Improvements in Crank Mechanisms.
Year: 1890

page_text: Date of Application, 16th Jan., 1890-Accepted, 22nd Feb., 1890
COMPLETE SPECIFICATION.
Improvements in Crank Mechanisms.
I, AUGUSTIN KLUGE, circuit school inspector, and resident of Schönfeldt, Silesia
in the German Empire, 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 :-
My invention relates to an improvement in Crank Shafts having double cranks, and
its object is to avoid the crank resting on the dead centre. In the construction
described in the following specification it is impossible for two cranks placed opposite
each other, to come together on their dead centres.
In order to make my invention more clear, I refer to the accompanying drawings,
in which similar letters denote similar parts throughout the several views.
Fig. 1 shows the mechanism as applied to tricycles bicycles and vehicles generally,.
moved by means of cranks and pedals, or handles.
Fig. 2 is an end elevation of Fig. 1 partly in section.
Fig. 3 shows a modification of Figs. 1 & 2.
Figs. 4 & 5 & 6 show diagrams illustrating the working of the mechanism.
The invention may be employed on bicycles tricycles or vehicles, in general driven
by crank axles, as also for single acting double cylinder engines.
Referring to Figs. 1 & 2: Two excentrics e e are fixed in similar positions to the
frame G of the tricycle, in which frame the crank shaft a runs passing through the
excentrics. To this shaft a the driving wheel or wheels of the machine are fixed.
The arms o and o' are keyed on to the driving shaft and have slits ss in which the
slide blocks t t move. Said slits in arms o o¹ lying parallel to tangents on opposite
sides of the circumference of the axle and on opposite sides of a diameter of the axle
joining such tangents. Slide blocks t t are pivoted to the cranks M M' at z z, whilst
arms M and M' are revoluble on excentrics è e.
The mechanism works in the following manner and its motion may be clearly seen
from figs. 4-5 and 1.
When crank M is pressed downwards by the pedal (Fig. 1) it moves the upper
arm of which is attached to it by slide block and pivot z downwards thus turning the
axle a which moves the arm o in an upward direction. Arm o forces crank M to
move upwards at the same time being attached to it by slide block t and pivot z
since this crank M is making its upward stroke and is consequently not under pressure
of the foot. Now this upward motion of arm M will take place more quickly than
the downward stroke of arm M³, which is retarded by the sliding of block t in slit s
of upper arm o, whilst block t of the lower arm o¹ lies in the end of its slit and
consequently follows the motion of its arm immediately (fig. 4). Thus the arm M
will have reached its upper dead centre before arm M¹ has got to its lower dead
centre (Fig. 5) so that M will be over its dead centre by the time M' has reached its
lowest point. On the downward stroke of arm M which now follows the arm M¹ will
be moved upwards more quickly exactly in the same manner as previously M.
The modification in Fig. 3 shows the slits in the arms o o' curved, in order to
obtain a more equal angular motion of the two cranks.
Fig. 6 shows the principle of the invention applied to an engine having two single
acting cylinders, the working of which will be obvious from the drawing.
Instead of making the blocks and pivots on cranks M and M² run in the slits in
arms o o¹, I can furnish the cranks with slits and allow pivots and blocks attached to
arms o o to slide in the same.

page_text: Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :
""
In double cranks revolving in one direction :
1. The combination of the two cranks mounted independently of each other on
fixed excentrics in which the crank axle runs and operating the axle by means of
arms oo having slits ss in which blocks t t slide, said blocks attached by pivots z z
to cranks M M³, said slits in arms o o¹ lying parallel to tangents on opposite sides of
the circumference of the axle, and on opposite sides of a diameter of the axle
ioining such tangents.
1.
2. The combination of arms o o' placed opposite each other on the crank axle
and having curved slots s³, in the manner and for the purpose specified.
Dated this 16th day of January 1890.
AUGUSTIN KLUGE.
By Rayner & Cassell,
37, Chancery Lane, London, Agents for the Applicant.