A fire apparatus includes a chassis, a front axle coupled to the chassis, a rear axle coupled to the chassis, a ladder assembly coupled to the chassis, and a stability system. The stability system includes at least one of (i) a front downrigger coupled to the chassis, (ii) a rear downrigger coupled the chassis, or an outrigger coupled to the chassis. The stability system is controllable to facilitate leaning the fire apparatus at least two degrees relative to a ground surface while maintaining full operational capability of the ladder assembly.

A step apparatus for a vehicle and a vehicle are provided. The step apparatus for the vehicle includes: a step; a lifting device including an arm assembly, the arm assembly including a plurality of pairs of arms, each pair of arms including a first arm and a second arm; and a driver pivotably connected to a first end of the first arm and a first end of the second arm of each pair of arms. A second end of the second arm of each pair of arms is pivotably connected to the step, a second end of the first arm of each pair of arms is pivotably connected to the vehicle, and the driver is configured to drive the arm assembly to be unfolded and folded to adjust a level of the step.

A step apparatus for a vehicle and a vehicle are provided. The step apparatus for the vehicle includes: a step; a lifting device including an arm assembly, the arm assembly including a plurality of pairs of arms, each pair of arms including a first arm and a second arm; and a driver pivotably connected to a first end of the first arm and a first end of the second arm of each pair of arms. A second end of the second arm of each pair of arms is pivotably connected to the step, a second end of the first arm of each pair of arms is pivotably connected to the vehicle, and the driver is configured to drive the arm assembly to be unfolded and folded to adjust a level of the step.

A level indication system includes a sensor system and a control system. The sensor system is positioned to acquire stability data regarding a stability characteristic of a vehicle at a current location. The stability characteristic includes at least one of a slope, a grade, or a jackknife angle. The control system is configured to determine whether the stability characteristic is within an operational range or a nonoperational range, provide an indication that the vehicle is reconfigurable at the current location into a state whereby the vehicle is operable at the current location in response to determining that the stability characteristic is within the operational range or an indication that the vehicle is not operable at the current location in response to determining that the stability characteristic is within the nonoperational range, and facilitate engaging a stabilization system of the vehicle in response to the stability characteristic being within the operational range.

A level indication system includes a sensor system and a control system. The sensor system is positioned to acquire stability data regarding a stability characteristic of a vehicle at a current location. The stability characteristic includes at least one of a slope, a grade, or a jackknife angle. The control system is configured to determine whether the stability characteristic is within an operational range or a nonoperational range, provide an indication that the vehicle is reconfigurable at the current location into a state whereby the vehicle is operable at the current location in response to determining that the stability characteristic is within the operational range or an indication that the vehicle is not operable at the current location in response to determining that the stability characteristic is within the nonoperational range, and facilitate engaging a stabilization system of the vehicle in response to the stability characteristic being within the operational range.

A stabilizing system includes a plurality of jacks, each operated by a corresponding hydraulic actuator. A hydraulic fluid transfer pump supplies hydraulic fluid to and receives hydraulic fluid from one or more pressure chambers of the actuator. A pilot-operated check or directional valve may be provided in fluid communication with one or more of the pressure chambers and configured to regulate the flow of hydraulic fluid to and from the pressure chamber. A directional control valve may connect the pump output with the jacks via respective pilot-operated directional valves. The directional control valve may include a plurality of switch positions respectively connecting the pump output with pairs of the jacks.

A stabilizing system includes a plurality of jacks, each operated by a corresponding hydraulic actuator. A hydraulic fluid transfer pump supplies hydraulic fluid to and receives hydraulic fluid from one or more pressure chambers of the actuator. A pilot-operated check or directional valve may be provided in fluid communication with one or more of the pressure chambers and configured to regulate the flow of hydraulic fluid to and from the pressure chamber. A directional control valve may connect the pump output with the jacks via respective pilot-operated directional valves. The directional control valve may include a plurality of switch positions respectively connecting the pump output with pairs of the jacks.

A fire apparatus includes a chassis, a front axle coupled to the chassis, a rear axle coupled to the chassis, a ladder assembly coupled to the chassis, and a stability system. The stability system includes at least one of (i) a front downrigger coupled to the chassis or (ii) a rear downrigger coupled the chassis, and an outrigger coupled to the chassis. The at least one of (i) the front downrigger or (ii) the rear downrigger and the outrigger are extendable and retractable to facilitate leaning the fire apparatus at least two degrees relative to a ground surface while maintaining full operational capability of the ladder assembly.

A fire apparatus includes a chassis, a front axle coupled to the chassis, a rear axle coupled to the chassis, a ladder assembly coupled to the chassis, and a stability system. The stability system includes at least one of (i) a front downrigger coupled to the chassis or (ii) a rear downrigger coupled the chassis, and an outrigger coupled to the chassis. The at least one of (i) the front downrigger or (ii) the rear downrigger and the outrigger are extendable and retractable to facilitate leaning the fire apparatus at least two degrees relative to a ground surface while maintaining full operational capability of the ladder assembly.

Provided is a jack device rendering an operation of changing the posture of a jack cylinder easy without using a device that actively changes the posture. The jack device includes an arm, a jack body including the jack cylinder, and a reaction-force application unit supported by the arm. The reaction-force application unit makes a reaction-force moment act on the jack body in all postures from the upright posture to the storage posture in response to a force applied from the jack body. The reaction-force application unit makes a reaction-force moment greater than a self-weight moment act on the jack body in the storage posture and makes a reaction-force moment smaller than the self-weight moment act on the jack body in the upright posture.