Improvements in or relating to the Manufacture of Boards, Plates, or Sheets from Leather-pulp.
Year: 1897

page_text: Date of Application, 19th Oct., 1897-Accepted, 8th Jan.,
1898
Improvements in or relating to the Manufacture of Boards, Plates, or
Sheets from Leather-pulp.
A communication from GASTON BRIGALANT, of Barentin, (Seine-Inférieure) in the
Republic of France, Manufacturer.
I, ALFRED JULIUS BOULT, of 111 Hatton Garden 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 ascer-
tained in and by the following statement:-
Leather waste has been utilised for manufacturing leather boards, plates or
sheets or pressed articles. For this purpose the leather waste was first converted
into a pulp then into a thin layer, on an ordinary paper-making machine, or
pressed. But the ordinary paper making machine is not suitable for manu-
facturing thick card board or thick leather plates or sheets.
In order to better explain the invention a description will be given on the
manufacture as it takes place on a card-board making machine.
The pulp is delivered by means of a cloth or a felt in the shape of a thin layer
between two press-rolls. The thin layer is wound round the upper roll and adheres
to it, and a board or layer of a certain thickness is formed by the addition of several
layers. In order to give to the board a certain density, it is necessary to exercise
a certain amount of pressure by means of a weight or a screw, but owing to the
viscous and greasy nature of the leather-pulp, the pressure which is necessary at
the beginning that is to say as long as the thickness of the card board is small
becomes after a time too great and crushes the layer. And if the pressure in the
beginning is made too small, the different layers wound up become afterwards
easily detached from each other.
This invention has for its object a device enabling the distance between the two
rolls or the pressure on the layer of pulp to be regulated as desired as this layer
increases in thickness. For this purpose either the roll is gradually raised or the
pressure is gradually reduced.
Figs. 1, 2, and 3 of the accompanying drawing show arrangements of this kind
The pressure is
in application to winding rolls of a card-board machine.
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33
exercised in this case by way of example, by means of weighted levers.
In fig. the weight A exercising the pressure is stationary on its lever 13 which
acts through the intermediary of a screw-thread rod C on the upper winding
roll D.
The thin layer of leather pulp is fed by a felt or a metal cloth E, passing over
the guide roller E', adjustable by means of the screw E², for the purpose of regu-
lating the more or less oblique inclination of the cloth E, in the well-known
manner, and passes between the two rolls D and F and adheres to the roll 1) and

page_text: 18 wound up thereon, and is detached from the said roll after it has attained the
desired thickness.
The lever B presses on a worm wheel H constituting a nut on the screw threaded
rod C, said wheel H when turning causing the roll D to rise or to descend. The
wheel H is operated by a worm keyed to the shaft J which is driven by means of
a chain K from an intermediate shaft L as shown in Fig. in side elevation.
the shaft L there is secured a pulley or friction wheel M which presses against a
corresponding pulley M¹ secured to the spindle of the upper roll D.
On
When owing to the repeated winding of layers the pulp layer has reached a
certain thickness, the wheel M¹ comes in contact with the wheel M which is then
caused to participate in its rotation. The shaft J thereupon begins to rotate and
causes the roll D to rise to a corresponding extent so that the roll is raised at each
revolution to the extent exactly equal to the thickness of one layer of pulp or to a
fraction of said thickness according to the compression it is desired to attain.
These differences of compression, that is to say of the amount to which the roll is
raised at each revolution are attained by varying the diameters of the chain-wheels.
The moment at which the raising of the roll is to begin varies according as the
wheel M is arranged more or less near the pulley M on the position of the
spindle L, so that the beginning of the raising can be regulated as desired. For
this purpose the bearing block of the spindle L on which a spring N rests in order
to press it always towards the spindle of the roll D, slides in a slotted bracket (
and is secured in the desired position by a screw P.
By means of this device the degree to which the roll is raised and the moment
at which it begins to rise can be regulated as desired.
Fig. 3 shows similar parts of a card-board press with pressure applied by means
of levers the only difference being that here the object is to uniformly reduce the
pressure after a certain time by causing the weight on the lever to move back.
The driving wheel Q of the roll drives an intermediate wheel Q¹ the spindle of
which is secured in a movable slotted support R. The wheel Q₁ drives a wheel Q³
keyed on a shaft S which transmits its movement by means of a worm gear T
acting on slide blocks U forming a nut, which by being advanced towards the
press cause the balance weight to advance thus reducing the pressure.
The slide U is of such construction that it can be readily brought back when
the desired thickness of the layer is obtained, without turning the screw, as shown
in Fig. 4, the slide U being in two parts pivotted about the rod Z and secured at the
top by a spring finger V. As the time at which the reduction of the weight of the
lever is to begin varies according to the nature of the pulp, the slide block U is
placed a greater or less distance behind the balance weight so that a certain
number of thin layers are wound up before the reduction of the weight begins.
On the other hand, by varying the diameter of the wheel Q2 the speed with which
the weight is moved is varied therefore also the amount of compression of the layer
of pulp is varied. By means of these devices layers of leather pulp may be made
up to 100 mm., and more in themselves which layer after having been compressed
and dried give boards or plates of 20-30 mm. thick the boards being very strong
and not liable to become unpasted or unjoined between the different layers this
being attained without necessitating the glueing together of different sheets.
These plates can then be used in any desired manner and in a great number of
ways for instance for forming heels, soles, toothed wheels etc.
Having now particularly described the nature of this invention as communicated
to me by my foreign correspondent and in what manner the same is to be per-
formed I declare that what I claim is:-
1. The manufacture of boards plates or sheets from leather pulp by passing the
pulp between two rolls and winding it on the upper roll the pressure exercised
being reduced automatically and gradually at a predetermined period either by the
roll being directly raised or by a weight placed on the pressure lever being moved

page_text: 80 as to reduce the leverage as the thickness of the pulp increases substantially as
described.
2. The combination and arrangement of parts constituting the complete
apparatus for effecting the automatic and gradual reduction of pressure on
winding rolls in leather board plate or sheet forming machines, substantially as
described and illustrated in Figure 1 or in Figure 2 of the accompanying
drawings.
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