U.S. patent application number 10/424813 was filed with the patent office on 2004-01-29 for connectors for towing cable and the like.
This patent application is currently assigned to Veneta Industries Inc.. Invention is credited to Smith, Jackson Andrew.
Application Number | 20040018042 10/424813 |
Document ID | / |
Family ID | 4163669 |
Filed Date | 2004-01-29 |
United States Patent
Application |
20040018042 |
Kind Code |
A1 |
Smith, Jackson Andrew |
January 29, 2004 |
Connectors for towing cable and the like
Abstract
A swivel connector for towing cable or conduit in which one head
portion includes a hollow body portion in alignment with the other
head portion, the latter having a shaft extending into said hollow
body portion and supported therein for rotation upon a combination
of a dual thrust bearing at each end selected from one of a
three-piece needle bearing, a flanged bearing and a radial thrust
ball bearing.
Inventors: |
Smith, Jackson Andrew;
(Abbotsforo, CA) |
Correspondence
Address: |
WELDON F. GREEN
Box 151
275 KING ST. EAST
TORONTO
ON
M5A 1K2
CA
|
Assignee: |
Veneta Industries Inc.
|
Family ID: |
4163669 |
Appl. No.: |
10/424813 |
Filed: |
April 29, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10424813 |
Apr 29, 2003 |
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09605825 |
Jun 29, 2000 |
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6554524 |
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Current U.S.
Class: |
403/78 |
Current CPC
Class: |
Y10T 403/592 20150115;
Y10T 403/32213 20150115; Y10T 403/32983 20150115; F16B 37/047
20130101; Y10T 403/32975 20150115; F16B 7/06 20130101; F16B 21/165
20130101; H02G 7/04 20130101 |
Class at
Publication: |
403/78 |
International
Class: |
F16D 001/12 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 30, 1999 |
CA |
2276 658 |
Claims
What I claim is:
1. In a swivel connector, a swivel head disposed at one end of a
generally hollow body portion and secured in rotational engagement
therewith, a swivel shaft presented by said swivel head within said
hollow body portion, means securing said swivel shaft within said
hollow body portion against separation and supporting said swivel
shaft for rotational movement therein, bearing means disposed
within said hollow body portion including a three piece dual thrust
bearing presented by said hollow body portion and enclosing said
swivel shaft at one end and one of a flanged Permaglide tm dual
thrust bearing, a radial thrust roller bearing and a three piece
needle thrust bearing enclosing said swivel shaft portion adjacent
the other end whereby the connector can be used to tow cable in
either direction.
2. In a swivel connector a first swivel head formation at one end,
including a swivel (shaft) portion extending inwardly therefrom,
and a second swivel head formation at the other end including a
generally hollow body portion surrounding said swivel shaft
portion, means presented by said hollow body portion to said swivel
shaft portion therewithin for supporting said swivel shaft portion
for rotation including dual thrust bearing means enclosing said
swivel shaft adjacent each end and means carried by said swivel
shaft portion at the inner end thereof for securing same against
separation from said hollow body portion.
Description
[0001] This application is a division of application Ser. No.
09/605,825, filed Jun. 29, 2000.
FIELD OF THE INVENTION
[0002] This invention relates to improvements in connectors for
towing cable or conduit or the like, i.e., for stringing cables
from pole to pole, hauling cable through underground conduits, and
more particularly to swivel connectors for use with power and
telephone cable, and especially to "disconnect" swivels whose
components separate under excess loading to preserve the cable
especially for use with fibre optic cable and for hauling conduit
for cable through underground bore holes.
BACKGROUND OF THE INVENTION
[0003] The swivel connector disclosed in U.S. Pat. No. 2,387,599
uses ball bearings travelling in a race defined by or secured to
opposed male and female components to interconnect and support same
for rotation in relation to each other which male and female
components thereof are to be connected to a hauling line and a
cable respectively.
[0004] Such swivel connector cannot be taken safely around a pulley
or bullwheel under load,
[0005] The swivel connectors revealed by U.S. Pat. Nos. 5,494,367
and 5,529,421 provide in one embodiment a first swivel head which
is attached to a swivel shaft secured within a hollow body by a
locking nut which in turn is connected to a second swivel head.
Tapered roller bearings support the swivel shaft for rotation in
one setting and transmit tensile loading from the shaft to the
hollow body.
[0006] A series of restrictive seals serve to block the passage of
debris from the outside to the interior.
[0007] In another embodiment the first and second swivel heads are
attached to an opposed pair of swivel shafts and likewise are
provided with restrictive seals with the object of utilizing the
capability of one swivel head should the other fail.
