US 3718263 A
A pair of transversely spaced elongated parallel rails are provided each having an inwardly directed track and an outwardly directed track. At least two carriages are mounted on these rails with each carriage having on each side two or more wheels. The wheels of one carriage are spaced apart transversely to such an extent that they will roll on the inner tracks of the rails, and the wheels of the other carriage are spaced apart transversely to a greater extent so as to roll on the outer tracks of the rails, with the arrangement being such that the carriages can pass one another on the rails.
Claims available in
Description (OCR text may contain errors)
United States Patent [191 Strecke 1 Feb. 27, 1973  TRAVERSING HOIST ARRANGEMENT  Inventor: Heinz Strecke, Lindenbaumstrasse  Foreign Application Priority Data Dec. 30, 1969 Germany ..P 19 65 450.3 June 15, 1970 Germany ..P 20 29 454.6
 US. Cl. ..2l2/l28, 104/91, 104/94,
 Int. Cl. ..B61b 3/02, B66c 19/00, E01b 25/22  Field of Search ..104/68, 94, 95, 91; 105/7, 105/153, l54,155;198/1,18, 99; 212/128 1,138,100 5/1915 Gale, Jr. ..198/18 FOREIGN PATENTS OR APPLICATIONS 333,206 2/1921 Germany ..105/7 471,992 2/1929 Germany 105/7 1,237,751 3/1967 Germany .105/7 Primary Examiner-Gerald M. Forlenza Assistant Examiner-Howard Beltran Attorney-Michael S. Striker 5 7 ABSTRACT A pair of transversely spaced elongated parallel rails are provided each having an inwardly directed track and an outwardly directed track. At least two carriages are mounted on these rails with each carriage having on each side two or more wheels. The wheels of one carriage are spaced apart transversely to such an extent that they will roll on the inner tracks of the rails, and the wheels of the other carriage are spaced apart transversely to a greater extent so as to roll on the outer tracks of the rails, with the arrangement being such that the carriages can pass one another on the rails.
16 Claims, 4 Drawing Figures PATENIED 3,718,263
SHEET 30F 4 Wmlar:
lie/m. Srkecz TRAVERSING HOIST ARRANGEMENT BACKGROUND OF THE INVENTION The present invention relates generally to conveying arrangement, and more particularly to an arrangement for conveying or transporting workpieces between working stations.
It is known to connect working stations by means of rails on which carriages are mounted for rolling movement, with engaging means being provided on the carriages for engaging workpieces which are to be transported from one to another of the working stations. It is also known, of course, to effect such essentially horizontal transportation by means of ropes, chains or the like, but the use of carriages has been found more advantageous because it makes it possible to transport the workpieces without having them swing in pendulum fashion, as would be the case if they were suspended from ropes, chains or the like. Thus, the workpieces can be precisely positioned and guided during their transportation.
In order to obtain maximum advantages from such carriage transportation it is desirable to subject the rollers or wheels as well as the rails on which they move to as little load as possible, and at the same time to thereby assure that the carriages move smoothly. This is accomplished by making the chassis of the carriage as long as possible. Unfortunately, the length of the chassis is limited by the length of the working station, that is the dimension of the working station in the direction longitudinally of the rails, because it is necessary in such conveying arrangements that two relatively closely adjacent working stations be capable of being simultaneously served by two carriages so that the chassis of the carriages must not be excessively long lest it interfere with a carriage at an adjacent working station.
It is clear, therefore, that this type of conveying arrangement is in need of further improvements which have, in fact, long been recognized as desirable but have not before been forthcoming.
SUMMARY OF THE INVENTION It is, accordingly, an object of the present invention to provide an improved conveying arrangement of the type under discussion which is not bereft of the aforementioned disadvantages.
Another object of the invention is to provide such an improved arrangement in which the carriage or carriages operate smoothly with a minimum of vibrations or other undesired movements.
