ifx Improvements in Adjustable Cranks and in Means for Transmitting Motion between Rotary and Reciprocatory Machine Elements.
Year: 1894

page_text: D te of Application 20th Nov., 1894-Accepted, 5th Jan., 1895
t
1
COMPLETE SPECIFICATION.
ifx
Improvements in Adjustable Cranks and in Means for Transmitting
Motion between Rotary and Reciprocatory Machine Elements.
I, SAMUEL HEY of 56 Low Street, Keighley in the County of York, Patent
Agent, do hereby declare the nature of this invention, as communicated to ine from
abroad by The Bouve, Crawford and Company Corporation, of Brockton,
Plymouth County, Massachusetts, United States of America, Engineers, and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement, that is to say :—
This invention relates to certain improvements in means for connecting rotary
and reciprocating machine elements, and is here shown as applied to a power
pump, for transmitting motion to the piston-rod thereof, from a rotary driving
element, although the invention may be applied to other mechanism.
One object of the invention is to arrange a system of levers or links connecting
the rotary and reciprocating elements which will insure a true rectilinear motion of
the reciprocating element, and also a quicker action thereof than could otherwise
be obtained.
Another object of the present invention is to provide means whereby a wrist-pin
may be adjusted with respect to the centre of rotation of its support while the
latter is in motion, and by the motion of the support.
To these ends, the invention. consists in certain novel constructions and arrange-
ments of parts which will be described and claimed hereinafter.
A construction by which the invention may be applied to a power, pump is
illustrated in the accompanying drawings ;-
Figure 1 shows a side elevation of the complete structure.
My n
Figure 2 shows an end view as seen from the left of Figure 1, with a longitudinal
section of the wrist-pin and controlling parts.
The reference letter a designates the cylinder of a power pump which rests on a
bed a²; a' the usual air-dome thereof; and ba standard erected on the upper side
of the cylinder. A tubular driving-shaft cis journalled in a bearing at the upper
end of the standard 6, and carries a crank-disc b having a radial adjustment slot b².
A pitman is fastened on a wrist-pin 2, which may be adjusted to different
positions in said slot. A bell-crank lever d has, a long arni d', which is. pivoted
at d² to the outer end of the pitman c', and a shorter arm d3 which is pivoted at d*
to the piston-rode of the pump. The bell-crank lever is pivoted at the junction of
its two arms to the outer end of a link or radius-bar f, as shown at f¹, and the inner
end of said link is pivoted at f* to the rigid standard b. A link or radius-bar g is
pivoted at one end g' to the bed a³, and at the opposite end o² to the middle of the
short arm d³ of the bell-crank lever:
K
The reciprocation of the pitman c' caused by the rotation of crank-disc b¹ vibrates
the long arm d' of the bell-crank lever, and produces a corresponding movement of
the short arm d of said lever. The link g being pivoted at one end g¹ to a
stationary support, its opposite end g', which is pivoted to the same arm of the bell-
crank lever, will describe, an arc of a circle; and the link, being also pivoted to a

page_text: 10
stationary support, its outer end, which is pivoted to the bell-crank lever at the
junction of its two arms, describes an arc of a circle. The result is a rectilinear
movement of the piston-rod e by reason of the upward movement of the pivot g**in
the arc of a circle, in the same degree as the pivot d' would move downward in the
arc of a circle if the pivot f' of the bell-crank lever was stationary. This latter
pivot is permitted to move upward in a corresponding degree by reason of being
supported by the link.f..
A screw is supported radially in a bearing on the disc b', and passes through
the base of the wrist-pin c³, said screw turning loose in its bearing and engaging a
screw-threaded bore in the wrist-pin.
A spur-gear i is affixed on the screw, and a spindle is supported in a radial
bearing on the disc, and carries affixed to it a spur-gear in mesh with the gear i,
and also has affixed to it at its inner end within the tubular hub of the disc, a bevel-
gear. A spindle m is rotatively supported concentrically with the disc, and has
affixed to its inner end a bevel-gear min mesh with the bevel-gear j².
A spindle in the form of a sleeve n is rotatively mounted on the spindle m and
supported in a bearing n in the tubular shaft c, and carries affixed to it a bevel-
gear n' which meshes with the gear e³.
The spindle m has a hand-wheel m³ affixed to it, and the sleeve n has a handle n³
affixed to it.
When neither of these handles is disturbed the adjustment of the crank-pin
remains unchanged. If it is desired to adjust the wrist-pin in one direction, the
handle m³ is taken hold of and held, and thus the gear m¹ is stopped, which causes
the gear and the radial spindle j to turn, and consequently the screw; and thereby
the wrist-pin is moved to the position desired.
To adjust the wrist-pin in the opposite direction, the handle n' is taken hold of
and held, which produces rotation of the radial spindle j in the reverse direction,
and moves the pin in the opposite direction from before.
Thus the wrist-pin may be adjusted to obtain the desired throw without stopping
the rotary support, but by employing the rotary motion of the same to effect the
desired movement of the wrist-pin.
It is evident the invention may be carried out by other means than here shown,
and is not limited in this respect.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, declare that what I
claim is ;--
1. A parallel motion for connecting rotary and reciprocating machine elements,
the same comprising a pitman connected with the rotary element, a bell-crank lever
connecting said pitman with the reciprocating element, a link pivoted to a stationary
support and to the bell-crank lever at the junction of its arm, and a link pivoted to
a stationary support and to one arm of the bell-crank lever.
2. The combination of a wrist-pin moveable toward and from the centre of its
support, a screw engaging said wrist-pin, a radial spindle on said support, gears
. connecting said spindle with the said screw, a spindle journalled concentric with
the rotary support and having a handle, and gearing connecting said concentric
spindle with the radial spindle.
3. The combination of a wrist-pin movable toward and from the centre of
rotation of its support; a pair of handles independently journallel concentric with
said support; and adjusting connections between each of said handles and the
wrist-pin, rotatively connecting the handles with the rotary support when said
handles are free to turn, and effecting movement of the wrist-pin toward or from
the centre of rotation, according as one handle or the other is held from turning,
substantially as described.
4. The combination of a wrist-pin moveable toward and from the centre of
rotation of its support, a screw engaging said wrist-pin, a spindle extending radially

page_text: of the said support and geared to the said screw and carrying a bevel-pinion, and
two spindles rotatively supported concentric with the support and each carrying a
bevel-gear in mesh with that on the radial spindle.
Dated this 19th day of November 1894..