GB2518736A

GB2518736A - An overhead conveyor, a carriage for an overhead conveyor and a method for conveying product along an overhead conveyor

Info

Publication number: GB2518736A
Application number: GB1413410.0A
Authority: GB
Inventors: John Francis Concannon
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-07-30
Filing date: 2014-07-29
Publication date: 2015-04-01
Also published as: GB201413410D0; IES20140182A2; IE20140183A1

Abstract

An overhead conveyor carriage 1 features a high grade engineering plastic wheel 10. The plastic may be Nylatron MC901. Also disclosed is a corresponding overhead conveyor system and method of usage. Use of a plastic wheel 10 may avoid the rust problems of previous metal wheels.

Description

I

An overhead conveyor, a carriage for an overhead conveyor and a method for conveying product along an overhead conveyoi" The present invention relates to an overhead conveyor, and the invention also relates to a carriage, and in particular, to a carriage for engaging an overhead conveying track of an overhead conveyor and for suspending product therefrom to be conveyed along the overhead conveyor. The invention also relates to a method for conveying product along an overhead conveyor.

In abattoirs and meat processing plants carcasses of animals are conveyed through the plant suspended from an overhead conveyor. In general, the carcasses are suspended from respective support hooks which depends downwardly from corresponding carriages which in turn are rollably engageable with an elongated conveying track, which is typically endless, of the overhead conveyor. Each carriage is typically comprises a carrier element within which a track engaging wheel is rotatably mounted for rollably engaging the conveying track. The support hook depends downwardly from the carrier element. Typically a plurality of carriages are rollably carried on the conveying track of the overhead conveying system. A conveying chain which is located above or adjacent the conveying track comprises an endless elongated chain having a plurality of spaced apart dogs depending downwardly or extending therefrom which engage the respective carriages for urging the carriages along the conveying track.

In general the carrier element of each carriage comprises a steel carrier bracket within which a steel track engaging wheel is rotatably mounted on a steel shaft carried in the carrier bracket. Unfortunately, the environment and in particular the atmosphere in such abattoirs and meat processing plants is relatively harsh, corrosive and dirty, and in general, the steel track engaging wheels rust as do the steel shafts on which the track engaging wheels are rotatably carried. Thus the track engaging wheels regularly seize on the shafts of the carriages. This is undesirable.

Additionally, in such known overhead conveying systems, the shaft, in general, is secured in the carrier element by nuts at respective opposite ends of the shaft, or alternatively, by a head at one end of the shaft, and a nut at the other end of the shaft. These nuts or heads as the case may be are liable to snag on downwardly extending supports from which the conveying track is suspended. This problem is particularly aggravated at bends or corners of the conveying track where the conveying track is bent to direct the carriages around a corner or bend.

There is therefore a need for a carriage for such an overhead conveyor which addresses at least some of the problems of the prior art. There is also a need for an overhead conveyor which addresses at least some of the problems of prior art overhead conveyors, and there is also a need for a method for conveying product on an overhead conveyor, which likewise addresses at least some of the problems of

prior art conveying methods.

The present invention is directed towards providing such an overhead conveyor, a carriage and a conveying method.

According to the invention there is provided a carriage for carrying a downwardly depending support element, the carriage comprising a carrier element for carrying the support element, a track engaging wheel rotatably mounted in the carrier element and being configured in the carrier element to rollably engage a conveying track with the support element depending downwardly therefrom, wherein the track engaging wheel comprises a high grade engineering plastics material.

Preferably, the track engaging wheel is rotatably carried in the carrier element by at least one bearing located in the track engaging wheel. Advantageously, the track engaging wheel is rotatably carried in the carrier element by a pair of bearings located in the track engaging wheel adjacent respective opposite sides thereof Ideally, each bearing is of stainless steel.

In one aspect of the invention the bearings are recessed into the track engaging wheel adjacent respective opposite sides thereof Preferably, the bearings are recessed into respective bosses located adjacent each side of the track engaging wheel. Advantageously, each bearing is flush with an adjacent side surface of the corresponding boss.

In one embodiment of the invention each bearing comprises a ball race bearing.

Preferably, each ball race bearing comprises an inner bearing ring and an outer bearing ring, both bearing rings being of stainless steel, and a plurality of ball bearings located between the bearing rings, the ball bearings being of stainless steel.

