Note: Descriptions are shown in the official language in which they were submitted.
CA 02846128 2014-03-17
= 1983P02CA
PIPE THREAD PROTECTOR WITH A DETENT
BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to thread protectors and, in
particular, to a thread
protector with a detent to restrain the thread protector against rotation
relative to a
threaded pipe end.
Description of the Related Art
[0002] It is known to use thread protectors to protect threaded pipe ends
from damage
during storage and transport. For example, United States Patent Number
4,139,023
discloses a pipe thread protector which is made of a resilient material and
has a cup-
shaped body which overlies the pipe threads to be protected. The outermost
portion of the
cup-shaped body is provided with protector threads complementary to the pipe
threads.
Inwardly of the protector threads, the cup-shaped body is provided with a
plurality of
tapered wedging ribs. These wedging ribs automatically center the cup-shaped
body on
the threaded pipe end as the pipe thread protector is urged over the pipe end
for
subsequent engagement of the protector threads with the pipe threads. The
wedging ribs
thereafter frictionally restrain the protector against rotation relative to
the pipe end.
[0003] United States Patent Number 4,553,567 discloses a protector for a
threaded
end section of a cylindrical part, such as pipe, which has a tubular body
having a plurality
of flexible ribs projecting from a wall of the body. The ribs, in an unflexed
condition,
extend at an acute angle in a forward direction toward the pipe upon which the
protector
is placed on the threaded end section of the pipe. The body is disposed in
space
telescoped confronting relation to the threaded end section of the pipe to
preclude
circumferential and radial destructive stress between the body and the
threaded end of the
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pipe. In one embodiment the ribs comprise first ribs engageable with the
threaded end
section of the pipe and second ribs located adjacent the first ribs in holding
engagement
with the threaded end section of the pipe.
[0004] It is of utmost importance that thread protectors do not loosen or
fall off
during use and expose pipe threads. A pipe is subject to vibration loading
when it is
transported in the form of a flat-bed truck or rail. Vibrations can cause
prior art protectors
to loosen or fall off and expose the pipe threads to severe damage. The
problem is made
worse under extreme weather conditions when hot temperatures cause female
thread
protectors to expand and cold temperatures cause male thread protectors to
shrink.
Changes in diameter caused by temperature fluctuations can make HDPE thread
protectors extremely susceptible to disengaging from the pipe threads and
vibrating loose.
SUMMARY OF THE INVENTION
[0005] It is an object of the present invention to provide a thread
protector with an
improved detent to restrain the thread protector against rotation relative to
a threaded pipe
end.
[0006] There is accordingly provided a thread protector provided with a
detent to
resist rotational motion of the thread protector relative to a threaded pipe
end.
[0007] A male one of thread protectors comprises a substantially closed
end and a
threaded outer annular wall extending from the substantially closed end. There
is a detent
disposed on the threaded outer annular wall. The detent is a resilient member
which
interrupts threading on the threaded outer annular wall of the thread
protector.
[0008] The detent may be a resilient member which is press fit into a
recess in the
threaded outer annular wall of the male thread protector. The male thread
protector may
include an annular flange at an open end thereof. There may be spaced-apart
bumpers
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= extending circumferentially along the annular flange. The bumpers may be
crescent-
shaped and each bumper may have a crescent-shaped recess. There may be an
opening
which extends through the substantially closed end of the male thread
protector.
[0009] A female one of thread protectors comprises a substantially closed
end and a
threaded inner annular wall extending from the substantially closed end. There
is a detent
disposed within an interior of the female thread connector. The detent
includes a resilient
flap with an edge which is spaced-apart from and facing the threaded inner
annular wall
of the female thread protector.
[0010] The female thread protector may include an elongate member
extending from
the substantially closed end and a socket in the resilient flap. The elongate
member may
be received by the socket. The elongate member may extend from the
substantially closed
end of the female thread protector in a direction parallel to a longitudinal
axis of the
female thread protector. The female thread protector may also include three
elongate
members extending from the substantially closed end and three sockets in the
resilient
flap. Each elongate member may be received by a corresponding one of the
sockets.
