Patent ID: 9598875
Date: 2017-03-21
CPC Classifications: E04H,F16B,F21V,F21W

Claim:
1. A safety latch system for a telescoping mast for a portable light tower having a towable trailer having a frame, an engine driven electrical generator, and a light assembly for attachment to the uppermost end of a telescoping mast member, which comprises: a stationary mast member of predetermined length having an upper end, and a first side, vertically oriented and attached to the frame, the stationary mast member defining a interior first cavity slideably receiving a first hoisting cable and a first telescoping mast member, the stationary mast member having an opening therethrough in the first side; the first telescoping mast member having a longitudinal length and base sized and configured to be slideably received within the first cavity of the stationary mast member for telescoping into and out of said cavity without rotating relative to the stationary mast member, the first telescoping mast member having a plurality of slots formed therein along its longitudinal length configured for alignment with the opening in the first side of the stationary mast member as the first telescoping mast member is telescoped into and out of the stationary mast member; a winch assembly fixed to the towable trailer; a first hoisting pulley attached to the upper end of the stationary mast member; a first hoisting cable operably attached at one end to the winch assembly, and configured to pass in front of the opening in the first side of the stationary mast member, and wound over the top of the hoisting pulley and threaded down within the first cavity between the cavity wall and an outside wall of the first telescoping mast member and attached, at the hoisting cable's second end, to the first telescoping member near its base; and a pivotable spring loaded safety latch assembly, having a latch at one end, and an idler roller at the other, attached to the stationary mast member and positioned between the first hoisting cable and the opening in the first side of the stationary mast member, and pivotable from a first, cocked, position wherein the idler roller is in rotational engagement with the first hoisting cable and the latch is outside the opening in the stationary mast member when the first hoisting cable is under tension, to a second, tripped, position wherein the latch passes through the opening in the stationary mast member and engages into a slot in the first telescoping mast member when the tension on the first hoisting cable is relieved.