[0008] The swivel connectors of U.S. Pat. Nos. 5,594,367 and
5,529,421 cannot, under load, be safely taken around a pulley or
bullwheel The breakaway swivel connector disclosed in U.S. Pat. No.
4,678,365 has a centre pin from which material has been removed
centrally internally thereof to create a shear factor so as to
limit the load applied to the cable in installing same on poles or
in underground ducts.
[0009] The breakaway connector of U.S. Pat. No. 5,122,007 uses
assorted mechanical pin-type breakaways to protect the cable from
damage in similar circumstances.
[0010] Both aforementioned breakaway connectors require replacement
parts to be reinstalled after each cable pull has been completed
and the sheared pin parts removed.
[0011] Each of the latter breakaway type connectors may require as
many as twenty-five (25) differently calibrated pins, preferably
colour coded for identification of the breaking tension for
installation either in the work place or in the field of operation.
Such an arrangement, however, gives rise to human error in the
selection of the requisite pin for the particular pull.
[0012] The breakaway components of the aforementioned U.S. Pat.
Nos. 4,687,365 and 5,122,007 have been designed to separate at plus
or minus ten (10) percent of their rated break load. Those limits,
however, are not always precise or finite in that machine shop
operations and the mechanical functions performed are also subject
to human error leading to possible failure of the cable pull.
[0013] Moreover, the latter mentioned swivel connectors likewise
are not designed to be safely taken around pulleys or bullwheels
under load.
[0014] Further, the swivel connectors of all aforementioned U.S.
patents operate safely only if loaded in one direction. Hence, if
incorrectly connected by attaching the wrong end to the cable to be
pulled, the swivel will fail and the cable pull aborted.
[0015] Other downside aspects inherent in the aforementioned
breakaway connectors are the necessary disassembly to replace the
break pins and the reassembly. Those steps can prove to be very
costly in a field situation because of down time, because of
potential loss of parts and the increased labour costs for
disassembling and reassembling.
OBJECTS OF THE IN ENTION
[0016] One principal object of this invention is to provide an
improved swivel connector which can be loaded in either direction,
that is, the swivel connector serves its purpose either way; and
will operate whether the pull exerted is applied through the
hauling line or through the cable itself.
[0017] Such swivel connector can include a separation or
"disconnect" structure for limiting the pulling load.
[0018] Another principal object is to provide a swivel connector
that can be taken safely around a pulley or bullwheel under
load.
[0019] Still another principal object of this invention is to
provide an improved separation or "disconnect" structure for a
connector of the category under consideration which compared to
known structures greatly minimizes the likelihood of damage to
power and telephone cable and particularly to fibre optic cable
during a cable pull whether overhead from pole to pole or
underground in PVC ducts or conduits, in vaults or otherwise and to
conduit hauled through underground bore holes.
[0020] Still another object is to provide an improved "disconnect"
connector which is fully reusable in a subsequent cable pull
without any dismantling or disassembly of the components thereof or
the replacement of parts in the reassembly of same, whereby human
error in selection of replacement parts and reinstallation is
entirely eliminated.
[0021] Another object of this invention is to provide an improved
swivel connector that can be more easily utilized in confined
spaces such as in riser ducts in high rise buildings, and follow a
shorter bend radius as compared to known swivel connectors
particularly when used in underground PVC ducts with its sweeps and
bends.
[0022] It is also a specific object to provide an improved swivel
connector of the type in which the separation or "disconnect"
tension characteristics have a substantially increased range of
from about 100 psi to 5,000 psi and beyond if so desired.
[0023] Other important objects are to provide connectors including
swivel connectors for the uses outlined which require low
maintenance, are economically manufactured, do not require special
tools in maintaining operability and have an extended operating
life by virtue of the improved structure of same.
FEATURES OF THE INVENTION
[0024] One feature of this invention resides in providing selected
bearings for a swivel connector structure in which the swivel shaft
is supported by and rotates within a bearing combination, in one
embodiment, of a three (3)-piece dual thrust needle bearing at one
end and by a flanged Permaglide.TM. bearing at the other end and in
another embodiment the combination of Permaglide.TM. washer bearing
and three (3)-piece needle dual thrust bearing at one end and a
roller bearing at the other end.
[0025] Both embodiments are suitably sealed preferably by a
Buna-N-0 ring against ingress of debris and to contain lubricant
which bearing combinations and seal confer upon the preferred
embodiments the capability to be pulled safely under load in either
direction; and further by reason of such combination of bearings
the longitudinal dimension of connectors can be reduced, greatly
facilitating travel through circuitous passageways and also around
sheaves, pulleys or bullwheels.
