Improvements in Valve-gear.
Year: 1894

page_text: Date of Application, 16th Oct., 1894-Accepted, 9th Feb., 1895
Improvements in Valve-gear.
I, ROBERT_MCCOLLUM FRYER, of 12120 Street, Washington, in the District
of Columbia, United States of America, Engineer, 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 :-
The objects of this invention are:
To avoid the use of eccentrics as a means for actuating valve-gear; to take
motion for actuating the valves directly from the moving parts of the engine to
which they belong; to control the valves of one cylinder of a compound engine
by or from the movable parts actuated by the other cylinder; to set the valves
by a preliminary or preparatory movement to a predetermined position and to
open and close from said predetermined position by separate and independent
movements; to move the valves with a differential movement, gradually increasing
towards, and diminishing from, the closed position; to provide means for varying
the throw of the valves; to provide means for varying the lead and to actuate
the valves by motion derived primarily from reciprocating parts of the engine
in contradistinction to continuously rotating parts.
To these ends, the invention consists in the construction, arrangement and com-
bination of parts as hereinafter fully described and as illustrated in the accompanying
drawings, which form a part of this Specification, and in which :
Fig. 1 represents my valve-gear in front elevation showing its application to the.
engine.
Fig. 2 is a plan view of the valve-operating arms and levers, showing their
connection with the engine valves, the view being taken on the line x-x in Fig. 1.
Fig. 3 is a plan view of the actuating levers, showing their connection with the.
oscillating shafts of the engine.
Fig. 4 represents in face and edge view, one of the valve-operating levers.
Fig. 5 represents in face and edge view one of the crank levers.
Fig. 6 is a vertical central section through the cylinder, valve chambers and
valves, of a steam engine showing the valves in their relative positions at a
predetermined point in the movement of the piston.
Figs. 7, 8, 9 and 10 represent details of construction hereinafter fully described.
In the accompanying drawings, and in the following description, I show and
describe the invention as being applied to rotary or oscillating valves, but I desire
to have it understood that it is applicable to other styles of valves, and that I do
not intend to limit myself in its application to any particular style.
And I desire also to have it understood that this valve gear is applicable to any
right angular engine and that its application is therefore not limited to the particular
engine described in the Letters Patent heretofore granted to me as hereinafter
stated.
A designates the high pressure, and B the low pressure cylinder, the piston of
one cylinder being connected with a crank arm C on a rock shaft 20, and that of
the other cylinder with a corresponding arm C' on a rock shaft 20%, the said
shafts 20, and 20b, being parallel with each other. Said shafts are also provided-
with outwardly-projecting arms D and D' which are both connected, by means of
connecting rods d, d, with a crank pin e, of the shaft to be driven.
The arms D D stand at substantially right angles to each other, so that when
the connecting rod actuated. by one engine is at the center the other connecting
rod is on the quarter, the said positions corresponding approximately with the full

page_text: and half strokes of the respective pistons, from which it follows that each
piston in its turn assists the other in passing the centre, and that dead centers are
entirely avoided.
This engine forms-no part of my present invention but forms the subject of
Letters Patent of the United States granted to me on the 21st day of August 1883,
No. 283704, and the foregoing description is given here merely for the purpose of
aiding the following description of the valve gear,
From the front end of the shaft 20 project horizontal pins or arms 24, 25, and
from the end of shaft 20%, extend similar pins or arms 22, 23, these pins or arms
being conveniently formed on cap pieces 21", and 21%, which are secured in any
suitable manner on the ends of the respective shafts.
The pins or arms of the respective shafts are preferably diametrically opposite
each other and so disposed that when the shafts are in their intermediate positions
(as when the engines by which they are respectively actnated are on the half
stroke) each pair of pins will be in the same vertical plane. This is for the
purpose
of permitting the actuating levers to extend from one shaft between the pins of the
other, as will be hereinafter more fully described.
A third pin 20°, projects from the shaft 20, slightly eccentric to the axis of the
latter, being so disposed that when the shaft is in the central position (as shown
in Fig. 1) the pin will be in the same horizontal plane with, and outside of, the axis
of the shaft.
A series of actuating levers 33, 34, 35, and 36 are fulcrumed on the pin 20°, and
extend horizontally in the direction of the opposite shaft 20%. The two outer
levers 33, 36, are longer than the inner ones 34, 35, they are supported on a
horizontal pin or bar 27, projecting on opposite sides of a disk or plate 27 mounted
on the pins 22, 23, the said levers having in their ends elongated eyes for the
reception of the supporting pin, whereby lost motion is provided for to permit the
oscillations of shaft 20%.
