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

Class
246
RAILWAY SWITCHES AND SIGNALS

Class definitions may be accessed by clicking on the class title, above.
Subclass definitions may be accessed by clicking on the subclass number, below.

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Subclass		Title
ClassTitle		===> RAILWAY SWITCHES AND SIGNALS
1R		MISCELLANEOUS
1C		. Signals and indicators
2R		TRAIN DISPATCHING
3		. Central signal control
4		. . Cab signal or train control
5		. . Selective
6		. Train-order cab signal or train control
7		. Train telegraphy or telephony
8		. . Inductive
9		. . Continuous contacts
10		. . . Traction rail return
11		. . . . Multiple contact
12		. . . Instruments in series
13		. . Emergency signal stations
14		. Station, block, or train-order signals
15		. . Safety systems
16		. . . Holders
17		. . Rotary, vertical axis
18		. . Double semaphore
2E		. Orientation
2F		. Frequency
2S		. Spacing
19		STAFF AND TABLET SYSTEMS
20		BLOCK-SIGNAL SYSTEMS
21		. Semi-automatic
22		. . Electromanual
23		. . . Cab signal or train control
24		. . . Circuit controllers
25		. . . Lock and block
26		. . . . Track-circuit control
27		. Automatic
28R		. . Electric
29R		. . . Radiant energy
30		. . . . Hertzian wave
29A		. . . . Electronic gaseous ionization devices
31		. . . Propulsion-current control
32		. . . . Current consumption
33		. . . Single track
34R		. . . Varying-current track circuit
35		. . . . Propulsion-current return
36		. . . . . Double rail
37		. . . . . . Impedance bond
38		. . . . Wireless distant control
39		. . . . Line-wire distant control
40		. . . . Single block
34A		. . . . Approach control
34B		. . . . Coded circuits
34C		. . . . Insulation breakdown
34D		. . . . Saturable reactors
34CT		. . . . Continuous track
41		. . . Direct current, normally closed, track circuit
42		. . . . Propulsion-current return
43		. . . . . Varying
44		. . . . Wireless distant control
45		. . . . . Current reversal
46		. . . . Line-wire distant control
47		. . . . . Cab signal or train control
48		. . . . . . Bridged insulated rail joint
49		. . . . . . Intermittent contact
50		. . . . . Current characteristic
51		. . . . . Overlapped blocks
52		. . . . . Home and distant
53		. . . . . Three position
54		. . . . Single block
55		. . . . . Cab signal or train control
56		. . . . . . Intermittent contact
57		. . . . . . Bridged insulated rail joint
58		. . . Direct-current, normally open, track circuit
59		. . . . Cab signal or train control
60		. . . . Distant-signal control
61		. . . Superimposed propulsion current
62		. . . Cab signal or train control
63R		. . . . Inductive
63C		. . . . . Continuous
63A		. . . . . Intermittent
64		. . . . Train-carried current supply
65		. . . . . Multiple continuous contacts
66		. . . . . . Sectional
67		. . . . . Single continuous contact
68		. . . . . . Sectional
69		. . . . . Intermittent contact
70		. . . . . . Rail circuit
71		. . . . . . Rail return
72		. . . . Propulsion-current signaling
73		. . . . Continuous contact
74		. . . . Intermittent contact
75		. . . . Bridged insulated rail joint
76		. . . . Track trip
77		. . . Counting in and out
78		. . . . Ratchet wheel
79		. . . . . Double opposed pawls
80		. . . . . . Parallel teeth
81		. . . Propulsion-current signaling
82		. . . . Rotary controller
83		. . . . Car-actuated controller
84		. . . . . Trolley or plow
85		. . . . Intermittent contact
86		. . . Train-carried current supply
87		. . . Line-current supply
88		. . . . Intermediate signal
89		. . . . Short sectional rail closure
90		. . . . Car-actuated controller
91		. . . . . Relay
92		. . . . Intermittent contact
28C		. . . Ballast leakage
