US3791375A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for sensing and warning of excessive ambulation force
Assignee: Individual
•
Filing: 1971-09-29
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Granted: 1974-02-12
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Expires: 1991-09-29
Abstract
Abstract Warning of excessive ambulation force, for limiting the application of weight on a lower extremity, usually in the recovery from orthopedic surgery of the lower extremity, is accomplished by a fluid-containing load cell which deflects and changes its volume in accordance with the amount of load thereon. A tubular connector connects the load cell fluid with a displacement-measuring device, for example, a bellows. A particular displacement limit, conveniently signaled with an electrical alarm indicates when predetermined load on the cell is reached.
Inventors
- 👤 E Pfeiffer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:01
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/103; A61B5/1036; Y; Y10; Y10S; Y10S128/00; Y10S128/905
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
211 words
A device for sensing and warning of excessive ambulation load force on the body when erect on the feet comprising: a load cell positionable to receive ambulation load, said load cell comprising upper and lower plates, spacer means between said upper and lower plates for maintaining said upper and lower plates in spaced condition, said spacer means comprising an elastomeric member extending around the periphery of said plates, said plates and said elastomeric member defining an enclosed fluid at ambient pressure which defines a volume in said load cell, said spacer means being resiliently deflectable by body forces so that said upper and lower plates are permitted to come closer together upon application of load downwardly on said upper plate to reduce said enclosed volume; a fluid tube connected to said enclosed volume; a bellows connected to said fluid tube and an electric switch contact connected to said bellows so that predetermined expansion of said bellows caused by fluid flow from said load cell to said bellows through said tube actuates said switch to cause signaling only when a predetermined load is reached and a resulting predetermined fluid flow has occurred, there being no signal below the predetermined ambulation force load and a warning signal above the predetermined ambulation force load.
Claim 2
Independent Claim
211 words
A device for sensing and warning of excessive ambulation load force on the body when erect on the feet comprising: a load cell positionable to receive ambulation load, said load cell comprising upper and lower plates, spacer means between said upper and lower plates for maintaining said upper and lower plates in spaced condition, said spacer means comprising an elastomeric member extending around the periphery of said plates, said plates and said elastomeric member defining an enclosed fluid at ambient pressure which defines a volume in said load cell, said spacer means being resiliently deflectable by body forces so that said upper and lower plates are permitted to come closer together upon application of load downwardly on said upper plate to reduce said enclosed volume; a fluid tube connected to said enclosed volume; a bellows connected to said fluid tube and an electric switch contact connected to said bellows so that predetermined expansion of said bellows caused by fluid flow from said load cell to said bellows through said tube actuates said switch to cause signaling only when a predetermined load is reached and a resulting predetermined fluid flow has occurred, there being no signal below the predetermined ambulation force load and a warning signal above the predetermined ambulation force load.
Claim 3
Dependent Claim
53 words
The device of claim 1 wherein said bellows-mounted electric switch contact faces an adjustable electric contact, the position of said adjustable electric contact permitting selection of bellows expansion due to fluid inflow from said load cell before switch actuation so that the load on said load cell which causes signaling can be preselected.
Claim 4
Dependent Claim
33 words
The device of claim 1 wherein first and second load cells are positionable to receive ambulation force under the same foot, and both of said load cells are connected to the same bellows.
Claim 5
Dependent Claim
51 words
The device of claim 1 wherein there are first and second load cells positionable under the foot foR which ambulation force is being sensed, said first and second load cells being respectively connected to first and second bellows, said first and second bellows being connected together for actuation of said switch.
Claim 6
Dependent Claim
51 words
The device of claim 1 wherein said load cell is surrounded with spacer material, and a covering covers said load cell and said spacer material, said covering, said load cell and said spacer material outlining a shoe area so that said load cell can be positioned with respect to a shoe.
Claim 7
Dependent Claim
36 words
The device of claim 5 wherein there are first and second load cells, each being peripherally surrounded by spacer material and each being covered so that the outlines thereof represent different positions of a shoe area.
Claim 8
Dependent Claim
38 words
The device of claim 6 wherein said first and second covered load cells are positioned within a rubber overshoe so that the load therein applied by a shoe can be sensed, and warning emitted for excessive ambulation force.
Claim 9
Dependent Claim
28 words
The device of claim 1 wherein said electric switch is connected to an audible signal for audibly signaling the reaching of the predetermined load on said upper plate.
Claim 10
Dependent Claim
21 words
The device of claim 1 wherein said resilient spacer means comprises an elastomeric member extending around the periphery of said plates.
Claim 11
Dependent Claim
10 words
The device of claim 1 wherein said plates are circular.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |