Improvements in Presses for the Manufacture of and Undercutting of Tiles, Bricks, and other Articles.
Year: 1897

page_text: Date of Application, 4th Oct., 1897
Complete Specification Left, 31st May, 1898-Accepted, 27th Aug., 1898
PROVISIONAL SPECIFICATION.
Improvements in Presses for the Manufacture of and Undercutting of
Tiles, Bricks, and other Articles.
I, THOMAS DALTON, of Weetwood, in the City of Leeds, Solicitor, do hereby
declare the nature of this invention to be as follows:-
It relates more particularly to presses for the manufacture of tiles for walls
ceilings and floors but it is also applicable to machines for the production of
bricks and other articles which it is desired to bind together or affix to some other
surface by means of cement plaster or other like substance. Its object is to pro-
duce during the operation of pressing an undercut in the back of a tile or in the
fixing surface of any other article into which the cement plaster or other sub-
stance used for fixing may enter and whereby the tile or other article may be
keyed to its bed instead of being held by cohesion alone.
carry out my invention as follows. I use a top plunger attached to the press-
ing screw by means of a neck passing through a ring formed at the bottom of the
pressing screw. The neck is furnished at its upper end with a collar whereby the
plunger may be lifted by the pressing screw and the neck is elongated so as to
permit a certain amount of free vertical motion within the ring. I construct
the plunger with a cavity. Through the top of the plunger over the centre of the
cavity I bore a hole for the purpose hereinafter mentioned. In the centre of the
cavity I use a rod or spindle the upper end of which passes through the aforesaid
hole. This centre rod or spindle is provided at its upper end with a collar and
is supported by a spiral spring both within the cavity. The length of the rod or
spindle is such that when the press is at rest (that is to say when the plunger is
lifted) it stands slightly above the top of the plunger.
In suitable bearings at the bottom of the plunger I use two small crossheaded
levers the cross heads of which are made roller shaped and the long arms of which
project upward (but they may be turned either inward or outward and may be
reduced in size even to that of a mere tooth) and on the side of each lever is a
stud projecting into a slot cut at any desired angle from the perpendicular in the
central rod or spindle. On the face of each cross head a tooth is formed extend-
ing partly across its face; the face of the tooth being in the line of the radius
drawn from the centre of oscillation of the cross head so that when the. cross head
is partially revolved the tooth is forced inward toward the middle of the
tile surface and so forms an undercut.
The action of my apparatus is as follows:--When it is desired to press a tile
the pressing screw first forces down the centre rod or spindle and then the slots
in the bottom acting on the studs on the levers partially revolves the crossheads
and so cause the teeth thereon to turn inward away from a right angle. As the
pressing screw continues its motion it forces down the whole plunger and the
pressure forces the clay around the teeth on the crossheads. When the pressure
is released the centre rod or spindle rises by means of the spiral spring and

page_text: thereby partialy revolves the crossheads backwards so that when the plunger is
drawn up by the pressing screw the teeth are clear of the undercut.
Instead of crossheaded levers rocking levers may be used operated by angular
or cam-like projections or by notches or teeth on the centre rod or spindle and
the undercut may be turned outward insted of inward. And instead of either
the cross headed levers or the rocking levers the lower end of the central rod or
spindle may be attached to and made to operate one or more under cutting blades
made to slide in grooves formed in the plunger head. The grooves may be
straight or circular in shape but if straight they must be constructed at an
angle and in either case they must be so constructed as that when the blade is
forced out by the descent of the spindle they may form a cavity in the back of
the tile. In the use of this method a slight rotary motion may be imparted to
the centre rod or spindle if desired so as to throw the blades circumferentially.
And instead of either crossheaded levers or rocking levers or sliding blades the
plunger head may be formed in two halves each furnished with a tooth or hook for
undercutting and operated by the centre rod or spindle operating through similar
mechanism to that before described, but when this latter alternative method is
used it is desirable that the tile bed should rise slightly concurrently with the
lifting of the top plunger so that the teeth or hooks may fall back without tear-
ing the undercut.
་
By obvious adaptation my apparatus other than the split head may be fixed
in the bottom instead of in the top plunger, but in this case it is better to suspend
the bottom plunger on a spring or by other means in order to obtain the necessary
play between it and the pressing block. But a split head may be used with the
bottom plunger, only in this case the head must be made in three or more
sections according to the direction of the undercut. The simplest form of this
is to make the undercut outwards in which case I make use of the end of the
centre spindle to form the middle section and for this purpose I make the (in this
case the upper) end wedge shaped and of the full width of the tile box. When
using this method I do not support the bottom plunger by spring or other means,
so that except when the tile is being lifted out of the press the centre and two
side sections of the split head form an even bottom for the tile box. When it
is desired to lift the tile clear of the box, the two side sections lift clear of the
centre one falling inward as 'they lift. When using a split head with the bottom
plunger the central rod or spindle may be made fast to the pressing block, and the
spiral spring may be dispensed with.
And besides the several uses herein before described the central rod or spindle
may be used as follows namely to partially rotate a disc furnished with hooks
at any desired distance from its circumference fitted into the plunger and forming
part of the pressing face. According to this method when the pressure comes on
the rod it partially rotates the disc so as to place the hooks in a forward position
and the tile is pressed with the hooks in that position. Then when the pressure
is released the disc turns backward and the hooks clear the undercut as the
plunger rises.
I do not confine myself to the use of one rod or spindle nor to the placing of
it or them in the centre. And in some cases they may be dispensed with and
the undercutting mechanism may be operated from the plunger frames and even
from the pressing block.
I provide means for the escape of any clay which may squeeze through the
interstices in the plunger head whether top or bottom.
Dated this Second day of October 1897

