IMPROVEMENTS IN RAISING AND LOWERING SHIPS' BOATS AND OTHER WEIGHTS, AND IN THE APPARATUS USED THEREFOR
Year: 1866

page_text: LETTERS PATENT to Thomas Thornton, of Dundee, in the County of
Forfar, North Britain, Solicitor, for the Invention of "IMPROVEMENTS IN
RAISING AND LOWERING SHIPS' BOATS AND OTHER WEIGHTS, AND IN THE
APPARATUS USED THEREFOR."-A communication from abroad by Digby
Murray, Master of the Ship "Mofussilite," lying in Bombay Harbour.
Sealed the 30th October 1866, and dated the 10th May 1866.
PROVISIONAL SPECIFICATION left by the said Thomas Thornton at the
Office of the Commissioners of Patents, with his Petition, on the
10th May 1866.
I, THOMAS THORNTON, of Dundee, in the County of Forfar, North Britain,
Solicitor, do hereby declare the nature of the said Invention of "IMPROVE-
MENTS IN RAISING AND LOWERING SHIPS' BOATS AND OTHER WEIGHTS, AND IN THE
APPARATUS USED THEREFOR," to be as follows, that is to say:-
This Invention has for its object the lowering of boats from steamers or
other vessels with perfect safety whilst the steamer or vessel is in motion, and
consists in the peculiar construction of the lower block of the purchase used
to lower the boat from the davit. The block is so arranged that the boat
may be freed either on touching the water, or at any desired distance
therefrom.
In one modification of the Invention it is preferred that the block should
be constructed entirely of iron with brass sheaves; this is not, however,

page_text: essential, as it may be composed of any suitable material. In the body of the
block there is a large space left between the sheaves to admit of a mortice to
let a bolt work up and down, which bolt acts as a key to the hook. The hook
acts as a tumbler which capsizes by it own weight when unkeyed, and it fits
into the lower part of the block, the neck being straight and at right angles
to the curve of the hook. A chain or rope is attached to an eye or link in
the head of the key, the upper part hooking to the upper block of the
purchase or elsewhere, as may be determined, having metal eyes every two
feet so as to admit of its being shortened or otherwise according to the heel
of the ship and the boat's height from the water; the intention being that the
whole weight of boat and men should be brought to bear on the chain just
before the boat touches the water, resulting in the starting of the key and the
immediate release of the boat. It is intended the key should work on anti-
friction rollers. In lowering the boat it is considered better, though not
essential, that it should be lowered by the ordinary falls until the chains
attached to the keys are nearly taut; the falls are then lowered, the weight
of the boat immediately comes on the chains, lifts the keys, the hooks capsize,
and the boat is free. This construction of block may be applied to other
mechanical purposes.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed 2
by the said Thomas Thornton in the Great Seal Patent Office on the
8th November 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
THORNTON, of Dundee, in the County of Forfar, North Britain, Solicitor, send
greeting. .
WHEREAS Her most Excellent Majesty Queen Victoria, by Her. Letters
Patent, bearing date the Tenth day of May, in the year of our Lord One
thousand eight hundred and sixty-six, in the 29th year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Thomas Thornton, Her special license, that I, the said Thomas Thornton,
my executors, administrators, and assigns, or such others as I, the said
Thomas Thornton, my executors, administrators, and assigns, should at any
time agree with, and no, others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might make,
uše, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-

