US3909819A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mailbox alarm
Assignee: Individual
•
Filing: 1974-04-22
•
Granted: 1975-09-30
•
Expires: 1994-04-22
Abstract
Abstract Alarm apparatus for indicating when mail has been delivered to a mailbox. A photocell inside the mailbox has an electrical characteristic dependent upon the presence of light in the mailbox, and this electrical characteristic is coupled to an alarm signal device inside a house. The alarm signal device latches on after mail has been delivered and light has entered the mailbox changing the electrical characteristic of the photocell.
Inventors
- 👤 Leslie M Radford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:00
CPC Classifications
A; A47; A47G; A47G29/00; A47G29/12; A47G29/1209; A47G29/121; A47G29/1212
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
35 words
Mailbox alarm apparatus comprising: an enclosed mailbox having an openable door; and photosensitive means for initiating activation of an alarm signal in response to light coming from outside the mailbox when the door is opened.
Claim 2
Dependent Claim
35 words
Mailbox alarm apparatus comprising: an enclosed mailbox having an openable door; and photosensitive means for initiating activation of an alarm signal in response to light coming from outside the mailbox when the door is opened.
Claim 3
Dependent Claim
54 words
The apparatus of claim 1 in which the photosensitive means includes: first means inside the mailbox when the door is closed for presenting at an output an electrical characteristic dependent upon the presence of light in the mailbox; and second means for coupling the output of the first means to an alarm signal assembly.
Claim 4
Dependent Claim
20 words
The apparatus of claim 2 in which the first means includes a photocell presenting a light-dependent resistance at an output.
Claim 5
Dependent Claim
13 words
The apparatus of claim 3 in which the photocell is a cadmium-sulfide cell.
Claim 6
Dependent Claim
24 words
The apparatus of claim 2 which further includes: an alarm signal assembly coupled to the output of the first means by the second means.
Claim 7
Dependent Claim
100 words
The apparatus of claim 5 in which the alarm signal assembly comprises: a power supply; an alarm signal device having a first terminal coupled to the power supply at a first point and having a second terminal; and switch means coupled between the second terminal of the alarm signal device and the power supply at a point of electrical potential different from that of the first point, for coupling the second terminal of the alarm signal device to the power supply when the output of the first means corresponds to a first condition when light is present in the mailbox.
Claim 8
Dependent Claim
15 words
The apparatus of claim 6 in which the second means is a pair of wires.
Claim 9
Dependent Claim
38 words
The apparatus of claim 6 in which the alarm signal device is a light and which further includes latching means for maintaining the second terminal of the light coupled to the power supply after the first condition arises.
Claim 10
Dependent Claim
97 words
The apparatus of claim 5 in which the alarm signal assembly comprises: a power supply; an audible alarm having a first terminal coupled to the power supply at a first point and having a second terminal; and switch means, coupled between the second terminal of the audible alarm and the power supply at a point of electrical potential different from that of the first point, for coupling the second terminal of the audible alarm to the power supply when the output of the first means corresponds to a first condition when light is present in the mailbox.
Claim 11
Dependent Claim
47 words
The mailbox alarm apparatus of claim 1 which additionally includes: latch means for maintaining activation of said alarm signal after said photosensitive means initiates and after light ceases coming into the mailbox from outside the mailbox whereby after the door is closed the alarm signal remains activated.
References Cited (Backward Citations)
US2968804A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |