Abstract: A master cylinder is described. The master cylinder includes a chamber delimited by a piston and supplied from a brake fluid reservoir installed on the top of the master cylinder by an end fitting engaged in a nozzle on the body of the master cylinder. The piston has a nose of reduced section upstream of its skirt guided in the bore hole of the master cylinder and the nozzle is connected to the chamber by a drill hole issuing into the chamber at least partly upstream of the piston in rest position. A valve module is installed in the drill hole to manage communication between the reservoir and the chamber as a function of the position of the piston and the pressure in the chamber with respect to the pressure in the reservoir.
November 17, 2020
Date of Patent:
August 9, 2022
Robert Bosch GmbH
Bruno Foirestier, Constantin Van De Velde, Cyril Pechaud, Enzo Perini, Jean-Pierre Michon, Laurent Lhuillier, Nicolas Quiniou, Thierry Coquart
Abstract: A main piston bushing for a service valve portion of a brake control valve includes a cylindrical sidewall defining a central passageway extending longitudinally through the main piston bushing, the central passageway being surrounded by an internal surface of the cylindrical sidewall. The central passageway is configured to receive the main piston assembly of the service valve portion. The internal surface of the cylindrical sidewall includes a first ramp and a second ramp defined therein, the first ramp and the second ramp being configured to engage a portion of the main piston assembly of the service valve portion to restrain movement of the main piston assembly.
May 24, 2013
Date of Patent:
January 31, 2017
Wabtec Holding Corp.
Jeffrey B. Skweres, Michael S. Plechey, Gary M. Sich
Abstract: There is provided a new and novel vehicle running control device for correcting a yaw angle of a vehicle toward the yaw direction intended by a driver, together with vehicle stability control, through generating yaw moments. In order to accomplish the yaw angle correction, the inventive device operates a yaw moment generating apparatus e.g. a steering apparatus, so as to generate a direction correcting yaw moment based upon an integration value of the deviations between an actual yaw rate and its target value. The direction correcting yaw moment may be generated for correcting the yaw angle deviation remaining after the stability control is ended.
Abstract: A master cylinder of the present invention is disposed with valve bodies (26a) and (28a). Support portions (26b) and (28b) on one end side of these valve bodies (26a) and (28a) are respectively supported in connecting opening portions (22) and (23) of a reservoir (21) so as to be rotatable using these support portions (26b) and (28b) as fulcrums. During the start of operation, when brake fluid flows out from hydraulic chambers (10) and (11) to the reservoir (21), the valve bodies (26a) and (28a) rotate and close such that the flow of the brake fluid is restricted by notches (22a) and (23a), and the dead strokes of pistons (5) and (6) become small. During intake of the brake fluid by pumps; when the brake fluid flows from the reservoir (21) to the hydraulic chambers (10) and (11), the valve bodies (26a) and (28a) rotate and open such that the brake fluid flows to the hydraulic chambers (10) and (11) without its flow being restricted, and fluid self-support performance is ensured.
Abstract: While an electric vehicle is traveling in a DC section, a ripple component detecting unit detects a ripple component appearing on a filter capacitor voltage and adds the ripple component onto an inverter frequency reference in such manner as to cancel an influence in a motor current caused by the ripple component. On the other hand, while in an AC section, a damping control component detecting unit detects a magnitude of fluctuation of a DC power supplied from a DC power line as a damping control component and adds the component, like the ripple component in the AC section, onto the inverter frequency reference in such manner as to cancel an influence in the motor current caused by the damping control component. Consequently, an output current from the inverter which is to be supplied to the induction drive motor becomes very steady of ripple-free and it improves comfort for passengers on the electric vehicle.
Abstract: A braking system is improved by addition of a spring brake pressure protection valve, to prohibit pressurization of the spring brakes prior to the build up of sufficient pressure to insure complete release of the spring brakes. This prevents the significant problems associated with known systems that permit operation of a tractor trailer with partially released spring brakes, which will cause unnecessary wear and reduced fuel economy. The spring brake pressure protection valve is located between the reservoir and the spring brakes, most preferably between the spring brake quick release valve and the spring brakes, or alternately, between the reservoir and the spring brake quick release valve.
Abstract: A spool type valve arrangement in which a booster spring is employed to overcome static friction of the spool valve O-rings and thereby assure prompt actuation of the spool valve member. The arrangement is such that the booster spring is only active through a limited distance of travel from release position toward application position, this limited distance of spool valve travel being selected so as to occur prior to any transition of the port connections controlled by the spool valve. In this manner, the spool valve return spring force need not be increased in order to reset the spool valve sufficiently to reestablish the original spool valve port connections.
Abstract: An improved freight brake emergency valve device having improved stability against undesired emergency brake applications, without loss of emergency sensitivity. Flow regulator in the form of a valve and choke combination or a choke itself is employed between the quick action chamber and the chamber normally subject to quick action chamber pressure on the side of the emergency piston opposite brake pipe pressure. This has the effect of momentarily reducing the volume of quick action chamber pressure in order to achieve an intensified pressure reduction in response to initial deflection of the piston member sufficient to counteract a momentary, spurious brake pipe pressure fluctuation.
Abstract: A service valve piston assembly for a freight brake control valve device in which the graduating valve is configured to cooperate with the associated slide valve to close off the application port via which auxiliary reservoir pressure acting on one side of the piston assembly feeds the brake cylinder prior to opening of the stability port via which the brake pipe pressure on the opposite side of the piston assembly is communicated with auxiliary reservoir pressure on the one side of the piston, thereby preventing the piston valve assembly from finding a quasi-lap position in which the brake cylinder continues to be pressurized.
Abstract: A freight brake control valve device for a railway vehicle having a service piston slide valve arranged with a detent to latch the service piston in preliminary quick service position until such time as the application pressure differential acting on the piston exceeds a predetermined value.
Abstract: A freight brake control valve device having an improved quick service function achieved by providing an additional volume upstream of the quick service limiting valve with which the brake pipe fluid under pressure is equalized during the second stage of quick service to achieve an intensified secondary quick service reduction of brake pipe pressure. Further, a smooth and continuous local reduction of brake pipe pressure occurs without any time lag at the time of transition from preliminary to secondary stage quick service. In a first embodiment of the invention, an exhaust passage separate from the brake cylinder exhaust passage is provided to assure venting of this additional volume in the event the brake cylinder retainer valve is set up. In a second embodiment, the additional volume is vented via the brake cylinder exhaust passage.
Abstract: A freight brake control valve device having an improved quick service function achieved by utilizing a common quick service volume during secondary quick service as well as preliminary quick service, in order to achieve an intensified secondary quick service reduction of brake pipe pressure. Further, a continuing local reduction of break pipe pressure is obtained without any time lag during transition from preliminary to secondary stage quick service. In a first embodiment of the invention, an exhaust passage separate from the brake cylinder exhaust passage is provided to assure venting of the preliminary quick service volume in the event the brake cylinder retainer valve is set up. In a second embodiment, the additional volume is vented via the brake cylinder exhaust passage.
November 5, 1987
Date of Patent:
October 11, 1988
American Standard Inc.
James E. Hart, Edward W. Gaughan, Theodore B. Hill