Fastener driving tool with improved valve

Claim 2

A valve system for controlling the flow of fluid under pressure to a fluid motor located in a tubular member, said system comprising: a housing, a tubular member positioned in said housing; a fluid motor located in said tubular member; a diaphragm valve support member movably supported in said housing adjacent an open end of the tubular member and having a first surface for moving toward said open end and defining an area outwardly of such end exposed to said fluid contained under pressure in said housing, said support member also defining a second surface opposite said first surface, said first surface outer area being subjected to a first biasing force due to said pressurized fluid in said housing tending to bias said support member away from the open end of the tubular member, said second surface being subjected to a second biasing force acting in opposition to said first biasing force; a resilient disc positioned in said housing to overlie and to close said open end, said disc terminating inwardly of the peripheral edge of said support member; means securing said disc to said first support surface inwardly of at least a portion of the disc periphery whereby said disc periphery is movable relative to said first support surface and relative to the portion of said disc secured to said first support surface, said support member biasing said disc into sealing engagement with said open end of said tubular member due to said second biasing force; and control means operable for releasing at least a portion of said second biasing force to allow said pressurized fluid in said housing to move said first support surface away from said open end while initially maintaining said resilient disc in sealing engagement with said open end, said resilient disc finally snapping away from said open end when the support member has become spaced from said tubular member, thereby instantaneously opening a large aperture to said open end of said tubular member to expose the tubular member to said pressurized fluid in said housing whereby said pressurized fluid may enter said tubular member through said open end to drive said fluid motor.

Claim 3

A valve system as in claim 1 in which said second surface is exposed to said fluid under pressure, and said control means for releasing at least a portion of said second biasing force includes a control valve controlling the application of said pressurized fluid to said second surface.

Claim 4

A valve system as in claim 1 in which said support member is supported upon an inner wall of said housing and divides said housing into a first chamber confronting said second surface and a second chamber about said tubular member said second chamber being continuously supplied with said pressurized fluid to furnish said first biasing force.

Claim 5

A valve system as in claim 3 in which said first chamber is also supplied with pressurized fluid to subject said second surface to pressure and thereby to provide at least a portion of said second biasing force and said control means is operable to cut off said pressurized fluid to said first chamber to thereby release at least a portion of said second biasing force.

Claim 6

A valve system as in claim 4 in which said fluid is air, and said control means includes a valve selectively connecting said first chamber to the atmosphere for releasing said pressurized air therein, and to a source of pressurized air for again supplying pressurized air to said first chamber.

Claim 7

A valve system as in claim 4 in which said first surface outer area extends between the inner wall of said housing and the outer wall of said tubular member and is generally annular in configuration.

Claim 8

A valve system as in claim 4 in which said resilient disc is substantially congruent with the open end of said tubular member.

Claim 9

A pneumatically operated fastener driving tool comprising: a housing adapted to contain air under pressure; a tubular member disposed within said housing and having an open end for exposure to said pressurized air; a piston slidably mounted within the tubular member and normally biased toward said open end, said piston being provided with a fastener driver on one side thereof opposite the side facing said open end; a closure member supported within said housing and positioned to extend across said open end and having a periphery engaging said housing, said closure member being movable between an open position spaced from said open end and a closed position adjacent said open end, said closure member having a first surface facing towards said open end and an opposite surface facing away from said open end, said closure member dividing said housing into a storage chamber on said first surface side maintaining pressurized air over said first surface, and an operating chamber on said opposite surface side, a compression spring in said operating chamber acting on said opposite surface, said storage chamber containing pressurized air providing a first force upon said first surface tending to move said closure member away from said open end; a resilient disc secured to said first closure member surface at a location inwardly of the periphery of said disc and sealingly engageable with said cylinder open end; control means for selectively admitting and exhausting pressurized air to said operating chamber, said air upon admittance providing a second force acting in conjunction with said compression spring to overcome said first force to bias said closure member toward said closed position and said disc into sealing engagement with said open end, said means thereafter exhausting said operating chamber to allow said closure member to move from said closed position to said open position under the influence of said first force, with said resilient disc initially maintaining sealing engagement with said open end under the influence of pressurized air admitted between said disc and said support member from said storage chamber, said disc finally snapping away from said open end against and toward said one closure member surface, thereby instantaneously opening said open end to said storage chamber pressurized air to drive said piston together with said fastener driver, said means thereafter again admitting pressurized air To said operating chamber to again seal said open end; and means for venting the air confined between said resilient disc and said piston when said disc is restored to sealing engagement with said open end, allowing said piston bias to return said piston to its original position near said open end.

Claim 10

A pneumatically operated fastener driving tool comprising: a housing adapted to contain air under pressure; a tubular member disposed within said housing and having an open end for exposure to said pressurized air; a piston slidably mounted within the tubular member and normally biased toward said open end, said piston being provided with a fastener driver on one side thereof opposite the side facing said open end; a closure member supported within said housing and positioned to extend across said open end and having a periphery engaging said housing, said closure member being movable between an open position spaced from said open end and a closed position adjacent said open end, said closure member having a first surface facing towards said open end and an opposite surface facing away from said open end, said closure member dividing said housing into a storage chamber on said first surface side maintaining pressurized air over said first surface, and an operating chamber on said opposite surface side, a compression spring in said operating chamber acting on said opposite surface, said storage chamber containing pressurized air providing a first force upon said first surface tending to move said closure member away from said open end; a resilient disc secured to said first closure member surface at a location inwardly of the periphery of said disc and sealingly engageable with said cylinder open end; control means for selectively admitting and exhausting pressurized air to said operating chamber, said air upon admittance providing a second force acting in conjunction with said compression spring to overcome said first force to bias said closure member toward said closed position and said disc into sealing engagement with said open end, said means thereafter exhausting said operating chamber to allow said closure member to move from said closed position to said open position under the influence of said first force, with said resilient disc initially maintaining sealing engagement with said open end under the influence of pressurized air admitted between said disc and said support member from said storage chamber, said disc finally snapping away from said open end against and toward said one closure member surface, thereby instantaneously opening said open end to said storage chamber pressurized air to drive said piston together with said fastener driver, said means thereafter again admitting pressurized air To said operating chamber to again seal said open end; and means for venting the air confined between said resilient disc and said piston when said disc is restored to sealing engagement with said open end, allowing said piston bias to return said piston to its original position near said open end.