IMPROVEMENTS IN CHAIN-CABLE STOPPERS
Year: 1869

page_text: LETTERS PATENT to William Robert Lake, of the "International
Patent Office, Southampton Buildings, London, Consulting En-
gineer, for the Invention of "IMPROVEMENTS IN CHAIN-CABLE STOPPERS."
-A communication from abroad by John John Emery, of South
Thomaston, and Philo Thurston, of Rockland, both in Maine,
United States of America.
COMPLETE SPECIFICATION filed by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition
and Declaration, on the 15th October 1869, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the "International Patent Office," Southampton
Buildings, London, Consulting Engineer, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
CHAIN-CABLE STOPPERS," and have petitioned Her Majesty to grant unto
me, my executors, administrators, and assigns, Her Royal Letters
Patent for the same, and have made solemn Declaration that the-same
has been communicated to me from abroad by John John Emery, of

page_text: South Thomaston, and Philo Thurston, of Rockland, both in Maine,
United States of America.
NOW KNOW YE, that I, the said William Robert Lake, do hereby
declare that the following Complete Specification, under my hand and
seal, fully describes and ascertains the nature of the said Invention, and
in what manner the same is to be performed, in and by the following
statement, reference being had to the accompanying Drawing forming
a part of this Specification.
In chain-cable-stoppers as heretofore constructed and applied to vessels
no provision has been made for the yield of the stopper under sudden
or severe strains, and this Invention has reference to such an application
or arrangement of a chain cable stopper mechanism as shall bring the
direct strain of the anchor and cable upon suitable cushions or springs,
in such manner as to ease off the sudden pull upon the links of the
chain when the movement of the anchor is suddenly arrested, thus
preventing the cable from parting and saving the deck from undue
strain.
The said Invention consists in giving to the pawl-carrier a capability
of movement in the direction of the strain exerted upon the pawl, and
in cushioning the carrier against suitable springs, so that when the
stopper or pawl is applied while the cable is running out the shock is
spent upon the springs.
The Drawing represents the bows of a vessel having a chain-stopper
embodying these improvements.
same.
A is a plan of the stopper-mechanism, and B a vertical section of the
a denotes the deck; b, the knight heads; c, the hawse-holes; d,
the cable; e, the windlass; f, the windlass bitts. Between the windlass
and the hawse-hole the chain runs through a guide 9, having two
vertical ears h which support a pin i, whereon is hung the stopper-pawl
or nipper k, which when it drops down rests at its point upon the chain-
link lying flatwise, so that the next link catching against the pawl is
effectually stopped thereby. The guide g is mounted and rides upon
two rods or bars by means of two tubes or cylinders m on opposite
sides of the guide and forming part thereof. The rods or bars are sup-
ported at their opposite ends by heads n on the top of bed-pieces o, and
while one end of each rod is confined in place by a nut on the screw
threaded end of the rod, the opposite end is bolted to the framing of the
deck by a link p with a suitable nut and screw, as seen at B. The

page_text: rods are longer than the tubes or cylinders m, and between the forward
end of each tube and the adjacent head rubber rings or cylinders q are
placed on the rods, these rings being preferably separated each from the
one adjacent to it (and the end one from the tube) by a metal washer r,
a rubber or leather washer 8 separating the opposite end of each tube
from the adjacent head.
It will be obvious that when the pawl is dropped and the chain is
caught by and draws upon the pawl the guide or pawl-carriage will
slide upon its rods, but that its movement will be resisted by the rubber
tubes acting as springs, the springs yielding sufficiently in all cases
whether the anchor be dropped and suddenly stopped by the pawl, or
the vessel be riding heavily at anchor, to relieve the frame or deck of
the vessel from undue strain and to prevent parting of the cable. Instead
of the sliding cylinders m each pawl-carrier may be provided with
ears t, as shown, the springs being placed between the ears as well as
between the ears and the heads. Metal springs may be used instead of
springs made of rubber or caoutchouc, but those described are considered
preferable.
By testing the capability of compression of the springs and the force
required to compress them within given distances, and indicating the
same upon a scale on the side of the bed-plate, it will be obvious that
the amount of strain upon the nipper or pawl will be shewn at all
times.
Having thus fully described the said Invention as communicated to
me by my foreign correspondent, I claim, a chain-cable-stopper-me-
chanism in which the strain upon the stopper pawl or nipper or the
pawl-carrier is borne by springs, substantially as described.
In witness whereof, I, the said William Robert Lake, have here-
unto set my hand and seal, this Fifteenth day of October, in
the year of our Lord One thousand eight hundred and sixty-
nine.
Witness,
HARRY WRAIGHT.
WILLIAM ROBERT LAKE. (L.S.)