The present disclosure relates to a massage apparatus comprising a flexible rack gear. A main frame comprises: a rack gear belt comprising a rack gear which is for moving a massage module, has a plurality of holes formed therein, is formed from a flexible material, and extends along a buttocks frame and a back frame comprised in the main frame, wherein the rack gear comprises a buttocks rack gear and a back rack gear and is formed without a connecting portion for connecting the buttocks rack gear and back rack gear; and a rack gear support part which is positioned below the rack gear belt to support the rack gear belt, and is formed from a flexible material. The massage module comprises: a pinion gear which comprises pinion gear teeth engaging the rack gear belt, and moves the massage module along the rack gear by means of rotation transmitted from an actuator; a connecting link for connecting the pinion gear and a guide roller; and the guide roller which rotates in contact with the rack gear support part by means of the movement of the pinion gear, and prevents the massage module from shaking.

A purpose is to improve movement characteristics of a linear extension and retraction mechanism. A robot arm mechanism includes a revolute joint and a linear extension and retraction joint. The linear extension and retraction joint includes a plurality of first connection pieces coupled together bendably on a bottom plate side and provided with a U-shaped cross section, and a plurality of second connection pieces coupled together bendably and each shaped like a flat plate. A foremost one of the plurality of second connection pieces is connected with a foremost one of the plurality of first connection pieces. The first and second connection pieces, when overlapped each other, form a columnar body by being constrained from bending. The columnar body is relaxed when the first and second connection pieces are separated from each other. An ejection section forms the columnar body by joining together the first and second connection pieces and supports the columnar body. A linear gear is formed on a surface of a bottom plate of each of the first connection pieces. A drive gear is engaged with the linear gears of the first connection pieces overlapped to the second connection pieces in the ejection section.

A linear extension and retraction mechanism includes a plurality of first connection pieces coupled together bendably; and a plurality of second connection pieces coupled together bendably, wherein back faces of the first connection pieces and back faces of the second connection pieces are overlapped each other, thereby generally forming a columnar body by constraining bending, and the columnar body is relaxed when the first and second connection pieces are separated from each other, the linear extension and retraction mechanism further including an ejection section adapted to support the columnar body.

An aircraft actuation system is disclosed that includes a pair of cylinders, a piston movably disposed in each cylinder, and a roller train that extends between the pistons in the two cylinders. A portion of the roller train is disposed beyond the cylinders to engage a pinion. Movement of the pistons in the two cylinders in opposite directions produces a corresponding movement of the roller train to in turn rotate the pinion. The roller train may be maintained in compression between its two ends by fluid pressure exerted on a common face of each of the pistons in the two cylinders. The cylinders may be disposed in non-colinear relation, including in parallel relation to one another. A guide may be used to maintain rollers of the roller train in a proper orientation for entry into a space between an outer race and the pinion.

A device for storing and extending a hose for supplying conditioned air to an aircraft on the ground or to any other interior space, includes: a tubular housing (11) extending along a longitudinal axis (Z) and having a free open first end, which tubular housing (11) can store a hose; a hose (1) in fluid communication with a conditioned air unit and having a free downstream end; a drive system (4) that can be used to control the extension and retraction of the hose (1) between a retracted position in which the downstream end of the hose (1) is located in the tubular housing (11), and an extended configuration in which the downstream end of the hose (1) is outside the tubular housing (11) and at a distance from the first end of the tubular housing (11). The drive system (4) has N=4 to 8 drive bearings (6.1-6.6) disposed perpendicularly to the longitudinal axis (Z) and connected to one another by N swivel joints (7.1-7.7), thereby forming a closed chain.

A cover lift system for a spa includes a lifter handle having an upper arm and a lower arm telescopically connected to the upper arm, the upper arm being configured for operative connection to a cover of a spa, and the lower arm being configured for pivotal connection to a base of the spa, and an adjuster mechanism associated with the lifter handle for selectively adjusting a length of the lifter handle to allow for use of the lifter handle with spas of varying sizes.

A sprocket transmission mechanism of a massage device contains: a driven box, a pair of hollow holders, and two bendable chains. The driven box is driven by two drive shafts of a motor beside the driven box. The pair of hollow holders are rotatably connected with the two drive shafts respectively and have two grooves, and the pair of hollow holders are connected inside two inner sides of a chair or a bed respectively. The two bendable chains are accommodated in the two grooves individually. The two drive shafts have four sprockets fitted on two sides thereof individually, and two driven sprockets are rotatably connected between the two sides of the two shafts respectively, such that the two bendable chains are inserted into the pair of hollow holders to mesh with and to drive the four sprockets and the two driven sprockets to rotate individually.

A cargo cover apparatus configured to selectively enclose a space above an upper surface of a cargo support bed may include at least one bulkhead mountable on the bed toward one said end of the bed, and a cover assembly mountable on the bed in a position between the forward and rearward ends of the bed and toward the at least one bulkhead. The cover assembly has a front end and a rear end, with one of the ends of the cover assembly being orientable toward the at least one bulkhead, and may be extendable and retractable to change a distance between the front end and the rear end of the cover assembly along the longitudinal axis of the bed. The apparatus also include a securing assembly configured to secure one of the ends of the cover assembly to the at least one bulkhead.

A cover lift system for a spa includes a lifter handle having an upper arm and a lower arm telescopically connected to the upper arm, the upper arm being configured for operative connection to a cover of a spa, and the lower arm being configured for pivotal connection to a base of the spa, and an adjuster mechanism associated with the lifter handle for selectively adjusting a length of the lifter handle to allow for use of the lifter handle with spas of varying sizes.

A sprocket transmission mechanism of a massage device contains: a driven box, a pair of hollow holders, and two bendable chains. The driven box is driven by two drive shafts of a motor beside the driven box. The pair of hollow holders are rotatably connected with the two drive shafts respectively and have two grooves, and the pair of hollow holders are connected inside two inner sides of a chair or a bed respectively. The two bendable chains are accommodated in the two grooves individually. The two drive shafts have four sprockets fitted on two sides thereof individually, and two driven sprockets are rotatably connected between the two sides of the two shafts respectively, such that the two bendable chains are inserted into the pair of hollow holders to mesh with and to drive the four sprockets and the two driven sprockets to rotate individually.