IMPROVEMENTS IN APPARATUS FOR LOWERING BOATS
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by Arthur Edmund Stebbing at the Office
of the Commissioners of Patents on the 2nd June 1877.
ARTHUR EDMUND STEBBING, of No. 1, Norfolk Terrace, West Kensington Park,
in the County of Middlesex. "IMPROVEMENTS IN APPARATUS FOR LOWERING
BOATS."
When a boat is lowered from the davits of a vessel into the water, it is of the
utmost importance that the boat should run freely down, and that when it becomes
buoyed on the water it should at once become detached at both ends from the tackle
by which it is lowered. My Invention relates to apparatus for this purpose.
I will first describe self-acting disengaging apparatus which I apply in the boat.
Near each end of the boat I mount a lever arm which passes through a ring
attached to the lowering tackle, but which is held by a catch in a nearly horizontal
position, and therefore ongaged with the tackle ring.
The two catches, namely, those for the two ends of the boat, are connected near
the middle of the boat to a weight, which, when the catches aro free, will withdraw
them from the levers above mentioned, thereby leaving those levers free to rise
towards a vertical attitude, so that the tackle rings can slip off them. Each of the
catches is, however, engaged by a notch with the lever in such a manner that while
the lever is trained upwards by the tension of the suspending tackle the catch
cannot be disengaged, but when the boat rests on the water sufficiently to relieve
the strain on both the levers, then both the catches become freed from the notches,
and the weight then withdraws them, leaving both the levers free as above
described.
The connection of the catches to one another, and to the weight which works
them, may be effected by rods or chains, on which the weight exerts a pulling
strain, or there may be a spindle carried on bearings along the boat, and having the
weight on an arm projecting froin it at any convenient part of its length, this
spindle operating the holding and release of the tackle levers in the following
manner. Each end of the spindle is made with a crank arm that can be turned
into such a position as to be over the tackle lever, and held there by the lever
entering a notch in it, but when both the levers are relieved from upward strain
they drop out of their respective notches, whereupon the weight causes the spindle
to turn, withdrawing its crank arm from their position over the levers, and tliereby
I Price 2.11

page_text: leaving them free. A similar arrangement of crank arms or slides may be worked
by rods or chains from a middle lever to which the weight is attached, the object of
the arrangement in all cases being that both catches must be relieved from the
strain of the levers before the levers themselves can be released so as to let go the
tackle.
.
The tackle itself may be worked in any known manner; I prefer, however, to
employ for this purpose a pair of barrels on a spindle extending along the rail of
the vessel, which spindle can be turned by winch or crab gearing, and can be
retarded or stopped by a break when the tackle is running out.
For the lowering tackle I prefer to employ a single chain or a chain with a single
moveable block, as this is not like a rope apt to become stiffened in cold weather,
and can run freely out, and in order to obtain greater power for lifting the boat I
provide in addition compound tackles of the ordinary kind, hung from the same
davits, which-for-that purpose .I make of T form, having at their top ends a
-cross-head, one_end_of_which carries the lowering tackle and the other end the
sising tookle