Conveyor System

Abstract

A conveyor system including a first load supporting track and a second load supporting track with an intermediate transfer portion. A powered conveyor is provided in association with each of the first and second tracks. A plurality of carriers are provided. Each of the carriers has a first dog that is in position for normal engagement with the pusher member of the conveyor and a second dog that is normally urged to an operative carrier pushing position but is held by the track out of operative position. At a transfer point a portion of the track is cut away for a distance sufficient to permit the second dog to move to operative carrier transferring position. Beyond the transfer point, a portion of the track is again cut away to permit the second dog to be cammed downwardly out of operative position.

Description

This invention relates to conveyor systems and particularly to power and free conveyor systems.

In power and free conveyor systems wherein carriers are moved along predetermined paths by engagement with conveyors, it is often necessary to transfer the carriers from one predetermined path to another. In one type of system, this transfer is achieved by providing a transfer conveyor that engages the carrier and transfers it between the predetermined paths. In another type of system, the carrier is moved from the one path toward the other and then pushed through the transfer area to the second path.

Among the objects of the present invention are to provide a power and free conveyor system of the latter type wherein a carrier is transferred from one predetermined path to another by pushing across a transfer zone; and wherein such system is achieved with minimum cost and maintenance.

SUMMARY OF THE INVENTION

A conveyor system including a first load supporting track and a second load supporting track with an intermediate transfer portion. A powered conveyor is provided in association with each of the first and second tracks. A plurality of carriers are provided. Each of the carriers has a first dog that is in position for normal engagement with the pusher member of the conveyor and a second pusher dog that is normally urged to an operative carrier pushing position but is held by the track out of operative position in carrier pushing position. At a transfer point a portion of the track is cut away to permit the second dog to move to operative carrier transferring position. Beyond the transfer point, a portion of the track is again cut away to permit the second dog to be cammed downwardly out of operative position.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary side elevational view of a conveyor system embodying the invention.

FIG. 2 is a fragmentary plan view of the system.

FIG. 3 is a fragmentary plan view of a modified form of conveyor system.

FIG. 4 is a fragmentary elevational view on an enlarged scale of a portion of the system shown in FIG. 1.

FIG. 5 is a fragmentary sectional view taken along the line 5--5 in FIG. 4.

FIG. 6 is a sectional view, parts being broken away, taken along the line 6--6 in FIG. 4.

FIG. 7 is a fragmentary side elevational view similar to FIG. 4 showing the parts in a different operative position.

FIG. 8 is a fragmentary side elevational view of a further modified form of the conveyor system.

DESCRIPTION

Referring to FIG. 1, the invention relates to a conveyor system wherein a power chain is adapted to selectively engage trolleys and move them in predetermined paths. The trolley motion is from right to left. Specifically, conveyor chain 10 is supported by chain trolleys 11 for movement along a track 12. The chain 10 includes longitudinally spaced pushers 13 that are adapted to engage carriers, as presently described, to move them. As shown, a carrier 15 comprising two or more longitudinally spaced trolleys (herein shown as three trolleys 16, 17, 18) pivotally interconnected by tie bars 19, 20 is provided for movement along track 21. The trolleys include wheels 22 that engage the lower flanges of spaced inwardly facing C-shaped channels of track 21 (FIG. 5). The foremost trolley 16 includes an actuating lever 23 that is operatively connected to a pusher dog 24 so that when lever 23 engages an obstacle or a projection 25 on the rear trolley 18 of the preceding carrier, the lever 23 is swung in a clockwise direction as viewed in FIG. 1 to lower the pusher dog 24 out of the path of a pusher 13. Such an arrangement is known as an accumulating conveyor system. The foremost trolley 16 further includes a pivoted hold-back dog 24a in accordance with conventional practice.

As further shown in FIG. 2, the system includes a second track 26 that extends at an angle from the track 21 and a switch tongue 27 that is operated to selectively guide the carrier 15 into the second track 26. The switch tongue 27 is controlled by signal devices such as are well known in the art, for example, as shown in the U.S. Pat. to Bishop No. 2,868,139. A second power chain 28 is provided in overlying relation to a portion of the track 26 and has pushers thereon adapted to pick up the carrier and move it along the track 26.

