US3882793A

US3882793A - Tow conveyor

Info

Publication number: US3882793A
Application number: US378005A
Authority: US
Inventors: Takao Wakabayashi
Original assignee: Nakanishi Metal Works Co Ltd
Current assignee: Nakanishi Metal Works Co Ltd
Priority date: 1972-07-10
Filing date: 1973-07-10
Publication date: 1975-05-13
Anticipated expiration: 1992-05-13
Also published as: DE2334978C3; JPS5551803B2; JPS4926980A; FR2192019B3; FR2192019A1; DE2334978B2; DE2334978A1

Abstract

A tow conveyor includes at least one carrier. Connected to the front and rear of the carrier are rod members extending forwardly downward and rearwardly downward respectively and pivotally movable in horizontal and vertical directions. Running assemblies free to move on guide rails are connected to the lower ends of the rod members respectively so as to be pivotally movable in horizontal and vertical directions. The front running assembly has an engaging dog projecting downward and the rear running assembly has a horizontal tilting plate. A trolley driven on endless rails has pivoted thereto a pusher engageable with the engaging dog and tilting dogs to be pivotally forced down by the tilting plate on the rear running assembly of a preceding carrier to thereby tilt the pusher through a link when the carrier approaches the preceding carrier.

Description

United States Patent 1 Wakabayashi [30] Foreign Application Priority Data July 10, 1972 Japan 47-69295 [52] U.S. Cl 104/170; 104/172 B; 104/172 5 [51] Int. Cl B61b 13/00 [58] Field of Search 104/172 B, 172 C, 172 BT, 104/172 S, 170,148 LM [56] References Cited UNITED STATES PATENTS 3,099,228 7/1963 Lingg 104/172 S 3,518,946 7/1970 Kavieff 104/172 B 3,548,751 12/1970 lzhelya et a1 104/148 LM [451 May 13, 1975 Primary Examiner-Evon C. Blunk Assistant ExaminerRobert Saifer Attorney, Agent, or FirmArmstrong, Nikaido & Wegner [57] ABSTRACT A tow conveyor includes at least one carrier. Connected to the front and rear of the carrier are rod members extending forwardly downward and rearwardly downward respectively and pivotally movable in horizontal and vertical directions. Running assemblies free to move on guide rails are connected to the lower ends of the rod members respectively so as to be pivotally movable in horizontal and vertical directions. The from running assembly has an engaging dog projecting downward and the rear running assembly has a horizontal tilting plate. A trolley driven on endless rails has pivoted thereto a pusher engageable with the engaging dog and tilting dogs to be pivotally forced down by the tilting plate on the rear running assembly of a preceding carrier to thereby tilt the pusher through a link when the carrier approaches the preceding carrier.

6 Claims, 20 Drawing Figures PATENIEDHAY13I975 3.882.793

SHEEI 2 OF 7 FIGJ.

PATENTED HAY I 3 I975 SHEET 3 OF 7 Q'j Bl-IIIIIII-IIIIII PATENTED MAY 1 3 I975 SHEET 1 SF 7 FIG.

PATENTED MAY 1 3:975 3. 882 793 saw 5 or 7 FIG. 11

7 All W 1.111 M M 78 I \ilil 7 aim I m H All!! I 1-H 1? ml P. W

TOW CONVEYOR BACKGROUND AND SUMMARY This inventionrelates to a tow conveyor, more particularly to a c'onve'yor'having a mechanism for effecting engagemeiitand disengagement between a carrier and a propelling pusher.

I Conventional "tow conveyors include those adapted to turn within a vertical plane and those turnable within a horizontal plane. The former are usable only for rectilinear transport, while the latter are somewhat adapted for three-dimensional transport but are not fully operable along a bent or flexed track unlike a trolley conveyor. The tow conveyor of this invention assures satisfactorythree-dimensional transport as achieved by the trolley conveyor. Further with the present conveyor, a required number of carriers can be accumulated as desired not only at a straight portion of the conveyor line but also at curved portions included in horizontal and vertical planes. When the carrier is moved by a pusher from an accumulated position, the engagement of the pusher with the carrier is always assured even if a trolley equipped with the pusher is driven at a high speed. Although the carrier of this conveyor has movable engaging and disengaging means for the above-mentioned accumulation, the means can be fixed to the carrier to render the carrier usable also as a hand-operated vehicle.

