IMPROVEMENTS IN SCREW JACKS
Year: 1876

page_text: LETTERS PATENT to Thomas Titley, of Leeds, in the County of York, for the
Invention of "IMPROVEMENTS IN SCREW JACKS."
"
of the Commissioners of Patents on the 13th March 1876.
THOMAS TITLEY, of Leeds, in the County of York. IMPROVEMENTS IN SCREW
JACKS."
My Invention refers to the constructing of screw jacks in such a manner that
not only do I obtain almost double the height of lift to that obtained with the
ordinary screw jack, but also the action in working is much quicker.
"
The standard of the screw jack is of ordinary construction; I provide a hollow
external screw, which is made to work into a nut in the standard. The hollow
external screw is provided with an internal nut, in which is made to work another
screw, cut of a different "hand or angle to the herein-before mentioned hollow.
external screw. When in operation the external screw being turned by means of
an ordinary ratchet arrangement or its equivalent the screw is caused to rise,
carrying with it the internal screw. As soon as the head of the internal screw
comes up to the object to be raised it immediately begins to work out of the nut
contained in the hollow external screw. By both screws rising at the same time
an object is lifted at much quicker speed without any apparent loss of power.
THOMAS TITLEY, of Leeds, in the County of York.
"IMPROVEMENTS IN SCREW

page_text: ordinary scrow jacks, but also the action in working is much quicker than
heretofore.
The standard of the screw jack is of ordinary construction. I provide a hollow
external screw, which is made to work into a nut in the standard. The hollow
external screw is provided with an internal nut, in which is made to work another
screw cut of a different "hand" or angle to the herein-before mentioned hollow
external screw. When in operation, the external screw being turned by means of
an ordinary ratchet arrangeinent or its equivalent, the screw is caused to rise,
carrying with it the internal screw. As soon as the head of the internal screw
comes up to the object to be raised it immediately begins to work out of the nut
contained in the hollow external screw. By both screws rising at the same time
an object is lifted up at much quicker speed than heretofore, and without any
apparent loss of power.
And in order that my Invention may be more completely understood reference
is given to the accompanying Sheet of Drawings, and to the letters and marks
thercon.
DESCRIPTION OF DRAWINGS.
Figure 1 is a side clevation; Figure 2, a vertical section; and Figure 3, a plan
looking at the top of a screw jack, constructed according to this Invention.
a is the standard of the screw jack which is of ordinary construction, and fitted
so as to slide freely on a bed plato b, being actuated thereon by the screw c which
works in a nut d fixed to the lower part of the standard a; e is a hollow external
screw which is provided with an internal nut, as shewn, in which is made to work
another screw f. The external screw e and internal screw are made of different
"bands," that is to say, one right hand and the other left hand; the threads in each
may be of different pitches, as shewn.
In order to operate the screw jack I provide a ratchet arrangement g, which
may be of ordinary construction, and keyed or otherwise fixed to the top of the
external screw e; to this ratchet arrangement is attached a lever h of suitable
length. When in operation, the external screw e being turned by means of the
ordinary ratchet arrangement g or its equivalent, the external screw e is caused to
rise, carrying with it the internal screw f; but as soon as the head of the internal
screw comes up to the object to be raised it immediately begins to work out of
the nut formed in the hollow external screw c. By both screws e and frising simul-
taneously out of their respective nuts, an object is lifted at a much quicker speed
than heretofore, and without any alteration or stoppage of the "jack," and also
without any apparent loss of power. The object may be lifted a much greater
height than can be obtained with the ordinary screw jack; the screw jack may be
used without the bed plate b.
Having now described the nature of my said Invention, and shown by Drawings
how the same may be carried into practice, I would have it understood that I do not
limit myself to the exact limits, details, or configuration of the various parts I have
explained and shewn, as the same may of course be varied or modified without
in any way departing from the nature of my Invention; but what I do claim and
desire to be secured to me by Letters Patent is, the arrangement, construction, and
combination of the screws cand f, and parts connected therewith, being so arranged
that when brought into operation they are caused to rise or fall simultaneously,
substantially as and for purposes herein set forth.
In witness whereof, I, the said Thomas Titley, have hereunto set my hand
and seal, this Ninth day of September, in the year of our Lord One
thousand eight hundred and seventy-siv