Improvements in Apparatus for Use in Modelling, Decorating and otherwise Working in Plastic Material.
Year: 1898

page_text: Improvements in Apparatus for Use in Modelling, Decorating and
otherwise Working in Plastic Material.
I, MELVIN BATCHLOR CHURCH, Managing Director of the Alabastine Company
British, Limited, of Church Street, South Lambeth, London, do hereby declare
the nature of this invention to be as follows:-
This invention relates to improvements in apparatus for use in modelling
decorating and otherwise working in plastic material, the principal use of the
apparatus being in the modelling or production of free hand relief decorations
on walls ceilings and other places, though it may be used for many other opera-
tions which involve the laying of a thick semi-liquid or plastic preparation on
suitable surfaces.
The apparatus consists of a cylinder or suitable chamber for holding the plastic
material or the like the walls of which should be of sufficient strength to resist
considerable pressure said cylinder being laid or carried in a frame or cradle in
such a manner that it may be readily removed therefrom for the purpose of chang-
ing or substituting for it a fresh cylinder with its charge when the first is empty.
The cylinder contains a piston moved by a screw having a slow pitch so as to pro-
vide considerable power and such screw is preferably operated by a worm and worm
wheel the latter surrounding the screw and by its revolution imparting to same a
slow forward motion. Means may be provided for throwing the parts in and out
of gear so that the screw may be quickly withdrawn (as by rotating it directly)
for the purpose of withdrawing the piston from the cylinder, an operation which
will enable the cylinder to be removed and changed. One form of device for
throwing the gearing out consists of a latch suitably carried which engages when
desired and can be removed at other times from a slot in the screw so that the screw
will sometimes have only a forward movement and at other times may be screwed
back through the worm wheel. A ball bearing may be provided for the worm
wheel if desired.
The cylinder is preferably open at the end and the piston fits same closely but
without packing or the like, the slight space left between the parts enabling air
to pass by; while to prevent the plastic material passing, the piston may be
grooved around its periphery such gooves filling with the material and checking
the escape of that behind same.
To the forward end of the cylinder is attached a flexible pipe and for enabling
this to be readily removed for cleansing, the end of the cylinder is removeable
in some suitable way the faces of the separate parts being also preferably grooved
in such a manner that the material will be prevented from passing between same.
The flexible pipe carries a nozzle and tap or valve, to which nozzle may be
applied various tips suited for the work to be done or produced such tips being
preferably revoluble when secured on the nozzle in order that they may be turned
when in use without the necessity of turning or twisting the flexible tube.

page_text: It is desirable that the tap or valve of the nozzle should work with a very slight
movement of the thumb of the operator and to effect this the nozzle is formed at
the valve part of an elongated form so that a long opening presenting a large
area can be formed in the valve and hence with a short throw or movement of the
valve a passage of the same area as the pipe can be obtained through the valve.
In one form of valve I may form the hole on one side of the plug portion of the
same or approximately the same section as the opening in the pipe and then reduce
this down to an elongated or oblong opening in the exit side. I have found that
there are certain limits in the dimensions of the elongated slot which should not
be exceeded for efficient working such limits being the relation of the length to the
width as the latter must be always sufficient or the plastic material will not pasз
through freely. The opening in the receiving side of the plug may in some cases
be made larger or deeper than the passage to it so that when it is rolled forward
slightly to open it partially there will still remain the full sized opening for an
unobstructed flow into it the reduction of flow taking place only in the discharging
side of the plug. The valve may be operated by a lever or levers having a long
plate for the thumb of the operator and controlled by a spring so as to be self
closing or by means of a trigger or the lever may carry means for attachment to the
operators hand by which it may be moved positively in both directions. Or the
valve may be operated by the pressure of the plastic material which will
act to open a plug to allow the material to pass, the operator closing
the plug to cut it off. The plug may be so shaped that the pressure is
more or less equalized on it to prevent it being opened with too great a force and
also so that it may not displace too much material when being closed.
The valve casing may be in halves or parts for the purpose of taking apart for
cleaning such parts being held together by suitable means such as dowel pins and
screw collars or screwed tubes one of which may form a part of the nozzle.
