Apparatus for monitoring the motion of shuttles in looms or the like

摘要

An apertured disk which is mounted on a shaft in a loom causes a first photocell to transmit a first signal once during each revolution of the shaft in a preselected angular position of the shaft, and a second photocell to transmit a second signal in response to each incremental angular displacement of the shaft through one degree. A counter is reset to zero in response to reception of each first signal, and the counter thereupon counts the second signals until the shuttle of the loom causes the generation of a third signal which is generated when the shuttle reaches a predetermined portion of its path. The counter displays or otherwise indicates the number of second signals which are generated between the generation of a first signal and the generation of the next following third signal. The means for transmitting second signals to the counter is a logic circuit which begins to transmit second signals to the counter on reception of a first signal, and terminates the transmission of second signals to the counter on reception of the next-following third signal. The number of second signals which are stored in the counter when the shuttle causes the generation of a third signal denotes the extent of angular displacement of the shaft from its preselected angular position.