Improvements in Hollow Building Blocks, and Apparatus for Making the same.
Year: 1897

page_text: Date of Application, 2nd Feb., 1897-Accepted, 29th May, 1897
Improvements in Hollow Building Blocks, and Apparatus for
Making the same.
A communication by EDWARD GODDARD DURANT, of Pasadena, California, United
States of America, Manufacturer.
I, WILLIAM PHILLIPS THOMPSON F.C.S., M.I.M.E., of The Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester, both in
the County of Lancaster, 118 New Street, Birmingham in the County of Warwick,
and 322 High Holborn in the County of Middlesex, Civil Engineer, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to hollow blocks made of burned clay, to be used as substitutes
for brick or stone in the erection of buildings, and in mechanism for making the same,
as hereinafter more fully set forth.
The object of this invention is to produce hollow building blocks of the various sizes
and forms required to form the walls of buildings, and to produce on one or more of
the surfaces of said blocks any style of ornamentation or figures desired; also to make
the surface of various colors, and to perforate the upper and lower walls of said blocks,
all to be accomplished by machinery, and preferably at one operation.
in
In carrying out this invention, fire clays or shale clays are preferably selected which
vitrify when burned, such as are used for terra cotta, being careful to select those
varieties that will give the most desirable tints or colors when burned, and that will
have the greatest strength. The clay is pulverized and reduced to a plastic condition
and is then formed into hollow blocks of the requisite form
suitable manner,
any
and size, by machinery.
For this purpose a machine is employed in which the plastic clay is forced by a
worm, screw, or piston, out through a tubular mold and cut off into lengths to
form blocks, in a manner well known among the manufacturers of brick, there being
many forms of these brick machines in cominon nse, and which therefore need not be
further described.
To adapt such a machine to the manufacture of these blocks, a tubular mold of the
proper form is secured to its mouth to impart to the clay as it is forced through the
same the desired form both external and internal.
Figs. 1, 2 and 3 are views of a mold for forming, embossing, perforating and
applying coloring material to the hollow blocks,--this particular mold being designed
to form blocks with a longitudinal partition in the center, the form of said blocks being
shown in perspective in Figs. 11 and 12, in cross section in Fig. 6, and in longitudinal
transverse section in Fig. 4.
The construction of the mold is shown in Figs. 1, and 3; Fig. 1 being a side
elevation; Fig. 2 a longitudinal vertical section, and Fig. 3 a horizontal section at
right angles to Fig. 2.
The mold consists of a rectangular tute A, inside of which are secured two smaller
tubes or cores B, B, there being a space for the passage of the clay Call around
between the walls of said tubes, this space being of a width equal to the thickness
that the walls of the block are to have, and which may be more or less as desired. By
forcing the plastic clay lengthwise through this tubular mold, there will be formed a

page_text: continuous hollow body of clay of the form shown in Fig. 1, and which as it protrudes
is automatically severed at right angles (by a cutting device such as is common in this
class of brick machines, and therefore not shown in the drawings), thus forming a
series of hollow blocks of uniform length and size.
As shown in Fig. 2, the top wall of the tube A is cut away to permit an embossing
roll to impinge upon the plastic clay as it emerges, and impress upon its upper
surface such figures as the surface of the roll shall be provided with, and which may
be of any style of ornamentation desired, the clay being supported against the
pressure of the roll during this operation, by the inner tubes or cores 13.
In order to produce perforations in the top and bottom walls of the blocks, two
wheels D, D, are provided and mounted at opposite sides of the mold as represented in
Fig. 3, the exterior walls of the mold A being cut away opposite the wheels as shown
to permit the tubular punches c to come into contact with and perforate the clay as it
is forced outward from the mold.
As shown in Fig. 3, the punches c project at right angles from a body which has at
each end a, a cylindrical journal mounted loosely in ears d, d, so as to slide to and fro
therein, the punch being prevented from tipping sidewise by transverse pins or
studs 0, which bear in slots in another pair of ears e, as shown. On the journals at
each side of the punch is placed a spring f, as shown, to ensure the punch assuming its
proper position when it enters the clay.
These perforating wheels may be rotated by contact with the clay as it is forced
outward, or by power; and spurs or points are arranged intermediate of the punches
to engage with the clay while the punches are not in contact therewith, and thus
cause the wheels to have a continuous and uniform movement, so as to bring the
punches into position to form the perforations at uniform distances.
Other devices may be substituted to make the perforations, but these are found to
answer the purpose, and hence are shown.
In order to impart to the embossed face of the blocks a different color or tint,
directly over the embossing roll F a hopper H is located as shown in Figs. 1 and 2, it
being provided with a feed roll and an adjustable slide g, for feeding and regulating
the coloring matter which is applied to the face of the roll and by it transferred to the
face of the clay.
This coloring matter is to be applied in a finely pulverized condition, to the entire
face of the roll, from which it is taken by the plastic clay as it passes under the roll,
thus coating that face of the block with a thin layer of the coloring matter. It also
serves to prevent the clay from adhering to the roll, and thus enables the latter to
leave upon the face of the block a clean sharp impression, whatever the figure or
ornamentation upon the surface of the roll may be.
The coloring matter may consist of a clay which when burned will be of a different
color or tint from that of the block itself it being well known that different clays
when burned will be of different colors or shades, depending upon the chemical and
mineral constituents of which they are composed.
Various mineral oxides may also be used as the coloring material, their selection
being determined by the chemist or person in charge, who is supposed to know in
advance what color, shade, or tint each will produce when burned in connection with
the clay, or can easily ascertain by experiment.
By these means, blocks for belt courses, cornice, caps and sills for doors and
windows, and other ornamental purposes can be readily produced, of any color or
shade desired, the blocks for the walls of the building being usually left of the
natural color produced by the baked clay.
From the foregoing description, it will readily be seen that hollow blocks of any
desired form in cross section may be produced by using a tubular mold of the
form desired; and that such blocks may have their outer face ornamented with any
style of figures, marks, or grooves desired, and be either left of the natural color
produced by the clay of which they are formed, or may be colored or shaded as
desired.
The blocks T may be made with or without the partition, and of any size desired;
:

