A pair of light barriers are mounted on a pair of spaced apart balustrade sockets located on opposite sides of an endless step conveyor-type escalator. The light barriers are positioned at the transition of upper and lower transisition arches to an inclined run of the conveyor. The light barriers each include a transmitter and receiver for emitting and receiving a light beam transversely to the direction of travel of the conveyor. The light beam is interrupted by side shields on the conveyor steps. An opening is formed adjacent a leading edge of each side shield and one or more openings are formed adjacent a trailing edge of each side shield. The trailing edge openings are formed as oblong holes each with a longitudinal axis extending with respect to the tread of the step at the same angle as the inclination of the inclined run of the escalator with respect to the horizontal. The oblong holes are formed at different angles corresponding to typical angles and inclination such that the side shields can be used with different standard escalator installations.

The present invention provides a chain wear monitoring device for monitoring chain wear in a chain drive conveyor system. The chain wear monitor electronically measures, calculates, records, and reports the amount of chain wear along the entire length of the conveyor chain. The monitor calculates the wear as the number of inches per nominal ten foot section of chain. A large diameter measuring wheel is rotatably mounted on a shaft extending from the monitor control box. An encoder connected to the wheel is used measure the distance of the chain and a proximity sensor counts the links. A magnetic assembly may be fixed to the chain to cause the monitor to automatically start and stop a data recording session for a chain on a conveyor system at the same spot each time the chain is monitored, facilitating section by section comparison of chain wear.

A glass machine system in accordance with presently preferred embodiments of the invention includes a glassware manufacturing machine for manufacturing articles of glassware and transferring the articles to a linear conveyor, at least one linear chain conveyor for receiving and transporting such articles from the machine, and a speed sensor for monitoring linear speed of the conveyor. The speed sensor includes a magnetic energy source, a magnetic energy sensor and bracketry mounting the source and sensor adjacent to the conveyor. The chain conveyor teeth affect magnetic energy coupling between the source and sensor as the conveyor passes adjacent to the sensor. Electronic circuitry is responsive to signals from the sensor for determining linear speed of the conveyor and maintaining a constant linear speed at the conveyor.

An automatic bottle handling machine comprises a storage hopper for bottles in random orientation, a plurality of conveyor channels having conveyors extending between the hopper and a corresponding plurality of drop chutes and selective reversing devices for turning around neck first bottles before reaching the drop chutes. A sensor in each drop chute detects the prolonged presence of a bottle therein to stop the corresponding conveyor. A yoke member below each sensor indefinitely arrests the downward movement of an incorrectly oriented bottle or a defective bottle having a spur or flash on the bottom thereof to stop traffic in the corresponding drop chute and thereby stop the supply of bottles by the corresponding conveyor until the offending bottle has been removed by the operator. Another sensor for detecting a crushed bottle may be provided at the upper end of each drop chute for similarly stopping the corresponding conveyor.

The run of a belt, such as a conveyor belt or a belt of a weighing scale, is monitored for keeping the belt in a substantially centered position. For this purpose, the belt has a marking element, and a stationary sensor is so arranged that it can scan at least two edges of the marking element. One marking edge extends perpendicularly to the belt running direction. The other marking edge extends at a slant or angle to the belt running direction. Thus, the sensor produces two marker signals at least one of which changes when the belt makes an off-center excursion. The two marker signals and a belt speed representing signal are processed in a computer to provide a belt deviation signal which may be used to correct the belt direction eitehr normally or automatically. The marking element has a triangular configuration and is so arranged that one side of the triangle extends substantially perpendicularly to the belt running direction.