Thermal probe assembly with mold-over crimp sensor packaging

• US 5,749,656 A
• Filed: 08/18/1997
• Issued: 05/12/1998
• Est. Priority Date: 08/11/1995
• Status: Expired due to Fees

• Current Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Kirkwood, Richard Darrell, Straub, Peter John, Boehm, Michael James
• Primary Examiner(s): GUTIERREZ, DIEGO F
• Application Number:
  US08/914,201
• Time in Patent Office: 267 Days
• Field of Search: 374/185, 374/208, 439/877, 439/874, 439/736, 338/28
• US Class Current: 374/185
• CPC Class Codes: G01K 7/22 the element being a non-linear resistance, e.g. thermistor G01K7/26 takes precedence
• CPC Class Codes: H01R 13/405 Securing in non-demountable manner, e.g. moulding, riveting

Abstract

The present invention generally includes a thermal sensor assembly for a vehicle application including an insert molded part having a thermistor/wire sub-assembly and terminal that are assembled with a "F" crimp and resistance welded that are insert molded to a pre-mold or connector that has a shut-off plate seal on the terminal'"'"'s insulation crimp. The invention provides a more robust package that is resistant to vibration, insulates the terminals from shorting and permits further handling of the sub-assembly without damage to the terminals. Further, the thermistor can be very small and a very small wire can be used to connect the terminal to the thermistor element. Because a smaller thermistor can be utilized, a much smaller probe tip can be design into the thermal sensor assembly. The insert molded part can either be a preform for press-fit applications or a male sensor connector for applications requiring a metal housing. The pre-molded plastic protects the terminals from short circuiting to the sensor shell or other terminal.

Claims

1. A thermal sensor comprising:

a thermistor and a pair of wires leading therefrom, each wire having an insulation covering a portion thereof so that one end of the wire is exposed, a male terminal for each wire, the male terminal having a metal crimp having a first finger crimped to the insulation covering the wire and a second finger crimped to the exposed end of the wire, and wherein the exposed end of the wire is resistance welded to the crimp;

a pre-mold sealing off on the first finger and encapsulating the second finger, the resistance weld, and only a portion of the first finger leaving a portion exposed.

2. A thermal sensor as set forth in claim 1 further comprising a metal housing secured to the pre-mold and surrounding the thermistor, and wherein the pre-mold further encapsulates a portion of each wire and a portion of each terminal so as to isolate the respective portions of each wire and terminal from each other and from the metal housing.

3. A thermal sensor as set forth in claim 1 further comprising a plastic housing secured to the pre-mold and surrounding the thermistor.