Improvements in Saws.
Year: 1892

page_text: The decision of the Comptroller-General, of the 6th day of May 1893, allowed,
under Section 18 of the Patents, &c. Act, 1883, an Amendment of this
Specification.
Date of Application, 25th June, 1892
Complete Specification Left, 22nd Nov., 1892-Accepted, 31st Dec., 1892
PROVISIONAL SPECIFICATION.
Improvements in Saws.
WILLIAM JUNGE, and CHARLES JUNGE, both of 19, Camden Street, Oakley
Square, London, N.W., Civil Engineers, do hereby declare the nature of this
invention to be as follows:-
According to this invention we provide band and similar saws having on one or
both sides channels which are designed to allow the passage of the waste directly
behind the saw. These channels, which may be of any suitable section, extend in a
straight or curved line from the front edge of the teeth obliquely to the back of
the blade. At the front part of the teeth they are deepened so as to form the
teeth with sharp edges for cutting the sides of the kerf, whilst they are preferably
widened a little towards the back of the blade to facilitate the passage of the waste
through them. Along the channels are ribs of any desired section, the front part
of which is generally undercut and is sharpened to cut the base of the kerf. Either
of the two cutting edges of each tooth may be straight or curved and form any
desired angle with the other. These cutting edges are by preference rearwardly
inclined in order to make a pulling cut. According as the channels are formed on
one side or on both sides of the blade the saw will cut one smooth and one
comparatively rough surface, which is required for certain classes of work, or
two smooth surfaces. In the former case the edge for cutting the base of the kerf
has also to cut one side of the latter, and must therefore be sufficiently undercut for
effecting this purpose.
We sometimes provide reciprocating saws on their back with a number of
projections or recesses for removing the waste from the kerf.
A band saw made according to our said invention may also be used in the form
of a ring secured in any appropriate manner upon a disc having gullets at its
periphery, the blade of such a band saw being in the same plane as the aforesaid
disc. When the teeth of this ring are worn the latter may be replaced on the disc
by another ring.
The teeth of our improved saws are arranged parallel to each other at an acute
angle with the front edge of the blade so as to form narrow wedge shaped recesses
between the points of the teeth, which recesses enable the latter to catch or bite
into the material to be cut, but are not intended for the accumulation of waste. By
reason of their direct connection the teeth possess very great stability, so that
lateral vibrations will be prevented. The saw blade is preferably tapered to the
back, in order to obviate the setting of the teeth and thus enable unskilled men to
keep the saw in order.
As the channels extend from the front edge to the back of the saw we obviate
the throat spaces for the collection of the waste, gain more material for the wear,
and increase the durability of the saw. And since the said channels allow the waste
to pass continuously behind the blade they will, save those of band saws made in
the form of rings fixed on discs, admit of the highest rate of feed even when cutting
•

page_text: through the very thickest wood. With our band saws the waste can cause but
little friction in its passage through the channels, because it will be displaced by a
wedge action produced by the sides of these channels to the rear of the blade, where
it will serve to hold the two sides of the kerf asunder and thus facilitate the work
of the saw. Owing to its cutting action the saw will overcome the resistance of the
material with the least expenditure of power; consequently the relative strength
and rigidity of the same are considerable, and as it produces a pulling cut we obtain
very smooth surfaces and clean, untorn edges, so that little or no finishing will be
needed. The number of teeth for a certain length of blade may be very small,
which during the action of the saw reduces the tension in the blade and permits of
thick logs being cut up by very narrow blades and with small motive power.
Inasmuch as the cutting edges of the teeth strike the fibres of the wood under the
most favourable conditions and make a pulling cut they will remain sharp for a longer
time than if they had to rasp or scrape off such fibres. The time necessary for the
sharpening and re-sharpening of our improved saws and for keeping them in order
is therefore reduced to a minimum.
Dated this 25th day of Lune 1802
HASELTINE, LAKE & Co.,
Agents for the Applicants.
COMPLETE SPECIFICATION (AMENDED).
Improvements in Saws.
We, WILLIAM JUNGE and CHARLES JUNGE, both of 19 Cainden Street,
Oakley Square, in the County of Middlesex, Civil Engineers 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 relates to band and other saws and consists chiefly in providing
channels in one or both sides of the blade to allow the continuous passage of the
"waste "from the saw teeth to the back of the blade thereby greatly facilitating
the work performed by the saw.
In the accompanying drawing,
Figure 1 represents a side view of part of a band saw constructed in conformity
with our invention.
Figure 2 is a transverse section of the same drawn to a larger scale.
Figure 3 is a section of a saw having channels of a somewhat different shape
from those of the saw shown in Figures 1 and 2.
Figure 4 shows a side view of a band saw designed for cutting metal and other
hard materials.
Figures 5, 6 and 7 are transverse sections on a larger scale of such a band saw
showing several shapes of cutting edges.
Figure 8 shows a side view of a hand saw embodying our invention.
Figure 9 illustrates the application of our improved band saw in the form of a
ring to a circular disc thus constituting a circular saw.
Figure 10 is an enlarged view of a portion of Figure 1.
In carrying our said invention into practice the blade a Figures 1, 4, 8 and 10
of a band or other saw is formed provided either on one or on both sides with
channels through which the "waste" cut by the saw is conducted directly behind
the blade. These channels, which may be of any suitable section, such as shown
by way of example in Figures 2 and 3, extend in a straight or curved line from the
front edge c c to the back d d of the saw. The angles made by the said channels
with the front and rear edges of the blade are arranged as determined by experience
for different classes of work to give the best results.
At the front part of the blade these channels are preferably deepened or bevelled
so as to form the teeth e with sharp chisel shaped edges /g for cutting the sides of
the kerf, whilst they are preferably widened a little towards the back d d of the