The screw is rotated by a suitable crank or handle by a labourer so as to exert
pressure upon the contents of the cylinder while in the case of decorative work
the nozzle end is operated by a skilled individual the pressure being applied only
while the flow of liquid is desired and stopped when the work ceases or when the
flexible pipe becomes too hard. In place however of being worked by hand, it
can be worked by power the operator himself controlling some device for throwing
the power on or off.
It will be seen that the force employed to drive the plastic material forward is
a screw and as such is a rigid one but it may be any other suitable mechanically
applied rigid force.
In apparatus of this class in which a heavy plastic material is driven through
a hose it is very desirable to be able to clean the hose thoroughly. I have found
that a very convenient device for this purpose consists of two or more rollers
between which the hose may be passed which may form an attachment for the
machine one or more of which rollers may be worked by a crank so that the
material may be squeezed out, the hose being afterwards passed again between
the rollers together with water if necessary.
I have found also that it is desirable in practice to lubricate the hose before
using same as the material is caused to flow more evenly.
גד
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1
1000
PHILIP M. JUSTICE, -
55 & 56, Chancery Lane, London, W.c.,
Chartered Patent Agent,
For the Applicant.

page_text: Improvements in Apparatus for Use in Modelling, Decorating and
otherwise Working in Plastic Material.
I, MELVIN BATCHLOR CHURCH, Managing Director of the Alabastine Company
British, Limited, of Church Street, South Lambeth, London, do hereby declare the
nature of this invention and in what manner the same is to be performed, to bo
particularly described and ascertained in and by the following statement:-
This invention relates to an apparatus designed to be used in modelling, decorat-
ing and otherwise working in plastic material, principally in the modelling or
production of free hand relief decorations on walls, ceilings and other surfaces.
It may be also used under other conditions or circumstances which involve the
laying of a thick plastic material on any kind of surface.
The general feature of the operation in which my invention is used consists in
forcing the plastic material by means of forcing apparatus which may be stationary
during the operation, the material being forced through a flexible hose, and
through a forming nozzle at its end, held and guided by the hand of the operator,
the said nozzle being directed by the operator in the formation of the figures and
the material being constantly delivered through the nozzle but under the control
of the operator.
The application of plastic material (such as calcined gypsum) in the form of a
stream, forced through a nozzle, and laid upon the wall or other surface to be
decorated, is subject to some peculiar conditions. The stream forced from the
nozzle must be continuous, and the pressure uniform or slightly increasing at the
end of the operation for emptying the chamber containing the plastic material.
Further, the flow of the material through the applying nozzle must be under the
control of the operator. In order that the stream may be continuous, the material
in the reservoir must be practically free from air. To maintain this uniform pres-
sure, controllable at the will of the operator, the pressure upon the material must
be positive, and for the best results, in uniformity of flow of the applied stream
of plastic material, the tube through which it is applied should be non-expansive.
The application of the material to walls and other surfaces, as a matter of course,
requires a flexible tube with an applying nozzle at the end thereof, and free move-
ment of the hand of the operator and a free but variable and controllable flow of
the material.
To provide for this I have invented a form of nozzle especially adapted to the
purpose
My invention designed to fulfil the conditions of this work, includes a cylinder
or equivalent chamber adapted to contain the plastic or similar material under
pressure, with means for applying positive pressure to said material, and with a
flexible pipe having a suitable nozzle connected with said chamber so that the
material may be forced through the said pipe or nozzle.
I have shewn in the accompanying drawings one form of machine constructed
according to my invention.
In these drawings.
Figure 1 is a perspective view of a complete machine.
Figure 2 is a longitudinal section on an enlarged scale through the cylinder,
piston and worm feeding device.
Figure 3 is a plan of these parts.
Figure 4 is a cross section on line a x Figure 2 the worm and worm wheel being
in elevation.
Figure 5 is a longitudinal section through the nozzle.

page_text: Figure 6 is a plan of same at right angles to Figure 5.
Figure is an elevation of the plug looking in one direction, and
Figure 8 is an elevation looking in the opposite direction.
In these drawings the chamber in which the plastic material is placed, is
represented as in the form of a cylinder A. This is the most convenient, but is not
an essential form. It should be of such strength as to withstand internal pressure
of at least 300 pounds to the square inch.
