Abstract: The present invention provides a method for synthesizing a 3-spiro three-membered ring indolinone derivative, which comprises under a protective atmosphere, reacting a 3-indol-ethanol compound as a reaction raw material at 20-60° C. in the presence of an additive and an organic base in an organic solvent, to obtain a 3-spiro three-membered ring indolinone compound after the reaction is complete. The additive is N-bromosuccinimide (NBS) or N-chlorosuccinimide (NCS). The method of the present invention does not require a metal catalyst, and the 3-spiro three-membered ring indolinone derivative is synthesized in one step in the presence of NBS or NCS. The reaction conditions are mild, the operations are simple and safe, and the yield is high.

Abstract: The present invention relates to a recoil reduction air gun and a method of reducing recoil of air guns when discharging. Said recoil reduction air gun comprises a cylinder that is slidably mounted to a main body of said air gun, and a recoil reduction device that is provided between the cylinder and a stock. Said recoil reduction device further comprises a recoil reduction spring seat, a first and a second springs, and a recoil rod.

Abstract: The present disclosure relates to the field of air rifles, and particularly to a gear-type air rifle gear cock structure, including a air cylinder, a gear cock controller, a rack, and a rack reset spring, the gear cock controller is fixedly connected with the air cylinder, and the rack is arranged between the air cylinder and the gear cock controller; the air cylinder includes a air cylinder body, a piston, and a magazine, the air cylinder body has a hollow structure with an air chamber inside, the piston is arranged in the air chamber inside the air cylinder body, the magazine communicates with the air chamber through an outlet pipe; two ends of the rack are a piston fixing end and a spring fixing end respectively, the piston fixing end is connected with the piston through a lug arranged at the piston fixing end, the spring fixing end is connected with the rack reset spring, two ends of the rack reset spring are respectively fixed on the rack and the air cylinder.

Abstract: The present disclosure relates to the field of air rifles, and particularly to a gear-type air rifle gear cock structure, including a air cylinder, a gear cock controller, a rack, and a rack reset spring, the gear cock controller is fixedly connected with the air cylinder, and the rack is arranged between the air cylinder and the gear cock controller; the air cylinder includes a air cylinder body, a piston, and a magazine, the air cylinder body has a hollow structure with an air chamber inside, the piston is arranged in the air chamber inside the air cylinder body, the magazine communicates with the air chamber through an outlet pipe; two ends of the rack are a piston fixing end and a spring fixing end respectively, the piston fixing end is connected with the piston through a lug arranged at the piston fixing end, the spring fixing end is connected with the rack reset spring, two ends of the rack reset spring are respectively fixed on the rack and the air cylinder.

Abstract: The present invention relates to a recoil reduction air gun and a method of reducing recoil of air guns when discharging. Said recoil reduction air gun comprises a cylinder that is slidably mounted to a main body of said air gun, and a recoil reduction device that is provided between the cylinder and a stock. Said recoil reduction device further comprises a recoil reduction spring seat, a first and a second springs, and a recoil rod.