Abstract: A mechanism for adjusting the height of the back support of a chair comprises a frame, a back support, a first link, and a second link. Two lateral plates extend vertically at the top of the frame. A U bracket is mounted on the rear wall of the back support, whose lateral plates have two symmetrically formed pairs of axle holes. At two ends of the first and the second links, there exist holes for respectively pivotably connected to those pairs of axle and pivot holes by axle pins. The lines defined by two pivot holes and two axle holes take special oblique angles, so that when those links rotate about the top Of the frame, the back support keeps vertical. When the links are placed vertically, the back support supports a sitter's back. When the links are placed horizontally, the back support supports a sitter's waist.

Abstract: A multipurpose mop is composed of a head, a neck, an urging mechanism, and a handle. The head is composed of an upper member and a lower member which is joined with the upper member by a retaining rod. The neck has a cross rod and a fastening portion. The neck is fastened with the head by the retaining rod which is put through a through hole of the cross rod of the neck. The fastening portion of the neck is engaged with the tubular head and the nut of the urging mechanism. The handle is fastened at one end thereof with the fastening portion of the neck via the urging mechanism. The head can be turned by the urging mechanism so as to position the head to maximize the cleaning effect. The head is capable of holding a mopping cloth, a bundle of bristles and a floor scraper.

Abstract: A mop including a telescopic sleeve, a handle grip coupled to one end of the telescopic sleeve, a mophead holder coupled to one end of the telescopic sleeve remote from the handle grip, a retractable handle mounted in the telescopic sleeve and having a top end inserted into a hole in the handle grip and a bottom end inserted into a hole in the mophead holder, a lever pivoted to the handle grip and coupled to the top end of the retractable handle, a mophead turned about a pivot on the mophead holder a ratchet transmission mechanism mounted in the mophead holder and coupled to the bottom end of the retractable handle by a steel cable and driven by the lever through the retractable handle and the steel cable to turn the mophead, a tape of rags having a fixed end fixedly secured to the mophead holder and a free end detachably connected to the mophead by a tape of loop and hook materials, the mophead holder being turned by the ratchet transmission mechanism to take up the tape of rags when the lever is pulled.