IMPROVEMENTS IN TRAVERSING LIFTING JACKS
Year: 1873

page_text: LETTERS PATENT to Benjamin Harrison, of Kingsland, in the County
of Middlesex, Engineer, for the Invention of "IMPROVEMENTS IN
TRAVERSING LIFTING JACKS."
Sealed the 20th February 1874, and dated the 27th December 1873.
PROVISIONAL SPECIFICATION left by the said Benjamin Harrison
at the Office of the Commissioners of Patents, with his Potition,
on the 27th December 1873.
I, BENJAMIN HARRISON, of Kingsland, in the County of Middlesex,
Engineer, do hereby declare the nature of my said Invention for "In-
PROVEMENTS IN TRAVERSING LIFTING JACKS," to be as follows:-
Hitherto travelling jacks have been restricted in the extent of their
traverse to the length of the frame on which they are mounted, thereby
causing great delay and inconvenience.
Now the object of my Invention is to obviate these inconveniences,
which I effect in the following manner :-I mount the body of the jack
upon strong wheels or rollors, the peripheries of which I serrate or cross

page_text: movement or adjustment in the framing or body A, the said movement;
being radial to the opposite bearing 2 and effected by means of a screw H
working through the bearing 1 and actuated by a ratchet lever or other
contrivance, or the adjustment of the bearing 1 may be effected by any
other convenient method.
.
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I represents the elevating portion of the jack which in this instance is
a screw raised or lowered by the worm wheel or nut K bearing or resting,
on the top of the framing or body A. and worked by a worm L, as shown;
but the said elevating portion of the jack may consist in and be worked
by a rack and pinion gear, or by hydraulic pressure, or by any other
well known arrangement of mechanism. The front side of the body or
framing A is open or slotted to its bottom edge, as shewn, so as to allow
of the projecting foot M of the screw or elevating portion I of the jack
to descend below the latter into the ground and thereby enable, a low
purchase to be taken at weights to be raised.
On lifting any weight in the ordinary manner by the projecting
foot M of the elevating portion I, the jack is prevented from tilting by
the supplementary or additional rollers or wheels G, G, which form an
extended base to the jack as before mentioned, and on which as well as
on the main rollers or wheels B, B¹, the whole apparatus takes its
bearing as on the base of any ordinary jack.
By turning the rollers or wheels B, B', and with them the supplementary
or additional rollers or wheels G, G', in cithor direction the jack can be
moved or travelled endwise along the ground accordingly to any required
5 distance, and at the same operation without the inconvenience or necessity
of packing up the weight and taking a fresh purchase, as is the case with
ordinary travelling jacks which are restricted in the extent of travel at
each purchase to the length of their travelling base or frame.
When desired also the jack when travelling may be guided or turned
o to the right or left by inclining the axlo of the roller B to that of the
roller B¹ in the manner previously mentioned; or the guiding arrange-
ment may be dispensed with and the apparatus shifted in the usual
manner. For special purposes the worms actuating the rollers or
wheels G, G, may be made to be readily thrown in or out of gear, with
5 the wheels so that the jack can be pushed along without their aid.
Ono special feature of my improvement consists in giving an increased
form and disposition of material to the lower portion of the framing or

page_text: body A, as shewn, whereby a greater rigidity and strength in the jack is
attained.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used
or carried into effect, I would observe in conclusion that what I consider
to be novel and original and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent is, the appli-
cation and uso of rollers or wheels combined or not with guiding
apparatus to lifting jacks, substantially as and for the purposes herein-
before described and illusted by my accompanying Drawings.
In witness whereof, I, the said Benjamin Harrison, have to this
my Specification set my hand and seal, the Twenty-sixth day of
June, One thousand eight hundred and seventy-four.
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