Patent ID: 7784388

Claim:
A blade clamping device comprising: a main body which including two opposited sidewalls and a base connected therebetween for defining a cavity for receiving a blade therein; a fixing device mounted between the two sidewalls; a pivot lever pivotly mounted on the main body about an axis, and having a handle formed at one end thereof, with the other end operably connected to the fixing device for moving fixing device between a first position and a second position, wherein in the first position the fixing device fixedly hold the blade, and in the second position the blade is released; a first support formed on the main body; a second support formed on the pivot lever; a spring biased between the first support and the second support such that three relative positions are formed between the pivot lever and the main body, wherein a line is defined by the longitudinal axis of the spring, and wherein in the first relative position, said line intersects and is perpendicular to the pivot axis of the pivot lever, such that the spring is fully deflected and will bias the lever towards the second relative position if the lever is moved in a first direction and will bias the lever towards the third relative position if the lever is moved in a second direction in the second relative position, the pivot axis lies at one side of the line and the fixing device fixedly holds the blade, in the third relative position, the pivot axis lies at the other side of the line and the blade is released; wherein in the first relative position, the biasing force of the spring is the greatest.