Key assembly for vehicle ignition locks

• US 20030051520A1
• Filed: 07/23/2002
• Published: 03/20/2003
• Est. Priority Date: 08/26/1993
• Status: Active Grant

• Current Assignee: Strattec Security Corporation
• Original Assignee: Strattec Security Corporation
• Inventors: McGuire, Ronald J., Schuster, William P., Janssen, David C.
• Granted Patent: US 6,948,344 B2
• Time in Patent Office: Days
• US Class Current: 70/278.3
• CPC Class Codes: E05B 19/04 Construction of the bow or head of the key; Attaching the bow to the shank
• CPC Class Codes: G06K 19/04 characterised by the shape
• CPC Class Codes: G06K 19/048 the record carrier being shaped as a key
• CPC Class Codes: G07C 9/00944 Details of construction or manufacture
• CPC Class Codes: Y10T 70/7079 Key rotated [e.g., Eurocylinder]
• CPC Class Codes: Y10T 70/7802 Multi-part structures
• CPC Class Codes: Y10T 70/7876 Bow or head
• CPC Class Codes: Y10T 70/7904 Magnetic features

Abstract

A method of decreasing resonant frequency shifting of an electrical circuit mounted on a vehicle key includes providing a frame in an opening in the head portion of a vehicle key and locating the transponder in the frame. The frame comprises substantially rigid non-metallic material, and the frame includes a support structure for supporting the transponder while decreasing forces produced on the transponder by thermal expansion and contraction of the head portion of the key, thereby decreasing shift in the resonance of the electrical circuit of the transponder. The frame, the transponder and the head portion of the key are overmolded providing an outer covering that encloses and protects the transponder.

Claims

1. A method of decreasing resonant frequency shifting of an electrical circuit of a transponder mounted on a substantially rigid vehicle key including a blade portion and a head portion, the key having an opening in one of said portions, comprising the steps of:

providing a frame in said opening of said vehicle key, the frame comprising a mounting portion of a substantially rigid non-metallic material and a support structure;

supporting the transponder in the frame with the support structure for lessening forces produced on the electrical circuit by thermal expansion and contraction of at least said one portion of the key, thereby decreasing resonant frequency shifting of said electrical circuit of said transponder; and

overmolding said frame, the transponder and said one portion of said key with an overmold material.

2. The method as defined in claim 1, wherein said overmolding step includes forming overmold material over at least the transponder and the head portion of said key for retaining said transponder on said key.

3. The method as defined in claim 2, wherein said overmold material is softer than said rigid non-metallic material.

4. The method as defined in claim 1, further including forming said support structure to include a plurality of tabs in contact with the transponder.

5. The method as defined in claim 1, including forming said support structure to include thin support portions in contact with the transponder, wherein the thickness of the thin support portions is less than the thickness of the transponder.

6. The method as defined in claim 1, further including forming said support structure to include at least one thin support portion having a first end contacting the transponder and having a second end contacting said overmolding material.

7. The method as defined in claim 1, further including forming at least said mounting portion of said frame of a material from the group consisting of polypropylene and hydrocarbon resin material.

8. An apparatus for decreasing resonant frequency shifting of an electrical circuit of a transponder mounted on a substantially rigid vehicle key including a blade portion and a head portion, said apparatus comprising:

a frame comprising a mounting portion of a substantially rigid non-metallic material, and a support structure for supporting the transponder while lessening forces produced on the transponder by thermal expansion and contraction of the head portion of the key, thereby decreasing resonant frequency shifting of said electrical circuit; and

an overmold material for containing said frame, the transponder and the head portion of said key.

9. The apparatus as defined in claim 8, wherein said frame is constructed and arranged to enable said overmold material to contact said transponder for retaining said transponder on said key.

10. The apparatus as defined in claim 8, wherein said overmold material is softer than said frame material.

11. The apparatus as defined in claim 8, wherein said support structure includes a plurality of tabs contacting the transponder.

12. The apparatus as defined in claim 8, wherein said support structure includes at least first and second thin support portions, at least one of said first thin support portions contacting the transponder, and the thickness of said thin support portions being less than the thickness of the transponder.

13. The apparatus as defined in claim 12, wherein at least a second one of said thin support portions is contacted by said overmold material.

14. A method of mounting a transponder on a substantially rigid vehicle key including a blade portion and a head portion, comprising the steps of:

molding a non-metallic frame including a mounting portion for mounting the transponder on said head portion of said key, said frame including a support structure for supporting the transponder primarily at sides of the transponder while allowing a majority of planar surface areas of the transponder to be located adjacent mold surfaces to reduce thermal shock due to contact with liquid molding material for said frame; and

overmolding at least a portion of said frame and the transponder with an overmold material.

