Patent US4443973A successfully refreshed from Google Patents.
US4443973A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Access door and framing apparatus for the access door's framework
Assignee: Naka Technical Laboratory Co Ltd
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Filing: 1981-07-14
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Granted: 1984-04-24
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Expires: 2001-07-14
Abstract
Abstract An access door is constituted by an outer framework adapted to be fitted in a rough opening formed in a building ceiling, wall, or the like, an inner framework set in an opening in the outer framework, a cover plate secured to the inner framework so as to close an opening in the inner framework, a pair of bearings and axis for pivotally connecting the inner framework to the outer framework, and a locking means for locking the inner framework to the outer framework when the inner framework closes the opening in the outer framework. The bearings are projected on one framework of the opposite inner surfaces of the outer framework and the opposite outer surfaces of the inner framework, and have U-shaped bearing surfaces. The axis are projected on another framework of the opposite inner surfaces of the outer surfaces of the inner framework, and pivotally supported to the bearings, respectively.
Inventors
- 👤 Hiromitsu Naka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:48
CPC Classifications
E; E04; E04B; E04B9/00; E04B9/003; E04F; E04F19/00; E04F19/08; E06; E06B; E06B5/00; E06B5/01
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
354 words
An access door comprising: an outer framework adapted to be fitted in a rough opening formed in a building ceiling, wall, or the like, said outer framework including four outer framework elements positioned in square so as to define four first corners, said four outer framework elements having first upper and lower inserting grooves at opposite ends thereof at the outer sides of each of said four first corners, and four outer framework corner members respectively disposed in said first upper and lower inserting grooves at said four first corners so as to hold said four outer framework elements in abutting relation at said four first corners; an inner framework set in an opening in the outer framework, said inner framework including four inner framework elements positioned in square so as to define four second corners, said four inner framework elements having second upper and lower inserting grooves at opposite ends thereof at the outer sides of each of said four second corners, and four inner framework corner members respectively disposed in said second upper and lower inserting grooves at said four second corners so as to hold said four inner framework elements in abutting relation at said four second corners; a cover plate secured to the inner framework so as to close the opening in the inner framework; a pair of bearings on one of the opposed inner surfaces of the outer framework and outer surfaces of the inner framework, said bearings having U-shaped grooves, respectively; a pair of bearing pins projecting from the other of the opposed inner surfaces of the outer framework and the outer surfaces of the inner framework, and pivotally supported in the bearings, respectively; and a locking means including a box extending through and secured to the cover plate, a shaft supporting bracket, a shaft fitted in the box and rotatably supported on the inner framework by the shaft supporting bracket, said shaft being operable from the outside of the cover plate, and locking bars pivotally connected to the shaft so as to be movable into and out of the outer framework upon the rotation of the shaft.
Claim 2
Dependent Claim
354 words
An access door comprising: an outer framework adapted to be fitted in a rough opening formed in a building ceiling, wall, or the like, said outer framework including four outer framework elements positioned in square so as to define four first corners, said four outer framework elements having first upper and lower inserting grooves at opposite ends thereof at the outer sides of each of said four first corners, and four outer framework corner members respectively disposed in said first upper and lower inserting grooves at said four first corners so as to hold said four outer framework elements in abutting relation at said four first corners; an inner framework set in an opening in the outer framework, said inner framework including four inner framework elements positioned in square so as to define four second corners, said four inner framework elements having second upper and lower inserting grooves at opposite ends thereof at the outer sides of each of said four second corners, and four inner framework corner members respectively disposed in said second upper and lower inserting grooves at said four second corners so as to hold said four inner framework elements in abutting relation at said four second corners; a cover plate secured to the inner framework so as to close the opening in the inner framework; a pair of bearings on one of the opposed inner surfaces of the outer framework and outer surfaces of the inner framework, said bearings having U-shaped grooves, respectively; a pair of bearing pins projecting from the other of the opposed inner surfaces of the outer framework and the outer surfaces of the inner framework, and pivotally supported in the bearings, respectively; and a locking means including a box extending through and secured to the cover plate, a shaft supporting bracket, a shaft fitted in the box and rotatably supported on the inner framework by the shaft supporting bracket, said shaft being operable from the outside of the cover plate, and locking bars pivotally connected to the shaft so as to be movable into and out of the outer framework upon the rotation of the shaft.
