Improved Guard for Circular Saws
Year: 1898

page_text: Improved Guard for Circular Saws.
JOHN CAMPBELL, 34, Tolson Street, Lower Broughton, Manchester, in the
County of Lancaster. Manufacturer of Guards for Wood-working Machinery, do
hereby declare the nature of this invention to be as follows;-
-
My invention has for its object the prevention of accidents to the operators
hands through coming in contact with the teeth of the saw and also prevents
pieces of wood being thrown from the back of the saw towards the operator.
One method of obtaining my object consists of a bracket fastened to the saw
bench, in this bracket I fit a shaft or slide upon which, the apparatus forming
the guard or cover is free to swivel so as to take it clear of the saw when it is
desired to examine or change same, the apparatus forming the guard consists of
a bracket free to swivel on the shaft as aforesaid and on it I mount a slide which
I preferably make with two rods, parallel to each other, and extending horizontally
over the top of the saw, and is kept from dipping below an horizontal position
by a suitable stop, at the ends of these rods I fix a bracket that serves as a slide
for the piece forming the guard for the front of the saw.
The riving knife is fitted on a small bracket that is free to move on the two
rods forming the slide and serves as a guard for the back of the saw as well
as an opener for the timber.
When it is desired to work with a small diameter of saw, the front guard being
mounted at the end of the two rods forming a slide, is moved close to the saw
teeth and, locked at the bracket that swivels on the bracket shaft, the riving
knife also being mounted on the two rods is brought close to the saw teeth at
the back and locked to the two rods, when useing a saw of large diameter the
front guard and riving knife is adjustel in the opposite direction.
Another method of attaining my object is to use a slide instead of the fixed
bracket fastened to the saw bench and mount on it the whole of the guarding
apparatus same as aforesaid described and, worked up and down by means of a
screw and handwheel this is necessary when changeing from larger to smaller
saws so that the guard may be brought close to the saw teeth by the vertical
adjustment of the guarding apparatus.
Dated this 5th day of July 1898

page_text: in the direction of the arrow 0 Fig. 1 and to prevent the apparatus falling too
far back a projection 10 on X comes in contact with a projection 11 on F, and
rests upon it and F cannot move owing to its being firmly held on the shaft by
the screw 4,
To bring the guard to its normal position it is re-swivelled back and the
catch 5 dropped into the slot in F.
When a smaller saw than that shown in Fig. 1 is to be guarded, the screws 2
and 2 are loosened and allows L, L1, H, and H 1 to be slided near to the teeth
of the smaller saw, the bolt 7 is also unscrewed and J slided nearer to the saw
teeth at the back, the whole of the apparatus is then lowered by the hand wheel
and screw to cover the top of the saw while K goes into the slot formerly occupied
by the larger saw and is shown by dotted lines in Fig. 7. The screws 2 and 2¹
and the bolt 7 is screwed fast and the apparatus thus forms a guard for the
smaller saw.
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 claia is:--
(1) In a guard for circular saws the horizontal slide above the saw bench
capable of vertical and horizontal adjustment to suit various diameters of saws
substantially as set forth and shown."
(2) In a guard for circular saws the horizontal slide above the saw bench
capable of vertical and horizontal adjustment, the swivel block into which the
horizontal slide is fixed and capable of swivelling so as to take the guarding
apparatus clear of the saw substantially as described and shown.
(3) In a guard for circular saws the horizontal slide above the saw bench a
riving knife capable of being adjusted and locked on such slide to suit saws of
various diameters substantially for the purpose as set forth and shown.
(4) In a guard for circular saws the combination of the slide L and L1 with
the horizontal slide above the saw bench capable of automatically adjusting itself
to suit work under operation substantially as described and shown."
Dated this 6th day of April 1899
JOHN CAMPBELL.