Year: 1886

page_text: I EDWARD TINCKNELL, of 9 Gloucester Terrace New Swindon in the county of
Wilts, Mechanical Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to the construction of what I term a valve gear compensator
and is applicable where one eccentric is used for one way working engines and also
to stationary, marine and locomotive engines fitted with any kind of valve gear.
The accompanying diagram will serve to illustrate the principle of my invention.
The part marked a, which is fixed to the motion plate or framing at b, is moved
backwards and forwards by the motion communicated by the eccentric and link
motion and describes an arc struck from the fixed point b. The part a, is carried
or actuated at the point c, and is connected to a projection at the bottom of the
guide bar which works a movable block in the slot of the part a, thereby giving a
variation of speed in the movement of the valve at such parts of the stroke as will
give the necessary action for utilizing the supply of steam to the best advantage.
The advantages to be derived from the employment of my invention over the
present system of working are numerous as will be seen from the following results
which are obtained thereby. It gives equal port openings in backward and
forward gear as well as back and front stroke in each gear, at the same time
retaining equal leads.
It gives equal cut offs at fifty five per cent of stroke, giving also a full port
opening.
It can be adjusted to any desired range of cut off.
Fifty per cent more space is obtained for expansion at full gear working than
can now be obtained by any existing valve motion. The pressure of steam at the
point of exhaust at full gear working, is, approximately speaking, eighty pounds
at the rate of one hundred and forty pounds per square inch boiler pressure, which
great waste, my compensator will reduce by one half; and it is a well known fact
that the efficiency or the performance of a given weight of steam can be more than
doubled by an efficient expansive system of working it, and that the more expan-
sively the steam is worked, the higher is the efficiency of the steam and a great
saving in fuel and water is effected.
I am enabled to open the exhaust at an earlier part of the stroke than hitherto
thereby ensuring a much more perfect exhaust before the return stroke of the
piston consequently dispensing with a large amount of back pressure.

page_text: A movement is produced on the valve which gives a quicker opening and closing
and results in a quicker cut off, than can be otherwise obtained.
The steam is regulated so as to utilize the same to the best advantage in the one
cylinder.
The engine is enabled to work more freely by relieving the crank at such points
where pressure is now brought to bear; the said pressure being diverted from the
crank pin to the crank axle bearing, boxes &c, thereby retarding the progress of
starting at full gear owing to the late cut off. The pressure brought to bear at
such points of the stroke (say from sixty five per cent) is rapidly converted into
friction on the axle bearing owing to the changing angles of the crank while
performing its work.
By my improvements a saving of fully twenty five per cent of steam will be
effected.
The engine will be enabled to get up speed much more quickly than at present
and will be thereby rendered a much better starter with its load.
It will also be better balanced while at full gear working and less liable to
breakages; the time required for repairs need not be curtailed (as is now frequently
the case) in addition to which the continual variation of cross twisting strains
which exist under the present system, will, to a great extent, be done away with.
Dated the 7th day of January 1886.
G. F. REDFERN,
4, South Street, Finsbury, London,
Agent for the Applicant..
Improvements in or Applicable to Steam Engine Valve Gear.
I, EDWARD TINCKNELL, of 9 Gloucester Terrace, New Swindon, in the County
of Wilts, Mechanical 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:-
"
My invention relates to the construction of what I term a "valve gear corrector
consisting of an oscillating link and sliding block worked from a fixed point and is
applicable where one eccentric is used for one way working engines and also to
stationary, marine and locomotive engines fitted with any kind of valve gear.
In order to enable my invention to be fully understood I will describe the same
by reference to the accompanying drawings in which figures 1 to 7 are sectional
elevations shewing my improvements applied to the link motion of the valve or
valves of steam engines having a reversing motion; figure 8 is an elevation of the
3

