Flow responsive pressure regulating unloader
First Claim
1. A flow responsive pressure regulating fluid unloader comprising a housing having an inlet port, an outlet port and a by-pass port, means connecting said inlet port to said outlet port, pressure regulating valve means connected between said inlet port and said by-pass port and adapted to dump fluid supplied to said inlet port above a set pressure to said by-pass port, a second valve connected between said inlet port and said by-pass port, means for closing said second valve in response to fluid flow to said outlet port and for opening said second valve in response to the absence of fluid flow to said outlet port.
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Accused Products
Abstract
A flow responsive pressure regulating unloader suitable for use between a positive displacement fluid pump and a fluid consuming device connected to the pump. The unloader includes a housing having an inlet port connected to an outlet port, and a by-pass port. A fluid pressure regulating valve is connected between the inlet port and the by-pass port to limit the maximum fluid pressure at the inlet port. A flow responsive valve also is connected between the inlet port and the by-pass port. Fluid flow from the inlet port to the outlet port creates a pressure drop across an orifice. The pressure differential is applied across a piston to close the flow responsive valve. When flow from the outlet ceases, the pressures across the piston become equal and the fluid pressure on the flow responsive valve opens the valve to divert fluid to the by-pass port.
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Citations
9 Claims
- 1. A flow responsive pressure regulating fluid unloader comprising a housing having an inlet port, an outlet port and a by-pass port, means connecting said inlet port to said outlet port, pressure regulating valve means connected between said inlet port and said by-pass port and adapted to dump fluid supplied to said inlet port above a set pressure to said by-pass port, a second valve connected between said inlet port and said by-pass port, means for closing said second valve in response to fluid flow to said outlet port and for opening said second valve in response to the absence of fluid flow to said outlet port.
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9. A flow responsive pressure regulating fluid unloader comprising a housing having an inlet port, an outlet port and a by-pass port, means including an orifice connecting said inlet port to said outlet port and wherein a pressure drop occurs across said orifice in response to fluid flow from said inlet port to said outlet port, pressure regulating valve means connected between said inlet port and said by-pass port and adapted to dump fluid at said inlet port above a set pressure to said by-pass port, a second valve connected between said inlet port and said by-pass port, means for closing said second valve in response to a pressure drop across said orifice and for opening said second valve in response to the absence of a pressure drop across said orifice.
Specification