A concomitant object of the invention is to provide such an improved conveying arrangement in which two adjacent working stations can be simultaneously served by two carriages, and in which the chassis of the respective carriages can be longer than the distance of the working stations from one another along the rails.
In pursuance of the above objects, and others which will become apparent hereafter, one feature of the invention resides in a conveying arrangement which, briefly stated, comprises elongated transversely spaced parallel rail means having a pair of inner tracks and a pair of outer tracks. At least two carriages are provided mounted on the rail means. One of these carriages has at least two first sets of lateral wheels spaced transversely by a first distance and rollingly engaging the inner tracks of the rail means, and the other of the carriages as at least two second sets of lateral wheels spaced transversely by a greater second distance and rollingly engaging the outer tracks so as to permit movement of the carriages past one another.
By resorting to the present invention it is possible to have the two carriages simultaneously serve two adjacent narrow working stations. On the other hand, by making it possible to have the chassis length of the carriages be greater than the distance between the two working stations, the carriages will run much more smoothly and quietly and will not be subjected to vibrations and similar disturbing motions. The utilization of-in the currently preferred embodimentonly two rails is very economical because it is quite easy to mount and adjust two rails so that they are in exact parallelism with one another, with many sources of error in parallel arrangement being thereby avoided. However, it is also possible for instance to use three or four rails if it is kept in mind that this will require more complicated mounting and adjusting efforts to eliminate the possibility of complete or partial nonparallelism and similar difficulties which will cause the carriages to run less than smoothly.
Each of the carriages may be provided on each lateral side with two or even a greater number of wheels, which term is intended to be generic and to employ any type of roller or similar element with which the carriage can engage the rails and move along the same. By using a relatively large number of such rails for each lateral side of the respective carriage, each wheel need absorb only a fraction ofthe total weight of the carriage and any load carried by it, so that the carriage will run more smoothly. At the same time this construction makes it possible to make the wheels themselves, or at least the portions thereof which engage the tracks of the rails, of an elastically yieldable material which in turn further reduces undesired motions of the carriage during movement, making it run more smoothly and also more quietly.
The rails may be of T-shaped cross-section or of H- shaped cross section, and the tracks may be provided on respectively inwardly and outwardly directed flanges thereof. The inner and outer track of the respective rails may be located in the same transverse plane, they may be located in superposed planes or they may be located in planes at different levels but be laterally offset with reference to one another. Of course, the inner and outer track may also each be provided on a separate rail, in which case it would then be necessary to provide two pairs of rails, namely an inner pair of rails and an outer pair of rails flanking the inner pair and provided with the outer tracks.
According to the invention it is also possible to have the terminal wheels on the respective carriages, that is the wheels located farthest apart in the direction of elongation of the respective carriage, be spaced from one another by a distance which is greater than the length of a working station, measured in the direction of elongation of the rails serving the station. The wheels may be surrounded by an endless elastically yieldable annulus which in turn engages the tracks.
It is also possible to provide the carriages for propulsion purposes with wheels or rollers which are driven and which frictionally engage surfaces of the respective rails other than the tracks, and these driven propulsion wheels may be biased into engagement with such surfaces by means of suitable biasing means and may be lifted off such surfaces if and when desired. Ordinarily it is also possible to provide the propulsion means in form of a band-drive associated with the respective carriage and convoluted about a plurality of support rollers which press it against the surfaces of the rails which are to be frictionally engaged, with the band being driven by a motor preferably mounted on the respective carriage. Finally, the carriages may also each be provided with a lifting device for the workpiece-engaging instrumentality, and the lifting device may be located within the confines delimited by vertical planes passing through the respective rails.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the drawing in detail, and firstly the embodiment illustrated in FIGS. 1-3, it is pointed out that the conveying arrangement there shown .is intended for use with carriages which have at their opposite ends respective frames provided with wheels. These carriages are supported by a pair of transversely spaced parallel rails 4 and 4a which are of inverted-T profile as illustrated. These rails are provided with respective inner flanges 5 and 5a, and with respective outer flanges 6 and 6a. The upper surfaces of the flanges 5 and 5a are the inner tracks and the upper surfaces of the flanges 6 and 6a are the outer tracks. Mounted on the rails 4 and 4a are two carriages W and W which differ from one another only in that the wheels 7 of the carriage W are supported on the upper surfaces of the inner flanges 5 and 5a, respectively, whereas the wheels 7 of the carriage W are supported on the upper surfaces of the outer flanges 6 and 6a, respectively.
