Note: Descriptions are shown in the official language in which they were submitted.
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The present invention is related to the
lockring tube joint disclosed in Canadian Patent No.
982,182 and is intended to extend the range of use of
lockring tube joints.
The present invention is directed to a tube
joint having axially overlapping tube members secured
by a lockring, and is summarized in the following
objects:
First, to provide a lockring tube joint which
utilizes a novelly arranged lockring having an entrance
cone frustum zone intended primarily to press the tube ;- ~;
members into intimate mutual contact, a cylindrical
zone maintaining such contact, followed by a second cone
frustum zone to effect radial constriction of the tube
members to provide high load concentration, and finally
a zone in which the tube members clear the lockring to
permit spring back of the tube members.
Second, to provide a lockring tube joint wherein
the lockring is provided with a set of three cone
frustum zones and alternate cylindrical zones to provide
a plurality of spaced regions in which the tube members
are radially compressed.
Third, to provide a lockring tube joint wherein
either of the tube members may be provided with ribs
at selected locations to provide localized regions of
increased radial compression for increased bonding and
sealing engagement between the tube members.
Fourth, to provide a lockring tube joint, as
indicated in the preceding object, wherein selected
ribs may be interrupted by axial channels whereby on
radial compressions torsional interlock between the
tube members is attained.
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Fifth, to provide a lockring tube joint which is particularly
adapted for the connection of tube members having relative thin walls with
respect to their diameters, as well as for tubes having relatively low
strengt:h material, but is not limited thereto.
Sixth, to provide a lockring tube joint wherein either tube n,ember
may be in the form of a connector collar of stronger material than the other
tube member and provided with ribs capable of being forced into the wall of
the other tube member for interlocking and sealing connection therewith.
Seventh, to provide a lockring tube joint which may utilize as a
par~ thereof a feature of the aforementioned patent namely an abrupt terminal
shoulder on the lockring permitting springback of the tube members to effect
additional interlock between the lockring and tube member.
Eighth, to provide a lockring secured joint in which the inner
member may be a solid shaft.
The lockring joint of the invention may be generally defined as a
joint comprising a lockring having internally a first cone frustum zone,
a cylindrical zone and a second cone frustum zone, joined in coaxial sequence,
the smaller end of the first cone frustum zone and the larger end of the
second cone frustum zone being equal in diameter to the cylindrical zone;
an outer tube member initially having an external diameter approximating
the larger end of the first cone frustum; and an inner member initially
slidably received in the outer tube member. The lockring is adapted to be
forced axially on the outer tube to effect in sequence radial compression
of the outer tube member and inner member in the regions of the first and
second cone frustum zones, thereby to form axially spaced regions in which
the members are in mutual bonding engagement.
Figure 1 is a side view of one embodiment of the lockring tube
joint, indicating fragmentarily a pair of inner tube members coupled by an
outer tube member and showing a lockring in its initial position.
Figure 2 is a fragmentary side view thereof showing one of the
lockrings in its final position.
Figure 3 is an enlarged longitudinal fragmentary sectional view
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thereof taken through 3-3 of Figure 1 showing a lockring in its initial
position.
Figure 4 is an enlarged longitudinal fragmentary sectional view
corresponding to Figure 3 showing the lockring in its final position.
Pigure S is an enlarged fragmentary sectional .
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view also corresponding to Figure 3 showing the lockring
in its final position.
Figure 6 is an enlarged fragmentary sectional
view showing another embodiment of the lockring tube joint
showing a pair of tube members, one having a bell end,
and showing the lockring in its final position after being
forced over the bell end from the open extremity thereof.
Figure 7 is an enlarged fragmentary sectional
view corresponding to Figure 6, but showing the lockring
in its final position after being forced over the flared
extremity of the bell end from the closed extremity thereof.
Figure 8 is a further enlarged fragmentary sectional
view taken within circle 8 of Figure 6.
Figure 9 is a fragmentary sectional view showing
a further embodiment of the lockring tube joint wherein
a pair of tube members have bell ends for assembly over an
internal coupling tube member, the parts thereof being
shown in position for assembly.
