US3771464A

US3771464A - Tow truck system

Info

Publication number: US3771464A
Application number: US00186636A
Authority: US
Inventors: H Reiche
Original assignee: Fromme Foerderanlagen GmbH
Current assignee: Fromme Foerderanlagen GmbH; FROMME GmbH
Priority date: 1971-10-05
Filing date: 1971-10-05
Publication date: 1973-11-13
Anticipated expiration: 1990-11-13

Abstract

The intersection between the main track along which vehicles are pushed and a non-powered spur track is controlled by a switch device. An endless drive associated partially w1th the main track and the spur track causes vehicles to move along the spur track by contacting a portion of the vehicle as it is moving along the main track.

Description

United States Patent [191 Reiche [451 Nov. 13, 1973 TOW TRUCK SYSTEM Inventor: Hans Joachim Reiche, Hummelweg,

Germany Assignee: Fromme, Foerderanlagen wetzrer oeraiasy Filed: Oct. 5, 1971 App]. No.: 186,636

U.S. Cl 104/172 BT, 104/172 S Int. Cl. B65g 17/20, 865g 17/38 Field of Search 104/172 BT, 172 R,

References Cited UNITED STATES PATENTS Burrows 104/172 BT 2,949,862 8/1960 Klamp l04/l72 BT Primary Examiner-Drayton E. Hoffman Attorney-Seidel, Gonda & Goldhammer [57] ABSTRACT The intersection between the main track along which vehicles are pushed and a non-powered spur track is controlled by a switch device. An endless drive associated partially with the main track and the spur track causes vehicles to r nove along the spur traek By contacting a portion of the vehicle as it is moving along the main track.

11 Claims, 6 Drawing Figures PATENIEDNUV 13 I975 SHEET 10F 2 60 can 11/7 Ill/1"! Fig. 3

TOW TRUCK SYSTEM This invention is directed to a tow vehicle system having a main track portion wherein vehicles are driven by some type of conveyor means. Associated with the main track at spaced points therealong, there are provided non-powered spur tracks. The movement of the conveyed vehicle along the main track is utilized to move the transferred or diverted vehicles for movement along the spur track.

It is known in systems proposed heretofore to have a spur track provided with an endless drive chain meshed with the main conveyor chain. The continuous pushing of the main spur conveyor by the main conveyor is an unnecessary strain on the latter. In addition, the continuous driving of the spur conveyor is unnecessary unless vehicles are disposed along the spur line.

In accordance with the present invention, the conveyor which extends along the spur track and partially along the main track is non-powered. Means are provided for intermittently moving the non-powered spur conveyor. Such means includes arms at spaced points along the spur conveyor which extend it to a position wherein they may be driven by a portion of a tow vehicle such as the tow pin. The spur conveyor extends along the main track for a length which is at least as long as the vehicles moving along the main track. The spur conveyor has arms thereon in pairs with the distance between the pairs of arms being at least one vehicle length.

It is an object of the present invention to provide a novel tow truck system wherein a non-powered spur intermittently utilizes the power of a main conveyor by contact with a portion of vehicles moving along the main conveyor immediately preceeding the intersection of the main track and the spur track.

For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIG. 1 is a partial plan view of a system in accordance with the present invention and illustrates the intersection of a spur track and a main track.

FIG. 2 is a section of the main drive conveyor and the non-powered spur conveyor where they overlap.

FIG. 3 is an elevation view of several lengths of the main drive conveyor of FIG. 2 with a tow pin on a vehicle pushing an arm on the spur conveyor.

FIG. 4 is a partial plan view of a second embodiment of a system constructed in accordance with the present invention.

FIG. 5 is a sectional view of the embodiment of the invention illustrated in FIG. 4.

FIG. 6 is a plan view of the device illustrated in FIG.

Referring to the drawing in detail, wherein like numerals indicate like elements, there is shown in FIG. 1 a portion of a tow truck system in accordance with the present invention. The intersection of the main conveyor track 1 and the spur track 3 is controlled by a switch 2. For purposes of description, the system of the present invention is mounted in a floor flush with the upper surface of floor 4.

A spur conveyor chain of the non-power type extends partially along the spur track 3 and extends partially along the main track 1. In FIG. 1, the vehicles 10 are moving from left to right under the influence of the main conveyor 5.

