Seal apparatus for pressure responsive electrical switch

• US 5,280,926 A
• Filed: 07/14/1992
• Issued: 01/25/1994
• Est. Priority Date: 07/14/1992
• Status: Expired due to Term

• Current Assignee: Sensata Technologies Incorporated (Sensata Technologies Holding Plc)
• Original Assignee: Texas Instruments, Inc.
• Inventors: Werner, Karl H., Sogge, Dale R.
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): CUMMINGS, SCOTT
• Application Number:
  US07/913,510
• Time in Patent Office: 560 Days
• Field of Search: 277/23, 277/152, 277/168, 277/169, 277/170, 200/83 P, 200/83 J, 200/83 N, 200/83 B, 200/83 Y, 200/302.1, 200/302.2, 200/302.3
• US Class Current: 277/641
• CPC Class Codes: F16J 15/106 homogeneous
• CPC Class Codes: H01H 35/34 actuated by diaphragm
• CPC Class Codes: Y10S 277/91 O-ring seal
• CPC Class Codes: Y10S 277/925 Snap fit feature for mounting or assembly of seal

Abstract

A normally open pressure responsive electrical switch is shown having upper and lower body members with a combination terminal and disc seat member sandwiched therebetween. An electrically conductive snap acting disc is disposed on the disc seat and is adapted to snap through a centrally disposed aperture in the terminal into electrical engagement with an electrical contact disposed on a terminal mounted in the lower body member. The upper body member has a bore extending therethrough which slidably mounts a pressure converter adapted to convert pressure from a pressure source to a force and apply the force to the disc. A flexible membrane is disposed over the bore with an O-ring received on an O-ring seat adjacent the bore in the upper body member. A wall extending around the seal seat is deformed to capture the O-ring at its seat.

Claims

1. Sealing apparatus comprising

a body having a top surface being formed with an aperture therein and an O-ring seat in the form of a circular wall extending upwardly from the top surface around the periphery of the aperture and spaced therefrom,

a flexible O-ring having an outside diameter selected to closely fit within the circular wall received on the O-ring seat,

the O-ring having a generally flat bottom surface and having a radially outer surface extending from the generally flat bottom surface upwardly a selected distance to an upper distal portion above the circular wall, the upper distal portion having an outer diameter which is less than the outer diameter of the flat bottom surface and at least an upper portion of the radially outer surface proximate to the top of the circular wall being frusto-conical in configuration, said frusto-conical surface portion having a longitudinal axis in which the frusto-conical surface portion forms an angle with the longitudinal axis up to approximately 10°

.

2. Seal apparatus according to claim 1 in which a lower portion of the radially outer surface contiguous with the flat bottom surface forms a cylindrical surface which extends upwardly to a point below the top of the circular wall.

3. Seal apparatus according to claim 2 further including a transitional surface extending between the lower portion of the radially outer surface and the upper portion of the radially outer surface.

4. Seal apparatus according to claim 1 in which the top surface of the circular wall is deformed inwardly into engagement with the upper portion of the radially outer surface of the O-ring.

5. Seal apparatus according to claim 4 in which the top surface of the circular wall is deformed continuously around the periphery of the aperture.

6. Seal apparatus comprising a body having a top surface with a selected portion thereon, an O-ring seat comprising a continuous wall spaced from and circumscribing the selected portion and extending around the periphery of the selected portion,

a flexible O-ring disposed on the O-ring seat, the O-ring having a generally flat bottom surface and having a radially outer surface extending from the generally flat bottom surface upwardly with a lower portion contiguous with the flat bottom surface which forms a cylindrical surface which extends upwardly to a point below the top of the continuous wall, an upper distal portion generally above the continuous wall with a transitional surface portion extending between the lower portion of the radially outer surface and the upper portion of the radially outer surface, at least said upper portion of the radially outer surface proximate to the top of the continuous wall being frusto-conical in configuration, the top wall being deformed into engagement with said at least an upper portion of the radially outer surface to lock the O-ring at its seat.

7. A seal apparatus according to claim 6 in which the top wall is deformed continuously around the periphery of the aperture.

8. Seal apparatus comprising a body having a top surface and an aperture in the top surface, an O-ring seat comprising a continuous wall spaced from the aperture and extending around the periphery of the aperture,

a flexible O-ring disposed on the O-ring seat, the O-ring having a generally flat bottom surface and having a radially outer surface extending from the generally flat bottom surface upwardly a selected distance to an upper distal portion above the continuous wall, at least an upper portion of the radially outer surface proximate to the top of the continuous wall being frusto-conical in configuration, said upper, frusto-conical surface portion of the O-ring having a longitudinal axis, the upper surface portion forming an angle with the longitudinal axis up to approximately 10°

, the top wall being deformed into engagement with said at least an upper portion of the radially outer surface to lock the O-ring at its seat.

9. Seal apparatus comprising a body having a top surface and an aperture in the top surface, an O-ring seat comprising a continuous wall spaced from the aperture and extending around the periphery of the aperture,

a flexible O-ring disposed on the O-ring seat, the O-ring having a generally flat bottom surface and having a radially outer surface extending from the generally flat bottom surface upwardly a selected distance to an upper distal portion above the continuous wall, at least an upper portion of the radially outer surface proximate to the top of the continuous wall being frusto-conical in configuration, said upper, frusto-conical surface portion of the O-ring having a longitudinal axis, the upper surface portion forming an angle with the longitudinal axis up to approximately 3°

, the top wall being deformed into engagement with said at least an upper portion of the radially outer surface to lock the O-ring at its seat.