IMPROVEMENTS IN THE METHOD OF WORKING SELF-ACTING GRAPPLE BUCKETS AND FORKS
Year: 1877

page_text: LETTERS PATENT to William Dent Priestman and Samuel Priestman, both of
Kingston-upon-Hull, in the County of York, Engineers, for the Invention of
"IMPROVEMENTS IN THE METHOD OF WORKING SELF-ACTING GRAPPLE
BUCKETS AND FORKS."
Sealed the 21st August 1877, and dated the 6th June 1877.
PROVISIONAL SPECIFICATION left by the said William Dent Priestman and
Samuel Priestman at the Office of the Commissioners of Patents on the 6th
June 1877.
WILLIAM DENT PRIESTMAN and SAMUEL PRIESTMAN, both of Kingston-upon-Hull,
in the County of York, Engineers. "IMPROVEMENTS IN THE METHOD OF WORKING
SELF-ACTING GRAPPLE BUCKETS AND FORKS.'
"
The object of, this Invention is to facilitate. the working of self-acting grapple
buckets or forks, whether such grapple buckets or forks be used with cranes,
winches, or crabs of the ordinary type, as at present in use, or in connection with a
certain double-barrelled crane or.winch, for which we obtained Letters Patent on
29th March 1877, No. 1243.
Self-acting grapple buckets or forks are used for automatically grappling material,
and then elevating it to certain heights and afterwards depositing the material
directly from the dipper to the right or to the left, or any other position that may
be required.
In carrying out this operation two chains or their equivalent are used, one being
the lifting chain and the other the opening or discharging chain, which latter, when
hauled upon, causes the bucket or fork to open and discharge its contents.
This Invention consists in a certain method or arrangement of working the
opening, discharging, or small chain (before referred to in connection with self-acting
grapple buckets or forks), which is carried round sheave blocks adapted for rope or
chain, as the case may be. The sheave blocks are fixed upon the crane, hoist, lift,
or other hoisting mechanism, in manner best suited for the work required, and
which will vary with circumstances. The number and size of sheaves we arrange
in accordance with.the depth to which the grapple bucket or fork is desired to
CD 01

page_text: travel. One sheave or set of sheaves is or are fixed in a sliding frame, to which is
attached a balance weight or weights. A pawl or catch and a break motion is fixed
to the rope or chain, either above the top sheave or set of sheaves, or in any other
place on the rope or chain suitable.
The working of this arrangement may be thus described:-Upon the raising of a
the grapple bucket or fork by the ordinary lifting chain the balance weight fixed
upon the lower sheave frame causes the same to descend, thus keeping the
discharging or small chain tight, the catch gear being so arranged that it grips the
chain or rope at any place where desired. The grapple bucket or fork having been
drawn to the top and the load discharged, the catch is thrown out of gear and the
break brought into action. The grapple bucket or fork is then lowered down and
ready for another lift.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Dent Priestman and Samuel Priestman in the Great Seal
Patent Office on the 3rd December 1877.
•
WILLIAM DENT PRIESTMAN and SAMUEL. PRIESTMAN, both of Kingston-upon-Hull,
in the County of York, Engineers. "IMPROVEMENTS IN THE METHOD OF WORKING
SELF-ACTING GRAPPLE BUCKETS AND FORKS.'
"
The object of this Invention is to facilitate the working of self-acting grapple
buckets or forks, diggers, and excavators, and all working skips, whether such
buckets, forks, or skips be used with cranes, winches, or crabs of the ordinary type,
as at present in use, or in connection with a certain winch or crane, for which we
obtained Letters Patent on 29th March 1877, No. 1243.
Self-acting grapple buckets, forks, or skips, or by whatever other name they may
be designated, are used for automatically filling themselves with and grappling
material, and then, by means of a crane or its equivalent, being elevated to certain
heights, and afterwards depositing the material directly from the bucket, fork, or
skip to the right or left, or any other position that may be required.
In carrying out this operation two chains or their equivalent are used, one being
the lifting chain and the other the opening or discharging chain, so that when the
lifting chain has stopped raising the opening or discharging chain by being hauled
upon, or by being held by a break, and the lifting chain slightly lowered, causes the
bucket, fork, or skip to open and discharge its contents.
This our present Invention consists in a certain method or block-and-break
arrangement for working the opening, discharging, or small chain before referred to
in connection with self-acting grapple buckets, forks, or skips. The said chain.is
carried round sheave blocks adapted for rope or chain, as the case may be. The
sheave blocks are fixed upon or in connection with the crane, hoist, lift, or other
hoisting mechanism, in manner best suited for the work required, and which will
vary with circumstances. The number and size of sheave we arrange in accordance
with the depth to which the grapple bucket, fork, skip, or their equivalent, is
desired to travel. One sheave or set of sheaves is fixed in a sliding frame, to which
is attached a balance weight or weights. A pawl or catch and a break motion is
fixed to the rope or chain, either above the top sheave or set of sheaves, or in any
other place on the rope or chain suitable.
The working of this arrangement may be thus described:-Upon the lifting or

