IMPROVEMENTS IN VALVES AND GEARING FOR SAME
Year: 1876

page_text: LETTERS PATENT to Herbert John Haddan, of the Firm of Herbert and
Company, Patent Agents, of 67, Strand, in the City of Westminster, Civil
Engineer, for the Invention of "IMPROVEMENTS IN VALVES AND GEARING FOR
SAME. A communication from abroad by Charles Brown, of Winterthur, in
the Empire of Germany.
Sealed the 6th February 1877, and dated the 11th August 1876.
PROVISIONAL SPECIFICATION left by the said Herbert John Haddan at the
Office of the Commissioners of Patents on the 11th August 1876.
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Patent Agents,
of.67, Strand, in the City of Westminster, Civil Engineer. "IMPROVEMENTS IN
VALVES AND GEARING FOR SAME." A communication from abroad by Charles
Brown, of Winterthur, in the Empire of Germany.
The improvements relate more particularly to valves intended for steam engines
worked at a high velocity, and consist in rendering said valves self-acting with a
changeable expansion by applying steam buffers to the valves, and working said
valves by means of slide bar or transfer gearing together with motion derived from
the machine, and thereby effecting a rapid opening and shutting of the valve
without loss, and without reaction by blows on the regulator.
The various parts may be made of metal and fitted together by any well known
mechanical means, and proportioned to the size and force of the engine to which
they are to be applied; the buffers may be formed by one cylinder working in
another charged from time to time with steam, and means provided for the escape
and renewal of such steam.

page_text: VALVES AND GEARING FOR SAME." A communication from abroad by Charles
Brown, of Winterthur, in the Empire of Germany.
The improvements relate more particularly to valves and goaring intended for
steam engines worked at a high velocity, and consist in rendering said valves self-
acting with a changeable expansion and applying steam buffers to the valves, and
working said valves by means of slide bar or transfer gearing together with motion
derived from the machine, and thereby effecting a rapid opening and shutting of
the valve without loss, and without reaction by blows on the regulator..
The various parts may be made of metal and fitted together by any well known
mechanical means, and proportioned to the size and force of the engine to which
they are to be applied; the buffers may be formed by one cylinder working in
another charged from time to timo with steam, and means provided for the escapo
and renewal of such steam.
The Invention will be further understood by reference to the accompanying
five Sheets of Drawings, where Figure 1. represents cross section of the steam cylinder
of a stationary steam engine provided with the improved valves, together with
portion of the gear mechanism attached to the cylinder; Figure 2, section through
the cylinder; Figure 3, ground plan of the cylinder.
The admitting or receiving valves A, A, (Figure 1) are equilibrated double seated
valves, with very narrow but even seat surfaces; A¹, A¹, are the wedged-in valve
scats with the corresponding double-smooth sent surfaces. These seats contain at
the top a piston B, B, the diameter of which is in proportion to the seat surface.
There is attached to this cylinder an exactly fitting hollow small cylinder C, closed
at the top with three or more arms cast in one piece with the body of the cylinder,
for the purpose of serving at the top as a guide to the valve as well as a buffer, so as
to avoid any violent concussion of the valve with its seat. A small valve (see
Figure 1) D moves in a vertical perforation of the piston B, B, which is open towards
the inside of the buffer chamber, and the vertical perforation keeps up a com-
munication with the outside steam chamber in the valve cover through three or
more small radial openings d, d. The small valve itself is likewise perforated in a
vertical direction for the sake of allowing the rapid discharge of the steam out of
the buffer chamber. The fixed piston is provided with a number of grooves so as
to render impossible any detrimental escape of steam from the buffer chamber.
A similar steam buffer placed in the inside of the valve cover is on account of the
lensity of the steam far more efficacious, and its size may be reduced very
considerably and in a far greater proportion than any air buffer placed externally
as sometimes donc. In the saine way the connection of the valve with the valvo
rod is a far more appropriate one than the one generally used with hinges or wedges
fitted to the rod.
Attention is drawn to the fact that the bottom part of the valve rod contains
two or more rings, fitting in a series of rings in the wooden grooves of a brass
matrice E divided in halves, which is screwed above to the small buffer cylinder.
The wooden grooves allow the small rod a certain lateral notion within the brass
matrice, preventing any pinching of the valve or the small rod, even if the action
happens not to be absolutely concentric. The surface both of the rings and the joints
being very large, the inconvenience of a rapid beating off between the rod and the
valve is next to impossible.
As
The valve rods F, F, themselves are made of hard bronze or phosphor bronze
carefully fitted into a comparatively deep groove in the top of the valve cover, and
contain likewise a number of grooves, the purpose of this arrangement being to
dispense with a stuffing box proper, which is difficult to keep air-tight; moreover,
the part of the spinde moving within the stuffing box is sure to be worn out.
it is, the upper part of the rod apparatus is closed by a box for the purpose of
lodging some cotton cords, which are easily compressed by a matrice made of brass.
Under the influence of such arrangement any escape of steam along the valve rod is
done away with. There is a joint or hinge attached to the upper end of the rod
provided with two or three matrices, which are intended to squeeze two or three

