IMPROVEMENTS IN VALVE GEARING
Year: 1880

page_text: แ
In the Matter of Letters Patent granted to Francis Carr Marshall, of
Tynemouth, in the County of Northumberland, Engineer, for the
Invention of "IMPROVEMENTS IN VALVE GEARING," bearing date the
14th October 1880 N° 4185.
TO ALL TO WHOM THESE PRESENTS SHALL COME I, FRANCIS CARR
MARSHALL of Tynemouth, in the County of Northumberland, Engineer, send
greeting,
WHEREAS Her Present Majesty Queen Victoria by Her Letters Patent under
the Great Seal of the United Kingdom of Great Britain and Ireland bearing date
the 14th day of October 1880 in the forty fourth year of Her reign did grant unto
me, my executors, administrators, and assigns, the sole privilege during the term
of fourteen years thence next ensuing to make, use, exercise and vend within the
United Kingdom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an invention for "IMPROVEMENTS IN VALVE GEARING,"
And Whereas in pursuance of the conditions of the said Letters Patent I did on
the 13th day of April 1881 cause a specification of the said invention in writing
under my hand and seal to be filed in the Great Seal Patent Office.
and third
And whereas since the filing of the said specification I have discovered that
the first
claims in the specification of the said Letters Patent are of doubtful
validity and I wish to avoid objections which may be made thereto, and to other parts of
the specification referred to below.
NOW KNOW YE that I, the said Francis Carr Marshall do hereby for the
aforesaid reasons (by and with the leave of Her Majesty's Attorney General) alter
and amend the said specification in manner following, that is to say ;-
On page 3 of the specification, as it is printed by Her Majesty's Printers, by
striking out all the words commencing with the word "or" in line 18 and
terminating with the word "point" in line 21.
Also on the same page by striking out the words "by preference" in line 29.
Also on the same page by striking out all the words commencing with the word
or in line 36 and ending with the word "used" in line 38.
"
On page 4 by striking out lines 18 to 23 inclusive commencing with “ When the
eccentric" and terminating with "described above."
Also on the same page by striking out all the words commencing with the word
"with" and ending with the word "lever" in line 24, and the parenthesis.

page_text: Also on the same page in line 27 by inserting after the word "in" the words
"the specification of."
"
"
Also on the same page by striking out from "though" in line 29 to "declare
in line 30, inclusive, and by substituting therefor the words following (that is to
say) it is to be noted that no claim is made to the use generally of an eccentric
and strap, a valve lever suspended from an arm on a reversing shaft by a radius
rod and a connecting rod to a valve spindle; but "
Also on the same page by substituting the word "is" for the words "to be" in
line 31.
Also on the same page by striking out the whole of lines 32 to 35 inclusive,
being the first claiming clause
Also on the same page, line 36 by striking out "2nd" at the commencement of
the line.
Also in the same line by striking out the words "the said."
"
Also in the same line by inserting after the word " gearing" the words of the
kind described above and illustrated in the accompanying drawings."
Also on the same page by striking out the whole of lines 39, 40 and 41 being
the third claiming clause.
And in order that the effect of this Disclaimer may be better understood the
following copy of the Specification as it will appear when such Disclaimer has been
made as aforesaid is appended, videlicet.
FRANCIS CARR MARSHALL, of Tynemouth, in the County of Northumberland,
Engineer. "IMPROVEMENTS IN VALVE GEARING."
.
These improvements relate to an arrangement of valves and gear for working
the same, in marine, locomotive, or other engines worked by steam or other elastic
vapour or fluid, requiring to be frequently reversed in their motion, or worked
at varying degrees of expansion regulated by hand, steam or hydraulic power or
by automatic governors of any description acting upon the said regulating power.
