GB1585368A

GB1585368A - Movable chain arrangement

Info

Publication number: GB1585368A
Application number: GB28630/77A
Authority: GB
Original assignee: Ferag AG
Current assignee: Ferag AG
Priority date: 1976-07-09
Filing date: 1977-07-07
Publication date: 1981-03-04
Also published as: SE7707964L; BE856492A; CH623283A5; FR2357443A1; IT1080572B; DE2728452A1; NL7707432A

Abstract

The arrangement has a flat-link chain (14) with a finite length. The flat-link chain (14) is guided by its links (16) in a rail (12). A drive section (11) for the flat-link chain (14) is installed in the course of the rail. In order to permit infinite rotating operation despite the finite length of the flat-link chain (14), and also in order to be able to change the course of the rail without removing the flat-link chain, the rail (12) has a self-contained course and a gap exists between the ends (17, 18) of the chain, the length of the chain being greater than the distance, measured along the rail (12), between the end and the beginning of the drive section (11). The arrangement (10) is suitable both for drive transmission and as an endless conveyor, operating in both directions of rotation, without any need for chain adjusters. <IMAGE>

Description

(54) A MOVABLE CHAIN ARRANGEMENT (71) We, FERAG AG, a Swiss Company of 8340 Hinwil, Switzerland, do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed to be particularly described in and by the following statement: The present invention relates to a movable chain arrangement of the type which incorporates a drive chain or chain conveyor comprising a finite strand or length of link chain which is guided at its hinges or joints in a rail or track and is driven along the track.

In German patent 22 41127 there is disclosed an arrangement of this type incorporating a chain conveyor, and associated with a device for drawing a paper web into a rotary printing machine. By virtue of the fact that the finite chain strand is guided at its hinges or joints the chain strand also can be pushed along the rail or track. However, the chain in this prior arrangement can only be driven back-andforth, i.e. in a work stroke and a return stroke, and therefore basically differs from true endless drives or conveyors which can be continuously operated.

On the other hand, there are known, for instance from French patent 1,052,693 and German patent publication 1 ,206,228, true endless conveyors of the type wherein an endless chain is guided in a rail or track, which, in turn, defines a closed course or path of travel. Such endless conveyors possess the disadvantage that the established path of travel which is defined by the rail cannot be altered without dismantling the chain and the rail, and also that the length of the rail must amount to an integer multiple of the length of a chain link. If, furthermore, the chain is not guided at its joints or hinges then it must be always stretched or tightened, i.e. placed under tension or load, which results in in creased frictional losses in the rail or track.

With the foregoing in mind, it is an object of the present invention to provide a movable chain arrangement which reduces or avoids the aforementioned drawbacks and limitations of the prior art constructions.

Another object of the present invention is to provide a movable chain arrangement, by means of which it is possible to reduce or avoid the aforementioned drawbacks of the to-and-fro operation without, however, having to accept the likewise mentioned drawbacks of a true endless conveyor.

According to the present invention, there is provided a movable chain arrangement comprising: a link chain having a finite chain strand and composed of chain links interconnected with one another at joints thereof; track means defining a closed path for guiding the link chain at said joints thereof; drive means for driving the link chain along said closed path; the link chain having opposed ends spaced from one another to define a gap therebetween; and the length of the gap between the ends of the chain strand being insufficient to interupt driving of the link chain by the drive means.

In one embodiment, the track means includes a first track portion and alternative further track portions connected to the first track portion by switch means operable selectively to direct the link chain along alternative closed paths defined by the first track portion and alternative ones of said further track portions, the drive means including a drive unit which drivingly cooperates with the link chain in the first track portion. The further track portions may comprise second and third track portions, switch means being located at each junction or branch between the first track portion and the second and third track portions.

The drive means may comprise a number of drive units or devices mutually spaced along the closed path or paths, the mutual spacing of the units or devices being less than the length of the chain strand.

In order that the invention may be more readily understood, reference will now be made to the annexed drawings, wherein: Figure 1 is a schematic illustration of a first embodiment of a movable chain arrangement employed as a chain conveyor; Figure 2 schematically illustrates a variant embodiment wherein a chain conveyor can be switched-over from a first path of travel to a somewhat shorter second path of travel; Figure 3 illustrates a further variant embodiment wherein the chain conveyor can be switched-over from a first path of travel to a second and longer path of travel; and Figure 4 illustrates an embodiment, similar to that of Figure 2, but employed as a drive or power transmitting arrangement instead of as a chain conveyor.

