Year: 1899

page_text: I, GEORGE ANDREW REES, of Daffarn Villa, Station Road, Lower Wincobank,
near Sheffield, in the County of York, Engineer, do hereby declare the nature of
this invention to be as follows:-
This invention relates to an improved trip gear and more especially applicable
for the operation of the inlet valves of steam engines in which the gear is con-
trolled by the governor.
The invention consists of an improved trip gear of simple construction by which
a very effectual regulation is attained.
In carrying the invention into effect as applicable to a steam engine a casting is
erected upon the valve chest above each inlet valve to form a guide for each
valve spindle and to support a dash pot as is usual with this type of valve gear
the valves used being preferably of the equilibrium mushroom form. Brackets
are attached to each casting to support a short horizontal shaft carrying loosely
thereon a trip lever, one arm of which is connected to the valve spindle and
operates it when the other arm is depressed. The shaft is oscillated through a
crank and connecting rod from a wrist plate situated between the two valves and
deriving motion from an eccentric. A tripper arm is carried by a pin supported
by two levers which are keyed on each of the horizontal shafts before referred to.
Each of the tripper arms is in the form of a bell crank lever and has a friction
roller mounted on one extremity while its other extremity is formed with a shoulder
which is caused to engage with the adjacent extremity of the trip lever as the
horizontal shaft is partially rotated by means of the connecting rod previously
referred to. The length of time that the tripper arm is in contact with the trip
lever during its downward movement determines the time that the inlet valve is
opened, and this is regulated by causing the friction roller on the extremity of
the tripper arm to come in contact with a conical or inclined surface which causes
the tripper arm on the movement of the connecting rod to oscillate upon its own
supporting pin and move its extremity out of contact or engagement with the trip
lever sooner or later according to the vertical position and shape of the said conical
or inclined surface. The vertical position of the conical or inclined surface which
thus determines the opening of the inlet valves is regulated from the governor.
The conical or inclined surface is preferably in the form of a cone carried by a
hollow rod or sleeve which is capable of vertical movement within a suitable
guide by such means as a bell crank lever deriving motion from the governor. The
cone is situated midway between the two valves and each of the tripper arms is
30 disposed as to make contact therewith alternately upon operation from the
wrist plate.
I do not limit my invention to the actual arrangement of parts as herein before

page_text: described as it is obvious that such may be modified in design while retaining
the essential features of my invention.
1000
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and
25, Cross Street, Manchester, Agents.
I, GEORGE ANDREW REES, of Daffarn Villa, Station Road, Lower Wincobank,
near Sheffield, in the County of York, 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:―
This invention relates to an improved trip gear and is more especially applicable
for the operation of the inlet valves of steam engines in which the gear is controlled
by the governor.
The invention consists of an improved trip gear of simple construction by which
a very effectual regulation is attained.
Figure 1 is a side elevation of part of a cylinder having my improved trip gear
mounted thereon.
Figure 2 is an end elevation of Figure 1 with one of the valve castings removed
and showing the trip mechanism.
Figures and 4 are views of the lever which may be substituted for the wrist
plate.
In carrying my invention into effect as applicable to a steam engine two
castings a are erected upon the valve chest above each inlet valve of the cylinder
to form a guide for each valve spindle and to support a dash pot as is usual with
this type of valve gear the valves being used preferably of the equilibrium mush-
room form. Brackets b are attached to each casting to support a short horizontal
shaft carrying loosely thereon a trip lever d, one arm of which is connected to
the valve spindle and operates it when the other arm is depressed. The shaft c is
oscillated through a crank pine and connecting rod f from a wrist plate gor
lever situated between the two valves and deriving motion from an eccentric.
A tripper arm his carried by a pin supported and operated by two levers k k,
which are keyed on each of the horizontal shafts c before referred to. Each of the
tripper arms is in the form of a bell crank lever and has a friction roller
or round nosed screw mounted on one extremity while its other extremity is
formed with a shoulder or bent m which is caused to engage with the extremity n
of the trip lever d as the horizontal shaft is partially rotated by means of the
connecting rod previously referred to. The length of time that the tripper arm his
in contact with the trip lever d during its downward movement determines the
time that the inlet valve is opened, and this is regulated by causing the friction
roller or screw on the extremity of the tripper arm to come in contact with a
conical or inclined surface o which causes the tripper arm h on the movement of
the connecting rod to oscillate upon its own supporting pin i and move its ex-
tremity m out of contact or engagement with the trip lever d sooner or later according
to the vertical position and shape of the said conical or inclined surface o. The
vertical position of the conical or inclined surface o which thus determines the
operating of the inlet valves is regulated from the governor. The conical or
inclined surface o is preferably in the form of a cone carried by a hollow rod or

page_text: is
sleeve P which is capable of vertical movement within a suitable guide q by such
means as a bell crank lever deriving motion from the governor. The cone
situated between the two valves and each of the tripper arms h is so disposed as
to make contact therewith alternately upon operation from the wrist plate or tee
lever.
I do not limit my invention to the actual arrangement of parts as hereinbefore
described, as it is obvious that such may be modified in design while retaining
the essential features of my invention.
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 what
I claim is:
1. In a valve for use upon an engine the combination of a trip lever connected
to the valve, a rocking shaft operated from the engine shaft, a tripper arm carried
by a lever arm on the rocking shaft and engaging the end of the trip lever, and
a movable surface under the control of the governor for engaging the tripper arm,
substantially as and for the purposes herein before described and as illustrated in the
accompanying drawings.
2. The combination of a movable surface under the control of the governor and
engaging a tripper arm whose fulcrum has motion in an are or the equivalent and
suitable mechanism for the operation of the valve of an engine substantially as
described and as illustrated.
3. The improved trip gear for operating the valve of an engine consisting of a
movable surface, tripper arm and auxiliary parts substantially as described and
illustrated.
"
101
1000