The invention will be described below in detail with reference to the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing an embodiment of the conveyor according to this invention and having a conveyor line of the circulating type constructed in a horizontal plane;

FIG. 2 is a side elevation of the conveyor of FIG. 1 with part of rails broken away;

FIG. 3 is an enlarged view in section taken along the line III-III in FIG. 2;

FIG. 4 is an enlarged side elevation showing a front running assembly having an engaging dog;

FIG. 5 is a view in section taken along the line VV in FIG. 4;

FIG. 6 is an enlarged side elevation showing a rear running assembly having a tilting plate;

FIG. 7 is a view in section taken along the line VII- VII in FIG. 6;

FIG. 8 is an enlarged plan view showing a trolley having a pusher and dogs for tilting the pusher;

FIG. 9 is side elevation of the trolley of FIG. 8;

FIGS. 10 to 13 are schematic side elevations showing accumulation of carriers in sequential order;

FIGS. 14. and are side elevations of the conveyor of this invention at ascending and descending portions of the conveyor line;

FIG..16 is a plan view showing a loop of endless conveyorlineand straight conveyor lines branching off the loop for guiding the carriers into or out from the loop; FIG. 17 is a side elevation in section showing a device for fixingthe rod member of the carrier;

. FIG. 18 is a view in section taken along the line XVIII XVIII in FIG. 17;

FIG. 19 is a view in section showing a modified device for fixing the rod member of the carrier and corresponding to FIG. 18; and

FIG. 20 is a view taken along the line XX-XX in FIG. 19.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS With reference to FIGS. 1 to 9 and FIG. 17, a loop of endless belt conveyor line 1 comprises first, second and

third rails

2, 3 and 4. Each pair of the first and

second rails

2 and 3 is composed ofa pair of steel members laterally U-shaped in section. The second rails 3 are placed on the first rails 2, and the

rails

3 and 2 are supported on a number of support members 6 spaced apart by a specified distance on the floor 5 and are positioned above the floor 5 in proximity thereto. The third rails 4 are made of a pair of U-shaped steel members which are disposed on the floor 5 at the opposite sides of the first and

second rails

2 and 3.

A carrier 7 is in the form of a framein its entirety and has front and rear elevated flat portions 8. The carrier 7 includes front and rear transverse beams 9 provided close to their opposite ends with horizontally rollable wheels 26 in contact with the third rails 4. The carrier 7 is therefore guided by the third rails 4. Fixed to the outer face of each transverse beam 9 at the midportion of its length is a laterally U-shaped connecting member 25 to which is connected by a pin 11 a cylindrical portion 10a formed at one end of a short upper connector 10, the connector being horizontally pivotable. A plate portion 1012 at the outer end of the connector 10 is loosely fitted in, and connected by a pin 13 to, a bifurcated end 12a of an elongated rod member 12 which is also bifurcated at the other end 1212. Thus the rod member 12 is pivotally movable in vertical directions (see FIG. 17). Connected respectively to the lower ends of the rod members 12 are front and

rear running assemblies

14 and 15 guided by the second rails 3. Each of the running

assemblies

14 and 15 includes an inverted U-shaped body 16, front and rear pairs of verti cal rollers 17 disposed at the left and right sidesof the body 16 in rolling contact with the lower faces of the second rails 3, a pair of front and rear horizontal rollers 18 disposed on the upper surface of the body 16, an upper plate 19 having a horizontal edge 19a projecting toward the carrier and a pin 20 extending vertically through the upper plate 19 and fixed thereto, with one of the horizontal rollers 18 mounted on the downwardly projecting portion of the pin 20. A cylindrical portion 21a formed at one end of a short lower connector 21 is mounted on the pin 20 in a horizontally pivotable manner. A plate portion 21b at the other end of the connector 21 is loosely fitted in, and connected by a pin 22 to, the lower bifurcated end 12b of the rod member 12. Accordingly, the running