Referring more specifically to FIG. 4, one of the succeeding trolleys, such as trolley 18 of the carrier 15, includes a pivoted pusher dog 30 that is pivoted intermediate its ends and counterweighted as at 30a so that the pusher dog end 31 thereof is urged normally to operative pushing position. However, pusher 30 has laterally extending projections 32 thereon which normally engage the underside of the upper horizontal flanges 33 of the tracks 21 so that the pusher dog 31 is normally in the position shown in FIG. 1, namely, out of the path of pushers 13. However, in the case of the transfer of the carrier from the track 21 to the track 26 by positioning of the switch tongue 27, a portion of each flange 33 is cut away as at 34 (FIG. 1) to permit the pusher dog to swing vertically counterclockwise under the action of the counterweight to the position shown in FIG. 4 and thereby be in position for engagement with a pusher 13 which will push the carrier 15 through the switching or transfer area into position for engagement of the leading power dog 24 with the pusher of a secondary chain 28 along second track 26. The longitudinal extent of cut away portion 34 is only sufficient to permit the upper end 31 of pusher dog 30 to pivot upwardly. As the carrier is moved further along track 21, projections 32 will now be above flanges 33 and the pusher dog 30 will be positively prevented from moving downwardly thereby. A further cut away portion 34a is provided beyond switch tongue 27 on the main track and at 34b along the branch track 28. A cam plate 35, 36 adjacent these portions 34a, 34b, will engage projections 32 and cam pusher dog 30 downwardly beneath flanges 33.

When the switch tongue 27 is actuated to divert the carrier, the pusher 13 which is in engagement with the pusher dog 24 will disengage from the pusher dog 24 as the foremost trolley 16 of carrier 15 is diverted to the track 26. The carrier 15 will then be momentarily stopped. However, by this time, the pusher dog 30 will have been moved upwardly so that a succeeding pusher 13 of the power chain will engage the pusher dog 30 and cause the carrier 15 to be moved further along the track 26 sufficiently to permit dog 24 to be picked up by a pusher of the second power chain 28. As the carrier is moved along track 26, cam 35 will engage projections 32 of the pusher dog to pivot it down at cut away portion 34b out of the path of the pusher of chain 28.

As shown in FIG. 2, the cut away portion 34 extends along the track 21 in the area preceding the switch tongue 27, that is, preceding the transfer. A carrier which is not switched off is pushed all the way through the switching area by engagement of its front dog 24 with a dog 13 of the power chain, so that the trailing dog 30 moves through this area without being in contact with a dog 13. As a result dog 30 is free to swing upward to its operating position at the start of the track flange cut-outs 34 and is forced down again at 34a.

Throughout the portion of the system wherein the transfer is achieved, the relative positions vertically of the power track 12 and carrier tracks 21, 26 remain constant and are not changed.

The invention is also applicable to the transfer of the carrier from one powered conveyor to another, for example, from a faster to a slower conveyor or from a slower conveyor to a faster conveyor. Specifically, as shown in FIG. 3, the carrier is adapted to move along a track 40 in a portion between spaced power conveyors 41, 42, each of which has pushers 43, 44. As the conveyor 41 moves over its turn or sprocket 45, the pusher 43 thereon which is in engagement with the pusher dog 24 of the carrier becomes disengaged interrupting or causing a stoppage of the carrier. At this point, cut away portions 34' along the track 40 permit the second pusher dog 30 of the carrier to pivot upwardly into the path of a succeeding pusher 43 which then pushes the carrier across the gap between the conveyors 41, 42 bringing the leading pusher dog 24 into position for engagement with the pusher 44 of the succeeding conveyor 42. As the carrier is pulled across the space between the conveyors 41, 42, the second pusher dog 30 is depressed by engagement with the cam 35' through cut away portions 34a' beneath the track 40 with the projections 32 of the pusher dog 30 below the flanges of track 40. In the form of trolley shown in FIG. 8, the pusher dog 30' is pivoted to the trolley body 18' forwardly of the body 18' so that the pusher and the counterweight 30b have the major portion thereof beyond body 18'.

