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 invention has for its object mechanism for converting a reciprocating
rectilinear motion into rotary motion, and vice versa, applicable as an attachment
to piston rods of steam engines and of locomotives, to produce rotary motion in the
belt wheel, fly-wheels or drivers of said structures, or to produce a reciprocating
motion in punches, pump rods or the like apparatus, when used in combination
with a crank or similar device caused to revolve. And the results stated.are
attained by at-attaching to a rectilinearly reciprocating piston rod or connecting bar,
a head having a slot or groove formed therein in which slot or groove a crank pin
or the equivalent of a crank pin works, and to which is given a rotary motion by
the action of the slot or groove.
In the accompanying drawings like lettors indicate like parts in all the figures.
Figure 1, illustrates the invention applied to the driving wheels of a locomotive;
and is a vertical section taken on the medial line of the piston rod.
Figure 2, illustrates a top plan view of the invention as shown in Figure 1.
Figure 3, illustrates a vertical longitudinal section of the "head."
A A, are the ordinary driving wheels of a locomotive mounted on their
respective shafts or axles B B as usual, the axles being attached to the frame of the
locomotive in any known manner, C C are pins which may be substantially the
same as the ordinary crank pins attached to locomotives as now generally con-.
structed and which are rigidly attached to the spokes or plate of the wheel at such
point between the tread and centre of the wheel as desired, depending upon the
desired length of piston stroke: D is an ordinary cylinder, attached to the frame
B
AR
•

page_text: .
of the locomotive in any known manner. E is the piston and F, the piston rod.
The cylinder is fitted with a stuffing box G and other appliances all as. usual.
HH are what may be called the "driving heads.". There is one for each driving
wheel and they preferably consist of a block or plate of metal although they may
be made of other material made integral with the piston rod, or as a separate piece
rigidly attached to it in any suitable manner. It may however be constructed of
several pieces bolted or otherwise fastened together, all that is essential being that
there should be a slot, groove or equivalent feature, for the reception of the pin C.
Through it is formed a slot I of such width that it will receive the crank pin C,
and of a length equal to a little more than the diameter of the circle described by
the crank pin, and its centre lengthwise should preferably be coincident with the
centre of rotation. Instead of the slot completely through the head H a groove
may be employed. K is a connecting rod rigidly attaching the two "driving
heads" H H together, thus being practically an extension of the piston rod F. The
connecting rod is preferably squared in cross section or at least made of some shape
other than round, and it passes through a hole of the same shape as itself made in
the guide or way block L, which is rigidly attached to any suitable part of the
frame of the locomotive. This guide or way block serves not only to support the
connecting rod but, owing to the hole through it being of some shape other than
round, and the connecting rod fitting it, it prevents the connecting rod from turning
over and consequently the "driving heads are held in a position to keep them in.
proper engagement with the crank pins. L' is another similar guide or way block
which may be placed behind the second driver, its purpose being the same as that
of L. Any suitable means for supporting, guiding and preventing rotation of the
connecting rods and the "driving heads" may be substituted for these guide or
way blocks.
It will of course be understood that when the invention is used on locomotives
or engines in which there are two cylinders and piston rods that the crank pins of
the respective drivingwheels, belt wheels, or fly wheels, as the case may be, are set on
the quarter relative to each other as usual in such structures, so that dead centres
are avoided..
The lost motion and wear of the sides of the slots I, and of the crank pins C, are
provided for as follows illustrated in Figure 3; M, M, are two solid bars or plates
of brass, or other suitable metal, which form the friction surfaces between the crank
pins and the inside of the slot, and in order that the wear may come on them and
not on the sides of the slot in the driving head, they are made a trifle shorter than
the slot is long, and project inwardly beyond the edges of the slot, and they are
rigidly attached to the follower keys N, N, which are set in recesses made for them
in the "driving heads "the back edge of the recesses and of the keys having an
inclination from a true vertical line but the front edge of the keys which rest
against and support the friction bars, M, are preferably perfectly vertical, and the
wearing surfaces of the bars made also perfectly vertical or at least on lines at
right angles to the plane of movement of the piston or other rod, the friction bara
or the keys, one or both, are made of such width that they bind strongly against
the sides of the recess in which they are contained so that they cannot be moved,
except by a blow of a hammer on the upper end of the keys or by the action of the
nuts O, on the ends of the keys. And whenever the friction bars or the crank pins
wear away so that lost motion results the keys are forced downwardly by such
blow of a hammer on their upper ends which causes them to slide slightly down
through the recess provided for them and thus by the action of the inclined surfaces
of the back side of the keys and of the recesses in which they are contained the
friction bars are forced slightly inward toward the centre of the slot I, and the lost
motion is taken up-the threaded nuts O, may also be provided which engage with
the ends of the keys, which are suitably threaded for the purpose so that the keys
may be drawn down and the adjustment of the friction bars attained if desired
with greater exactness than by the employment of the strokes of a hammer. The

