AU427098B2 - Improvements relating to liquid transfer apparatus - Google Patents

Description

241 3 0 1 This invention relates.to liquid transfer apparatus,

particularly for transferring liquid between two

containers whose positions relative to one another are

variable, e.g. between a ship moored at a jetty and a

tank on shore.

Apparatus for this purpose is known which comprises

a rigid tubular jib defining a first liquid flow tube

and which is pivotally mounted at or adjacent its inner

end on a suitable fixed support for rotation about a

first horizontal axis, and a rigid tubular drop arm

pivotally mounted at or adjacent the outer end of the

jib for rotation about a second horizontal axis parallel to

the first axis and defining a second liquid flow tube

connected to the first tube, the said first and second

tubes being connectible to the respective containers

between which transfer of liquid is to be effected, and

suitable counterweight means being mounted on an

extension of the inner end of the jib to balance the jib

and the drop arm about the pivotal mounting of the jib

on the support. In such an apparatus the balance of the

parts will be upset when the drop arm is pivoted away from

its position relative to the jib in which the jib and drop

arm are balanced by the said counterweight means (which

position is usually one in which the drop arm hangs

vertically) and it has therefore been proposed to provide

427. 098

24,130 71 secondary counterweight means movably mounted in the

region of the said support for balancing the drop arm about its pivotal connection to the jib, such secondary

counterweight means being connected to the drop arm via an articulated linkage so as to follow the movements of the drop arm relative to the jib. In this manner balance of the whole apparatus is achieved with the movable parts in any of their possible relative positions, but only with the apparatus either dry or wet and not in both of such conditions. In other words, if the apparatus is

fully balanced when dry, when the jib and drop arm are. filled with liquid during operation the balance of the movable parts about the support and in particular the balance of the drop arm about its pivotal connection with the jib will be upset. This is a serious problem, particularly when the apparatus is of a size suitable for .use in loading and unloading the oil storage tanks of very large ships such as so-called "supertankers" as any substantial imbalance will then be liable to throw large stresses on the jib support and upon fittings on a ship) to which the outer end of the drop arm is connected. We have now discovered that the problem of balancing the drop arm about its pivotal connection with the jib both when the apparatus is dry and when it contains liquid may be reduced or even substantially obviated by

427.098

24,13 017 arranging for the liquid in the apparatus to contribute to

such balance, and the manner in which we achieve this is

by directing the liquid to flow via an articulated

linkage which is pivotally movable with the drop arm

relative to the jib and which linkage is arranged at least

partially to balance the drop arm about its pivotal

connection to the jib. More specifically, comparing an

apparatus according to the present invention with a known

apparatus in which the liquid flowed along the jib itself

and the drop arm was connected to the inner end of the

jib via a three-sided articulated linkage which substantially

defined a parallelogram in conjunction with the jib,

application of the present invention to that apparatus.

involves leading the liquid around the said three-sided

linkage instead of along the jib.

Thus viewed from one aspect the invention provides

liquid transfer apparatus comprising a rigid jib pivotally

mounted on a support for rotation about a first horizontal

axis, a rigid drop arm pivotally connected to the jib

at or adjacent the outer end of the latter for rotation

about a second horizontal axis parallel to said first axis,

said drop arm constituting or carrying a liquid flow tube

connectible to a first liquid container, counterbalancing

means connected to the jib-and arranged at least partially

to balance the movable parts of the apparatus about said

2 7 098

241 30/71 first axis, a three-sided articulated linkage pivotally

mounted to extend between the regions of said first and

second axes and having one of its linkage elements

constituted by an extension of the drop arm, the elements-

of said linkage being movable with the drop arm relative

to the jib and being arranged at least partially to

balance the drop arm about said second axis, and said

linkage elements constituting or carrying a liquid flow

conduit whose outer end is connected to the said liquid

flow tube of the drop arm and whose inner end is

connectible to a second liquid container, whereby liquid

present in said conduit in operation contributes to the

balancing of the drop arm about the said second axis.

In such an arrangement the pivotal axis at one end of

the said three-sided linkage will be the said second axis,

i.e. that about which the drop arm pivots relative to

the )ib. The pivotal axis at the other end of the said

linkage, i.e. in the region of the said first axis,

may as-in a-preferred embodiment coincide with the

said first axis in which case, if the inner and outer

elements of the three-sided linkage are of the same length,

a parallelogram linkage will be formed by the combination

of the three-sided linkage and the part of the jib between

the said first and second axes. It is not essential,

however, that the inner pivotal axis of the said three-sided

427. 098

9 coincide, as the linkage and the said f ir~ ilould

inner element of the three-sided linkage could be pivotally

connected to the jib either inwardly or outwardly of the

said first axis, or indeed above the latter on support

means extending laterally from the jib is desired.

