Improvements in Valve Motions for Steam and other Engines.
Year: 1892

page_text: Date of Application, 29th Aug., 1892
Complete Specification Left, 29th May, 1893-Accepted, 1st July, 1893
PROVISIONAL SPECIFICATION.
Improvements in Valve Motions for Steam and other Engines.
I, HAROLD WILHELM WIDMARK of Helsingborg, Sweden, Engineer, do hereby
declare the nature of this invention to be as follows:-
This invention relates to radial valve gear, in which the valve spindle is moved
by a lever connected by a link to a slot link block and by another link to the
crosshead of the piston rod and where the slot link receives its motion from the
connecting rod.
Also the invention relates to modifications of such radial gear. Valve gearing in
accordance with the invention and adapted to a locomotive engine is shewn by
Figure 1 of the annexed drawings.
The lever A is connected direct with the valve spindle B and by the link C to
the block in the slot link D. Also the lower end of the lever A is connected by
the link E to a lever F which receives its motion from the connecting rod. This
latter connection replaces the usual connection to the crosshead.
The slot link D oscillates in the usual way on a fulcrum G. An arm H is fixed
to the slot link and through this arm and by means of the lever F and a short
link the slot link receives from the connecting rod its needful oscillation.
The opposite end of the lever F is jointed to a block, which is guided to travel
in a straight line. The connection between the lever F and the link I is made at
a point intermediate between the fulcrum of the lever upon the guide-block and the
extremity of the slot-link arm.
This link I then by the positions which it assumes when at work entirely corrects
or compensates the error which otherwise would be caused by the varying angularity
of the lever F in the different positions during the revolution.
In consequence of the joint action of the lever F and the link I the perpendicular
distance between the centre M in the slot link arm and the centre N in the
connecting rod will be the same in every position of the crank.
In this arrangement the valve is solely moved by the connecting rod from the
centre point N.
Figure 2 shews a similar arrangement of valve gear in accordance with the
invention in which the lower end of the lever A receives its motion from the cross-
head in the way hitherto usual, and in which the upper end of the lever is guided
in an arc by the radius arm O.
Figures 3 and 34 shew a modification in which a combination of radial links is
substituted for the slot link. The pin P in the link C is by this linkage guided in
the same are as that in which the block of the slot link would be guided. The
links from the extended oscillating arm R, in reversing the engine, move the
pin S of the lever T in a circular arc. One end of this lever T is perforated with
oval holes and slides on pins fixed in the oscillating arms R. The other end of the
lever T, at which is the pin P moves in an arc, which has the length of the link C
for its radius.
Dated this 27th day of August 1892.

page_text: COMPLETE SPECIFICATION.
Improvements in Valve Motions for Steam and other Engines.
I, HAROLD WILHELM WIDMARK, of Helsingborg, Sweden, 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 radial valve gear in which the valve spindle is moved
by a lever connected by a link to a slot link block and by another link to the cross-
head of the piston rod and where the slot link receives its motion from the
connecting rod.
Also the invention relates to modifications of such radial gear. Valve gearing
in accordance with the invention and adapted to a locomotive engine is shewn by
Figure of the drawings annexed to my Provisional Specification.
The lever A is connected direct with the valve spindle B and by the link C to the
block in the slot link D. Also the lower end of the lever A is connected by the
link E to a lever F which receives its motion from the connecting rod. This latter
connection replaces the usual connection to the crosshead.
The slot link D oscillates in the usual way on a fulcrum G. An arm H is fixed
to the slot link and through this arm and by means of the lever F and a short
link I the slot link receives from the connecting rod its needful oscillation.
The opposite end of the lever F is jointed to a block, which is guided to travel
in a straight line. The connection between the lever F and the link I is made at a
point intermediate between the fulcrum of the lever upon the guide block and the
extremity of the slot-link arm.
This link I then by the positions which it assumes when at work entirely corrects
or compensates the error which otherwise would be caused by the varying angularity
of the lever F in the different positions during the revolution.
In consequence of the joint action of the lever F and the link I the perpendicular
distance between the centre M in the slot link arm and the centre N in the connecting
rod will be the same in every position of the crank.
In this arrangement the valve is solely moved by the connecting rod from the
centre point N.
Figure 2 shews a similar arrangement of valve gear in accordance with the
invention in which the lower end of the lever A. receives its motion from the cross-
head in the way hitherto usual, and in which the upper end of the lever F is guided
in an arc by the radius arm 0.
Figures 3 and 34 shew a modification in which a combination of radial links is
substituted for the slot link. The pin P in the link C is by this linkage guided in
the same arc as that in which the block of the slot link would be guided. The
links Q from the extended oscillating arm R, in reversing the engine, move the
pin S of the lever T in a circular arc. One end of this lever T is perforated with
oval holes and slides on pins fixed in the oscillating arms R. The other end of the
lever T at which is the pin P moves in an arc, which has the length of the link C
for its radius.
In all the figures it will be observed that the connection between the pins M
and N (in Figure 1 or the corresponding pins in the other figures) is effected by a
lever and link so proportioned and arranged that the vertical distance between the
pins remains constant.
This method of connection has the same effect as if the slot link (or equivalent
combination of links) and the connecting rod although really near together were
connected by one link of infinite length.

page_text: 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 arrangement substantially as described wherein the connection between
the slot link D and the connecting rod is effected by a lever F jointed to the
connecting rod at N and guided at the other end in a straight or curved course and
a short link I connecting the centre M on the slot link arm H to a point inter-
mediate in the length of the aforesaid lever F; this arrangement being such that
the vertical distance from M to N remains constant in all positions; the angularity
of the link I compensating that of the lever F.
2. The lever F and link I arranged as aforesaid and in combination with links
forming a substitute for the slot link.
3. Valve motions substantially as represented by the annexed drawings.
H. WILH. WIDMARK.