Improvements in Stone Dressing Machines.
Year: 1893

page_text: Norway),
Date of Application (in United Kingdom), 23rd Dec., 1893
Complete Specification Left, 23rd Dec., 1893-Accepted, 27th Jan., 1834
COMPLETE SPECIFICATION.
Improvements in Stone Dressing Machines.
I, SIGURD THORLEIF HAUSEN of Drammen Norway 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 refers to machines applicable for all kinds of working in stone by
chipping. The machine may be arranged as a fixed or as a portable machine but I
shall here only describe it as a fixed one. One feature of this machine is that the
spindles or bars which carry the chisels or tools and which generally are arranged
in a row side by side are raised from the work by means of suitable mechanism,
such for instance as a cam shaft and thereby compress a spring, by preference
compressed air, in a cylinder wherein works a piston carrying the tool bar; when
the latter is free of the raising mechanism the compressed air knocks it down upon
the work. If compressed air is used as the spring complete facility is given for
regulating at will the force of the blow upon the work by varying the air pressure.
In order however also to regulate and limit the blow so that the chisel shall not
strike deeper in soft parts of the stone than in hard I provide under the said piston
or under another piston fixed to the tool bar an air cushion which stops the piston
in its descent. In this way a powerful blow is obtained which at the same time
may be regulated exactly as to force and length of stroke according to the kind of
work. Another feature in this machine is that the tool bars with the whole
mechanism may be placed vertically or slanting as desired so that for the first or
coarse cut the chisel may be made to work under an angle against the work and
thereby imitate the position of the chisel in hand work.
The accompanying drawing shews a machine constructed with the aforesaid
features and arranged for squaring stone. Fig. 1 is a front view and Fig. 2 a side
Fig. 3 is enlarged vertical section through the box shaped frame containing
the tool bar bearings.
view.
The chisels A are fixed to the ends of a row of comparatively heavy_tool bars B
which are guided vertically in bearings C on the front wall of a box D serving as
frame for the main parts of the machine. This frame is by hollow gudgeons E
hung in blocks F which are guided between the vertical guide bars & that form
the fixed standard frames of the machine and wherein the blocks F can be slided
up or down by means of the screw spindles H, the uut I therefor in the form of a
worm wheel, and the worm J which can be rotated by chain and sprocket wheel or
in other suitable manner. The box frame D can thus be raised and lowered and
be turned round its gudgeons E so as to assume any desired slanting position and
to be held therein by means of a slotted rod K or one such on each side.
Through the hollow gudgeons E passes a spindle L which outside carries fast
and loose pulley and within the box frame is fitted with a row of double cams M
which gear with lugs N on the tool bars B. The shape of the parts M and N is
uch as to cause the least possible shock or knock each time of gearing. The

page_text: cams on the spindle may either be so arranged that they all lift all the tool bars at
the same time or so that the tool bars are lifted in succession, whereby the working
of the machine will be smoother.
To the
Each tool bar D is at its upper end provided with a piston rod O with piston F
working in a cylinder R. The cylinders R are fixed to the upper end of the box
frame and are connected with each other by a passage S which is cast on.
latter is connected a pipe from an air compressing pump by the aid of which the
desired working pressure can be kept constant in all the cylinders. In the lower end
of the cylinder is placed an annular air cushion T of rubber against which the piston
strikes when or immediately after the chisel has struck the stone. By this means
is attained that the blow is suitably checked and that the chisel can give a sharp
powerful blow of short duration which is the most suitable for working in stone.
The rubber cushion may be dispensed with if a stuffing box is provided round
the piston rod, but this may easily give rise to leakage and the action of the air
cushion suffer change. But the rubber cushion being surrounded by walls
everywhere remains unchanged as it cannot expand. At a short distance above
the rubber cushion a hole U is drilled whereby the space under the piston
communicates with the outer air; the blast produced by the descent of the piston
may be utilized for blowing away the stone dust and grit from the working face by
leading a pipe V from that hole down to the chisel. To prevent dust from being
sucked into the cylinder in the ascent of the piston a valve box W is provided
having two valves whereby the air is drawn in from above and blown out through
the pipe below.
The machine may evidently without material change be constructed with helical
springs for giving power instead of compressed air, but I believe that compressed
air is the most suitable and in the long run the cheapest.
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 1
claim is:
1. A machine for dressing stone the chisel bars or tool bars B of which are
in connection with a spring by preference in the form of a cylinder with compressed
air wherein works a piston fixed to the tool bar with a lifting mechanism which
compresses the spring so that the latter when the tool bar become free of the
lifting mechanism, causes the chisel to strike against the stone and with a cushion
which together with the piston serves to limit the downward blow substantially as
set forth.
2. In a stone dressing machine as firstly claimed the arrangement of the said
cushion in the form of an annular air filled rubber cushion T placed under the
piston and the arrangement of a pipe from a hole in the cylinder immediately
above the cushion leading down to the face of the stone for blowing air thereupon
and removing dust and grit.
3. In a stone dressing machine arranging the tool bars in a frame hung in
gudgeons in blocks which are movable up and down in the machine standards so
that the gudgeons can be shifted round in the blocks for enabling the chisels to be
worked at any desired angle to the face of the stone.
4. The construction of stone dressing machine described with reference to the
drawings.
Dated this 23rd day of December 1902.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.