page_text: COMPLETE SPECIFICATION.
Improvements in Presses for the Manufacture of and Undercutting of
Tiles, Bricks, and other Articles.
I, THOMAS DALTON, of Weetwood, in the City of Leeds, Solicitor, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:
The invention relates more particularly to presses for the manufacture of tiles
for walls, ceilings and floors but it is also applicable to machines for the produc-
tion of bricks and other articles which it is desired to bind together or affix to
some other surface by means of cement plaster or other like substance. Its object
is to produce during the operation of pressing an undercut in the back of a tile
or in the fixing surface of any other article into which the cement plaster or
other substance used for fixing may enter and whereby the tile or other article
may be keyed to its bed instead of being held by cohesion alone.
My invention was designed more especially for use in the top plunger or die
of a tile or a brick press but it is also applicable to the bottom plunger or die.
There is however or at least there may be a slight difference in the apparatus
-ding to whether it is to be used in the top or bottom which difference will
be hereafter described:
My operating mechanism consisting essentially of a hollow plunger with a
central rod mounted on a spiral spring may be used with many different forms
of head or die and I therefore prefer in this specification to speak of the head or
die as a distinct part of the plunger whether top or bottom.
I carry out my invention as follows:-When it is used with a top die I use a
top plunger made to slide vertically in the usual way attached to the pressing
screw by means of a neck passing through a ring formed on or attached by any
suitable means to the bottom of the pressing screw and the neck is furnished at
its upper end with a collar or fast washer whereby the plunger may be lifted
by the pressing screw. The neck is also elongated so as to permit a certain
amount of free vertical motion within the ring and the plunger is formed with
a cavity in the centre. This form of apparatus is illustrated in Figs. 2 and 4 of
the drawings. But instead of the ring a partially hollow spindle may be used
(hereinafter referred to as a sleeve) of the full length and to take the place of
the slide of a plunger of ordinary construction and of square circular or other
approved section having a cavity at the top into which is inserted a split collar
for receiving and retaining the end of the pressing screw and instead of a slide
with a neck at the top as first above mentioned an inner hollow spindle or sliding
piece may be used provided with a collar some distance away from the end for
lifting purposes. This alternative or sleeve form of apparatus is illustrated in
Figs. 5 to 9 of the drawings. Through the top of the plunger in the first case
or through the top of the inner sliding piece in the alternative method (for the.
action is the same in either case) and over the centre of the cavity I bore a hole
for the purpose hereinafter mentioned. In the centre of the cavity I use a rod or
spindle the upper end of which passes through the aforesaid hole. This centre
rod or spindle is provided at its upper end with a collar or fixed washer and is
supported by a spiral spring both within the cavity. The length of the rod or
spindle is such that when the press is at rest, that is to say when the plunger
is lifted, it stands slightly above the top of the plunger or the inner sliding
piece as the case may be. The bottom of the rod or spindle projects below the
bottom of the plunger or sliding piece as the case may be and into the attached
head or die and is shaped according to the particular way the head may be fitted
to give the undercut desired. For instance it may be more or less heart shaped

page_text: and provided with slots cut at any desired angle from the perpendicular so as to
operate studs on the lever arms of the undercutters or it may be wedge shaped
or it may be toothed on its sides and it may be made to operate several under-
cutters at the same time. I do not confine myself to any one or more shapes.
And instead of shaped rod ends links may be used (see Fig. 12) extending from
the centre rod to the ends of the lever arms of the undercutters as a means of
operating the latter.
To the bottom of the plunger when made as first described or at the bottom of
the inner sliding piece when made according to the alternative method above
described I attach the head or die. This may be fitted in various ways.
According to one method I use in suitable bearings at or near the pressing face
of the die two small crossheaded levers the crossheads of which are made roller
shaped and the long arms of which project upward and on the side of each lever
that is to say on the long arm thereof is a short stud projecting into a slot formed
in the lower end of the centre rod or spindle as above mentioned. On the face
of each crosshead a tooth is formed which may extend wholly or partly across
its face the face or front edge of the tooth, being either in or slightly in advance
of the line of the radius drawn from the centre of oscillation of the crosshead so
that when the crosshead is partially revolved the tooth is forced inward toward
(or it may be away from) the middle of the length of the tile surface and so
forms an undercut. But the arms of the levers of the crossheads may be turned
either inward or outward instead of being vertical and may be reduced in size
even to that of a mere tooth as shown in Fig. 10. And the teeth on the face of
the crossheads as also of every other form of undercutter hereinafter described
may be either straight curved or hooked in vertical cross section.
The action of my apparatus as applied to the top plunger is as follows:-When
it is desired to press a tile the pressing screw first allows the plunger (and there-
with the die) to drop to the level of the material to be pressed and then forces
down the centre rod or spindle and (when this is provided with slots as above-
mentioned) the slots in the bottom acting on the studs on the levers partially
revolve the crossheads and so cause the teeth thereon to turn inward (or outward
if so designed) away from a right angle. As the pressing screw continues its
motion it forces down the whole. plunger and the pressure forces the clay around
the teeth on the crossheads. When the pressure is released the centre rod or
spindle rises by means of the spiral spring and thereby partially revolves the
cross-heads backward so that when the plunger is drawn up by the pressing
screw the teeth are clear of the undercut.
The spiral spring ought not to be stronger than needful to withdraw the teeth
from the undercut without tearing otherwise there may be a danger of two pres-
sures vertical and lateral at the same time which may produce a hollow in the
face of the tile. But this danger can be effectually prevented by the use of
suitable means 'to prevent the descent of the plunger to the top of the material
to be pressed before the central rod has been first forced down and to prevent
the return of the plunger after the pressing has been performed and the screw
begins to lift until the central rod has lifted and so cleared the teeth of the under-
cut. This may be effected by, amongst others, the following method namely,
by forming at the side of the bottom of the plunger or inner sliding piece as the
case may be or on the head or die a rib or ribs to serve as holding pieces (an
indent may be used instead) and making the plunger in the course of its descent
to push past or between a rubbing spring or springs which shall be of sufficient
strength to compel the descent of the central rod before the plunger or inner
sliding piece as the case may be and afterwards hold the plunger down so that
the lifting of the pressing screw shall be necessary to pull it back again. By
this means the undercutting teeth are always in their forward or cutting position
before entering the tile material. But I do not regard it as generally necessary
to make use of a check spring. I have devised it because in one of the modified
forms which I have tried of my apparatus I encountered the defect I have

