Improvements in the Manufacture of Corrugated Laths for Venetian Blinds.
Year: 1893

page_text: Date of Application, 15th Nov., 1893-Accepted, 20th Jan., 1894
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Corrugated Laths for Venetian
Blinds.
I DAVID CLARKE of 21 Langley Road Small Heath Birmingham in the
County of Warwick, Engineer, 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:-
In
This invention has for its object improvements in the manufacture of corrugated
laths for Venetian blinds, composed of paper, paper and woven linen, cotton, or flax
cloth in combination & cupro-ammonium paper, whether in the form of paper, or
woven ligneous tissue. The corrugation of laths for Venetian blinds, composed of
these materials in the direction of their length imparts to them great strength, and
allows the use of a thinner and lighter material than could be otherwise used, and
this my invention refers to the process and means by which these corrugated laths
can be manufactured with accuracy and rapidity. Various means and appliances
have been tried for the manufacture of these laths, namely, pressure between a
pair of corrugated cylinders or longitudinal rolls, having their flutes or corrugations
running longitudinal and parallel to their axes. Also pressure between two corru-
gated or grooved rolls having their grooves running at right angles to their axes,
and also plane pressure between two corrugated metal blocks or dies, the lower
block being distinguished as the female die, and the upper, as the force or male die,
this press being the one more generally used for corrugating sheets of metal.
this form of longitudinal press the force or male die, is generally made in one solid
block of metal, with the number of flutes or corrugations required worked in it
upon the under face immediately over the corresponding flutes or corrugations in
the lower die or bed. If the corrugations or flutes in the force or male die are
extended to the full width, and are equal in number to the flutes or corrugations in
the female die below it, for forming a number of corrugations, at one time, then the
material submitted to this pressure between the dies will not be perfectly corrugated,
and will be liable to fracture and split along the length of the imperfectly formed
corrugations. It has therefore been found in practice that it is not possible to
produce more than one perfect corrugation with each depression of the male force
or upper die, and also, that the corrugation of the material must be commenced at
the edge of the material it is proposed to corrugate, the sheet of material being
gradually moved under the press one corrugation at a time until the whole sheet is
finished. All these appliances have been found more or less imperfect, and
altogether unsuitable for the corrugation of laths for Venetian blinds composed of
the materials herein referred to as paper, paper and woven linen, cotton, or flax
cloth in combination & cupro-ammonium paper. Whether in the form of paper or
woven ligneous tissue, not only is the process too slow and complicated for the
production of laths at a reasonable commercial price, but it is irregular and
uncertain in the formation of the edges of the laths, which in all cases must be
equal on each side and of one uniform curvature. If the laths are produced with
unequal edges, it is impossible to cut and trim the edges after corrugation without
reducing them to various and indefinite widths, and laths of unequal widths are
useless for the manufacture of Venetian blinds. By my invention these difficulties
and irregularities and defects are completely and successfully overcome, and
corrugated laths composed of the specified materials now become articles of public
utility, and of considerable commercial value.
In the process and with the appliances I have enumerated the corrugation of the

page_text: lath would have to be commenced at one of the edges of the same running length-
wise of the lath, or at one end. By this my invention the corrugation is
commenced in the centre of the lath. By this change in the point at which the
work of corrugation is started, and by the appliance herein to be described, I am
able to produce laths that are perfect in their form and configuration, and equally
divided and properly curved along their edges, and such laths can be manufactured
with considerable rapidity.
For the accomplishment of this I use a longitudinal press, with a bottom die and
upper force. But instead of having the upper force in one rigid piece of metal,
with only one point of contact with the die below, I construct my force or male die
in sections or separate blades, or strips of metal, having as many points of contact
as there are flutes in the die below. The two outer blades are constructed with
grooves on their outer edges, corresponding with the outer bead of the die below,
and these blades or sections are constructed and arranged to work singly and in
pairs from the centre of the force in its width to the sides, so that the same can be
raised or depressed at the will of the operator by means of levers, screws, cams, or
eccentrics, the ends of the sections or blades of metal forming the force are provided
with grooves, or slide blocks in which they slide upwards and downwards, and with
clips of metal for connecting them to the slide rods above, the rods being connected
to levers, screws, cams, or eccentrics. When the central blade of.the force is
depressed, the lath is divided equally down the centre in the direction of its length
by the formation of one corrugation in the centre, the other blades remaining in
position above the die or bed. The material on each side of the central corrugation
(already formed) is left free from pressure. This freedom from pressure on that
part of the material on each side of the central corrugation while it is held in
position by the central blade, allows the material to be gathered into the flutes of
the die below, when the depression of the blades working on each side of the
central blade is made without undue strain or fracture of the material, and the same
result is produced by pressing down the external blades of the force with the
grooved edges, this last depression completes the corrugation of the lath.
