Rear trolley dog for power and free push through transfer

Claim 2

In a conveying system having a trolley movable from a main line into a secondary line at a transfer zone, said conveying system having a series of spaced pusher members and said trolley having a contact member for engagement by a pusher member for propelling the trolley, the improvement comprising a normally upright dog on the trolley behind the contact member, a locking element on the trolley to lock the dog in the upright position when the locking element is in locking position, a cam in the transfer zone for movement of said locking element into locking position, said trolley being pushed through the transfer station by a following pusher member contacting the dog after the contact member has disengaged from the pusher member.

Claim 3

In a conveying system having a trolley movable from a main line into a secondary line by way of a transfer zone, said conveying system having pusher members and said trolley having a contact member for engagement by a pusher member for moving the trolley, the improvement comprising a locking element on the trolley, a normally upright dog behind the contact member, said dog being yieldable when struck by a moving pusher member, a cam at said transfer zone, said cam engaging the locking element in the transfer zone for movement of the locking element into operative position, said locking element in operative position engaging the dog and holding it in the upright position for engagement with the next following pusher member for positively pushing the trolley through the transfer zone after disengagement of the preceding pusher member from the contact member.

Claim 4

In a conveying system having a trolley movable from a main line into a secondary line by way of a transfer zone, said conveying system having pusher members and said trolley having a contact member for engagement by a pusher member for moving the trolley, the improvement comprising a locking element on the trolley, a normally upright dog behind the contact member, said dog being yieldable when struck by a moving pusher member, a cam at said transfer zone, said cam engaging the locking element in the transfer zone for movement of the locking element into operative position, said locking element in operative position engaging the dog and holding it in the upright position for engagement with the next following pusher member for positively pushing the trolley through the transfer zone after disengagement of the preceding pusher member from the contact member.

Claim 5

In a conveying system having a trolley movable through a transfer zone from a main line to a secondary line. said conveying system having a series of spaced pusher members and having a contact member on the trolley for engagement by a pusher member to advance the trolley, the improvement comprising a dog pivotally mounted on the trolley, said dog having a counterweight normally to hold the dog in an upright position, said dog being yieldable when unlocked to permit passage of the pusher, a locking element to lock the dog in the upright position, a cam at the transfer zone, said cam engaging said locking element and moving said locking element into locking engagement with said dog, said dog being engaged by the next following pusher member for positively pushing the trolley through the transfer zone after the contact member has disengaged from the preceding pusher member.

Claim 6

In a conveying system having a trolley movable through a transfer zone from a main line to a secondary line. said conveying system having a series of spaced pusher members and having a contact member on the trolley for engagement by a pusher member to advance the trolley, the improvement comprising a dog pivotally mounted on the trolley, said dog having a counterweight normally to hold the dog in an upright position, said dog being yieldable when unlocked to permit passage of the pusher, a locking element to lock the dog in the upright position, a cam at the transfer zone, said cam engaging said locking element and moving said locking element into locking engagement with said dog, said dog being engaged by the next following pusher member for positively pushing the trolley through the transfer zone after the contact member has disengaged from the preceding pusher member.

Claim 7

In a conveying system having a trolley movable from a main line track to a secondary line track at a transfer area, said conveying system having a series of spaced pusher members on the main line track and said trolley having a contact member for engagement by a pusher member for movement of the trolley, the improvement comprising a normally upright dog mounted on the trolley behind the contact member for engagement by a pusher member after disengagement of the preceding pusher member from the contact member, means to lock the dog in the upright position in the transfer zone for positive propulsion of the trolley through the transfer zone and onto the secondary line track, said means to lock the dog including a locking cam on the trolley movable into engagement with the dog to hold the dog in the upright position, said dog yIeldable outside the transfer zone to permit a pusher to depress the dog and advance to the trolley contact member.

Claim 8

In a conveying system having a trolley movable from a main line track to a secondary line track at a transfer area, said conveying system having a series of spaced pusher members on the main line track and said trolley having a contact member for engagement by a pusher member for movement of the trolley, the improvement comprising a normally upright dog mounted on the trolley behind the contact member for engagement by a pusher member after disengagement of the preceding pusher member from the contact member, means to lock the dog in the upright position in the transfer zone for positive propulsion of the trolley through the transfer zone and onto the secondary line track, said means to lock the dog including a locking cam on the trolley movable into engagement with the dog to hold the dog in the upright position, said dog yIeldable outside the transfer zone to permit a pusher to depress the dog and advance to the trolley contact member.

Claim 9

The apparatus of claim 4 wherein a lifting cam is provided on the main line track at the transfer zone to move the locking cam into operative position.

Claim 10

In a conveying system having a forward trolley and a rear trolley supporting a carrier, said forward and rear trolleys supported on a track and said carrier movable from a main line track to a secondary line track at a transfer zone, said conveying system having a series of spaced pusher members, said forward trolley having a contact member for engagement by a pusher member for normally moving the carrier, the improvement comprising a unitary dog pivoted in the rear trolley, said rear trolley having a stop member located rearwardly of the pivotal axis of said dog, said dog normally disposed in a lowered non-operative position to allow passage of the pusher members, a cam attached to the track preceding the transfer zone, said dog having a shank portion with a hub for pivoting said dog in the rear trolley, said dog having a tab extending from the top of the shank portion and overlying said cam, said tab on the dog engaging said cam in the transfer zone to raise the dog to its operative position, said dog further having a stepped section at the outer end of the shank portion, said stepped section resting on said stop member when said dog is in the non-operative position and when said dog is in the operative position, said stepped section is engageable with the next following pusher member for positively pushing the carrier through the transfer zone after the contact member on the forward trolley has disengaged from the preceding pusher member.

Claim 11

In a conveying system having a forward trolley and a rear trolley supporting a carrier, said forward and rear trolleys supported on a track and said carrier movable from a main line track to a secondary line track at a transfer zone, said conveying system having a series of spaced pusher members, said forward trolley having a contact member for engagement by a pusher member for normally moving the carrier, the improvement comprising a unitary dog pivoted in the rear trolley, said rear trolley having a stop member located rearwardly of the pivotal axis of said dog, said dog normally disposed in a lowered non-operative position to allow passage of the pusher members, a cam attached to the track preceding the transfer zone, said dog having a shank portion with a hub for pivoting said dog in the rear trolley, said dog having a tab extending from the top of the shank portion and overlying said cam, said tab on the dog engaging said cam in the transfer zone to raise the dog to its operative position, said dog further having a stepped section at the outer end of the shank portion, said stepped section resting on said stop member when said dog is in the non-operative position and when said dog is in the operative position, said stepped section is engageable with the next following pusher member for positively pushing the carrier through the transfer zone after the contact member on the forward trolley has disengaged from the preceding pusher member.