초록 ▼

A vehicle convertible top has hydraulic cylinders for moving the top between extreme raised and lowered positions. The cylinders each have a pair of fluid translating ports each connected to ports in an elongated housing. A reversible hydraulic pump is in one end of the housing, while a reservoir is

A vehicle convertible top has hydraulic cylinders for moving the top between extreme raised and lowered positions. The cylinders each have a pair of fluid translating ports each connected to ports in an elongated housing. A reversible hydraulic pump is in one end of the housing, while a reservoir is in the other end, separated by a pump cap. The pump cap houses two fluid circuits each connected to a housing port and each including an end of cycle hydraulic locking device which comprises a normally-closed valve and a valve actuator in each circuit. In one direction of pump operation, one of the valves is opened by pressure fluid in the one circuit to enable the outflow of the pressure fluid to the cylinders. The other valve is forced open by its actuator, in response to pressure in the one circuit, to enable the return flow of fluid to the pump through the other circuit. The one valve closes when the pump ceases operation, preventing fluid backflow through the one circuit to the pump. Reverse operation is similar. The pump cap includes makeup valving connected to the reservoir to accommodate fluid requirements due to cylinder displacement differential. At both cycle ends, the top is hydraulically locked in extreme raised and lowered positions to facilitate top latching and top stowage. A manually-operated bypass is provided in the pump cap to vent both circuits to the reservoir to enable manual top operation in the event of a pump failure.

대표청구항 ▼

In a vehicle having a convertible top, a hydraulic cylinder for moving the convertible top between extreme raised and lowered positions and having a pair of fluid translating ports, a hydraulic fluid reservoir, and a motor-driven reversible hydraulic pump connected to the reservoir during operation

In a vehicle having a convertible top, a hydraulic cylinder for moving the convertible top between extreme raised and lowered positions and having a pair of fluid translating ports, a hydraulic fluid reservoir, and a motor-driven reversible hydraulic pump connected to the reservoir during operation and having a first fluid translating circuit connected to a cylinder port for driving the cylinder to raise the top and a second fluid translating circuit connected to the other cylinder port for driving the cylinder to lower the top, and end of cycle locking device comprising a normally-closed circuit valve in the first circuit that is opened by pressure fluid from the pump to enable outflow of pressure fluid to the cylinder in the first circuit during pump operation in one direction, wherein the valve closes when the pump ceases operation, thus preventing the backflow of fluid through the first circuit to the pump which locks the top in extreme raised position, a valve actuator for the circuit valve operable in response to pressure fluid in the second circuit during pump operation in the other direction to open the circuit valve to enable the free return flow of pressure fluid through the first circuit, a second normally-closed circuit valve in the second circuit that is opened by pressure fluid from the pump to enable outflow of pressure fluid to the cylinder in the second circuit during pump operation in the other direction, wherein the second circuit valve closes when the pump ceases operation, thus preventing the backflow of fluid to the pump through the second circuit to hydraulically lock the top in extreme lowered position, a valve actuator for the second circuit valve operable in response to pressure fluid in the first circuit during pump operation in the one direction to open the valve to enable the free return flow of pressure fluid in the second circuit, said first and second valves comprising the only flow restrictions between the pump and the actuator in either circuit, a bypass including a normally-closed bypass valve connecting each circuit to the reservoir, and a manual actuator for opening the bypass valves to permit fluid flow from the second circuit to the reservoir to unlock the top in either extreme position to enable manual movement of the top when the pump is not operating.