CONVEYOR TRACK ARRANGEMENT WITH OVERHEAD CARRIAGES

Abstract: A conveyor track arrangement with carriages suspended on rotatable track-forming shafts and provided with rollers which are in rolling contact with the shafts so as to propel the carriages along the track (1), comprises straight and, alternately, curved interconnected track elements (4, 6), the end portions of which are coaxial and rigidly interconnected. Each of the curved track sections comprises an elongate flexible rubber rod (6) which is rotatable by means of at least one of the adjoining track sections (4). The straight track sections preferably comprise rigid tubes (4) which, at each end, comprise a per se known coupling (7) with which a pin (8) is fixedly connected, said pin being inserted and nonrotatably fastened in the adjoining end portion of the rotating rubber rod (6). A carriage is thus driven from the rotating tube (4), through a driven curve (2), i.e. the rubber rod (6) rotating at the same speed, and over to the next tube (4) so as to be further moved forward. According to a preferred embodiment, the flexible rubber rod (6) is supported by means of several pairs of roller bearings (12) which are in rolling contact with the circumference of the rod (6).

Description: CONVEYOR TRACK ARRANGEMENT WITH OVERHEAD CARRIAGES The present invention relates to a conveyor track arrangement with carriages suspended on rotatable track- forming shafts and provided with rollers which are in frictional and rolling contact with the shafts so as to propel the carriages along the track by rotation of the shaft. There are several types of conveyor systems with overhead carriages hooked on a track and provided with inclined rollers which are in rolling and frictional contact v/ith a normally tubular conveying shaft. The friction between the rollers and the rotating tube propels the carriages along fixed tracks. The carriages may have the shape of e.g. a basket for carrying products, or a hanger for articles of clothing or the like v/hich are to be subjected to various manufacturing operations. In these known conveyor systems, the carriages are moved by means of a rigid and relatively long con¬ veyor tube which is caused to rotate by special driving means. The trad s included in the conveyor systems are open or closed and may have quite irregular shapes, for which reason it must be possible to change the direction of the tracks in various ways. This may involve 90° curves, sidings etc. to which the carriages must be firmly linked on curved, fixed rails positioned above the rotating tube. To this end, the carriages are provided with wheels which are caused to roll against the fixed rails, while the carriage is raised out of its frictional contact with the tube. The driven movement of the carriage changes into a free rolling movement during which the carriaσe is supoorted by the wheel instead of the inclined rollers mentioned above. In these systems, the junctions between the driven track sections, i.e. the rigid rotating tubes, and the free ro linσ -rack sections, i.e. the fixed overlying overlying rails, frequently cause difficulties since the carriages are readily stopped and, at worst, become stuck. To make the entire system function in a satis¬ factory manner, it must be possible to control the speed of the carriages so as to avoid, collisions and overly irregular spacings between the carriages. The variations in speed at the junctions between the driven and the nondriven track sections can thus jeopardise the function of the entire conveyor system, and therefore it is desirable to provide a system which can operate entirely with driven track sections. DE-OS 2,653,009 discloses a device for moving objects along a guide rail in the form of a rotating shaft v/ith which inclined rollers mounted, on suspension means are in frictional contact (see Fig. 1). As appears from Figs 9-12, the device is mainly intended to be used for v/indow curtains or draperies for partitioning a room. The shaft of this known device may have the shape of a plastic tube which forms a gently curved guide rail for the curtain (see Fig. 7). The device is an example of the prior art technique on v/hich the present invention is based, but is not adapted to be used in a conveyor system with overhead carriages, v/here both straight and curved track sections for propelling the carriages are included. The object of the invention is to eliminate the drawbacks discussed above by providing a conveyor track arrangement operating with overhead carriages which are propelled along both straight and curved track sec- tions and need not be hooked on fixed rails for free rolling movement, and whose speed is not changed to such an extent that the function of the entire conveyor track is jeopardised. A further object is to provide an arrangement which makes it possible to reduce the number of drive units for the driven track sections. A still further object is to provide an arrangement which renders t oossihle to reduce the total cost of the carriage conveyor track and which provides for easy adπustment of said conveyor track after assembly. These objects are achieved in that the inventive arrangement mentioned by way of introduction is characterised in that the track comorises straight and, alternately, curved interconnected track sections, the end portions of which are coaxial and riqidly inter¬ connected, and that each of the curved track sections comprises an elongate flexible member which is rotatable by means of at least one of the adjoining track sections. Accordmα to a preferred embodiment, the flexible member is a polyurethane rubber tube, the two ends of which are connected to couplings for rotating the tube. Such a couoling whjch, for example, is of the type as described m Sv/edish patent 8008530-1, comprises a pin rigidly connected therewith, said pin being inserted and nonrotatab 1 y fastened J n one end portion of the f1 exible tube. Many advantages are obtained bv means of the invention, one being the possibility of forming the conveyor track with very sharp curves. Practical tests have shown that 90° curves with a radius as small as 300 mm function quite satisfactorily. The invention and its many advantages will be de¬ scribed in detail below, reference being had to the accomoanying drawing lllustratmα a preferred embodiment of the inventive arranqe ent. ~ ισ . 1 is a plan view, partly m section, of an arrangement according to the invention J n the form of a dri en curve. Fin. 2 is a cross-sectional view of the curve along line II-II in Fig. 1, with a carriage thereon. Fig. 3 is a cross-section of an alternatively designed rod included 3 n the arrangement according to tne invention. Fig. 1 snows a oart of a horizontal conveyor track as seen fro-" above, generally designated 1 and comprising a driven 9C curve 2 throuσh which an overhead carriaσe 3 carrying a load (not shown) is movable (see Fig. 2). The conveyor track 1 comprises shaft-like, straight track sections in the form of rigid tubes 4 which are rotated by driving means (not shown) so as to propel, in known manner, the carriage 3 by the frictional and rolling contact betv/een the tubes 4 and inclined rollers 5 mounted on the carriage 3. The curve 2, i.e. the curved track section, com¬ prises a flexible member which in the drawing is shown as an elongate solid rod 6 which, however, may just as well be tubular, and practical tests have demonstrated that the tubular form is the most advantageous one. The rod 6 preferably consists of polyurethane rubber or similar material . The ends of the rubber rod 6 are rigidly connected to the coaxially positioned ends of the tubes 4. The tubes include per se knov/n couplings 7 which are pre¬ ferably of the type disclosed in SE 8008530-1 and there¬ fore need not be here described in detail . For connecting the tubes 4 to the rubber rod 6, each coupling 7 com¬ prises a pin 8 rigidly connected therev/ith and inserted into a hole 9 in the end portion of the rubber rod 6. The hole 9 also accommodates a reinforcement sleeve 10 which, like the pin 8, is provided with transverse bores into which a transverse locking pin 11 is inserted for nonrotatably fastening the pin 8 in the end portion of the rod 6. In this manner, the rubber rod 6 is rota¬ table by means of the straight tubes 4 via the couplings 7, such that the carriage 3 is driven from a straight track section, via the rotating rubber rod 6 over to the next straight track section. The speed of rotation is the same, and therefore the junction between the straight and the curved track sections presents no problem. The curved section of the conveyor track 1 also comprises pairs of relatively small underlying ball bearings 12 which serve to support this section and are in rolling contact with the circumference of the flexible rotating rubber rod 6. It v/ill be appreciated that the supporting function can also be achieved in other ways which, however, v/ill not be here described. As shown in Fig. 2, the carriage 3 also comprisesaan overlying, free rolling wheel 13 which - and this is somewhat outside the scope of this invention - can be switched off from the track and caused to roll on a fixed, nonrotatable rail or siding optionally included in the system, as discussed by way of introduction in the general part of the specification. Fig. 3 is a cross-sectional view of a rod 14 which corresponds to the rod 6 as described above, but which has, as an alternative, a square hole 15 into which a pin (not shown) is insertable from the end to be fastened in the rod 14. The pin v/hich corresponds to the pin 8 described above, has a shape conforming to the hole 15. The advantage obtained, by this type of rod 14 and pin is that no further means is required for fastening the pin in the hole 15, but the pin imparts a torque directly to the walls of the hole 15. It will be appreci¬ ated that the hole and the pin adapted thereto may have a different polygonal cross-section. The invention thus makes for a conveyor track in which the carriages on both curved and straight track sections are propelled by a rotating member. In this manner, the number of drive units for the track sections can be reduced, and thus the cost of the entire arrange¬ ment. Moreover, the junctions between the driven and the nondriven track sections are eliminated, v/hich have been causing the difficulties mentioned by v/ay of in¬ troduction. Of course, a curved track section can be connected, directly to another curved track section. Finally, it should be emphasised that the invention rr.ay be modified in many different ways within the scope of the appended claims. A oerson skilled in the art realises that the arranσenent aceordino to the inven- tion may be positioned in different planes and be differently inclined, without departing from the inven¬ tive idea. Many other types of curves, either above or below 90°, can be provided. A specific field of application is when the con¬ veyor track is used for moving carriages betv/een diffe¬ rent floors. In this case, use is made of a relatively long, straight track section, corresponding to the tube 4, which is inclined betv/een the floors and each end of which must have a minor angled portion comprising a flexible member and a coupling of the type described above. One condition that must be fulfilled in all cases is that the friction is sufficient betv/een the different track sections and the inclined rollers of the carriage.

