CERTAIN IMPROVEMENTS IN MARINE STEAM ENGINES
Year: 1839

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
MURDOCK, of No. 11, Great Cambridge Street, Hackney Road, in the County
of Middlesex, Mechanical Draftsman, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Seventh day of November, in the third year of Her reign, did, for
Herself, Her heirs and successors, give and grant unto me, the said James
Murdock, Her especial licence, full power, sole privilege and authority, that I,
the said James Murdock, my exors, adñiors, and assigns, or such others as I,
the said James Murdock, my exors, admiors, or assigns, should at any time
agree with, and no others, from time to time and at all times during the term
of years therein expressed, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, my
Invention of "CERTAIN IMPROVEMENTS IN MARINE STEAM ENGINES;" in which said
Letters Patent is contained a proviso, that I, the said James Murdock, shall
.cause a particular description of the nature of my said Invention, and in what
manner the same is to be performed, to be inrolled in ler said Majesty's
High Court of Chancery within six calendar months next and immediately
after the date of the said in part recited Letters Patent, as in and by the same,
reference being thereunto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
James Murdock, do hereby declare that the nature of my Invention consists
in the construction and application of certain mechanism between the paddle
or propelling wheels of boats and ships, and the steam engines by which they
are actuated, for the purpose of promptly disengaging them from each other,
and of readily re-engaging them in a firm and durable manner whenever those
measures may become expedient or desirable. And the manner in which the
same is to be performed I will now proceed to explain by several examples,
illustrated by a series of Drawings hereunto annexed; in which Drawings it
should be premised (to avoid prolixity of explanation) that the recurrence of
the same letters of reference indicate the same parts, although viewed in a
different position.
Figure 1 exhibits an elevation (facing the side of the vessel), and Figure 2
shows a transverse section, of an apparatus wherein one of the effects above
mentioned is obtained by the firm adhesion of two extensive conical surfaces
forced into intimate contact, and the other effect is obtained by the disunion of
those surfaces. At a is shown a portion of the engine shaft; b, the engine
crank and c, the crank pin, to which the connecting rod is attached; d is the
paddle shaft, on the extremity of which is firmly keyed a cylindrical drum e, e,
on the periphery of which is a vertical flange f that faces the crank. In the
angle or rebate g so formed between the flange f and the periphery of the
drum is fitted a ring h, h, the sectional form of which is exhibited in Figure 2.
This ring is capable of a sliding motion on the periphery of the drum, in a
direction parallel to its axis, but it is prevented from slipping round the same
by the interposition of two feathers at i, i. The outside circumference of the
ring his turned as accurately as possible to a conical surface, and so as to cor-
respond exactly with the inclination of another conical surface formed on the
inner circumference of an external ring k, to which the crank pin is keyed.
At 1, 1, are screws, which are tapped through the ring h, or work through nuts
fixed to the same, and turn in collars made in the ring f, which prevents them
from advancing or receding. To the other end of the screws are keyed small
spur pinions m, m, which gear into a toothed ring n, which is made to turn on
antifriction rollers 0, 0, by a band p going round the same, and a pulley q. At
1 is a friction roller, mounted at one end of a weighted lever s, and employed
to give the requisite tension to the band to draw round the ring n; but as soon
as the engines are united to the paddle wheels, the weighted end of this lever
is to be raised to take off the pressure. From these mechanical arrangements
it will become obvious that when the toothed ring is drawn round in one direc
tion, the pinions will simultaneously turn the screws, and thereby cause the two

page_text: conical surfaces of the rings h and k to become united by forcible contact, and
thereby unite the action of the engine and paddle shafts; also, that when it is
required to disunite the paddles from the engine, the turning of the toothed
ring and pinions and screws in the reverse direction will set at liberty the
two conical surfaces, and permit the two shafts to revolve independantly of
cach other.
The next example of my Invention which I shall describe also operates by
the adhesion of conical surfaces; but the mechanism by which forcible contact
and separation are effected is different, as shewn by Figures 3, 4, 5, 6; whereof
Figure 3 represents an elevation facing the engine crank, Figure 4 a vertical
section, Figure 5 an elevation partially in section, and Figure 6 a plan. At a
is the paddle shaft; b, a drum, with a conical periphery, and firmly keyed to
the said shaft; on the boss of the drum b is mounted another drum c, which
has a cylindrical circumference, near to which it has an aperture for the recep-
tion of the crank pin d, which is keyed therein. Upon the periphery of the
drum c an inclined or spiral groove e is cut. At f is an external ring f, one
portion of which interiorly is formed cylindrical to fit the drum c, and the other
is formed conical to fit the drum b. At 9, 9, are two pins, passing through the
ring f, and entering into the spiral groove e. At h is another spiral groove cut
on the periphery of the ring f, into which the bent end of a lever i (which
turns upon a fulcrum k, but has no lateral motion,) fits. If the bent end of
the lever be pressed into the groove h, and the engine be set in action in the
forward motion, the bent end in traversing the groove h will force the ring f
into close contact with the conical periphery of the drum b, and it will be
retained in contact by the pins g, g, which work in the groove e, and the paddle
shaft will be carried round by the crank; but on reversing the motion of the
engine, the ring f will be removed from contact with the drum b. and each
shaft will then be free to revolve independently of the other; as soon as the
engines are connected with the wheels, the lever is to be withdrawn from the
groove, as shewn in dotted lines.
:
A third example of my Invention is illustrated by the apparatus delineated
at Figures 7 and 8, whereof 7 is an elevation facing the ship's side, and
Figure 8 an end view of the same. At a is the engine shaft; b, the crank;
c, the crank pin; d, a hanging pall or drag link suspended from the end of
the crank pin; e is the paddle wheel shaft; f, a cylindrical drum firmly keyed
thereto, and having a notch or recess in the periphery to receive the tooth of
the pall; g is a wheel made to turn on the boss of the drum f, and shaped on
its circumference into a projecting cam h, the outermost edge of which coin-
cides with the periphery of the drum, and which is of sufficient breadth fully

