Frederick L Plouff

48788996, Nov 7, 1989

Feb 26, 1988

7/160712

Frederick L. Plouff - Wakefield MA

A61M 500

604110

The disposable syringe comprises a cylindrical barrel having a side wall, an axis, and two ends, one of which, the distal end, has an inlet-outlet end for the administration of fluids. A cylindrical plunger is mounted snugly and fluid tight for axial movement within the barrel. An actuating rod has one, distal end connected to the plunger. The barrel at its other, proximal end has means for guiding the actuating rod axially. One or more pins of spring material are within the barrel, one, proximal end imbedded in the barrel side wall, and the other, free distal end located nearer the distal end of the barrel then the location of the proximal end of the pin. The plunger is movable from a position nearer the proximal barrel end to a position nearer the other, distal barrel end beyond the distal end of the pin, the barrel head on such movement camming the pin head outward from its normal position toward the wall of the barrel until the free end is freed by elasticity of the pin to return to its normal position radially within the wall, whereby on such movement the head is captured by the interposed pin free end to prevent return movement of the head toward the proximal end of the barrel thereby to prevent re-use of the syringe.

50909622, Feb 25, 1992

Apr 28, 1989

7/344992

Maurice J. Landry - Nashua NH
Frederick L. Plouff - Wakefield MA

FLP Enterprises, Inc. - Andover MA

A61M 500

604110

A single use syringe in the form of a cylindrical barrel with a first end attached to a hypodermic needle. A plunger and piston in the barrel draw liquid into the syringe through the hypodermic needle and eject the liquid through the hypodermic needle. The plunger includes a detent formed at an intermediate location. An insert at the second end of the barrel includes at least one cantilevered, longitudinally extending resilient arm with a follower at a free end thereof that rides over the plunger. When the plunger is pushed to a final position, the follower drops into the plunger detent to block any further longitudinal motion of the plunger and piston preventing any subsequent use.

51279061, Jul 7, 1992

Apr 2, 1991

7/679323

Maurice J. Landry - Nashua NH
Frederick L. Plouff - Wakefield MA

FLP Enterprises, Inc. - Andover MA

A61M 500

604110

A single use syringe in the form of a cylindrical barrel with a port end attached to a hypodermic needle. A plunger and piston in the barrel transfer liquid into or from the syringe through a port end. The plunger includes a locking structure formed at a predetermined position. An insert at a remote end of the barrel includes at least one cantilevered, longitudinally extending resilient arm with a radially acting, inwardly extending follower at a free end thereof that rides over the plunger. When the plunger moves to a locking position, the follower engages the plunger locking structure to block any further longitudinal motion of the plunger and piston preventing any subsequent use of the syringe.