Sealing member with visible pressure and temperature indication

Patent metadata

Field	Value
Publication number	US-9631726-B2
Application number	US-201514798724-A
Country	US
Kind code	B2
Filing date	Jul 14, 2015
Priority date	Jul 14, 2015
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

A sealing member for a machine may include an elastomeric body configured to fit at least partially into a recess defined in at least one of two sealing surfaces of two mating parts of the machine. The elastomeric body may include a visible indicator portion extending out from between the two mating parts. The elastomeric body may further include an elastomeric compound, and at least one of a thermochromic dye and a piezochromic dye mixed into the elastomeric compound, wherein the thermochromic dye is adapted to change color upon exposure of the elastomeric body to a temperature above a threshold temperature, and the piezochromic dye is adapted to change color upon exposure of the elastomeric body to a pressure above a threshold pressure.

First claim

What is claimed is:

1. A sealing member for a machine, comprising:
an elastomeric body configured to fit at least partially into a recess defined in at least one of two sealing surfaces of two mating parts of the machine, the elastomeric body including:
a visible indicator portion extending out from between the two mating parts;
an elastomeric compound;
a thermochromic dye; and
a piezochromic dye,
wherein the thermochromic dye is adapted to change color upon exposure of the elastomeric body to a temperature above a threshold temperature, and the piezochromic dye is adapted to change color upon exposure of the elastomeric body to a pressure above a threshold pressure.

2. The sealing member of claim 1 , wherein the elastomeric body includes a flexible coating applied to a sealing component configured for engagement between the two sealing surfaces of the two mating parts of the machine.

3. The sealing member of claim 2 , wherein the flexible coating includes at least two layers applied to the sealing component.

4. The sealing member of claim 3 , wherein one of the at least two layers applied to the sealing component includes the thermochromic dye, and another of the at least two layers includes the piezochromic dye.

5. The sealing member of claim 4 , wherein the change in color of at least one of the thermochromic dye or the piezochromic dye upon exposure of the elastomeric body to a temperature above the threshold temperature or a pressure above the threshold pressure results in a second of the at least two layers that is applied to the sealing component over a first of the at least two layers becoming colorless and transparent so that a change in color of the first of the at least two layers is also visible.

6. The sealing member of claim 1 , wherein the change in color of at least one of the thermochromic dye or the piezochromic dye is irreversible.

7. The sealing member of claim 1 , wherein the change in color of at least one of the thermochromic dye or the piezochromic dye is reversible.

8. The sealing member of claim 1 , wherein the thermochromic dye and the piezochromic dye are mixed into the elastomeric compound.

9. A sealed sub-assembly of a machine, the sealed sub-assembly comprising:
a first machine part, the first machine part having a first sealing surface;
a second machine part configured to mate with the first machine part, the second machine part having a second sealing surface; and
an elastomeric body configured to be retained between the first and second sealing surfaces, the elastomeric body including:
a visible indicator portion extending out from between the two machine parts;
an elastomeric compound;
a thermochromic dye; and
a piezochromic dye,
wherein the thermochromic dye is adapted to change color upon exposure of the elastomeric body to a temperature above a threshold temperature, and the piezochromic dye is adapted to change color upon exposure of the elastomeric body to a pressure above a threshold pressure.

10. The sealed sub-assembly of claim 9 , wherein the elastomeric body includes a flexible coating applied to a sealing component configured for engagement between the two sealing surfaces of the two mating parts of the machine.

11. The sealed sub-assembly of claim 10 , wherein the flexible coating includes at least two layers applied to the sealing component.

12. The sealed sub-assembly of claim 11 , wherein one of the at least two layers applied to the sealing component includes the thermochromic dye, and another of the at least two layers includes the piezochromic dye.

13. The sealed sub-assembly of claim 12 , wherein the change in color of at least one of the thermochromic dye or the piezochromic dye upon exposure of the elastomeric body to a temperature above the threshold temperature or a pressure above the threshold pressure results in a second of the at least two layers that is applied to the sealing component over a first of the at least two layers becoming colorless and transparent so that a change in color of the first of the at least two layers is also visible.

14. The sealed sub-assembly of claim 9 , wherein the change in color of at least one of the thermochromic dye or the piezochromic dye is irreversible.

15. The sealed sub-assembly of claim 9 , wherein the thermochromic dye and the piezochromic dye are mixed into the elastomeric compound.

16. A method of maintaining a sealed interface between two mating parts of a machine, the method comprising:
assembling the two mating parts with an elastomeric body positioned between two surfaces of the two mating parts of the machine, the elastomeric body including:
a visible indicator portion extending out from between the two mating parts;
an elastomeric compound;
at least one of a thermochromic dye; and
a piezochromic dye,
wherein the thermochromic dye is adapted to change color upon exposure of the elastomeric body to a temperature above a threshold temperature, and the piezochromic dye is adapted to change color upon exposure of the elastomeric body to a pressure above a threshold pressure;

receiving an indication of a color change of the visible indicator portion correlating to the elastomeric body having been exposed to at least one of a temperature above a threshold temperature and a pressure above a threshold pressure;
disassembling the two mating parts and removing the elastomeric body from between the two mating parts; and
replacing the elastomeric body with another elastomeric body.

Assignees

• Caterpillar Inc

Inventors

• Sabotta Christian Earl
• Flanigan Sarah Talbot
• Cline Jay Hamilton

Classifications

• G01L1/24

  by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis {using infrared, visible light, ultraviolet} · CPC title

• G01K11/12

  using changes in colour, translucency or reflectance · CPC title

• F16J15/02 Primary

  between relatively-stationary surfaces (F16J15/46, F16J15/48 take precedence) · CPC title

• F16J15/064 Primary

  the packing combining the sealing function with other functions · CPC title

• F16J15/3296

  Arrangements for monitoring the condition or operation of elastic sealings (F16J15/326 takes precedence); Arrangements for control of elastic sealings, e.g. of their geometry or stiffness · CPC title