The intermediate levers 34, 35, are supported on and controlled by a horizontal
pin 27, which also projects on both sides of the disk 27 diametrically opposite the
pin 27, so that by the oscillations of the shaft the levers connected with the
respective pins 27*, and 27%, are alternately moved in opposite directions, one pair
being raised and the other pair lowered. The levers being of different length the
pins 27, and 27 are placed at such relative distances from the center of motion
that the two pairs of levers shall be moved through corresponding distances that is
to say so that at corresponding distances from the fulcrum 20°, they shall have the
same vertical movement.
On the ends of the arms 22, 23, is a disk or plate 26 which carries a fulcrum
pin 26°, projecting from both sides (see Fig. 3) the said pin having the same
relation to the axial line of the shaft 20", that the pin 20%, has to that of shaft 20*.
Four levers 29, 30, 31, 32, are fulcrumed on the pin 26, corresponding in length
and arrangement with the levers 33 to 36 as above described, but extending in the
opposite direction. The inner, and shorter, levers 30, 31, are supported aud
actuated by a cross-pin 28*, carried by a disk or plate 28 mounted on the ends of
the arms 24, 25, and the outer and longer levers by a pin 28b, also carried by said
disk or plate, the said pins 28*, and 28, having the same relation to the axial
line of shaft 20, that the pins 27 and 27" have to that of shaft 20%, as above
described. Thus when the engines are in operation the oscillatory movements of
the shafts 20, and 20%, impart vibratory movements to the levers in pairs, one pair
of each series being raised as the other pair is lowered.
The system of levers thus far described are the actuating levers from which the
valve gear is operated as will be hereinafter described.
In front, and at the sides, of engine A are two rods or shafts 18ª, 18b, secured
by cap plates 18 upon any suitable supports (not shown) and on these rods or
shafts are loosely mounted, in alternating arrangement, four lever-arms 5, 6, 7,
and 8, constructed substantially as shown in Fig. 4, and four series of crank levers,
constructed substantially as shown in Fig. 5, the crank levers on one shaft being

page_text: in engagement with, and operated by, the lever-arms on the opposite shaft, as will
be more fully explained.
Referring to Fig. 4, which represents in detached view the lever-arm marked "5"
in Fig. 1, it will be seen that at the free end are two parallel arms 5°, and 5º, bound
together by a tie-piece 5³, said arms forming a yoke for the reception of a sliding
box 12 which receives the right angular boss on the end of the engaging crank-arm.
Each set of cranks comprises arms which may be integral with each other, or
formed separately and united together, as may be found preferable by the
mechanic.
In Fig. 5 (which represents the set of arms marked 6, 6 and 6 in Fig. 1)
I show them formed separately and connected together by a sleeve 19 upon which
they are rigidly secured, side by side, in proper angular relation to each other, the
said sleeve having an internal diameter corresponding with the size of the shaft or
rod 18, upon which it is mounted. The arm 6º, which is somewhat longer than
the arms 6. 6, has at its end a right angular boss or stud 6, which engages the
sliding box 12 as above stated, and forms the connection with the lever-arm 6 on
the opposite supporting shaft 18. The two arms 6b, and 6º, are arranged at
corresponding opposite angles with relation to the arm 6, as shown in Fig. 5.
Preferably I make the boss or stud 6º, movable, as indicated in Fig. 5, by setting
it in a slot 6. By adjusting it towards or from the axis of the arm oª the leverage
may be varied and the throw of the valves regulated.
While I have described only one lever-arim it will be understood that the four
arms 5, 6, 7, and 8, are all alike, and of the same size, and that each arm controls
one set of crank levers, the four sets being also alike the several arms of each set
being designated by corresponding reference marks.
1, 2, 3, 4, designate the valve chambers of the cylinder A, and 1º, 2º, 3ª and 4ª
those of the cylinder B, the said chambers being disposed at top and bottom, and
at opposite sides, of their respective cylinders. The valves within said chambers
have projecting stems 10, each provided with a crank 9 rigidly fixed thereon, said
cranks being coupled by means of links 11, with the crank-arms on the shafts 18"
and 18, each set of crank-arms controlling two valves, as represented in Fig. 1.
