Improvements in Lifting Jacks.
Year: 1889

page_text: Date of Application, 8th Jan., 1889
Complete Specification Left, 27th Aug., 1889-Accepted, 28th Sept.. 1889
PROVISIONAL SPECIFICATION.
Improvements in Lifting Jacks.
I JAMES MERRITT SMITH of Greenwich in the County of Fairfield and State of
Connecticut United States of America do hereby declare the nature of this invention
to be as follows:-
This Invention relates to a lifting jack more particularly designed for carriage use.
The jack consists of a post or standard terminating at its lower end in a foot piece,
a hollow bar or case which encloses the upper end of the post and is adapted to slide
up and down thereon, and a curved lever which is fulcrumed on the post or standard
and connected with the hollow bar or case. The standard is in the form of a solid
flat bar vertically slotted and provided with a series of downwardly inclined pockets
adapted to receive the fulcrum-pin of the lever. The lever is connected at its curved
inner upper end with the hollow case by side links which are fitted at their upper and
lower ends over bosses on the sides of the case and lever respectively, and secured by
screws or otherwise. The pivoted connection of these links with the curved upper inner
end of the lever is so situated in relation to the fulcrum-pin that on depressing
the lever the hollow case is raised to give the required lift. As the fulcrum
support is in the single stationary standard, a firm central support is obtained, not
liable to twist the fulcrum-pin out of line and not requiring any nicety of adjust-
ment to keep it in position. The lover is forked at its inner end and is provided
with a stop so arranged that when the lever is fully down the links will be
vertical, or in other words a straight line drawn through the upper and lower
pivots of the links will if extended also pass through the axial line of the fulcrum
pin or nearly so, and this stop by coming against the standard will maintain the
alignment of the pivots and fulerum pin. By this means any shifting of the
fulcrum pin is prevented and the jack is readily secured in its raised position.
Dated this 8th day of January 1889.
J. M. SMITH.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.
COMPLETE SPECIFICATION.
Improvements in Lifting Jacks.
I, JAMES MERRITT SMITH, of Greenwich, in the County of Fairfield, and State of
Connecticut, United States of America, Carriage Smith, 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 :-
This Invention relates more particularly to lifting jacks for carriages; but the
purpose for which the jack is to be used is immaterial só far as the invention is
concerned.
Reference is to be had to the accompanying drawings forming part of this specifi-
cation in which figure 1 represents a partly-Sectional and broken side elevation of a
lifting jack embodying my invention. Figure 2 is a vertical section of the same on.
line figure 1. Figure 3 is a transverse section on line y-y figure 1; and
figure 4 a like section on line - figure 1. Figures 5 and 6 are detail views
of certain parts hereinafter referred to. Similar letters of reference indicate corre-
sponding parts in all the figures.
A is a vertical stationary post or standard having a base or foot piece b. This
standard which is in the form of a solid flat bar, has a lateral vertical slot c
through it having at its one edge a series of downwardly-inclining branch slots or
[Price 8d1

page_text: .
pockets d the lower walls of which form rests or fulcrum supports for the fulcrum-
pin or bolt of the operating lever B. C is a hollow bar or case. constituting
the lifting upright of the jack and which is constructed to enclose and slide up
and down the post A that operates as a guide and lateral support to said lifting
case C. The top of this sliding case C is provided with a platen-head which
may, if desired, be provided with a central aperture gend lips or horns h
and an extension or additional horn below the head f, to adapt the jack to
carriage use. To lighten the construction of the case it may have its sides
perforated, as at k. The curved operating lever arm B which may be adjusted by
means of the vertical slot e to place its fulcrum pin e in. any one of the notches
or branch slots d according to the height the lifting case C is required to start
from, is connected at its curved inner upper end with the sliding lifting case C
by means of opposite side links D D which are fitted at their upper and lower
ends over bosses m m on the sides of the case and operating lever B respectively
and are secured by screws n and washers o, or otherwise. The pivoted connection
of these links D D with the curved inner upper end of the operating lever Bis
above or so situated in relation with the fulcrum pine when in any one of the
fulcrum supports d that on working the lever B down it raises the hollow case C to
give the necessary lift.
1
By the fulcrum supports or rests, d being in the single stationary post or
standard A, a firm central support is obtained for the fulcrum pin e not subject
to twist of said pin out of line or requiring that nicety of adjustment to keep it in
line as when the fulcrum supports for the pin are divided and on opposite sides
or outside of the lifting bar as is the case when the lifting bar is within the
stationary post or standard. The lifting bar or case too, is centrally guided in
its up and down movement.
The operating lever B is slotted on its inner end, as at s, to receive within or
through it the post A and so that the side links 1) D will be free to work on
opposite sides of the post. A and said lever is provided at the lower back end of
said slots with a stop a¹ arranged so that when the lever is fully down or its
main portion is in an approximately horizontal position, as shewn in figure 1, the
links DD will be in an approximately vertical position or, in other words, a
straight line drawn through the upper and lower bosses or pivots of the links-will,
if extended, also pass through the axial line of the fulcrum pin e or nearly so and
the stop a then resting against the edge of the post A will secure such relative
positions of the link pivots and fulcrum pins in approximate alignment with each
other when the lever B is fully down. This causes the line of resistance when
the lifting bar or case is fully raised, to be directly over or it may be a trifle
on the inside to prevent shifting of the fulcrum pine which makes the jack auto-
matically lock itself when raised and prevents the load from deflecting the links D D
outward and lowering the lifting case C and raising the lever B. This forins a
very simple and efficient means of automatically securing the jack in its raised
position.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is;
1. In a lifting jack the combination of the post or standard A having a longi-
tudinal slot c and branch slots & in communication with the longitudinal slot at its
one edge and forming a series of fulcrum rests or supports one above the other, the
hollow outer lifting bar or case C enclosing said standard, a lever provided with a
fulcrum pin or attachment adapted to fit and rest within either of the branch slots d
and in approximate central relation beneath the lifting case, and the side links D
connecting said lever with the case C, substantially as specified.
2. The combination with the hollow lifting case C and the central post or standard A
provided with one or more fulcrum rests or supports, of the lever B provided with a
stop arranged when said lever completes its downward stroke to bear against the post

page_text: or standard, and the side links D connecting the lifting case with said lever above the
fulcrum of the latter and in alignment or thereabout with the axial centre of the
fulcrum when the lever is fully depressed, essentially as, and for the purpose, herein
set forth.
3. The combination of the central post or standard A having a longitudinal slot c
and branch slots or pockets d forming variable fulcrum rests or supports, the hollow
lifting bar or outer case C, the slotted lever B provided with a stop a', fulcrum
pine, and upper arm or portion 1, and the side links D in pivoted connection with the
lifting case and with the arm or portion of the operating lever and with their pivots
in approximate alignment with the fulcrum of the lever when the latter completes its
downstroke and is arrested by its stop, substantially as shewn and described.
Dated this. 26th day of August 1880
J. M. SMITH.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.