The spur conveyor 6 extends around

sheaves

7 and 8. Sheave 7 is sufficiently far in advance of the switch 2 so as to extend for a distance which is in excess of the length of the vehicles 10. The conveyor 6 is provided at spaced points therealong with sets of arms 9. The sets of arms 9 include a first arm 9a and a second arm 9b which are linearly spaced from one another along the conveyor 6 by a gap. The gap between the

arms

9a and 9b is sufficient so that the tow pin 1011 on the vehicles will engage the arm 9a without contacting arm 9b. Thereafter, as arm 9b comes around the sheave 7, it will be positioned behind the tow pin 10a by a distance of approximately 6 inches.

The vehicle 10 has a tow pin 10a which depends downwardly and extends through a main slot so that the lower end of the tow pin is engaged by a face 5a on the main conveyor 5.

When a tow pin 10a engages the arm 9a, it drives the spur conveyor 6 over a distance corresponding approximately to about twice the length of the vehicles 10. When a vehicle 10 appropriately trips the switch 2, or the switch 2 is activated in any conventional manner, the vehicle will then be transferred from the main track to the spur track 3. At this transfer point, the vehicle 10 will coast into the spur track 3 and then stop since the spur track 3 is non-powered. The next vehicle which comes along the main track 1 will engage an arm 9a and move the spur conveyor 6 for a short distance corresponding approximately to twice the length of a vehicle. This will cause the transferred or diverted vehicle to move further on down the spur track 3. Movement of the vehicles along spur track 3 is accomplished by contact between arm 9b on the spur conveyor 6 and the tow pin on the vehicle 10. Eventually the vehicles along the spur track 3 will lose contact with the conveyor 6 as the vehicles move beyond the guide sheave 8 and continue along the spur track 3 for any desired operation such as storage, loading, unloading, etc.

Thus, it will be seen that the spur conveyor 6 is intermittently driven by contact with a portion of vehicles moving along the main track. In this manner, continuous driving and power necessary for such continuous driving of the spur conveyor is eliminated. Also, contact between a power driven vehicle moving along the main track 1 and the rear end of the diverted vehicle is avoided.

A second embodiment of the invention is illustrated in FIGS, 4, 5 and 6. As seen in those Figures, the second embodiment comprises an overhead conveyor system utilizing an overhead conveyor for driving the trucks.

At the spur, an endless chain 21 which functions as a loop coupling member is mounted for rotation about

sheaves

22 and 23. The chain runs adjacent the shunt conveyor track portion 20. The endless chain 21 is provided with a plurality of outwardly directed dogs 24 which engage guiding rollers 25b which are supported by the trucks 25. Each truck 25 supports one set of guiding rollers at each end.

As seen in FIG. 5, a drive conveyor 26 having a depending member 27 is operative to engage the portion of the member supporting the guiding rollers 25b to move truck 25 into the switching zone. As seen in FIG. 5, the guiding

rollers

25b and 25b are provided with upwardly and downwardly directed engaging members. The upwardly directed engaging member is for engagement with members 27 on the drive conveyor. The downwardly directed member is engaged by dogs 24 in the area adjacent chain 21.

The

dogs

24,, 24 24 24 are shown in detail in FIG. 6. Each of the engagement dogs 24 comprises a generally flat plate pivotally mounted on endless chain 21 for rotation in a horizontal plane. The extent of its rotation is limited by an arcuate slot formed therein. A heavy duty spring 24a biases the dog so that it normally overlies the conveyor track 20. It is constrained from further rotation by virtue of a raised pin which projects a short distance through the other end of the slot.

Normally, the dogs 24 are in the position illustrated. However, if subjected to a heavy load such as when the track is jammed, the plate rotates out of the path of the conveyor section against the force of spring 24a.

The spacing between adjacent dogs is at least the length of one of the trucks 25. The total number of dogs is such that when one of the dogs is engaged by an arriving truck 25b moving into truck portion 20, another dog, such as dog 24 is in a position where it may move into the position of the first dog 24,. This occurs before the chain 21 comes to rest.

As the trucks 25 are moved by conveyor 21 they push the trucks in advance such as truck 25b This may continue until the entire spur is filled with trucks or until the trucks being pushed are engaged by another drive conveyor.

As with either of the embodiments of the invention described, trucks which are delivered into the secondary track portion 20 stand closely behind each other.

Where a power conveyor is provided both before and after the shunt track portion 20, the power conveyor may comprise two different types of driving systems. One such system comprises circulating chains. In another system only one chain is used, but this chain passes out of engagement with a truck after it reaches the shunt track portion 20, and then re-engages that truck to draw it away from the opposite end of the shunt track portion 20.

