Year: 1895

page_text: Date of Application, 21st Feb., 1895
Complete Specification Left, 21st Nov., 1895-Accepted, 21st Dec., 1895
FREDERICK EDWARDS 62 Bishopsgate Street Within London, E.C. do hereby
declare the nature of this invention to be as follows:-
―:
My invention consists in improvements in derricks; in order to facilitate lifting
& moving heavy weights.
For derricks such as are commonly used on board steamers, I fit a crosstree on
the mast and connect the spans to it; the crosstree is of special construction,
having the following features, very strong to take heavy loads-able to resist heavy
twisting or torsional stresses.
The points to which the spans are attached, may, when required, stand a long
way out from the mast-the points to which the spans are attached may be placed
in any position relatively to the heel of the derrick; thus enabling the best position
to be used.
Two (or more if desired) places are provided on the crosstree for each derrick;
enabling the derrick to be supported from any one of them; each giving the
derrick a natural tendency to hang in a position due to the position of the point
from which it is suspended.
Another feature of my invention consists in making the derrick, after having
lifted a weight, work automatically from one position to another; and then, after
having lowered the weight, work automatically back again to it's first position,
ready to lift another weight, when the operation is again repeated: to carry this into
effect, I fit the derrick with two spans, each span leading to the position or point
of suspension, which will make the derrick move to one of the two positions required
when working; but, instead of connecting each of the spans, to their relative
positions of suspension, I pass them through a pulley block and lead them down to
the heel of the derrick; the blocks through which they pass being connected to
the positions before referred to, instead of the spans themselves.
One of the spans has its lower end, at the heel of the derrick, connected to a
fixed eye-bolt or other fitting placed specially to receive it; this is the span
which supports the derrick when there is no load on it, and consequently the
derrick swings into the position due to it's point of suspension; that is, it hangs
over the weight that has to be lifted. The other span has it's lower end, at the
heel of the derrick, passed through a block and is then connected to the ordinary
block or pulley now in general use at the heel of each derrick-in other words
the leading block through which the derrick chain works.
When a weight is lifted with the derrick, the leading block, owing to it's position,
has a load upon it amounting to nearly double that of the weight on the derrick;
consequently this load comes on the last mentioned span; and this span at once
commences to lift the derrick from the other point of suspension, and would go on
doing so, but as this is not required, I fit a stop to the leading block, which
allows it to travel sufficiently to take the weight of the derrick and no more:
consequently when the weight of the derrick is supported by the last mentioned
span, the derrick has a natural tendency to move to the other position due to
the change in the point from which it. is suspended; and this tendency remains
until the derrick is relieved of the weight. When the weight is taken off the
derrick, the weight of the derrick once more comes on the first span, and the
derrick moves back to its original position ready to lift another weight.

page_text: By changing the positions of the lower ends of the spans at the heel of the
derrick, the whole action is reversed; by which means the derricks can be used
to work either way; that is to say, move the weights either way, as in the case
of a steamer, to move them in or to move them out, such as loading and unloading.
21st February 1895.
G. E. WORTHINGTON,
For Fred. Edwards.
Improvements in Derricks.
I, FREDERICK EDWARDS of 62 Bishopsgate Street Within, in the City of
London, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
My invention has reference, to improvements, in that kind of apparatus known as
derricks comprising what is called à boom or derrick pivoted at its lower end or
heel chain or rope called a span whereby the boom or derrick is supported at its
upper end or head and suitable tackle for raising and lowering weights, and my
improvements in such apparatus have for their object to facilitate the lifting and
moving of heavy weights.
'In derricks such as are commonly used on board steamers, I fit a crosstree on the
mast and connect the spans to it; the crosstree is of special construction, being
very strong to take heavy loads and able to resist heavy twisting or torsional
stresses.
The points to which the spans are attached may, when required, stand a long way
out from the mast; also the said points may be placed in any position relatively to
the heel of the boom or derrick thus enabling the best position to be used.
Two
(or more if desired) places are provided on the crosstree for each boom or derrick
enabling the latter to be supported from either or any one of them.; each giving the
boom or derrick a natural tendency to hang in a position due to the position of
the point from which it is suspended, or, in other words, a tendency to assume.a
position corresponding to that of the point of suspension for the time being.
Another feature of my invention consists in making the boom or derrick, after
having lifted a weight, work automatically from one position to another; and then,
after having lowered the weight, work automatically back again to its first position,
ready to lift another weight, when the operation is again repeated.
In the accompanying illustrative drawings,
Fig. 1 represents in side elevation so much of a double derrick according to my
invention as is needful to a description thereof, one of the booms or derricks and its
gear being omitted and a crosstree being shewn which would support + booms or
derricks. In this view the boom or derrick D.is represented as being supported by
the two spans S S² hereinafter more particularly referred to.
Fig. 2 is an elevation of the mast and crosstree at right angles to Fig. 1.
Fig. 3 is a plan with the crosstree shown and some parts omitted. In this view
the boom or derrick is represented in the position it occupies when supported, as
mentioned with reference to Fig...
Fig. 4 is another plan with the crosstree and some other parts omitted but
showing some parts not represented in Fig. 3.
Fig. 5 is a detail view to a larger scale.
Figs. 6 and 7 are views corresponding to Figs. 1 and 3 but shewing the boom or
derrick shifted to one side by a pull on the span S2.
According to the arrangement illustrated, I fit the boom or derrick D with two
spans, S, S² respectively, each span leading to the position or point of suspension,

