Patent US3879770A successfully refreshed from Google Patents.
US3879770A
Expired / Lapsed
US
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Fluid operated bathtub lift
Assignee: Grant Airmass Corp
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Filing: 1974-01-11
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Granted: 1975-04-29
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Expires: 1994-01-11
Abstract
Abstract A bathtub lift system comprises a fluid operated lift composed of three, coaxially mounted tubular members. A main tube is fixed in position on a base and carries within it a sleeve-like thrust tube which carries a piston assembly at its lower end. A tie rod secures the thrust tube to the piston and the outer carrier tube rests on the upper end of thrust tube on a low friction bearing. A chair or the like, is rotatably mounted on the carrier tube. The thrust tube and carrier tube move together axially relative to the main tube under the influence of fluid pressure applied to the piston through the base, to move the chair into or out of a tub or the like. The carrier tube is rotatable through 360* to swing the chair over or exterior to the tub, without transmission of torque to the piston assembly. The chair is secured to the carrier tube by means of a fixed hook member on the carrier tube engaging a horizontal bar on the chair. The chair is prevented from being inadvertently dislodged by a positively locked latching hook which overlaps the engagement of the bar with the fixed hook. The latching hook must be lifted to free the chair from the two hooks.
Inventors
- 👤 Benton H Grant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:35
CPC Classifications
A; A61; A61G; A61G7/00; A61G7/10; A61G7/1001; A61G7/1003; A61G7/1013; A61G7/1019; A61G7/104; A61G7/1044; A61G7/1049; A61G7/1059; A61G7/1073; A61G7/1076
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
316 words
A fluid operated bathtub lift system comprising, in combination: A. a base, 1. means forming a fluid pressure chamber on said base, and 2. means forming at least one fluid passageway; B. a cylindrical main tube vertically mounted to said base in substantially fluid-tight relationship about said pressure chamber, 1. and having a bearing member secured adjacent the top of said main tube, a. said bearing member having means forming a central opening therethrough; C. a cylindrical carrier tube telescopically mounted for axial and rotational movement over said main tube, 1. the inner diameter of said carrier tube exceeding the outer diameter of said main tube by an amount sufficient to leave an annular clearance space of predetermined radial dimension therebetween, 2. a top plate attached to said carrier tube; D. a thrust tube assembly mounted for axial movement within said main tube and carrying means forming a piston assembly adjacent the lower end thereof and rotatably supporting said carrier tube on the upper end thereof, said thrust tube assembly comprising 1. a thrust tube supported at its lower end on said piston assembly and rotatably supporting at its upper end the top plate of said carrier tube, with said piston assembly and said carrier tube top plate being spaced by a thrust tube around a central rod, 2. said thrust tube passing through said central opening of said bearing member, and 3. low friction bearing means on said thrust tube assembly between said carrier tube top plate and said piston assembly; E. a plurality of clearance rings secured on one of said main tube and said carrier tube at selected spaced positions along the length thereof and extending into said clearance space, 1. said clearance rings each having a thickness dimension which is slightly less than the said radial dimension of said clearance space; and F. human body supporting means mounted on said carrier tube.
Claim 2
Dependent Claim
316 words
A fluid operated bathtub lift system comprising, in combination: A. a base, 1. means forming a fluid pressure chamber on said base, and 2. means forming at least one fluid passageway; B. a cylindrical main tube vertically mounted to said base in substantially fluid-tight relationship about said pressure chamber, 1. and having a bearing member secured adjacent the top of said main tube, a. said bearing member having means forming a central opening therethrough; C. a cylindrical carrier tube telescopically mounted for axial and rotational movement over said main tube, 1. the inner diameter of said carrier tube exceeding the outer diameter of said main tube by an amount sufficient to leave an annular clearance space of predetermined radial dimension therebetween, 2. a top plate attached to said carrier tube; D. a thrust tube assembly mounted for axial movement within said main tube and carrying means forming a piston assembly adjacent the lower end thereof and rotatably supporting said carrier tube on the upper end thereof, said thrust tube assembly comprising 1. a thrust tube supported at its lower end on said piston assembly and rotatably supporting at its upper end the top plate of said carrier tube, with said piston assembly and said carrier tube top plate being spaced by a thrust tube around a central rod, 2. said thrust tube passing through said central opening of said bearing member, and 3. low friction bearing means on said thrust tube assembly between said carrier tube top plate and said piston assembly; E. a plurality of clearance rings secured on one of said main tube and said carrier tube at selected spaced positions along the length thereof and extending into said clearance space, 1. said clearance rings each having a thickness dimension which is slightly less than the said radial dimension of said clearance space; and F. human body supporting means mounted on said carrier tube.