In this arrangement the movement of the valve is derived from an eccentric
secured to (or by preference made solid with) the crank shaft and having its
eccentricity virtually coincident with the crank. The strap embracing, this
eccentric, is made solid with or firmly secured to its rod and constitutes the
eccentric lever. The working direction of this lever is at right angles to that of
the valve's motion. The valve rod is attached to the extreme end and at an
intermediate point in its length the lever is suspended by a link to a pin or fulcrum
in the outer end of an arm on the reversing shaft. By moving this arm from one
extreme to the other of its arc (of about 60 degrees) the engine is reversed; when
it is in its middle position the steam passages will only open the amount fixed upon
as the "lead" opening and the engine is free to move either back or foreway, and
by bringing the arm into, any intermediate position (on either side of its middle
position) either by hand direct or by steam or hydraulic power actuated by hand or
automatically by the governor (acting upon the valve gear of the reversing engine)
any required degree of expansion may be obtained or the speed of the engine
regulated:
The valve used with this gear is made dissimilar ended, having, in the case of
slide valves one or more openings for steam inlet at the top or end away from the
gear, over that or those at the bottom or end nearest the gear, and in the case of
cylindrical valves, either one or more valves at top than at bottom, or one at top
larger in diameter than that at bottom. These additional openings may be direct
through, the plate forming the valve face, or indirect by a passage at the back of
the valve and taking the additional steam, for the top end from the lower end of
the valve (as in what is known as the "trick" valve).
Str
Πολύτυπον ότι TIDA TENAG

page_text: Figure 1 Sheet 1 is the elevation of an arrangement of vertical engine with the
cylinder in section shewing the valve gear arranged to give equal steam openings
by means of a dissimilar ended valve. A is the cylinder B the piston shewn at the
top of the stroke C a portion of the bedplate F is an eccentric fixed upon or made
solid with the crank shaft G, on the same side as the crank H I is the eccentric rod
or valve lever one end of which embraces the eccentric the other is attached to.
the connecting rod O and the intermediate pin to a radius rod J, which vibrates
on a pin in the end of the reversing lever K; L is the reversing weigh shaft. The
engine is reversed by means of a worm M, and sector N. or other suitable
arrangement, either by hand, steam, or other motive power. Motion is commu-
nicated to the valve Q through the connecting rod O and the valve spindle P,
the slide valve Q has two steam edges on the top or outer end and one on the
bottom or inner end, giving a gross steam opening at the top or outer end equal
to that at the bottom or inner end, as the excess of upward vertical motion over
the lap is about double of that downward as will be seen from the orbit of the
eccentric rod pin traced out at R.
Figure 2 Sheet 1 is a plan of the gear as above described
"
Figure 1 Sheet 2 shews an arrangement of the gear where a trick" valve is
used. The letters A, B, F, G, H, I, J, O, P, and Q, indicate as before the cylinder,
piston, eccentric, crank shaft, crank, eccentric lever, radius rod, connecting rod,
valve spindle, and slide valve respectively.
Figure 2 Sheet 2 is a diagram of the gear arranged to work a cylindrical valve.
The letters referring to precisely the same parts as in Figure 1, the Figure explains
itself Or, cylindrical valves, dissimilar ended by being made larger in diameter at
top or outer end than at bottom or inner end, may be used when their application
is convenient.
When it is desired to use ordinary similar ended valves, the difference between
the upward and downward motion is compensated by levers on a working shaft as
fully described and illustrated in the specification of my Patent of 1879 N° 2138.
Having now described the nature of my Invention and the manner in which
it may be applied, it is to be noted that no claim is made to the use generally of
an eccentric and strap, a valve lever suspended from an arm on a reversing
shaft by a radius rod and a connecting rod to a valve spindle; but that what I
consider novel and therefore claim as secured to me by Letters Patent is :-
In conjunction with valve gearing of the kind described above and illustrated
in the accompanying drawings the use of dissimilar ended valves of the common
slide, "trick" slide, or cylindrical construction substantially as shewn and
described.
In Witness whereof I the said Francis Carr Marshall have hereunto set my
hand and seal this fourteenth day of June, in the year of Our Lord one thousand
FRANCIS CARR MARSHALL (L.S.)
FRANCIS CARK MARSHALL (LS.)
To the Commissioners of Patents for Inventions,
I hereby grant my Fiat giving leave to the above named Francis Carr Marshall
to file in the Office of the Commissioners of Patents for Inventions, with the
Specification to which the same relates, the above written Disclaimer and
Memorandum of Alteration.
