Destructible type switch having frangible conductive element

• US 3,936,621 A
• Filed: 10/15/1974
• Issued: 02/03/1976
• Est. Priority Date: 10/17/1973
• Status: Expired due to Term

• Current Assignee: Imperial Chemical Industries Limited (Nouryon BV)
• Original Assignee: Imperial Chemical Industries Limited (Nouryon BV)
• Inventors: Palin, Alfred, Slack, John Wesley
• Primary Examiner(s): Scott, James R.
• Application Number:
  US05/515,018
• Time in Patent Office: 476 Days
• Field of Search: 200/61.08, 200/300, 340/421
• US Class Current: 200/61.08
• CPC Class Codes: B01J 19/0053 Details of the reactor
• CPC Class Codes: B01J 19/0073 Sealings sealings for pressure vessels per se F16J15/00
• CPC Class Codes: E05B 17/00 Accessories in connection with locks buffers E05F5/00; means for preventing rattling of wings E05F7/04; means for taking the weight of the wing E05F7/06
• CPC Class Codes: H01H 3/00 Mechanisms for operating contacts for tap changers H01H9/0027; thermal actuating or release means H01H37/02

Abstract

A detector comprises a brittle support for an electrical conductor adapted to fit adjacent a closure (e.g. a bursting disc) so that when failure occurs, electrical continuity in the conductor is broken by fracture of the support and cannot be fortuitously remade.

Claims

1. A detector for the detection of a rupture of a closure member, operable by the breakage of an electrical circuit to detect the said failure, comprising a U-shaped brittle electrical conducting element having its ends supported in a housing and the U-shaped portion protruding from said housing, electrical leads extending through the wall of said housing and making electrical contact with said ends of said brittle conducting element, means mounting said housing adjacent a rupturable closure member in vessel in a position such that the protruding U-shaped portion of said brittle conducting element is disposed in a place which ensures fracturing of said portion upon rupture of the closure member whereby when said portion fractures into a plurality of fragments, electrical continuity between the electrical leads is broken and the fragments cannot dispose themselves in any way which restores the electrical continuity under the conditions consequent upon the failure.

2. A detector according to claim 1 wherein the electrical conducting element is a layer of metal deposited on a U-shaped glass substrate.

3. A detector according to claim 2 wherein the glass substrate is in the form of a tube.

4. A detector according to claim 3 wherein the tube is coated on an internal surface with a layer of metal.

5. A detector according to claim 1 wherein the electrical conducting element comprises a brittle tubular support having deposited thereon a layer of conducting material.

6. A detector according to claim 5 wherein the layer of conducting material is deposited on an internal surface of the tubular support.

7. A detector according to claim 5 wherein the tubular support has a cylindrical form externally over a portion of its length.

8. A detector according to claim 5 wherein the conducting material is a metal.

9. A detector according to claim 8 wherein the metal is silver.