FILTER DEVICE IN TUBULAR FITTING FOR MEDICAL INJECTION EQUIPMENT AND THE LIKE

• US 3,817,389 A
• Filed: 01/15/1973
• Issued: 06/18/1974
• Est. Priority Date: 01/15/1973
• Status: Expired due to Term

• Current Assignee: Sherwood Medical Company (Medtronic Plc)
• Original Assignee: Theodore E. Weichselbaum
• Inventors: Weichselbaum, Theodore E.
• Primary Examiner(s): Zaharna, Samih N.
• Assistant Examiner(s): Burks, Richard W.
• Application Number:
  US05/323,726
• Time in Patent Office: 519 Days
• Field of Search: 128/214B,214C 210/446,448,451,452,457,496
• US Class Current: 210/448
• CPC Class Codes: A61M 2005/1652 Filter with duct, e.g. filtering element incorporated in a flow line, tube, duct
• CPC Class Codes: A61M 5/165 Filtering accessories, e.g. blood filters, filters for infusion liquids A61M1/14 , A61M1/34, A61M1/3627, A61M1/3679, A61M1/3687 take precedence; needle sets with incorporated air inlet filters A61M5/162
• CPC Class Codes: A61M 5/3145 Filters incorporated in syringes
• CPC Class Codes: B01D 35/00 Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
• CPC Class Codes: B01D 35/18 Heating or cooling the filters
• CPC Class Codes: B29C 65/46 heated by induction
• CPC Class Codes: B29C 65/7847 using vacuum to hold at least one of the parts to be joined vacuum work holders in general B25B11/005
• CPC Class Codes: B29C 66/5344 said single elements being substantially annular, i.e. of finite length, e.g. joining flanges to tube ends B29C66/5346 takes precedence
• CPC Class Codes: B29C 66/612 Making circumferential joints
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/7392 characterised by the material of at least one of the parts being a thermoplastic
• CPC Class Codes: B29C 66/742 to metals or their alloys
• CPC Class Codes: B29C 66/8322 Joining or pressing tools reciprocating along one axis
• CPC Class Codes: B29K 2023/12 PP, i.e. polypropylene
• CPC Class Codes: B29K 2067/003 PET, i.e. poylethylene terephthalate
• CPC Class Codes: B29K 2069/00 Use of PC, i.e. polycarbonates or derivatives thereof, as moulding material
• CPC Class Codes: B29L 2031/14 Filters optical filters B29L2011/0066, sieves or screens B29L2031/737
• CPC Class Codes: B29L 2031/7544 Injection needles, syringes

Abstract

A cylindrical, cup-shaped, porous, sintered powdered metal filter is sealed in a tubular thermoplastic fitting (e.g., the needle-retaining hub of a hypodermic needle or an adaptor or a connector in the line of an intravenous infusion set) by forcefitting the open end of the filter within an annular bead on the interior wall of the tubular fitting and induction heating the filter so that the thermoplastic bead will flow into the pores of the filter to form a continuous ring seal between the filter and the interior wall of the fitting.

Claims

1. A filter device for medical infusion and injection equipment and the like, comprising:

a generally cylindrical, cup-shaped, porous, sintered powdered metal filter element having an open distal end and a closed proximal end;

a tubular, thermoplastic fitting having a longitudinal passage extending axially therethrough;

a radially-inwardly projecting annulus on the internal peripheral wall of said longitudinal passage;

means defining a radially inwardly projecting seat on the internal peripheral wall of said longitudinal passage;

said filter element having a peripheral edge at said open distal end thereof;

said peripheral edge of said filter element being disposed on and in contact with said seat of said fitting;

said radially inwardly projecting annulus on the internal peripheral wall on said longitudinal passage having been softened and forced into pores of said filter element along a continuous peripheral ring adjacent to said peripheral edge of said open distal end of said filter element.

2. A filter device for medical infusion and injection equipment and the like, comprising:

a tubular member formed of relatively rigid thermoplastic, said tubular member having an internal annular projection therein;

a sintered, porous, powdered metal filter having an end surface and a continuous peripheral wall extending from said end surface;

said annular projection of said tubular member and said peripheral wall of said filter being sealed to one another along a continuous peripheral ring as a result of said filter and said annular projection having been heated to a temperature such that a portion of said annular projection flowed into pores of said peripheral wall of said filter and the subsequent cooling of said filter body and said annular projection.

3. The filter device of claim 2 wherein said filter is made from stainless steel particles.

4. The filter device article of claim 2 wherein said thermoplastic is a polycarbonate.

5. The filter device of claim 2 wherein said thermoplastic is a polyethylene terephthalate.

6. The filter device of claim 2 wherein said thermoplastic is a polypropylene.

7. A filter device for use as a part of an apparatus for the infusion or injection of parenteral fluid comprising:

a fitting formed of relatively rigid thermoplastic having an interior peripheral wall defining a passage therethrough;

an annular projection on said interior wall; and

a shoulder on said interior wall;

said shoulder being spaced from said projection;

a sintered, porous, powdered stainless steel tubular filter having a closed end and a continuous peripheral wall extending from said end and adapted for a force fit into said annular projection and to abut said shoulder in said fittinG;

said annular projection and said peripheral wall of said filter being in leakproof relation as a result of said filter and said annular projection having been heated to a temperature such that a portion of said projection flowed into pores of said peripheral wall and the subsequent cooling of said filter and said projection.