Improvements in the Manufacture of Concrete Paving Slabs, and in the Machinery therefor.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Concrete Paving Slabs, and in
the Machinery therefor.
I, HERBERT HENRY HODKIN 22 Empire Road, City of Sheffield, Concrete
Worker, do hereby declare the nature of my invention to be as follows:-
My invention relates to the manufacture of concrete slabs such as are used for
footpaths and other analogous purposes and to the apparatus used therein.
The chief part of the apparatus consists of a table with a planed metal top upon
which are arranged four adjustable strips forming a rectangular frame which may
be reduced or enlarged to suit the size of the intended slab.
The strips which are preferably of usual configuration of angle iron are secured
in the desired position by bolts passing through slots both in the strips and also in
the table top; and through the table top within the frame I arrange a number of
lifting pins, which normally are flush with the table but can be simultaneously
raised by means of one or more treadles under the table, and be retained in such
raised position until released.
Metallic lifting plates of the various sizes of the different slabs are also used;
one of these plates is placed within the frame before mentioned fitting easily therein
and resting upon the table.
The concrete is then filled within the frame and rammed solid over all its area
and against the sides of the frame, the surface is then levelled by means of a metal
straightedge and when this is done the foot lever or treadle is pressed down forcing
up the pins and raising the lifting plate with the concrete slab in its semi-plastic
condition, above the edge of the frame.
.
Suitably constructed lifting keys are then inserted into holes in the edges of the
lifting plates by which the plate and slab are carried to the stacking frame.
The stacking frame consists of corner pieces of peculiar construction, which can
be built up, one upon another as high as required; they interlock one with another
and also with the edges of the lifting frame, so that the whole frame is bound
together and accidental displacement is avoided.
The locking action is effected by means of vertical tongues and grooves, and the
lifting plates have depending edges which fit into corresponding grooves formed in
a projection upon each corner piece.
When slabs of greater depth than that of the frame are required, loose strips are
inserted under the sides of the frame to raise them to the desired height.
•
Dated the 13th dow of Ano 1905

page_text: Improvements in the Manufacture of Concrete Paving Slabs, and in
the Machinery therefor.
I HERBERT HENRY HODKIN of 22 Empire Road City of Sheffield, Concrete
Worker do hereby declare the nature of this invention and in what manner the
same has to be performed, to be particularly described and ascertained in and by
the following statement :-
My invention relates to the manufacture of concrete slabs, such as are used
for footpaths and other analogous purposes and to the apparatus used in such
manufacture.
The apparatus is illustrated in the annexed sheet of drawings, in which:
Fig. 1, is a perspective view of the table upon which the slabs are moulded.
Fig. 2, a perspective view of the stacking frame with the slabs in position.
Fig. 3, an enlarged perspective view of one of the corner pieces.
The chief part of the apparatus consists of a table A, having a perfectly flat top,
which preferably is made of metal having its top surface planed true, and upon
which I arrange four adjustable metal strips or frame sides B, which form a
rectangular frame capable of being enlarged or reduced to suit the size of the
intended slab.
The strips or frame sides B, are preferably made of angle iron, and are secured
to the table top by means of bolts and nuts C, passing through slots in the strips
aud also through the table top.
4
Within the frame a number of lifting pins D, pass through the table in corre-
sponding holes, and underneath the table they combine and are secured to the end
of one or more levers E, by which they can be raised from their normal position
which is flush with the table top, to the height of the strips, either more or less, by
the action of the foot upon the foot levers E.
The foot levers are retained when pressed down by a catch action in the guide
piece H, which may simply consist of a side notch into which the lever will
automatically spring when pressed down by the foot, or other equivalent device.
Metallic lifting and carrying plates F, seen in Fig. 2, of the various sizes of the
different slabs, are also used; one of these plates is placed within the frame, or
space formed by the strips B, before mentioned, fitting easily therein and resting
upon the table.
The concrete is then poured within the frame and rammed into a solid mass, so
as to fill the frame, and the surface is levelled by means of a metal straightedge.
When this is done the foot lever E, is pressed down which forces up the lifting
pins D, raising the plate with the slab of concrete in its semi-plastic condition
above the edges of the strips or frame B, in which position it is sustained by the
beforementioned catch.at H, until it is removed by the attendants.
'
Suitably formed keys are inserted into holes made in the edges of the metal plate
upon which the slab rests, and the plate and slab are carried to the stacking
frame.
↓
The stacking frame shown in Fig. 2 consists of a number of corner pieces G, of
peculiar construction which can be built up one úpon another as high as required,
one set of four being required for each slab S.
Each corner piece is a facsimile of the others so that they are interchangeable,
the narrow top part G2, fits into the opening G³, of the piece above, the edges of
which are bevelled to fit into the grooves in the edges of G³.
A corner bracket G', upon which the corner of the carrying plate F, rests, is
provided with a groove G', which engages with a corresponding ridge or strip upon
the underside of the plate F, by which arrangement the several parts interlock and

page_text: are bound together and any accidental displacement is avoided. Other equivalent.
means may he employed, such as a pin upon the corner bracket G* and a hole or
recess in the underside of the plate.
When slabs of greater depth than that of the frame are required, loose strips or
washers may be inserted under the strips B, to raise them to the required height.
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 the construction of concrete slabs, a table fitted with adjustable strips.
forming a slab frame, vertically moving raising pins for lifting the slab out of
the frame, and one or more foot levers for operating same, as herein before.
described, and substantially as shown in Fig. 1 of the drawings.
2. In the manufacture of concrete slabs, a stacking frame, consisting of coruer
pieces which interlock with each other, constructed in the manner hereinbefore-
described and as shown in Figs. 2 & 3 of the drawings.
3. The system or method of manufacture of concrete slabs by moulding them in
an adjustable frame fixed upon' a table, raising them from the frame by foot levers,.
and stacking them in a specially constructed stacking frame which is built up with.
each slab of concrete substantially as hereinbefore described and set forth.
Dated the 8th day of May 1896.
ROBT. F. DRURY, C.P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant..