Gasket with encased load sensor

• US 5,121,929 A
• Filed: 06/24/1991
• Issued: 06/16/1992
• Est. Priority Date: 06/24/1991
• Status: Expired due to Term

• Current Assignee: Key Safety Systems, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Fel-Pro Incorporated
• Inventors: Cobb, David A.
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): DePumpo, Daniel G.
• Application Number:
  US07/719,742
• Time in Patent Office: 358 Days
• Field of Search: 277/2, 277/166, 277/235 R, 277/235 B, 73/768, 73/775, 73/862.47, 73/862.48
• US Class Current: 277/317
• CPC Class Codes: F16J 15/064 the packing combining the sealing function with other functions
• CPC Class Codes: G01L 1/20 by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids of piezo-resistive materials G01L1/18; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
• CPC Class Codes: G01L 5/0061 Force sensors associated with industrial machines or actuators for the specific machine or actuator involved see relevant class, e.g. F01, F04, F16, B66, E21

Abstract

A load sensing gasket having a gasket body defining a service opening for fluids and having a load sensor encased in a cavity in the body. The gasket body comprises a first gasket layer providing a first outer gasketing surface and a first inner surface, a second gasket layer providing a second outer gasketing surface and a second inner surface, the inner surfaces together defining the cavity and side walls for defining a perimeter for the cavity. The load sensor includes confronting electrodes and a pressure sensitive electrically resistive material between the electrodes and conductors extending outwardly of the perimeter. A seal between the first and second gasket layers around the load sensor seals the electrodes in the cavity from fluids when the gasket is in use.

Claims

1. A load sensing gasket having a gasket body defining at least one service opening for fluids and having a load sensing means encased in said body, said gasket body comprising

a first gasket layer providing a first outer gasketing surface and a first inner surface,

a second gasket layer providing a second outer gasketing surface and a second inner surface,

said inner surfaces defining a cavity having confronting surface portions and side wall means for defining a perimeter for said cavity, said load sensing means being disposed in said cavity,

said load sensing means comprising first electrode means in said cavity adjacent said one surface portion, second electrode means confronting said first electrode means and disposed adjacent the other surface portion, a pressure sensitive electrically resistive material between said first and second electrode means, and conductors for said first and second electrode means extending outwardly of said perimeter, each said conductor terminating in a contact, and

sealing means between said first and second gasket layers around said load sensing means to seal said electrode means within said cavity from fluids when the gasket is in use.

2. The gasket of claim 1, and wherein said first and second gasket layers are plastic.

3. The gasket of claim 1, and wherein said first and second electrode means comprise multiple pairs of first and second electrodes, said pairs being spaced from each other in said cavity.

4. The gasket of claim 1, and wherein said load sensing means further comprises a pair of thin sheets mounting said first and second electrode means, respectively, in said confronting relationship.

5. The gasket of claim 1, and wherein the first and second inner surfaces are spaced slightly apart from each other around said cavity so that when said gasket is loaded, forces may be applied to said load sensing means without substantial forces being taken up by the gasket body.

6. The gasket of claim 1, and wherein the thickness of said load sensing means is slightly greater than the depth of said cavity as defined by said gasket layers.

7. The gasket of claim 1, and wherein said cavity entirely surrounds a service opening.

8. The gasket of claim 1, and wherein said cavity is defined in part by recesses in each of said first and second gasket layers.

9. The gasket of claim 1, and wherein said cavity is a recess defined by one of said first and second gasket layers.

10. A load sensing gasket having a gasket body defining at least one service opening for fluids and having a load sensing means encased in said body, said gasket body comprising

a first plastic gasket layer providing a first outer gasketing surface and a first inner surface,

a second plastic gasket layer providing a second outer gasketing surface and a second inner surface,

said inner surfaces defining a zone having confronting surface portions, said load sensing means being disposed in said zone,

said load sensing means comprising first electrode means in said zone adjacent said one surface portion, second electrode means confronting said first electrode means and disposed adjacent the other surface portion, a pressure sensitive electrically resistive material between said first and second electrode means, and conductors for said first and second electrode means extending outwardly of said zone, each said conductor terminating in a contact, and

sealing means between said first and second inner surfaces around said load sensing means to seal said electrode means within said zone from fluids when the gasket is in use.

11. The gasket of claim 10, and wherein said first and second electrode means comprise multiple pairs of first and second electrodes, said pairs being spaced from each other in said zone.

12. The gasket of claim 10, and wherein said zone entirely surrounds a service opening.