IMPROVEMENTS IN THE MANUFacture OF CORRUGATED METAL REVOLVING SHUTTERS, AND IN MACHINERY FOR THE SAME.
Year: 1872

page_text: LETTERS PATENT to Alexander Clark, of Rathbone Place, in the
County of Middlesex, Engineer and Revolving Shutter Manu-
facturer, for the Invention of "IMPROVEMENTS IN THE MANUFacture
OF CORRUGATED METAL REVOLVING SHUTTERS, AND IN MACHINERY FOR THE
SAME.
"
Sealed the 7th February 1873, and dated the 1st November 1872.
PROVISIONAL SPECIFICATION left by the said Alexander Clark at
the Office of the Commissioners of Patents, with his Petition, on
the 1st November 1872.
I, ALEXANDER CLARK, of Rathbone Place, in the County of Middle-
sex, Engineer and Revolving Shutter Manufacturer, do hereby declare
the nature of the 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 improvements in the manufacture of cor-
rugated metal revolving shutters of the kind for which Letters Patent

page_text: were granted to me, bearing date May 2nd, 1872, No. 1322, according
to which the shutter is so corrugated that when coiled up the
corrugations will fit on one another, whereby the shutter is caused to
occupy much less space than hitherto, and to work with less noise.
The main feature of the Invention consists in corrugating the sheet
of metal on a corrugated cylinder by the aid of suitable dies, which
may be operated in various ways, and the sheet may either be coiled on
said cylinder as the work progresses, or it may be first coiled up and
then placed round the cylinder, and the several thicknesses of metal
corrugated at one operation.
One 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 die I
employ a corrugated cylinder or cylindrical die which rests on an under
girder, and is rotated after each 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 coiled up and corrugated,
which also gives the sheet the desired self-coiling property. The corru-
gated sheet is then uncoiled and removed from the cylinder. 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.
According to another arrangement the corrugated cylinder is partly
surrounded by a rigid curved frame of the same width as the sheet to be
corrugated, forming a curved continuation of a horizontal table. The
sheet of metal is laid upon a series of suitably shaped dies, consisting of
parallel bars, and the sheet of metal is fed together with the dies between
the corrugated cylinder and the curved frame, the sheet and dies being
carried round by the rotation of said cylinder. By the pressure of the
dies which are confined by the curved frame the metal sheet is forced
into the corrugations of the cylinder and caused to conform to the shape

page_text: thereof, after which the dies pass out of the frame, and the sheet of
metal is coiled or wrapped on the corrugated cylinder until the whole
shutter is corrugated. In this manner the first coil of metal serves to
form the next, which in turn determines the form and size of the
corrugations in the succeeding coil, and so on. The dies must be in
series (one series for each coil of the sheet metal on the cylinder) of.
decreasing size, as the space within the curved frame is lessened each
time a fresh coil is added. In this manner the shutter is coiled into the
precise form it is intended to take when fitted.
According to another method, the plain sheet of metal is first coiled
on itself and placed within a circle of dies round the corrugated cylinder
and at a suitable distance therefrom. The circle of dies are brought in
successively or simultaneously towards the centre, preferably two at a
time, one on each of the opposite sides of the cylinder. By this means
the several thicknesses of the sheet metal are simultaneously forced up
and caused to conform to the periphery of the corrugated cylinder. The
dies first forced inwards remain in that position, and clamp the sheet
metal against the cylinder until all the dies are forced in, when they are
all released or drawn back, leaving the sheet now completely corrugated
and coiled or closely wrapped round the corrugated cylinder, from which
it is then removed.
My Invention also relates to means for checking or retarding the
movement of the shutters for preventing the noise made when the
shutter is raised and lowered rapidly. For this purpose I employ one
or more "flys," like that used in a clock, set in motion by the movement
of the shutter itself for checking the same by the resistance of the air to
the motion of the "flys." These "flys" may be applied and operated in
various ways. For instance, two such flys may be employed, each
attached to a vertical screw rod placed in the grooves and rotated by a
nut carried on the shutter, or they may be mounted on the bottom bar
of the shutter and driven through suitable gearing by friction wheels
running in the shutter grooves and operated by the movement of the
shutter, or the flys may be geared with the roller on which the shutter
coils.
By another method the shutter is raised or lowered by means of the
vertical screws, which in this case will be reared together and anounted

