Improvements in or relating to Crank Driving Mechanism or Gear.
Year: 1899

page_text: Date of Application, 20th Nov., 1899-Accepted, 2nd June, 1900
COMPLETE SPECIFICATION.
Improvements in or relating to Crank Driving Mechanism or Gear.
I, HEINRICH LOEWE, of Prinz Regentenstrasse 56, Deutch-Wilmersdorf, near
Berlin, in the Empire of Germany, Engineer, 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: -
The object of the present invention is a crank driving mechanism which may
be used for instance on cycles motor vehicles, steam engines, and the like and
which presents a variable leverage of high efficiency.
A sliding block fixed on the crank axle transfers its rotary movement to a link
which is movable in guides on a disk thus causing the latter to revolve. In order
to increase the velocity ratio a second sliding block can be fixed on the said
disk engaging on the one side again into a movable link on the second disk,
which arrangement may be repeated as often as desired, thus at each time
increasing the velocity ratio accordingly.
In the annexed drawing the improved crank mechanism is shown in two
different forms of construction as employed for a cycle.
Fig. 1 is a front elevation and
Fig. 2 a section of the single form of construction.
Figs. 3 and 4 similar views of a form of construction in which the mechanism
is employed in duplicate one beside the other.
Tightly fixed to the crank axle is a sliding block b which is so guided in
the link that the latter follows each of the revolutions of the crank axle k and
therefore also of the crank. is a ring fixed stationary to the frame by aid
of a clamp. The centre of ring is eccentric with that of the crank axle.
Inside this ring d revolves a disk e which is perforated for the sake of lightness.
It carries on its front two guide bars f between which the link moves. In the
example shown the disk e carries also a chain wheel g from which the movement
may be transferred to the driving wheel by means of a chain. Disk e, guide
bars f and chain wheel are fastened together and revolve together.
At all points where friction occurs ball bearings or friction rollers may be
arranged, thus reducing the friction to a minimum."
The action is as follows:
The sliding block when put into rotation causes the link c to participate
therein, but the latter being held in the guides f of the disk e will therefore
cause the said disk e to rotate in the stationary ring d so that the link c is at the
same time moved in its guides f.
It is evident that the active length of the lever depends on the position which
the centre of disc e has with regard to the centre of crank axle a. If both
centres coincided so that the disc e were not fixed eccentrically, the length of the
diameter of the disc would be the same as that of the crank. The greater the
cccentricity of the two centres, the greater will also be while preserving the same

page_text: dimensions, the leverage exerted by the crank upon the link e, the disc e and
the sprocket wheel g fastened to the latter.
It is therefore possible in making the eccentricity variable by suitable means
to have a means in hand of varying leverage according to the different position
of the lever, the length of the latter increasing from the highest to the lowest,
and decreasing from the lowest to the highest position.
Figs. 3 and 4 show a form slightly modified in which a small toothed wheel
is revolved by the link which by means of a second sliding block engages into a
second link revolving a second disk transferring the movement to another toothed
wheel and a chain wheel connected therewith from which the movement is
transferred to the driving wheel by means of a chain or the like. For the sake of
clearness the respective parts having the same form are marked with the same
reference letters, those having a different form are marked with the same letters
and the index numeral whilst the parts of the second arrangement are marked
with corresponding capital letters.
The crank shaft a carries a tightly fixed sliding block b having movement in
the link . The latter is movable in the guides f arranged on a ring e¹ rotating in
a stationary ring d' screwed to the casing forming part of the frame. The ring el
being internally toothed puts a toothed wheel A turning freely on the axle a in
motion. A second sliding block B is tightly joined with the said toothed
wheel A and guided in a second link C which can move in the same manner as
before described in the guides 1 fastened on the ring E. The latter running in
a stationary ring 1) is provided with internal teeth and transfers its motion to
a toothed wheel G tightly joined with the chain wheel K but revolving freely
on the crank axle a.
Of course the toothed wheel & could again be connected with a sliding block
engaging into a third link putting in motion a ring and a loosely turning toothed
wheel in the manner before described.
SO
In this manner the velocity ratio can be increased as much as desired.
The casings is provided with short lengths of tubing as shown in Fig. 3
that it may be fastened directly on the frame tubes rr thus enabling the whole
mechanism to be arranged symmetrically in the centre plane of the bicycle.
This would prevent the bicycle from inclining to the side on which the chain
wheel is arranged as was hitherto the case.
The casings may also be protected against penetration of dust by a cover p
(Fig. 4) screwed on to the sides thereof. This at the same time enables all the
working parts to run in oil thus obtaining the smoothest possible working and
the least possible wear of the parts.
As already mentioned the before described crank mechanism can also be used
for other purposes than cycle driving, for instance especially for motor vehicles.
If the combined form be used for driving screw propellers on vessels, it would
allow of using slowly running engines thus avoiding all harmful vibrations so
destructive to vessel's hulls.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. In a crank lever mechanism, a sliding block fixed on the crank shaft
ing into a link which is movable in guides on a rotating ring running in a
engag
stationary ring eccentrically to the crank shaft and means for transferring this
motion substantially as shown and described.
4
5
2. In a crank lever mechanism, a sliding block fixed on the crank shaft
engaging into a link which is movable in guides in a ring rotating in a stationary
disk arranged eccentrically to the crank shaft, this ring being provided with
internal teeth, a toothed wheel running in said ring and turning freely on the
crank shaft, a second sliding block being joined with said toothed wheel and 5
guided in a second link which is movable in another guide on a second rotating

page_text: ring running in a stationary disc arranged eccentrically to the crank shaft the
rotating ring bearing internal teeth, a second toothed wheel running in said
toothed ring and being joined to a driving wheel, substantially as shown and
described.
Dated this 20th day of November 1899
HERBERT HADDAN & Co.,
Agents to Applicant, 18, Buckingham Street, Strand, W.C.