US3791560A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Seals (psc-14)
Assignee: PRECISION SAMPLING CORP
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Filing: 1970-08-21
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Granted: 1974-02-12
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Expires: 1990-08-21
Abstract
Abstract A method, and the apparatus formed by encapsulating and stress forming a thermoplastic material upon a male member, e.g., the needle or plunger of a syringe, or both, to provide a durable and effective leak-proof seal when inserted within enclosing walls defining an opening of restricted diameter. A portion of the said male member is capped with an oversized thermoplastic material, the cap is then reduced in size to correspond to the diameter of the member with which it is to be mated in forming the seal, and then heated up to or just below the softening temperature of the thermoplastic material, generally up to about 425*F., and preferably to about 300*F. The heat stressed member, which is characterized as having very thin layers or films of the stress formed thermoplastic covering the external surface of the member, can then be inserted into snug fit within the mating bore, e.g., the barrel of a syringe, and the tight fit will endure because of the elastic memory of the material by virtue of which it tends to expand to its former size and shape thereby pressing against the enclosing side walls forming the bore.
Inventors
- 👤 R Harris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:30
CPC Classifications
A; A61; A61M; A61M5/00; A61M5/178; A61M5/31; A61M5/315; A61M5/31511; A61M5/31513; B; B29; B29C; B29C55/00; B29C55/30; B29C65/00; B29C65/56; B29C65/565; B29C66/00; B29C66/01; B29C66/05; B29C66/10; B29C66/12; B29C66/122; B29C66/1222; B29C66/1224; B29C66/50; B29C66/51; B29C66/53; B29C66/534; B29C66/5344; B29C66/61; B29C66/612; A61M5/31525; A61M5/31531; B29C66/126; B29L; B29L2031/00; B29L2031/748; B29L2031/7494; B29L2031/753; B29L2031/7544; Y; Y10; Y10S; Y10S251/00; Y10S251/90
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
122 words
In combination, apparatus defined by an enclosing wall forming a tubular barrel, a reciprocable plunger of substantially uniform outside diameter fitted snugly within the bore of the barrel, a thermoplastic material, encapsulating the forward end of the plunger, heat stressed at a temperature below the melting point of said thermoplastic material, and reduced in thickness from a former greater thickness to a thickness ranging from about 0.001 inch to no greater than about 0.005 inch, the sum-total diameter of the plunger inclusive of the total thickness of the heat stressed thermoplastic material ranges up to about 0.042 inch, and the said thermoplastic material fits tightly and enduringly within the bore to form an effective leak-proof seal about the annulus of the plunger.
Claim 2
Dependent Claim
122 words
In combination, apparatus defined by an enclosing wall forming a tubular barrel, a reciprocable plunger of substantially uniform outside diameter fitted snugly within the bore of the barrel, a thermoplastic material, encapsulating the forward end of the plunger, heat stressed at a temperature below the melting point of said thermoplastic material, and reduced in thickness from a former greater thickness to a thickness ranging from about 0.001 inch to no greater than about 0.005 inch, the sum-total diameter of the plunger inclusive of the total thickness of the heat stressed thermoplastic material ranges up to about 0.042 inch, and the said thermoplastic material fits tightly and enduringly within the bore to form an effective leak-proof seal about the annulus of the plunger.
Claim 3
Dependent Claim
55 words
The apparatus of claim 1 wherein the tubular barrel is the barrel portion of a needle syringe, and the needle at the forward end of the barrel at the location wherein it is fitted onto the barrel is also provided with a similar heat stressed seal which prevents leakage about the annulus of the needle.
Claim 4
Dependent Claim
145 words
In apparatus constituting a small diameter male member, a portion thereof of which is of reduced diameter to provide a retention surface for an encapsulating thermoplastic covering material which, when pressed within enclosing walls defining a restricted opening of substantially corresponding diameter, forms an effective leak-proof seal the improvement which comprises providing a male member, inclusive of the thickness of the encapsulating covering thermoplastic material, of no greater than about 0.042 inch in diameter, and an encapsulating thermoplastic material of thickness ranging from about 0.001 to about 0.005 inch, said thermoplastic material having been reduced to said thickness from a material of greater thickness and heat set under stress at the reduced thickness at a temperature just below the softening temperature of the thermoplastic material, and said heat stressed thermoplastic material fits tightly and enduringly within the enclosing walls to form an effective leak-proof seal.
Claim 5
Dependent Claim
145 words
In apparatus constituting a small diameter male member, a portion thereof of which is of reduced diameter to provide a retention surface for an encapsulating thermoplastic covering material which, when pressed within enclosing walls defining a restricted opening of substantially corresponding diameter, forms an effective leak-proof seal the improvement which comprises providing a male member, inclusive of the thickness of the encapsulating covering thermoplastic material, of no greater than about 0.042 inch in diameter, and an encapsulating thermoplastic material of thickness ranging from about 0.001 to about 0.005 inch, said thermoplastic material having been reduced to said thickness from a material of greater thickness and heat set under stress at the reduced thickness at a temperature just below the softening temperature of the thermoplastic material, and said heat stressed thermoplastic material fits tightly and enduringly within the enclosing walls to form an effective leak-proof seal.
Claim 6
Dependent Claim
23 words
The apparatus of claim 3 wherein the thickness of the encapsulating heat set thermoplastic material ranges from about 0.0015 to about 0.0025 inch.
Claim 7
Dependent Claim
28 words
The apparatus of claim 3 wherein the diameter of the male member, inclusive of the thickness of the thermoplastic material, ranges from about 0.025 to about 0.042 inch.
Claim 8
Dependent Claim
11 words
The apparatus of claim 3 wherein the thermoplastic material is Teflon.
Claim 9
Dependent Claim
16 words
The apparatus of claim 3 wherein the male member is a needle of a micro syringe.
Claim 10
Dependent Claim
16 words
The apparatus of claim 3 wherein the male member is a plunger of a micro syringe.
Claim 11
Dependent Claim
24 words
The apparatus of claim 3 wherein the encapsulating thermo-plastic material has a history of having been heat-treated at temperatures ranging up to about 425*F.
Claim 12
Dependent Claim
22 words
The apparatus of claim 9 wherein the history of heat treat-ment was conducted at temperatures ranging from about 200*F. to about 300*F.
References Cited (Backward Citations)
DE386164C
Cited
US2473734A
Cited
US2473733A
Cited
US2608334A
Cited
CH274619A
Cited
US2895773A
Cited
US3050059A
Cited
US3093526A
Cited
US3147753A
Cited
CH411243A
Cited
US3290946A
Cited
US3537453A
Cited
US3577850A
Cited
US3619478A
Cited
US3634924A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |