Improvement in Valve-gears.
Year: 1897

page_text: Date of Application, 23rd Feb., 1897-Accepted, 5th June, 1897
Improvement in Valve-gears.
I, STEPHEN VERNER GODDEN, of No. 116 North 9th Street, Philadelphia, in
the County of Philadelphia, and State of Pennsylvania, United States of America,
Gentleman, do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in
and by the following statement, reference being had to the accompanying
drawing, and to letters of reference marked thereon, which form a part of this
specification:-
This invention relates to a new and useful improvement in valve-gears, but more
especially to those known as "link motions," and has for its object to produce a
device which when interposed between the eccentric and slide-valve will so alter
the motion imparted to the slide-valve from the eccentric as to time the move-
ments of said valve relative to the piston-stroke in such manner as to produce the
maximum effect of the steam upon the piston-head; and with this end in view my
invention consists in the details of construction and combination of elements
hereinafter set forth and then specifically designated by the claims.
In order that those skilled in the art to which this invention appertains may
understand how to make and use the same, I will describe its construction and
operation in detail, referring by number to the accompanying drawing, forming a
part of this specification, and in which―
Figure 1 represents a portion of a locomotive with my improvement attached
thereto;
Fig. 2, an enlarged side elevation of the device, the valve and rocker-arms being
omitted;
Fig. 3, a cross-section at the line a of Fig. 2;
Fig. 4, a horizontal section at the line Y y of Fig. 2;
Fig. 4, a horizontal section at the line y y of said figure; and
Fig. 5, a side elevation of the frame of the device, showing the position of the
sliding box.
Similar numbers denote like parts in the several views of the drawing.
1 is a frame of such shape as to support the operating parts of the device, and
this frame is adapted to be bolted in any convenient manner to the framework of a
locomotive about midway of the slide-valve rod.
Formed with the upper portion of the frame 1 is a housing 2, in which is fitted
the box 3, so as to have a limited vertical movement, and prevented from withdrawal
from said housing by the yoke 4, held in place by suitable bolts 5, for a purpose
hereinafter explained.
6 is a cam pivoted by the bolt 7 to the box 3, so as to be capable of being swung
to and fro.
8 is a block adapted to slide within the T-shaped groove 9, formed in the frame,
and to this block is pivoted the heel of the cam 6 by means of the bolt 10. Thus
t will be seen that upon imparting an oscillatory movement to this block the cam
will be caused to rock upon the bolt 7, and as the block 8 can have no vertical
motion it follows that the box 3, in which the bolt 7 is fastened, will move up and
down within its housing to compensate for the varying relative positions of the
bolt 10 and the bolt 7.
11 is a groove formed in the cam 6, the contour of its walls being such as to
impart a varying motion to the bolt 12, which passes through said slot and is
secured by riveting or otherwise in the T-block 13, similar in cross-section to the
block 8, and adapted to slide in the T-shaped groove 9, so that upon the cam 6
Prien 21

page_text: being oscillated, as before described, a to-and-fro motion will be imparted to this
block 13 by said oscillations, and this to-and-fro movement will be altered and
varied by the action of the walls of the cam-slot upon the bolt 12.
In applying this device to a locomotive or other engine the valve-rod is divided
and the rear section 14, which is attached to the rocker-arm 15, is pivoted to the
cam 6 by the bolt 10 or a suitable sleeve 16, surrounding said bolt, and the front
section 17 is pivoted by the bolt 12 to the block 13; or a sleeve 18 may be
interposed between said rod and bolt, so that when motion is imparted to the
rocker-arm by the usual eccentric mechanism, the cam 6 will be caused to oscillate
about the bolt 7, transmitting its motion to the valve-rod 17, plus or minus
the motion produced upon said valve-rod by the contour of the walls of the
cam-slot 11.
It is a well-known fact in steam-engineering that the eccentric movement in
general used for operating the slide-valve of an engine does not properly time
said valve relative to the piston-stroke, and thereby great loss of efficiency is
occasioned, since the steam during the portion of its admission to the cylinder is so
" wired "
as to limit its effectiveness upon the piston-head, and also the steam upon
the dead side of the pisten is not properly freed during its exhaustion and considerable
back-pressure is occasioned by the too quick return movement of the valve. These
difficulties I have entirely overcome, as by the use of my device I am enabled to so
time the lap and lead of a slide-valve from the motions of the eccentric as to
cause said valve to dwell or move more rapidly through portions of its travel,
thus preventing the "wiring" of the steam during its admission to the cylinder or
exhaustion therefrom, and by altering the contour of the walls of the cam-slot
more or less back-pressure may be had, as occasion may require.
In case it becomes desirable to throw out of action the cam-slot and transmit
the movement of the eccentric directly to the slide-valve it is only necessary to
remove the bolt 7 and pass a bolt through the hole 19 and screw it into the hole 2',
formed in the block 13, which will so connect the cam 6 to the blocks 8 and 13 as
to cause it to move therewith in a direct line, which will have the effect of uniting
the sections 14 and 17 of the valve-rod.
While I have shown my improvement as adapted and applied to a locomotive in
which a link-reversing gear is used, it is obvious that it is equally applicable to
single-eccentric engines.
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 device of the character described, a frame having a suitable housing,
a block moving vertically in the housing, a cam pivoted to the block, a second
block 8, moving in a longitudinal groove of the frame, a block 13, slidable in the
groove with the block 8, said block 13 having a pin working in a circular aperture,
rods 14 and 17 for transmitting motion to and from the cam as and for the purpose
described.
2. In a device of the character described, the frame 1, block 3, having a limited
movement within suitable housings upon said frame, cam 6, pivoted to said
blocks, block 8, sliding within a groove in the frame, and to which the housing of
said cam is pivoted, block 13, also sliding in said groove, groove 11, the walls of
which are so disposed as to transmit motion to said block 13, and the rods 14
and 17, for transmitting motion to and from said cam, as and for the purpose set
forth.
Dated this 22nd da of 1007
J. P. BAYLY,
18 Fulham Place, London, W., Agent for Applicant.