Note: Descriptions are shown in the official language in which they were submitted.
CA 02259397 1998-12-31
DESCRIPTION
The invention concerns a valve arrangement for control of a fluid passage
between a first and a second fluid chamber as well as a writing device equipped
with it.
Basically, there is currently a requirement for valves that are miniaturized
and can be constructed in a simple manner, due to the miniaturization that is
taking place in many technical fields, which [valve] can be utilized, among other
things, for control purposes in micropneumatics and microhydraulics.
Technologies relatinq to medicine and writing devices also require such valves.
A valve arrangement wi~h~n the s~pe of a cathet~r ~nstn~ction
ac~rding to the prea~ble of patent cla~m 1 iS kna~n fran EP-A-250 891.
Th~rewith there is pmvided an elongated t~bing pie~, clo~ed at one
end, which iS sl~yLl~:r~d by an ~nsert l~p to a ring area at the erx~.
A r~tary }~tton is positioned an a hand kncb, said rotary btltton being
joined wi~h a stiletbD-like actuating strut in the lumen of the tubing
piece, which in its ~ n proo~e~ to the free end thereof and is
anchored there. By r~tation of the knob, the head of the ~lhing pie oe
is twist~hle via the a~Lul~ing strut relative to the r~n~;~ing tubing
piece so that the non s~Ll~ened area i5 tors~ in itself. Slot~,
which are provided there, open due to this b~rsion and unblock fluid
p~s~e bet~een the lur~ of the tibing piece and the outside spaoe.
qhe prior art arrangement i6 disadvantageous due to the fact that
for producing tDr~ion of the non-sLr~.~thened p~rtion of the tubing
piece, there must ~e provided a relatively expensive arrangement.
Especially two areas of the tub~ pieoe, namely, the sLl~n~U~ned area
on the one h2nd and, on the other hand, the cap being rigid (firm) by
themselves, m~st nevertheless be oon~ected t~ each oth OE via a flexible
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intf~ te piece in or~3er to enable torsion of this ir~t~i~te
pi~oe ~ard act-~atir~ the v~lve. Fur~enrDre, rotatianal actuation
of the actl~ating part for producir~ rsi~n is achievable only ~:tt~
an exE~sive kr~bllL~. h~r~le.
lh~s, ~n the c:ase of the prior art, the prabl~n is that a ~ralve
arrangem~nt,~ose ~nstruction is relatively ex}~ensi~e, is also very
carplicated to ac~tu.3te (operate).
In order to solve this problem, the invention concerns a valve device of the
typed named initially with the following features:
-- a hose part of elastomer material, whose wall outer side stands in
contact with a first fluid chamber and whose inside space or lumen is joined with
a second fluid chamber,
-- one or more penetrating slots in the wall of the hose part, which are
to be closed in the underformed state of the part, due to the restoring force
of the elastomer material inherent in the material, and which can be opened by
deformation of the hose part, and
- an actuating part on the hose part, by means of which, the hose
part can be deformed in order to control the flow of fluid through the slot.
It is clear from the above combination of f~atures that a valve for the
throughput control of gases and liquids that is to be actuated mechanically forms
the basis for the subject of the invention. The two mentioned fluid chambers may
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therefore be two closed volumes or also a supply space and its surroundings or
atmosphere, as will be explained in the following in more detail on the basis of an
example.
The hose part advantageously comprises silicone material. This reduces
the production expense for the valve arrangement according to the invention,
since silicone tubing can already be obtained in many dimensions and qualities
as a commercially mass-produced application for the valve. Silicone is
compatible with skin and tolerated by the body.
Most preferably, the actuating part is formed as a tube piece sitting in the
lumen of the hose part, and ending in front of its slot region. This construction
assures small actuating forces and a perfect discharge of the fluid passing
through the slot that has been opened by deformation, from the first to the
second fluid chamber.
The arrangement and the precise configuration of the slots in the hose
part can be established each time oriented toward the application. It must only
be assured that the slots are closed in the undeformed state of the hose part.
These must thus involve fine cuts and not coarse openings in the wall of the
hosing part.
In order to obtain a response characteristic of the valve that is
independent of the direction of deformation, it may be preferred to provide one or
more peripherally-running series of slots in the hose part.
,
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By a fluid-tight mounting of the hose part each time in front of its two ends,
a clean attachment of the hose part as well as a separation between the two fluid
chambers is obtained.
In summary, the following can be named as advantages of the valve
arrangement according to the invention: Its corrosion resistance and very high
chemical resistance, particularly against acids and bases - no metallic parts
need to be used; its very small space requirement; and the small actuating
forces. Further, the valve arrangement can be used in a broad temperature
range. Not lastly, only those materials are used, which exclude a buildup of
sparks, so that the valve arrangement can be utilized also in an environment that
is at risk of explosion.
As a preferred application of the valve arrangement according to the
invention, application in a writing device is provided for the regulation of the flow
of ink between an ink reservoir of the writing device and its writing tip.
Relative to the claimed further development of the writing device with such
a valve arrangement, in order to avoid unnecessary repetition, refer to the
following description, in which the valve arrangement itself and a writing device
provided therewith, including additional features, characteristics and advantages
will be explained in detail on the basis of the attached drawings.
Here:
Figs. 1 and 2 show schematic views of the valve arrangement in closed
and open position;
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.~ ; 4
Figs. 3 and 4 show an enlarged representation of the hose part in the
unstressed and deformed state; and
Figs. 5 and 6 show schematic longitudinal sections through a marking pen
with a closed and opened valve arrangement.
