Note: Descriptions are shown in the official language in which they were submitted.
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THIS INVENTION relates to a device for dosing a
, flowing fluid stream with an additive.
', BACKGROUND OF THE INVENTION
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~;,;, A recent development in the lubrication of
, pneumatic machines is described in United States Patent No.
3724601. The lubricator of this patent is fitted upstream of
the pneumatic machine and includes a body which receives a
! collapsible cartrid~e. The air enterin~ the lubricator
impinges on a hag ~orming part of the cartrid~e and collapses
f.,, 10 it~ Collapse of the cartrid~e expels its contents ;nto the
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,' air stream flowing through the lubricator to the pneumatic
, machine.
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The luhricatox disclosed in the U.S. patent pro-
vides an answer to many of the problems which haye pla~ued
the lubrication art for a number of years. It permits a
steady, controlled rate of lubricant flow to the pneumatic
machine, avoiding the periods of lubricant starvation and
then over-lubrication which were characteristic of the
lubricators used previously. The lubricator is being put
into service in many parts of the world and is generally
fulfilling the world-wide need for a reliable lubricator.
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The present invention seeks to provide a lubrica-
tor which operates in much the same way as the lubricator
described and which, in fact, can use the same lubricant
cartridge. The lubricator of the present invention can be
employed where, for some reason, the prior lubricator is not
acceptable.
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There are various factors which can mitigate
against acceptance of the~prior lubricator. For example,
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the prior lubricator has a body of synthetic plastics mater-
ial on which static electricity can build up. In, for
- 20 example, mines where there may be a gaseous atmosphere, such
a lubricator cannot be used because of the danger of an
explosion following discharge of static. The lubricator of
this invention can be fabricated in metal, or can be a metal
casting, and in this form there can be no ~uestion of a
static build-up.
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Another possible factor is cost. In some parts of
the world a metal casting is cheaper than the equivalent
plastics moulding. A third factor is that there is some
prejudice against the use of plastics mater;als. Thus, it
is not always accepted that a plastics casing will resist
crushing to the same extent as its metal counterpart.
According to the present invention there is pro-
vided a device for dosing a flowing fluid stream with an
additive, the device comprising an elongated body closed at
one end and open at the other, first and second lateral
inlets to the body, the first lateral inlet being closer to
the closed end of the body than the second lateral inlet,
means defining a fluid flow path which path enters said body
through said second inlet and which is further connected to
said body via said first lateral inlet, and a plug inserted
into said body through said open end thereof, there being
sealing means which co-operate with said body and said plug
to divide said body into a first chamber communicating with
said first inlet and a second chamber communicating with
said second inlet, the plug having a bore which passes
therethrough, said bore placing the first-chamber in
communication with the exterior of the body and there being
at least one passage in said plug placing said bore in com-
munication with said second chamber.
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Said body can be constituted hy a len~th of metal
pipe, preferably steel, and said means can also be a length
of metal pipe, again preferably steeI, of smaller diameter
than the pipe o~ said body. The two lengths of pipe can be
arranged parallel to one another with a short length of
piping connecting the parallel pipes and constituting the
first inlet to the body. A right angled bend can connect the
smaller diameter pipe to the larger diameter pipe and
constitute the second inlet.
Sald plug can carry two sets of sealing means, the
first set, when the plug is in the body, lying between the
first and second inlets and the second set lying between the
second inlet and the open end of the body. A series of
radial ports can be provided for placing said second chamber
in communlcation with said bore of the plug.
A bayonet-type connection can be provided for
securing the plug to the body. The plug itself can further
include an annular shoulder which forms part of the surface
of said bore and which faces away from said first chamber.