In an alternative embodiment of the invention each bearing comprises a bushing.

Preferably, the bushing is of stainless steel.

In another aspect of the invention each bearing is sealed to prevent the ingress of dirt, moisture and other foreign matter into the bearing.

In a further aspect of the invention a shaft is carried in the carrier element, and the track engaging wheel is rotatably carried on the shaft. Preferably, the shaft is of is stainless steel. Advantageously, each bearing is carried on the shaft.

In one aspect of the invention the track engaging wheel is located coaxially on the shaft.

In another aspect of the invention each bearing is rigidly mounted on the shaft.

In another embodiment of the invention an upper part of the carrier element comprises an inverted u-shape bracket, having opposite spaced apart first and second side limbs joined by and extending downwardly from an upper cross-member, the track engaging wheel being located between the first and second side limbs. Preferably, the shaft extends between and is carried in the first and second side limbs. Advantageously, the shaft extends through respective carrier bores in the first and second side limbs.

In one aspect of the invention the shaft terminates at one end in a head, and in the opposite end in a screw thread for engaging a nut for securing the shaft in the carrier element. Preferably, the first and second side limbs are located between the head and nut of the shaft. Advantageously, the head of the shaft is a low profile head, and is of depth not more than 7mm. Ideally, the depth of the head of the shaft is approximately 6.5mm.

In one aspect of the invention the head of the shaft and the nut are of stainless steel.

In another aspect of the invention the support element is swivelably coupled to the carrier element about a first swivel axis. Preferably, the first swivel axis about which the support element is swivelable relative to the carrier element extends substantially vertically.

In another aspect of the invention the support element is swivelably coupled to the carrier element about a second swivel axis perpendicular to the first swivel axis.

Preferably, the second swivel axis about which the support element is swivelable relative to the carrier element extends substantially horizontally.

In one embodiment of the invention the first side limb extends downwardly to engage the support element beneath the track engaging wheel.

In another embodiment of the invention a coupling means is provided for swivelably coupling the support element to the carrier element about the first swivel axis.

In one aspect of the invention a lower distal end of the first side limb terminates in a lower cross-member extending transversely from the first side limb beneath the track engaging wheel, and the coupling means comprises a spigot extending from the support element rotatable in a corresponding swivel bore in the lower cross-member.

Preferably, the spigot extends downwardly from the lower cross-member and terminates in a first eye bracket.

In another aspect of the invention the support element comprises a support hook extending downwardly from a second eye bracket swivelably engaged in the first eye bracket and swivelable about the second swivel axis.

Preferably, the track engaging wheel is configured to engage an upwardly facing wheel engaging surface of the conveying track.

In one aspect of the invention the track engaging wheel comprises a track engaging groove extending circumferentially around an outer circumferential surface of the wheel for engaging the conveying track. Preferably, the track engaging groove is formed between a pair of radially extending spaced apart side flanges extending radially from and circumferentially around the track engaging wheel adjacent the circumferential surface thereof Advantageously, the side flanges of the track engaging wheel embrace the conveying track with the conveying track engaged within the track engaging groove of the track engaging wheel.

In one embodiment of the invention the track engaging wheel comprises Nylatron MC9O1 engineering plastics material.

Additionally the invention provides an overhead conveyor comprising a conveying track and a plurality of carriages according to the invention rollably engageable on the conveying track, with the track engaging wheels of the respective carriages rollalby engaging the conveying track.

In one embodiment of the invention which the conveying track comprises an elongated rail having an upwardly facing wheel engaging surface and opposite side surfaces extending downwardly from the upwardly facing wheel engaging surface.

In another embodiment of the invention the side flanges of the track engaging wheel of each carriage extend downwardly below the upwardly facing wheel engaging surface of the conveying track to embrace the respective opposite side surfaces of the conveying track with the conveying track rollably engaged in the track engaging groove of the corresponding track engaging wheel.

In a further embodiment of the invention the conveying track is of rectangular transverse cross-section, having a pair of opposite major surfaces which form the respective side surfaces of the conveying track, and an upwardly facing minor surface which forms the upwardly facing wheel engaging surface.

Preferably, the respective carriages engage the conveying track with the corresponding support elements located beneath and depending downwardly below the conveying track.

