Improvements in and relating to Disengaging Mechanism for Ships' Boats and the like.
Year: 1891

page_text: Date of Application, 15th Sept., 1891
Complete Specification Left, 14th June, 1892-Accepted, 16th July, 1892
PROVISIONAL SPECIFICATION.
Improvements in and relating to Disengaging Mechanism for Ships'
Boats and the like.
We, DAVID ALEXANDER CROMBIE, Architect, 34 St. Andrew Square, and
EDWARD ROBERTSON FLETCHER, of 24 Queens Crescent Merchant, both in the
City and County of Edinburgh, do hereby declare the nature of our invention to
be as follows:-
This invention has reference to and comprises a new or improved construction, or
arrangement and combination of the parts of holding and disengaging mechanism
or appliances for being used in conjunction with the davits for raising and lowering
ships' boats, and instantaneously releasing them.
'
The improved appliances consist of an open fixed gap or slotted metal gab each
fitted through a mortise in the bow and stern or seat platform of the boat and
preferably secured by a solid stem standard screwed or otherwise secured to the
keelson direct below. The slot or gab of each standard is formed vertical and
rounded at the top on oppposite sides for the loose ring or shackle at the end of the
hoisting davit gear entering and resting on the bottom of the slot, so that the lower
end of a short fulcrum catch lever preferably fitted with an antifriction roller would
pass in through the ring or shackle and secure it in its slot, the lever being fulcrumed
by a horizontal pin at one side at top of the gab, to act in a lateral slot at right
angles to the slotted gab. This lever would have a curved or horizontal weighted
arm projecting out on the same side as the fulcrum, so that the weight on this lever
would always tend to keep the vertical catch lever in its locked position across the
slot in the fixed gab with the centre or axis of the antifriction pulley beyond the
centre of the slot, so that any pull on the ring or loose shackle of the hoisting
tackle would tend to keep the lever locked until the weighted lever was lifted
by hand.
To simultaneously disengage these locking levers at the bow and stern of the
boat, the weighted levers which would project horizontally towards each other or
towards the same side of the boat would each be connected to one end of a light
chain or cord carried up over guide pulleys on the underside of the seat, the other
ends of both chains.or cords being connected to opposite sides of a wheel or double
armed lever or their equivalent with one hand lever to actuate them by one person,
so as to draw both chains simultaneously and lift both weighted and catch levers
against a stop and disengage and free the shackles of both hoisting chains of the
davit at the bow and stern at the same instant as the boat was lowered into or
reached the water. The chains or cords may also. by the first part of the motion be
made to turn and disengage a swivelling or sliding locking catch acting on the
weighted levers, just before freeing the disengaging levers of the shackles.
Dated the 14th Sentember 1891
:
W. R. M. THOMSON & Co..
96, Buchanan Street, Glasgow, Agents.
96, Buchanan Street, Glasgow, Agents.
COMPLETE SPECIFICATION.
Improvements in and relating to Disengaging Mechanism for Ships'
Boats and the like.
We, DAVID ALEXANDER CROMBIE, Architect, 34 St. Andrew Square, and
EDWARD ROBERTSON FLETCHER, of 24 Queens Crescent, Merchant, both in the
City and County of Edinburgh, do hereby declare the nature of our invention

page_text: and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement in writing, reference being had to
the accompanying drawings:-
This invention has reference to and comprises a new or improved construction, or
arrangement and combination of the parts, of holding and disengaging mechanism
or appliances for being used in conjunction with the davits for raising and lowering
ships' boats, and instantaneously releasing them.
And in order that our said invention and the manner of performing or carrying
the same into effect or practice may be properly understood, we have hereunto
appended an explanatory sheet of drawings in which the same reference letters are
use to indicate corresponding parts in all the figures where shown.
Fig. 1 is a longitudinal sectional elevation broken away at B* B*, of a boat B B
showing our improved holding and disengaging mechanism applied thereto, and
Figures 2 and 3 are side and end views of the improved mechanism detached and
to a large scale.
Referring to these drawings,-The improved appliances consist of two open fixed
gap or slotted metal gabs A¹ A", each fitted through a mortise at the bow B, and
stern B or seat platform B₁ of the boat, and preferably formed or secured on the
top of a solid stem standard A screwed or otherwise secured at A to the
keelson B direct below. The slot or gab part A of each standard A., is formed
vertical and rounded at the top on opposite sides for the loose ring or shackle C,
attached to the hoisting blocks C¹ of the davit gear entering and resting on or near
the bottom of the slot A, so that the lower end of a short fulcrum counterweighted
catch lever D D', preferably fitted with an antifriction roller D' would pass in
through the ring or shackle C and secure it in its slot A2, the lever D D' being
fulcrumed by a horizontal pin at D" at one side at the top of the gab part A", to
act in a lateral slot at right angles to the slot A' of the gab. This lever D D' has
a curved or horizontal weighted arm D' projecting out on the same side as the
fulcrum D, so that the weight on this lever would always tend to keep the vertical
catch part
D D³ of the lever in its locked position across the slot A2 in the fixed
gab with the centre or axis of the antifriction pulley D' beyond the centre of the
slot, so that any pull on the ring or loose shackle C of the hoisting tackle C¹, C',
would tend to keep the lever D D' locked until the weighted arm D₁ was lifted by
hand or otherwise. Or instead of the armn D' being weighted it may be pulled to
its normal locked position by a spring. To simultaneously disengage these locking
levers D D', at the bow and stern B B₁ of the boat the weighted levers D
which would project horizontally towards each other or towards the same side of
the boat would each be connected as shown particularly in Figure 1, to one end of
a light chain, wire or other cord a carried up over guide pulleys a' on the underside
of the seat B the other ends of both chains or cords a being connected to opposite
sides of a wheel b, as shown in the detached edge and plan view Figure 4, or it
may be a double armed lever or other equivalent fitted preferably near the centre
of the boat with one hand lever 6 on the spindle 6 of the wheel 6 to actuate them
by one person, so as to draw both chains a a simultaneously and lift both weighted
and catch levers D D¹, against a stop A³ at the top A", of the gab part and
disengage and free the shackles C of both hoisting blocks C, C', of the davit at
the bow and stern B.B', at the same instant as the boat was lowered into or reached
the water. The chains or cords a a may also by the first part of the motion be
made to raise or turn and disengage a swivelling or sliding locking catch acting on
the weighted levers D D', just before freeing the disengaging catch D2 of the
shackles C. One arrangement of this securing catch is shown dotted-in in Figures 1
and 2, and consists of a vertical sliding spring bolt a fitted in the 'head part D of
the lever D D', with a spiral spring an always pushing it down into a locking
recess at A' in the top of the standard A, shown in these two figures, and with a
pulling stem and eye a³ for raising and disengaging it by another end a of the
cord a, which when pulled first lifts this bolt a just before lifting the lever 'D' to

page_text: disengage the shackle rings C C, the falling of the weighted arm D' always putting
this catch a into its locked position as shown in the figures.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is.-
First. The constructing and use of holding and disengaging mechanism for ships'
boats with open fixed slotted gaps or gabs in combination with swivelling or
oscillating catch levers, substantially as herein described in reference to and shown
in the accompanying drawings.
Second. The arrangement and combination of holding and disengaging mechanism
for ships boats with swivelling catch levers, disengaging cords and locking catches,
substantially as and operated in the manner herein described, in reference to and
shown in the accompanying drawings.
בד
110
1000
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.