IMPROVEMENTS IN FRET-SAWS
Year: 1884

page_text: 1, AUGUST BREUKER of Breitenfeld near Voerde in the province of Westfalia
German Empire, Mechanic do hereby declare the nature of my invention for
IMPROVEMENTS IN FRET-SAWS to be as follows:-
。
The ordinary coksaws are provided with a device for adjusting the claws
between which the saws are held so that the saw blades may be used for any short
length because it often happens that the thin blades break.
This ordinary adjusting device consists of a screw spindle passing through the
handle of the saw and at the end of which one of the claws is fastened, thus this
claw can be screwed forward or backwards.
This arrangement is somewhat complicated and expensive.
I make the ends of the bow of the cock saw where the blade fastening claws are
fixed adjustable simply by making the saw bow of steel and twisting the back of
the bow at right angles as shown at A, B fig. 1, 2 & 3 of the accompanying
drawing so that the bow acts freely like a spring & as shown by the dotted
lines BC & B C' a saw blade of any practical length can be used with my new
cock saw and the ends of the bow are adjustable in the simplest manner.
Instead of making the bow in one piece of spring steel, the arrangement shown
by fig. 4 & 5 may be adopted, where the back of the bow is made of spring steel
only which is rivetted to the shanks of the bow.
I claim as my invention "A Cock Saw which is made adjustable for any
practical length of saw blade by having the back of its. bow made of spring steel
and twisted at right angles so that the open ends of the shanks of the bow may
be conveniently brought close. to each other or separated, as may be, desired.”
DAL
2
L
3004
.

page_text: I AUGUST BREUKER of Breitenfeld near Voerde in Westfalia German Empire
Mechanic do hereby declare the nature of my invention for IMPROVEMENTS IN FRET
SAWS and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
The ordinary fret saws are provided with a device for adjusting the claws
between which the saws are held so that they may be used for any short length of
saw as it often happens that the thin saws break. This ordinary adjusting device
consists in a screw spindle passing through the handle of the saw and at the end
of which one of the claws is fastened, thus this claw can be screwed forward or
backwards.
The arrangement just described is somewhat complicated and expensive. I
make the ends of the bow of my fret saws, where the claws for fastening the
saw plates are fixed, adjustable simply by making the saw bow of steel and
twisting the back of the bow at right angles as shown at A & B fig. 1, 2 & 5, so
that the bow acts freely like a spring & as shown by the dotted lines B C¹ & B C³
a saw plate of any practical length may be used with my new fret saw end the
ends of the bow are adjustable in the simplest manner.
Instead of making the bow in one piece out of spring steel the arrangement
shown by fig. 4 & 3 may be adopted, where the back of the bow is made of spring
steel only and rivetted to the iron shanks of the saw bow.
With this improved spring bow it might however happen that, if a saw plate
breaks and they often do break-the free end of tho saw bow B C springs out
too much in consequence of tho action of the spring and so might cause damage,
I add a guard EF to the bow fig. 6 & 8 which is hinged or hooked to the lower
shank of the bow and hooked ower the other and which can be shifted forward on
one side, taking an inclined position, if a short saw is fixed between the-claws and
if the upper shank B C takes the position shown in fig. 6 in dotted lines..
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
1.) A fret saw which is made adjustable for any particular length of saw plate,
by having the back of its bow made of spring steel twisted at right angles so that
the open ends of the shanks of the bow can be conveniently brought close to each
other or separated as may, be desired.
2.) The making of the bow of such saws in one piece wholly of steel, fig. 1, 2,
5, 6 & 8, or by rivetting the straight shanks to the twisted steel spring back
fig. 3 & 4.
3.) The use of a guard E F, fig. 6 & 8 with such fret saws to prevent that the
free shank of the bow should spring out too far in case of breakage of a saw plate.