Describing now the drawings, the chain conveyor 10 illustrated by way of example in Figure 1 will be seen to comprise drive means in the form of a drive unit 11 as well as a substantially tubular hollow rail or track 12 which extends from the inlet to the outlet of the drive unit and defines a closed course or path of travel. The hollow track 12 possesses a longitudinal slot 13 which extends over its entire length. This longitudinal slot 13 as illustrated extends parallel to the lengthwise direction of the track 12 in the outer periphery thereof, although it could alternatively be located at the apex of the track profile which is closer or further removed from the observer of the drawing, or it could follow a twisted or tortuous path with respect to the lengthwise direction of the track 12.

Internally of the hollow track 12 there is arranged a finite length or strand 1 4a of a ball-and-socket joint-link chain 14, the chain links 15 of which have been conveniently illustrated in the form of lines, whereas the ball-and-socket joints or hinges 16 which interconnect neighbouring chain links 15 with one another have been simply shown as circles.

The hinge heads at the two ends of the ball-andsocket joint-link chain 14 have been designated 17 and 18. At a uniform spacing from one another, in this embodiment at each fifth chain link 15, entrainment members 19 are attached at the chain 14, these members being shown for the sake of simplicity as rods which extend through the longitudinal slot 13. These rods will in practice be appropriately formed at their free ends in accordance with the use of the chain conveyor 10, for instance as simple stops, as load hooks, as grippers or as formed or shaped elements which are accommodated to the shape of the material or other objects to be transported.

The drive unit 11 comprises a drive element driven by a motor 20, which may be advantageously a transmission or geared motor, the drive element cooperating in a form-locking or positive manner with the section of the balland-socket chain 14 which extends through the drive unit 11. In this embodiment, the drive element comprises a drive worm 21, into the worm threads 21a of which there engage the joints or hinges 16, although the drive element could be a sprocket gear or wheel having appropriately profiled or shaped outer periphery. The drive worm 21 is drivable both in the direction of the arrow 22 as well as in the direction of the arrow 23, i.e. the drive of the chain 14 is reversible, so that such chain can revolvingly travel in the track 12 either in a clockwise or counter-clockwise direction.

The track 12 is built up, in a manner similar to that of the tracks of a model train, from modules or individual sections which abut one another at the abutting locations 24 shown in broken lines. In Figure 1 it will be seen that both straight sections 25, as well as curved sections 26 each describing an arc of about 45" are provided.

Having now had the benefit of the foregoing description of the embodiment of Figure 1, the following observations can be made: Since the spacing between the ends 17 and 18 of the ball-and-socket joint-link chain 14 is less than the drive path, i.e. the portion of the closed path along which the chain is in positive or form-locking engagement with the drive worm 21, the continuous drive of the chain 14 in either direction is assured. The section of the chain 14 which leaves the drive unit 11 is compressively loaded, that chain section which moves towards the drive unit 11 is loaded tensionally or under traction, and the spacing of successive entrainment members 19 is merely altered by the amount of the unavoidable yet slight play in the hinges or joints 16.

The modified chain conveyor 10 illustrated in Figure 2 incorpprates in the track 12 two switchable junctions or branches 27 and 28.

Consequently, the path of travel of the chain 14 can be switched-over from a first path of travel to a second path of travel. Both paths of travel have a common portion designated I and containing the drive unit 11. This portion I is either augmented by a portion II or a portion III to define a complete closed path of travel by carrying out an appropriate switching operation at the branches 27 and 28 by means of switch elements or means 27a and 28a, respectively. The path of movement of the chain 14 thus can be switched-over from a path of movement governed by the portions I and II to a path of movement governed by the portions I and III by suitably switching-over the switch elements 27a and 28a. In the embodiment of Figure 2, the total length of the path of travel determined by the portions I and II is somewhat greater than the path of travel determined by the portions I and III. However, this is immaterial as long as the total length of the shorter path of travel, in this case determined by the portions I and III, is greater than the length of the ball-and-socket joint-link chain 14, and the spacing between the ends 17 and 18 of the chain, when travelling along the longer path, is less than the drive path within the drive unit 11.

The conditions are depicted differently for the embodiment shown in Figure 3. In this case, by means of two switchable branches or junctions 29 and 30 containing the switch elements 29a and 30a, respectively, the first path of travel composed of the portions I and II can be switched-over to a second path of travel composed of the portions I and III, the total length of the latter path being considerably greater than the length of the former path and of the link chain 14. In order to ensure that the chain 14 is driven continuously, there is there fore incorporated in the portion III a further drive unit 11', the maximum spacing of which from the drive unit 11, measured along the track 12, is less than the length of the chain 14.

As shown by the chain-dot line 31, the drive units can be operatively coupled with one another in any suitable fashion, for instance by standard coupling means, so that they not only operate synchronously and in the same direction, but also in the correct phase relation with regard to the incoming links of the chain 14.