28E		. . . Economy use of line wire
28F		. . . Checking circuits
28G		. . . Light-out
28H		. . . Intermittent light
28K		. . . Transformer
93		. . Combined fluid pessure and electric
94		. . . Cab signal or train control
95		. . . Track-circuit control
96		. . Electromechanical
97		. . . Cab signal or train control
98		. . . Track-circuit control
99		. . . Clockwork
100		. . Fluid pressure
101		. . . Cab signal or train control
102		. . Mechanical
103		. . . Cab signal or train control
104		. Manual
105		. . Electric
106		. . . Lock and block
107		. Recorders
108		TIME INDICATION, AUTOMATIC
109		. Flow retarded
110		. Time limit expired
111		GRADE-CROSSING TRACK PROTECTION
112		. Semi-automatic
113		. Automatic
114R		. . Electric
115		. . . Cab signal or train control
114A		. . . Cross-over protection
116		. . Fluid pressure
117		. Cab signal or train control
118		DRAWBRIDGE PROTECTION
119		. Cab signal or train control
120		ROADWAY-DEFECT PROTECTION
121		. Electric
122R		TRAIN-POSITION INDICATION
123		. Automatic time recording
124		. Train annunciators or indicators
122A		. Miniature model
125		ELECTRIC AUTOMATIC HIGHWAY SIGNALS, MINE DOORS, AND GATES
126		. Car-actuated controller
127		. . Gates and doors
128		. Normally open track circuit
129		. . Short sectional rail closure
130		. Normally closed track circuit
131		INTERLOCKING
132		. Electric actuation
133		. . Electric locking
134		. . . Route locking
135		. . . Return-release indication
136		. . Mechanical locking
137		. . . Return-release indication
138		. . . . Locked slide
139		. Fluid-pressure actuation
140		. . Electrically controlled valve
141		. . . Return-release indication
142		. . Return-release indication
143		. Manual actuation
		. . Switch stands
144		. . . Signal-actuating
145		. . . . Double lever
146		. . Electrical locking
147		. . Mechanical locking
148		. . . Preliminary
149		. . . . Tappets
150		. . . Tappets
151		. . . Detector bars
152		. . . Compensators
153		. . . . Counterweight
154		. . . . . Intermittent grip
155		. . . Rod-saving devices
156		. . . . Selectors
157		. . . . . Electric
158		. . . . Switch and lock movements
159		. Detached locking, check locking, or key control
160		. Approach locking
161		. Retarded-release mechanism
162		. Switch or signal indicators
163		. Derails
164		SLOTTING AND CONTROL
165		. Electric
166		PILOT OR SIGNAL CARS
166.1		SIGNALLING BETWEEN OCCUPANTS OF A TRAIN
167R		CAB SIGNAL OR TRAIN CONTROL
168		. Train parting
168.1		. Wheel slip
169R		. Train defect
169A		. . Hot bearing detectors
169D		. . Radiant energy type
169S		. . Sound detectors
170		. Derailment
171		. . Contact trips
172		. . . Frangible
173		. . Inertia trips
174		. Highway or station, automatic
175		. . Code signal
176		. Switch signals
177		. Block entrance initiated
178		. . Electric or magnetic control
179		. . . Bridged insulated rail joint
180		. . . Cab-circuit controller
181		. . . Mechanical actuation
182R		. Speed-control systems
182A		. . Track brake speed control
182B		. . Automatic vehicle-carried braking
182BH		. . Humped, unpowered cars
182C		. . Automatic vehicle-carried speed comparison circuits
182AA		. . Yard-switching, dispersed
182AB		. . Yard-switching, centralized
183		. Manual-control systems
184		. Service stop
185		. Recording devices
186		. Motive-power control
187R		. . Electric
187A		. . . Remote control
187B		. . . Non-mechanical control of vehicles from wayside
187C		. . . Control of vehicle from leading vehicle
188		. . Fluid-pressure-actuated throttle
189		. Engineer's brake-valve actuation
190		. Train-pipe-valve structure
191		. Visual cab signals
192R		. Train mechanism
193		. . Electric or magnetic
