IMPROVEMENTS IN SLIPS FOR RAISING SHIPS AND VESSELS.
Year: 1860

page_text: LETTERS PATENT to John Grantham, of 31, Nicholas Lane, in the City
of London, for the Invention of "IMPROVEMENTS IN SLIPS FOR RAISING
SHIPS AND VESSELS.'
Sealed the 11th October 1860, and dated the 28th April 1860.
PROVISIONAL SPECIFICATION left by the said John Grantham at the
Office of the Commissioners of Patents, with his Petition, on the
28th April 1860.
I, JOHN GRANTHAM, of 31, Nicholas Lane, in the City of London, do
hereby declare the nature of the Invention for "IMPROVEMENTS IN SLIPS FOR
RAISING SHIPS AND VESSELS," to be as follows:-
This Invention consists in applying a worm wheel and screw to drive the
main shaft on which the drum used for moving the chain is applied, in
substitution of spur wheels heretofore interposed between the first mover and
the main shaft. By such means the necessary power for raising a ship or
vessel on a slip is obtained in a more simple and advantageous manner than
heretofore.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Grantham in the Great Scal Patent Office on the
27th October 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
GRANTHAM, of 31, Nicholas Lane, in the City of London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of April, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-third year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
John Grantham, Her special licence that I, the said John Grantham, my
executors, administrators, and assigns, or such others as I, the said John
Grantham, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN SLIPS FOR
RAISING SHIPS AND VESSELS," upon the condition (amongst others) that I, the
said John Grantham, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should par-
ticularly describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed in
the Great Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Grantham, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say :-
This Invention consists in applying a worm wheel and screw to drive the
main shaft on which the drum used for moving the chain is applied, in
substitution of spur wheels heretofore interposed between the first mover and
the main shaft. By such means the necessary power for raising a ship or
vessel on a slip is obtained in a more simple and advantageous manner than
heretofore,
Having thus stated the nature of my said Invention, I will proceed to
describe more fully the manner of performing the same.

page_text: By reference to the annexed Drawings the nature of my Invention will bo
understood.
Figure 1 is the side elevation; Figure 2 is the plan; Figure 3 is a section
through the shafts and wheels that give motion from the first mover to the
screw, and Figure 4 is an end view. The same letters refer to the same parts
in each Drawing.
:
A, A, are the side frames that support the machine; B, B, are two steam
cylinders which give motion to the horizontal shaft C, on which are the bevel
wheels D and E which run loose on the shaft; between these is the clutch F,
so formed as to act on either D or E. These wheels give motion to the
wheels G or H, attached to the upright shaft I, resting on the lower cross
frame K. On the shaft I is the screw or worm L, which works into tho
worm wheel M, and this gives inotion to the shaft N on which is staked the
drum wheel O, and this gives motion to the pitched chain P, that moves
the cradle on which ships are placed to be hauled up. On the horizontal
shaft C is also placed the surging pulley Q.
I will now describe the mode of working the machinery.-When the vessel
is to be drawn up the clutch F is thrown into connection with the wheel D,
which is shown to be one-third of the diameter of the wheel G into which it
works, reducing the speed of the upright shaft to one-third that of the horizon-
tal shaft, or is otherwise so proportioned as to give the desired velocity to the
rest of the machine and the pitch chain. But in lowering the ship it is
sometimes found desirable to check it by means of a chain and capstan or
some other similar contrivance, a work always attended with danger, but in
my improved machine it is done by moving the clutch F into gear with the
wheel E, thus reversing the upright shaft and the rest of the machinery, at a
speed, however, three times as great as the upward motion. The empty
cradle can be raised by a light chain working on the surging pulley Q. It will
also be seen that the clutch F may be so placed that both the wheels D and E
will be out of gear, and the engines and shaft C may, for a time, be employed
in driving other machinery.
I would remark that the machinery may be driven by other means than by
the two steam engines shown in the Drawing, and although I prefer the
arrangement shown in the Drawing I do not confine myself thereto as varia-
tions may be made therein, for instance, the requisite gearing for obtaining

page_text: and varying the speed of the main shaft may be interposed between a worm
wheel shaft and the drum wheel or main shaft, or otherwise..
Having thus described the nature of my Invention, and the manner of per-
forming the same, I would have it understood, that I make no claim to any of
the mechanical parts separately, but what I claim is the application of a worm
wheel and screw to drive the main shaft on which the drum used for moving
the chain, is applied in substitution of the spur wheels heretofore imposed
between the first mover and the main shaft.
In witness whereof, I, the said John Grantham, have hereunto set my
hand and seal, this Twenty-seventh day of October, in the year of our
Lord One thousand eight hundred and sixty.
JOHN GRANTHAM. (L.S.)