page_text: friction wheels mounted on the bottom rail, and travelling in the grooves
may be geared together and operated by rotating the rod or long-arm,
commonly used to move the shutter up and down, or the shutter may be
raised and lowered by a rope or ropes passing over pullies on the frame
of the opening and on the shutter, the action of which resembles that of
ordinary hoisting tackle.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Clark in the Great Seal Patent Office
on the 1st May 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
CLARK, of Rathbone Place, in the County of Middlesex, Engineer and
Revolving Shutter Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the First day of November, in the year
of our Lord One thousand eight hundred and seventy-two, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Alexander Clark, Her special licence
that I, the said Alexander Clark, my executors, administrators, and
assigns, or such others as I, the said Alexander Clark, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN THE MANUFACTURE OF CORRUGATED METAL REVOLVING SHUTTERS, AND IN
MACHINERY FOR THE SAME," upon the condition (amongst others) that I,
the said Alexander Clark, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Inven-
tion, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within' six
calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Alexander Clark, do hereby declare
the nature of my said Invention, and in what manner the same is to

page_text: be performed, to be particularly described and ascertained in and by
the following statement, reference being had to the Sheet of Drawings
hereunto annexed, and to the letters and figures marked thereon (that
is to say):
My Invention relates to improvements in the manufacture of corru-
gated metal revolving shutters of the kind for which Letters Patent were
granted to me bearing date May 2nd 1872, No. 1322, according to
which the shutter is so corrugated that when coiled up the corrugations
will fit one on the other, whereby the shutter is caused to occupy much
less space than hitherto, and to work with less noise.
The main feature of the Invention consists in corrugating the sheet of
metal on a fluted or corrugated cylinder or mandril by the aid of suitable
dies, which may be operated in various ways as hereafter more fully
described, and the sheet may either be coiled on said cylinder or mandrel
as the work progresses, or it may be first coiled up and then placed
round the mandrel, and the several thicknesses of metal corrugated at
one operation. This I now find to be the most expeditious method, and
I therefore prefer it to the other.
It is illustrated in the accompanying Drawings, in which Figures 1.
and 2 show a front and end elevation respectively of a corrugating
machine operating on this principle. Figure 3 is a cross section of the
corrugated cylinder or mandril and the dies shown full size, the dies
being closed upon the mandril.
A and B, Figures 1 and 2, are a pair of frames, the one of which A
is fixed and supported on columns C, and carries the upper die a, whilst
the other B, carrying the lower die b, is movable, and is supported on
the plunger D of a hydraulic press, the frame being guided in its
vertical movement by guides B¹ sliding on columns C. E, cylinder of
the hydraulic press. d is the fluted cylinder or mandril suspended at
the ends in slotted brackets g, or by chains or otherwise, so that when
the under die 6 is lowered the mandril d will descend and hang clear of
the two dies so as to permit of the corrugated sheet being withdrawn
and another applied. For this purpose one of the brackets g is made
detachable to admit of the coiled sheet of metal being placed on and
taken off the mandril. Both dies and mandrel are of cast or wrought
iron truly planed, and of the form in outline more clearly seen in

