectively actuating the holding means.

13. Feeding apparatus as claimed in claim 12, wherein the fixed device is an actuator fixed on the frame and the actuating means is a switch on the turntable.

14. Feeding apparatus as claimed in any preceding claim, wherein a single source of power only is required to be fed to the turntable, namely that for the holding means.

15. Feeding apparatus as claimed in claim 14, wherein the holding means has vacuum sucker(s) as its active element(s) for which the source of power to the turntable is a vacuum line.

16. Feeding apparatus as claimed in any preceding claim, wherein the apparatus is adapted for feeding nestable objects and the first or input station is a de-nest station, which comprises a pair of front blades which are controllably withdrawable from in front of a stack of the objects and a pair of laterally acting gripping jaws for holding back subsequent objects when the front blades are withdrawn for transfer of the front object to the turntable.

17. Feeding apparatus as claimed in claim 16, wherein the gripping jaws are replaced by a second pair of blades for controllably engaging in front of the second object.

18. Feeding apparatus as claimed in any preceding claim, including at least one object processing station.

19. Feeding apparatus as claimed in any preceding claim, including a plurality of turntables are provided, with transfer stations therebetween.

20. Apparatus for feeding objects from one station to another for their processing substantially as hereinbefore described with reference to the accompanying drawings.