assemblies

14 and 15 are pivotally movable in vertical directions. Fixedly fitted in the front end of the body 16 of the front running assembly 14 is part of an engaging dog 23 which is T-shaped as seen from the front. The dog 23 has a lower end which coincides with the under faces of the second rails 3 and a rear slanting portion 23a. Extending over the lower end of the body 16 of the rear running assembly 15 is a horizontal tilting plate 24, part of which is fitted in and fixed to the lower end. The under end face of the plate 24 is positioned substantially at the same level as the under faces of the second rails 3. Slanting portions 24a are formed at the front and rear ends of the tilting plate 24 respectively.

An endless chain 27 is reeved around a drive sprocket wheel to be driven by an unillustrated motor and a driven sprocket wheel and is coextensive with the conveyor line 1.

A trolley 28 comprises a body 32 made of a pair of side plates secured to an upright member 30 fixed at left and right to the upper surface of a link of the chain 27 and spaced apart by a specified distance with a spacer 31 extending between the upper ends of the side plates approximately at the middle of their length, trolley rollers 33 disposed at the opposite sides of the body 32 in rolling contact with the lower faces of the first rails 2, a pusher 35 tiltably supported on a pivot 34 at an upper rear end portion of the body 32, two pusher tilting dogs 36 tiltably mounted on a pivot 38 at a midportion of front end of the body 32 with a spacer 37 interposed therebetween, two links 39 connecting the two dogs 36 to the pusher 35 and a reverse travel preventing dog 41 interposed between the two dogs 36 and tiltably supported thereon by a pivot 40. Normally, the pusher 35, pusher tilting dogs 36 and reverse travel preventing dog 41 remain in upright position by virtue of the weight of portions thereof lower than the

pivots

34, 38 and 40, with their upper ends projecting between the second rails 3. The pusher 35 and dogs 36 are provided, at inner faces of their lower ends, with

stoppers

44 and 45. The front ends of the links 39 are connected to the pusher tilting dogs 36 by a pin 42 positioned above the pivot 38. The rear ends 39b of the links 39 are pivotally connected to the pusher 35 by a pin 43 positioned at a lower level than the pivot 34. The space between the two parallel pusher tilting dogs 36 is greater than the width of the engaging dog 23 but smaller than the width of the tilting plate 24.

As shown in FIG. 2, the carrier 7 is driven leftward in the drawing along with the drive chain 27 by engagement of the pusher 35 of the trolley 28 with the engaging dog 23 of the running assembly 14 connected to the rod member 12. Although not shown, a number of carriers follow the carrier 7 at specified spacing that is determined by the spacing of the trolleys 28 on the chain 27, therefore by the spacing of the pusher 35.

A number of carriers travelling in a continuous fashion will be accumulated at a specified position in the manner described below with reference to FIGS. to 13. A first carrier 7A (FIG. 10) is travelling with a trolley 28 by virtue of engagement with the pusher 35 as described above. A stopper (not shown) which is adapted to project into and retract from the path of travel of the upper portions of the pusher tilting dogs 36 on the trolley 28 projects into the path, upon contact with which the dogs 26 incline backward. This movement is transmitted through the links 39 to the pusher 35, which is therefore inclined forward and disengaged from the engaging dog 23. Consequently, the first carrier 7A is brought out of connection with the travelling trolley 28 and stopped. By the term first carrier herein referred to is meant the first of a number of the travelling carriers to be stopped. When the first carrier 7A is brought to a halt in this way, the second and following carriers are still travelling along with the drive chain 27. As the second carrier 7B approaches the first carrier 7A which has already been stopped, the pusher tilting dogs 36 of the trolley 28 connected to the second carrier 78 come into contact with the tilting plate 24 of the rear running assembly of the first carrier 7A (see FIG. 11). As the trolley 28 further advances, the dogs 36 are inclined by the tilting plate 24 in its stopped position, with the result that the pusher 35 is also inclined as described above and disengaged from the engaging dog 23. Thus the second carrier 7B is also brought to a halt (see FIG. 12). The dogs 36, reverse travel preventing dog 41 and pusher 35 pass under the tilting plate 24 in inclined state, whereupon they are brought to the original upright position by gravity (FIG. 13). When the