[0026] Another feature of this invention resides in providing an
interconnection between opposed surfaces of mating male and female
components of a connector in the form of a selection of a spring
loaded resilient steel ball mounted within an elongated passageway
in either mating component to seat lowermost against an annular
lip. The lip is so shaped as to project a portion of the resilient
steel ball beyond the opposed surface thereof and into a
circumferentially extending matching recess or groove formation
presented by the opposed surface of the other mating component,
which spring loading of the steel ball can be so calibrated as to
be forced from such groove formation and out of its seat into the
elongated passageway only when the tensile loading applied to the
mating components exceeds the spring loading applied to the
resilient steel ball.
[0027] As a consequence of that arrangement the swivel components
will separate or "disconnect" before the cable ruptures or is
otherwise damaged.
[0028] When separation occurs no parts are destroyed. The steel
ball forced from the groove formation into its passageway after
separation is then restored to its seated disposition by the
associated spring so that the mating components can simply be
reconnected by exerting the required compression force to
reestablish mating relation.
[0029] More particularly in one embodiment of the invention the
elongated passageway with its seating lip extends outwardly to the
exterior from the opposed surface of such mating component
generally radially or at right angles. Where multiple spring loaded
steel balls are to be utilized in such embodiment several spaced
apart passageways with seating lips can be selectively arranged in
opposed pairs or in equidistant separation so as to achieve greater
control over the applied loading for releasably securing the
components against separation.
[0030] It is also contemplated in accordance with the invention
that in the case of such embodiment where multiple spring-loaded
steel balls are utilized in one mating component several
circumferentially extending groove formations in suitably spaced
apart relation can be formed in the opposed surface of the other
mating component which arrangement through selection of appropriate
springs, balls and loading factors can be used to control
separation of the components upon reaching their respective load
limits.
[0031] Still more particularly another aspect of this invention
resides in selecting a stainless steel helical spring element which
will operate effectively within a confined space as in the
elongated passageway mentioned, preferably a stainless steel wave
spring and further, which can be calibrated in that setting through
an appropriate ratchet dial set screw engagement so as to
selectively finitely exert pressure over a range of between 100 psi
to 5,000 psi or greater through the compression spring seat bearing
upon the stainless steel ball.
[0032] Another feature of this invention resides in providing an
alternative passageway configuration for housing the spring loaded
stainless steel ball in the embraced or male mating component for
presentation to the matching circumferential recess or groove
formation of the embracing or female mating component which
alternative passageway includes a first portion extending generally
inwardly from an exposed end of the embraced or male mating
component and generally parallel to the opposed surface thereof
which first portion intersects with a second portion extending
outwardly therefrom lowermost and angled so as to intersect with
such opposed surface and terminating in the annular lip or
seat.
[0033] With such alternative passageway so shaped a component of
the force exerted by the set screw setting and wave spring is first
transmitted from the spring seat to a first resilient stainless
steel ball located lowermost in the first passageway portion which
engages a second stainless steel ball located lowermost in the
second angled portion and forces it into seating engagement with
the annular lip and so establish a modified release level or
disconnect limit for the mating components under tensile and other
forces.
[0034] With this arrangement the length of the passageway can be
increased without increasing the diameter of the part which allows
for increasing the extent of the spring element and increased
loading of the steel ball.
[0035] More particularly the forces to be exerted by the wave
spring in the foregoing alternative setting utilizing two stainless
steel balls against the second ball located lowermost in the second
angled passageway are first applied to the first or inner ball
located lowermost in the first parallel passageway portion which
contacts and transmits the forces to the second ball occupying the
angled portion and seated on the annular lip all through
appropriate selection of dimensions for the passageway portions
steel balls and wave spring element.
[0036] Another feature resides in providing the first portion of
the aforesaid alternative passageway with a slightly increased
diameter as compared to the diameter of the angled portion and
providing steel balls of corresponding diameters with appropriate
clearances.
[0037] It is also contemplated that the alternative passageway
configuration be further modified to include at least two opposed
angled portions lowermost leading from the first passageway portion
and to opposed or spaced apart seating annular lips with the wave
spring loading transmitted by the centrally located steel ball
lowermost in the first parallel passageway portion to the two steel
balls each occupying one of the angled passageway portion and
seated against the opposed or spaced apart lips thereof to project
beyond the bounding longitudinal surface thereof and into
engagement with the opposed circumferential groove formation.
[0038] Still another feature resides in providing a unitary
resilient steel ball and spring element so that placement of same
within the cylindrically shaped passageway in certain embodiments
is facilitated and the process of assembly streamlined.
