Power and free conveyor system with positively controlled dog

Claim 2

In a conveyor system comprising a track, a plurality of trolleys which run on the track, a power driven element supported for movement along a path parallel to the track, a plurality of driving dogs on the power driven element and dogs on at least some of the trolleys for co-operation with the driving dogs on the power driven element, the improvement wherein: there is provided on at least one of said trolleys a dog which is settable in a selected one of an operative position and an inoperative position with respect to the driving dogs of the power driven element and in a generally horizontal plane, there is provided at a first position along the track first control means for acting on the settable dog of said one trolley when said one trolley passes said first position in such a manner as to set the dog positively in its operative position, and there is provided at a second position along the track second control means for acting on the settable dog when said one trolley passes said second position in such a manner as to set the dog positively in its inoperative position.

Claim 3

In a conveyor system comprising a track, a plurality of trolleys which run on the track, a power driven element supported for movement along a path parallel to the track, a plurality of driving dogs on the power driven element and dogs on at least some of the trolleys for co-operation with the driving dogs on the power driven element, the improvement wherein: there is provided on at least one of said trolleys a dog which is settable in a selected one of an operative position and an inoperative position with respect to the driving dogs of the power driven element, said settable dog is mounted on said one trolley for movement about a pivot axis which is substantially vertical when the trolley is on a horizontal length of track, there is provided at a first position along the track first control means for setting the settable dog of said one trolley positively in its operative position when said one trolley passes said first position, and there is provided at a second position along the track second control means for setting the settable dog positively in its inoperative position when said one trolley passes said second position.

Claim 4

In a conveyor system comprising a track, a plurality of trolleys which run on the track, a power driven element supported for movement along a path parallel to the track, a plurality of driving dogs on the power driven element and dogs on at least some of the trolleys for co-operation with the driving dogs on the power driven element, the improvement wherein: there is provided on at least one of said trolleys a dog which is settable in a selected one of an operative position and an inoperative position with respect to the driving dogs of the power driven element, said settable dog is mounted on said one trolley for movement about a pivot axis which is substantially vertical when the trolley is on a horizontal length of track, there is provided at a first position along the track first control means for setting the settable dog of said one trolley positively in its operative position when said one trolley passes said first position, and there is provided at a second position along the track second control means for setting the settable dog positively in its inoperative position when said one trolley passes said second position.

Claim 5

The improvement according to claim 2 wherein said settaBle dog is rigidly connected to at least one arm which projects radially of said pivot axis for engagement with the control means.

Claim 6

The improvement according to claim 3 wherein the control means comprises a plurality of abutments spaced from one another along the track.

Claim 7

The improvement according to claim 3 wherein the settable dog is rigidly connected to two arms which project in diametrically opposite directions with respect to the pivot axis for engagement with the control means.

Claim 8

The improvement according to claim 2 wherein stop means is provided for limiting pivotal movement of the settable dog to a range of approximately 90*.

Claim 9

The improvement according to claim 2 wherein: holding means is provided for preventing pivotal movement of the settable dog during periods when the dog is required to remain in one of its operative and inoperative positions, the holding means comprises an element rigidly secured to the settable dog, the track defines a longitudinally extending slot, said element normally lies within said slot, there is clearance between said element and the boundaries of said slot, along parts of the track, said clearance is insufficient to permit pivoting of said element with the settable dog about said axis, and along further parts of the track, said clearance is sufficient to permit pivoting of said element with the settable dog about said axis.

Claim 10

The improvement according to claim 2 wherein: holding means is provided for preventing pivotal movement of the settable dog during periods when the dog is required to remain in one of its operative and inoperative positions, the holding means comprises a latch, said latch is mounted on the trolley for movement between holding and releasing positions in the former of which it holds the dog in one of the operative and inoperative positions and in the latter of which positions of the latch the dog is free to pivot, and the control means is arranged for displacing the latch to its releasing position preparatory to displacing the dog between its operative and inoperative positions.

Claim 11

The improvement according to claim 8 wherein said latch is pivotally mounted on the trolley and the control means comprises a cam which engages with the latch as the trolley passes the cam to pivot the latch to its releasing position.