Patent ID: 6945143

Claim:
A self-adjustable universal spanner comprising: a spanner head member and a brake piece having the same width as said spanner head member and operatively connected thereto, said spanner head member including a jaw portion for seating a bolt head and an open slot formed in the jaw portion, wherein the jaw portion includes a flat surface formed in the front lower thereof, and wherein the open slot includes a pin escape groove in a base thereof and a spring insert groove formed in the rear upper side of the jaw portion, and a guide groove for deviation prevention formed in the upper wall of the open slot; said brake piece member having a sloped contact surface, a guide protrusion of a width less than a width of said brake piece member, and a elastic support pin, wherein the sloped contact surface is formed in the tip bottom of said brake piece member, and the guide protrusion is provided with an escape preventing shoulder formed protrusively thereon, and the elastic support pin is installed in the rear end of the brake piece member, and wherein the brake piece member is slidably inserted in the open slot of the spanner head member such that the guide protrusion fits within the guide groove of the open slot; and a deviation preventing pin, wherein the deviation preventing pin limits an extension of the brake piece member upon insertion in the front pin hole of the guide groove.