US Patent Class 434
EDUCATION AND DEMONSTRATION



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Current as of: June, 1999
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  DF  CLASS NOTES
1  DF  DETECTION OR RANGE DETERMINATION OF DISTANT OBJECT BY APPARATUS USING SENSOR OF ELECTROMAGNETIC OR SOUND ENERGY
2  DF  .~ Radar
3  DF  .~.~ Cathode ray screen display simulated by light means (e.g., light spot projected onto screen, etc.)
4  DF  .~.~ Optical means (e.g., image projector, etc.) or light or sound sensor (e.g., television camera, microphone, etc.) included in a simulator
5  DF  .~.~ Interference simulation
6  DF  .~ Sonar
7  DF  .~.~ Interference simulation
8  DF  .~.~ Simulation of Doppler shift of echo
9  DF  .~.~ Simulation of plural detector system
10  DF  .~.~ Simulation by use of sound recording
11  DF  ORGANIZED ARMED OR UNARMED CONFLICT OR SHOOTING
12  DF  .~ Self-propelled projectile
13  DF  .~.~ Launched underwater
14  DF  .~ Aerial warfare
15  DF  .~.~ Bombing
16  DF  .~ Gunnery
17  DF  .~.~ Gunfire spotting
18  DF  .~.~ Gun recoil simulation
19  DF  .~.~ Gun aiming
20  DF  .~.~.~ Cinematographic or cathode ray screen display
21  DF  .~.~.~ Training apparatus using beam of infrared, visible light, or ultraviolet radiation
22  DF  .~.~.~.~ Beam sensor included in apparatus
23  DF  .~.~.~ Means (e.g., target, terrain model, etc.) marked or pierced to simulate projectile impact point
24  DF  .~.~ Gun loading or projectile preparation (e.g., fuse setting, etc.)
25  DF  .~ Water warfare
26  DF  .~.~ Periscope view simulation
27  DF  .~ Range finding
28  DF  AIRCRAFT WIND DRIFT SIMULATION
29  DF  VEHICLE OPERATOR INSTRUCTION OR TESTING
30  DF  .~ Flight vehicle
31  DF  .~.~ Automatic pilot
32  DF  .~.~ Model viewed and maneuvered by trainee from point remote therefrom
33  DF  .~.~ Helicopter
34  DF  .~.~ Outer space vehicle
35  DF  .~.~ In flight
36  DF  .~.~.~ With simulation of night or reduced visibility flight
37  DF  .~.~ Aircraft, aircraft simulator, or means connected thereto traveling on ground or water during simulated flight training