Claim 3
Dependent Claim
25 words
means forming at least one fluid passageway; B. a cylindrical main tube vertically mounted to said base in substantially fluid-tight relationship about said pressure chamber,
Claim 4
Dependent Claim
25 words
means forming at least one fluid passageway; B. a cylindrical main tube vertically mounted to said base in substantially fluid-tight relationship about said pressure chamber,
Claim 5
Dependent Claim
49 words
a top plate attached to said carrier tube; D. a thrust tube assembly mounted for axial movement within said main tube and carrying means forming a piston assembly adjacent the lower end thereof and rotatably supporting said carrier tube on the upper end thereof, said thrust tube assembly comprising
Claim 6
Dependent Claim
49 words
a top plate attached to said carrier tube; D. a thrust tube assembly mounted for axial movement within said main tube and carrying means forming a piston assembly adjacent the lower end thereof and rotatably supporting said carrier tube on the upper end thereof, said thrust tube assembly comprising
Claim 7
Dependent Claim
13 words
said thrust tube passing through said central opening of said bearing member, and
Claim 8
Dependent Claim
13 words
said thrust tube passing through said central opening of said bearing member, and
Claim 9
Dependent Claim
68 words
The bathtub lift system defined in claim 1 wherein said thrust tube assembly further comprises a loosely fitted rod positioned in the upper end of said thrust tube, a guide plate around the upper end of said thrust tube and having at least a plurality of diameters slightly less than the inner diameter of said carrier tube, with said low friction bearing means being positioned on said rod.
Claim 10
Dependent Claim
50 words
low friction bearing means on said thrust tube assembly between said carrier tube top plate and said piston assembly; E. a plurality of clearance rings secured on one of said main tube and said carrier tube at selected spaced positions along the length thereof and extending into said clearance space,
Claim 11
Dependent Claim
50 words
low friction bearing means on said thrust tube assembly between said carrier tube top plate and said piston assembly; E. a plurality of clearance rings secured on one of said main tube and said carrier tube at selected spaced positions along the length thereof and extending into said clearance space,
Claim 12
Dependent Claim
44 words
The bathtuB lift system defined in claim 1 wherein said low friction bearing means comprises a bushing made of polymeric material, said bushing resting on a low friction washer, said washer being secured over the top of the upper end of said thrust tube.
Claim 13
Dependent Claim
59 words
The bathtub lift system defined in claim 1 wherein said thrust tube is formed in two sections, with a stop member secured around a central rod extending from said piston assembly upwardly between said two thrust tube sections, said stop member limiting upward movement of said thrust tube assembly by engagement of said stop member with said annular bearing.
Claim 14
Dependent Claim
43 words
The bathtub lift system defined in claim 1 wherein one of said clearance rings is secured around and adjacent the outer top of said main tube and a second of said clearance rings is secured around the outer bottom of said main tube.
Claim 15
Dependent Claim
20 words
The bathtub lift system defined in claim 3 wherein said clearance rings are made of a low friction polymeric material.
Claim 16
Dependent Claim
115 words
The bathtub lift system defined in claim 1 wherein said human body supporting means comprises, G. a hook means secured to said carrier tube for supporting a chair frame; H. a chair means having a horizontal support bar extending from the hook of said chair and engageable with said hook means; and I. a latching means pivotally disposed above said hook means and having a downwardly extending end portion engageable with said horizontal support bar from above and overlapping an upturned portion of said hook means, whereby said latching means prevents said horizontal bar from being disengaged from said hook means without lifting of said latching means by other than upward movement of said bar.
Claim 17
Dependent Claim
58 words
The bathtub lift system defined in claim 7 wherein said latching means further comprises a dog member rotatably secured to a portion of said latching means and engageable with a portion of the latching means to positively lock the end portion of said latching means into overlapping position with respect to said upturned portion of said hook means.
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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) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |