Ball joint having service life indicator

• US 5,163,769 A
• Filed: 01/30/1991
• Issued: 11/17/1992
• Est. Priority Date: 01/30/1991
• Status: Expired due to Fees

• Current Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Dresselhouse, Kurt F.
• Primary Examiner(s): Reese, Randolph A.
• Assistant Examiner(s): SHACKELFORD, HEATHER CHUN
• Application Number:
  US07/647,729
• Time in Patent Office: 657 Days
• Field of Search: 403/27, 403/132, 403/133, 403/139, 403/140, 403/135, 403/225, 403/226
• US Class Current: 403/27
• CPC Class Codes: B60G 7/005 Ball joints B60G7/006 takes precedence; for steering linkage B62D7/16; ball joints per se F16C11/06
• CPC Class Codes: F16C 11/0647 Special features relating to adjustment for wear or play; Wear indicators
• CPC Class Codes: F16C 2326/05 Vehicle suspensions, e.g. bearings, pivots or connecting rods used therein in general B60G
• CPC Class Codes: Y10T 403/20 with indicator or inspection means
• CPC Class Codes: Y10T 403/32721 Elastomeric seat
• CPC Class Codes: Y10T 403/32737 including liner, shim, or discrete seat
• CPC Class Codes: Y10T 403/32778 Completely spacing the members

Abstract

A ball joint comprises a socket, a stud, and an elastomeric bearing. The bearing is bonded to the ball end of the stud and supports the ball end of the stud for movement in the socket. The bearing has a service life indicator surface extending across an opening in the socket. The service life indicator surface is forced by the socket into a predetermined shape. The service life indicator surface moves out of its predetermined shape in response to separation of the bearing from the ball end of the stud.

Claims

1. A ball joint comprising:

a socket defining a chamber, a first opening into said chamber, and a second opening into said chamber;

a stud comprising a ball in said chamber and a shank extending from said ball through said first opening;

an elastomeric bearing bonded to said ball and supporting said ball for movement in said socket; and

said bearing having means for indicating separation of said bearing from said ball, said indicating means including a service life indicator surface of said bearing spaced from said ball and extending at least partially across said second opening, and a portion of said bearing which is deformed between said socket and said ball to force said service life indicator surface into a predetermined shape, said service life indicator surface moving out of said predetermined shape in response to separation of said bearing from said ball.

2. A ball joint as defined in claim 1 wherein said predetermined shape is concave, said service life indicator surface being movable out of said concave shape toward a flattened shape in response to separation of said bearing from said ball.

3. A ball joint as defined in claim 1 wherein said bearing has an indicator portion extending through said second opening, said service life indicator surface being on said indicator portion.

4. A ball joint comprising:

a socket defining a chamber, a first opening into said chamber, and a second opening into said chamber;

a stud comprising a ball in said chamber and a shank extending from said ball through said first opening;

an elastomeric bearing bonded to said ball and supporting said ball for movement in said socket, said bearing having a service life indicator surface spaced from said ball; and

said socket having surface means formed around said bearing to force said service life indicator surface into a predetermined position extending at least partially across said second opening, and to force said service life indicator surface to move out of said predetermined position in response to separation of said bearing from said ball.

5. A ball joint as defined in claim 4 wherein said service life indicator surface has a predetermined shape when in said predetermined position, and moves out of said predetermined shape when moving out of said predetermined position.

6. A ball joint as defined in claim 5 wherein said predetermined shape is concave, said service life indicator surface moving toward a flattened shape and in a direction outward of said second opening when moving out of said concave shape.

7. A ball joint as defined in claim 4 wherein said bearing comprises a service life indicator portion extending out of said second opening, said service life indicator surface being on said service life indicator portion.

8. A ball joint comprising:

a socket having a first opening, a second opening, and an inner surface defining a chamber;

a stud comprising a ball in said chamber and a shank extending from said ball out of said first opening;

an elastomeric bearing bonded to said ball and supporting said ball for movement in said chamber, said movement causing stresses which over time cause said bearing to separate from said ball; and

said bearing having means for indicating separation of said bearing from said ball, said indicating means including a service life indicator surface spaced from said ball and extending at least partially across said second opening, said service life indicator surface moving in a direction outward of said second opening in response to separation of said bearing from said ball.

9. A ball joint as defined in claim 8 wherein said service life indicator surface changes shape when moving in response to separation of said bearing from said ball.

10. A ball joint as defined in claim 9 wherein said service life indicator surface has an initial concave shape and moves toward a flattened shape in a direction outward of said second opening in response to separation of said bearing from said ball.