Note: Descriptions are shown in the official language in which they were submitted.
2 1 ~
Wo 93~19695 PCTf~T93~00046
A PIPE ELBOW
The presant invention relates to a pipe elbow, ~rparticùlar for
connecting a dental suction tube to a connector block of a tube
support unit, with a first length of pipe that can be plugg~d in
so as to form a seal and which can be rotated in a coupler
[socket end~ and with a second length of pipe that can be
connecte~ to th~ suction tub~.
A pipe elbow of this kind is describ~d, for exampla, in EP-A 390
951; this is secured in the coupler of the connector block by
means of an O-ring. The axis of rotation is horizontal, so that
the conn~cted suction tube hangs downwards and is protected in
the connection area despite frequent oscillatory movements~
It is the task o~ the pres~nt invention to improve the swivelling
support provided by this kind of piple elbow.
According to the present invention, this has been achieved in
th~t it incorporates an outer supporting spigot o~ the a~is of
rotation of the f irs~ length oP pipe . Bilateral suppoxt of the
pipe elbow is mad~ po~sible because o~ this, ~ecausa ~he
supporting spigot can be held in a moun~ing or the likP so as to
be able to 8wivel. Th~: eal that fits into the coupllng is only
loaded~perpendicularly to the axi5 o~ rotation by the weight of
the uspended su~ti~n tube. S~nce neither shearing forc~s nor
f~r¢es!that work in the direction of withdrawal ar~ present,
rotatability iB al~o impro~ed because o~ the smallex amount o~
friction.
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WO 93/lg695 pcT/A~r93~ooo46
A preferred embodiment is such that it incorporates a shut-off
devic~ that is arranged at the corner with a diaphragm that is
acted on by a pressure medium, with both lengths of pipes opening
out into the pressure surface of ~his. Because of the
conf iguration of the diaphragm corner valve, tl~:uction tube can
~e shut off in a very simple manner without any requirement for
significantly greater space. The supporting ~pigot can, for
instance, project from the cover of the pres~ure chamber of the
diaphragm corner valve. If necessary, the pressure medium can
also be introduced into the pre~sure chamber through the
supporting spigot.
Another embodiment i~; suc:h that the f irst length of pipe is
curved and the supporting spigQt proj ects on the outside of the
curve. It is preferred that the cuxve of the first length of
pipe therl amounts to approximately 4 ~ .
A ~urther pref erred e~bodiment is æuch that wider end areas of
both lengths of pipes open out in the pressure surface of the
diaphr~gm that is acted upon by a pre~sure medium. Because OI
the approximately funnel-shaped or conic:al widening to the
pressure arld sea:l ing surfac:es of the diaphragm it is possible to
k~ep the paæsage cross~ sec:tlon at l~ast equal to the cro~s-
section of the l~ngth of pipes, even in the diaphragm area, as
well, sinc~e the eibow area i enlarged. In ~particular, if the
pre~:sure ~urface is confined e sentially to a transition edge
betw en the two lengths of pipe~;, khere are no surfaces to impede
the flow and on whic:h depo~its of ma~erial that can hinder the
contac:t pressure can build up. B~c:ause~ of this, within the~
~ontact pressure area there is only the clamping edge of the
diaphra~n and the line of separation between the two lengths of
pipe or the funnel surfac~s of the two end areas. This
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WO 93~19695 PCT/A~1!93~00046
embodiment is also possible without a supportiny spigot that lies
on the axis of rotation.
Th present invention will be described in greater detail below
on the basis of the drawings appended hereto 7 w~out being
restricted ther~to~ These drawings show the following:
igure 1: a preferred e~bodiment o~ the pipe elbow according to
the pre ent invention in an obli~ue view facing the
inner side o~ the elbow;
igure 2: a plan view of the pipe elbow perpendicular to the axis
of rotation;
igure 3: an incline view rotated through appr~ximat~ly 90 of
the embodiment shown in figure 1 with the valve cham~er
open.
A pipe elbow co~prises two lengths O:e pipes 1, 2. Of these,
length of pipe 1 is used to connect a coupl~r lo o~ a connecting
block and thi~ i5 connect~d to a mounting 11. When used as a
pipe elbow for connecting a dantal suction tube, th~: connector
block is provided on a tube support unit, when preferably two
su¢tion tubes be ins~rted from o~po~ite sides into the conneator
block, through two pipe elbows according to the pre~ent
inventi~n, these heing rotatable about a common axis.
A supporting spigot 9 i5 locatèd on the axis of rotation B of the
first length of!pipe 1; this extends from the wall that i~
opposite the opening o~ length of pipe 1 and is upported either
on or in the mounting 11 so as to be able to rotate. Thus~ the
pipe elbow has a second ~upporting area that protects th~ push
connection and the æeal 5 b~tween the length of pipe 1 and the
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WO S3/19695 PCT/AT93~00046
coupler 10. The pipe elbow al o has a valve chamber 3 that is
inclined relative to the two lengths of pipe 1, 2 and defined by
a diaphragm 4 as a s~ut-off de~ice.
Figure 3 shows the pipe elbow with the valve c~er 3 opened.
The end areas 12, 13 of the length of pipes 1, 2 widen out in the
mannr of a funnel, or mor~ or less conically to the contact
surface ~, which thus forms only a narrow concave transitional
step between the two lengths o~ pipes 1, 2. This avoids the
formation of deposits that could hinder the seal-type seating of
the membrane (not shown herein)~ In addition, the cross-section
of the pipe elbow is not restri~ted in the area of the diaphragm,
for the pipe elbow is widened by the expansion or widening of the
l~ngths of pipe and th~o inside of the elbow. As an example ~ the
valve chamber 3 is closed off by a cover (not shown herein) that
can be cemented, welded or snapped intc) place and which clamps
the diaphragm 4.
A c:onn~ctor 6 is provided ~or the introduc:tion of the pressure
medium and this is formed, in particular, on the cover. I~ the
pressure in the ~ralve chamber 3 is higher th~n in the length of
pipes 1, 2, lthe diaphragm 4 }g pressed against the pressure
surface 7 and the passage thrc)ugh the pipe holder is blocked.
If, in c:ontra~t to this t the pre~;~ure is less, then the diaphragm
i~; raised from the contac:t æurface 7 and the passage is opened.
Because of th~ fact that th~ cover of the valve chamber 3 lies
against ~he outside o~ the elbow, the cQnneator 6 that also
serves as the supporting spigot 9, with the pipe elbow then
forming a simple curve. In the embodiment that is shown, the
1~3ngkh o~ pipe 1 is curved khrough approximately 45 ~ so that the
~;upporting ~pigot 9 passes the valve cham~er 3 at ~he side. The
supporting spigot ~ could also form a branch or feed channel.
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WO 93/~9695 PC~A~g3/00046
A dent~l ~uction tube can, if necessary, contain an additional
line, perhaps in the form of a second tube of smaller diameter.
The pu~h coupling on the suction tube then includes two O-rings
and a peripheral groove that runs between these, and in which the
intermediat~ tube ends. A pipe elbow that is ~table for
conne~ting a suction tube of this kind incorporates a length of
pipe 2 which has a second connector 14 in the area that
corresponds to the paripheral groove when the suction tube is
connected.
If the supporting spigot 6 also forms a channel, the connector 14
can be conne ted to this through a tube or the like but also
opens out within the length of pipe 1, into a peripheral groove.
In this way, the additional line can pa~s round the ~hut-off
device externally.
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