The invention relates to fluid operated devices such as hand tools or other actuated equipment and, more particularly, to a valve structure enabling a modulation feature of the tool or equipment.
In U.S. Pat. No. 6,341,621, a fluid operated device or tool 10 is shown, which includes a valve structure 36 that functions as a combined over-pressure relief and pressure release mechanism.
Once the tool 10 has performed its work, valve structure 36′ becomes the mechanism for releasing and resetting the tool 10. Over-travel of the pump piston 20 away from the bulkhead 12 beyond its normal pumping range will cause the valve structure 36′ to travel to the right in
Although the valve structure 36′ works well for its intended purpose, the valve structure can be improved to modulate the pressure in the drive chamber C.
Thus, there is a need to provide a valve structure in a fluid operated device to provide modulation of the device.
An object of the invention is to fulfill the need referred to above. In accordance with the principles of the present invention, this objective is achieved by providing a pressure releasing valve structure for a fluid operated device. The device has an orifice constructed and arranged to be in fluid communication with a pressure chamber. The valve structure includes a body having first and second ends. A valve member is provided at the first end of the body and is constructed and arranged to seal the orifice. A first spring is associated with the first end of the body and is constructed and arranged to cause the valve member to seal the orifice under certain pressure conditions in the pressure chamber. A second spring is associated with the second end of the body and is constructed and arranged to compress thereby reducing a force exerted by the first spring, permitting the valve member to move to a non-sealing position to open the orifice under pressure conditions in the pressure chamber lower than would be required absent the provision of the second spring.
In accordance with another aspect of the invention, a fluid operated device is provided and includes surfaces defining a pressure chamber constructed and arranged to contain fluid. Surfaces also define an orifice in fluid communication with the pressure chamber. The device includes a valve structure having a body with first and second ends. A valve member is provided at the first end of the body and is constructed and arranged to seal the orifice. A first spring is associated with the first end of the body and is constructed and arranged to cause the valve member to seal the orifice under certain pressure conditions in the pressure chamber. A second spring is associated with the second end of the body and is constructed and arranged to compress thereby reducing a force exerted by the first spring, permitting the valve member to move to a non-sealing position to open the orifice under pressure conditions in the pressure chamber lower than would be required absent the provision of the second spring.
Other objects, features and characteristics of the present invention, as well as the methods of operation and the functions of the related elements of the structure, the combination of parts and economics of manufacture will become more apparent upon consideration of the following detailed description and appended claims with reference to the accompanying drawings, all of which form a part of this specification.
The invention will be better understood from the following detailed description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like parts, in which:
With reference to
As in the tool 10 of
In the embodiment of
Aorifice 42*PSIchamber C=(Fspring 38−Fspring 50)=F
Thus, it can be seen that the additional spring 50 exerts a force in a direction opposite of the force exerted by spring 38. Thus, by employing spring 50, the ball valve 40 will unblock (open) orifice 42 at a pressure lower than that required to move the ball valve in the embodiment of
It is contemplated to employ a conventional ball screw coupled with rod 58 (
It can be appreciated that the valve 40 need not be limited to ball valve, but the valve 40 can be conical or other shapes that are constructed and arranged to seal an opening.
The foregoing preferred embodiments have been shown and described for the purposes of illustrating the structural and functional principles of the present invention, as well as illustrating the methods of employing the preferred embodiments and are subject to change without departing from such principles. Therefore, this invention includes all modifications encompassed within the spirit of the following claims.
This application is based on U.S. Provisional Application No. 60/625,132, filed on Nov. 5, 2004, and claims the benefit thereof for priority purposes.
Number | Name | Date | Kind |
---|---|---|---|
4241644 | Schertler | Dec 1980 | A |
6035634 | Tupper et al. | Mar 2000 | A |
6341621 | Tupper et al. | Jan 2002 | B1 |
6581630 | Kaneko | Jun 2003 | B1 |
6837266 | Fredrickson et al. | Jan 2005 | B2 |
Number | Date | Country | |
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60625132 | Nov 2004 | US |