Preferably the inner and outer elements of the said three-

sided linkage are of substantially equal length between

their pivotal connections so that the medial element

extends substantially parallel to the jib but laterally

spaced from the latter.

In some embodiments of the invention the said three-

sided linkage may be such as substantially wholly to balance

the drop arm about the said second axis without the use

of any further counterbalancing means. The major part

of the counterbalance provided by the said linkage in such

circumstances is provided by the medial element thereof

and is dependant on the weight of that element and its

lateral spacing from the jib, which spacing must be

limited if the apparatus is not to become unwieldy.

Balance of the drop arm about the second axis may thus be

achieved by way of the said three-sided linkage alone if the iiikagehil~ iti,-ai-p-rticularly the medial one,

are substantially heavier than the drop arm, e.g. if such

elements are of steel and the drop arm of aluminium

alloy. If, on the other hand, the drop arm is of steel

427. 098

24,1 30,71 it will usually be necessary to add secondary counter-

balancing means to the said three-sided linkage, and such

counterbalancing means may most conveniently comprise

counterweights mounted so as to be situated close to the

said first axis and thus not to have any undesirably

large effect on the balance of all of the movable parts

of the apparatus about the said first axis in opposition

to the aforementioned counterbalancing means connected

to the jib. Secondary counterbalancing means associated'

with the said linkage may, indeed, positively contribute

to the balance of the apparatus about the jib if mounted

so as to be on the inward side of the said first axis when

the drop arm is hanging vertically, and in these circum-

stances the counterbalancing means connected to the jib

need only partially balance the movable parts of the

apparatus about the said first axis.

The elements of the said three-sided linkage could

if desired carry separate and interconnected tubes making

up the -said liquid flow conduit. Preferably, however,

the linkage elements themselves are tubular and are liquid-

tightly interconnected to define the said conduit, whilst

the outer one of the three linkage elements forms an

integral tubular extension of the drop arm. If it is

desired to achieve substantially the same degree of balance

of the drop arm about the said second axis both when the 2r 'ij

24,13 071 apparatus is dry and when liquid is flowing therein by

means of the three-sided linkage alone, i.e. without

any secondary counterbalancing means, all of the tubular

elements of the linkage, together with the drop arm,

will preferably be of the same internal cross-sectional

area assuming the tubes to be made of the same metal

and of the same wall thickness) so that all of their

weights will increase in the same proportion when

liquid is flowing in them. The features of the apparatus of the invention as so

far discussed are such as to achieve at least partial

balance of the drop arm about the said second axis both

when the apparatus is dry and when liquid is flowing

therein. It will be appreciated, however, that in the

apparatus as so far described, balance of all of the

movable parts about the said first axis is only achieved

when the apparatus is either wet or dry, but not in both

of such conditions. Thus if the first mentioned counter-.

balancing means connected to the jib (and the secondary

counterbalancing means if it is arranged to contribute to

427. 098

24130 P, the balance about the said first axis as previously

parts about mentioned) is arranged to balance the movable the balance the said first axis when the apparatus is dry, is filled about such axis will be lost when the apparatus

with liquid, and vice versa. We have also discovered

overcome that this disadvantage can be at least partially

in a very economical fashion by making the jib tubular

and balancing the apparatus about the saia first axis e.g. with the jib tube at least partially full of liquid,

water, but with the apparatus otherwise dry; then, when

the liquid flow conduits of the apparatus are being

filled with liquid at the beginning of a transfer operation,

sufficient liquid may be removed from the tubular jib

to substantially maintain the balance about the first

axis. Thus in a preferred embodiment of the invention the

said. jib is at least partially of tubular construction

.to provide a tubular chamber for containing liquid,

which chamber is provided with means for enabling the

quantity of liquid therein to be adjusted. A jib

constructed in this manner thus provides a variable

counterweight, and does so in a very economical fashion

because all that is required is to use a liquid-tight

tubular member, e.g. a box-section or circular-cylindrical

girder, to form the jib and to provide it with liquid

inlet and outlet means connectible to a suitable pump.

