Improvements in Crabs or Winches and similar Hauling or Lifting Tackle.
Year: 1893

page_text: Date of Application, 30th June,
1893
Complete Specification Left, 30th Mar., 1894-Accepted, 12th May, 1894
PROVISIONAL SPECIFICATION.
Improvements in Crabs or Winches and similar Hauling or
Lifting Tackle.
I, CHARLES CLEMENT WALKER, of Lilleshall Old Hall near Newport, in the
County of Salop, Engineer, do hereby declare the nature of this invention
(a communication to me by Friedrich Weck, of 49, Elizabeth Street, Melbourne,
Australia, Engineer) to be as follows:-
My invention relates to crabs or winches and similar hauling or lifting tackle.
In using an ordinary winch it is well known that at every revolution of the
barrel the rope travels a distance equal to its thickness along the barrel, causing
it to arrive at the end opposite to the one started from and necessitating a cessation
of the winding process, the fixing the working rope in front of the crab and the
moving back to its original position of the coil of rope upon the barrel after
releasing the handpull thereby causing a considerable loss of time and risk of
accidents.
According to this invention I use two barrels placed parallel instead of one;
each barrel being grooved circumferentially and so adjusted longitudinally that the
rope or the like will pass from barrel to barrel into consecutive grooves which
prevent it from travelling lengthwise.
Either one or both of the barrels may be driven and the ropes may run either
parallel or crossed.
My improved gearing gives a steady pull free from the "jerk" which is so
apparent in the capstan shaped barrel, whereby the life of the ropes will be
considerably lengthened and probably many accidents averted which are liable to
occur by a short release and sudden check of a rope stretched a long distance and
its falling weight causing a momentum which throws a greater stress upon it than
the steady load it may have to pull.
Dated the 30th day of June 1802
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Crabs or Winches and similar Hauling or
Lifting Tackle.
I, CHARLES CLEMENT WALKER, of Lilleshall Old Hall, near Newport, in the
County of Salop, Engineer, do hereby declare the nature of this invention
(a communication to me by Friedrich Weck, of 49, Elizabeth Street, Melbourne,
Australia, Engineer) and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
This invention relates to crabs or winches and similar hauling or lifting tackle.
In using an ordinary winch it is well known that at every revolution of the
barrel the rope travels a distance equal to its thickness along the barrel, causing
it to arrive at the end opposite to the one started from and necessitating a cessation
of the winding process, the fixing of the working rope in front of the winch and
the moving back to its original position of the coil of rope upon the barrel
after releasing the hand-pull, thereby causing a considerable loss of time and risk
of accidents.

page_text: According to this invention use two barrels placed parallel instead of one,
each barrel being grooved circumferentially and so adjusted longitudinally that the
rope or the like will pass from barrel to barrel into consecutive grooves which
prevent it from travelling lengthwise.
Either one or both of the barrels may be driven and the ropes may run either
parallel or crossed.
To enable the invention to be fully understood I will describe the same by
reference to the accompanying drawing, in which :-
:―
Figures 1 and 2 are respectively a longitudinal section and plan of a double
purchase crab constructed according to the said invention :
Figures 3 and 4 are a side elevation and plan shewing the arrangement when the
rope is crossed:
Figures 5 and 6 are a longitudinal section and sectional plan respectively
shewing a pair of barrels fixed to a ship's winch in place of the usual two
capstan-head shaped barrels :
Figure 7 is a plan view shewing an arrangement wherein one barrel is driven
whilst the other revolves freely on its spindle.
Similar letters of reference indicate corresponding parts in the several figures.
a is the framing of the apparatus, and b, b' are the barrels which as shewn are
provided with a series of circumferential grooves c, c. d is the rope which as shewn
in Figures 1 and 2 runs from top to top and bottom to bottom of the barrels over
which it passes in the grooves. As shewn in Figures 1 and 2 also the barrels b, b'
are both represented as being positively driven, for which purpose their shafts
carry respectively spur-wheels e and e' with which a driving pinion f engages.
Instead of running the rope from top to top and bottom to bottom as just
described it may run from the top of one barrel to the bottom of the other, as
shewn in Figures 3 and 4. In this arrangement it will be obvious that the two
barrels must be rotated in opposite directions for which purpose the motive power
is communicated directly to the barrel through the medium of the pinion f
engaging with the wheel e on the shaft of the said barrel, the other barrel b' being
driven by its wheel e engaging with the wheel e.
When a pair of barrels is fixed to a ship's winch in place of the usual two
capstan-head shaped barrels which protrude beyond the side frame of the winches
they are each firmly fixed to a spur-wheel h, which wheels h, h gear into each
other and are able to run freely on the single and double purchase spindles, but
each is provided with a clutch such as i by which it may be fixed to its spindle so
as to rotate with it. Both barrels rotate with equal speed (which corresponds
with the speed of the spindle whose barrel is driven by means of the clutch) but in
opposite directions although the barrel which is loose upon its spindle always
rotates in the same direction as its spindle though at the speed of the other
spindle. By this arrangement the pulling can be changed by means of the
clutches from single to double purchase and vice versa without letting go of the rope
or even slacking it.
It is not necessary that both barrels should be driven or be capable of being
driven one may be allowed to run free on a fixed or independently running spindle
as shewn in Figure 7 where the barrel to the left is fixed to its spindle, and the
other one revolves freely on its spindle, which spindle is running at a greater speed
than itself but in the opposite direction.
Figure 7 would not be used in practice except in a possible case where a slow
pull up and a quick lower or vice versa were required, when a clutch in connection
with each barrel would enable the rope to travel slow on the double purchase in
one direction and return fast on the single purchase without reversing the motive
power of the winch; but if so constructed and the rope were crossed as shewn in
Figures 3, 4 and 5, it would work in the same manner as the winch illustrated in
Figures 5 and 6 with the exception, that, only one barrel being driven by the
motive force, owing to the absence of the equal sized spur-wheels constraining their
conjoint motion, double the number of laps would have to be made to give the

page_text: same amount of adhesion of the rope as in the case where both barrels assist in
pulling.
It may in some cases prove advantageous to use the gear as shewn in Figure 7
but in ships' winches when using grooved barrels in place of the capstan-head
shaped ends it is best to have the said barrels as short as possible, and hence by
connecting the two barrels with each other the advantage is obtained of being
able to use shorter barrels than would be required were only one barrel driven.
The improved gearing hereinbefore described gives a steady pull free from the
"jerk" which is so apparent in the capstan-shaped barrel whereby the life of the
ropes will be considerably lengthened and probably many accidents averted which
are liable to occur by a short release and sudden check of a rope stretched a long
distance and its falling weight causing a momentum which throws a greater stress
upon it than the steady load it may have to pull.
Although the invention is shewn as applied to a double barrelled crab or winch
it is to be understood that the invention is also applicable to capstans working
vertically.
This invention is not confined to the form of the crab illustrated nor to the other
ordinary details; for instance, the usual ratchet and pawl is not shewn but will of
course be provided where it is required in lifting crabs.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
:-
1. In hauling or lifting apparatus two grooved barrels adapted to be used
simultaneously by the same rope or chain either one or both barrel or barrels being
driven by the motive power and the ropes running parallel or crossed substantially
as hereinbefore described and illustrated in the accompanying drawing.
2. In hauling or lifting apparatus of the kind herein before described the arrange-
ment of clutches or other similar means for changing the speed of the rope
substantially as described by reference to Figures 5 and 6 of the accompanying
drawing.
3. The manufacture and use of the improved crabs or winches hereinbefore
described and illustrated in the accompanying drawing.
Dated this 30th day of March 1894.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.