Year: 1895

page_text: Date of Application, 8th Jan., 1895-Accepted, 21st Sept., 1895
On Sheet 1, Fig. 1 shews a front view of the valve gear, Fig. 2 a side view, and
Figs. 3, 3, and 4 portions of the gear to illustrate the action, and on Sheets 2
and 3, Figs. 5 and 6 (Sheet 2) and 7 and 8 (Sheet 3) are diagrammatic views
showing the " spanner "and"
cam gear in two positions for each stroke of the
"
"
engine.
Referring to Sheet 1, Figs. 1 and 2, the piston is at the top of the cylinder
about to commence the downward stroke, all the valves being now closed, and the
engine at rest. The steam and exhaust valves SVT, SVB, and EVT, EVB of the
double beat or equilibrium form, are contained in the "nozzle" boxes 2, 2ª, and I, 14,
respectively steam entering by the branch 3 and exhausting by the branch 4, the
top and bottom valve boxes being connected by the steam and exhaust side pipes 5
and 6 on which are brackets 7, fitted with carriages 8, 84 in which work the top
and bottom weigh-bars 9, 94 each of which carries a hollow "sleeve weigh-
bar 10, 104 working freely upon the weigh-bars 9, 94. The top weigh-bar 9 has
keyed upon it the bottom exhaust spanner 11, the arm 12, the handle 13, the
escapement sector 14, and the cam 15; the "sleeve" weigh-bar 10 having keyed
upon it the top steam spanner 16, a handle (specially desirable for winding engines)
not shewn, and the arm 17 for actuating the steam valve SVT, the dash-pot arm 17B
and the arm 17 carrying the stud 18 by means of which the arm 17 is retained in
position by the pawl catch 19, until released by the cam 15. The bottom weigh-
bar 94 has keyed upon it the top exhaust spanner 11, the arm 124, the handle 21,
the escapement sector 144, and the cam 154, the "sleeve" weigh-bar 10 having
keyed upon it the bottom steam spanner 164, a handle (specially desirable for
winding engines) not shewn, and the arm 17ª for actuating the steam valve SVB,
the dash-pot arm 17D and the arm 17 carrying the stud 18 by means of which the
arm 17 is retained in position by the "pawl" catch 194 until released by the
cam 154. The escapement lever 22 is pivoted at its centre upon a pin 23 and holds
the escapement sectors 14, 14ª keyed upon the top and bottom weigh-bars 9, 9ª in
position until the tappet 24 or 214, adjustable in its frame 32 or 324 on the plug
rod, in its downward or upward stroke acting upon the spanner 11, or 11ª rotates
Price Rd7

