摘要:
The proportioning valve assembly may be screwed into a complementary-shaped opening in a master cylinder. The valve assembly includes a differential area piston biased by a spring toward the outlet which communicates with the rear brakes. The master cylinder includes a pair of passageways which communicate primary fluid pressure and secondary fluid pressure directly to the differential area piston of the proportioning valve assembly to displace the piston to a balanced position. If there is a failure of pressure in the primary brake circuit, the proportioning valve assembly actuates the differential area piston to permit fluid flow to bypass the piston and be communicated directly to the rear brakes of the vehicle. Upon failure, a differential area sleeve surrounding the piston moves to actuate an electrical failure warning switch.
摘要:
A master cylinder (12) having a switch (70) which is activated by either a magnet (78) carried by a float (76) in a reservoir (40) or a pin (66) moved by a differential area piston (52). The switch (70) had a first blade (82) connected a source of electrical current (106) through an indicator light (124) and a second blade (88) connected to an electrical ground (114). A reed switch (100) is connected to the first (82) and second (88) blades and responds to the magnet to close an electrical circuit to operate the indicator light (124) if a low fluid level is present in the reservoir (40). A first contact (96) on the first blade (82) is positioned in switch 70 by a non-electrical conductive actuation pin (66) that extends through the housing (22) of the master cylinder (12). A second contact (94) on the second blade ( 88) has a projection (92) that engages the housing (22) of the master cylinder (12) to define a fixed location for the first contact (94) and establish a fixed gap between the first (94) and second (96) contacts. If a pressure differential is created in the master cylinder (12) between the fluid pressure supplied to operate the wheel brakes (18) and (20), the differential area piston (52) moves and brings the second contact (96) into engagement with the first contact (94) to close the electrical circuit and activate the indicator light (124).
摘要:
The proportioning valve assembly (40, 140) may be screwed into a complementary-shaped opening in a master cylinder (10). The valve assembly (40, 140) includes a differential area piston (50, 150) biased by a spring (70, 170) toward the outlet (21, 121) which communicates with the rear brakes. The master cylinder (10) includes a pair of passageways (16, 18) which communicate primary fluid pressure and secondary fluid pressure directly to the differential area piston (50, 150) of the proportioning valve assembly (40, 140) to displace the piston (50, 150) to a balanced position. If there is a failure of pressure in the primary brake circuit, the proportioning valve assembly (40, 140) actuates the differential area piston (50, 150) to permit fluid flow to bypass the piston (50, 150) and be communicated directly to the rear brakes of the vehicle.
摘要:
The proportioning valve assembly (40, 140) may be screwed into a complementary-shaped opening in a master cylinder (10). The valve assembly (40, 140) includes a differential area piston (50, 150) biased by a spring (70, 170) toward the outlet (21, 121) which communicates with the rear brakes. The master cylinder (10) includes a pair of passageways (16, 18) which communicate primary fluid pressure and secondary fluid pressure directly to the differential area piston (50, 150) of the proportioning valve assembly (40, 140) to displace the piston (50, 150) to a balanced position. If there is a failure of pressure in the primary brake circuit, the proportioning valve assembly (40, 140) actuates the differential area piston (50, 150) to permit fluid flow to bypass the piston (50, 150) and be communicated directly to the rear brakes of the vehicle.
摘要:
The positioning ring (44) for a hydraulically operated warning device (80) may be utilized for any hydraulically movable piston or sleeve (52) which, when properly assembled, causes a warning device (80) to effect an initial mode of response. The positioning ring (44) has a reduced inner diameter portion (41) separated from an enlarged inner diameter portion (43) by way of a radial shoulder (42). The enlarged inner diameter portion (43) abuts a shoulder (17) of a surrounding housing (11) and the radial shoulder (42) abuts a shoulder (59) of the piston or sleeve (52). The housing (11) may contain a warning device (80) which engages the piston or sleeve (52) such that if the piston or sleeve (52) is displaced in an axial direction the warning device (80) is operated. Should the centering ring (44) be mis-assembled or not included in the assembly, either the misassembled positioning ring (44) or the lack of the positioning ring ( 44) permits the piston or sleeve (52) to be moved to a position where the warning device (80) is operated to provide an indication that the positioning ring (44) is either misassembled or missing from the assembly.