[0039] Other features are to be found in the improved connectors,
according to the invention, in that not only can the dimensions of
the mating components be reduced through the selection of bearings
and their dispositions as earlier mentioned but also through the
simplification of the "disconnect" structure while maintaining the
requisite loading capabilities; which reduced dimensions confer
greater flexibility and endurance when passed around sheaves or
pulleys or bullwheels or where a cable is pulled through the
convolutions of conduits in buildings or buried, all for greater
economic benefit.
[0040] Further advantages arise out of simplification of the
connector structure in the steps of manufacture and assembly in the
workplace and in the field with the savings in time and effort
promoting greater profitability.
[0041] These and other objects and features of the invention are
apparent in the following description to be read in conjunction
with the sheets of drawings illustrating the preferred
embodiments.
DRAWINGS
[0042] FIG. 1 is a perspective view of the exterior of one
preferred embodiment of swivel connector constructed in accordance
with the invention;
[0043] FIG. 2 is a cross-sectional view of one embodiment of swivel
connector taken along the lines 2-2 of FIG. 1 in which the
displaceable spring-loaded steel ball assembly is presented by the
embracing mating female component to the circumferential groove in
the embraced mating male component thereof and includes one
preferred embodiment of the improved bearing combination to provide
dual thrust and to take care of side loading;
[0044] FIG. 3 is a cross-sectional view similar to FIG. 2 of a
modified embodiment of the displaceable structure depicted in FIG.
2 with the remainder of the swivel connector broken away.
[0045] FIG. 4 is a cross-sectional view similar to FIGS. 2 and 3 of
a further modified embodiment of the displaceable structure thereof
with the remainder of the connector broken away;
[0046] FIG. 5 is a cross-sectional view similar to FIG. 2 of an
alternative embodiment of displaceable structure in which the
spring-loaded steel ball assembly is presented by the embraced male
mating component and the circumferential groove formation by the
embracing female mating component thereof and includes the same
embodiment of bearing combination to provide dual thrust and
counter side loading.
[0047] FIG. 6 is a cross-sectional view similar to FIG. 5 of an
alternative embodiment of swivel connector with the displaceable or
disconnect structure comparable to that depicted in FIG. 5 and
including the other preferred embodiment of bearing combination
constructed in accordance with the invention to provide dual thrust
and counter side loading;
[0048] FIG. 7 is an enlarged view of the seated spring loaded ball
assembly of FIG. 2 with the remainder of the connector broken
away;
[0049] FIG. 8 is a view similar to FIG. 7 in which the spring and
ball of the assembly are shown as integral or unitary;
DESCRIPTION
[0050] The improved swivel connector depicted in FIG. 1 and
revealed in cross-section in several modifications in FIGS. 2, 3
and 4 and in still other modifications in FIGS. 5 and 6 all include
a swivel head formation 12 with associated clevis structure 13 at
one end, having an integral tapped shaft portion 14 projecting into
and supported for rotation within a centrally located hollow body
formation 16.
[0051] Where the elements of the connectors are arranged in the
same disposition those elements are given the same numbers in the
several drawings.
[0052] Central hollow body formation 16 is provided at the opposite
end with a second swivel head formation generally indicated at 18
in FIGS. 1 to 4 and at 18a in FIGS. 5 and 6 each with an associated
clevis structure 19 and 19a respectively.
[0053] Clevis structures 13 and 19, 19a respectively, are suitably
formed with each having one opening tapped to cooperate with the
threaded shaft of a bolt (not shown) for securing the loop or eye
of a hauling line and a cable to be towed all in a manner well
understood in the field.
[0054] The embodiments of the swivel connectors of FIGS. 2 and 5
disclose a preferred arrangement of bearings for supporting swivel
shaft portion 14 for rotation within central hollow body formation
16 and includes a three (3)-piece needle dual thrust bearing 20 and
a flanged Permaglide.TM. bearing 21 for taking side loads.
[0055] The alternative bearing combination of the swivel connector
illustrated in FIG. 6 includes likewise a three (3)-piece needle
thrust bearing 20, a three (3)-piece axial angular contact ball
bearing 22 and a Permaglide.TM. washer bearing 23 in supporting
swivel shaft portion 14 for rotation in hollow body formation
16.
[0056] In either arrangement of bearings both dual thrust and
countering of side loading are provided so that the swivel
connectors will safely operate whether pulled in either direction
and especially can be safely taken around pulleys, sheaves and
bullwheels.
[0057] Swivel head formation 12 is interconnected to central hollow
body formation 16 by a bolt 24 threaded into the tapped shaft
portion 14 with the head 25 having an extent to engage through a
suitable bearing spacer washer 25a in FIGS. 2 and 5, the outer
retainer face of the three (3)-piece needle dual thrust bearing 20
with the opposed retainer face engaging the opposed surface 26 of
internal annular shoulder formation 27 presented by hollow body
formation 16.
