What follows are the subclasses from one class of the Manual of Classification for US patents. As you scroll through the list and encounter a class/subclass of interest, you can jump back to the top and retrieve patent titles by entering the class/subclass in the box below.
Enter a class/subclass code here to get a list of patent titles. Use
any of the following forms:
363-131 121-55A 14-.5
that is, no embedded spaces, class and subclass seperated by a dash, and any
subclass letters capitalized. Currently Design Patent titles (those in the
classes of the form Dxx.yy) are not retreivable.
Class Number: 181
Class Title: ACOUSTICS
Subclass Subclass
Number Title
.5 MISCELLANEOUS
* SPEAKING TUBES
18 .Systems
19 .Alarms and indicators
20 .Combined mouth and ear pieces
21 .Mouthpieces
22 .Tubes
30 AUDITORIUM
101 GEOPHYSICAL OR SUBSURFACE EXPLORATION
102 .Well logging
103 ..Programmed or timer-controlled
104 ..Directional source or detector
105 ..Bore hole or casing condition
106 ..Seismic wave generation
107 .Programmed or timer-controlled
108 .Seismic source and detector
109 ..Aerial
110 ..Underwater
111 ..Plural sources
112 ..Plural detectors
113 .Seismic wave generation
114 ..Vehicle-mounted
115 ..Bubble suppression or control
116 ..Explosive
117 ...Gas
118 ....Underwater
119 ..Fluid means
120 ...Underwater
121 ..Moving weight
122 .Seismic wave detection
123 ECHO SYSTEM
124 .Altitude or depth detection
125 SOUND LOCATION
126 ANATOMIC OR PROSTHETIC RELATION
127 .Dentiphone
128 .Ear and mouth
129 ..Ear
130 ..Auditory canal insert
131 ...Stethoscope
132 ...With diaphragm
133 ...Deflector type
134 ...Eardrum
135 ...Ear insert
136 ..Deflector type
137 ..Receiver
138 MECHANICAL TELEPHONE
139 WAVE GENERATION AND DETECTION
140 WITH VESSEL
141 COMBINED
142 WAVE GENERATION
143 MOVING SOUND PRODUCER OR DEFLECTOR
144 PLURAL DIAPHRAGM SOUND SOURCESS
145 .Plural chambers
146 .With sound-asborbing means
147 .Three diaphragms
148 DIAPHRAGM AND ENCLOSURE
149 .Moisture proof
150 .Recessed (e.g., wall-mounted, etc.)
151 .With sound-absorbing means
152 .With horn
153 .Rounded enclosure (e.g., curved, etc.)
154 .Inclined diaphragm
155 .Reflector baffle
156 .Reflex baffle
157 DIAPHRAGM
158 .Microphone type
159 .With horn
160 .With resonant chamber
161 .With direct mechanical connection to drive unit
162 ..Stylus bar
163 .Plural dependent diaphragms
164 .Sectional diaphragm
165 ..Concentric annular section
166 .With damping means
167 .Critically defined material or coating
168 ..Metallic material
169 ..Fibrous material
170 ..Laminated type
171 .Mounting or suspension means
172 ..Elastic suspension means
173 .Particular shape
174 ..Variable thickness
175 SOUND-MODIFYING MEANS
176 .Lens
177 .Intensifying horn
178 ..Collapsible
179 ..With particular mounting structure
180 ..Material
181 ..With vibratory filaments
182 ..With resonant chamber
183 ...Double wall
184 ..Having apertures in walls
185 ..With sound-path restriction
186 ...Adjustable
187 ..Plural intensifying portions
188 ...Similar portions
189 ..Multisection housing
190 ...Separable
191 ..With external sound deflector
192 ..Particular shape of the horn
193 ...Spiral sound path
194 ...Doubly folded sound path
195 ...Wide angle annular outlet
196 .Within tubular means
197 ..Adjustable
198 .Housing or enclosure (e.g., sound confining and absorbing)
199 ..Speaker type
200 ..Machine type enclosure
201 ...Offfice type devices (e.g., typewriters, teleprinters, etc.)
