Disc brake#Calipers

The brake caliper ( rare: brake caliper ) is the part of a disk brake, the brake pads on the brake disk zuspannt. Wherein hydraulic actuating the pads are pushed by one or several movable piston, wherein a mechanical actuation of the brake disk by means of appropriate lever.

Basics

Calipers are most often made in cast iron version. A basic distinction between

• Fixed caliper
• Floating caliper
• Pendulum saddle (also: tipping semitrailer ).

Fixed caliper

The fixed caliper carries at least two opposite brake pistons that press the pads on the disc. Further, it is possible to arrange on the inner and outer side a plurality of pistons to each other, which improves the pressure distribution on the contact surface of pad and disc. This technology optimizes not only braking performance, especially the braking comfort.

A special form of fixed caliper is the single-piston fixed caliper brake, as it is sometimes used in modern bicycle disc brakes. Here, the washer is mechanically deformed by the piston and the left brake pad and is pressed against the fixed right hand surface. Thus, a relatively simple and easy with good brake Braking was possible. The deformation of the plate is minimum (<1 mm ) and non -binding.

Floating caliper

When floating caliper or the piston calliper is placed behind one of the two friction linings, while the piston away from the brake pad is firmly attached to the floating caliper. In foundation brakes the piston is due to the small available space, usually on the side facing away from the wheel side of the caliper. The caliper is mounted slidably in the axial direction of the brake disc (floating). If the piston is pressurized, the floating caliper directed thanks to its linear guide made ​​so that both brake pads are pressed with the same force to the brake disc. In the course of wear of the friction linings of the brake caliper is displaced by the amount of wear of the friction lining remote from the piston in the direction of the piston as the piston moves by the amount of wear of the friction linings of both in the opposite direction.

Pendulum saddle

The pendulum saddle ( tipping semitrailer ) usually has only one piston. The brake caliper is rotatably mounted about an axis which is perpendicular to the axis of rotation of the brake disc. In the course of wear of the caliper resulting from a rotary or tilting movement. New brake pads have a wedge-shaped cross-section which approximates during wear of rectangular cross -section. This design has not been enforced because of the uneven pad wear and the related uneven braking effect on the wear of time.

Operation

Wherein each hydraulic actuation of the brakes can be improved by arranging a plurality of hydraulic piston adjacent to each other, the pressure distribution on the contact surface of pad and disc.

The side of the brake pad, to which the rotating disc first comes in contact with the brake pad, is called running up side, the other side of the running section. The braking effect at the ascending side is in principle more, since the brake pad by the disc rotation has a tendency to wedge. If a brake pad is applied with a plurality of hydraulic piston, then in order to ensure uniform wear on the ascending side of a smaller pistons are provided which exerts less force.

The caliper is basically at a fixed relative to the wheel torque arm.