Fluid delivery equipment

Two components, such as a support tube and handset of a herbicide delivery lance, are interconnected in a manner which provides an electrical connection between leads in the tube and the handset respectively. Fluid communication is also provided between a flexible tube in the tube and a passage of the handset. The leads on the tube are connected to two terminal plates situated on the outer surface of the tube. These terminal plates move into positions opposite bosses on a sleeve provided on the handset when the tube is pushed into the sleeve. Screws, engaging bushes accommodated in the bosses, are then screwed into contact with the terminal plates to secure the tube in position. The screws also complete the electrical circuit between the leads. One of the components includes a valve which includes an operating member. Displacement of the operating member against the action of a spring not only opens the valve, but also actuates an electrical switch.

This invention relates to fluid delivery equipment, and particularly, 
although not exclusively, to a coupling for connecting two components 
together in such a way that an electrical connection is made between 
electrical leads carried by the two components. The invention is 
particularly, although not exclusively, concerned with such couplings in 
which fluid passageways in the two components are also connected together 
in a fluid-tight manner. The present invention also relates to a valve 
suitable for use in fluid delivery equipment. 
There exist hand-held lances for delivering herbicide which comprise a 
handset and a delivery head which is connected to the handset by a tubular 
support. The handset is held by the operator, and the tubular support 
enables him to position the delivery head just above the ground to be 
treated. 
In a known form of such a lance, the tubular support accommodates not only 
an internal, flexible tube for conveying the herbicide from the handset to 
the delivery head, but also electrical leads for the supply of power to an 
operating motor contained within the head. The support is manufactured as 
a separate component from the handset, and consequently, in connecting the 
support to the handset, three conditions must be satisfied: firstly, the 
connection must be rigid so that the support and the handset move as a 
unit; second, the connection between the flexible tube and the ducting 
within the handset must be made in a fluid-tight manner; and thirdly, the 
electrical leads must be connected to a source of electrical power. This 
source of electrical power may be a battery housed either in the handset 
or in a backpack carried by the operator. 
In the known lance, the electrical connections are made separately from the 
process of fitting the support to the handset. The connection between the 
support and the handset is made by screwing the support into the handset 
to achieve a fluid-tight seal between the flexible tube and the ducting in 
the handset. This seal is made between surfaces extending transversely of 
the length of the support, and a sealing element in the form of a washer 
may be provided between these surfaces. The electrical leads emerge 
through a hole in the wall of the support for connection to the power 
source. 
According to one aspect of the present invention there is provided a 
coupling between first and second components which are each provided with 
electrical leads and fluid passageways for conveying a liquid, the 
components being telescopically engageable with each other to bring the 
respective fluid passageways into communication with each other, the first 
component being provided with an electrically conductive element to which 
the lead of the first component is connected, the second component also 
having an electrically conductive element, to which the lead of the second 
component is connected, the components being secured together in the 
engaged position by an electrically conductive securing element which 
makes electrical contact with both of the conductive elements thereby to 
connect the leads to each other. 
When the present invention is applied to a lance for delivering herbicide, 
the first component will be the tubular support, while the second 
component will be part of the handset. For example, the second component 
may comprise a valve assembly of the handset. Normally in these 
circumstances, the first component will be made from an electrically 
insulating material, and there will be two leads in each of the 
components. 
The electrically conductive element or elements of the first component may 
be accommodated in recesses in the outer surface of the first component. 
The or each lead will then pass through the wall of the first component 
and be connected, for example by soldering, to the conductive element in 
the recess. 
The conductive element of the second component may comprise a bush, which 
may be internally screwthreaded to receive a screwthreaded fastener 
serving as the securing element. 
Where the coupling is to carry fluids, as, for example, in a herbicide 
lance, the components may have fluid passageways which, when the 
components are engaged together, make fluid-tight contact with each other. 
For example, the passageway in the first component may comprise a tube 
provided with an end fitting which is sealingly received within a bore 
provided at the end of the passageway in the second component. By 
providing the sealing engagement at a longitudinal surface, the need to 
maintain the two components pressed axially together is avoided. The 
second component may be provided with a valve for controlling the flow of 
fluid through the passageways. 
According to another aspect of the present invention, there is provided a 
valve comprising a body having two aligned bores of different diameter, 
and an inlet and an outlet aperture, each opening into a different one of 
the bores, a closure member being provided which is sealingly engageable 
with a transition surface between the bores, the closure member being 
connected to an operating member for displacing the closure member to open 
and close the valve, the valve including an adjustable electrical 
component and the operating member having an operating rod which extends 
from the closure member in a direction away from the transition surface to 
operate the electrical component upon displacement of the operating member 
.

