Manual of U.S. Patent Classification
as of June 30, 2000

Class
303
FLUID-PRESSURE AND ANALOGOUS BRAKE SYSTEMS

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Subclass definitions may be accessed by clicking on the subclass number, below.

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Subclass		Title
ClassTitle		===> FLUID-PRESSURE AND ANALOGOUS BRAKE SYSTEMS
1		MISCELLANEOUS
2		MULTIPLE SYSTEMS
3		. Fluid pressure and electric
4		. Fluid pressure and vacuum
5		MULTIPLE FLUID-RECEIVING DEVICES
6.01		. Multiple motors
6.1		. . Brake and door
7		. . Sectional train
8		. . . Multiple brake valves
9		. . Supplementary in emergency
9.61		. . Separate and simultaneous control
9.62		. . Apportioning control
9.63		. . . Failure responsive
9.64		. . . Motorcycle
9.65		. . . Manual
9.66		. . . For pneumatic system
9.67		. . . Inertia
9.68		. . . . Inertia weight
9.69		. . . Load
9.71		. . . Having significant pressure control by front brake
9.72		. . . Having multiple pistons affecting fluid flow
9.73		. . . Having significant output feature
9.74		. . . . Multiple outlets
9.75		. . . Detail
9.76		. . Spring operated motor
10		WITH PUMP
11		. Pressure control
12		. Vacuum
13		MULTIPLE CONTROL
14		. Double heading
15		. Fluid and electric
16		. . Automatic electric
17		. . . Electric impulse
18		EXTERIOR CONTROL
19		. Deadman type
121		SPEED-CONTROLLED
122		. With failure responsive means
122.01		. . Traction failure
122.02		. . Antilock failure with warning
122.03		. . Failure related to brake condition (e.g., wear, sensor or switch operation) with indicator
122.04		. . Electric system failure (no warning)
122.05		. . . Electronic or electric component (e.g., speed detector, failure sensing) with warning
122.06		. . ABS failure detected via time period of sensed wheel lock or wheel speed signal
122.07		. . Time signal error (no warning)
122.08		. . Active circuit testing
122.09		. . Pressure failure
122.1		. . . With warning
122.11		. . . Detected via stroke sensor
122.12		. . . Pump failure detection
122.13		. . . Auxiliary pressure failure
122.14		. . . . With warning
122.15		. . . Pneumatic
123		. For a tractor-trailer type vehicle
124		. . Electric brake
125		. Automatic braking including speed governor or hydraulic retarder
126		. . Aircraft
127		. Pneumatic
128		. . For a railway vehicle (e.g., train)
129		. . . With speed governor (hydraulic or inertia)
130		. . . . Compared to fixed reference
131		. . . Plural similar inputs
132		. . . Speed responsive and other conditions (e.g., acceleration, pressure, track hazard, friction)
133		. . . Traction control
134		. . . Compared to fixed reference
135		. . . Automatic
136		. . . Pseudo-speed
137		. Motorcycle
138		. Speed, deceleration, or ABS indication
139		. And traction control
140		. . With yaw control
141		. . With engine torque power take-off (PTO) control
142		. . Motor control
143		. . With four wheel drive or all wheel drive
144		. . Intersecting traction and skid occurrence
145		. . Odd condition (e.g., fuel supply cut-off, modulating valve)
146		. With yaw control
147		. . From speed sensors
148		. . From split coefficient of friction (mu)
149		. Split coefficient of friction (mu)
150		. Specific mu determination
151		. Traction-motor vehicle
152		. Regenerative brakes
153		. Lead signal control for antiskid
154		. Multiple control signal with multiple threshold
155		. Braking pressure demand or braking force desire
156		. Pulse frequency or time period controlling pressure rebuild
157		. Pressure release control
158		. Pressure reapply control
159		. Wheel pressure delay compared to reference
160		. Pressure or specific condition (e.g., deceleration) determines wheel speed instead of direct speed sensor
161		. Current or voltage ramp proportional to vehicle speed
162		. Current control of linear piston drive motor
163		. Slip ratio
164		. Slip time versus nonslip time
165		. Variable target slip values
166		. Wheel speed sensor and braking pressure sensor
167		. Brake force or pressure determined from speed sensors
168		. Wheel generated pulse signal control (speed sensor)
169		. Left or right speed comparison
170		. Select high wheel speed versus select low
171		. Wheel speed versus pseudo vehicle speed (e.g., from deceleration)
172		. . By direct feedback or instant wheel control
173		. . By comparison of plural wheel speeds
174		. Previously stored wheel speed information
175		. Incipient or imminent skid measured
176		. Antilock control disabled or altered for acceleration or speed ranges
177		. Sensing jerk, acceleration, or deceleration
178		. . Wheel deceleration to find velocity error
179		. . Rotary and linear inertia
180		. . Rotary inertia
181		. . Linear inertia or accelerometer (includes pendulum type)
182		. . Accelerometer versus wheel rotation sensor
183		. . Specific acceleration or deceleration determined electronically