[0011] There may be a tab extending substantially perpendicular from the
resilient
flap of the female protector. There may be a plurality of spaced-apart ribs
extending
about and between the threaded inner annular wall and the substantially closed
end of the
female thread protector. There may be an annular ring which passes through the
ribs. The
female thread protector may include spaced-apart bumpers extending
circumferentially
along the substantially closed end thereof. The bumpers may be crescent-shaped
and each
bumper may have a crescent-shaped recess. There may be an opening which
extends
through the substantially closed end of the female thread protector.
[0012] A combination of a pipe and a thread protector comprises a pipe
with an inner
wall and a male threaded pipe end and a thread protector with a substantially
closed end
and a threaded inner annular wall extending from the substantially closed end.
There is a
detent disposed within an interior of the thread protector. The detent
includes a resilient
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= flap with an edge which is spaced-apart from and facing the threaded
inner annular wall
of the thread protector. The detent frictionally engages the inner wall of the
pipe when the
threaded pipe end of the pipe and the thread protector are threadedly engaged,
thereby
resisting rotational motion of the thread protector relative to the threaded
pipe end of the
pipe
[0013] The thread protectors disclosed herein address the
deficiencies of known
thread protectors with the addition of a detent that resists rotational motion
of the thread
protector under various temperatures.
BRIEF DESCRIPTIONS OF DRAWINGS
[0014] The invention will be more readily understood from the
following description
of the embodiments thereof given, by way of example only, with reference to
the
accompanying drawings, in which:
[0015] Figure 1 is a perspective view of an improved male thread
protector;
[0016] Figure 2 is another perspective view of the male thread protector;
[0017] Figure 3 is a sectional view of the male thread protector;
[0018] Figure 4 is a perspective, exploded view of the male thread
protector and a
female threaded pipe end;
[0019] Figure 5 is a perspective view showing the male thread
protector partially
threaded into the female threaded pipe end;
[0020] Figure 6 is a perspective view showing the male thread
protector fully
threaded into the female threaded pipe end;
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[0021] Figure 7 is a sectional view showing the detents of the male
thread protector
frictionally engaging threading of the female threaded pipe end;
[0022] Figure 8 is a perspective view of an improved female thread
protector;
[0023] Figure 9 is another perspective view of the female thread
protector;
[0024] Figure 10 is a sectional view of the female thread protector;
[0025] Figure 11 is another sectional view of the female thread protector
showing the
female thread protector engaged with a male threaded pipe end;
[0026] Figure 12 is a perspective, exploded view of the female thread
protector and a
male threaded pipe end;
[0027] Figure 13 is perspective view showing the female thread protector
partially
threaded about the male threaded pipe end;
[0028] Figure 14 is perspective view showing the female thread protector
fully
threaded about the male threaded pipe end; and
[0029] Figure 15 is a perspective end view of the female thread
protector.
DESCRIPTIONS OF THE PREFERRED EMBODIMENTS
[0030] Referring to the drawings and first to Figure 1, an improved male
thread
protector 10 for protecting a female threaded pipe end is shown. The male
thread
protector 10 has a male threaded annular wall 12 which extends between an open
end 14,
which is best shown in Figure 1, and a substantially closed end 16 which is
best shown in
Figure 2. The threaded annular wall 12 is an outer annular wall of the male
thread
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,
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protector 10. There is an annular flange 18 at the open end 14 of the male
thread protector
10. Spaced-apart bumpers 20, 22, 24 and 26 extend circumferentially along the
annular
flange 18. The bumpers assist in impact protection. The bumpers are each
crescent-
shaped and are provided with a respective central recess, for example, a
crescent-shaped
recess 28 as shown for one of the ribs 20 in Figure 1. The recesses in the
bumpers may
receive an installation or removal tool and also reduce the material required
to make the
male thread protector. There is a small opening 29, shown in Figure 2, which
extends
through the substantially closed end 16 of the male thread protector 10. The
opening
allows airflow through the pipe to minimize condensation.
[0031] The male thread protector 10 is also provided with a plurality of
spaced-apart
detents, for example detents 30 and 32, in the threaded annular wall 12. The
detents 30
and 32 interrupt threading on the threaded annular wall 12. In this example,
the detents 30
and 32 are resilient and are made of an elastomeric material. As shown in
Figure 3, for
one of the detents 30, the detent 30 is press fit into a corresponding recess
34 in the
threaded annular wall 12 of the male thread protector 10. Referring now to
Figures 4 to 6,
the detents 30 and 32 come into frictional engagement with threading 36 of a
female
threaded pipe end 38 when the male thread protector 10 is threaded into the
female
threaded pipe end 38 to resist rotational motion of the male thread protector.
