IM- PROVED APPARATUS FOR DETACHING OR DISENGAGING BOATS FROM DAVIT TACKLE AT SEA OR ELSEWHERE.
Year: 1876

page_text: LETTERS PATENT to Jacob Sturton Johnson, of Okehampton, Devon, and John
St. John Stukeley Johnson, of Saltash, Cornwall, for the Invention of "IM-
PROVED APPARATUS FOR DETACHING OR DISENGAGING BOATS FROM DAVIT
TACKLE AT SEA OR ELSEWHERE.
Sealed the 21st December 1876, and dated the 29th August 1876.
PROVISIONAL SPECIFICATION left by the said Jacob Sturton Johnson and
John St. John Stukeley Johnson at the Office of the Commissioners of Patents
on the 29th August 1876.
JACOB STURTON JOHNSON, of Okehampton, Devon, and JOHN ST. JOHN STUKE-
LEY JOHNSON, of Saltash, Cornwall. "IMPROVED APPARATUS FOR DETACHING OR
DISENGAGING BOATS FROM DAVIT TACKLE AT SEA OR ELSEWHERE,"
This relates to apparatus for detaching or disengaging boats from davit tackles,
and consists of a locking and unlocking device for the simultaneous detachment of
hinged catches or hooks, one at each end of the boat, that take into eyes or links
on the ends of chains, or into eyes affixed to the blocks, in lieu of the hooks at
present used.
Within the boat, and passing longitudinally through blocks, which serve as
guides, and are secured to the upper side of the keel, are two rods, which are
advanced and withdrawn by levers, so that the ends of the said two rods take (as
bolts) into two vertical sliding blocks, one at each end of the boat, and which side
blocks carry hinged catches or hooks on their upper extremities, destined to take
into the eyes on the ends of the chains depending from the davits. The levers for
actuating the longitudinal bolt rods consist of an upright pin working in steps in
the centre of the boat, which pin carries a cross arm on its lower end, and has.
attached at its upper end an arm or other means for turning the pin around. The
cross arm on said pin is connected by short connecting rods with snugs on the bolt
rods, and on turning the pin around to the right or left, said bolt rods, through the
cross arm and connections, will be actuated to hold or release the vertical guide
pieces and hooks.
The hinged catches or hooks upon the upper extremities of the vertical slides are
retained in their position when the boat is suspended from the davits by pierced
plates of metal affixed to or let into the thwarts, as circumstances may require, and
on the slides being released by the withdrawal of the bolt rods spring upwards a

page_text: short distance, thereby allowing the ends of the hinged catclics to clear the sides of
the pierced plates, consequently releasing the eyes or links attached to the davit
tackles or blocks.
When the boat is slung the ordinary davit tackle is employed to hoist her, and
when in position the eyes attached to the davit tackles me passed over the hooks
on the vertical slide pieces, and the bolt rods are actuated to retain the slide
pieces. On the boat being disengaged the pin, cross arm, and connections are
actuated to draw said bolt rods and release the hooks. Thus the boat, simultano-
ously disengaged at both ends from her davit tackles will strike the water on an
even keel, and free from her connections.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Jacob Sturton Johnson and John St. John Stukeley Johnson in the
Great Seal Patent Office on the 28th February 1877.
JACOB STURTON JOHNSON, of Okehampton, Devon, and JOHN ST JOHN STUKE-
LEY JOHNSON, of Saltash, Cornwall. LMPROVED APPARATUS FOR DETACHING
OR DISENGAGING BOATS FROM DAVIT TACKLE AT SEA OR ELSEWHERE."
The object of this Invention is to procure a simultaneous action at each end, and
at both ends of a boat, for detaching and re-attaching davit tackles, by means of
two separate rods or draw bais placed longitudinally upon the keel, said bars
sliding in such guides or bearers as may be necessary, and engaging and disengag-
ing with the holes or piercings of pierced perpendicular slides.
Beneath any thwart, or such thwart as the build of the boat may render most
suitable, a perpendicular shaft is placed, the lower extremity of which rests in a
step or socket on the keel, and its upper end in a socket under the thwart. To the
upper extremity of this shaft a lever or aim is affixed, which extends to one or
other side of the, boat, and said lever is acted upon so as to turn the perpendicular
shaft around, or partially so, by a connecting rod possessing one or more universal
joints, or by similar contrivance.
-
The simultaneous action of the two longitudinal rods or draw bars is effected by
an appliance affixed to the lower extremity of the perpendicular shaft, and that
appliance may consist of either of the following devices, viz,-First, an ordinary
single eccentric action, that is, a cross aim fixed to or forming part of the per-
pendicular shaft, to each extremity of which said cross arm is jointed a connecting
rod, the ends of said connecting rods being clutched one upon cach of the draw
bais; second, a single or double crank action, that is, by cranking the shaft, third,
a primary archimedian screw action, by which the two rods or draw bars will be
drawn together or "shot" apart by the action of studs upon the ends of the bars playing
in grooves or curved slots in a plate or plates of metal attached to the perpendicular
shaft; fourth, a toothed wheel working horizontally or vertically upon ratchets or
ratchets working into a cog wheel.
Each of the draw bars has clutched to its end a bolt, which bolts work in metal
blocks bolted to the keel of the boat, said blocks being mortised for the reception
of the base of the perpendicular slides, and through said base of the slides are
provided holes for the reception of the bolts clutched to the ends of their draw bars.
The slides work in stanchions or uprights, which are grooved or slotted for the
reception of studs affixed to the slides, or the slides may work in slotted tubes or
pipes, and these stanchions, tubes, or pipes are raised from the keel of the boat to
such or any thwart as may be most suitable, and through such thwart a hole is
taken to allow the head of the slide to pass up In the head or upper extremity
of the slides a hook of peculiar construction is jointed, which hook cannot release
itself of any weight until the slide is allowed to rise, and to this hook the davit
tackles are made fast. The bolts passing through the holes, provided in the base of

