Improvements in Valve-gear for Reversing the Motion of Steam and other Motive Power Engines.
Year: 1890

page_text: Date of Application, 18th Apr., 1890
Complete Specification Left, 19th Jan., 1891-Accepted, 28th Feb., 1891
PROVISIONAL SPECIFICATION.
Improvements in Valve-gear for Reversing the Motion of Steam and
other Motive Power Engines.
I, JOHN WILD, of Falcon Iron Works, Oldham, in the County of Lancaster,
Engineer, do hereby declare the nature of this invention to be as follows
--
In my improved valve-gear I employ only one eccentric or preferably a return
crank which I set in such a position that by moving the connecting or eccentric
rod together with the slotted lever hereinafter described through an angle equal
to double the angle of advance which would be given to an eccentric if employed
in the ordinary way to give motion to the valve. The movement of the valve will
be such as to allow for the lap required giving at the same time the requisite
amount of lead in both the backward and the forward motions.
Coupled to the end of the before mentioned connecting or eccentric rod and
carried on trunnions which are fixed in a suitable position between the two ends
of the slot I fix the before mentioned slotted lever which is of a suitable shape
and so constructed that a die carried by the outer end of the valve rod may slide
freely from one end of the slot in the lever to the other end with perfect freedom
so that when the engine is put in motion and the said die is at one end of the slot
motion will be given to the valve in one direction and when the die is at the
opposite end of the slot motion will be given to the valve in the opposite direction
so that by moving the slotted lever together with the connecting or eccentric rod
through the before-mentioned angle motion will be given to the valve in opposite
directions and at the same time give sufficient lead to the valve as hereinbefore
described
COMPLETE SPECIFICATION.
Improvements in Valve-gear for Reversing the Motion of Steam and
other Motive Power Engines.
I, JOHN WILD, of Falcon Iron Works, Oldham, in the County of Lancaster,
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 :-
The improvements constituting this invention have for their object the con-
struction of a reversing gear for steam or other motive power engines so as to
dispense with the eccentric link motion or other forms of reversing gear and to
replace them with a simple strong but still an efficient valve-gear which will be
readily understood and also occupy less room than the eccentric link motion and
at the same time have an entire absence of complicated mechanism or delicate parts
which are so common in other forms of reversing valve-gears.
By the accompanying drawing one method of applying this invention is shewn.
Fig. 1 being a side elevation and Fig. 2 a plan.
I will now proceed to describe my improved valve-gear
As will be seen from the accompanying drawings the valve spindle J is actuated
by means of the slide block I which in turn is actuated by means of the slotted
lever A which has a pivot E near its centre upon which it rocks. The slotted
lever being actuated by means of the rod C₁ from the return crank B the
angle ABC representing double the angle of advance and also the amount of
vertical movement given to the slotted lever and the outer end of the driving rod C¹
when reversing. The angle A B¹ D representing the angle of advance for the

page_text: backward motion of the engine and the angle A B C representing the angle of
advance for the forward motion of the engine.
In Fig. 1 the gear is shewn in such a position as to give a forward motion to
the engine. F is the reversing shaft. K is the radius lever carrying the slotted
lever by means of the pivot E as before mentioned and K is the reversing lever.
Now it will be seen that if the radius lever K be lifted up (carrying with it
the slotted lever A¹) so that its centre will coincide with the line F G that the
slotted lever A' will be changed from a lever of the first to a lever of the second
kind and that a motion nearly opposite to the motion previously given will be given
to the valve rod and that motion will be in advance of the motion of the engine
equal to the angle A B D representing the angle of advance and thereby giving
an opposite motion to the engine.
It must be distinctly understood however that I do not confine myself to this
particular method of applying my invention as for instance the same result could
be arrived at by employing an eccentric for actuating the gear. The radius
lever K might also have the centre upon which it rocks placed in the centre or
thereabouts of the crank-shaft or it might even be dispensed with and replaced
by a slide fitted with a suitable shoe carrying the slotted lever and raised or
lowered in any convenient way and in that case the slotted lever would be straight.
Having now particularly described and ascertained the nature of my inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1st. A reversing gear for steam or other motive power engines with a radius
lever slotted lever driving rod and return crank or eccentric substantially as
hereinbefore described and illustrated by the accompanying drawings.
2nd. A reversing gear for steam or other motive power engines in which the
backward and the forward motion are given by the same agent and in which the
angle of advance for either motion is obtained by moving the driving rod and
slotted lever through an angle equal to double the angle of advance.
Dated this Seventeenth day of January One thousand eight hundred and