In the embodiment of Figure 4 the chain 14 functions as a drive or power-transmitting chain instead of as a conveyor chain. The drive element of the drive unit 11 in this case is a sprocket wheel or gear 32, the outer peri phery of which is profiled or shaped so as to be complementary to the corresponding profile or shape of the links of the chain 14. The sprocket wheel 32 is driven for instance in the direction of the arrow 33. The path of the chain 14 can be switched-over, as in Figure 2, by means of the switchable branches or junctions 27 and 28 containing switch elements 27a and 28a, respectively, from a first closed path of travel composed of the portions I and II to a second likewise closed path of travel composed of the portions I and III. The portions II and III are associated with respective drive elements in the form of power take-off gears or wheels 34 and 35, respectively, peri pherally shaped or profiled similar to the sprocket wheel 32. Each of the power takeoff gears or wheels 34 and 35 projects into the hollow track 12 and engages in a formlocking or positive manner with the chain 14.

This embodiment, which is comparable to a power transmission from a drive element selectively to one of two power take-off elements, affords the advantage that even when the power take-off elements are not coaxial, the power transmission can be switched-over during operation from one power take-off element to the other. In the present case, where there is provided a ball-and-socket joint-link chain by way of example, the axis of the drive element can be skewed or disposed obliquely to the axes or shafts of the power take-off elements, which, in turn, also need not be parallel to one another. What is important is that the spacing between the ends 17 and 18 of the chain (in Figure 4) is less than the length of the drive path, i.e.

the section of the chain 14 which is in en gagement with the sprocket wheel 32. The chain, as already mentioned, can be loaded both compressively as well as under tension, since its hinges or joints are guided in the track 12.

The advantages of the various embodiments of movable chain arrangements herein described will be readily apparent and self-evident. The link chain 14, apart from the force which is to be transmitted, is not exposed to any additional tensional stress. This reduces the requisite idling power, especially then when the hinges or joints 16 are guided by roller bodies in the track 12. The adaptation or modification of the movable chain arrangement to other fields of application, that is to say, to other paths of travel or movement, is simple and can be accomplished, when using switchable branches or junctions, even by carrying out a simple switching or position reversing operation. The alternate loading of the chain in tension and compression particularly favors the lubrication of the hinges or joints.

WHAT WE CLAIM IS: 1. A movable chain arrangement comprising: a link chain having a finite chain strand and composed of chain links interconnected with one another at joints thereof; track means defining a closed path for guiding the link chain at said joints thereof; drive means for driving the link chain along said closed path; the link chain having opposed ends spaced from one another to define a gap therebetween; and the length of the gap between the ends of the chain strand being insufficient to interrupt driving of the link chain by the drive means.

2. The arrangement as claimed in Claim 1, wherein the drive means includes at least one drive unit which drivingly cooperates with the link chain along a portion of the closed path, the length of the gap between the opposed ends of the link chain being less than the length of the drive path portion.

3. The arrangement as claimed in Claim 2, wherein the drive means includes plural said drive units mutually spaced along said closed path, the length of the link chain being greater than the maximum path length between the drive path portions of successive drive units.

4. The arrangement as claimed in Claim 1, 2 or 3, wherein the track means includes a first track portion and alternative further track portions connected to the first track portion by switch means operable selectively to direct the link chain along alternative closed paths defined by the first track portion and alternative ones of said further track portions, the drive means including a drive unit which drivingly cooperates with the link chain in the frist track portion.

5. The arrangement as claimed in Claim 4, wherein said further track portions comprise second and third portions, and wherein switch means are located at each junction between the first track portion and the second and third track portions.

6. The arrangement as claimed in Claim 4 or 5, wherein the portions of the paths defined by the further track portions are of mutually different lengths.

7. The arrangement as claimed in Claim 4, 5 or 6, wherein the drive means includes an

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

link chain 14. In order to ensure that the chain 14 is driven continuously, there is there fore incorporated in the portion III a further drive unit 11', the maximum spacing of which from the drive unit 11, measured along the track 12, is less than the length of the chain 14.

As shown by the chain-dot line 31, the drive units can be operatively coupled with one another in any suitable fashion, for instance by standard coupling means, so that they not only operate synchronously and in the same direction, but also in the correct phase relation with regard to the incoming links of the chain 14.

