Leakage-sound detecting apparatus

• US 5,602,327 A
• Filed: 09/06/1995
• Issued: 02/11/1997
• Est. Priority Date: 03/25/1993
• Status: Expired due to Term

• Current Assignee: Fuji Tecom, Inc.
• Original Assignee: Fuji Tecom, Inc.
• Inventors: Kitazume, Kouji, Torizuka, Yukio, Uno, Hiroshi
• Primary Examiner(s): BROCK, MICHAEL J
• Application Number:
  US08/524,085
• Time in Patent Office: 524 Days
• Field of Search: 73/40.5 A, 73/592, 73/649, 73/642, 73/644, 367/180, 367/188, 181/207, 181/208, 181/198, 310/321, 310/323, 310/328
• US Class Current: 73/40.50A
• CPC Class Codes: G01M 3/243 for pipes
• CPC Class Codes: H04R 17/00 Piezoelectric transducers; Electrostrictive transducers piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners H10N30/00

Abstract

A leakage-sound detecting apparatus is provided for efficiently detecting water leakage in a plastic pipe by increasing sensitivity to a low frequency sound component and efficiently reducing stray noise, as well as protecting a piezoelectric element. To this end a detection portion and a pedestal portion are connected through a mechanical resonant member formed of a soft material. A low frequency sound component is amplified by the resonant member, and high frequency components are substantially attenuated. In an alternative arrangement a detection portion and a mechanical resonant member mounted on a pedestal portion are connected through a buffer portion having a buffer member arranged therein. When a shock is applied to the bottom of the pedestal portion, due to the apparatus being dropped for example, the buffer member is compressed, and no overload is applied to a piezoelectric element.

Claims

1. A leakage-sound detecting apparatus in which a detection portion having a piezoelectric element encased in a casing and a pedestal portion made of a rigid material are connected through a mechanical resonant member made of a soft material, wherein a lower extending portion incised with internal threads is provided on the lower wall portion of a casing of the detection portion, a buffer-member supporting portion bored with an insert hole is provided on the upper surface portion of the mechanical resonant member, the lower end of the lower extending portion is located at the insert hole, the lower extending portion and the buffer-member supporting portion are connected by a stop screw, and a buffer member is arranged between the lower wall portion of the casing and the buffer-member supporting portion to form a buffer portion.

2. A leakage-sound detecting apparatus according to claim 1 wherein said buffer member comprises a lumpy member formed of a foamed rubber material.

3. A leakage-sound detecting apparatus according to claim 1 wherein said buffer member comprises a member formed of a rubber material having a hardness of from 20 to 40 Hs and having a number of protrusions stood upright on a thin-wall plate-like portion.

4. A leakage-sound detecting apparatus in which a detection portion having a piezoelectric element encased in a casing and a pedestal portion made of a rigid material are connected through a mechanical resonant member made of a rubber material such as urethane rubber and neoprene rubber having a hardness of from 10 to 50 Hs, wherein a lower extending portion incised with internal threads is provided on the lower wall portion of a casing of the detection portion, a buffer-member supporting portion bored with an insert hole is provided on the upper surface portion of the mechanical resonant member, the lower end of the lower extending portion is located at the insert hole, the lower extending portion and the buffer-member supporting portion are connected by a stop screw, and a buffer member is arranged between the lower wall portion of the casing and the buffer-member supporting portion to form a buffer portion.

5. A leakage-sound detecting apparatus according to claim 4 wherein said buffer member comprises a lumpy member formed of a foamed rubber material.

6. A leakage-sound detecting apparatus according to claim 4 wherein said buffer member comprises a member formed of a rubber material having a hardness of from 20 to 40 Hs and having a number of protrusions stood upright on a thin-wall plate-like portion.