The existing method of tightening large screws is generally 1. After the nut is screwed to the connected piece by hammering + nut angle method, use a casing to connect the lever arm of the wrench, or use a free hammer to hammer the plate handle, Rotate the nut an additional angle to obtain the required preload. This is not only a primitive and labor-intensive fastening method, but also has great limitations, such as limited space, or the screw itself is a rotating shaft and so on, it is difficult to use this method.
The circlip is a common limiting element in the mechanical field, which is mainly used to limit the axial limit of mechanical parts. At present, the common circlips on the market are all circular rings with an opening. The circular ring has a certain elastic deformation capacity. When in use, the circlip can be detachably assembled to the mechanical on the part. However, the defect of the circlip adopting the one-piece ring is that the circlip is easily broken when frequently disassembled and used, and the service life is short.
Yueluo 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 3 the material cut out when screwing in the screw can be discharged without any accumulation, the dependent claims reflecting many advantages of further embodiments.
At present, the connecting shafts of commonly used food processing knives on the market generally use square bayonet, which is not easy to install parts, and it is time-consuming and laborious when replacing parts; Increased processing costs. There is also a link structure with a circular bayonet on the market, but it is easy to loosen and not firm after the entire food processor is used for a period of time, which affects the use of the machine. Therefore, a connection structure that is easy to operate and simple to process is urgently needed.
The surfaces of the existing door panels are spliced together by fasteners such as nails and bolts. For example, a door body structure for a production line disclosed in CN203807555 is used for the doors of each chamber of the coating production line. The size of the mechanism is the same, and the left and right sides of the door body can be freely opened and closed; the chamber door and the door frame are detachably connected by multiple sets of sealing components, and the sealing components include hinge devices and locking parts.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: single head nylon column isolation column, security monitoring copper column camera screws, A480 nuts, countersunk head cross nylon screws and other products, we can provide you with The right fastener solution for you.