OVERHEAD CONVEYOR SYSTEM

Abstract: There is disclosed an overhead conveyor system (1) which comprises a single generally oval overhead rail (2) having an upper running surface (5), and a trolley (3) having at least one flanged wheel (4) engageable with the upper running surface for movement of the trolley along the rail. The trolley comprises a cradle (6) on which the flanged wheel (4) is rotatably mounted, support means (10) mounted on the cradle and serving for the suspension of one or more articles to be transported by the trolley, and a guide in the form of one or more guide wheels (16) engageable with a lower region (18) of the rail (2) in order to locate the trolley laterally relative to the rail.

Description: OVERHEAD CONVEYOR SYSTEM This invention relates to an overhead conveyor system comprising an overhead rail, and a trolley movable along said rail and from which trolley an article can be suspended for movement between working stations disposed along the path of the overhead rail. An overhead conveyor system according to the invention is particularly suitable for use in a factory for moving articles between working stations at which successive operations can be carried out during the complete formation or fabrication of the articles. The invention has been developed primarily, though not exclusively, with a view to providing an overhead conveyor system for use in a garment-making factory, in which case the "articles" will be partly-formed garments which require a sequence of manufacturing steps before completion of the garment. The articles are conveyed between working stations disposed along the path of the overhead rail, by being suspended from trolleys which run along an upper guide or running surface of the rail. Usually, each trolley will carry a batch of articles, and the operative at each working station can reach out and remove articles sequentially from the batch on the trolley, carry out any necessary work on the article, and then return the article to the trolley, or to a further trolley, for conveyance to the next working station at which further work is carried out. One example of working stations, and means for transferring articles between each working station and a trolley on an overhead rail is disclosed in more detail in the specification of our published European Patent Application (Publication No 145147) . The overhead conveyor system disclosed herein is particularly, though not exclusively, suitable for use with the working stations disclosed in the specification of our aforesaid application. The overhead conveyor system of the invention is based on the use of an overhead rail having an upper running surface, and a trolley having wheels which run along this surface. This provides a simpler construction than some existing conveyor arrangements (one of which is described in more detail below) and which is particularly suitable for use (if desired) in an automated conveyor arrangement. Insofar as the invention provides an overhead rail with a trolley which runs on the upper running surface thereof, giving the advantages of (a) easy mounting and dismounting of the trolley on and from the rail, (b) simple construction and (c) facility for automation, it is necessary to provide a guide arrangement on the trolley which can impart lateral stability to the trolley, especially when the trolley has reached a working station at which article transfer takes place which is liable to exert a turning moment on the trolley about the longitudinal axis of the rail. According to the invention there is provided an overhead conveyor system which comprises an overhead rail having an upper running surface, and a trolley having at least one flanged wheel engagable with said upper running surface for movement of the trolley along said rail, in which the trolley comprises: a cradle on which said flanged wheel is rotatably mounted; support means mounted on said cradle and serving for the suspension of one or more articles to be transported by the trolley; and a guide which is engagable with a lower region of the rail in order to locate the trolley laterally relative to the rail. The support means may comprise an arm rigidly mounted on the cradle, and preferably mounted rigidly at one end on the cradle, and having the other end"engaged by a SUBSTITUTE SHEET releasable latch which serves to retain the article(s) suspended from the arm. In a preferred arrangement, the guide comprises a wheel which is arranged to run along the underside of the rail, and it may have two axially spaced annular flanges, one of which has a smaller diameter than the other to permit the trolley to be disengaged from the rail by pivoting about the upper flanged wheel. In an alternative arrangement, the support means comprises a support block mounted on the cradle, and- preferably a peg or other releasable retainer is suspended from the support block and serves to suspend releasably an article from the trolley. The peg is preferably connected to the block via a swivel, to enable the suspended article to be rotated relative to the cradle. The support means, in a further arrangement, may comprise an elongate support suspended from the trolley and extending longitudinally thereof, the support having a plurality of article suspension points spaced apart along its length. In a still further arrangement, the support means may comprise an upright support suspended from the cradle and carrying at its lower end a rotatable article suspending device, which may carry a plurality of circumferentially spaced article suspension points. To enable the height of articles suspended from the trolley to be varied, preferably the upright support is vertically adjustable relative to the cradle. In order to automate the raising or lowering of the articles, to suit the requirements of operatives arranged at