US 4,947,922 AGranted

Tensioning stretched-canvas frame and method for use

OwnerJohn Stobartinventor

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Abstract

A tensioning stretched-canvas frame and method of use is disclosed characterized by the end portion of adjacent frame members having complementary cavities formed therein which receive a spring insert adapted to persistently force the frame members apart against the retention of canvas stretched taut thereover. The spring insert resists both rotation within the cavities and bending in the plane of the frame, accordingly making the assembled frame resistent to twisting between the frame members, distortion of the frame area, and warping of the frame's plane. A disposable bridging member may be temporarily used to maintain the frame members in abutting contact against the spring forces during initial stretching of the canvas.

Claims6

Dependent claims

An expansive frame apparatus comprising:

a plurality of frame members each having end portions disposed in an abutted orientation to an adjacent member to frame an area;
a central bore formed at said end portion of each frame member, which central bore aligns with a corresponding central bore in the corresponding end portion of an adjacent frame member;
a middle cavity formed coaxial with said central bore at said end portion of each frame member, which middle cavity aligns with a corresponding middle cavity in the corresponding end portion of an adjacent frame member;
a counter bore formed coaxial with said central bore and middle cavity at said end portion of each frame member, which counter bore aligns with a corresponding counter bore in the corresponding end portion of an adjacent frame member;
biasing means, fitting between adjacent frame members and extending into said central bore and counter bore thereon, whereby said biasing means, when rotated, is adapted to exert a camming force on said frame members, thereby forcing the frame members apart from abutting contact;
wherein each of said plurality frame members end portions are mitered to abut corresponding end portions of an adjacent frame member in a complementary fashion, wherein said biasing means comprises a biasing member having a cam portion and a biasing wheel portion rigidly affixed to said cam portion;
a plurality of camming surfaces affixed to said cam portion and adapted to exert said camming force on said frame members when said biasing means is rotated;
a cam-opposing surface formed on said central bore, said cam opposing surface shaped to provide a camming interface between said central bore and said camming surfaces on said cam portion for forcing the frame members apart from abutting contact;
finger hold means disposed on said biasing wheel of said biasing means for applying a force couple to said biasing wheel to rotate said biasing means;
a rigid disk complementary to and receivable in said middle cavities in said end portions of said frame members, wherein said rigid disk and said middle cavity are cooperatively configured so that said rigid disk fits tightly within said middle cavities, thereby insuring that adjacent frame members will not twist relative to one another;
and
a clearance aperture centrally located on said rigid disk, shaped to receive through complementary features of said clearance aperture said cam portion and said camming surfaces of said biasing means, and thereby allow said cam portion to be received into said central bore.

9 more elements

Dependencies are inferred from the claim text.

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Abstract

An expansive frame apparatus comprising:

a plurality of frame members each having end portions disposed in an abutted orientation to an adjacent member to frame an area;
a central bore formed at said end portion of each frame member, which central bore aligns with a corresponding central bore in the corresponding end portion of an adjacent frame member;
a middle cavity formed coaxial with said central bore at said end portion of each frame member, which middle cavity aligns with a corresponding middle cavity in the corresponding end portion of an adjacent frame member;
a counter bore formed coaxial with said central bore and middle cavity at said end portion of each frame member, which counter bore aligns with a corresponding counter bore in the corresponding end portion of an adjacent frame member;
biasing means, fitting between adjacent frame members and extending into said central bore and counter bore thereon, whereby said biasing means, when rotated, is adapted to exert a camming force on said frame members, thereby forcing the frame members apart from abutting contact;
wherein each of said plurality frame members end portions are mitered to abut corresponding end portions of an adjacent frame member in a complementary fashion, wherein said biasing means comprises a biasing member having a cam portion and a biasing wheel portion rigidly affixed to said cam portion;
a plurality of camming surfaces affixed to said cam portion and adapted to exert said camming force on said frame members when said biasing means is rotated;
a cam-opposing surface formed on said central bore, said cam opposing surface shaped to provide a camming interface between said central bore and said camming surfaces on said cam portion for forcing the frame members apart from abutting contact;
finger hold means disposed on said biasing wheel of said biasing means for applying a force couple to said biasing wheel to rotate said biasing means;
a rigid disk complementary to and receivable in said middle cavities in said end portions of said frame members, wherein said rigid disk and said middle cavity are cooperatively configured so that said rigid disk fits tightly within said middle cavities, thereby insuring that adjacent frame members will not twist relative to one another;
and
a clearance aperture centrally located on said rigid disk, shaped to receive through complementary features of said clearance aperture said cam portion and said camming surfaces of said biasing means, and thereby allow said cam portion to be received into said central bore.

9 more elements