Abstract: A strap feed assembly wraps a flexible strap around an item. A drive wheel is connected to a reversible drive motor for feeding and reversing the strap to wrap the strap around the item and to tension the strap once it is wrapped therearound. A controller operates the drive motor to control the speed, acceleration, direction of rotation, and tensioning of the strap. The velocity and acceleration of the drive motor are varied depending on the nearness of completion of the feeding and tensioning. Variable tension is achieved by monitoring the current drawn by the drive motor and comparing same to predetermined values to stop reversal and therefore tensioning.

Abstract: A method and apparatus for assembling heat exchanger elements includes a pallet comprising a frame and a plurality of blocks slidably aligned on each side of the frame with opposed pairs of blocks slotted to receive pairs of plates dropped into the pallet. Lead screws driven by servomotors and engaging the blocks position the blocks at the loading station and control the block spacing (determined at each station by the screw pitch) to allow plate insertion or to allow insertion of fin elements between the plates. To quickly move the pallet into the station auxiliary lead screws connected to the main screws engage the blocks of the pallet outside the loading station to assert positive controlled advancement force on the pallet.

Abstract: A method and apparatus for assembling heat exchanger elements includes a pallet comprising a frame and a plurality of blocks slidably aligned on each side of the frame with opposed pairs of blocks slotted to receive pairs of plates dropped into the pallet. Lead screws driven by servomotors and engaging the blocks position the blocks at the loading station and control the block spacing (determine at each station by the screw pitch) to allow plate insertion or to allow insertion of fin elements between the plates. To quickly move the pallet into the station auxiliary lead screws connected to the main screws engage the blocks of the pallet outside the loading station to assert positive controlled advancement force on the pallet.

Abstract: A heat exchanger header is formed of a tube plate and a header plate having indentations that cooperate with the tube plate to form a row of tank chambers for interconnecting heat exchanger tubes joined to the tube plate. The tube plate has ribs extending between adjacent tube apertures that are contacted at a point midway along their length by respective projections from the indentations on the tank plate.