work stations along the length of the rail, one or more power operated devices may be arranged at predetermined positions along the path of the rail, and so as to be engagable with the upright support of a trolley when the latter moves to the particular predetermined position. The power operated device then engages with the upright support SUBSTITUTE SHEET and, upon operation of the device, it can cause any required raising or lowering of the upright support to suit the requirements of an operative at the predetermined position. Conveniently, the power operated device is mounted at a work station, and may be mounted on and extend upwardly from a work table. The device is preferably pneumatically operated, and engages with a projection extending laterally of the upright support. Preferably, the trolley has a pair of flanged wheels arranged one in front of the other, with respect to the rail on which they run, and each wheel may be carried at the upper end of a vertical arm which extends upwardly from the main frame of the trolley. The guide may then be mounted on, or form a part of one or both of said arms. In the preferred illustrated embodiments there are two guide members comprising a second pair of flange wheels rotatably mounted on the arms so as to lie vertically beneath the abovementioned first pair of wheels, said second pair of wheels rolling along the underside of the rail. However, for certain applications, a single guide wheel may be provided which when two flanged wheels are provided (for engaging the upper running surface of the rail) , may be mounted substantially symmetrically with respect to the (overhead) flanged wheels. The rail is preferably shaped in the form of a flattened oval, and conveniently is formed of hollow one- piece construction. In any of the preferred embodiments of the invention, the trolley can readily be mounted on and dismounted from the rail. Furthermore, there is a simple construction of the rail and the trolley. According to a further aspect of the present invention there is further provided a fixing bracket for suspending the rail from a stand, the bracket comprising an upper portion for fixing the bracket to part of the stand at a SUBSTITUTE SHfcET desired position, a lower portion including means to fix the rail to the bracket and an intermediate portion which is bent away from the rail in order to allow a clear passage for the trolley. The conveyor system according to the invention may be used to advantage in a garment-making factory, in which a number of working stations are arranged along the path of the rail, and the operative at each station can readily remove partly formed garments from the trolley in order to carry out the required work at that station. Embodiments of an overhead conveyor system, according to the invention, will now be described in detail, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a perspective side view of a first embodiment of an overhead rail and trolley mounted thereon; Figure 2 is a partial end view taken in the direction of the arrow X in Figure 1; Figure 3 is a perspective view illustrating a fixing bracket for suspending the rail on a stand; Figure 4 is a side view of a second embodiment; Figure 5 is an end view of the second embodiment; Figure 6 is a schematic side view of a third embodiment; Figure 7 is a schematic side view of a fourth embodiment; and, Figure 8 is a schematic view showing the co-operation between an overhead conveyor system according to the invention and a working station. Referring to Figures 1 and 2, an overhead conveyor system 1 comprises an overhead rail 2 and a trolley 3 which has a pair of flanged wheels 4 for rolling along the upper running surface 5 of the rail. The wheels 4 are arranged one beind the other, with respect to the rail 2 on which they run. A cradle 6 of the trolley 3 is suspended from the wheels 4 by means of two vertical arms 7 on which the !_"- Baβ! ^ S SSU 1 !a?E_&SWT5T 11 wheels 4 are rotatably mounted about axles 8. The cradle 6 is suspended from the lower ends of the vertical arms 7, which ends are bent so as to extend generally horizontally and perpendicular to the longitudinal axis of the rail. The mounting means 9 fixing the cradle to the arms 7 allow a certain degree of play or pivoting so that the cradle can twist slightly relative to the arms. This allows the trolley successfully to negotiate bends in the rail. The cradle 6 is provided with support means mounted thereon and serving for the suspension of one or more articles to be transported by the trolley, and taking the form of a rigidly mounted horizontal support arm 10. The arm 10 is rigidly mounted thereon at one end on the cradle so that the arm extends generally longitudinally of the rail, at least when the trolley is travelling along the rail. In the embodiment shown in Figure 1, the arm 10 is rigidly welded to the cradle but has a bend 11 somewhere in the central region of the arm so that the free end 12 of the arm extends laterally of the rail, whilst still lying in the same horizontal plane. A latch member 13 is pivotally mounted on cradle 6 for pivotable movement about pivot axis 13a, the lower end of the latch engaging within a slot 14 in the free end of the arm. This serves to prevent garments which have been suspended from the arm 10 by means of clips or pegs 15 from sliding off whilst trolley 3 is in motion. In order to counteract the effect of the clockwise (when viewed in direction X) turning movement exerted by the weight of garments suspended on arm 10, a guide is provided on the cradle 6 which is engagable with a lower region of the rail and which also serves to locate the trolley laterally relative to the rail. The guide comprises a pair of guide members in the form of a second pair of flanged wheels 16 rotatably mounted on vertical arms 7 on axles 17. The