Year: 1898

page_text: Date of Application, 24th Aug., 1898
Complete Specification Left, 21st Nov., 1898-Accepted, 18th Mar.; 1899
THOMAS EDWARDS CROSSINGHAM, Works Manager, Bushey Park, Bristol,
THOMAS FIELD HOBBS, Managing Partner, Canons Marsh, Bristol, do hereby
declare the nature of this invention to be as follows:-
The object of our invention is to provide a guard for circular saws which shall
automatically move upwards a little in advance of the material to be sawn & which
shall also automatically protect the saw on completion of sawing.
There have been several attempts to attain this end but in daily working it has
been found the guards obstruct the view of the work or saw, are heavy to work or
what is equally objectionable the fixings of the guard have to be removed to
sharpen the saw; the result being that the guard soon falls out of use. Besides
this many fixings make crosscutting difficult or impossible.
We overcome all these objections in our invention by raising the guard (which
may itself be made of stout wire or celluloid on an iron frame) automatically by
means of levers which balance the guard within a pound or so, the said levers being
connected together by a flexible or other well known means to allow of the move-
ment of the fence to which one of the levers is attached, the latter lever being
provided with a friction wheel which is moved forward and upward by the material
to be cut, thereby raising the guard to a height strictly in accordance with the
thickness of the material. The wheel and guard may be arranged to stand always
off the bench 1 or 2 inches so that in cutting thin stuff the guard is not required
to be raised & is yet sufficiently close down to protect the workman. A riving
knife can be used in conjunction with the guard.
Figs. 1, 2 & 3 illustrate several ways in which we carry out our invention.
A is the guard covering the saw. J is a standard fixed to one corner of the
bench & which carries the lever or levers C attached to guard. The balance
weight B is cast as a portion of a pulley to which the cord D) is attached at one
end, and the other end of cord is attached to the similar balance E connected to the
lever on which is 'the friction wheel G working against the fence H.
For small saws i.e. below 12 inches, we use either Eig. 1 working parallel to
the saw or Fig. 2 working at right angles to the saw & we rivet the lever C to the
guard. For larger saws we prefer to use double levers CC pivotted to guard so as
to cause it to move upwards in an arc parallel to the bench as in Fig. 3.
Having now particularly described and ascertained the nature of our invention
and in what manner it is performed we declare that what we claim is:-
The construction of an automatic saw guard raised by means of balanced levers
worked from the fence.
1000

page_text: THOMAS EDWARDS CROSSINGHAM, Bushey Park, Bristol Works Manager,
THOMAS FIELD HOBBS, Canons Marsh, Bristol Managing Partner, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
-
The object of our invention is to provide a guard for circular saws, which shall
automatically move upwards a little in advance of the material & to only such
height as will freely admit the timber to be sawn & which shall also automatically
& completely protect, the saw, on completion of sawing.
There have been several attempts to attain this end, but in daily working it has
been found that (a) the guards as hitherto constructed obstruct the view of the
work or saw, (b) are heavy to work, or what is equally objectionable (c) the fixings
of the guard, have to be removed to sharpen the saw; the result being that the
guard soon falls into disuse. Besides this, many fixings make cross-cutting
difficult, or impossible unless removed.
We overcome all these objections in our invention by raising the guard (which
may itself be made of stout wire, or celluloid on an iron frame) automatically, by
means of levers which balance the guard within a pound or so, the said levers
being connected together by flexible or other well known means to allow of the
movement of the fence, to which one of the levers is attached, the latter lever being
provided with an antifriction wheel which is moved forward & upward by the
material to be cut, thereby raising the guard to a height strictly in accordance with
the thickness of the material. The wheel & guard may be arranged to stand always
off the bench 1 to 2 inches so that in cutting thin stuff, the guard is not required
to be raised & is yet sufficiently close down, to protect the workmen. A riving
knife can be used in conjunction with the guard if desired.
Figs. 1, 2 & 3 in the drawings left with our Provisional Specification illustrate
several ways in which we carry out our invention.
A is the guard covering the saw, J is a standard fixed to one corner of the
bench & which carries the lever or levers C fixed to guard. The balance
weights B are conveniently cast as portions of a pulley to which the cord 1) is
attached at one end & the other end of the cord to the similar balance E connected
to lever F on which is the antifriction wheel G working against the fence H.
For small saws-i.c.-below 12 inches we use either Fig. 1 working parallel to
the saw or Fig. 2, working at right angles to the saw & we rivet the lever C to
the guard. For larger saws we prefer to use double levers CC, connected by a
link to insure parallel movement of guard to which the levers are pivoted so as to
cause it to move upwards in an are parallel to the bench as in Fig. 3.
Having now particularly described & ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is:-
The construction of an automatic saw guard raised by means of balanced levers
worked from the fence.
THOMAS EDWARDS CROSSINGHAM.
THOMAS FIELD HOBBS.