Key assembly for vehicle ignition locks

• US 6,427,504 B1
• Filed: 01/27/1998
• Issued: 08/06/2002
• Est. Priority Date: 08/26/1993
• Status: Expired due to Fees

• Current Assignee: Strattec Security Corporation
• Original Assignee: Strattec Security Corporation
• Inventors: Schuster, William P., Janssen, David C., McGuire, Ronald J.
• Primary Examiner(s): Gall, Lloyd A.
• Application Number:
  US09/014,311
• Time in Patent Office: 1,652 Days
• Field of Search: 704/08, 702/781, 702/782, 702/783, 702/784, 702/785, 702/786, 702/787, 703/95, 704/13, 702/76, 702/77, 702/79--83, 702/791, 702/831
• 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. The combination comprising:

a substantially rigid vehicle key including a blade portion and a head portion;

a transponder having first and second surfaces; and

apparatus for mounting the transponder on the key, said apparatus comprising;

a frame including a mounting portion of a first substantially rigid non-metallic material, and a support structure of said first material for supporting the transponder, said support structure including a first series of individual tabs contacting said first surface of the transponder only near corners of the transponder and a second series of individual tabs contacting said second surface of the transponder only near corners of the transponder; and

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

2. The combination as defined in claim 1, wherein said frame is constructed and arranged to enable said second material to contact said transponder for retaining said transponder on said key.

3. The combination as defined in claim 1, wherein said second material is softer than said first material.

4. The combination as defined in claim 1, wherein said mounting portion is spaced from the transponder on a plurality of sides of the transponder, defining voids between the transponder and the mounting portion, said voids extending substantially the length of the sides of the transponder, and wherein said second material fills said voids.

5. A vehicle key assembly comprising:

a substantially rigid key having a blade portion and a head portion;

a transponder; and

a molded structure including a frame of a non-metallic material 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 surfaces 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, said planar surfaces having a length and a width, said support structure including a plurality of finger-like projections overlying said planar surfaces of the transponder, each of said projections contacting one of said planar surfaces of the transponder over only a portion of the length and width of the planar surface, providing substantially point contact with the transponder; and

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

6. The vehicle key assembly as defined in claim 5, wherein said overmolded structure substantially encloses said frame, the transponder and said head portion of the key, and wherein said frame is configured to enable said overmolding material to contact and retain the transponder.

7. The vehicle key assembly as defined in claim 5, wherein said overmolding material is softer than said frame material.

8. The vehicle key assembly as defined in claim 5, wherein said support structure contacts the transponder with support portions thinner than a height of a side of the transponder.

9. The vehicle key assembly as defined in claim 8, wherein at least one of said support portions helps contain the transponder on one side of said one support portion and contacts said overmolding material on another side of said one support portion.

10. The combination comprising:

a substantially rigid vehicle key including a blade portion and a head portion;

a transponder including an electrical circuit; and

apparatus for mounting the transponder on the key and decreasing resonant frequency shifting of the electrical circuit of the transponder when mounted on the substantially rigid vehicle key, said apparatus comprising;

a frame including a mounting portion of a first substantially rigid non-metallic material coupled to the key and spaced apart from the transponder on a plurality of sides of the transponder, and a support structure of said first material interposed between said mounting portion and the transponder in contact with the transponder, the frame 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, said support structure including at least a first series of thin individual support tabs and a second series of thin individual support tabs contacting the transponder on first and second surfaces, respectively, only at corners of the transponder and the thickness of said thin support tabs being less than the thickness of the transponder; and

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

11. The combination as defined in claim 10, wherein at least a second one of said thin support tabs is contacted by said second material.

12. A vehicle key assembly comprising:

a substantially rigid key having a blade portion and a head portion,

a transponder including a coil at one end thereof, the transponder having a first generally planar surface and a second generally planar surface extending parallel to said first planar surface;

a molded structure including a non-metallic frame 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 said coil at said one end of the transponder spaced from a metal portion of the key by a portion of said support structure, said portion of said support structure including a void which extends at least between said first and second planar surfaces at said one end of the transponder substantially the length of said one end of the transponder; and

an overmolded structure enclosing said frame and the transponder with a portion of said overmolded structure filling said void.

13. A vehicle key assembly comprising:

a substantially rigid key including an integral blade portion and head portion;

a transponder, the transponder being generally rectangular in shape and having a first generally planar surface and a second generally planar surface extending parallel to said first planar surface; and

an undermold structure of a first material supporting said transponder on said key, said undermold structure defining a plurality of individual tabs contacting the transponder, including a first series of tabs located only at corners of the first planar surface and a second series of tabs located only at corners of the second planar surface; and

an overmold structure of a second material, said overmold structure substantially enclosing said undermold structure, said transponder and said head portion.

14. The vehicle key assembly as defined in claim 13, wherein the undermold structure defines a plurality of pairs of matched tabs, first and second tabs of each matched pair of tabs extending along said first and second planar surfaces, respectively, of the transponder, with the tab pairs being located along the sides of the transponder near diametrically opposed corners thereof.

15. The vehicle key assembly as defined in claim 14, wherein the plurality of pairs of matched tabs comprise four pair of matched tabs, each tab pair being located at a different corner of the transponder.

16. The assembly as defined in claim 13, wherein the transponder is offset relative to the axis of the blade of the key.

17. The vehicle key assembly as defined in claim 13, wherein the second material is softer than the first material, and wherein the material of the overmold structure comprises the majority of material that contacts the transponder.

18. The assembly as defined in claim 13, wherein the undermold structure includes a compressible material.