Improvements in or Connected with Shields for Circular Saws for Protection against Accidents.
Year: 1889

page_text: Date of Application, 6th June, 1889-Accepted, 13th July, 1889
CUMI MELE
DIECIFICATION.
Improvements in or Connected with Shields for Circular Saws for
Protection against Accidents.
1, JACOB WEISS, of No. 27, Marktstrasse, Bielefeld, in the Kingdom of Prussia
and German Empire, Manufacturer, do hereby declare the nature of my said inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
In the annexed drawings will be found represented an arrangement according to
this invention for protection against accidents by circular saws. This arrangement
can easily be applied over the saw, acts with safety, and does not interfere with
the workman.
Figures 1 and 2 shew the mechanisms of this protector in elevation, in its lowered
and in its partly raised positions.
Figure 3 is a plan of same; and
Figure 4 is a cross section at the line x. x. Figure 1.
With reference to Figure 1, behind the blade of the saw a a splitting wedge b
is fixed to the bench by means of counter-sunk screws. This splitting wedge
comes in line with the centre of the blade a and keeps the two protection shields d
and d in position. The shields cover the saw completely. The foremost shield is
a frame which is provided with a projecting arm e towards the forepart, consisting
of two members firmly connected at the upper end (Figures 2 and 4).
This projecting arm e is provided with and carries two side pieces g, g¹, hinged
at fand free to move sideways on the said arms e. Where the arm e is attached
to d, a slotted slide 1 (Figure 4) is adapted to slide between the members of the
arm e and is guided by the same, and by the cheeks, h. The knob of the slide i¹
is weighted and is provided at its lower end with plates, ¿¹¹, which lie closely in
front of the blade of the saw.
The side pieces g, g', have projecting teeth, k, which lie and work in recesses
formed in the outer members of the slide, so that when the side pieces g, g¹,
are lifted, the slide will be raised.
Behind the slide are cams m, m³, fastened in such a way to a shaft 1, that
they will turn; this shaft is borne by the protection shield d. These cams are
provided with studs n. On the surface of the protection shield d there are provided
studs o which limit the travel of the cams m, ml. The protection shield d' is a
light hood fitting over the splitting wedge b. When at rest, the apparatus is in
the position shewn in Figure 1; but when the operation of sawing begins, the
whole mechanism of the forward shield is raised by the wood inserted under
it; the cams m, m³, rest upon the wood, and as they are provided with rough
edges, they turn as the wood is fed forward, so that the studs n are moved down-
wards and with them the teeth k of the arms g, g¹, and the slide borne by said
arms, said slide, owing to its weight, fails down and rests upon the wood to be
sawn as do likewise the arms 9, g¹.
It is quite impossible that the fingers of the workman can get in front of the
slide, for the latter can only move perpendicularly, and the workman would
receive warning by the descending slide, not to touch the wood. Even the
strongest pressure of the fingers sideways cannot raise the slide; at the utmost it
becomes more firmly wedged, and it is therefore quite impossible that the fingers can
be wounded.
As soon as the piece of wood under operation has been pushed forward to the
extent that the slide ¹ no longer rests upon it, its own weight immediately causes
it to fall upon the saw bench, and no further pushing of the wood can take place.

page_text: The piece of wood under operation can also be moved backwards without
hindrance, for as soon as the wood, on going back, reverses the cams m, m², (which
are stopped by the studs o when the studs n are in their lower position) and while
the wood is being pushed forward) the studs n lift the teeth k and thereby the
slide, so that the piece under operation can be run backward by this arrangement
without impediment.
The arrangement of the mechanisms is such that all length and cross-cut sawings
can be done without impediment, the circular saw remaining covered and accidents
being impossible.
Having now particularly described and ascertained the nature of my said Inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
First. A protection arrangement for circular saws characterized by the combination
of a wedge, b, shields, d, d', cams, m, m¹, and devices, g, g',-k, k³, operating
substantially in the manner and for the purposes set forth.
Second. A shield for circular saws adapted to operate substantially in the manner
and for the purposes set forth.
Third. The improved shield for circular saws constructed as set forth with
reference to the Drawings.
Dated this 5th day of June 1889
CHEESBROUGH & ROYSTON,
15, Water Street, Liverpool, Patent Agents.