A pair of self-locking pliers includes three body structures pivotally connected. Each of the three body structure has a slot, and a shaft engages in the slots. The slots cooperate to surround a space and the shaft is constrained in the space. Two of the three body structures include two jaws and are pivotal relative to each other between a first position in which the two jaws are disposed adjacent to each other, and a second position in which the two jaws are disposed apart from each other. The first, second, and third slots are adapted to releasably restrain the shaft, thereby preventing the first, second, and third body structures from pivoting relative to each other.

A pair of self-locking pliers includes three body structures pivotally connected. Each of the three body structure has a slot, and a shaft engages in the slots. The slots cooperate to surround a space and the shaft is constrained in the space. Two of the three body structures include two jaws and are pivotal relative to each other between a first position in which the two jaws are disposed adjacent to each other, and a second position in which the two jaws are disposed apart from each other. The first, second, and third slots are adapted to releasably restrain the shaft, thereby preventing the first, second, and third body structures from pivoting relative to each other.

The present invention provides an open-close device, including a first member, a second member, a third member and a fourth member; the second member is rotatably connected to the first member, the third member is rotatably connected to the first member, the fourth member is rotatably connected to the second member and rotatably connected to the third member; the open-close device further includes an angle adjusting device which is provided at a joint between the third member and the first member, for adjusting the bending angle of the third member with respect to the first member.

The present invention provides an open-close device, including a first member, a second member, a third member and a fourth member; the second member is rotatably connected to the first member, the third member is rotatably connected to the first member, the fourth member is rotatably connected to the second member and rotatably connected to the third member; the open-close device further includes an angle adjusting device which is provided at a joint between the third member and the first member, for adjusting the bending angle of the third member with respect to the first member.

A pliers has jaw portions incorporating gripping faces for the clamping of the desired workpiece, two pivotal handle portions and a sprung toothed strut positioned between the handles. A bow shaped resilient portion, incorporated within the second arm portion, when the pliers are operated this resilient portion imparts a useful superior sprung pressure upon the clamped workpiece by the gripping face of the jaws. The second arm and bend promoting portion are contiguous with each other. The jaws can further be usefully locked in the required clamping position upon the workpiece by a toothed sprung strut pivotally attached to the first and second arms and conveniently being locked or unlocked according to the locking switch pivotal within the first arm.

A pliers has jaw portions incorporating gripping faces for the clamping of the desired workpiece, two pivotal handle portions and a sprung toothed strut positioned between the handles. A bow shaped resilient portion, incorporated within the second arm portion, when the pliers are operated this resilient portion imparts a useful superior sprung pressure upon the clamped workpiece by the gripping face of the jaws. The second arm and bend promoting portion are contiguous with each other. The jaws can further be usefully locked in the required clamping position upon the workpiece by a toothed sprung strut pivotally attached to the first and second arms and conveniently being locked or unlocked according to the locking switch pivotal within the first arm.

The present invention relates to an open-close handheld apparatus and a method of adjustment of the angle between the handheld portions thereof. The open-close handheld apparatus includes a first member and a second member. The first member includes a first clamping portion and a first handheld portion. The second member includes a second clamping portion and a second handheld portion. The first clamping portion and the second clamping portion are rotatably and movably connected via a first axle pin. The first clamping portion and the second clamping portion open and close relative to each other, the plane in which the open-close path thereof is located is an open-close plane. The first handheld portion is rotatably connected to the first clamping portion. The plane in which the rotation path of the first handheld portion is located is the same as or parallel to the open-close plane. A locking arrangement is provided at the joint between the first handheld portion and the first clamping portion, used for locking or unlocking the first handheld portion and the first clamping portion.

The present invention relates to an open-close handheld apparatus and a method of adjustment of the angle between the handheld portions thereof. The open-close handheld apparatus includes a first member and a second member. The first member includes a first clamping portion and a first handheld portion. The second member includes a second clamping portion and a second handheld portion. The first clamping portion and the second clamping portion are rotatably and movably connected via a first axle pin. The first clamping portion and the second clamping portion open and close relative to each other, the plane in which the open-close path thereof is located is an open-close plane. The first handheld portion is rotatably connected to the first clamping portion. The plane in which the rotation path of the first handheld portion is located is the same as or parallel to the open-close plane. A locking arrangement is provided at the joint between the first handheld portion and the first clamping portion, used for locking or unlocking the first handheld portion and the first clamping portion.

A blade-replaceable cutting tool includes: a first handheld portion; a second handheld portion rotatably connected to the first handheld portion; a cutting structure rotatably connected to the first handheld portion, the cutting structure including a blade mounting plate rotatably mounted to the first handheld portion and a blade detachably mounted to the blade mounting plate; and a locking mechanism configured to lock the blade on the blade mounting plate when in contact with the blade, and to unlock the blade when separated from the blade, so that the blade can be detached from the blade mounting plate.

A blade-replaceable cutting tool includes: a first handheld portion; a second handheld portion rotatably connected to the first handheld portion; a cutting structure rotatably connected to the first handheld portion, the cutting structure including a blade mounting plate rotatably mounted to the first handheld portion and a blade detachably mounted to the blade mounting plate; and a locking mechanism configured to lock the blade on the blade mounting plate when in contact with the blade, and to unlock the blade when separated from the blade, so that the blade can be detached from the blade mounting plate.