SYSTEME DE STRUCTURE DE BARRE DE CIVIERE EN CANEVAS DOTE D'UN MECANISME DE FIXATION DE CANEVAS A FENTE A BILLE INTEGREE

CANVAS STRETCHER BAR FRAMING SYSTEM WITH A BUILT IN BALL SLOT CANVAS FASTENING SYSTEM

Abrégé anglais

Disclosed is a Friction Fit Canvas Stretcher Bar Framing System with a
combined built in Ball
Slot Canvas Fastening System. It is specifically designed for Artists and for
those who
commercially produce picture frames and ready to hang art that has been done
on canvas or a
similar type of material. Designed for quick easy manual or automated
mechanical mounting.
This unique interlocking friction fit framing and fastening system does not
require any tools to
assemble and it does not require any special skills or tools to properly
stretch and attach canvas
or similar type material onto a frame. Uniform, precision cut, interlocking,
frame sections
consisting of straight and curved sections, each with a protruding male end
and a recessed
female end connect together by aligning a male end over top of a corresponding
sections
female end and then pressing down. The male end slides into the female end to
form a tight
friction fit connection and a perfect 90 degree corner. Frame sections come in
various standard
stretcher bar lengths, widths, depths and profiles and can easily be assembled
to form
rectangular, square, round and oval shaped frames in an array of sizes. Canvas
is evenly
stretched and attached to a frame using a unique built in Ball Slot Fastening
System and 2
rubber splines which are reusable and unlike staples, adhesives and clamps
they are easy to
install and uninstall and they do not cause any damage to the canvas or to the
frame. Frame
sections can easily be assembled and disassembled and canvas can be attached
and detached
for compact shipping and for repeated use.

Revendications

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CLAIMS
1. A stretcher bar framing and fastening system for stretching, re stretching,
mounting,
dismounting, attaching and detaching artist canvas comprising
a plurality of precision cut, interlocking, interchangeable, variable lengths,
side bar sections
featuring a press together friction fit joining and connecting method
utilizing a protruding male
plug on one end and recessed female socket on the other end that interconnect
to form an array
of various sizes of square, rectangular, round and oval frames;
a female socket on one end having an open cavity, having side walls, which is
open at the open
end and closed at the adjacent end;
a male plug on the opposite end, having sidewalls for insertion through a
corresponding
sections top open end of said cavity of said female socket end;
a male plug end is fully inserted down into the open end of said cavity, to
engage, mate and
interlock said plug member to said female socket member;
a fastening ball slot on the back side of each side bar section to stretch,
attach and secure
canvas to said stretcher bar frame with a rubber spline and;
a stretcher bar front side surface, on all side bar sections, having an
extending, protruding,
rounded outside edge, which a canvas is stretched over, that slopes downward
towards the
front side surface.
2. The stretcher bar frame according to claim 1 wherein each side bar section
has a protruding
male plug and a recessed female socket positioned at opposite ends.
3. The stretcher bar frame according to claim 1 wherein the length and width
can be increased
or decreased by adding or removing side bar sections to form an array of
various sizes of
square, rectangular, round or oval frames.
4. The stretcher bar according to claim 1 wherein each section having a male
plug end and
female socket end being adapted to mate with and affix to an adjacent section
when said plug
end is pressed downward into a said socket end.
5. The stretcher bar according to claim 1 wherein said means for quickly
decoupling and
disassembling stretcher bar frame sections and canvas for storing, shipping or
for repeated use.

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6. A stretcher bar fastening system for mounting, stretching, attaching,
removing and
reattaching artist canvas comprising:
a plurality of friction fitting side bar sections featuring two parallel ball
slots on the back side
surface on each stretcher bar section for stretching, fastening and securing
of said canvas.
7. The fastening system according to claim 6 wherein two parallel ball slots
stretches and
secures the said canvas around the perimeter of the said stretcher bar frame
by inserting said
rubber splines.
8. The fastening system according to claim 6 wherein one or more parallel ball
slots stretches
and secures art canvas or similar type art medium on to the back of a picture
frame by inserting
said rubber splines.
9. The fastening system according to claim 6 wherein a plurality of the said
two parallel ball slots
are configured on said exposed back side thereof, to provide access to said
splines for
purposes to mounting, remounting, stretching, re-stretching, or dismounting of
canvas along
four variable length edges.
10. The fastening system according to claim 6 wherein a plurality of ball
slots are configured on
said exposed back side thereof, to provide a receptacle for a plurality rubber
splines to be
uniformly in pairs, along each of the two edges that run substantially
parallel to each along the
corresponding length-wide edges.
11. The fastening system according to claim 6 wherein a plurality of said ball
slots are
configured on said exposed back side thereof, to provide access to said
splines for purposes of
adjusting and sustaining stretching tension of said canvas.
12. The fastening system according to claim 6 wherein a plurality of said ball
slots are
configured on said exposed back side thereof, to provide access to said
splines for purposes of
adjusting and correcting shifting and non-uniform distribution of tensional
stress in a canvas.
13. The fastening system according to claim 6 wherein said ball slot provides
a method of
securing canvas, including in particular art canvas and similar type flexible
art medium, onto
stretcher bar frame using said rubber spline enabling easy removal of said
canvas for storage
and shipping.

Description

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Description
BACKGROUND OF THE INVENTION
Field of the invention. The present invention relates to the field of
Stretcher Bar Framing and
Canvas Stretching for art canvas and similar type material. More particularly
this is a unique
stretcher bar framing system and combined ball slot fastening system that does
not require any
tools or any canvas stretching or mounting experience to use. Precision cut,
interchangeable
frame sections press together to form tight friction fit connections and
perfect 90 degree rigid
corners. The combined unique Ball Slot canvas fastening system that is built
into the back of
each frame component allows for fast easy even stretching and mounting of
canvas without
tools and without causing any damage to the canvas or to the stretcher bar
frame. Both the
framing system and the fastening system can be assembled and disassembled
repeatedly
without damage. The uniformity of the friction fit framing system and the
uniformity of the
combined built in ball slot canvas mounting system allows for quick easy
manual mounting and
fully automated mechanical mounting.

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Prior Art
In the field of art, canvas paintings are traditionally attached to a wooden
frame comprised of
wooden sections commonly referred to as stretcher bars that provide support
for stretched
canvas. Stretcher bar sections are assembled by means of interlocking dove
tail ends wedged
together to form a corner. Canvas or similar type material is stretched around
and over the front
of the stretcher bars using special canvas pliers and then attached to the
back side of the frame
by using staples or nails. Final tension to the canvas is achieved by
inserting wood wedges into
the corners of the frame and driving them in. Because of it's simplicity and
low cost to
manufacture this early 1930 prior art US1870492A has become the industry
standard. Some of
the known challenges that arise with using this type of system is that it
requires a
knowledgeable and skilled person to be able to keep the frame square and warp
free while
stretching and stapling the canvas evenly around the back side of it. Due to
it's design the
corners of this frame system can not be fastened together in any way without
rendering the
wood wedge tensioning system useless. Keeping an unsecured frame square while
stretching
canvas over it can be time consuming and frustrating. If a mistake is made
while stapling the
canvas to the frame, the staples have to be pulled out further damaging the
canvas and the
frame and the process is started over.
Several inventions have come out since the earliest patented stretcher bar
frame system. All of
them have unique variations of achieving the same end result which is
stretching and attaching
canvas art to a frame. There are variations of stretcher bar frame components
and how they go
together and there are variations of attaching the canvas to the frame The
commonality
between past and current prior art is that they all require knowledge and
skill to properly stretch
and mount canvas evenly. They all require tools and or fasteners to assemble a
frame and or to
stretch and mount the canvas and they all use some sort of stapling, clamping
or adhesives to
fasten the canvas to a frame which causes damage to the canvas and or to the
frame. None of
them are uniformly designed for fully automated mechanical mounting.
The present invention addresses and overcomes the shortcomings of all known
prior art.