page_text: which will make the derrick move to one of the two extreme positions required
when working, S being supported at P and S2 at P2; but instead of connecting
each of the spans itself to its respective point of suspension P or P³ I pass it
through a pulley block, span S through pulley block B, and span S' through
pulley block B2 and I connect pulley block B to 'the crosstree at P.and pulley
block B3 at P'.
Span S has its lower end connected to a fixed eye-bolt E or other fitting placed
specially to receive it; this is the span which supports the boom. or. derrick D when
there is no load on it and the clamp or compressor hereinafter mentioned is not in
use. When the boom or derrick is so supported it assumes the position due to P
being the point of suspension for the time being, that is, it hangs over the weight
that has to be lifted. The other span S has its lower end passed through the
block B and is then connected to the ordinary block or pulley L B now in general
use at the heel of each derrick; in other words, the "leading block" through
which the derrick chain works.
When the weight is lifted with the derrick, the leading block, owing to its
position, has a load upon it amounting to nearly double that of the weight on the
boom or derrick D; consequently this load comes on the span S2 and this span
would at once commence to lift the boom or derrick D from the other point of
suspension P², and would go on doing so, but, as this is not required, I provide a
stop X which allows the leading block to travel sufficiently to cause span S² to
take the weight of the derrick in any required position and no more.
When the weight of the boom or derrick D is supported by the span S2 the boom
or derrick D has a natural tendency to move to the other position due to the change
in the point from which it is suspended (P2) and this tendency remains until the
boom or derrick is relieved of the weight, when the boom or derrick once more
comes on the first span S and moves back to its original position ready to lift
another weight.
In order to prevent the boom or derrick from working automatically from one
position to another until after it has lifted the weight or the derrick chain
sufficiently to clear the coamings and bulwarks I provide a clamp or compressor Y
through which the span S² is passed. As will be seen on reference to Fig. 5 the
clamp or compressor comprises two jaws y y¹ pivoted at their lower ends; a stirrup y²
hinged to y encircles the upper ends of the jaws and is provided with a screw
spindle y by means of which the jaws can be caused to clamp or compress the
span S², thereby holding the same and preventing the raising or lowering of
the boom or derrick and its consequent lateral movement from one position to
another.
By changing the positions of the lower ends of the spans at the heel of the
derrick, the whole action is reversed, by which means the derricks can be arranged
to work either way; that is to say, to move the weight either way, as, in the case
of a steamer, to move them in as in loading, or out, as in unloading.
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. Providing the boom or derrick with two spans leading to separate points of
suspension, such as pulley blocks carried by a cross tree, so arranged that by a pull
on the span located at that side at which it is required to lower the weight
suspended to the boom or derrick it will be moved to that side.
2. A derrick comprising a boom or derrick, a cross tree, suitable spans connected
to the boom or derrick and passing through supporting devices, such as pulley
blocks which are carried by the crosstree, at opposite sides of the vertical plane
which contains the longitudinal axis of the boon or derrick when in the position
represented in Fig. 3 of the drawings, and means for causing a pull to be exerted
upon the span located at that side towards which it is desired to move the boom or
derrick.

page_text: 3. In a derrick providing the boom or derrick (D) with spans having different
points of support and so arranged in connection with the chain or rope to which the
load is suspended that by the load the suspension of the boom or derrick can be
shifted from one point of support to another, substantially as described.
4. A derrick comprising a boom or derrick (D) and means for supporting or
suspending it in such a manner that, after a weight has been lifted, the said boom
or derrick will be in an automatic manner shifted laterally from one position to
another and, after the weight has been lowered, the boom or derrick will be in an
automatic manner returned to its first position in readiness to lift another weight.
5. My improved derrick as described and shown.
Dated this 20th November 1895.
FRED. EDWARDS.
W. Lloyd Wise,
46 Lincoln's Inn Fields, W.C., Chartered Patent Agent.