Key having an air coil antenna and a method of construction

• US 5,732,579 A
• Filed: 05/29/1997
• Issued: 03/31/1998
• Est. Priority Date: 11/30/1994
• Status: Expired due to Fees

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Mittertrainer, Peter, D'Hont, Loek
• Primary Examiner(s): Gall, Lloyd A.
• Application Number:
  US08/865,583
• Time in Patent Office: 306 Days
• Field of Search: 70/276-283, 70/395, 70/408, 70/413, 235/375, 235/380, 340/825.54, 340/825.31, 340/825.69, 340/825.72, 307/10.2, 307/10.3, 307/10.7
• US Class Current: 70/278.2
• CPC Class Codes: E05B 19/00 Keys; Accessories therefor key modifications or attachments preventing removal from the lock E05B11/005; key rings A44B15/00; key cases A45C11/32; key holders A47G29/10; making keys, see the relevant places, e.g. B21D53/42; milling grooves in keys B23C3/35
• CPC Class Codes: G07C 9/00944 Details of construction or manufacture
• CPC Class Codes: Y10T 70/7073 Including use of a key
• 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 key (10) is provided that includes a key body (12) having a forked end. The forked end comprises a first tine (14) and a second tine (16). A transponder (20) is disposed between the first tine (14) and the second tine (16). The transponder (20) is operable to generate signals. An air coil antenna (18) is coupled to the key body (12) proximate the forked end and is electrically coupled to the transponder (20). The air coil antenna (18) is operable to transmit signals generated by the transponder (20).

Claims

1. A key, comprising:

a key shank having a first end and an opposed second, forked end, the forked end comprising a first tine and a second tine, thereby reducing eddy currents;

a transponder disposed between the first tine and the second tine, the transponder operable to generate signals; and

an air coil antenna, disposed outside said transponder and attached to the key shank adjacent each of the tines and electrically coupled to the transponder, the air coil antenna operable to transmit signals generated by the transponder.

2. The key of claim 1, further comprising a grip encasing the transponder, the air coil antenna, and the forked end of the key shank.

3. The key of claim 1, wherein the air coil antenna is disposed flush with the forked end of the key shank.

4. The key of claim 1, wherein the key shank is constructed from metal.

5. The key of claim 1, wherein the key shank is constructed from plastic.

6. A method of constructing a key for use in a contactless key identification system, comprising the steps of:

providing a key shank having a first end an opposed second, forked end, wherein the forked end comprises a first tine and a second tine;

disposing a transponder between the first tine and the second tine, the transponder operable to generate signals; and

providing an air coil antenna, disposed outside said transponder, and attaching said air coil antenna to the key shank adjacent each of the tines and electrically connecting the air coil antenna to the transponder, such that the antenna is operable to transmit signals generated by the transponder.

7. The method of claim 6, further comprising the step of encasing the transponder, the antenna, and forked end of the key shank in a grip.

8. The method of claim 6, wherein the step of attaching comprises attaching the air coil antenna to the key shank such that the air coil antenna is disposed flush with the forked end of the key shank.

9. The method of claim 6, wherein the step of providing a key shank comprises providing a key shank constructed from metal.

10. The method of claim 6, wherein the step of providing a key shank comprises providing a key shank constructed from plastic.