202 ...Electical type devices (e.g., transformers, motors, etc.))
203 ...Reaction engine test chamber
204 ...Internal-combustion engine
205 ...Partial enclosure or shroud
206 .By wave interference
207 .Mechanical vibration attenuator
208 ..Damping of flexural structure
209 ..Relatively moving parts
210 .Sound absorbing fence or screen (e.g., jet engine or vehicle
noise)
211 .Combined
212 .Muffler, fluid conducting type
213 ..Reaction engine type
214 ...Upstream (e.g., intake silencer)
215 ...With adjustable outlet nozzle
216 ....Longitudinally adjustable section
217 ...Removable silencer unit (e.g., mobile)
218 ...Ground installation silencer
219 ...With adjustable internal baffles
220 ...With disparate fluid mingling
221 ....Liquid
222 ...With sound absorbing material
223 ..Silencer for firearms
224 ..Sound absorbing ventilating duct or curb (e.g., a/c, heat, air
flow type)
225 ..With fan to assist fluid flow
226 ..With adjustable fluid flow
227 ..Pipe-muffler (e.g., tail pipe type)
228 ..With exhaust pipe
229 ..Carburetor, burner, or compressor intake silencer
230 ..Pneumatic type motor (e.g., air hammer, etc.)
231 ..With solid particle separator (e.g., spark arrestor, vacuum
cleaner, etc.)
232 ..Separate distinct units serially connected
233 ..Liquid motion silencer
234 ...Water-closet type
235 ..Underwater discharge
236 ..With muffler cut-out
237 ..With pressure relief safety valve
238 ..Multiple distinct inlets and/or outlets
239 ...Outlets
240 ..Manifold type
241 ..Adjustable muffler (i.e., internal or external parts)
242 ..Mouthpiece (e.g., telephone, microphone, etc.)
243 ..With repair, replacement, or quick disassembly
244 ..Corrosion prevention
245 ...Internally coated parts
246 ...Nonmetallic
247 ..Straight-through passage
248 ...Continuous conduit
249 ....With expansion chamber
250 .....And side branch
251 .....And multi-passage
252 ...With sound absorbing material
253 ...With muffler bypass
254 ....Valve controlled
255 ...Expansion chamber
256 ..With sound absorbing material
257 ...And multi-passagee
258 ...Pervious material interposed in flow path
259 ..With disparate fluid mingling
260 ...Liquid
261 ....Sprayed
262 ...Induced by suction
263 ....Motion induced
264 ..With baffle or baffle structure
265 ...Retroverted
266 ....And side branch chamber
267 ...Coaxial foraminous walls
268 ...Multi-passage
269 ...Expansion chamber type
270 ....With alternating partial baffles along the length of casing
271 ....With adjustable or flexible wall
272 ....Plural chambers
273 ....And side branch chamber
274 ....With centrifugal flow
275 ....And multi-passage
276 ...Side branch
277 ...Movable baffle
278 ....Biased
279 ...Spiral
280 ....Helical
281 ...Perpendicular and/or oblique
282 ...Casings
283 ....Air or liquid cooled
284 .Sound absorbing panels
285 ..Load bearing block type structure
286 ..Specific acoustical properties or dimensions
287 ..Movable/foldable panels
288 ..Cellular
289 ..Light permeable
290 ..Multilayer panel or wall structure
291 ...With membrane outer layer
292 ...With perforated or porous face and honeycomb-like core
293 ..With channels or cavities in surface layer
294 ..Materials
295 .Space absorbers
296 .Methods
* ******************************
* CROSS-REFERENCE ART COLLECTIONS
* ******************************
400 WAVE COUPLING
401 .Earth
402 .Liquid
403 REFRIGERATOR COMPRESSSOR MUFFLER
404 HOBBY CRAFT ENGINE MUFFLER