Improvements in the Manufacture of Tiles and Apparatus therefor.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Tiles and Apparatus therefor.
I, WILLIAM HEWITT, trading as Godwin & Hewitt, of Victoria Tile Works,
Hereford, in the county of Hereford, Tile Manufacturer, do hereby declare the
nature of this invention to be as follows:-
This invention relates to the manufacture of tiles with undercut recesses therein
and to apparatus for forming such recesses.
In carrying out my invention I employ a circular block the face of which is
formed with a number of undercut serrations the said block being provided on
its periphery with inclines adapted to work in inclined recesses in the top or
bottom plate of the die as the case may be.
Suitable means such as springs normally keep the serrated surface of the block
projected the required distance from the surface of the face plate.
By this arrangement it will be obvious that when the die is pressed into the box
the serrated block will be moved inwards at the same time partly rotating whereby
the serrations on the block will form undercut recesses in the tile.
on the pressure being relieved the block will be turned and raised by the spring
so as to free the tile.
The serrations on the block are so shaped as to give proper clearance on being
windrawn from the tile.
In some cases the face plate is depressed to form the undercut recesses in the tile.
For discharging the tile when the die is used as a bottom plate I can employ
discharging rods in which case no spring is required.
Dated this 11th day of January 1897.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
Improvements in the Manufacture of Tiles and Apparatus therefor.
I, WILLIAM HEWITT, trading as Godwin & Hewitt, of Victoria Tile Works,
Hereford, in the county of Hereford, Tile Manufacturer, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:.
-
This invention relates to the manufacture of tiles with undercut recesses therein
and to apparatus for forming such recesses.
In carrying out my invention I employ a circular block the face of which is
formed with a number of undercut serrations or ribs the said block being provided

page_text: on its periphery with spirally arranged lugs adapted to work in corresponding
recesses or grooves in the top or bottom plate of the die as the case may be.
Suitable means such as springs normally keep the ribbed surface of the block
projected the required distance beyond the surface of the plate upon which the
back of the tiles is moulded and known as the back plate.
The ribs on the block are so shaped that they will free themselves from the
recesses in the tiles.
In some cases the back plate is depressed to form the undercut recesses in the
tile.
To enable my invention to be fully understood I will describe the same by
reference to the accompanying drawings, in which:-
Figure 1 is a sectional elevation of a tile mould constructed according to my
mvention and of the kind wherein the circular block for forming the undercut
recesses in the tiles is on the top die and adapted to free itself from the undercut
recesses formed in the tile by moving outwards relatively with the said die; and,
Figure 2 is an underside or face view of the top die;
Figure 3 is an elevation of the circular block detached; and,
Figure 4 is a face view of the same;
igure 5 is a sectional view of the back plate in which the circular block
works; and,
Figure 6 is an underside view of the said back plate;
Figure 7 is a view of the back of a tile formed in the above described apparatus ;
and,
Figure 8 is an edge view of the same;
Figure 9 is a sectional elevation of a tile mould wherein the circular block is
arranged in the lower die and adapted to free itself from the undercut recesses
in the tile by moving inwards relatively with the said die;
Figure 10 is a view similar to Figure 9 of a mould wherein a modified form of
circular block is used and wherein the die is adapted to be moved outwards
relatively with the said circular block to free the latter from the tile;
1
igure 11 is a plan view of the same below the line 11-11 Figure 10;
Figures 12 and 13 are respectively an elevation and a plan of the circular block
detached; and,
Figures 14 and 15 are respectively a plan view and a transverse section of the
plate in which the said block works;
Figures 16 and 17 are respectively a plan view and an edge view of a tile
formed in the modified mould."
Similar letters of reference indicate corresponding parts in the several figures.
a is the mould box, is the bottom die which fits into and slides within the
said mould box, c is the top die for compressing the material of which the tiles are
formed into the mould box, and d is the circular block for forming the undercut
recesses.
C
In the arrangement of my invention shewn in Figures 1 to 6 the top die c which
is formed in two parts connected by screws e, e has formed in it a circular recess f
to receive the circular block (Figures 3 and 4). In the walls of the said recess
in the back part of the die is a series of spirally arranged slots g, (Figures 5
and 6) in which work the spirally arranged lugs h, h on the circular block d,
the front or face part of the die serving as an abutment against which the
lugs h, h impinge (as shewn in Figure 1) to limit the outward movement of the
circular block d under the action of a spring i arranged behind the said block. As
shewn this spring does not bear directly against the block d but against a plate j
pivotally mounted upon a pin k on the back of the said block in order that the
spring shall not have the tendency to impart a rotary movement to the block in
either direction but leave it absolutely free to partially rotate in the desired
manner under the action of the slots g and lugs h. If desired, however, the said
plate and pin can be dispensed with the spring which may be of any suitable
kind acting directly upon the block.