page_text: MENTS IN RAISING AND LOWERING SHIPS' BOATS AND OTHER WEIGHTS, AND IN THE
APPARATUS USED THEREFOR," a communication from Digby Murray, Master of the
Ship "Mofussilite," lying in Bombay Harbour, upon the condition (amongst
others) that I, the said Thomas Thornton, by an instrument in writing under
my hand and seal, should particularly 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 Thomas Thornton, 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, reference being had to the acccompanying Drawings, and to the
letters and figures marked thereon, that is to say :-
This Invention has for its object the lowering of boats from steamers or
other vessels with perfect safety whilst the steamer or vessel is in motion, and
consists in the peculiar construction of the lower block of the purchase used
to lower the boat from the davit. The block is so arranged that the boat
may be freed either on touching the water or at any desired distance there-
from. The block may be composed of any suitable material. In the body of
the block there is a larger space left than in ordinary blocks between the
sheaves to admit of a mortico being cut to allow a bolt to work up and down,
which bolt acts as a key to the hook. The hook acts as a tumbler which
capsizes by its own weight when unkeyed, and it fits into the lower part of
the block, the neck being straight and at right angles, or nearly so, to the
curve of the hook. A chain or rope is attached to an eye or link in the head
of the key, the upper part hooking to the upper block of the purchase or
elsewhere, as may be determined, having metal eyes every two feet, so as to
admit of its being shortened or otherwise, according to the heel of the ship
and the boat's height from the water. The intention being that the whole
weight of the boat and men should be brought to bear on the chain just before
the boat touches the water, resulting in the starting of the key and the
immediate release of the boat. It is intended the key should. work on
antifriction rollers. In lowering the boat it is considered better, though not
essential, that the boat should be lowered by the ordinary falls until the chains
or laniards attached to the keys are nearly taut; the falls are then lowered,
the weight of the boat immediately comes on the chains, lifts the keys, the
hooks capsize, and the boat is free. This block may be applied to several
mechanical purposes.

page_text: And in order that the said Invention may be properly understood I shall
now proceed more particularly to describe the system, mode, or manner in or
under which the same is or may be used or practically carried into effect,
reference being had to the several Figures upon the explanatory Sheet of
Drawings which I have hereunto appended, and in which similar parts are
indicated by corresponding letters of reference, that is to say:-
Figure 1 is a side elevation, Figure 2 a front elevation, and Figure 3 a
transverse section on the line a, a, Figure 2, of the improved block.
In all the Figures the body of the block A is by preference made of wood
or iron, but it may be constructed of any other suitable material. In the
body of the block two oblong openings B are cut in for the reception of the
pulleys C and C', which turn in the ordinary manner upon a central sheave c, c,
as shown. That portion of the body of the block situate between the two
pulleys C, C¹, is hollowed out to admit the upper shank end of the tumbler
hook D, as well as the bolt E used for withdrawing it, as herein-after
described.
The action of the block is as follows:-A boat or other object which has
to be lowered and released at any given distance below the block or blocks,
from which it is suspended, being lowered by the ropes F and G; it may be
released at any point by steadying, taut, and making fast the laniard H
attached to the draw bolt E; the falls being then let go the weight is imme-
diately brought on the laniards lifting the draw bolt, which being withdrawn
the shank of the suspension hook is free, and the hook being of such form
that it immediately overturns on the centre bolt K, Figures 1, 2, and 3. The
hook being permanently attached to the body of the block by means of the
brackets L
When it is required to lower the boat or other object, this is effected by
means of letting out the ropes F and G to the required length; the laniard
being "rove" through a block at the end of the davit and made fast at the
desired time, either on board or in the boat (in the case of lowering a boat),
as may be preferred, so that the release is instantaneously effected, two blocks
being used.
It is to be understood that blocks with a greater number of sheaves than
two may be employed and constructed under this Invention; for instance,
three sheaves may be used constituting triple blocks, in which case the shank
of the hook D is forked and fits into a recess on each side of the middle
sheave, the bolt E being correspondingly forked. It being evident to practical
seamen or block constructors, from what I have herein-before specified and
shown in the appended Sheet of Drawings, that blocks with any number of

page_text: sheaves may be constructed according to my said Invention, it is not necessary
herein to further describe them.
Having now described the nature of the said Invention, and the manner
in which the same is or may be used or practically carried into effect, I would
observe in conclusion that what I consider novel and original, and therefore
claim as the Invention secured to me by the herein-before in part recited
Letters Patent is,―
First, the general arrangement and construction of blocks, as herein-before
described, or any mere modification thereof.
Second, the application to and connection with blocks of a suspension hook
capable of being released in the manner as herein-before described, or any
mere modification thereof.
In witness whereof, I, the said Thomas Thornton, have hereunto set
my hand and seal, this Sixth day of November, One thousand eight
hundred and sixty-six.