Syringes for making precision volume measurements

Claim 2

A syringe comprising a barrel, a main bore in the barrel opening at one end thereof, a needle receiving bore in the other end of the barrel substantially coaxial with the main bore and communicating therewith, a hollow needle removably engaged in the needle receiving bore, a syringe plunger extending through the main bore and the needle receiving bore to precisely engage within the hollow needle, sealing means in said needle receiving bore and including a resilient seal through which the plunger slidably moves, and means holding the needle in the needle receiving bore with the inner end of the needle in sealing engagement with said resilient seal, said means comprising a threaded boss on the end of the barrel, an internally threaded nut engaged with the boss the nut having an aperture through which the needle extends, shoulder means on the needle and a tapered helical spring acting between the nut and the shoulder means to resiliently urge the needle into sealing engagement with the seal.

Claim 3

A syringe according to claim 1 wherein a plunger support tube is secured at one end in the needle receiving bore and extends through the main bore, said plunger being slidable in said support tube, and the resilient seal is disposed in the needle receiving bore between the end of the support tube And the end of the needle.

Claim 4

A syringe comprising a barrel, a main bore in the barrel opening at one end thereof, a needle receiving bore in the other end of the barrel substantially coaxial with the main bore and communicating therewith, a hollow needle removably engaged in the needle receiving bore, a syringe plunger extending through the main bore and the needle receiving bore to precisely engage within the hollow needle, sealing means in said needle receiving bore and including a resilient seal through which the plunger slidably moves, and means holding the needle in the needle receiving bore with the inner end of the needle in sealing engagement with said resilient seal said means comprising a threaded boss on the end of the barrel, an internally threaded nut engaged with the boss the nut having an aperture through which the needle extends, shoulder means on the needle and resilient means acting between the nut and the shoulder means to resiliently urge the needle into sealing engagement with the seal, and secured to an operating button on the outer end of the plunger slidable in the main bore, the inner end of the sleeve engaging with the inner end of the main bore when the plunger reaches the limit of its movement in the needle, and volume indicating graduations on the barrel corresponding to axial positions of the sleeve which result in predetermined volumetric capacities of the needle.

Claim 5

A syringe comprising a barrel, a main bore in the barrel opening at one end thereof, a needle receiving bore in the other end of the barrel substantially coaxial with the main bore and communicating therewith, a hollow needle removably engaged in the needle receiving bore, a syringe plunger extending through the main bore and the needle receiving bore to precisely engage within the hollow needle, sealing means in said needle receiving bore and including a resilient seal through which the plunger slidably moves, and means holding the needle in the needle receiving bore with the inner end of the needle in sealing engagement with said resilient seal said means comprising a threaded boss on the end of the barrel, an internally threaded nut engaged with the boss the nut having an aperture through which the needle extends, shoulder means on the needle and resilient means acting between the nut and the shoulder means to resiliently urge the needle into sealing engagement with the seal, and secured to an operating button on the outer end of the plunger slidable in the main bore, the inner end of the sleeve engaging with the inner end of the main bore when the plunger reaches the limit of its movement in the needle, and volume indicating graduations on the barrel corresponding to axial positions of the sleeve which result in predetermined volumetric capacities of the needle.

Claim 6

A syringe comprising a barrel, a main bore in the barrel opening at one end thereof, a needle receiving bore in the other end of the barrel and an intermediate bore between the main bore and the needle receiving bore and coaxial therewith, the intermediate bore being of a diameter less than the diameter of both the main and needle receiving bores, a hollow needle in the needle receiving bore, a syringe plunger extending through the main bore to engage within the hollow needle, the plunger having an inner section of a diameter to slidably engage the main bore and an outer section of a diameter to engage closely within the needle and the intermediate bore, a resilient, annular seal in the needle receiving bore between the inner end of the needle and the inner end of the bore, and fastening means including a coil spring surrounding the needle and engaged with shoulder means on the needle and applying an axial force to urge resiliently the inner end of the needle into sealing engagement with the seal and compressing the seal against the inner end of the needle receiving bore.

Claim 7

A syringe comprising a barrel, a main bore in the barrel opening at one end thereof, a needle receiving bore in the other end of the barrel and an intermediate bore between the main bore and the needle receiving bore and coaxial therewith, the intermediate bore being of a diameter less than the diameter of both the main and needle receiving bores, a hollow needle in the needle receiving bore, a syringe plunger extending through the main bore to engage within the hollow needle, the plunger having an inner section of a diameter to slidably engage the main bore and an outer section of a diameter to engage closely within the needle and the intermediate bore, a resilient, annular seal in the needle receiving bore between the inner end of the needle and the inner end of the bore, and fastening means including a coil spring surrounding the needle and engaged with shoulder means on the needle and applying an axial force to urge resiliently the inner end of the needle into sealing engagement with the seal and compressing the seal against the inner end of the needle receiving bore.

Claim 8

A syringe according to claim 4 wherein the needle has a probiscus of a diameter less than that of the inner end portion of the needle into which the plunger slidably moves.

Claim 9

A syringe according to claim 4 wherein a repetitive delivery assembly is mounted on the barrel and connected to the plunger, the assembly including a member adjustably clamped to the outer surface of the barrel, elongated rod means extending through a hole in the member parallel with the axis of the main bore, means connecting the outer end of the rod means to the plunger for axial movement therewith, and shoulder means on the other end of the rod means engageable with the member to limit outward movement of the plunger wherein the barrel has volume indicating graduations on its outer surface corresponding to axial positions of the plunger for various volumetric capacities of the syringe.

Claim 10

A syringe according to claim 6 wherein the barrel has volume indicating graduations on its outer surface corresponding to axial positions of the plunger for various volumetric capacities of the syringe.