Further the invention provides a method for conveying product along an overhead conveyor, the method comprising locating a carriage according to the invention on a conveying track of the overhead conveyor with the track engaging wheel rollably engaging the conveying track and with the support element depending downwardly from the carriage, supporting the product on the support element of the carriage and urging the carriage with the product supported thereon along the conveying track.

Preferably, the carriage is urged along the conveying track by a corresponding dog on an endless conveying chain of the overhead conveyor.

The invention will be more clearly understood from the following description of a preferred embodiment thereof, which is given by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a carriage according to the invention, Fig. 2 is a side elevational view of the carriage of Fig. 1, Fig. 3 is an end elevational view of the carriage of Fig. 1, Fig. 4 is an exploded perspective view of the carriage of Fig. 1, Fig. 5 is an exploded end elevational view of the carriage of Fig. 1, Fig. 6 is a side elevational view of the carriage of Fig. 1 in use on a conveying track of an overhead conveyor also according to the invention, and Fig. 7 is an end elevational view of the carriage of Fig. 1 on the conveying track of Fig. 6.

Referring to the drawings there is illustrated a carriage according to the invention indicated generally by the reference numeral 1 for use in an overhead conveyor also according to the invention and indicated generally by the reference numeral 2. The overhead conveyor 2 comprises a conveying track 3 formed by a rail 6 of rectangular cross-section along which the carriage 1 is urgeable for conveying product in this case an animal carcass suspended from a support element, namely, a support hook 4 of stainless steel depending downwardly from the carriage 1. Such overhead conveyors will be known to those skilled in the art. In this embodiment of the invention the conveying track 3 is endless, and carries a plurality of the carriages 2.

An endless conveying chain (not shown) is located and supported above the conveying track 3 from which a plurality of spaced apart dogs (also not shown) extend downwardly for engaging respective ones of the carriages 1 spaced apart along the conveying track 3 for urging the carriages 1 along the conveying track 3, for in turn conveying the animal carcasses along the overhead conveyor.

The carriage 1 comprises a carrier element 5 which comprises an upper inverted u-shape bracket 7 having respective opposite spaced apart side limbs, namely, a first side limb 8 and a second side limb 9 extending downwardly from an upper cross-member 11. The u-shape bracket 7 is of stainless steel and is formed by bending a single strip of stainless steel material.

A track engaging wheel 10 is rotatably carried in the carrier element 5 on a shaft 12 as will be described below. The shaft 12 extends between and is carried on the first and second side limbs 8 and 9 of the u-shape bracket 7. The shaft 12 defines a main rotational axis 13 about which the track engaging wheel 10 is rotatable. The shaft 12 at one end terminates in a low profile head 14, and at the other end in a screw thread 15 which is engageable by a corresponding threaded nut 16. The shaft 12, the head 14 and the nut 16 are of stainless steel material. The shaft 12 extends through respective carrier bores 17 in the first and second side limbs 8 and 9, and is secured in the carrier element 5 by the head 14 engaging the first side limb 8 and the nut 16 engaging the second side limb 9. In this embodiment of the invention the head 14 is of depth d of 7mm in order to minimise the danger of the head 14 snagging on downwardly extending supports (not shown) from which the conveying track 3 is suspended.

The track engaging wheel 10 is rotatably carried on the shaft 12 by a pair of bearings 18 of stainless steel. The bearings 18 are ball race bearings and each bearing 18 comprises an outer ring 19, an inner ring 20 and a series of balls (not shown) located between the inner and outer rings 19 and 20 for facilitating relative rotational movement between the outer and inner rings 19 and 20. The inner rings 20 of the respective bearings 18 are of stainless steel and engage the shaft 12 with an interference fit. The outer rings 19 of the respective bearings are also of stainless steel and engage the track engaging wheel 10 with a tight interference fit. The balls (not shown) are also of stainless steel. Bearing seals 24 are provided on the respective opposite sides of the bearings 18 in order to seal the bearings 18 to prevent the ingress of moisture, dirt and other foreign matter into the bearings 18 and the balls (not shown) thereof.

