A folding chair includes front and rear supports that fold and/or retract into central beams to reduce the space occupied by the chair in a folded configuration. A backrest is coupled to the central beams with a hub that allows an angle of the backrest relative to the central beams to be selected and for the backrest to be folded flat relative to the central beams. One or more actuators and pin actuators may control the relative movements of the backrest, front support, rear support, and central beams.

A folding chair includes front and rear supports that fold and/or retract into central beams to reduce the space occupied by the chair in a folded configuration. A backrest is coupled to the central beams with a hub that allows an angle of the backrest relative to the central beams to be selected and for the backrest to be folded flat relative to the central beams. One or more actuators and pin actuators may control the relative movements of the backrest, front support, rear support, and central beams.

A quick release and reconnectable structure to allow additional movement beyond the limit of a powered arm providing assistance in the opening of a cover of an enclosure includes a support base, a connector, and a lock. The connector is slidably arranged on the support base and can be separated from the support base. The lock comprises a locking body and a clamping shaft. The locking body is positioned on the support base. The clamping shaft is slidably positioned on the locking body. A holding hole is defined in the connector. The sliding direction of the clamping shaft intersects with the sliding direction of the connector along the support base, and the clamping shaft can be inserted into or withdrawn from the holding hole.

A rotating structure includes a rotating part and a fixing piece. The rotating part has a lateral perforation part, the lateral perforation part is for perforating an object; the fixing piece is combined to the lateral perforation part and the object, so that the rotating part is movably combined with the object for making the rotating part rotate or move the object. Accordingly, the rotating structure of the present disclosure has the effects of simplicity of operation, saving labor and convenience.

A drone propeller of the present invention includes a plurality of blades and a rotary shaft, wherein the blades comprise a rotation retaining unit connected to the rotary shaft side, a separation and detachment unit that is on the outer side of the blades and is to be separated when damaged, and a breakage inducing unit which connects the rotation retaining unit and the separation and detachment unit and is damaged during a collision.

A drone propeller of the present invention includes a plurality of blades and a rotary shaft, wherein the blades comprise a rotation retaining unit connected to the rotary shaft side, a separation and detachment unit that is on the outer side of the blades and is to be separated when damaged, and a breakage inducing unit which connects the rotation retaining unit and the separation and detachment unit and is damaged during a collision.

The positioning pin has a pin body and a biasing element. The pin body defines a slit through which at least a portion of the biasing element is able to extend through. The pin body can be configured to be at least partially inserted into a working surface hole and help position an object. The biasing element has an engagement element that is able to bias the working object in a direction of the slit.

A locking device for securing a wear element in a support in an earth moving machine includes a central shaft with a first right hand threaded segment and a second left hand threaded segment. Locking elements are screwed onto the threaded segments. Both threaded segments are attached to one another and are suitable for transmitting rotational movement between both threaded segments. A coupling of the threaded segments can comprise a disc with two faces, each of them opposite one end of the threaded segments. Between each of the faces and the end of the threaded segment there is a tongue and groove extending to a first diameter and a second diameter, respectively, such that the disc and the threaded segments are suitable for moving with respect to one another.

A locking device for securing a wear element in a support in an earth moving machine includes a central shaft with a first right hand threaded segment and a second left hand threaded segment. Locking elements are screwed onto the threaded segments. Both threaded segments are attached to one another and are suitable for transmitting rotational movement between both threaded segments. A coupling of the threaded segments can comprise a disc with two faces, each of them opposite one end of the threaded segments. Between each of the faces and the end of the threaded segment there is a tongue and groove extending to a first diameter and a second diameter, respectively, such that the disc and the threaded segments are suitable for moving with respect to one another.

A connecting structure connecting a first device and a second device rigidly but readily demountably comprises a housing having a top cover and a bottom cover to form an internal space. A connector which has an engagement block, a sliding block, and an insert block engages with the second device. A push button having a knob movably mounted on the housing, a sprung hooking structure having a guiding slot engaging with the sliding block, and a hook engaging with the second device provide demountable. The push button resists the engagement block via a through hole of the top cover, the connecting structure being combined with the connector to link with the hooking structure.