Note: Descriptions are shown in the official language in which they were submitted.
11~85595
BACKGROUND OF THE INVENTION
This invention relates to a locking assembly for interconnecting two
adjacent members with aligned apertures therethrough, such locking assembly being
particularly suited to coupling links and similar chain type connections although
certainly not being limited to such environment.
Coupling links comprising two generally U shape half links hingedly joined
by means of a pin held in pos;tion by some form of locking mechanism are well known
in the art. Reference may be had, for example, to Fink U.S. Patent No. 3,828,550,
assigned to the assignee of the present invention. Reference may also be had to U.S.
Patent Nos. 1,513,729; 3,134,221 and 3,373,560 described in the background of the Fink
patent.
The coupling link disclosed in the Fink patent has been operationally and
commercially quite successful. Such coupling link includes a retaining means for the
coupling link hinge pin consisting of a body having a bore therethrough and a
counterbore at one end thereof and a spring clip retained in said counterbore with the
inner diameter of said spring clip being slightly smaller than the bore of the body and
in coaxial alignment therewith embracingly to engage a central locking groove on the
hinge pin to fix the axial position of the same. This spring type retention means
provides a tight and dependable axial lock for the hinge pin under normal conditions of
20 operation.
Occasionally, however, the coupling link is intentionally tampered with in
an attempt to disassemble the coupling link. Although the retention means disclosed in
the Fink application will resist relatively high axial loads on the hinge pin, the coupling
link can be disassembled when the axial load reaches a magnitude sufficient radially to
expand the spring clip to permit the pin to be released.
Accordingly, it is the primary object of the present invention to provide a
locking assembly for interconnecting coupling half links or the like that is easily
assembled but not easily disassembled. This object is accomplished by hinge pin
retaining means consisting of either a drive pin received in a blind end bore for receipt
30 in the hinge pin locking groove or Q totally contained spring clip positively urged into
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the square shoulder hinge pin locking groove. Both of these
retention forms are relatively easily manufactured and installed
and provide a coupling link, that resists disassembly.
It is another object of the present invention to
provide a tamper-proof locking assembly for joining two members
having aligned apertures in which one of the body members ir-
removably contains the retention pin in a blind end bore. By
using one of the members to be joined for such purpose, the
individual members, such as the clevis, the chain, and the
retention pin, may be separately sent and relatively easily
field assembled into a substantially permanent combination.
Moreover, such assembly eliminates the need for an additional
body member and precludes inadvertent and/or intentional
removal of the retention pin that may occur in the clevis
locking assemblies shown in U.S. Patent Nos. 3,959,909:
3,962,755, and 3,962,810.
Other objects and advantages of the present invention
will become apparent as the following description proceeds.
In accordance with one aspect of the present invention,
there is provided a locking assembly in combination with two
members having aligned apertures to interconnect the two mem-
bers when so combined comprising a hinge pin having a groove
therein inserted through said aligned apertures, retention
means to hold the hinge pin in a preselected axial position
in which the members are coupled to said hinge pin for inter-
connection, said retention means including a blind end bore
intersecting and aligned with the hinge pin groove when the
hinge pin is inserted and a locking pin driven into said blind
end bore for partial receipt in said hinge pin groove to effect
the couple, with the inserted end of the pin being enclosed
by the blind end bore to preclude removal of such locking pin
~y a reverse driving force.
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To the accomplishment of the foregoing and related
ends, the invention, then, comprises the features hereinafter
fully described and particularly pointed out in the claims,
the following description and the annexed drawings setting
forth in detail a certain illustrative embodiment of the
invention, this being indicative, however, of but one of the
various ways in which the principle of the invention may be
employed.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
Fig. 1 is an elevation of an-assembled coupling link
employing the drive pin to lock the hinge pin in a preselected
axial position;
Fig. 2 is a cross-section taken along line 2-2 of
Fig. 1 showing the interrelationship between the drive pin,
the locking assembly body, and the hinge pin with groove;
Fig. 3 is a partial elevation of an assembled coup-
ling link showing in section an alternative locking assembly
with spring clip and biasing means,
Figs. 4 through 6 are identical sections generally
taken along line A-A of Fig. 3 showing the sequence of assem-
bly ~rom initial hinge pin insertion (Fig. 4), to
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partial hinge pin insertion (Fig. 5) to final hinge pin insertion with the spring clip
received in the locking groove (Fig. 6);
Fig. 7 is a partial elevation of a locking assembly similar to that shown in
Figs. 3 through 6 but illustrated in combination with a clevis-type joining link;
Fig. 8 is a side elevation showing the locking assembly of the present
invention coupling a chain to an eye-link with clevis, with the chain being shown in
phantom lines for clarity of illustration;
Fig. 9 is a fragmentary cross section taken along the plane 9-9 in Fig. 8
showing the locking pin driven into the blind end bore and received in the groove of the
10 hinge pin; and
Fig. 10 is a fragmentary side elevation similar to Fig. 8 in which a second
locking pin is driven into the other clevis leg to provide a fail safe coupling.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to Fig. 1, the coupling link indicated generally at 1 includes
two substantially identical U shape half links 10, each of which has a clevis 12 at the
terminal portion of one leg and a tongue-like projection 14 at the terminal portion of
the other leg. The clevis and tongue portions are respectively provided with apertures
16 and 18 that are in axial alignment when the ends of the half links are interdigited by
positioning the tongues 14 in the opposing clevises 12 as shown in Fig. 1. A locking
20 assembly indicated generally at 20 is employed hingedly to interconnect the U shape
half links 10 at their interdigited ends.