15. The method as defined in claim 14, wherein the step of overmolding includes molding said overmolding material in contact with the transponder for retaining said transponder on said key.

16. The method as defined in claim 15, wherein said overmolding material is softer than said frame.

17. The method as defined in claim 14, including forming said support structure to include a plurality of tabs in contact with the transponder.

18. The method as defined in claim 14, including forming said support structure to include thin support portions in contact with the transponder, wherein the thickness of the thin support portions is less than the thickness of the transponder.

19. The method as defined in claim 14, including forming said support structure to include at least one thin support portion having a first side contacting the transponder and having a second side contacting said overmolding material

20. The method as defined in claim 14, including using a compressible material to form said support structure.

21. The method as defined in claim 14, wherein the step of molding includes injecting molding material through at least one gate, which splits the molding material into portions which flow along an exterior surface of the transponder.

22. The method as defined in claim 14, wherein the step of molding includes injecting molding material through at least one gate, to a corner of the transponder, splitting the molding material into two portions.

23. The method as defined in claim 22, including positioning a deflecting device at said corner of the transponder for protecting the transponder while the undermold material is being injected into the mold.

24. An apparatus for mounting a transponder on a substantially rigid vehicle key having a blade portion and a head portion, said apparatus comprising:

a molded structure comprising a non-metallic frame for mounting the transponder on said head portion of said key, said frame including a support structure supporting the transponder at sides of the transponder while allowing a majority of opposing planar surface areas of the transponder to be located adjacent mold surfaces during molding of the frame and support structure to reduce thermal shock due to contact with liquid molding material for said frame; and

an overmolded structure at least partially enclosing said frame and the transponder.

25. The apparatus as defined in claim 24, wherein said overmolded structure substantially encloses said frame, the transponder and said head portion of the key, and wherein frame enables overmolding material to contact and retain the transponder.

26. The apparatus as defined in claim 24, wherein said overmolding material is softer than said frame material.

27. The apparatus as defined in claim 24, wherein said support structure contacts the transponder with only a plurality of isolated tabs.

28. The apparatus as defined in claim 24, wherein said support structure contacts the transponder with support portions thinner than a height of a side of the transponder.

29. The apparatus as defined in claim 28, wherein at least one of said support portions help contain the transponder on one side of said support portion and contact said overmolding material on another side of said support portion.

30. An apparatus for mounting a transponder, said apparatus comprising:

a substantially rigid vehicle key comprising an integral blade portion and head portion;

an undermold structure supporting said transponder; and

an overmold structure substantially enclosing said undermold structure, the transponder and said head portion.

31. The apparatus as defined in claim 30, wherein the undermold structure defines a plurality tabs, the tabs extending along the planar surfaces of the transponder.

32. The apparatus as defined in claim 30, wherein the undermold structure defines a plurality of pairs of matched tabs, the tabs of each pair of tabs extending along planar surfaces of the transponder, with the tab pairs being located along the sides of the transponder near diametrically opposed corners thereof.

33. The apparatus as defined in claim 32, wherein the plurality of pairs of tabs comprise four pair of tabs, each tab pair being located at a different corner of the transponder.

34. The apparatus as defined in claim 30, wherein the transponder is offset relative to the axis of the blade of the key.

35. The apparatus as defined in claim 30, wherein the material of the overmold structure is softer than the material of the undermold structure, and wherein the material of the overmold structure comprises the majority of material that contacts the transponder.

36. The apparatus as defined in claim 30, wherein the undermold structure includes a compressible material.

37. An apparatus for mounting a transponder on a substantially rigid vehicle key having a blade portion and a head portion;

said apparatus comprising;

a molded structure comprising a frame for mounting the transponder on said head portion of said key, said frame including a support structure supporting the transponder and defining a region at least above a surface of the transponder; and

an overmolded structure at least partially filling the region for enclosing the transponder.

38. An apparatus for mounting a transponder on a substantially rigid vehicle key having a blade portion and a head portion, the transponder including an antenna at one end thereof, said apparatus comprising:

a molded structure comprising a non-metallic frame for mounting the transponder on said head portion of said key in a transponder mounting region that is at least partially defined by a metal portion of the key head that at least partially encircles the transponder and which absorbs torsional and bending forces applied to the vehicle key in use;

said frame including a support structure supporting the transponder at sides of the transponder and with at least said one end of the transponder spaced from a metal portion of the key defining a gap at least between said one end of the transponder and said metal key portion; and

an overmolded structure enclosing said frame and the transponder.