Abstract: A machine for interrupting a portion of an otherwise continuously moving web of material to enable one or more manufacturing operations to be performed on the stopped portion of the web while the remaining portions of the web are advanced continuously. The machine is interposed between a pair of other machines in a production line in which one of the machines continuously feeds the web to the interrupting machine and the other machine continuously draws the web from the interrupting machine. The interrupting machine includes means to take up the web fed continuously to the interrupting machine as well as means for storing and paying out a length of web from the outlet end of the machine. The web is advanced and stopped in precisely controlled incremental lengths to insure proper registration of the stopped portion of the web with the manufacturing instrumentalities mounted on the interrupting machine.

Abstract: A machine for cutting and sealing bags from a web of thermoplastic sheet material includes low inertia drive rolls to feed the thermoplastic sheet in closely controlled, incremental lengths. The drive rolls are driven by a fluid motor which is controlled by a stepping motor. The sheet is fed to a cutting and sealing head which has means for gripping the fed segment of the web to hold it in position to be cut and sealed. Sealing is effected by resistance wires on the head which are applied to the thermoplastic sheet. The amount of electrical energy applied to the resistance heating wires is controlled and measured carefully to avoid overheating or underheating of the wire.

Abstract: A moving web or sheet of material in which an operation is to be performed, such as punching of a hole, is advanced past a pneumatic edge position sensor which is mounted on a carriage for movement transversely toward and away from the edge of the web. The movable carriage also supports the mechanism which is to perform the particular operation (e.g., a hole punching device) and a pneumatic cylinder is connected to the carriage to effect its movement toward or away from the edge of the web to follow any lateral displacement of the web. Operation of the motor is controlled in response to a change in position of the edge of the moving web with respect to the edge position sensor by a pneumatic control system which provides an immediate operation of the motor in response to the sensor and without a hunting tendency.