page_text: the weigh-bar 9 or 94, thereby causing the escapement sector 14, or 14ª to allow
the escapement lever 22 to turn on its centre 23 and also causing the cam 15 or 15
to release the catch 19 or 194, when the four balance weights 26, 27 or 26, 27ª
(working in dash pots) attached. by rods (indicated by centre lines) to four
arms 178, 17, 17 and 170 (also indicated only by centre lines) keyed on the weigh-
bars 10, 104 and 9, 94 respectively, open a top steam and bottom exhaust valve
or vice versa.
The action at starting is as follows: The engineman pulls back the escapement
lever 22 against the resistance of a spring or balance weight 224, releasing the top
sector 14 and the balance weight 27 on the weigh-bar.9, rotates the arm 12, and
opens the bottom exhaust valve; at the same time the cam 15. rotates by the action
of the balance weight 27A and releases the stud 18 in an arm 17° from the pawl
catch 19 thus allowing the balance. weight 27 to rotate, the sleeve 10 and open the
top steam valve and the engine then commences the downward stroke.
.1
It is from this point necessary to refer also to Figs. 5 and 6, on Sheet 2 and to
Figs. 7 and 8 Sheet 3, which shew diagrammatically in two positions to a larger
scale, the top and bottom weigh-bars.9, 94 with the hollow sleeve weigh-bars 10, 10%,
and their spanners 11, 114 and 16, 164, arms 12, 124 and 17, 174, with rods to top
and bottom exhaust and steam valves, pawl catches 19, 194, and cams, 15, 15ª.
The valve gear is now in the position shewn on Fig. 6 Sheet 2, and Fig. 7 Sheet 3,
shewn respectively the top and bottom weigh-bars, and, as the piston, descends, and
with it the plug rod, the end of the "tappet" slide 25, which has been adjusted to
the required point of cut off, strikes the spanner 16 and closes the top steam valve,
the "pawl"catch 19 engaging with the pin 18 in the arm 17, on the sleeve 10
(as in Figs. 5 & 6 Sheet 2) the bottom, exhaust valve remaining open till the stroke
is completed, except the required amount of compression to "cushion" the piston,
when the tappet 24, which has been adjusted to the required compression point,
strikes the spanner 11 and closes the bottom exhaust valve and is held permanently
by the sector 14 which engages with the top catch of the escapement lever 22.
The sector 14 (previously engaged with the top catch of the escapement lever)' now
rotating forces the said lever 22 out of its normal position, thus causing the
sector 144 to be released therefrom, thereby allowing the valves to be now opened
for the upward stroke..
The piston now being at the bottom of the cylinder and the bottom exhaust
valve closed, the upward stroke commences, the top exhaust valve and the bottom
steam valve being opened by the balance weights, the "tappet" 24 having mean-
while, as before stated, in its descent disengaged the escapement lever 22 and set
free the pawl 144 enabling the appropriate balance, weight 26 to operate, and cause
the shaft 94 to revolve, and open the top exhaust valve, EVT and carry with it the
cam 154 which, operating the pawl catch 194, allows the appropriate balance
weight 26 to act and revolve the hollow shaft 104, thus opening the bottom steam
valve SVB, and, the upward stroke commences, the spanners and other gear being
now in the position shewn on Fig. 5 Sheet 2, and Fig. 8 Sheet, 3,, shewing
respectively the top and bottom weigh-bars and sleeve 9 94 and 10 104 respectively.
As the upward stroke proceeds to completion the same operations are performed in
the same sequence, as before described on the downward stroke, the working of the
engine being entirely automatic.
"
""
3'1
3.
Figs. 3, 34 and 4 Sheet 1 shew, in plan, side elevation, and end view, a device
which I propose to employ when required, as for instance in the case of winding
engines, by which the gear can be, operated temporarily by hand until the handles
are released when the action continues automatically. This is effected by
temporarily disconnecting the arms 17 and 174, which normally open and close
the top and bottom steam valves by automatic action, from the sleeve weigh-
bars 10, and 104 so that steam can be admitted to either, or both sides of the piston
at will, independently of the position of the piston in the cylinder thereby enabling
the engine to be instantly reversed or brought to rest in case of emergency.
"Referring to these figs. which shew the bottom solid weigh-bar 94 and the
4.1.

page_text: When
hottom hollow sleeve weigh-bar 104. The sleeve weigh-bar 104 is divided as shewn
on Figs. 3 and 34 the left hand portion carrying the spanner 16* and the right hand
portion the bottom steam valve arm 17A and a handle 284 attached to it.
the engine is working automatically these two portions are connected by a bolt 294
actuated by a bell crank 304 attached to a rod 314 controlled by a spring 32ª and
carried along the handle 284. When the bolt 294 is withdrawn the steam valve
can be worked by hand, independently of the "tappets" and "spanners" by the
handle 284, the brakesman keeping the bolt withdrawn at the same time, until
automatic working is resumed, when he releases the rod 31A and the spring 32ª
causes the bolt to be shot into the socket on the left hand portion of the sleeve
weigh-bar 104.
Similar mechanism on the top sleeve weigh-bar 10 controls the operation of the
top steam valve, the brakesman holding both the handles 284 and 21 (controlling
one steam and exhaust respectively) or 28 and 13 (controlling the other steam and
exhaust valve respectively), one in each hand whilst handling the engine.
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
1st. Improvements in tappet valve gear enabling the steam to be cut off at any
point of the stroke, independently of the exhaust, by means of solid and hollow
weigh-bars, each operating separately corresponding steam and exhaust valves in
combination with disconnecting gear, on the hollow weigh-bars, by which the
engine can be controlled by hand, steam being admitted to either, or both, sides of
the piston at any point of the stroke to reverse the motion of the engine or bring it
to rest in case of emergency, and then instantly to restore the automatic action of
the valve gear, substantially as described and shewn.
2nd. In combination with such or similar valve gear, operating by solid and
hollow weigh-bars, the application of "cams" fixed on and rotating with the solid
weigh-bars, which", cams release catches and set free arms controlling a top or
bottom corresponding steam and exhaust valve, so as to open in their proper
sequence, by the action of counter balance weights or other equivalent devices,
substantially as described and shewn.
Dated this 8th day of Januar 1905
T. J. DANSON, F. Inst. P.A.,
Chartered Patent Agent, Newcastle-upon-Tyne,
Agent for Applicant.