| 摘要 |
<p>The invention relates to an oil burner fuel pump assembly. The assembly has three construction features which are (1) a cut-off valve which opens fully immediately after the pump is started and snaps shut immediately after the pump is turned off, (2) a regulating valve for maintaining a constant pressure for the nozzle and (3) a by-pass valve for instantly unloading the cut-off valve when the pump is turned off. A restriction to the fluid being exhausted in the pressure regulating function provides a pressure drop which is utilized to maintain the by-pass valve in an inoperative position during operation of the assembly. When the pump pressure diminishes the pressure drop likewise recedes and this recession is sensed by the by-pass valve which responds by moving to an operative position for unloading the cut-off valve.</p> |