38  DF  .~.~ Simulation of view from aircraft
39  DF  .~.~.~ View simulating means located on belt or cylinder
40  DF  .~.~.~ View simulating means located on element having spherical surface
41  DF  .~.~.~ Simulation of night or reduced visibility flight
42  DF  .~.~.~.~ Runway outlining or approach lights simulated
43  DF  .~.~.~ View simulated by cathode ray screen display
44  DF  .~.~.~ View simulated by projected image
45  DF  .~.~ Simulation of feel of control means (e.g., flight control stick, etc.)
46  DF  .~.~ Ground trainer agitated to simulate rough air buffeting or engine induced vibration of aircraft
47  DF  .~.~ Display or recordation of simulated flight path of ground trainer
48  DF  .~.~ Aircraft sound simulation
49  DF  .~.~ Aircraft or ambient condition simulated electrically or indicated by instrument or alarm
50  DF  .~.~.~ Takeoff or preparation therefor
51  DF  .~.~.~ Aircraft attitude (e.g., roll, etc.)
52  DF  .~.~.~ Ice formation or aircraft weight
53  DF  .~.~.~ Pressure
54  DF  .~.~.~ Propulsion means or accessory
55  DF  .~.~ Tiltable or turnable ground trainer
56  DF  .~.~.~ With fan or simulated propeller
57  DF  .~.~.~ With means for stabilizing trainer when idle
58  DF  .~.~.~ By fluid actuated piston/cylinder ram
59  DF  .~.~ Simulation of flight generated force applied to aircraft occupant
60  DF  .~ Sail-equipped vehicle
61  DF  .~ Bicycle or motorcycle
62  DF  .~ Automobile or truck
63  DF  .~.~ Model viewed and maneuvered by trainee from point remote therefrom
64  DF  .~.~ Driver's skill measured by time or vehicle travel distance
65  DF  .~.~ Recordation of driver's performance
66  DF  .~.~ Real vehicle used in instruction or testing
67  DF  .~.~.~ Vehicle positioned on rollers, belt, or platform
68  DF  .~.~.~ Obstacle or other means contacted by improperly driven vehicle
69  DF  .~.~ Simulation of view from vehicle
70  DF  .~.~.~ View simulating means located on belt or cylinder
71  DF  .~.~ Manipulation of gear shift lever or clutch pedal
72  DF  ARCHITECTURE, INTERIOR DECORATION, OR INDUSTRIAL PLANT LAYOUT
73  DF  .~ Magnet included in display or demonstration
74  DF  .~ Brick, tile, roofing, or siding
75  DF  .~ Curtain or wall, ceiling, or floor cover
76  DF  .~.~ Light, mirror, or image projector included in display or demonstration
77  DF  .~.~ Roller-mounted belt or strip included in display or demonstration
78  DF  .~.~ Plaque (e.g., disk, etc.) turnable relative to index (e.g., window in card, etc.) to selectively align different points on plaque therewith
79  DF  .~.~ Building or room interior represented pictorially or by model
80  DF  .~ Representation of furniture, bathroom or kitchen accessory, or cabinet placeable in different locations on representation of room interior
