U.S. patent application number 10/433268 was filed with the patent office on 2004-03-11 for sealing system and gasket therefor.
Invention is credited to Beele, Johannes Alfred.
Application Number | 20040045233 10/433268 |
Document ID | / |
Family ID | 19772495 |
Filed Date | 2004-03-11 |
United States Patent
Application |
20040045233 |
Kind Code |
A1 |
Beele, Johannes Alfred |
March 11, 2004 |
Sealing system and gasket therefor
Abstract
A sealing system (1) comprising an at least substantially
cylindrical tube (2) and at least two sealing collars (4) at least
partially made of an elastic material, which are arranged round the
tube in spaced-apart relationship for sealing confinement by
collaring of the tube in a bushing (3) which is co-axial with said
tube, a special feature being the fact that the spacing (a) between
the sealing collars is less than 25 mm, said sealing collars
comprising an expandable material, in such an amount and of such a
composition that the sealing collars will expand in the case of a
fire, in such a manner that they will become wedged in the
bushing.
Inventors: |
Beele, Johannes Alfred;
(Aalten, NL) |
Correspondence
Address: |
William B Patterson
Moser Patterson & Sheridan
Suite 1500
3040 Post Oak Boulevard
Houston
TX
77056
US
|
Family ID: |
19772495 |
Appl. No.: |
10/433268 |
Filed: |
September 29, 2003 |
PCT Filed: |
November 27, 2001 |
PCT NO: |
PCT/NL01/00862 |
Current U.S.
Class: |
52/220.8 ;
52/219 |
Current CPC
Class: |
F16L 5/04 20130101 |
Class at
Publication: |
052/220.8 ;
052/219 |
International
Class: |
E04C 002/52 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 30, 2000 |
NL |
1016749 |
Claims
1. A sealing system comprising an at least substantially
cylindrical tube and at least two sealing collars at least
partially made of an elastic material, which are arranged round the
tube in spaced-apart relationship for sealing confinement by
collaring of the tube in a bushing which is co-axial with said
tube, characterized in that the spacing between the sealing collars
is less than 25 mm, with said sealing collars comprising an
expandable material, in such an amount and of such a composition
that the sealing collars will expand in the case of a fire, in such
a manner that they will become wedged in the bushing.
2. A sealing system according to claim 1, wherein the spacing
between the sealing collars is less than 20 mm, in particular less
than 15 mm, more in particular 10 mm or less.
3. A sealing system according to claim 1 or 2, wherein the sealing
collars comprise circular outer ribs and circular inner ribs, which
outer ribs have an outside diameter which is larger than the inside
diameter of the bushing, and wherein the inside diameter of the
inner ribs is at most substantially equal to the outside diameter
of the tube.
4. A sealing system according to claim 1, 2 or 3, wherein the
sealing collars each comprise at least two shell members, whose
abutting boundary surfaces extend at least substantially in axial
direction, wherein the rear flanks, seen in the direction of
insertion, of the outer, serrated ribs extend in radial direction
and the inner ribs are arranged in pairs in the radial area of the
outwardly extending tips of the outer serrated ribs.
5. A sealing system according to any one of the preceding claims
1-4, wherein the inner ribs of the sealing collars are trapezoidal
in shape, seen in the direction of the axial longitudinal
section.
6. A sealing collar apparently suitable for use in a sealing system
according to any one of the preceding claims 1-5.
Description
[0001] The invention relates to a sealing system comprising an at
least substantially cylindrical tube and at least two sealing
collars at least partially made of an elastic material, which are
arranged round the tube in spaced-apart relationship for sealing
confinement by collaring of the tube in a bushing which is co-axial
with said tube.
[0002] Such a sealing system is generally known. In the fitted
position of the known system, an air space is present between the
sealing collars, which air space is bounded by the bushing and, as
already said before, the sealing collars. In the case of a fire,
for example on one side of the bushing, the excellent thermal
insulation properties of said air space prevent the other side of
the bushing becoming (too) hot for some time. In practice it has
become apparent, however, that the temperature in the air space can
run up so high when there is a fire that the sealing collars are
forced out owing to the increased pressure prevailing within the
air space, with all its adverse consequences as regards fire
safety. After all, if the known system is fitted in a ship's deck,
for example, fire can freely propagate through the bushing and into
the ship when the sealing collars are forced out and the sealing
function is thus lost.
[0003] The object of the invention is to overcome the
above-indicated drawback of the prior art, and in order to
accomplish that objective, a sealing system of the kind referred to
in the introduction is characterized in that the spacing between
the sealing collars is less than 25 mm, with said sealing collars
comprising an expandable material, in such an amount and of such a
composition that the sealing collars will expand in the case of a
fire, in such a manner that they will become wedged in the bushing.
