Improvements in Trip Valve Gear.
Year: 1890

page_text: Date of Application, 16th Oct., 1890
Complete Specification Left, 16th July, 1891-Accepted, 29th Aug.. 1891
PROVISIONAL SPECIFICATION.
Improvements in Trip Valve Gear.
We, WILLIAM HORNSBY and ROBERT EDWARDS, both of Spittlegate Iron
Works, Grantham, in the County of Lincoln, Engineers, do hereby declare the
nature of this invention to be as follows:-
:-
This invention relates to trip valve gear, and it comprises the improvements
hereinafter described.
In constructing this valve gear we mount on a pin or shaft a lever which can be
oscillated by a cam eccentric or the like and we cause the end of this oscillating
lever to press down, on its downward movement, a projection on a hanging trip
lever or arm which is attached directly to a valve spindle or to an oscillating lever
that is attached to a valve spindle. The hanging trip arm at one of its ends is
controlled by a stop whose position can be varied by hand or by the governor
so as to cause its projection to either be entirely clear of the first named
oscillating lever on its downward movement or to be released from it in any
required position.
The first named oscillating lever is either made in duplicate or is double ended
so that two hanging trip arms each connected to a valve spindle can be actuated.
An intermediate rod is sometimes arranged between the ends of the oscillating
lever or levers and the trip arm or lever.
Instead of the end of an oscillating lever pressing down the projection on a
hanging trip arm or lever, we cause a projection on the end of an eccentric or cam
rod to effect this, the said eccentric or cam rod end being suitably guided by a link,
or in a slot or slide, so as to cause it to nove in the direction required.
Dated the 16th day of October 1890.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Trip Valve Gear.
We, WILLIAM HORNSBY and ROBERT EDWARDS, both of Spittlegate Iron
Works, Grantham, in the County of Lincoln, Engineers, 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:-
This invention relates to trip valve gear, and it comprises the improvements
hereinafter described.
In constructing this valve gear we mount on a pin or shaft a lever which can be
oscillated by a cam, eccentric or the like and we cause the end of this oscillating
lever to press down, on its downward movement, a projection on a hanging trip
lever or arm which is attached directly to a valve -pindle or to an oscillating lever
that is attached to a valve spindle. The hanging trip arm at one of its ends is
controlled by a stop whose position can be varied by hand or by the governor
so as to cause its projection to either be entirely clear of the first named
oscillating lever on its downward movement or to be released from it in any
required position.
The first named oscillating lever is either made in duplicate or is double ended
so that two hanging trip arms each connected to a valve spindle can be actuated.

page_text: An intermediate rod is sometimes arranged between the ends of the oscillating
lever or levers and the trip arm or lever.
Instead of the end of an oscillating lever pressing down the projection on a
hanging trip arm or lever, we cause a projection on the end of an eccentric or cam
rod to effect this, the said eccentric or cam rod end being suitably guided by a link,
or in a slot or slide, so as to cause it to move in the direction required.
To enable our invention to be fully understood we will describe how it can be
carried into practice by reference to the accompanying drawings, in which :-
Figure 1 is an elevation of a trip valve gear constructed according to our
invention, in which an oscillating lever acts on the trip arm or lever, and
Figure 2 is a sectional elevation of the arrangement in which an eccentric rod
acts on the trip arm or lever.
Similar letters in both the figures indicate similar or corresponding parts.
Referring to Figure 1, A indicates the lever arranged to be oscillated by
rods A', A² connected to a suitably arranged eccentric or the like (not shown in the
drawing) operated by the engine: B is the pin or shaft on which the lever A which
is shewn made double ended oscillates; E, E indicate the hanging trip arins or
levers adapted to be operated by the arms of the oscillating lever A. C, C are
the oscillating levers to one end of each of which one of the hanging trip arms or
levers E is attached. Each lever C works on a pin D and is connected by its other
end to a valve spindle K, H is the stop for controlling the motion of the trip arm
or lever E which is provided with an arm G which comes in contact with the said
stop for this purpose; the stops II are connected by suitable rods or levers to a
governor or are held in a fixed position. The lower end of the trip arm or lever is
adapted as shewn at F to engage the end of the oscillating lever A.
The action is as follows:
On the lever A being oscillated its ends, as they move down come against the
ends F of the trip levers and thereby oscillate the lever C so as to raise the valve
spindles K. When the arms G of the trip levers come in contact with the
stops H they cause the trip levers to disengage from the oscillating lever A thus
allowing the valves to drop and close, the moment at which the disengagement
shall take place being regulated by the position to which the governor moves the
stops H or in which they are fixed.
In Figure 2 A is the eccentric rod having a projection B₁ thereon which presses
down the hanging trip arm or lever E. C is the oscillating lever to which the trip
lever is attached and which is connected to the valve spindle K. L is the link for
guiding the end of the eccentric rod A and causing it to move in the required
direction. His the stop arranged under the arm G of the trip lever for controlling
the action of the latter and which is regulated by the means hereinbefore described
with reference to Figure 1.
The action is as follows:-
On the eccentric rod A moving downwards the projection B thereon engages
with the hanging trip lever E and causes that end of the lever C to which the trip
lever is attached to be depressed, the other end consequently rising and lifting the
valve. When the end of the arm G of the trip lever comes in contact with the
stop H the trip lever is released from engagement with the projection B on the
eccentric rod A and the lever C is thus allowed to resume its normal position.
Instead of making the stop H in the form of a lever as shewn it can be in
the form of a cam or wedge if required to better resist the trip lever when it
strikes it.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In a trip valve gear an oscillating lever so arranged that it can engage a
hanging trip arm or lever attached to one end of another oscillating lever connected

page_text: to the valve spindle or direct to the valve spindle a suitably arranged stop being
provided the position of which is regulated by hand or by a governor whereby the
trip arm is disengaged at the required moment substantially as hereinbefore
described.
2. In a trip valve gear an eccentric rod or cam rod adapted to engage a hanging
trip arm or lever mounted on one end of an oscillating lever, the other end of which
is connected with a valve, a suitably arranged stop being provided by which the
moment of engagement with the hanging trip arm can be varied by hand or by the
governor substantially as hereinbefore described.
3. The improved trip valve gears substantially as hereinbefore described and
illustrated respectively in Figures 1 and 2 of the accompanying drawings.
Dated the 16th der of Lul 1001
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.