Figure 10 is an enlarged fragmentary sectioanl
view thereof showing the lockring tube joint in its assembled
condition.
Figure 11 is a further enlarged fragmentary
sectional view taken within circle 11 of Figure 10.
Figure 12 is an enlarged fragmentary transverse
sectional view taken through 12-12 of Figure 9 wherein
an interlocking rib is modified to provide axial channels
to increase torsional interlock.
Figure 13 is a fragmentary transverse sectional
view taken through 13-13 of Figure 10 wherein the modified
rib is shown when effecting a torsional interlock.
Figure 14 is a fragmentary longitudinal sectional
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view of a further embodiment of the constrictor ring joint
with the parts in their initial position.
Figure lS is a fragmentary longitudinal sectional
view thereof corresponding to Figure 14, but showing the
parts in their secured position.
Figure 16 is a fragmentary transverse sectional
view thereof taken through 16-16 of Figure 14.
Figure 17 is a transverse sectional view thereof
taken through 17-17 of Figure 15.
Figure 18 is a fragmentary sectional view corres-
ponding to the region within circle 18 of Figure 14 illus-
trating a modification of the interlocking rib.
Figure 19 is a fragmentary view of the internal
surface thereof taken from 19-19 of Figure 18.
Figure 20 is a fragmentary sectional view similar
to Figure 18, showing a further modification.
Referring to Figures 1 through 5, the construction
here illustrated is particularly suited to provide a high
strength connection between a pair of tubes and a surround-
20 ing collar. The lockring tube joint includes a pair of ~;
inner tubes 1 having confronting end regions 2. The adjacent
portions of the inner tubes are received in an outer tube
or collar 3 which inludes a pair of opposed internal tapered
sealing and seating regions 4 which are elastically engaged
by the end regions 2. Otherwise, the interior of the ~ ;
outer tube is cylindrical.
The collar is provided with a centrally locatedexternal stop flange 5. Adjacent opposite sides of the
stop flange, the collar is provided with external tapered
regions 5. Continuing from each region 6, the collar
includes a first external cylindrical region 7 terminating -~
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at an external constrictor flange 8, the far side of which
is tapered as indicated by 9. Continuing from the tapered
side 9 i5 a second externally cylindrical portion 10.
Each extremity of the collar is externally beveled as
indicated by 11.
Each side of the collar 3 receives a lockring
12 having a short cylindrical entrance end 13, the extremity
of which may be beveled. Continuing axially inward from
the entrance end 13, the lockring includes an initial
internally tapered or cone frustum region 14 which joins
to an internal cylindrical region 15. The region 15 joins
to a final internally tapered or cone frustum region 16
terminating at an abrupt shoulder 16a.
The embodiment of the lockring tube joint as
shown in Figures 1 through 5 is assembled as follows:
During pre-assembly a prelubricated pair of lock-
rings is positioned so that their entrance ends 13 overlie
the flanges 8 as shown in Figure 3. Next, the pair of
tubes 1 is inserted in the collar, keeping a light end
force on the tubes. Finally opposed axial forces are
applied simultaneously to both lockrings to force the lock-
rings onto the collar 3. Initially, the final tapered
regions 16 of the lockrings are spaced from the collar
so that the axial force applied to each constrictor ring `
is first converted to a constriction force applied to the
corresponding flanges 8.
It is desirable that the dimensions of the collar
and the selection of the metal comprising the collar, be
such that some axial buckling of the collar between the
flanges 8 and the stop flange 5 may occur to the extent
that a stronger elastic seating and sealing connection
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is formed between the end regions 2 and the tapered sealing
regions 4.
Continued movement of the lockrings causes the final -
tapered regions 16 to compress the external regions 10
of the collar while the cylindrical region 15 moves over
the flange 8 without exerting a further constricting force -
thereon. When the lockrings 12 are in their final position -
abutting the stop flange 5, the outer tube forms a pair of
first constricted regions 17 and second constricted regions
18 and each inner tube forms a corresponding main or first
constricted region 19 and a second constricted region 20
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as shown in Figure 5. Between the constricted regions the ~
.
outer and inner tubes undergo some elastic recovery; and,
in particular, elastic recovery of the tubes occurs immed~
iately beyond the shoulder 16a of the lockring. The sharp
edge of the flange 8 aids in keeping the lockring in place.