page_text: mentioned by reason as I believe of my using too great an amount of travel to
the undercutting tooth and also because it assimilates the action of the top to
that of certain forms of my apparatus as applied to the bottom die and hereinafter
described.
With the apparatus as above described and instead of cross-headed levers in the
head or die, rocking levers (by which I mean as well double ended and three
ended levers as partially revolving cutters) may be used operated by angular or
cam like projections or by notches or teeth on the centre rod or spindle or by
links therefrom or by being hinged (fixed or loose) thereto and the undercut may
be turned outward instead of inward. And instead of either cross-headed or
rocking levers the head or die may be fitted with one or more undercutting
blades (see Fig. 13) made to slide in grooves formed in the head or die and
attached to and operated by the centre rod or spindle. The grooves may be
straight or circular in shape but if straight they must be constructed at an angle
and in either case they must be so constructed that when the blades are forced
out by the descent of the spindle they may form an undercut cavity in the back
of the tile. In the use of this last mentioned method a slight rotary motion may
be imparted to the centre rod or spindle by (amongst other methods) the use of
a stud made to slide in a groove cut at an angle from the perpendicular within
the plunger or inner hollow spindle or sliding piece as the case may be so as to
throw the blades circumferentially but I attach no importance to this inasmuch
as the undercuts must of necessity be all in the same direction.
And instead of either cross-headed levers or rocking levers or sliding blades the
head or die may be formed in halves with the line of separation vertical between
them, each furnished with a tooth or undercutting ledge and operated by similar
mechanism to that before described but I do not advocate this method for
amongst other reasons, when this latter alternative method is used it is necessary
that the tile bed or bottom die should rise concurrently with the lifting of the top
die to enable the sections of the top die to fall apart without tearing the under-
cut. With such a head or die as last described 'the undercut must be inward.
But the undercut may be turned outward by the use of the bottom of the central
rod as a wedge between the other parts of the head (thus making the head or
die in 3 sections) and the parts may be so arranged that it shall not be necessary
to lift the bottom die concurrently with the top one. I prefer however to make
the head or die with an outer frame enclosing the moveable parts as shown in
Figs. 5 and 9 of the drawings.
My apparatus as used for the top die may be inverted and used for the bottom
die but inasmuch as the motion must in either case proceed from the pressing
screw the relative motions of the head or die and the central rod will be reversed
so that the die will descend on to the rod when pressure is applied and will lift off
the rod when the pressure is released. I exhibit several forms of my apparatus
as applied to the bottom die as well as a method of assimilating to the bottom
die the action of the apparatus as used with a top die.
When the sleeve form of apparatus is used a rim or collar must be constructed
outside the upper end as a means of suspending it from the table. The rim or
collar may be enlarged to a plate the full size of the tile box if desired. The
thrust of the central rod will be on the lower end of the sleeve. The spiral spring
around the central rod will serve as a means of suspending the die on the rod.
second spiral spring may be introduced between the inner and outer slide to take
the weight off the former and the attached head or die thus leaving the central
spring to operate the central rod only. The second spring will also provide for
the necessary play of the central rod. But I prefer to lift the head or die by
positive thrust from below by means of the ordinary lifting mechanism and for
this purpose I make the lower end of the inner slide with divided ends passing
through slots or holes cut or formed in the lower end of the sleeve and projecting
a sufficient distance to give the required amount of lift. The action of this
method is as follows:-When the lifter rises it strikes the divided ends thereby

page_text: lifting the inner slide. When this has partially lifted the lifter strikes upon the
bottom of the sleeve and then the whole apparatus lifts together.
But a hollow plunger consisting of a hollow spindle with a central rod and
spring only may be used and I prefer this form of apparatus. The hollow spindle
is attached to the head or die as in the case of a top die and no other suspension
is needed. I assimilate the action of this form of apparatus to that used with a
top die as follows:-To take the thrust of the central rod I provide a cross bar
under the table (intermediate between the table and the lifter) made with a
central boss into which is screwed a cylindrical bush with a flanged top for the
purpose of providing an adjustable bearing for the central rod. On the top of
this there rests a stop piece consisting of a disc with radial slot holes for receiving
the projecting ends of the hollow spindle. I make the end of the hollow spindle
with suitable projections so as to pass through the aforesaid radial slots so as to
come in contact with the lifter. This is a method I have used in the press I
have used but I do not confine myself to this particular method. The action of
this form of apparatus is as follows:-When the lifter rises it strikes the lower
ends of the above mentioned projections thereby lifting the hollow spindle, the
central rod remaining stationary until when the hollow spindle has partially lifted
its bottom strikes upon the collar on the bottom of the central rod and then the
hollow spindle and the central rod lift together.
But the method of operating the central rod may be varied according to the
direction of the undercut desired, also according to the form of undercutters to
be used. For instanco when using a head or die formed in 3. sections the top
of the central rod may be made cross headed with the arms of the cross-head
made to pass through and slide vertically either within a bridge constructed in
the middle section of the die or within slots cut through the upper end of the
hollow spindle so as to transmit the motion of the central rod to the parts outside
of those attached to and supported by the hollow spindle. In this case the cross
bar bearing below the table and the forked ends of the hollow spindle may be
dispensed with and the central rod may rest directly upon and be operated by
the lifter. This may be the case also when using a head or die fitted with rock-
ing undercutters to form an undercut inward as shown in Fig. 24. The method
of operating the central rod will also vary according to the method of lifting
employed that is to say whether it be by a fork,working into a collar on the
plunger or by means of a thrust from below. In some cases (as for instance in
the case of a bottom die in 3 sections) it is desirable to use a holding down spring
which may be spiral outside the plunger using the underside of the table top
as a buttress.
And in some cases the inside spring may be dispensed with as in
Figs. 30 and 39.
Head's or dies may be used with the bottom plunger of like construction as used
with the top plunger. Even a head or die formed in halves only may be used
if it be made to lift simultaneously with the lifting of the top plunger above the
box and its outer sides be flange tapered at the upper end but I do not advocate
this method. I prefer to make the head in 3 or more sections as hereinbefore
described with reference to the top die. When using a bottom head or die made
in 3 sections it is not necessary to support the die by spring or other means so
that except when the tile is being lifted out of the press the centre and 2 side
sections of the split head 'form an even bottom for the tile box except as required
to produce the undercut. When the tile is being lifted clear of the box the two
side sections of the head lift clear of the centre one moving inward as they lift.
When using a head of this construction for a brick press the central rod or
spindle may if preferred be made fast to the pressing block and the spiral spring
may be dispensed with.
And besides the several uses herein before described the central rod or spindle
may be used as follows namely to partially rotate a disc furnished with hooks or
other undercutting projections at any desired distance from its circumference
fitted into the die whether top or bottom and forming part of the pressing face.