second pair of wheels are flanged, but are not identical to the first pair, the difference being that one of the flanges 16a is of reduced diameter so as to allow the trolley to be removed from the rail if necessary. Thus the trolley primarily runs along the upper surface 5 of the rail, but at the same time the lower pair of wheels rollingly engage the undersurface 18 of the rail to provide a restoring force. Figure 3 illustrates a fixing bracket 25 for suspending the rail 2 from a stand 26 of which there may be provided several. The bracket comprises an upper externally threaded portion 27 which is secured at a desired height relative to the stand 26 by means of a nut 28. Continuous with the upper portion 27 is an intermediate portion 29 which is bent away from the rail so as to allow free passage of the trolley. The intermediate portion 29 terminates in a lower portion 30 which is welded to a fixing plate 31, the fixing plate 31 being bolted or otherwise secured to the rail 2 by bolts 32 or similar. While the embodiment of Figures 1 and 2 shows two overhead flanged wheels (4) , for certain applications it may be sufficient for only a single overhead flanged wheel to be provided. A further embodiment is shown in Figures 4 and 5, in which a pair of upper flanged wheels 44 are arranged closely adjacent to each other, one at each end of a horizontal support arm 45, and running on the upper surface of rail 2 in the form of an oval tube. The support arm 45 is carried at the upper end of an upright support arm 46, and a single guide wheel 47 is rotatably mounted on a lower end of the upright arm 46 for rotation about a horizontal axis, and to engage the underside of the rail 2. (The arms 45 and 46 therefore form the "cradle" of the trolley) . As can be seen from Figure 5, the single guide wheel 47 is cut-away at its side remote from the support arm 46, to permit ready lifting-off of the trolley, by outward pivoting about the upper flange wheels 44, when required. SUBSTITUTE SHEET A support block 48 is carried by the lower end of the upright support arm 46 to permit 360° rotation of any article suspended from the trolley. There is shown a peg 49 from which a garment hanger can be suspended, which is in turn suspended from the support block 48 via a tensile link 50 and a swivel 51. This embodiment can be used for automation, and for transporting and manufacturing single or multiple items. As shown, there are two upper flanged wheels 44, and a single lower guide wheel 47. However, a single upper flanged wheel may be provided, operating in conjunction with a pair of lower guide wheels if required. Referring now to Figure 6 of the drawings, there is shown a third embodiment of trolley which is designated generally by reference 52 and which has a pair of upper and lower rollers running respectively along the upper and lower running surfaces 5 and 18 respectively of single overhead rail 2. In this embodiment, the support means which is mounted on the cradle comprises an elongate support 53 which is suspended from the trolley and which extends longitudinally thereof, the support 53 having a plurality of article suspension points 54 spaced apart along its length. One or more articles, such as partly formed garments, can then readily be suspended from the suspension points 54 by means of any suitable releasable retainers, such as pegs. Referring now to Figure 7, a fourth embodiment of trolley is designated generally by reference 55, and has a pair of upper rollers running on the upper running surface 5 of the rail 2, and a single lower roller (guide) running on the under surface 18 of the rail 2. In this embodiment, the support means mounted on the cradle comprises an upright support 56 which is suspended from the cradle and which carries at its lower end a rotatable article suspending device 57. The device 57 is rotatable, and carries a plurality of circumferentially spaced article €§1 f~?) <ς*~~ suspension points 58. As shown schematically in Figure 7, the upright support 56 is vertically adjustable relative to the cradle, to vary the height of articles suspended therefrom, to suit operating requirements, and particularly the requirements of operatives arranged at work stations along the path of the overhead rail 2. Although not shown in Figure 7, means may be provided to enable the device 57 to be slid radially outwardly of the axis of upright support 56 (along a suitable radial guide extending upwardly of the support 56) to vary the positioning of the suspended articles relative to the path of the overhead rail 2, and thereby to suit the requirements of an operative at any particular work station. The device 57 will still be rotatable about its central axis,- but off-set from the axis of the support 56. To automate the raising and lowering of the support 56, one or more power operated devices are arranged at predetermined positions along the path of the rail 2, for engagement with the upright support 56 when the trolley moves to the particular predetermined position. The power operated device is designated by reference 59, and is shown in more detail in Figure 8. By way of example only, the power operated device 59 is shown in Figure 8 as being mounted on and extending upwardly from a work table at a work station 60, and preferably takes the form of a pneumatic ram having a projecting actuator arm 59a engagable with a projecting lug 56a of the support 56. Thus, when the trolley approaches the work station 60, the actuator arm 59a can come into engagement with lug 56a, and following operation of the device 59, preferably under automatic triggering, the support 56 can then be raised or lowered to the required height to suit the requirements of the operative at the work station 60. An adjustable bracket 61 may be arranged to permit variation in the datum height of the device 59.

