Patent Application
20050109972
The invention relates generally to a fuel cell for a combustion gas-powered tool. More particularly, the invention relates to a connector for connecting a valve of the fuel cell to the combustion gas-powered tool.
Fuel cells for a combustion gas-powered tool, and connectors for connecting a valve of a fuel cell to a combustion gas-powered tool, are known. U.S. Pat. No. 5,115,944 discloses a fuel cell of the type having an outer canister containing a pressurized propellant, an inner bag containing a dispensable fluid, and a valve for dispensing the fluid to a combustion gas-powered tool. When the valve is open, the pressurized propellant collapses the inner bag and forces the fluid to be dispensed from the inner bag through a valve stem of the open valve. U.S. Pat. No. 6,523,860 discloses an adapter system for connecting a valve of a fuel cell to a combustion gas-powered tool. The adapter system includes two components—an adapter and a molded insert. The molded insert is secured within a passageway in the adapter, then the adapter is placed onto the fuel cell such that a valve stem of the fuel cell is inserted into a first end of the molded insert. A base portion of the adapter includes barbs that engage a rolled seam of the fuel cell canister to secure the adapter onto the fuel cell. With the adapter secured to the fuel cell, the molded insert secured within the adapter, and the fuel cell valve stem inserted into one end of the molded insert, a fuel metering valve stem on the tool is inserted into a second end of the molded insert for abutting engagement with the fuel cell valve stem.
It would be desirable to have a fuel cell having a simplified connector for engaging with a fuel inlet of a combustion gas-powered tool. It would also be desirable to have a connector that can be affirmatively connected directly to a valve stem of the fuel cell, and for the connector to be easily connected with a stem of a fuel metering valve in the combustion gas-powered tool so as to establish a leak resistant fluid conduit between the fuel cell and the fuel metering valve. It would also be desirable to have a connector which is permanently connected to a fuel cell and/or which can be easily affixed to the fuel stem.
The above needs are met, and the shortcomings of prior art are overcome by the fuel cell connector of the invention. In particular, the invention provides a fuel cell having a unitary connector. The connector may have a first end that is secured directly to a valve stem of the fuel cell. The second end of the connector may be adapted to be easily engaged with a fuel metering valve in a combustion gas-powered tool, so as to establish a leak resistant fluid conduit between the fuel cell and the fuel metering valve.
According to one embodiment, a fuel cell includes a body, and a valve having a stem for releasing dispensable fluid from the body. A unitary member is secured to the body by its first end being fixedly secured to the stem. The member has a connector formed at a second end, and a fluid conduit extending between the first and second ends, such that the connector is adapted for sealingly engaging a dispensable fluid inlet.
The stem may extend parallel to a first axis, and the fluid conduit may extend parallel to the first axis. The connector may include an aperture that is circumscribed by a channel. The first end of the member may approximate a conical section, and the second end of the member may approximate a cylindrical section. The stem axis may be both parallel and collinear with the axis of revolution for the first and second ends. The connector may be a female fitting adapted for engaging a male inlet stem. The second end may include an outer flange and an inner flange spaced from, and circumscribed by the outer flange, the inner flange being adapted for engaging a fluid inlet stem. The fuel cell may be combined with a tool having a fluid inlet. The fluid inlet may include a male stem, wherein the female fitting is engaged with the male stem to provide a fluid tight seal.
In another embodiment, a method for connecting a fuel cell to a tool having a dispensable fluid inlet is provided. The fuel cell includes a body containing a dispensable fluid, a stem and valve. The valve is opened by depressing the stem. The method includes the steps of providing a unitary adapter fixedly secured to an end of the stem, the adapter defining a fluid passageway extending between the stem and a connector formed at an end of the adapter; and engaging the dispensable fluid inlet with the connector so that there is a fluid-tight seal formed between the fuel cell stem and the dispensable fluid inlet.
