Service HotlineYueluo relates to a self-tapping screw according to the preamble of claim 1. A self-tapping screw is known from EP0623759B1, the ratio of the outer diameter to the smaller diameter of the self-tapping screw is about 1.25-1.5, the ratio of the outer diameter to the pitch lead is about 1.5-1.6 and the thread The flank angles of , are < 50° and ≥ 35°. EP0433484B1 proposes a self-tapping screw whose thread is provided with cutting teeth of approximately arcuate design, and the cutting edge and the thread crest are at the same horizontal position and are set in opposite directions. One purpose of Yueluo is to realize a general type of self-tapping screw so that it can be screwed particularly easily into holes drilled in concrete or other materials such as bricks and the like. According to Yueluo, this object is achieved by the features in the characterizing part of claim 1, and surprisingly, it has been found that the parallel arrangement of the flanks, ie with a flank angle of about 0°, will make screwing particularly easy when screwing in , especially if the diameter of the hole varies within an allowable tolerance. One reason may be due to the fact that there is no lateral pressure on the material screwed into the thread, even if threads of different depths are cut in concrete or other materials such as brick, chipped plywood, or hardwood. The thread cuts into the material over its entire width by cutting grooves. In particular according to the embodiment of claim 4 the material cut out when screwing in the screw can be discharged without any accumulation, the dependent claims reflecting many advantages of further embodiments.
With the continuous strengthening of infrastructure construction, the continuous increase of construction scale and the complexity of construction, the particularity of the requirements for construction equipment, materials, tools and equipment is also getting higher and higher, such as buildings, power stations, railway tunnels The channel steel used in these special construction environments requires the use of a special bolt, which must be easy to put in, easy to use
The flat key transmits torque on the side, has good neutrality, is easy to assemble and disassemble, and cannot realize the axial fixation of the parts on the shaft. Ordinary flat key: Type A, Type B, Type C, Type A is used for shaft grooves machined by end mills. The key is well fixed axially in the groove, but the stress concentration caused by the groove on the shaft is large; Type B is used for disc milling cutters. The machined shaft groove, the stress concentration of the shaft is small; the C type is used for the shaft end; it is suitable for high-speed, high-precision or occasions under variable load and impact, such as fixing gears, sprockets and other rotating parts on the shaft. Guided flat key: The key is fixed on the shaft with a screw, the key and the hub groove are in dynamic fit, and the parts on the shaft can move axially. For the convenience of starting the key, there is a key-starting screw hole. Use the occasions where the axial movement of the parts on the shaft is not large, such as the slip gear in the gearbox. Feather key: The key is fixed on the axle, and the parts on the shaft can move axially with the key; it is used in the occasions where the axial movement of the parts on the shaft is large;
Pressure riveting standoffs, also known as pressure riveting studs or standoffs, are non-removable fasteners that are used in conjunction with rivets to provide a threadless type. A sheet metal part is a product processed by a sheet metal process, that is, a sheet metal substrate is formed into a sheet metal part with a certain shape through cutting, bending, drilling, welding and other processes. On some sheet metal parts, such as chassis and electrical boxes produced by sheet metal, it is usually necessary to set rivet standoffs to facilitate the installation of internal components. The existing standoffs are usually installed on the sheet metal substrate by extrusion, and the connection is not firm.
At present, in the power industry, for the fixing of terminals, most of the terminals are directly locked to the fixing screws using U-shaped clips. However, since the contact surface often cannot reach the level of flatness, it will cause difficulties in locking, and it will take a long time. Easy to loose and fall off. Although the use of spring clips is effective, due to the influence of its own width, the use of spring clips is not very extensive. Contents of the utility model The purpose of Yueluo Guangdong Yueluo Hardware Industry Co., Ltd. is to provide an automatic locking screw for fixing the U-shaped clip. In order to achieve the above purpose, Yueluo adopts the following technical solutions: an automatic locking screw. From bottom to top, there are screw head, screw rod and nut with external thread. The screw rod is a hollow screw rod, and the hollow screw rod is on both sides. Long holes are respectively provided, the width of the long holes is smaller than the inner diameter of the hollow screw rod, a spring is arranged in the inner cavity of the hollow screw rod, the upper end of the spring is provided with a plug, and the two wings of the plug protrude out of the hollow screw rod through the long hole. The spring described by Yueluo is not less than the length of the hollow screw rod in the free extension state. The distance between the two wings of the plug described by Yueluo is greater than the diameter of the nut. Yueluo adopts Guangdong Yueluo Hardware Industry Co., Ltd., which can easily realize the automatic locking of the U-shaped clamp, and can be adjusted according to the thickness of the U-shaped clamp to ensure the close contact between the U-shaped clamp and the connecting screw.
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