dogs

36, 41 and pusher 35 reach the position of the engaging dog 23 of the front running assembly 14 of the first carrier 7A, the stopper positioned in front of the engaging dog 23 inclines the

dogs

36, 41 first and then pusher 35, permitting the same to pass under the engaging dog 23 free of trouble. The drive chain 27 continues to travel, and the third and following carriers are brought to a halt in like manner in succession, each adjacent the preceding one.

To travel the group of stopped carriers, the stopper halting the first carrier 7A is removed from the path of travel of the tilting dogs 36. This permits a pusher 35 advancing from behind the carrier on the travelling chain 27 to come into engagement with the engaging dog 23 of the front running assembly 24. Thus the first carrier 7A starts to advance along with the drive chain 27. By virtue of advance of the first carrier 7A, the rear running assembly 15 of the first carrier 7A positioned in proximity to the front running assembly 14 of the second carrier 78 moves away, permitting a following pusher 35 to remain upright and come into engagement with the engaging dog 23 of the second carrier 78. This advances the carrier 78. Similarly, the stopped carriers are initiated into forward travel in succession at an interval corresponding to the distance between the pushers 35.

According to the construction described, it is impor tant to provide two parallel pusher tilting dogs 36 which are spaced apart by a distance greater than the width of the engaging dog 23 but smaller than the width of the tilting plate 24. If only one dog 36 is provided in opposing relation to the pusher 35, the dog 36 which approaches the engaging dog 23 earlier than the pusher 35 and strikes the dog 23 first would be inclined when the carrier 7 is moved from the stopped position as described above, consequently tilting the pusher 23 through the movement of the links 39. Since the dog 36 is designed to stand up upon passing under the engaging dog 23, the pusher will also stand up but if the chain is driven at a high speed, the pusher 35 will pass under the dog 23 before the pusher 35 returns to a level where it is engageable with the dog 23. It would them be impossible to connect the carrier 7 to the trolley 28 and the carrier 7 would remain stopped against travel. Since such pivotal movement of the pusher 35 is effectd by the similar movement of the tilting dog 36, the dog 36 need only be prevented from tilting in such case. According to this invention, therefore, the two dogs 36 are adapted to move past the engaging dog 23 at its opposite sides, free of contact therewith (see FIG. 5).

It is noted that the front running assembly 14 having the engaging dog 23 is pivotally movable in horizontal and vertical directions with respect to the rod member 12, which in turn is pivotable in horizontal and vertical directions with respect to the carrier 7. Accordingly, throughout the horizontal portion of the loop of endless conveyor line 1 part of which is shown in FIG. 1, ascending portion 1a (see FIG. 14) and descending portion lb included in the line 1, the carrier 7 can be travelled three-dimensionally by the movement of the chain 27 which is flexible three-dimensionally, without permitting the disengagement of the pusher 35 from the engaging dog 23. Further inasmuch as the rear running assembly having the tilting plate 24 is connected to the carrier 7 in the same manner as the front running assembly 14, both the running

assemblies

14 and 15 can be brought close to each other even in curved portions in horizontal and vertical planes to assure accumulation.

