A Combined Guard and Guide for Circular Saw Benches and analogous Tools.
Year: 1897

page_text: Date of Application, 13th Apr., 1897
Complete Specification Left, 7th Jan., 1898-Accepted, 19th Mar., 1898
PROVISIONAL SPECIFICATION.
A Combined Guard and Guide for Circular Saw Benches and
analogous Tools.
EDWARD WILLIAMS, 20, Sealand Road, Chester, Machinist, do hereby declare
the nature of this invention to be as follows:-
This invention is an improved guard for circular saw benches for protection
against accidents to which is attached a roller for guiding the timber in lieu of
the hands at the most dangerous and critical part of the operation. The apparatus
constructed according to my invention consists of a hood or shield which covers
This hood or shield is carried on a
the teeth in front, and partly over the saw.
radial arm supported by a standard fixed at behind the back part of saw and the
shield is automatically kept in position by means of weights, which also are at
back of saw. To the fore part of this hood or shield is attached an adjustable
roller. When the timber drawn or pushed towards the saw comes in contact
with this roller the pressure brought against it opens out the shield to allow
the timber to pass between it and the saw, and as soon as the timber is through the
weights from behind causes the shield to again close instantly over the saw. The
said roller mounts over and runs on the face of the plank and guides it towards
the saw. The said hood or shield is adjustable to any size saw; this is attained by
means of a V slide working at a right angle, the shield so moving downward and
backward or upward and forward at the same ratio. This slide again is worked
by means of a threaded spindle at top end of which there is fixed a hand wheel
Dated this 12th April 1897.
A Combined Guard and Guide for Circular Saw Benches and
analogous Tools.
I, EDWARD WILLIAMS, of 20, Sealand Road, Chester, in the County of Chester,
Machinist, 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 an improved guard for circular saws or analogous
tools to prevent accident to sawyers and others and is designed to provide a guard
which shall possess all of the following characteristics:-It entirely covers the part
of the saw above the bench; can be adjusted to any size of saw; can be swung
round out of the way for changing saws or sharpening; prevents pieces of timber

page_text: knots or sawdust being thrown over from the back by the saw when running and is
automatic in its action.
It consists essentially of a guard constructed with a hood which covers the teeth
at front and on top, pivoted to a radial arm which is supported at one end upon
a screw set in an inclined position, whereby the turning of the screw raises the
hood, and at the same time draws it forward, or vice versa. Also in a sliding
extension for the front edge of the hood and one or more rollers to press against
the timber as it travels forward to the saw.
It will be fully described with reference to the accompanying drawings, in
which it is shewn in position applied to circular saw:
Fig. 1. Front elevation.
Fig. 2. Plan.
Fig 3. Front elevation showing guard turned back and saw clear.
Fig. 4. End elevation.
The circular saw A the saw bench B and the protecting knife or blade C placed
behind the saw are of any ordinary construction.
In front of and extending over the top of the saw I place a swinging hood D
with a front plate d. and top curved plate d. The hood D is pivoted to an arm E,
so as to be capable of swinging or opening in a horizontal plane to allow timber
to enter between it and the saw A at the front and to come out under it at back
of saw and also to permit of it being turned into the position shown in Fig. 3
(and by dotted lines in Fig. 2) leaving the saw clear to be removed or sharpened.
The pivot e upon which the hood D swings, is placed behind the plane of the saw
so that but little force is required to move or open the hood to allow of the timber
to enter and so that the movement to one side for this purpose shall not be
sufficient to uncover the saw.
The arm E is mounted in a slide f in a bracket F in which it is raised and
lowered by a screw G from which it stands out at right angles. The bracket F
is affixed to the saw bench, and the screw G extends from one end to the other of
the slide and is inclined to the vertical (at an angle of about 45°) so that the
movement of the screw to raise the arm E and with it the hood D also advances
the arm and hood towards the front of the saw. This movement prevents the front
edge of the hood coming into contact with the saw when a large saw is introduced
and also prevents it standing out too far from a small saw. The screw G is turned by
a hand wheel g.
The length of the arm E is such that the bracket F can be set a considerable
distance behind the saw and thus be completely out of the way when the saw is
in action and not interfere with the free passage of the timber past the saw.
To the front end of the hood D I bolt a sliding extension piece H by which
the hood can be, extended to any desired length so that as it is raised up to
accommodate a larger saw the extension piece H can be lowered to a level with the
bench B to cover the front of the saw.
In flat cutting of wide timber the extension piece H is lifted sufficiently high
to allow the timber to pass under it and the hood D then remains stationary.
At the front end of the hood I fix a small roller K against which the end of the
timber M comes in contact as it is pressed forward to the saw, the roller mount-
ing it causes the hood D to swing back on its pivot e sufficiently far to admit the
timber.
Above the roller K is placed a second roller L fixed to the hood D which presses
against the timber and holds up and guides the last corner of the timber in lieu
of the hand at the most dangerous and critical part of the operation.
The hood D is held in position when in operation by a weight N connected to
the hood by a cord n passing over a pulley o supported by a bracket O fixed to
the saw bench. The cord n is connected to the hood D by a set screw n¹. The
hood is provided with a stop e¹ to prevent it being drawn too far forward by the
weight N and with a stop ell to prevent it swinging too far back in the reverse
direction.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. A guard for circular saws constructed with a swinging hood pivoted to move
in a horizontal plane clear of the saw blade the arm upon which it is mounted
being raised and lowered in an inclined slide by means of a screw so that the hood
advances or recedes as it is raised or lowered to cover saws of greater or less
diameter substantially as described.
2. A guard for circular saws constructed with a swinging hood pivoted to move
in a horizontal plane a supporting arm to which the hood is pivoted an inclined
bracket in which the supporting arm moves up and down as required a screw
fitted to the inclined bracket for raising and lowering the hood and an adjust-
able extension piece fitted to the front of the hood to cover the front edge of the
saw when the hood is raised substantially as described.
3. In a guard for circular saws the combination with a swinging hood pivoted
to move in a horizontal plane of a roller such as K by which the guard is held open
as the timber passes and of a roller such as L to hold and guide the last corner
of the timber to the saw, substantially as described.
4. A guard for circular saws having the several parts constructed and arranged
in combination substantially as described and shown.
Dated this 6th day of January 1898.
WM. P. THOMPSON & Co.,
6, Bank Street, Manchester, Patent Agents.