Also elastic recovery of the outer tube 3 locks the lock-
ring in its final position.
It should be noted that by providing the cylindrical
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regions 10 and 15 which may be dimensioned to provide a
sliding fit, the force required to constrict the flange
8 and to constrict the region 10 do no occur simultaneously
but occur in sequence. - ~ ~
Stated otherwise, while the collar 3 may be designed ~ -
to permit some buckling, the force required to constrict -
the flange 8 is a localized force exerted by the tapered ~ ~
region 14 while the cylindrical portion 15 slides over ~ -
the cylindrical region 10. Then, during constriction of the
region 10, the force required is confined to the localized
force exerted by the tapered region 16 plus a moderate
frictional force between the flange 8 and the cylindrical
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portion 15.
Referring to Figures 6 through 11, the lockring
21 here illustrated is shown in conjunction with various
embodiments of the ~ube members. The lockring is provided
internally with a series of alternate tapered or cone
frustum zones and cylindrical zones; more particulary, the
lockring includes a beveled leading end 22, followed con-
secutively by a cylindrical zone 23, a first tapered cone
frustum zone 24, a second cylindrical zone 25, a second
tapered or cone frustum zone 26, a third cylindrical
zone 27, a third tapered or cone frustum zone 28, and
finally a rudimentary cylindrical zone 29, the lockring
terminating in an abrupt shoulder 30. In some cases to
increase the strength of the lockring in the region of
the shoulder 30, the lockring may be provided with an
extension 31, as shown in Figures 6 and 7.
Referring to Figures 6 and 7, the lockring is
shown as joining a pair of tube members 32 and 33, the tube
member 33 having a bell extremity 34 into which the tube - ;`
20 member 32 extends. In this arrangement, the lockring ~-
21 is forced over the open end of the bell. In Figure 7
the lockring 21 has been forced over the flared end 35
of the bell.
While the lockring 21 is not limited to use on ~-
tube members of soft material such as soft aluminum, the
lockring is particularly suited for such use.
Operation of the lockring when used in conjunction
with the tube members 32 and 33 as shown in Figure 6, 7 and
8 is as follows:
The cylindrical zone 23 of the lockring forms a
sliding fit over the bell extremity 34 whether it be
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positioned over the open orthe flared end 35. As the
lockring is forced on, the first tapered zone 24 ~orces
the bell enlargement into intimate contact with the tube
2 compensating for dimensional tolerance as indicated in
Figure 8. After intimate contact is made the tapered zone
24 effects an initial simultaneous constriction of the two
tube members.
As no further constriction occurs in the second
cylindrical zone 25, the force required is materially less
than if the zone 25 were tapered. The friction force in
the cylindrical zone may be minimized by a conventional ~`
high strength lubricant, such as graphite or a fluorcarbon,
applied to the interior of the lockring or the outer bell
extremity.
Added force is, however, required as the tapered
zone 25 is moved onto the bell extremity; the amount of
added force being predetermined by the axial length of
tapered zone 26. Further constriction does not occur `~-
during movement of the third cylindrical zone onto the -
bell extremity.
Finally, maximum constriction occurs as the final -~
tapered zone 28 is forced onto the bell extremity 34.
As the shoulder 30 passes onto the bell extremity 34, the
tube members undergo recovery of spring back in proportion
to the resiliency of the material. This provides a strong
locking force resisting removal of the lockring.
The series of tapered regions spaced by cylindrical
zones not only reduces materially the force required to
install the lockring, but also provide a spaced series of
major sealing contacts as well as distributing any bending
load that may be applied to the tube members. The long
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cylindrical contacting zones provide resistance to torque.