81  DF  VISUAL ART OR CRAFT, ARTISTIC ADORNMENT, OR COLOR TRAINING OR DEMONSTRATION
82  DF  .~ Sculpture or craft involving manual carving or shaping
83  DF  .~ Shape defined by filament (e.g., string, etc.)
84  DF  .~ Color application (e.g., painting, etc.)
85  DF  .~ Drawing
86  DF  .~.~ Animal or human body model having movable parts
87  DF  .~.~ Stencil
88  DF  .~.~ Tracing
89  DF  .~.~ Model support
90  DF  .~.~ Grid included in drawing aid or scene viewer
91  DF  .~.~ Perspective
92  DF  .~.~ Orthogonal projection
93  DF  .~ Flower arranging or landscaping
94  DF  .~ Hair or wig styling
95  DF  .~ Decorative sewing, needlework, weaving, or textile designing
96  DF  .~ Design formed of identical or complementary elements
97  DF  .~.~ Strips
98  DF  .~ Color display
99  DF  .~.~ Personal appearance or wearing apparel
100  DF  .~.~.~ Cosmetic or nail polish
101  DF  .~.~ Produced by spinning means (e.g., plural rotating color disks, etc.)
102  DF  .~.~ Produced by superposed color filters
103  DF  .~.~ Including mixing receptacle or holder for color material
104  DF  .~.~ Including relatively rotatable elements (e.g., concentrically mounted color disks, etc.)
105  DF  .~.~ Automobile
106  DF  ASTROLOGY
107  DF  BUSINESS OR ECONOMICS
108  DF  .~ Work schedule
109  DF  .~ Record keeping
110  DF  .~ Coin or currency identification or counterfeit detection
111  DF  CELESTIAL NAVIGATION
112  DF  COMMUNICATION AIDS FOR THE HANDICAPPED
113  DF  .~ Tactile reading aid (e.g., Braille, etc.)
114  DF  .~.~ Converting information to tactile output
115  DF  .~.~ Braille writing slate
116  DF  .~ Converting information to sound
117  DF  .~ Writing guide for the blind
118  DF  COMPUTER LOGIC, OPERATION, OR PROGRAMMING INSTRUCTION
126  DF  FLUID FLOW OR WAVE MOTION
127  DF  FOOD
128  DF  GAME, BOARD OR TABLE TYPE
129  DF  .~ Using playing card
130  DF  GEOGRAPHY
131  DF  .~ Terrestrial globe or accessory therefor
132  DF  .~.~ Relief globe
133  DF  .~.~ Having diverse use (e.g., pencil box, etc.)
134  DF  .~.~ Having magnet associated therewith
135  DF  .~.~ Having plural planar or curved surfaces (e.g., flat or frustoconical surfaces, etc.)
136  DF  .~.~ Rotated by mechanical drive
137  DF  .~.~ Collapsible or arranged for convenient assembly, disassembly, or storage
138  DF  .~.~.~ Inflatable
139  DF  .~.~ With means representing vehicle moving relative to earth
140  DF  .~.~.~ Space vehicle
141  DF  .~.~ With means indicating distance between points on earth
142  DF  .~.~ With means indicating time at different points on earth
143  DF  .~.~ With means demonstrating solar illumination of earth
144  DF  .~.~ With means demonstrating wind currents over earth
145  DF  .~.~ With internal light
146  DF  .~.~ With means to facilitate finding or reading indicia thereon
147  DF  .~.~ With map segment attachable thereto (e.g., continent, nation, etc.)
148  DF  .~.~ With suspension type support
149  DF  .~ Means indicating time at different points on earth
150  DF  .~ Map or terrain model
151  DF  .~.~ With model or sample of natural or man-made item associated therewith
152  DF  .~.~ Relief
153  DF  .~.~ Means for facilitating location of different points on map
154  DF  HISTORY OR GENEALOGY
155  DF  IDENTIFICATION OF PERSON OR HANDWRITING ANALYSIS
156  DF  LANGUAGE
157  DF  .~ Foreign
158  DF  .~ Shorthand
159  DF  .~ Alphabet letter formation, recognition, or sequencing
160  DF  .~.~ Letter formed by segments
161  DF  .~.~ Letter displayed upon manipulation of mechanism
162  DF  .~ Writing or printing by hand
163  DF  .~.~ Tracing
164  DF  .~.~.~ Slotted or grooved path
165  DF  .~.~ Writing sample included in teaching means
166  DF  .~.~ Mechanical means for teaching proper position of body part while writing
167  DF  .~ Spelling, phonics, word recognition, or sentence formation
168  DF  .~.~ Magnet included in teaching means
169  DF  .~.~ Electrical component included in teaching means
170  DF  .~.~ Color used in teaching means
171  DF  .~.~ Letter or word bearing elements (e.g., cards, blocks, etc.) with interfitting surface configurations
172  DF  .~.~ Letter-bearing elements (e.g., cards, blocks, etc.) selectively aligned to form word or sentence
173  DF  .~.~.~ Letter-bearing belt or reel-mounted strip
174  DF  .~.~.~ Rotatably mounted letter bearing element
175  DF  .~.~.~ Letter-bearing elements slidable between different grooves
176  DF  .~.~ Display of word or picture upon correct manipulation of teaching means
177  DF  .~.~ Crossword puzzle aid
178  DF  .~.~ Reading
179  DF  .~.~.~ Speed
180  DF  .~.~.~.~ Projected image of reading matter
181  DF  .~.~.~.~ Apertured mask moved past reading matter carrier
182  DF  .~.~.~.~ Reading matter carrier moved past viewing position
183  DF  .~.~.~.~ Pacer moved down reading matter carrier
184  DF  .~.~.~ Directionality training (e.g., for dyslexics, etc.)
185  DF  .~ Speech
186  DF  MAGNETIC OR GYRO COMPASS
187  DF  MEASUREMENT OF LENGTH OR VOLUME
188  DF  MATHEMATICS
189  DF  .~ Base conversion or use of base other than ten
190  DF  .~ Magnet included in teaching means
191  DF  .~ Arithmetic
192  DF  .~.~ Chalkboard or equivalent means having readily erasable surface
193  DF  .~.~ Manually manipulated numeral shaped elements
194  DF  .~.~ Numeric value represented by weight placed on balance
195  DF  .~.~ Manually manipulated elements having size proportional to numeric value
196  DF  .~.~.~ Fraction representing elements
197  DF  .~.~ Indicia-bearing belt or reel-mounted strip
198  DF  .~.~ Plaque (e.g., disk, etc.) turnable relative to index (e.g., window in card, etc.) to selectively align different points on plaque therewith
199  DF  .~.~ Plaque slidable relative to index (e.g., window in card, etc.) to selectively align different points on plaque therewith
200  DF  .~.~ Manually manipulated pin or peg
201  DF  .~.~ Electric component included in teaching means
202  DF  .~.~ Keyboard or like manually manipulated array (e.g., slides, levers, etc.)
203  DF  .~.~ Apertured elements threaded on elongate means (e.g., abacus, etc.)
204  DF  .~.~.~ Elements manually placed on or removed from elongate means during use
205  DF  .~.~ Means having number of marks (e.g., dots, etc.) or associated physical units (e.g., sticks, indentations, etc.) corresponding to numeric value
