IMPROVEMENTS IN GUARDS FOR CIRCULAR SAWS A communi.
Year: 1882

page_text: LETTERS PATENT to Jasper Wetter of New Wandsworth Surrey for an
Invention of IMPROVEMENTS IN GUARDS FOR CIRCULAR SAWS A communi.
cation to him from abroad by Gretschel and Heinemann, of Leipzig, in the
Kingdom of Saxony
PROVISIONAL SPECIFICATION left by the said Jasper. Wetter at the
Office of the Commissioners of Patents on the 11th November 1882.
JASPER WETTER of New Wandsworth, Surrey, "IMPROVEMENTS IN GUARDS
FOR CIRCULAR SAWS," a communication to me from abroad by Gretschel and
Hinemann, of Leipzig, in the kingdom of Saxony.
This invention has for its object to prevent accidents to workmen, while operating
circular saws. It consists in securing to an adjustable horizontal shaft two
movable guards, one in front, and the other at the back of the saw, the front guard
being composed of two perforated vertical plates placed right and left of the saw-
blade and guided by two sleeves, which are movable along the horizontal shaft and
can be fixed in any suitable position, while the back guard comprises also movable
sleeve secured to the said horizontal shaft and carrying two vertical spring bolts,
one right and one left of the saw blade, each of which bolts carries at the bottom a
roller pressed on the block of wood by means of a spring, so as to prevent the
block of wood from accidentally slanting upward while being sawed. The movable
shaft can be adjusted in a horizontal sleeve carried by the lower extremity of a
vertical or inclined bolt, which is capable of sliding up and down in a fixed bearing
and can be fixed in the latter at the required height.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Jasper Wetter in the Great Seal Patent Office on the 9th May
1883.
JASPER WETTER of New Wandsworth, Surrey, "IMPROVEMENTS IN GUARDS
FOR CIRCULAR SAWS," a communication to me from abroad by Gretschel and 5
Heinemann, of Leipzig, in the Kingdom of Saxony.
The accidents which so frequently take place during the working of circular
saws, have suggested various constructions of guards which, however, are more or
less imperfect and only partly answer the purposes of a perfect guard for circular
EWS.
The tendency of the saw, to depress the wood on one side and to lift it on the other
side, as well as the frequent jolting of the wood to be cut and the tilting resulting
therefrom, are the main points to be considered in the construction of an efficient
guard.
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The present invention has for its object to remove the risks which occur to the
workman in consequence of these conditions, and in describing it reference will
be had to the accompanying drawings Figs. 1 to 6, of which Fig. I is a
longitudinal section, Fig:-2:-a-cross-section, Fig. 3.another cross-section and Fig. 4.
a horizontal-section-of-a-guard applied to a circular saw while Figs. 5 and 6 show
the whole machine on a smaller scale.
The circular saw K is secured to the bench A in any suitable manner and
provided with a guard in front and one at the back. The two guards are mounted
on the horizontal shaft F supported by the column S which is secured to the ceiling
or in any other suitable manner. The column S is provided at its lower end with
the guide-sleeve D¹. The vertical shaft E can be moved up and down in the guide
sleeve D' and fixed in the required position by means of the set screws and a key,
or it may be rendered automatically adjustable within certain limits according to
the thickness of the wood to be cut.
The vertical shaft E is provided at its lower end with the sleeve D, through which
passes the shaft F.
Mounted on the shaft F are the guards G and H.
The guard G consists of the two steel plates ff enclosing the saw-blade on
both sides.
"
The metal plates ff are provided with apertures, i for the purpose of allowing
the saw dust to escape.
The plates ff are connected with the guide sleeves ll and may be of such a size
as to cover the whole saw blade, or only the front part, that is to say where the
blade moves downward.
To prevent the blade from slanting upward the apparatus is provided with an
clastic holding-down fork consisting of the sleeve m which is also adjustable on the
shaft F by means of groove and feather and set scrow.
The sleeve m is provided on both sides with slots n n in which are guided the
posts Pp supporting the rollers resting on both sides of the cut of the wood
and which prevent the wood from slanting upward.
It will be seen that the working blade is enclosed by the guards G. H so as to
avoid the danger to the hands which results from the lateral displacement or tilting
of the wood, and that the slanting upward of the word is prevented by the elastic
rollers.

page_text: CLAIM.
A guard for circular-saws, consisting of the metal plates, ff adjustable on the
shaft F and a holding-down fork likewise adjustable on the shaft F and provided
with rollers r, r adapted to exert an elastic pressure on the wood by means of
springs, in combination with the rod E mado adjustable in the guide sleeve D',
substantially as described.
In Witness whereof I, the said Jasper Wetter have hereunto set my hand and
cool this ninth day of Mov AD 1882
J. WETTER (L.S.)