Side bosses 25 extend from respective opposite sides 27 of the track engaging wheel 10, and are coaxial with the main rotational axis 13 of the track engaging wheel 10. Recesses 29 extending into the side bosses 25 accommodate the corresponding bearings 18 therein with the bearings 18 being flush with adjacent side surfaces 30 of the corresponding side bosses 25. The diameter of the recesses 29 are dimensioned so that the outer rings 19 of the respective bearings 18 engage the corresponding recesses 29 with a tight interference fit.

The track engaging wheel 10 is of a high grade engineering plastics material, which in this embodiment of the invention comprises Nylatron MC9O1 engineering plastics material. A track engaging groove 32 extends circumferentially around the outer circumferential periphery of the track engaging wheel 10 for rollably engaging an upwardly facing wheel engaging minor surface 33 of the rail 6 of the conveying track 3. The track engaging groove 32 is formed between a pair of spaced apart side flanges 34 which extend radially from and circumferentially around the outer circumferential periphery of the track engaging wheel 10. The spacing between the side flanges 34 of the track engaging wheel 10 is slightly greater than the width of the rail 6 of the conveying track 3 between respective opposite spaced apart major side surfaces 36 of the rail 6 of the conveying track 3, so that the track engaging wheel 10 is freely rollable along the conveying track 3. The side flanges 34 embrace the rail 6 of the conveying track 3 when the track engaging wheel 10 is in rollable engagement with the conveying track 3 with the conveying track 3 engaged in the track opening groove 32, so that the side flanges 34 retain the track engaging wheel in the rollable engagement on the conveying track 3.

The first side limb 8 of the carrier element 5 extends downwardly below the track engaging wheel 10, and is bent adjacent its lower distal end to form a lower cross-member 38, which extends transversely from the first side limb 8 inwardly beneath the track engaging wheel 10. A coupling means for swivelably coupling the support hook 4 to the carrier element 5 about a substantially vertically extending first swivel axis 39 comprises a spigot 40 rotatably engaged in a swivel bore 42 in the lower cross-member 38 about the first swivel axis 39. The spigot 40 extends downwardly is from the lower cross-member 38 and terminates in a first eye bracket 43. The first eye bracket 43 swivelably engages a second eye bracket 45 of the support hook 4 for swivelably coupling the support hook 4 to the spigot 40, and in turn, to the carrier element 5 about a substantially horizontally extending second swivel axis 47. A radial flange 49 extending circumferentially around the spigot 40 retains the spigot 40 captive in the swivel bore 42 in the lower cross-member. The spigot 40, the first eye bracket 43 and the radial flange 49 are of stainless steel material. The support hook 4 and the second eye bracket 45 are formed in one piece from a single piece of stainless steel material.

In use, a plurality of the carriages 1 are located on the conveying track 3 with the track engaging wheels 10 of the respective carriages 1 rollably engaged on the conveying track 3 and with the support hooks 4 depending downwardly from the corresponding carrier element 5 of the respective carriages 1. The carrier elements of the respective carriages 1 are engaged by the corresponding dogs (not shown) depending downwardly from the endless conveying chain (also not shown) which is located at a level above the conveying track 3 and above the carriages 1. The dogs (not shown) are configured to engage the corresponding carriages 1 adjacent the upper cross-member 11 of the corresponding carrier element 5, so that when the endless conveying chain is driven along and above the conveying track 3, the dogs (not shown) urge the carriages 1 along the conveying track 3.

Animal carcasses, or other products which are to be conveyed by the overhead conveyor 2, along the conveying track 3 are engaged on corresponding ones of the support hooks 4 of the respective carriages 1, with the animal carcasses or products depending downwardly from the support hooks 4. The conveying chain (not shown) is then activated and the animal carcasses or products depending downwardly from the support hooks 4 are conveyed along the conveying track 3 by the corresponding carriages 1.

The invention has many advantages. By virtue of the fact that the track engaging wheel of each carriage is of plastics material and the bearings are of stainless steel, there is no danger of rusting or corrosion or seizing of the track engaging wheel in is the corresponding carriage. Additionally, by virtue of the fact that the head of the shaft on which the track engaging wheel of each carriage rotates is a low profile head there is no danger of the carriage snagging on any of the parts of the overhead conveyor. The seals in the bearings also prevents any risk of dirt and other particular or corrosive matter entering the bearings of the track engaging wheel of each carriage, thus further avoiding any risk of seizing of the track engaging wheel in the corresponding carriage.

