Power and free conveyor system utilizing power track and dog elevation to prevent jamming conditions at transfers and switches
AssigneeFord Motor Company
InventorsDennis W. Desilets, Raymond L. Carlson, Steven J. Dale
Life of this patent
Estimating the term…
Abstract
A power and free conveyor system is provided which utilizes a difference in height between the wipe in power trolley and the wipe out power trolley, with or without a camming down of a retractable wide dog of the free trolley, to allow the wipe in power chain to wipe in over the retractable dog without any possibility of lateral interference. Thereafter the elevation of the wipe in power trolley and the wipe out power trolley are the same. Improved stop device operating to push down the retractable dog and therefore cause disengagement of the retractable dog from the power chain dog are also provided.
Claims76
In a power and free conveying system having a wipe in power chain, a wipe out power chain and a free track spaced vertically from both said wipe in power chain and said wipe out power chain and including a free trolley having a retractable dog supported on said free track for movement therealong, the improvement comprising:
- a) the elevation of said wipe in power chain being sufficiently different from the elevation of said wipe out power chain during a switching or transfer operation to allow said wipe in power chain to wipe in over said free trolley without engaging said retractable dog of said free trolley.
In a power and free conveyor having at least one transfer portion, and including at said transfer portion a wipe in power chain having a wipe in dog, a wipe out power chain having a wipe out dog, and a free trolley having a multi-position retractable wide dog supported on a free track spaced vertically from said wipe in power chain and said wipe out power chain for movement along said free track when said free trolley is engaged by said wipe in power chain and or said wipe out power chain, the improvement comprising:
- a) the elevation of said wipe in power chain at said transfer portion of said power and free conveyor being sufficiently different from the elevation of said wipe out power chain to allow said wipe in dog to wipe in over said retractable wide dog without engaging said power dog;
- said wipe in power chain travelling together with said wipe out power chain for a sufficient distance to effect a transfer.
In a power and free conveyor having at least one transfer portion, and including at the transfer portion a wipe in power chain having a wipe in power dog, a wipe out power chain having a wipe out power dog, and a free trolley having a multi-position retractable wide power dog supported on a free track spaced vertically from said wipe in power chain and said wipe out power chain for movement along said free track when said free trolley is engaged by said wipe in power chain and/or said wipe out power chain, the improvement comprising:
- a) a cam down bar provided at said transfer portion of said power and free conveyor and acting on said wide dog to move said wide dog from a fully extended position to a cammed down position;
- and
- b) the elevation of said wipe in power chain at said transfer portion of said power and free conveyor being sufficiently different than the elevation of said wipe out power chain to allow said wipe in chain dog to wipe in over said retractable wide dog while said wide dog is in its cammed down position without engaging said dog, said wide dog moving to said fully extended position after passing out from under said cam down bar.
A power and free conveying system including:
- a) a wipe in power chain assembly including a wipe in chain dog;
- b) a wipe out power chain assembly including a wipe out chain dog;
- c) a free track assembly spaced vertically from said wipe out power chain assembly and said wipe in power chain assembly;
- d) a free trolley supported on said free track assembly for movement there along;
- said free trolley including a retractable dog for engagement with said wipe in power chain and/or said wipe out power chain;
- e) said retractable dog having a cammed down position where said dog only partially engages said wipe out chain dog while said retractable dog is traveling along said free track for a pre-determined distance while said wipe in power chain wipes into position over said retractable dog.
A power and free conveying system comprising:
- a) a track assembly including a wipe in power track, a wipe out power track, and a free track spaced vertically from said power tracks;
- b) a wipe in power trolley supported on said wipe in power track for movement there along;
- c) a wipe out power trolley supported on said wipe out power track for movement there along;
- d) a free trolley supported on said free track for movement there along, said free trolley including;
- i) a moveable holdback dog engageable and disengageable with said wipe in power trolley and/or said wipe out power trolley,
- ii) a retractable dog having a first or fully extended position engageable with said wipe in power trolley or said wipe out power trolley, said retractable dog being held in said first or fully extended position by the action of a counter weight attached to said free trolley, a second or cammed down position wherein the elevation of said retractable dog is slightly greater than the elevation of said movable hold back dog, said retractable dog being held in said cammed down position when in an interference zone by a fixed, immovable, cam down bar, and a third or fully retracted position disengageable with said power trolley and engageable with said hold back dog to rotate said hold back dog and fully lower said free trolley to disengage said free trolley from said power trolley upon the said counter weight engaging another one of said free trolley, or a stop means;
- e) the fixed, immovable cam down bar to hold said retractable dog in said cammed down position when said free trolley is in an interference zone, and
- f) a stop means for stoping said free trolley, said stop means being separate and distinct from said immovable cam down bar.
In a power and free conveyor of the type having at least one switch, and including at the switch a wipe in power chain having a wipe in pusher dog, a wipe out power chain having a wipe out pusher dog, and a free trolley having a retractable wide dog supported on a free track spaced vertically from said wipe in power chain and said wipe out power chain, the improvement comprising:
- a) a cam down bar provided proximate said switch and acting on said retractable wide dog to move said retractable wide dog from a fully extended position to a cammed down position;
- and
- b) the elevation of said wipe in power chain at said transfer portion of said power and free conveyor being sufficiently different than the elevation of said wipe out power chain to allow said wipe in chain dog to wipe in over said retractable wide dog while said wide dog is in its cammed down position without engaging said wide dog, said wide dog moving to its fully extended position after passing out from under said cam bar.
A method of transferring a free trolley from engagement with a wipe out power dog in a power and free conveyor system to a wipe in power dog without jamming conditions said method including the steps of:
- a) providing a cammed down bar proximate the point of transfer to move a retractable dog on said free trolley to a cammed down position while;
- b) providing that the wipe in power chain is at a position higher than the wipe out power chain for at least the zone where lateral interference between the wipe in power chain and the retractable dog could occur;
- and
- c) returning the elevation of the wipe in power chain to the elevation of the wipe out power chain after the interference zone.
Dependencies are inferred from the claim text.