page_text: According to this method when the pressure comes on the rod it partially rotates
the disc so as to place the hooks in a forward position and the tile is pressed with
the hooks in that position. Then when the pressure is released the disc turns
backwards and the hooks clear the undercut as the plunger rises. But I regard
this method also as of no importance as the effect would only be the same as
that obtained by Messrs. Holroyd & Bond by the method described in their
Specification No. 4602 of the year 1896.
I do not confine myself to the use of one rod placed in the centre of the
plunger. Two or more rods may be used placed elsewhere than in the centre.
And in some cases rods whether one or more may be dispensed with. One of the
methods I have used in connection with the bottom die of rods placed elsewhere
than in the centre is illustrated in Figs. 27 to 29 of the drawings and is as
follows: I use a head screwed on to a spindle of the ordinary type. In the head
are mounted beneath a top plate two rocking or partially revolving undercutters,
(levers in effect though not in shape), with the long ends projecting outward and
loosely hinged to push pieces sliding loosely in recesses in the ends of the head
each fitted with a foot which as it lifts on the descent of the head on to the press-
ing table top compresses. a spiral spring held in position by a buttress piece also
within the recess. The peculiar form of rocking lever in this case is necessary to
prevent the passage of material beneath the top plate when the cutting tooth is
pulled backward by the descent of the push piece on the lifting of the head. The
push pieces may be of any desired form instead of that herein and in my drawings
described and pulling springs may be used instead of pushing springs.
And one of the methods I have devised for use in connection with a bottom die
whereby rods such as herein before described are dispensed with is illustrated in
Fig. 39 and as follows:-I use a head constructed as in the last case (in fact I
have used the same head for both experiments) but I use a rocking lever with the
long end projecting downward instead of outward and I dispense with the buttress
pieces the springs and the push pieces. I cut slot holes in the sides of the tile
box near the bottom and through each hole I pass a bar with a wedge shaped
finger at the end pointing upward but a space is left above the bar and the top
of the slot. The straight side of the finger is pushed into the depth of the recess
in the head. The sloping side faces the box side. When the die is lowered the
long end of the rocking lever is deflected by the finger wedge (which in this form
is the equivalent of the centre sliding rod in the apparatus firstly herein before
described) into the slot in the box side thereby forcing the undercutting tooth
forward. Then when the die is raised and as it rises the long end of the rocking
lever is withdrawn from the slot and forced again into the vertical position by the
box side. And a further method which I designed in order to dispense with
cutting the tile box is illustrated in Fig. 30 to 33 and is as follows:-I use a head
in all respects like as in the last instance except that the long end of the rocking
lever is shortened and made not the full width of the recess. And to get the
motion I use a plate between the bottom of the tile box and the pressing table upon
which are two vertical standards the outer sides of which are of just sufficient dis-
tance apart as to fit within the tile box whilst their width and thickness are such
as to fit into the recesses in the ends of the pressing head and allow the head to
slide freely upon them. These standards are to take the place of the wedge and
of the slot in the last method. And accordingly a sloping hole is cut through
them from the inner to the outer sides. But it may be the reverse way if desired.
The space above the whole on the outer sides is tapered top and bottom to form a
push and pull piece and is cut away in front to allow the lever end to pass. The
space below the hole serves as a wedge to deflect the lever arm into the hole on the
other side. For this purpose the lever end is tapered on both sides and the outer
side is formed with a heel to ensure a sufficient amount of motion.
A modified form of apparatus in which the principle of my invention is con-
tained is illustrated in Figs. 41 & 42 of my drawings and is fully described in my
description of the drawings,

page_text: I do not confine myself to the several forms of head or die herein before or in
my drawings described for many forms may be used but whatever form I may
prefer to use I do not confine myself to any particular shape or number of under-
cuts though I generally prefer two or four parallel with the edge of the tile.
I provide for the escape of material pressed in past the undercutters but the
escape holes are not shown in all cases.
To enable my invention to be fully understood and readily carried into effect
I further refer to the accompanying drawings.
Fig. 1 represents a portion of that part of a press for making tiles which stands
above the table showing my improved apparatus in position attached to the press-
ing screw. My apparatus is shown in full line but the slide is drawn so as to show
both a front view and a side view side by side for the purpose of showing the
method of retaining the split collar. The rest or that which is usual is shown in
chained dot.
Fig. 1 is a vertical section of one form of undercut in the back of a tile as
made by my apparatus.
Fig. 1 is a plan of the undercut back of the same tile.
Fig. 1 is a vertical section of another form of undercut in the back of a tile
made by my apparatus.
Fig. 1 is a plan of the undercut back of the same tile as referred to in Fig. 1°.
Fig. 2 is a broken vertical section of a top plunger in what for distinction I
call the ring form of my apparatus as firstly herein before described with a head
or die attached fitted and operated as also firstly herein before described.
Fig. 3 is a broken vertical side section showing the head or die in half sections
through the lines K L and M N respectively in Fig. 2.
Fig. 4 is a plan of the top of the head or die.
A is a top plunger shown broken in its length suspended from the ring a
attached to the pressing screw in any desired way by means of the neck C. b is
a nut screwed into the open end of the ring a so as to form a flange thereon. The
neck C consists of a short hollow spindle formed with a collar C₁ at its upper end
so as to be held within the ring a by means of the nut and its lower end is
screwed into the plunger A. d is the centre rod or spindle with a loose collar or
fast washer e pinned thereon. f is the spiral spring. 9 is the top of the head H
forming the top die formed with a neck g screwing into the plunger A. d is the
flattened end of the central rod descending into the head H for the purpose of
operating the undercutters fitted therein. The top. g is attached to the other
portion of the head H by bolts 1 1. H consists of a square frame bolted to g and
a covering plate 2 forming the face of the die. 33 are slots formed in the flattened
end of the central rod and designed to produce an undercut inward that is to
say toward the middle of the tile surface 44 are cross headed levers mounted on
pins passing from side to side of the head near the face of the die. 5 5 are the
long arms thereof projecting upward and 6 6 are studs mounted on the sides of the
long arms and working into the 'slots 3 3. 77 are teeth or undercutting ridges
formed across the face of the cross headed levers. But if desired the cross headed
levers may be made to oscillate around the edge of the cover plate instead of on
pins as shown.
Fig. 5 is a vertical section of my improved apparatus in the sleeve form with
a head or die H attached.
Fig. 6 is a side elevation of the central rod.
Fig 7 is a plan of the same thing.
Fig. 8 is a back view of the undercutting wedge.
Fig. 9 is a plan of the attached head or die.
h is the sleeve (an alternative of a mere ring) attached to the pressing screw by a
split collar at j and k is a retaining nut screwed into the sleeve. 7 is an inner
slide formed with a cavity in the centre the alternative of the plunger when used
without the sleeve, the part of which represents the neck when my apparatus is
nsed without the sleeve and represents the collar in the like case. 9 is a guide