The lance shown in FIG. 1 comprises a handset 2 from which extends a rigid 
support member in the form of a tube 4. The tube 4 carries a delivery head 
6 which accommodates an electric motor (not shown) for driving a 
distribution element 8 in the form of a spinning disc. 
A tube 10 extends from the handset 2 for connection to a container of 
herbicide. The handset 2 is also provided with a valve (not visible in 
FIG. 1) which can be operated by means of a trigger 12. A battery 
providing the source of power for the motor in the head 6 is accommodated 
in the handset 2, and the voltage applied to the motor in the head 6 can 
be controlled, in order to control the speed of the disc 8, by means of a 
control knob 14. 
In use of the equipment shown in FIG. 1, herbicide flows through the tube 
10, the handset 2 and the tube 4 to the head 6. From the head 6, the 
herbicide flows at a metered rate to the spinning disc 8 which discharges 
the herbicide by centrifugal force to form droplets which fall onto the 
ground to be treated. 
FIGS. 2 and 3 represent the region of connection between the tube 4 and the 
handset 2. The handset 2 is represented by a valve 16 which has an 
operating member 18 provided with a head 20 which is acted upon by the 
trigger 12 shown in FIG. 1. The valve has a body 22 from which projects a 
spigot 24 on which the tube 10 is fitted. The body 22 also has an outlet 
connector 26 on which a sleeve 28 is fitted. The inner wall of the sleeve 
28 is provided with a rib 30. 
The sleeve 28 has two outwardly projecting, oppositely disposed, bosses 32. 
Each boss has a central bore 34 in which a bush 36 is accommodated. Each 
bush is made from an electrically conductive material, such as brass, and 
has attached to it a lead 38. The leads 38 are connected at their opposite 
ends to the control device operated by the control knob 14. 
The bushes 36 are internally screwthreaded and receive screws 40. These 
screws 40 extend through an opening 42 in the wall of the sleeve 28 to 
emerge into the interior of the sleeve 28. 
The tube 4 accommodates a flexible inner tube 44, the purpose of which is 
to convey herbicide to the head 6. At the end of the tube 44 shown in FIG. 
2, there is provided an end fitting 46. This fitting 46 has a spigot 48 
which receives the tube 44 and an enlarged head 50 which carries and 
O-ring 52. 
At its end region, the tube 4 has a longitudinal groove 54 which 
corresponds to the rib 30 in the sleeve 28. 
Two leads 56 extend through the interior of the tube 4 from the motor in 
the head 6 to a terminal plate 58. Each terminal plate 58 is accommodated 
in a correspondingly-shaped recess 60 in the outer surface of the tube 4, 
the lead 56 passing through an opening 62. 
In order to connect together the two components, the groove 54 is aligned 
with the rib 30, and the tube 4 is pushed into the sleeve 28. The two 
components thus engage one another telescopically, and eventually the head 
50 of the fitting 46 will enter the connector 26. The O-ring 52 will 
provide a fluid-tight seal between the tube 44 and the interior of the 
connector 26, so connecting the tube 44, via the valve 16, to the tube 10. 
When the tube 4 has been pushed fully home into the sleeve 28, the terminal 
plates 58 will be disposed opposite the screws 40, as shown in FIG. 3. 
These screws can then be tightened down onto the terminal plates 58, so 
completing the electrical circuit constituted by each lead 56, its 
terminal plate 58, the screw 40, the bush 36 and the lead 38. At the same 
time, the screws 40 will secure the tube 4 within the sleeve 28. To 
provide added security, the terminal plates 58 may be provided with 
inwardly directed depressions or recesses into which the screws 40 enter. 
It will be appreciated that the tube 4 itself and the sleeve 28 are made 
from material which is an electrical insulator, for example plastics 
material. 
The valve 16 is shown in more detail in FIG. 4. The body 22 is provided 
with two aligned bores 64 and 66, the bore 66 having a smaller diameter 
than the bore 64. An inlet aperture 68 opens into the bore 64, and an 
outlet aperture 70 opens into the bore 66. 
The operating member 18 extends through the bores 66 and 64 and, at its 
lower end (as seen in FIG. 4), extends through a retainer 72, which is 
fixed axially with respect to the body 22. Upwards movement of the 
operating member 18 is limited by a circlip 73 which abuts the retainer 
72. The retainer 72 may be in two interlocking parts which are separately 
inserted through two diametrically opposite slots (not shown) in the body 
22 to surround the operating member 18. The operating member 18 emerges 
from the top end of the body 22 through an opening 74. An O-ring 76 is 
provided to prevent leakage from the bore 66 past the operating member 18. 
