Who invented the cross screwdriver ?
Cross screw and cross screwdriver were invented by Henry Henry in 30s of last 30s. First, it is used on the assembly line of the car. So cross screws and cross screwdrivers are also called PHILPS screws and PHILPS screwdrivers.
In order to apply a small torque to a word screw, people think of a slot on the head of the screw, and the screw can be loosened and loosened conveniently by the corresponding type of screwdriver. However, with the rapid development of science and technology, the application of screws is becoming more and more extensive, and the shortcomings of screws and screw knives are also presented. First, the slot of the screw head can not be screwed out once it is damaged. The longer the length of the slot is, the easier it is to be destroyed in the process of being twisted. In order to shorten the length of the slot, improve the capacity of the slot to resist damage and transfer the torque of the same size, people think of using the cross slot to bear the same torque, but the length of a slot is half short, but the ability to resist damage is greatly strengthened. The screwdriver was originally a glyph and could not be used for the screws in the cross slot. Only a cross screwdriver and a cross slot screw were produced. So there are two kinds of screwdrivers.
The slotted screws have been used since machines. It is impossible to replace the screws on the old machine. The cross screwdriver can not be used on a single notch. The screw with one notch is still in production, so we need to reserve a screwdriver. In this way, most of the new machines are cross slot screws, and the old ones are still in use. There are two kinds of screwdrivers at the same time.
A screwdriver is a tool used to twist the screw to force its position, usually with a thin wedge, which can be inserted into the slot or concave of the head of the screw – Jing Jin Ji Lu Jin Yu and Shaanxi dialect called “screwdriver”, Anhui, and Hubei are called “screwdrivers”, and the middle and western regions are called “Changjiang”, the Yangtze River Delta region It is called “rotary chisel”. There are two main words (minus sign) and cross (positive sign). There are also six corner screwdrivers, including two inner six corners and six outer corners.