Year: 1898

page_text: ROBERT JONES, Engineer, 3, Merlin Street, Johnstown, Ruabon, North Wales,
do hereby declare the nature of this invention to be as follows:-
An arrangement for the protection of circular saws while in motion especially
the front portion of same by means of levers and a balance weight fixed on stand
or suspended underneath the bench, with a curved piece of angle iron or hard
wood fixed to one lever and projecting through slot of bench in front of saw to
any desired height. Attacheil to another lever is a piece of iron with tapered
top projecting through the bench about 1 inch so that when the weight of timber
comes upon this the front guard falls below the level of bench leaving the saw
clear for cutting, immediately the weight of timber goes off the guard it rises
up to follow and covers the front of saw. In addition to this automatic action
the guard may also be worked by treadle which is attached to balance weight.
This front arrangement is worked in conjunction with a curved piece of steel
same thickness as saw covering back & top portions of same with one end fixed
in rack at back of saw, the other end fixed to arm bolted to bench or to bracket
suspended from above.
For larger size saws there is an extension piece hinged to top end of back
knife with pulley attached to side of other end which falls a certain distance
down front of saw to meet the upward motion of the bottom front guard altogether
forming a complete guard over the exposed parts of a circular saw.
Dated this 10th day of November 1898
I, ROBERT JONES, of 3, Merlin Street, Johnstown, Ruabon, North Wales,
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 improvements in guards for circular saws designed
with the object of more efficiently protecting workmen attending them from
accident or disablement.
Hitherto the guards in use for this purpose have been principally operated
from above the saw bench, that is to say the guard has been lifted up by the
timber, or where it has not been movable after being once set for the particular
work in hand, the cutting portion of the saw at the front side has been exposed

page_text: for a few inches. Thus the protection afforded is only of a partial nature. On
the other hand my invention avoids these defects and consists essentially in the
use of a movable guard operated from above the saw bench automatically by
placing the timber on the latter so as to cause the guard to descend below the table
whilst sawing is proceeding and to rise above the bench and cover the saw at the
front immediately the timber has passed the cutting edge. My invention also
embraces the use of a foot or hand lever for operating the guard and the com-
bination of a guard operated in any of the ways described with a stationary guard
covering the top and back portions of the saw.
The invention will be fully described with reference to the accompanying draw-
ings in which
Fig. 1 is a longitudinal section of a saw bench with my improvements applied,
Fig. 2 a cross section,
Fig. 3 a detail view of the stationary portion of the guard and
Fig. 4 a partial plan showing more clearly how the movable guard is guided
by the saw bench.
Referring to these drawings a is the saw bench and b the saw both being of the
usual construction. At the underside of the saw bench or to a bracket c fixed
to the latter is pivoted two levers d and e. The former dis pivoted on a pin
or stud supported by the arm of the bracket e and the latter on a pin or stud
carried by the other arm g. Both these levers at the front end are coupled
together by a link the lower end of which is suitably formed and attached to
a counter balance weight i just inside the bench frame. At the opposite end
lever has secured to it by set screws, pins or the like an arm j the upper end
of which passes through the slot in the saw bench in front of the saw, the extreme
end being somewhat inclined as shown. "This arm j is adjustable along the
leverd as may be required by the size of the saw, the lever being formed with
holes for the purpose or with a slot. Lever e is formed with similar holes Z
or a slot in which is a pin or adjustable stud m to or on which is pivoted a curved
guard n. This guard is slack on the pin or the pin is slack in the hole and
is preferably made of angle iron so that one side of it may cover the saw teeth at the
side whilst the other covers them at the front. It is also curved to correspond
more or less closely with the saw and is guided and kept from contact with the
latter by the front side of the angle iron resting in a slot o formed in the saw
bench or in the packing piece p in front of the saw. The top portion of the saw
is protected by a curved blade q which can be adjusted both backwards and
upwards in accordance with the size of the saw in use by means of the slotted
arm and wheels and slotted bracket t. These portions of the guard are, how-
ever, old and well known. The blade 7 is preferably V-shaped at the end so as
to assist in supporting the curved guard n when the latter is above the saw bench.
The whole of the parts are nicely balanced so that when a piece of timber is
placed upon the arm j the latter is depressed and owing to the differential
pivoting of the levers, by the time the arm disappears beneath the bench the
guard is also beneath it, the weight being correspondingly raised. During
cutting the timber keeps the guard below the bench but as the rear end of the
timber is passing the cutting edge of the saw the guard n follows the timber and
rises into protective position.
In cases where I wish to depress the guard n independently of the timber I
employ a foot lever pivoted to the saw bench and attached at its rear end to
the balance weight so that the latter can be lifted up, thus allowing the guard n
to descend. A hand lever may be used in place of the foot lever. Again where
do not wish to change guard n for a longer or shorter one in accordance with
the diameter of saw I prefer to attach to the end of the blade g a loose piece v
pivoted to the latter and covering the intervening space between the knife and
guard n. The piece is prevented coming into contact with the saw by a
projecting piece w, and may at the front end be formed similar to the end of
the knife or may carry a small pulley & against which the guard n could come

page_text: in contact when rising to its protective position, and which would also enable
the timber to pass easily beneath it.
By these means a guard covering the whole upper portion of the saw is pro-
vided and with such a guard in use accidents are practically impossible.
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
1. The improved guard for circular saws consisting of a curved guard such as n,
levers such as d and e, arm j, and balance weight such as i with or without a
foot lever such as u substantially as described.
2. In a guard for circular saws the combination of parts n, d, e, j and i with
an adjustable blade or knife such as q with or without an extension piece such
as substantially as described.
3. The improved guard for circular saws constructed, arranged and operated
substantially as described and shown with reference to the accompanying drawings.
F
1000
WILLIAM H. TAYLOR,
Swan Chambers, 69, Market Street, Manchester,
Agent for the Applicant.