While the track engaging wheel of each carriage has been described as being rotatably carried on the shaft by a pair of stainless steel ball race bearings, it is envisaged that a single stainless steel ball race bearing may be sufficient for rotatably mounting the track engaging wheel on the shaft. Indeed, in certain cases it is envisaged that the stainless steel ball race bearings may be omitted and the track engaging wheel of each carriage may be rotatably mounted directly on the shaft.

It is further envisaged that the track engaging wheel of each carriage may be rotatably carried on a bushing which would in turn be carried on the shaft. The bushing would be rigidly mounted relative to the shaft, and typically, would be clamped between the side limbs of the carrier element, and the track engaging wheel would be rotatable on the bushing, and ideally the bushing would be of stainless steel.

Claims

Claims 1. A carriage for carrying a downwardly depending support element, the carriage comprising a carrier element for carrying the support element, a track engaging wheel rotatably mounted in the carrier element and being configured in the carrier element to rollably engage a conveying track with the support element depending downwardly therefrom, wherein the track engaging wheel comprises a high grade engineering plastics material.
2. A carriage as claimed in Claim 1 in which the track engaging wheel is rotatably carried in the carrier element by at least one bearing located in the track engaging wheel.
3. A carriage as claimed in Claim 1 or 2 in which the track engaging wheel is rotatably carried in the carrier element by a pair of bearings located in the track engaging wheel adjacent respective opposite sides thereof.
4. A carriage as claimed in Claim 2 or 3 in which each bearing is of stainless steel.
5. A carriage as claimed in any of Claims 2 to 4 in which the bearings are recessed into the track engaging wheel adjacent respective opposite sides thereof
6. A carhage as claimed in Claim 5 in which the bearings are recessed into respective bosses located adjacent each side of the track engaging wheel.
7. A carriage as claimed in Claim 6 in which each bearing is flush with an adjacent side surface of the corresponding boss.
8. A carriage as claimed in any of Claims 2 to 7 in which each bearing comprises a ball race bearing.
9. A carriage as claimed in Claim 8 in which each ball race bearing comprises an inner bearing ring and an outer bearing ring, both bearing rings being of stainless steel, and a plurality of ball bearings located between the bearing rings, the ball bearings being of stainless steel.
10. A carriage as claimed in any of Claims 2 to 7 in which each bearing comprises a bushing.
11. A carriage as claimed in Claim 10 in which the bushing is of stainless steel.
12. A carriage as claimed in any of Claims 2 to 11 in which each bearing is sealed to prevent the ingress of dirt, moisture and other foreign matter into the bearing.
13. A carriage as claimed in any preceding claim in which a shaft is carried in the carrier element, and the track engaging wheel is rotatably carried on the shaft.
14. A carriage as claimed in Claim 13 in which the shaft is of stainless steel.
15. A carriage as claimed in Claim 13 or 14 in which each bearing is carried on the shaft.
16. A carriage as claimed in any of Claims 13 to 15 in which the track engaging wheel is located coaxially on the shaft.
17. A carriage as claimed in any of Claims 13 to 16 in which each bearing is rigidly mounted on the shaft.
18. A carriage as claimed in any preceding claim in which an upper part of the carrier element comprises an inverted u-shape bracket, having opposite spaced apart first and second side limbs joined by and extending downwardly from an upper cross-member, the track engaging wheel being located between the first and second side limbs.
19. A carriage as claimed in Claim 18 in which the shaft extends between and is carried in the first and second side limbs.
20. A carriage as claimed in Claim 19 in which the shaft extends through respective carrier bores in the first and second side limbs.
21. A carriage as claimed in Claim 19 or 20 in which the shaft terminates at one end in a head, and in the opposite end in a screw thread for engaging a nut for securing the shaft in the carrier element.
22. A carriage as claimed in Claim 21 in which the first and second side limbs are located between the head and nut of the shaft.
23. A carriage as claimed in Claims 21 or 22 in which the head of the shaft is a low profile head, and is of depth not more than 7mm.
24. A carriage as claimed in any of Claims 21 to 23 in which the depth of the head of the shaft is approximately 6.5mm.
25. A carriage as claimed in any of Claims 21 to 24 in which the head of the shaft and the nut are of stainless steel.
26. A carriage as claimed in any preceding claim in which the support element is swivelably coupled to the carrier element about a first swivel axis.
27. A carriage as claimed in Claim 26 in which the first swivel axis about which the support element is swivelable relative to the carrier element extends substantially vertically.
