Reversible programmer for electric circuits

Claim 1

In a heating system for controlling the temperature conditions of a space including a heat pump having a plurality of electrical heating elements, a programmer to sequentially energize and deenergize said heating elements, a thermostat responsive to the temperature of the space to actuate said programmer, a source of power, and circuitry means for interconnecting said heat pump, programmer and thermostat; the improvement wherein said programmer provides a regulated control sequencE in both a forward and a reverse direction and comprising: a generally arcuate rotatable cam having an initial position and a final position; a plurality of actuatable control switches coaxially circumscribing at least a portion of the periphery of said cam; means carried by said cam for sequentially actuating said control switches upon rotation of said cam; thermostatically controlled motor means for driving said cam in a forward direction between the initial position toward the final position incident to a demand for heat or in a reverse direction absent a demand for heat, whereby said control switches are either sequentially actuated to energize said heating elements or sequentially disengaged to deenergize said heating elements respectively; first limit switch means for deenergizing said motor means to prevent it from operating in the reverse direction when said cam is in the initial position; second limit switch means for deenergizing said motor means to prevent it from operating in the forward direction when said cam is in the final position; and, clutch means for drivingly connecting said cam to said motor means.