page_text: corrector, and figure 9 is a diagram illustrating the results of the use of my valve
gear corrector; figures 1 to 7 are drawn to a scale of about one sixteenth full size,
and figures 8 and 9 about one quarter full size. Similar letters in figures 1 to 8
represent similar parts.
•
In figure 1 my corrector takes the place of and serves the purpose of a valve
spindle guide, and the said figure represents the most advantageous mode of its
application as the link being suspended the motion will work to the best
advantage.
دو
Referring to the said figure 1, and to figure 8, a, is the "corrector or oscillating
link having a slot a¹, the said link being attached at a², to the motion plate,
framing, guide bar, cylinder or bed plate of the locomotive or other engine to
which it is desired to apply my invention the corrector being applicable to all
kinds of valve gear motion. Working within the slot a¹, is a block a³, loosely
attached to the valve spindle c¹, of the slide valve c²; h, h, are the usual eccentrics
attached to the usual reversing link h¹, by the eccentric rods h³, h³, the slide block
working in the said link being connected to the corrector a, by means of the slide
rod b and link b¹. The link b¹ is attached to the oscillating link a, at a shorter
distance from its pivot a², than the valve spindle c¹, thereby giving the slide valve
a longer travel than if the link b¹ were connected directly to the valve spindle c',
in the usual manner or to the eccentric only as in a non-reversing engine.
The dotted lines shewn in figure 8 at d, and e, indicate the extreme extent of
travel of the valve spindle c', when working with the reversing link h¹, in full
gear; and the radius at f, to the centre line c, of the valve spindle c¹, at g, shews
the extent to which the corrector a, moves over the block during its forward and
backward motion, consequently lengthening or shortening (as the case may be) the
distance from a², to c, thereby giving a motion to the valve which varies in speed;
as will be seen by reference to the diagrams shewn in figure 9 in which the full
lines indicate the gear corrected and the dotted lines the gear uncorrected and to
the explanation hereinafter given I obtain a quick opening and retain the maximum
port opening during a great portion of the stroke of the piston, that is to say, the
valve arrives at a point of rest which equals the length of the straight portion of
the slide valve diagram lines resulting in a very quick cut off; at the same time
I obtain eighty per cent additional expansion space.
The diagrams illustrated in figure 9 were taken from a full sized model in the
first, third, fifth and eighth notches. The said figure shews the cylinder face upon
which the slide valve works in section and the measurements of which, videlicet,
the width of exhaust port, width of bar, width of steam ports, and width of metal
outside the steam ports are drawn extended so as to represent the length of stroke.
The said extended part is divided into the number of inches equalling the piston
travel videlicit, 24 inches, and the spaces on which the full and dotted diagram
lines are drawn, are intended to illustrate the steam ports on both sides of the
exhaust port: From these lines or slide valve diagrams the conditions of the
valve movement can be seen, or the true position of the valve in relation to all
points of the piston travel, videlicit, the point of lead, port opening, duration of
full port, to the point of cut off.
The proportion of measurements shewn in figure 8 will be found suitable for
one inch and seven eighths outside lap giving one inch and one eighth port opening
and three sixteenths of an inch lead.
In this case the eccentric sheaves would be moved forward, increasing the
angular advance in order to overcome the additional lap and equal the desired lead.
It will be seen from the valve diagram, figure 9, that the cut-off is later at the
forward stroke than at the back stroke the corrector being adjusted for this
purpose so as to render the beat of the engine more uniform.
In figure 2 the same results are obtained by means of the corrector as by the
arrangement shewn in figure 1, but the link is not shewn suspended as in figure 1.
In figure 3, where the corrector is attached to the motion plate, it will be seen
that the corrector does not act as a valve spindle guide; nevertheless the results

page_text: are practically the same in the movement on the valve or valves as those obtained
from figures 1 and 2; the valve or valves may be either cylindrical, or the ordinary.
D' shape.
Figures 4, 5, 6 and 7 represent four different valve gears, shewing the adaptability
of the corrector to each motion, these four illustrations will be sufficient to show
that the corrector is equally applicable to any kind of valve gear motion.
The above table shewing the working of the slide valve, was taken from the
link motion illustrated in figure 1, equalling 24 inches stroke or piston travel.
The figures on the lines marked A indicate the gear working in the usual manner
without the corrector applied, while those on the lines marked B indicate the gear
as shewn on the drawings with the corrector applied; the letter B against the
figures denotes the bare measurement whilst the letter F denotes the full measure-
ment. It will be seen from the table that the same was taken with the reversing