page_text: the sides, prevent them from rising, but when the bolts are withdrawn, the slides
rise in response to any weight upon them, and in rising allow the hooks at their
upper extremities to clear a lining in the thwarts, and thereby to detach themselves.
This lining of the thwart is constructed with a hinged flap or dipping plate affixed to it,
and said flap or plate is so constructed and counterpoised by means of a spring or weight
attached to a lever that while yielding readily to any downward pressure it cannot
11se to any upward pressure, and this arrangement constitutes the attaching gear.
In order that the Invention may be well understood we have hereunto annexed
a Sheet of Drawings illustrative thereof, in which-
Fig, 1 is a longitudinal section of a boat with the improvements attached, and.
representing the parts in position for suspending, raising, or lowering the boat.
Fig. 2, a plan view shewing the first herein-before described arrangement for.
actuating the draw rods.
Fig. 3, a section at line x, x, Figs. 1 and 2, showing the perpendicular shaft for
actuating the draw bars.
Fig. 4, a sectional front view of thwart with grooved stanchion, in which works
the perpendicular slide, but with slide removed.
Fig. 5, like view, with slide in position for being locked on the draw bar and
bolt, being "shot" ready for attaching the davit tackles.
Fig. 6, like view, shewing position of slide and hook after withdrawing the draw
bar and disengaging the hooks from the davit tackles.
And Figs 7 and 8, sectional side views of Figs. 5 and 6 respectively.
A is the keel of the boat; B, thwarts; C, CT, longitudinal draw bars, C³, bolts
jointed on ends of draw bars, and thus constructed so as to allow of their working
freely, even in the event of any bending of the keel from suspension and weights;
D, guides or bearers bolted to the keel, and through which the draw bars C, C¹,
work, E, perpendicular shaft which through a lever or arm, and jointed connecting
rod F (Fig. 2) will be turned around, or partially so, to the right or left, according
as to whether the rod F is pulled or replaced, G, is a cross arm fixed to the
perpendicular shaft E, or forming part thereof; H, connecting rods jointed to the
ends of cross arm G, and clutched at H' to the draw bars. The other herein-before
described arrangements for actuating the draw bars C, C¹, and bolts C are not
illustrated, as they are mechanical equivalents well known, and such as any
practical workman could set up I, are slides, and a studs thereon, working in
grooves b of stanchions K; B¹ is the thwart or seat to which stanchions K are
secured, and c a hole provided in said thwart, through which the slide works; M
are hooks jointed in the head of the slides; d (Fig 6) the hole or piercing in base
of slide I for reception of bolt C²; D¹ is the recessed guide block into recess e
whereof the base of slide falls previously to being locked by bolt C³, as clearly
shewn by Figs. 7 and 8.
The hole in the thwart is furnished with a metal lining, and f is the flap or
dipping plate hinged thereto, but the weight or spring counterpoise of said dipping
plate is not shown, as its application will vary according to circumstances or
available space, as will be well understood and readily effected by any practical
workman. The position of this dipping plate, when depressed for attaching the
tackles, is shown in broken lines, Fig. 7.
The lump or projection g on the slide I is for the purpose of preventing the
extremity of the hook M from falling close against the slide I, whereby the engage-
ing of said hook with the eyes, blocks, or links on the davit tackles will be faci-
litated when such davit tackle attachment is passed down through the hole c
O (Fig. 1) represents the line of the davit tackles, and in this Figure is also
represented the hooks engaged with the links of the tackles for suspending, raising,
or lowering the boat.
To disengage the boat, after being lowered by the tackle in the ordinary way,
the person in charge of her will draw the rod F to actuate the perpendicular shaft
E, cross arin G, and draw bars C, C², to withdraw the bolts C and release the slides

page_text: I and hooks M. Thus the boat simultaneously disengaged at both ends from the
davit tackles will strike the water on an even keel, and free from her connections.
Having now described the nature and particulars of our said Invention for
detaching or disengaging boats from davit tackles at sea or elsewhere, we claim,-
First. Procuring sinultaneous action at each end and at both ends of a boat by
drawing together or shooting apart two longitudinal bars, actuated and working
substantially as herein described and set forth.
Secondly. The use of a rising slide, which may work in grooved or slotted
stanchions, or in slotted tubos or pipes, substantially as and for the purpose set
forth.
Thirdly. The use of the hook on the rising slide, working so as to secure or
release the davit tackles of a boat, substantially as set forth.
And, Fourthly. The hinged flap or dipping plate serving in combination with the
hook on the rising slide for re-attachment of the davit tackles, substantially as set
forth.
In witness whereof, I, the said John St. John Stukeley Johnson, for and
on behalf of myself and the said Jacob Sturton Johnson, have hereunto
set my hand and seal, this Twenty-seventh day of February, One thousand
eight hundred and seventy-seven.
J. ST. JOHN STUKELEY JOHNSON. (L.S.)