Preferably, the spacing between the sealing collars is less than 20
mm, in particular less than 15 mm, more in particular 10 mm or
less. As a result, the thermal insulation properties of the air
space will be retained in the case of a fire, whilst eliminating
the risk of the pressure running up so high therein that the
sealing collars are forced out, partially because of the fact that
the sealing collars will swell as a result of the expansion
reaction, thus fixing themselves in position in the bushing. At the
very most, the sealing collars can be forced out over a distance of
a few millimetres in the case of a fire, but they will remain
substantially in position in such a case, as a result of which
their sealing function is retained.
[0004] In one preferred embodiment of a sealing system according to
the invention, the sealing collars comprise circular outer ribs and
circular inner ribs, which outer ribs have an outside diameter
which is larger than the inside diameter of the bushing, and
wherein the inside diameter of the inner ribs is at most
substantially equal to the outside diameter of the tube. In
particular, the sealing collars each comprise at least two shell
members, whose abutting boundary surfaces extend at least
substantially in axial direction, wherein the rear flanks, seen in
the direction of insertion, of the outer, serrated ribs extend in
radial direction and the inner ribs are arranged in pairs in the
radial area of the outwardly extending tips of the outer serrated
ribs. The inner ribs of the sealing collars are preferably
trapezoidal in shape, seen in the direction of the axial
longitudinal section.
[0005] The advantages of the above aspects will be explained in
more detail hereafter in the description of the figures.
[0006] The invention also relates to a sealing collar apparently
suitable for use in a sealing system according to the
invention.
[0007] The invention will now be explained in more detail with
reference to a figure shown in a drawing, which schematically shows
a sealing system according to the invention in perspective
view.
[0008] The figure shows a sealing system 1, comprising a metal (for
example steel or copper) tube 2 of cylindrical cross-section, a
bushing 3, likewise made of a metal (for example aluminium or
steel), which extends co-axially with the tube 2, as well as two
rubber sealing collars 4. Said sealing collars 4 are fitted in
spaced-apart relationship round the tube 2 in the annular space
between the tube 2 and the bushing 3 for the purpose of retaining
the tube 2 in the bushing 3 in a gastight and watertight manner.
The bushing 3 is fitted in a steel ship's deck 6, for example, or
in any other wall, partition or the like.
[0009] Each sealing collar 4 of elastic rubber is preferably formed
of two identical, shell-shaped collar halves 4', 4", whose abutting
boundary surfaces extend in axial direction. The collar halves 4',
4" are provided with ribs 8 of right-angled triangular
cross-section on the outer side and trapezoidal ribs 9 on the inner
side. When the sealing collars 4 are forced into the annular space
5 and around the tube 2, the ribs 8 thereof are compressed by the
bushing 3, as a result of which respective ribs 9 positioned
opposite said ribs 8 will undergo a diameter reduction, so that
they will press on the outer side of the tube 2 forcefully and
sealingly. As a result of the pressures that are thus produced in
the rubber, the abutting boundary surfaces of the collar halves 4',
4" of a sealing collar 4 are furthermore squeezed together
sealingly, without external pressure means being required.
[0010] Extensive tests have shown that in the case of a fire, for
example on one side of the ship's deck, the air space 7 that is
present between the sealing collars 4 provides excellent thermal
insulation, it is true, thus helping prevent excessive heating of
the other side of the ship's deck 6, but that the fire will cause
the air temperature in the air space 7 to run up so high that the
resulting increasing air pressure in the air space 7 will force the
sealing collars 4 out of the annular space 5 in such a case. It
stands to reason that the adverse effects will be incalculable in
that case, since a seal is no longer provided as a consequence of
the function of the sealing collars 4 being lost (after all, said
sealing collars no longer surround the tube 2 in the annular space
5). It has become apparent that wrapping the bushing 3 in rock wool
is not a suitable solution for keeping the temperature in the air
space 7 within acceptable bounds in the case of a fire.
[0011] The invention is based on the hitherto unrealised insight
that a solution for the phenomenon referred to above can be
provided by selecting a spacing of less than 25 mm between the
sealing collars 4, and thus also a smaller length of the annular
space 17, and forming the sealing collars 4 of an expandable
material, in such an amount and of such a composition that the
sealing collars 4 will expand in such a manner that they will
become wedged in the bushing 3 in the case of a fire. As a result,
the thermal insulation provided by the air space 7 will not be lost
when there is a fire, whilst the air pressure therein can at no
time run up so high that the sealing collars are forced out of the
annular space S. At the very most, the sealing collars 4 can be
forced out over a width of one or more ribs 9 in the case of a
fire, but the sealing collars 4 will remain substantially in
position in such a case, as a result of which their sealing
function is retained. The expandable rubber material of the sealing
collars 4 comprises in particular expandable graphite. It has been
proved by experiments that this graphite is extremely suitable for
causing the sealing collars 4 to expand in the case of a fire.
[0012] Preferably, the spacing mm between the sealing collars 4 is
less than 20 mm, in particular less than 15 mm, more in particular
less than or equal to 10 mm.
[0013] The invention is not restricted to the above-described
variant, but also other embodiments fall within the scope of the
invention as defined in the appended claims.
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