Self-contained gas powered surgical stapler

Improved gas powered surgical stapling apparatus including a pneumatic piston and a longitudinally movable staple driver for advancing a staple to a staple forming position and then forming the staple, a relatively low force beig required to advance the staple to the staple forming position and a relatively high force being required to form the staple, wherein the improvement comprises a mechanical linkage between the pneumatic piston and the staple driver for producing from a substantially constant force provided by the pneumatic piston throughout its driving stroke the relatively low force required during the advance of the staple to the staple forming position and the relatively high force required during forming of the staple, the mechanical linkage comprising:

• a four bar linkage disposed in a plane parallel to the translational axis of the staple driver and having a first hinge connection attached to the staple driver, an opposite second hinge connection fixed at a point on an axis through the first hinge connection parallel to the translational axis of the staple driver, and third and fourth hinge connections respectively spaced on opposite sides of the axis through the first and second hinge connections;
• and
• cam means connected to the pneumatic piston and having first and second cam surfaces for respectively operating on the third and fourth hinge connections to push the third and fourth hinge connections substantially parallel to the translational axis of the staple driver during a first portion of the driving stroke of the pneumatic piston corresponding to the advance of the staple and to push the third and fourth hinge connections toward one another during the remainder of the driving stroke of the pneumatic piston corresponding to forming the staple.

Improved gas powered surgical stapling apparatus including a pneumatic piston and a staple driver for advancing a staple to a staple forming position and then forming the staple, a relatively low force being required to advance the staple to the staple forming position and a relatively high force being required to form the staple, wherein the improvement comprises:

• a mechanical linkage between the pneumatic piston and the staple driver for producing from a substantially constant force provided by the pneumatic piston throughout its driving stroke the relatively low force required during the advancce of the staple to the staple forming position and the relatively high force required during forming of the staple;
• a manually operable control;
• means responsive to momentary operation of the manually operable control for normally causing the pneumatic piston to perform one complete cycle of operation including a driving stroke followed by a return stroke which returns the piston to its initial condition;
• and
• means responsive to operation of the manually operable control during the driving stroke of the pneumatic piston for interrupting the driving stroke and causing the piston to return to its initial condition.

Improved gas powered surgical stapling apparatus including a pneumatic piston and a staple driver for advancing a staple to a staple forming position and then forming the staple, a relatively low force being required to advance the staple to the staple forming position and a relatively high force being required to form the staple, wherein the improvement comprises:

• a mechanical linkage between the pneumatic piston and the staple driver for producing from a substantially constant force provided by the pneumatic piston throughout its driving stroke the relatively low force required during the advance of the staple to the staple forming position and the relatively high force required during forming of the staple;
• a manually operable control;
• and
• means responsive to momentary operation of the manually operable control for normally causing the pneumatic piston to perform one complete cycle of operation including a driving stroke followed by a return stroke which returns the piston to its initial condition, the means responsive to momentary operation of the manually operable control including:
• (a) a movable cam member mounted so that it normally travels with the pneumatic piston and having a driving stroke cam surface and a return stroke cam surface;
• (b) a cam follower for normally engaging the driving stroke cam surface during a driving stroke of the pneumatic piston and the return stroke cam surface during a return stroke of the piston and for causing pneumatic pressure to be applied to the pneumatic piston only while engaged with the driving stroke cam surface;
• and
• (c) means for initiating motion of the movable cam member so that the cam follower engages the driving stroke cam surface in response to operation of the manually operable control.

Improved gas powered surgical stapling apparatus including a pneumatic piston and a longitudinally movable staple driver for advancing a staple to a staple forming position and then forming the staple, a relatively large motion of the staple driver at relatively low force being required to advance the staple to the staple forming position and a relatively small motion of the staple driver at relatively high force being required to form the staple, wherein the improvement comprises a mechanical linkage between the pneumatic piston and the staple driver for producing from a substantially constant force provided by the pneumatic piston throughout its driving stroke the relatively large motion at relatively low force required to advance the staple followed by the relatively small motion at relatively high force required to form the staple, the mechanical linkage comprising:

• a toggle mechanism including (a) first and second bars, (b) a first pivotal mounting for the first bar, the first pivotal mounting having a fixed location, (c) a second pivotal mounting for the second bar, the second pivotal mounting being connected to the staple driver, and (d) a pivotal connection between the first and second bars intermediate the first and second pivotal mountings;
• and
• a wedge-shaped member connected to the pneumatic piston for operating the toggle mechanism, the wedge-shaped member having an end surface remote from the pneumatic piston and an inclined surface intermediate the end surface and the pneumatic piston, the end surface contacting the toggle mechanism adjacent the pivotal connection to apply a force to that portion of the toggle mechanism substantially parallel to the axis of motion of the staple driver during advance of the staple, and the inclined surface contacting the toggle mechanism adjacent the pivotal connection to apply a force to that portion of the toggle mechanism substantially perpendicular to the axis of motion of the staple driver during formation of the staple.