page_text: 4
but for convenience in laying them in a wall, they are usually made 16 inches long,
8 inches high, and 4, 6, 8, 10, and 12 inches in width.
The block which is preferred for ordinary walls is shown in Fig. 11. It is formed
with three ribs o, on its upper and lower surfaces, these ribs being located directly
over the vertical walls, so that when laid in a wall as shown in Fig. 12, the entire
pressure will be thrown upon the vertical walls.
Upon the inner faces of the top and bottom walls of the blocks, a rib k is formed
adjacent to the side walls, as shown more clearly in Figs. 4, 6, 11 and 12.
In order to secure accurate alignment of the blocks in the wall, and an air tight
joint, joint strips are provided as shown in Fig. 5. These joint strips have their
outer faces coated with cement, one end being inserted between the outer wall and
the rib as shown in Fig. 12, and then the next block in the course is crowded
end wise toward the one already laid, as shown in Fig. 4, thereby causing the other
end of the joint strip to enter between the ribs and wall of that block.
It will be seen that as the blocks are forced together end wise, they will be brought
into exact alignment, and that a perfectly tight joint will be secured, the joint on the
In lieu of these
outer face being subsequently filled or tucked in the usual manner.
ribs and strips, thimbles of the proper size to fit in the ends of the blocks may be
used to accomplish the same purpose, these being more especially adapted to unite
columns and vertically arranged blocks formed in sections. By this method of
.forming the joints it will be seen that they can be made air tight, and that even if the
mortar should be removed from the joint between the ends of the blocks outside of
the joint strips, the joint would still be air tight; and thus each course of blocks will
form a continuous air chamber on each side of the partition l.
In order that the air chambers in one tier of blocks may be connected with the air
chambers in the tiers above and below, the perforations a in the top and bottomn walls
of the blocks are so located that when the blocks are laid so as to break joints as
shown in Fig. 12, the perforations in one tier will register with those of the tiers
above and below, and thus there will be formed a wall having an inner and an outer
air chamber, extending, from, bottom to top of the wall; or, if the wall be built of
single instead of double blocks, then it will have a single air chamber within it, these
air chambers serving to exclude heat cold and moisture, and may be used for the
purposes of warming and ventilation if desired.
The perforations may also be used for inserting electric wires, or pipes for conveying
gas, water, compressed air or refrigerating fluids for cooling the rooms as may be
desired by the owner or occupant.
In order to close these air chambers at the corners of the wall, or wherever openings
are to be formed in the wall, blocks V Fig. 12 are provided and inserted of the
proper size, these blocks being set. with their open ends at top and bottom, their solid
sides thus closing the ends of the air chambers in the tier.
As shown in Fig. 8 these corner blocks V are provided on two of their exterior
faces with ribs or projections n to engage in the open ends of the adjoining horizontal
wall blocks T, thereby locking them securely in place. Or, in case a door or
window be located next to these corner blocks, these exterior ribs n, serve to lock the
frame L in place, as shown in Figs. 8 and 8B.
In, like manner ribs are formed on the exterior faces of angle blocks M
and N, as shown in Fig. 8, so that when set they will be securely locked to each
other.
:.
It is obvious that the caps, sills and jambs for doors and windows may be made
in the same manner, as shown in Fig. 13, in which R indicates the cap, N the jamb,
and P the sill of a window—the jamb N being made either of full length, or of sections
as may. be preferred..
-
In Fig. 7 a portion of a sill on a larger scale is shown, its upper face being inclined
to shed the water, as is customary.
The jambs for doors and windows are made as shown in Figs. 9 and 10, with
lips or projections u to engage with the ends of the adjoining blocks, so as to lock
them securely in place, these lips being arranged to fit within, or outside of the

