Abstract: An automated warehouse storage system including a multilevel storage array with storage distributed along multiple aisles. Each aisle of which has a set of storage levels and each level has storage locations distributed along the aisle. The guideway network extending through the multilevel storage array and configured for autonomous vehicles to move along the guideway network within the multilevel storage array. The guideway network including an inter-aisle guideway spanning at least two of the multiple aisles and a set of guideway levels extending in an aisle of the multiple aisles and disposed so that each guideway level is at a different one of the storage levels and the vehicles on the guideway level can access the storage locations distributed along the aisle.

Abstract: A flow rate sensor for use with an air filter channels air flow to energize an audible sound generator upon development of an air pressure differential within the sensor above a settable threshold, which pressure differential results from a reduction in the air flow rate through the air filter due to clogging of the air filter by filtered matter.

Abstract: A pressure change responsive sensor and related vacuum operable switch assembly capable of operation from the manifold of an internal combustion engine to activate a signal in anticipation of the application of the brakes of an automobile. The vacuum operable switch assembly is an improvement on the applicant's U.S. Pat. No. 3,639,898 for Differential Pressure Control System And Switch Means Therefor, and is capable of adjustment to function with internal combustion engines having different manifold vacuum characteristics.

Abstract: A low voltage audio fire alarm system fully integrated in a paging and music speaker system. The alarm circuits including pull-boxes and automatic fire, smoke and heat detection apparatus and the audio circuits are fully and continuously supervised against component failure by means of a plurality of current responsive relays. The audio path including the speaker system and associated amplifiers is continuously monitored by a low level supersonic 26KC signal. Fail-safe features utilizing multi-contact switches and relays are incorporated throughout the system to prevent inadvertent silencing of alarms in the absence of an alarm condition.