Such locking assembly 20 includes a cylindrical body member 22 interposed
between the interdigited ends of the half links and substantially spanning the distance
therebetween. Such cylindrical body 22 has a first, longitudinal bore 24 extending
therethrough from end to end. Such body 22 has a second, transverse bore 26 therein
which partially intersects the longitudinal bore 24, as best shown in Fig. 2. The second
transverse bore 26 has an exposed open end 28 and a blind end 30 within the body 22.
The locking assembly 20 also includes a hinge or joining pin indicated
generally at 34. Such hinge pin 34 includes a central annular locking groove 36 of
30 reduced diameter having spaced sidewalls 38 that are perpendicular to the longitudinal
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axis of the hinge pin 34. The hinge pin 34 is substantially coextensive in length to the
overall width of the coupling link with interdigited ends as best shown in Fig. I
wherein the ends of the hinge pin 34 are just slightly exposed at each side thereof when
assembled.
To assemble the U shape half links 10 into a coupling link 1, the ends of the
U shape half links 10 are interdigited once the chains to be joined thereby are
respectively received on the curved shanks of such U shape half links. The cylindrical
body member 22 is then positioned between the interdigited half links and the hinge pin
34 inserted until both ends of the same are just visible at the lateral extremes of the
10 coupling link. Such position of the hinge pin 34 places the locking groove 36 thereof in
transverse alignment with the second, transverse bore 26 in body 22.
A locking pin 42 is then driven through opening 28 into the second,
transverse bore 26. Such locking pin is driven until the leading edge thereof abuts the
blind end 30 of the bore 26, with the portion of the locking pin 42 passing through the
longitudin~l bore 24 being received in the groove 36 tightly to hold the hinge pin 34 in
the preselected axial position. The sidewalls 38 of the groove 36 and the tight fit of
the drive pin 42 in transverse bore 26 do not permit the locking assembly to be
disassembled by axial loads placed upon the hinge pin 34. Moreover, the blind end 30
of the second, transverse bore 26 precludes access to the drive pin 42 from the other
20 side of the body 22 whereby the same cannot be removed therefrom by application of a
reverse driving force. As illustrated, the locking or drive pin 42 is a roll-type pin
having abutted but slightly spaced ends permitting radial contraction of the same
during driving for a tight frictional fit with the second transverse bore. Alternatively,
other structural forms, such as a grooved drive pin, could be used to accomplish the
same purpose.
Referring now to Figs. 3-6, a second form of locking assembly has been
illustrated wherein like parts to the first form hflve been denoted by like numerals. As
best shown in Fig. 3, the locking assembly 20 includes a generally cylindrical body 50
having a longitudinal bore 52 therethrough and a coaxial counterbore 54 of larger
30 diameter at one end thereof. A split spring clip 56 is positioned near the blind end of
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the counterbore 54. One side of the spring clip 56 is engaged by a U shape biasing
device 57 made from spring steel or the like. Such U shape biasing device has rounded
ends 58 that engage the inner diameter of the counterbore 54 while the central portion
thereof engages the outer diameter of the spring clip 56 normally to urge the same to
a position offset with respect to the longitudinal axis 59 of the body 50. As best shown
in Fig. 4, such offset position of the spring clip 56 results in a portion thereof spatially
intersecting the imaginary continuation of bore 52 into counterbore 54.
The spring clip 56 and biasing device 5~ may be held in position by a sleeve
60, which is received in the counterbore 54 and connected to the body 50. Such sleeve
60 has a bore 62 therethrough that is equal in diameter to and coaxial with the bore 52.