page_text: abutting blocks, as preferred. In Fig.
the jamb is shown provided on its opposite
face with two projections or ribs t, t, thus forming a recess in which the door or
window frame W is set and securely held.
Fig. 10 represents another form of jamb, with the wooden trimmings applied to
complete the inside finish, the space inside forming a box for the weights which
balance the sash and glass.
In order to build projecting or bay windows, which have other than right angles,
angle blocks M are made as shown in Figs. 8 and 8A, which are provided with
vertical ribs to interlock with jambs N as shown. In Figs. 8 and 84, L represents
the wooden frame locked in the face of the jamb N, and S indicates the sash of a
window.
These angle blocks may be made with their sides standing at any desired angle, and
thus be adapted to form bay windows or other projections at any angle to the main
wall desired. They are also provided with interlocking ribs as shown, so that when
set, all will be securely locked in place.
Columns for porches, etc. will be made of the same material, round, square,
octagonal or fluted, with suitable caps and bases made by hand molds or otherwise,
and of full length or in sections; and thus the walls, porches, etc. may be made entirely
of terra cotta.
From the foregoing description it will be seen that by means of suitably shaped
molds any desired form may be imparted to the blocks; and that by means
of suitable embossing rolls they may have any style of figure or ornamentation
impressed upon their exposed face, and that they may be made of any color or shade
desired.
The advantages of this building material are many, and apparent. It is fireproof,
is indestructible by exposure to the elements, will form a wall which will prevent the
passage of moisture to the interior, and will afford a much better protection against
both heat and cold than a solid wall of either brick or stone. Being many times
lighter than brick or stone, their transportation is correspondingly less, and being
very much larger than brick, a wall can he laid much more rapidly and cheaply. By
their use buildings can be made far more ornamental with little or no increase
in cost.
Actual tests show that these blocks possess a strength may times in excess of
the weight they are required to sustain in an ordinary building; and for basement
walls, or any place where extra strength is required, it is only necessary to make them
with thicker walls, and which can be readily done by simply using an inside mold or
core of less diameter.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me
by my foreign correspondent, I declare that what I claim is :―
1. A tubular building block composed of baked clay or terra cotta constructed
with internal ribs for the reception of joint strips as shown, whereby it is adapted for
use in the construction of walls for buildings.
2. Forming the blocks with exterior ribs o as shown, so that when laid in a
wall the weight or pressure will be directly over or on the vertical walls of said
blocks.
3. A rectangular tubular building block having perforations in its upper and
lower walls so located that when the block is laid in a wall the perforations
will register with the perforations in the blocks above and below it, as shown and
described.
4. Uniting the open ended tubular blocks or sections by means of the ribs k
and joint pieces i, or by thimbles adapted to fit in the adjoining ends of the blocks or
sections.
5. The corner blocks V provided with exterior ribs or projections n arranged to
engage in the open ends of the wall blocks, or with frames L, substantially as shown
and described.

page_text: 6. Angle blocks M N provided with interlocking projections and recesses substan-
tially as shown and described.
7. A hollow jamb block, provided on one face with ribs or projections to receive
and hold a frame, and with ribs or flanges on its opposite face to lock it to the
adjoining wall blocks, as shown and described.
8. In a machine for forming hollow building blocks, the combination of the tubular
dies and the wheels D provided with punches for forming perforations in the
walls of the block, as the clay is forced out of the die, substantially as shown and
described.
9. In combination, the forming dies A, B, the embossing roll F, and the hopper H
arranged to deliver coloring material to the embossing roll, said parts being arranged
to operate substantially as and for the purpose herein described.
Dat this 1st day of February 1897
WM. P. THOMPSON & Co.,
Agents.