Claims: CLAIMS 1. A conveyor track arrangement with carriages (3) suspended on rotatable track-forming shafts and provided with rollers (5) v/hich are in frictional and rolling contact with said shafts so as to propel said carriages (3) along said track (1) by rotation of the shaft, said track (1) comprising straight and, alter¬ nately, curved interconnected track sections (d, 6), the end portions of v/hich are coaxial and rigidly inter¬ connected, c h a r a c t e r i s e d in that each of said curved track sections comprises a round elongate, flexible and solid or tubular rod (6; 14)) having a smooth circumference and being rotatable by means of at least one of the adjoining track sections (4), and that couplings (7) betv/een said straight and curved track sections H, 6) comprise a pin (8) rigidly con¬ nected therewith, said pin being inserted and nonrota- bly fastened in one end portion of said flexible rod (6; 14) . ?.. An arrangement as claimed in claim 1, c h a - r a c t e r i s e d in that said rod (6; 14) consists of rubber or similar material. 3. An arrangement as claimed in claim 1 or 2, c h a r a c t e r i s e d in that said flexible rod (6; 14) is supported by a plurality of roller bearings (12) which are in rolling contact v/ith the circumference of said rod ( 6; 14 ) . Δ . An arrangement as claimed in any one of the preceding claims, c h a r a c t e r i s e d in that said rod (14) comprises, at each end portion, a hole (15) which is polygonal in cross-section and into which said pin having the same cross-sectional shape is in¬ serted.

Inventors: CHRISTIANSSON CARSTEN, CHRISTIANSSON, CARSTEN
Applicants: OEHRNELL CONVEYORSYSTEM AB
Application year: 1987
Main classification: B65G29
IPC codes: B61B13, B65G19, B65G35, E01B25