The leading or inserted edge 63 of said sleeve 60 forms a shoulder positively to engage
and retain the spring clip 56 and biasing device 57.
The locking assembly 20 in the form shown in Figs. 3 through 6 also
includes a hinge pin 64 having chamfered ends 66 and a centrally positioned locking
groove 68 of reduced diameter. Such pin 64 is substantially coextensive in length with
the width of the coupling link 1 and has a diameter just slightly smaUer than the
diameter of bore 52.
For purposes of assembly, the ends of the half links 10 are interdigited once
the chains to be joined by the coupling link 1 are respectively positioned about the
20 curved shanks of such half links. The cylindrical body member 50 is then positioned
between the interdigited ends so that the bore therethrough is in axial alignment with
the holes 16 and 18 in the clevis and tongue ends of the half links. The hinge pin 64 is
then advanced through either side of the interdigited ends and into the cylindrical body
50. The sequence of the hinge pin assembly movement through the cylindrical body 50
is illustrated in Figs. 4 through 6.
As shown in Fig. 4, the chamfered end 66 of pin 64 is just engaging the split
spring clip 56. Continued advancement of the pin 64 results in the chamfered end 66
camming the spring clip 56 from its normally offset position of Fig. 4 to a position
coaxial with the longitudinal axis of the body 50 as shown in Fig. 5. This camming
30 movement results in the split spring clip 56 spreading to surrolmd the major diameter
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of the hinge pin 64 as it moves therethrough and also results in the ends 58 of the
biasing device 57 spreading apart with the center portion thereof flattening out to
permit the lateral movement of the spring clip 56 to a coaxial position. When the
hinge pin 64 has been advanced to the fully inserted Fig. 3 position, the locking groove
68 therein of reduced diameter is axially aligned with the spring clip 56. At such
point, the spring clip naturally radially contracts due to the elastic nature of the
material tightly to embrace the locking groove 68 as shown in Fig. 6. Simultaneously,
the biasing device 57 made from spring material also returns to its original shape
positively to drive the spring clip 56 into its offset position, thereby to hold such spring
clip in the locking groove. The use of the biasing device 57 as an additional retention
means to the contraction of the split ring spring clip 56 acts to increase the load
necessary to separate the locking assembly.
Referring now to Fig. 7, a joining link indicated generally at 72 includes a
clevis 74 at one end thereof and an oppositely extending flange 76 at the other end
thereof. Such flange 76 is provided with an aperture 77 therethrough which receives
the terminal link 78 of a first length of chain. The clevis 74 is provided with aligned
apertures 80 which cooperate with the locking assembly, indicated generally at 81, to
connect the terminal link 82 of another length of chain to the joining body, thereby
selectively to interconnect the two lengths of chain.
The body member of the locking assembly 81 is substantially identical in
structure to the body member disclosed in Figs. 3 through 6, and accordingly the same
reference numerals with the suffix A have been used thereon. The body member
indicated generally at 50A cooperates with 8 pin 84 having a head 85, a shank 86, a
reduced diameter locking groove 87, a tip 88 of equal diameter to shank 86, and a
chamfered leading end 89. The locking groove 87 has one inclined or tapered sidewall
90 at the leading edge thereof and a second sidewall 92 oriented generally
perpendicularly to the axis of the pin 84.
To connect link 82 to the clevis 74, the body member 50A is positioned
adjacent such clevis axially to align the apertures 80 with the bore 52A, and the link 82
is then internested in the clevis 74 so that the open center thereof is similarly in axial
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alignment with such apertures. The pin ~4 is then driven through the clevis and into
the body member SOA moving from left to right as viewed in Fig. 7. During
advancement of the pin through body member 50A, the chamfered leading end 89 cams
the offset split spring clip 56A into a coaxial position with respect to the body member
50A thereby permitting the pin to pass. When the locking groove 87 is brought into
axial alignment with the split spring clip 56A, the latter naturally contracts to
embrace the locking groove and is simultaneously driven into the same by the U shape
biasing spring 57A.
If disassembly of the connection just described is desired, the leading end
of pin 84 may be driven from right to left as viewed in Fig. 7. The tapered sidewall 90
of locking groove 87 engages the spring clip 56A during such pin movement and cams
the same outwardly into coaxial position with respect to the body 50A to permit the
pin to be released. The angularity of the taper for the inclined wall of the groove 87
may be varied depending upon the desired degree of difficulty for disassembly. As the
inclined wall or shoulder 90 of the groove 87 approaches an orientation perpendicular
to the axis of the pin 84, the connection formed by the locking assembly requires
greater axial forces to be exerted on the pin to effect disassembly.
