MENTS IN MECHANISM FOR CONVERTING RECIPROCATING INTO ROTATORY MOTION
Year: 1884

page_text: We, JOHN KIRKWOOD, of 236 Leith Walk, Leith, in the County of Mid Lothian,
North Britain, Zinc Bath Manufacturer, and JAMES KIRKWOOD, of the same place
Bath Maker, do hereby declare the nature of our said invention for IMPROVE-
"
MENTS IN MECHANISM FOR CONVERTING RECIPROCATING INTO ROTATORY MOTION
"
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:—
Oar said Invention has for its object to improve the construction and action of
mechanism for converting reciprocating into rotatory motion, and the principal
applications of our Invention are those in which the foot is employed for producing
the motion. Thus, we believe that with our improved mechanism, tricycles, lathes,
sewing machines, and the like can be driven with less waste of power or effort than
by means of existing apparatus.
In carrying out our Invention the axle or shaft to which rotatory motion is to
be imparted, is arranged to receive the motion from an intermediate wheel or
pulley which turns through an arc or angle alternately in opposite directions, but
which by means of a ratchet wheel and pawl or other equivalent arrangement acts
on the axle or shaft only when moving in one direction. Our Invention has special
reference to the intermediate wheel or pulley and to the means for communicating
the action of the foot to it and for returning it after each stroke. Our intermediate
wheel is a pulley with a grooved rim and a cord having one end fixed at one part
of the rim passes partly round the pulley and has its other end fixed to a stirrup
or treadle which in some modifications works down and up on a vertical guide.
With this arrangement the force of the foot when tbrust vertically downwards acts
with uniform leverage throughout its stroke upon the intermediate wheel or pulley.
For returning the intermediate wheel or pulley after each stroke there is fixed to
its rim one end of a rubber cord which acts as a spring its other end being secured
to a suitable fixed point. This rubber cord becomes stretched and laid round the
pulley rim when the pulley is being turned by the action of the foot, and turns the
pulley back again when the foot is raised the pulley also drawing up the stirrup or
treadle. A helical metal spring may be substituted for the rubber cord.

page_text: And in order that our said Invention and the manner of performing the same
may be properly understood we hereunto append a sheet of explanatory drawings
to be hereinafter referred to and representing our improved mechanism.
Figure, 1, on the accompanying sheet of drawings is a sectional front or edge
view showing a pair of our driving motions as applied to a tricycle. Figure, 2, is
a side or face view partly corresponding to figure, 1, and partly showing the
application of our mechanism for driving what is ordinarily the crank shaft of a
lathe. Figures 3 and 4, are sectional views showing modifications of some details.
In these drawings the same reference numerals are used to mark the same or like
parts wherever they are repeated.
In the arrangement shown in figures 1 and 2, the axle, 5, has placed loosely on it
a pulley, 6, made with two grooved rims, 6, 7, for giving different leverages, and
having jointed on one of its spokes an eccentric sector, 8, to act on a small wheel or
boss, 9, fixed on the axle, 5. The surfaces of the boss, 9, and sector, 8, are grooved
to give increased frictional hold, and the combination acts like what is known as
the "silent feed" A light spring, 10, keeps the sector, 8, in contact with the boss, 9,
and when the pulley, 6, with the sector, 8, turns in the direction of the arrow in
figure, 2, the sector bites or grips the boss, 9, and causes it and the axle, 5, to turn
with the pulley; but when the pulley turns in the opposite direction the sector 8,
frees itself and does not turn the boss, 9.
In figures, 3, and 4, a larger wheel or pulley, 11, is shown as substituted for the
boss, 9, being fixed on the axle, 5, and the inside of the smaller grooved rim, 7, is
formed with ratchet-like grooves in which are placed a number of rubber balls, 12.
When the pulley, 6, turns in the direction of the arrow in figure, 4, the balls, 12, get
jammed in the narrower parts of the grooves between the rim, 7, and the wheel, 11,
and cause the wheel, 11, and axle, 5, to turn; but when the pulley, 6, moves in
the opposite direction the balls, 12, get to the wider parts of the grooves and the
motion is not communicated to the wheel, 11. The arrangements shown in the
several figures for communicating the motion from the pulley, 6, to the axle, 5, are
preferable to an ordinary ratchet wheel and pawl; but the ratchet wheel and pawl
or any other known device acting in the same way may be used if considered
desirable in any case.
For turning each intermediate piece or pulley, 6, there is fixed to a suitable part
of either of the grooved rims, 6, or 7, a cord, 13, the other end of which in the
arrangement shown in figures, 1, and 4, is fixed to a stirrup or treadle, 14, fitted to
slide on a vertical guide rod, 15. In the case of a tricycle this guide rod, 15, is at
its upper and lower ends fixed by brackets 16, 17, to the frame, 18, of the tricycle;
and in the case of other machines for which this sliding stirrup, 14, may be suitable,
this guide rod, 15, may be fixed to the framing of the machine in whatever way
may be found most convenient, but it should always be placed in a position in
which it is as nearly tangential to the pulley, 6, as can be conveniently managed.
For turning back the pulley, 6, after each downward stroke of the foot, there is
fixed to the rim of the pulley one end of a rubber cord, 19, (figures, 2, and 4) which
has its other end fixed to any convenient point at a fixed distance from the pulley,
as for example to the bottom bracket or holding piece, 17, of the guide rod, 15, as
shown in figure, 4. When the pulley, 6, is turned by pushing down the stirrup, 14,
the rubber cord, 19, becomes stretched and partly wound on the pulley and in
consequence of its resilience turns the pulley back whenever the foot is raised
again.
In the tricycle arrangement shown in figure, 1, the parts for turning the axle, 5,
are in duplicate those for each side being quite separate and independent. It is
intended that the rider shall press down his right and left feet alternately and if he
does so he can make the driving action practically uniform and continuous; the
rider can however operate with his feet in various ways without causing any
inconvenience.
In applying our driving motion to a lathe as partly indicated in figure, 2, there
may a single pulley, 6, and its accessories at the middle of the shaft, 5, with the

page_text: cord, 13, fixed to the middle of the usual foot board, 20, or there may be two of
the pulleys, 6, these being placed near the ends of the shaft, 5, and their cords, 13,
being fixed to the ends of the footboard, 20.
Having thus particularly described the nature of our said Invention and in what
manner the same is to be performed we proceed to ascertain the distinctive features
of novelty thereof by declaring that what we claim is :—
In mechanism for converting reciprocating into rotatory motion, the combi-
nation of a stirrup or treadle guided or arranged to move vertically or nearly
so, with a cord fixed to and winding on the grooved rim of a pulley which transmits
the motion and with a spring cord also fixed to and winding on the rim of the
pulley the parts being arranged and operating substantially as hereinbefore
described.
D
1004
EDMUND HUNT,
Applicants' Agent.