Thus, the valves in chambers 12, and 3", are controlled and operated by the crank-
arms 5* 5° and 5° these crank-arms being in turn controlled and operated by the
lever-arm 5; the valves in chambers 2 and 4ª by the crank-arms 6ª 6º 6º, and
lever-arm 6; those in chambers 1 and 3 by crank-arms 7ª 7° 7° and by lever-arm 7,
and those in chambers 2 and 4 by crank-arms 8* 8b 8c and lever-arm 8. The arms 7
and 8 which control the valves in chambers 1, 2, 3, 4, being respectively in their
depressed and elevated positions the valves stand in the relative position indicated
in Fig. 6 in which the steam ports through which steam is admitted to the
cylinder, are supposed to be at the left hand side, marked St, and the exhaust
ports at the right hand side marked Ex. the piston P being near the completion of
its downward stroke.
During the downward stroke of the piston steam is admitted through the valve
chamber 1, as indicated by arrows, the lower steam port being closed, and the
exhaust is effected through the chamber 4, the valve in chamber 2 being closed.
When the positions of the arms 7 and 8 are reversed, the valves controlled thereby
will also be reversed, those in chambers 1 and 4 being closed and those in
chambers 2 and 3 being opened, steam being then admitted through chamber 3 and
exhausted through chamber 2. The connections for effecting these movements
and reversals will now be described.
The arms 5, 6, 7, 8, are provided respectively at corresponding points in their
lengths with horizontally projecting studs 5 6 7 and 8 and on the respective
studs are links 13, 14, 15, and 16, which are connected with the actuating levers 29
to 36 by link rods as represented in Fig. 1, each link being connected with two
levers. Thus, under the arrangement illustrated in the drawings link 13 is con-
nected by link rods 13 and 13 with levers 29, 30; link 14 by rods 14* and 14°
with levers 31, 32; link 15 by rods 15 and 15 levers 33, 34, and link 16 by

page_text: rods 16 and 16 with levers 35 and 36, each link being thus connected with one
long and one short lever of the same series from which it follows that as the said
levers are vibrated, as above explained, one end of each link will be raised and the
other end lowered, and the lever bars on which the respective links are mounted
will thus also be raised and lowered, the amount of vertical movement so imparted
to the levers being regulated by the position of the links, as usual in link motions.
While in the drawings I show no means for shifting the links it will of course
be understood that they are to be shifted as circumstances may require, and that
any ordinary or appropriate shifting mechanism may be employed.
The operation of the mechanism thus described is as follows:
The parts being in the position indicated in the drawings, the high pressure
piston at the half stroke on the downward movement, and the low pressure piston
at the beginning of the downward stroke, the series of actuating levers 29, 30,
31, 32, the two lever-arms 5, 6, and the valves controlled thereby will all stand in
an intermediate position, the valves in chambers 2" and 3" being then at the
beginning of their opening movement and those in the chamber 1 and 4ª at the
end of their closing movement; or to be more exact, the opening movement of
the valves in chambers 2 and 3 will already have commenced, for by reason of the
eccentricity of the fulcrum pin 26, the right hand ends of the levers 29, 30, as
viewed in Figs. 1 and will have passed below the central position when the
opposite or left hand ende are in the central position so that the opening
movement of the valves from their central position commences at the instant
when the pin 26°, passes the horizontal centre. The valves are of greater width
than the ports so that in their central positions they overlap both sides of the
ports and they are-or should be so adjusted that they will stand in their central
positions when the pin 26 is in its central position, or in the same horizontal
plane with the axis of the shaft 20%, and the eccentricity of the pin 26" is such
that when the latter is in its lowest position as indicated in Fig. 1, the steam
and exhaust valves will have moved the distance of their lap to the point where
the admission of steam for the opposite or return stroke begins.
The shaft 20 having now reached the limit of its movement the movement in
the opposite direction, indicated by the arrow in Fig. 1, begins, the effect of which,
provided the shaft 20 were at rest, would be to return the valves to the positions
from which they were moved by the preceding oscillatory movement of shaft 20°,
but the shaft 20° being now in its central position and moving in the direction o
said preceding movement of shaft 20° it follows, by reason of the greater distance
of the pins 28 and 28 from the center of motion that the left hand ends of the
actuating levers will be depressed faster than the right hand ends are raised, so
that the central points, at which the link rods are connected, will still move down-
ward, continuing the movement of the valves until they are fully opened, the
opening movement continuing until the shaft 20ª reaches the limit of its movemet.t
and being completed when said shaft reaches said limit.
