Improvements in the Stands of Theodolites and other Surveying Instruments.
Year: 1890

page_text: United States of America),
Date of Application (in United Kingdom), 25th July, 1890
Complete Specification Left, 25th July, 1890-Accepted, 27th Sept., 1890
COMPLETE SPECIFICATION.
Improvements in the Stands of Theodolites and other Surveying
Instruments.
I JOHN RUSSELL HANLON of Pennington in the County of Mercer and State of
New Jersey United States of America Vice President of Pennington Seminary and
Teacher of Mathematics do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described ard ascertained in
and by the following statement:-
-
The invention relates to improvements in the stands of theodolites and field-
transits the object being to provide means whereby the telescope can easily have its
height adjusted after the instrument has been levelled; and it consists in the con-
struction arrangement and novel combination of parts hereinafter described, illustrated
in the drawings and particularly pointed out in the claims.
In the accompanying drawings in which similar letters of reference designate
corresponding parts
Figure 1 represents a perspective view of the top or head of a theodolite or transit
stand embodying the invention.
Fig. 2 represents a central vertical section thereof.
The instruments in question are usually mounted on tripods and the height desired
is obtained by moving the legs of the tripod nearer together or farther apart after
which the plates are levelled. The levelling of the plates frequently changes the
height so that it is sometimes necessary to readjust the instrument several times
before it can be levelled at the desired height. By means of my invention this is
obviated, as the telescope has its height accurately adjusted after being levelled.
Referring to the drawings by letter, A designates the limb or upper plate of the
instrument B the lower or levelling plate, O the spindle rising from the plate B
and DD the adjusting screws all of ordinary construction.
E is a boss depending from the limb or upper plate and recessed at e to receive the
upper end of the spindle, which is tapered slightly upward from the lower plate B.
The said boss has its lower portion e' threaded externally and reduced in diameter
below the circumferential shoulder e².
F is a cylinder sleeve fitting on the spindle below the said boss and turning
thereon. is a clamping collar surrounding said sleeve at its lower end above the
plate B, and g is a clamping screw engaging in suitable openings in the lugs or
on the spindle
ears g', g of said collar in order to bind the sleeve when necessary,
and prevent it turning thereon.
The outer surface of the sleeve F above the clamp G is screw threaded to engage
the similarly threaded interior surface of an outer cylindrical sleeve H, the upper end
of which screws upon the threaded part of the boss E and abuts against the
shoulder &².
The sleeve H is provided with the longitudinal slits or slots h, h extending upwards
from its lower end to a suitable height and preferably three in number and equi-
distant.
I is a clamping-collar similar to the collar G surrounding the sleeve H over said

page_text: slits and i is a clamping screw engaging in suitable openings in the ears or lugs of
said clamp to bind the outer sleeve on the inner sleeve and prevent it from rotating
thereon. The slits in the outer sleeve enable the clamp I to bind said sleeve on the
inner sleeve and prevent it turning thereon.
When the clamp G is loosened, the instrument can be turned laterally to any desired
angle.
The operation of the invention is as follows: Tighten the clamp G to prevent
the inner sleeve from turning on the spindle. Then loosen the clamp I and screw
the outer sleeve up to any desired height on the inner sleeve. Then tighten the
clamp I and loosen the clamp G and the instrument may then be turned laterally
to any desired angle the height of the telescope remaining unchanged.
The device is of simple construction and by it much trouble and time may be saved
in the use of the theodolite and transit.
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 :-
1. The combination of the outer internally threaded sleeve with its upper end
attached to the limb or upper plate the inner externally threaded sleeve engaged
within the outer sleeve and a suitable clamp by means of which the outer sleeve may
be prevented from turning on the inner sleeve substantially as specified.
2. The combination of the outer internally threaded sleeve H provided with longi-
tudinal slits extending upward a suitable distance from its lower end, the limb or
upper plate attached to the upper end of said outer sleeve, the inner externally
threaded si eve engaging in the outer sleeve and the clamping collar surrounding the
outer sleeve over the slits substantially as specified.
3. The combination with the spindle rising from the lower plate the inner externally
threaded sleeve rotatable on the spindle and the clamping collar surrounding said
sleeve below its threa le portion and just above the lower plate of the outer internally
threaded sleeve provided with slits extending upward a sufficient distance from its
lower end the upper plate secured to the upper end of the outer sleeve, and the
clamping-collar surrounding the outer sleeve over the slits substantially as specified.
4. The combination with the outer vertical longitudinally split and internally
threaded outer sleeve and the limb or upper plate detachably secured to the upper
end of said sleeve of the inner externally threaded sleeve engaged within said outer
sleeve and a suitable clamp to bind the two sleeves together and prevent independent
rotation substantially as specified.
Dated this 25th day of I……. 1800