BALL VALVE LOCKING DEVICE

DISPOSITIF DE VERROUILLAGE DE CLAPET A BILLE

English Abstract

A valve body is provided with a locking post formed with the valve body to extend externally of the body generally parallel to the direction that the valve stem extends; the locking post and valve stem are provided or shaped with surfaces that enable the reception of a locking pin which can be inserted into a locking position by a user manually or with the aid of a tool supplied by the manufacturer of the locking pin or device; the valve mechanism will be tamper resistant in use in view of the absence of sufficient leverage to turn the valve stem by hand.

French Abstract

Un corps de clapet est pourvu d'un poteau de verrouillage formé avec le corps du clapet pour se prolonger à l'extérieur du corps généralement parallèlement à la direction dans laquelle se prolonge la tige du clapet; le poteau de verrouillage et la tige du clapet sont fournis ou formés de surfaces qui permettent la réception d'une goupille de verrouillage qui peut être insérée manuellement dans une position de verrouillage par un utilisateur ou à l'aide d'un outil fourni par le fabricant de la goupille de verrouillage ou du dispositif; le mécanisme de clapet sera inviolable en cours d'utilisation étant donné l'absence d'un effet de levier suffisant pour faire tourner la tige de soupape à la main.

Claims

What is claimed is:
1. A lockable valve having a valve body, a flow passage through said
valve body, a valve member disposed in said body and movable between a flow
blocking position and a flow permitting position, said valve body having an
opening, a valve stem connected at one end to said valve member and extending
through said opening in said valve body, said valve stem having a surface
shaped
to cooperate with a tool for rotating said valve stem about a central
longitudinal
axis of said valve stem and said valve member to effect movement of said valve
member between said flow blocking and flow permitting positions, a locking
post
extending from the exterior of said valve body and having a surface facing
said
valve stem with a first portion of said surface of said locking post
cooperating with
a portion of said valve stem and a second portion of said surface of said
locking
post being spaced from said valve stem and including a shaped recess, said
valve
stem having a flat surface portion facing said second portion of said surface
of said
locking post so that when a locking pin having a width sufficient to span a
distance
between said flat surface portion of said valve stem and said shaped recess,
rotation of said valve stem is prevented.
2. The invention as claimed in claim 1, wherein said locking post and
valve body are integrally formed.
3. The invention as claimed in claim 1, wherein said locking post and
valve stem extend generally parallel to one another.
4. The invention as claimed in claim 1, wherein said valve body
includes a collar that at least partially surrounds said valve stem.
5. The invention as claimed in claim 1, wherein said locking post is
spaced radially from the axis of the valve stem.
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Description

