US3902948A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for forming curved stairways
Assignee: Individual
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Filing: 1974-06-13
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Granted: 1975-09-02
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Expires: 1994-06-13
Abstract
Abstract The invention relates to an apparatus in the form of a jig and a method for forming a curving stairway. The jig comprises a generally circular center supporting post with a plurality of radially extending horizontal arms mounted thereon. These arms are swingably mounted on the post in a vertically stacked arrangement and are angularly displaceable from each other to form a helical path. Upwardly extending retainer members are mounted on the arms and these members with the arms therebetween form a jig defining the path of the stairway. The retainers serve to retain inner and outer concentrically curved plates forming ends of stair treads which are assembled between the plates. A complete stairway of wood, concrete or metal can be constructed on the jig, after which the jig is separated from the completed stairway to be used for the construction of another stairway.
Inventors
- 👤 Jose Morros
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:37
CPC Classifications
E; E04; E04F; E04F21/00; E04F21/26; E04G; E04G13/00; E04G13/06; E04G13/062; Y; Y10; Y10S; Y10S269/00; Y10S269/904; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1043; Y10T156/1044
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
119 words
An apparatus for forming a curved stairway comprising: a. a generally circular vertical center supporting post: b. a plurality of radially extending horizontal arms mounted on said post, said arms being vertically stacked on said post and being horizontally swingable for angular displacement with respect to each other, thereby forming a helical path; and c. upwardly extending retainer members mounted on said arms, said retainer members and arms forming therebetween a jig defining the path of the stairway with said retainer members serving to retain inner and outer concentrically curved plates forming ends of stair treads which are assembled between the plates to construct a stairway, said retainers, arms and post being separable from the constructed stairway for re-use.
Claim 2
Independent Claim
119 words
An apparatus for forming a curved stairway comprising: a. a generally circular vertical center supporting post: b. a plurality of radially extending horizontal arms mounted on said post, said arms being vertically stacked on said post and being horizontally swingable for angular displacement with respect to each other, thereby forming a helical path; and c. upwardly extending retainer members mounted on said arms, said retainer members and arms forming therebetween a jig defining the path of the stairway with said retainer members serving to retain inner and outer concentrically curved plates forming ends of stair treads which are assembled between the plates to construct a stairway, said retainers, arms and post being separable from the constructed stairway for re-use.
Claim 3
Dependent Claim
18 words
An apparatus according to claim 1 wherein load supports for said arms are provided distal from the post.
Claim 4
Dependent Claim
20 words
An apparatus according to claim 2 wherein lateral bracing members are provided for fixing the angular displacement of the arms.
Claim 5
Dependent Claim
15 words
An apparatus according to claim 1 wherein each retainer member is movable along an arm.
Claim 6
Dependent Claim
32 words
An apparatus according to claim 1 wherein each retainer member comprises a pair of upstanding posts with a small gap therebetween, said gap being adapted to receive and retain the curving plates.
Claim 7
Dependent Claim
23 words
An apparatus according to claim 5 wherein each post is rigidly fixed to a base member which is adjustably fixed to an arm.
Claim 8
Dependent Claim
23 words
An apparatus according to claim 6 wherein a cross bar is pivotally connected between the upper ends of said posts across the gap.
Claim 9
Dependent Claim
24 words
An apparatus according to claim 1 wherein each arm includes at one end thereof a tubular sleeve member which swingably mounts on said post.
Claim 10
Dependent Claim
17 words
An apparatus according to claim 8 wherein said sleeve members rest on each other in stacked relationship.
Claim 11
Dependent Claim
27 words
An apparatus according to claim 8 wherein each arm includes at the end remote from said sleeve a clamp member for receiving and holding a vertical support.
Claim 12
Independent Claim
109 words
A METHOD OF CONSTRUCTING A CURVED STAIRWAY WHICH COMPRISES. A, ALIGNING A JIG HAVING A PLURITY OF VERTICALLY STUCKED RADIALLY EXTENDING HORIZONTAL ARMS MOUNTED ON A VERTICAL POST SUCH THAT THE ARMS ANGULARLY DISPLACED WITH RESPECT TO EACH OTHER TO FORM A HELICAL PATH. B. POSITIONING A PAIR OF SUBSTANTIALLY VERTICAL RETAINER MEMBERS IN SPACED RELATIONSHIP ON EACH ARM WHEREBY THE RETAINERS ON THE PLURITY OF ARMS FORM A JIG DEFINING THE PATH OF A CURVING STAIRWAY, C. POSITIONING STRINGER MEMBERS ADJACENT SAID RETAINERS AND RESTING ON SAID ARMS, D. CONSTRUCTING STEPS BETWEEN SAID STRINGERS TO FORM A SELFSUPPORTING STAIRWAY AND E, SEPARTING THE JIG FROM THE CONSTRUCTED STAIRWAY.
Claim 13
Independent Claim
109 words
A METHOD OF CONSTRUCTING A CURVED STAIRWAY WHICH COMPRISES. A, ALIGNING A JIG HAVING A PLURITY OF VERTICALLY STUCKED RADIALLY EXTENDING HORIZONTAL ARMS MOUNTED ON A VERTICAL POST SUCH THAT THE ARMS ANGULARLY DISPLACED WITH RESPECT TO EACH OTHER TO FORM A HELICAL PATH. B. POSITIONING A PAIR OF SUBSTANTIALLY VERTICAL RETAINER MEMBERS IN SPACED RELATIONSHIP ON EACH ARM WHEREBY THE RETAINERS ON THE PLURITY OF ARMS FORM A JIG DEFINING THE PATH OF A CURVING STAIRWAY, C. POSITIONING STRINGER MEMBERS ADJACENT SAID RETAINERS AND RESTING ON SAID ARMS, D. CONSTRUCTING STEPS BETWEEN SAID STRINGERS TO FORM A SELFSUPPORTING STAIRWAY AND E, SEPARTING THE JIG FROM THE CONSTRUCTED STAIRWAY.
Claim 14
Dependent Claim
31 words
A method according to claim 11 wherein the stringers are constructed in the jig by laminating wood strips and step treads are permanently fixed to the stringers to form the stairway.
Claim 15
Dependent Claim
53 words
A method according to claim 11 wherein the stringers are strips of sheet material and a deck of sheet material is placed on said arms between the stringers to create a concrete mold, concrete steps are constructed within said mold to produce a self-supporting stairway and thereafter the jig and mold are removed.
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) | 1978-09-01 | 1979-03-03 | 1979-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-01 | 1983-03-03 | 1983-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-01 | 1987-03-03 | 1987-09-02 | $7700.00 | Window Closed / Lapsed |