194		. . . Inductive
195		. . . Intermittent contact
196		. . . Cab-circuit controller
197		. . . . Magnetically actuated
198		. . Single-direction actuation
199		. . Frangible
200R		. . Lever actuated
200A		. . . Lever perpendicular inclined less than 45 degree
200B		. . . Lever transverse relative to direction of travel
192A		. . Train-carried electric contact mechanism
201		. Track trips
202		. . Electric or magnetic
203R		. . Pivoted
203A		. . . Single vertical pivot on which track trip turns
203B		. . . Single vertical pivot; strike rod transverse of track
203C		. . . Single horizontal pivot on which track trip turns
203D		. . . Single horizontal pivot; strike rod transverse of track
203E		. . . Horizontal pivot, vertical rod, strike rod perpendicular
204		. . Vertical motion
205		. . Lateral motion
206		. . Fixed
207		. . Portable
167A		. Train approach warning for work cars
167M		. Magnetic rail
167D		. Vehicle-vehicle distance measuring
208		CAR-DISPLAYED CROSSING SIGNALS
209		PASSENGERS' STATION SIGNALS
210		TORPEDO MECHANISM
211		. Electric
212		. Magazine
213		. . Vertical
214		. . Rotary
215		. Car attached
216		. Hand placing devices
217		AUDIBLE SWITCH AND SIGNAL INDICATORS
218		ELECTRIC ACTUATION
219		. Control circuits
220		. Switch signals
221		. Motor systems
222		. . Return-indication-current generation
223		. . Three-position signals
224		. . Home and distant signals
225		. . Reciprocating armature
226		. . . Controller-actuated switches
227		. . . . Opposed magnets
228		. . . . . Circuit changers
229		. . . . . Tandem contacts
230		. . . . Alternate throw
231		. . . Opposed magnets
232		. . . . Circuit changers
233		. . . . Tandem contacts, switches
234		. . . . Parallel contacts, switches
235		. . . . . Circuit controller
236		. . . Alternate throw
237		. . . Fly-back
238		. . . . Latch or clutch release
239		. . . . Switches
240		. . Rotary armature
241		. . . Opposed motors
242R		. . . Circuit changers
242A		. . . . Overload release
242B		. . . . Dual selector circuit
242C		. . . . . Remote lever, local selector
243		. . . Fly-back
244		. . . . Latch or clutch release
245		. Car-actuated generators
246		. Car-actuated circuit controllers
247		. . Wheel or train counting
248		. . Retarded action
249		. . Electric or magnetic
250		. . Single-direction actuation
251		. . Vertically sprung rail
252		. . Trolley or plow actuated
253		. Switch or signal actuated controllers
254		. Trolley-completed circuits
255		. Car-wheel-completed circuits
256		. Relays
257		FLUID-MOTOR ACTUATION
258		. Electric control
259		. . Car-controlled switches
260		. Signals
261		. Gates
262		MECHANICAL-MOTOR ACTUATION
263		. Electric control
264		POINT THROWERS
265		. Magnetic
266		. Modifier switch
267		. . Directing-grooves
268		. Wedging wheel
269		. Sliding shoe
270R		VEHICLE-ENERGY ACTUATION
271		. Fluid transmission
272		. . Gates
273		. Continuous-rail crossings
274		. Switch-connected frogs
275		. Continuous-rail frogs
276		. . Spring rail
277		. Automatic turnouts
		. Switch stands, automatic
278		. . Facing setting
279		. . . Manual control
280		. . . Resetting
281		. . . . Vehicle restrained
282		. . . Trailing setting
283		. . . . Yielding rail
284		. . Trailing setting
285		. . . Yielding rail
286		. . . . Spring-clutch
287		. . . . . Coaxial spring
288		. . . . Counterweight
289		. . . . Frangible
290		. . Trailing fly-back
291		. . . Spring actuated
292		. Signals and gates, automatic
293		. . Highway crossing
294		. . . Visual and audible
295		. . . Audible
296		. . . . Bells, single stroke
297		. . Track mechanism
298		. . . Single direction
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