Pneumatic service emergency actuators for trucks, buses and trailers

Claim 2

In a brake operating device in which a push rod is moved between applied and release positions by air pressure, but must be maintained in an applied condition when there is no air pressure and must also be manually releasable from the applied condition, the improvement comprising: a spring plate coupled to the push rod; a rear housing; a heavy duty barrel spring extending the spring plate and rear housing to urge the spring plate forwardly to move the push rod to an applied position; said spring plate being located within said rear housing and being unrestrained against lateral movement therein; a threaded member having a forward end engaged with the spring plate and a rearward end; nut means coupling the rearward end of the threaded member to the rear housing so that the threaded member can be advanced rearwardly to pull the spring plate rearwardly and compress the barrel spring until the coils thereof at least partially nest in one another; and first and second guide means disposed respectively on said spring plate and rear housing for centering the spring plate on the rear housing along most of the travel distance of the spring plate, including the travel portion thereof when the heavy duty spring becomes fully compressed, to assure that the barrel spring coils can properly nest in one another, said first and second guide means including tapered members, one lying within the other at all positions of the spring plate, said tapered members closely nesting in one another as the spring plate closely approaches its most rearward position at which the coils of the barrel spring being to nest in one another but said tapered members permitting wide lateral movement of the spring plate at its most forwarD position, and the forward end of the threaded member being free to laterally shift position with the spring plate when the plate is at its most forward position.

Claim 3

A brake operating assembly for a vehicle comprising: a slideably mounted push rod for applying and releasing a vehicle brake; a heavy duty spring (45) mounted to urge the push rod to an applied condition to apply the brake; an emergency actuator (36) pressurizable to move the push rod against the force of said spring to a release position, to release the brake when the vehicle has built up sufficient pneumatic pressure to permit later stopping; a service actuator (35) pressurizable to move the push rod to an applied condition to apply the brake to thereby stop the vehicle in normal operation; a lighter duty spring (30) urging the shaft toward a release position to release the brake, so that if the heavy duty spring is disabled at a time when there is no pneumatic pressure the brake can release; and means for manually disabling the heavy duty spring to release the brake, including a threaded member (43) extending along the axis of the spring, a spring-engaging member (46) coupling the forward end of the threaded member to the forward end of the heavy duty spring, rear housing means (12) for abutting the rear end of the heavy duty spring, and a nut (42) threaded on the shaft and abutting the rear housing means so that when the nut is tightened it compresses the heavy duty spring to disable it, said disabling means forming guiding means for guiding the abutting member in axial movement towards and away from the rear housing means; said guiding means including a pair of tapered guide members, one of them (49) on the spring-engaging member and the other (52) on the rear housing means, one of said guide members surrounding the other throughout the range of movement of the spring-engaging member, said guide members being tapered in width so that they closely nest in one another when the abutting member moves to its furthest rearward position, but said tapered members forming a large lateral clearance between one another when the abutting member moves to its furthest forward position.

Claim 4

A brake operating assembly for a vehicle comprising: a slideably mounted push rod for applying and releasing a vehicle brake; a heavy duty spring (45) mounted to urge the push rod to an applied condition to apply the brake; an emergency actuator (36) pressurizable to move the push rod against the force of said spring to a release position, to release the brake when the vehicle has built up sufficient pneumatic pressure to permit later stopping; a service actuator (35) pressurizable to move the push rod to an applied condition to apply the brake to thereby stop the vehicle in normal operation; a lighter duty spring (30) urging the shaft toward a release position to release the brake, so that if the heavy duty spring is disabled at a time when there is no pneumatic pressure the brake can release; and means for manually disabling the heavy duty spring to release the brake, including a threaded member (43) extending along the axis of the spring, a spring-engaging member (46) coupling the forward end of the threaded member to the forward end of the heavy duty spring, rear housing means (12) for abutting the rear end of the heavy duty spring, and a nut (42) threaded on the shaft and abutting the rear housing means so that when the nut is tightened it compresses the heavy duty spring to disable it, said disabling means forming guiding means for guiding the abutting member in axial movement towards and away from the rear housing means; said guiding means including a pair of tapered guide members, one of them (49) on the spring-engaging member and the other (52) on the rear housing means, one of said guide members surrounding the other throughout the range of movement of the spring-engaging member, said guide members being tapered in width so that they closely nest in one another when the abutting member moves to its furthest rearward position, but said tapered members forming a large lateral clearance between one another when the abutting member moves to its furthest forward position.

Claim 5

The brake operating apparatus described in claim 8 wherein: the first tapered guide member surrounds the second tapered guide member; said spring-engaging member has a rearwardly facing tapered protuberance; and said second tapered guide member has walls at its forward end that form a tapered recess for receiving said protuberance when the abutting member is moved to its most rearward position.