Data:
AL
1004

page_text: PROVISIONAL SPECIFICATION left by the said Francis Carr Marshall at
the Office of the Commissioners of Patents on the 14th October 1880.
FRANCIS CARR MARSHALL, of Tynemouth, in the County of Northumberland,
Engineer. "IMPROVEMENTS IN VALVE GEARING."
These improvements relate to an arrangement of valves and gear for working
the same in marine, locomotive, or other engines worked by steam or other elastic
vapour or fluid, requiring to be frequently reversed in their motion, or worked at
varying degrees of expansion, regulated by hand, steam, or hydraulic power or by
automatic governors of any description acting upon the said regulating power.
In this arrangement the movement of the valve is derived from an eccentric
secured to (or by preference made solid with) the crank shaft and having its
eccentricity virtually coincident with the crank. The strap embracing this
eccentric is made solid with or firmly secured to its rod and constitutes the eccentric
lever. The working direction of this lever is at right angles to that of the valve's
motion. The valve rod is attached to the extreme end, and at an intermediate
point in its length the lever is suspended by a link to a pin or fulcrum in the outer
end of an arm on the reversing shaft, or the eccentric being fixed with its
eccentricity virtually opposite the crank, the lever may be suspended to the arm on
reversing shaft by its outer end, the valve rod being attached at an intermediate
point. By moving this arm from one extreme to the other of its arc (of about 60
degrees) the engine is reversed; when it is in its middle position the steam passages
will only open the amount fixed upon as the "lead" opening, and the engine is
free to move either back or foreway, and by bringing the arm into any intermediate
position (on either side of its middle position) either by hand direct, or by steam,
or hydraulic power, actuated by hand or automatically by the governor (acting

page_text: upon the valve gear of the reversing engine) any required degree of expansion may
be obtained or the speed of the engine regulated.
The valve used with this gear is made by preference dissimilar ended, having,
in the case of slide valves, one or more openings for steam inlet at the top or end
away from the gear, over that or those at the bottom or end nearest the gear, and
in the case of cylindrical valves, either one or more valves at top than at bottom or
one at top larger in diameter than that at bottom. These additional openings may
be direct through the plate forming the valve face, or indirect by a passage at the
back of the valve and taking the additional steam for the top end from the lower
end of the valve (as in what is known as the "trick" valve), or for small engines,
where the equality of admission is not so important, similar ended valves may
be used.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Francis Carr Marshall in the Great Seal Patent Office on the
13th April 1881.
FRANCIS CARR MARSHALL, of Tynemouth, in the County of Northumberland,
Engineer. "IMPROVEMENTS IN VALVE GEARING."
These improvements relate to an arrangement of valves and gear for working the
same in marine, locomotive, or other engines worked by steam or other elastic
vapour or fluid, requiring to be frequently reversed in their motion, or worked at
varying degrees of expansion regulated by hand, steam, or hydraulic power, or by
automatic governors of any description acting upon the said regulating power.
In this arrangement the movement of the valve is derived from an eccentric
secured to (or by preference made solid with) the crank shaft and having its
eccentricity virtually coincident with the crank. The strap embracing this eccentric,
is made solid with or firmly secured to its rod and constitutes the eccentric
lever. The working direction of this lever is at right angles to that of the valve's
motion. The valve rod is attached to the extreme end, and at an intermediate
point in its length the lever is suspended by a link to a pin or fulcrum in the outer
end of an arm on the reversing shaft, or the eccentric being fixed with its
eccentricity virtually opposite the crank, the lever may be suspended to the arm on
reversing shaft by its outer end, the valve rod being attached at an intermediate
point. By moving this arm from one extreme to the other of its arc (of about 60
degrees) the engine is reversed; when it is in its middle position the steam passages
will only open the amount fixed upon as the "lead" opening, and the engine is
free to move either back or foreway, and by bringing the arm into any intermediate
position (on either side of its middle position) either by hand direct, or by steam,
or hydraulic power, actuated by hand or automatically by the governor (acting
upon the valve gear of the reversing engine) any required degree of expansion may
be obtained or the speed of the engine regulated.