The use of the locking assembly 81 in combination with the clevis 74 has
been illustrated and described in context with Fig. 7 to demonstrate the versatility of
the invention disclosed herein. It will be appreciated, of course, that the locking
assembly of Figs. 1 and 2 could also be used with clevis 74. In fact, the locking
assemblies disclosed herein can be used to interconnect any two members having
apertures therein that can be axially aligned.
Turning now to Fig. 8, an eye link indicated generally at 101 includes a
clevis 103 at one end thereof having spaced legs 104 and 105 to define a throat 107
therebetween. Leg 104 includes a uniform diameter bore 109 extending therethrough.
The other clevis leg 105 includes a bore 110, having the same diameter as bore 109, and
a counterbore 111 therein, with such bore and counterbore cooperatively defining a seat
113 therebetween.
The end chain link 115 of chain 116 may be inserted into the clevis throat 107
to align the elongated aperture therein with bores 109 and 110. A hinge pin 118, having
an annular, reduced diameter groove 119 therein, may then be inserted into such aligned
bores and aperture to be coextensive therewith, with the major diameter of the pin 118
being only slightly smaller than the diameter of the bores 109 and 110 to provide a
relatively snug fit therebetween. The leading end of hinge pin 118 engages the seat 113
properly to position the hinge pin relative to the clevis. In such position, the annular
reduced diameter locking groove 119 is in transverse axial alignment with a blind end
bore 121 in clevis leg 104. Such blind end bore partially, perpendicularly intersects the
top of bore 109 in such clevis leg and terminates adjacent such bore, as best shown in
Fig. 9.
A locking pin 122 may then be driven into the blind end bore into abutment
with the end face thereof. In such position, a portion of the locking pin is received in
the annular reduced diameter groove 119 in hinge pin 118 positively to retain the same in
its inserted position. The blind end bore precludes access to the inserted end of the
retention pin thereby to eliminate any possibility of a removal force being applied to
such end. Moreover, the square shoulders on groove 119 and the split rolled locking pin
122 driven into the blind end bore 121 positively retain the hinge pin 118 in the desired
axial position, thereby to increase the axial load necessary on the hinge pin to
disassemble the coupling.
By thus capturing the end link 115 of chain 116, the eye link and chain are
20 permanently coupled by easy field assembly for subsequent use. The two spaced
encompassing legs 104 and 105 of clevis 103 and the positively retained locking pin
preclude removal of the end chain link. Although the clevis form is illustrated for this
function, it will be appreciated that a single ear on a chain link component could be
used if a radial enlargement was provided on the locking pin at its opposite end to
perform the abutment function of clevis leg 105 against link 115.
Turning now to the slightly modified clevis shown in Fig. 10, wherein like
reference numerals have been used to identify like parts shown in Figs. 8 and 9, clevis
leg 105 has a uniforrn diameter bore 125 extending therethrough. A second blind end
bore 127 in leg 105 perpendicularly partially intersects bore 125. Hinge pin 118 is
30 provided with a second reduced diameter annular groove 128 axially spaced from the
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first groove 119 by a distance equal to the spacing between blind end bores 121 and 127
so that the grooves 119 and 128 respectively are in transverse alignmer.t with such blind
end bores 121 and 127 when hinge pin 118 is inserted through the aligned apertures as
shown in Fig. 10. Such hinge pin 118 preferably has a length equal to the overall width
of the clevis to permit both ends thereof to be held flush with the lateral extremes of
the clevis legs to align the spaced grooves with the blind end bores. Locking pins 122
and 130 may then be respectively driven into blind end bores 121 and 127 to pass through
grooves 119 and 128 to secure hinge pin 118 in place positively to interconnect the clevis
and chain. The two locking pins and spaced hinge pin grooves may be used to provide a
10 fail safe system, whereby one locking pin retains the connection in the unlikely event
of failure of the other locking pin.
Other modes of applying the principle of the invention may be employed,
change being made as regards the details described, provided the features stated in any
of the following claims or the equivalent of such be employed. For example, the
clevis form shown in Fig. 10 could be used with the hinge pin of Figs. 8 and 9, with a
single locking pin then being driven into the blind end bore in alignment with the hinge
pin groove. Similarly, the biased spring clip shown in Figs. 3-7 could be positioned
within a clevis leg to perform the locking function of the drive pin disclosed in Figs. 8-
10.
