Improvements in Lifting Jacks or Apparatus for Raising and Lowering.
Year: 1888

page_text: Improvements in Lifting Jacks or Apparatus for Raising and
Lowering.
I FRANCIS HENRY SLEEPER of Coaticook in the Province of Quebec in the
Dominion of Canada, Mechanic 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 has for its object the production of a novel and simple lifting
jack or apparatus for raising and lowering one possessing great power and efficiency.
The lifting jack herein described is composed of a base or standard closed at one
end to form a seat, a lifting piece fitted to slide in the base and provided with a screw
threaded hub; a lifting screw which has one of its ends resting in the said seat and
its other end engaging the threaded hub of the lifting piece to elevate the said lifting
piece, and gearing wholly within the base to actuate the lifting screw.
Figure 1 is a side elevation of my invention, partially broken out, to shew the
actuating mechanism, and
Figure 2 a section of Figure 1 on the line -
one side to show a portion of the gears a³, a².
looking down and broken out at
In the accompanying drawings A is a base or standard of cast iron or steel, closed
at one end to form a step, see Figure 1, for the lifting screw b.
A lifting piece B is fitted to slide in the base A in such manner, that it cannot
rotate in the same but can move freely up or down.
This is accomplished by slotting the lifting piece longitudinally, as at 6', in which
slot the locking ear 62 enters, the said locking ear 2 being secured to any suitable
projections from the base A by means of a pivot pin b³.
The lifting piece is provided at its top with a suitable cross-head, and has within it
a hub B¹, partially shewn in section in Figure 1, screw-threaded to receive one end

page_text: of the lifting screw b, the other end of the said screw resting in the step c in the
centre of the closed end of the standard A.
The screw has a gear a secured to its lower end, and a beveled gear a having a
downwardly extended-hub is loosely fitted eccentrically upon the screw and rests upon
the gear a
The beveled gear a' is moved by a second
pawl-carrying crank a' and ratchet a² upon the which is actuated by means of a
attached.
shaft a³, to which the bevel gear a¹ is
The pawl-carrying crank a¹ is provided with a lever a, which may be used to increase
the leverage, and as the crank and ratchet are placed upon the horizontal shaft a³, the
lever, when used, moves in a vertical plane and is used in the same manner as the
pump lever of a hydraulic jack, and as the ratchet is double acting it may be used
either to raise or lower the lifting piece b.
The hub of the bevel gear a is turned to form an eccentric, the throw of which is
equal to the difference in diameter between the gear A' and a.
The gear a is double having external teeth, that engage with those of the internal
gear A which is integral with the base A, and internal tooth which engage with those
of the gear a².
The operation of the jack is as follows: the crank a¹ is turned in the required
direction, and gives its motion by means of the pawl and ratchet to the shaft a³, and
thence to the beveled gears a and a.
As the bevel gear a rotates about the screw b, the gear a", which is fitted loosely
upon the eccentric hub of the bevel a³, is also carried about the screw b, but as the
external teeth of the gear a engage with those of the internal gear A¹, the gear ασ
will be rotated on its axis only in proportion to the difference in the number of teeth
in the gear A and the external part of the gear aº.
As the gear a so rotates on its axis, its internal teeth engage with the teeth of the
gear a and cause it and the screw b, to which the said gear a' is fastened, to rotate
in the same direction in proportion to the difference in the number of teeth in the
gear a and the internal part of the gear a..
The screw b as it rotates to the left or right engages the screw-threaded hub B' and
causes the lifting piece to ascend and descend, and as the base A is of sufficient
strength to prevent any cramping or binding, the whole power of the screw is brought
to bear directly upon the work.
The screw and gearing being entirely within the base A are protected from dust or
injury in any way and can be kept well oiled, the friction being thereby much less in
proportion to the power than in the ordinary form of lifting jack.
I do not claim the particular shapo of this lifting jack or of its component parts,
nor do I bind myself to any proportion or size of gearing, as it will be necessary to
arrange the construction of the same according to the power required and the spaco
to be occupied.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. In a lifting jack or apparatus for raising and lowering, the base closed at one
end to form a seat, and a lifting piece fitted to slide in the base and provided with a
screw-threaded hub, combined with a lifting screw having one of its ends resting in
the said seat and its other end engaging the threaded hub of the lifting pieco to
elevate or depress the said lifting piece, and gearing wholly within the base, to actuate
the lifting screw, substantially as described.
2. In a lifting jack or apparatus for raising and lowering, the base A closed at ono
end to form a seat c, and the internal gear A', combined with the lifting screw b, and
gear a fast upon the said lifting screw, and with gearing to operate the same,
substantially as described.
3. In a lifting jack or apparatus for raising and lowering, a baso closed at one end,
and provided with an internal gear A', a lifting piece, and a lifting screw and its

page_text: attached gear a', combined with the gear at actuated by a pawl and ratchet, and
the intermediate gears a³, and aº, substantially as and for the purpose described.
4. In a lifting jack, or apparatus for raising and lowering, a base closed at one
end and provided with an internal gear A', a lifting piece sliding therein and slotted
as at 6, and the locking device consisting of the car b pivoted at 63, the said ear
being adapted to enter said slot and lock the lifting piece, and a lifting screw and its
attached gear a', combined with the gear a actuated by a pawl and ratchet, and the
intermediate gears aº and a, substantially as and for the purpose described.
Dated the 10th day of March 1000:
WM. BROOKES & SON,
55 & 56, Chancery Lane, London,
Agents for the Applicant.