The valve used with this gear is made by preference dissimilar ended, having,
in the case of slide valves, one or more openings for steam inlet at the top or end
away from the gear, over that or those at the bottom or end nearest the gear, and
in the case of cylindrical valves, either one or more valves at top than at bottom, or
one at top larger in diameter than that at bottom. These additional openings may
be direct through the plate forming the valve face, or indirect by a passage at the
back of the valve and taking the additional steam for the top end from the lower
end of the valve (as in what is known as the "trick" valve), or for small engines,
where the equality of admission is not so important, similar ended valves may
be used..
In order that my Invention may be more properly understood, I now proceed to
describe the Figures and diagrams upon the Sheets of Drawings herewith.
Figure 1, Sheet 1, is the elevation of an arrangement of vertical engine with the
cylinder in section, shewing the valve gear arranged to give equal steam openings
by means of a dissimilar ended valve. A is the cylinder; B, the piston shewn at
the top of the stroke; C, a portion of the bedplate; F is an eccentric fixed upon or
made solid with the crank shaft G on the same side as the crank H; I is the
eccentric rod or valve lever, one end of which embraces the eccentric, the other is
attached to the connecting rod O, and the intermediate pin to a radius rod J which
vibrates on a pin in the end of the reversing lever K; L, is the reversing weigh
shaft. The engine is reversed by means of a worm M and sector N, or other

page_text: suitable arrangement, either by hand, steam, or other motive power. Motion is
communicated to the valve Q through the connecting rod O and the valve spindle P;
the slide valve Q has two steam edges on the top or outer end and one on the bottom
or inner end, giving a gross steam opening at the top or outer end equal to that at the
bottom or inner end, as the excess of upward vertical notion over the lap is about
double of that downward, as will be seen from the orbit of the eccentric rod pin
traced out at R.
Figure 2, Sheet 1, is a plan of the gear as above described.
Figure 1, Sheet 2, shews an arrangement of the gear where a "trick" valve is
used. The letters A, B, F, G, H, I, J, O, P, and Q, indicate as before the cylinder,
piston, eccentric, crank shaft, crank, eccentric lever, radius rod, connecting rod,
valve spindle, and slide valve respectively.
Figure 2, Sheet 2, is a diagram of the gear arranged to work a cylindrical valve.
The letters referring to precisely the same parts as in Figure 1, the Figure explains
itself; or, cylindrical valves, dissimilar ended by being made larger in diameter at
top or outer end than at bottom or inner end, may be used when their application
is convenient.
When the eccentric is fixed virtually opposite the crank the valve lever is
suspended by its outer end from the arm on reversing shaft by means of the radius
rod and the valve connecting rod is attached at an intermediate point (as described
and illustrated in my Patent of 1879, No. 2138), the valves, whether of the
dissimilar ended, cylindrical or of the "trick" construction, being operated in the
same manner as with the gear shewn on Drawings and described above.
When it is desired to use (with either of the arrangements of valve lever)
ordinary similar ended valves, the difference between the upward and downward
motion is compensated by levers on a working shaft, as fully described and
illustrated in my Patent of 1879, No. 2138.
Having now described the nature of my Invention and the manner in which it
may be applied, though I do not confine myself to details, which may be varied
to suit varying circumstances, I declare that what I consider novel and therefore
claim as secured to me by Letters Patent to be,-
1st. The combination of mechanism constituting the valve gearing, consisting of
an eccentric and strap, a valve lever suspended from an arm on the reversing shaft
by a radius rod, and a connecting rod to valve spindle, arranged and operating
substantially as shewn and described.
2nd. In conjunction with the said valve gearing the use of dissimilar ended
valves of the common slide, "trick" slide, or cylindrical construction, substantially
as shewn and described.
3rd. In conjunction with the said valve gearing, operating through levers on
the valve spindle, the use of ordinary valves of common slide or cylindrical
construction, substantially as described.
In witness whereof, I, the said Francis Carr Marshall, have hereunto set my
hand and seal, this Twelfth day of April, in the year of our Lord One
thousand eight hundred and eighty one.