Staple driving device with improved staple jam clearing mechanism

Claim 1

A staple driving device comprising means defining a staple drive track, a staple driving element slidably mounted in said drive track for downward movement through a staple driving stroke and upward movement through a return stroke, said drive track defining means including a rigid structure having opposed flat side surfaces defining the sides of said drive track for guidingly engaging the legs of a leading staple during the driving movement thereof, a forwardly facing flat surface extending between said side surfaces for guidingly engaging the rear surface of a leading staple during the driving movement thereof, and longitudinally extending surfaces defining an opening of a staple-shaped configuration extending fowardly into communication with said drive track defining surfaces, staple magazine means for receiving a stick of staples and feeding successive leading staples forwardly into said drive track through said staple-shaped opening to be driven outwardly of said drive track into a workpiece by said staple driving element during the staple driving stroke thereof, said drive track defining means also including a rigid member mounted on said rigid structure forwardly of said staple-shaped opening for (1) translational movement in a direction parallel with the movement of said staple driving element between a locked operating position and a raised unlocked position and (2) pivotal movement between said raised unlocked position and a forwardly extending open access position, said rigid member having (1) staple stop surface means facing rearwardly when said rigid member is in said locked operative position for engaging the forward surface of a leading staple after the feeding movement thereof through said staple-shaped opening by said magazine means, (2) staple guiding surface means facing rearwardly when said rigid member is in said locked operative position for guidingly engaging the forward surface of a leading staple during the driving movement thereof by said staple driving element, and (3) cam surface means extending downwardly and forwardly from the upper end of said staple stop surface means when said rigid member is in said locked operative position operable (1) when said rigid member is pivoted from said unlocked position into said open access position to permit limited forward movement of a leading staple fed through said opening, and (2) when said rigid member is pivoted from said open access position to move a leading staple rearwardly into a position of alignment with said drive track.