Apparatus for stitching with synthetic resin staples or tacks

Claim 1

A sewing apparatus for stitching a thick work such as leather or hard plastic, said apparatus comprising: a bed adapted to receive thereon work; a rigid arm fixedly positioned above the bed; an external cylinder integrally fitted at an end of the arm; an internal cylinder slip-fitted into the external cylinder along the axis of the external cylinder and having at a lower end thereof outwardly extending work presser means for pressing against the bed the work received thereon; means, operatively connected between said external and internal cylinders, for selectively vertically moving said internal cylinder with respect to said external cylinder between an upper position whereat said work presser means is spaced from said bed and a lower position whereat said work presser means presses work against said bed, said internal cylinder moving means comprising a first rack on an outer wall of said internal cylinder, a first pinion engaged with said first rack and pivotally supported on said external cylinder, and a first lever for rotating said first pinion and thereby moving vertically said first rack and said internal cylinder; a guide cylinder slip-fitted into the internal cylinder and having a lower end defined by two laterally spaced downwardly extending members having respective outer surfaces bevelled to define sharpened ends, said guide cylinder having therein a vertical passage extending between said sharpened ends; means, operatively connected between said internal cylinder and said guide cylinder, for selectively vertically moving said guide cylinder with respect to said internal cylinder between a lower position whereat said sharpened ends pierce the work to form openings therein and an upper position raising said sharpened ends above the thus pierced work, said guide cylinder moving means comprising a second rack on an outer wall of said guide cylinder, a second pinion engaged with said second rack and pivotally supported on said internal cylinder, and a second lever for rotating said second pinion and thereby for moving vertically said second rack and said guide cylinder; p1 staple feeder means for housing a supply of synthetic resin staples arranged in a row and for feeding the staples sequentially through said external, internal and guide cylinders into said vertical passages; staple driver means, provided inside said vertical passage and arranged to slide along the axis of the guide cylinder; driving means, mounted in said rigid arm and operatively connected to said staple driver means, for moving said staple driver means downwardly within said vertical passage and thereby for driving downwardly an endmost staple positioned in said vertical passage and inserting legs of the staple through openings formed previously by said sharpened ends of said guide cylinder; and recessed anvil means, formed in a surface of the bed aligned with said staple drive means, for pressing and deforming the ends of the staples.