Improvements relating to Eye-pieces for Sighting Telescopes.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements relating to Eye-pieces for Sighting Telescopes.
I, WILLIAM OTTWAY, Optician, 178, St. John Street Road, Clerkenwell,
London, do hereby declare the nature of this invention to be as follows:-
My invention relates to that form of eye-piece in which the cross wires are
placed between the two lenses, and the object of the invention is to obtain the
perfect adjustment of the eye-piece in a more simple and efficient manner than
heretofore.
In carrying out this invention, I first obtain an approximate adjustment, before
the eye-piece is put together, and I then complete the adjustment after the eye-
piece is in the telescope.
"
For the purpose of approximate adjustment, I mount the frame carrying the
cross-wires in a long screwed fitting, which I attach to the tube forming the
outer portion of the eye-piece, in such a manner that an approximate adjustment
will be obtained, and then, for the purpose of completing the adjustment, the
eye-lens or cell is mounted in a long sleeve, which is intended to project into
the eye-piece, and which is fitted with a screw-fitting of suitable character, and
so placed that, by turning the eyepiece from the outside, the final adjustment
may be conveniently and readily effected.
1000
NEWTON & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements relating to Eye-pieces for Sighting Telescopes.
I, WILLIAM OTTWAY, Optician, 178, St. John Street Road, Clerkenwell,
London, 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 invention relates to that form of eye-piece in which the cross wires are
placed between the two lenses, and the object of the invention is to obtain the
perfect adjustment of the eye-piece in a more simple and efficient manner than
heretofore.
In carrying out this invention, I first obtain an approximate adjustment before
the eye-piece is put together, and I then complete the adjustment after the eye-
piece is in the telescope.
For the purpose of approximate adjustment, I mount the frame carrying the
cross wires in a long screwed fitting, which I attach to the tube forming the

page_text: outer portion of the eye-piece, in such a manner that an approximate adjustment
will be obtained, and then, for the purpose of completing the adjustment, the
eye lens or cell is mounted in a long sleeve, which is intended to project into
'the eye-piece, and which is fitted with a screw-fitting of suitable character, and
so placed that, by turning the eyepiece from the outside, the final adjustment
may be conveniently and readily effected.
In the accompanying drawings,
Fig. 1 is a longitudinal view, partly in section, of an eye-piece of the
Huyghenian form, constructed according to my invention; and
Fig. 2 is a cross section on the line -, Fig. 1.
A is a tube carrying the lens B and the eye-piece lens C. D is a collar which
screws into this tube A, and carries the tube E with a ring or flange F, to
which are secured the cross wires G (see Fig. 2).
His a long externally screwed fitting carrying the eye-piece lens C, and
working in the collar D which is screwed to receive it, so as to vary, as required,
the distance of this lens C from the cross wires G.
For the purpose of taking up slackness or wear, I slit the screwed part of the
collar 1), so as to give a slight grip on the fitting H. When the fitting H is
in the middle of its run, the eye lens C will be adjusted to suit a normal eye.
and any further adjustment is effected by screwing the eye-piece fitting H in o
out of the collar I), as the case may be.
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
1. The means as herein shown and described for obtaining the perfect adjust
ment of the eye-piece in sighting telescopes.
2. An eye-piece for sighting telescopes, in which the eye-lens is mounted in
a fitting adapted to be screwed in or out of a collar forming part of the body
of the eye-piece, as and for the purpose set forth.
Dated this 2nd day of February 1900