§
Luxuse
Patent Intelligence
Sign In
← Back to Patent Explorer
EP0188017A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Electroacoustic calling device

Assignee: Philips Electronics UK Ltd
•
Filing: 1985-11-26
•
Granted: —
•
Expires: 2005-11-26
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract @ An electroacoustic calling device comprises a two part housing (100,101) containing a piezoelectric disc (103) mounted between two knife edges (109, 110) and a loudspeaker cone (104) which is attached to the centre of the piezoelectric disc by means of an adhesive. The upper part (101) of the housing has an aperture (102) through which sound waves are emitted. A closure member (105) for controlling the size of the aperture and hence the volume of sound emitted is urged against the surface of the housing by means of an arm (107) which is pivotally mounted on a boss (108). The closure member (105) is in the form of a disc which is located in a recess (106) in the arm (107) and is urged against the housing by means of a projection (112) in the recess (106). The essentially point contact between the disc and recess allows the disc to align accurately with the surface of the housing.

Inventors

  • 👤 Harold Ernest Barnes

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-10 02:36
CPC Classifications
G; G10; G10K; G10K9/00; G10K9/12; G10K9/122; G10K9/18

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 149 words
An electroacoustic calling device comprising an electroacoustic transducer mounted in a housing, said housing having an aperture or a group of apertures in a wall thereof through which aperture(s) sound waves may be emitted from the housing, said device further comprising a closure member having a surface which is movable across the wall of the housing to cover to a great or lesser extent said aperture(s), the profile of the surface of the closure member and the exterior surface of the wall in the region of the aperture(s) being complementary, characterised in that the surface of the closure member is urged against the exterior surface of the wall of the housing by means of a universal bearing so that when the closure member is moved to completely cover the aperture(s) leakage of sound waves between the surface of the member and the exterior surface of the wall is minimised.
Claim 2
Dependent Claim 149 words
An electroacoustic calling device comprising an electroacoustic transducer mounted in a housing, said housing having an aperture or a group of apertures in a wall thereof through which aperture(s) sound waves may be emitted from the housing, said device further comprising a closure member having a surface which is movable across the wall of the housing to cover to a great or lesser extent said aperture(s), the profile of the surface of the closure member and the exterior surface of the wall in the region of the aperture(s) being complementary, characterised in that the surface of the closure member is urged against the exterior surface of the wall of the housing by means of a universal bearing so that when the closure member is moved to completely cover the aperture(s) leakage of sound waves between the surface of the member and the exterior surface of the wall is minimised.
Claim 3
Dependent Claim 52 words
An electroacoustic calling device as claimed in Claim 1, characterised in that the closure member may comprise a plate located in a recess in an arm which is pivotted about a point on the housing so that rotation of the arm about the pivot causes the plate to move across the aperture(s).
Claim 4
Dependent Claim 28 words
A device as claimed in Claim 2, characterised in that the plate is provided with a projection which forms a point contact with the bottom of the recess.
Claim 5
Independent Claim 22 words
A device as claimed in any of Claims 1 to 3, characterised in that the surface of the closure member is planar.
Claim 6
Independent Claim 17 words
A device as claimed in any preceding claim in which the electroacoustic transducer comprises a piezoelectric disc.
Claim 7
Dependent Claim 16 words
A.device as claimed in Claim 5, in which a loudspeaker cone is attached to the disc.

References Cited (Backward Citations)

US2126566A Cited
GB2082018A Cited
EP0087908A1 Cited

USPTO Annuity & Maintenance Windows

Maintenance schedule is calculated for granted US utility patents.

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag