Improvements in Guards for Circular Saws and other like Machines.
Year: 1898

page_text: PROYIDIONAL SPECIFICATION.
Improvements in Guards for Circular Saws and other like Machines.
I, JOSEPII WHITELEY, Clowes Street Works, Chapel Street, Salford, in the
County of Lancaster, Engineer, do hereby declare the nature of this invention to
be as follows:-
My improvements relate to a guard or screen for shielding circular saws plain-
ing machines or other revolving serrated discs which may be regarded as dangerous
to the attendant or operator.
In carrying my invention into practical effect I arrange a hollow semi-circular
hood, proportioned to amply cover the saw or revolving cutter. The fence side
of the hood is cut away or left open whilst the front or mouth thereof is designed
to slope inwards for the purpose of accommodating the timber to be cut.
The hood proper rests upon a series of rollers and these may be covered with
rubber or other elastic substance if found desirable.
The hood being an essential feature of my invention it is capable of being
designed in several forms. Thus it may take the form of a plain simple cover
to shield the saw or cutter; or it may be made with sliding segments arranged
in such manner that when it is desirable to replace one saw or cutter with another
of different diameter the segments slide in or out, and thus enlarge or decrease
the diameter of the hood-the position of the segments being secured by means
of a wing nut on the front or face of the hood.
In another system of constructing the hood so as to make it capable of accom-
modating different diameters of cutters I design the front or face thereof to take
the form of two curved sections working on a pivot and capable of being expanded
or contracted at the will of the operator and then fixed in position by means of
a binding nut on the end of the pivot.
The hood is then attached to a slide rod working in a suitable guide over head
and in connection with a supporting pillar.
The top portion of the slide rod is arranged to carry a weighted chain suitably
slung over carrier pulleys and in such manner that the whole system becomes
balanced or partly balanced by the counter weight at the end of the chain.
In cases where the conditions are favourable the chain and balance weight may
be arranged to work on carrier pulleys fixed to the cealing or wall of the building
for the purpose of keeping a clear course.
The action of the appliance briefly described is as follows:-
When the timber to be cut is pressed into the sloping mouth of the hood the
pressure or leverage tends to raise the hood and allow the timber free admission
to the saw or cutter. When the timber has passed through or is withdrawn the
hood automatically drops over the saw or cutter and screens the same from danger
or accident.
In cases where the thickness of the timber is unusually great for its free

page_text: entrance into the open mouth the operator may raise the hood by pulling at the
chain or by depressing a lever in connection with the chain or otherwise by means
of a handle attached to the front part of the hood.
Dated this 5th day of September 1898
Improvements in Guards for Circular Saws and other like Machines.
I, JOSEPH WHITELEY, of Clowes Street Works, Chapel Street, Salford, in the
County of Lancaster, 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:—
My improvements relate to a guard or screen for shielding circular saws,
planing machines or other revolving serrated discs which may be regarded as
dangerous to the attendant or operator.
And in order that my invention may be more fully understood I have caused to
be appended hereunto one sheet of drawings marked with letters of reference
indicating like parts in the various figures.
Figs. 1, 3, 4 & 6 are side views, and Figs. 2 & 5 end views of Figs. 1 & 6 respec-
tively of various forms of guards or screens. Figs. 7, 8 & 9 are side views showing
the guard or screen applied to a circular saw in various ways.
In carrying my invention into practical effect and referring to the figures
generally, I arrange the said guard or screen in the form of a hollow semi-circular
hood a proportioned to amply cover the saw or revolving cutter b. The fence side
of the hood a is cut away or left open, whilst the front or mouth thereof may be
designed to slope inwards for the purpose of accommodating the timber to be cut.
The hood a rests upon, or is furnished with a series of rollers c and these may
be covered with rubber or other elastic substance if found desirable.
The said hood being an essential feature of my invention it is capable of being
designed in several forms. Thus it may take the form of a plain simple cover,
to shield the saw or cutter, as shown in Figs. 1 & 2, or it may be made with sliding
segments, as shown in Fig. 3, arranged in such manner that when it is desirable
to replace one saw or cutter with another of different diameter, the segments
slide in or out and thus enlarge or decrease the diameter of the hood the position
of the segments being secured by means of a wing nut d on the front or face of
the hood.
In another system of constructing the hood a so as to make it capable of accom-
modating different diameters of cutters, see Fig. 4, I design the front or face
thereof to take the form of two curved sections e, each working on a pivot f and
capable of being expanded or contracted at the will of the operator and then fixed
in position by means of a binding nut d on the end of the said pivot.
In case of a hand feed planing machine the hood a is formed as shown in
Figs. 5 & 6, closed at each end and segmental.
In order to facilitate the manipulation of the hood a, I attach same to a slide
rod g, see Figs. 7 & 8, working in a suitable guide h over head and in connection
with a supporting pillar i.
The top portion of the slide rod g is arranged to carry a weighted chain k suit-
ably slung over carrier pulleys and in such manner that the whole system
becomes balanced or partly balanced by the counter weight at the end of the
chain, the said weight being adapted to slide in the supporting pillar i.
For the purpose of keeping a clear course and in cases where the conditions are
favourable the chain and balance weight may be arranged to work on carrier

page_text: pulleys fixed to the ceiling or wall of the building, say by means of the guide h
and bracket m, as shown in Fig. 9, the weight being adapted to slide on the
guide h.
The action of the appliance briefly described is as follows;-
When the timber to be cut is pressed into the mouth of the hood the pressure
or leverage tends to raise the hood and allow the timber free admission to the
saw or cutter. When the timber has passed through or is withdrawn the hood
automatically drops over the saw or cutter and screens the same from danger or
accident. In cases where the thickness of the timber is unusually great for the
free entrance into the open mouth, the operator may raise the hood by pulling at
the chain or by depressing a lever in connection with the chain or otherwise by
means of a handle o attached to the front part of the hood.
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:-
1st. A safety guard for circular saws and other like machines, consisting of a
hood or screen suspended by means of a chain and weight and adapted to be
raised or lowered to accommodate the size of revolving cutter and size of material
to be cut, all substantially as set forth.
2nd. The hood or screen a specified in the preceding claim, having a shank g
adapted to slide in a guide h suitably supported and suspended therein by means
of a chain k running over a carrier pulley and having a balance weight n, all
substantially as set forth.
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester,
Agents to Applicant.