Claims
- 1. A trigger actuating mechanism for moving an end effector device in a surgical instrument between retracted and extended positions, said mechanism comprising:
- a frame integral with said instrument, said frame defining a guide channel;
- a trigger lever pivotally mounted to said frame for rotation about a pivot axis offset from said frame guide channel, said trigger lever defining a cam channel offset from said pivot axis;
- a drive pin disposed in said trigger cam channel and extending into said frame guide channel;
- a link pivotally connected at a first location to said drive pin and pivotally connected at a second location to said end effector device; and
- a spring effectively acting between said frame and trigger lever to bias said trigger lever to an unactuated position in which said end effector device is at one of said retracted and extended positions.
- 2. A trigger actuating mechanism in accordance with claim 1 in which
- said guide channel and cam channel lie generally in parallel planes with a portion of said cam channel overlapping a portion of said guide channel at any pivoted position of said trigger lever.
- 3. A trigger actuating mechanism in accordance with claim 1 in which
- each said guide channel and cam channel has a straight surface for engaging said drive pin and an arcuate surface for engaging said drive pin.
- 4. A trigger actuating mechanism in accordance with claim 3 in which
- said frame has a proximal end and a distal end;
- said guide channel straight surface extends from said guide channel arcuate surface towards said frame distal end; and
- said cam channel straight surface extends from said cam channel arcuate surface towards said frame proximal end.
- 5. A trigger actuating mechanism in accordance with claim 1 in which
- said cam channel has a first straight surface for engaging said drive pin and a second straight surface for engaging said drive pin;
- said second straight surface is oriented at an oblique angle to said first straight surface; and
- said end effector device includes a former bar for advancing a staple in said instrument.
- 6. A trigger actuating mechanism in accordance with claim 1 in which
- said trigger actuating mechanism further includes
- (a) a set of teeth in said frame, each said tooth defining a camming surface and an abutment surface;
- (b) a pawl mounted at a first location to said trigger lever and defining an engaging portion at a second location for moving in one direction along said teeth camming surfaces and for engaging said teeth abutment surfaces when movement of said engaging portion in the opposite direction is attempted during a portion of the stroke.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of application Ser. No. 08/259,322, filed Jun. 10, 1994, pending, which prior application is a continuation-in-part of the U.S.A. utility patent application Ser. No. 07/959,184 filed Oct. 9, 1992, now U.S. Pat. No. 5,381,943 and entitled "Endoscopic Surgical Stapling Instrument With Pivotable And Rotatable Staple Cartridge."
US Referenced Citations (145)
Foreign Referenced Citations (3)
Number |
Date |
Country |
40157 |
Nov 1981 |
EPX |
39560 |
Nov 1981 |
EPX |
0116220A1 |
Aug 1984 |
EPX |
Divisions (1)
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Number |
Date |
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Parent |
259322 |
Jun 1994 |
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Continuation in Parts (1)
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Number |
Date |
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Parent |
959184 |
Oct 1992 |
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