IMPROVEMENTS IN APPLYING THE POWER OF STEAM ENGINES TO PADDLE SHAFTS USED IN PROPELLING VESSELS
Year: 1840

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
TREWHITT, of Newcastle-upon-Tyne, in the County of Northumberland, Esquire,
send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Seventh day of August, in the fourth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said Henry
Trewhitt, Her especial licence, full power, sole privilege and authority, that I,
the said Henry Trewhitt, my exors, adiñors, and assigns, or such others as
I, the said Henry Trewhitt, my exors, adññiors, 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, the
Invention of "IMPROVEMENTS IN APPLYING THE POWER OF STEAM ENGINES TO
PADDLE SHAFTS USED IN PROPELLING VESSELS," communicated to me by a certain
foreigner residing abroad; in which said Letters Patent is contained a
proviso,
that I, the said Henry Trewhitt, shall cause a particular description of the
nature of the said Invention, and in what manner the same is to be performed,
to be inrolled in Her said Majesty's High Court of Chancery within six

page_text: 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...
NOW KNOW YE, that in compliance with the said proviso, I, the said
Henry Trewhitt, do hereby declare that the nature of the said Invention, and
the manner in which the same is to be performed, are fully described and
ascertained in and by the following statement thereof, reference being had to
the Drawing hereunto annexed, and to the figures and letters marked thereon
:(that is to say):
-
The Invention relates to a mode of applying the crank pins of paddle
shafts in such manner that either of the paddle wheels may be disconnected
from the working of the engines, and again connected and worked by the
engines with great facility, the crank pin to each paddle wheel being connected
to its shaft by means of a band or strap acting on a cylindrical surface affixed
on such paddle shaft.
And in order that the Invention-may-be-most-fully understood and readily
carried into effect, I will proceed to describe the Drawing hereunto annexed,
where the same letters of reference are used to indicate similar parts wherever
they occur..
3.2.1
"
DESCRIPTION OF THE DRAWING.
Figure 1 represents a side view of so much of the parts of a steam engine
as will.enable me to explain the Invention; Figure 2 is a front view of the
same parts as are shewn in Figure 1; 'and Figure 3 is a side view of some of
the parts shown on a larger scale. a, a, is part of the framing of the engine;
shews part of one of the paddle shafts; the other paddle shaft being similar,
the description of the one shewn will apply to both. On the shaft 6 is affixed
the cylinder c, which has a groove formed on the periphery to receive the strap
hereafter described; this groove I prefer to be lined with copper. is the
crank pin, by which the paddle shaft b is driven by the working of the engine;
this crank pin is affixed or keyed as usual in the crank e of the middle shaft,
and in place of having a similar crank to the shaft 6, that shaft,-as-above.
explained, has a cylinder affixed thereto, and the crank pin d is affixed to a
strap which is applied to the cylinder c, and when it is required to drive the
shaft 6 the strap is caused to bind tightly on the cylinder c, in order, by the
holding thereby produced, to cause the cylinder c with the strap f to act as a
crank to the shaft b, and thereby give motion to that shaft; and when it is
desired that the paddle-shaft 6 should be disconnected from the working of the
H

page_text: engines, then the strap f does not bind on the surface of the periphery of the
cylinder c, but the strap can be carried round by the crank pin without offering
any holding to the cylinder c.
The nature of the strap f being shewn will
readily be understood on examining the Drawing, and the mode of tightening
and relieving it I will now describe. g is a cross head, which enters into the
slits formed in the ends of the strap, as is shewn; h is what I call a
cushion, it having a curved surface to fit part of the cylinder c, and it is
between such curved surface h and the curved surface of the strap that the
cylinder is held fast, when required to drive the shaft b. This cushion h is
retained-in its place by being affixed. to two bars 2;i, one on each side of the
cross head g, by which means the cushion will not be moved when driving.
the wedge surface of the bar j, such bar at its two ends entering into the
slits or openings formed in the ends of the strap and between the cross head
and cushion, as shewn; and when the wedge is caused to press the cushion
tightly on the periphery of the cylinder c, that cylinder will be held sufficiently
to drive the shaft b, and in order to prevent the bar j from moving after being
properly set or driven, screws may pass through the bar into the cross head g
Two filling pieces k, k, are used, which are inserted in the remainder of the
slits or openings of the strap which are not filled by the cross head and the
bar j, and thus serve as guides to the bar j, such filling pieces being retained
in their places by screws passing through plates into the filling pieces, and thus
holding the same.
From the above description, aided by the Drawing, a workman will readily
understand the nature of the Invention, and he will readily perceive that a
paddle wheel shaft may with facility be disconnected and again connected
whenever it is desirable so to do.
Having thus described the nature of the Invention, and the manner of
performing the same, I would have it understood that I lay no claim to
any of the parts separately, nor do I confine myself to the precise form
thereof, so long as the Invention be retained; but what I claim as the Inven-
tion is, the mode herein described of applying the crank pins of paddle shafts
as above described.
In witness whereof, I, the said Henry Trewhitt, have hereunto set my
hand and seal, this Third day of February, in the year of our Lord One
thousand eight hundred and forty-one.
HENRY (L.S.) TREWHITT.

page_text: AND BE IT REMEMBERED, that on the Third day of February, in the
year of our Lord 1841, the aforesaid Henry Trewhitt came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, and all and everything 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 February, in the year of our Lord One thousand
eight hundred and forty-one.