Abstract: A height-adjustable desk includes a base, a top board, a link mechanism, a height-adjusting member, and an operating member. The top board is configured to be vertically elevated with respect to the base. The link mechanism is disposed between the base and the top board so as to support the top board such that the top board may be elevated, the link mechanism including a plurality of link members. The height-adjusting member is formed to be extendable at a desired length and determining a height of the top board with respect to the base according to a length thereof. The operating member fixes the height-adjusting member so that the height-adjusting member maintains the desired length.

Abstract: A gas cylinder includes: a base tube including a cavity; a spindle inserted into the cavity and performing a reciprocating motion in a longitudinal direction of the base tube; a cylinder mounted in the spindle and charged with gas; a piston dividing the cylinder into an upper chamber and a lower chamber; a valve portion sealing an upper portion of the cylinder and including a pipe holder having a cavity through which the gas is introduced; a flow prevention portion inserted into the spindle and having an inner surface contacting a surface of the spindle; and a spindle guide disposed between the base tube and the spindle and mounted to include at least a portion of the flow prevention portion.

Abstract: Disclosed is a height-adjustable bed including: a base; a support frame placed on an upper surface of the base; a mattress stably placed on an upper surface of the support frame; and a height adjusting device connected to the support frame and the base to adjust the height and tilt of the support frame, wherein the height adjusting device includes a gas spring or a spring lever to manually adjust the height of the support frame.

Abstract: The present invention relates a height-adjustable desk including: a base; a top board provided so as to be vertically elevated with respect to the base; a link mechanism disposed between the base and the top board so as to support a top board such that the top board may be elevated and including a plurality of link members; a height-adjusting means formed to be extendable at a desired length and determining the height of the top board with respect to the base according to a length thereof; and an operating means for fixing the height-adjusting means so that the height-adjusting means maintains the desired length.

Abstract: A gas cylinder includes: a base tube including a cavity; a spindle inserted into the cavity and performing a reciprocating motion in a longitudinal direction of the base tube; a cylinder mounted in the spindle and charged with gas; a piston dividing the cylinder into an upper chamber and a lower chamber; a valve portion sealing an upper portion of the cylinder and including a pipe holder having a cavity through which the gas is introduced; a flow prevention portion inserted into the spindle and having an inner surface contacting a surface of the spindle; and a spindle guide disposed between the base tube and the spindle and mounted to include at least a portion of the flow prevention portion.