An Improvement in Link Motions for Steam and other Fluid Pressure Engines.
Year: 1893

page_text: Date of Application, 30th June, 1893
Complete Specification Left, 21st Mar., 1894-Accepted, 12th May, 1894
PROVISIONAL SPECIFICATION.
An Improvement in Link Motions for Steam and other Fluid
Pressure Engines.
I, WALTER THOMAS WARD of Bramdean in the County of Hants, Engineer
do hereby declare the nature of this invention to be as follows:-
My invention relates to a construction and arrangement of the link motion used
for reversing and varying cut off in steam and other engines worked by elastic fluid,.
the object which I have in view being to render the gear for this purpose more
light and simple than that usually employed. I provide only one eccentric which I
link to near the one end of a lever pivotted about its middle, this lever having in it
a curved slot fitted with a sliding block. The crosshead of the slide valve, which
works in guides, is linked by a connecting rod to the sliding block, and a pin on
this connecting rod is linked to one arm of a lever the other arm of which forms a
handle having a spring catch engaging in a notched quadrant. By moving this
handle, the sliding block, to which the slide valve is linked, is moved up or down
in the curved slot. When the block is at the middle of this slot, the slide valve
receives no motion; when the block is moved in the one direction from the middle
of the slot the slide valve receives more or less movement suited for the revolution.
of the engine shaft in the one direction; when the block is moved in the opposite.
direction, the slide valve receives movement suited for the revolution of the shaft
in the opposite direction.
Dated this 30th day of June 1893.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improvement in Link Motions for Steam and other Fluid
Pressure Engines.
I, WALTER THOMAS WARD of Bramdean in the County of Hants, 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:
My invention relates to a construction and arrangement of the link motion used.
for reversing and varying "cut off" in steam and other engines worked by elastic
fluid. The object which I have in view is to render this gear more light and
simple than that usually employed.
I shall describe my invention referring to the accompanying drawings.
Fig. 1 is a front view and Fig. 2 is a side view of a link motion according to my
invention.
I provide only one eccentric E which I link to near one end of a lever L pivotted
at P to the fixed frame, this lever having in it a circularly curved slot fitted with a.
sliding block B. The crosshead C of the slide valve which works in a guide is
linked by a connecting rod R to the sliding block B, and a pin N on this connecting.
rod is linked to one arm of a lever H, the other arm of which forms a handle having
a spring catch G engaging in a notched quadrant Q. By moving this bandle, the
block B is made to take different positions in the curved slot. When the block is.
at the middle of this slot the slide valve receives no motion, when the block is.

page_text: moved in the one direction from the middle of the slot, the slide valve receives
more or less movement suited for the revolution of the engine shaft in the one
direction. When the block is moved in the opposite direction, the slide valve
receives movement suited for the revolution of the shaft in the opposite direction.
The farther the block is moved from the middle part of the slot the greater is the
stroke given to the slide valve.
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 :-
A link motion for a steam or other fluid pressure engine consisting of a circularly
slotted lever pivotted about its middle and worked by a single eccentric linked to
its one end, a block fitted to slide in the curved slot of the lever and linked to the
slide valve, and hand lever and connections for moving the block along the slot
substantially as described.
Dated this 10th day of March 1904
ABEL & IMRAY,
Agents for the Applicant.