A quick disconnect assembly is disclosed for joining two members. The assembly is comprised of two circular steel bushings, a cylindrical steel pin and a steel spring ring. The bushings include axial circular openings and are each disposed in one of the legs of the first member so that they are axially aligned. The pin includes an annular groove in which is disposed the spring ring. The second member has a circular bearing at one end which has a circular opening extending axially therethrough. Connection of the first and second members is accomplished by positioning the second member between the legs of the first member so that the bearing opening is in axial alignment with the bushings openings. The pin is then inserted into the three aigned openings from one end. Insertion is aided by chamfers which help to compress the spring ring. When the pin is fully inserted, the spring ring expands because of its resiliency and abuts against an annular shoulder in the opening of the first bushing to retain the pin in position. Disconnection is accomplished by pulling the pin out of the openings. Pin removal is impeded by the annular shoulder. A second annular shoulder in the other bushing acts to retain the pin in a partially withdrawn position.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to quick disconnect assemblies for joining two 
members and, more particularly, to a quick disconnect assembly for joining 
a rod and a clevis. 
2. Description of the Prior Art 
In the prior art a commonly used quick release pin for joining a rod and a 
clevis is comprised of a tubular shank member, a pair of steel balls and a 
spring-loaded cylindrical member. The cylindrical member has an annular 
groove and is disposed to move axially within the tubular shank. The balls 
are disposed within a pair of bores extending radially through the tubular 
shank. 
In the installed position, when the prior art pin is fully inserted within 
openings in both clevis legs and in the rod, the cylindrical member is 
axially positioned by the spring to force the balls radially outwardly 
from the tubular member and into engagement with an annular groove within 
the opening in one of the clevis legs, thereby locking the pin in place. 
Removal or insertion of the pin is accomplished by depressing the 
cylindrical member against the spring bias into the tubular member to a 
position where the groove on the cylindrical member aligns with the balls. 
The action releases the outward force on the balls and allows them to 
retract into the radial bores in the tubular member, thereby disengaging 
them from the groove in the clevis leg and allowing the pin to be slidably 
removed from the clevis and rod openings. 
Although this prior art quick release pin is generally adequate for many 
applications, it suffers from several particular shortcomings which 
preclude its use under certain conditions. Because of its inherent method 
of operation, the prior art pin contains a radially enlarged portion to 
provide for depressing the cylindrical member and for gripping the pin for 
removal and insertion. This causes the pin to be excessively large, 
thereby denying its use in small areas. The prior art pin is also subject 
to freezing, rendering it useless under adverse environmental conditions. 
In addition, the cost of manufacturing and assembling the prior art pin 
makes it economically impractical for certain applications. All of these 
shortcomings as well as others are overcome by the present invention. 
An object of the present invention is to provide a simplified quick 
disconnect assembly for joining two members which can be made small for 
use in applications where space is limited. 
A further object of the present invention is to provide such a quick 
disconnect assembly which may be inexpensively produced in volume 
quantities. 
A further object of the present invention is to provide such a quick 
disconnect assemby which is not susceptible to failure under adverse 
environmental conditions. 
A further object of the present invention is to provide such a quick 
disconnect assembly which will prevent pin loss and facilitate reassembly. 
SUMMARY OF THE INVENTION 
Briefly stated, there is provided, in accordance with the present 
invention, a quick disconnect assembly for joining two members being 
comprised of two circular steel bushings, a cylindrical steel pin and a 
steel spring ring. The first bushing includes a circular opening extending 
axially therethrough and is disposed within a first leg of the first 
member. The second bushing includes a circular opening extending axially 
therethrough and is disposed within a second leg of the first member. Both 
of the bushing openings are axially aligned. The pin includes an annular 
groove in which is disposed the spring ring. The second member has a 
circular bearing at one end which has a circular opening extending axially 
therethrough. 
Connection of the first and second members is accomplished by positioning 
the second member between the legs of the first member so that the bearing 
opening is in axial alignment with the bushing openings. The pin is then 
inserted into the three aligned openings from one end. Pin insertion is 
aided by chamfers on the insertion side of the bushing and bearing 
openings which help compress the spring ring. When the pin is fully 
inserted, the spring ring expands because of its resilience and abuts 
against an annular shoulder in the interior of the opening in the first 
bushing. 
