An actuator arm lock suitable for use with an actuator which has an actuator arm and an actuator body The actuator arm lock comprises a lock ring suitable for clamping around an actuator arm. The lock ring comprises a circumferentially extending element and a locking element. The circumferentially extending element comprises first and second element ends and an inner surface which faces towards the actuator arm when the actuator arm lock is in use, and the circumferentially extending element is configured to partially extend around the actuator arm. The locking element comprises first and second locking ends and is configured to extend at least between the first and second element ends of the circumferentially extending element. The first locking end of the locking element is engaged with or engageable with the first element end of the circumferentially extending element.

A fluid actuator arrangement comprises a piston rod member, at least two cylinders each said cylinder having a piston body, and a clamping mechanism associated to each cylinder. Each clamping mechanism is arranged to engage and disengage the piston body of the cylinder to the piston rod member. The fluid actuator arrangement comprises further a control element arranged to control a back and forward movement of the respective piston body so that forward movement is slower than the backward movement and to control the movement of the respective piston bodies in relation to each other such that at least one piston body is always moving forward and such that an overlap exists wherein at least two of the piston bodies are moving forward simultaneously during a cycle.

A welding gun includes: a moving mechanism portion (ball screw mechanism) for moving a movable electrode back and forth; a motor that includes a rotor and drives the moving mechanism portion to move the movable electrode back and forth; and a brake mechanism that prevents rotation of the rotor during a braking operation, wherein the brake mechanism includes an annular brake disc that is attached to an outer peripheral surface of the rotor and rotates integrally with the rotor, and a clamping portion that prevents rotation of the brake disc by clamping the brake disc during the braking operation.

A modular fluid actuator system is provided for generating a relative motion between a first fluid transfer chamber of a first module unit and a piston rod arrangement in an axial direction. The modular fluid actuator system comprises a fluid supply, a valve device coupled to the fluid supply and to the first fluid transfer chamber, a control unit coupled to the valve device for controlling the relative motion between the first fluid transfer chamber and the piston rod arrangement, the first fluid transfer chamber is coupled to a first sleeve portion exhibiting a first expandable hollow space arranged for fluid communication with the valve device via the first fluid transfer chamber.

A fluid actuator arrangement comprises a first cylinder housing including a first head member and a second head member; a first piston body is slidable arranged in said first cylinder housing; the first piston body divides the first cylinder housing interior into a first cylinder chamber and a second cylinder chamber, at least the first cylinder chamber is coupled to a fluid supply. The first piston body exhibits a first through-bore and a second through-bore that extend through the first piston body in an axial direction; a first piston rod is arranged slidable in the first through-bore and a second piston rod is arranged slidable in the second through-bore; and the first through-bore comprises a first engagement and disengagement device and the second through-bore comprises a second engagement and disengagement device, which are arranged for providing individual engagement or disengagement to or from the respective first and second piston rod.

A system for operating a circle drive gear of a machine includes a pump configured to output pressurized fluid, an implement control valve fluidly coupled to the pump, a bi-directional hydraulic motor located downstream of the implement control valve and fluidly coupled to the implement control valve via a first delivery line and a second delivery line. The hydraulic motor has an output shaft that is configured to be rotatively driven by pressurized fluid output by the pump. A brake is disposed on the output shaft of the hydraulic motor and engages with the output shaft with the help of a spring force for reducing a rotational speed of the output shaft in a brake engage state. The brake operatively disengages from the output shaft in a brake release state with the help of fluid pressure in at least one of the first delivery line and the second delivery line.

Electromagnetic locking devices, systems, and methods are provided. The electromagnetic locking devices, systems, and methods are configured to lock an actuating arm of an actuator in any desired position between and including a fully extended position and a fully retracted position with respect to an outer cover of the electromagnetic locking device and/or system. The electromagnetic locking devices, systems, and methods described herein may include an unpowered deformable member that imparts fail-safe functionality thereto.

A locking device for fixing a sliding element is disclosed. The locking device employs a cylindrical membrane surrounding a sliding rod element, where both the membrane and the rod are enclosed within a housing. The rod slides freely relative to the membrane until an oil pressure is increased within the oil chamber, the oil chamber being enclosed by the membrane. The pressure within the oil chamber causes the membrane to temporarily deform and press against the rod, thus fixing the rod in a particular position. When the oil pressure is lowered below a threshold value, the membrane returns to its original shape and the rod continues to freely slide within the apparatus. The membrane is very thin yet capable of repeatable use. The membrane spans continuously along the entire portion of the rod within the fixing region of the device, thus creating a precise and powerful fixing means.

A welding gun includes: a moving mechanism portion (ball screw mechanism) for moving a movable electrode back and forth; a motor that includes a rotor and drives the moving mechanism portion to move the movable electrode back and forth; and a brake mechanism that prevents rotation of the rotor during a braking operation, wherein the brake mechanism includes an annular brake disc that is attached to an outer peripheral surface of the rotor and rotates integrally with the rotor, and a clamping portion that prevents rotation of the brake disc by clamping the brake disc during the braking operation.

A method for operating a telescopic device and the elongated telescopic device per se comprises a support element formed to encompass first and second telescopic element mounted so as to be telescopically slidable relative each other in a longitudinal direction; the support element comprises a support element fluid actuator assembly; the first telescopic element is arranged to encompass the second telescopic element and comprises a first fluid actuator assembly. The support element fluid actuator assembly is fixed to an interior portion of the support element and is arranged for engagement or disengagement to a first envelope surface of the first telescopic element and wherein the first fluid actuator assembly is fixed to a first interior portion of the first telescopic element and is arranged for engagement or disengagement to a second envelope surface of the second telescopic element.