page_text: 25
blade, as shown in Figure 10, to facilitate the passage of the "waste through
them.
Between the channels are ribs of any desired section, the front part gi of
each of which may be undercut and is sharpened to form a chisel shaped edge for
cutting the base of the kerf. The part of each tooth is morcover preferably bevelled
as indicated clearly in Figure 10 and thus forms with the groove b an inclined cutting
edge g, i.
Either of the two cutting edges fg and gi of each tooth e may be straight or
curved and form any desired angle with the other. These cutting edges are by
preference rearwardly inclined, as shown, in order to make what is known as a
pulling cut.
According as the channels are formed on one side or on both sides of the blade
the saw will cut either one smooth and one comparatively rough surface, which is
required for certain classes of work, or two smooth surfaces. In the former-ease
the edge-y-i-for-cutting the base of the kerf has also to ent one-side-of the latter
and may be underent for this purpose:
As shown in the drawing, the teeth e of our improved saw are arranged parallel
with each other at an angle with the front edge cc of the blade so as to form narrow
wedge shaped recesses gfy between the points y of the teeth, which recesses enable
the latter to catch or bite into the material to be cut, but are not intended for the
accumulation of waste.
The teeth of this saw may be set in any suitable manner, but for certain purposes
it will not be necessary to set them, the blade being preferably made thinner at the
back of the saw than at the front.
'
In a band saw for cutting metal and other hard materials it is not desirable to
provide cutting edges for the sides of the kerf, the edges for the base performing
the whole work, as shown in Figures 4 to 7.
Each edge for cutting the base may in this case be constructed for taking out
either the whole width of the kerf, as shown in Figure 5, or only a part of such
width, as indicated in Figures 6 and 7.
We may provide on some kinds of saws, such as the various forms of hand saws,
frame saws, jig saws and the like, a number of projections or recesses at the back
thereof for the purpose of removing the waste from the kerf.
A band saw made according to our said invention may also be used in the form
of a ring & Figure 9 secured in any appropriate manner, for example by brazing,
upon a disc having gullets m in its periphery, and arranged with its blade in the
same plane as the aforesaid disc. When the teeth of this ring are worn the ring
may be removed from the disc, and replaced by another one. In some cases the
ring may be formed solid with the disc l.
The teeth of our improved saw possess very great stability and are not subject
to lateral vibrations. As the gullets for the collection of the "waste" are dispensed
with, more material is obtained for wear and the durability of the saw is
increased.
23
With our improved saws the "waste causes but little friction in its passage
through the channels rearward where it serves to hold the two sides of the kerf
asunder and thus relieves the pressure on the saw, and, owing to its improved
cutting action, friction is reduced, less power is required and smoother surfaces are
obtained.
The number of teeth in a given length of bladé may be very small, thus reducing
the tension in the blade and permitting of heavy work being done by narrow blades
and with small motive power, and inasmuch as the cutting edges of the teeth attack
the fibres of the wood under the most favourable conditions and make a pulling cut
they will remain sharp for a longer time than if they had a rasping or abrading
action on the fibres. The time necessary for the sharpening and re-sharpening of
our improved saws and for keeping them in order is therefore reduced to a
minimum.
1

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
-
1. A saw so constructed that the "waste" made when sawing is free-to-pass
obliquely towards, or to, the back of the blade, or the 1
-purpose specified.
3. 1. A saw having channels formed in one or both sides thereof, said channels
extending from the cutting edges in an oblique direction towards, or to the back of
the blade, substantially as described, for the purpose specified.
2. In a saw, the provision of channels in one or both sides of the blade to conduct
the "waste" obliquely towards, or to, the back of the said blade, said channels
forming at their lower ends chisel shaped cutting edges, substantially as described.
4. 3. A saw having channels in the side thereof extending from the front to the
back of the blade in combination with edges for cutting either the entire width of
the kerf, or a fraction thereof, substantially as described, for the purpose specified.
4. A circular saw comprising a disc having gullets m in its periphery, in
combination with a blade & secured on the disc, or forming part thereof, and
provided with inclined channels in the sides thereof extending from the outer to
the inner periphery, substantially as described, for the purpose specified.
6. 5. Saws constructed substantially as described with reference to either of the
forms illustrated in the drawings, and operating as, and for the purpose, specified.
Dated this 22nd day of November 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.