Occasionally, it will be desired to remove the carrier 7 from the loop of the endless conveyor line 1 or, conversely, to place the carrier 7 onto the line 1 or to use the removed carrier in the same manner as a handoperated vehicle. This invention can fulfil such need. Referring to FIGS. 16 to 18, the loop of endless conveyor line 1 is provided, along extensions from the opposing straight line portions, with a straight conveyor line 46 for removing the carrier and a straight conveyor line 47 for guiding the carrier onto the loop. The straight conveyor line 46 for removal includes a pair of front and rear pits 48 each of which accommodates a rod fixing device 49.

Carrier stoppers

50 and 51 are disposed to the rear of the points where the

straight conveyor lines

46 and 47 branch off the endless conveyor line 1, with respect to the direction of advance of the vehicles. It is not necessarily needed for the

conveyor lines

1, 46 and 47 to be equipped with the third rails 4 for guiding the carriers 7 but the carriers per se may be travelled directly on the surface of the floor 5. Since the carriers 7 are driven manually on the

straight conveyor lines

46 and 47, these lines need not be equipped with the drive chain 27. Accordingly, the

conveyor lines

46 and 47 do not have the first rails 2 for guiding the trolleys 28 suspending the chain 27. On the

conveyor lines

46 and 47, the second rails 3, L-shaped in cross section, are positioned below the surface of the floor 5, namely below the third rails 4. At the position of the pits 48, the rails 3 include segments 3a having a length capable of supporting the running

assemblies

14 and 15. If it is desired to transfer a carrier 7 onto the straight conveyor 46, following carriers are stopped by the stopper 50 in the foregoing manner, and the carrier 7 is manually transferred onto the conveyor line 46. If it is desired to place an additional carrier 7 onto the conveyor line 1, an advancing carrier and following carriers on the line 1 are stopped by the stopper 51 and the additional carrier 7 is placed onto conveyor line 1 to precede the stopped carriers.

Under each of the front and rear flat portions 8 of the carrier 7 at a midportion of width thereof, there is a space 63 for accommodating the rod member, at one side ofwhich there is fixedly provided a short holder 50 in the form ofa square tube. A square rod-like support member 51 having a downward projection 51a at its one end is slidingly inserted into the holder 50 in a transverse direction.

The rod member fixing device 49 comprises a stationary plate 53 secured to the upper end of a support frame 52, a hydraulic cylinder 54 extending vertically from the under face of the stationary plate 53 and fixed thereto, a lift table 57 supported on the upper end of piston rod 55 of the hydraulic cylinder which extends upward through the stationary plate 53 and having guide rods 56 extending downward through the stationary plate 53 at opposite sides of the rod 55, a horizontal hydraulic cylinder 59 fixed to a support 58 supporting the segments 3a and secured to the upper face of the lift table 57 and a support member engaging member 62 fixed to the end of the piston rod 60 of the hydraulic cylinder 59 and having a recess 61. Although FIGS. 17 to 19 show the device for the rear running assembly 15 only, the device for the front running assembly 14 also operates exactly in the same manner as will be described below. When a carrier 7 is placed onto the straight conveyor line 46 for removal with the running assembly 15 positioned on the segments 3a, the hydraulic cylinder 54 is actuated to project its piston rod and to thereby elevate the lift table 57 as indicated in the chain line, permitting the rod member 12 to pivotally move about the pin 13. When the distal end of the rod member reaches the space 63 in the carrier 7, the hydraulic cylinder 54 is brought out of operation to stop the lift table 57. While the hydraulic cylinder 54 is in operation, another hydraulic cylinder 59 is also operated to project its piston rod 60. Thus while being elevated along with the lift table 57, the engaging member 62 is moved leftward in FIG. 18 to the extremity of its horizontal and vertical movement, where the recess 61 comes into engagement with the downward projection 51a of the support member 51 in its pulled-out position. Subsequently, the piston rod is retracted to move the support member 51 rightward along with the engaging member 62 as indicated in a chain line, whereby the support member 51 is positioned beneath the rod member 12. The piston rod 55 is thereafter retracted to lower the lift table 57. At this time, the rail segments 3a separate from the running assembly to descend with the lift table 57. Consequently, the rod member 12 is received by the support member 51 and is held to the carrier 7 and will not cause any trouble, so that the carrier can be used as a hand-operated vehicle. To return the rod member 12 and the running assembly to the original state, the foregoing procedure is followed in the reverse manner.