"42'i. 09 8

24,1 3 07 Water is a readily available commodity in the usual

anticipated circumstances of use of apparatus according

to the invention, i.e. on a jetty.

Apparatus according to the invention may, as is

conventional, incorporate a conduit for the flow of

gas or vapour out of a container, e.g. a ship's tank, to

which liquid is being transferred in operation, such a

provision being of particular importance when such vapour

is inflammable and/or poisonous and cannot therefore

be allowed to escape to atmosphere. Such a conduit may be

of a flexible nature, mounted to run along the drop arm

and the jib. However, if the jib is of tubular

construction and is not to be used as a variable counter-

weight in the manner described above it may very

conveniently, in accordance with a further feature of the

invention, be used as part of such a gas or vapour conduit.

The inner end of the said liquid flow conduit around

the three-sided linkage of the apparatus is, as already

mentioned, connectible to a second one of two containers

between which liquidis to be transferred in operation.

This provision could simply take the form of one element

of a liquid-tight connecting means provided at the inner

end of such conduit-for connection to such a container,

e.g. via a flexible hose. Preferably, however, the

support upon which the jib is mounted incorporates a

427 098

2!,l 3 0/71 liquid flow tube extending between a base region of the

support (where it is connectible to such a container via

a hose or other conduit means) and the region of the said

first axis, at which region such tube is liquid-tightly

connected to the inner end of the said liquid flow

conduit,

Preferably the said support is so arranged as to be

compensated against thermal expansion and contraction of

the said liquid flow tube in operation. In a preferred

embodiment the said support comprises one or more elongate

support members extending longitudinally of the said liquid

flow tube and connected thereto at regions spaced length-

wise of the tube, the or each said support member being

formed to define a liquid flow conduit connected into the

said liquid flow tube at its opposite ends.

Thus, in operation, liquid being transferred will

flow through the or each said support member as well as

through the said liquid flow tube and differential thermal

expansion between the tube and the support member(s) is

thus substantially obviated.

Preferably, as is conventional in liquid transfer

apparatus of the general kind with which the invention

is concerned, the whole apparatus is mounted on its

said support for rotation about a vertical axis, whilst

.auniversally adjustable connector assembly is provided

-11- 427. 098

24.130O,71 as to provide at the outer end of the-drop arm, such the body of three degrees of rotary freedom between a ship, with which* the drop-arm and a fitting, e.g. on operation. said connector assembly is engaged in readily In order that the invention may be more now be described understood one embodiment thereof will accompanying by 'way of example and with reference to the

drawings, in which:- liquid Figure 1 is a view in side elevation of a invention; transfer apparatus according to the transfer Figure 2 is a plan view of the liquid

apparatus; view on the Figure 3 is a vertical cross-section~al

line 111-111 of Figure 1;- from the right- Figure 4 is an end elevation as seen

hand side of Figure 1; showing the Figures 5 and 6. are diagrammatic views from that shown in apparatus ini two positions different

Figures 1 to 4; to the balance Figures 7 and 8 are diagrams relating about its pivotal of the drop arm of the apparatus

connection of the jib; and-

balance of all Figure 9 is a diagram relating to the about the main of the movable parts of the apparatus

support thereof.

24,13 Referring to Figures 1 to 4, the apparatus comprises

a support in the form of a standpost 1 including a vertical

liquid flow tube 2, which standpost will in operation be

rigidly connected to a suitable ground point, for example

a jetty when the apparatus is to be used for transferring

liquid between a storage tank on a ship and a storage

container on land. The standpost 1 is constructed to be

substantially free from differential expansion of its

parts in operation, by the adaptation of its four support

members 3 to define four subsidiary liquid flow tubes

surrounding the tube 2 and of smaller diameter than the

latter. The subsidiary flow tubes are connected into the

main tube 2 at their bottom and top ends 4 and 5 for flow

of liquid therethrough.

The apparatus incorporates a number of liquid-tight

swivel joints interconnecting the various liquid flow

tubes thereof and the first of such joints, indicated at 6,

is at the top of the liquid flow tube 2 of the standpost 1

and permits the rotation of the whole apparatus about

the vertical axis of the standpost. The swivel joint 6

could alternatively be positioned at the base of the

standpost in which case the whole standpost would be free

to rotate about its vertical axis; such an arrangement

is preferred when the apparatus is to be remotely controlled

from a suitable power source.

