IMPROVED MECHANICAL ARRANGEMENTS, FOR RAISING, LOWERING, AND DISENGAGING SHIPS' BOATS AND OTHER PONDEROUS BODIES
Year: 1859

page_text: PROVISIONAL SPECIFICATION left by Reuben Jones and Daniel Stothard
at the Office of the Commissioners of Patents, with their Petition, on
the 30th December 1859.
We, REUBEN JONES, of Trinity Terrace, Trinity Square, Southwark, in the
County of Surrey, and DANIEL STOTHARD, of Peacock Street, Newington, in
the County of Surrey, do hereby declare the nature of the said Invention for
"IMPROVED MECHANICAL ARRANGEMENTS, FOR RAISING, LOWERING, AND DISENGAGING
SHIPS' BOATS AND OTHER PONDEROUS BODIES," to be as follows:-
As regards the improved mechanical arrangements above mentioned, they
consist, first, of an improved construction of block for raising and lowering
ponderous bodies; and, secondly, of improved mechanism, either separate from,
or it may be used in combination with, the aforesaid blocks for raising,
lowering, and disengaging ships' boats from the tackles which suspend them.
The construction of the aforesaid block is as follows:-It consists of three
pullies, or one sheave and two small pullies, two of which revolve on fixed
axes, and the other and intermediate pulley has its axis fixed in the pulley,
and said axis fits into curved slots formed in the side plates of the block, so.
as to be capable of moving up and down the same. By thus constructing
blocks, the necessity for employing blocks with two or more sheaves, as com-
monly practised, is dispensed with; less rope is required in consequence of
its only having to pass over the aforesaid sheave and between the two pullies,
the effect being as follows:-In proportion to the amount of weight attached
to one end of the rope, in like proportion will be the pressure upon the
foresaid moveable pulley, thereby squeezing or wedging the rope between.

page_text: the two aforesaid pullies, and thus producing the same effect as would be
produced by passing a rope round a cleat in lowering weights, as commonly
practised, with this advantage, that by this Invention the rope is not rubbed,
consequently lasts much longer. In connection with the aforesaid block or
two blocks suspended from the head of the "davits" of a ship, (or the
aforesaid pullies and sheave may be attached to the head of the "davits," so
as to form a part thereof,) we employ the following mechanism for raising,
lowering, and disengaging ships' boats, that is to say, underneath the middle
"thwart" of the boat we affix two uprights, across which we pass pins, on
which are hooks and catch levers, the outer ends whereof pass in opposite
directions. The ends of said catch levers are connected together by a rope
or chain, which passes loosely over the top of the "thwart." A single rope
passes from each of the aforesaid blocks over a broad pulley fixed at the stem
and stern of the boat, and to the end of each rope a link of iron is fastened,
so that when such links are each passed over their respective hooks aforesaid,
and the boat raised from above, the boat cannot by any means become dis-
engaged from the "davits" until she touches the water, when, by pulling the
rope which is across the middle "thwart" as aforesaid, the hooks will be
disengaged, and the ropes will pass under the pullies at the head and stern of
the boat, and by these means the boat will be disengaged stem and stern at
the same time.