Improvements in Crank Connections for Pumping, Compressor, and other Engines.
Year: 1890

page_text: Date of Application, 20th May, 1890-Accepted, 28th June, 1890
COMPLETE SPECIFICATION.
Improvements in Crank Connections for Pumping, Compressor, and
other Engines.
We JOHN EDMUND TRENOUTH BARTLETT, Engineer, of 1719 G. Street, Washington
in the District of Columbia, and WILLIAM JOHANN DIETRICH KEUFFEL, Merchant, of
No. 127 Fulton Street in the City of New York in the State of New York, United
States of America, do hereby declare the nature of this invention and in what
the same is to be performed, to be particularly described and ascertained in
and by the following statement:—
manner
It has been found, in practice, that a much higher speed is required for the pistons
of steam cylinders than for the pistons of pumps or compressors employed for
pumping liquids, or for pumping or compressing elastic fluids. The object of our
invention is to provide for these differences of speed between the steam or motor piston
and the pump piston, in a very simple and effective manner, and to this end our
invention consists in the combination hereinafter described and claimed.
In the accompanying drawing,
Fig. 1 represents a vertical longitudinal sectional view of an engine embodying our
invention.
Fig. 2 is a plan view of the same, corresponding to Fig. 1.
Fig. 3 is a plan view, and Fig. 4 an end view of a two-throw-crank, and Fig. 5 is
a diagram representing a side view of a pump and motor, illustrating a modification.
of our invention.
Like letters of reference indicate corresponding parts in all the Figures.
A designates a driving or motor cylinder piston, B a driven or pump cylinder
piston of shorter stroke than the driving piston. In this example, the stroke of the
former is represented as nearly or quite three times longer than that of the latter.
The driving piston may be that of a steam cylinder, and the driven piston that of a
pump for compressing or pumping elastic fluids or liquids.
C designates a two-throw crank on the engine or crank shaft D, to which crank
the pistons may be connected in any suitable manner, as in this example, by the usual
connecting rods pivotally connected with the piston rod cross-heads, and with the crank
pins, the throw of the crank pins corresponding severally to the stroke of the pistons
to which they are connected."
The cylinders must be attached rigidly and firmly in the usual manner to a suitable
frame or frames or engine bed or bed plate E E.
A¹ designates the driving piston cylinder, and B¹ the cylinder of the driven
piston; a and a piston rods; b and 6' cross-heads; c and c¹ cross head guides ;
d and d' connecting rods; e and e' crank pins or wrist pins of the compound two-
throw crank. ff indicate bearings for the engine or crank shaft, and 9 g fly wheels
on said crank shaft.
The central cross section of the single central long-throw crank pin e, to which
the driving or motor piston is connected, is located in the vertical plane of the axis of
the driving or motor piston cylinder, and in this example is also located in the
vertical plane of the driven or pump cylinder axis, and the crank pin e is formed
between the inner faces or sides of two long-throw crank arms hh. Upon the
outer faces or sides of the opposite ends of said arms, upon opposite sides of the
central long-throw crank pin, are the two short-throw crank pins e¹ and e¹, to which
the pump piston is connected by the parallel connecting rods a¹ d pivoted on pins i i
of the cross-head 61, on opposite sides of the driven or pump piston rod a¹. The ends
of the two crank pins e and e', respectively opposite to the arms / h, are severally
and rigidly connected to the shaft D by the short-throw crank arms jj. By means
of this construction, the central long-throw crank pin e, arms h h, and end of rod d

page_text: connected to said pin, will, in making a revolution, pass freely between the connect-
ing rods d¹ d¹, and the force applied to the crank pin e, through the connecting rod d,
will be transmitted through the two crank pins el e¹ at equal distances from
the crank pine on opposite sides of it, and hence there will be no tendency to
cramp the shaft in the bearings ff, which are outside the crank on opposite sides
thereof.
The compound two-throw crank may be "built up" in separate pieces, or it may be
forged and be "machine dressed" to the required form.
This kind of a compound crank may be adapted to a single engine with a fly wheel,
or to a two or three cylinder compound engine, or to a triple or quadruple expansion
engine, and the several compound two-throw cranks can be so disposed at such angles
with each other, as to secure the best results, by connecting two or three or more
of said cranks together, and the axial lines of the piston cylinders may be at any
required angle with each other, as, for example, the said axial lines may be coincident
with each other, as represented in Figs. 1 and 2, or at any angle, as represented in
the diagram Fig. 5.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
The combination with the motor piston of an engine and a pump piston to be driven
thereby, of a shaft, two bearings for the said shaft, a two-throw crank in said shaft,
arranged between said bearings, and having a single central crank pin of a longer
throw, and two outer crank pins of shorter throw, arranged in line with each other on
opposite sides of said central crank pin, a connecting rod between the motor piston
and said central crank pin, and two connecting rods, one for each of said outer
crank pins between the latter crank pins and the pump piston, substantially as
described.
Dated this 20th day of Mar 1900.