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SUMMARY OF THE INVENTION
The object of the present invention is to provide a simple, quick and easy to
use system to
manually or mechanically mount canvas art to a stretcher bar frame. The entire
system utilizes
uniform precision cut, interlocking stretcher bars consisting of straight and
curved sections, each
with a protruding male end and a recessed female end. Four sections are joined
together to
form a frame. Sections are joined together by aligning the male end of one
section over top of
another sections female end and then applying downward pressure the male end
slides down
into the female opening to form a tight friction fit connection and a perfect
90 degree rigid
corner. Frame sections come in various standard stretcher bar lengths, widths,
depths and
profiles and they can easily be assembled to form rectangular, square, round
and oval shaped
frames in an array of sizes. Cross bar sections are provided for support in
larger frames and are
attached to the frame using the same joining method to form a tight friction
fit connection.
Canvas is evenly stretched over the frame and attached to the back using a
unique built in Ball
Slot Canvas Fastening System which consists of 2 parallel ball slots that run
down the back side
of every section and 2 rubber splines which are used to evenly stretch and
fasten the canvas to
the back side of the frame. Unlike staples, adhesives and clamps rubber
splines are easy to
install and uninstall and they do not cause any damage to the canvas or to the
frame. Canvas
can easily be attached and detached without damage and frame sections can
easily be
assembled and disassembled for repeated use.

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BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are included to provide a further understanding of
the invention,
and are incorporated in and constitute a part of this specification. The
drawings illustrate
embodiments of the invention and, together with the description and summary of
the invention
serve to explain the principles of the invention.
FIG.1-1 is a top view of a typical straight stretcher bar section.
FIG.1-2 is a top view of a protruding male end on a typical straight stretcher
bar section.
FIG.1-3 is a top view of a recessed female end on a typical straight stretcher
bar section.
FIG.2 is a top view of the parallel ball slots that are located on the back
side of a typical
stretcher bar section.
FIG.3 is a view of a cross section view of a typical stretcher bar section.
FIG.3-1 is a cross section view of the first ball slot that along with the
spline holds the canvas in
position and applies pre tension.
FIG.3-2 is a cross section view of the second ball slot that along with the
spline locks the canvas
in position and applies even final tension.
FIG.4 is a top view of an assembled rectangle frame with cross supports.
FIG.4-1 is a top view of a connected typical straight stretcher bar section
that is used for large
frames.
FIG.4-2 is a top view of a connected typical straight stretcher bar section
that has a recessed
female socket centered in the middle of the stretcher bar to accept a cross
bar support.
FIG.4-3 is a top view of a typical horizontal cross bar section that has two
male ends.
FIG.4-4 is a top view of a typical vertical cross bar section that has two
male ends and two
recessed female sockets centered in the middle of the bar.
FIG.5 is a top view of the back of an assembled rectangle frame that shows the
two parallel ball
slots.
FIG.6 is a top view of an assembled round frame with cross supports.
FIG.6-1 is a top view of a typical curved stretcher bar section.
FIG.6-2 is a top view of a protruding male end on a typical curved stretcher
bar section.
FIG.6-3 is a top view of a recessed female end on a typical curved stretcher
bar section.
FIG.6-4 is a top view of a typical horizontal cross bar section in a round
frame that has two male
ends.
FIG.6-5 is a top view of a typical vertical cross bar section in a round frame
that has two male
ends and two recessed female sockets centered in the middle of the bar.
FIG.7 is a top view of the back of an assembled round frame that shows the two
parallel ball
slots.
FIG.8 shows step one in attaching the canvas to the frame. It is a cross
section view of a
section of an assembled frame and it's upside down placement centered on top
of the canvas
(FIG.8-1).

