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US3696372A
Expired / Lapsed
US
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Ladder warning device
Assignee: Individual
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Filing: 1970-09-21
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Granted: 1972-10-03
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Expires: 1990-09-21
Abstract
Abstract A warning device involving a rigid section of ladder is pivotally suspended from a tank, tower, building or the like and adapted to move slightly upon an intruder placing weight upon the section of ladder. Means are provided for biasing the ladder section in one direction, with the arrangement being such that upon an intruder placing weight upon the ladder, it overcomes this bias and actuates a warning device. The warning device may take the form of a switch which, when actuated, operates an alarm at a remote location, thus alerting a guard or the police of the trespass by the intruder. Significantly, all aspects of this device are inconspicuous, the motion of the ladder is slight, and the intruder in almost all instances will be unaware of the fact that his presence has been detected. Also, the arrangement resets itself automatically, and cannot be actuated by an accumulation of snow and ice.
Inventors
- 👤 Leo Lawrence Garrett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:29
CPC Classifications
E; E06; E06C; E06C7/00; E06C7/003; E06C9/00
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
184 words
A warning device for preventing an intruder from climbing undetected upon a ladder comprising a comparatively rigid section of ladder equipped with a plurality of rungs and having an upper end and a lower end, stationary support means disposed adjacent the upper end of said section of ladder, for forming the principal support for said section of ladder, the upper end of said section of ladder being directly and pivotally attached to said support means for rotational deflection to a slight extent under the weight of a person stepping on the rungs, but not downward deflection, thus minimizing the extent of ladder travel and the conspicuousness of the motion, means biasing said section of ladder in a given direction about said pivotal support means, said section of ladder tending to pivot about said support means in a direction opposite said given direction upon weight being placed upon said section of ladder, and motion detection means disposed in cooperative relation with said section of ladder to sense the slight motion about said support means resulting from the placement of weight upon said section of ladder.
Claim 2
Dependent Claim
184 words
A warning device for preventing an intruder from climbing undetected upon a ladder comprising a comparatively rigid section of ladder equipped with a plurality of rungs and having an upper end and a lower end, stationary support means disposed adjacent the upper end of said section of ladder, for forming the principal support for said section of ladder, the upper end of said section of ladder being directly and pivotally attached to said support means for rotational deflection to a slight extent under the weight of a person stepping on the rungs, but not downward deflection, thus minimizing the extent of ladder travel and the conspicuousness of the motion, means biasing said section of ladder in a given direction about said pivotal support means, said section of ladder tending to pivot about said support means in a direction opposite said given direction upon weight being placed upon said section of ladder, and motion detection means disposed in cooperative relation with said section of ladder to sense the slight motion about said support means resulting from the placement of weight upon said section of ladder.
Claim 3
Dependent Claim
27 words
The warning device as defined in claim 1 in which said motion detection means resets itself automatically after the removal of weight from said section of ladder.
Claim 4
Dependent Claim
19 words
The warning device as defined in claim 1 in which said comparatively rigid section of ladder is substantially straight.
Claim 5
Dependent Claim
24 words
The warning device as defined in claim 1 in which said comparatively rigid section of ladder forms at least a portion of circular staircase.
Claim 6
Dependent Claim
24 words
The warning device as defined in claim 1 in which said motion detection means is arranged to actuate an alarm in a remote location.
Claim 7
Dependent Claim
202 words
A warning device for preventing an intruder from climbing undetected upon a ladder, said ladder comprising a comparatively fixed section, adjacent which a comparatively movable section is supported as a continuation thereof, said comparatively movable section being rigid and having a plurality of rungs, and having an upper end and a lower end, stationary support means disposed adjacent the upper end of said comparatively movable section of ladder, for forming the principal support for latter section of ladder, said upper end of said comparatively movable section of ladder being pivotally attached to said support means such that said upper end can deflect rotationally to a slight extent under the weight of a person stepping on the rungs but not downwardly, thus minimizing the extent of ladder travel and the conspicuousness of the motion, means biasing said movable ladder section in a first direction about said pivotal support means, said movable ladder section being movable in a direction opposite said first direction as a result of the weight of an intruder thereon, and motion detection means arranged to be actuated at such time as said movable ladder section is moved in a direction opposite said first direction, whereby an alarm may be given.
