IMPROVEMENTS IN STEAM ENGINES AND BOILERS
Year: 1868

page_text: PROVISIONAL SPECIFICATION left by Hubert Ellis Smith at the
Office of the Commissioners of Patents, with his Petition, on the
10th March 1868.
I, HUBERT ELLIS SMITH, of Hereford Iron Works, in the Town and
County of Hereford, Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN STEAM ENGINES AND BOILERS," to
be as follows:-
My Invention relates first to improvements in the self-acting variable
expansion gear and reversing motion of steam engines. I key a plate
on the crank shaft, in which plate and in line with the crank I fix a
stud which engages in a small slot formed in a V-shaped projecting
part on the eccentric, the slot permitting the eccentric to move slightly
backwards and forwards in the direction of motion of the valve when
the crank is on the dead centre. The eccentric is provided with a
slightly curved opening or slot through which the shaft passes, the
eccentric being placed loosely thereon. When the crank is on a dead
centre the valve must be just ready to open the port so that the
centre of the eccentric must be the distance of the lap of the valve
out of centre. Assuming the centre of the eccentric to be on a
level with that of the shaft, then if the eccentric be moved out of this

page_text: central position in one direction by means of the opening or slot
through which the shaft passes the engine would run overhand, and
if moved to the opposite position the engine would run underhand.
The fixed stud before mentioned as passing through the projecting
V part of the eccentric, which eccentric is otherwise loose on the shaft,
would cause it to describe an arc when traversed across the shaft, thereby
altering the position of the valve. To obviate this I introduce a
link moving freely on the shaft as a centre, and connected to the
eccentric by a stud or pin about half way between the centre of the
small slot first mentioned and the centre of the eccentric. When
the eccentric is traversed in one direction across the shaft on the
fixed stud as a centre, the pin connecting the link of the eccentric
performs an arc in the opposite direction, forming a kind of parallel
motion and causing the eccentric to pass across the shaft in a straight
line, by traversing the fixed stud along the slot in the V part
eccentric with which it engages, forming a movable centre. In order
to traverse the eccentric across the shaft from one side to the other,
I employ two wedges passing through the slot in the eccentric, one
on either side of the shaft, which wedges are capable of sliding
longitudinally on the shaft more or less in the slot of the eccentric.
Each of these wedges is attached to one arm of a lever by means of
connecting rods, said lever being pivoted on the shaft at right angles
to the crank. This lever is capable of oscillating motion in the direction
of the wedge, and is provided at each end with a weight or ball.
When the lever is at right angles to the shaft the wedges will project
equally through the eccentric, into the slot of which they fit on either
side, keeping it in its mid position. If one wedge is withdrawn by
oscillating the lever in one direction the other wedge will be moved in
the opposite direction and be projected further through the eccentric,
which will thereby be traversed across the shaft in the direction of the
advancing wedge. By oscillating the lever in the opposite direction,
the motion of the wedges and consequently of the eccentric will be
reversed. This balanced lever is oscillated in either direction by means
of a hand lever pivotted to the framing of the engine, its upper end
being also weighted, while the lower end is provided with a clutch
which engages with a collar sliding on the crank shaft and attached to
the first lever by means of a connecting rod. When the oscillating
lever is placed in its extreme position to start the engine in either
direction the weight of the hand lever would preponderate on one

page_text: side of its axis and tend to keep the balanced oscillating lever in that
position until the engine has attained such a speed that the centrifugal
force of the weights of the oscillating lever (which revolves with the
shaft) is sufficient to overcome the gravity of the weighted hand lever,
so that as the engine increased in speed the balls of the oscillating
lever would tend to run in a straight line, thus placing the eccentric
nearer its mid positiou by means of the wedges above described and
cutting off the steam earlier. In this manner the engine can be
readily reversed or placed to work at any degree of expansion.
My Invention further relates to improvements in the construction
of steam boilers or generators. I propose to employ a series of vertical
wrought-iron tubes placed side by side in close contact. I prefer to
arrange them in rows, one row along each side, one in the middle, and
one at the end of the boiler, the rows of tubes forming the sides of the
flues. The vertical tubes in each row are connected at their lower
ends to longitudinal pipes which serve to connect the water space of
all the tubes together. In order to obtain a tight joint the lower
ends of the vertical tubes are reduced, and a flange or disc of the
same diameter as the tube is shrunk on the reduced end which is
further recessed into an aperture bored in the longitudinal pipe for
its reception. Each vertical tube is secured to the longitudinal pipe by
means of bolts and flanges on the latter connected to the flanges or
discs on the vertical tubes, the bolts being secured by nuts which
compress an india-rubber washer on the end of the vertical tube, and
so form a tight joint. Fire-brick arches are thrown across from the
sides to the central row of tubes, the lower arch forming the top of
the lower flue and also the bottom of the upper or return flue, the
top of which is formed by the upper arch. These flues are further
divided longitudinally by the central row of vertical tubes. Cast-iron
plates are laid on the flanges or discs of the vertical tubes above the
longitudinal pipes to form a bottom to the flue. The top end of each
vertical tube in the steam space is closed permanently by welding,
a central hole being made therein to receive a small bent tube
connecting the vertical tube with the receiver by means of unions.
These bent tubes permit of the free expansion and contraction of the
vertical tubes.
My Invention further relates to a means by which muddy water

page_text: along the sides of the boiler I place tanks divided horizontally into
compartments by means of perforated plates. The middle compartments
I fill with cotton waste or other fibrous material, through which the
water passes from the upper to the lower compartments, whereby it
is filtered and rendered fit for use in the boiler.