Fastener devices, such as lock-pins

Details Fastener devices, such as lock-pins Fastener devices, such as lock-pins

2001-10-02

2003-05-27

Saether, Flemming (Department: 3679)

Expanded, threaded, driven, headed, tool-deformed, or locked-thr

Headed fastener element with nut, washer, securing means or cap

Draw bar or draft key fastener

C411S349000, C411S513000, C411S552000

Reexamination Certificate

active

06568894

ABSTRACT:

TECHNICAL FIELD
The present invention is directed generally to fasteners for joining two or more structures together and, more particularly, to lock-pins, such as lock-pins that are installable and removable from a single side of a joint or other installation.
BACKGROUND
There are many ways that lock-pins and similar devices can be used to join two or more structures together at a common joint. Lock-pins for this purpose generally have a head of some type toward a head end, a locking element of some type toward an opposite tip end, and a cylindrical shaft therebetween. Such lock-pins are typically installed by inserting the tip end through a hole on the “near-side” of a joint until it emerges on the “far-side” of the joint. The locking element is then installed or otherwise implemented toward the tip end to retain the lock-pin in the joint, thereby making a structural connection.
FIGS. 1A through 1D
collectively are side views of some common lock-pins in accordance with the prior art.
FIG. 1A
, for example, illustrates a lock-pin
100
having a head
101
and a cylindrical shaft
102
. A bore
103
extends perpendicularly through the tip end of the shaft
102
and can removably receive a coffer pin
104
or a similar device as a separate locking element. Lock-pin devices similar to the lock-pin
100
can be used for myriad applications, including shackle-type installations. U.S. Pat. Nos. 5,114,260 to Hart et al., 5,460,418 to Falls, 4,102,124 to Swager, and 6,023,927 to Epstein disclose but a few such lock-pin devices.
Other lock-pins are similar to the lock-pin
100
, except they do not use a cotter pin type locking element. U.S. Pat. No. 1,799,934 to Strid, for example, discloses a lock-pin that uses a continuous wire spring resiliently inserted through the bore
103
as a locking element that retains the pin once installed. U.S. Pat. No. 2,399,119 to Howell, U.S. Pat. No. 4,205,586 to MacNeill, and U.S. Pat. No. 5,599,150 to Edwards et al., all embody designs similar to Strid. One advantage of these lock-pins over the lock-pin
100
is that their locking elements can be installed, removed, and reinstalled through the bore
103
more easily than the cotter pin
104
.
In many applications, it will be desirable to install a lock-pin through a hole where no access exists to the far-side of the hole where the tip of the lock-pin emerges. For ease of reference, such an installation will be referred to throughout this disclosure as a “blind” installation. A common feature of all the prior art lock-pins discussed above is that they require access to the tip end of the shaft
102
after the shaft has been inserted through a hole so that a separate locking element can be installed in the bore
103
. This feature renders these lock pins essentially useless in blind applications. Another common shortcoming associated with all these lock-pins is that the separate locking element, whether it be a cotter pin or a wire spring, can easily be lost or misplaced, thereby frustrating installation and again rendering the lock-pin essentially useless.
FIG. 1B
is a side view of a lock-pin
110
in accordance with the prior art that does not use a separate locking element. The lock-pin
110
has pull-ring
111
moveably attached toward the head end of a cylindrical shaft
112
. A rotatable locking element
114
is rotatably attached toward the tip end of the shaft
112
, and a coil spring
115
is coaxially disposed over the shaft in compression against the locking element. The locking element
114
is rotated to an unlocked position in axial alignment with the shaft
112
for installation of the lock-pin
110
through a hole (not shown). After installation, the locking element
114
is rotated approximately 90 degrees to a locked position as illustrated to prevent the lock-pin
110
from backing out of the hole. The coil spring
115
keeps the locking element
114
in this locked position unless or until the locking element is manually rotated to the unlocked position.
U.S. Pat. No. 5,437,515 to Kuramoto et al. discloses a lock-pin that is similar to the lock-pin
110
shown in FIG.
1
B. In Kuramoto, however, the locking element is maintained in the locked position by way of a positioning member inserted radially through the locking element. U.S. Pat. No. 5,112,155 to Jackson and U.S. Pat. No. 4,822,197 to DeMartino et al. have locking mechanisms similar to that disclosed in Kuramoto, but they do not require a positioning member. Although lock-pins like that shown in
FIG. 1B
do not require a separate locking element as does the lock-pin shown in
FIG. 1A
, they nevertheless still cannot be used as a removable fastener in blind installations where there is no access to the tip end of the shaft
112
to rotate the locking element
114
as necessary to retain or remove the lock-pin.
FIGS. 1C and 1D
illustrate some prior art lock-pins that can be installed from only one side of an installation application and thus are useable in blind applications. Shown in
FIG. 1C
, for example, is a quick-release pin
120
that can be installed with access to only the near-side of a joint. The quick-release pin
120
is similar, but not identical, to the lock-pin disclosed in U.S. Pat. No. 5,845,898 to Halder et al. The quick-release pin
120
consists of a spring-loaded plunger
125
that movably extends longitudinally through the center of a cylindrical shaft
122
from a head end toward a tip end. By pressing the spring-loaded plunger
125
, two balls
124
located at the tip end of the shaft
122
are allowed to retract radially inward until flush with the outer surface of the shaft, thereby allowing the quick-release pin
120
to be inserted through a hole (not shown). When the spring-loaded plunger
125
is released, it pushes radially outward against the two balls
124
causing the balls to protrude radially outward and act as locking elements that retain the lock-pin
120
in the hole.
One shortcoming of the quick-release pin
120
of
FIG. 1C
is that manufacturing considerations prevent the balls
124
from protruding very far outboard of the shaft
122
. As a result, the quick-release pin
120
cannot hold two structures together effectively unless the shaft
122
is a very close fit in the corresponding hole through which the quick-release pin is inserted. Hole tolerances often cannot be held close enough to make this type of lock-pin useful or cost effective. In addition, the ball-type locking elements of this type of lock-pin are prone to release prematurely where vibration or substantial axial loads are present. Furthermore, the complicated assembly of the quick-release pin
120
, in addition to its plurality of elements, can make it expensive to manufacture and hence costly to the consumer.
FIG. 1D
is a side view of yet another lock-pin
130
in accordance with the prior art that can be used in blind applications. The lock-pin
130
has a pull-ring
131
moveably attached toward a head end of a cylindrical shaft
132
, and a single spring-loaded ball
134
located toward a tip end of the shaft. The lock-pin
130
is intended to be installed by simply pressing it into a hole with sufficient force to overcome the spring-loaded ball
134
causing it to retract into its hole. The lock-pin
130
is accordingly removed by pulling on the pull-ring
131
with a force of similar magnitude. As should be apparent to those of ordinary skill in the art, the lock-pin
130
is a poor choice for those applications that could be subjected to a substantial axial load in service, because of the tendency for such an axial load to overcome the spring-loaded ball
134
and disengage the lock pin.
In addition to the various prior art lock-pins discussed above, a safety hitch-type lock-pin having a shaft with a coaxial longitudinal bore is disclosed in U.S. Pat. No. 5,199,733 to DeLorme. In DeLorme, a lock-rod is inserted through the bore from the head end and is connected to two flanges embedded into respective slots toward the tip end. Rotation of the lock-rod causes the flanges to rotate outward, thus retainin

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