Claims

I claim:

1. In a conveyor system, the combination comprising

means defining a first load supporting track,

a first conveyor having a portion thereof adjacent said track and including longitudinally spaced pusher members,

a plurality of carriers for movement along said track,

each said carrier having a first pusher dog,

each said carrier having a second pusher dog,

said second pusher dog being movable to and from operative position where it may be engaged by a pusher member on the conveyor,

said second pusher dog being urged upwardly into operative position,

generally horizontal portions of said track extending toward and overlying a portion of said second pusher dog to engage said second pusher dog and hold said second pusher dog in inoperative position,

said second pusher dog being within the vertical confines of said track when held in inoperative position,

a second load supporting track,

means for guiding said carrier between said first and second load supporting tracks,

said generally horizontal portions of said track in advance of the area of said guiding means extending toward said second pusher dog a lesser distance and thereby permitting said second pusher dog to move upwardly in position for engagement with a pusher member of the conveyor whereby when a carrier is moved to said guiding means, a pusher member of said conveyor becomes disengaged from said first dog and a succeeding pusher member engages said second dog to push said carrier between said load supporting tracks,

said generally horizontal portions of said track extending toward and overlying a portion of said second pusher dog in the area of said guiding means,

said generally horizontal portions of said track beyond said guiding means extending toward said second pusher dog a lesser distance,

and means at said last-mentioned area beyond said guiding means engaging said secondary dog and moving said dog downwardly out of the path of the pusher members and into engagement with the generally horizontal portions of said track.

2. The combination set forth in claim 1 including a second conveyor movable along said second track for engaging a dog of said carrier to move said carrier along said second track.

3. The combination set forth in claim 1 wherein said track comprises spaced channels having horizontally extending flanges, the flanges of said channels extending inwardly toward one another and normally overlying and engaging said portion of said second dog to hold it in inoperative position.

4. The combination set forth in claim 1 wherein said carrier comprises a plurality of trolleys,

said first pusher dog being on the foremost trolley,

said second pusher dog being on a succeeding trolley.

5. The combination set forth in claim 1 wherein said second pusher dog is pivoted to said carrier and is counterweighted so that it normally is urged into the path of said pusher members on said conveyor.

6. The combination set forth in claim 1 wherein said second pusher dog comprises a portion of an element pivoted to the carrier and counterweighted so that the dog is normally in the path of the pusher members on the conveyor.

7. The combination set forth in claim 1 wherein said last-mentioned means comprises portions of said track extending into the path of said portion of said second pusher dog.

8. The combination set forth in claim 3 wherein said last-mentioned means for moving said second dog comprises portions of said flanges of said track.

9. In a conveyor system, the combination comprising

means defining a first overhead load supporting track,

a first conveyor having a portion thereof adjacent said track and including longitudinally spaced pusher members,

a plurality of carriers for movement along said track,

each said carrier having a first pusher dog,

each said carrier having a second pusher dog,

said second pusher dog being movable to and from position where it may be engaged by a pusher member on the conveyor,

said second pusher dog being biased upwardly into operative position,

generally horizontal portions of said track extending toward and overlying a portion of said second pusher dog to engage said second pusher dog and hold said second pusher dog in inoperative position,

said second pusher dog being within the vertical confines of said track when held in inoperative position,

a second overhead load supporting track,

overhead means for guiding said carrier between said first and second load supporting tracks,

said generally horizontal portions of said track in the area of said last-mentioned means being cut away to extend toward said second pusher dog a lesser distance and thereby permit said second pusher dog to move upwardly in position for engagement with a pusher member of the conveyor whereby when a carrier is moved to said guiding means, a pusher member of said conveyor becomes disengaged from said first pusher dog and a succeeding pusher member engages said second pusher dog to push said carrier between said load supporting tracks,

said track having portions thereof beyond said guiding means disengaged from said secondary pusher dog to permit said dog to be moved downwardly into engaged relation with said track.

10. The combination set forth in claim 9 wherein said track comprises spaced inwardly facing C-shaped channels having horizontally extending flanges, the upper flanges of said channels normally overlying and engaging said portion of said second dog to hold said dog in a position out of engagement by said pusher member.

11. The combination set forth in claim 9 wherein said last-mentioned means comprises portions of said track extending into the path of said portion of said second pusher dog.

12. The combination set forth in claim 9 wherein said last-mentioned means for moving said second dog comprises portions of said flanges of said track.