page_text: pin screwed into the sleeve with its point projecting into a slot cut into the side
of the inner slide to prevent twisting. m is the centre rod or spindle with a
loose collar pinned thereon. o is the spiral spring. is the top of the head H
forming the top die formed with a neck screwing into the inner slide lis
the bottom end, in this case formed in the shape of a wedge of the central rod
descending into the head H for the purpose of operating the undercutters fitted
therein. The top p is attached to the other portion of the head H by bolts as
shown. H consists of a square frame as before. 8 8 are wedges each provided
with a projecting ledge or tooth 8' 8' at the bottom and extending over a part of
the bottom surface of the die. The wedges 88 are mounted and slide freely on
pins 99 screwed into the sides of the head H and are kept in contact with d by
spiral springs 10 10 also mounted on the pins 9 9. The action of this form of
head is as follows:-The descent of the central rod forces the wedges 8 8 apart
to form the undercut and when it rises again the springs 10 10 force them back
again so as to clear the undercut. 11 11 are escape holes.
Fig. 10, 11, 12, 13 are vertical sections of other forms of heads or dies which.
may be used with the apparatus described in Figs. and 5. In each of these
figs, the head is provided with a face plate.
The
In Fig. 10 the central rod is shown toothed on its sides and as operating
undercutters 12 12 provided with teeth on their backs instead of lever arms.
rest of the figure is obvious.
In Fig. 11 the central rod end d is shown wedge shaped and as operating
between the long arms of tumblers 13 13 constantly held in contact therewith by
springs 14 14 mounted on pin's or studs 15 15 as described in Fig. 5. The rest
of the figure is obvious.
In Fig. 12 the cross headed levers 14 14 are shown as operated by links 15 15
from the central rod d which in this case is shown as provided with an additional
spring 16, at its lower end. The rest of the figure is obvious.
In Fig. 13 the central rod is shown with a flattened end do to which are hinged
blades 17 17 made to slide in grooves 18 18 for the purpose of forming the under-
cut. The rest of the figure is obvious.
Fig. 14 is a vertical section showing my apparatus inverted as used for a bottom
die with the inner sliding piece shown (optionally) supported on a spiral spring.
Fig. 15 is a plan taken on the line A B in Fig. 14. q is the sleeve formed with
a flanger to suspend it from the table ss are slot holes cut in the bottom of the
sleeve, is the bottom plate of the head or die formed with a neck screwing into
the inner sliding piece consisting of a partially hollow spindle containing the
central rod and the spiral spring as in the case of the apparatus used with a top
die. wowo are the divided ends of the inner hollow spindle or sliding piece made
capable of passing through the slot holes ss and project below them during the.
operation of presing, is a bottom thrust lifter as ordinarily used y is a spiral
spring the use of which is optional supporting the sliding piece v. The rest of
the figure is obvious. The action of this form of apparatus is as follows:-
When the lifter rises it strikes the divided ends wow of the inner hollow
spindle thereby lifting it. When this has partially lifted the lifter strikes the
bottom of the sleeve g and then the whole apparatus lifts together.
Fig. 16 is a vertical section of my apparatus as used for a bottom die without
sleeve.
Fig. 17 is a plan of the disc showing the slot holes and spigot A is the central
boss of a cross bar beneath the pressing table. B is a cylindrical bush screwed into
the central boss to regulate the vertical travel of the central rod. C is the lifter.
D is a disc to take the thrust of the central rod (shown formed with a neck to
slide within the cylindrical bush B and with a spigot on the top) furnished with
radial slot holes Di D¹. E E are the divided ends of the hollow spindle or plunger
made capable of passing through the radial slot holes D' D'. The rest of the
figure is obvious. The action is similar to that last above described.