page_text: thin steel plates with underlaid trestle plates. The small steel plates form an elastic
medium and are so situated as to lessen the retrograde motion of the rod and
valve.
Sheet II. and III. show the so-called external gear and its connection with the
regulator, videlicet, Figure 4, side view; Fig. 5, front view; Figure 6, ground plan;
and Figure 7, counter guide, key, and slide bar straight leader; and Sheet I., Figure I.,
in an especial manner the motion between the valve boxes. The positive motion for the
admitting valve starts from a point S at about one third of the length of the pushing
rod, by means of a lateral pushing rod, the other end of it marked T being laid
down from the radius R in a circular arc. At another point Q at about half of the
length of the guiding rod (which, whilst the engine is in motion describes an elliptical
curve Q), the rod is connected with a vertical pendulum rod P, the upper end of
which N is guided up and down through a counter guide in an almost retilineal
direction. This straight line assumes, according to the position of the regulator,"
either a vertical (Figure 7), or an oblique position (Figure 4). A few centimeters.
below the point N in a moveable groove of the pendulum rod P, the one end of M
of the guiding rod M is connected at a point, the other end M¹ of the guiding
rod M embraces a lever L, which forming one piece with the bar K swings round a
horizontal pin J. The support H screwed on the cylinder to which is fastened the
aforesaid pin J contains at the top two additional pins G¹, G¹, used as turning
points for both the angular levers G, G. The shanks of these angular levers.
pointing downwards carry hardened steel plates of a small size for the stroke of the
bar K, whilst the other outside ends of the horizonal shanks are formed as forks
and encircle an open nut-shaped piece of steel; this latter encloses a cover h, h,
(see Sheet I.). This cover slides on an external cylindrical straight conductor up
and down the valve cover lid, and its motion being transferred by the medium of
two small columns to the before-mentioned elastic steel plates. A third pin at the
top of the support H forms the counterpoise for a screw which is pushed by a
bundle of flat springs against the upper edge of the fork G, G. The bar K is now
enabled to turn without hindrance from its middle position to the right and left
round a very small corner, and not touching the stroke plates.
The construction and fittings of the bar K, as well as the position of the stroke
plate, are such that the first contact between both of them has to take place quite
close to the fulcrum J of the bar K, however in such manner that the point of
contact is raised higher. The last contact between the bar K and the small stroke
plate is consequently a very slow one, hence the quiet working of the valve.
A rapidly repeated stroke alters the relation of the levers between the bar K and
corner levers with a doubly increased velocity; the valves after the first slow
stroke are raising themselves constantly for their opening, permitting the steam
rushing after or behind the piston to follow the same without experiencing any
check.
The counter-guide, koy, slide bar, straight leader, and the connections between
the regulator are explained by the Figures 4, 5, 6, and 7, Sheets II. and III. The
vertical working of the regulator cover imparts by means of the ordinary regulator
a certain annular motion to the axle U which is shared by the double arins U¹, U₁,
which in consequence assume a horizontal direction, the regulator being in an
elevated position (Figure 7), and an inclined direction, the regulator being low
(Figure 4). Both ends of the double arm have joints within which counter-guiding
arms are partly turning, and these latter are in their turn connected between
themselves by a third joint, so that the point N of the pendulum rod P describes a
nearly straight line. With the view of the opening of the valve always taking
place at the same point the length of the pendulum rod P, and the position of the
axle U are regulated and act independently of the turning of the double arm and
the position of the regulator, so that the point M of the guiding rod has to be, no
matter what may be the situation or position of the regulator, exactly symmetrical
below the axle U, and the distance described by it from the centre lino is the
measure for the front opening, which consequently remains permanent.
These

page_text: arrangements establish a perfectly quiet and smooth working of the regulator. The
slight pressure on M² and N during the period of the opening of the valve exercises
so small and insignificant an influence on the working of the regulator, as to allow
of the same working in a steady and uniform way.
The advantages attained by this gear are the following, videlicet:-1, applica-
tion of great speed, even to valve engines, which are put in the position of
making 150 revolutions per minute; 2, smaller engines will suffice to do the
work, thereby saving outlay and working expense; 3, considerable simplification of
the mechanism and an important reduction in wear and tear, also saving to a
large extent expenses for repairs; 4, easy applicability of the valve gear as a "link
gear," therefore adapted for tram or track engines. The "counter-guide and
straight leader" may be likewise advantageously used for the motion of steam
slides of locomotives.
Sheet IV. represents the application in all its details to two arrangements one an
ordinary locomotive, the other a "Belpaire" engine.
Sheet IV. demonstrates the whole of the construction of the latter. The piston
is according to this system working on a curve through a balance and connecting
rod. Attached to the connecting rod A is a pin putting in motion the rod B. The
extremity of the same receives in the described manner a rectlinear motion through the
double-armed lever C, and the counter-guides D and E. The position of the double-
armed lever C, which is ruled through the link gear lever H by means of lever F
and rod G regulates the magnitude or extent of the lift of the point J on the bar A,
as this point has to travel through a more or less elliptical orbit. This point J, as
shown in the Drawing, rules the slide K. This gear is acting in the capacity of
expansion and link gear. As "expansion gear" it offers, compared with ordinary
arrangements the advantage, that it renders possible to create more degrees of
expansion and a more accurate distribution of steam. As "link gear" its con-
struction is advantageous, because the handling of the link gear lever is very easy,
requiring on the part of the manipulator less strength and effort, than the ordinary
connecting gear;" when accompanied by the counter-guido straight leader it is
easy to do away with the detrimental influence of short guiding rods on the precise
distribution of steam, by rising and lowering the upper extremity of the pendulum
rod through a slight displacement of the joints at the double-arm C.
Sheet V. shows two diagrams of working which will speak for themselves.
In witness whereof, I, the said Herbert John Haddan, have hereunto set my
hand and seal, this Seventh day of February, in the year of our Lord One
thousand eight hundred and seventy-seven.