-13- 427 098

244 30171 After the first swivel joint 4 at the top of the

st and post 1, the liquid flow line turns through 90' via

an elbow 7, and at this point a second swivel joint 8 is

positioned. The axis of rotation A of the swivel joint

8 is horizontal and this axis is the "first horizontal

axis" previously referred to herein.

At this region two 1-section arms 9 adapted to mount

counterweights 10 are pivotally mounted fJr rotation about

the axis A, one of the arms 9 being bolted to a flange

of a rotatable sleeve mounted adjacent the swi vel joint-8

and the other arm 9 being mounted on a bearing carried-

by a horizontal cross shaft 11 secured to the elbow 7.

At their forward ends the arms 9 are secured to, and

support between themselves, a jib.12 in the form of a box-

section girder which extends rearwardly into close

proximity to the elbow 7. Thus both the jib 12 and the

counterweights 10 are mounted via the arms 9 to rotate

in concert about the axis 4.

A tubular drop arm 13 defining a liquid flow tube is

pivotally mounted at the outer end of the jib 12 by means

of a pair of bushes 14 one on each side of the drop arm

so that the latter is rotatable relative to the jib 12 about

a horizontal axis B which is the "second horizontal axis"

previously referred to herein. An integral tubular

extension 15 of the drop arm 13 extends above the connection

09 -4-42-1 8

.24,130,71 of the latter to the jib 12.

The extension 15 of the drop arm 13 constitutes the

outer element of a three-sided linkage pivotally mounted to

extend between the first and second horizontal axes A and

B of the apparatus. All of the three elements of such

linkage are in the form of liquid flow tubes which are

liquid-tightly interconnected at the pivotal connections

between such elements and thus constitute a liquid flow

conduit extending between the regions of the first and

second horizontal axes A and B. The inner element of

the said three-sided linkage is constituted by a tube 16

connected at its inner end to the aforementioned swivel

joint 8 so as to rotate about the first horizontal axis

A and at its outer end to a third swivel joint 17 of the

apparatus which latter joint is again rotatable about,a

horizontal axis parallel to the axes A and B. The medial

element of the three-sided linkage comprises a liquid-

flow tube 18 extending from the swivel joint 17 to a

fourth swivel joint 19 where it is connected to the drop

arm extension 15 for rotation about a horizontal axis

parallel to those already mentioned.

A connector assembly 20 is provided at the bottom

end of the drop arm 13, incorporating three further swivel

joints 21, 22 and 23 and terminating in a connector 24

for connection with a liquid container, e.g. to a storage

427. 098

24,130 /7 tank of a ship via a fitting on the deck when the transfer

apparatus is mounted on a jetty. The three swivel joints

21, 22 and 23 of the connector assembly 20 provide the

three degrees of rotary freedom necessary for universal

adjustability of the body of the drop arm 13 relative to a

fitting with which the connector 20 is engaged in operation.

It will be noted that the length of the medial tube

18 of the three-sided linkage is substantially the same

as the length of the jib 12 between the first and second

horizontal axes A and B, and that the tube 16 and the

drop arm extension 15 are of substantially the same

length and are substantially parallel with one another.

Thus the three elements 16, 18 and 15 of the linkage

constitute a parallel motion assembly whereby, upon pivotal

movement of the drop arm 13 relative to the jib about

the second horizontal axis B, the medial tube 18 of the

linkage is maintained in parallelism with the jib. Thus

the three elements of the three-sided linkage together

with the jib constitute a parallelogram linkage.

In some forms of the invention balancing of the drop

arm 13 about the second horizontal axis B is achieved

entirely by means of the three-sided linkage described

above, and balance of all of the movable parts of the

apparatus about the first horizontal axis A is achieved

by means of the counterweights 11 on the arms 10 which

-16- 427. 098

2W43 027' arms constitute, in effect, an extens ion of the jib

inwardly of the first horizontal axis. If, however, the

relative weights of the tubes constituting the three-

sided linkage and the drop arm are such that balance of

the drop arm about the axis B cannot be achieved by means

of the linkage elements alone, i.e. if the drop arm is

too heavy to be balanced by the linkage, secondary

counterbalancing means must be associated with the linkage,

and this is the case in the illustrated embodiment of the

invention. Thus in the illustrated apparatus secondary

counterweights 25 are mounted on an arm 26 forming a

rearward extension of the tube 18 and, in use of the

apparatus, are adjusted to provide the necessary assistance

in balancing the drop arm about the axis B. In the

illustrated arrangement, as the counterweights 25 are

situated rearwardly of the axis A when the drop arm is

hanging vertically, they will also contribute to the balance

of all of the miovable parts of the apparatus about the

axis A:

The tube 16 of the three-sided linkage is reinforced

by an arm 27 pivotally mounted at its lower end for

rotation about the first horizontal axis A and connected

near to its upper end by a transverse connecting member 28

to a bearing coaxial with the swivel joint 17, so that the

arm 27 will rotate about the first horizontal axis A in

427. 098

24,130171 concert with the inner tubular element 16 of the linkage.