FIGS. 19 and 20 show a modified device for fixing the rod member. According to this modification, the running assembly is supported, instead of receiving the rod member by the support member. Fixed to the flat portion 8 of the carrier 7 on the under face of its rear end are two U-shaped holders spaced apart by a distance slightly greater than the width of the running assembly 15. A plate-like support member 71, transversely received in the holders 70 in slidable manner, has downward projections 71a at its opposite ends and a cutout 71b formed in its rear portion toward one end thereof and corresponding to the horizontal projecting edge 19a of upper plate 19 of the running assembly 15.

A horizontal hydraulic cylinder 73 having a piston rod 72 extending therethrough is fixedly mounted on the lift table 57. The piston rod 72 carries at its opposite ends vertical horn-like engaging members 74 the inner faces of which are spaced apart by a distance coinciding with the length of the support member 71. P0- sitioned slightly under the upper ends of the engaging members 74 is a support rod 76 for a rail segment 75 made of a U-shaped steel member, the support rod 76 being parallel to the piston rod 72 and secured in position.

To fix the rod member 12 to the carrier 7, the lift table 57 is raised. At this time, the piston rod 72 and the support member 71 are positioned toward the right as indicated in solid line in the drawings. When the lift table 57 is raised, the horizontal projecting edge 19a of the running assembly 15 passes through the cutout 71b in the support member 71 and is positioned thereabove, and the engaging members 74 engage the outer side faces of the downward projections 71a of the support member 71. In this state the hydraulic cylinder 73 is operated to force the piston rod 72 leftward, shifting the support member 71 leftward as indicated in the chain lines in the drawings and thereby displacing the cutout 71b from the position of the horizontal projecting edge 19a. When the lift table 57 is lowered along with the rail segment 75, the support member 71 receives the horizontal edge 19a, whereby the rod member 12 is held to the carrier 7.

What is claimed is:

l. A tow conveyor comprising the combination of at least one carrier, first rails disposed close to the floor, second rails disposed on the first rails in parallel thereto, an engaging means connected to the carrier pivotally movable in the horizontal and vertical directions and having rollers in rolling contact with the second rails, at least one trolley including rollers in rolling contact with the first rails, a drive means connected to the trolley to move the trolley along the first rails, and a pusher mounted on the trolley for engagement with the engaging means and projecting upward from the first rails to connect the carrier to the trolley and to thereby move the carrier along with the trolley, wherein the engaging means is positioned in front of the carrier and a disengaging means is provided in the rear of the carrier, the disengaging means being connected to the carrier pivotally movable in the horizontal and vertical directions and having rollers in rolling contact with the second rails, the trolley further including a pusher tilting dog mounted thereon in from of a pusher and projection upward from the first rails to disengage the pusher from the engaging means by being pivotally forced down by the disengaging means of a preceding carrier and to thereby separate the carrier from the trolley, and, wherein the pusher tilting dog and the pusher are tiltably supported by pivots on the trolley and normally remain upright by virtue of the weight of their portions below the pivots, the trolley including a link having a front end pivoted to the pusher tilting dog at a position above its pivot and a rear end pivoted to the pusher at a position below its pivot.