That end in which the piston is inserted is left open. The piston fits snugly
in the cylinder, but is made without packing and not air-tight under pressure.
I have discovered in operating this kind of machine, that with an air-tight work-
ing piston an amount of air will be forced along by the piston, to such an extent
as to materially interfere, at times with the continuous discharge of a full stream
from the nozzle and that without packing the piston may be made close fitting
enough to prevent the escape backwards, of the plastic material. For this purpose
therefore I use a somewhat elongated, unpacked piston B, of substantially the
proportions shewn, and fitted to admit the backward passage of the air, under pres-
sure applied by the piston to the material in front of it, but opposing the return
of the material. The piston is provided with grooves a a (Figure 2) which may be
about one half inch wide and three sixteenths of an inch deep and the plastic
material is forced into these grooves in operation in working with the material
and this makes more effective the operation. The pressure first fills one groove
and sometimes, according to the consistency of the material, fills the second groove
also and the material becomes dry and sets, making a very effective stop for the
flow of the material backward.
Supposing the cylinder to be filled with the material, except a space at the
rear open end, the piston is inserted and pushed forward, necessarily enclosing
an amount of air. As heretofore stated, a positive pressure is required to force
the piston against the material. The material for which the apparatus is mainly
designed is a composition in which the principal ingredient is pulverized calcined
gypsum in a plastic condition, sufficiently thick to maintain its position in raised
figures when so laid upon the wall, with which sufficient glue is used to make it
adhesive. For the purpose of applying this pressure the piston is provided with a
threaded spindle C having a low pitch and a crank c at its rear end. When the
nut (which is here shown as a worm wheel 16) through which the screw passes is
held stationary the turning of the spindle will cause the piston to advance with
quick positive motion and to press unyieldingly against the contents of the
cylinder Pressure applied in this manner to the contents, would be insufficient
ordinarily for the work and I have therefore designed other or additional means
by which the labourer can apply a greater amount of pressure in the same
positive manner.
If the direct action of the screw be used as may be, when the piston is first
moved forward into the cylinder after a filling of said cylinder, the turning of
the screw is necessary. For this purpose the forward end of the screw is capable
of rotation in the head of the piston, which, for convenience, is made hollow.
The forward end of the screw has an annular groove, in which fits a halved plate 4
held to the head by bolts 15. The end of the screw bears directly on the head
of the piston.
When greater force is required the worm gear shown in brought into use.
For this the screw is carried through blocks in a box P on the inner surface of the
wall of which is fixed a bearing plate q for the worm nut 16. The plate has on its
face an annular grove, for anti-friction balls 18. Against this is placed the worm
nut 16 threaded on the screw spindle C. The worm nut is enclosed between the
blocks which hold it in place. The other side of the block may also have a ball
bearing if desired. A. worm 20 on the cross-shaft s, which is turned by a crank
or hand wheel, serves when the screw spindle is held against turning, to cause
the piston to advance. This shafts may be provided with a ball bearings for
anti-friction purposes. In place of being worked by hand the screw may be

page_text: worked by power the operator controlling some device for throwing the power on
or off.
When the operation of the screw with the increased power is desired, rotation
of the shaft is arrested by means of a latch or key. 21 which moves in guides in
the box, and may be dropped into a slot 22 in the spindle.
The cylinder is laid in a trough in the table Q, so that when the piston is with-
drawn the cylinder may be removed as for filling. It may be conveniently held
in place by means of a metal strap D pivoted at D¹ and held to the frame at the
other end by a pin D2 or otherwise. The table is supported on a frame Q¹ pro-
vided with casters, so that it may be moved readily as the work progresses. The
cap E of the cylinder to which the hose is attached is also removable, and may
be replaced by a cover, when the cylinder is to be filled. When the discharge
end is so covered, the cylinder is turned with the open end up, and the material
is settled by jolting, so as to fill all the interstices and expel the air therefrom.
This cap is readily removable by means of the lugs E and wedge blocks shown and
the faces of the abutting discs or plates or one of them may be grooved as at E
to prevent the material escaping. The cap has a conical reduced discharge pro-
jection to the end of which is attached a hose.
After a charge has been used it is necessary to clean the hose and other parts
before the material sets. For this purpose I have provided a pair of squeezing
rollers, on the frame Q¹. I have made them tapering as shown for the purpose of
applying lighter and then heavier pressure.
The rollers are marked 25 and the handle for turning them 26. Handles 27
are applied to the frame for facilitating the movement of the same.
It will be understood that the apparatus rests upon the floor or any suitable
support and as the material may have to be applied to the wall or ceiling the
nozzle which is used directly in the application of the material must be freely
movable at a considerable distance from the forcing apparatus. For conveying
the plastic material therefrom from the forcing chamber to the nozzle I use a
flexible hose F. While this hose must be flexible so that the nozzle may be moved
freely about while the operator is laying the material upon the walls or ceiling,
the conditions require that this hose should be non expansible, and yet adapted
to be compressed to expel the material for cleaning, I have found a rubber lined
braided hose most suitable for the purpose. The material in the hose is of course
under pressure and any expansion of the hose due to elasticity of the material
would vary the pressure at the nozzle and impair the positiveness of the discharge.
I therefore use a non-expansible hose so that the original positiveness of movement
imparted to the material is maintained throughout its movement to the discharge.
This I have found to be practicable, notwithstanding the fact that the stream
of the material forced from the nozzle by pressure applied behind the whole mass,
at the forcing apparatus, must be often diminished and checked sometimes wholly.
By practical operation I have found that the plastic material used in this apparatus,
has sufficient elasticity to relieve the positive forcing apparatus and the hose, and
prevents any injurious shock.
The nozzle for the work of laying the material upon the desired surface should
be arranged so that the hose will not kink in use and for this purpose it may be
capable of revolving on the end of the hose under pressure, such as through the
medium of the neck piece F¹ which is revoluble in or on a socket piece 12 on the
end of the hose. The main valve chamber R Figures 5 and 6 is formed in two
parts 4 and 5 for convenience of construction, the parts being held together by
screws 6 or screws and dowel pins or suitable devices. The hole from the rear
into the valve seat, may be round, but the passage through the valve plug is made
of special form to meet the special conditions. The work requires that the flow
of the material should be completely under the control of the operator, who grasps
the nozzle in his hand, and the valve which controls the flow must be manipulated
by the thumb and finger. Under such circumstances large sweep of movement is
not possible and should be avoided as the conditions require quick change in the

page_text: size of the valve passage, with very little movement of the valve. The sluggish-
ness of the plastic or semi-liquid material in its movement through small passages,
have necessitated a special form of valve passage and this in its simplest form
according to my invention consists of an elongated opening presenting a large
area so that with a short movement a passage of the same area as the pipe can be
obtained.
A
The valve plug is shown at H, Figures 5, 7, and 8. It is of the ordinary
cylindrical form, and turns in a corresponding seat in the valve chamber R.
stud 8 on the plug end inside the flange 9 moves in a cutaway portion of the block,
forming the chamber so as to limit the movement of the valve's rotation. The
squared shank of the valve receives a lever 10 which is held by a nut 11. A
spring 12 holds the valve closed. Pressure with the thumb on one end of the
lever, or pulling by the finger on the other, against the spring, will turn the valve,
more or less according to the amount of pressure, to open the valve. Or the
valve trigger or lever may carry means for attachment to the operator's hand by
which it may be moved positively in both directions. Or the valve may be
operated by the pressure of the plastic material which will act to open a plug to
allow the material to pass, the operator closing the plug to cut it off. The orifice
for ingress to the valve seat may be made round to correspond with the hose as
stated, and may correspond with a similar opening on the rear side of the plug
or valve H, such opening in the plug being altered to an elongated opening on the
exit side. But I prefer to form the plug H as shown with an enlarged flared
opening of elongated form on the rear side which alters or converges to the smaller
rectangular opening H in the forward or exit side of the valve. By this arrange-
ment there will still remain the full sized opening for an unobstructed flow of
the material into the entering side of the valve even when the valve has been
rolled forward to open it partially the reduction of flow taking place only on the
discharging side. This opening H2 on the discharging side corresponds with the
opening on that side of the valve seat, the two registering exactly, when the valve
is in an open position. The rear opening in the valve is shown in Figure 7 and
the front in Figure 8.
