Patent ID: 7281693

Claim:
A ball head assembly for a tripod comprising: a holding base having a top and a bottom; a clamping collar attached to the holding base; a ball rotatably attached to the clamping collar and having a top and a bottom; a holder attached to the top of the ball to hold an instrument on the holder; and an anti-escape mechanism mounted on the holding base, connected to the ball and comprising a supporting rod extending through the bottom of the holding base and having a spherical end rotatably connected to the bottom of the ball and a threaded end extending out from the bottom of the holding base; a supporting block mounted around the supporting rod and rotatably mating with the bottom of the holding base; a dragging member mounted around the supporting rod and having a first end abutting against the supporting block and a second end; and a nut screwed onto the threaded end of the supporting rod and abutting against the second end of the dragging member.