Retracting push-rod assembly for conveyors

Claim 2

In a power and free type conveyor having a track (10), a continuously moving propelling member (13) and a plurality of trolleys (10) mounted for travel along said track; a linkage on said trolley for connecting said trolley to said propelling member, said linkage having both a pivotally mounted arm (20), which when erected engages said propelling member and an obstruction sensing lever (29) pivotally mounted to said trolley, the improvement in said linkage comprising: an actuating link (26) rigidly connected to said arm at the pivotal mounting thereof for pivotal movement with said arm; said sensing lever being connected to said link through a hinge (40); said hinge having a lost motion means a first portion of which is on said sensing lever and a second portion of which is on said link forming a lock at each extremity of movement of said sensing lever and said link for allowing said link to rotate about the pivotal mounting of said arm and positively holding said arm at all times against any movement other than simultaneously with said sensing lever.

Claim 3

A linkage for power and free conveyors as described in claim 1 wherein said lost motion means at said hinge has a slot (27) of shallow U-shaped in one portion of said hinge and a pin (28) seated in said slot and mounted on the other portion of said hinge; the U-shape of said slot and the shape of the walls of one end of said slot being such that a positive interference relationship is created therebetween when said driving member in erected position urges said hinge to flex.

Claim 4

A linkage for power and free conveyors as described in claim 1 wherein the pivotal mounting of said sensing lever is intermediate said ends and, as said arm and sensing lever shift between said first and second positions, said hinge shifting from one side to the other of a line connecting the centers of pivotal movement of said arm and sensing lever, the arcuate path (C) of movement of the end of the slot seating said pin being curved oppositely from the path of travel (B) of said pin causing positive interference between the pin and the walls of said slot and forming said lock when force is applied to the free end of said arm urging it to shift from its erected position.

Claim 5

In a power and free-type conveyor having a track (12), a continuously moving propelling member (13) and a plurality of trolleys (10) mounted for travel along said track; a linkage on said trolley for connecting said trolley to said propelling member, said linkage having both an arm (20), which when erected engages said propelling member and an obstruction sensing lever pivotally mounted to said trolley, the improvement in said linkage comprising: an actuating link (26) rigidly connected to said arm for pivotal movement with said arm; a hinge (40) connection between said sensing lever and said link having a pin (28) on one of said sensing lever and said link and a slot (27) in the other thereof receiving said pin therein; said slot having a first portion and a second portion, said portions being arranged at an angle to each other; said sensing lever upon engaging an obstruction ahead of a trolley being pivotable from a first position to a second position and in so doing pivoting said arm from erected position to a retracted position out of propelling member engagement; as said sensing lever and arm shift between said positions said pin traveling from one end of said slot the full length of both portions of said slot and returning to its original position at said one end thereof and when seated at said one end with said arm erected forming a lock positively holding said arm against pivotal movement under forces acting upon said arm and urging it to retract.

Claim 6

In a power and free-type conveyor having a track (12), a continuously moving propelling member (13) and a plurality of trolleys (10) mounted for travel along said track; a linkage on said trolley for connecting said trolley to said propelling member, said linkage having both an arm (20), which when erected engages said propelling member and an obstruction sensing lever pivotally mounted to said trolley, the improvement in said linkage comprising: an actuating link (26) rigidly connected to said arm for pivotal movement with said arm; a hinge (40) connection between said sensing lever and said link having a pin (28) on one of said sensing lever and said link and a slot (27) in the other thereof receiving said pin therein; said slot having a first portion and a second portion, said portions being arranged at an angle to each other; said sensing lever upon engaging an obstruction ahead of a trolley being pivotable from a first position to a second position and in so doing pivoting said arm from erected position to a retracted position out of propelling member engagement; as said sensing lever and arm shift between said positions said pin traveling from one end of said slot the full length of both portions of said slot and returning to its original position at said one end thereof and when seated at said one end with said arm erected forming a lock positively holding said arm against pivotal movement under forces acting upon said arm and urging it to retract.