page_text: Figure 3, in which the dies are shown as closed upon the mandril
with about 10 or 12 thicknesses or coils of sheet metal (not shown)
between them.
The following is the method of operation :-The sheet of metal is coiled
up into the form of a roll of rather larger internal diameter than the
greatest diameter of the mandril d, but the exact relative proportions
can only be found by experiment as they vary according to the size of
the mandril, and the depth of the grooves, the thickness of the sheet to
be corrugated, and the number of coils. It is however important that
the sheet should not be coiled into too large or too small a form, as in
the one case the sheet would not be corrugated regularly, and in the
other it would either be torn or the corrugations would be imperfectly
formed. I find that with a mandril of the diameter and size of corruga-
tions shown in Figure 3 a sheet of metal known as No. 28 gauge, and
12 feet in length, should be coiled up into a roll whose internal diameter
is 4 inches. The metal sheet thus coiled up is bound round with two
or more narrow hoops or bands of the same metal to retain it in form
whilst it is being corrugated, it is then slipped on the mandril d, and
the end thereof which was detached from its bracket or chain being
again attached, the lower frame B is forced up, and the mandril is com-
pressed between the upper and lower dies, which force the sheet metal
into the grooves of the mandril and thus corrugate the several thick-
nesses at once. After the two opposite sides of the roll of sheet metal
have thus been corrugated the under die is lowered to admit of the
mandril being turned a quarter round, and the operation is then re-
peated, after which the mandrel is again turned partly round and the
operation repeated as often as required until the whole sheet is properly
corrugated. By this means the sheet is quickly corrugated and at same
time rendered self-coiling, in the form for which I obtained the Letters
Patent before referred to, that is with the corrugations of the outer
coils coinciding with and fitting on those of the inner coils as therein
described

page_text: It will be evident that the mandril need not be a complete cylinder, but
might be of the form comprised between the red lines x, x, Figure 3,
the dies being formed along the top and bottom surface only. In this
case however the sheet metal would require to be turned on the mandril
after each compression of the dies, the mandril remaining in the same
position. This is however more troublesome and less perfect than the
cylindrical mandrel, and I have simply referred to it to illustrate a
possible modification in the form of the mandrel.
Another method and machine for corrugating the sheet metal upon a
grooved cylinder or mandrel is illustrated in front elevation in Figure 4.
The machine resembles the machines commonly used for corrugating
metal, and consists of an upper frame A moving in guides in the side
standards, and carrying the upper die a, and of an under frame B.
In lieu of the fixed under die I employ the fluted cylinder or
mandril d, which in this case rests on the frame B, and serves as the
under die.
Figure 5 shows on a larger scale a cross section of this cylindrical die,
and the under frame B. The edge of the metal sheet to be corrugated
is secured to the cylinder d by being inserted in a narrow slot as shown.
Up-and-down motion is imparted to frame A by eccentrics F on a
shaft G in the usual manner, and the cylindrical die is rotated to the
extent of a corrugation after each descent of the upper die, and by the
combined action of the upper die and the rotating die the sheet is
corrugated and at same time lapped closely around said cylinder. This
is continued until the entire sheet is thus coiled up and corrugated, after
which it is removed from the cylinder. The frame B is lowered a certain
distance after each revolution of the cylinder d to compensate for the
addition to its diameter of the metal coiled upon it, the traverse of the
upper die being always the same. This is effected by fitting frame B to
move in vertical guides, and supporting it at the ends on screw rod H,
geared together, and operated by hand when required.
According to another arrangement, illustrated in Figure 6, which is a
cross section of the mandrel and dies, L is a curved frame or plate,
strengthened at intervals by external ribs L', and forming a curved
continuation of a table M. Said frame L is of the width of the sheet to
be corrugated, and it is curved to a circle described from the centre of
the fluted cylinder or mandrel d, which revolves within it. N are a

page_text: Fourthly. Corrugating sheet metal upon a fluted cylinder or mandrel
rotating within a curved frame, and operating in combination with bars
or dies, substantially as described and shown in Figure 6.
In witness whereof, I, the said Alexander Clark, have hereunto
set my hand and seal, this Thirtieth day of April, in the year
of our Lord One thousand eight hundred and seventy-three.
ALEX. CLARK. (L.S.)