Patent ID: 7828007

Claim:
An automatic control device for an injection pump used to inject a fluid into a source of a pressurized gas; the injection pump comprising a shaft that extends and refracts, and a linkage mounted to the shaft for actuating the injection pump; the linkage having first and second portions respectively corresponding to extension and refraction of the shaft, the automatic control device comprising: a) a two position toggle valve, driven by the pressurized gas, to pulse between first and second positions that correspond to the extension and retraction of the shaft, respectively; b) a driver, coupled to the toggle valve, having first and second single-point contact surfaces corresponding to the first and second portions of the linkage of the injection pump; and c) an overstroke mechanism to prevent overdriving the injection pump beyond full extension; in which the toggle valve pulses in a two-stroke cycle between the first and second positions to couple the respective first and second single-point contact surfaces of the driver to the respective first and second portions of the linkage, thereby alternatively causing the extension and retraction of the shaft of the injection pump.