IMPROVE- MENTS IN PREPARING THE SURFACES OF SLABS OR SHEETS MADE OF FIBROUS AND CEMENTING MATERIALS
Year: 1857

page_text: LETTERS PATENT to Charles Frederick Bielefeld, of Wellington Street,
Strand, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN PREPARING THE SURFACES OF SLABS OR SHEETS MADE OF FIBROUS
AND CEMENTING MATERIALS."
Sealed the 23rd September 1857, and dated the 9th April 1857..
PROVISIONAL SPECIFICATION left by the said Charles Frederick Bielefeld
at the Office of the Commissioners of Patents, with his Petition, on the
9th April 1857.
I, CHARLES FREDERICK BIELEFELD, of Wellington Street, Strand, in the
County of Middlesex, do hereby declare the nature of the Invention for
"IMPROVEMENTS IN PREPARING THE SURFACES OF SLABS OR SHEETS MADE OF
FIBROUS AND CEMENTING MATERIALS," to be as follows:-
This Invention has for its object improvements in preparing the surfaces of
slabs or sheets made of fibrous and cementing materials. Heretofore in order
to prepare the surfaces of such slabs and sheets it has been usual to render
the same even and smooth by hand, by planes, rubbers, or otherwise. Now I
have found, after a series of experiments, that more uniform surfaces may be
produced on such fibrous slabs or sheets and at less cost by mechanical means.
of
The combinations of machinery necessary for carrying out such process
5 rubbing may be considerably varied; but the essential feature of the machinery
required is, that rubbers of burr stone or of other suitable material should be

page_text: caused to pass over the fibrous surfaces to be prepared in such manner that
the lines of action on such surfaces may be constantly varying, and for this
purpose it is considered most desirable that not only should the rubbing
surfaces have a regular motion communicated to them, but that the fibrous
slabs or sheets should also have motion communicated to them in a direction
to cross the motion communicated to the rubbing surfaces. The arrangement
of machinery preferred consists of a revolving disc or discs or holders having
burr stones fixed or set therein, which works with a table or bench having a
reciprocating motion communicated thereto; or the compound motions may be
communicated to one of these parts, whilst the other part of the machine
remains stationary. This mechanical rubbing is not only applied to render
the fibrous surfaces even preparatory to receiving facing compositions, but
also after such facing compositions have been spread or applied on such
surfaces.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Frederick Bielefeld in the Great Seal Patent Office
on the 9th October 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
FREDERICK BIELEFELD, of Wellington Street, Strand, in the County of
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Ninth day of April, in the year of our Lord. One
thousand eight hundred and fifty-seven, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Charles Frederick Bielefeld, Her special licence that I, the said Charles
Frederick Bielefeld, my executors, administrators, and assigns, or such others
as I, the said Charles Frederick Bielefeld, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN PREPARING THE SURFACES OF SLABS OR SHEETS MADE
OF FIBROUS AND CEMENTING MATERIALS," upon the condition (amongst others)
that I, the said Charles Frederick Bielefeld, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Invention,

page_text: and in what manner the same was to be performed, and cause the same to
be filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Charles Frederick Bielefeld, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say:-
This Invention has for its object improvements in preparing the surfaces of
slabs or sheets made of fibrous and cementing materials. Heretofore in
order to prepare the surfaces of such slabs and sheets it has been usual to
render the same even and smooth by hand, by planes, rubbers, or otherwise.
Now I have found, after a series of experiments, that more uniform surfaces
may be produced on such fibrous slabs or sheets and at less cost by
mechanical means. The combinations of machinery necessary for carrying
out such process of rubbing may be considerably varied; but the essential
feature of the machinery required is, that rubbers of burr stone or of other
suitable material should be caused to pass over the fibrous surfaces to be
prepared in such manner that the lines of action on such surfaces may be
constantly varying, and for this purpose it is considered most desirable that
not only should the rubbing surfaces have a regular motion communicated to
them, but that the fibrous slabs or sheets should also have motion com-
municated to them in a direction to cross the motion communicated to the
rubbing surfaces. The arrangement of machinery preferred consists of a
revolving disc or discs or holders having burr stones fixed or set therein,
which works with a table or bench having a reciprocating motion com-
municated thereto; or the compound motions may be communicated to one
of these parts, whilst the other part of the machine remains stationary. This
mechanical rubbing is not only applied to render the fibrous surfaces even
preparatory to receiving facing compositions, but also after such facing.
compositions have been spread or applied on such surfaces.
And in order that my said Invention may be most fully understood and
readily carried into effect, I will proceed to describe the Drawings hereunto
annexed.
DESCRIPTION OF THE DRAWINGS.
a machine which I employ for preparing or grinding the surfaces of rough
slabs or sheets made of fibrous and cementing materials. a is the main axis
of the machine, which is driven by a strap passing over the pulley a¹; the