When therefore the valve is turned to open, the elongated rectangular form of
the valve opening, and the arrangement of the longer walls in planes parallel with
the valve axis, enables the valve to open at once, to the full lateral extent of the
opening. It is therefore necessary only to turn the valve a space equal to the
breadth across the passage taken across the axis of the valve, to get the full
opening. At the same time the round stream is made gradually to conform to
this rectangular opening, by the converging walls of the cavity in the rear portion
and the obstruction is minimized. The valve opening, however, should not be
greatly enlarged laterally and divergent in cross section as a very narrow passage
greatly obstructs the flow. The delivery end 13 of the nozzle is made of a separate
piece, and is fitted to turn on an extension 14 of the nozzle, being retained in place
by set screws 15 which engage with an annular groove in the nozzle. Exchangeable
ends or tips are provided having passages of different cross section, to correspond
with the design of the work to be done. By the use of a rotatable delivery end
(and a rotatable nozzle if desired) the stream may be laid flatwise or on edge, or
inclined, as the making of the figures may require, without turning the nozzle or
any forcing implement held in the hand. Without this rotatable discharging
tip or nozzle, it would be impossible to execute certain forms of decoration pro-
perly as the hand or arm cannot be turned completely over when holding such a
device and at the same time maintain the proper position of the discharge but
with this movement every variety of motion may be secured.
It will be seen that the force employed to drive the plastic material forward is
a screw and as such is a rigid one but it may be any other suitable mechanically
applied rigid force.
I have found also that it is desirable in practice to lubricate the hose before
using same as the material is caused to flow more evenly.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is―
1. A machine for working in plastic material comprising a chamber for the
material, and means for mechanically applying a positive rigid pressure to the
material in said chamber to expel it therefrom, substantially as described.
2. A machine for working in plastic material comprising a chamber for said
material, a hose leading therefrom, means for mechanically applying an initial
pressure to the material and supplemental means for mechanically applying a
final pressure to said material, substantially as described.
3. In a machine for working in plastic material a cylinder adapted to hold
said material, having an open rear end, in combination with a piston adapted to
permit the rearward passage of the air, but to obstruct the rearward flow of the
plastic material, substantially as described.
4. In a machine for working in plastic material, a chamber or cylinder for the
plastic material and a piston fitting the cylinder snugly but without packing
having means for preventing the backward escape of the material while permitting
the escape of air, substantially as described.
5. In a machine for working in plastic material, a chamber or cylinder and a
free fitting piston having a groove in its periphery, substantially as and for the
purpose described.
6. In a machine for working in plastic material a hose, having a nozzle or tip
rotatable on same substantially as and for the purpose described.
7. In a machine for working in plastic material a valve for controlling the flow
of the material having an elongated opening so that with a short movement a
passage of large area can be quickly obtained, substantially as described.
8. In a machine for working in plastic material a valve for controlling the flow
of the material having a rectangular opening in front, said opening flaring to the
rear, substantially as and for the purpose described.
9. A nozzle for a machine for working in plastic material, having a cylindrical
valve, with a contracted front opening, and an enlarged rear opening, and a seat
having an opening on one side of smaller size than the enlarged opening in the
valve substantially as and for the purpose described.
10. In a machine for working in plastic material a chamber or cylinder, a piston,
a spindle having a low pitch thread passing through a nut and turning means
for the spindle for operating the piston, substantially as described.
11. In a machine for working in plastic material a piston and cylinder, a
threaded spindle for the piston and a worm nut engaging the spindle and a worm
gear for turning the nut and forcing forward the spindle, substantially as described.
12. A machine for working in plastic material provided with a hose and forcing
means and means for cleaning the hose by compression to force out the material
contained within it, substantially as described.
13. In a machine for working in plastic material a cylinder, a piston, a screw
for operating same and means for operating the screw directly and for multiplying
the power as desired and for the purpose substantially as described.
14. In a machine for working in plastic material, a cylinder open at one end,
a removable piston, a removable cap for the contracted end of the cylinder, and a
flexible hose, substantially as described.
Dated the 20th day of Nov 1800
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London,
Chartered Patent Agent,
For the Applicant.