Improvements in Governors and Valve Movement for Gas Engines
Year: 1891

page_text: Date of Application, 2nd June, 1891--Accepted, 4th July, 1891
COMPLETE SPECIFICATION.
Improvements in Governors and Valve Movement for Gas Engines,
1. FERDINAND BOSSUARDT, of the firm of F. Bosshardt & Co. of 4 Corporation
Street, Manchester, in the County of Lancaster, Engineer, and Patent Agent, do
hereby declare the nature of this invention which has been communicated to me
from abroad by Frank Atwood Huntington, 38, Broadway, New York, of the
United States of America, Engineer, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement :-
This invention relates to gas engines of that class in which the operation of the
inlet and exhaust valves of the cylinder is controlled by the crank shaft through
valve stems extending to the said crank shaft.
My invention relates more especially to the valve lifting mechanism, and to an
improved governor for regulating the inlet valve according to the speed of the
engine.
In the best type of gas engines, as now used, the valves are opened only once
for two complete revolutions of the crank or stroke of the piston. Were they
opened at every stroke it would be a simple matter to provide direct acting cams
on the crank shaft so arranged as to lift the inlet and exhaust valve stems at
proper intervals. To allow alternate revolutions of the operating eccentric to have
no effect upon the valves, has hitherto required very complicated and expensive
mechanism, the practical operation of which has been far from satisfactory. The
object of my invention is to provide a simple valve moving device operated from
one end by the crank shaft which, without multiplication of parts will accurately
and unfailingly, operate these valves at alternate strokes, and which from the
simplicity of its construction, and the consequent strength of the parts will need
practically no repairs.
Without at this point going into details of the construction of my valve moving
device, it is proper to give a general idea of its essential features.
A casing is provided on the side of the engine frame through which the crank
shaft passes; the valve stems enter this casing and are struck and lifted by teeth
which form a spur gearing upon a rotating ring. The movement of this ring by
which it raises the valve stems, is imparted to it by an eccentric keyed upon the
crank shaft and loosely enclosed by the ring. The ring is differentially geared to
an internal gear upon the inside of the casing, the ratio of teeth on the ring and
casing being, for example, as 6 to 13. Consequently the rotation of the eccentric
and the successive engagement of the teeth of the ring with those of the casing
gives a slow rotation to the ring in a direction opposite to that of the eccentric,
the movement of the ring being a distance of one tooth space on the casing at each
complete rotation of the eccentric. This will be readily understood by those
acquainted with the operation of differential gearing, but it will be duly
explained in greater detail hereinafter. This rotation of the ring causes it to
alternately miss and strike the valve stems at each revolution of the eccentric.
For a complete comprehension of my invention reference must be made to the
accompanying drawings, in which :—
Fig. 1 is a transverse section on the line of the crank shaft of an engine.
Fig. 2 is a longitudinal section of the casing which contains the valve operating
mechanism, and of said mechanism.
Fig. 3 is a transverse section of the same.
A represents a portion of the frame of an engine, and B the crank shaft supposed
to derive motion as usual, from a reciprocating piston rod. None of the operative
parts of a gas engine are shown in these drawings, as their exhibition is unneces-