184		. . Acceleration-deceleration versus timing
185		. . Sensing deceleration then acceleration
186		. Front-rear axle apportioning or speed difference
187		. Diagonal wheels apportioning arrangement
188		. All wheel apportioning arrangement (e.g., cross coupling)
189		. Independent control for each wheel
190		. Four-wheel drive or all wheel drive
191		. Odd condition or device detection (e.g., fluid or brake temperature, hill holder, anti-squeal controller, acoustic emission)
192		. . Vehicle inclination
193		. . With sonar or radar type sensor
194		. . Hop or bounce (from vibration or oscillation) signal
195		. . Spurious signal
196		. . . For rough road
197		. . With feeler wheel
198		. . Speed and vehicle load condition (e.g., cargo)
199		. Electric control circuit detail
112		. Torque sensing
113.1		. Having a valve system responsive to a wheel lock signal
113.2		. . With traction control
113.3		. . . Including booster
113.4		. . Including a stroke sensor
113.5		. . With system apportioning control
114.1		. . Including hydraulic power booster
114.2		. . . Parallel boosters
114.3		. . Including pneumatic power booster
115.1		. . System controlled by expansible chamber type modulator
115.2		. . . Having electric control
115.3		. . . Having vacuum motor control
115.4		. . . Having pump pressure control
115.5		. . . . Pump pressure operates fluid motor
115.6		. . . Including flywheel control (e.g., motorcycle type)
116.1		. . Including pump with system solenoid valve
116.2		. . . Having pressure line isolated from master cylinder line
116.3		. . Vehicle wheel operated pump
116.4		. . System pump structure detail
117.1		. . Spool valve
118.1		. . Pneumatic (relay or motorman) type
119.1		. . System controlled by solenoid valve
119.2		. . . System solenoid valve detail
119.3		. . . Housing for plural solenoids
20		ELECTRIC CONTROL
22.1		LOAD CONTROL
22.2		. Empty and load type
22.3		. . Alterable for different classes of service
22.4		. Failure responsive
22.5		. Responsive to fluid pressure spring
22.6		. Railway vehicle
22.7		. . Detail
22.8		. Detail
24.1		INERTIA CONTROL
25		AUTOMATIC AND DIRECT
26		. Supplementary control pipe
27		. Direct on control-pipe reduction
28		AUTOMATIC
29		. Supplementary control pipe
30		. Supplementary reservoir pipe
31		. Vacuum
32		. Equilibrium
33		. Equalizing valves
34		. . Rotary type
35		. Synchronizing
36		. . Release
37		. . Quick action
38		. . . Service
39		. . . Control pipe to chamber
40		. Application valve
41		. Preliminary valve movement
42		. . Emergency preventers
43		. Slow-reduction emergency
44		. Secondary service operation
45		. Positive-movement equalizing valve
46		. Augmented feed to motor
47		. Train rear end first
48		DIRECT
49		. Liquid link
50		MOTORMAN'S VALVES
51		. Conductor type
52		. Multiple motors
53		. . Engine and train
54		. Equalizing
55		. . Preliminary discharge
56		. Details
		CHARGING
57		. Plurality of pressures
58		. Reuse
59		. Outlet-pressure control
60		. . Maintaining
61		. Intermittent
		. Motor
62		. . Motor-movement control
63		. . Failure-system pressure
64		. Auxiliary reservoir
65		. . Motor remaining charged
66		. Control pipe
67		. . Preventers
		RELEASING
68		. Motor
69		. . Quick
70		. . Venting auxiliary reservoir
71		. . Fluid-pressure retracting
72		. . Delayed
73		. . . Blow down
74		. . . Graduated
75		. . Preventers
76		. . . Motorman valve control
77		. . . Control-pipe pressure
78		. . . Auxiliary-reservoir control
79		. . . Loaded valve
80		. Auxiliary reservoir
81		. Control pipe
82		. . By action of control-pipe pressure
83		. . To chamber
84.1		FLOW RETARDER
84.2		. Isolation valve
85		SUPPLEMENTARY RESERVOIR
86		MISCELLANEOUS OPERATIONS ON CONTROL PIPE
87		PULSATION NEUTRALIZERS
89		LOCKS
90		PIPELESS VALVES
		******************************
		CROSS-REFERENCE ART COLLECTIONS
		******************************
900		ABS throttle control
901		ABS check valve detail
		******************************
		DIGESTS
		******************************
DIG 1		Pressure comparison
DIG 2		Brake control by pressure comparison
DIG 3		. Electrical pressure sensor
DIG 4		. . Pressure signal used in electrical speed controlled braking circuit
DIG 5		Acceleration peak detection
DIG 6		Axle differential control
DIG 7		Small tire digest
DIG 8		Antichatter
DIG 9		Plural processors
DIG 10		Valve block integrating pump, valves, solenoid, accumulator, etc.
DIG 11		Accumulator
DIG 12		Air over hydraulic brake system

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Questions regarding this report should be directed to:

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Information Products Division
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Washington, DC 20231

tel: (703) 306-2600
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Last Modified: 6 October 2000