Claim 8
Dependent Claim
202 words
A warning device for preventing an intruder from climbing undetected upon a ladder, said ladder comprising a comparatively fixed section, adjacent which a comparatively movable section is supported as a continuation thereof, said comparatively movable section being rigid and having a plurality of rungs, and having an upper end and a lower end, stationary support means disposed adjacent the upper end of said comparatively movable section of ladder, for forming the principal support for latter section of ladder, said upper end of said comparatively movable section of ladder being pivotally attached to said support means such that said upper end can deflect rotationally to a slight extent under the weight of a person stepping on the rungs but not downwardly, thus minimizing the extent of ladder travel and the conspicuousness of the motion, means biasing said movable ladder section in a first direction about said pivotal support means, said movable ladder section being movable in a direction opposite said first direction as a result of the weight of an intruder thereon, and motion detection means arranged to be actuated at such time as said movable ladder section is moved in a direction opposite said first direction, whereby an alarm may be given.
Claim 9
Dependent Claim
28 words
The warning device as defined in claim 6 in which said motion detection means resets itself automatically after the removal of weight from said movable section of ladder.
Claim 10
Dependent Claim
29 words
The warning device as defined in claim 6 in which said fixed and movable ladder sections are substantially straight sections, disposed at a comparatively steep angle against a structure.
Claim 11
Dependent Claim
26 words
The warning device as defined in claim 6 in which said fixed and movable ladder sectioNs together form at least a portion of a curved ladder.
Claim 12
Dependent Claim
24 words
The warning device as defined in claim 6 in which said motion detection means is arranged to actuate an alarm in a remote location.
Claim 13
Dependent Claim
163 words
A warning device for preventing an intruder from climbing undetected upon a ladder comprising a comparatively rigid section of ladder equipped with a plurality of steps, stationary support means disposed adjacent an upper end of said section of ladder, for forming the principal support for said section of ladder, the upper end of said section of ladder being pivotally attached to said support means, such that said upper end can deflect rotationally to a slight extent under the weight of a person stepping on the steps, but not downwardly, thus minimizing the extent of ladder travel and the conspicuousness of the motion, said section of ladder tending to pivot slightly about said support means upon weight being placed upon said section of ladder, and motion detection means disposed in cooperative relation with said section of ladder, to sense motion about said support means resulting from the placement of weight upon said section of ladder, and to give an alarm at a remote location.
Claim 14
Dependent Claim
163 words
A warning device for preventing an intruder from climbing undetected upon a ladder comprising a comparatively rigid section of ladder equipped with a plurality of steps, stationary support means disposed adjacent an upper end of said section of ladder, for forming the principal support for said section of ladder, the upper end of said section of ladder being pivotally attached to said support means, such that said upper end can deflect rotationally to a slight extent under the weight of a person stepping on the steps, but not downwardly, thus minimizing the extent of ladder travel and the conspicuousness of the motion, said section of ladder tending to pivot slightly about said support means upon weight being placed upon said section of ladder, and motion detection means disposed in cooperative relation with said section of ladder, to sense motion about said support means resulting from the placement of weight upon said section of ladder, and to give an alarm at a remote location.
Claim 15
Dependent Claim
20 words
The warning device as defined in claim 11 in which said comparatively rigid section of ladder is substantially vertically disposed.
Claim 16
Dependent Claim
25 words
The warning device as defined in claim 11 in which said comparatively rigid section of ladder forms at least a portion of a circular staircase.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-03 | 1976-04-03 | 1976-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-03 | 1980-04-03 | 1980-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-03 | 1984-04-03 | 1984-10-03 | $7700.00 | Window Closed / Lapsed |