A photographing system for an ultralow-height counterweight-free vehicle-mounted jib, comprising a base (10), a rotating part, a jib, and a damping part. The rotating part comprises a housing (1) provided above the base (10), a frame (37), counterweight blocks (36), a servo electric cylinder (35), a motor (38), a pinion (40), and a large gear (41). The servo electric cylinder (35) is connected to a rapid abutting structure (2) by means of a clamping member (43). The rapid abutting structure (2) is connected to the jib. The other end of the jib is connected to a gimbal camera mounting plate (6) by means of the damping part. The damping part comprises damping springs (8) and a universal joint structure consisting of a pitch damping rod and left and right swing damping rods. A air spring (34) is provided between the frame (37) and the clamping member (43). One end of the air spring (34) is connected onto the clamping member (43), and the other end of the air spring (34) is connected onto the frame (37). A jib body is driven by the servo electric cylinder to perform a pitch motion, and the weight carried by the front end of the jib body is balanced by the air spring, so that the system is counterweight-free.

Provided is a jib connection structure for restraining a projectable/retractable jib from swinging sideways in a state where the jib is suspended from a boom tip end part, the jib connection structure including: jib connection shafts projecting horizontally toward both sides from a boom tip end part; and jib base end engagement parts respectively provided to bifurcated jib base end parts. Each jib base end engagement part is U-shaped into which the jib connection shaft can be fitted, and is provided with an insertion hole into which a pin for preventing the jib connection shaft from slipping out is inserted. The insertion hole in one jib base end engagement part is arranged more toward the outside than a U-shaped bottom part. When a jib is suspended from the boom tip end part, the left and right pins engage with the respective jib connection shafts, and the jib is suspended at two points.

Provided is a jib connection structure for restraining a projectable/retractable jib from swinging sideways in a state where the jib is suspended from a boom tip end part, the jib connection structure including: jib connection shafts projecting horizontally toward both sides from a boom tip end part; and jib base end engagement parts respectively provided to bifurcated jib base end parts. Each jib base end engagement part is U-shaped into which the jib connection shaft can be fitted, and is provided with an insertion hole into which a pin for preventing the jib connection shaft from slipping out is inserted. The insertion hole in one jib base end engagement part is arranged more toward the outside than a U-shaped bottom part. When a jib is suspended from the boom tip end part, the left and right pins engage with the respective jib connection shafts, and the jib is suspended at two points.

An apparatus assists in retaining a rope in connection with a sheave on a boom. The apparatus includes a retainer supported by the boom for swinging outwardly relative to the sheave from a first position adjacent to the sheave for assisting in retaining the rope therein and a second position for facilitating removing the rope from the sheave. A holder may be provided for holding the retainer in the second position, so that the operator's hands are freed for other tasks. A receiver may also be provided for temporarily receiving a locking pin once removed from the retainer, thus helping to guard against loss.

A boom mountable breaker system and a method of using same for interrupting electrical transmission through a portion of an energized conductor downstream of a desired break location. The method includes: mounting the jumper onto the energized conductor across the desired break location so as to form an electrically conductive first parallel electrical path; installing an in-line opener in the energized conductor at the desired break location on the energized conductor; positioning the breaker at the desired break location on the energized conductor, and electrically connecting the breaker, while open, across the desired break location and across the opposite ends of the jumper so as to form a second parallel electrical path when the breaker is closed; closing the breaker to thereby complete the second parallel electrical path; removing the jumper from across the desired break location; and, opening and then removing the breaker.

The disclosure relates to an assembly head for a telescopic boom that can be separated into an inner and an outer boom set and that is reversibly mountable at an inner telescopic section of the outer boom set. The assembly head comprises a pulley head having deflection pulleys and a telescopic tube section that is arranged the pulley head, that can be pushed into the inner telescopic section from its end, and that has a substantially smaller length than the inner telescopic section. The disclosure further relates to a separable telescopic boom having an assembly head in accordance with the disclosure, to a mobile crane having a telescopic boom in accordance with the disclosure, and to a method for the self-assembly of an assembly head in accordance with the disclosure at the outer boom set of a telescopic boom.

The disclosure relates to an assembly head for a telescopic boom that can be separated into an inner and an outer boom set and that is reversibly mountable at an inner telescopic section of the outer boom set. The assembly head comprises a pulley head having deflection pulleys and a telescopic tube section that is arranged the pulley head, that can be pushed into the inner telescopic section from its end, and that has a substantially smaller length than the inner telescopic section. The disclosure further relates to a separable telescopic boom having an assembly head in accordance with the disclosure, to a mobile crane having a telescopic boom in accordance with the disclosure, and to a method for the self-assembly of an assembly head in accordance with the disclosure at the outer boom set of a telescopic boom.

A self-propelled vehicle used to lay pipe sections within trenches located on sloped terrain, and a method for using it, including: an undercarriage carrying a vehicle chassis and capable of climbing sloped terrain; a rotating platform which can be maintained level relative to the sloped terrain; and a boom with an angled boom head, capable of using two independent winch cables to lift and position individual pipe sections having differing lengths and diameters. The vehicle may be used to sequentially lift two or more pipe sections, one at a time, and to swing and position the pipe sections in a trench, end-to-end.

Provided is a jib connection structure capable of connecting a jib base end engagement part and a jib connection shaft even when a boom undergoes natural extension, and capable of restraining a jib from swinging sideways in a state where the jib is projected. This jib connection structure includes: jib connection shafts projecting horizontally toward both sides from a boom tip end part; and jib base end engagement parts respectively provided to bifurcated jib base end parts. Each jib base end engagement part is U-shaped into which the jib connection shaft can be fitted, and is provided with an insertion hole into which a pin for preventing the jib connection shaft from slipping out is inserted. When the jib base end engagement part and jib connection shaft are connected, a gap is formed between the pin and jib connection shaft. When a jib is projected, the gap becomes smaller.

Provided is a jib connection structure capable of connecting a jib base end engagement part and a jib connection shaft even when a boom undergoes natural extension, and capable of restraining a jib from swinging sideways in a state where the jib is projected. This jib connection structure includes: jib connection shafts projecting horizontally toward both sides from a boom tip end part; and jib base end engagement parts respectively provided to bifurcated jib base end parts. Each jib base end engagement part is U-shaped into which the jib connection shaft can be fitted, and is provided with an insertion hole into which a pin for preventing the jib connection shaft from slipping out is inserted. When the jib base end engagement part and jib connection shaft are connected, a gap is formed between the pin and jib connection shaft. When a jib is projected, the gap becomes smaller.