It is to be noted that while the shafts 20 and 20 perform their oscillatory
movements at an uniform rate of speed, and the pins 28 and 28" move through
equal angular distances in equal times, the said pins travel in a vertical direction
from either limit of angular movement towards the central position, indicated in
Fig. 1, at a constantly increasing rate of speed and from the central position in
either direction at a constantly diminishing rate of speed. Therefore, the valves
being on the point of opening or closing when the said pins are in the central
position they are opened and closed with a quick sharp movement, giving a
practically instantaneous action, the effect of which cannot fail to be appreciated
by engineers.
The above description relates to the valves of cylinder B actuated through
levers 29, 30, 31, 32, lever arms 5 and 6, and crank-arms 5 and 6ª. The valves of
cylinder A are actuated in the same manner through levers 33, 34, 35, 36, lever
arms 7 and 8, and crank-arms 7 and 8, but the piston of cylinder B being at the
limit of its upward stroke, ready to begin the return stroke and its valves

page_text: respectively at the opening and closing points, the piston P of cylinder A, will be
at the half stroke, and its valves at the limit of their movement in one direction,
those in chambers 1 and 4 being fully open and those in chambers 2 and 3 fully
closed, the said valves being then ready to begin their movements in the directions
indicated by the arrows. These valves being actuated from shaft 20, as soon as
the latter begins its movement in the direction indicated by the arrow in Fig. 1,
the levers 33, 34, and the lever-arms 7 and 8 will be respectively raised and
lowered, the initial movements being comparatively slow and the rate of movement
gradually increasing towards the central position, as above described with reference
to the levers 29 to 32, and the lever arms 5 and 6.
The valves being considerably wider than the ports which they control will, by
reason of the differential movement of the actuating mechanism, start slowly and
travel with a gradually accelerating movement towards their new or reversed
positions.
The valves in chambers 1 and 4 being now fully open, move gradually towards
their respective ports and close the same, the final closing movement being effected
as the pins 27 and 27 near the central point in their travel from one position to
the other and when they are moving at their highest rate of speed and at the same
time the valves in chambers 2 and 3 are opened by corresponding movements.
It will be understood from the foregoing that each shaft imparts to the valves of
the cylinder from which it is actuated the initial or preparatory motion by which
they are set to the positions where the active movements begin, and that the active
operations of admitting and cutting off steam are effected from the opposite shaft,
so that the valves of each cylinder are partly controlled by both shafts, being first
set to a preparatory position by the shafts actuated by their own cylinders, and
then opened and closed through connections with the other shaft. By varying the
eccentricity of the pins 20 and 26, the extent of the initial or preparatory
movements of the valves may be varied and varying lap provided for, and for this
purpose I mount said pins in movable blocks 26b adapted to be adjusted towards
and from the axial line of the shafts in radial slots 40, 41, formned respectively in
the cap piece 21", and the plate 26, as illustrated in Figs. 7 and 9. Also, by
adjusting the pins 27* 27 and 28ª 28b, a greater or less angular movement may be
imparted to the actuating levers, and consequently the throw of the valves may be
varied at will to give the cylinders more or less steam, as circumstances may
require. In Fig. 8 I show the pins 28 and 28° supported by blocks 42, 43,
adjustable towards and from the center in a slot or way 44 formed in the plate 28.
In Fig. 10 I show the pins 27* and 27" similarly mounted in blocks 45, 46, which
are adjustable in a slot or way 48 formed in plate 27.
I do not wish to be understood as limiting myself to the exact details of con-
struction shown and described, because to the skilled mechanic and engineer many
changes and modifications will readily suggest themselves, and I therefore desire to
have my claims construed to cover and include any mere modifications adapted to
accomplish the same results in substantially the same way. For example, I may
dispense with the reversing links and with one half of the actuating levers 29, etc.,
and connect the remaining levers directly with the respective lever-arms 5, 6, 7, 8,
then by shifting the pins 27 27 28ª and 28 or such of said pins as the remaining
levers may be connected with, to the opposite sides of the axes of the respective
shafts 20 20 as explained with reference to Figs. 8 and 10, the direction of move-
ment of the levers relatively to the direction of movement of the shafts being
thereby reversed whereby the engine will also be reversed without the use of
reversing links.