摘要:
A proportioning valve (40) is disposed within a stepped bore (13) of a master cylinder (10). The proportioning valve (40) defines with the stepped bore (13) a primary pressure receiving chamber (26) and a secondary pressure receiving chamber (28). The proportioning valve (40) includes a two-part piston (58) which includes a primary piston part (52) and a secondary piston part (54) coupled together by a lost motion coupling (53, 55). The piston parts (52, 54) are biased apart by a spring (78), and a sleeve (43) is disposed about the two-part piston (50). Seals (46, 47, 69) are disposed about the primary piston part (52), sleeve (43) and secondary piston part (54) to define an intermediate vented chamber (90), wherein a vent (19) communicates with a reservoir. Pressure failure within the primary receiving chamber (26) causes the primary piston part (52) to be displaced and close off the vent (19 ) so that fluid pressure is trapped within the intermedaite chamber (90) to prevent the secondary piston part (54) from effecting the metering of fluid flow through an outlet (21).
摘要:
A master cylinder having a housing with a first bore therein for retaining a pair of pistons which move in response to an input force and develop fluid pressure to effect a brake application. A second bore in the housing carries a differential area piston connected to the pressure chambers. A reed switch retained in the housing is aligned with a first magnet located on a float in a reservoir and a second magnet is attached to the differential area piston. A ferromagnetic shield located between the reed switch and second magnet has first and second openings located in a plane on either side of the reed switch. Should a failure occur in either pressure chamber, the differential area piston moves to allow magnetic field to pass through the openings in the shield and activate the reed switch to develop a warning signal and inform an operator of a failure mode condition in the master cylinder.
摘要:
The brake system in-line fast fill valve (10) of the present invention comprises a valve housing (12) which may be threadably inserted within the body of a master cylinder so that an inlet (28) at one end of the fast fill valve (10) communicates with an outlet (39) from a pressure chamber (33) of the master cylinder (30). The valve housing (12) includes a stepped bore (22) having a differential area fast fill piston (40) receiving slidably therein a poppet piston (60). A first seal (50) is disposed about a reduced diameter portion (46) of the fast fill piston (40) and axially opposite a second seal (52) disposed at an enlarged diameter end (48) of the fast fill piston (40). The second seal (52) is received about a second radially enlarged end (62) of the poppet piston (60), the poppet piston (60) extending through the fast fill piston (40) and an end opening (44 ) within the fast fill piston (40), with a third seal (56) disposed about a first poppet end (66) and abutting a reduced diameter end (42) of the fast fill piston (40). A first spring (72) biases the poppet piston (60) into engagement with the fast fill piston (40), and a second spring (74) extends between a second radially enlarged end (68) of the poppet piston (60) and a radial wall (23) of said stepped bore (22). The enlarged ends (48, 68) of the pistons (40, 60) are disposed within a fast fill chamber (24) which communicates with an outlet (20) of the fast fill valve housing (12). The fast fill valve (10) effects a quick transmittal of fluid to a brake piston, and effects a slight delay in the transmission of higher pressure to the brake so that the fast fill valve (10) function as a hold-off valve.
摘要:
A proportioning valve assembly (10) in a housing (12) is pressure responsive to control the flow of fluid to a wheel brake. A proportioning valve (20) is disposed within a chamber (26) having an inlet (33) and outlet (114), the inlet (33) receiving pressure from a pressure generator such as a master cylinder. A poppet (80) of the proportioning valve (20) is connected by a shaft (90) with a plunger (100) disposed within another chamber (30), the other chamber (30) being isolated from fluid pressure in the chamber (26) housing the proportioning valve. A fluid-containing chamber (13) contains an inertia sensing mass (40) which engages a valve mechanism (34) that controls fluid communication between the fluid-containing chamber (13) and other chamber (30). A friction element (120) of the wheel brake engages a braking torque responsive valve (140) which communicates fluid pressure to a chamber (30a). The position of the poppet (80) is adjusted by the braking torque responsive valve (140) in order to eliminate the variable effects of friction elements having a variation in lining thickness and coefficient of friction.
摘要:
A master cylinder includes a housing movably supporting a pair of pistons and carrying a fluid reservoir assembly. The fluid reservoir assembly carries a differential area piston and a float which cooperate to activate a single reed switch, thereby generating a warning signal for a vehicle operator.