IMPROVEMENTS IN GUARDS FOR CIRCULAR SAWS
Year: 1884

page_text: I JOHN DRURY, of Laceby, near Grimsby in the County of Lincoln, Engineer
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
GUARDS FOR CIRCULAR SAWS," 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 the object of
the Invention being to provide a guard which will effectually prevent any person
from being caught by the teeth of the saw when working and which will also
prevent anything being thrown from the back of the saw against the workman;
the guard is automatic in its action and can easily be adjusted to existing saw
benches.
t
My improved self-acting guard is constructed of two curved arms hollow or
grooved on their undersides and extending over the circumference of the saw above
the bench; the said arms are pivotted to a bar or carrier having a sliding vertical-
motion on a standard bolted to the saw bench, the said sliding motion being
communicated by means of a screw and a band wheel; the said bracket also
carries two pendent arms one hanging on each side of the saw and capable of
partial rotation round the said bracket.
In order to enable my'Invention' to be fully understood I will describe the same
by reference to the accompanying 'Drawing in which Figure 1, is a plan and
Figure 2, an end view of a circular saw bench and saw with my improved guard
applied thereto; Figure 3, is a section on line: A B of Figure 1; Figure 4, is a
front elevation shewing the position occupied by the parts forming the guard when
a piece of wood is being cut by the saw. Similar letters in all the Figures represent
similar parts
a, and b, are the two curved arms formed hollow or grooved on their undersides
as shewn at Figure 2, so as to cover or shield the teeth of the saw c,; the arms a,
and b, extend over the circumference of the saw above the bench d, as shewn and
are suitably curved so as to yield to the pieces of wood as they are pressed against.
the saw; e, is the bar or carrier on one end of which the arms a, and b, are pivotted
at f, and which forms a stop against which the arms bear when in their normal
position and whereby their downward movement is limited; the other end of the
carrier e, slides vertically upon the standard g, its movement being effected by
operating the hand wheel h, which turns loosely in the bracket or arm i, and
through which passes the vertical screw j; by these means the height of the guard
can be regulated according to the work and to suit different sizes of saws; the
.

page_text: standard or upright g, is fixed to the saw bench d, in any suitable manner such as
by screw bolts and nuts passing through the base plate q, as shewn; k, and.l, are
the two pendent arms hanging one on each side of the saw c, and capable of partial
rotation round the carrier e, so that they will yield to .pressure in one direction but
will remain rigid when pressed in the opposite direction their movement being
limited by pins or stops m, on the carrier e, over which pins or stops pass the
slots o, in the collars p, of the arms k, and 1,; these arms which hang vertically
downwards when in their normal position, as in Figure 3, prevent any wood or the
like from being thrown from the back of the saw towards the workman as they
will only yield to pressure in a direction towards the back of the saw.
By these improvements it will be seen that when no work is being performed
by the saw and the parts of the guard are consequently in their normal position as
shewn in Figures 1, 2 and 3, the arms a, and b, will shield the teeth of the upper
half of the saw and prevent anything being caught by the saw teeth and damage
being done to a person or article which might fall against or over the saw, and the
arms k, and 1, will form a stop to anything which may be thrown forward by the
saw towards the workman. The curved shape of the arms a, and b, will allow
them to yield and give passage to the pieces of wood as they are passed over the
bench when being cut by the saw; the arms k, and I, also give way to the wood
and both sets of arms rest upon the wood as seen in Figure 4, until it is cut
through by the saw when they automatically fall into their normal position or
position of safety as shewn in Figures 1, 2 and 3. The improved guard can with
facility be fixed to any existing circular saw bench it only being necessary to bolt
the plate q, to the bench as shewn in the Drawing..
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:
Firstly. The combination of parts forming the improved guard for circular saws
as hereinbefore described and represented in the accompanying Drawing,
Secondly. In a guard for circular saws the combination with the pivotted arms a,
and b, of the sliding carrier e, and pendent arms k, and l, capable of partial rotation
round the said carrier all arranged and operating substantially in the manner and
for the purposes hereinbefore described and represented in the accompanying
.Drawing.
. Thirdly. In a guard for circular saws the employment of arms or shields grooved
on their undersides. and suitably curved as and for the purposes hereinbefore
described and represented in the accompanping Drawing.
Fourthly. In a guard for circular saws the employment of pendent arms capable
of partial rotation so as to yield to pressure in one direction but which will resist
pressure in the other direction substantially as and for the purposes herein before
described and represented in the accompanying Drawing.