A support element for positioning a first element, in particular a cover, on a second element, in particular a housing, includes an annular disk-shaped base body that can be positioned on a support rod fastened on the second element, the base body having on a first end face a support surface for making supporting contact with the first element, where the support element has, on the first end face, a plastically deformable projection forming the support surface.

A two-position gate valve has a gate defining a full-flow passageway therethrough and defining a restricted-flow passageway therethrough, without defining a closed position. The full-flow passageway has an entrance with a first area and an exit with a second area, the second area being smaller than the first area, and the full-flow passageway continuously tapers from the entrance to the exit thereof. The restricted-flow passageway has an entrance with a third area and has an exit with a fourth area, the fourth area being smaller than the first area, the second area, and the third area, and the restricted-flow passageway continuously tapers from the entrance to the exit thereof. Flow through the full-flow passageway is in a first direction and flow through the restricted-flow passageway is also in the first direction and the ratio of the fourth area to the second area is in a range of 5 to 15.

A vehicle braking system includes an assistance device, having a vacuum pump driven by an engine for communicating vacuum to a chamber of the assistance device. A control valve is interposed along a fluid line between the pump and the chamber. The control valve is in its first operative condition, where the inlet side of the vacuum pump communicates with the chamber, when the pressure within the chamber is above a predetermined value; and is in its second operative condition, where the inlet side of the vacuum pump communicates with the atmosphere, when pressure within the chamber is below a predetermined value. In this second condition the pump intakes air from and feeds air into the atmosphere, thereby reducing the energy consumption by the engine required for driving the pump during stages where, within the chamber there is a vacuum sufficient for the regular operation of the braking system.

A vehicle braking system includes an assistance device, having a vacuum pump driven by an engine for communicating vacuum to a chamber of the assistance device. A control valve is interposed along a fluid line between the pump and the chamber. The control valve is in its first operative condition, where the inlet side of the vacuum pump communicates with the chamber, when the pressure within the chamber is above a predetermined value; and is in its second operative condition, where the inlet side of the vacuum pump communicates with the atmosphere, when pressure within the chamber is below a predetermined value. In this second condition the pump intakes air from and feeds air into the atmosphere, thereby reducing the energy consumption by the engine required for driving the pump during stages where, within the chamber there is a vacuum sufficient for the regular operation of the braking system.

A check valve of a vacuum booster device is provided with a main body assembled in a vacuum pressure inlet port, a first passage, an accommodating portion and a second passage, a valve seat formed in the first passage, a valve body accommodated in the accommodating portion, and a spring which urges the valve body toward the valve seat. The spring is configured to include an end coil portion which engages with a spring seat, an expanding and contracting coil portion which expands and contracts and is separated from a flange portion of the valve body, and a linking coil portion which is separated from the flange portion and the spring seat and links the end coil portion and the expanding and contracting coil portion.

A check valve of a vacuum booster device is provided with a main body assembled in a vacuum pressure inlet port, a first passage, an accommodating portion and a second passage, a valve seat formed in the first passage, a valve body accommodated in the accommodating portion, and a spring which urges the valve body toward the valve seat. The spring is configured to include an end coil portion which engages with a spring seat, an expanding and contracting coil portion which expands and contracts and is separated from a flange portion of the valve body, and a linking coil portion which is separated from the flange portion and the spring seat and links the end coil portion and the expanding and contracting coil portion.

A pneumatic brake booster having a vacuum chamber and a working chamber in a booster housing separated from one another by an elastic diaphragm. The diaphragm bears in regions against a diaphragm plate axially displaceable between a zero position and a maximum stroke. An axial spacing between the zero position and the maximum stroke defines a stroke range of the brake booster. The diaphragm has a rolling fold which, during the displacement of the diaphragm plate, rolls on a rolling region on an inner wall of the booster housing. In order to offer a solution in which it is the intention for a modular system for different stroke ranges to be formed more efficiently and for the efficiency loss to be minimized or avoided, the booster housing has, in the rolling region, a tapered, conical portion with a cone angle 8 and an axial extent >*stroke range.

A pneumatic brake booster having a vacuum chamber and a working chamber in a booster housing separated from one another by an elastic diaphragm. The diaphragm bears in regions against a diaphragm plate axially displaceable between a zero position and a maximum stroke. An axial spacing between the zero position and the maximum stroke defines a stroke range of the brake booster. The diaphragm has a rolling fold which, during the displacement of the diaphragm plate, rolls on a rolling region on an inner wall of the booster housing. In order to offer a solution in which it is the intention for a modular system for different stroke ranges to be formed more efficiently and for the efficiency loss to be minimized or avoided, the booster housing has, in the rolling region, a tapered, conical portion with a cone angle 8 and an axial extent >*stroke range.

A brake booster for a vehicle is provided. The booster includes a casing formed by a combination of a front and rear shell. A diaphragm divides the casing into a constant and a variable pressure room. A circumference of a front side end seals a valve body combined with the diaphragm and a rear portion penetrates the rear shell. A high pressure air passage selectively provides high pressure air from the rear portion to the variable pressure room and a bypass passage selectively provides atmospheric air to the variable pressure room. A check valve provides high pressure air passed a turbo charger and an intercooler to the variable pressure room through the high pressure air passage. An input rod advances and retreats through an air valve of the valve body. An output rod delivers force based on displacement of the air valve and the diaphragm to a master cylinder.

A brake booster for a vehicle is provided. The booster includes a casing formed by a combination of a front and rear shell. A diaphragm divides the casing into a constant and a variable pressure room. A circumference of a front side end seals a valve body combined with the diaphragm and a rear portion penetrates the rear shell. A high pressure air passage selectively provides high pressure air from the rear portion to the variable pressure room and a bypass passage selectively provides atmospheric air to the variable pressure room. A check valve provides high pressure air passed a turbo charger and an intercooler to the variable pressure room through the high pressure air passage. An input rod advances and retreats through an air valve of the valve body. An output rod delivers force based on displacement of the air valve and the diaphragm to a master cylinder.