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FIG.9 shows step two in attaching the canvas to the frame. It is a cross
section view of the
canvas wrapped around the frame and the placement of the spline (FIG.9-2) over
ball slot
number 1. (FIG.9-1)
FIG.10 shows step three in attaching the canvas to the frame. It is a cross
section view of the
canvas wrapped around the frame and shows the pre tension spline 1 inserted
down into ball
slot one (FIG.10-1). It also shows the placement of spline 2 (FIG.10-2) over
ball slot two
(FIG.10-3).
FIG.11 shows step four in attaching the canvas to the frame. It is a cross
section view of the
canvas wrapped around the frame and shows the final tension spline 2 inserted
into ball slot two
(FIG.11-1).
FIG.12 is a cross section view of an assembled stretcher bar frame with the
canvas installed.
FIG.13 is a cross section view of a normal picture frame with the canvas art
installed utilising the
unique Ball Slot Canvas Fastening System.

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DETAILED DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION
The present invention relates to a novel and unique friction fit stretcher bar
framing system and
novel and unique ball slot canvas fastening system. The friction fit stretcher
bar frame system
consists of precision cut frame sections (FIG.1) that can be made from wood,
aluminum or
plastic composites. Sections come in various standard stretcher bar lengths
and in various
widths, thicknesses and profiles. They come in straight lengths (FIG.1) for
rectangle and square
frames as well as curved sections (FIG.6-1) for round and oval frames. Each
end of a straight
section has been precision cut on a 45 degree angle and has a male end that
protrudes from
one end (Fig.1-2.) and a recessed female opening on the other end (FIG.1-3).
Each end of a
curved section has been cut straight and has a male end that protrudes from
one end
(Fig.6-2.)and a female opening that is recessed on the other end (Fig.6-3.).
The back side of
each section (FIG. 2) has 2 parallel ball slots (FIG. 2-1 and FIG. 2-2) also
shown in cross
section drawing (FIG. 3-1 and FIG. 3-2).
Frames are assembled by joining 4 sections (FIG. 1) together. In the case of a
rectangle frame
2 plural sections of equal length are joined to 2 other plural sections that
are equal in length.
Sections are joined together by lifting and a placing one section over another
section and
aligning the male end (FIG. 1-2) up to the female opening (FIG. 1-3) in the
section underneath it
and then applying downward pressure the male end is pressed into the lower
female end
forming a tight rigid friction fit 90 degree corner. The remaining sections
are joined together in
the same manner to form a closed rectangle frame. Cross sections (FIG.4-1, 4-
2, 6-4 and 6-5)
provide for extra support in larger frames.
Stretching and attaching canvas to the frame is done by first laying the
canvas art face down on
a flat surface. The assembled frame is then placed upside down (FIG.8.) and
centered on top of
the canvas. The canvas is then neatly wrapped around the outside of the frame
(FIG. 9) and the
corners are neatly folded. Starting at a corner and working your way around
the frame, the
canvas is gently pulled inward applying slight tension while pressing spline 1
(FIG. 9-2) into ball
slot number one (FIG. 9-1). As the spline on top of the canvas is pushed down
into the ball slot
it compresses to fit into the slot pulling the canvas down with it. Once the
spline contacts the
bottom of the ball slot it re expands locking the canvas in place. Spline 1
and ball slot 1 holds
the canvas evenly in place and applies pretension to the canvas (FIG. 10-1).
The second spline
(FIG. 10-2) is then pressed into ball slot 2 (FIG. 10-3) to apply even final
tension to the canvas
(FIG. 11).
To remove the canvas simply find the ends of the splines and pull them upward
to release the
canvas. FIG. 12 shows a cross section view of an assembled stretcher bar frame
with the
canvas installed. FIG. 13 shows a cross section view of a common picture frame
with the
canvas installed on the back using The Ball Slot Canvas Fastening System.

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The specifications and drawings of this invention may be embodied and
practices in other
specific forms and modification without departing from the spirit and
essential characteristics
thereof. The present embodiments therefore are considered in all respects as
illustrative and not
restrictive. The scope of the invention is indicated by the appended claims
rather than by the
foregoing description. All variations, substitutions, departures, and changes
that come within the
meaning and range of equivalency of the claims therefore are intended to be
embraced therein.