Two-stage speed controller

A two-stage speed controller, comprising:

• a main body, which is formed with a first port and a second port in communication with each other, and a primary channel and a secondary channel for flowing of a fluid, the primary channel allowing fluid to flow from the first port and the second port into the main body, the secondary channel allowing fluid to flow in a single direction to a pressure accumulation chamber, the second port receiving a sliding-axle seat arranged therein;
• a sliding axle assembly, which comprises:
• a main axle having an end penetrating in sequence through an elastic element and a sub-axle to fit to an internal wall of the main body, the main axle and the sub-axle defining therebetween a balance channel, the main axle having an opposite end to which a regulation assembly is mounted, the regulation assembly comprising a knob connecting member connecting a rotary regulation knob, one end of the sliding axle assembly forming, in combination with the sliding-axle seat, a valve, characterized in that the pressure accumulation chamber is connected with and in communication with a primary throttle channel, and the sub-axle is formed with a secondary throttle channel arranged in a transverse direction thereof, wherein when the fluid flows through the first port, with the valve being in a closed condition, the fluid is allowed to flow to outside of the valve by means of the primary channel, the balance channel, the secondary channel, the primary throttle channel, and the secondary throttle channel, and in combination with the second port, driving the sliding axle assembly to start to move upwards to open the valve, and when the fluid is kept continuously circulating and flowing through the valve in combination with the secondary throttle channel, the sliding axle assembly is kept upward opening the valve to allow a cylinder connected to the main body to advance in two stages of speeds of initial acceleration and high speed;
• when the valve carries out fast discharging from an open condition, the fluid flows, through a combination of all the channels, to the first port to allow the sliding axle assembly to gradually move downward to close the valve, together with the primary throttle channel and the secondary throttle channel, to allow the valve to be adjusted to fully close, allowing for cushioning of impact of a back-and-forth operation of the cylinder.