2. A tow conveyor comprising the combination of at least one carrier, first rails disposed close to the floor, second rails disposed on the first rails in parallel thereto, an engaging means connected to the carrier pivotally movable in the horizontal and vertical directions and having rollers in rolling contact with the second rails, at least one trolley including rollers in rolling contact with the first rails a drive means connected to the trolley to move the trolley along the first rails, and a pusher mounted on the trolley for engagement with the engaging means and projecting upward from the first rails to connect the carrier to the trolley and to thereby move the carrier along with the trolley, wherein the engaging means is positioned in front of the carrier and a disengaging means is provided in the rear of the carrier, the disengaging means being connected to the carrier pivotally movable in the horizontal and vertical direction and having rollers in rolling contact with the second rolls, the trolley further including a pusher tilting dog mounted thereon in fron of a pusher and projecting upward from the first rails to disengage the pusher from the engaging means by being pivotally forced down by the disengaging means of a preceding carrier and to thereby separate the carrier from the trolley, wherein the trolley has two parallel pusher tilting dogs spaced apart by a distance greater than the width of an engaging dog disposed at the lower end of the engaging means and smaller than the width of a tilting plate disposed at the lower end of the disengaging means.

3. The tow conveyor as set forth in claim 2 wherein a reverse travel preventing dog is interposed between the two pusher tilting dogs and is tiltably supported by a pivot and normally remains upright by virtue of weight of its portion below the pivot.

4. A tow conveyor comprising the combination of at least one carrier, first rails disposed close to the floor, second rails disposed on the first rails in parallel thereto, an engaging means connected to the carrier pivotally movable in the horizontal and vertical directions and having rollers in rolling contact with the second rails, at least one trolley including rollers in rolling contact with the first rails, a drive means connected to the trolley to move the trolley along the first rails, and a pusher mounted on the trolley for engagement with the engaging means and projecting upward from the first rails to connect the carrier to the trolley and to thereby move the carrier along with the trolley, wherein the engaging means is positioned in front of the carrier and a disengaging means is provided in the rear of the carrier, the disengaging means being connected to the carrier pivotally movable in the horizontal and vertical directions and having rollers in rolling contact with the second rails, the trolley further including a pusher tilting dog mounted thereon in front of a pusher and projecting upward from the first rails to disengage the pusher from the engaging means by being pivotally forced down by the disengaging means of a preceding carrier and to thereby separate the carrier from the trolley, and which includes a fixing means for holding the engaging means and the disengaging means to the under face of the carrier, respectively.

5. The tow conveyor as set forth in claim 4 wherein the fixing means comprises a support member for supporting a rod member connecting a running assembly to the carrier pivotally movably in vertical directions and a holder secured to the under face of the carrier to hold the support member slidably.

6. The tow conveyor as set forth in claim 5 further comprising a loop of endless conveyor line including the first rails and the second rails, a straight conveyor line branching off the endless conveyor line and including the second rails, and a lift table supporting a rail segment and an engaging member for operating the support member, the rail segment forming part of the second rails in the straight conveyor line and having a length corresponding at least to the length of the running assembly.

Claims

1. A tow conveyor comprising the combination of at least one carrier, first rails disposed close to the floor, second rails disposed on the first rails in parallel thereto, an engaging means connected to the carrier pivotally movable in the horizontal and vertical directions and having rollers in rolling contact with the second rails, at least one trolley including rollers in rolling contact with the first rails, a drive means connected to the trolley to move the trolley along the first rails, and a pusher mounted on the trolley for engagement with the engaging means and projecting upward from the first rails to connect the carrier to the trolley and to thereby move the carrier along with the trolley, wherein the engaging means is positioned in front of the carrier and a disengaging means is provided in the rear of the carrier, the disengaging means being connected to the carrier pivotally movable in the horizontal and vertical directions and having rollers in rolling contact with the second rails, the trolley further including a pusher tilting dog mounted thereon in from of a pusher and projection upward from the first rails to disengage the pusher from the engaging means by being pivotally forced down by the disengaging means of a preceding carrier and to thereby separate the carrier from the trolley, and, wherein the pusher tilting dog and the pusher are tiltably supported by pivots on the trolley and normally remain upright by virtue of the weight of their portions below the pivots, the trolley including a link having a front end pivoted to the pusher tilting dog at a position above its pivot and a rear end pivoted to the pusher at a position below its pivot.