I will now proceed to describe the drawings of which there are four sheets, the
same letter on each sheet refers to the same part of the press or machine.
Figure 1, Sheet one, is a full size cross section of the moveable die or bed, and
a section of the upper force or male die, showing the position of the separate
blades 0.0.0.0. O, forming the force, and the manner in which they are fixed to
the clips K. K. K. K K K and also its position in relation to the fluted or female die
below A. A. The action of the blades upon the material is indicated by the dotted
lines V. V. and W. W.
Figure 2, Sheet two, is a front elevation of the press or machine, showing
the die A. A. with the force J above it, and the connection of the slide
rods C. C. C. C. C. C. with the clips of the blades K. K. K. K. K. K. also the slide
blocks L. L. in which the ends of the blades O. 0. 0. 0. O. work.
Figure 3, Sheet three, is a cross sectional elevation of the machine, showing the
position of the divided force J, with its separate blades O. 0.0.0. O in relation to
the beds or dies A. A. when not in use, and also the connection of the slide
rods, C. C. C. C. C. C. with the levers B. B. B. B. B. B. and the adjusting nut Q
for regulating the depth of the corrugation.
Figure 4, Sheet four, is a general plan of the press or machine, showing the
general arrangement of die A. A. levers B. B. B. B. B. B. weights E. E. E. E. E. E.
fulcrums D. D. rails 7. 8 and 9 handles H. H. wheels M. M. and adjusting
bolts I. I. for regulating the position of the die A. A. and fixing it with its central
corrugation immediately under the central blade of the force J.
Figure 5, Sheet one, are sectional diagrams showing the process of corrugation
from the flat blank U. U. to the finished lath X X.
Having given a general description of the drawings, I will now proceed to describe
and indicate the various parts of the press as marked by the letters and figures on
the sheets of drawings.

page_text: A. A. is the corrugated female bed or die. B. B. B. B. B. B. are levers for
applying the pressure of the blades of the force J. to the material to be
corrugated. C. C. C. C. C. C. are the slide rods connecting the blades with the
levers.. D.D. are fulcrum pedestals supporting the levers B.
E. E. E. E. E. E. are
balance weights for the levers. F. F. F. F. are rails upon which the die or
or bed A. A travels. G. G. are guide plates for preventing latteral play in the
levers B. B. H. H. are wood handles for moving the die or bed A. A. backwards
and forwards upon the rails F. F. I. I. are adjusting or regulating bolts for
adjusting the dead travel of the die or bed A. A. and are set in connection with
the stop N. J. is the force or male die constructed with separate blades of
metal O. 0. 0. 0. 0. The letter J. refers to the force in its complete state, and
not to its divisions and sections separately. K. K. K. K. K. K. are metal clips by
which the blades of the force are attached to the slide rods C. C. C. C. C. C.
L. L. are the slide blocks in which the ends of the blades of the force work.
M. M are the grooved wheels of the die A. A. running upon the rails F. F.
O. O. O. O. O. are the metal blades of the force or male die shown in section in
solid black. P. P. P. P. are distance pieces attached to each blade of the force J.
to prevent the blades springing outwards when the pressure is applied.
Q. Q. Q. Q. Q. Q. are set nuts, with lock nuts above for setting and adjusting
the rods and blades of the force J. to the exact depth of corrugation required.
S. S. are guides fixed upon the die, A. A. and are adjusted to the dead width of
the flat lath, so that the true centre of the lath may be ascertained with rapidity
and without measuring each lath. T. T. are chambers formed in the bed or
die A. A. for receiving the heating pipes or other appliances for heating the same.
