Year: 1888

page_text: Date of Application, 3rd Apr., 1888
Complete Specification Left, 3rd Jan., 1889
Complete Specification Accepted, 23rd Feb., 1889
I JOHN WILLIAM MELLING of 11 Birkett Bank Wigan in the County of Lancaster
Engineer do hereby declare the nature of this Invention to be as follows:-
My invention is chiefly applicable to winding engines but it may be applied to
engines of various types more particularly those in which double beat valves are
employed.
In applying my improvements to a winding engine fitted with double beat admission
valves I employ a compound lever in place of the ordinary or main lever for operating
each admission valvo. This compound lever is pivoted at one end to the frame and
connected by links to the valve rod as usual but in place of the tappet or lifter acting
directly upon the main lever so as to govern both the opening and closing of the
valve 1 interpose an improved arrangement of mechanism by which the admission
valve may be closed and steam cut off at any point desired quite independently of the
position of the tappet.
To effect this I pivot to the end of each of the main levers a lifting piece which lies
over and rests upon the tappet the opposite end of this piece stands below one end of
a sinall elbow trigger or its equivalent also pivoted to the main lever and held in one
position by a spring or weight. Pivoted or supported above each main lever and
directly above the upper arm of the trigger is a cam which can be moved so as to
come in contact with the trigger and close the valve at an earlier or later stage of its
movement as desired this cam is moved by a rod that is coupled to the middle of a
lever one end of which is connected to the governor and the other end to a lever by
which the engineman can adjust the position of the cam independently of the governor
or by which he can increase or decrease the effect of the governor when it is
regulating the position of the cam to suit the load or the adjusting of the cam may be
done directly by either the engineman or the governor.
When the tappets are moved to open the valves they raise the pivoted lifting pieces
which in their turn lift the triggers and raise the levers which continue to rise and
77

page_text: open the valves the full lift of the tappet or until the trigger comes in contact with
the cam when its upward movement is arrested and the other end moved from off the
lifting piece thus releasing the main lever and allowing it to fall and close the valve.
The lifting piece is pivoted to the main lever preferably immediately above the centre
of the tappet at which point the lifting movement of the lever and valve commences
slowly and then the valve is lifted more quickly as the end of the tappet comes into
action.
The trigger may either be released by the cam as described or any other independent
releasing motion may be employed or in place of a cam to push off the trigger an
adjustable wedge pièce or its equivalent may be used.
Dated this 31st day of March 1888

page_text: I JOHN WILLIAM MELLING of 11 Birkett Bank Wigan in the County of Lancaster
Engineer do hereby declare the nature of this Invention, and in what mannor the
same is to be performed, to be particularly described and ascertained in and by the
following statement :-
•
My invention is chiefly applicable to winding engines but it may be applied to
engines of various types more particularly those in which double beat valves are
employed.
In applying my improvements to a winding engine fitted with double beat admission
valves I employ a compound lever in place of the ordinary or main lever for operating
each admission valve. This compound lever is pivoted at one end to the frame and
connected by links to the valve rod as usual but in place of the tappet or lifter acting
directly upon the main lever so as to govern both the opening and closing of the
valve I interpose an improved arrangement of mechanism by which the admission
valvo may be closed and steamn cut off at any point desired quite independently of the
position of the tappet.
To effect this I pivot to the end of each of the main lovers a lifting piece which lies
over and rests upon the tappet the opposite end of this piece stands below one end of
a small elbow trigger or its equivalent also pivoted to the main lever and held in one
position by a spring or weight. Pivoted or supported above each main lever and
directly above the upper arm of the trigger is a cam which can be moved so as to
come in contact with the trigger and close the valve at an earlier or later stage of its
movement as desired this cam is moved by a rod that is coupled to the middle of a
lever one end of which is connected to the governor and the other end to a lever by
which the engineman can adjust the position of the cam independently of the governor
or by which he can increase or decrease the effect of the governor when it is regulating
the position of the cam to suit the load, or the adjusting of the cam may be done
directly by either the engineman or the governor.
When the tappets are moved to open the valves they raise the pivoted lifting pieces
which in their turn lift the triggers and raise the levers which continue to rise and
open the valves the full lift of the tappet or until the trigger comes in contact with
the cam when its upward movement is arrested and the other end moved from off the
lifting piece thus releasing the main lever and allowing it to fall and close the valve.
The lifting piece is pivoted to the main lever preferably immediately above the centre
of the tappet at which point the lifting movement of the lever and valve commences
slowly and then the valve is lifted more quickly as the end of the tappet comes into
action.
The trigger may either be released by the cam as described or any other independent
releasing motion may be employed or in place of a cam to push off the trigger an

