Improvements in Machinery for Cutting and Dressing Stone, Marble, Carbon, and other Hard Substances.
Year: 1884

page_text: Improvements in Machinery for Cutting and Dressing Stone,
Marble, Carbon, and other Hard Substances.
JAMES RETTIE of 27 Kirby street Hatton garden in the County of Middlesex
Engineer do hereby declare the nature of my invention for CUTTING AND DRESSING
STONE MARBLE, CARBON AND OTHER HARD SUBSTANCES to be as follows:―
.
According to my.
invention I use a frame similar in shape to that of an ordinary
saw bench to which I fit a sliding top in such manner that it may be moved
forward or backward at will Upon this frame in suitable bearings I mount
a spindle upon which I fix one or more metal dises according to the number of cuts
to be made or the shap of the moulding required Longitudinaly to the spindel
and at a convenient distance from the periphery of the disc or discs I provide
a bar which is held in position by a pair of brackets which are attached to and
project above the frame for that purpose.
Upon this bar I hinge a number of levers equal to the number of discs-each
of these levers is made to carry a small roller toothed in a similar manner to that
of the wheel of an ordinary milling or nurling tool.
When motion is given to the discs & the toothed rollers are brought in contact
with and held firmly to the peripherys of the discs by means of the levers which
are held down by springs or weights provided for that purpose the result is the
rollers are caused to roll rapidly upon the peripherys of the discs and impress
numerous indentations thereon.
I prefer to cut the teeth of the rollers diagonaly across the face one half of them
leading in one direction and the other half being cut at right angles to them so
that whilst the discs are revolving the indentations will be crossed and thus
produce upon the periphery of the discs a surface similar in character to that of
a bastard cut file.
To perform the opperation of cutting, the material to be cut is fixed firmly to the
sliding top and by its movement is pressed to the roughed edges of the revolving
discs which by contact with the material are being worn more or less but at the
same time are being continualy provided as it were with fresh teeth by the
indenting action of the rollers.

page_text: It will be readily understood that the discs may be used in cutting down to
their smallest usefull diameter without detaching them from the spindle, thus
saving much time and labour now lost in sharpening and setting in cases where
toothed discs are used, whilst a great advantage is derived from the roughed edges
of the discs when used in conjunction with sand and water,
In applying my invention for the purpose of moulding the edges or dressing the
surfaces of the material I emplow discs the peripherys of which have been shaped
in such manner that they will by their cutting action impart to the material the
required designe the roughed surface being given to their peripherys by the
indenting action of the rollers applied in the manner before described.
Dated this 24th day of November 1908.

page_text: Marble, Carbon, and other Hard Substances.
I JAMES RETTIE of 27 Kirby Street, Hatton Garden in the county of
Middlesex, Engineer, do hereby declare the nature of my said invention for
"IMPROVEMENTS IN MACHINERY FOR CUTTING AND DRESSING STONE, MARBLE,
CARBON AND OTHER HARD SUBSTANCES," and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:-
According to my invention which is represented at Figures 1 and 2 of the
annexed drawings I use a frame A similar in shape to that of an ordinary saw-
bench to which I fit a sliding top B in such manner that it may be moved forward
or backward mechanically or by hand.
Upon this frame in suitable bearings I mount a spindle C upon which I fix one
or more metal discs D according to the number of cuts to be made or the shape of
the moulding required, longitudinally to the spindle and at a convenient distance
from the periphery of the disc or discs I provide a bar E which is held in position
by a pair of brackets F attached to and projecting above the frame A.
Upon the bar E I hinge one or a number of forked levers F1 which carry guide
discs H H and also between them small rollers G toothed in a similar manner to
that of the wheel of an ordinary milling or knurling tool. When motion is given
to the discs D and the toothed rollers G brought in contact with and held firmly to
the peripherys of the discs D by means of the levers F which are held down by
springs I (or weights) provided for that purpose the result is the rollers G are
caused to roll rapidly upon the peripherys of the discs D and impress numerous
indentations thereon.
J is a roller mounted upon a bar K carried by bearings L fixed to the main
frame A; this roller J is provided with grooves around its circumference for the
edge of the discs D to move in and be guided to prevent their buckling during
the action of cutting.
I prefer to cut the teeth of the rollers G diagonally across the face, one part of
them leading in one direction and the other part being cut at right angles to them
as at Figure 3 so that whilst the discs D are revolving the indentations will be
crossed and thus produce upon the peripherys of the discs a surface similar in
character to that of a bastard cut file."
To perform the operation of cutting, the material to be cut is fixed firmly to the
sliding top B and by its movement is pressed to the roughened edges of the
revolving cutting discs D, which by contact with the material are being worn more
or less but at the same time are being continually provided as it were with fresh
teeth by the indenting action of the rollers G.
It will be readily understood that the discs D may be used in cutting down to
their smallest useful diameter without detaching them from the spindle, thus
Baving much time and labour now lost in sharpening and setting in cases where
ordinary toothed discs or circular saws are used whilst a great advantago is derived

page_text: from the roughened edges of the discs D when used in conjunction with sand and
water. In applying my invention for the purpose of moulding the edges or
dressing the surfaces of any hard material I employ discs D³ as shown at Figure 4,
the peripherys of which have been shaped in such a manner that they will by
their cutting action impart to the material the required design the roughened
surface being given to their peripherys by the indenting action of the indenting
rollers G applied in the manner before described.
In the drawings I have shown the rotation of the discs D being effected by spur
gearing M M from a driving shaft N whose opposite end has a fast and loose
pulley P, Q, but it may be driven direct the movement of the sliding top B being
effected mechanically by the gear R.
When the dimensions of the material to be cut is too great to admit of it being
done by the circular cutters D I employ an endless flat metal band the cutting
edge of which is roughened in the same manner as the peripherys of the discs D,
this endless metal band may be actuated by pullies similar in manner to that of an
ordinary band saw and may be worked vertically, horizontally or diagonally as the
circumstances require, and may in its application be employed with or without
sand and water according to the character of the material to be cut.
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
I claim is
The application of milling or knurling tools to the cutting edges of metal cutters
for the purpose of roughening or toothing them continuously and simultaneously
with their blunting or wearing away during the operation of cutting stone, marble
carbon or other hard substances as herein described and illustrated by the accom-
panying drawings.