Improvements in Mechanism for the Conversion of Rectilinear into Rotatory Motion.
Year: 1894

page_text: PROVISIONAL SPECIFICATION.
Improvements in Mechanism for the Conversion of Rectilinear into
Rotatory Motion.
SYDNEY BUTLER of Park Works, Langley Lane, Vauxhall, Surrey, Engineer,
do hereby declare the nature of this invention to be as follows:-
The object of this invention is the construction of a mechanical movement chiefly
for bicycles and tricyles or foot and hand power machines whereby rectilinear
motion is converted into rotatory motion without the inconvenience of dead points,
and whereby a saving is effected over the ordinary pedal motion in the distance
travelled by the foot, the proportion being as twice the diameter to the circum-
ference of a circle, or as 2 to 3.141.
The shaft or spindle to be rotated is fitted with pinions running loose on same,
which drive the shaft by ratchet, frictional clutch, brake strap or other similar
action, so that the pinions revolve the shaft in one direction only. Geared into the
pinions are straight racks working in guides, which are driven with a reciprocating
motion, and, if worked by the feet, suitable foot plates or stirrups may be attached
to the racks on which the feet act. A rack and pinion is used for each foot and
the two racks may be so connected together that when one rack is at the end of its
stroke the other is at the commencement. This action may be attained by placing
a spur pinion between the racks, working on a fixed pin, and geared into corre-
sponding teeth on the racks; by a cord or chain passing over a loose pulley, the
ends of the cord or chain being attached to each rack; by a lever working on a
central pin with the opposite ends of the lever driving each rack or in any other
suitable manner.
It will be obvious that when the two racks are thus made to drive each other,
the power may be applied to one rack only, as would be the case when both a
pulling and a pushing action is used as a motive power.
I sometimes use pinions or wheels permanently fixed to the shaft to be rotated,
driving them by suitable racks or otherwise in such a manner that they engage
with the pinions or wheels when driven in one direction only and become disengaged
during the return stroke.
Dated this 22nd day of October 1894.
Improvements in Mechanism for the Conversion of Rectilinear into
Rotatory Motion.
I, SYDNEY BUTLER of Park Works, Langley Lane, Vauxhall, in the County
of Surrey, 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 :-
This invention has for its object the construction and adaptation of a mechanical
movement or movements chiefly applicable to foot and hand power machines such

page_text: as bicycles, tricycles, boats, or machines driven by manual labour, whereby the
rectilinear motion of the hand or foot is converted into rotatory motion in an easier
and more direct manner than by the ordinary rotating crank, and whereby the
distance travelled by the hand or foot is reduced as nearly as possible in the
proportion of twice the diameter to the circumference of a circle, or as nearly as
possible in the proportion of 2 to 3.141.
In carrying out my invention I fit the driving shaft of the machine with suitable
pinions or drums which, when driven, rotate the shaft in one direction by ratchet
gear, frictional clutch, brake strap or other similar action but are free to move in
a contrary direction without driving the shaft. When using toothed pinions I gear
into them straight racks working in suitable guides and attach to them foot plates
or stirrups for foot power or handles for hand power. A pinion and rack is used
for each foot or hand and I connect them in such a manner that when one is in its
forward motion the other is in its backward motion. This action may be attained
by placing a pinion between the racks, working on a fixed pin, and geared into
corresponding teeth on the racks; by a cord or chain passing over a loose pulley,
the ends of the cord or chain being attached to each rack; by a lever working on
a central pin with the opposite ends of the lever driving each rack, or in any other
suitable manner. When I use drums instead of pinions I obtain the same action
by employing a bar instead of a rack to the ends of which I attach a chain, cord
or band and wind the two chains or bands round the drum in contrary directions
attaching the other ends to the drum so that the reciprocating motion of the bar
will drive the drum forwards or backwards. The action of either of the above is
the same.
When the foot or hand moves in one direction the ratchet or clutch in
the pinion engages with the shaft and when it moves in the contrary direction the
shaft becomes disengaged, but as the other foot or hand is moving in a contrary
direction the power is being constantly applied. It will also be obvious that when
the two racks are thus made to drive each other a pulling and a pushing action
may be used on one rack or bar only so as to constantly rotate the shaft. To
avoid friction as much as possible in the working of the apparatus I sometimes use
instead of perfectly straight racks or bars very slightly curved ones which are
practically equal to them. These racks or bars then form a segment of a large
circle and are connected by a bar or otherwise to a boss working on a pin or
spindle which is placed at the centre. I sometimes also use pinions or drums
permanently fixed to the shaft and drive them by suitable racks or otherwise in
such a manner that they engage with the pinions or drums when driven in one
direction only and become disengaged during the return stroke. Several forms of
clutches may be used for connecting the pinions or drums to the driving shaft of
the machine such as the ordinary toothed ratchet and pawl, the V groove and
pawl, the wedge or the roller grip, and to facilitate the easy movement of the
pinion or drum on the shaft ball bearings may be used. Any number of these
appliances may be adapted to drive the same shaft where the power of several
nien is required or the apparatus may be fitted for one man to use both hands
and feet.
With this apparatus there are practically no dead centres and no variation of
leverage as in an ordinary crank inotion, and the driving shaft can be started in
any position.
In the annexed drawings I show some of the means I adopt in carrying out my
invention.
Fig. 1 & Fig. 2 are end and front views of toothed pinions and racks having
ratchet attachments to the driving shaft, the racks being connected together by a
band passing over a loose pulley working on a fixed pin, and
Fig. 3 shows a drum and bar driven by bands in place of the pinion and rack.
The drum in this form of apparatus drives the shaft by a frictional pawl working
in a V groove.
Fig. 4 shows a slightly curvilinear rack guided by a radial arm working on a
central pin.

page_text: A. A is the driving shaft. B. B. the ratchet wheels. C the ratchet pawls or
springs. D. D the pinions. E E the racks. F. F. the pedals or handles.
G. G. the loose pulley working on a fixed pin. H. H. the connecting band for
the two racks passing over the pulley G. A similar band H and pulley G may be
also applied to the other end of the racks E. E. H' the drum. I the bar. J the
radial arm guided by the central pin K. Loue of the flexible bands connected at
one end to the bar I at the point M and to the drum H' at the point N, and
O the other flexible band connected to the bar I at the point P and to the
drum H at the point Q. R is the ✓ groove, and S the frictional pawl attached
to the drum H¹ and working in the V groove R.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
In the conversion of rectilinear or slightly curvilinear motion into rotatory motion
for hand or foot power machines the application of pinions or drums turning the
motion shaft by ratchet or frictional gearing and actuated by rectilinear or slightly
curvilinear racks or bars, substantially as described.
Dated this 13th day of July 1895.
SYDNEY BUTLER.