28. A carriage as claimed in any preceding claim in which the support element is swivelably coupled to the carrier element about a second swivel axis perpendicular to the first swivel axis.
29. A carriage as claimed in Claim 28 in which the second swivel axis about which the support element is swivelable relative to the carrier element extends substantially horizontally.
30. A carriage as claimed in any of Claims 18 to 29 in which the first side limb extends downwardly to engage the support element beneath the track engaging wheel.
31. A carriage as claimed in any of Claims 18 to 30 in which a coupling means is provided for swivelably coupling the support element to the carrier element about the first swivel axis.
32. A carriage as claimed in Claim 31 in which a lower distal end of the first side limb terminates in a lower cross-member extending transversely from the first side limb beneath the track engaging wheel, and the coupling means comprises a spigot is extending from the support element rotatable in a corresponding swivel bore in the lower cross-member.
33. A carriage as claimed in Claim 32 in which the spigot extends downwardly from the lower cross-member and terminates in a first eye bracket.
34. A carriage as claimed in Claim 33 in which the support element comprises a support hook extending downwardly from a second eye bracket swivelably engaged in the first eye bracket and swivelable about the second swivel axis.
35. A carriage as claimed in any preceding claim in which the track engaging wheel is configured to engage an upwardly facing wheel engaging surface of the conveying track.
36. A carriage as claimed in any preceding claim in which the track engaging wheel comprises a track engaging groove extending circumferentially around an outer circumferential surface of the wheel for engaging the conveying track.
37. A carriage as claimed in Claim 36 in which the track engaging groove is formed between a pair of radially extending spaced apart side flanges extending radially from and circumferentially around the track engaging wheel adjacent the circumferential surface thereof
38. A carriage as claimed in Claim 37 in which the side flanges of the track engaging wheel embrace the conveying track with the conveying track engaged within the track engaging groove of the track engaging wheel.
39. A carriage as claimed in any preceding claim in which the track engaging wheel comprises Nylatron MC9O1 engineering plastics material.
40. A carriage for an overhead conveyor, the carriage being substantially as described herein with reference to and as illustrated in the accompanying drawings.is
41. An overhead conveyor comprising a conveying track and a plurality of carriages as claimed in any preceding claim rollably engageable on the conveying track, with the track engaging wheels of the respective carriages rollably engaging the conveying track.
42. An overhead conveyor as claimed in Claim 41 in which the conveying track comprises an elongated rail having an upwardly facing wheel engaging surface and opposite side surfaces extending downwardly from the upwardly facing wheel engaging surface.
43. An overhead conveyor as claimed in Claim 42 in which the side flanges of the track engaging wheel of each carriage extend downwardly below the upwardly facing wheel engaging surface of the conveying track to embrace the respective opposite side surfaces of the conveying track with the conveying track rollably engaged in the track engaging groove of the corresponding track engaging wheel.
44. An overhead conveyor as claimed in Claim 42 or 43 in which the conveying track is of rectangular transverse cross-section, having a pair of opposite major surfaces which form the respective side surfaces of the conveying track, and an upwardly facing minor surface which forms the upwardly facing wheel engaging surface.
45. An overhead conveyor as claimed in any of Claims 41 to 44 in which the respective carriages engage the conveying track with the corresponding support elements located beneath and depending downwardly below the conveying track.
46. An overhead conveyor substantially as described herein with reference to and as illustrated in the accompanying drawings.
47. A method for conveying product along an overhead conveyor, the method comprising locating a carriage as claimed in any of Claims 1 to 40 on a conveying track of the overhead conveyor with the track engaging wheel rollably engaging the conveying track and with the support element depending downwardly from the carriage, supporting the product on the support element of the carriage and urging the carriage with the product supported thereon along the conveying track.
48. A method as claimed in Claim 47 in which the carriage is urged along the conveying track by a corresponding dog on an endless conveying chain of the overhead conveyor.
49. A method for conveying product along an overhead conveyor, the method being substantially as described herein with reference to and as illustrated in the accompanying drawings.