IMPROVEMENTS IN SCREW LIFTING JACKS.
Year: 1877

page_text: 733
LETTERS PATENT to Martin Benson, of No. 9, Southampton Buildings, London,
for the Invention of "IMPROVEMENTS IN SCREW LIFTING JACKS.'
A com-
munication from abroad by Jacob O. Joyce, of Dayton, in the State of Ohio,
United States of North America.
Sealed the 21st August 1877, and dated the 26th March 1877.
"
PROVISIONAL SPECIFICATION left by the said Martin Benson at the Offico
"IMPROVEMENTS IN
of the Commissioners of Patents on the 26th March 1877.
MARTIN BENSON, of No. 9, Southampton Buildings, London.
SCREW LIFTING JACKS."" A communication from abroad by Jacob O. Joyce, of
Dayton, in the State of Ohio, United States of North America.
My improvements consists in constructing screw lifting jacks in such a manner
that the nut or nuts may be unshipped from the screw, so that the screw may be
lifted directly up or down for applying the jack direct to its work to avoid the
necessity of turning the screw up or down to suit the position of of the object to
be lifted or acted on for the purpose of saving time in applying the jack to use.
The accompanying Drawings illustrate one method of constructing the jack.
Fig. 1 is in part a sectional elevation through the nut stock and screw; and
Fig. 2 is a transverse section through the nut and stock of the jack.
D is the stock usually made of cast or wrought iron, if desired, or other suitable
material, and provided with a slot to receive the two nuts B, B; the nuts are
provided with guide pins a, a, and work in oblong openings C, C, in the stock, so that
the nut B, B, may be unshipped or detached from the screw A, either by lifting the
screw up or drawing the nuts away from it, which permits of the screw being placed
up or down to suit the elevation of the work, and thereby save time in turning
the screw up or down to the proper position for applying the jack to use.
Instead of guide pins a, a, passing through the nuts B, B, to guide the nuts to
and from the scrow A, as described, the nuts may be provided with tongues and the
stock with grooves for guiding and holding the nuts in the stock of the jack, or any
other known method may be employed for holding the nuts, and shipping and
Dell

page_text: unshipping them from the screw. The nuts B, B, fall into gear with the screw as
soon as the screw comes to rest by their own gravity.
The improvement is applicable to any of the known screw jack, including the
traversing jack. The threads on the nuts B, B, are usually cast on them, and the
nuts may be made of brass or cast malleable iron.
The Drawings fully show the form of the thread on the screw, and general
arrangements of parts sufficient to be understood by skilled persons in the art.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Martin Benson in the Great Seal Patent Office on the 23rd August
1877.
227
MARTIN BENSON, of No. 9, Southampton Buildings, London. "IMPROVEMENTS IN
'SCREW LIFTING JACKS.' A communication from abroad by Jacob O. Joyce, of
Dayton, in the State of Ohio, United States of North America.
My improvement consists in constructing "screw lifting jacks" in such a manner
that the nut by splitting or dividing it into two or more parts may be unshipped
from the screw, so that the screw may be lifted directly up or down for applying
the jack direct to its work to avoid the necessity of turning the screw up or
down to suit the position of the object to be lifted or acted on for the purpose of
saving time in applying the jack to use.
The accompanying Drawings show the construction of the jack, of which,—
Fig. 1 is an elevation of the instrument.
Fig. 2 is a longitudinal sectional elovation through the nuts, stock, and screw.
Fig. 3 is a transverse section through the nuts and stock.
Fig. 4 is a top view of a ratchet lever of ordinary construction for working the
screw of the jack; and Fig. 5 is a separate side view of the nut.
D is the stock usually made of cast or wrought iron (if desired), or other suitable
material, and provided with a slot to receive the two half or split nuts B, B; the
nuts are provided with guide pins a, a, ono at each, and work in two oblong angular
openings C, C, in the stock D, so that the nuts B, B, may be unshipped or detached
from the screw A either by lifting the screw up or drawing the nuts away from it
by the rings d, d, shewn in Fig. 1 and 5, which permits of the screw being placed
up or down to suit the elevation of the work, and thereby save time in turning the
screw up or down to the proper position for applying the jack to use.
angle of the slots C, C, in the stock of the jack are usually made of an angle of 45°
with the axis of the screw, but for all cases the angularity of the slots must be
sufficient to prevent the half or split nuts B, B, from unshipping themselves from
the screw A. by reason of the load or pressure on the screw while the jack is
in use.
The
Instead of guide pins a, a, passing through the nuts B, B, to guide the nuts to
and from the screw A, as described, the nuts may be provided with tongues and the
stock with grooves for guiding and holding the nuts in the stock D of the jack, or
any other known method may be employed for holding the nuts, and shipping and
unshipping them from the screw. The nuts B, B, fall into gear with the screw as
soon as the screw comes to rest by their own gravity.
The improvement is applicable to any of the known screw jacks, including the
traversing jack. The threads on the nuts B, B, are usually cast on them, and the
nuts may be made of brass, cast, or cast malleable iron.
The Drawings fully show the form of the thread on the screw; in this case an
ordinary ratchet lever f is used for working the screw A, as represented, but if
desired the screw may be provided with a spherical head, and holes made through it
at right angles for receiving an ordinary lever for working the screw; the smaller
screw jacks will be thus constructed.

page_text: Instead of the stock D being made wholly of cast iron the body portion of it for
the smaller jacks (if desired) may be made of wrought-iron tubing of the required
strength, and the foot and nut portion of the jack made of cast metal and screwed
to the tubing, forming the body of the jack, and the screw A. of the smaller jacks (if
desired) may be worked by a hand wheel instead of a lever.
Having now described the construction and working of my improvement, what
I claim as my Invention is, the manner of constructing, working, and using the
nuts or split nuts B, B, provided with guide pins a, a, or their mechanical
equivalents working in angular oblong slots C, C, in the stock D or their mechanical
equivalents, all for the purposes as herein-before described.
In witness whereof, I, the said Martin Bouson, have hereunto set my hand
and seal, this 13th day of August, in the year of our Lord 1877.
MARTIN RENSON Gol