Secondary lock for medical tube coupling

#Many tubular administration sets for administering medical fluids such as parenteral solutions or blood are in current use. In this use, it is often desired to connect one of such sets with another, for example to add supplemental medications and the like to a stream of parenteral solution being delivered to a patient. Various systems of this type are commercially available.

#Often, the various sets to be connected together make their connection through a so-called Luer connection, which is a simple, tapered tube which connects into a correspondingly tapered receptacle. This connection, while simple and easy to make and break, carries with it the hazard that it can accidentally come apart. Such is of course most undesirable in any circumstance, and particularly in the field of medical solution administration sets where sterility is a critical question and the like.

#The PiggyMate safety clamp has been marketed by Trend Medical Inc. This device includes a toothed rack having a sliding member carried on it. Both the sliding member and one end of the toothed rack include transversely extending retention members, each of which may be used to grip a connected tubular set member. In the Trend Medical device, the sliding member slides toward the one end which carries the retention member, but the sliding member cannot slide in the other direction. Thus, when the Trend Medical safety clamp has its sliding member advanced, it may not be possible to reuse the device. Similarly, if one by accident slides the sliding member too far forward to effectively grip the particular pair of connected sets, the device is no longer useable since the sliding member cannot be retracted.

#FIG. 1 is a perspective view of the secondary lock of this invention shown to be retaining a pair of connected tubular members which constitute parenteral solution sets;

#FIG. 2 is a sectional view taken along line 2--2 of FIG. 1; and

#FIG. 3 is a sectional view taken along line 3--3 of FIG. 2.

#Referring to the drawings, the secondary lock 10 of this invention may be made of an integrally molded piece of appropriate plastic, defining a toothed rack 14, plus a first transversely extending retention member 16, made up of a pair of jaws 18, between which there may be retained parenteral solution administration set 20.

#Elongated body 12 carries sliding member 22 which is shown to surround rack 14 and to be in substantially slidable relation with it. Slidable member 22 carries a second transversely extending retention member 24 which comprises another pair of jaws 26, defining between them a space 28 to receive another set member 30. The specific functioning and design of jaws 18 may be identical to that of jaws 26, if desired.

#Sliding member 22 also defines a pawl 32, which defines a tip 34 which is capable of fitting in between the individual teeth 36 of rack 14 as shown in full lines in FIG. 2. Pawl 32 is shown to be carried on sliding member 22 by a pair of opposed, integral, flexible hinges 38, which connect pawl 32 to the remainder of sliding member 22. The entire sliding member 22 and pawl structure may be integrally molded.