Year: 1889

page_text: object to produce cut-off mechanism and reversing gear that shall be so constructed
and organized as to give a positive "lead" at all points of the cut-off both in the
forward and backward motion, that is to say, the lead will commence at the same
position of the crank, no matter at what portion of the stroke the steam may be cut
off. By the term "lead" I mean the opening of the valve for the admission of steam
into the cylinder, to act as a cushion for the piston at the ends of the stroke, that is
before and at the passage of the centers by the crank. It is of course well understood
that by cutting off the steam early in the stroke the consumption of steam and
consequently the consumption of fuel is greatly reduced while at the same time
enormous power can be developed by using the steam expansively. Heretofore,
however, so far as I am aware, it has been impossible for engineers to avail themselves
of the full expansive power of the steam for the reason that if the steam was cut off
early in the stroke the effect was, owing to inherent defects in the valve mechanism,
to give so much "lead" as to cause a back pressure of steam on the piston, thus
greatly impairing the efficiency of the engine. With an early cut-off the lead has
heretofore been irregular. My invention enables me to insure a positive "lead," that
is, a "lead" beginning at the same position of the crank, no matter at what portion
of the stroke of the piston the steam may be cut off. I am thus enabled to secure the
full expansive power of the steam, and to effect an enormous saving in the consumption
of fuel by reducing the amount of steam required to run the engine. This is
especially true of locomotives where the loads required to be drawn, and the grades,
are subject to great variation.

page_text: With these ends in view I have devised the simple and novel construction, of which
the following description, in connection with the accompanying drawings, is a speci-
fication, similar numbers being used to denote like parts in all the Figs.
Fig. 1, is a front elevation illustrating the application of my invention to a marine
engine, the steam chest being removed.
Fig. 2, a side elevation corresponding with Fig. 1, the cylinder being in section.
In both of these views the reversing lever is shown in the central position, that is,
a position in which if the engine started at all, it would be liable to move in either
direction, dependent upon outside circumstances.
Fig. 3, a view showing the application of iny invention to a locomotive, the cylinder
being in section, the lifting shaft, lifting rod, saddle, link, &c. being in position to
cause forward movement of the locomotive; and
Fig. 4, is a similar view, the lifting shaft, lifting rod, link, saddle, &c. being in
position to cause backward movement.
1, denotes the frame-work, 2, the crank journaled in a boss 3, 4, the eccentrics, 5,
the eccentric straps, 6, the eccentric rods, 7, the cylinder, 8, the piston, 9, the piston
rod, 10, the steam ports, 11, the exhaust port, 12, the valve, 13, the valve stem, at
the lower end of which is a guide 14, moving in ways 15, 16, the link, 17, the link
block, journaled on a stud 18, projecting outward from the valve stem guide, 19, the
saddle, 20, the reach rod, 21, the quadrant, 22, the reversing lever, and 23, a set
screw whereby the reversing lever is locked to the quadrant after adjustment to
cut off the entrance of steam into the cylinder.
I have simply enumerated these elements for the reason that their construction
and arrangement may be greatly varied without departing from the principle of my
invention, as for instance in Figs. 3, and 4, in which I have shown my invention as
applied to a locomotive. In this form the reversing lever is not shown, it being at
the rear end of the locomotive. 22", denotes the lifting shaft, and 22b, the lifting
rod, which are of ordinary construction and common to all locomotives. The valve
stem in this form is made in two parts jointed together, the outer end of the outer
part being pivoted to a lever 24, the opposite end of said lever being pivoted to link
block 17. 25, in both forms denotes rods pivoted to opposite onds of link 16, each
rod being pivoted to one of the eccentric rods, and 26, denotes rocker arms, one end
of said rocker arms being pivoted at a fixed point 27, the opposite end of each rocker
arm being pivoted to one of the eccentric rods, and to one of the rods 25, at the
pivotal point of said rods to each other, as is clearly shown in the various Figs. of
the drawings. The link is an arc of a circle, the center of which is the pivotal point
of the rocker arms, eccentric rods and rods 25, to each other, when the crank is at its
highest point, as is clearly shown in Fig. 1. In the form shown in Fig. 1, when the
.reversing lever is swung toward the left, a forward movement of the engine is
produced, and when it is swung toward the right a reverse movement is produced.
The special construction and arrangement of the cylinder, piston, valve, and other
necessary parts is not of course of the essence of my invention.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. In a cut-off and reversing mechanism the combination with the valve, valve
stem, eccentrics and eccentric rods, of an are shaped link, a block connected to the
valve stem upon which said link slides, a reach rod connected to the link, rods 25,
pivoted to the opposite ends of the link, and each pivoted to one of the eccentric rods,
and rocker arms pivoted to a fixed point and to the eccentric rods and rods 25, at
their pivotal points to each other, substantially as set forth.
2. The combination with the eccentric rods, an are shaped link and link block 17,
of rods 25, pivoted to opposite ends of the link and to the eccentric rods, and rocker
arms pivoted to a fixed point and to the eccentric rods and rods 25, at their pivotal
points to each other

page_text: 3. The combination with the eccentric rods, rods 25, and rocker arms, pivoted to a
fixed point and to the eccentric rods and rods 25, at their pivotal points to each other,
of a link to the opposite ends of which rods 25, are pivoted and which is an are of a
circle of which the pivotal point of the rocker arms, eccentric rods and rods 25, is the
center.
4. The combination with the eccentric rods, an arc shaped link, having saddle 19,
and link block 17, of rods 25 pivoted to opposite ends of the link and to the eccentric
rods, rocker arms pivoted to a fixed point and to the eccentric rods, and rods 25, at
their pivotal points to each other, and a reach rod pivoted to the saddle.
5. The combination with the eccentric rods, an are shaped link and link block 17,
of rods 25, pivoted to the opposite ends of the link and to the eccentric rods, rocker
arms pivoted to a fixed point and to the eccentric rods, and rods 25, at their pivotal
points to each other, a reach rod pivoted to the link, a valve and a valve stem
connected to link block 17, whereby movement of the link acts to change the point
of cut-off but without changing the lead of the valve.
בז
1.
1000