Module assembly with mounting integrity detection including deformable washer

• US 20060198110A1
• Filed: 03/01/2005
• Published: 09/07/2006
• Est. Priority Date: 03/01/2005
• Status: Active Grant

• Current Assignee: Delphi Technologies, Inc. (Aptiv PLC)
• Original Assignee: Delphi Technologies, Inc. (Aptiv PLC)
• Inventors: Hunkeler, Hugh R., Patterson, James F.
• Granted Patent: US 7,161,087 B2
• Time in Patent Office: Days
• US Class Current: 361/747
• CPC Class Codes: H05K 5/0073 having specific features for mounting the housing on an external structure
• CPC Class Codes: H05K 5/0204 Mounting supporting structures on the outside of casings

Abstract

A module is mounted to a object with a fastener and a special washer. The fastener engages the object through a mounting opening in mounting portion of a module case. The washer has a first portion extending obliquely outward and downward to be deformed between the fastener head and an electrically non-conducting surface of the mounting portion and thus increase a mounting force on the module with mounting advancement of the fastener. The washer has a second portion extending axially into the internal opening to contact an electrically conducting insert therein and thus create a series electrical circuit from the typically grounded object through the fastener, washer and insert to a detecting circuit, which verifies that the module is securely mounted with a predetermined mounting force.

Claims

1. A module assembly comprising:

a case having at least one electrically non-conducting mounting portion with an internal wall defining a mounting opening therethrough, the mounting portion further including an electrically conducting insert extending partly into the mounting opening internally of the mounting portion and adapted for connection to an electric potential detecting circuit,

an electrically conducting fastener comprising a head and a shank, at least one portion of the internal wall of the mounting portion being adapted for guiding the shank therethrough for mounting engagement with an object but without contacting the electrically conducting insert,

an electrically conducting washer surrounding the shank adjacent the head thereof, the washer having at least one first portion extending obliquely outward and away from the head of the fastener to be deformed between the head of the washer and a surface of the mounting portion and thereby exert a mounting force on the case as the fastener is advanced through the mounting opening into engagement with the object,

the washer having a second portion projecting from the first portion adjacent the head of the fastener axially away from the head and adjacent the shank into the mounting opening to engage the electrically conducting insert within the mounting opening in the same advancement of the shank to complete a series circuit from the electrically conducting insert through the washer and the fastener to the object at the reference potential and thus signal the achievement of a desired mounting force when the object is maintained at a predetermined reference potential and the electrically conducting insert is connected to a potential detecting circuit.

2. The module assembly of claim 1 wherein the first portion of the washer comprises at least one portion of a frustro-conical surface.

3. The module assembly of claim 1 wherein the first portion of the washer comprises a plurality of obliquely radial spokes joined at their radially outward ends by an annular portion.

4. The module assembly of claim 1 wherein the second portion of the washer comprises a cylindrical member around the shank of the fastener.

5. The module assembly of claim 1 wherein the engagement of the shank of the fastener with the object is a threaded engagement.

6. The module assembly of claim 1 wherein the internal wall of the mounting portion comprises a first axial portion located on an opposite axial side of the electrically conducting insert from the surface of the mounting portion and a second axial portion of the internal wall of the mounting portion located on the same axial side of the electrically conducting insert as the surface of the mounting portion, and the first axial portion of the internal wall is adapted to receive the shank of the fastener and prevent contact thereof with the electrically conducting insert.

7. The module assembly of claim 6 wherein the first axial portion of the internal wall of the mounting portion defines a first cylindrical region having a first radius adapted for receiving the shank of the fastener, the electrically conducting insert is confined radially outside a second cylindrical region coaxial with the first cylindrical region and having a second radius larger than the first radius, and the second axial portion of the internal wall of the mounting portion is confined radially outside a third cylindrical region of the mounting portion coaxial with the first cylindrical region and having a third radius greater than the second radius.

8. The module assembly of claim 1 wherein the object is maintained at a first predetermined reference potential and the potential detecting circuit comprises an impedance element connected between the electrically conducting insert and a current source at a second predetermined reference potential and means for detecting a voltage between the electrically conducting insert and the impedance element.

9. The module assembly of claim 8 wherein the shank of the fastener extends through the inner wall of the mounting portion into engagement with the object.

10. The module of claim 8 wherein the object is a component of a vehicle.

11. The module of claim 10 wherein the case further contains an accelerometer for sensing an acceleration of the object.

12. The module of claim 1 wherein the shank has a threaded axial portion separated from the head by a non-threaded portion and the second axial portion of the washer surrounds and is retained on the non-threaded portion by the threaded portion.