IMPROVEMENTS IN THE MANUFACTURE Of CORRUGATED METAL REVOLVING SHUTTERS AND IN MACHINERY FOR THE SAME
Year: 1872

page_text: "
PROVISIONAL SPECIFICATION left by Alexander Clark at the Office
of the Commissioners of Patents, with his Petition, on the 7th
August 1872.
I, ALEXANDER CLARK, of Rathbone Place, in the County of Middlesex,
Engineer and Revolving Shutter Manufacturer, do hereby declare the
nature of tho said Invention for "IMPROVEMENTS IN THE MANUFACTURE Of
CORRUGATED METAL REVOLVING SHUTTERS AND IN MACHINERY FOR THE SAME," to
be as follows:-
My Invention relates to the manufacture of corrugated metal re-
volving shutters, and consists 1st, in improvements in the method of
joining or uniting the several plates or sheets of which the shutter is
composed. Hitherto the sheets of steel have been separately corrugated
by a suitable machine and afterwards united by riveting to form one
corrugated sheet of metal, which then required to be coiled to give it the
desired tendency to coil or wind itself up.
According to my present-Invention I unite the plates by folding the
edges together in the manner described hereafter and corrugato-and-coil
the entire sheet at one operation by the machinery which also forms parts

page_text: of this Invention; the shutter being made with corrugations increasing
in size towards the lower part, so that when coiled up the corrugations
will fit on one another according to the Invention for which I obtained
Provisional Protection dated May 2nd 1872, No. 1322, whereby the
shutter is caused to occupy much less space when coiled up than
hitherto, and to work with but little noise.
In carrying out my Invention the edges of the sheets to be united
having been first trimmed are bent or folded over by means of a machine
somewhat resembling machines for corrugating steel shutters hitherto in
use, and provided with suitable dics of the length of the sheet. The two
folded edges are next hooked together and submitted to the action of
a press or machine having suitable dics by which the joint is clenched
and the union of the parts perfected. The sheet is then ready to be
corrugated in the manner and by the machinery next described.
I may
first mention that the sheet may be corrugated, with the joints of the
several plates formed as above described parallel to the corrugations or
obliquely or at right angles thereto according to circumstances, but
where the space to be occupied by the coiled shutter is limited I prefer
to make the joints and corrugations parallel.
The method of and machine for corrugating the sheet are as follows:
-The machine resembles the machines commonly used for corrugating
metal in which an upper die carried on a frame or girder having an up
and down motion is employed.
In lieu of the fixed under dic I employ a corrugated cylinder or
cylindrical die which rests on an under girder and is rotated after cach
descent of the upper die to the extent of one corrugation by suitable
ratchet and pawl gearing. The edge of the sheet to be corrugated is
attached to the corrugated cylinder, and, by the combined action of the
upper die and rotating under die or corrugated cylinder, the sheet is
corrugated or caused to conform to the periphery of the said cylinder,
and at the same time coiled on the same. This is continued until the
entire sheet is so coiled up and corrugated, which also gives the sheet
the desired self-coiling property. The corrugated sheet is then uncoiled
and removed from the cylinder. The effect of this method of cor-
rugating is that the sheet is corrugated and coiled up in the precise
manner it is intended to when fitted, that is to say, the corrugations of
the outer coils are made to coincide with and fit on and in those of the

page_text: coil next within, as described in my said former application. The girder
or frame on which the corrugated.cylinder rests is lowered a. certain
distance at each revolution of, the corrugated cylinder to compensate for
the increased diameter of the latter, by the metal sheet coiling upon it,
the traverse of the upper girder and die being always the same.