Disconnection is accomplished by pulling the pin out of the openings and 
removing the rod. Pin removal is impeded by the annular shoulder which 
inhibits the compression of the spring ring. A second annular shoulder 
located in the interior of the opening in the second bushing acts to 
retain the pin in a partially withdrawn position.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1 and 2, there are shown a first member or clevis 12 and 
a second member or rod 10 adapted to be held in assembled relation by the 
quick disconnect assembly of the present invention. The clevis 12 may be 
made of aluminum or any other suitable rigid material and has two legs 16 
and 18 at one end. The rod 10 may be made of steel or any other suitable 
material and includes an end bearing 14 at one end. The end bearing 14 has 
a generally circular opening 20 extending axially through the center and 
is positioned between the clevis legs 16 and 18. Axially as used herein 
means a direction along the axis Y--Y shown in FIG. 1. 
A circular steel bushing 22 is adapted to reside within a circular opening 
24 near the end of clevis leg 16. A second circular steel bushing 32 is 
adapted to reside within a circular opening 34 near the end of clevis leg 
18. Bushings 22 and 32 have axially aligned circular openings 26 and 36 
extending axially through their respective centers. The rod 10 is 
positioned between clevis legs 16 and 18 so that the bearing circular 
opening 20 axially aligns with bushing circular openings 26 and 36. 
A circular pin 46 constituted of steel or any other suitable rigid material 
has a shank portion 46a, a head portion 46b and a tip end 46c. The shank 
portion 46a is receivable within bushing circular openings 26 and 36 and 
within circular opening 20 in order to connect the clevis 12 to the rod 
10. The head portion 46b has a first circular annular flange member 48 
having a diameter which is slightly larger than that of the shank portion 
46a. The flange member 48 acts as a stop means for limiting the insertion 
of the shank portion 46a by abutting against bushing 32 when the shank 
portion 46a is fully inserted into circular openings 36, 20 and 26, as 
shown in FIG. 1. Alternatively, flange member 48 could be made slightly 
larger than is shown in FIG. 1 so that it would abut against the side of 
clevis leg 18, to limit the insertion of shank portion 46a. A second 
circular annular flange member 50 having a diameter which is slightly 
larger than that of flange member 48 is located on the end of the head 
portion 46b and serves as a convenient handle for holding the pin 46 
during insertion or withdrawal. 
The shank portion 46a includes an annular groove 52 near tip end 46c. A 
resilient member 54 is disposed within the annular groove 52. In the form 
of the invention shown, the resilient member 54 is an arcuate flat spring 
ring, as best seen in FIG. 3, constructed of an approximately 270.degree. 
arc of stainless steel spring wire or any other suitable resilient 
material. 
The interior of the circular opening 26 in bushing 22 includes a 
sharp-edged annular shoulder 30 which is engageable by the spring ring 54 
in order to retain the pin 46 in an inserted position as shown in FIG. 1. 
Due to sharp edge 31, shoulder 30 also acts to inhibit the compression of 
the spring ring 54, thereby necessitating a high withdrawal force in order 
to remove the pin 46 from bushing 22. In this manner, inadvertent or 
accidental removal of the pin 46 is precluded. 
The interior of the circular opening 36 in bushing 32 includes a second 
sharp-edged annular shoulder 40 which is engageable by the spring ring 54 
in order to retain the pin 46 in a partially withdrawn position as shown 
in FIG. 2. Due to sharp edge 41, the shoulder 40 also acts to inhibit the 
compression of the spring ring 54, thereby necessitating a high withdrawal 
force in order to remove the pin 46 from bushing 32. In this manner, 
inadvertent or accidental removal of the pin 46 is precluded. 
The bushing circular openings 26 and 36 each contain an annular lead-in 
chamfer 28 and 38, respectively. These chamfers, when engaged by the 
spring ring 54, facilitate compression of the spring ring and thereby 
provide for easy insertion of the pin 46 into bushings 32 and 22. The 
bearing circular opening 20 has annular chamfers 42 and 44 on each side 
which are engageable by the spring ring 54 in order to facilitate the 
compression of spring ring for easy movement of the pin 46 through the 
bearing 14 during insertion and withdrawal. The tip end 46c of the pin 46 
also contains an annular chamfer 56 in order to facilitate insertion of 
the tip end 46c into the circular opening 36 in bushing 32. 
In operation, once the rod 10 is positioned between clevis legs 16 and 18 
so that circular openings 36, 20 and 26 are properly aligned, the tip end 
46c of the pin 46 is inserted into bushing circular opening 36 and the 
shank portion 46a of pin 46 is simply pushed into circular openings 36, 20 
and 26 until the flange member 48 abuts bushing 32. The initial insertion 
of the pin 46 is aided by chamfer 56. Chamfers 38, 44 and 28 all act to 
facilitate the compression of spring ring 54 as the pin 46 moves into 
circular openings 36, 20 and 26, respectively, thereby resulting in a low 
pin installation force. 