For a better understanding of the present
invention, and to show how the same may be carried into
effect, reference will now be made, by way of example, to
the accompanying drawings in which:-
Figure 1 is an axial section, partly in elevation,
throuyh a device in accordance with the present tnvent~on;
Figure~2 ~s an axial sec~ion throug~ a plug o~ the
device;
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Fisure 3 is a fragmentary di~rammatic elevation illus-
trating the means provided for securin~ the plu~ o~ Figure
2 to the body of the device;
Figure 4 is an axial section thxough a modified plug;
and
Fiyure 5 illustrates a further ~orm of body.
The device illustrated in Figure 1 is intended
primarily for dosing with a lubricant an airstream flowing
to a piece of pneumatic apparatus such as a rock drill. The
device, generally referenced 10, includes a body 12 composed
of a length of steel piping. One end of the body 12 is
closed by an end wall 14 which is welded-in and the other
end of the body 12 receives a plug 16 which will be
described in more detail hereinafter.
A pipe 18, which forms part of the air flow path
to the pneumatic apparatus, is arranged parallel to the body
12 and has an externally threaded inlet at ~0. The pipe 1
18 mounted on the body 12 by a right angled bend 22 and by
a ~hort length of piping 24. The bend 22 and piping 24 con-
stitute lateral lnlets to the body 12 and place the pipe 18in communication with the body 12 at two spaced locatlons.
The ~ody of the plug 16, which can be machined
from steel stock but which is pre~erably cast, is ~enerally
cylindrical in form and has a central b~xe 26 which 'A
passes axially therethrough. T~e ~nnex end of the boxe
26 communicates ~ith a main chambex 28 o~ the body 12
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and is of smaller diametex than the remainder of the bore
26 (see particularly Fiyure 2). This gives rise to a
shoulder 30 which encircles the bore and which is engaged
by, and retains, a flexible rib forming part of the nozzle
S structure of a lubricant car~ridge (not shown). The
cartridge is pushed into the plug from the left hand end,
as viewed in Figures 1 and 2, after the plug has been
removed from the body 12. This will be described in more
detail hereinafter.
A single 0-ring 32 encircles the bod~ of the plug
16 near one end thereof and, when the plug is in position,
seals-off the inlet constituted by the piping 24 from the
inlet constituted by the bend 22. The plug body carries
two further 0-rings 34 which seal the inlet constituted by
the bend 22 off from the open end of the body 12. The 0-
rings are not shown in Figures 2 and 3 but grooves 32.1,
34.1 and 34.2 which receive these rings are illustrated.
The plug body is waisted between the 0-rings 32
and 34 thereby to provide an annular chamber 36 which
en¢ircles the plug. The bend 22 opens into the chamber 36.
Radial passages 38 place the bore 26 in communicatlon with
the chamber 36 and hence with the inlet constituted by the
bend 22.
~he portion of the plug which is outside the body
12 when the plug is in the position shown in Figure 1 is
knurled or scalloped to enable the plug readily to be
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turned. The knurling or scalloping ls provided on a ring-
like portion 40 o the plug.
Two short pins 42 protrude outwardly at diametri-
cally opposed locations of the plug 16, the pins being
between the grooves 3~.1 and 34.2 and the ring like portion
40.
A short strengthening sleeve 44 is welded to the
body 12 and two diametrically opposed slots 46 (see Figure
3) are provided in the portion of the body 12 strengthened
by the sleeve 44. The slots 46 are both L-shaped. The plug
i8 secured in position by entering the pins 42 in the
axially extending portions of the slots 46, and then
rotating the plug so that the pins move into the circum-
ferentially extending portions of the slots 46. It will be
noted from Figure 3 that these latter portions are recessed
on one side to receive the pins 42.
In use of the device, an air supply hose (not
shown) is connected to the inlet 20 and a further hose (not
shown) le~ding to the rock drill or other pneumatic
apparatus, is connected to internal threading 48 of the
plug 16. With the plug removed from the body, a cartridge
~not shown) containing lubricant is releasably secured
thereto. Normally, the cartridge comprises a bag of
synthetic plastics material with a noæzle structure secured `-
thereto. The nozzle structure includes a fine metering
bore which is closed by a portion of the nozzle structure.