206  DF  .~.~ Rotatable wheel-shaped element (e.g., ring, disc, cylinder, etc.) having indicia on perimeter thereof
207  DF  .~.~ Color used in teaching means
208  DF  .~.~ Ball, block, or disk
209  DF  .~.~ Division or multiplication
210  DF  .~.~ Place value relative to decimal point
211  DF  .~ Geometry, trigonometry, or physical mathematic model structure
212  DF  .~.~ Pythagorean theorem
213  DF  .~.~ Property of sphere or spheroid
214  DF  .~.~ Property of circle or ellipse
215  DF  .~.~ Demonstration means using relatively turnable elements
216  DF  .~.~ Demonstration means using filament (e.g., string, etc.) to define geometric shape
217  DF  METEOROLOGY
218  DF  NUCLEAR ENERGY OR RADIOACTIVE RADIATION DETECTION OR SIMULATION
219  DF  OCCUPATION
220  DF  .~ Air traffic control
221  DF  .~ Audiometry
222  DF  .~ Code communication
223  DF  .~.~ Visual signalling
224  DF  .~ Electricity or electronics
225  DF  .~ Dairying, farming, ranching, or other occupation involving care of plants or animals
226  DF  .~ Fire fighting
227  DF  .~ Keyboard operation (e.g., typing, key punching, etc.)
228  DF  .~.~ Means for selectively illuminating character on simulated keyboard
229  DF  .~.~ Means for selectively rendering key operable or inoperable
230  DF  .~.~ Means for selectively producing sound of character
231  DF  .~.~ Practice keyboard having individually depressible keys
232  DF  .~.~.~ With means to display character upon depression of key
233  DF  .~.~ Means on hand or finger for indicating finger to be used
234  DF  .~ Soldering or welding
235  DF  PARLIAMENTARY PROCEDURE
236  DF  PSYCHOLOGY
237  DF  .~ Cooperation of plural pupils
238  DF  .~ Behavior or performance display (e.g., board for showing completed chores, etc.)
239  DF  RADIO NAVIGATION
240  DF  .~ Light sensor included in simulator of radio navigation equipment
241  DF  .~ Simulation of upwardly directed airfield or landing approach marker radio beam
242  DF  .~ Simulated radio signal generated by use of data storage means
243  DF  .~ Simulated bearing or position or vehicle relative to radio transmitter or directional beam indicated to trainee by instrument
244  DF  .~ Simulation of radio directional beam carrying Morse code signal
245  DF  RELIGION
246  DF  .~ Rosary
247  DF  PHYSICAL EDUCATION
248  DF  .~ Basketball
249  DF  .~ Bowling
250  DF  .~ Dancing
251  DF  .~ Football, soccer, or rugby
252  DF  .~ Golf
253  DF  .~ Skiing
254  DF  .~ Swimming
255  DF  .~ Traversing ground (e.g., crawling, running, etc.)
256  DF  .~ Body model with articulated parts
257  DF  .~ Picture or image of body included in display or demonstration
258  DF  .~ Developing or testing coordination
259  DF  .~.~ Associating dissimilar objects with apertures or pegs having matching size, shape, or color
260  DF  .~.~ Manipulation of tool or fastener (e.g., zipper, shoelaces, etc.)
261  DF  .~.~ Tracing
262  DF  ANATOMY, PHYSIOLOGY, THERAPEUTIC TREATMENT, OR SURGERY RELATING TO HUMAN BEING
263  DF  .~ Dentistry
264  DF  .~.~ Means mounting upper and lower tooth models for relative movement
265  DF  .~ Cardiac massage or artificial respiration
266  DF  .~ Simulation of body sound
267  DF  .~ Anatomical representation
268  DF  .~.~ Simulation of flow of body liquid
269  DF  .~.~ Including superposed sheets respectively depicting different body parts
270  DF  .~.~ Head or part thereof
271  DF  .~.~.~ Eye
272  DF  .~.~ Internal organ, blood vessel, or nerve
273  DF  .~.~.~ Female genital
274  DF  .~.~ Skeleton or bone
275  DF  .~.~.~ Palpation or manual force application (e.g., chiropractic adjustment, etc.)
276  DF  SCIENCE
277  DF  .~ Crystal structure model or display having discrete element (e.g., geometric shape, light, etc.) representing atom