page_text: "
sary to a complete understanding of the present invention. The crank shaft B
passes through a circular casing C bolted to the engine frame (Fig. 2) which is
provided with openings a, b. for the admission of the inlet and exhaust valve
stems, D, E, cach stem being forced into the casing by springs and having
shoulders e to limit their movement. The valves themselves are not shown but they
may be of any desired kind adapted to be operated by a reciprocating stem. The
valve operating mechanism is contained by the casing C and will be best under-
stood by reference to Fig. 2. The interior of the casing is circular in form, and
on the internal periphery is a series of spurs, teeth or projections c.
The crank
shaft which passes centrally through the casing, has keyed to it an eccentric F
surrounding which is a loose collar or ring G having spurs or teeth adapted to
engage with those upon the casing as shown in Figure 2. The valves are intended
to open only at every other stroke of the piston, and as these teeth constitute
the valve stem lifters, it is necessary that the eccentric be allowed to make a
complete revolution without causing them to strike such stems. In the arrange-
ment shown in Figure 2 the valve stems enter the casing "quartering
or 90°
apart in operating the engine therefore, commencing with the exhaust, that valve
is opened and then after a quarter revolution of the crank shaft, the inlet valve.
The crankshaft then finishes that revolution and makes another, complete before
again opening the exhaust valve. I now describe how this is accomplished. The
ring G is shown as provided with 6 teeth and the casing C with 13 teeth c.
The constant rotation of the eccentric shifts the position of the loose ring in the
direction of travel of the eccentric and causes its teeth to engage successively with
the casing, but the actual motion of the ring relative to and independent of the
eccentric is a slow rotation in the opposite direction. The casing and ring form a
differential gearing and therefore at each complete revolution of the shaft in the
direction of its arrow, each tooth of the ring will be carried one tooth space in
the direction of its arrow. For example one tooth is shown in Fig. 2 in position
to lift the inlet valve as soon as the eccentric shall have made a quarter turn.
When the eccentric comes round again this tooth has moved with the arrow one
space, and it requires another complete revolution of the eccentric to bring another
tooth on the ring opposite to the inlet valve stem.
In Figure have illustrated my invention as adapted to engines in which the
valve stems instead of entering the casing at right angles to each other are placed
side by side. In this case provide the crank shaft with two eccentrics F, F¹ set
quartering on the shaft and each carrying a toothed ring. The operation of this
device is precisely similar to that last described the change in the position of the
valve stem being exactly compensated for by the use of two cams 90° apart. This
will be readily understood without detailed explanation.
I have provided for my improved valve motion, a special form of governor for
automatically closing or partly closing the inlet valve when the speed becomes too
great. This governor is shown in Figure 1 where H represent a loose collar
adapted to slide upon the crank shaft and having a circular groove for the lever h
of the governor balls I pivoted upon a collar J fixed on the shaft. An arm K
extend from the collar H through a slot in the casing and is connected to the valve
stem D.
When the speed is increased to too great an extent the collar H is drawn
out, as the balls spread, and the valve stem is pulled directly outward through the
slot and therefore out of reach of the teeth g so that the valve is not opened until
the speed decreases sufficiently to permit the governor, to return the valve stem to
its original position.
It will be seen that all the parts of my improved device are simple in construction
and may thus be made exceedingly strong. Practically they will run indefinitely
without repairs and it is only necessary to occasionally fill up the casing with oil to
take up what little friction is caused by the internal gearing.
I claim as my invention :-
1. In a gas engine the combination of a toothed ring onerated by an eccentric

page_text: upon the engine shaft, a valve stem adapted to be lifted by said ring, and a speed
governor connected directly to said valve stem whereby it may be moved out of
line with said ring, substantially as set forth.
2. A valve lifter for gas engines composed of a stationary internal gear, and a
toothed ring geared differentially thereto and operated by an eccentric upon the
crank shaft, substantially as set forth.
3. A valve lifter for gas engines consisting of a toothed ring geared differentially
to and within enclosing casing and operated by an eccentric upon the crank shaft,
substantially as described.
4. In a gas engine the combination of a valve stem, a valve stem lifter, a shaft
carrying a sliding collar and governor balls, for operating the collar and a rigid
connection between the collar and valve stem for operating it positively into and
out of line with the lifter, substantially as described.
5. In a gas engine and in combination a casing through which passes the crank
shaft of the engine, valve stems entering said casing, an eccentric on the crank
shaft, a loose ring surrounding the eccentric and differential teeth on the casing and
ring, substantially as described.
6. In a gas engine the combination of a casing, valve stems entering said casing,
a ring shifted by an eccentric on the crank shaft and differential teeth upon
the ring and casing all constructed and arranged so that the teeth on the said
ring lift said valve stems at alternate revolutions of the crank shaft, substantially as
described.
7. The combination of a casing secured to the engine frame, valve stems, entering
the casing a crank shaft passing through said casing and having an eccentric fixed
upon it, a ring loose on the eccentric and provided with an even number of teeth, and
a series of teeth on the casing equal in number to one more then twice as many as
those on the ring all constructed and arranged so that cach complete revolution of
the eccentric causes the ring to move in the opposite direction a distance equal to
one tooth space on the casing substantially as described.
8. A valve moving mechanism for gas engines, consisting of a fixed casing having
an internal spur gearing, a ring within such casing operated by an eccentric on the
engine shaft, and provided with differential spur gearing whereby it derives
rotation in a direction opposite to that of the eccentric all in combination with valve
stems entering the casing substantially as described.
a
9. The combination of a casing secured to the engine frame, the engine shaft
passing through said casing and having valve lifting devices mounted upon and
operated by it, and spring-pressed valve stems entering said casing and provided
with stops to limit their motion substantially as described.
Dated this 1st day of June 1891
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester, Agents to Applicant.