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The nozzle structure furthex includes an encircli.ng,
outwardly dixected, circumferentially extending rib. Said
portion o the n~zzle structure is removed, for example by
cutting, thereby to open the metering bore and the nozzle
structure is then pushed into the bore 26. This causes the
rib to be deflected so that its overall diameter is reduced
as it passes through the narrow portion of the bore 26, the
rib then springing outwardly so that the cartridge is
retained by engagement between the ri~ and the shoulder 30.
With the cartridge leading, the combined plug and cartridge
structure is entered in the-body 12 so that the cartridge
lies in the major chamber 28 between the two inlets to the
body. The plug adopts the position shown in Figure l in
which the inlets are sealed-off from one another. The only
exit from the hody is through the bore 26.
A valve upstream of the inlet 20 is then opened
so that air flows through the pipe 18 and, via the bend 22,
into the chamber 36. From the chamber 36 it flows through
the passages 38 to the central bore 26 and thus to the hose
connected to the plug 16. A static pressure prevails in
the main ~hamber of the body 12 by virtue of the connection
. constituted by the piping 24. It will be understood that
there is no air flow through the main chamber of the body
12. This.is because of the provision of the O-ring 32 and
because the nozzle structur~ of the cartridge itself seals-
off the central bore 26. The static pressure, acting on
the external suraces of the bag which ~orms part ~f the
lubricant cartridge, tends to collapse the bag and urge the
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contents thereof through the fine metering bore of the
nozzle structure and into the region of the bore 26 which
lies within the passages 38. As air flows into this region
from all sides, there is considerable turbulence and
lubricant emerging from the metering bore into the passage
is atomised and then carried by the flowing air to the
pneumati~ apparatus.
Once the bag of the cartridge is exhausted, the
plug and cartrid~e are removed from the body, the old
cartridge detached from the plug and discarded, and a new
cartridge inserted into the bore 26 after its metering bore
has been opened. The plug and cartridge combination is then
xeturned to the body.
In the form described, the nozzle structure of the
cartridge includes the fine bore for metering flow. In a
modlfied form an insert 50 having an axial metering bore is-
provided in the bore 26, this being shown in Figure 4. The
insert 50 is screwed into a narrower portion of the bore and
the shoulder 30 then forms one face of a groove 52 which
encircles said narrower portion. The groove 52 serves to
receive said rib of the nozzle structure. If a cartridge
having a threaded nozzle is used, then the lip 54 serves as
the matching thread of the plug 16.
Turning finally to Fi~ure 5, this shows a body
whlch ls in one piece. The raference numexals applied to
~igure 5 correspond ts thbs~ use~ ~n F~ure 1 with the
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addition of the suffix .1. The herd 22 and piping 24 are
replaced by apertures 22.1 and 24.1 throu~h the wall o~ the
body 12.1, and one bound~ng wall o~ the pipe 18.1 is
constituted by part of the wall of the body 12.1. The body
12.1 ls closed at one end by an ~ntegral end wall 14.1 and
slot~ 46.1 are provided at the other end of the body~
The plug 16 which fits the body 12.1 is as shown
in Figure 4 and has not been illustrated in Figure 5.
In a modified form, the aperture 24.1 is substan- ~,
tially decreased in size. For example, its cross-sectional
area can be the same as, or approximately the same as, the
. metering bore of the insert 50 in Figure 4. In this form
the insert 50 is used and the chamber 28 receives a charge
of lubricant dispensed from a cartridge or from a bulk
supply,
When the pneumatic drill Ls in operati~n, pressure
pulses at a frequency of up to 2000 per minute exist in the
pneumatic line. These pulses act on the lubricant charge
through the metering bore in tha insert 50 and through the
small aperture 24.1 and expel lubricant into the flowing air
~tream at steady rate.
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