The engaging step may include inserting a male stem of the tool into an aperture of the connector and the aperture may include structure for press-fitting the male stem into the aperture. The press-fitting step may include forcibly inserting an end of the inlet stem beyond a ridge provided on the adapter.
Additional features and advantages of the invention will be set forth or be apparent from the description that follows. The features and advantages of the invention will be realized and attained by the structures and methods particularly pointed out in the written description and claims hereof as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation without limiting the scope of the invention as claimed.
The accompanying drawings, which are included to provide a further understanding of the invention, are incorporated in and constitute a part of this specification, illustrate preferred embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:
a is a cross-sectional view of the connector of
b is a top view of the connector of
c is a bottom view of the connector of
A fuel cell connector of the invention provides a one-piece member which connects a fuel cell to a valve stem of a metering valve in a combustion gas-powered tool. When connected, a fluid-tight seal may be established between the fuel cell contents and the tool without the use of additional fitting structure. A lower portion of the connector member may be fixed to the valve stem of the fuel cell, and an upper portion of the connector member may be adapted for a press fit on the valve stem of the metering valve. In this regard, the upper portion of the connector member may include a flexible wall having an inner diameter that is slightly less than the outer diameter of valve stem on the metering valve, to provide a frictional and/or interference-type hold on the metering valve stem, and a gap may be disposed radially outward from the flexible wall to provide a space for the displaced wall in the flexed condition. A fluid conduit is formed between the lower and upper portions so that a dispensable fluid may pass from the fuel cell, through the fuel cell valve stem and the metering valve stem, to a metering valve of the combustion gas-powered tool.
A preferred embodiment of a fuel cell and connector of the invention is illustrated in
Referring to
As noted earlier, upper portion 34 forms a connection to a metering valve stem on a combustion gas-powered tool. Upper portion 34 includes an outer wall 35b, an inner wall 35c, and a base portion 35a. Outer wall 35b includes an outside surface 46 and an inside surface 48. Inner wall 35c includes an outside surface 50 and an inside surface 52. Each surface 46, 48, 50 and 52 is in the form of a right cylinder. Inside surface 52 forms a right cylinder having a diameter d1. Surface 48 and surface 50 define a gap 54 which may be useful as a means for increasing flexibility of the wall 35c when receiving a slightly larger dimensioned stem of a metering valve. As such, inner wall 35c can be sized to flex when the metering valve stem of the combustion gas-powered tool is received in portion 34, as described below. Thus, gap 54 maybe thought of as a flexure space for resilient inner wall 35c. Inside surface 52 defines an upper portion of fluid conduit 32 and extends along the longitudinal axis A-A to flange 44. Flange 44 also provides a stop for the metering valve stem. A material that yields (rather than an elastic material) upon insertion of the metering valve may alternatively be used. Such engagements may also be used for end 36.
In use, connector 30 is fixed to stem 20 by either an adhesive or heat shrink. Fuel cell 10 may then be packaged and delivered with a connector 30 secured thereto. Thus, in one embodiment of the invention, there is provided a fuel cell having a integral connector for connecting the fuel cell to a tool. In another embodiment, connector 30 may be delivered separately and then secured to the end of a fuel cell, such as the fuel cell disclosed in U.S. Pat. No. 5,115,944.
As illustrated in
With the lower portion 36 of connector member 30 secured to the valve stem 20, and the upper portion 34 of connector member 30 press fit on the valve stem 56, a dispensable fluid may pass from the fuel cell 10 through valve stem 20, fluid conduit 32, and valve stem 56, to the metering valve 58 of a combustion gas-powered tool.
In a preferred embodiment, upper portion 34 is adapted to receive a protruding stem and as such, a female type fitting is formed. Additionally, outer walls 35b may be sized such that when connector 30 is to be connected to stem 56, walls 35b assist with aligning conduit 32 with stem 56.
Although the foregoing description is directed to the preferred embodiments of the invention, it is noted that other variations and modifications will be apparent to those skilled in the art, and may be made without departing from the spirit or scope of the invention.
