Fastener driving device with enhanced sequential actuation

A fastener driving device comprising

• a frame structure presenting a handle portion constructed and arranged to be gripped by a user enabling the user to handle the device in portable fashion;
• nosepiece structure operatively fixed with respect to said frame structure defining a fastener drive track;
• a fastener driving element slidably mounted in said drive track;
• a manually actuated fastener driving system carried by said frame structure constructed and arranged to move said fastener driving element through successive operating cycles each including a drive stroke and a return stroke;
• a magazine assembly carried by said frame structure having fixed structure defining a fastener feed track leading to said drive track and movable structure constructed and arranged to enable a package of fasteners to be loaded in said magazine assembly and fed along said feed track so that the leading fastener of the fastener package is moved into said drive track to be driven outwardly thereof into a workpiece during the drive stroke of the fastener driving element;
• an actuating member constructed and arranged with respect to said frame structure to be moved rectilinearly in a direction generally parallel with said drive track between a normally biased inoperative position and an operative position;
• a trigger member constructed and arranged with respect to said frame structure to be manually pivoted between an inoperative position and an operative limiting position thereabove;
• a work contact assembly constructed and arranged with respect to said frame structure to be moved from a normally biased inoperative position into an operative position in response to the movement of said device into cooperating engagement with a workpiece;
• said work contact assembly including an upper structure movable along a generally rectilinear path between an inoperative position corresponding with the inoperative position of said work contact assembly and an operative position thereabove corresponding to the operative position of said work contact assembly;
• and
• an enabling member having one end pivotally connected to said trigger member, an opposite end operatively associated with an upper end of said upper structure and a central portion disposed below a lower end of said actuating member;
• a spring constructed and arranged with respect to said enabling member and said frame assembly to bias said enabling member into a normal inoperative limiting position with respect to said trigger member;
• the opposite end of said enabling member being constructed and arranged with respect to the upper end of said upper structure so that when said enabling member and said trigger member are in the inoperative positions thereof movement of said upper structure from the inoperative position thereof into the operative position will move the opposite end of said enabling member through a first arcuate path into a first position of said enabling member during which the central portion thereof in inoperable to move said actuating member into the operative position thereof;
• said enabling member when in said first position being constructed and arranged to move into a second position in response to the manual movement of said trigger member into the operative limiting position thereof during which the central portion of said enabling member is operable to move said actuating member into the operative position thereof;
• the relationship between the enabling member, said trigger member and said upper structure being such that (1) said enabling member is retained in said second position so long as said trigger member and said work contacting assembly are retained in the operative positions thereof, and (2) when said enabling member is in said second position and said trigger member is retained in the operative limiting position thereof said enabling member will be moved into a third position in response to a predetermined movement of said upper structure toward the inoperative position thereof either by virtue of the normal rebound of the device at firing or by a manual movement of said device away from the workpiece;
• the relationship between said actuating member and said enabling member being such that the movement of said enabling member between the second and third positions thereof is operable to allow said actuating member to move into the normally biased inoperative position thereof;
• the opposite end of said enabling member being movable through a second arcuate path during the movement of said enabling member from the second position thereof into the third position thereof so as to be out of the rectilinear path of said upper structure if the upper structure is moved back into the operative position thereof while said trigger member is retained in the operative limiting position thereof;
• the opposite end of said enabling member when said enabling member is in said third position being biased to move through a third arcuate path by the release of said trigger member from the manual movement thereof into the operative limiting position thereof;
• the third arcuate path of movement of the opposite end of said enabling member being configured to move the opposite end of said enabling member (1) into a position overlying the upper end of said upper structure when said upper structure is disposed in the inoperative position thereof and (2) into abutting engagement with said upper structure when the upper structure is in the operative position thereof.