“AIST”Tools—Make Work Efficient
Pliers have many kinds and are widely used. They are indispensable hand tools for clamping and cutting workpieces in various industrial assembly, repair and installation. However, it has a common basic structure, that is, any hand with pliers county consists of three parts: clamping head, pin and clamping handle. Pliers basic principle is to use two lever, in the middle of a point, cross linked together with peg, enable both ends to relative activities, as long as the operating end with the hand, pinch objects can make the other side. In order to reduce the user operation is used in the effort, according to the principle of mechanical lever on, usually make nipper plier handle longer than head, that can use a smaller force gain strong holding force, to meet the use requirements.
The three parts of the pliers are as follows:
A handle for holding. The clamping handle designed according to the principle of ergonomics is convenient for more safe and comfortable grip. The connecting shaft, this is the connecting shaft of the pliers. The joint must move smoothly without any looseness, making it easy for one hand to open or close the pliers easily. Clamp head with clamping jaws or cutting edge. The nippers are finely ground to a suitable shape. The two shear edges (with springs) must be very sharp and precisely closed to each other, making it easy to cut the wire.
This translates a small force (such as the hand applied to the clamping arm) into a larger force, allowing the pliers to grip or shear effectively. When the external force applied to the clamping arm increases with the lever rate, the force exerted on the clamping nozzle generates a clamping external force. If you want to produce a large force, the distance from the center to handle pliers riveting position must be as long as possible, from the clamping mouth or shear mouth's distance to the center of the rivet must be as short as possible. But many pliers increased largely hand, where difficult to control because they just make the homework easier, for example: the assembly of electronic devices and the application of electronics and precision engineering, etc.
Pliers are usually forged from alloy and non-alloy structural steel. For general pliers, they are made of high quality carbon structural steel with 0.45% carbon content. High quality and heavy duty pliers are made from high carbon and/or alloy elements such as chromium or vanadium.
The origin of pliers in Europe can be traced back to more than 1000 BC. In casting, pliers can be used to hold hot iron blocks. The shape of the forged pliers has remained unchanged. The types of pliers expanded with the development of handicraft industry, commerce and industrialization. Universal clamps have been developed to 100 types. Special pliers are also on the increase. Of course, these special pliers are not always available in general use. Germany is the only country with more than 1m pliers a month, about 50% of them exported. Most of them are general purpose pliers, such as shear pliers, steel pliers and water pump pliers.
As for functionality, the differences are as follows:
1. Shear pliers, which can be used for cutting or trimming (side shear pliers, front shear pliers, cutting pliers, etc.).
2. Steel wire pliers, which can be used for cutting and clamping (steel wire pliers, crane pliers, electronic pliers, etc.).
Regarding the hinge structure, the differences are as follows:
1. Butt joint, such as woodworking pliers. Butt joint at the top of the pliers without milling and riveting.
2. Single shear hinge, such as steel pliers. The joint is processed by milling, half the thickness of the milling, so that two pairs of pliers are inserted into each other.
3. Casing-type hinge. One handle is provided with a groove, allowing another handle to pass through the groove and hinge at the joint. Casing type twisted pliers - other than water pump pliers - are costly because they are more difficult to make with hard alloy steel. Therefore, compared with the first two methods, it is relatively less important.