CA 02306332 2000-04-19
Ball Valve Locking Device
Field of the Invention
The present invention relates to a locking structure for a ball valve and,
more specifically, to a locking device that will be able to effectively
accommodate
with a modest change a number of different kinds of locking pins which are
available from manufacturers. Further, the present invention will provide a
locking structure which is less costly to manufacture and will more reliably
operate to protect the ball valve from unauthorized operation either in the
open or
closed positions.
Background of the Invention
In the water and gas distribution fields, it has long been necessary to
provide locking devices for valves to control the supply of water and gas to
consumers, for safety reasons, during assembly of a system and for a number of
other reasons. Chief among these are the prevention of unauthorized taking of
the fluid being supplied and safety reasons in case of a requirement for
cutoff of
the fluid being supplied in the event of leakage in a distribution system. One
common kind of locking system involves the use of a locking post that extends
externally of the valve body generally perpendicular to the valve stem and is
provided with through apertures which cooperate with an aperture provided in
the
valve stem handle so that an operator can prevent rotation of the valve stem
by
inserting a locking member through the aligned apertures of the locking post
and
valve stem handle. A separate locking device is then typically required to
secure
the locking member in place. These and other types of arrangements are
relatively expensive to manufacture. In addition, such systems are subject to
hand operation with relative ease and thus have not satisfied the primary
reasons
for their incorporation into a valve structure. Furthermore, in many
instances,
locking in the open position is not possible without additional devices.
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CA 02306332 2000-04-19
Summary of the Invention
The present invention avoids the difficulties of the locking devices of the
prior art and provides a very reliable and less expensive locking system and
one
which can be easily modified to accommodate different locking pins which are
available from manufacturers of such devices. Further, the locking system of
this
invention will be less subject to successful tampering than the prior art
structures
now available.
In a preferred embodiment, the valve body is provided with a locking post
formed with the valve body to extend externally of the body generally parallel
to
the direction that the valve stem extends. The locking post and valve stem are
provided or shaped with surfaces that enable the reception of a locking pin
which
can be inserted into a locking position by a user manually or with the aid of
a tool
supplied by the manufacturer of the locking pin or device. The valve mechanism
in the present invention will be tamper resistant in use in view of the
absence of
sufficient leverage to turn the valve stem by hand.
The foregoing and other advantages will become apparent as
consideration is given to the following description and accompanying drawings,
in
which:
Brief Description of the Drawings
Figure 1 is a perspective view of the valve with a locking pin in place;
Figure 2 is a top plan view of the valve of Figure 1; and
Figure 3 is sectional view taken along lines 3-3 of Figure 2;
Figure 4 is a side elevational view of a valve stem used with the structure
of the present invention.
Detailed Description of the Best Mode for Carrying Out the Invention
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Referring to the drawings, wherein like numerals refer to corresponding
parts throughout the several views, there is shown in Figure 1, a perspective
view of the lockable valve generally designated at 10. The valve 10 includes a
main body 12 and, at one end an opening 14 to a through passage provided in
the body 12. The body 12 is formed with a collar 18 on one side thereof which
surrounds a major portion of an operating valve's stem 20. The opening 14 may
be surrounded with a nut shaped surface 16 to facilitate engagement of a tool
on
this portion of the body 12.
Referring to Figure 2, there is shown a top plan view of the valve 10 of
Figure 1 with a locking pin 22 in place between the opposed surfaces of the
stem 20 and a locking post 24. The locking post 24 is formed integrally with
the
body 12 and extends radially relative to the axis A and generally parallel to
the
direction in which the stem 20 extends. The location of the locking post may
be
as illustrated or rotated 90 from the position shown in accordance with the
manufacturer's preference.
Referring now to the sectional view of Figure 3, it will be seen that the
through passage includes a pair of recesses such as at 26 spaced apart along
the axis A of the through passage and which support sealing rings such as at
28.
The sealing rings, in turn, rotatably support a ball valve element 30 which is
provided with a through passage 34. The upper portion of the ball 30 is formed
with a recess 36 which receives one end of the stem 20. The end of the body 12
opposite the end 14 is provided with a threaded coupling member 38 which
carries one of the recesses 26 and a sealing ring 28. The threaded inter-
engagement between the member 38 and the threaded interior of the through
passage in the valve body 12 maintains the compressive force exerted on the
ball 30 of the valve member.
The above described ball valve 10 is typically operated by a separate tool
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CA 02306332 2000-04-19
having a socket for engaging the stem 20 to enable a user to rotate the stem
to
move the ball element and its passage between a flow blocking position and a
flow permitting position relative to the through passage of the valve body 12.
As noted above, in the past, it has been the practice to provide a through
bore in the locking post as well as in the exposed portion of the valve stem
mechanism or a handle arm attached to the valve stem to permit a locking
member to penetrate through both the locking post and the valve stem handle
arm to effect the desired locking of the stem against rotation. However, the
task
of providing the bore in these members with the correct positioning and sizing
has proved to be an expensive manufacturing operation. This operation is
avoided with the structure of the present invention. Specifically, the upper
portion of the locking stem 24 has a inner face 42 which is provided with a
semi-
circular groove 44 for cooperating with a portion of the locking pin 22. In
the
illustrated embodiment, the confronting face of the upper portion of the stem
20 is
also set back a small distance to accommodate the insertion of the pin 22 as
shown in the closed position. Also, the confronting face 46 of the valve stem
20
is flat to cooperate with the cylindrical surface of the pin 22 to resist
turning with
the pin 22 in place as shown. It is also preferable and within the teachings
of the
present invention to provide the radial extent of the locking post 24 so that
with
the pin 22 in place, the stem 20 is not exposed or, at least, its exposure is
decreased for access by a tool.
The locking pin 22 will be provided by a manufacturer who will also supply
a tool for locking and unlocking the pin. A number of different types of pins
are
available from various manufacturers of these types of devices. As shown in
Figure 2, the typical locking pin 22 will have enlarged ends 22a and 22 b to
prevent removal once installed between the locking post 24 and the valve stem
20. The large end to 22a will typically be removable with a special tool, as
noted
above, to allow unlocking of the valve 10. A number of other shapes may be
employed to effect the locking with the insertion of a rigid member between
the
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locking post 24 and be valve stem 20.
In Figure 4, the shape of the valve stem 20 is shown more clearly prior to
attachment to the ball valve element 30. The cylindrical portions of the same
diameter are located at the ends 50 and 52 of the stem 20 and a reduced
diameter portion 54 is located between these ends for the purpose of securely
engaging the locking pin either in the open or closed positions.
Having described the invention, it will be apparent to those skilled in this
art that various modifications may be made to the invention without departing
from the spirit of the invention as described above.
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Representative Drawing