Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02266023 1999-03-08
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CLEANING LANCE
The present invention relates to a cleaning lance, of the
type used for cleaning the exterior of vehicles for example.
Such cleaning lances normally incorporate a barrel having a
high pressure nozzle which is used to direct a high pressure
water jet at the exterior of the vehicle. Such cleaning
lances are normally supplied with pressurised water from a
pump driven by an electric motor or a petrol engine and in
many cases detergent is fed into the water flow at the site of
the pump.
FR-1,363,426 discloses a cleaning lance having a mixing
chamber in which an axially directed water jet sucks in air
from an air inlet and detergent from a detergent inlet and
forms a foam which is ejected axially from the outlet of the
lS chamber. The air inlet and detergent in let are diametrically
opposed within the mixing chamber.
FR-A-2,519,881 discloses a hand held cleaning lance
having two barrels mounted on a common body and valve means
incorporated in the body of the lance and operable by the user
to switch pressurised fluid from an inlet of one barrel to an
inlet of the other barrel, the barrels being arranged to form
jets of different characteristics and the valve means
comprising a freely movable valve member which is retainable
by fluid pressure to selectively block said inlets.
However, in FR-A-2,519,881 the two barrels are located
side by side and the movable valve member is movable by
inclining the lance slightly about its longitudinal axis.
Since only one of the barrels is connected to a detergent
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CA 02266023 1999-03-08
bottle, and the barrels are in any case of different lengths
and bore sizes, an unbalanced arrangement results, which is
not ergonomic.
A further problem with the above arrangement is that the
valve member easily rolls from one side to the other lf
pressure is interrupted, so it is possible to accidentally
switch to a detergent stream. This can be dangerous because
detergent is sometimes corrosive.
/ US-A-4202495 discloses a nozzle head selector for one or
more nozzles located at the end of a single barrel, the
selector being located at the nozzle end of the barrel. The
selector has a changeover device formed by a ball which moves
under gravity when the pressure is turned off to allow
changeover of jets without changing the nozzle head, the jet
being selected by slightly turning the barrel. Such a
changeover device in being located at the nozzle end is able
to operate under lower pressures and although some leakage may
be acceptable at the nozzle end, no leakage is acceptable at
a user end of a cleaning lance.
The present invention seeks to at least partially
mitigate the foregoing difficulties.
In accordance with this invention there is provided a
cleaning lance as claimed in claim 1 herein.
Other preferred features of the invention are defined in
the dependent claims.
The above arrangement is more ergonomic than that of FR-
A-2,519,881 and particularly in view of US-A-4202495 by
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CA 02266023 1999-03-08
particularly havlng a valve means comprising an elongate
arcuate (preferably semi-circular~ chamber having an inlet and
having respective spaced apart outlets çommunicating with the
barrels, a rolling or sliding valve member (such as a steel
ball for example) being located in the chamber and being
arranged to move within the chamber to block one of the
outlets on tilting the lance and to block the other of the
outlets automatically (e.g. by the action of gravity) when the
pressure is interrupted. To this end, the lance is preferably
provided with trigger means for blocking fluid pressure to
enable such movement of the valve member and for reapplying
fluid pressure to maintain the valve member in position
against the last-blocked outlet: by fluid pressure irrespective
of the angle of tilt of the lance.
Preferably, however, the valve means is latched by fluid
pressure which allows for rap:id change in comparison with a
non-latching, manually operated arrangement which involves a
significant delay and dividing of the flow.
Further preferred features are defined in the dependent
claims.
A preferred embodiment of the invention is described
below by way of example only with reference to Figures l and
2 of the accompanying drawings wherein:
FIG. lA is a longitudinal cross-section showing the
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r proximal end and mid-portion of a cleaning lance in
accordance with the invention;
FIG. lB shows the distal portion of the cleaning lance
of Fig. lA, and
FIG. 2 is a section taken on II-II of Figure lA.
Referring to Figure lA, an elongate cleaning lance is
shown to comprise a water inlet 1 provided with a trigger
attachment (not shown) for applying and releasing water
under pressure. The water inlet 1 communicates with a valve
comprising a steel ball 14 whlch runs within a semi-circular
ball valve chamber 15 as best seen in Figure 2. The ball 14
has a lower default position in which it blocks an inlet 18
to the foamer barrel 12 and has an upper position at which
it blocks an inlet 17 to a pressure stream barrel s which
generates a water jet. As shown in Figure 2, the path of
the steel ball 14 between these two extreme positions is
- 20 semi-circular and accordingly it can be moved between these
two positions by tilting the lance about its longitudinal
axis after releasing the pressure with the trigger
attachment connected to water inlet 1.
- AWater
jet is formed within a mixing chamber 19 by a Venturi nozzle
3 which is supplied with high pressure water by conduit 6
from inlet 18. The resulting jet draws in detergent 11 via
a feed tube 10, mounting 8, detergent conduit 7 and needle
valve 2 which controls the flow of detergent into the mixing
chamber 19. The resulting mixture of water and detergent
exits the mixing chamber via a further Venturi nozzle 4
which draws in air by Venturi action through an annular air
inlet 20 which communicates with an annular passage 21
(Figure lB) which in turn has an air inlet open 23 to the
atmosphere. The mixture of air, water and detergent passing
along the foamer barrel 12 is foamed by a mesh 13 (Figure
lB) and forms a stream of cleaning foam. The mesh is a
conventional mesh of plastics material (polypropylene or
nylon).
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W 09X/037J~ PCT/GB97/02373
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Annular passage 21 extends axially of the lance around
barrel 12 and at its end remote from that end coupled with
air inlet 20 there is provided one or more axially extending
walls circumferentially spaced about the outer peripheral
surface of the barrel 12 and defining passages therebetween
communicating with the external at:mosphere via opening(s) 23
in the external surface of barre]. 12 prior to but adjacent
to foaming mesh 13 in the direction of movement of the water
detergent and air mixture through barrel 12. Therefore
when air is required it is drawing through opening 23 into
the passages between walls 22 and then into the Venturi 4
via the annular passage 21 and air inlet 20.
A removable detergent cartriclge 9 provided with its own
detergent feed tube 10 and associated cap is attachable to
mounting 8 by a standard bayonet fitting (not shown).
Referring to Figure 2, it will be noted that the ball
14 will normally fall to the lower position at which it
blocks inlet 18 by the action of gravity. On releasing the
water pressure at inlet 1 and tilting the lance anti-
clockwise by 180~ about its longitudinal axis, the ball 14
can be moved to block inlet 17 and at this point pressure
can be reapplied by the trigger (not shown) to maintain the
ball in this position and form a foam jet by flow through
inlet 18 to mixing chamber 19. When it is desired to wash
off the foam, the water pressure is momentarily released by
releasing the trigger, the lance is tilted slightly about
its longitudinal axis to enable the ball 14 to roll back to
its lower position, and fluid pressure is then reapplied by
the trigger, allowing water to flow directly via inlet 17 to
the upper barrel to form a cleaning stream.
The cleaning lance of the pre,ent invention can be used
not only for vehicle cleaning but: also for other cleaning
applications, such as abattoir sanitising for example.