page_text: Fig. 18 is a vertical section of a form of my apparatus as used with a com-
pound crosshead and operated direct from the lifter the head or die being formed
in 3 wedge shaped sections.
Figs. 18 to 18" are details thereof.
Fig. 18 is a front view of the cross head.
Fig. 18" is an end view thereof.
Fig. 18 is a plan thereof.
Fig. 18 is a section of the centre wedge showing its attachment to the hollow
spindle.
Fig. 18 is an outside elevation.
Fig. 18 is a vertical section.
Fig. 18 is an outside end elevation of one of the side wedges.
Fig. 18 is a side elevation thereof.
Fig. 19 is a sectional plan with the centre wedge removed showing the upper
end of the hollow spindle and the mounting of the side wedges.
Fig. 20 is a plan showing form of undercut F is the hollow spindle formed in
two parts the upper part F¹ of which screws into the lower and is formed as shown
in detail in vertical section in Fig. 18° and in plan in Fig. 19. F is a flanged
nut screwed into the bottom of the hollow spindle. G is the central rod with
loose collar G attached and H is the spiral spring operating the central rod as
in other cases. J is a holding down spring shown of spiral form outside the
hollow spindle and resting on the flanged nut F3 and buttressing against the
underside of the table top 19 is a central wedge (corresponding to the shaped rod
end in previous figures) attached to F1 by bolts as shown. 20 20 are side wedges
mounted and oscillating on pins 21 21 supported by the outer ends of the cross
head with their lower ends resting on the table top to take the weight of the
thrust. 22 22 are trip projections formed on the side wedges. 23 is the cross
head made in one piece with the central rod and 'shown in detail in Figs. 18 18"
and 18. The rest of the figures is obvious. The action is as follows: When the
lifter rises it strikes the bottom of the central rod thereby lifting the side wedges
and then the trip projections striking against the projecting edges 19' 191 of the
central wedge cause the side, wedges to fall inward. When the lifter strikes the
bottom of the hollow spindle the whole apparatus lifts together.
Fig. 21 exhibits a form of split head made in halves as applied to a top die and
operated by a central rod and inclined slots as described in Fig. 2 Sheet 2 operating
on pins passing through from side to side of the split head. The rest of the
figure is obvious.
Fig. 22 is a similar form of split head made in halves as applied to a bottom
die but in this case the sides are shown tapered to form a clearance from the
undercut.
Fig. 23 is a cross elevation of the head showing the cavity for receiving the
flattened end of the central rod. The lifting of the die is effected by means of a
hollow spindle with divided ends as described in Fig. 16. The central rod lifts
with the head until clearance is effected by the die lifting above the top of the
tile box. The rest of these figures is obvious.
Fig. 24 is an alternative form of my apparatus in which the undercutters are
moved to and held in their forward position by the thrust of the spiral spring and
are made to clear the undercut by the direct action of the lifter on the bottom of
the central rod. The figure shows the central rod as lifted.
Fig. 25 is a half plan showing form of undercut.
Fig. 26 is a half section through A B in Fig. 24 showing undercutter mounted
on pin held in position by a screwed ferrule.
24 is the pear shaped head of the central rod. 25 25 are undercutters adapted
to this particular form of central rod. 26 26 are projections formed solid with
the rest of the undercutter. The descent of the central rod will throw the under-
cutting teeth into their forward or cutting position. The rest of the figure is
obvious.

page_text: Fig. 27 is a vertical section of a form of apparatus as used with a bottom die
in which the operating rods are placed elsewhere than in the centre.
Fig. 27 is a plan of the block showing the ends adapted for receiving the push
pieces.
Fig. 28 is a plan of the undercutter showing the projecting ends adapted to fit
into the corresponding slot holes shown in Fig. 29.
Fig. 29 is an elevation of the back of one of the push pieces.
27 is a top plate bolted by flush headed bolts to the top of the block 28 screwed
on to a spindle 29 of the ordinary type. 30 30 are the partially revolving under-
cutters with the long ends projecting outward and tailed so as to work loosely
into suitable holes 35 in the push pieces 31 31 sliding loosely in the recesses 32 32
formed in the block 28. 31ª 31 are flanges to receive the thrust of the spiral
springs 33 33. 34, 34 are buttress pieces constructed solid with or screwed to
the block 28. 36, 36, are steadying pins with ferrule ends as shown in Fig. 26.
Fig. 30 is a vertical section of another form of head screwed on to a spindle of
the ordinary type.
Fig. 31 is a back elevation of the undercutters.
Figs. 32 & 33 are respectively an elevation and a vertical section of the
standard 39 showing part of the base plate.
The block and top plate are formed as described in Fig. 27. 37, 37 are under-
cutters with the tail ends projecting downward instead of outward 38 is a base
plate placed between the tile box and the table top. 39, 39, are standards cast
solid therewith and formed with an inclined slot or pathway to receive and act
as guides and operate the undercutters as the block lifts or lowers. The under-
cutters oscillate in bearings as in Fig. 27 and are supported on pins with ferrule
ends as shown in Fig. 26. The rest of the figure is obvious.
Fig. 34 is a vertical section of another form of head or die alternative to that
described in Fig. 24 giving an undercut outward and.of similar form to that
produced by the the apparatus shown in Fig. 5.
Fig. 35 is a plan looking down on the top of the central rod.
The head is mounted on a hollow spindle and operated by a central rod and
spiral spring as in Fig. 24. 40 is the head or top end of the central rod made
wedge shaped with projecting horns made with slot holes 41 41 for receiving the
tail ends of the undercutters. The rest of the figure is obvious.
Figs. 36 37 and 38 are other forms of head or die mounted on a hollow spindle
and operated by a central rod and spiral spring as in the case described in Fig. 16.
Holding down springs may be used if desired. The rest of the figures is obvious.
Fig. 39 is a vertical section of a form of head or die mounted on a spindle of
the ordinary type and in which adjustable finger wedges 46 and slots in the tile
box are made to serve the purpose of a central rod and in which all springs are
dispensed with. The flattened bar portion of the finger wedges passes through
the slot cut through the side of the tile box and is itself provided with a slotted
bolt hole and is adjustably secured to the pressing table outside the tile box by
bolts not shown. The rest of the figure is obvious. The finger wedge serves also
to regulate the extent of the undercut.
Fig. 40 is a vertical section of a form of head or die alternative to that last
described in which the tile box is constructed in sections and a separate finger
wedge is dispensed with. The figure needs no further description.
Figs. 41 and 42 exhibit a modified form of apparatus in which the principle
of my invention is contained. In these cases a slide 42 as ordinarily used is pro-
vided with a flange 43 at its lower end and in addition (and instead of the ordinary
screw for attaching the die) with a projecting piece 44 arranged to enter within'
the frame H of the head. The projecting piece 44 may be shaped in divers ways
in like manner as the end of a central rod for which it is a substitute and the head
will be provided with undercutters adapted to the shape of the projecting pieces.
Between the head H and the flange 43 on the slide I insert a spring of any suit.
able form (shown in bent form at 45 at one side of Fig. 41 and in spiral form

