A towable crash-attenuating vehicle is shown having a frame; at least two axles coupled to the frame, each of the axles having wheels attached thereto; a ballast coupled to the frame; deflection shields coupled to the right and left sides of the frame, wherein the deflection shields cover the frame and a majority of the wheels on each side of the vehicle; a tow connection coupled to the front of the frame; an impact attenuator coupled to the rear of the frame; wherein the vehicle is provided with a brake system, and wherein the vehicle is provided with an mechanism for locking and unlocking the brake system.

A towable crash-attenuating vehicle is shown having a frame; at least two axles coupled to the frame, each of the axles having wheels attached thereto; a ballast coupled to the frame; deflection shields coupled to the right and left sides of the frame, wherein the deflection shields cover the frame and a majority of the wheels on each side of the vehicle; a tow connection coupled to the front of the frame; an impact attenuator coupled to the rear of the frame; wherein the vehicle is provided with a brake system, and wherein the vehicle is provided with an mechanism for locking and unlocking the brake system.

Valves having a sprung gate of various constructions are disclosed. In one embodiment, the sprung gate includes a first endless elastic band having an inner perimeter defining an open space sandwiched between a first gate member and a second gate member that each define an opening therethrough in an open position portion thereof. The first endless elastic band is sandwiched therebetween with its open space oriented for alignment with the opening in both of the first and second gate members, which are aligned with one another to form a passage through the sprung gate. In one aspect, the first endless elastic band in positioned inward a distance from the outer sides of the first and second gate members and spaces the first gate member a distance apart from the second gate member thereby defining a channel having a bottom defined by the first endless elastic band.

Valves having a sprung gate of various constructions are disclosed. In one embodiment, the sprung gate includes a first endless elastic band having an inner perimeter defining an open space sandwiched between a first gate member and a second gate member that each define an opening therethrough in an open position portion thereof. The first endless elastic band is sandwiched therebetween with its open space oriented for alignment with the opening in both of the first and second gate members, which are aligned with one another to form a passage through the sprung gate. In one aspect, the first endless elastic band in positioned inward a distance from the outer sides of the first and second gate members and spaces the first gate member a distance apart from the second gate member thereby defining a channel having a bottom defined by the first endless elastic band.

A piston assembly is provided for an unloader valve of an air compressor. The assembly comprises an unloader piston having a first bore of a first diameter, and a second bore of a second diameter which is smaller than the diameter of the first bore. The assembly also comprises a coil spring having a central opening, one end portion disposed in the second bore, and an opposite end portion extending into the first bore. The assembly further comprises a balance piston including a head portion sized to be disposed in the first bore, a first stem portion extending from the head portion and having a diameter smaller than the first and second bores, and a second stem portion extending from the first stem portion and extending into the central opening of the coil spring and having a diameter smaller than the first stem portion.

A piston assembly is provided for an unloader valve of an air compressor. The assembly comprises an unloader piston having a first bore of a first diameter, and a second bore of a second diameter which is smaller than the diameter of the first bore. The assembly also comprises a coil spring having a central opening, one end portion disposed in the second bore, and an opposite end portion extending into the first bore. The assembly further comprises a balance piston including a head portion sized to be disposed in the first bore, a first stem portion extending from the head portion and having a diameter smaller than the first and second bores, and a second stem portion extending from the first stem portion and extending into the central opening of the coil spring and having a diameter smaller than the first stem portion.

A control device calculates an estimate of negative intake pressure based on the relationship between the rotation speed of a crankshaft and a throttle opening degree (Step S24). Then, the control device sets the estimate PE of the negative intake pressure, which is calculated in Step S24, to a greater value as combustion efficiency of CNG used in engine operation becomes higher (Step S25). When the corrected estimate PE of the negative intake pressure becomes smaller than or equal to a reference value PTh (Step S26: YES), the control device starts a negative pressure recovery procedure (Step S27).

An electrohydraulic pressure control device for vehicle brake systems, including at least one electronic control unit, at least one hydraulic unit and at least one electric motor for driving a hydraulic pump, wherein the electronic control unit is mechanically connected to the hydraulic unit and is sealed off from the outer environment in at least one connection zone to the hydraulic unit by a circumferential, in particular elastic sealing material, and the sealing material extends along an edge of the substantially cuboid-shaped hydraulic unit, wherein the edge is formed by a face of the cuboid-shaped hydraulic unit facing the electronic control unit and at least one face of the cuboid-shaped hydraulic unit not facing the electronic control unit, and the sealing material at least partially covers both cuboid faces in the connection zone and/or sealing zone.

An electrohydraulic pressure control device for vehicle brake systems, including at least one electronic control unit, at least one hydraulic unit and at least one electric motor for driving a hydraulic pump, wherein the electronic control unit is mechanically connected to the hydraulic unit and is sealed off from the outer environment in at least one connection zone to the hydraulic unit by a circumferential, in particular elastic sealing material, and the sealing material extends along an edge of the substantially cuboid-shaped hydraulic unit, wherein the edge is formed by a face of the cuboid-shaped hydraulic unit facing the electronic control unit and at least one face of the cuboid-shaped hydraulic unit not facing the electronic control unit, and the sealing material at least partially covers both cuboid faces in the connection zone and/or sealing zone.

An arrangement of motor vehicle units includes a vacuum pump, a power brake unit, a pump which pumps a hydraulic fluid with a control pressure, and a control valve. The vacuum pump comprises a pump rotor, a coupling element, a control connection, a coupling arrangement switchable by the control connection to lock/unlock the coupling element with the pump rotor, and a suction connection. The power brake unit comprises a negative pressure chamber connected with the suction connection. The control valve, when unlocked, switches the control pressure of the hydraulic fluid through to the control connection to unlock. The control valve comprises an actuator acted on by a pressure of the negative pressure chamber which switches the control pressure through to the control connection if the pressure in the negative pressure chamber is greater than a threshold pressure so that the switchable control valve is switched into its unlocked state.