U. U. is a sectional diagram of the flat lath before corrugation. V. V. is a sectional
diagram of the lath showing the first corrugation formed in the centre of the
lath. W. W. is a sectional diagram of the lath after the formation of corrugation
on each side of the central corrugation. X X is a sectional diagram of the
finished lath.
Having now fully described the various parts of the press, I will now proceed to
more minutely describe the process of corrugation by this means. The laths having
been cut to their desired lengths, and to their desired widths, three inches or there-
abouts, the material having been softened to make it pliable a lath is taken by the
workman and placed between the guides S. S. adjusted to the die or bed A. A. the
die having been previously heated to a temperature of 200° degrees Fahrenheit or
thereabouts (at which temperature it must be maintained) the bed or die A. A. is
then taken by the handles H. H. and moved along the rails F. F. until it is
immediately under the blades of the force J the central blade being directly over
the central flute or corrugation in the die A. A. this point being fixed and
determined by the adjusting and regulating bolts I. I. in connection with the
stop N. Then the rod marked 7, connecting two of the levers B. B. which are
attached to the slide rods C. C. and the central blade of the force J. is drawn
down, and the material is forced into the central flute of the die below by the
central blade of the force J, the first or central corrugation is then formed and the
lath takes the shape shown in the diagram Figure 5, Sheet one, and indicated by
the letters V. V. After this is accomplished, the rod marked 8. is drawn down
in like manner, and one corrugation on each side of the central corrugation is
formed, and the lath takes the shape shown in the diagram Figure 5, marked W. W..
When this has been done, and while the three blades of the force J already applied
are firmly down upon the material, rod 9. is drawn down, and the two outside blades
of the force J descend upon the remaining portion of the material not corrugated, and
force it into the remaining flutes of the die, and by means of the grooves on the
outer edges of the blades, over the external beads running along each edge of the
die A. A. finishing the edges on each side of the lath with regularity and neatness,
The die or
at the same time giving them the required amount of curvature.
bed A. A. is then released from the pressure of the blades of the force J, and
drawn back, and the lath is finished as shown in Figure 5, Sheet one, and

page_text: marked X X. I desire it to be understood that I do not confine myself to the
same number, size, or thickness of blades as shown on the drawings. It may be
necessary to increase or decrease their number according to the number of
corrugations required, or to increase or diminish their strength according to the
size of the corrugations required.
Neither do I confine myself to the exclusive use of levers for the depression of
the blades of the force J, these may be worked by means of screws, cams, or
eccentrics, and I may find it convenient to use one or other of these means, in
preference to the levers shown upon the drawings.
Having now particularly described the nature of my said invention, and in
what manner the same is to be performed, I declare that what I claim is.
First. The principle of starting or commencing the corrugation of lath for
Venetian blinds (composed of paper, paper and woven linen, cotton, or flax cloth in
combination & cupro-ammonium paper, whether in the form of paper, or woven
ligneous tissue) in the centre of the lath running lengthwise, and working in the
remaining corrugations from the centre to the sides or edges of the lath, as
described in this my Specification and drawings.
Second. The construction and arrangement of an upper force or male die for
a longitudinal press in separate blades or sections, for corrugating laths for
Venetian blinds (composed of paper, paper and woven linen, cotton, or flax cloth
in combination & cupro-ammonium paper, whether in the form of paper, or woven
ligneous tissue) such blades or sections, to be made of metal of a suitable width,
length and thickness, the ends of which shall work in grooves or slides, and be
connected with plates or metal clips to slide rods working in properly made slide
holes or bushes above them, and acted upon by levers, screws, cams, or eccentrics,
the blades working separately or in pairs, and being formed on their lower edges
to fit into the grooves or corrugations of the bed below, the two outside blades
having grooves worked upon their outer edges to correspond with the outer bead
on the fluted bed as shown on the drawings and described. The whole of the
sections or blades of metal in combination forming and constituting the male die,
above the female die of such press, as set forth, illustrated, and described.
The other parts and combinations of the press form no part of my claim, which
is substantially as illustrated and described.
Dated his 12th day of Novemba 1002
DAVID CLARKE.