There is a transversely extending transition 78 between the bores 64 and 
66. As shown in FIG. 4, the transition 78 is perpendicular to the 
longitudinal axis of the operating member 18, but it could also be 
inclined. Adjacent the transition 78, the operating member 18 carries a 
closure member 80 which is provided with a sealing ring 82 for engagement 
with the transition 78. Some distance below the closure member 80, the 
operating member 18 carries a stop member 84, which has a sealing ring 86 
engaging the bore 64. The stop member 86 is positioned below the aperture 
68 in all operative positions of the valve 16. 
A spring 88 acts between the retainer 72 and the stop member 84 in order to 
bias the closure member 80 into abutment with the transition 78. 
In the position shown in FIG. 4, the operating member 18 is biased upwardly 
by the spring 88 so that the sealing ring 82 makes fluid-tight contact 
with the transition 78. Fluid entering the bore 66 through the inlet 
aperture 70 is thus prevented from flowing into the bore 64 and thence 
through the outlet aperture 68. However, when the head 20 is depressed, by 
operation of the trigger 12 (FIG. 1), the operating member 18 is moved 
against the action of the spring 88, and the closure member 80 moves away 
from the transition 78. Fluid flowing through the aperture 70 into the 
bore 66 can then flow past the closure member 80 into the bore 64, and 
thence through the outlet aperture 68. 
An advantage of the valve construction shown in FIG. 4 is that none of the 
sealing rings 76, 82, 86 passes across the mouth of an aperture during 
operation. Thus, the danger of the sealing rings being damaged during 
operation is reduced. 
A printed circuit board 90 is provided at the bottom of the body 22, 
carrying control circuitry for controlling the motor in the head 6. The 
circuit board includes a microswitch 92 which is operable upon 
displacement of the operating member 18. Thus, depression of the head 20 
serves not only to open the valve 16, but also to supply power to the 
motor through the leads 56. 
A further embodiment of the valve 16 is shown in FIGS. 5 and 6. This valve 
comprises a body 94 having a collar 96 for receiving the head 50 of the 
supply duct 44. The body 94 also has an outlet spigot 98 for receiving the 
tube 10. The interior of the body 94 comprises a first bore 100 and a 
larger, second bore 102. At the transition between the bores 100 and 102 
there is a frusto-conical transition surface 104. An outlet duct 106 
extends eccentrically from the interior of the collar 96 into the smaller 
diameter bore 100, and an inlet duct 108 extends through the spigot 98 
from the larger diameter bore 102 at a position adjacent the transition 
surface 104. 
An operating member 110 is disposed within the bores 100 and 102. The 
operating member 110 has an actuating head 112 for engagement by the 
trigger 12 to operate the valve 16. The operating head 112 is connected by 
a stem 114 and a frusto-conical portion 116 to a spool 118, from which 
extends an operating rod 120. A spring 122 extends around the operating 
rod 120 and acts between the spool 118 and a retainer 124. As shown in 
FIG. 6, the retainer 124 is a two-part component, comprising a male part 
126 and a female part 128. The male part 126 has two spigots 130 which, 
when the retainer 124 is assembled, engage within recesses 132 in the 
female part 128. The male part 126 has a lug 133 to assist removal of the 
retainer 124 when dismantling the valve 16. 
The body 94 has a through slot 134, defined between parallel side walls 
136. To assemble the valve, the operating member 110 is inserted from 
below, as shown in FIG. 5, and the spring 122 is then fitted over the 
operating rod 120 and compressed by any suitable means. The two components 
126 and 128 of the retainer 124 are then inserted from opposite sides of 
the slot 134 to surround the operating rod 120. The two components 126 and 
128 are retained together by cooperation between the spigots 130 and the 
recesses 132. During insertion, the components 126 and 128 are guided 
towards one another by cooperation between side surfaces 138 and the 
surfaces 136 of the slot 134. 
A printed circuit board, corresponding to the circuit board 90 in FIG. 4, 
is fitted to the lower end of the valve 16 of FIG. 5, this circuit board 
being provided with a microswitch 140. 
In the position shown in FIG. 5, the valve 16 is closed. A sealing ring 142 
provided on the frustoconical portion 116 makes sealing engagement with 
the transition region 104 in the body 94, so preventing flow of fluid from 
the inlet 108 to the outlet 106. Depression of the operating member 110, 
by means of the trigger 12 (FIG. 1) moves the sealing ring 142 away from 
the transition region 104, and permits the flow of fluid through the 
valve. At the same time, the resulting downwards movement of the operating 
rod 120 causes actuation of the microswitch 140, so energising the motor 
in the spraying head 6, to rotate the disc 8. Sealing rings 144 and 146 
prevent undesired leakage of the fluid through the bores 100 and 102 
respectively.