Because of the flared end 35, axial compression
against the bell extremity exerts a radially outward force
tending to buckle the bell extremity. This is minimized
b~ the series arrangement of cylindrical and tapered zones
permitting relatively thin walls. If extremely thin walls,
or walls of soft material are re~uired, the lockring may
be applied at the flared end 35 as shown in Figure 7,
placing the bell extremity 34 under tension instead of
compression.
While an integral belled tube extremity is shown,
it should be noted that an outer sleeve or coupling may
be substituted.
Referring to Figures 9, lO and ll, the lockring
tube joint here illustrated includes internal tube or collar
36 having an annular stop shoulder 37. Adjacent to the stop
shoulder 37, the internal tube forms a first cylindrical
portion 38 terminating at a first external annular compres-
sion flange 39 of low profile. The axially inner edge of
the flange 39 forms an abrupt margin 40 and the axially
outer edge of the flange forms a tapered margin 41.
The flange 39 is joined to a second cylindrical
portion 42 of slightly smaller diameter than the first
cylindrical portion 38. The second cylindrical portion 42
is joined to a second annular compression flange 43 also
having an abrupt margin 40 and a tapered margin 41. The
second flange 43 is joined to a third cylindrical portion
44 of slightly less diameter than the second cylindrical
portion 42. The tube is provided with a beveled extremity
45.
The internal tube or collar 36 receives an external
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tube 46 which is actually the cylindrical bell end of a
continuing tube 47 joined to the tube 46 by a flared por-
tion 48, the internal diameter of the external tube 46 is
uch as to be slidable over the first or larger external
flange 39.
The lockring 21 as previously described completes
the tube connection.
The lockring tube joint as shown in Figures 9,
10 and 11 is assembled as follows:
The internal tube 36 is inserted into the external
tube 46 until the external tube 46 is abutting the stop ~ `-Yi
shoulder 37. The lockring 21 is initially positioned on the
continuing portion 47 beyond bell end 46 of the tube. The
internal dimensions of the lockring are such that the first
cylindrical portion 23 fits over the beveled portion 48 of
the external tube or bell end 46. When the lockring is
forced thereover the series of tapered and cylindrical zones
function as described in regard to Figures 6, 7 and 8.
The first compression flange 39 is disposed within -
the boundaries of the second cylindrical portion 25 of the
lockring 21 when the leading end of the lockring is in
abutment with the stop shoulder 37. The flange 39 causes
further compression of the internal tube 36 at this region
and the compression forces cause localized flow of the
material comprising the external tube around the flange 39
to effect a strong interlocking and sealing connection -
therebetween. Similarly, the third cylindrical portion 27
of the lockring 21 compresses the external tube 46 about
the second flange 43 to form a second locking and sealing
connection, an enlarged view thereof being shown in
Figure 11.
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Finally, as described in regard to Figures 6, 7
and 8, a third interlock is effected by the tapered portion
28 and the abrupt shoulder 30 formed at the trailing end
of the lockring 21. The abrupt shoulder 30 becomes locked
in place by reason of the fact that the internal tube 36
and external 46 are capable of limited springback when the
constriction force of the lockring is removed.
It should be noted that, for purposes of illustra-
tion, the radial dimension of the compression flanges 39
and 43 have been exaggerated. Actually, their radial
dimension may be in the order of .012 inches (.3 mm). ~;
The material or materials comprising the internal -
tube 36 and external tube 46 are preferably mallable with
some resiliency for example, copper or aluminum as well as
various alloys. The lockring 21 is formed of material which
together with greater wall thickness makes it substantially
stronger than the tubes 36 and 46 and may have greater
resiliency for example, but not by way of limitation, the
lockring 21 may be formed of steel or of higher strength
alloys. In addition the wall thickness of the lockring 21
is substantially greater than the wall thickness of the tubes -~
36 and 46. As the wall thickness is increased, the unit
strength of the lockring 21 may be decreased. The strength
of the lockring is further enhanced, at the high stress area ;
of the shoulder 30, by the extension 31.