In the embodiment of Figure 4 the chain

14 functions as a drive or power-transmitting chain instead of as a conveyor chain. The drive element of the drive unit 11 in this case is a sprocket wheel or gear 32, the outer peri phery of which is profiled or shaped so as to be complementary to the corresponding profile or shape of the links of the chain 14. The sprocket wheel 32 is driven for instance in the direction of the arrow 33. The path of the chain 14 can be switched-over, as in Figure 2, by means of the switchable branches or junctions 27 and 28 containing switch elements 27a and 28a, respectively, from a first closed path of travel composed of the portions I and II to a second likewise closed path of travel composed of the portions I and III. The portions II and III are associated with respective drive elements in the form of power take-off gears or wheels 34 and 35, respectively, peri pherally shaped or profiled similar to the sprocket wheel 32. Each of the power takeoff gears or wheels 34 and 35 projects into the hollow track 12 and engages in a formlocking or positive manner with the chain 14.

This embodiment, which is comparable to a power transmission from a drive element selectively to one of two power take-off elements, affords the advantage that even when the power take-off elements are not coaxial, the power transmission can be switched-over during operation from one power take-off element to the other. In the present case, where there is provided a ball-and-socket joint-link chain by way of example, the axis of the drive element can be skewed or disposed obliquely to the axes or shafts of the power take-off elements, which, in turn, also need not be parallel to one another. What is important is that the spacing between the ends 17 and 18 of the chain (in Figure 4) is less than the length of the drive path, i.e.

the section of the chain 14 which is in en gagement with the sprocket wheel 32. The chain, as already mentioned, can be loaded both compressively as well as under tension, since its hinges or joints are guided in the track 12.

The advantages of the various embodiments of movable chain arrangements herein described will be readily apparent and self-evident. The link chain 14, apart from the force which is to be transmitted, is not exposed to any additional tensional stress. This reduces the requisite idling power, especially then when the hinges or joints 16 are guided by roller bodies in the track 12. The adaptation or modification of the movable chain arrangement to other fields of application, that is to say, to other paths of travel or movement, is simple and can be accomplished, when using switchable branches or junctions, even by carrying out a simple switching or position reversing operation. The alternate loading of the chain in tension and compression particularly favors the lubrication of the hinges or joints.

WHAT WE CLAIM IS: 1. A movable chain arrangement comprising: a link chain having a finite chain strand and composed of chain links interconnected with one another at joints thereof; track means defining a closed path for guiding the link chain at said joints thereof; drive means for driving the link chain along said closed path; the link chain having opposed ends spaced from one another to define a gap therebetween; and the length of the gap between the ends of the chain strand being insufficient to interrupt driving of the link chain by the drive means.
2. The arrangement as claimed in Claim 1, wherein the drive means includes at least one drive unit which drivingly cooperates with the link chain along a portion of the closed path, the length of the gap between the opposed ends of the link chain being less than the length of the drive path portion.
3. The arrangement as claimed in Claim 2, wherein the drive means includes plural said drive units mutually spaced along said closed path, the length of the link chain being greater than the maximum path length between the drive path portions of successive drive units.
4. The arrangement as claimed in Claim 1, 2 or 3, wherein the track means includes a first track portion and alternative further track portions connected to the first track portion by switch means operable selectively to direct the link chain along alternative closed paths defined by the first track portion and alternative ones of said further track portions, the drive means including a drive unit which drivingly cooperates with the link chain in the frist track portion.
5. The arrangement as claimed in Claim 4, wherein said further track portions comprise second and third portions, and wherein switch means are located at each junction between the first track portion and the second and third track portions.
6. The arrangement as claimed in Claim 4 or 5, wherein the portions of the paths defined by the further track portions are of mutually different lengths.
7. The arrangement as claimed in Claim 4, 5 or 6, wherein the drive means includes an

additional drive unit associated with at least one of the further track portions, and synchronised with the drive unit associated with the first track portion.
8. The arrangement as claimed in any preceding claim, wherein the link chain comprises a chain conveyor, and the track means comprises a generally tubular track in which the link chain is guided, the track including a slot extending continuously along the length of the closed path to accommodate members carried by the link chain and including entrainment portions disposed externally of the track.
9. The arrangement as claimed in any of Claims 1 to 7, wherein the link chain comprises a drive chain for transmitting power from the drive means to power take-up means, and the track comprises a generally tubular track in which the link chain is guided, the link chain drivingly cooperating with the power take-off means along a portion of the closed path, the length of which path portion is greater than the length of the gap between the opposed ends of the link chain.
10. A movable chain arrangement substantially as hereinbefore described with reference to Figure 1 of the accompanying drawings.
11. A movable chain arrangement substantially as hereinbefore described with reference to Figure 2 of the accompanying drawings.
12. A movable chain arrangement substantially as hereinbefore described with reference to Figure 3 of the accompanying drawings.
13. A movable chain arrangement substantially as hereinbefore described with reference to Figure 4 of the accompanying drawings.