Claim 6

A brake operating assembly comprising in combination, a first chamber (32), a first diaphragm (35) mounted in said chamber adjacent one end thereof, a reciprocable brake actuating shaft (29) mounted axially in said chamber and extending exteriorly of the other end of said first chamber, a disc (31) connected to one end of said shaft and engaging one side of said first diaphragm, a conical spring (30) nested against said disc and urging said first diaphragm and said shaft toward said one end of said first chamber, a pressure fluid inlet port (25) to said first chamber on the side of said first diaphragm nearest said one end, a second chamber (33) located inside an emergency actuator casing (12) and mounted adjacent said one end of said first chamber, an aperture (51) at said one end of said first chamber and the adjacent end of said second chamber and providing a fluid-tight passage between said first and second chambers, a second diaphragm (36) mounted in said second chamber and spaced from said passage, a rigid cylindrical push rod (38) mounted for reciprocating movement longitudinally along the axis of said shaft, said cylindrical push rod having a fluid-tight sliding fit through said aperture with its opposite ends normally bearing against the adjacent face of a respective one of said diaphragms, said emergency actuator casing having an outwardly flaring side wall, a powerfuL barrel configurated spring (45) including a spring piston plate (46) bearing at one end thereof and enclosed by said emergency actuator casing with said spring piston plate held against the central area of said second diaphragm solely by an internal conically shaped first guide member (49) extending toward an inner wall of said emergency actuator casing, the other end of said powerful barrel spring being nested to positioning means therefor carried by the outer wall of the internal conically shaped second guide member (48) of said emergency actuator casing, said spring piston plate (46) and the adjacent end of said powerful barrel spring being freely supported within said emergency actuator casing free of sliding engagement with any other surface of said brake operating assembly during expansion and retraction of said powerful barrel spring thereby allowing substantial lateral movement of the spring piston plate without any risk of said spring piston plate cocking or binding whereby operation of the emergency actuator is assured, means (24) for normally supplying pressurized air to the surface of said second diaphragm opposite the side contacting said piston plate and effective to hold said powerful barrel configurated spring means compressed against the emergency actuator casing inner wall in contact therewith whereby said powerful barrel configurated spring means is effective to drive said brake shaft if and when the pressure is relaxed on said last mentioned surface of said second diaphragm; said spring piston plate further has a center portion engaged with a bolt (43) to prevent rotation of the bolt, a manually operable member comprising a washer-faced nut threadably mounted on the outer end of said bolt and a locking device arranged to limit the extent of axial motion of said washer-faced nut along the threaded shank of said bolt.

Claim 7

A brake operating assembly comprising in combination, a first chamber (32), a first diaphragm (35) mounted in said chamber adjacent one end thereof, a reciprocable brake actuating shaft (29) mounted axially in said chamber and extending exteriorly of the other end of said first chamber, a disc (31) connected to one end of said shaft and engaging one side of said first diaphragm, a conical spring (30) nested against said disc and urging said first diaphragm and said shaft toward said one end of said first chamber, a pressure fluid inlet port (25) to said first chamber on the side of said first diaphragm nearest said one end, a second chamber (33) located inside an emergency actuator casing (12) and mounted adjacent said one end of said first chamber, an aperture (51) at said one end of said first chamber and the adjacent end of said second chamber and providing a fluid-tight passage between said first and second chambers, a second diaphragm (36) mounted in said second chamber and spaced from said passage, a rigid cylindrical push rod (38) mounted for reciprocating movement longitudinally along the axis of said shaft, said cylindrical push rod having a fluid-tight sliding fit through said aperture with its opposite ends normally bearing against the adjacent face of a respective one of said diaphragms, said emergency actuator casing having an outwardly flaring side wall, a powerfuL barrel configurated spring (45) including a spring piston plate (46) bearing at one end thereof and enclosed by said emergency actuator casing with said spring piston plate held against the central area of said second diaphragm solely by an internal conically shaped first guide member (49) extending toward an inner wall of said emergency actuator casing, the other end of said powerful barrel spring being nested to positioning means therefor carried by the outer wall of the internal conically shaped second guide member (48) of said emergency actuator casing, said spring piston plate (46) and the adjacent end of said powerful barrel spring being freely supported within said emergency actuator casing free of sliding engagement with any other surface of said brake operating assembly during expansion and retraction of said powerful barrel spring thereby allowing substantial lateral movement of the spring piston plate without any risk of said spring piston plate cocking or binding whereby operation of the emergency actuator is assured, means (24) for normally supplying pressurized air to the surface of said second diaphragm opposite the side contacting said piston plate and effective to hold said powerful barrel configurated spring means compressed against the emergency actuator casing inner wall in contact therewith whereby said powerful barrel configurated spring means is effective to drive said brake shaft if and when the pressure is relaxed on said last mentioned surface of said second diaphragm; said spring piston plate further has a center portion engaged with a bolt (43) to prevent rotation of the bolt, a manually operable member comprising a washer-faced nut threadably mounted on the outer end of said bolt and a locking device arranged to limit the extent of axial motion of said washer-faced nut along the threaded shank of said bolt.