1.  Field of Invention
The present invention relates to a system for maintaining a quick connect coupling in its coupled position.  More particularly, the present invention relates to a spring biased latching means for securing the lever arms of a quick release, cam action coupling in a closed disposition. 
2.  Prior Art And General Background
The broad concept of using an encircling, pivoted two-piece clamp to join pipe sections together is shown in the patents to Jolliffe et al (U.S. Pat No.  196,807 issued Nov. 6, 1877), Eastman (U.S. Pat.  No.  1,185,487 issued May 30, 1916), Brewer (U.S. Pat.  No.  1,518,479 issued Dec. 9,1924), and Perrin et al (U.S. Pat.  No.  3,828,403 issued Aug. 13, 1974).  These prior art clamps, unlike the present invention, encircle a full 360 degrees of the pipe sections to be joined and are designed for a narrowly limited range of pipe diameter sizes.  Additionally the clamps of the prior art are designed to accomplish the actual joining, securing and sealing of the sections of pipe.  The clamps of the prior art are either designed to be of an exact preset final internal diameter as in Jolliffe et al and Perrin; or the clamps are somewhat adjustable by the use of a screw or bolt as in Eastman and Brewer. 
The prior art of clamping generally shows the use of a spring to bias a 360 degree band taut around a milk crock in the patent to Bronson (U.S. Pat.  No.  740,390 issued Oct. 6, 1903), once again in a application which accomplishes the sealing of the joint itself by means of a completely encircling, continuous band. 
In the patent to Moore et al (U.S. Pat.  No.  3,439,943 issued Apr. 22, 1969) a retainer member, not an encircling clamp, is included with one of the pivot arms to prevent the lever arm from becoming disengaged. 
Other coupling patent which may be of general background interest are U.S. Pat.  No.  2,033,142 and 2,518,026. 
3.  General Discussion of the Invention
In a quick disconnect coupling a pair of levers is pivotally mounted on a socket member for camming cooperation with a plug member to quickly attach or detach the plug and socket members.  When the lever arms are in the proper position to cause the camming action to seal the coupling, either lever may be accidentally jostled from its position.  If this should occur, the plug and socket members are no longer sealed, and the passage through the coupling is no longer leak proof.  The present invention solves this problem by securing the lever arms with a partially encircling clamp having a biasing force, so that the lever arms can not move out of their closed dispositions without intentional disengagement of the safety clamp clamp of the present invention. 
The illustrated embodiment of the present invention accomplishes this by surrounding the socket coupling housing and the two opposing lever arms.  The present invention constricts the outward movement of the arms in such a manner as to hold them secure against the body of the coupling. 
The clamping arms or rigid element of the preferred embodiment of the present invention, in contrast to the prior art, only encircle approximate 270 degrees of the pipe circumference, are designed to make contact only at a limited number of specific points, at least some of which have flat, face-to-face surface engagements, and is used primarily if not exclusively as a safety measure to prevent a separate pipe joining mechanism from becoming undone.  The present invention utilizes a spring biasing mechanism to close off the gap between the ends of the two encircling arms and to maintain the clamp in a secure relationship with the separate coupling, causing the clamp to prevent the coupling from coming loose.