Claim 3
Dependent Claim
35 words
An access door as claimed in claim 1 in which said other of the opposed outer framework corner members and inner framework corner members have fixing holes therein fixingly holding said pair of bearing pins.
Claim 4
Dependent Claim
42 words
An access door as claimed in claim 1, in which each of said pair of bearings has projecting portions narrowing the upper portion of the opening into the U-shaped grooves so as to snap fit said bearing pins in said U-shaped grooves.
Claim 5
Dependent Claim
36 words
An access door as claimed in claim 1, in which each of said pair of bearings is a pressed metal piece having a projecting land with a U-shaped recess therein for fitting said bearing pins therein.
Claim 6
Dependent Claim
44 words
An access door as claimed in claim 1, further comprising bearing brackets fixed to the one of the opposed outer framework and inner framework surfaces at the positions of the bearings, and each bearing is integral with a corresponding one of the bearing brackets.
Claim 7
Dependent Claim
49 words
An access door as claimed in claim 5, in which each of the bearing brackets has a grooved sleeve extending through the corresponding outer or inner framework and a knock pin force fitted into the grooved sleeve for securing the bearing bracket to the corresponding outer or inner framework.
Claim 8
Dependent Claim
123 words
An access door as claimed in claim 1, in which the locking means comprises a pair of locking bars on the inner framework, guide members on said inner framework slidably supporting the forward ends of each of said pair of locking bars, a pair of locking bar receivers on the outer framework for receiving the forward end of the corresponding locking bars, a tapping washer having sawteeth therein extending through the cover plate, a cylinder lock mounted in said tapping washer and secured to the inner framework by the shaft supporting bracket, a control plate fixed to the shaft from the cylinder lock and connected to the base end of each of the locking bars, respectively, and a key for the cylinder lock.
Claim 9
Dependent Claim
32 words
An access door as claimed in claim 7, in which said shaft has a groove at its end, and said locking means has a locking bar stop constituted by a leaf spring.
Claim 10
Dependent Claim
47 words
An access door as claimed in claim 1, in which the outer framework has a framework web with flanges on the top and bottom thereof, and said web has locking bar receivers for receiving the forward end of each of the locking bars of the locking means.
Claim 11
Dependent Claim
34 words
An access door as claimed in claim 9, in which each locking bar receiver has a locking bar receiving hole and a pocket extending outwardly from the web beneath the locking bar receiving hole.
Claim 12
Dependent Claim
24 words
An access door as claimed in claim 10, in which the pocket is warped spherical, and the warped spherical pocket has a curled lip.
Claim 13
Dependent Claim
31 words
An access door as claimed in claim 9, in which the locking bar receivers each have a locking bar receiving hole, and said locking bar receiving hole has a curled lip.
Claim 14
Dependent Claim
111 words
An access door as in claim 1, wherein each of said four outer framework corner members are right-angled and have first locking holes therein, each of said four outer framework elements having first deformed portions at opposite ends thereof projecting into said first locking holes for locking said four outer framework corner members to said four outer framework elements; and each of said four inner framework corner members is right-angled and has second locking holes therein, each of said four inner framework elements having second deformed portions at opposite ends thereof projecting into said second locking holes for locking said four inner framework corner members to said four inner framework elements.
Claim 15
Dependent Claim
32 words
An access door as claimed in claim 13, in which at least one inner framework corner member has a guide for at least one of the locking bars of the locking means.
Claim 16
Dependent Claim
278 words
An access door comprising: an outer framework adapted to be fitted in a rough opening formed in a building ceiling, wall, or the like, said outer framework comprising four outer framework elements and four outer framework corner members holding said four outer framework elements together; an inner framework set in an opening in the outer framework, said inner framework comprising four inner framework elements and four inner framework corner members holding said four inner framework elements together; a cover plate secured to the inner framework so as to close the opening in the inner framework; a pair of bearings on one of the opposed inner surfaces of the outer framework and outer surfaces of the inner framework, said bearings having U-shaped grooves, respectively; a pair of bearing pins projecting from the other of the opposed inner surfaces of the outer framework and the outer surfaces of the inner framework, and pivotally supported in the bearings, respectively; and a locking means including a box extending through and secured to the cover plate, a shaft supporting bracket, a shaft fitted in the box and rotatably supported on the inner framework by the shaft supporting bracket, said shaft being operable from the outside of the cover plate, and locking bars pivotally connected to the shaft so as to be movable into and out of the outer framework upon the rotation of the shaft; each of the four outer framework corner members and each of the four inner framework corner members being right-angled and having a pair of locking holes; at least one inner framework corner member having a guide for at least one of the locking bars of the locking means.
