Improvements in Valve Gear for Steam Engines.
Year: 1898

page_text: Date of Application, 18th Apr., 1898-Accepted, 27th Aug., 1898
COMPLETE SPECIFICATION.
Improvements in Valve Gear for Steam Engines.
I, FERDINAND BOSSHARDT, of the Firm of F. Bosshardt & Co., of 4, Corporation
Street, Manchester, in the County of Lancaster, Patent Agent, do hereby declare
the nature of this invention which has been communicated to me from abroad by
Johann Rudolf Frikart, of 24, Karlstrasse, München, in the German Empire,
Engineer, 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 improvements in the "Corliss" type of valve gear for
steam engines.
In this type of valve gear a metallic knob is caused during each revolution of
the engine by the trip levers contacting with each other after having been dis-
engaged, which knocks increase in number in accordance with the increase in the
revolutions of the engine.
These knocks cause the engine to run noisy and the said contacting parts to
wear unduly.
The object of my invention is to provide means whereby the said defects are
obviated, i.e. means which will permit of running "Corliss" engines at a high
speed without abnormal wear and noise of the contacting parts.
And in order that my invention may be more fully understood I have caused
to be appended hereunto one sheet of drawings marked with letters of reference
indicating like parts in the various figures, Figs. 1 3 & 5 being front views partly
in section, Fig. 2 a sectional view from below and Fig. 4 a sectional side view
of my improved "Corliss" gear.
In carrying out my invention and referring to the figures generally, I mount
loosely upon the bearing A of the valve spindle D a lever B, the stud C of which
has motion imparted directly or indirectly from an eccentric or other element.
Upon the spindle D is keyed a second lever F, the stud E of which is furnished
with a spring or other suitable appliance which presses in the direction of the
arrow, shown in Figs. 1 & 3.
Between the stud C which always oscillates with the lever B, and the stud E
carried by the lever F secured to the valve, a toggle link C, G, E is arranged
which when stretched, i.e. when the three points C, G, E are in a straight line,
will bear against an abutment H, arranged upon the boss of the lever F (Figs. 1
& 2) whilst the link stud G is formed with an extension J carrying the stud I.
The action of the mechanism described is as follows;-
When the stud C is oscillated from the right to the left by the eccentric, the
toggle link C, G, E will stretch, as shown in Fig. 1, the lever F turn and the
valve thereby open; but as soon as the shoulder L on the rod K secured to the
stud I, contacts with the abutment M, see Fig. 5, which may be stationary or
oscillating, and on the further turn of the lever B, the link C, G, E will bend, i.e.
the point G leaves the straight line C, E, and the spring or other appliance press-
ing upon the stud E then brings the lever F back to its original position and

page_text: thereby closes the valve again, the toggle lever then bent being prevented from
further transmitting motion from the lever B to lever F.
The period during which the valve may remain open can be varied by adjust-
ing the lever N by hand or through a speed governor, which adjustment causes
the shoulder L of the rod K sooner or later to contact with the abutment M and
by bending the toggle link C, G, E, correspondingly stop the action of the con-
stantly moving lever B upon the lever F secured to the valve.
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:
In valve gear for steam engines of the "Corliss" type, a device for operating
the valves consisting chiefly of a toggle link C, G, E, arranged between the lever B
actuated by an eccentric and the lever F keyed upon the valve spindle, which link
remains stretched whilst the valve is open and is bent through the action of an
abutment M the moment the steam supply is cut-off, the said abutment being
rendered adjustable by a speed governor or by hand and the said valve being
closed by a spring or other suitable appliance, all substantially as set forth.
Dated this 16th day of April 1898.
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester, Agents to Applicant.