page_text: And in order that my Invention may be fully understood and readily carried into
effect I will describe the accompanying three Sheets of Drawings reference being had
to the figures and letters marked thereon.
Figure 1 is a front elevation of one form of engine with double beat valves to which
my improved valve gear is applied.
Fig. 2 is an end elevation of the same.
Fig. 3 is a front elevation partly in section and Fig. 4 a plan of a modification of
the arrangement illustrated by Figs. 1 and 2 to meet cases where a later cut off is
required.
Referring first to Figs. 1 and 2.-
a designates the valvo chest or box which contains both the admission and the
exhaust valves, 6 is the admission valve spindle and c the exhaust valve spindle, ɗ is
the double cam or tappet secured on the rocking shaft e, and fis the exhaust valve
lifter, all the foregoing parts being of the ordinary construction.
and
The steam valve lifter is a compound one consisting of the main arm or lever
the short lever or lifting piece g¹ which is pivoted at g on the main lever 7 and at the
other end during the operation of opening the admission valve abuts against the ond
of a small elbow lover or trigger g³ which is pivoted on the main lever g; attached to
the lifting piece g¹ is a small bolt g' which passes freely through a snug or flange on
the main lever and is for the purpose of preventing the lifting piece g¹ falling too
low during the downward movement of the tappet d; on this bolt is coiled a spiral
spring the function of which is to check the movement of the lifting piece g¹ while
being released from the trigger g³ and also to insure the lifting piece moving down
low enough to allow the trigger to pass over it, this movement of the trigger over the
lifting piece being caused by the action of a small flat spring g which is secured to the
main lever. Above the trigger g³ and on a shaft carried in bearings in the frame i
is fixed a cam h¹ which is so shaped as that by turning the shaft it can either he
withdrawn out of reach of the trigger g³ in its upward movement or it can be brought
into contact with said trigger at the commencement of its upward movement or at
any intermediate point. It will be readily seen that whenever the trigger 9³ comes
into contact with the cam the lifting piece g¹ will be released the admission valve
at once closed by the fall of the lever g and steam cut off quite independently of the
movement of the tappet d. In some cases the spindle 6 of the admission valve has an
extension arranged to work in a dash pot j. The position of the cam h¹ may be
regulated by having a lever and link going to the engineman or to the governor or
by preference, and particularly in the case of winding engines, the link ² is attached
to a lever at or about the centre; one end of the lever is supported on a movable
block or slide h* to which is coupled a rod ³ controlled by the engineman and the
other end is connected by a rod to the governor. In the latter case the position of
the cam could be changed at will by the engineman and in addition would be
regulated automatically by the governor.
I have for convenience of description referred to the parts in the singular number
only but it is obvious that the parts are in duplicate there being an admission and an
exhaust valve at each end of the cylinder and a rod h is employed to couple the
governing mechanism to the valve gear of the other engine.
In some cases where a governor is used on winding engines I so connect the
governor rod to the cam shaft as that when the main reversing lever is drawn towards
the centre when the engines are running it puts the governor out of action so that the
engines may have full steam thrown against them by the engineman in cases of
emergency, but I lay no special claim to such a device.
In the alternative arrangement illustrated by Figs. 3 and 4 the triggers 9 are
caused to release the lifting pieces g¹ by means of the rods which have Hanged ends
and are actuated by the flanged double cam k. This cam is fixed on a stud k³ which
is carried and is free to be turned axially in a rocking lever i to which a reciprocating
motion as indicated by the arrow Fig. 4 is imparted from any convenient moving part
of the engine. Thus as the lever m is rocked it carries the cam with it and this
movement corresponds or nearly so with the movement of the piston. On the stud k¹

page_text: is fixed a lever by which the position of the cam k may be regulated; this lever k²
is connected by a link k either to the governor or to the engineman or by preference
to the lever has before described which in this case also is shown connected by a
rod / to another engine.
If the reciprocating cam k be set so that its greatest diameter is brought into line
with the ends of the rods the flange on the cam will not be brought into contact with
said ends and consequently the triggers g³ will not be drawn off the ends of the lifting
pieces g but if the shorter parts of the cam are brought in line then the flange thereon
comes into contact with the ends of the rods almost at the beginning of the
reciprocating movement of the cam and so draws off the triggers g³ and releases the
lifting pieces thereby closing the valves. Again by setting the cam k to any
intermediate position a corresponding change in the time of the cut off can be
effected.
When the trigger g³ is drawn off its lifting piece g' a spiral spring is compressed
between the trigger g³ and an abutment 9 on its main lever g; on the return
movement of the cam k the said spring a draws back the rod land forces the trigger g
against a stud 8 into position ready for the next stroke. The ends of the rods
are guided by slots in the stand and are free to follow the movement of the main
levers g.
In place of the double lever ³ and connections herein shown and described for
controlling the position of the cams h¹ or k any suitable arrangement of mechanism
for the purpose may be employed.
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. The combination with the main lifter of the admission valve of a fluid pressure
engine and the tappet d or equivalent for operating said lifter, of a lifting piece
pivoted to the lifter and released at the required moment by a trigger or elbow lever
also pivoted on the lifter and arranged to be actuated either directly or indirectly by
a cam or equivalent the position of which can be controlled either automatically from
the governor or by hand or by both so as to vary the time of cut off substantially in
the manner and for the purposes herein described with reference to the Drawings
annexed.
2. The several constructions and combined arrangements of parts embodying my
improvements in or relating to the valve gear of fluid pressure engines substantially
as and for the purposes herein set forth and as illustrated by the accompanying
Drawings.