Patent ID: 9239065
Filing Date: 2016-01-19
CPC Classification: B60K,F02N,F15B

Claim Text:
1. A unitary hydraulic soft start system for use in starting a hydraulic motor, the system comprising: a housing; a pressure source port defined in the housing for receiving pressurized hydraulic fluid from an associated hydraulic pressure source; a hydraulic motor located in the housing to which the hydraulic pressure source supplies fluid to start the hydraulic motor; a drain port defined in the housing and positioned in a downstream location from said hydraulic motor; a pilot operated flow control valve located in the housing and including a pilot, an inlet, and an outlet, the inlet being in fluid communication with the pressure source port and the outlet being in fluid communication with the hydraulic motor; a first flow restricting orifice located in the housing in fluid communication with and disposed between the pressure source port and the hydraulic motor; a second flow restricting orifice located in the housing in fluid communication with and disposed between the pilot and the hydraulic motor; and wherein when pressurized hydraulic fluid is supplied to the pressure source port, a first fluid flow is passed from the pressure source port via the first orifice to the hydraulic motor placing the hydraulic motor in a first partially-actuated low power state, a portion of the first fluid flow being passed via the second orifice to the pilot placing the valve in an open state after an actuation pressure is reached and allowing a second fluid flow to pass from the pressure source port to the hydraulic motor, the second fluid flow being higher than the first fluid flow, thereby placing the hydraulic motor in a second fully-actuated high power state subsequent to the first partially-actuated low power state.