Improvements in or relating to Means for Raising and Lowering Ships' Boats.
Year: 1891

page_text: Date of Application, 11th Mar., 1891
Complete Specification Left, 11th Dec., 1891-Accepted, 16th Jan., 1892
PROVISIONAL SPECIFICATION.
Improvements in or relating to Means for Raising and Lowering
Ships' Boats.
We, JOHN HENRY BELL, Iron and Rivet Manufacturer and CHARLES SAUTER,
Ship Captain both of North Cliff, Roker, Sunderland in the County of Durham
do hereby declare the nature of this invention to be as follows:-
Our invention refers to improvements in or relating to means for raising &
lowering ships' boats and apparatus therefor.
To effect our purpose we construct the davit of a somewhat peculiar form in
order to enable a rack and pinion or worm mechanism preferably arranged
segmentally or in the form of a quadrant to operate it. The davit, and apparatus
may be centred towards the outer ends of the skids near the ship's side so as to
vibrate under the action of the tooth mechanism for the purpose of swinging out or
in the boat. From eyes or points of attachment on arms arranged towards the
extremities of the davits the boat is hung by pendants leading to blocks or rings
arranged towards either end of the boat whence the pendants are led to a central
windlass drum or equivalent device situated preferably immediately below a thwart.
This may be operated by worm and rack or teeth gear and provided or not as
required with a frictional brake to control the same.
The boat can thus be lowered by one person operating from within the same.
The raising of the boat is effected by tackles suspended from the davits.
The latter operated as above described may be likewise arranged to actuate the
outer chocks securing the boat.
This may be effected by the davit or a part thereof falling on or coming against
a shoulder or catch of the chock lever thus causing the latter to rise up and secure
the boat; the release of the outer chocks may be effected by the action of lifting
the boat in the davit in the first instance which allows the outer chocks to fall over
and thus give a free passage for swinging out the boat.
The general arrangement is subject to modifications in design and detail although
the above description is a fair adumbration of the nature of the invention.
Dated this 10th day of March 1891.
A. CRAWHALL CHAPMAN,
Newcastle-upon-Tyne, Agent.
COMPLETE SPECIFICATION.
Improvements in or relating to Means for Raising and Lowering
Ships' Boats.
We, JOHN HENRY BELL, Iron and Rivet Manufacturer, and CHARLES SAUTER,
Ship Captain both of North Cliff, Roker, Sunderland, in the County of Durham
do hereby declare the nature of this invention and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement :-
Our invention refers to improvements in or relating to means for raising and
lowering ships' boats.
To effect our purpose we construct the davit of a somewhat peculiar form in
order to enable a rack and pinion or worm mechanism preferably arranged
segmentally or in the form of a quadrant to operate it. The davit and apparatus
may be centred towards the outer ends of the skids near the ship's side so as to vibrate
[Price 8d.]

page_text: under the action of the tooth mechanism for the purpose of swinging out or in the
boat. From eyes or points of attachment on arms arranged towards the extremities
of the davits the boat is hung by pendants leading to blocks or rings arranged
towards either end of the boat whence the pendants are led to a central windlass
drum or equivalent device situated preferably immediately below a thwart. This
may be operated by worm and rack or teeth gear and provided or not as required
with a frictional brake to control the same.
The boat can thus be lowered by one person operating from within the same.
The raising of the boat is effected by tackles suspended from the davits.
The latter operated as above described may be likewise arranged to actuate the
outer chocks securing the boat.
This may be effected by the davit or a part thereof falling on or coming against
a shoulder or catch of the chock lever thus causing the latter to rise up and secure
the boat; the release of the outer chocks may be effected by the action of lifting
the boat in the davit in the first instance which allows the outer chocks to fall over
and thus give a free passage for swinging out the boat.
We will describe our invention with reference to the accompanying drawings in
which
Figure 1 shows a side view of the davit and gear in its outward position with the
boat swung out ready to lower,
Figure 2 being a similar view of the same in its inward position with the boat
resting on the chocks.
Figure 3 is a plan view of Fig. 1, and
Figure 4 is an elevation of the windlass or capstan for raising and lowering
"the boat.
Referring to the drawings, the elbow-shaped arms a represent the davits centred
at a and the segmental racks or quadrants a² are formed or built in one with them
so as to form in each case one strong frame.
These davit and rack frames are mounted or centred in brackets a³ formed on
the stanchions son which also the ends of the skids s¹ rest and are secured as
shown. The said frames are designed to vibrate under the action of the pinions a
mounted on shafting a secured in brackets as which latter may be bolted to the
skids. Handles are provided for operating the pinions and davits.
e are the chock levers centred at ef in brackets c².
When the davit is in the position shown in Fig. 1, the chock levers have
automatically fallen over into the position shown in this figure, but when the davits
are being worked back into the position shown in Fig. 2, by the tooth mechanism
above described, at a certain point the pin or stop on the davit engages with the
short arm of the chock lever which has the effect of gradually raising the chock
lever until, when the boat and davit are fully in, it assumes the desired position
shown in Fig. 2, thus further securing the boat in its position. As soon as the
davit is sufficiently raised for swinging out the boat again, the chocks again fall
over and thus give a free passage for the clearance of the boat.
.d is a windlass or drum preferably placed at the centre of the boat under a
thwart. Its barrel may be operated by the simple mitre gearing shown in Figs. 3
and 4 in which e is the handwheel e¹ the pinion and the mitre spur on the barrel
end. is a handwheel for tightening or slackening the friction contact between
the friction strap e and the drum, so as to afford means for controlling and braking
the latter.
In Fig. 3 part of the thwart is shown removed in order to illustrate this arrange-
ment, the brackets for which may be secured to the underside of the thwart.
In working our invention, the boat can be lowered by one man operating the
drum d by means of the mitre and friction gearing above described, the cable
passing off the drum through rings or pulleys at i to the davit arms.
For hoisting the boat out of the water ordinary block and tackle gear attached
to the eyem in the davit arm is used and the boat is then swung inwards onto the
chocks as above described.

page_text: 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 :-
1. In combination with the elbow-shaped arrangement of davit arm and
segmental rack or quadrant constituting in each case one frame, centred and
operated by tooth and pinion or worm gearing as set forth, the automatic chock
device consisting of a chock lever with a long and short arm the latter of which is
designed to be operated by a pin or stop in the davit so as to raise the chock or
allow it to lower when the boat is being swung inwards or outwards substantially
as herein set forth.
2. The general arrangement or combination of parts for chocking and unchocking
boats and for swinging them outwards or inwards as regards the ship and for
lowering and rehoisting them substantially as herein described and illustrated in
the accompanying drawings.
Dated this 8th day of December 1891.
A. CRAWHALL CHAPMAN,
3, St. Nicholas Buildings, Newcastle-on-Tyne, Patent Agent.