Four embodiments of a reluctance type rotational speed sensor are disclosed. In the first embodiment, an annular magnet circumscribes a sensing coil having a unitary rotor nested within it, and is disposed between two elements which comprise the stator. In a second embodiment, a magnet is disposed between two halves which comprise a rotor, the entire assembly nesting within a sensing coil and being disposed between the two stator elements. In the third embodiment, the rotor carries multiple magnets in an axially opposed position with respect to teeth formed on the stator. The magnetic flux in the magnetic circuit increases and decreases as the rotor magnets alternate between aligned and non-aligned positions enabling measurement of angular speed in accordance with the increase and decrease of magnetic flux. Any of the first three embodiments may be used, with minor modifications, in environments where a rotating shaft turns within a stationary bore, or where a rotating bore turns about a stationary shaft. The fourth embodiment incorporates the features of the first three and further includes a caliper-like stator and coil assembly which may be removed for service without requiring extensive disassembly.

Unitary rotational speed sensor

A parking brake for motor vehicles has a brake cable (21) acting on at least two wheel brakes and an engine drive assembly (28), which applies a tensile force to the brake cable (21) or relieves it thereof for closing and opening the wheel brakes For automatic actuation of the parking brake independently of the driver in a drive or parking situation of the vehicle suited thereto, a control electronics unit (30) is provided, which is connected to a rotational speed sensor (32, 33) for sensing of the wheel speed, to a direction of rotation sensor (34, 35) for sensing the wheel's direction of rotation (11, 12) or the torque direction on the driving axle (10) and to a transmission shift lever position sensor (36) and is designed in such a way that in a small wheel speed range beginning at zero the direction of rotation signal of the direction of rotation sensor (34) is continuously compared with the shift lever position signal of the shift lever position sensor (36) and a signal for opening or closing of the wheel brakes is triggered according to whether these coincide or not (Fig 1)

Parking brake for motor vehicles

A circumferential type wheel speed sensor is axially fitted in removable fashion over a specially designed elastomer sleeve molded to the outside of a cylindrical casing wall. The sleeve also fills in and seals an array of slots cut through the wall, which cooperate with teeth on a flux ring to create a strong signal. The sensor can be removed for service without removing or creating exposing openings through the seal.

Servicable wheel speed sensor assembly

An automobile wheel bearing unit of the kind which has an external member (1) to be mounted on the chassis of an automobile, an internal member (2) on one end of which is mounted a wheel, rolling elements (7, 8) interposed between the external member (1) and internal member (2), and a cage (9). The internal member (2) is rotatably mounted to the external member (1) via the rolling elements (7, 8) by a nut (6). An annular member (10) having a plurality of projec­tions (10a) on an end face thereof is mounted on the other end of the internal member (2) opposite to the end thereof to which the wheel is mounted, and rotates in conjunction with the internal member (2). The nut (6) and annular member (10) are covered with a sealing member (11) mounted on the external member (1). A rotational detector (12) is mounted to the sealing member (11), and positioned between an inner peripheral surface of the sealing member (11) and an outer peripheral surface of the nut (6) in a manner facing the projections (10a) of the annular member (10) and detects a rotational speed of the annular member (10). The rotational detector (12) so sealed can detect the rotational speed with good precision over an extended period.

Automobile wheel bearing unit

The invention relates to a process and a system for aiding a starting movement of a vehicle. Problems occur particularly when starting on a hill or on a steeply sloping road because it is difficult or impossible for the vehicle operator to simultaneously release the foot brake pedal and operate the accelerator pedal and thus provide an engine torque necessary for the corresponding starting operation. It is an object of the invention to provide a process and a system for aiding a starting movement of a vehicle by means of which the starting movement can be carried out without problems and in an uncomplicated manner and without endangering other traffic participants. In the process and system according to the invention, this is achieved in that the rest position of the vehicle is ensured by means of a braking intervention by way of an external power or secondary brake circuit if the braking force exercised by the vehicle operator is not sufficient. The engine torque generated by the driving engine of the vehicle is sensed and the braking intervention is terminated as of a defined engine torque.

Process and system for aiding a starting movement of a vehicle

A measurement sensing device for detecting a rotational speed or rotational speed change, particularly of vehicle wheels, which essentially consists of a rotor and of a stator constructed as magnet and equipped with an annular coil, whereby an A.C. voltage proportional to the rotational speed is induced in the stator by the rotation of the rotor; the rotor and stator are thereby so combined into a structural unit that the rotor is so rotatably supported relative to the stator at the latter or at a part connected therewith that during operation no changes in radial or axial spacing between rotor and stator occur.

Measurement-sensing device for determining a rotational speed or rotational speed change, preferably of vehicle wheels

A device for a parking brake - especially the foot control type - on a motor vehicle is described, the locking mechanism of which, locking it in the brake application position, can be unlocked both by manual release and by automatic release when starting the motor vehicle. In this case, automatic release is performed as a function of identification signals taking account of running criteria of the motor vehicle, which can be fed to a control module, which signals, correspondingly combined by a logic unit of the control module according to the starting situation, lead to a trigger signal for triggering of the locking mechanism.

Device for a parking brake on a motor vehicle

A multi-circuit brake installation for vehicles, in which two transmitter brake pistons which possess differently large effective brake pressure piston areas and which are hydraulically connected with each other, operate within a master brake cylinder actuatable at will by means of a servo-assist; these two transmitter brake pistons are connected into a respective brake circuit and are provided with corresponding means for limiting the relative movement with respect to one another, whereby control means are provided independent of the brake circuit for disengaging the hydraulic drive connection between the two transmitter pistons, which are displaced positively into the disengaging position exclusively upon the occurrence of a critical value of the servo-assist.

Multi-circuit brake installation for vehicles

In a high-pressure accumulator for hydraulic systems, the gas accumulator space is formed by a partly diaphragm-like hollow body which is held under prestress by an elastic casing.

High-pressure accumulator for hydraulic systems

A servo brake system with at least two circuits, equipped with a tandem master cylinder, in which two working pistons are arranged coaxially one behind the other; a transmission shifting device thereby automatically shifts in case of failure of the servo installation to a larger pedal travel with a mechanically applied brake pressure that is reduced within permissive limits; the working piston of the actuating side thereby includes a bore coaxial to the other working piston, in which a plunger piston is guided which is actuatable by the input piston.

Werner Kruse

Papers

Measurement-sensing device for determining a rotational speed or rotational speed change, preferably of vehicle wheels

Device for a parking brake on a motor vehicle

Multi-circuit brake installation for vehicles

High-pressure accumulator for hydraulic systems

Servo brake system