Stretching Frame for Picture-canvas
Year: 1896

page_text: Stretching Frame for Picture-canvas.
RICHARD CARL ERTEL, Merchant, at Hamburg in Germany, Louisenhof, do
hereby declare the nature of this invention to be as follows:-
The frames used up to date nearly exclusively for painters canvas were so-
called wedge-frames, whereon the canvas was stretched as tight as possible nailing
its sides on the edges of the frame whereupon the stretching of the linen was completed
by driving in wedges at the corners.
Not to speak of the necessity to make an incision in the canvas at the corners of
these old wedge frames, the connection being grove and tongue, this incision
preventing a secure nailing down at the corners, this enfeebling of the very ends of
the frame wood often caused disagreeable splittings.
It also often happens that in old pictures the wedges get loose or even drop.
altogether.
All these inconveniences are put a complete stop by the following invention.
The four frame wood pieces of the new frame are on their opposite ends
bevelled at an angle of 45°.
A dowel of the lateral pieces sliding in a bore-hole of the opposite frame wood,.
serves as a guide.
In the same manner in the side-pieces there are also fixed in each corner screws,.
sliding in other bore-holes. A screw-nut embracing the screw protrudes at a notch.
When the canvas is to be tightened on this above described frame, the linen may
be fixed by nails on the wood right to its furthermost end. By means of a nut-
driver the screw nuts are thereupon turned toward their frame-wood stretching the
canvas in such an uniform manner not being attainable with wedge-frames. The
double guidance by means of the dowels and the screws in each corner prevent the
possibility of the frame getting warped by the tightening of the canvas.
Dated, Hamburg, the 3rd of June 1896.
RICHARD CARL ERTEL,
Inventor.
I, RICHARD CARL ERTEL, Merchant, at Hamburg, Luisenhof, in Germany, do
hereby declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
My invention relates to improvements in frames to which canvas is attached,
and as commonly used by artists for oil and other paintings, and has for its object the

page_text: providence of better and more secure means of stretching the canvas after being
fastened to the frame, in lieu of the common method of driving wedges into the
corners of the frame to expand the same in order to obtain the same results,
which in practice has been found unsatisfactory.
In the accompanying drawing,
Fig. 1 is a back view of the corner of a frame showing my improvement. The
remaining three corners of a complete frame being similar in construction.
Fig. 2 is a sectional view on a line (xy) of Fig. 1.
Fig. 3 shows manner in which the canvas is fastened to the frame by nails or tacks.
In the drawing similar letters of reference indicate like parts in the different views
thereof.
(d) and (b) are the sides of a frame mitered at their adjoining ends. One end of
each side piece is provided with a boring (a) for the reception of a dowel pin (c)
in the adjoining frame piece. The dowel (c) in connection with the boring (a) into
which the same projects when the frame pieces are in position, acts as a guide and
retains the same at the correct angle to each other when expanded or contracted by
means hereinafter described.
(e) is a threaded bolt pointed on one end and driven into the same end of the frame
piece as the dowel, and on an angle with the same. This bolt passes into a boring (f)
of the adjoining frame piece, and like the dowel (c) also acts as a guide. On the
back side of the frame piece and at a right angle to the boring (f), a recess (^)
is provided to allow a nut (g) carried by the bolt (e) to be freely turned by a wrench
or other suitable means. By turning the nut to the left the same will butt against
the side of the recess as shown in Fig. 1 and cause the frame pieces to separate,
and vice versa by turning the nut in the opposite direction.
In practice each corner of a frame is constructed as shown and described, and
the canvas is secured to the frame by nails, or tacks as shown in Fig. 3 after
which the canvas can be readily and easily stretched to the desired tension.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is :
The combination of the mitered frame pieces having a fixed dowel and threaded
bolt on one corner, borings directly opposite the same for the reception of said
dowel and bolt, and an adjusting nut upon the bolt within a recess formed near the
corner of the frame for the purpose substantially as described.
Dated Hamburo 18th December 1806
RICHARD CARL ERTEL,
By Carl O. Lange,
Agent.