In large engines where the shafts are far apart and where by reason of the
distance between them it is impracticable, under the arrangement above described
to impart to the actuating levers sufficient vibratory or angular movement to give
the valves the required throw, or where the required space is not available between
the said shafts, a construction and arrangement substantially such as illustrated in
Fig. 11 may be adopted.

page_text: 50, 51 designate two counter-shafts provided with crank-arms 52, which are
coupled with similar cranks 53 on the shafts 20* 20° by connecting rods 54, so that
the oscillations of the last named shafts impart similar movements to the counter-
shafts. The counter shafts may be located relatively to the shafts 20 and 20° as
may be preferred or found expedient.
.In the drawing I show them above and between but they may be located below
and between, or in the same horizontal plane, as will be readily understood. The
actuating levers 34, etc., instead of being connected with the engine shafts 20° 20° as
above described, and as illustrated in Figs. 1 and 3, are connected in the same
manner with, and actuated by, the counter shafts 50, 51. The countershafts may
be located at such distance apart as may be found desirable or expedient.
The closer they are together the shorter will be the levers, and the greater the
angular or vibratory movements imparted to the latter.
By making the crank arms 52 53, of different lengths the extent of the rotary
movements imparted to the countershafts may be varied. In Fig. 111 represent
an extensible actuating lever (marked 34) made in two parts 54, 55, telescoped
together, whereby the shifting of the pins 27° etc., is provided for.
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 valve gear, the combination with the valves, of an actuating lever, means
for imparting vibratory movements alternately to the respective ends of said lever,
and a connection between the valve and lever at an intermediate point in the length
of the latter.
2. In a valve gear for steam engines, the combination with the valve, of an
actuating lever, two alternately reciprocating devices so connected with the
respective ends of said lever as to impart unequal vibratory. movements thereto,
and a connection uniting the valve with the lever between said reciprocatory
.devices.
3. In a valve gear for steam engines, the combination of two parallel oscillating
shafts, a lever having fulcra on said shafts eccentric to the axes thereof, a valve,
and a connection between the valve and lever at a point between said shafts.
4. In a valve gear for steam engines, the combination with the valve, of an
actuating lever, means for imparting independent vibratory movements
to the
respective ends of said lever, and a reversing mechanism between the valve and
lever at an intermediate point, in the length of the latter.
5. In a valve gear the combination with the valves, of a plurality of actuating
levers, two alternately or successively reciprocating devices connected respectively
with opposite ends of said levers to impart unequal vibratory or angular movements
thereto, each end of each lever moving on the connection at the opposite end as a
center, and connections between intermediate points in the lengths of said levers
and the valves for imparting motion to the latter.
6. In a valve gear the combination with the valves of two successively or
alternately reciprocating devices, a plurality of levers having their opposite ends
connected with the respective reciprocating devices, a plurality of levers having
their opposite ends connected with the respective reciprocating devices to receive
unequal vibratory or angular movements therefrom, and link connections between
said levers and the valves.
7. In a valve gear, the combination of two rotary. reciprocating shafts, a series
of levers having their opposite ends connected with the respective shafts, the con-
nections being at different distances from the respective centers of motion, whereby
unequal vibratory movements are imparted to the respective ends of the levers and
-connections between the valves and levers at intermediate points between the said
.shafts.
8. In a valve gear, the combination of two rotary reciprocating shafts, a series
of levers having fulcra on one of said shafts at points eccentric to its axis, and

page_text: having connections with the other shaft at relatively greater distances from its axis,
whereby unequal vibratory or angular movements are imparted to the two ends of
said levers, and connections between the valves and levers at points between said
shafts.
9. In a valve gear, the combination of two rotary reciprocating shafts, a series
of levers having fulcra on one shaft eccentric to the axis thereof and connected in
pairs with the other shaft at opposite sides of its axis, whereby the reciprocating
movements of the shafts will impart motion to the fulcrumed ends of all the levers
in the same direction and to the opposite ends of the respective pairs in opposite
directions, and connections between said levers and the valves for operating the
latter.
10. In a valve gear, the combination of two rotary reciprocating shafts, a series
of levers having fulcra on one of said shafts, and having connection with the
opposite shaft, in pairs, on opposite sides of its axis, said connections being adjust-
able towards and from the axis, whereby the throw of the lovers may be varied
and adjusted, and connections between said levers and the valves for operating the
latter.
Dated this 16th day of October 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicant.