Improvements in Lifting Jacks.
Year: 1898

page_text: Date of Application, 26th May, 1898-Accepted, 10th Sept., 1898
Improvements in Lifting Jacks.
We, GEORG EWALD SCHMIDT, and HUGO KOTTHAUS, both of Remscheid,
Germany, Manufacturers, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
Our invention relates to improvements in lifting jacks and it has for its object
to raise a load to double the height of the length of the rack by using two racks
placed side by side one of them, supporting the load and capable of being raised
out of the box or casing of the lifting jack the other standing on the ground
serving to raise the casing together with the first named rack by a special arrange-
ment of wheels and pinions, which are so fixed on their respective spindles that
they can be set in or out of gear and by a separate set of ratchet wheel and pawl.
Fig. 1 is a side view of the new lifting jack both racks and casing in their
lowest or turned down position, one of the sides plates taken off;
Fig. 2 is a front view of Fig. 1, a front plate taken off;
Fig. 3 is a side view showing the casing partly raised and also the respective
rack raised out of the casing;
Fig. 4 is a cross section along line I-I of Fig. 1;
Fig. 5 is a section along line II-II of Fig. 2 with the gear wheel keyed fast in
working order;
Fig. 6 is a similar section with the key pushed out of working order with the
gear wheel;
A is the box or casing of the lifting jack, which is preferably made of plates
rivetted or otherwise put together; stiffening stays B and B are placed where
found desirable; the top of the casing is closed, but allowing the rack C to pass
through, this rack has a claw or foot D at its lower end passing through a slot E
in the side A¹ of the casing. At the bottom the casing is open and the rack F
enters therein from below; at its foot this rack is provided with a block G forming
the support and footstand of the lifting jack. It will be seen that both racks C
and F are guided by the stays B and B and that they are guiding each other.
Crossways in the casing and journalled in the side plates A1, A2 are placed the
shafts or spidles H1, H2, H3, H and H. H being the first motion shaft and
having the crank handle J fixed upon it and a pinion K; this pinion gears into
the wheel K' upon the spindle H to which are also keyed the pinions L, L', and
the first of these again is in gear with the wheel M on the spindle H³, which
also carries the pinion M', and this gears into the rack C.
At the outer end of spindle H³ is keyed thereon a ratchet wheel N working
together with a pawl N¹ conveniently fixed to the casing.
As described so far it will be easily understood that by turning the handle J
in the direction indicated by the arrow (Fig. 3) the rack C will be raised out of
the casing the ratchet wheel N and pawl N₁ prevent the running back of the
rack and the load placed thereon.
Now the pinion L₁ is in gear with the intermediate wheel O on spindle H
and this wheel sets in motion the wheel P on spindle H5 to which is keyed the

page_text: pinion P¹ which is in gear with the rack F. At the end of spindle H³ is a ratchet
wheel Q working together with a pawl Q', and it will be understood that by
turning the handle J, as stated before, the casing with all parts, connected
thereto will be raised or wound up along the rack F and therefore a load upon
the rack C will be raised at double the speed and double the height attained by
an ordinary lifting jack with same length of the rack.
Now in working, as described before, double the power will be required, if the
handle is turned at the same speed, as in a lifting jack with a single rack, because
the load is raised at double the speed. This is not desirable in all cases and
therefore means are provided allowing slow working by setting out of gear either
of the racks F and until the other has raised the load the height corresponding
to its length, thus both racks can be put in gear alternately and the load is
raised to the full height of the capacity of this litting jack in two periods. Figs. 5
and 6 show the device for setting in and out of gear the wheel P permitting
this working in two steps. The wheel and pinion 1, "are held on the shaft H³
by a key S; this key can be shifted in an axial direction so that the wheel P
thereby will be coupled to the shaft as in Fig. 5 or that it will be free to turn
round upon the shaft as in Fig. 6, and it will be easily understood, that when
the key S is in the position shown by Fig. 6 the wheel P will be turned round
on the shaft Hs without setting this in motion and then of course the pinion P¹
is also held still and no raising of the casing A takes place. In exactly the same
manner the wheel M is keyed to its shaft H³. Hence it follows that a load can
be raised by rack working alone and like in an ordinary lifting jack in the
first period, when the wheel P is held loose on shaft H and if hereupon the wheel P
is keyed fast and the key of wheel M is brought into the position shown in Fig. 6
with regard to wheel P the load can be raised by further turning the handle and
by thus raising the casing together with the rack C.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:
1.) In a lifting jack the combination of a hollow casing A with a rack U guided
in said casing by stays B and B and by a foot D passing through a slot E in
said casing, a crank FJ on a spindle H journailed in the side plates of said
casing and carrying a pinion K; a wheel K gearing with pinion K, said wheel K
being keyed on a shatt H2 also journailed in the side plates of the casing and
carrying pinions L and L', a wheel M gearing with pinion L, said wheel M being
held by a sliding key on a shaft Hs again journalied in the side plates of the
casing and carrying a pinion Mi' which gears into the said rack C and lifting it
when set in motion as described and illustrated and for the purpose set forth.
2.) In a lifting jack the combination of a hollow casing A with a rack C, a
rack F at the side of rack C, both guided by stays B and B₁; a footblock Gat
the lower end of rack F; a crank J on a spindle it', journalled in the side plates
of said casing; a pinion K on said spindle gearing with a wheel K¹ on a shaft H²
also journalled in the side plates of the casing; a pinion L on said shaft H²
gearing with a wheel M. being held by a sliding key on a shaft H³, this shaft
being also journalled in the side plates of said casing and carrying a pinion M¹
gearing with said rack C, on a shaft H an intermediate wheel O gearing with the
pinion L'; a shaft H³ carrying a wheel P keyed to the shaft by a sliding key S
and gearing with said wheel and a pinion P1 gearing with the rack F, the
whole as described and illustrated and for the purpose set forth.
3.) In a lifting jack the combination of a hollow casing A with a rack C, a
rack F at the side of rack C, said rack F having a footblock G at the lower end
a crank J on a spindle H¹ journalled in the side plates of the casing, a pinion K
on said spindle gearing, with a wheel K on a shaft H2; pinions L and L¹ on said
shaft H, the first one gearing with a wheel M on a shaft H³, which is also jour-
nalled in side plates of said casing, a pinion M' held by a sliding key on shaft H³

page_text: and gearing with the rack C; an intermediate wheel on a shaft H+ and gearing
with said pinion L'; a wheel P gearing with wheel O and being so held on a
shaft H that by a sliding key S it will be coupled to said shaft H or according
to the position of the key it will be allowed to turn loosely round on said shaft,
5 which also, carries a pinion P', gearing with the rack F; the whole as described
and illustrated and for the purpose set forth.
Dated this 18th day of May 1898
GEORG EWALD SCHMIDT,
HUGO KOTTHAUS,
Per Karl J. Mayer, Agent.