Abstract: A winch for moving loads with a continuous cable over varying distances that consists of a winch drum (10) with a fixed sleeve (26) to maintain proper laydown and separation of cable (34) on the drum (10). The sleeve (26) is helically grooved on its interior surface to form a space for the winch cable (34) to be guided therein. Pull force is mostly the result of the tension adjusted on the endless cable, the friction between the cable (34) and drum (10), the diameter of the drum, and the number of turns of cable (34) on the drum (10). The number of turns of cable (34) on the drum (10) is determined by the length of the drum (10) and sleeve (26) and the number of grooves machined into the sleeve's interior surface.

Abstract: A system for supplying conditioned air through a duct to an area to be treated by the conditioned air, the system having an area thermostat that tends to maintain the temperature of the area at a selected set point temperature of the thermostat. The thermostat provides a signal in relation to the temperature sensed by the thermostat. A damper unit is provided for controlling the flow of air from the duct to the area. A controller that is non-readily accessible in the area and is remote from the thermostat directs a signal to the damper unit to operate the same in relation to the value of the signal of the thermostat and in relation to the air pressure in the duct to compensate for pressure changes originating elsewhere in the system whereby the controller tends to maintain the air flow to the area at the rate called for by the signal of the thermostat regardless of the air pressure in the duct.

Abstract: A differential pressure transmitter having structure for producing an output pneumatic signal from a pneumatic source in relation to the air velocity pressure of air flowing in the passage structure that senses the difference between the total pressure and the static pressure of the air flowing in the passage, and structure for extracting the square root of the air velocity pressure of the air from the pneumatic output signal as the pneumatic output signal is being produced so that the pneumatic output signal is substantially linear with respect to the air velocity of the air flow in the passage whereby the transmitter comprises a linear air velocity transmitter. The structure for extracting the square root comprises a substantially flat cam surface.