Conveyor means

Claim 1

A pallet type conveyor comprising: a transporting track having a length extending in the direction in which products are to be transported and having a plurality of successive block units; a transporting pallet on which products to be transported can be carried and mounted on said track for movement therealong in the direction of the length of said track, said pallet having means cooperating with said track for confining a cushion of compressed air between said pallet and said track for supporting said pallet above said track; compressed air supply means for supplying compressed air to said block units in succession and to direct the compressed air against the transporting pallet for supporting said pallet; a plurality of linear motor portions forming one part of a linear motor means, one such portion being only in the central part of each of said block units and spaced from the preceding and succeeding linear motor portions for driving said transporting pallet along said track in the direction in which products are to be transported, said pallet having thereon means forming the remainder of said linear motor means, each such portion of said linear motor means being sufficiently long for giving said pallets sufficient momentum to enable them to reach the next successive portion, the spacing being sufficiently great that if a pallet is caused to stop between two such portions the force produced by the linear motor means is insufficient to move the pallet; blade means on said pallet in line with the flow of compressed air against said pallet from said compressed air supplying means and oriented to move said pallet in the direction of the length of said track; compressed air supply control means for controlling the supply of compressed air to the respective block units to supply compressed air at a first pressure just sufficient to support said pallet above said track and insufficient to drive said pallet along said track when striking said blade means, and for controlling the supply of compressed air to discontinue the supply of compressed air to one block unit after the pallet has passed said one block unit and to start supply of compressed air to a next successive block unit just before the pallet starts to pass said one block unit, and for controlling the supply of compressed air for increasing the pressure of compressed air supplied to said block units to a second pressure higher than said first pressure and sufficient to moving said pallet in the direction of the length of said track when it strikes said blade means, whereby when a pallet is stopped or blocked from being transported at a position between said linear motor portions where it is not able to be driven by said linear motor means, said compressed air supply control means can be actuated to supply compressed air at said second pressure sufficient to move said pallet to a position where it can again be driven by said linear motor means.