The secondary counterweights 25 are so positioned as

to enable the whole apparatus to be turned over "on its

back" about the first horizontal axis A, to a position

illustrated in Figure 6, so that joint 19 and the pivotal

connection between the drop arm 13 and the jib 12 are

brought near to the ground rearwardly of the standpost 1,

without the counterweights 25 fouling the'standpost;

this facility is of advantage when it is desired to

service or repair those parts of the apparatus in the

region of the connection between the drop arm and the jib.

Figure 5 shows the apparatus in its "parked" position

in which it will usually be placed when not in use.

The arrangement in the above illustrated apparatus

whereby the path of liquid flow between the enb of the

jib is around the three-sided linkage embodies an

important advantage,not previously mentioned, over earlier

proposals in which the liquid flow between the jib ends

was via a tube rigidly secured along the jib. With such

earlier proposals difficulties-were encountered due to

differential expansion of the jib and the liquid flow tube

which it carried, as a result of the temperature

differential brought about between such members when liquid

was flowing in the tube. This difficulty is avoided by the

present arrangement in which the liquid flow between the

-18- .427, 098

241 3 0171 ends of the jib is not via a tube rigidly connected to

the latter.

The principal advantage of the present arrangement,

however, is that the balance of the drop arm about its

pivotal connection to the outer end of the jib, assuming

such balance to be achieved when the apparatus is dry, is

not greatly upset when liquid is flowing through the

various tubes. The reason for this is that such liquid

flows in the elements of the three-sided linkage which

partly balance the drop arm about its pivotal mounting

so that, although the drop arm of course becomes heavier

when liquid is flowing through it, so do those elements

which partly counterbalance it. In apparatus where it is

possible to omit the secondary counterweights

substantially the same degree of balance can be achieved

when the apparatus is respectively wet and dry, so long

as the arrangement is such that the increase.in weight of

each of the tubes 16, 18 and 15 and of the drop arm 13,

upon being filled with liquid, is in the same proportion.

Assuming that all of these tubes are of the same metal

and wall thickness, this effect can clearly be achieved

by making them all of the same internal cross-sectional

area.

There remains the problem of maintaining the balance

of the whole apparatus about the axis A, both when wet

and when dry, and this problem is overcome to at least

a substantial extent in the illustrated embodiment of the

-19- 427 098 present invention. 2413 0/71 Thus the jib 12, which it will be recalled comprises a box-section girder, is closed at its opposite ends so as to form a tubular liquid-tight chamber and-is provided with an inlet/outlet fitting (not shown) for connection to a pump for pumping liquid into and out of such chamber whereby the quantity of liiiii in the chamber at any time may be selectively adjusted. This problem enables the whole'apparatus to be substantially balanced about the axis A, both when wet and when-dry, in the following manner. When the apparatus is to be put to use, but before any liquid which is to be transferred is introduced into it, the jib tube is filled with liqiild and any necessary adjustment is made to the main counterweights 10 to balance the apparatus about the axis A; the apparatus is thus balanced dry.' The liquid to be transferred is then introduced gradually 'intd the liquid flow line through the apparatus, thus- tending to upset the balance about axis A, but at the same time liquid is pumped out of the tubular jib so as substantially to maintain the balance, until the liquid- flow line is full. It will be noted that this facility for ubstntially maintaining the balance about the axis A is achieved'at very low cost, simply by making the tubular jib liquid-tight and providing it with a liquid inlet/outlet fitting.

427, o9

2413 0171 The apparatus incorporates a gas and vapour return

line in the form of a flexible pipe 29 ectending from the

outer end of the drop arm 13 to the base of the standpost

1 for the flow of poisonous or inflammable gas or vapour

out of a tank, e.g. a ship's tank, which is being filled

via the apparatus. In the illustrated apparatus, in which

the tubular jib is used for balancing purposes about the

axis A as just described, the pipe 29 is run alongside the

jib. However, if the jib is not to be used for balancing

in the manner just described, it can be employed as part

of the gas and vapour return line, with a substantial

saving in cost in that the length of the flexible tube

29 between the ends of the jib will then be omitted.

