Patent ID: 6045117
Filing Date: 2000-04-04
Classification: F16K

Abstract:
A gate valve comprisinga valve body provided in a sealed chamber, capable of opening and closing an opening portion of the sealed chamber, and capable of sealing the opening portion by inclination with respect to said opening portion,a valve rod to one end portion of which said valve body is fixed, held so that it can move straight and incline, and provided so as to project from an interior of said sealed chamber to an outside of the sealed chamber and hold the sealed state of said sealed chamber by a sealing means,an inclination mechanism connected to said valve rod and inclining the valve rod,a driving means connected to said valve rod via said inclination mechanism and supplying a drive force required for the straight movement and inclination of said valve rod, anda lock mechanism for holding the sealed state of said opening portion by said valve body; wherein:said driving means is a cylinder apparatus having a piston rod, one end of which is connected to said inclination mechanism via a connection plate, a piston fixed to the other end of the piston rod, and a cylinder unit for accommodating this piston inside it;said lock mechanism comprisesa lock plate which is fixed to said connection plate along the drive direction of said piston rod, on one surface of which an inclined guide surface being formed, and in which a lock hole is formed in a direction perpendicular to the drive direction of said piston rod,a small cylinder provided at a predetermined position with respect to said cylinder apparatus, anda lock piston accommodated in said small cylinder, on one end of which a lock pin capable of being fit in said lock hole by being guided by said inclined guide surface is formed, and the other end of which is biased by a resilient member so as to project to a position at which said lock pin can abut against one surface of said lock use plate from said small cylinder;a supply port for supplying a compressed fluid for driving said lock piston in a direction in which said lock pin is accommodated in the small cylinder into said small cylinder is formed in said small cylinder;said supply port is communicated with a supply path for supplying the driving medium for driving said valve body in an opening direction into the cylinder unit of said cylinder apparatus; andwhen said cylinder apparatus is driven in a direction sealing the opening portion by said valve body, said lock pin is guided by the inclined guide surface of said lock use plate and fit in said lock use hole, the movement of said connection plate is locked, and the sealed state by said valve body is held, and when said cylinder apparatus is driven in a direction opening the opening portion by said valve body, the compressed fluid is supplied into said small cylinder through the supply path to said cylinder apparatus, and the engagement between said lock pin and sa lock hole is released.