page_text: bevelled wheel a², mounted on the same axis, drives the bevelled wheel b, and
so gives motion to the spur wheel c, which is mounted on the same axis. On
the axis dis another spur wheel e, working with and driven by the wheel c.
At the lower end of the axis dis mounted the circular cast-iron frame f
baving at its periphery a series of triangular apertures for receiving pieces of
burr stone f, f, which project beyond the under surface of the frame, and are
fixed in their places by screws passing through the frame, and also by plaster
of Paris or other cement. The slab or sheet to be acted on by the grinding
surfaces is placed on the table g, which receives a to-and-fro longitudinal
motion along the rails h, the wheels g', on which the table runs, resting on
these rails. And in order to convey the necessary movement to the table,
racks g, g, are fixed to its under side, and into these pinions h (shown by red
lines in Figure 2) work: On the same axis as these pinions there is a large
spur wheel h¹, which is driven by the pinion i, mounted on the axis of the spur
wheel, and this receives motion from the pinion j, on the axis of the conical
pulley, and the amount of the motion so transmitted may be varied as
required by shifting the band which passes between the conical pulley j¹ and
the corresponding pulley & from one groove to another of the pulleys. On the
axis of the pulley k are mounted three drums k, l, l; the centre drum is
fixed to the axis, and the other two run loosely thereon from these drums to
the small drum a: On the axis a two leather belts pass, and one of these
belts is crossed between the drums; therefore, when the belt on the pulley k²
is changed, by pushing the belt which was previously driving on to its loose
pulley, and at the same time drawing the other belt on to the fast pulley, the
motion of the table g will be reversed, and the two leather belts are in this
way shifted by a fork, which receives motion from levers so arranged as to be
acted on by pins placed in holes in the edge of the table; and by changing
these pins from one hole to another, the distance over which the table travels
can be adjusted to the size of the slab or sheet under treatment. The
pressure of the grinding surface on the slab or sheet is regulated by changing
the position of the counterbalance weight on the lever m; and when it is
required to raise the grinding surface entirely off the table to remove
the slab or sheet, or for other purposes, the hand lever n is employed.
In order to prevent the grinding surfaces from being removed more than
the required quantity from the surface of the slab or sheet the screw stop o
is employed, and this, when the grinding surfaces have descended to the
required extent, come in contact with the nut p on the suspension rod p¹.
At the upper part of the screw stop o is a worm wheel, with which works a
screw on the extremity of the axis q, and this axis by means of bevilled pinions

page_text: receives motion from the axis r, so that by turning the hand wheel at the
extremity of this axis the stop o may be raised or lowered, as required: In
order to assist the grinding action of the burr stones, sharp grit is spread 'on
the surface of the slab or sheet during the operation. When a uniform surface
has been obtained the slab or sheet is coated with a surfacing composition,
and when this composition is hard the slab or sheet is removed to another
machine, of which Figure 4 is a plan, and Figure 5 a longitudinal section.
This machine is for the purpose of given a uniform surface to the composition.
a is the main axis, and a² is a pinion mounted thereon; this takes into and
drives the spur wheel 6 on the axis 6, which has at its other extremity a
disc b. 3 is a pin fixed to the face of the disc 62; and c is a connecting rod,
connecting the pin b and the rocking frame d, which thus receives a to-and-fro
motion, the amount of this motion depending on the position of the pin 6³ on
the face of the disc 6, and this may be adjusted as required by sliding it in a
slot formed for the purpose on the face of the said disc. Figure 6 is a front
view of the frame d, showing the way in which it is supported on the centres d';
at its upper part it receives the ends of the several connecting rods e, c, and
through these its motion is communicated to the rubbers f, f, formed of
cast or wrought-iron frames, having stones of a fine grain, or felt, or other
suitable material set in them. 9, 9, are small guide rollers to prevent the
connecting rods e, e, swaying from side to side during their to-and-fro move-
ment.
The slab of material to be prepared is placed on the table h, which is
supported on wheels h', and is capable of traversing longitudinally on the rails i, i,
so as to expose every part of the slab to the action of the rubbers. The longi-
tudinal motion is given to the table by means of a screw j, having at one of its
sides a bevilled toothed wheel k, which receives motion from the shaft / by
means of the bevelled wheels m, n, o, and the intermediate shaft p.
The shaft may be driven by means of crossed bands shifted from fast to
loose pulleys thereon, as already described in reference to Figures 1, 2, and 3.
Figure 7 is a plan of a machine of the same description as that shown at
Figures 4 and 5, but so modified that two tables and sets of rubbers
may be
used in combination with one rocking frame d. Figure 8 is a side view of a
machine arranged in a somewhat different manner from that shown at
Figures 4 and 5, but which may be employed in lieu thereof. a is the main
axis, which by means of the bevilled wheels e and c drives the vertical shaft d.
On this shaft the four arms e, e, e, e, are mounted, (they are shown in plan at
Figure 9.) Each of the arms e carries a shaft f, having at its lower extremity
a circular rubber g, constructed, as already described, of an iron frame, in which
a surface of grit stone is fixed, and at its upper extremity a toothed wheel h,

page_text: taking into the teeth of the fixed circular rack i, so that when the machine
is in motion the rubbers g, g, have a compound movement given to them, that
is to say, they all revolve round the central axis d, and at the same time they
each rotate on their own axis f. The slab or sheet to be acted on is placed on
the table j, which has a longitudinal to-and-fro motion given to it in the way
already described.
Having thus described the nature of my Invention, and the manner of
performing the same, I would have it understood that I do not confine myself
to the details of the machines shown by the Drawings; but what I claim is,
the improvements herein described in preparing the surfaces of slabs or sheets
made of fibrous and cementing materials.
In witness whereof, I, the said Charles Frederick Bielefeld, have hereunto
set my hand and seal, this Ninth day of October, in the year of our
Lord One thousand eight hundred and fifty-seven.
Witness,
JNO. ALCOCK.
CHARLES F. BIELEFELD. (L.S.)