Improvements in or relating to the Working of Materials of Slight Tensile Strength in Presses.
Year: 1893

page_text: Date of Application, 25th Sept., 1893-Accepted, 28th Oct., 1993
JOB DUTE DE DOITICATION.
Improvements in or relating to the Working of Materials of Slight
Tensile Strength in Presses.
A communication from EMIL SALTZKORN, Consul, and LUDWIG NICOLAI,
Manufacturer, both of Lobtauer Strasse 20, Dresden, Saxony, German Empire.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, 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 :-
The present invention relates to a process for working in the draw or stamping
press, materials which in consequence of their structure are liable to tear when
subjected to tension as certain kinds of metal plate, wood and straw-board, some
thin or light kinds of leather etc. These can accordingly at present not be worked
in these presses, as in consequence of the strong tension and friction arising in the
process they are either partially burst or entirely torn.
The present invention relates to a method based on the employment of a
protecting cap or cover made of paper, tissue, metal or the like for the purpose of
preventing the material to be worked in the press from being torn. This protecting
cap or cover may have the form of a disc or plate, star or strip and is placed
underneath the material to be worked for the purpose of transferring in the first
instance to the protecting cover the tension and friction which ensue when the die
penetrates the mould. The protecting cover is hence tightly pressed against the
material and the pressure in this way distributed over a large surface.
By the employment of the above protecting cover it becomes possible to work on
the draw or stamping press even the lightest or thinnest materials such as easily
torn straw and wool-board as well as card boxes, rolls etc.
In the accompanying drawings,
Figure illustrates the employment of a protecting cover in a stamping press
the mould or matrix being shown in section.
Figure 2 is a plan illustrating a protecting cover composed of strips.
A protecting cover in the form of a strip or plate of a material offering
resistance but possibly also yielding to tension e.g. woven tissue-paper-
indiarubber-metal and the like is laid underneath the material to be worked on
that side of it which is turned away from the die e and turned towards the
plunger, this tension-resisting material receives the pressure resulting from the
tension and friction which ensue when the die e is passed into the matrix f which
pressure is consequently distributed over the whole surface of the protecting
cover.
Since however the resisting material of the cover is tightly pressed against and
adheres to the non-resisting material to be worked, the former will not only
distribute this pressure but also its own power of resistance over the whole surface
of the latter and thereby prevent any weakening of it at isolated spots.
In place of a protecting cover of woven tissue, paper, indiarubber and the like a
specially manufactured cover of elastic metal may be employed, in which the
bottom is connected with the lateral walls, which may form a complete whole or
consist of strips, by means of hinges or otherwise.
A few single strips a' (Figure 2) say of elastic steel plate may also be employed.
For this purpose the protecting cover a consisting of a plate or star or separate
strips is held on the punch 6 by means of a plate screwed up on it; the
material to be worked e.g. cardboard, leather, metal plate etc. being then laid
upon this plate and held fast in the usual manner by the stretching ring d. When

page_text: the die e passes into the stock f the protecting cover is first bent upwards and then
applies itself tightly against the material to be worked.
Having now particularly described and ascertained the nature of the said
invention as communicated to me by my foreign correspondents, and in what
manner the same is to be performed, I declare that what I claim is;-
In the working of materials of feeble resistance to tension in presses laying over
the material to be worked a protecting cap or cover of paper woven tissue
indiarubber metal or similar substance in the form of a plate star or separate strips
by which cover the pressure is received and distributed over the whole surface of
the material operated upon and the tearing of the material prevented substantially
as described.
Dated this 25th day of September 1893
W. P. THOMPSON & BOULT,
Of London, Nottingham, Liverpool, and Manchester,
Agents for the Applicant.