IMPROVED MECHANISM FOR CONVERTING RECIPROCAL INTO ROTARY MOTION AND THE CONVERSE
Year: 1884

page_text: COMPLETE SPECIFICATION.
I, CHARLES HENRY LA DUE, of Number 1841, third Avenue, New York City,
State of New York, United States of America, Engineer do hereby declare the
nature of my said invention for IMPROVED
MECHANISM FOR CONVERTING
RECIPROCAL INTO ROTARY MOTION AND THE CONVERSE 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 this invention is to convert reciprocating motion into rotary
motion without the use of a crank, and the invention consists principally in
forming in any suitable device attached to the shaft an eccentric groove or slot in
which a stud or its equivalent secured to the connecting or piston rod works so
that the thrust of the piston will act against the curved surface of the groove and
thus cause the wheel to revolve.
The device is likewise applicable to mechanism in which the power is derived
from a revolving crank whereby, through the instrumentality of the invention, a
properly supported bar may be given a rectilinear reciprocating motion adapted to
operate a punch, a pump rod or similur device.
The invention also consists in supporting and guiding the free end of the piston
rod or the connecting rod, on the shaft rotated by it, this may be done by extending
the shaft past the wheel and in forming the piston rod or connecting rod with a
slot or other suitable guiding and supporting surface with which the shaft engages
so that the shaft acts as a guide to the movement of the piston rod or the
connecting rod as the case may be, or the support for the rod may be at any other
part of the shaft.
Reference is to be had to the accompanying drawings forming part of this
specification in which similar letters of reference indicate corresponding parts in all
the figures.
Figure 1, is a side elevation of a steam locomotive showing the invention applied
thereto.

page_text: A, A, represent two of the drive wheels of the locomotive, B, B, the axles which
reach past the drive wheels A when it is desired to use them as guides or ways
for the piston rod and C represents one of the piston rods which is reciprocated by
steain entering the steam cylinder D in the ordinary way. The drive wheels A
have formed in them eccentric to the axles B, the grooves or slots a, which describe 5
a circle, the diameter of which is equal to the length of the piston stroke, and in
these grooves or slots work the rollers b, journaled upon the studs c, secured to
the connecting rod C'. The connecting rod C' is preferably formed with the
slots d, through which the protruding ends of the axles B pass as shown clearly in
Figure 2, so that the axles serve as guides to the reciprocating movement of the 1
connecting rod C' and to avoid the dead centres the drive wheels upon the opposite
side of the locomotive from that shown in the drawings will be arranged upon the
axles with the eccentric grooves therein, one-quarter of a turn ahead or one-quarter
The free end of the
of a turn in rear of the grooves in the wheel A A.
piston rods may be supported and guided by the ordinary ways or in any other
desired manner but it is preferable to slot the piston rod and allow latteral
projection of the axles B for this purpose as stated, and instead of the piston rod
being slotted it may be supported in any other suitable manner on the shaft as for
instance by a guide or way-block mounted on a sleeve which embraces the shaft
but does not turn with it, and such sleeve or other equivalent device may engage
with the shaft at some other point than on a projecting end thereof.
By the arrangement described it will be seen that the connecting rods C' are but
extensions of the piston rods C, and that they reciprocate in a direct line and that
the studs c, working in the eccentric grooves a, cause the wheels to revolve without
the employment of cranks.
The eccentric grooves or slots a, may be a plain groove or slot with straight
sides, but it is preferable to form it with inclined sides as shown in Figures 2 and 3,
in which case the rollers b, will be made cone-shaped to fit the grooves, and these
cone-shaped rollers, will be made adjustable in the connecting rod C', to take up
any wear of the groove or roller; and in some cases the eccentric a, may be formed
by means of separate castings f,f, secured concentric to each other to the face of
the wheels by means of bolts or rivets as shown in Figuro 3, or in any other
desired manner so that the invention may be applied to wheels already in use.
A pin rigidly attached to the end of the piston rod with conical end may be
employed instead of the conical roller but it is preferable to use the roller for the
sake of reducing friction.
Although the invention is shown in the drawings as applied to a steam loco-
motive it will be understood that it may be applied to shafts and wheels generally
where a reciprocating motion is to be converted into a rotary motion.
and
And it is also to be understood that the invention is applicable to such structures
as punches, pump rods and the like in which substantially the same mechanical
principles are involved but with the difference that in such structures the power
will emanate from the shaft, it being caused to rotate by any suitable means,
that then the punch rod or plunger, or the pump rod as the case may be, being
suitably supported and guided in any suitable manner, as, for instance by ways;
will move in rectilinear lines and with a reciprocating motion.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performe.l, I declare that what
I claim is:
First: The grove a having inclined edges in combination with the connecting
rod having the adjustable cone shaped roller or pin 6 substantially as and for the
purposes set forth.
Second: The eccentric groove a formed by the separate castings f secured to the
wheel substantially as and for the purposes set forth.
Third: The axles B, reaching past the wheels A in combination with the
connecting rod C' provided with slots d and studs c which latter work in the

page_text: eccentric grooves a formed in the wheel A substantially as and for the purposes
set forth.
Fourth: A rotatable shaft extending beyond the journals which support it in
combination with a reciprocating rod or bar supported and guided by the projecting
5 end of the rotatable shaft substantially as and for the purposes set forth.
Fifth The combination of a reciprocating bar or rod, a revolvable shaft and
means whereby the reciprocating bar or rod is supported and guided by the shaft
substantially as and for the purposes set forth.
Dated thin 10th ...
1004