Claim 17
Dependent Claim
278 words
An access door comprising: an outer framework adapted to be fitted in a rough opening formed in a building ceiling, wall, or the like, said outer framework comprising four outer framework elements and four outer framework corner members holding said four outer framework elements together; an inner framework set in an opening in the outer framework, said inner framework comprising four inner framework elements and four inner framework corner members holding said four inner framework elements together; a cover plate secured to the inner framework so as to close the opening in the inner framework; a pair of bearings on one of the opposed inner surfaces of the outer framework and outer surfaces of the inner framework, said bearings having U-shaped grooves, respectively; a pair of bearing pins projecting from the other of the opposed inner surfaces of the outer framework and the outer surfaces of the inner framework, and pivotally supported in the bearings, respectively; and a locking means including a box extending through and secured to the cover plate, a shaft supporting bracket, a shaft fitted in the box and rotatably supported on the inner framework by the shaft supporting bracket, said shaft being operable from the outside of the cover plate, and locking bars pivotally connected to the shaft so as to be movable into and out of the outer framework upon the rotation of the shaft; each of the four outer framework corner members and each of the four inner framework corner members being right-angled and having a pair of locking holes; at least one inner framework corner member having a guide for at least one of the locking bars of the locking means.
Claim 18
Dependent Claim
55 words
An access door as claimed in claim 15 in which said outer framework is comprised of four outer framework elements and four outer framework corner members holding said four outer framework elements together; and said inner framework comprising four inner framework elements and four inner framework corner members holding said four inner framework elements together.
Claim 19
Dependent Claim
262 words
An access door comprising: an outer framework adapted to be fitted in a rough opening formed in a building ceiling, wall, or the like; an inner framework set in an opening in the outer framework; a cover plate secured to the inner framework so as to close the opening in the inner framework; a pair of bearings on one of the opposed inner surfaces of the outer framework and outer surfaces of the inner framework, said bearings having U-shaped grooves, respectively; a pair of bearing pins projecting from the other of the opposed inner surfaces of the outer framework and the outer surfaces of the inner framework, and pivotally supported in the bearings, respectively; bearing brackets fixed to the one of the opposed outer framework and inner framework surfaces at the positions of the bearings, each bearing being integral with a corresponding one of the bearing brackets, each of the bearing brackets having a grooved sleeve extending through the corresponding outer or inner framework and a knock pin force fitted into the grooved sleeve for securing the bearing bracket to the corresponding outer or inner framework; and a locking means including a box extending through and secured to the cover plate, a shaft supporting bracket, a shaft fitted in the box and rotatably supported on the inner framework by the shaft supporting bracket, said shaft being operable from the outside of the cover plate, a pair of locking bars pivotally connected to the shaft so as to be movable into and out of the outer framework upon the rotation of the shaft.
Claim 20
Dependent Claim
262 words
An access door comprising: an outer framework adapted to be fitted in a rough opening formed in a building ceiling, wall, or the like; an inner framework set in an opening in the outer framework; a cover plate secured to the inner framework so as to close the opening in the inner framework; a pair of bearings on one of the opposed inner surfaces of the outer framework and outer surfaces of the inner framework, said bearings having U-shaped grooves, respectively; a pair of bearing pins projecting from the other of the opposed inner surfaces of the outer framework and the outer surfaces of the inner framework, and pivotally supported in the bearings, respectively; bearing brackets fixed to the one of the opposed outer framework and inner framework surfaces at the positions of the bearings, each bearing being integral with a corresponding one of the bearing brackets, each of the bearing brackets having a grooved sleeve extending through the corresponding outer or inner framework and a knock pin force fitted into the grooved sleeve for securing the bearing bracket to the corresponding outer or inner framework; and a locking means including a box extending through and secured to the cover plate, a shaft supporting bracket, a shaft fitted in the box and rotatably supported on the inner framework by the shaft supporting bracket, said shaft being operable from the outside of the cover plate, a pair of locking bars pivotally connected to the shaft so as to be movable into and out of the outer framework upon the rotation of the shaft.