page_text: It will be noticed that the recess f in which the circular block d moves is of such
depth as to permit of a backward movement of the said circular block against the
pressure of the spring i.
1, are the radial ribs or projections upon the surface of the circular block d
and m, m are the grooves between the said ribs. These ribs are undercut on one
side to form lips n, n and the tops or shoulders of the ribs and the bottoms of
the grooves are rounded, as shewn in Figure 1, so that the highest parts of the
shoulders and the deepest parts of the grooves are a short distance back from the lips
as clearly shewn in Figure 1. The object of this formation of the ribs and grooves
is that when the circular block rotates in the required direction to free itself from
the recesses formed in the tile there should be no abrading of the bottoms of the
recesses in the tile or destruction of the sharpness of the lips upon the undercut
edges of the said recesses. The said ribs 1, l'and the lugs h, h must be arranged
in such relation to each other that when in the downward movement of the die
to compress the material in the mould the circular block is pressed back into the
recess against the pressure of the spring and thereby partially rotated, the
lips n of the ribs shall be forced towards the material in order to ensure
the moulding of sharp edges to the recesses in the tile, and that when the pressure
upon the moulded tile is relieved the said block shall rotate so as to move the
lips n away from the correspondingly moulded lips upon the tile. The upper die
having been lifted the lower die is raised to bring the tile out of the mould.
The tile made in the apparatus hereinbefore described is shewn in Figures 7
and 8.
$
'
Although I have shown the upper die as the back plate the arrangement of
the dies may be reversed so that the lower die is the back plate.
In the modification of my invention shewn in Figure 9 the circular block d
instead of being carried in the upper die is carried in the lower die and is
designed to be moved below the surface of the said die 6 in order to withdraw it
from the moulded tile. To permit of this I employ what is known as double
discharging gear, that is to say, of mechanism which is capable of positively moving
the die and the circular block d relatively with one another, the die 6 being
connected by a tube with one part of the discharging gear and the circular
block d by a rod d passing through the said tube and connected to another part
of the discharging gear.
It is to be understood that the circular block when moved relatively with the
die b rotates slightly upon its axis, owing to the arrangement of the spiral lugs h
thereon working in grooves g, g-
In making a tile in this apparatus the die and circular block being in the
relative position shewn in Figure 9, the required quantity of material is introduced
into the mould and compressefl to the desired extent by the top die c. The
circular block d is then drawn below the surface of the die to free it from the tile
and then the die with the block still below its surface is raised to bring the
tile out of the mould.
The tile made in this mould is the same as that shewn in Figures 7 and 8.
In the modification of my invention shewn in Figures 10 to 15 the circular
block d is represented as provided with a series of spiral lugs o, o, Figures 12
and 13, which are adapted to work in corresponding openings 1, 2 formed in
the die as shown in Figures 14 and 15 in such a manner that the relative move-
ment of the die and circular block causes the axial rotation of the latter. The
said lugs o, o are of such length that when the surfaces of the circular block
between the said lugs are in contact with the underside of the surface plate of
the die b, the ends of the lugs o, o will project above the surface of the die (as
indicated in Figure 10) the desired extent to form the recesses in the tile. A
spring 9 which may be of india-rubber or other suitable material is arranged
in a recess in the circular block d and bears with its upper end against the under
side of the upper part of the die b tends to draw the said projecting ends of the
lugs o, o into the die.

page_text: In the die 6 below the circular block d is a series of stop pins r, r., which rest
upon a rigid base ring s and are of such length that when the die b is in its lowest
position the ends of the lugs o, o will project to the desired extent above the
surface of the die b. The discharging mechanism connected to the die 6 by
the rod b' serves by its weight to normally retain the said die in its lowest position,
at shewn in Figure 10.
The tile having been moulded in the usual manner the die b is raised, the
circular block remaining stationary as regards a vertical movement (owing to
the spring a holding it down against the pins r, r) but rotating slightly upon its
axis. When the top of the die is level with the top of the lugs o, o the bottom
of the recess f in the die 6 comes into contact with the heads of the pins r, r so
that the continued upward movement of the said die to lift the tile out of the
mould carries the circular block upwards with the die.. The shape of the recesses
formed in the tile by the circular block used in this modification will be clearly
understood by reference to Figures 16 and 17.
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
1 claim is:-
1. The improved apparatus for the manufacture of tiles wherein a circular block
having a series of ribs or projections upon its surface for forming the undercut
recesses in the tiles is arranged to have a slight rotary motion upon its axis to
disengage the said ribs or projections, from the recesses which they form in the
tiles, substantially as described.
,
2. The improved apparatus for the manufacture of tiles wherein a circular block
having a series of ribs or projections upon its surface is arranged in such relation
to the back plate of the die that under the pressure applied to the material of
· which the tiles are formed when moulding the tiles a vertical movement takes
place between the said circular block and the face of the back plate, the said
circular block also having a slight rotary movement iniparted to it, substantially
as, and for the purpose, described.
3. In apparatus for the manufacture of tiles wherein a circular block having a
slight movement of rotation relatively with the face is employed, forming the
ribs upon the surface of the said block, substantially in the manner described and
illustrated in Figures 1, 2 and 3 of the accompanying drawings.
4. Apparatus for the manufacture of tiles with recesses, constructed, arranged
and operating substantially in the manner herein before described and illustrated
in Figures 1 to 6 of the accompanying drawings.
5. The modified forms of apparatus constructed and operating substantially as
described wita references to Figures 9 and Figures 10 to 15 of the accompanying
drawings.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.