[0058] In the arrangement illustrated in FIG. 6 the bearing spacer
washer 25a bears against a Permaglide.TM. washer bearing 23 which
in turn engages three (3)-piece needle bearing 20.
[0059] The flanged Permaglide.TM. bearing 22 surrounding shaft
portion 14 in FIGS. 2 and 5 engages the inner surrounding surface
of the shoulder formation 27 with the flanged portion 28 entered
between the opposed surfaces of shoulder formation 27 and the body
portion 29 of swivel head formation 12.
[0060] Central hollow body formation 16 is provided with an
internal channel 30 in the surface abutting swivel head formation
12 in which a suitable O-ring seal 31 is registered to bar entry of
dirt, water and debris, O-ring seal preferably having the
characteristics of a Nitrile Buna-N-O-ring which is preferably
glued into place in its seat.
[0061] According to FIG. 6 the head 25 of bolt 24 engages through
annular bearing spacer washer 25a and Permaglide.TM. washer bearing
23, the three (3)-piece needle dual thrust bearing 20 with axial
angular contact ball bearing 21 positioned as shown to counter side
loading as well as thrust applied in either direction.
[0062] The hollow body formation 16 of the connectors shown in
FIGS. 2, 3, 4, 5, and 6 are releasably threadably connected as at
32 to the elements or components of the disconnect structure of
swivel head formations 13, 18 and 18a respectively, at the other
end.
[0063] The characteristics and advantages of the bearing
combinations of the swivel connectors shown in cross-section in
FIGS. 2 and 5 and the alternative illustrated in FIG. 6, all of
which give rise to dual thrust and all of which counter side
loading, allowing the connector to be safely pulled in either
direction around pulleys, sheaves or bullwheels and through
circuitous ducts will be described in more detail in paragraphs to
follow.
[0064] Disconnect Structures
[0065] The disconnect structure of swivel head formation 18 shown
in cross-section in FIGS. 2, 3, 4, 7 and 8 includes a first mating
or female component 33 whose body portion has a generally
cylindrically shaped open ended cavity or socket 35 defined by
inner surface 36 and end wall 37.
[0066] The first mating or female component 33 is provided with an
open-ended, two-step diameter passageway 38 extending generally
radially inwardly therethrough including an inner portion 39 and an
outer threaded portion 40. Inner portion 39 intersects with inner
longitudinal surface 36 of socket 35.
[0067] A resilient stainless steel spherical ball 41 of a diameter
corresponding substantially to that of inner portion 39 of
passageway 38 but with requisite clearance and hardened to RC 58-62
is positioned at the bottom of inner passageway portion 39. In that
disposition spherical ball 41 is seated against an integral annular
lip 42 formed at the inner end of passageway 38 and so shaped that
spherical ball 41 protrudes beyond lip 42 only up to between
twenty-five (25) percent to forty (40) percent, a minor portion of
its girth.
[0068] The generally cylindrically shaped longitudinal surface 44
of shaft portion 46 of the second mating or male component 48
presented by central hollow body formation 16 through threaded
connection 32 is axially aligned with and closely embraced by
surrounding inner surface 36 of the first mating or female
component 33 but with the opposed surfaces 36,44 having sufficient
clearance for sliding fit longitudinally and to allow for requisite
displacement under the swivelling action of the components.
[0069] In the embodiment of FIG. 2 male shaft portion 46 has a
suitably shaped 360 degree circumferential groove formation 50
formed in surface 44 which groove formation cross section matches
the curvature of the protruding portion of the selected stainless
steel spherical ball 41 presented beyond annular lip 42 with ball
41 engaging or registering in groove formation 50 so as to
releasably connect the mating elements 33, 48 under the loading
force of a suitable helically shaped spring 52 disposed within
passageway 38.
[0070] Preferably spring 52 is a suitably dimensioned stainless
steel compression wave spring for nesting within inner portion 39
of passageway 28 and with its integral seat against stainless steel
spherical ball 41. Wave spring 52 is so configured as to bear
against and urge stainless steel ball 41 against lip formation 42
under the forces imposed by a suitable stainless steel hex set
screw 54 threaded into the open end of passageway 38.
[0071] With spring-loaded stainless steel ball 41 registering in
perimetral groove formation 50 mating female and male components
33,48 of the embodiments of FIGS. 2 and 4 are held against
separation but also establish, in effect, a swivel connection
therebetween.
