Motion by Treading without Cranks.
Year: 1885

page_text: Motion by Treading without Cranks.
I EWALD BRUNCKER, Civil Engineer, of Sieglar near Troisdorf, in the German
Empire, do hereby declare the nature of my said invention for "A NEW OR
IMPROVED APPARATUS, FOR PRODUCING A ROTATORY MOTION BY TREADING,
WITHOUT CRANKS," and in what manner the same is to be performed, to be
particularly described, and ascertained, in and by the following statement:—
The present arrangement for producing a rotatory motion by treading has the
following disadvantages :-
1st The person treading must always make the same stroke, regulated by the
crank.
2nd Two dead points result from the crank, and these even during work, often
cause a running back of the driving axle.
The object of this invention is to abolish the above mentioned defects, heavily
felt in machine tools, sewing and other machines and apparatuses.
The motion of a treadle without a crank acts as shewn in the accompanying
drawing.
In Figs. 1 and 2 W is the axle to be turned by treading on which the fast disc
or boss S sits, around which the band B. is placed, whose ends are united by the
pins The latter forms, either with the pint in the connecting rod H one
piece Figs. 1 and 2, or rests with this in the clips L as a single bolt Figs. 3 and 4,
or are otherwise suitably united to each other.
In the given arrangement the band B being loose in its position upon S will
remain so when H goes up, sliding round S, while during the descent of H.
B immediately contracts and causes the disc S with its axle W to turn to the left
If however the upper end of the band is connected with t¹ and the lower with t
on the going up of H a turning to the right of W will result while on the descent
B turns loose round S By this arrangement one can produce by means of the
connecting rod H any required motion of the axle the direction being detirmined
by the ends of the bands independant of all other arrangements If the pin / be
placed in the hole the lever arm and with it the power will be increased.
Figa 5 and 6 show how the motion up and down can be used for the rotation of
the axle W. At one end R¹ of the treadle R turning in the bearings Q the two

page_text: united connecting rods H and H¹ are fastened to the bands B and B¹ upon the fast
discs S and S¹, the arrangement of the ends of the bands is opposite see Fig. 6.
The bar B will on that account cause by the descent, but the bar B₁ by the ascent,
the turning to the left of W If H and H' were fastened on the opposite sides R¹
and R from R the points of application of H and H' with B and B would lie on
the same side, and the bands receive the same arrangement of motion with the
pins a a¹ It is not necessary that H and H¹ should be near each other, while
S S¹ could also be fastened upon the axle W where required suitable to the
treadles R.
Having now particularly described and ascertained the nature of my said 1
invention and in what manner the same is to be performed I declare that what
I claim is
The apparatus for producing a rotary motion by the treadle without a crank
consisting of one or several connecting rods K, moved by treading, which are
united fast or loose with the bands B laid around the discs S in such a way that 1
the bands are contracted by the rod H on the going up, or down, by which
arrangement, rotation of S and of the impelling axle, united with it, is effected.
Dated this 17th day of December 1885.
LORENTZ ALBERT GROTH,
Agent for the Inventor.