Claim 21
Dependent Claim
290 words
An access door comprising: an outer framework adapted to be fitted in a rough opening formed in a building ceiling, wall, or the like; an inner framework set in an opening in the outer framework; a cover plate secured to the inner framework so as to close the opening in the inner framework; a pair of bearings on one of the opposed inner surfaces of the outer framework and outer surfaces of the inner framework, said bearings having U-shaped grooves, respectively; a pair of bearing pins projecting from the other of the opposed inner surfaces of the outer framework and the outer surfaces of the inner framework, and pivotally supported in the bearings, respectively; and a locking means including a box extending through and secured to the cover plate, a shaft supporting bracket, a shaft fitted in the box and rotatably supported on the inner framework by the shaft supporting bracket, said shaft being operable from the outside of the cover plate, a pair of locking bars pivotally connected to the shaft so as to be movable into and out of the outer framework upon the rotation of the shaft, guide members on said inner framework slidably supporting the forward end of each of said pair of locking bars, a pair of locking bar receivers on the outer framework for receiving the forward ends of the corresponding locking bars, a tapping washer having sawteeth therein extending through the cover plate, a cylinder lock mounted in said tapping washer and secured to the inner framework by the shaft supporting bracket, a control plate fixed to the shaft from the cylinder lock and connected to the base end of each of the locking bars, respectively, and a key for the cylinder lock.
Claim 22
Dependent Claim
290 words
An access door comprising: an outer framework adapted to be fitted in a rough opening formed in a building ceiling, wall, or the like; an inner framework set in an opening in the outer framework; a cover plate secured to the inner framework so as to close the opening in the inner framework; a pair of bearings on one of the opposed inner surfaces of the outer framework and outer surfaces of the inner framework, said bearings having U-shaped grooves, respectively; a pair of bearing pins projecting from the other of the opposed inner surfaces of the outer framework and the outer surfaces of the inner framework, and pivotally supported in the bearings, respectively; and a locking means including a box extending through and secured to the cover plate, a shaft supporting bracket, a shaft fitted in the box and rotatably supported on the inner framework by the shaft supporting bracket, said shaft being operable from the outside of the cover plate, a pair of locking bars pivotally connected to the shaft so as to be movable into and out of the outer framework upon the rotation of the shaft, guide members on said inner framework slidably supporting the forward end of each of said pair of locking bars, a pair of locking bar receivers on the outer framework for receiving the forward ends of the corresponding locking bars, a tapping washer having sawteeth therein extending through the cover plate, a cylinder lock mounted in said tapping washer and secured to the inner framework by the shaft supporting bracket, a control plate fixed to the shaft from the cylinder lock and connected to the base end of each of the locking bars, respectively, and a key for the cylinder lock.
Claim 23
Dependent Claim
32 words
An access door as claimed in claim 18, in which said shaft has a groove at its end, and said locking means has a locking bar stop constituted by a leaf spring.
Claim 24
Dependent Claim
248 words
An access door comprising: an outer framework adapted to be fitted in a rough opening formed in a building ceiling, wall, or the like; an inner framework set in an opening in the outer framework; a cover plate secured to the inner framework so as to close the opening in the inner framework; a pair of bearings in one of the opposed inner surfaces of the outer framework and outer surfaces of the inner framework, said bearings having U-shaped grooves, respectively; a pair of bearing pins projecting from the other of the opposed inner surfaces of the outer framework and the outer surfaces of the inner framework, and pivotally supported in the bearings, respectively; and a locking means including a box extending through and secured to the cover plate, a shaft supporting bracket, a shaft fitted in the box and rotatably supported on the inner framework by said shaft supporting bracket, said shaft being operable from the outside of the cover plate, and locking bars pivotally connected to the shaft so as to be movable into and out of the outer framework upon the rotation of the shaft, the outer framework having a framework web with flanges on the top and bottom thereof, said web having locking bar receivers for receiving the forward end of each of the locking bars of the locking means, each locking bar receiver having a locking bar receiving hole and a pocket extending outwardly from the web beneath the locking bar receiving hole.