Claims: CLAIMS 1. An overhead conveyor system (1) which comprises an overhead rail (2) having an upper running surface (5) and a trolley (3) having at least one flanged wheel (4) engagable with said upper running surface for movement of the trolley along said rail, in which the trolley comprises: a cradle (6) on which said flanged wheel (4) is rotatably mounted; support means (10) mounted on said cradle and serving for the suspension of one or more articles to be transported by the trolley; and, a guide (16) which is engagable with a lower region of the rail in order to locate the trolley laterally relative to the rail. 2. A conveyor system according to Claim 1, in which the guide comprises a wheel (16) arranged to run along the underside (18) of the rail (2) . 3. A conveyor system according to Claim 2, in which the guide wheel (16) comprises two axially spaced annular flanges, one of which (16a) has a smaller diameter than the other to permit the trolley (3) to be disengaged from the rail (2) by pivotting about the upper flanged wheel (4) . 4. A conveyor system according to any one of the preceeding claims, in which the support means comprises an arm (10) rigidly mounted on said cradle. 5. A conveyor system according to Claim 4, in which the arm (10) is rigidly mounted at one end on the cradle, and the other end is engaged by a releasable latch (43) to retain articles suspended from the arm (10) . 6. A conveyor system according to any one of Claims 1 to 3, in which the support means comprises a support block (48) mounted on the cradle. 7. A conveyor system according to Claim 6, in which a peg (49) is suspended from the support block (48) and serves to suspend releasably an article from the trolley. 8. A conveyor system according to Claim 7, in which the peg (49) is connected to the block (48) via a swivel (51). 9. A conveyor system according to any one of Claims 1 to 3, in which the support means comprises an elongate support (53) suspended from the trolley and extending longitudinally thereof, the support having a plurality of article suspension points (54) spaced apart along its length. 10. A conveyor system according to any one of Claims 1 to 3, in which the support means comprises an upright support (56) suspended from the cradle and carrying at its lower end a rotatable article suspending device (57) . 11. A conveyor system according to Claim 10, in which the article suspending device (57) carries a plurality of circu ferentially spaced article suspension points (58) . 12. A conveyor system according to Claim 10 or 11, in which the upright support (56) is vertically adjustable relative to the cradle to vary the height of articles suspended therefrom. 13. A conveyor system according to Claim 12, including a power operated device (59) arranged at a predetermined position along the path of the rail and engagable with the upright support (56) when the trolley moves to said predetermined position, said device (59) being operable to raise or lower the support (56). 14. A conveyor system according to Claim 13, in which the power operated device (59) is arranged at a work station (60) . 15. A conveyor system according to Claim 14, in which the device (59) is mounted on and extends upwardly from a work table. 16. An overhead conveyor rail system (1) which extends along a predetermined path with at least one work station (60) arranged alongside said path, and a trolley €5!- ■ (3) movable along said path in order to convey at least one article suspended therefrom to the work station (60) , in which the trolley comprises: a cradle (6) ; a support (56) mounted on the cradle (6) and serving for the suspension of one or more articles to be transported by the trolley (3) ; and, means permitting raising and lowering movement of the support (56) relative to the cradle (6) in order to vary the height of the suspended article; and in which a power operated device (59) is arranged at a predetermined position along said path and is engagable with said support (56) , as the trolley moves to said position, in order to raise or lower the support (56) to suit the requirements of an operative at said work station (60) . 17. A conveyor system according to Claim 16, in which the support (56) is an elongate upright support. 18. A conveyor system according to Claim 16 or 17, ' in which the power operated device (59) is mounted on a work table (60) .

Inventors: BROOK KEVIN, O'KEEFE MICHAEL, BROOK, KEVIN, O'KEEFE, MICHAEL
Applicants: GENT S R PLC, S R GENT PLC
Application year: 1988
Main classification: B61B3
IPC codes: B61B13, B65G9