A modular staircase is disclosed. The modular staircase includes a first staircase section having a plurality of steps and a first support member detachably connected to the first staircase section. Further, the modular staircase includes a second stair module having a second staircase section including a plurality of steps and a second support member detachably connected to the second staircase section and to the first support member. The modular staircase further includes a third stair module having a third staircase section including a plurality of steps and a retractable third support member detachably connected to the third staircase section and to the second support member. The third support member may be configured to raise or lower the third staircase section relative to the second staircase section.

A closed-loop hydraulic control system that may arrest the motion of attached devices in the event of loss of electrical or hydraulic power or in the event of an emergency. Gangways from a ship to a platform and ladders on fire trucks may have hydraulic control systems that allow for free motion in several different directions in order to keep stability in rough waters or shifting ground. If the gangway or ladder begins to fall due to loss of hydraulic power or a failure in the securing of one end, the closed-loop control system may detect these situations and actuate the closing of valves to limit or stop the falling motion of the gangway or ladder. Various control or damping algorithms may be employed to yield a desired and controlled arresting of motion.

A closed-loop hydraulic control system that may arrest the motion of attached devices in the event of loss of electrical or hydraulic power or in the event of an emergency. Gangways from a ship to a platform and ladders on fire trucks may have hydraulic control systems that allow for free motion in several different directions in order to keep stability in rough waters or shifting ground. If the gangway or ladder begins to fall due to loss of hydraulic power or a failure in the securing of one end, the closed-loop control system may detect these situations and actuate the closing of valves to limit or stop the falling motion of the gangway or ladder. Various control or damping algorithms may be employed to yield a desired and controlled arresting of motion.

Disclosed is a harvesting combine having a cab for an operator, a wheel assembly adjacent to a stairs assembly having a top and a bottom, and an improved stairs assembly for accessing the cab by the operator. The improved stairs assembly in a deployed state is angled outwardly from the top of the stairs assembly. The stairs assembly is rotatably connected about its bottom to both raise the stairs assembly and move its bottom inwardly. The stairs assembly is movably connected by a track assembly about its top so as to permit the top of the stairs assembly to move inwardly and upwardly when the stairs assembly is raised from its deployed state. The stairs assembly may be angled outwardly from the top end of the stairs assembly to an angle from the vertical of greater than 15 and may be rigidly anchored at its lower end.

Disclosed is a harvesting combine having a cab for an operator, a wheel assembly adjacent to a stairs assembly having a top and a bottom, and an improved stairs assembly for accessing the cab by the operator. The improved stairs assembly in a deployed state is angled outwardly from the top of the stairs assembly. The stairs assembly is rotatably connected about its bottom to both raise the stairs assembly and move its bottom inwardly. The stairs assembly is movably connected by a track assembly about its top so as to permit the top of the stairs assembly to move inwardly and upwardly when the stairs assembly is raised from its deployed state. The stairs assembly may be angled outwardly from the top end of the stairs assembly to an angle from the vertical of greater than 15 and may be rigidly anchored at its lower end.

An telescopic ladder for a vehicle. The telescopic ladder comprises a first ladder section and a second ladder section, with each ladder section comprising a front portion and a rear portion and each including opposing sides extending from the front portion to the rear portion. The second ladder section is configured to telescopically extend from the first ladder section. The telescopic ladder further includes an extension support for facilitating the extension of the second ladder section from the first ladder section. The extension support includes at least one front roller assembly positioned adjacent to a front portion of the first ladder section, at least one pair of side roller assemblies positioned on the sides of the first ladder section, and at least one pair of cam-follower assemblies positioned on the sides of the second ladder section adjacent to the rear portion of the second ladder section.

A convertible ramp system facilitates transfer of personnel between spaced elevations. The ramp system includes a deck assembly, a convertible main ramp, and a convertible extension ramp. The convertible main ramp has a proximal end hinged to the deck assembly and a distal end adapted for being mechanically lifted and lowered relative to the deck assembly. Both the main ramp and the extension ramp incorporates an adjustable frame assembly and a series of simultaneously articulating foot treads carried by the frame assembly. The ramps are selectively convertible between a stairway configuration and a substantially flat and continuous runway configuration.

A convertible ramp system facilitates transfer of personnel between spaced elevations. The ramp system includes a deck assembly, a convertible main ramp, and a convertible extension ramp. The convertible main ramp has a proximal end hinged to the deck assembly and a distal end adapted for being mechanically lifted and lowered relative to the deck assembly. Both the main ramp and the extension ramp incorporates an adjustable frame assembly and a series of simultaneously articulating foot treads carried by the frame assembly. The ramps are selectively convertible between a stairway configuration and a substantially flat and continuous runway configuration.

An emergency descent system includes at least one descent means formed as a ladder which is articulated on at least one supporting unit on bearing means provided for this purpose, and the descent means is designed to be unfolded about this bearing means out of a rest position in which the descent means is disposed parallel to the support means and into a working position, wherein a push-out unit and a pivot unit operatively connected thereto by means of a catch are associated with the descent means and the pivot unit drives the push-out unit by the kinetic energy generated during the unfolding, wherein the push-out unit moves away from the supporting unit at a first acute angle, wherein in the operating position the push-out unit forms an acute angle with the supporting unit and the pivot unit is held at an obtuse angle relative to the push-out unit on a stop associated with the supporting unit.

An emergency descent system includes at least one descent means formed as a ladder which is articulated on at least one supporting unit on bearing means provided for this purpose, and the descent means is designed to be unfolded about this bearing means out of a rest position in which the descent means is disposed parallel to the support means and into a working position, wherein a push-out unit and a pivot unit operatively connected thereto by means of a catch are associated with the descent means and the pivot unit drives the push-out unit by the kinetic energy generated during the unfolding, wherein the push-out unit moves away from the supporting unit at a first acute angle, wherein in the operating position the push-out unit forms an acute angle with the supporting unit and the pivot unit is held at an obtuse angle relative to the push-out unit on a stop associated with the supporting unit.