Syringe/plunger coupling
First Claim
1. An injector for injecting fluids from a syringe into an animal subject comprising:
- a plunger drive ram bidirectionally movable along an axis;
a motor drivingly coupled to said drive ram to selectively advance and retract said drive ram along said axis;
a syringe mount engageable with a syringe to position said syringe relative to said injector to permit said drive ram to engage and move a plunger within said syringe;
a coupling mechanism located at and movable with the forward end of said drive ram for engagement with a coupling element extending rearwardly from the plunger of a syringe engaged by said syringe mount, said coupling mechanism including first and second movable members having faces spring-biased relative to each other, which each bear a plurality of teeth, movement of said members altering the distance between said faces to permit said faces to slide along and grip the rearwardly extending coupling element of a syringe plunger upon relative advancement of said ram toward said coupling element and to retract the syringe plunger with reduced lost motion therebetween upon initiation of relative rearward movement of the drive ram with respect to the syringe plunger; and
a control circuit controlling said motor to selectively bidirectionally advance and retract said drive ram and syringe plunger to transfer fluid from and to said syringe respectively.
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0 Petitions
Accused Products
Abstract
A medical fluid injector, replaceable syringe, and coupling mechanism to engage the syringe plunger to the plunger drive ram of the injector are provided wherein coupling involves a cam cleat-like mechanism, thereby allowing for cooperative movement between the plunger drive ram and syringe plunger. The coupling mechanism of the plunger drive ram is provided with first and second movable members, each having toothed, arcuate surfaces, while the coupling mechanism of the syringe plunger is provided with a knurled extension. Disengagement of the coupling mechanism is facilitated by translational movement of a face plate located on the forward end of the injector housing.
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Citations
11 Claims
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1. An injector for injecting fluids from a syringe into an animal subject comprising:
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a plunger drive ram bidirectionally movable along an axis;
a motor drivingly coupled to said drive ram to selectively advance and retract said drive ram along said axis;
a syringe mount engageable with a syringe to position said syringe relative to said injector to permit said drive ram to engage and move a plunger within said syringe;
a coupling mechanism located at and movable with the forward end of said drive ram for engagement with a coupling element extending rearwardly from the plunger of a syringe engaged by said syringe mount, said coupling mechanism including first and second movable members having faces spring-biased relative to each other, which each bear a plurality of teeth, movement of said members altering the distance between said faces to permit said faces to slide along and grip the rearwardly extending coupling element of a syringe plunger upon relative advancement of said ram toward said coupling element and to retract the syringe plunger with reduced lost motion therebetween upon initiation of relative rearward movement of the drive ram with respect to the syringe plunger; and
a control circuit controlling said motor to selectively bidirectionally advance and retract said drive ram and syringe plunger to transfer fluid from and to said syringe respectively. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
a cylindrical barrel;
a plunger snugly slidable in said cylindrical barrel, said plunger having a rearwardly facing drive ram engaging coupling element thereon in the shape of a rearwardly facing extension exhibiting no discontinuity in its transverse cross-sections along the portion of said extension gripped by said coupling mechanism; and
a discharge tip in fluid communication with said cylindrical barrel.
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10. The injector of claim 9 wherein said extension is knurled.
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11. The injector of claim 9 wherein said injector comprises injector mating sections positioned about said syringe mounting, and said syringe comprises syringe mating sections positioned in a plane perpendicular to the axis of the body of the syringe and arranged so as to align with the injector mating sections.
Specification