Improvements in Valve-mechanism applicable for use in Direct-acting Pumping and other Engines.
Year: 1892

page_text: Date of Application, 1st Oct., 1892-Accepted, 3rd Dec., 1892
COMPLETE SPECIFICATION.
Improvements in Valve-mechanism applicable for use in
Direct-acting Pumping and other Engines.
I, HENRY GEORGE HOLBOROW, of The Lodge, Stonehouse, in the County of
Gloucester, Mechanical 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 method of and apparatus for operating
the steam-distributing valves of direct-acting pumping and other engines in which
the action of the valve-mechanism is partly of a permissive character; that is to
say, the movement of the controlling valve is not wholly dependent upon motion
derived from an eccentric or similar directly-connected and positively-acting
mechanism.
In direct-acting pumping engines having no crank-shaft and in which the steam-
distributing valve is operated without the aid of an eccentric, considerable difficulty
has been experienced in securing certainty and regularity of action. In duplex
engines, the difficulty has been partly overcome by working the valve of each
engine from the piston-rod of the other engine; and in single-cylinder engines,
by the employment of two valves, one depending for its motion upon the action of
the other; whilst the latter is operated directly from the piston-rod; it being
essential in engines of this class that the main steam-valve, serving to directly
distribute the steam to the cylinder, should be worked by some agency other than
by direct connection with the rod of the piston to which it distributes the steam.
According to my improved method of construction, the main steam valve is
subjected to the influence of two forces; namely, one derived from direct com-
munication with the piston-rod, and the other resulting from the action of a
compressed spring, or of compressed air or other aeriform fluid. The steam-valve,
during the first portion of its motion, is actuated directly from the piston-rod; the
latter part of its motion resulting from the release of the compressed spring or
equivalent device.
The accompanying drawings illustrate the application of my invention to a
direct-acting pumping engine; Fig. 1 being a part longitudinal section and part
side elevation, and Fig. 2 a plan view. A is the steam-cylinder and B the piston,
to the rod 6 of which one extremity of a vibrating lever C, pivotted at c, is con-
nected. The opposite extremity of the lever C is connected by means of a rod d
and links dd to the valve-spindle of the slide-valve D. The rod d passes
freely through a block E which is carried in a fork at the upper end of the lever C;
the rod being furnished on either side of the block E with collars e e. The valve-
spindle is also fitted with a block F, arranged to slide between collars ff and
attached to the links d¹ d'. G is a body supported on a spiral spring H mounted
as shewn; the body G being guided at g and attached to a radius-bar G¹ pivoted
at gl. To the head of the part G is attached a link or pair of links J; the opposite
extremity or extremities thereof being connected to the rod d, and at the same
point one arm of the vibrating lever K is attached. This lever is mounted on a
fixed centre k, and may be weighted at its upper extremity. are stops to limit
the motion of the lever K. The action of the mechanism is as follows:-When
the piston is at the back end of its stroke, the parts occupy the positions represented.
Upon the piston advancing, the lever C is vibrated, the first effect of its movement
after the block E reaches the stop e being to force the body G downwards against
the resistance of the spiral spring H, the pivot k being fixed while both centres of the
link J are movable. The further advance of the piston B and travel of the lever C
operates by direct action to move the slide-valve D; the vibrating lever K and

page_text: the link J meanwhile assuming the opposite angle of inclination to that shewn in
the drawing, and permitting the force stored in the spring H to become auxiliatory
to that derived directly from the movement of the lever C and rod d. This auxiliary
action of the spring H ensures the completion of the movement or travel of the slide-
valve D, and avoids any risk of the regular working of the engine being interrupted
in consequence of imperfect action on the part of the steam-distributing valve.
During the travel of the piston in the opposite direction the movements of the
parts are reversed, but the effects which ensue are precisely similar in character.
The action of the spring H upon the slide-valve D is regulated and timed in
relation to the movements of the piston by adjusting the positions of the stops e e,
ff. upon the rod d and valve-spindle d².
For the metallic spring H, pneumatic means may be substituted; the head G
forming or being connected with a piston fitted in an air-tight cylinder. Or the
lever K may be extended upwards as shewn, and provided with a weight of adequate
size; the auxiliary action of the apparatus being then dependent on gravity.
Although, for the purpose of illustration, I have described my invention as
applied to a direct-acting pumping engine, I would have it understood that I do
not regard the same as restricted thereto. Valve-mechanism of my improved type
may, for instance, be applied to Corliss and other engines having crank-shafts; the
slide-valve-eccentric and strap being under such circumstances dispensed with, and
their attendant friction avoided.
Having thus particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I claim :—
1. The improved construction of valve-mechanism for direct-acting pumping and
other engines, arranged or operating substantially as herein described.
2. In operating the distributing valve of a direct-acting pumping or other engine,
the employment of auxiliary means, such as the spring H and lever system JK,
for completing the travel of the said valve, substantially as herein described.
3. In valve-mechanism for use with direct-acting pumping and other engines, the
combination, with a piston B, piston-rod and vibrating lever C, of the spring-
borne head G, levers J, K, rods d d furnished with suitable stops, and slide-valve D,
substantially as and for the purpose herein set forth.
Dated the 26th day of September 1892.
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.C., Chartered Patent Agent.