Abstract: A multi-stage mast module is cooperable with a mast lift. The mast lift includes a base supporting the multi-stage mast module and a platform coupled with the multi-stage mast module. The multi-stage mast module includes a mast unit including a plurality of telescoping mast sections, and a multi-stage drive connected between the telescoping mast sections of the mast unit. Gas springs are connected between the telescoping mast sections of the mast unit. The gas springs act between the adjacent ones of the telescoping mast sections.

Abstract: A mast lift includes a base and a telescoping mast coupled with the base and extending upward from the base. The telescoping mast has a support section fixed to the base and a movable section movably connected and displaceable relative to the support section between a retracted position and an extended position. A top cap is secured to the movable section, and a platform is supported by the top cap and the movable section. A gas strut acts between the support section and the movable section and biases the movable section toward the extended position. A threaded driving rod is connected between the top cap and the base and extends through a fixed nut assembly.

Abstract: A self-propel accessory provides an easily attachable optional drive function for a platform device. The platform device is supported by a device frame including a wheel at a rear end and a post at a front end. The self-propel accessory includes an accessory frame attachable to the device frame via a bracket, a driving wheel connected to the accessory frame, a motor operatively coupled with the driving wheel, and a handle connected to the accessory frame. The accessory frame is pivotable between a disengaged position and an engaged position, and a weight of the platform device biases the accessory frame toward the disengaged position.

Abstract: A mast lift includes a base and a telescoping mast coupled with the base and extending upward from the base. The telescoping mast has a support section fixed to the base and a movable section movably connected and displaceable relative to the support section between a retracted position and an extended position. A top cap is secured to the movable section, and a platform is supported by the top cap and the movable section. A gas strut acts between the support section and the movable section and biases the movable section toward the extended position. A threaded driving rod is connected between the top cap and the base and extends through a fixed nut assembly.

Abstract: A self-propel accessory provides an easily attachable optional drive function for a platform device. The platform device is supported by a device frame including a wheel at a rear end and a post at a front end. The self-propel accessory includes an accessory frame attachable to the device frame via a bracket, a driving wheel connected to the accessory frame, a motor operatively coupled with the driving wheel, and a handle connected to the accessory frame. The accessory frame is pivotable between a disengaged position and an engaged position, and a weight of the platform device biases the accessory frame toward the disengaged position.

Abstract: A mast lift includes a base, a platform, and a lifting assembly connected between the base and the platform. The lifting assembly moves the platform between a lowered position and a raised position. A threaded driving rod is connected between the base and the lifting assembly, and a gas strut acts between the base and the lifting assembly and biases the lifting assembly and the platform toward the raised position.

Abstract: A lift system is coupled between a work platform and a mast on a mast lift. The lift system includes an overload clutch that slips upon an overload on the lift system, an overrun brake that prevents the lift system from running beyond a fully lowered position and that prevents the lift system from running if the platform is hung up, and an emergency brake. The lift system is safe and lightweight and is effective for controlling a position of the work platform on the mast.

Abstract: A lift system is coupled between a work platform and a mast on a mast lift. The lift system includes an overload clutch that slips upon an overload on the lift system, an overrun brake that prevents the lift system from running beyond a fully lowered position and that prevents the lift system from running if the platform is hung up, and an emergency brake. The lift system is safe and lightweight and is effective for controlling a position of the work platform on the mast.

Abstract: A multi-stage mast module is cooperable with a mast lift. The mast lift includes a base supporting the multi-stage mast module and a platform coupled with the multi-stage mast module. The multi-stage mast module includes a mast unit including a plurality of telescoping mast sections, and a multi-stage drive connected between the telescoping mast sections of the mast unit. Gas springs are connected between the telescoping mast sections of the mast unit.

Abstract: A lift system is coupled between a work platform and a mast on a mast lift. The lift system includes at least one lifting rope connected between the work platform and the mast via an idler roller and a hoist drum connected to the work platform. The idler roller is displaceable between an engaged position and a disengaged position based on an amount of tension on the lifting rope. A spring is connected to the idler roller and urges the idler roller toward the engaged position. A carriage latch assembly includes a carriage latch hook coupled with the idler roller and a pin secured to the mast. When the idler roller is disposed in the engaged position, the carriage latch hook is engageable with the pin.

Abstract: A mast lift includes a base, a platform, and a lifting assembly connected between the base and the platform. The lifting assembly moves the platform between a lowered position and a raised position. A threaded driving rod is connected between the base and the lifting assembly, and a gas strut acts between the base and the lifting assembly and biases the lifting assembly and the platform toward the raised position.

Abstract: A retractable wheel assembly includes a wheel frame supporting a wheel, and a pivot bracket assembly secured to the wheel frame. The pivot bracket assembly is displaceable between an extended position and a retracted position. A biasing mechanism is coupled with the pivot bracket assembly. The biasing mechanism urges the pivot bracket assembly toward the extended position when the pivot bracket assembly is in the extended position and urges the pivot bracket assembly toward the retracted position when the pivot bracket assembly is in the retracted position.

Abstract: A lift system is coupled between a work platform and a mast on a mast lift. The lift system includes an overload clutch that slips upon an overload on the lift system, an overrun brake that prevents the lift system from running beyond a fully lowered position and that prevents the lift system from running if the platform is hung up, and an emergency brake. The lift system is safe and lightweight and is effective for controlling a position of the work platform on the mast.

Abstract: A slip clutch acts between a shaft and a housing. The slip clutch includes an oil reservoir within the housing and one or more slipping surfaces disposed in the oil reservoir that are keyed to the shaft and possibly alternately to the housing. The slipping surfaces may include stacked plates or washers. Each of the washers includes an oil groove or other structure on one surface thereof that maintains a consistent film of oil on the washer surfaces. The stacked washers slip relative to one another such that the shaft rotates relative to the housing upon an application of torque that exceeds a predetermined torque.

Abstract: A load equalizing rope termination serves to prevent a load imbalance between a pair of rope leads of a rope termination. The rope termination includes an end section such as an end loop and the pair of rope leads attached to a pair of rope ends. A rope termination fitting includes a base support member over which the end section is supported, and a pair of load equalizing support members disposed upstream of the base support member and over which the rope ends are supported. The engagement between the rope ends and the equalizing support members prevents a load imbalance of the rope leads.

Abstract: A method of activating a drive system with a portable power source includes performing at least two actions between the power source and the drive system to effect activation. Performing any one of the two actions without the other of the two actions will not activate the drive system. The power source is preferably a hand-held power drill or a power pack.

Abstract: A lift system is coupled between a work platform and a mast on a mast lift. The lift system includes at least one lifting rope connected between the work platform and the mast via an idler roller and a hoist drum connected to the work platform. The idler roller is displaceable between an engaged position and a disengaged position based on an amount of tension on the lifting rope. A spring is connected to the idler roller and urges the idler roller toward the engaged position. A carriage latch assembly includes a carriage latch hook coupled with the idler roller and a pin secured to the mast. When the idler roller is disposed in the engaged position, the carriage latch hook is engageable with the pin.

Abstract: A load equalizing rope termination serves to prevent a load imbalance between a pair of rope leads of a rope termination. The rope termination includes an end section such as an end loop and the pair of rope leads attached to a pair of rope ends. A rope termination fitting includes a base support member over which the end section is supported, and a pair of load equalizing support members disposed upstream of the base support member and over which the rope ends are supported. The engagement between the rope ends and the equalizing support members prevents a load imbalance of the rope leads.