Delivery gun for dispensing bone bement from a cartridge, the gun having a multi-link linkage and capable of dispensing the cement at different flow rates

A gun for dispensing bone cement from a cartridge, said gun including:

• a casing, said casing having a front end;
• a cradle attached to said casing so as to be located forward of the front end of said casing, said cradle shaped to receive a cartridge containing bone cement;
• a drive rod mounted to said casing so as to extend forward of said casing, said drive rod having a forward end shaped to act against a piston integral with the cartridge and said drive rod being moveably mounted to said casing so that the forward end of said drive rod can abut and push the piston away from said casing;
• a drive mechanism, said drive mechanism including a gripping member disposed in said casing that is positioned to engage said drive rod so that the forward movement of said gripping member results in said gripping member engaging said drive rod and urging said drive rod forward;
• a linkage assembly, said linkage assembly including:
• a trigger, said trigger being pivotally mounted to said casing to pivot about a first axis and having an exposed section that extends out of said casing for manual actuation;
• a first link disposed in said casing and having a first end pivotally coupled to said trigger so as to be displaced upon the pivoting of said trigger;
• and
• a second link pivotally mounted to said casing so as to pivot around a second axis, said second link being pivotally coupled to said first link and wherein said gripping member is positioned to be displaced by the pivotal movement of said second link so that said gripping member undergoes forward movement that results in the like forward movement of said drive rod;
• a third link moveably connected to said linkage assembly for displacement by said linkage assembly, said third link having:
• an engaged position in which said third link, when displaced by said linkage assembly, engages said gripping member so as to cause forward movement of said gripping member and the like forward movement of said drive rod wherein, the forward movement of said drive rod as a result of said third link moving said gripping member is at a higher speed than when the movement of said second link results in the forward movement of said gripping member and said drive rod;
• and a disengaged position in which the said third link does not engage said gripping member so that the displacement of said third link by said linkage assembly does not result in forward movement of said gripping member so that the movement of said trigger results in said second link moving said gripping member forward.

A gun for dispensing bone cement from a cartridge, said gun including:

• a casing, said casing having a front end;
• a cradle attached to said casing so as to be located forward of the front end of said casing, said cradle shaped to receive a cartridge containing bone cement;
• a drive rod mounted to said casing so as to extend forward of said casing, said drive rod having a forward end shaped to act against a piston integral with the cartridge and said drive rod being moveably mounted to said casing so that the forward end of said drive rod can abut and push the piston away from said casing;
• a drive mechanism, said drive mechanism including:
• a trigger, said trigger having an exposed section that extends out of said casing for manual actuation, said trigger being pivotally mounted to said casing;
• a first link pivotally coupled to said trigger, said first link being disposed in said casing;
• a second link pivotally mounted to said casing said second link being pivotally coupled to said first link for displacement by said first link;
• a first pawl pivotally connected to said first link for displacement by said first link, said first pawl having an engaged position in which said first pawl, when displaced by said first link, presses against said drive rod so as to cause forward movement of said drive rod and a disengaged position in which said first pawl, when displaced by said first link, does not engage said drive rod;
• and
• a second pawl pivotally connected to said second link for displacement by said second link, said second pawl positioned to engage said drive rod so that when said second pawl is displaced by said second link, said second pawl presses against said drive rod so as to cause forward movement of said drive rod
• wherein, said first and second links and said first and second pawls are arranged so that:
• when said first pawl is in the engaged position and displaced by said first link, the displacement of said first pawl results in the forward movement of said drive rod at a higher speed than when said second pawl moves said drive rod;
• and when said first pawl is in the disengaged position, the movement of said trigger results in said first link, said second link and said second pawl cooperating to move said drive rod forward.