Claim 25
Dependent Claim
248 words
An access door comprising: an outer framework adapted to be fitted in a rough opening formed in a building ceiling, wall, or the like; an inner framework set in an opening in the outer framework; a cover plate secured to the inner framework so as to close the opening in the inner framework; a pair of bearings in one of the opposed inner surfaces of the outer framework and outer surfaces of the inner framework, said bearings having U-shaped grooves, respectively; a pair of bearing pins projecting from the other of the opposed inner surfaces of the outer framework and the outer surfaces of the inner framework, and pivotally supported in the bearings, respectively; and a locking means including a box extending through and secured to the cover plate, a shaft supporting bracket, a shaft fitted in the box and rotatably supported on the inner framework by said shaft supporting bracket, said shaft being operable from the outside of the cover plate, and locking bars pivotally connected to the shaft so as to be movable into and out of the outer framework upon the rotation of the shaft, the outer framework having a framework web with flanges on the top and bottom thereof, said web having locking bar receivers for receiving the forward end of each of the locking bars of the locking means, each locking bar receiver having a locking bar receiving hole and a pocket extending outwardly from the web beneath the locking bar receiving hole.
Claim 26
Dependent Claim
24 words
An access door as claimed in claim 20, in which the pocket is warped spherical, and the warped spherical pocket has a curled lip.
Claim 27
Dependent Claim
81 words
An access door comprising: an outer framework adapted to be fitted in a rough opening formed in a building ceiling, wall, or the like; an inner framework set in an opening in the outer framework; a cover plate secured to the inner framework so as to close the opening in the inner framework; a pair of bearings on one of the opposed inner surfaces of the outer framework and outer surfaces of the inner framework, said bearings having U-shaped grooves, respectively;
Claim 28
Dependent Claim
81 words
An access door comprising: an outer framework adapted to be fitted in a rough opening formed in a building ceiling, wall, or the like; an inner framework set in an opening in the outer framework; a cover plate secured to the inner framework so as to close the opening in the inner framework; a pair of bearings on one of the opposed inner surfaces of the outer framework and outer surfaces of the inner framework, said bearings having U-shaped grooves, respectively;
Claim 29
Dependent Claim
165 words
a pair of bearing pins projecting from the other of the opposed inner surfaces of the outer framework and the outer surfaces of the inner framework, and pivotally supported in the bearings, respectively; and a locking means including a box extending through and secured to the cover plate, a shaft supporting bracket, a shaft fitted in the box and rotatably supported on the inner framework by said shaft supporting bracket, said shaft being operable from the outside of the cover plate, and locking bars pivotally connected to the shaft so as to be movable into and out of the outer framework upon the rotation of the shaft, the outer framework having a framework web with flanges on the top and bottom thereof, and said web having locking bar receivers for receiving the forward end of each of the locking bars of the locking means, the locking bar receivers each having a locking bar receiving hole, and said locking bar receiving hole having a curled lip.
Claim 30
Dependent Claim
165 words
a pair of bearing pins projecting from the other of the opposed inner surfaces of the outer framework and the outer surfaces of the inner framework, and pivotally supported in the bearings, respectively; and a locking means including a box extending through and secured to the cover plate, a shaft supporting bracket, a shaft fitted in the box and rotatably supported on the inner framework by said shaft supporting bracket, said shaft being operable from the outside of the cover plate, and locking bars pivotally connected to the shaft so as to be movable into and out of the outer framework upon the rotation of the shaft, the outer framework having a framework web with flanges on the top and bottom thereof, and said web having locking bar receivers for receiving the forward end of each of the locking bars of the locking means, the locking bar receivers each having a locking bar receiving hole, and said locking bar receiving hole having a curled lip.
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) | 1987-04-24 | 1987-10-24 | 1988-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-24 | 1991-10-24 | 1992-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-24 | 1995-10-24 | 1996-04-24 | $7700.00 | Window Closed / Lapsed |