When the flange member 48 abuts bushing 32, the pin 46 is in a fully 
inserted position as shown in FIG. 1 and the spring ring 54 has expanded 
to its uncompressed position in which it extends beyond the diameter of 
the shank 46a. In this position the spring ring 54 will engage the 
shoulder 30 upon any rightward movement of the pin 46, thereby preventing 
any accidental dislodgement of the pin 46. Leftward movement of the pin is 
effectively prevented by the engagement of the flange member 48 with the 
bushing 32. 
As noted above, insertion of the pin is accomplished by a simple pushing 
motion. There is no need to perform any additional functions which had 
been required in the prior art. 
Removal of the pin 46, when desired, is easily accomplished by pulling 
outwardly on the flange member 50 so that the spring ring 54 abuts with 
shoulder 30 and is compressed. Since shoulder 30 is sharp-edged, rather 
than chamfered, the withdrawal force required to compress the spring ring 
54 is much greater than that required for pin insertion. Once the spring 
ring 54 is compressed the pin 46 may easily be withdrawn from bushing 22. 
Chamber 42 facilitates the compression of the spring ring 54 for an 
equally easy withdrawal of pin 46 through bearing 14. 
Once the pin 46 has been removed from bushing 22 and the bearing 14 to the 
position shown in FIG. 2, the rod 10 may be removed from its position 
between clevis legs 16 and 18 for servicing. The pin 46 will be retained 
in its partially withdrawn position within bushing 32 by the spring ring 
54 and shoulder 40. This is a highly desirable feature because not only 
does it prevent the pin from falling out and being potentially lost, but 
it also provides for easier reassembly of the rod and clevis since the pin 
is already lined up in the bushing opening. 
Complete removal of the pin 46, if desired, is accomplished by pulling 
outwardly on the flange member 50 so that the spring ring 54 is compressed 
within the inner diameter of bushing 32. Since shoulder 40 is sharp-edged 
rather than chamferred, the withdrawal force required will also be much 
greater than that which was required for pin insertion. Once the spring 
ring 54 is compressed, the pin 46 may easily be withdrawn from bearing 32. 
ALTERNATE EMBODIMENT 
Referring now to FIG. 4, there is shown an alternate embodiment of the 
quick disconnect assembly of the present invention. Rod 10, clevis 12, and 
bearing 14, circular pin 46 and spring ring 54 are essentially as 
described in detail above. Clevis legs 16 and 18 contain axially aligned 
circular openings 60 and 62 respectively extending axially therethrough. 
Circular openings 60 and 62 each contain an annular lead in chamfer 68 and 
70 respectively to facilitate compression of the spring ring 54 for easy 
insertion of the pin 46. 
The interiors of circular openings 60 and 62 include sharp-edged annular 
shoulders 64 and 66 respectively. Shoulder 64 is engageable by the spring 
ring 54 to retain the pin 46 in an inserted position as shown in FIG. 4. 
Due to sharp edge 65, shoulder 64 also acts to inhibit the compression of 
the spring ring 54 thereby necessitating a high withdrawal force to remove 
the pin 46 from the circular opening 60. Likewise, shoulder 66 is 
engageable by the spring ring 54 in order to retain the pin 46 in a 
partially withdrawn position (not shown). Due to sharp edge 67, shoulder 
66 also acts to inhibit the compression of the spring ring 54 thereby 
necessitating a high withdrawal force in order to remove the pin 46 from 
the circular opening 62. In this manner, inadvertent or accidental removal 
of the pin 46 is precluded. 
The operation of this alternate embodiment of the present invention is 
essentially as described in detail above. 
From the foregoing description it can be seen that in either embodiment 
heretofore shown the present invention provides a quick disconnect 
assembly for joining a rod and clevis which can be made as small as is 
necessary for a particular operation while still maintaining maximum 
load-carrying capacity. Because of its simple push/pull method of 
operation with a minimum of moving parts, this assembly is much less 
likely to be affected by adverse environmental operating conditions. A 
feature of this invention is that the pin may be retained in a partially 
withdrawn position thereby effectively preventing loss of the pin and 
facilitating reassembly. In addition, because of its overall simplicity, 
the present invention is highly suitable for automated volume production, 
thereby making it much less expensive to produce and use. 
It will be obvious to one skilled in the art that changes can be made to 
the above-described invention without departing from the broad inventive 
concepts thereof. It is to be understood, therefore, that this invention 
is not limited to the particular embodiments disclosed, but it is intended 
to cover all modifications which are within the spirit and scope of the 
invention as claimed.