Improvements in Fret Saw Machine Frames.
Year: 1897

page_text: Date of Application, 6th Oct., 1897-Accepted, 4th Dec., 1897
COMPLETE SPECIFICATION.
Improvements in Fret Saw Machine Frames.
We, HOBBIES, LIMITED, of 12 Paternoster Square, in the City of London, and
HERBERT JEWSON, of East Dereham, in the County of Norfolk, 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;-
This invention relates to a fret saw machine frame which is of a light and rigid
character and is constructed in such a manner as to secure a vertical stroke to
the saw and to maintain the saw at the same tension throughout the stroke.
In the accompanying drawings Fig. 1 is a side elevation of the top part of a fret
saw machine frame constructed in accordance with this invention, Figs. 2 and 3
are vertical sections taken on the lines 22 and 33 respectively of Fig. 1 and Fig. 4
is a horizontal section taken on the line 4 4 of Fig. 2. The same letters of reference
where they occur are used to indicate the same or corresponding parts in all the
Figures.
The saw frame A is made of tubular steel of oval cross-section as shown in
Figs. 1, 2 and 3, and is provided with the usual adjusting and clamping devices B
and C. D represents the legs of the machine stand, which is furnished with treadle
driving mechanism, and to the upper end of which said stand the bracket G is
secured by means of suitable lugs E and bolts F. The said bracket G may of course
he formed in one with the underframe D of the machine. Mounted in suitable
bearings in the bracket G is the spindle J fast on which is the band wheel H and
two driving wheels K and K¹. The wheels K and K¹ serve to balance the recipro-
cating parts of the machine and to provide for regularity of motion of the spindle J.
To a crank pink on the wheel K is linked a connecting rod L the other end of
which is linked on the neck of a bolt M which is passed through a plunger N
and secured by a nut m. The plunger N reciprocates in a vertical guide P, which
latter forms part of or is secured to the bracket G. The upper end of the plunger
is provided with a cross head O to which the saw frame A is secured by a suitable
clamping arrangement R. S is the work-table which can be adjusted in an
inclined position in the ordinary way by bolting the slotted lugs on the underside
thereof in the required position to the lug g on the bracket G.
The action is as follows;-When the band wheel H rotates, the spindle J and
driving wheels K and K¹ also rotate, and the crank and conecting rod cause the
reciprocation of the bolt M and plunger N and the latter is by the guide P' con-
strained to travel in a vertical path. The saw frame A being secured on the upper
end of the Plunger N partakes of its movement and the saw is thus given a vertical
stroke. The frame A being made of steel tubing, by its resiliency, maintains the
saw at the same tension at all parts of the stroke.
It will be understood by those having a knowledge of the art that the invention
is applicable to hand machines which are clamped to a bench and operated by a
hand wheel, as well as to treadle machines.

page_text: -
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. A fret saw machine frame consisting of a bracket, secured to or formed on a
suitable stand provided with treadle mechanism, said bracket carrying a band
pulley on the spindle of which is a driving wheel connected by a crank and con-
necting rod to a plunger located in a vertical guide in or on the bracket, said,
plunger carrying the saw frame all combined to operate substantially as described"
with reference to the accompanying drawings.
2. A fret saw machine frame consisting of a bracket, having means for clamping
it to a bench, said bracket carrying a driving wheel connected by a crank and
connecting rod to a plunger located in a vertical guide in or on the bracket, said
plunger carrying the saw frame all combined to operate substantially as described
with reference to the accompanying drawings.
3. In fret saw machine frames of the kind indicated, making the saw frame
of tubular metal as and for the purposes herein described.
4. The herein described improved fret saw machine frame operating substantially
in the manner set forth and illustrated in the accompanying drawings.
Tatal thi th dev
1907
F. W. GOLBY
36 Chancery Lane, London, W.C. Patent Agent for the Applicants.