Carriage W has a frame 2 on which the wheels 7 are mounted for rotation, and a similar frame 2 carrying the wheels 7' is provided for the carriage W. The length of the frames 2 and 2 as seen in the direction of elongation of the rails 4 and 4a is greater than that of the remaining components of the carriages W and W. This makes it possible for these carriages to move much closer together as seen longitudinally of the rails than the length of the frames 2 and 2' would ordinarily permit if the rollers or wheels 7 and 7' were to run on one and the same track, rather than on inner and outer tracks, respectively.
Inasmuch as the carriages W and W are identical except for the transverse spacing of their respective wheels 7 and 7, only the carriage W will be described hereafter. It is to be understood that the reference numerals employed for designating components of the carriages W and W are identical except that the components of the carriage W are identified with reference numerals which are the same as those used to identify components of the carriage W but have added thereto a prime symbol.
Discussing now the carriage W as a representative of both carriages, it is pointed out that the frame 2 is mounted on a pair of parallel horizontal supports 8a and 8b. These are connected to form a rigid frame by the transverse braces 80. An arm 11 is pivoted to the member 8a approximately below each of the frames 2 and its end portion is engaged by a spring 13 whose cover end in turn is supported via a rod 12 by the opposite element 8b. The arms 11 are connected with one another by two parallel supports 25 which are connected by cross braces 8d. A motor 21 and journals for a shaft 26 driven by the motor 21 are supported on the cross braces 8d, and rollers 9 are mounted on the opposite ends of the shaft 26. These rollers 9 engage from below the center of the rails 4 and 4a and are urged against them by springs 13. The rollers 9 can thus be driven by the motor 21 when the same is energized and due to their frictional engagement with the rails 4 and 4a they will then advance the carriage W longitudinally of the rails. When the arms 11 are pivoted downwardly, the rollers 9 are moved out of engagement with the rails 4 and 4a so that the carriage W will stop. The downward pivoting of the arms 1 1 is effected by means of a rod 14 which is axially shiftable and acts upon the upper end of the rod 12.
A lifting device is provided on the element 8a and located within the space which is delimited by vertical planes passing through the rails 4 and 4a. This lifting device utilizes two vertical U-shaped profiled elements 10 which are secured to the element and which guide a horizontal guide member 17 each. A cross brace 17a rigidly connects the guide elements 17 which latter together support a rod 1 the end of which is provided with receivers 3 for receiving the elements capable of supporting workpieces to be transported. Each guide element 17 is connected with an end portion of a chain 18 which is trained about a lower reversing roller 19 and leads to a counterweight 20 which in turn is connected with a rope l5 trained about a rope drum 26 and connected with the rod 1. The rope drums 26 are both connected by means of a shaft 23 which can be driven by a motor 22 so that energization of the motor 22 in a desired sense can serve for raising and lifting the lifting devices and thereby any workpieces supported by them.
The rollers 7 may be provided with a soft surface, such as a laminar elastically yieldable surface, which engages the respective tracks, because the weight acting upon them is distributed over many such rollers. However, the rollers may also be surrounded by bandshaped element 24 as shown in FIG. 3.