It will thus be seen that liquid transfer apparatus

may be provided in accordance with the invention in which,

in addition to being substantially fully balanced when .dry, the balance both of the drop arm about its pivotal

connection to the jib and of the whole apparatus about its support is maintained at least to a substantial extent when liquid is flowing through the apparatus, thus reducing stresses on the support and on fittings, e.g. on a ship,,to which the drop arm is connected in operation. Also the fact that the jib carries all of the major loads such as weight and wind pressures means that the proper function of the pipe-work in carrying the liquid flow is

-21- 427. 098

2413017, not interferred with; tI iu the liquid carrying pipe-

work, being relieved of major loads and thermal stresses,

can be designed almost entirely on the basis of its

liquid-carrying function. Furthermore, the fact that

the loads on the swivel joints in the liquid flow path

are substantial ly lower than in known apparatus leads to

a considerable increase in safety of operation.

Finally, the manner in which balance of the drop

arm about the axis B and of the whole apparatus about the

axis A is achieved will be explained mathematically with

the aid of the diagrams of Figures 5 to 7. In-these

diagrams:-

*Irepresents the weight of counterweights

*2represents the weight of counterweights

*W 3 represents the weight of element 16;

W4 represents the weight of element 18;.

W5 represents the weight of elements 13 and 15;

and W6 represents the weight of the jib 12.

The indicated weights of the parts mentioned above

of course refer to the total weights of those parts and

any ancillary equipment movable therewith; for example

W 3 includes the weight of the-arm 27 and W

the weight of the connector assembly 20. The lengths

of the various elements are indicated by appropriate

symbols in the diagrams and the distances from the various

-22- 4240.

2 1 3 Op7 pivot points at which the various weights may be regarded

as acting are also indicated.

Referring first to the balance of the drop arm about

axis B with reference to Figures 7 and 8, with the jib

horizontal and the other parts of the apparatus in a

position defined by the angle P the reactions due to the

loads are as follows:-

X sin3[W3 x 3 (L x4 W2 (L x2 -I-R cosp

Y sinp[Wx 5 .w W2 2 cos

For equilbrium X Y, so:-

sinP[w3 3 R (L x4) w(L x2) J =sinp[W 5 w{w 2

Dividing by sinp, multiplying by R cosp, and adding

gives:-

W.R W5 W4R (1) It can thus be seen that, for the illustrated system,

balance of the drop arm about the axis B is independent

of the angle and therefore such balance can be achieved

if the unit loads and the centres of gravity of such

loads satisfy the equation

Referring now to the primary balance of all of the

movable parts of the apparatus about the first horizontal

axis A with reference to Figure 9, for such balance to be

S achieved the moments about the axis A must be zero.

S Thus, taking moments about axis A

S-23- 427 098

24,13 017. W 6 x6 cosa W x lcosa W5 L cosa x 5sin(a P)J

W4 x 4 cosa Rsin(a p)J- W33 sin (a P) W2 Rsin(a 3) x2 cosa 0

But W2R W5x 5 W4R W3x3 from (1)

So W 6 x 6 cosa W 1 x1 cosa WSLcosm

Wxcosa W 2 x 2 cosa 0

which gives.

W1 W6 x6 W5 L W4 W2 (2)

It can thus be seen that, for the illustrated system,

balance of the moving parts of the apparatus about

the axis A is independent of the angles a and P, and

therefore that primary balance can be achieved if the.

loads and the centres of gravity of such loads satisfy

the above equation

-24- 427. 098

22443 0171 THE CLAIMS DE~FlIIG THE INVENTIOfl ARE AS FOLLOWS-:

jib 1. Liquid transfer apparatus comprising a rigid about a first pivotally mounted on a support for rotation connected to horizontal axis, a rigid drop arm pivotally for the jib at or adjacent the outer end of the latter to said Srotation about a second horizontal axis parallel a first axis, said drop arm constituting or carrying container, liquid flow tube connectible to a first lfquid arranged counterbalancing means connected to the jib and the at least partially to balance the movable parts of

apparatus about said.first axis, a three-sided articulated regions linkage pivotally mounted to extend between the

of said first and second axes and having one of its drop linkage elements constituted by an extension of the with the- arm, the elements of said linkage being movable least drop arm relative to the jib and being arranged at

partially to balance the drop arm about .said second axis, liquid and said linkage elements constituting or carrying a

flow conduit whose outer end is connected to the said is liquid flow tube of the drop armand whose inner end

connectible to a second liquid container, whereby liquid

present in said conduit in operation contributes to the balancing of the drop arm about the said second axis.

