Year: 1894

page_text: Date of Application, 16th Jan., 1894-Accepted, 24th Feb, 1894
16g pa
France, Marble Mason, 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 is designed to facilitate the cutting of stones and other hard
mineral substances, and consists of forming the teeth of the saw separately from
the blade, by the insertion of specially prepared cutting points with a chisel shaped
end, made of a fine quality of tempered steel, such as that known as diamond steel,
Wolframm steel or by other names. These teeth are so attached to the blade or
plate of the saw that they can be removed for sharpening or renewing.
I will now describe the invention with reference to the accompanying drawings
in which
Fig. 1, shows a portion of a saw furnished with adjustable teeth A.
Fig. 2, shows part of a saw fitted with reversible teeth D which are sharp at both
ends.
Fig. 3 shows a section of Fig. 1 at the line O-P.
Fig. 4, shows a section of Fig. 1 on the line QR Fig. 1.
Fig. 5, shows the application of my adjustable teeth to a circular saw.
Fig. 6, shows the application of my invention to a straight saw.
Fig. 7, shows a front and side view of a band saw constructed on my system,
which is applicable also to many other kinds of saws.
The figures lettered A to N at the top of the drawing indicate various forms.
which the said teeth may assume at their cutting edges. When made to cut at
both ends they can after being worn down in use, be reforged if desired, or being of
small value can be thrown away and replaced with new. They can be set in the
saw S at a distance of about 10 or 12 centimeters apart the interstices forming a
space to contain the waste material made during the travel of the saw. They are
maintained in position by a spring T and a pawl U Figs. 1 and 2, so that they
cannot escape during work. When used at one end and become blunt or worn, they
are turned, and when again blunt are replaced with others or reformed as before
stated. When used on soft stone they will last a long time, and when used on a
hard stone such as the volcanic stone of Volvic the cost is inconsiderable not
exceeding four pence or thereabouts per square metre.
The double-ended type of tooth as shewn in Fig. 2 is however less advantageous
for most purposes than those shown in Fig. 1, which can be made of a superior
quality of steel, and consequently cost more. The reason of this superiority is that
a high-grade steel which does not require to be tempered so carefully, does not so
soon lose its temper in use. The length of these teeth is about 100 millimetres and
they lose about one and a half millimetres each time they are sharpened. The
plate of the saw in which they are fixed is grooved to receive them in line, with a
gradually diminishing length. Supposing forty-five teeth to be set in a saw, the
last would probably become reduced from 0.034 millimetres before use to
0.032 millimetres after work. Each time the teeth are sharpened the smallest
is replaced by a new one, and all are moved backward one step. In this way each
tooth passes through forty-five different places in the saw. I estimate the cost
inclusive of sharpening as scarcely one centime per square metre for soft stone and
seven to eight centimes for Volvic hard stone. The operation of sharpening
requires motive power which I estimate at about four centimes per horse
per hour.

page_text: In all the outlines shown the teeth are applied to strong plates of which the
thickness is necessary both for circular, cross cut, and vertical saws, but in the case
of band saws, the blades of which are thin in order to pass round the pulleys the
outlines C, and D, are not applicable, but the others are. I have shown only
fourteen outlines of teeth, but they might be multiplied indefinitely.
In the band saw I would remark that the invention is applied similarly to that
for cross-cut saws except that the plate is made wider to give the strength required
and the pulleys I, must be of large diameter because of the width of the plates and
their consequently decreased pliability. The driving pulleys may have projecting
tenons to engage with the recesses o, between the teeth of the saw, to prevent the
teeth slipping in passing over the pulley as in consequence of the stone dust falling
from the teeth of the saw at each revolution it is difficult to obtain the necessary
adhesion. Referring to the band saw the carriage on which the stone is placed
advances automatically with a regulated speed of about 0-001-0-015, 0.002 milli-
metres whilst the ribbon saw traverses the distance from one tooth to the other
and in order to give a better bite to the teeth the carriage is set at an acute angle
of about 88° in place of a right angle. The speed of the ribbon saw is about
twelve to fifteen centremetres per second. This machine will cut blocks two
metres in height provided the ribbon saw is kept well stretched and cannot oscillate
from right to left. Another application of my movable teeth consists in a straight
or cross cut saw fixed in an inclined position and against which the stone is
gradually advanced. The stone is carried forward upon a carriage to which is
attached a steam engine travelling on a toothed rail or rack or by some other
mechanical device.
Having now particularly described and ascertained the nature of my said inven-
tion, I declare that what I claim is :
The method of making saws with removable adjustable teeth for sawing stone
and all other purposes for which they are adaptable, such saws to be either straight,
circular or band saws or any other kinds said teeth to be made of any suitable steel
and with one or both ends sharpened, and held in place by a spring pawl as herein
described and set forth.
Deted this 16th day of January 1894.