[0072] The resistance to displacement of wave spring 52 and steel
ball 41 under loading applied to mating components 33 and 48 is
determined by the setting of threaded set screw 54 within the
threaded passageway portion 40 of passageway 38 which can be
appropriately calibrated to establish a scale of imposed spring
loading of ball 41.
[0073] Preferably a ratchet dial set screw well known in the field
will be chosen in that greater precision in calibration is
available with that option.
[0074] When the applied tensile loading of first and second mating
components 33,48 by a hauling line connected to swivel head
formation 18 through the associated clevis 19 and bolt (not
illustrated) to tow a cable connected by a pulling eye (not
illustrated) to the clevis 13 and bold (not illustrated) of swivel
head formation 12 exceeds the preset compressive force established
by set screw 54 and compression wave spring 52 against steel ball
41, steel ball 41 will be expelled or displaced from perimetral
groove formation 50 in a direction outwardly from annular lip 42
into the inner portion 39 of passageway 38 thereby freeing the
mating components 33 and 48 to separate longitudinally.
[0075] More particularly, when the pulling forces overcome the
preset tension of wave spring 52 steel ball 41 is forced out of
perimetral groove formation or recess 50 in male shaft portion 46
and into passageway 38 of the female portion 33 against the
resistance of wave spring 52 thereby releasing components 33 and 48
and permitting the connector to separate or "disconnect".
[0076] The "disconnect" tension of wave spring 52 can be calibrated
by pull testing on an hydraulic test bench. By increasing or
decreasing the force applied to compression wave spring 52 against
the steel ball 41 through turning of set screw 54 in accordance
with the scale established in pull testing the release tension can
be set to operate within a selected range.
[0077] The preferred nested compression wave spring 52 is suited
for limited space applications and superior to other mechanical
alternatives including a standard stainless steel helical spring.
In comparison to a helical spring the required operating space for
a wave spring 52 to achieve the desired tension is reduced by 50%.
Moreover, wave compression springs are load-bearing and exhibit
non-binding axial compression that will function in static or
dynamic conditions and are preferred.
[0078] In the first embodiment illustrated in FIG. 2 an assembly of
a single stainless steel ball 41 with nested wave compression
spring 52 and set screw 54 is utilized. The invention, however,
contemplates that more than one such assembly can be
introduced.
[0079] With reference to FIG. 3 an opposed second passageway 38a
including a lower portion 39a and upper threaded portion 40a is
drilled and tapped into the female portion 33 of the swivel head
formation 18.
[0080] Similarly an integral annular lip 42a is shaped to seat
stainless steel ball 41a to protrude therefrom and together with
wave spring 52a and set screw 54a so that ball 41a registers within
the same circumferential groove formation or recess 50 in surface
44 of male shaft portion 46.
[0081] Alternatively as shown in FIG. 4 a further modified female
socket 35b and male shaft portion 46b are shown as extended and
provided with two (2) perimetral groove formations or recesses 50b,
50c in spaced apart relation which groove formations serve to
anchor the spring-loaded spherical steel balls 41b, 41c presented
by suitably spaced apart radially extending passageways 38b, 38c
formed in a matching extended female body portion 33b.
[0082] By providing multiple groove formations and spring-loaded
ball assemblies in spaced apart relation as shown in FIG. 4 and
opposed in the manner of FIG. 3, if desired, the forces generated
to resist separation can be more finely tuned to provide greater
precision in establishing "disconnect" tension levels or
limits.
[0083] Also it is to be understood that the configuration of the
female socket 35 and that of the male shaft portion 46 of the
embodiment shown in FIG. 2 can be further modified, if desired,
each to present succeeding mating sections of different diameters
and each provided with the requisite perimetral groove formations
and passageways with spring-loaded ball assemblies as depicted in
FIGS. 3 and 4 to further modify and control disconnect tension to
be set for a particular job.
[0084] With reference to FIG. 5 the modified swivel connector shown
in cross-section utilizes the same swivel head formation 12 at one
end including the tapped shaft portion 14 projecting into central
hollow body formation 16 as in the connector of FIG. 2.
[0085] Central hollow body formation 16 of FIG. 5 presents at the
opposite end a modified swivel head formation 18a.
[0086] The embodiment of FIG. 5 utilizes the same preferred
combination of bearings for supporting swivel shaft portion 14 and
includes the same three (3)-piece needle dual thrust bearing 20 and
flanged Permaglide.TM. thrust bearing 21 as shown in FIG. 2 and for
taking side loads.
[0087] Swivel head formation 12 through the tapped swivel shaft 14
is shown connected by threaded bolt 34 to central hollow body
formation 16 for swivelling action or rotation about the aforesaid
bearing combination in the same manner disclosed in FIG. 2.