page_text: raising of the grapple bucket, fork, skip, or their equivalent, by the ordinary lifting
chain in connection with a crane or its equivalent, the slack of the opening or
discharging chain is taken in by the balance weight, which is fixed upon the lower
sheave frame, causing the same to descend, thus, keeping the opening or discharging
chain tight. The break gear is so arranged that the opening or discharging chain
or rope can be gripped at any place when desired, and the contents of the bucket,
fork, skip, or their equivalent, discharged by the main or lifting chain being slightly
lowered. After such discharge the break is thrown out of gear and the bucket, fork,
skip, or their equivalent, lowered for another lift.
That our Invention may be clearly understood we have hereunto annexed two
Sheets of Drawings illustrative thereof, marked with letters and figures of reference
corresponding with those in the following explanation. In all the Figures the same
letters of reference, so far as they are applicable to the Figures, indicate the same or
corresponding parts.
Upon reference to the Drawings,-
Figure 1 is a side elevation of a block-and-break arrangement according to our
Invention, as applicable to self-acting buckets, forks, skips, or their equivalent;
Figure 2 is a front view of Figure 1.
Figure 3, Sheet 2, is a side elevation of a steam crane constructed according to our
former Patent, No. 1243, A.D. 1877, with our present Invention of block-and-break
arrangement applied thereto; Figure 4, Sheet 1, is a front view of Figure 3.
Figures 5 and 6 illustrate a self-acting grapple bucket, to the working of which,
or its equivalent, our Invention is particularly applicable.
Upon reference to the Drawings, Figures 1 and 2, it will be seen that a is the
opening, discharging, or small chain before referred to in connection with self-acting
buckets, forks, skips, or their equivalent. The end of the chain a at a¹ is led by
being passed round a sheave or its equivalent, and over the jib of a crane or its
equivalent to the discharging or opening connection or mechanism or attachment of
a self-acting bucket, fork, or skip. The other portion of the chain is led round or
through a break arrangement, such as b, and from thence round the fixed sheaves,
such as c, and the sliding or moving sheaves, such as d, alternately, the chain
eventually being fixed to one or other of the sheave frames, as at c. The sheaves d
are connected by means of the chain ƒ passing round the pulley / to the sliding
weight ki.
A block-and-break arrangement, as illustrated at Figures 1 and 2, may be applied
to the working of the discharging or opening chain of all buckets, forks, skips, or
their equivalent, the operation being that as the bucket, fork, skip, or their equiva-
lent is raised by the main or lifting chain the sliding weight causes the sheaves d
to extend from the sheaves c, and thus take in the slack of the opening, discharging,
or "kecking" chain a. When the required lift and position has been attained the
break is brought into operation by the break lever i, thus holding the chain a, so
that when the inain lifting chain is slightly slacked or lowered the weight is brought
on to the chain a, and thus the bucket, fork, skip, or their equivalent is opened,
discharged, or "kecked." Upon the break being released the bucket or its equivalent
by its superior weight descends and draws the chain a together with the sheaves d
and weight k ready for another lift.
The carrying out of our Invention is further exemplified by Figures 3 and 4.
Upon reference to these Figures it will be seen that a steam crane is illustrated.
This is constructed according to our former Invention and Letters Patent, No. 1243,
A.D. 1877. The barrel A which winds the main or lifting chain B is made to lift
or cant by the hand eccentric lever C, so that the movement or friction wheel D can
be brought into gear and contact with the motion friction pinion E, or with the
break F, as may be required. The opening, discharging, or "kecking" chain may
be referred to in two portions, the portion at as leading over the jib sheave H to the
bucket or its equivalent, and the portion a as leading round the strap break b, and
round the fixed sheaves c and the sliding sheaves & in connection with the weight k,
and working on the side of the boiler N. The handle lever i of the break b thus

page_text: controls the working of the opening, discharging, or "kecking" chain a, a¹, and the
eccentric handle lever C by its connection with the crane barrel A controls the
working of the lifting or raising chain B.
In operation it will be seen that by putting the crane into gear by the handle C,
and at the same time releasing the break 6 by the handle i, the crane lifts the
bucket or its equivalent with its load by means of the chain B, and simultaneously
the weight K takes in the slack of the discharging chain a, a¹. Upon the crane
being thrown out of gear by the bandle C, and the break b being applied by the
handle i to the opening, discharging, or "kecking” chain a, a¹, and the chain B
being slightly slacked by again actuating the lever C, the bucket, fork, or its
equivalent opens, discharges, or "kecks," and is ready to be lowered for another
load, which is effected by releasing both chains.
Having now set forth the nature of our said Invention for improvements in the
method of working grapple buckets and forks, skips, or their equivalent, and shown
a system, mode, or manner in or under which the same is or may be used or
practically carried into effect, we would have it understood that our Invention is
capable of various modifications with regard to the number of sheaves and the
position of the sheaves, the sliding weight, and the position of the weight, the break
mechanism, and the position of the break. We would also have it understood that
our Invention is applicable to the working of all buckets, forks, skips, diggers, or
by whatever name they may be known, that are self-acting, or required to be
opened, discharged, or "kecked." We would also have it understood that our
Invention is applicable to be used in connection with all kinds of cranes, winches,
crabs, or other hoisting mechanism of any type. What we claim as our Invention
and secured to us by the herein-before in part recited Letters Patent is,-
First. The method of working the opening, discharging, or "kecking" chain of
buckets, forks, skips, or their equivalent by the use of sheaves and pulleys in
connection with a weight or weights, and thereby elongating the lift or haul, and a
break for arresting the lift and holding the chain, as herein described and set forth.
Second. The combination and arrangement of sheaves, such as c and d, and a
weight, such as k, for operating an opening or discharging chain, such as a, in
connection with a bucket, fork, skip, or their equivalent, and arrested and held by a
break, such as b, substantially as herein described or set forth and shown in the
Drawings hereto annexed, or any modification thereof.
In witness whereof, we, the said William Dent Priestman and Samuel
Priestman have hereunto set our hands and seals, this Twenty-eighth day
of November, in the year of our Lord One thousand eight hundred and
seventy-seven.
WILLIAM DENT PRIESTMAN. (L.S.)
SAMUEL PRIESTMAN.
(L.S.)