Referring to Figures 12 and 13, should it be desir-
~: able to increase the resistance to torsional forces, the
annular rib 39 or 49 may be provided with a ring of axially ~ -
extending channels 39a (which may be only a few thousandths
of an inch deep). When the lockring 21 is forced in place,
some material forming the outer tube 46 flows into the
channels 39A as indicated by 46A in Figure 13. The
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utilization of the tube joint to withstand torsional
loads is further illustrated in Figures 14 through 21.
Referring to Figures 14 through 17, the constriction
illustrated includes an inner tube 49 of initially uniform
climension and an outer tube or union collar 50 having an
external stop 51, an external tapered section 52 adjacent
each side thereof and an internal tapered section 53 under-
lying each external tapered section. Continuing from each
tapered section is a portion 54 of reduced wall thickness -
10 which joins a portion having circumferentially separated
external boss or rib segments 55 with beveled leading
surface 56 and circumferentially separated internal boss
or rib segments 57. Beyond each pair of boss or rib seg-
ments 55 or 57 is a second portion 58 of reduced wall
thickness which joins a final cylindrical portion having
an internal land or rib 59.
The outer tube 50 receives a lockring 60 which
may be essentially the same as the lockring 12; that is,
including a short cylindrical entrance end 13, an initial
20 internally tapered region 14, an internal cylindrical
section 15, and a final internally tapered region 16,
terminating at an abrupt shoulder 16a.
Assembly of the tube joint as shown in Figures
14 through 17 is as follows:
When the lockring 60 is forced over the outer tube
50, the first cone frustum bore 14 engages the external
boss segments 55 pressing the internal boss segments 57
~ into the inner tube producing spaced depressions forming
s interlocking regions 61 which resist torsional loads as
30 well as axial loads.
Simultaneously, the trailing shoulder 16a of the
lockring 60 is forced over the portion of the outer tube
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having the internal land 59 causing the internal land
59 to press into the inner tube 49 and form a constricted
sealing zone 62. Elastic spring back occurs in both the ~ .
tubes so that the sealing zone defines an obtuse V shape. :~
Also, simultaneously, the initial or first conical
bore 14 engages the external tapered portion 52 of the
outer tube and also applies an axial compression force.
The increasing assembly force may cause buckling of the por-
tions of reduced wall thickness 54 and 58, which in turn
causes the extremity of the inner tube 49 to wedge further
against the internal tapered portion 53 to form a preloaded ~-
support area and a seal here in addition to the seal formed
in the constricted sealing zone 62. ~ :
The leading extremity of the lockring 60 engages
the stop 51 so as to position the cylindrical portion or -
bore lS over the external boss segments 55 and to position
the trailing shoulder 16 midway between the ends of the
internal land 59. If desired, the stop 51 may be omitted -
and thelockring may have a rearward cylindrical portion and
internal stop flange.
In the first embodiment shown in Figures 1 through
5, while the flange 8 of the outer tube 3 is indicated as
continuous, it may be segmented, and conversely the boss
segments of the embodiment shown in Figures 14 through 17
may be continuous or ribs, also both features may be -
incorporated in one flange configuration. More particularly,
referring to Figures 18 and 19, in place of the internal
boss segment 59, an internal annular rib 63 may be provided
having an internally sloping surface, a portion of which is
provided with a series of slots 64. When a constrictor
joint provided with a rib 63 is secured, the inner tube locks
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into the slots 64, however the adjacent portion of the inner
tube provides a sealing connnection with the smooth portion
of the rib 63. Referring to Figure 20, a similar result
may be obtained by providing a stepped portion which is slotted
in opposite directions.
While the members 1, 32, 36 and 49 have been indicated
as tubes, each may be a solid shaft or mandrel. In this case,
the depth of the constricted zones are minimal; however, the
radial compression of the corresponding outer tubes may
readily be such as to obtain an interference fit or mechanical
interlock sufficiently strong as to be suitable, for example,
to secure a gear on a shaft, the gear having one or two side
extensions, each comparable to a section of the outer tube.
Having fully described my invention, it is to be -
understood that I am not to be limited to the details herein
set forth, but that my invention is of the full scope of the
appended claims.
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