4_7 09

Claims (1)

1. 241i3 o 2. Apparatus as claimed in claim 1, wherein the pivotal

   axes at the ends of the said three-sided linkage are

   the said first and second axes.

   3. Apparatus as claimed in claim 1 or 2, wherein the

   inner and outer elements of the said three-sided linkage

   are of substantially the same length between their pivotal

   connections.

   4. Apparatus as claimed in any of claims 1 to 3, wherein

   the said three-sided linkage is arranged so as itself

   substantially wholly to balance the drop arm about the

   said second axis.

   Apparatus as claimed in any of claims 1 to 3, wherein

   the said three-sided linkage carries secondary counter-

   balancing means arranged so as, in conjunction with the

   said linkage, substanti'ally wholly to balance the drop

   arm about the said second axis.

   6. Apparatus as claimed in claim 5, wherein the said

   secondary counterbalancing means is mounted adjacent the

   pivotal connection between the inner and medial elements

   of the said three-sided linkage.

   7. Apparatus as claimed in claim 6, wherein the said

   secondary counterbalancing means is mounted so as to be

   on the inward side of the said first axis when the drop

   arm is hanging vertically, so as to contribute to the balancing of the apparatus about the said f irst axis.

   8. Apparatus as claimed in claim 6 or 7, wherein the

   said secondary counterbalancing means is mounted on the

   medial element of the said three-sided linkage.

   9. Apparatus as claimed in any of the preceding claims,

   wherein the th.ree linkage elements of the said three-

   sided linkage are tubular and are liquid-tightly inter-

   connected to def ine the said liquid f low conduit.

   Apparatus as claimed in claim 9, wherein the said

   drop arm constitutes a liquid flow tube and the outer

   element of the said three-sided linkage is a tubular

   continuation of the drop arm.

   11. Apparatus as claimed in any of the preceding claims,

   wherein the. said jib is at least partially of tubular

   construction to provide a tubular chamber f or containing

   liquid, which chamber is provided with means for enabling

   the quantity of liquid therein to be adjusted.

   12. Apparatus- as claimed in claim 11, wherein the said

   tubular chamber is provided with liquid inlet and outlet

   means connectible to a liquid pump.

   13. Apparatus as claimed in claim-11 or 12, wherein the

   said jib comprises a box-section girder closed at its

   ends.

   14. Apparatus as claimed in any of the preceding claims,

   including a liqid-tight conduit extending at least from

   -27- 47 9

   24,113 Ov-' the region of the outer end of the drop arm to the region

   of said first axis, for the flow of gas or vapour out of

   a container to which liquid is to be transferred in use

   of the apparatus."

   Apparatus as claimed in claim 14, except when

   dependent on any of claims 11 to 13, wherein the said jib

   is of tubular fluid-tight construction and constitutes

   part of said gas or vapour conduit.

   16. Apparatus as claimed in any of the preceding claims,

   wherein the said support on which the jib is mounted

   incorporates a substantially rigid liquid flow tube

   extending between a base region of the support and the

   region of the said first axis, at which region such tube

   is liquid-tightly connected to the inner end of the

   said liquid flow conduit.

   17. Apparatus as claimed in claim 16, wherein the said

   support is so arranged as to be compensated against

   thermal expansion and contraction of the said-liquid flow

   tube in operation.

   18. Apparatus as claimed in claim 17, wherein the said

   support comprises one or more elongate support members

   extending-longitudinally of the .said liquid-flow tube and

   connected thereto at regions spaced lengthwise of the

   tube, the or each said support member being formed to

   define a liquid flow conduit connected into the said liquid

   r- flow tube at its opposite ends.

   19. Liquid transfer apparatus substantially as herein-

   before described with reference to the accompanying

   drawings.

   D A T E Dthis 6th day of January, 1971.

   UICO WHEEATON U.K. LIMITED By its Patent Attorneys: CALLIIAN A) VEWTON.

   -29- 427.-098

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