Patent US4130728A successfully refreshed from Google Patents.
US4130728A
Expired / Lapsed
US
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Combined mounting for through-the-wall viewer and intercom
Assignee: Individual
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Filing: 1978-03-23
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Granted: 1978-12-19
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Expires: 1998-03-23
Abstract
Abstract Seeing and talking through a wall or closed door is conveniently provided by the combination of a one-way observation telescope projecting through the door and a pair of intercom units, one on each side of the door. Each intercom housing has a flange with a hole such that the units may be supported cooperatively by the telescope ends. Each housing may also have protruding tips against the door surface to prevent rotation of the housing.
Inventors
- 👤 Stephen L. Grauel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:50
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/02; H04M1/0291; E; E06; E06B; E06B7/00; E06B7/28; E06B7/30; E06B2007/305
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
145 words
An improved through the wall audio visual communication apparatus for a door, or the like, having a one-way viewing tube extending therethrough, the improvement comprising: a pair of hollow housings containing a two-way communication circuit including a pair of microphone/speakers; a circuit control switch in one of the housings; each housing having a back wall for flatly contacting opposing vertical wall surfaces of said door and each having a centrally apertured flange projecting beyond one end of the housing in the plane of the respective back wall for receiving respective end portions of said one-way tube and securing said housings to said door, each said housing having an opening in its wall opposite said back wall for the passage of audio waves to and from the microphone/speakers; and, a circuit control switch arm rotatably mounted on said one housing connected with the circuit control switch.
Claim 2
Dependent Claim
145 words
An improved through the wall audio visual communication apparatus for a door, or the like, having a one-way viewing tube extending therethrough, the improvement comprising: a pair of hollow housings containing a two-way communication circuit including a pair of microphone/speakers; a circuit control switch in one of the housings; each housing having a back wall for flatly contacting opposing vertical wall surfaces of said door and each having a centrally apertured flange projecting beyond one end of the housing in the plane of the respective back wall for receiving respective end portions of said one-way tube and securing said housings to said door, each said housing having an opening in its wall opposite said back wall for the passage of audio waves to and from the microphone/speakers; and, a circuit control switch arm rotatably mounted on said one housing connected with the circuit control switch.
Claim 3
Dependent Claim
21 words
The combination according to claim 1 and further including: a doorbell switch mounted on the second housing opposite said one housing.
Claim 4
Dependent Claim
40 words
The combination according to claim 2 and further including: door surface penetrating tips struck out from the material forming said back wall of each said housing for preventing rotation of the respective housing about the axis of said one-way tube.
References Cited (Backward Citations)
US2169874A
Cited
US3404234A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-12-18 | 1982-06-19 | 1982-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-18 | 1986-06-19 | 1986-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-18 | 1990-06-19 | 1990-12-19 | $7700.00 | Window Closed / Lapsed |