Improvements in Saws.
Year: 1890

page_text: Date of Application, 20th Nov., 1890
Complete Specification Left, 17th Sept., 1891-4ccepted, 20th Feb.,
1592
PROVISIONAL SPECIFICATION,
Improvements in Saws.
I, WILLIAM JUNGE, of 19, Camden Street, Oakley Square, Camden Town,
London, N.W., Civil Engineer, do hereby declare the nature of this invention to be
as follows:
My invention relates to saws.
According to this invention I provide the teeth of saws alternately on their right
and left hand side at or near the top with a narrow recess or groove of any suitable
depth and shape from the front to the rear in such a manner that extremely sharp.
knife-edges for cutting the two sides of the kerf are produced. The upper part of
the teeth may be made of any desired transverse section. Along the top of the
teeth is preferably formed a thin ridge constituting a sharp knife-edge for cutting
the base of the kerf. This ridge may either extend from the front to the rear of the
teeth or occupy only part of their width. The front of the teeth which presents the
knife-edge working at the side of the kerf may be either perpendicular or
forwardly or rearwardly inclined to the base, I prefer however in most cases to
arrange the point of the teeth as much as practicable to the rear relatively to the
base, with the object of enabling the saw to cut on the principle of the pulling
stroke.
Both the wear and renewal of these teeth can take place either radially or spirally,
or radially and spirally.
My invention is applicable to saws having teeth made in one piece with the
blade and also to those provided with exchangeable teeth.
In this improved saw the dust or waste produced by one tooth passes through
the aforesaid lateral recess or groove in the same into the throat space in front of
the following tooth by which it is removed from the kerf.
By reason of the extremely sharp knife-edges and small thickness of the upper pari
of the teeth the material to be cut will offer comparatively little resistance, so that
these teeth present great strength and stability, and are less subject to vibrations,
springing and heating than if the teeth strike flat upon the fibres of the material,
whilst the cutting action on the principle of the pulling stroke obviates the buckling
and bending of the saw. Owing to these various features the number of the teeth
can be considerably decreased, thus reducing the time needed for the formation and
sharpening of new and worn teeth to a minimum. Moreover the improved saw
works steadily, produces very smooth surfaces, causes little friction, obviates
breakage, cracking, buckling and bending, and relatively to its effectiveness does
not require much motive power for its operation..
·הויב
Namamban 1200
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Saws.
I, WILLIAM JUNGE, of 19, Camden Street, Oakley Square, Camden Town,
London, N.W., Civil Engineer, 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 :—
My invention relates to saws and has for its object to provide them with teeth

page_text: presenting sharp knife edges for cutting the material, and having clearance spaces
for the waste.
With the saws heretofore employed the fibres of the material are more or less
torn off by a rasping or scraping action of the teeth, the front part of which is
usually either square or slightly beveled. If with a view to approximating a cutting
action the angle formed by the bevel be reduced below a certain degree the saw
does not perform its work any more satisfactorily, because the sawdust then becomes
jammed between the beveled part of the teeth and the material, and gives rise to
various inconveniences.
These and other serious defects incidental to the saws used up to the present
time are obviated by my said invention, which is hereinafter described with
reference to the accompanying drawing.
Fig. 1 is a side elevation showing by way of example part of a circular saw with
teeth constructed on the improved principle..
Fig. 2 represents a plan, partly in section on the line æ―æ, Fig. 1.
Fig. 3 is a front view,
Fig. 4 a transverse section on the line y-y, Fig. 1, and
Fig. 5 a rear view, showing one of the said teeth to an enlarged scale.
In carrying my invention into practice I provide saws with teeth having
alternately on their right and left hand side, at or near the top, longitudinal
recesses or grooves a of suitable shape extending from the front b c to the rear de.
I prefer to make these recesses or grooves somewhat wider at the rear than in front
to afford proper clearance for the waste. Their depth gradually increases from
about the middle to the front of the teeth so as to form the latter with sharp knife
edges which are designed to cut the sides of the kerf. These knife edges b f
may be either perpendicular or forwardly or rearwardly inclined to the base c e of
the teeth, and the same may also be the case with the square part fa and the
rear de.
9
Along the top bd of the teeth are preferably formed flanges or lips made of
any appropriate section and presenting sharp knife edges adapted to cut the base
of the kerf, the point of these knife edges either coinciding with, or being situated
in front of, beside or behind the point of the cutting edges f
In my improved saw the waste produced by one tooth is not removed from the
kerf by this tooth, but passes through the recess or groove in the same into
the throat space in front of the following tooth, whereby its removal is effected.
The widening of the recesses or grooves towards the rear facilitates the passage of
the waste through the same.
My invention is applicable to saws having their teeth made in one piece
with the disc or blade, and also to those provided with inserted or exchangeable
-teeth.
As the teeth of my saw act with sharp knife edges upon the material to be cut
the latter will offer but little resistance, consequently these teeth possess com-
paratively great strength and stability, and are much less subject to vibration,
springing and heating than if they had to tear off the fibres of the material. A
saw having such teeth is moreover less liable to buckle, bend or crack, it works
steadily and uniformly, does not easily get out of order, lasts a long time, produces
extremely smooth surfaces and clean edges, causes but slight friction, and requires
comparatively small motive power. The waste produced being either granular or
fibrous, dust will not float in the air to any great extent in the rooms occupied by
the workmen, thus rendering the conditions of work more favourable than hitherto
and diminishing the liability of such dust to cause fire through explosion. The
number of the teeth may be very small, and the time needed for the formation and
sharpening of the same is reduced to a minimum.
The value of my improved saw lies chiefly in the very smooth surfaces and clean
edges produced, so that little or no finishing is needed, and in the considerable
saving of material, labour and motive power.

page_text: 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 I
claim is :-
A. saw having teeth provided with longitudinal recesses or grooves alternately on
either side at or near the top thereof so as to form sharp knife edges and clearance
spaces, substantially as, and for the purposes, above specified.
Dated this 17th day of September 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.