Removable push electrical fitting for electrical metallic tubing or EMT having improved pullout resistance
View Patent ↗An electrical fitting having a gripping device with a plurality of gripping tabs forming a helix or spiral. The gripping tabs have a twist creating increased pullout resistance and easier disassembly. The electrical fitting permits electrical metallic tubing or EMT to be quickly attached to and removed from the electrical fitting without disassembling the fitting or cutting the tubing. A body with a locking end having a plurality of griping tabs receives an end of the tubing pushed into the fitting. The gripping tabs securely hold the tubing preventing loosening or removal. The helix or spiral and twist formation of the griping tabs permits easy removal of the tubing by rotating the tubing counter-clockwise.
1. An electrical fitting comprising:
a body having a first and second end;
a locking device placed in the first end of said body; and
a plurality of gripping tabs forming a helix or spiral held in said locking device, each of said plurality of gripping tabs having a twist;
whereby a tube can be pushed into said locking device and held by said plurality of gripping tabs and the twist provides additional rigidity improving pullout resistance and the helix or spiral and the twist formation of said plurality of gripping tabs permits easy removal of the tube by rotating the tube counterclockwise.
2. An electrical fitting as in claim 1 further comprising:
an electrical box connector formed on the second end of said body,
whereby the electrical fitting can be connected to an electrical box.
3. An electrical fitting as in claim 2 wherein:
said electrical box connecter comprises a threaded end placed on the second end and a locknut.
4. An electrical fitting as in claim 1 further comprising:
a second locking device placed in the second end of said body; and
a second plurality of gripping tabs forming a helix or spiral held in said second locking device, each of said second plurality of gripping tabs having a twist;
whereby two tubes may be coupled.
5. An electrical fitting as in claim 1 further comprising:
a contact rib formed on a surface of a bore in said body and extending radially into the bore in said body by an increasing radial dimension while progressing axially or longitudinally relative to said body.
6. An electrical fitting as in claim 1 wherein:
the twist ranges from six and eight degrees.
7. An electrical connector for attaching electrical metallic tubing to an electrical box comprising:
a body having a first and second end and an aperture in the first end;
a locking device formed on the first end of said body;
a plurality of gripping tabs forming a helix or spiral with each gripping tab of the plurality of gripping tabs having a twist, said gripping device secured to said locking device;
a threaded end formed on the second end of said body; and
a locknut placed on said threaded end,
whereby an electrical metallic tubing can be pushed into said locking device and held by the plurality of gripping tabs and the twist provides additional rigidity improving pullout resistance and the helix or spiral and the twist formation of said plurality of gripping tabs permits easy removal of the electrical metallic tubing by rotating the electrical metallic tubing counterclockwise.
8. An electrical connector for attaching electrical metallic tubing to an electrical box as in claim 7 further comprising:
a contact rib formed on said body and extending radially into said body by an increasing radial dimension while progressing axially or longitudinally relative to said body towards said locking device.
9. An electrical connector for attaching electrical metallic tubing to an electrical box as in claim 7 wherein:
the helix or spiral has a pitch of substantially two degrees.
10. An electrical connector for attaching electrical metallic tubing to an electrical box as in claim 7 wherein:
the twist ranges from six to eight degrees.
11. An electrical connector for attaching electrical metallic tubing to an electrical box as in claim 7 wherein said plurality of gripping tabs further comprises:
a circular shaped flat rim adapted to be securely held within said locking device;
a tapered angled portion formed onto said flat rim;
a flat ramp formed onto to said tapered angle portion; and
wherein said plurality of gripping tabs are formed onto said flat ramp and are angled inward towards said body.
12. An electrical connector for attaching electrical metallic tubing to an electrical box as in claim 11 wherein:
the twist ranges from six to eight degrees relative to a plane of said circular shaped flat rim.
13. An electrical connector for attaching electrical metallic tubing to an electrical box as in claim 11 further comprising:
a washer having a circular aperture placed adjacent said circular shaped flat rim;
a crimp formed on said locking device holding said washer adjacent said circular shaped flat rim and said locking device; and
a dimple formed in said crimp,
whereby said washer is forced against said circular shaped flat rim and said locking device formed on said body preventing relative rotation of said plurality of gripping tabs and said body.
14. An electrical connector for attaching electrical metallic tubing to an electrical box as in claim 7 wherein:
one of said plurality of gripping tabs comprises a high end gripping tab having a rounded corner with a cutting edge.
15. An electrical connector for attaching electrical metallic tubing comprising:
a body having a threaded end with a threaded end bore having a first diameter, a body bore having a second diameter, and a conical portion forming a locking end;
an intermediate shoulder formed between the threaded end bore and the body bore;
a plurality of contact ribs formed adjacent said intermediate shoulder and extending longitudinally into said body and radially outward by increasing radial amounts progressing from said intermediate shoulder towards the locking end;
a shoulder formed on a large diameter end of the conical portion;
a locking device comprising a circular shaped flat rim abutting said shoulder, a tapered angled portion formed onto the circular shaped flat rim, a flat ramp formed onto the tapered angled portion, and a plurality of gripping tabs formed onto the flat ramp and angled inward towards said body, each of the plurality of gripping tabs having a twist;
a washer having a circular aperture sized to receive the electrical metallic tubing placed within the conical portion of said body and adjacent the circular shaped flat rim of said locking device;
a crimp formed around a circumference of the large diameter end of the conical portion, whereby said crimp holds said locking device and said washer into the conical portion of said body;
a plurality of dimples pressed into said crimp forcing said washer and the circular shaped flat rim against said shoulder formed on the large diameter end of the conical portion, whereby said locking device is prevented from rotating relative to said body; and
a locknut threaded on the threaded end of said body,
whereby the electrical metallic tubing can be pushed into said locking device and held by the plurality of gripping tabs with the twist providing additional rigidity improving pullout resistance and removed by rotating the electrical metallic tubing placed in the circular aperture counter-clockwise permitting easy removal of the electrical metallic tubing.
16. An electrical connector for attaching electrical metallic tubing as in claim 15 wherein:
the flat ramp forms a pitch of two degrees.
17. An electrical connector for attaching electrical metallic tubing as in claim 15 wherein:
one of the plurality of gripping tabs comprises a high end gripping tab having a rounded corner cutting edge.
18. An electrical connector for attaching electrical metallic tubing as in claim 15 wherein:
the twist ranges from between six and eight degrees relative to a plane of the circular shaped flat rim.
19. An electrical coupler for coupling two tubes comprising:
a body having a first and second end and an aperture in the first end and the second end;
a first locking device comprising a first plurality of gripping tabs forming a helix or spiral secured to the first end of said body, each of the first plurality of griping tabs having a first twist; and
a second locking device comprising a second plurality of gripping tabs forming a helix or spiral secured to the second end of said body, each of the second plurality of griping tabs having a second twist,
whereby a respective electrical metallic tubing can be pushed into said first and second locking devices and effectively joined, with the first and second twist providing additional rigidity improving pullout resistance and removed by rotating the respective electrical metallic tubing placed in the aperture in the first end or the second end counter-clockwise permitting easy removal of the respective electrical metallic tubing.