[0088] Swivel head formation 18a in FIG. 5 as distinguished from
swivel head formation 18 of FIG. 2, includes a mating male
component 60 whose body portion 62 presents a cylindrically shaped
projection 64 bounded by a longitudinally extending cylindrical
surface 66.
[0089] Body portion 62 is provided with an open-ended two (2) step
diameter passageway 68 extending longitudinally of mating male
component 60 from the bight 70 of clevis portion 19a centrally
along male shaft projection 64 and includes inner portion 72 and
outer threaded or tapped portion 73 terminating in an angled
portion 74 innermost which intersects with surface 66 of male
projection 64.
[0090] A resilient stainless steel spherical ball 4 Id of a
diameter corresponding substantially to that of the inner portion
72 of passageway 68 but with requisite clearance and hardened to RC
58-62 is positioned adjacent the bottom of inner portion 72 under
the force of wave spring 75 and set screw 76. In that disposition
spherical ball 41d is seated in tangential engagement against the
surface of a second spherical ball 41e of the same characteristics
which in turn engages or seats against an integral annular lip 78
so shaped that spherical ball 41e protrudes beyond lip 78 only up
to between twenty-five (25) percent to forty (40) percent, a minor
portion of its girth.
[0091] The generally cylindrically shaped surface 80 of socket 82
in mating female component 84 is releasably threadably connected as
at 32a to central hollow body 16 and embraces the surface 66 of
mating male component 60 and presents a matching groove formation
86 to spherical ball 41e with opposed surfaces 66,80 having
sufficient clearance for longitudinal sliding fit and to allow for
requisite displacement under swivelling action of the
components.
[0092] FIG. 6 details a variation in the disconnect structure shown
in FIG. 5 wherein a second angled inner passageway 74f is provided
and so arranged that a third such ball 41f of the same
characteristics is so disposed therein as to seat against the
annular lip 78f to present a minor portion of ball 41f beyond
opposed surface 66 into registration with the matching groove
formation 86.
[0093] In this alternative the centrally located ball 41d is in
tangential contact with both balls 41e and 41f which under the
force imposed by wave spring 75 under the setting of set screw 76
fully register within the same mating groove formation 86 of the
female component 84.
[0094] It is to be understood that the embodiments of the
disconnect structures of FIGS. 5 and 6 also constitute a swivel
connection between the male and female elements 60 and 84
interconnected by the projecting portions of the balls 41e and 41f
registering in the groove formation 86.
[0095] Such an arrangement exhibited by all embodiments of the
connectors enhances the utility of the connectors in that any
additional swivelling action will tend to reduce twisting and
thereby serve to maintain the disposition of the hauling line and
towed cable.
[0096] It is to be noted that the female component 84 in the
embodiment of FIG. 6 is provided with a suitable grease valve 88
located in passageway 90 for, delivery of lubricant to the internal
cavity of hollow body formation 16.
[0097] Also it is to be noted that a circumferential recess 92 for
the reception of an additional O-ring 94 is provided at the point
of connection of the female component 84 to the hollow body portion
16 as a further barrier to the ingress of dirt, water and other
contaminating material.
[0098] The Bearing Structures
[0099] The employment of a three (3)-piece needle bearing 20 in
combination with a single flanged Permaglide.TM. thrust bearing 21
allows the swivel connector 18 to be pulled in either direction
directing thrust to the thrust bearings in either direction and
eliminating seizing of the hollow body portion 16 and shaft portion
14 when the connector is pulled around a sheave, pulley or
bullwheel.
[0100] The Permaglide.TM. flanged thrust bearing 21 and the three
(3)-piece needle bearing 20 are preferably welded or pressed fit
into the housing presented by the hollow body portion 16 with a
bonding paste.
[0101] The Permaglide.TM. flanged thrust bearing 21 can be placed
on either end of the shaft portion 14 to reduce any excess shear
factor that may develop when tensile loading is applied to the
connector.
[0102] The Permaglide.TM. flanged thrust bearing 21 also supports
the body of shaft portion 14 minimizing damage to that element.
[0103] Where the Permaglide.TM. flanged thrust bearing 21 is
introduced and welded or pressed fit to the surfaces of the
respective swivel head 12 formation and hollow body formation 16
both shaft and body wear are minimized.
[0104] The preferred O-ring 31 to be disposed within the machined
groove 30 on the swivel end of the hollow body portion 16
accommodates a Nitrile Buna N-O-ring with a hardness of 98 sealing
out dirt, water and debris.
[0105] As indicated such O-ring is preferably glued in place into
its seat.
