Improvements in Guards for Circular Saws.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Guards for Circular Saws.
We, FREDERICK JAMES WEST and RICHARD JERVIS HODGES,; of 7 to 25, Ash
Grove, Mare Street, Hackney, in the County of London, Saw Mill Proprietors,
do hereby declare the nature of this invention to be as follows:-
This invention has reference to guards for circular saws.
According to our invention we employ two curved pieces or guards which are
respectively attached at one end to opposite arms of a holder, the normal position
of which is above the centre vertical line of the saw. The guard pieces are con-
centric with the saw, or approximately so, and cover or protect about one half
of the periphery of the same. They are adjustable in the holder by means of
slots and wing nuts or otherwise so that they can be lengthened or contracted as
required. The guard holder is preferably of approximately 1 shape the two
horizontal arms serving to hold the ends of the guards as above described. The
height of the holder and therefore that of the guards is adjustable and this can
be conveniently effected by screw-threading the vertical arm of the holder so that
it can be raised or lowered by means of nuts. The holder is carried by a
horizontal rod or bar which can be slid in a bracket or standard on the saw bench
so as to withdraw the guard from the saw when this requires sharpening or for
other purpose. The said sliding rod can be fixed in the normal position by a
tightening screw.
To one side of one of the guards above described we fix a vertical guard plate
by means of screws or otherwise.
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London,
Chartered Patent Agents.
We, FREDERICK JAMES WEST and RICHARD JERVIS HODGES, of 7 to 25; Ash
Grove, Mare Street, Hackney, in the County of London, Saw Mill Proprietors,
0 do hereby declare the nature of this invention and in what manner the same is to
Price 8d1

page_text: be performed, to be particularly described and ascertained in and by the following
statement:
This invention has reference to guards for circular saws.
According to our invention we employ two curved pieces or guards which are
respectively attached at one end to opposite arms or ends of a holder, the normal
position of which is above the centre of the saw and in the vertical plane of the
same. The guard pieces are concentric with the saw, or approximately so, and
cover or protect about one half of the periphery of the same. They are adjustable
in the holder by means of slots and fly nuts or otherwise so that they can be
lengthened or contracted as required. The guard holder is preferably of
approximately 1 shape the two horizontal arms serving to hold the ends of the
guards as above described. The height of the holder and therefore that of the
guards is adjustable and this can be conveniently effected by screw-threading
the vertical arm of the holder so that it can be raised or lowered by means of
nuts. The holder is carried by a horizontal rod or bar which can be slid in a
bracket or standard on the saw bench so as to withdraw the guard from the saw
when this requires sharpening or for other purpose. The said sliding rod can
be fixed in the normal position by a tightening screw.
To one side of one of the guards above described we fix a vertical guard plate
by means of screws or otherwise.
:
A suitable form of guard constructed in accordance with this invention is
illustrated by the accompanying illustrative drawings in which:-
Figures 1, 2 and 3 are respectively a side elevation; a front end elevation,
and a plan of our improved guard fitted to a large saw.
Figure 4 is a side elevation showing the same guard adapted to a much
smaller saw which has been substituted for the large saw above referred to.
Referring to Figures 1, 2 and 3, A indicates the circular saw mounted on a
saw spindle B in the saw bench C. D, D₁ are the two curved guard pieces
which are attached at one end to the respective opposite arms E', E of the
shaped holder E. They are arranged in the plane of the saw and are made of
flat metal strip of a thickness about equal to the thickness of the teeth of the
largest saw which the guard is designed to take, and of sufficient radial depth
to ensure a suitable degree of stiffness when the guard is in position. These
guard pieces are made concentric with the largest size of saw intended to be
protected, and their respective lengths are such that when the guard is in its
highest operative position as shown, the rear guard piece D¹ will cover or protect
the whole of the back of the saw, whilst the front guard piece ]) is made shorter
so as to leave the front of the saw exposed to the extent required by the stuff
being sawn, and thus allow free passage to the stuff on its return. The guard
pieces are adjustably attached to the respective arms of the holder E by means
of fly nut screws F, F¹ that are mounted in holes in the holder arms and extend
through slots G, G¹ which are formed in the guard pieces approximately con-
centrically to the periphery of the saw. Each slot G, G¹ is formed at its inner
end with a short portion g, gl at right angles to the main portion of the slot
for a purpose hereinafter referred to. The slot G extends practically the entire
length of the front guard piece D, whilst the slot G¹ in the rear guard piece D¹
extends only from the inner end of the latter for a length about equal to the
length of the rear arm of the guard holder E. The vertical arm E2 of the
1 shaped guard holder is screw-threaded so that it can be raised or lowered by
means of nuts H in the vertical plane of the saw in an eye I¹ of a horizontal
rod or bar I which can be slid in a bracket or standard J on the saw bench so as
to withdraw the guard from the saw when required. The sliding rod I can be
fixed in the normal position by a tightening fly nut screw K.
by limiting the return movement of the sliding rod I, serves to facilitate the
A stop pin L
replacing of the guard centrally over the saw.
To one side of the rear guard piece D¹ there is fixed by means of rivets a
vertical guard plate M which gives additional protection to the pulling.out boy

page_text: at the back of the saw. The lower end of the back guard piece D₁ with the
vertical guard plate M may be steadied in the saw bench slot B' by means of
wooden wedges. N indicates a piece of wood being sawn. The saw cut opens
out to a sufficient extent to allow of passing the combined thickness of the back
guard piece with the attached guard plate.
For sharpening or changing the saw it is only necessary to loosen the fly
nuts F, which hold the back guard piece D', and raise the latter out of the
slot B; then to loosen the fly nut K which holds the sliding bar I, and push
the whole guard out of the way.
In order to adjust the guard to the smaller saw A¹ which is shown in Figure 4
substituted for the large saw A, shown in Figure 1, the holder E is lowered by
suitably slacking the nuts H until the lower edge of the holder just clears the
top of the saw A¹; the fly nuts F being loosened to allow of tilting the front
guard piece D downward so as to just clear the saw. Then the fly nuts F
are loosened, and the rear guard piece D with the guard plate is likewise tilted
downward to just clear the saw. The guard is then in the position shown in
Figure 4.
The right angled slot portions gġl in the front and rear guard pieces D, D¹ are
designed to allow the said pieces to be tilted further inwards when required so as
to enable the guard to conform more closely to the different sizes of saws.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we wish it to be
understood that we are aware that saw guards consisting of curved plates lying
in the plane of the saw, and also adjustable curved front guard pieces mounted
on a main hood or guard, have been proposed; and we do not, therefore, broadly
claim such arrangements, but we declare that what we claim is:-
1. A guard for circular saws, consisting of a holder capable of vertical adjust-
ment in the vertical plane of the saw, with a curved front guard piece and with
a curved flat back guard piece, said front and back guard pieces being adjustably
attached on opposite sides or ends of said holder, substantially as and for the
purposes described.
2. In a guard for circular saws, of the kind referred to in the preceding
claim, forming the guard pieces at their inner ends with right-angled slot
portions for the purpose of enabling the guard pieces to conform more closely
to the contour of small saws, substantially as described and shown.
3. The improved guard for circular saws, constructed, arranged and operating
substantially in the manner as and for the purposes described with reference to
the accompanying illustrative drawings.
Dal 1000
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London,
Chartered Patent Agents.