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In a snap-in electrical connector for attaching helical metal cable and conduit to a junction box or the like, the connector having the locking ring with flexible tabs engageable with the cable/conduit, the improvement wherein the tabs have legs angled inwardly of the ring at specified angles, tips

In a snap-in electrical connector for attaching helical metal cable and conduit to a junction box or the like, the connector having the locking ring with flexible tabs engageable with the cable/conduit, the improvement wherein the tabs have legs angled inwardly of the ring at specified angles, tips that form specified angles with the legs, and tip ends that are biased relative to the legs in the same direction. The specified angles of the legs, tips and tip ends provide improved pull-out strength, electrical conductivity and stability for a wide range of sizes and types of cable and conduit, including metal clad cable, armored cable, and flexible metal conduit, made of aluminum and steel.

대표청구항 ▼

What is claimed is: 1. A snap-in electrical connector for helical metal cable and conduit comprising: a) a body having a leading end engageable in a hole of a junction box, a trailing end, and at least one locking ring chamber having a longitudinal axis, b) a spring steel locking ring in said chamb

What is claimed is: 1. A snap-in electrical connector for helical metal cable and conduit comprising: a) a body having a leading end engageable in a hole of a junction box, a trailing end, and at least one locking ring chamber having a longitudinal axis, b) a spring steel locking ring in said chamber, said locking ring including outwardly extending locking tabs engaged in holes in said body, and three inwardly extending tabs including a trailing tab and a leading tab that extend toward each other and a middle tab between said trailing and leading tabs, c) each of said tabs having a leg extending inwardly of said chamber toward said leading end, a cable/conduit engaging tip bent at an angle with respect to said leg, and a tip end, said tip ends being spaced along said longitudinal axis of said chamber and being biased relative to said legs in the same angular direction so as to follow and engage the bottom of the helical groove of the cable/conduit when inserted into said body with said chamber. 2. A snap-in electrical connector as claimed in claim 1, wherein said tip ends are biased at an angle in a range from about 9��-20��. 3. A snap-in electrical connector as claimed in claim 2, wherein said tip end of said leading tab has a biased angle of about 10��, said tip end of said trailing tab has a biased angle of about 20��, and said tip end of said middle tab has a biased angle of about 9��. 4. A snap-in electrical connector as claimed in claim 1, wherein the tip end of said middle tab is concave so as to provide two points of engagement with the bottom of the helical groove of a cable/conduit. 5. A snap-in electrical connector as claimed in claim 1, wherein said middle tab is longer that said trailing and leading tabs. 6. A snap-in electrical connector as claimed in claim 1, wherein the leg of said middle tab is concavo-convex along its length. 7. A snap-in electrical connector as claimed in claim 1, including two locking ring chambers, each having one of said locking rings. 8. A snap-in electrical connector as claimed in claim 1, wherein locking ring has a thickness and hardness of about 0.020 gauge and 45-50 Rockwell C., and wherein said legs form included angles with said ring in the range of about 35��-55��. 9. A snap-in electrical connecter as claimed in claim 8, wherein the legs of said trailing and leading tabs form included angles of about 42��, and the leg of said middle tab forms an included angle of about 52��. 10. A snap-in electrical connector as claimed in claim 8, wherein said tips form included angles with said legs of about 135��. 11. A snap-in electrical connector as claimed in claim 1, wherein: i) the legs of said trailing and leading tabs form included angles with said ring of about 42��, ii) the leg of said middle tab forms an included angle with said ring of about 52��, iii) said tips of said tabs form included angles with their legs of about 135��, iv) the biased angle of said leading tab is about 10��, v) the biased angle of said trailing tab is about 20��, vi) the biased angle of the tip end of said middle tab is about 9��. 12. A snap-in electrical connector locking ring having a leading end, a trailing end and a longitudinal axis extending between said ends, said ring comprising outwardly extending, concavo-convex locking tabs and inwardly extending, cable/conduit tabs including a leading tab, and a trailing tab that extend toward each other and a middle tab between said leading and trailing tabs, each of said inwardly extending tabs including a leg projecting toward said leading end, a tip formed at an angle to said leg, and a tip end formed at an angle to said tip, said tip ends being biased in the same angular direction corresponding to the helical angle of a cable/conduit engage by said connector, and said inwardly extending tabs being spaced from each other along said longitudinal axis by a distance such that said tips can capture the helical groove of a metal cable and conduit with said biased end tips engaging the bottom of the groove. 13. A snap-in electrical connector locking ring as claimed in claim 12, wherein said middle tab is longer than said leading and trailing tabs, and is concavo-convex along its length, and wherein the tip end of said middle tab is concave.