Nail feed mechanism

Claim 1

In a fastener driving apparatus including a fastener driving element movable through a cycle of operation including a drive stroke and a return stroke, an improved mechanism for feeding successive fasteners from a fastener package into a position to be driven by said fastener driving element during the drive stroke thereof, the fastener package being in the form of a strip of circular headed nails interconnected in series with their shanks in spaced parallel relation, said mechanism comprising a nose piece assembly defining an elongated drive track receiving said fastener driving element therein during the operating cycle thereof and a nail feeding track communicating laterally with said drive track, an actuating member carried by said nose piece assembly for movement through an operating cycle including an operative stroke in a direction along the extent of said nail feeding track toward said drive track and a return stroke, nail feeding means operatively connected with said actuating member for movement through operative and return strokes therewith and mounted for movement relative to said actuating member for resiliently biased lateral movement into a nail feeding position extending across said nail feeding track, said nail feeding means having first surface means operable during successive operative strokes of said actuating member with said nail feeding means in said feeding position to engage successive second nails of a fastener package Along the trailing shank surface thereof and to successively move the leading nails of the package into said drive track, said nail feeding means having second surface means spaced from said first surface means in a direction inwardly of said drive track a distance less than the spacing between the axes of adjacent nail shanks for engaging the trailing shank surface of the last nail of the package during an operative stroke of said actuating member so as to move the last nail of the package into a position within the drive track wherein the shank is disposed substantially entirely within the drive track and the trailing portion of the head is disposed within the nail feeding track, said nosepiece assembly including downwardly and forwardly inclined cam surface means disposed at the juncture between said nail feeding track and said drive track in a position to be engaged by the trailing portion of the head of a nail moved by said second surface means into said position when such nail is initially moved outwardly of said drive track during the drive stroke of said fastener driving element to thereby cam said nail fully within said drive track for substantially axial aligned subsequent movement outwardly thereof, and nail holding means mounted on said nose piece assembly for resiliently biased movement toward a nail holding position, said nail holding means including first surface means operable when said nail holding means is disposed in said nail holding position to be engaged by the shanks of successive nails within said nail feeding track during the feeding movement thereof so as to move said nail holding means out of said nail holding position and permit said nail holding means to be resiliently biased back into said nail holding position at the end of each successive nail feeding movement, said nail holding means including second surface means operable when said nail holding means is disposed in said nail holding position to engage the trailing shank surfaces of successive nails in said nail feeding track during successive return strokes of said actuating member so as to prevent movement thereof in a direction away from said drive track, said nail feeding means including second surface means operable when said nail feeding means is disposed in said nail feeding position to be engaged by the shanks of successive nails within said nail feeding track during successive return strokes of said actuating member so as to move said nail feeding means out of said feeding position and permit the same to be resiliently biased back into said nail feeding position at the end of each successive return stroke of said actuating member.