A reusable universal modular unit, which may be used alone or in combination with one or more similar units to form a production line, is provided for facilitating manual and/or mechanized work or assembly operations on a product supported on a carrier having a reusable standardized base section and an expendable component supporting nest section. Each modular unit includes a work table having at least one work station thereon, a self-contained conveyor for transporting carriers to and away from the work station and a carrier handling system at each work station for disengaging a carrier from the conveyor, locating and locking it at a fixed work position to facilitate assembly operations and for thereafter reengaging the carrier with the conveyor for transport away from the work station. A production line of any suitable length is formed by arranging the units serially in end-to-end relation. Provisions are made for easily adding accumulator units at selected locations along the line.

A circular path non-synchronous manufacturing system wherein a continuously rotating horizontal plate or ring driven by a motor reducer combination carries pallets, each with an integral fixture for holding a workpiece, having means for precise location and clamping at automatic work stations. The pallets proceed independently from station to station where they are stopped, located, clamped for the duration of the work operation and released for frictional drive to the next station independent of other pallets which may queue up behind any pallet during its operation in the work station.

A method and apparatus for automatically changing interchangeable machining tool heads carried by a tool carrier. The tool heads are suspended from an overhead trolleyway by leading and trailing trolleys, with the leading trolley carrying a probe and a vertical finger and the trailing trolley carrying an inclined guide. The vertical finger selectively engages a block carried on an overhead moving chain for moving the tool head toward the tool carrier. The probe extends in the direction of tool head travel and is responsive to proximity of the probe to the inclined guide of another tool head or to a pneumatically-actuated stop for disengaging the vertical finger from the chain. A shuttle bar assembly simultaneously loads and unloads tool heads from the tool carrier by engaging a block on each of the tool heads and moving the tool heads horizontally to loaded and unloaded positions. The tool carrier, carrying a tool head and a portion of removable trackway, moves horizontally from a tool head loading station for performing machining on a workpiece. The tool carrier includes coupling elements for removably clamping the tool head to the carrier and a drive mechanism for operating a plurality of tool work elements carried on the tool head.

A workpiece moving machine comprising: an elongate frame with an endless belt mounted on the frame and extending between the ends of the frame. A plurality of trolleys are slidably mounted on the frame for movement along the frame. Each trolley has a clamp for selectively holding a workpiece to the trolley. A first clutch on each trolley selectively connects the trolley to one run of the belt to move the trolley along the frame in one direction and a second clutch on each trolley selectively connects the trolley to the other run of the belt to move the trolley along the frame in the opposite direction. A brake on each trolley selectively brakes the trolley to the frame to prevent its movement along the frame.

A manufacturing machine such as an automatic assembly machine is disclosed which includes a work station which can include linear motion devices and rotary motion devices. A conveyor system is disclosed for transporting a workpiece to and from the work station, and positioning means are disclosed for precisely positioning the workpiece to the work station.