Pipe coupling for female screw

Details Pipe coupling for female screw Pipe coupling for female screw

2000-07-07

2002-06-04

Dayoan, B. (Department: 3627)

Pipe joints or couplings

Essential catch

With manipulator

C285S305000, C285S033000, C285S034000, C285S035000

Reexamination Certificate

active

06398268

ABSTRACT:

BACKGROUND OF THE INVENTION
This invention relates to a pipe coupling for a female screw which has a male screw to be connected to a female screw port formed in a fluid pressure device.
Japanese Patent No. 2758380, for example, discloses a pipe coupling for a female screw which has a male screw to be connected to a female screw port formed in a fluid pressure device.
FIGS. 8 and 9
show the basic structure of the pipe coupling disclosed in the patent.
FIG. 8
is a sectional view of the pipe coupling, showing its non-connected state, and
FIG. 9
is an enlarged view of a section A incorporated in the pipe coupling. In the following description, the words “forward (front)” and “rearward (rear)” mean the right-hand direction and the left-hand direction in
FIG. 8
, respectively.
As shown, the pipe coupling for a female screw disclosed in the patent comprises a cylindrical body
100
, arm members
103
provided at the front end of the body
100
, and a sliding rod
104
fitted in the body
100
. The cylindrical body
100
includes a front cylinder
101
and a rear cylinder
102
. The front and rear cylinders
101
and
102
are connected to each other by screwing a male screw provided on the outer peripheral surface of a front end portion of the rear cylinder
102
, into a female screw formed in the inner peripheral surface of a rear end portion of the front cylinder
101
. Further, a connecting cylinder
105
is fitted on a connecting section of the front and rear cylinders
101
and
102
. A cylindrical stepped arm base
106
is engaged with the inner peripheral surface of the front cylinder
101
. The arm members
103
are supported by the front end of the arm base
106
so that they can swing about their respective support shafts
107
. The arm members
103
are arranged to swing between an open position in which they are parallel to the longitudinal central axis of the cylindrical body
100
, and a closed position in which they are inclined to the axis. The front end portions of the arm members
103
project forward (i.e. in the right-hand direction in the figure) from the front end of the front cylinder
101
. Engagement portions (male screw portions)
108
are formed on the outer peripheral surfaces of front end portions of the arm members
103
, so that they will be engaged with the female screw portion formed in the inner surface of a female screw port
115
in a fluid pressure device, when the arm members
103
are in the open position.
A cylindrical seal holder
109
is fitted in a front end portion of the front cylinder
101
. An O-ring
110
is fitted on the outer peripheral surface of the seal holder
109
, thereby airtightly sealing a clearance between the seal holder
109
and the front cylinder
101
. A seal ring
111
is fitted in a front end portion of the seal holder
109
. The rear end of the seal holder
109
is slidably inserted between the inner peripheral surface of the front cylinder
101
and the outer peripheral surface of the arm base
106
. The seal holder
109
is always urged in the right-hand direction in the figure by a spring
112
located between itself and the arm members
103
. As a result, the seal ring
111
is also urged in the right-hand direction in the figure.
In the open position, the opposed inner surfaces of the arm members
103
are parallel to each other. At this time, the distance between the opposed inner surfaces of the arm members
103
is substantially the same as the outer diameter of a lock pin
113
, described later, incorporated in the sliding rod
104
. On the other hand, in the closed position, the distal ends of the arm members
103
contact each other and the diameter of the contact portion of the male screw portions
108
is small, as is shown in FIG.
8
.
When the lock pin
113
is inserted between the arm members
103
, the outer peripheral surface of the lock pin
113
is engaged with the inner surfaces of the arm members
103
, thereby outwardly opening the arm members
103
and keeping them in the open position.
The operation of connecting the pipe coupling constructed as above to a port in a fluid device will be described with reference to
FIGS. 8 and 9
. First, in the state shown in
FIG. 8
, the distal ends of the arm members
103
are inserted into the female screw port
115
of the fluid device, thereby further forwarding the pipe coupling and pushing the seal holder
109
into the front cylinder
101
against the urging force of the spring
112
with the seal ring
111
at the seal holder
109
side kept in contact with the fluid device. After that, the pressing surface
116
of the sliding rod
104
, which constitutes the rear end of the rod, is pushed forward, thereby inserting the lock pin
113
between the arm members
103
and causing the arm members
103
to swing about the support shafts
107
and assume the open position. As a result, the male screw portions
108
formed of the front end portions of the arm members
103
are engaged with the female screw portion formed in the inner peripheral surface of the female screw port
115
of the fluid device. Further, in this state, the seal ring
111
is in contact with the end surface of the female port
115
, thereby sealing a clearance between the pipe coupling and the fluid device, and also maintaining a state in which the pipe coupling is prevented from being disconnected from the fluid device.
When, in the connecting operation, the arm members
103
assume the open position about the support shafts
107
, it is possible that the peaks of the thread of the male screw portions
108
of the arm members
103
will be aligned with the peaks of the thread of the female screw portion formed in the inner surface of the female screw port
115
, and hence the male and female screws will not be engaged with each other. In this case, it is necessary to slightly move the pipe coupling forward or backward so as to shift the arm members
103
by half of one peak of the thread, in order to engage the screws with each other. When backwardly shifting the arm members
103
by half of one peak, with the rear end
109
a
of the seal holder
109
kept in contact with a stepped portion
101
a
formed in the inner peripheral surface of the front cylinder
101
as shown in
FIG. 9
, the seal holder
109
urged by the spring is shifted forward by half of one peak, and therefore the screws can be engaged with each other. However, when, in order to engage the screws, forward shifting the arm members
103
by half of one peak, and backward shifting the seal holder
109
, urged by the spring, by half of one peak, the seal holder
109
cannot be shifted backward since the rear end
109
a
comes in contact with the stepped portion
101
a
. Accordingly, the arm members
103
cannot be shifted forward, which means that the screws cannot completely be engaged with each other (an unstable connecting state is established). If in this state, the screws are still tried to be engaged with each other, it is necessary to press the cylindrical body
100
by pressing the sliding rod
104
with an excessive force, or to press the cylindrical body
100
itself to thereby significantly deform the seal ring
111
. This indicates a low operability of the pipe coupling, and may adversely affect the durability of the seal ring. Moreover, when, in order to engage the male screw
108
with the female screw formed in the inner surface of the port
115
, the sliding rod
104
is inserted between the arm members
103
to open the arm members
103
, and also the arm members are shifted backward by half of one peak so as to eliminate the defective engagement of the screws, in a state in which the spring
112
is not compressed (not warped), i.e. in a state in which the seal holder
109
is not pushed into the front cylinder
101
against the urging force of the spring
112
, it is possible that the seal ring
111
of the seal holder
109
will be separated from the end face of the female screw port
115
, thereby causing defective sealing.
BRIEF SUMMARY OF THE INVENTION
It is a main object of the inventi

Affiliated with

Also associated with

Rating

Pipe coupling for female screw does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Pipe coupling for female screw, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pipe coupling for female screw will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2976167