[0106] The characteristics of Permaglide.TM. flanged thrust bearing
21 are disclosed in a brochure entitled Permaglide.TM. Plain
Bearings (PAH-US069604) issued by Ina Bearing company Limited and
is described as maintenance free and constituted by three layers:
steel or bronze backing, bronze layer and sliding layer. A 0.2 to
0.35 MM thick porous bronze layer (tin bronze or tin/lead bronze)
is sintered on to the steel or bronze backing.
[0107] In a rolling operation the pores of the bronze layer are
completely filled with a mixture of polytetrafluorethylene (PTFE)
and lead (Pb). On top of the bronze layer a 0.01 to 0.03 MM thick
sliding layer of polytetrafluorethylene (PTFE) and lead (Pb) is
applied.
[0108] The outer diameter faces and butt joint of the
Permaglide.TM. plane bearings are coated with a tin flash for
protection against corrosion. The bronze backing gives the plane
bearings of this material high corrosion resistance and good
thermal conductivity.
[0109] The Permaglide.TM. flanged thrust bearing 21 is well suited
for rotating and oscillating motion and has a high load carrying
capacity, good sliding properties and reduces stick slip to a
minimum, has a low coefficient of friction and no welding tendency
with metals.
[0110] The materials of such bearing also have good embedding
properties, no absorption of water and, therefore, no swelling, and
chemically resistance because of the suitable electroplating and
steel backing, faces and back joint faces.
[0111] It is also noted that the Permaglide.TM. materials are
electrically conductive with no electrostatic charging and have low
mass and minimum space requirements.
[0112] Each three (3)-piece bearings 20 and 22, respectively,
consists of two (2) case hardened and precision ground steel flat
washers joined together with either an assembly of needle rollers
or balls and retainers disposed therebetween. One source of such
bearings is Torrington.TM..
[0113] Such three (3)-piece bearings have dual thrust as well as
three times the thrust load rating of other bearing types, and in
the disposition shown in connectors embodying the invention allow
for those connectors to be pulled in either direction and still
maintain a high thrust as compared to other known types of
connectors which exhibit only one-way thrust.
[0114] One-way thrust bearings can result in bearing damage as the
pulling forces are applied incorrectly through the swivel head
which ultimately will cause serious damage to a fibre-optic cable
being pulled or towed.
[0115] By the use of the dual thrust three (3)-piece bearing
assemblies 20,22 or in conjunction with the Permaglide.TM. flanged
thrust bearing 21 or washer bearing 23 as shown in relation to the
swivel shaft portion 14 in the illustrated embodiments a
dual-purpose thrust is established.
[0116] More particularly a dual thrust three (3)-piece needle
bearing 20 can be installed on both ends of the shaft portion 14 of
the connector of FIGS. 1,4 or 6 or a combination of one of a radial
thrust ball bearing 22 on one end for radial load and a dual thrust
three (3)-piece bearing 20 on the opposite end allowing for dual
purpose thrust in whatever direction the load is applied.
[0117] Depending on the application any combination of the three
types of bearings, Permaglide.TM. flanged thrust bearing 21 or
washer bearing 23, the three (3)-piece needle thrust bearing 20 or
radial ball bearing 22 may be used in conjunction with one another,
achieving dual thrust in either direction.
[0118] "Disconnect" Characteristics
[0119] The configuration of the stainless steel spring-loaded ball
assemblies of the embodiments of FIGS. 5 and 6 allows for greater
spring tension. The configuration of the passageway is no longer
confined to the body wall thickness of the components of the swivel
connector in order to achieve the necessary tension but to the
length and diameter of the male body portion permitting greater
tension to be applied to the compression spring to achieve
approximately a seventy-five (75) percent increase in tension,
resulting in a higher disconnect rating.
[0120] Further, if greater than 5,000 psi disconnect capacity is
required the dimensions of the components of the swivel connectors
can be increased, the nested compression wave spring diameters
increased and if using a helical spring the wire diameter can be
increased and suitably heat treated, all of which provide for
grater disconnect tension.
[0121] The components of the connectors, in accordance with the
invention, are all derived from suitable high-strength stainless
steel.
[0122] Each connector embodying the invention can be metal-stamped
to show the disconnect load range for the particular swivel
connector to minimize error.
[0123] When the applied forces to the connectors overcome the
disconnect tensions the spring-loaded ball assemblies are displaced
into the passageways allowing the components to disconnect and
separate. To reset the separated units are reunited by snapping
them back together when aligned, with the spring-loaded ball
assemblies registering in the respective groove formations.
[0124] It will be understood that the preferred embodiments of the
invention have been described and illustrated, and that persons
skilled in this field may alter or vary the arrangement or
relationships disclosed without departing from the spirit and scope
of the invention as defined in the appended claims.
* * * * *