Year: 1888

page_text: Date of Application, 7th July, 1888
Complete Specification Left, 8th Apr., 1889
Complete Specification Accepted, 1st June, 1889
DRUMMOND ALEXANDER MURDOCH Engineer Princes & Clarendon Docks, Engi-
neering Works, Belfast, in the County of Antrim Ireland do hereby declare the nature
of this invention to be as follows:-
-
From any standing part of the Engine, the sole plate, Cylinder frame work or
Condenser, I erect or fix a Bracket Casting bored and prepared to receive a turned
shaft.
In this Bracket, 1 fit a turned shaft, which oscillates in the Bracket as a bearing.
On the shaft is fixed a double ended wiper, which is provided with a Joint or Eye
at each end.
I now employ a bar or lever of any material, or section, this lever has at each
end suitable Joints. One end of the lever is fitted to the end of wiper. The other end
is connected to the valve spindle. The Body or middle of this lever, is fitted and
prepaired to receive a sliding Block, which slides longitudinally along the lever.
I now suspend like a pendulum, from the cylinder, (or other convenient standing
part) a sliding pivoted Block, this Block is provided with a suitable slot, and is
accurately fitted to the lever. This slot runs transversely through the block. Two
pivots or turned bearings are fixed to the Block, and at right angles to the Slot. To
these pivots two links are fitted and suspended from a Joint or casting fixed to the
cylinder.
I connect this Block to the wiper by a connecting rod. One end of the rod is fitted
to the pivot on the sliding Block, the other end is attached to the wiper, which is
provided with a Joint to receive same. Thus the motion of the wiper is conveyed to
the sliding Block giving it a horizontal motion along the lever. This Block oscillates
on the turned pivots, by the action of the lever being raised by the wiper.
To any convenient part of wiper I connect the excentric rod of the engine.
Action. The motion or travel of the excentric, acting on the wiper, makes one end
or arm of wiper descent, while the other arm is ascending, and as boath ends describe
a circular path, the sliding Block is pressed towards the end of the lever; by the
connecting rod, connected to the wiper, at one end while the other end of wiper 18
97

page_text: raising the lever and simultaneously drawing it through the Block, by the circular
movement of the wiper, and as the lever is all the time acting on the sliding Block as
a fulcrum. The moments, of the lever, continually vary and as one end of the lever is
moved from the fulcrum, or sliding Block, the other end of the lever is that distance
nearer to the Block, and, visa, versa. By the application and arrangement of the
lever & connections 1 convert the regular motion of the excentric into an irregular
varying motion, greatest velocity at the begining and end of the stroke and
slowest at the middle. I also obtain a greater port opening, with less travel than the
ordinary valve.
To meet the requirements of various types of engines and for greater substantiality,
I employ a forged pillar of Iron or steel instead of the Bracket.
The wiper may be in two seperate parts, each arm being distinct and seperately
fixed to shaft.
The motion of the excentric may be given to a special wiper.
An auxillary link may be attached to the sliding Block, and the connecting rod
connected to it, this link may be supported by a guide.
Instead of suspending the sliding Block, I may use a Bracket Casting, provided
with slide bars or slipperways, with a pair of slides to which the sliding Block is fitted.
This Bracket may have a projecting arm to carry the wiper shaft.
Or I may substitute pillars with slots to receive sliding Bars, the pivots of sliding
Block being fitted to same.
Or, the lever may be provided with a slot, cut longitudinally along itself. Into
which I fix a sliding Block, which I place in a Joint, the other end of Joint is
connected to the soleplate, or other standing part of engine, or I may apply a parallel
motion.
These different forms of slides are all to the same purpose, viz. to guide and support
the sliding Block.
I employ various sections of sliding Block for the different sections of levers and
slides.
I may dublicate any of the parts. The connecting rods, lever, links, wipers slide
Blocks, Brackets, slides &c.
The lever may be of any section or two levers may be fixed together, and a sliding
Block fitted between them.
The connection to the valve spindle may be so that the sliding Block passes it,
the Block is provided with a suitable slot to premit same.
Thus I still further
decrease the motion at the centre line, and use inside lap, on the valve.
The motion of this gear may be obtained directly from the engine, excentric rod 'or
it may be attached to the cod block of a quadrant, or by links from the quadrant, or
from any moving part of engine or from an auxillary motion.
To work the valve at different grades of expansion, I may lengthen or shorten any
of the links, rods, levers &c. or I may alter the position of the sliding Block or I may
disconnect the connecting rod and fix the Block stationary.
I may apply this gear to the ordinary slide valve, or to the piston, or to a spec. slide
valve.
Where travel of valve is not of great moment, I simplify the gear thus Within two
fixed Brackets, or guides I fit a sliding Shaft provided with a Joint at one end, to which
I connect the excentric rod, and at a distance froin the end I place another Joint or
eye to this I attach the lever and also the connecting rod as above described, all the
other parts being identically similar, to the parts mentioned above.
Dated this 5th day of July 1888.

