Pneumatic fastener driving apparatus with an improved valve

A pneumatic powered fastener driving apparatus, comprising:

• a) a housing including a compressed air chamber;
• b) a cylinder disposed within said housing and fluidly coupled to said compressed air chamber;
• c) a piston slidably disposed within said cylinder for reciprocating movement therein, said piston dividing said first cylinder into first and second portions;
• d) a fastener driving element connected to said piston;
• e) a main valve positioned adjacent said first cylinder portion and moveable between a closed position blocking communication between said compressed air chamber and said first cylinder portion, and an open position;
• f) a membrane extending between said main valve and said housing, said membrane being substantial supported by surfaces of said main valve and said housing during movement to prevent its stretching during operation of said apparatus, said membrane being disposed between said main valve and said cylinder forming an air tight seal therebetween whenever said main valve is in its closed position, said membrane blocking said exhaust from said first cylinder portion whenever said main valve is disposed to its open position;
• and
• g) a trigger valve fluidly coupled to said compressed air chamber for controlling said main valve, wherein upon activating said trigger valve compressed air is released from said main valve disposing said main valve to its open position and supplying compressed air to said first cylinder portion driving said piston and said fastener driving element.

A pneumatic powered fastener driving apparatus, comprising:

• a) a housing;
• b) a cylinder disposed within said housing;
• c) a piston slidably disposed within said cylinder for reciprocating movement between a first home position and a second position remote therefrom, said piston dividing said cylinder into first and second portions;
• d) a main valve disposed within said housing and having a support surface positioned adjacent said first cylinder portion;
• e) a first compressed air chamber fluidly coupled via a trigger value to said main valve;
• f) said housing comprising a first fluid passageway extending between said first compressed air chamber and said first cylinder portion, a second cavity disposed on an opposite side of said main valve relative to said first cylinder portion, a second fluid passageway extending from said first compressed air chamber via said trigger valve to said second cavity, and a third fluid passageway extending from said first cylinder portion to atmospheric pressure, said main valve disposable between a third home position wherein said third passageway is opened and a fourth position wherein said third passageway is blocked and said first fluid passageway is opened;
• g) a flexible membrane extending between said housing and said main valve, said support surface of said main valve supporting said membrane as said main valve moves between its third and fourth positions;
• h) return means for disposing said piston to this first home position;
• i) a fastener driving element extending from said piston;
• and
• j) said trigger valve actuable from a fifth rest position to a sixth position wherein said second fluid passageway is opened releasing a flow of compressed air from said second cavity and disposing said main valve to its fourth position, wherein said first fluid passageway is opened releasing compressed air into said first cylinder portion to drive said piston and said fastener driving element to its second remote position, said flexible membrane being disposed between said cylinder and said main valve whereby said flexible membrane forms an airtight seal therebetween when said main valve is dispose din its third home position and said flexible membrane blocking said third passageway when said main valve is disposed in its fourth position to prevent the escape of compressed air therethrough.