Seal for a joint or juncture – Seal between fixed parts or static contact against...
Reexamination Certificate
1999-10-14
2003-01-07
Swann, J. J. (Department: 3677)
Seal for a joint or juncture
Seal between fixed parts or static contact against...
C138S030000
Reexamination Certificate
active
06502828
ABSTRACT:
TECHNICAL FIELD
The present invention relates to an end seal which is one kind of a sealing device.
PRIOR ART
As a pressure apparatus provided with an end seal, an accumulator
51
shown in
FIG. 9
has been heretofore known, the accumulator being constituted as described below.
That is, first, cover members
54
,
55
are welded and secured to opposite ends of a tubular shell
53
to provide a housing
52
, the housing
52
housing therein an operating member
56
provided with a bellows
57
and an end member
58
. The bellows
57
has one end secured to one cover member
54
, and the other end secured to the end member
58
, whereby the interior of the housing
52
is divided by the bellows
57
and the end member
58
into an internal gas chamber
59
and an external pressure chamber
60
of the bellows
57
and the end member
58
.
One cover member
54
on the left side in the figure is provided with an injection hole
61
for injecting gas into a gas chamber
59
, and a plug member
62
for closing the injection hole
61
is mounted on the injection hole
61
. Accordingly, the plug member
62
is removed and gas having predetermined pressure is injected into the gas chamber
59
from the injection hole
61
. After injection, the injection hole
61
is closed by the plug member
62
to thereby seal the gas having predetermined pressure into the gas chamber
59
.
Further, the other cover member
55
on the right side in the figure is provided with a mounting portion
63
provided with a thread portion
64
for connecting the accumulator
51
to a pressure pipe such as an oil pressure pipe not shown, and with a pressure introducing port
65
for introducing pressure within the pressure pipe into a pressure chamber
60
. Accordingly, the accumulator
51
is connected to the pressure pipe in the mounting portion
63
so that the pressure within the pressure pipe is introduced from the pressure introducing port
65
into the pressure chamber
60
.
The accumulator
51
provided with the above-described constitution has a function to absorb a pulsation of pressure generated, for example, in the pressure pipe by keeping the balance between the sealed gas pressure in the gas chamber
59
and the pressure in the pressure chamber
60
. However, when the pressure within the pressure chamber
60
during operation, that is, the pressure within the pipe should extremely lower, the bellows
57
is inflated due to a pressure difference between the inside and the outside to possibly be buckled and broken.
Accordingly, in the above-described accumulator
51
, measures therefor are taken such that an end seal
66
is mounted on the end of the end member
58
by a baking means so that the pressure in the pressure chamber
60
is not lowered to a level below a predetermined value by the sealing action of the end seal
66
. That is, when the pressure in the pressure chamber
60
lowers during operation, the bellows
57
extends so long that the end seal
66
mounted on the end of the end member
58
comes in close contact with an end portion
55
a
of the other cover member
55
, and therefore, the pressure chamber
60
is intercepted from the pressure introducing port
65
by the sealing action of the end seal
66
caused by the close contact. Accordingly, even if the pressure in the pressure pipe further lowers after the interception, the pressure in the pressure chamber
60
is not lowered to thereby keep the balance between the sealed gas pressure in the gas chamber
59
and the pressure in the pressure chamber
60
to prevent the bellows
57
from being inflated.
However, in the above-described conventional accumulator
51
, it is set so that the end seal
66
is mounted on the end of the end member
58
as mentioned above, and the end seal
66
is sandwiched between the end portion
55
a
of the cover member
55
and the end member
58
being moved toward the end portion
55
a
due to the predetermined pressure difference. Therefore, the end seal
66
is sandwiched between the end portion
55
a
and the end member
58
in a compressed state to receive large load, which is repeated every expansion and contraction of the bellows
57
resulting from a pressure variation, resulting in an inconvenience that a phenomenon of a permanent set of fatigue occurs relatively early in the end seal
66
whereby the sealing performance of the end seal
66
rapidly lowers.
SUMMARY OF THE INVENTION
A first object of the present invention is to improve an end seal for sealing an end of a pressure apparatus such as an accumulator and other apparatuses.
A second object of the present invention is to prevent an early occurrence of a permanent set of fatigue in a seal member.
A third object of the present invention is to provide an end seal capable of securing the stable sealing performance for a long period of time.
A fourth object of the present invention is to provide an end seal having construction in which a seal is hard to be removed from a housing.
An end seal according to one form of the present invention comprises an end seal for sealing between an end portion and an operating member moving toward said end portion. There is a seal member mounted on said end portion. When said operating member comes in contact with said end portion and stops or is stopped by a stopper, a seal lip pressed by sealing fluid pressure into close contact with said operating member is provided on said seal member.
In an end seal according to a further form of the present invention, an annular rigid member is provided on the inner peripheral side of a seal member, and an outer peripheral surface of an extreme end of said rigid member arranged on the inner peripheral side of a seal lip of said seal member is formed in the form of a divergent taper adjusting to a shape of said seal lip.
An end seal according to another form of the present invention comprises an end seal for sealing between an end portion of a housing and an operating member moving toward said end portion. There are provided a seal member inserted in a non-adhesive manner into a recessed seal mounting portion provided on said end portion, and an annular rigid member secured to said housing on the inner peripheral side of said seal member. When said operating member comes in contact with said end portion and stops or is stopped by a stopper, a seal lip pressed by sealing fluid pressure into close contact with said operating member is provided on said seal member. On said rigid member is provided a divergent tapered extreme end positioned on the inner peripheral side of said seal lip to backup said seal lip and to prevent said seal member from slipping out from said seal mounting portion.
In an end seal according to another form of the present invention, a rigid member is inserted into a fluid flow passage provided in a housing, and a difference in-level locating portion provided on the outer peripheral surface of said rigid member runs into a difference in-level locating portion provided on the inner surface of said fluid flow passage to thereby specify the inserting depth of said rigid member.
In an end seal according to still another form of the present invention, a rigid member is inserted into a fluid flow passage provided in a housing, and a proximal end of said rigid member positioned forwardly of an inserting direction is enlarged in diameter after insertion into engagement with said housing to thereby prevent said rigid member for slipping out from said fluid flow passage.
In the above-described end seal, the seal member is mounted not on the operating member on the moving side but on the end portion on the stationary side. Moreover, in a state that the operating member moving toward the end portion comes in contact with the end portion and stops, or is stopped by a stopper separately provided on the end portion, a seal lip of the seal member of said end seal is pressed by the sealing fluid pressure into close contact with the operating member to thereby provide the sealing action. Accordingly, sealing is not done in a state that the seal member is strongly
Jacobson & Holman PLLC
NDK Corporation
Rodgers Matthew E.
Swann J. J.
LandOfFree
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