Improved gas powered surgical stapling apparatus including a pneumatic piston and a staple driver movable parallel to the axis of the pneumatic piston for advancing a staple to a staple forming position and then forming the staple, a relatively large motion of the staple driver at relatively low force being required to advance the staple to the staple forming position and a relatively small motion of the staple driver at relatively high force being required to form the staple, wherein the improvement comprises a mechanical linkage between the pneumatic piston and the staple driver for producing from a substantially constant force provided by the pneumatic piston throughout its driving stroke the relatively large motion at relatively low force required to advance the staple followed by the relatively small motion at relatively high force required to form the staple, the mechanical linkage comprising:

• a four bar linkage disposed in a plane parallel to the axis of the pneumatic piston and having a first hinge connection attached to the staple driver, an opposite second hinge connection fixed at a point on an axis through the first hinge connection parallel to the axis of the pneumatic piston, and third and fourth hinge connections respectively spaced on opposite sides of the axis through the first and second hinge connections;
• and
• cam surfaces connected to the pneumatic piston for operating on the third and fourth hinge connections to push the third and fourth hinge connections substantially parallel to the axis of the pneumatic piston during a first portion of its driving stroke corresponding to the advance of the staple and to squeeze the third and fourth hinge connections toward one another during the remainder of the driving stroke of the pneumatic piston corresponding to forming of the staple.

A self-contained gas powered holder for holding and actuating a cartridge containing surgical staples to cause at least one staple to be advanced to a staple forming position and then formed into a completed staple, a relatively low force being required to advance the staple to the staple forming position and a relatively high force being required to form the staple, comprising:

• a source of pressurized pneumatic fluid;
• a pneumatic cylinder pneumatically connected to the source of pressurized pneumatic fluid;
• a pneumatic piston mounted for reciprocal motion in the cylinder;
• and
• a mechanical linkage between the pneumatic piston and the actuatable part of the cartridge for producing from a substantially constant force provided by the pneumatic piston throughout its driving stroke the relatively low force required to cause the cartridge to advance the staple to the staple forming position and then the relatively high force required to cause the cartridge to form the completed staple, the mechanical linkage including:
• (1) a longitudinally movable link member coupled to the actuatable part of the cartridge;
• (2) a toggle mechanism including (a) first and second bars, (b) a first pivotal mounting for the first bar, the first pivotal mounting having a fixed location, (c) a second pivotal mounting for the second bar, the second pivotal mounting being connected to the link member, and (d) a pivotal connection between the first and second bars intermediate the first and second pivotal mountings;
• and
• (3) cam means connected to the pneumatic piston for slidably contacting a surface of the toggle mechanism to push the pivotal connection in a direction substantially parallel to the axis of motion of the link member during the advance of the staple to the staple forming position and to push the pivotal connection in a direction substantially perpendicular to the axis of motion of the link member during forming of the staple.

A self-contained gas powered holder for holding and actuating a cartridge containing surgical staples to cause at least one staple to be advanced to a staple forming position and then formed into a completed staple, a relatively low force being required to advance the staple to the staple forming position and a relatively high force being required to form the staple, comprising:

• a source of pressurized pneumatic fluid;
• a pneumatic cylinder pneumatically connected to the source of pressurized pneumatic fluid;
• a pneumatic piston mounted for reciprocal motion in the cylinder;
• and
• a mechanical linkage between the pneumatic piston and the actuatable part of the cartridge for producing from a substantially constant force provided by the pneumatic piston throughout its driving stroke the relatively low force required to cause the cartridge to advance the staple to the staple forming position and then the relatively high force required to cause the cartridge to form the completed staple, the mechanical linkage including:
• (a) a four bar linkage having a first hinge connection coupled to the actuatable part of the cartridge, an opposite second fixed hinge connection, and third and fourth hinge connections respectively spaced on opposite sides of the axis through the first and second hinge connections;
• and
• (b) cam means connected to the pneumatic piston and having first and second cam surfaces for respectively operating on the third and fourth hinge connections to push the third and fourth hinge connections substantially parallel to the axis through the first and second hinge connections when the relatively low force is required and to push the third and fourth hinge connections toward one another when the relatively high force is required.

A self-contained gas powered surgical stapler for advancing a staple to a staple forming position and then forming the staple, a relatively low force being required to advance the staple to the staple forming position and a relatively high force being required to form the staple, comprising:

• a source of pressurized gas in the stapler;
• a pneumatic actuator including a cylinder and a piston reciprocally mounted in the cylinder;
• gas conduit means including valve means for selectively conducting pressurized gas from the source of gas to the pneumatic actuator to drive the piston in a driving stroke;
• a longitudinally reciprocal staple driver for advancing and forming the staple;
• and
• mechanical coupling means between the piston and the staple driver for converting the substantially constant force available from the piston to the relatively low force required to advance the staple to the staple forming position during a first portion of the driving stroke of the piston and to the relatively high force required to form the staple during a second portion of the driving stroke of the piston, the mechanical coupling means including:
• (1) a toggle mechanism including (a) first and second bars, (b) a first pivotal mounting for the first bar, the first pivotal mounting having a fixed location, (c) a second pivotal mounting for the second bar, the second pivotal mounting being connected to the staple driver, and (d) a first pivotal connection between the first and second bars intermediate the first and second pivotal mountings;
• and
• (2) cam means connected to the pneumatic piston for slidably contacting a surface of the toggle mechanism to push the first pivotal connection in a direction substantially parallel to the reciprocal axis of the staple driver during the advance of the staple to the staple forming position and to push the first pivotal connection in a direction substantially perpendicular to the reciprocal axis of the staple driver during forming of the staple.