This will
necessitate an additional rotational force to thread the male thread protector
10 into the
female threaded pipe end 38. An additional rotational force will also be
required to
unthread the male thread protector 10 from the female threaded pipe end 38.
This helps
ensure that the male thread protector 10 is not unintentionally loosened or
removed from
the female threaded pipe end 38. Figure 7 shows the detent 30 frictionally
engaging the
threading 36 of a female threaded pipe end 38.
[0032] An improved female thread protector 50 is shown in Figures 8 and 9.
The
female thread protector 50 has a female threaded annular wall 52 which extends
between
an open end 54, which is best shown in Figure 8, and a substantially closed
end 56 which
is best shown in Figure 9. The threaded annular wall 52 is an inner annular
wall of the
female thread protector 50. Spaced-apart bumpers 58, 60, 62 and 64 extend
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circumferentially along the substantially closed end 56 of the female thread
protector 50.
The bumpers assist in impact protection. The bumpers are crescent-shaped and
each is
provided with a central recess, for example, a crescent shaped recess 66 as
shown for one
of the bumpers 58 in Figure 9. The recesses in the bumpers may receive an
installation or
removal tool and also reduce the material required to make the female thread
protector.
There is a generally cylindrical recess 68 in the substantially closed end 56
of the female
thread protector 50. The recess 68 is concentric with the threaded annular
wall 52 and
thus provides an interior of the female thread protector 50 with an annular
interior portion
as can best be seen in Figure 10.
[0033] A plurality of spaced-apart impact energy absorbing ribs, for
examples ribs 72
and 74, extend about and between the threaded annular wall 52 and the
substantially
closed end 56 of the female thread protector 50. The ribs extend radially as
best seen in
Figure 15. These ribs provide a crash zone which helps protect the pipe if the
female
thread protector is subject to an impact. There is also a solid annular ring
75, shown in
Figures 10 and 15, which passes through the ribs to provide a seal between the
end of the
pipe and the female thread protector by eliminating interruptions by the ribs.
There is a
small opening 76, shown in Figures 8 and 10, which extends through the
substantially
closed end 56 of the female thread protector 50. The opening allows airflow
through the
pipe to minimize condensation.
[0034] The female thread protector 50 is also provided with a detent 78
shown in
Figures 10 and 15. In this example, the detent includes a resilient flap or
flange 83
mounted on three elongate members 80a, 80b and 80c. The elongate members 80a,
80b
and 80c extend from the substantially closed end 56 of the female thread
protector 50 in a
direction parallel to a longitudinal axis 100 of the female thread protector.
The resilient
flange 83 has three sockets 81a, 81b and 81c. As shown in Figure 10 for one of
the three
sockets 81a, the socket 81a fits tightly over an outer end 79 of the elongate
member 80a.
The resilient flange 83 extends in a plane generally perpendicular to the
longitudinal axis
100 of the female thread protector 50. The resilient flange 83 has an outer
edge 84 which
is spaced-apart from and faces the threaded annular wall 52. There is a tab 82
extending
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from the resilient flange 83 generally parallel to the elongate members 80a,
80b and 80c
when the resilient flange 83 is substantially planar as shown in Figure 10.
The tab 82 may
facilitate coupling and decoupling of resilient 83 and the three elongate
members 80a,
80b and 80c. Referring now to Figure 11, the resilient flange 83 of the detent
78 comes
into frictional engagement with an inner wall 86 of a male threaded pipe end
88 when the
female thread protector 50 is threaded onto the male threaded pipe end 88. In
particular,
the resilient flange 83 flexes and frictional engages the inner wall 86 of a
male threaded
pipe end 88. The detent 78 thus resists rotational motion of the female thread
protector
50. This necessitates an additional rotational force to allow the female
thread protector 50
to be threaded into the male threaded pipe end 88. An additional rotational
force will also
be required to unthread the female thread protector 50 from the male threaded
pipe end
88 to resist inadvertent loosening or removal of the thread protector with
respect to the
pipe. Figures 12 to 14 show the female thread protector 50 being threaded onto
the male
threaded pipe end 88.
[0035] It will be understood by a person skilled in the art that many of
the details
provided above are by way of example only, and are not intended to limit the
scope of the
invention which is to be determined with reference to the following claims.
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