A portable derrick system for use in hoisting and lowering loads at a plurality of job sites, comprising, in combination: a boom subassembly, a boom head subassembly, a mast support subassembly, a mast head subassembly, a load-carrying line, a winch capable of cooperating with said line, power means for driving the winch, means for pivoting the boom assembly, means for controlling said pivoting means, the foregoing elements of the invention capable of being transported by humans to elevated positions such as, without limitation, rooftops and terraces, and wherein the aforementioned are capable of repeated assembly and disassembly at a plurality of job sites and serving to facilitate the elimination of the need for a street-level crane.

A hoisting platform system configured to permit transport of loads to and between floors of a building. The system includes a roof lift having a pair of beams resting on a roof and jutting out therefrom. The roof lift includes a winch coupled to and positioned over the beams. The roof lift includes a mounting structure extending upwardly from the beams with a plurality of cables coupled to and extending from a top region of the mounting structure downwardly at an angle. The cables are fixedly coupled to the roof. The hoisting platform system includes a floor deck disposed below the roof lift. The floor deck is coupled to a floor of the building and extending outwardly therefrom.

The invention disclosed an apparatus for lifting and sliding a structure attached to the wall, comprising a lifting platform extending out over the building on the roof, and a synchronous lifting and sliding system which is arranged on the lifting platform; wherein the lifting platform comprises two platform beams extending out over the building, and a lifting beam placed on the platform beam; the synchronous lifting and sliding system comprises a hydraulic lifter arranged on the lifting beam, a hydraulic push instrument kit connected to the lifting beam, and a controller; A connecting rod is connected to one end of the hydraulic push instrument kit, and several installing holes are arranged at regular intervals on the connecting rod; The distance between the adjacent installing holes of the connecting rod matches with a stroke of the hydraulic push instrument kit; An installing ear-plate is provided on the platform beam to connect with the connecting rod.

An apparatus for lifting and sliding a structure to be attached to a wall of a building, including a lifting platform extending outwardly from the building, and a synchronous lifting and sliding system which is arranged on the lifting platform. The lifting platform has two platform beams extending outwardly from the building, and a lifting beam placed on the platform beams. The synchronous lifting and sliding system has a hydraulic lifter arranged on the lifting beam, a hydraulic jack connected to the lifting beam, and a controller. A connecting rod is connected to one end of the hydraulic jack, and several installing holes are arranged at regular intervals on the connecting rod. The distance between the adjacent installing holes of the connecting rod matches a stroke of the hydraulic jack. An installing ear-plate is provided on the platform beam to connect with the connecting rod.

An extendable needle davit assembly has an extendable beam comprising a fixed beam portion, and a telescopic beam portion slidably receivable within a distal end of the fixed beam portion. An intermediate lateral bracing frame holds the extendable beam at an angle. The fixed beam portion is a single-piece construction, and a proximal end of the fixed beam portion is anchored. An upper end of the bracing frame is attached to a distal attachment point of the fixed beam portion, such that a distal portion of the fixed beam portion extends beyond the bracing frame. A lower portion of the bracing frame is attached to a proximal attachment point of the fixed beam portion by means of a rear brace.