page_text: to cover the side of the notch. By turning the wheel g in the direction of the
arrow, the inclined side of the cam is brought to bear against the under side
of a pin i, which projects from the side of the pall and thereby gradually lifts
the pall out of the notch, and it then covers the side of the notch. The two
shafts are thereby disengaged, and can revolve separately, the cam preventing
the pall from falling into the notch during such revolution. To re-connect the
shafts, the cam is turned the reverse way of its former movement, so as to
uncover the side of the notch; and the engine being set slowly in motion, the
pall when it arrives at the notch will fall into the same, and the motion of
the cam being then continued the prong k, which projects from the circum-
ference of the cam wheel, wiil press upon the upper side of the pin i, and
firmly draw down the pall into the notch and retain it there. The cam
wheel g is turned by a worm wheel m, actuated by an endless screw n, the
axis of which passes through a slot in the standard o, o, and has a winch fixed
on its extremity. When the two shafts are working together the endless
screw is thrown out of gear by dropping the standard into the position shown
by the dotted lines p, p, which allows the axis to fall into the position of the
dotted line 9, I. At s is a spring to counteract the weight and centrifugal
force of the pall, and to force it into the notch.
Figures 9, 10, and 11, are increly explanatory of the construction of the
pall. A portion of the metal is cut out of the middle of the joint, as shown
at t, in the plan Figure 9; and a ring or collar, of which Figure 10 is a plan,
and Figure 11 an elevation, is fitted into the cavity, and is fixed to the crank
pin by the bolts v, v, which also pass through the spring s, and attach it to the
collar.
A fourth example of my Invention consists in the arrangement of mechanism
delineated at Figures 12, 13, and 14; whereof Figure 12 is an elevation facing
the vessel's side, Figure 13 a section of the same, and Figure 14 a plan. At
a is the paddle wheel shaft, and a drum firmly keyed to the same; at c is
the crank pin, and a collar fixed thereon, faced on the two sides to an angle
corresponding with the oblique sides of two bolts e and f. These two bolts
are made to slide in suitably formed cavities made in the drum b, by the action
of two cams and h, which work in recesses made in the bolts. On the axes
of these two cams are mounted two spur pinions i, i, (Figure 12,) that gear
into a spur wheel k, fixed on the boss of the drum b; to this wheel is attached
a worm wheel m, which is driven by an endless screw n, on the axis o.
Revolution being therefore given to the latter by the winch p, the motion.
is communicated to the worm wheel, spur wheel, and pinions, and by them
to the cams, causing the latter, when turned in one direction, to project the

page_text: bolts, as shown in the Drawing in full lines, and when turned in the reverse
directions to withdraw the bolts into their cavities, as expressed by the dotted
lines drawn in connection therewith. When the crank pin c is in the position
shewn in the Drawing, between the two bolts e and f, it must necessarily carry
the drum with it in its revolution, and consequently the paddles and the
engine crank revolve together; on the contrary, when the bolts are withdrawn
the paddle wheels and the engine crank may revolve independently of each
other. It should be observed, that the two cams 7 and h are fixed upon their
axes in such positions as to act successively in moving the bolt, although they
revolvo simultaneously. For instance, suppose the bolts and cams to be in
the position shewn by the dotted lines (at which time the shafts are supposed
to be disconnected, and it be desired to reconnect them), the following is the
course of action:-The engine is set slowly in motion, and the cams are turned
in the direction of the arrows by the agency of the endless screw and worm
wheel, until the bolt e is projected from its recess by the cam g. During this
period, the concentric portions of the cam h are operating on the bolt f, and
the latter consequently remains stationary. When the the crank pin comes
in contact with the bolt e, the motion of the cams is continued, and this causes
one of the excentric sides of the cam to operate upon the bolt f, and pro-
jects it from its recess, whilst the concentric portions of the cam g act upon
the bolt e, which therefore remains stationary. The reversal of the motion of
the winch draws first the bolt f and then the bolt e into their recesses, and the
two shafts are again separated to revolve independently. When the engines
are in operation, the endless screw is thrown out of gear by dropping it into
the position shewn by the dotted lines q, q.
Having now described the nature of my Invention, and the manner in which
the same is to be carried into effect, I desire that it shall be clearly understood
that I do not limit myself to those particular arrangements, as the principle of
my Invention admits of others of equal or nearly equal efficacy; and that the
said principle (or characteristic feature) of my Invention doth consist in fixing
immoveably a drum or other appendage performing a similar office, fast to the
paddle-wheel shaft, and in connecting the crank pin of the engine to the
periphery of the said drum by means of certain moveable adjuncts, as bolts,
friction brakes, palls, or other equivalent mechanism, adapted to effect a ready
union and disunion of the aforesaid crank pin and drum.
In witness whereof, I, the said James Murdock, have hereunto set my
hand and seal, this Fifth day of May, in the year of our Lord One
thousand eight hundred and forty.
JAMES (L.S.) MURDOCH.

page_text: AND BE IT REMEMBERED, that on the Fifth day of May, in the year
of our Lord 1840, the aforesaid James Murdock came before our said Lady
the Queen in Her Chancery, and acknowledged the Specification aforesaid,
and all and every thing therein contained and specified, in form above written.
And also the Specification aforesaid was stamped according to the tenor of the
statute made for that purpose.
Inrolled the Sixth day of May, in the year of our Lord One thousand
eight hundred and forty.