IMPROVEMENTS IN SPIRIT- LEVELS
Year: 1880

page_text: LETTERS PATENT to Walter Warder Vaughn, Carpenter, and Asa Clark,
Physician, both of Stockton, County of San Joaquin, State of California,
United States of America, for an Invention of "IMPROVEMENTS IN SPIRIT-
LEVELS
COMPLETE SPECIFICATION filed by the said Walter Warder Vaughn and
Asa Clark at the Office of the Commissioners of Patents on the 25th October
1880.
WALTER WARDER VAUGHN, Carpenter, and ASA CLARK, Physician, both of
Stockton, County of San Joaquin, State of Calfornia, United States of America.
"IMPROVEMENTS IN SPIRIT-LEVELS."
Our Invention relates to certain improvements in spirit levels, and it consists in
the combination with a level having the tubes of the level and plumb placed
midway between the sides, and opening equally to both sides of a reflector, which
is pivoted or journaled above the tube, so that the angle of the reflection may be
changed froin one side to the other and thrown outward to any desired degree.
It further consists in partially enveloping or conting the bubble tube with a
reflecting surface, whereby the image of the bubble in the reflector will be rendered
more distinct, as will be more fully described by reference to the accompanying
Drawings, in which,—
Fig. 1 is a view of the level in a horizontal position, looking at it from below.
Fig. 2 shows the plumb in a vertical position.
Fig. 3 shows the shape of the reflector by which the image of the bubble is
thrown outward so as to be easily seen.
Figure 4 is a modification of the device.
A is the body of our level, which is made of wood or metal in the usual manner,
and it is provided with a longitudinal central tube B filled with a liquid so as to
show a bubble of air in the center when the body A is perfectly horizontal. A
transverse tube is fitted in the level at C for a plumb, these tubes being similar to
the ordinary construction of spirit levels. We have found it most convenient to
form our reflector by having the metal plates or reflectors D, E, polished and
burnished upon the lower surfaces, or plated with nickel or some metal which will
not tarnish. We have shown at E the manner of pivoting or suspending the
Prinn 21

page_text: reflector, so that the image of the air bubble may be thrown downward and
outward to either side and at any desired angle. The journals of this reflector
may be extended from its sides into the sides of the opening in which it is placed;
or if desired an arın F may extend upward from its back and have its upper
A spiral spring
end pivoted in the top of the opening, as shown in Fig. 4.
surrounds the axle of the reflector, and its tension serves to hold the reflector at any
angle desired. By this construction the whole mirror may be swung out from the
interior of the opening which will enable it to show the image of the bubble more
distinctly. In order to render the image of the bubble distinct in obscure light or
in ordinary use, we have enveloped the bubble tube with a bright reflecting
surface which extends around, beneath it, and up the sides, as shown. This
envelope may be independent of the tube, or it may be applied directly in the
same manner as the back of a mirror. A perfectly white backing may also be
used, but we have found the reflecting surface to give the best results and to
greatly assist in making the image of the bubble visible. In order to apply the
level to parts which are out of reach, we employ a rod G which has a screw cut
upon one end. This screw is adapted to fit a socket in one end of the level when
it is desired to test the plumb of a vertical post or wall at a considerable height.
A similar socket is fitted to the lower side of the level, and the rod may be screwed
into this socket to raise the level up to an elevated floor or beam. When not in use
the rod may be inserted into a hole which is made through the level longitudinally,
and by screwing the end into a socket at the further end of the hole, or by other
suitable means, it will be held securely in place. The additional expense is trifling
and the advantages considerable.
Having thus described our Invention, what we claim as new and desire to secure
by Letters Patent is,--
1st. The level A with its tubes B, C, in combination with the mirrors D, E,
situated above the tube and made adjustable, as shown, so as to throw the reflection
of an air bubble downward and outward to any desired angle, substantially as
herein described.
2nd. The level A with its tubes B, C, and the mirrors D, E, adapted to throw
the reflection of the air bubble downward, as shown, in combination with the rod G,
whereby the level may be applied and observed at points above the observer,
substantially as herein described.
In witness whereof, we, the said Walter Warder Vaughn, and Asa Clark,
have hereunto set our hands and seals, this Sixth day of September, in the
year of our Lord One thousand eight hundred and eighty.