An Improvement in Screw Threads.
Year: 1892

page_text: Date of Application, 16th Feb., 1892
Complete Specification Left, 28th Oct., 1892-Accepted, 3rd Dec., 1892
PROVISIONAL SPECIFICATION.
An Improvement in Screw Threads.
We, THOMAS SMITHIES TAYLOR, WILLIAM TAYLOR, and HERBERT
WILLIAM HOBSON, all of Slate Street, Leicester, in the County of Leicester,
Scientific Instrument Makers, do hereby declare the nature of this invention to
be as follows:-
In screwing a male screw, especially one of considerable diameter and fine pitch
into a female screw, it is often very difficult to hit on the position where the
threads should become engaged and to hold the screws in the proper axial direction
to ensure the engagement. Our invention relates to means of facilitating the
engagement of screws of this kind particularly such as are employed for telescopes,
photographic lenses, and other optical instruments. For this purpose, we cut off
at the front end of the screw the usual tapering portion of the male thread so as
to begin the thread from a point where it is of full section or nearly so, and in
like manner we cut off the tapering portion of the female thread at the mouth, we
can then enter the point of the male screw freely into the mouth of the female,
and turning either of them backwards, we can bring the threads into such a position
that the end of the one thread passes the end of the other and snaps into position
for engagement, so that, on now turning either in the right direction, the screwing
is at once started.
In order still farther to facilitate the engagement of the threads, the two
screwed pieces may have visible or palpable marks upon them to be brought into
coincidence by the operator when the two screws are in position for at once
engaging.
Dated this 16th day of February 1892.
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
An Improvement in Screw Threads.
We, THOMAS SMITHIES TAYLOR, WILLIAM TAYLOR and HERBERT
WILLIAM HOBSON, all of Slate Street, Leicester, in the County of Leicester,
Scientific Instrument Makers, 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 :-
In screwing a male screw, especially one of considerable diameter and fine pitch
into a female screw, it is often very difficult to hit on the position where the
threads should become engaged and to hold the screws in the proper axial direction
to ensure the engagement. Our invention relates to means of facilitating the
engagement of screws of this kind. particularly such as are employed for telescopes,
photographic lenses and other optical instruments. For this purpose, we treat the
screws as we shall describe with reference to the accompanying drawing which
shews a male screw A in elevation and a female screw B in section. We cut off
at the front end of the screw the usual tapering portion of the male screw, so as
to begin the thread from a point such as C where it is of full section or nearly so,
and in like manner we cut off the tapering portion of the female thread at the
mouth so that this thread also begins abruptly as indicated at D. We can then
enter the point of the male screw freely into the mouth of the feinale, and turning
either of them backwards, we can bring the threads into such a position that the
Doll

page_text: end C of the one thread passes the end D of the other and snaps into position for
engagement, so that on now turning either in the right direction, the screwing is at
once started.
In order still farther to facilitate the engagement of the threads, the two
screwed pieces may have visible or palpable marks upon them to be brought into
coincidence by the operator when the two screws are in position for at once
engaging.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, we declare that what we
claim is :-
Removing the tapering portions of screw threads at their termination, substan-
tially as and for the purpose set forth.
Dated this 21st day of October 1892.