48results about How to "To achieve the purpose of safe use" patented technology

The invention relates to a flame retardant antistatic toughening PVC (Poly Vinyl Chloride) pipe for methane. The pipe is produced and prepared by adding a nanometer strengthening and toughening material and an antistatic and fire retardant material to polyvinyl chloride resin. According to the flame retardant antistatic toughening PVC pipe for methane, the coordinative antistatic effects of alkyl sulfonic acid and conductive carbon black as well as the coordinative flame retardant smoke suppression effects of antimonous oxide, and tricresyl phosphate or aluminium hydroxide are fully utilized, so that the purpose of safely using the flame retardant antistatic toughening PVC pipe for methane in the methane transportation filed can be achieved along with the outstanding toughening and strengthening material. Compared with the traditional plastic pipe, the flame retardant antistatic toughening PVC pipe for methane has relatively high durable performance and relatively high safety, is specifically suitable for the fields of outdoor branch pipes for methane and home-entering introducing pipes, can effectively improves the safety in use, reduces the possibility that a pipeline is cracked and leaks gas due to an accidental impacting and the possibility that the pipeline causes an antistatic fire due to the reduced whole antistatic effect, cannot fuel the fire in case the fire occurs, generates little smoke, and reduces the risk of the fire to the affected residents and firefighters.

Provided is a brake device of a cart. A rolling element (7) capable of rotating is arranged in the middle of a through cavity (11), the rolling element (7) is linked together with a wheel (3), radial protruding portions (71) are distributed on the circumference of the rolling element (7), a notch (72) is formed between every two adjacent protruding portions (71), an inserting column (4) capable of moving upwards and downwards is arranged in the through cavity (11) in a supporting column (1) located above the rolling element (7), and the top of the inserting column (4) is connected with a pulling rope (2). When the rolling element (7) rotates to a position, below the inserting column (4), of the notches (72), the structure including that the lower end of the inserting column (4) can be inserted into one of the notches (72) and the inserting column (4) can be pulled out of the one of the notches (72) through the pulling rope (2) is arranged in the through cavity (11). The brake device of the cart has the advantages that whether the cart operates on a planar road surface or a slope road surface, as long as no external force acts, the inserting column in the supporting column can be automatically inserted into one of the notches, and the cart can be automatically stopped; accordingly, the purpose of safe using is realized.

The invention belongs to the field of medical injector, and specially relates to an injector capable of retracting the needle automatically, which comprises a needle barrel, a needle, a push-rod handle and a push-rod body. A piston sealed with an inner wall of the needle barrel is sleeved on the outer circumference at the upper end of the push-rod handle. The push-rod handle is provided on the lower end. The push rod is in a hollow structure. An annular convex shoulder converging inwards is formed on the upper end of the push-rod body. A chuck is disposed on the annular convex shoulder. A blind hole with an opening upward is arranged in the middle of the upper portion of the chuck. An annular concave slot is provided in the middle of the chuck and disposed in the inner cavity of the push-rod body. A spring capable for completely pulling the chuck into the inner cavity of the push-rod body is disposed in the inner cavity of the push-rod body. When the push-rod body is pushed to the bottom of the matched injector needle barrel, the needle of the injector abuts against the chuck, and the upper portion of the chuck is inserted into an end portion of the needle far away from a tip of the needle. The invention is simple in structure, convenient for use, low in cost, easy for large scale production, and suitable for the injector capable of retracting the needle automatically.