Patent ID: 7257918

Claim:
Improvement in a double action, hammer trigger mechanism for a firearm of a known type having a frame, a barrel for receiving a cartridge, a slide arranged to move longitudinally between a forward and a rearward position with respect to said barrel, said slide being spring-loaded in a forward direction and adapted to move in a rearward direction when the cartridge is fired, said slide defining a cam surface, a firing pin longitudinally slidable in the slide so as to strike the cartridge, a hammer arranged to pivot about a first pivot point on the frame, said hammer having a double action let-off pin disposed thereon and also defining a sear notch, spring biasing means urging said hammer toward the firing pin, a spring-loaded sear arranged to pivot about a second pivot point on the frame, said sear including a lip for cooperating with the sear notch to hold the hammer cocked when the hammer is pivoted against said spring biasing means, a trigger arranged to pivot about a third pivot point on the frame, said trigger having a trigger pivot pin thereon that is disposed so as to move in said forward direction when the trigger is pulled, a transfer bar having a first end connected to said trigger pivot pin, said transfer bar defining a transfer bar notch disposed to receive said double action let-off pin so as to enable said transfer bar to pivot the hammer in a cocking direction against said spring biasing means when the trigger is pulled, and a transfer spring biasing the first finger toward said cam surface, said improvement being characterized by: a single action let-off pin disposed on said sear, said transfer bar including a first finger cooperating with said cam surface when the slide is in a forward position, said transfer bar further including a second finger arranged to engage said single action let-off pin and pivot the sear when the trigger is pulled so as to release the hammer when the sear is holding the hammer cocked, said transfer bar first finger being arranged to cooperate with the slide cam surface to move said transfer bar notch away from the double action let-off pin to release the hammer when the trigger is pulled further to a double action let-off position when the sear is not holding the hammer cocked.