page_text: DRUMMOND ALEXANDER MURDOCH Mechanical Engineer Princes & Clarendon
Docks Engineering Works Belfast, Co. Antrim 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 :--
The principle feature of my invention is the employment of a lever which tilts or
oscillates upon a moveable fulcrum. The fulcrum is peculair as it is in no way fixed
to the lever but is so constructed that it may travers and retravers, the full length or
any part of the lever, while the lever has at the same time a sliding motion through
the fulcrum. By this means I gain constantly varying moments at either end of the
lever, and as the moment at one end of the lever is increased, the moment at the
opposite end is correspondingly reduced and, vice versa. I give to the valve a
resultant motion of four decided motions, viz. the oscillating movement of the lever
on its fulcrum, the motion of the lever through the block, the motion of the block
along the lever, and the oscillating of the block on its axis.
The general arrangement of the parts of my gear, is as follows.
To any convenient standing part of the engine, the cylinder soleplate, uprights
or framework I erect and fix one or more brackets, into which I place a turned
wiper shaft. On this, shaft I fix a double ended wiper. I now employ a lever or
straight bar, one end of which I fit to the wiper, the opposite end is connected to
the valve spindle. On this lever I place a sliding block or fulcrum, which is supported
from its axis, by a swinging or pendelum link. A link connects the sliding Block
with the opposite end of the wiper, the excentric rod is also connected to the wiper.
The fulcrum or sliding block which I employ is peculair, the body of it is cored
out or hollow or is forged with a recess, so as to exactly correspond to the section
of the lever. It is fitted to the lever a working fit, so that it may slide along any
part of the lever. It is provided with two pivots, or axles substantially fixed to
the body of the block, and projecting at right angles to the plane in which the
lever acts. The pivots or axles may be forged or cast on the block, or they may
be fixed to the block by screws or screwed into the Block, their use is to form an
axis or bearing for the block to oscillate upon. Brass fitting strips or plates may
be fitted round the walls of the hallow and provided with regulating Screws so
that the wear & tear of the block may be taken up. This Block differs from
the ordinary cod block, as it is only used as a fulcrum for the lever to tilt or
oscillate upon.
The lever which I employ is a plane straight Bar, provided with Joints or Eyes
at either end. One end is connected to the valve spindle the other end to the
wiper. The middle part or body of the lever may be of any suitable section,
round, square or rectangular. The Body forms a bearing surface for the sliding
block, or fulcrum. This lever is novel, as it is not fixed to the fulcrum, but is 20
fitted that it may slide backwards and forwards through the block.

