Hand tool having a joint lock mechanism

A hand tool having a joint lock mechanism, comprising:

• a head having a rear end, the rear end having a convex pivotal portion;
• a handle having a front end, the front end having a concave pivotal portion pivotally coupled to the convex pivotal portion, the concave pivotal portion having a first side, a second side opposite to the first side, and a bottom side coupled to the first side and the second side;
• a fastening device disposed through the convex pivotal portion and the concave pivotal portion and pivotally coupled to the convex pivotal portion while fixedly coupled to the concave pivotal portion, the convex pivotal portion and the bottom side of the concave pivotal portion defining a receiving space;
• and
• a joint lock mechanism disposed between the convex pivotal portion and the concave pivotal portion, characterised in that:
• the bottom side of the concave pivotal portion has an inclining surface inclining forwardly from the first side to the second side;
• the joint locking mechanism comprises:
• a first engaging device disposed at the convex pivotal portion;
• and
• a second engaging device, comprising;
• a pull button having a front end and a rear end and received in the receiving space and moveable from an unlocked position at the first side to a locked position at the second side;
• and
• a biasing device disposed at the front end of the handle and protruding from the bottom side of the concave pivotal portion;
• when the pull button is at the unlocked position, the biasing device is adapted to provide the pull button with a forward force such that a gap is formed between the rear end of the pull button and the bottom side of the concave pivotal portion;
• when the pull button is at the locked position, the biasing device is adapted to provide the pull button with a stopping force such that the pull button is prevented from moving back to the unlocked position, and the front end of the pull button is adapted to engage the first engaging device.