Patent ID: 6469409
Filing Date: 2002-10-22
Classification: B23Q,H02K,Y10T

Abstract:
A brake apparatus for a moving apparatus driven by a linear motor, the linear motor having a movable member and a stator which are disposed to face across an air gap from each other, the moving apparatus having a first member attached to the movable member and a second member attached to the stator, the first member moved along the stator when the linear motor is energized, the first member allowed to move downward by gravity along the second member when the linear motor is not energized and the first member is within a moving range thereof, a movement of the first member being controlled electrically in normal operation of the linear motor, the brake apparatus comprising:a cylinder device having a cylindrical member attached to the second member and a piston connected to the first member, the cylindrical member having both end portions including a first cylinder end on a side of the first member and a second cylinder end on the opposite side of the first cylinder end, the cylindrical member defining a first fluid chamber between the piston and the first cylinder end; a fluid supply source that supplies fluid under pressure to the first fluid chamber of the cylinder; a first regulating valve disposed on a fluid path between the first fluid chamber of the cylinder and the fluid supply source, the first regulating valve capable of opening and closing, the fluid flowing in the fluid path and the first fluid chamber while the first regulating valve is open and the fluid fixed in the fluid path and the first fluid chamber while the first regulating valve is closed; and a controller that opens the first regulating valve during normal operation of the linear motor and closes the first regulating valve either when power supply to the linear motor is interrupted or when the linear motor is stopped in an emergency.