page_text: around a steadying pin on the other side of the figure and in spiral form at 45ª
in Fig. 42) to keep the head at the end of its motion away from the flange on the
slide and thus provide the required motion for the return of the undercutters after
pressure has been applied. Guide pins as shown on the left of Fig. 41 working
into corresponding holes may be provided to keep the head steady and free from
twisting.
Since I made my invention hereinbefore described and since filing my Pro-
visional Specification I have made search to ascertain if and to what extent my
invention had been anticipated by other inventors In this way I have become
aware of amongst others the following specifications hereinafter mentioned and
in so far as any part of my invention is anticipated by them I desire to disclaim
such part. But in order to make it clear what I claim I deem it well to point out
what I think are the points of resemblance between the inventions therein
described and my invention and wherein I think my invention differs.
Messrs. Craven Dunnill & Co. in their Specification 20280 of the year 1891
show in Figs. 6 and 7 a bottom die constructed with wedge shaped undercutters
prevented from moving vertically by pins h h and operated by central wedges
attached to a moveable bottom plate. The central wedges are dovetailed into the
undercutters and as they slide up or down impart motion to the latter. I do not
claim that method. In the die used by me described in Figs. 5 to 9 my central
wedge is not connected with the undercutters nor do I use a moveable bottom
plate and the return movement of the undercutters is effected by springs mounted
on studs or pins on which the undercutters are also mounted and moreover my
invention is applicable as well to the top as the bottom die. These patentees
exhibit also the moveable bottom plate mounted on a hollow supporting column
enclosing the lifting rod but there the resemblance ceases as they do not show any
operating mechanism and by my method the head or die is mounted on a hollow
plunger or bottom spindle and the central rod is used only for producing the
movement of the wedge shaped pieces to form the undercut.
The further invention of Messrs. Craven Dunnill & Co. described in their
Specification 6661 of the year 1893, consisting of a bent form of undercutters
sliding in grooves in the head and in or on an auxiliary bottom plate presents no
point of resemblance to my apparatus except that it is operated by a tube enclos-
ing a rod as shown in their previous invention. Their method also differs from
mine in that it is applicable only to a bottom die and that the undercuts are all
on the outer edges of the underside of the tiles and in that the undercutting blades
seem all to point in the same direction relatively to the sides of the tiles which
lessens the security of the undercutting.
A still further invention of Messrs. Craven Dunnill & Co. described in their
Specification 17366 of the year 1894 consists of a casting mounted on a central
rod enclosed and moving vertically within a box or case the top of which forms
the surface of the die whilst the casting itself forms the opposite side. Upon the
sides of the casting are mounted sliding or undercutting blades made to slide
through slots in the top of the enclosing box which is supported by a spiral spring
within it and around the central rod so that the undercutting sliding pieces are
normally kept within the top of the box. When pressure is applied to the box
top it compresses the spring and so causes the sliding pieces to project through
the top to be again withdrawn when the pressure is removed. The differences
between this method and my method as described in Fig. 13 are that my heads
are rigidly enclosed on all sides and that my sliding piece is enclosed within the
head and consists of the bottom of my central rod and that the motion of the
undercutters in my case is effected through the central rod and not the hollow
tube, and that the springs in my case are in the ram or plunger and not in the
head or die and further that my apparatus is applicable to any form of head and
not merely to one such as shown by Messrs. Craven Dunnill & Co. I disclaim the
particular method described by them but adhere to my own methods herein
before and in my drawings described.

page_text: The invention described by George Viggars in his Specification No. 7198 of the
year 1896 consisting of one or a series of tumblers fitted in a recess in the bottom
die differs from my method in that my method is applicable as well to the top as
the bottom die and that according to my method the tumblers revolve on solid
bearings bored from the outside and not on pins (the pins in my case being used
only as steadying pins) and that in my case I rotate the tooth from the undercut
only and not below the die surface. I admit that his method of. operation is very
similar to that of operation by means of a slot cut in the pressing box side herein-
before and in Fig. 39 described by me also to that of a plate fitted with standards
as hereinbefore and in Figs. 30 to 33 described and I abandon those methods in
80 far as they are covered by his invention but not further or otherwise.
The invention of James Elijah Brindley described in his Specification No. 224
of the year 1897 that is to say of undercutters operating on the under edges of the
tile consisting of two pieces of metal pivotted to the bottom die of such shape
and attached together in such manner that the upper extremities separate or
recede from each other by the action of springs differs from my invention in that
it is applicable only to the bottom die it makes use of a different spring operating
in a different way and is operated by the lower ends of the working pieces sliding
on the table top and not from the central rod of a hollow plunger. I lay no claim
to undercutters of the shape and mounted and operated as described by Mr.
Brindley.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
1. In presses for the manufacture of tiles bricks and other articles from plastic
material made with undercut surfaces and in combination with a pressing die
whether top or bottom a plunger formed with a cavity in the centre and whether
or not formed of a single hollow spindle or of an inner hollow spindle or sliding
piece working within an outer partially hollow spindle or sleeve a central rod
having a short vertical motion passing through the cavity and extending beyond
each end thereof provided with a collar or fast washer thereon and mounted on a
spiral spring within the cavity one end of the rod being provided with a suitably
shaped end adapted to the forin of undercutters to be used as a means of operating
undercutters in or on the attached head or die and also operated substantially as
hereinbefore described.
2. In presses for such purpose as in Claim 1 mentioned and in combination
with a bottom pressing die and a hollow plunger constructed according to one of
the several forms herein before and in my drawings described a stop piece beneath
the table made capable of being lifted by the lifter in the usual way as a means
of operating undercutters in or on the attached head or die substantially as herein-
before described.
3. In presses for such purpose as in Claim 1 mentioned and except as herein-
before disclaimed heads or dies fitted with cross headed levers, rocking levers,
partially revolving cutters, sliding blades (with or without rotary motion) or
wedge pieces within an outer frame or made in halves or in wedge shaped sections
without an outer frame in combination with and operated by the central rod of
a hollow plunger substantially as herein before described or by one of the several
forms of apparatus in my drawings described for the purpose of producing under-
cuts in the back of a tile or other article.
4. In presses for such purpose as in Claim 1 mentioned and in combination
with a top pressing die the apparatus (other than the head or die) herein before and
in Figs. 2 to 4 of the drawings described (but without restriction as to the shape
of the part marked & in the drawings) consisting essentially of an inverted hollow
spindle end with a nut screwed into the end thereof forming a flange attached to
the pressing screw by the usual means a hollow plunger with a hole through the