page_text: The wiper is forged double ended, one end is fitted to the lever, this end is
provided with a suitable Joint or pivot to connect it to the lever, the other end
is fitted to the connecting link, which conveys the motion of the wiper to the slide
Block, between the ends of the wiper is forged a bos, which is bored out to fit the
wiper shaft. Two single wipers may be used by placeing them directly opposite each
other. The arms of the wiper are placed at right angles to the valve spindle at Half
stroke of valve. I gain an important advantage by the use of this wiper so situated.
From it I derive four distinct motions. The similtanious motion of the lever, and
the tilting of the sliding block, the movement of the lever through the block, and the
Block along the lever in an opposite direction. The valve receives a resultant motion
of the four motions just described, which is equal to the motion derived from many
levers on various fulcrums. The block is supported from its axis by a forked link or
pair of plain links, which are fitted to a Joint or bracket fixed to some standing part
of the engine, the cylinder sole plate or uprights. The link or links are so fitted that
the may swing like a pendelum to & fro, carrying the sliding block with them. They
prevent the block moving in the direction of the valve spindle and keeps the block
moveing in the plane in which the lever acts, that is at right angles to the valve spindle.
I may substitute these links, by slide bars fixed to some standing part of the engine.
Slide Blocks are fitted to the axles or pivots of the sliding fulcrum, and the blocks are
placed on or between the slides.
The link which connects the slide Block with the wiper is a plain link or connecting
rod. One end is fitted to the wiper, the other end to the axle of the slide Block or I
may employ an auxillary link which I attach to the axle or pivot of the Sliding
fulcrum, and connect the wiper link to this auxillary link. I may support this link
by another swinging link. The use of this auxillary link is to give a longer
connecting rod, or link, from the wiper. The pendelum, or swinging links may be
so arranged as to form a parallel motion and carry the sliding Block in a straight line
at right angles to the valve spindle.
The Brackets are fitted substantially to some standing part of the engine. They
are provided with brasses or bushes to fit the shaft, and have provision for taking up
wear & tear.
The wiper shaft is fitted to these brackets. It is provided with suitable Journals
and the wiper or wipers already described are fixed or same.
The valve spindle may be connected directly to the end of the lever, or by ordinary
links, the valve spindle need not necissiarly be connected to the extreme end of the
lever, but may be connected to any part of same, so that the sliding Block or fulcrum,
may pass it, and place it intermediate between the sliding block and the wiper end.
The excentric rod may be connected to the wiper or a special wiper may be fitted
on the wiper shaft for same. Where reversing motion is employed, I employ a link,
which I connect to the cod block & wiper this link may be made long and its end
supported by a swinging link.
I may duplicate any of the parts, links, levers or Blocks.
I may at any time disconnect the link from wiper to sliding Block, so that the
block will only have a tilting or oscillating movement. The lever having both the
tilting motion & the sliding motion through the block, as already described.
As a substitute for the wiper, I may erect a sliding bar, to carry the end of the
lever. The lever is fitted to the Bar by a pin or joint provided on the bar to this
joint or pin is connected the link on sliding fulcrum, the slide Bars or pendelum
links & fulcrum Block are all similar to those already described. The excentric rod is
connected to the sliding bar, the bar moves parallel to the valve spindle.
In the accompanying drawing I have shewn my gear applied to an upright engine.
A represents the bracket.
B the wiper shaft.
W Double ended wiper.
L Lever.

page_text: N Crank shaft & Excentric.
I vary the expansion by disconnecting the connecting link, between the wiper and
sliding block, and fixing the sliding block stationary as already described, or I may
increase the length of the link or shorten it. at pleasure.
I may also lengthen or shorten either arm of the wiper.
These parts have a series of holes in them, similar to the joint hole at the end of
each so that the corresponding connection, may be connected to any hole in the
series, or they may be provided with a slot and the joint pin may be fixed in the
slot by a nut & coller.
The gear may be further varied by changeing the position of the excentric or by
altering the throw of the excentric.
The gear may be still further varied, by placeing the connecting link, from the
valve spindle, at any intermediate point or position on the lever.
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
1. The employment of a lever having a moveable oscillating fulcrum acting in
conjunction with a wiper at one end & valve spindle at opposite end, so that
the lever is similtaniously raised and pressed through the Block or moveable
fulcrum, while the fulcrum is drawn along the lever and tilted or oscillated upon
its axis, and visa versa.
2. The employment of a lever having a fixed oscillating fulcrum, acting in
conjunction with a wiper at one end & valve spindle at other end, so that the lever
is similtaneously raised and pressed through the Block or fulcrum, while the fulcrum
is only oscillated upon its axis, and vica versa.
3. A special sliding or moveable fulcrum or Block provided with recess to receive
lever and having pivots or axles projecting from it at right angles to the Body and
having fitting linuers & screws to take up wear.
4. The suspending of the moveable fulcrum, by forked connecting rods or links.
5. The placing of the moveable fulcrum between slide Bars or guides.
6. The suspending of the moveable fulcrum by rods so placed as to form a parallel
motion.
7. The right to attach valve spindle to any position along the lever.
8. The application of a guide bar as a substitute for the wiper.
9. The application of a double ended wiper or pair of single wipers, connected to the
lever & fulcrum Block by links..
111
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