Valve arrangement 1 according to the invention is shown in highly
schematic form in Figs. 1 and 2. Its core piece is a short hose part 2 of silicone
material, which is mounted in front of its two open ends 3, 4 in a fluid-tight
manner in a housing part 5. Housing part 5 belongs to a first fluid chamber 5', in
which a fluid, e.g., a liquid stands. Hose part 2 on the outer side of its wall is thus
surrounded by the liquid in first fluid space 2 between the mounting places at the
two open ends. Lumen 6 of hose part 2, by its two openings 7, 8, opens up into
a second fluid chamber, which is designated in its entirety as 9 in Figs. 1 and 2
and is indicated by the broad-hatched surface. A tube piece 10 as an actuating
part is inserted into lumen 6 of hose part 2 through one opening 7, and this
terminates just before the region of slot 11 in hose part 2.
An example of the shaping and configuration of slot 11 is shown in Figs. 3
and 4. Three rows of peripherally running slots 11 are provided approximately in
the middle with reference to the length of hose part 2. Slots 11 are microfine
cuts, which run through the wall of the hose part.
Valve arrangement 1 is shown in closed position in Fig. 1. Slots 11 are
closed due to the restoring force of its silicone è~astomer material inherent in the
material residing in hose part 2, so that fluid found in housing part 5 (first fluid
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chamber 5') with slight overpressure cannot enter through slot 11 into lumen 6 of
hose part 2.
Upon action of a force F onto tube piece 10 projecting from hose part 2,
hose part 2 is deflected and deformed, as can be seen in Fig. 2. Slots 11, which
lie on the extended side of hose part 2, are opened by this deformation and fluid
or gas can pass over from housing part 5 (first fluid chamber 5') through the slots
into lumen 6 of hose part 2 and from there through openings 7,8, into second
fluid chamber 9. The mentioned opening of slots 11 is exaggerated in Fig. 4, but
presented so that it is obvious.
If force F no longer acts, then hose part 2 again becomes straight and
slots 11 are closed all around. The fluid connection between first fluid chamber
5' and second fluid chamber 9 is thus again interrupted.
A practical example of the application of the valve arrangement presented
in Figs. 1 through 4 is shown in Figs. 5 and 6. This involves a marking pen M
shown schematically in section, which has a conventional cylindrical or flattened
tube-shaped apparatus housing 12 with conically running housing tip 13.
Housing 12 surrounds a reservoir 14 for the writing fluid of the marking pen.
An opening 15 is provided in housing tip 13, in which [opening] one end 7
of hose part 2 is mounted by its outer side in a fluid-tight sealing manner. Hose
part 2 arranged coaxially to the longitudinal axis of apparatus housing 12 is
further arranged by its other end 4 in an apparàtus holding element 16 in housing
12, which has passage openings 17 for the writing fluid. Opening 8 of hose part
2 Iying at end 4 is tightly sealed by a plug 18 in the form of a silicone cord piece.
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Writing tip 19 of marking pen M is inserted by its shaft 20 into opening 7 Iying
opposite, which lies outside apparatus housing 12. Writing tip 19 itself forms the
actuating part for valve arrangement 1, whereby its shaft 20 reaches further up to
just in front of slots 11 in hose part 2. Writing tip 19 with shaft 20 is further
produced from fiber material, as is usual for marking pens M for transport of
writing fluid based on capillary action.
Opening 21 of the apparatus housing turned away from housing tip 13 is
moreover closed by a cap 22, in which a pressure equilibration element 23 in the
form of a hydrophobic, semipermeable membrane is inserted. The latter is
welded ultrasonically with cap 22.
The control of the flow of ink in marking pen M will be explained on the
basis of Fig. 6:
If marking pen M is placed on a sheet of paper 24, as is indicated very
schematically in Fig. 6, and then force F is introduced onto writing tip 19, hose
part 2 will deflect from shaft 20 of writing tip 19 and deform. In this way, slots 11
in hose part 2 open, so that the !iquid present in reservoir 14 (first fluid chamber)
can enter into lumen 6 of hose part 2 and will be transported via capillary forces
into writing tip 19 onto sheet of paper 24. According to the above terminology,
the latter forms practically the second fluid chamber. As soon as marking pen M
is removed from the substrate and force F is removed, hose part 2 again
becomes straight and the flow of ink from resefvoir 14 to writing tip 19 is
interrupted.
~ ,
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Finally, the advantages of the writing device according to the invention, as
have been described above, are summed up as follows:
-- The regulation of the flow of ink is conducted by an uncomplicated,
cost-favorable valve system.
-- The functional principle is applicable to many types of writing
pastes and liquids, as well as for cosmetic fluids.
-- The tank content of the writing device is determined only by the
housing size and is thus arbitrarily selected within certain limits.
-- More than 90% of the writing fluid can be utilized. From this results
an essentially higher productivity with the same filling quantity in comparison to
fiber storage systems.
-- The writing behavior is independent of the residual tank content.
-- The writing device is secure against shock, i.e., when dropped,
there is no sudden appearance of writing fluid and associated blotches.
-- The writing device can be configured in a refillable manner.
-- The writing tip can be arbitrarily shaped ànd can be designed in an
exchangeable manner, since it is inserted only into the hose part.
-- The writing device is optimally recyclable, since the individual parts
are easy to dismantle and separate, based on the simple construction.
.. . . . .