page_text: centre of the top thereof and provided with a neck at the upper end thereof pro-
jecting through so as to slide freely, with a short vertical motion within the afore-
said hollow spindle end a central rod and spiral spring formed fitted mounted
and operated and operating substantially as and for the purpose herein before
described.
5. The like apparatus and for the like purpose as in Claim 4 mentioned but
modified as shown in Fig. 12 of the drawings.
6. In presses for such purpose as in Claim 1 mentioned and in combination with
a top pressing die the modified form of apparatus (other than the head or. die)
sulystantially as herein before and in Figs. 5 to 9 of the drawings described (but
without restriction as to the shape of the part marked in the drawings) con-
sisting essentially of a partially hollow spindle attached to the pressing screw by
a split-collar or other usual means and serving as the slide and an inner hollow
spindle or sliding piece with a collar formed thereon and a central rod provided
with a collar or fast washer and mounted on a spiral spring constructed operated
and operating as hereinbefore described or any modification of such apparatus
substantially the same for the purpose of operating undercutters in the attached
head or die.
7. In presses for such purpose as in Claim 1 mentioned and in combination
with a bottom pressing die the modified form of apparatus other than the head or
die herein before and in Figs. 14 & 15 of the drawings described and operated and
operating as described (but without restriction as to the shape of the part marked d
in the drawings) and whether or not the inner hollow spindle or sliding piece
is mounted on a spiral spring as shown and in which the bottom of the sleeve is
slotted and used as a stop for the central rod and the inner hollow spindle or
sliding piece is formed with a divided bottom end or any modification of such
apparatus substantially the same for the purpose of operating undercutters in
the attached head or die.
8. The like apparatus and for the like purpose as in Claim 7 mentioned but in
which the inner hollow spindle or sliding piece is mounted on a spiral spring
and in which the slot holes in the sleeve and divided ends of the inner hollow
spindle or sliding piece are dispensed with.
9. In presses for such purpose as in Claim 1 mentioned and in combination
with a bottom pressing die the modified form of apparatus other than the head
or die substantially as herein before and in Figs. 16 & 17 of the drawings described
and operated and operating as described (but without restriction as to the shape
of the part marked in the drawings) consisting essentially of a hollow bottom
plunger attached to the head or die and formed with a divided bottom end a
central rod mounted on a spiral spring within the plunger a stop piece and a cross
bar with an adjustable boss or any modification of such apparatus substantially
the same for the purpose of operating undercutters in the attached head or die.
10. In presses for such purpose as in Claim I mentioned and in combination
with a bottom pressing die the modified form of apparatus (other than the head
or die) substantially as herein before and in Figs. 18 to 20 of the drawings
described and operated and operating as described consisting essentially of a
hollow bottom plunger and a central rod mounted on a spring within the plunger
one end of which rod projects below the bottom of the plunger so as to be operated
directly by the lifter and the other end of which is provided with a cross head the
arms of which are made to pass through and slide within a recess formed in the
central section of a split head such arms being also cross headed for the purpose
of supporting the two outer parts of a head or die formed in 3 sections and
whether or not such outer parts are provided with trip projections or any modifi-
cation of such apparatus substantially the same for the purpose of operating
undercutters in the attached head or die.
11. In presses for such purpose as in Claim 1 mentioned and in combination
with a bottom pressing die the modified form of apparatus other than the head or
die hereinbefore and in Figs. 24 to 26 of the drawings described operated and

page_text: operating as described (but without restriction as to the shape of the part
marked 24 in the drawings) in which the lower end of the central rod passes
through so as to project beyond the bottom of the plunger so as to be operated
directly by the lifter the clearance of the undercutting teeth being effected by the.
lifting of the rod without crosshead or any modification of such apparatus sub-
stantially the same for the purpose of operating undercutters in the attached
head or die.
12. In presses for such purpose as in Claim 1 mentioned and in combination
with the plunger of a bottom pressing die a holding down spring whether spiral
or otherwise connected therewith as seen in spiral form at J in Fig. 18.
13. In presses for such purpose as in Claim 1 mentioned and except as herein-
before disclaimed heads or dies formed or fitted with undercutters of the several
forms in Figs. 2 & 3, 5 to 9, 10 to 13, 18, 21, 22, 24, 27, 30, 34, 36, 37 & 38 of the
drawings described constructed as described in combination with and operated by
a suitably shaped end on the central rod of a hollow plunger according to one of
the several forms herein before and in Figs. 2, 3 & 5, 10 to 13, 16, 18, 21, 22, 24,
34 & 36 to 38 of the drawings described for the purpose of producing undercuts
in the back of a tile or other article.
14. In presses for such purpose as in Claim 1 mentioned a head or die mounted
on a spindle or plunger of ordinary form fitted with undercutters in one of the
several forms herein before described operated by push pieces in lieu of a central
rod and placed elsewhere than in the centre of the die and spiral or other springs
as or substantially as hereinbefore and in the drawings Figs. 27 to 29 described
or operated by wedge pieces (as the equivalents of the shaped ends of a central rod
placed elsewhere than in the centre substantially as in Figs. 30 to 33 and 39
and 40 of the drawings described for the purpose hereinbefore described.
15. In presses for such purpose as in Claim 1 mentioned and in combination
with heads or dies intended to produce undercut surfaces the use of solid plungers
with projecting ends made to slide vertically within such heads or dies and the
general construction and arrangements of parts substantially as herein before
described and operating as described and as illustrated in Figs. 41 & 42 of the
drawings.