A double-reeved lifting device includes a lower reeve block secured to a lifting hook and an upper reeve block, wherein the two reeve blocks include reversible connection means adapted to be reversibly configured between a connected configuration and a disconnected configuration. The reversible connection means include a locking mechanism and a complementary locking structure having a frame securely supporting a bolt. The locking mechanism includes a chassis having a locking channel provided with a mouthpiece through which the bolt is configured to enter and exit and slide in the locking channel respectively upon a relative approach or distancing between the two reeve blocks, and at least one latch pivotally mounted on the chassis so as to pivot inside the locking channel, the latch provided with a free end adapted to engage with the bolt.

A manually operated counterweight hoist including a batten operable to support a load, an arbor operable to support one or more counterweights, a hand line operable to move the batten or the arbor, a brake operable to prevent movement of the arbor and the batten by constricting movement of the hand line, a brake actuator operable to activate the brake, a sensor that measures a speed of the arbor, and a controller including an electronic processor. The controller is operatively coupled to the sensor and the brake actuator. The controller is configured to receive a measurement signal from the sensor, determine whether the speed of the arbor exceeds a threshold based on the measurement signal, and activate the brake actuator when the speed of the arbor exceeds the threshold.

A backdrive braking element is provided for preventing backdrive of a shaft. It includes a poly-lobed locking mechanism including an unlock shaft that has a polygon shaped inside profile and is coupled to a poly lock drive and brake assembly. The poly lock drive and brake assembly includes a plurality of poly lock drive and brake segments and is contained within the interior cavity of a housing.

The invention discloses a power-loss triggering device, including: a frame, an electromagnet and an impact bar; the impact bar vertically and movably penetrates through the frame; an energy storage piece is arranged and the energy storage piece may exert a downward action force on the impact bar; when the electromagnet is energized, the impact bar is positioned through electromagnetic force; when the electromagnet loses power, the impact bar loses a holding power from the electromagnet and conducts a downward impact movement under the action force of the energy storage piece. The power-loss triggering device is implemented through the electromagnet and an intermediate mechanism. In this invention, the electric current, the energy consumption and the cost of the electromagnet are reduced, the service life of the long-time energized electromagnet is prolonged.

A propulsion unit includes a platform, a propulsion assembly, and a tether. The propulsion assembly facilitates selective launching of a tire deflation device from the platform. The tether is coupled to the platform and is configured for attachment to a deflation device.

A gear apparatus for controlling movement of an output by an input coupled to a power source. The apparatus an input member coupled to the input, an output member coupled to the output and the input member so that movement of the input member causes movement of the output, a selectably releasable member coupled to the input member and the output member, wherein the selectably releasable member remains in a fixed position while the input member and the output member move, and a releasable member brake mechanism coupled to the selectably releasable member, wherein the releasable member brake mechanism is arranged to prevent movement of the selectably releasable member when the input member and the output member move and to allow back driving of the selectably releasable member.

An overhead lift includes a lift strap, a motor, an electromagnetic brake, and a release assembly. The motor includes a rotatable shaft coupled to the lift strap. The electromagnetic brake is coupled to the rotatable shaft and has an engaged state and a disengaged state. The release assembly is engaged with the electromagnetic brake. The release assembly incudes a release lever engaged with the electromagnetic brake and a release strap. The release lever is moveable between a first position and a second position, wherein the release lever switches the electromagnetic brake to the disengaged state when in the second position. The release strap is coupled to the release lever. Tensioning of the release strap moves the release lever from the first position to the second position thereby switching the electromagnetic brake to the disengaged state.

A brake or a clutch includes a central shaft, an output-side threaded driver, an output brake plate, an input brake plate, and an input-side threaded driver. The output-side threaded driver and the input-side threaded driver are rotationally locked to the central shaft, such as by splines. The output-side threaded driver is threaded to the output brake plate and the input-side threaded driver is threaded to the input brake plate. The output brake plate is threaded to the input brake plate in a direction opposite the threaded engagement of the drivers to the brake plates. The brake or clutch may include two stator plates and three friction discs located between the output brake plate and the input brake plate.

A double-reeved lifting device includes a lower reeve block secured to a lifting hook and an upper reeve block, wherein the two reeve blocks include reversible connection means adapted to be reversibly configured between a connected configuration and a disconnected configuration. The reversible connection means include a locking mechanism and a complementary locking structure having a frame securely supporting a bolt. The locking mechanism includes a chassis having a locking channel provided with a mouthpiece through which the bolt is configured to enter and exit and slide in the locking channel respectively upon a relative approach or distancing between the two reeve blocks, and at least one latch pivotally mounted on the chassis so as to pivot inside the locking channel, the latch provided with a free end adapted to engage with the bolt.

A gear apparatus for controlling movement of an output by an input coupled to a power source. The apparatus an input member coupled to the input, an output member coupled to the output and the input member so that movement of the input member causes movement of the output, a selectably releasable member coupled to the input member and the output member, wherein the selectably releasable member remains in a fixed position while the input member and the output member move, and a releasable member brake mechanism coupled to the selectably releasable member, wherein the releasable member brake mechanism is arranged to prevent movement of the selectably releasable member when the input member and the output member move and to allow back driving of the selectably releasable member.