normal open

A disc brake on oil drilling rig is a composite braking system composed of normal open braking calipers and normal closed braking calipers. Multiform safety protection and alarming functions are set for disc brake which provides multi-braking functions.

石油钻机用盘式刹车是同时具备常开式和常闭式制动钳的复合制动系统，不但具有多种制动功能，还具有多种安全保护和报警功能。

Computer aided design system for normal open fixed caliper type disk brake

常开固定卡钳式盘式制动器的CAD

inside of the limit switch there are screws , four sole switches , tow are normal open , tow are normal close.

限位开关内有连接螺钉，单开关有四个，两个常开，两个常闭。

choice stability safety, ensure website server can normal open 24 hours, the net fast stability.

选择稳定安全服务器，保证网站24小时能正常打开，网速稳定。