The embodiment illustrated in FIG. 4 is somewhat different from that of FIGS. 1-3. I-Iere transportation of the carriages along the rails 5 is effected in that spring pressure serves to press against the underside of each rail 5 three rollers 9a, 9b and 9c. An endless drive band 27 is turned about the rollers 9a, 9b and 9c being pressed by them against the underside of the respective rail 5. It is further turned about a roller 28 which is journalled at the end of a lever arm 29 which is so mounted that it can be pivoted about the axis of a motor 21 which drives the roller 28. Thus, motor 21 can drive the roller 28 and via the roller 28 the tape or band 27 so that the same, being urged into frictional engagement with the underside of the respective rail 5 by the rollers 9a, 9b and 9c, transports the respective carriage along the rails. When it is desired to terminate motion of the carriage the motor 21 can be energized, or else the arm 29 can be pivoted upwardly, both actions having the result of terminating advancement of the carriage.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
While the invention has been illustrated and described as embodied in a conveying arrangement, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:
1. A conveying arrangement, comprising elongated transversely spaced parallel rail means having a pair of inner tracks and a pair of outer tracks; at least two carriages mounted on said rail means and having identically dimensioned chassis located at least substantially in a common transverse plane, one of said carriages having at least two first sets of lateral wheels spaced transversely by a first distance and each composed of a plurality of longitudinally spaced first wheels rollingly engaging said inner tracks, and the other of said carriages having at least two second sets of lateral wheels spaced transversely by a greater second distance and each composed of a plurality of longitudinally spaced second wheels rollingly engaging said outer tracks, so as to permit movement of said carriages into and past one another, the longitudinal spacing of the wheels of the respective sets being greater than the length of the respective chassis; and engaging and conveying means provided on each of said carriages and including lifting means for workpieces and the like.
2. A conveying arrangement as defined in claim 1, wherein said wheels have track-engaging surfaces and are composed, at least in the region of said surfaces, of resiliently yieldable material.
3. A conveying arrangement as defined in claim 1,
wherein said wheels each have a main portion provided with a circumferential surface, and an endless annular portion of elastically yieldable mate rial encirclin said main portion in engagement with said surface an provided with a track-engaging outer face.
4. A conveying arrangement as defined in claim 1, wherein said rail means extends between at least two spaced working stations each having a given length; and wherein said carriages are elongated and the respective sets of wheels are spaced longitudinally of the associated carriage by a distance greater than said given length.
5. A conveying arrangement as defined in claim 1, wherein said rail means comprises at least two parallel rails of T-shaped cross-section with said inner and outer tracks being provided on respective inwardly and outwardly directed flanges of said rails.
6. A conveying arrangement as defined in claim 1, wherein said rail means comprises at least two parallel rails of H-shaped cross-section with said inner and outer tracks being provided on respective inwardly and outwardly directed flanges of said rails.
7. A conveying arrangement as defined in claim 1, said rail means comprising at least two parallel rails each having one of said inner and one of said outer tracks.
8. A conveying arrangement as defined in claim 7, wherein said inner and outer tracks of each rail are locatedin superposed planes.
9. A conveying arrangement as defined in claim 7, wherein said inner and outer tracks of each rail are located side by side in a common plane.
10. A conveying arrangement as defined in claim 7, wherein said inner and outer tracks of each rail are located in different superposed planes.
11. A conveying arrangement as defined in claim 1, said rail means comprising at least two inner rails each provided with one of said inner tracks, and at least two outer rails flanking said inner rails and each provided with one of said outer tracks.
12. A conveying arrangement as defined in claim 1, at least some of said wheels of each of said carriages being driven wheels and bearing against said rail means in frictional engagement therewith.
13. A conveying arrangement as defined in claim 12; and further comprising biasing means biasing said driven wheels against said rail means.
14. A conveying arrangement as defined in claim 13; and disengaging means for disengaging said driven wheels from said rail means.
15. A conveying arrangement as defined in claim 1; further comprising drive means for said carriages each comprising a drive band, a plurality of rollers about which said drive band is convoluted and which urge the same into frictional contact with said rail means, and motor means for advancing said drive band longitudinally of itself and of the respective carriage.
16. A conveying arrangement as defined in claim 1, said rail means including at least two transversely spaced rails; and said lifting means being arranged within the confines of imaginary vertical planes intersecting the respective rails.