Apparatus for placing staples in laparoscopic or endoscopic procedures

Claim 1

Surgical apparatus for driving surgical fasteners into body tissue comprising: a) a frame (600); b) a distal portion (758) defining a longitudinal axis and extending distally from said frame, said distal portion including: i) an elongated support (778) having a distal member accommodating a replaceable cartridge assembly (836), the replaceable cartridge assembly including a plurality of surgical fasteners (842) slidably mounted therein, and having a tissue engaging surface; ii) an elongate anvil member (796) having a fastener forming surface (818) and one end pivotally retained in said elongated support such that an anvil member is movable between an open position and a closed position wherein the fastener forming surface is in close co-operative alignment with the tissue engaging surface of the cartridge assembly; iii) means (602) for moving the anvil member between the open position and the closed position; iv) means (636) with a stroke for ejecting the surgical fasteners from the cartridge assembly, whereby the fasteners engage the fastener forming surface; and v) means (850) for disabling the apparatus after a single actuation of the ejecting means (636); the apparatus being characterised in that: the anvil member is aligned lengthwise with the longitudinal axis and said one end is the proximal end of the anvil member; in that the apparatus is suitable for endoscopy or laparoscopy and in that the distal portion is an endoscopic portion; in that: gas sealing means (742) atmospherically isolate the endoscopic portion and the frame; and in that: the means for moving anvil member between the open position and the closed position comprises: a) on the anvil member (796) a camming surface (822) transversely arcuate with a defined radius of curvature; and b) a collar tube (752) disposed around at least a portion of the elongated support, said collar tube having a distal camming surface (756) with a defined transverse radius of curvature and further being movable between a first position in which the distal camming surface is located proximally to the proximal end of the arcuate camming surface (822), and a second position in which the distal camming surface is located distally to the proximal end of the arcuate camming surface, the distal camming surface co-operating with the arcuate camming surface such that when the collar tube (752) is moved from the first position to the second position, the arcuate camming surface is urged to the closed position, and wherein the distal camming surface (756) on the collar tube (752) has a radius of curvature which is shorter than the radius of curvature of the arcuate camming surface (822).