Patent Grant
7194857
(a) Field of the Invention
The present invention relates to ventilation valves, and particularly to a ventilation valve of a hydraulic jack, wherein when the jack is not operated, a valve hole is opened; the vent of a cap of the jack is communicated with the oil storage tank of the jack so as to maintain the equilibrium of the pressure of the oil storage tank; thereby the piston of the pump can suck oil successfully so that the oil is absorbed into the oil chamber of the pump to be saturated therein.
(b) Description of the Prior Art
In the lifting process of a prior art jack, a piston of a pump absorbs oil from an oil storage tank into an oil chamber of a pump. Then oil is transferred into an inner oil tank. By the reciprocal operation of above process, the jack can lift upwards gradually. In the prior art design, the oil storage tank of a hydraulic jack is sealed completely. When the pump operates initially, the oil in the oil storage tank passes through the oil chamber of the pump and enters into the inner oil tank. The oil storage will reduce gradually. The less the oil storage, the smaller the pressure of the oil storage tank. As a result, the pressure will approach to a vacuum pressure. Thereby, the pumping operation becomes difficult so that the piston can absorb oil successfully. Moreover, the oil absorption cannot be in an optimum saturation condition. Thus, in each lifting process, a maximum efficiency can not be achieved.
Accordingly, the primary object of the present invention is to provide a ventilation valve of a hydraulic jack dedicated to be mounted at an outer wall of an oil storage tank of a hydraulic jack. The hydraulic jack includes a valve seat, a valve ball, and a cap.
Another object of the present invention is to provide a ventilation valve of a hydraulic jack, wherein when the jack is not operated, a valve hole is opened; the vent of a cap is communicated with the oil storage tank of the jack so as to maintain the equilibrium of the pressure of the oil storage tank; thereby the piston of the pump can suck oil successfully so that the oil is absorbed into the oil chamber of the pump to be saturated therein.
A further object of the present invention is to provide a ventilation valve of a hydraulic jack, wherein when the oil of the jack flows along a return path in the oil buffer chamber between the valve seat and the cap, the valve ball will close the valve hole of the valve body by the upward ejection of the valve ball since a large amount oil in the oil groove returns to the oil storage tank rapidly in a high pressure so as to prevent the oil from flushing out.
Another object of the present invention is to provide a ventilation valve of a hydraulic jack, wherein at the moment that the valve ball ejects upwards rapidly, an oil buffer chamber can buffer high pressure draining oil until the oil return operation of the jack is accomplished after wholly descents. Since the pressure of the oil storage tank is reduced, the valve ball will fall down due to the gravitational effect so as to open the valve hole and as a result, the surplus gas is released. Thereby, the pressure of the oil storage tank of the jack is in equilibrium state with the atmosphere.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing.
Referring to
The valve seat 21 is a hollow seat and one end thereof has a threaded section 11, which is locked to an outer wall of an oil storage tank 101 of a hydraulic jack 10 and is communicated to the oil storage tank 101. An O ring 12 serves to seal the connection portion of the valve seat 1 and the oil storage tank 101. An interior of the valve seat 1 can receive a valve body 2. An upper end of the valve body 2 is installed with a buckling ring 13. An upper section of the valve seat 1 is extended with an oil buffer chamber 14 for storing oil temporarily.
The valve body 2 is a hollow body and is received in the valve seat 1. An upper end of the valve body 2 is formed with a valve hole 21 having a valve ball 3 therein. A lower end of the valve body 2 is formed with a stopping pin 22 or a proper stopper for hindering the valve ball 3 to fall out. An outer wall of the valve body 2 has an annular groove 23 for embedding an oil seal 24.
The valve ball 3 is installed within the valve body 2. By the raising and descending of the valve body 2, the valve hole 21 of the valve body 2 is controlled to be closed (referring to
The cap 4 can be made of flexible plastic and an inner wall of the cap 4 has an annular rib 41 (referring to
The ventilation valve made of above components will be installed to the outer wall of the oil storage tank 101 of the hydraulic jack 10. When the hydraulic jack 10 is not operated, the valve ball 3 of the ventilation valve will fall down due to gravitational effect (referring to
When the oil of the jack 10 flows along a return path, in the oil buffer chamber 14 between the valve seat 2 and the cap 4, the valve ball 3 will close the valve hole 21 of the valve body 2 by the upward ejection of the valve ball 3 since a large amount oil in the oil groove 102 returns to the oil storage tank 101 rapidly in a high pressure (referring to
The present invention is thus described. It will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
| Number | Name | Date | Kind |
|---|---|---|---|
| 1656430 | Dybens | Jan 1928 | A |
| 3113587 | Hendley | Dec 1963 | A |
| 4945947 | Westra et al. | Aug 1990 | A |
| 5465576 | Miller | Nov 1995 | A |
| 6439506 | Schlegel et al. | Aug 2002 | B1 |
| Number | Date | Country | |
|---|---|---|---|
| 20040172938 A1 | Sep 2004 | US |