page_text: friction bars may however if desired be the full length of the slot I, and be attached
to the keys by a dovetailed groove so that the keys will slide on them.
The operation of the invention is simple. Assume that the pin C, is in the
position shown in Figure One, steam is let on in front or behind of the piston, as
the case may be, and, depending thereon, the piston rod will move in or out of the
cylinder, and will move the driving head in accordance with its movement. The
bars at the sides of the slot or groove I, will impinge against the pin C, and rotate
the wheel or shaft, as the case may be, to which the pin is attached-Thus at each
double stroke of the piston the pin C, describes a complete revolution.
When the invention is employed to operate punches, pump rods and such
structures of course the relative arrangement of the parts is altered as will be
understood by any one familiar with this art. For instance, a crank or equivalent
device will be the source of power from which a projecting pin or equivalent device
will engage with the slot I, and the rod corresponding to the piston rod will be
supported and compelled to move rectilinearly by a suitable box or ways through
or over which the rod will move.
When the invention is applied to ordinary stationary engines a pin similar to a
crank pin may be attached to an arm or equivalent device fastened to the main
shaft of the engine or upon any suitable part of the main balance, or belt wheel,
or in any other desired manner and in any suitable place.
There are many advantages flowing from the use of the invention, among them
are the following:-The engine or locomotive is made lighter; the cumbrous yoke
usually used on engines is done away with-and also the pitman and its cross head;
the joints between the pitman and the cross head' in which it works, which are
continually getting out of order, are done away with; there are fewer bearings
requiring oil; also there is a reciprocating motion pure and simple not a combined
reciprocating and circular movement, hence the apparatus moves with more
smoothness and occasions much less tremor than when both these motions are
present and requires somewhat less power, also the invention enables an engine to.
start nearer the dead point than by the old constructions. And the valve rods
may be connected to the piston or connecting rod more conveniently than on the
present engines, and there being fewer parts and a less number of moving surfaces
accident to the engineers are not so apt to occur.
The details of construction shown are not essential they be considerably departed
from and still the invention be employed.
It is obvious that the device may be set vertically as well as horizontally and also
at any desired angle.
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
First A rectilinearly reciprocating rod provided with a slot or groove, a crank
pin adapted to slide in the slot or groove and a guide for the rod substantially as
and for the purposes set forth.
Second: The combination of a piston rod, a guide for the free end of the piston
rod, a connecting rod one end of which engages with the free end of the piston rod,
and a groove or slot formed in or attached to the connecting rod and a crank pin
adapted to slide in the said slot or groove, substantially as and for the purposes
set forth,
Third: The combination of the "driving head" H, provided_with the slot or
groove I, and a crank pin-adapted to slide in the slot or groove I, substantially as
and for the purposes set forth.
:
Fourth The combination of the "driving head" H, provided with the slot or
groove I, and the wearing bars M, and the keys N, substantially as and for the
purposes set forth.
Fifth The combination of a slotted or grooved block or plate guided and
supported and a crank pin adapted to slide in the groove or slot in the block,

page_text: whereby a rotary motion imparted to the crank pin will produce a reciprocating
motion in the block and a reciprocating motion imparted to the block will produce
a rotary motion in the crank pin substantially as and for the purposes set forth.
Dated this 10th day of November 1884.