page_text: handle in four different positions, videlicet, in the 1st, 3rd, 5th, and 8th notches, the
first notch being full gear, and the 8th mid-gear, or, in other words, out of gear; so
that the difference between the two conditions of working shewn by the figures
on lines A and B can be clearly seen. A supplies steam for nearly 75 per cent
and B for 55 per cent of piston travel; both A and B give the same amount of
port opening but B cuts off the supply more quickly than A owing to the valve or
valves opening and closing the cylinder ports more quickly with B than with A;
B's action upon the valve or valves is almost equivalent to the " Corliss' gear," and
the table shows that in the first notch, or at full gear working, the space for
expansion is increased 80 per cent, whereby the steam is utilized to a much greater
advantage; and in the 8th notch or at mid-gear working, it will be seen that B is
working more expansively than A, consequently the cut off is rendered quicker or
shorter, retaining approximately the same points of exhaust as at present.
The valve which gave the figures on lines A, had 1 inch outside lap; that which
gave those on lines B, had 2 inches outside lap. The valves for both A and B
had no inside lap. It must be understood that any extent of outside lap may be
adopted, the valve gear corrector being adjusted accordingly, allowing the eccentric
sheaves to retain their original amount of throw.
The advantages to be derived from the employment of my invention over the
present system of working are numerous as will be seen from the following results.
It gives equal port openings in backward and forward gear as well as back and
front stroke in each gear and also retains equal leads.
It can be adjusted to give equal cut off at any desired point of the piston travel
giving at the same time the required amount of port opening.
Eighty per cent more space for expansion is obtained than can now be procured
by any valve gear excluding the "Corliss' Gear."
I am enabled to open the exhaust at an earlier part of the stroke than hitherto
thereby ensuring a much more perfect exhaust, before the return stroke of the
piston, consequently dispensing with a large amount of back pressure.
The steam is regulated so as to utilize the same to the best advantage in the one
cylinder.
A saving of over twenty five per cent in fuel and water will be effected.
The application of the corrector does not necessitate any alteration to whatever
valve gear it may be attached as the same throw and position of eccentric sheave
or sheaves, length of eccentric rods and position of weigh shaft can be employed
as at present; in addition to which the corrector will allow of any desired alteration
in lead, port opening or cut off being made without interfering with any conditions
that may be required to remain. Being able to obtain the maximum port opening
at an earlier part of the stroke and to retain the same for a large portion of the
travel of the piston in addition to obtaining a quick cut off which prevents wire
drawing the steam the expansion commencing at-say half stroke-is more than
sufficient for the further propelling of the crank (which is known from the fact that
the pressure of exhaust is, in most cases, seventy five and eighty pounds per square
inch) which has practically done its work being as it were built up with the power
previously applied to it.
Comparing the results given by the "Corliss' Gear" with the present system of
working I find that the pressure which is brought to bear (during the rotary action
of the crank) on the crank pin at such points of crank angle-say seventy five per
cent of stroke where the cut off now takes place-is converted into friction on the
axle bearings, boxes, &c. whereby much power or turning force is lost. This loss
would be prevented by adopting the early and quick cut off and the engine. would
be at liberty to work more freely and consequently get up speed more easily.
By the use of my invention the travel of the valve will equal approximately six
inches, whereas under the present system it only equals four and a half inches
at full gear working, consequently the six inches travel effects a more perfect
lubrication on the faces.

page_text: My corrector when applied to "Hackworth's Gear," figure 7, will correct the
defects of that gear rendering it adjustable for any desired range of cut off,
whereas the required port opening can only be obtained now by adopting a very
late cut off, which necessitates the notching of the link to a point of very acute
angle whereby the gear is rendered almost impracticable.
The arrangement of the corrector is so simple and effective that very little
additional expense is incurred in applying it to any existing valve gear.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that I do
not claim the oscillating link worked or actuated by the guide bar or eccentric
rod or rods, but what I claim is:
1. The fitting of a sliding link block directly to the end of the valve spindle,
the said block being worked or actuated by an oscillating link; or the said block
fitted to the guide bar working or actuating an oscillating link as shewn in
figure 3, thereby correcting and adjusting the motion or action of any valve gear,
and resulting in a quick opening and quick closing of the cylinder ports, giving a
cut off 100 per cent quicker than can be obtained without its use in addition to
adding 80 per cent more space for expansion, thereby effecting a saving of upwards
of 25 per cent in fuel substantially, as set forth.
2. The valve gear corrector herein before described and illustrated in the accom-
panying drawings.