While the invention has been described with reference to a number of embodiments thereofit is apparent many other forms and embodiments will be obvious to those skilled in the art in view of the foregoing description. Thus, the scope of the invention should not be limited by the foregoing description but rather only by the scope of the claims appended hereto.

I claim:

1. A tow truck system comprising a main track having a powen driven conveyor for moving vehicles therealong, a spur intersecting said main track and along which vehicles may be diverted from the main track, an intermittently driven spur conveyor, said spur conveyor having a portion extending along the main track and a portion extending along the spur, said spur conveyor having arms extending outwardly therefrom for contact with vehicles to effect intermittent movement of the spur conveyor as the vehicles are driven by said power conveyor along that portion of the main track which overlaps said first portion of the spur conveyor.

2. A system in accordance with claim 1 including a switch controlling the intersection between said main track and said spur, said first portion of said spur conveyor extending from said intersection for a distance of approximately twice the length of vehicles adapted to move along said main conveyor.

3. A system in accordance with claim 1 wherein said spur conveyor is provided with sets of arms linearly spaced from one another at spaced points along the length of said spur conveyor.

4. A system in accordance with claim 3 wherein the distance between the sets of arms on said spur conveyor is approximately one half the length of said first portion of the spur conveyor.

5. A tow truck system comprising a main track having a power driven conveyor for moving vehicles the realong, a spur intersecting main track and along which vehicles may be diverted from the main track, an intermittently driven spur conveyor, said spur conveyor having a portion extending along the main track and a portion extending along the spur, said spur conveyor having arms extending outwardly therefrom for contact with vehicles to effect intermittent movement of the spur conveyor as the vehicles are driven by said power conveyor along that portion of the main track which overlaps said first portion of the spur conveyor, and said arms on said conveyor first portion extend into said main track at an elevation about the elevation of the main track power conveyor for contact with tow pins on vehicles moving the main track.

6. A tow truck system comprising a main track having a power driven conveyor for moving vehicles therealong, a spur intersecting said main track along which vehicles may be diverted from the main track, a switch controlling said intersection between the spur and the main track, a spur conveyor having the first portion extending along the main track upstream from the switch and a second portion extending along said spur, said spur conveyor being an endless chain, said spur conveyor having arms extending horizontally therefrom at spaced points therealong, the arms on said first portion of said spur conveyor extending into the main track at an elevation below floor level and above the elevation of said power driven conveyor for contact with tow pins on vehicles moving along the main track, whereby vehicles moving along the main track and the overlapping portion of said spur conveyor will cause said arms to intermittently move said spur conveyor.

7. A system in accordance with claim 6 wherein said first portion of said spur conveyor extends upstream along said main track for a distance corresponding to a length greater than the length of one vehicle moving along the main track.

8. A tow truck system comprising a main track having a power driven conveyor for moving vehicles therealong, a spur intersecting said main track, an intermittently driven spur conveyor, said spur conveyor being disposed adjacent said spur, a plurality of outwardly directed members supportedby said spur conveyor for contact with vehicles to effect intermittent movement of the spur conveyors as the vehicles are driven by said power conveyor into said spur.

9. A system in accordance with claim 8 wherein said outwardly directed members are held outwardly by yieldable means.

10. A system in accordance with claim 9 wherein the distance between adjacent outwardly directed members is at least the same as the length of one of said vehicles.

11. A system in accordance with claim 8 wherein drive means for said vehicles is provided in said spur,

said drive means being spaced from said spur conveyor.

Claims

5. A tow truck system comprising a main track having a power driven conveyor for moving vehicles therealong, a spur intersecting main track and along which vehicles may be diverted from the main track, an intermittently driven spur conveyor, said spur conveyor having a portion extending along the main track and a portion extending along the spur, said spur conveyor having arms extending outwardly therefrom for contact with vehicles to effect intermittent movement of the spur conveyor as the vehicles are driven by said power conveyor along that portion of the main tRack which overlaps said first portion of the spur conveyor, and said arms on said conveyor first portion extend into said main track at an elevation about the elevation of the main track power conveyor for contact with tow pins on vehicles moving the main track.

8. A tow truck system comprising a main track having a power driven conveyor for moving vehicles therealong, a spur intersecting said main track, an intermittently driven spur conveyor, said spur conveyor being disposed adjacent said spur, a plurality of outwardly directed members supported by said spur conveyor for contact with vehicles to effect intermittent movement of the spur conveyors as the vehicles are driven by said power conveyor into said spur.

11. A system in accordance with claim 8 wherein drive means for said vehicles is provided in said spur, said drive means being spaced from said spur conveyor.