278  DF  .~ Molecular model or display having discrete element representing atom or radical
279  DF  .~.~ Model having helical chain of elements (e.g., DNA model, etc.)
280  DF  .~.~ Atom or radical represented by element formed of sheet material
281  DF  .~ Model or display demonstrating structure or property of atom or radical
282  DF  .~.~ Indicia chart (e.g., periodic table, etc.)
283  DF  .~ Means demonstrating physical property (e.g., osmotic pressure, solubility, etc.) of substance
284  DF  .~ Astronomy
285  DF  .~.~ Representation of light generating celestial body
286  DF  .~.~.~ Light spot
287  DF  .~.~.~ Celestial globe
288  DF  .~.~.~.~ And earth representation
289  DF  .~.~.~ Finding or identifying aid
290  DF  .~.~.~ Simulation of sun and earth
291  DF  .~.~.~.~ Simulation of motion of earth and another major planet around sun
292  DF  .~.~.~.~ And moon
293  DF  .~.~.~.~.~ Moon model moved around earth model by mechanical or electrical means
294  DF  .~.~.~.~.~.~ By belt drive
295  DF  .~ Biology or taxidermy
296  DF  .~.~ Specimen display
297  DF  .~.~.~ Specimen enclosure
298  DF  .~ Chemistry or metallurgy
299  DF  .~ Geology
300  DF  .~ Physics
301  DF  .~.~ Electricity or magnetism
302  DF  .~.~ Statics or dynamics
303  DF  .~.~ Optics
304  DF  TELLING TIME OR CALENDAR READING
305  DF  VEHICLE MOVEMENT OR TRAFFIC ACCIDENT OR CONDITION
306  DF  VOTING MACHINE OR BALLOT MARKING
307 R  DF  CATHODE RAY SCREEN DISPLAY AND AUDIO MEANS
307 A  DF  .~ Karaoke
308  DF  AUDIO RECORDING AND VISUAL MEANS
309  DF  .~ Common carrier for visual means and audio recording
310  DF  .~.~ Carrier used with image projector
311  DF  .~.~ Card, sheet, or block
312  DF  .~.~.~ Reading head moved past stationary audio track
313  DF  .~.~.~.~ Manually
314  DF  .~ Image projector
315  DF  .~.~ With code on image carrier for controlling operation of apparatus
316  DF  .~.~ With code on audio carrier for controlling operation of apparatus
317  DF  .~ Visual information in book form
318  DF  .~ Audio recording on disk
319  DF  AUDIO RECORDING
320  DF  .~ Listener's voiced response recorded
321  DF  .~ Operation of apparatus controlled by listener's response to question or problem
322  DF  QUESTION OR PROBLEM ELICITING RESPONSE
323  DF  .~ Cathode ray screen display included in examining means
324  DF  .~ Image projector included in examining means
325  DF  .~.~ And light detector
326  DF  .~ Mark transfer sheet (e.g., carbon paper, etc.) included in examining means
327  DF  .~ Correctness of response indicated to examine by self-operating or examinee actuated means
328  DF  .~.~ Involving heat or chemical reaction
329  DF  .~.~ Involving fluid flow
330  DF  .~.~ Involving magnetic attraction
331  DF  .~.~ By optical element (e.g., mirror, color filter, lens, etc.)
332  DF  .~.~ Reward dispensed for correct answer
333  DF  .~.~ Picture or pattern completed by examinee placing plaques bearing portions thereof in correct relation
334  DF  .~.~ Hand-held element insertable to different depths in apertures respectively representing right and wrong answers
335  DF  .~.~ By means including electrical component
336  DF  .~.~.~ Response of plural examinees communicated to monitor or recorder by electrical signals
337  DF  .~.~.~ Light detector
338  DF  .~.~.~ Part of electric circuit completed when examinee places end of flexible lead, or means connected thereto (e.g., plug, etc.), in contact with another element
339  DF  .~.~.~ Part of electric circuit completed when examinee depresses portion of sheet having electric conductor associated therewith
340  DF  .~.~.~ Part of electric circuit completed when examinee places free element in contact with another element
341  DF  .~.~.~.~ Correct answer indicator lamp carried by free element
342  DF  .~.~.~ Question or problem located on endless belt or reel mounted strip
343  DF  .~.~.~ Size or shape of, or aperture in, free element controls indication of response correctness
344  DF  .~.~.~ Correct answer illuminated
345  DF  .~.~ Size or shape of, or aperture in, free element cntrols indication of response correctness
346  DF  .~.~ Correctness of response indicated when examinee physically alters element other than by marking it
347  DF  .~.~ Correct answer displayed on side of element opposite side displaying question or problem
348  DF  .~.~ Correct answer hidden until examinee moves element
349  DF  .~.~.~ Means for receiving examinee's written response
350  DF  .~ Response of plural examinees communicated to monitor or recorder by electrical signals
351  DF  .~.~ Wireless signals
352  DF  .~.~ With means for indicating first examinee to respond
353  DF  .~ Grading of response form
354  DF  .~.~ Comparison of response form with standard answer form
355  DF  .~.~.~ Light detector sensing response
356  DF  .~.~.~ Electrical means sensing conductive mark representing response
357  DF  .~.~.~ Means sensing aperture representing response
358  DF  .~.~ Light detector sensing response
359  DF  .~.~ Electrical means sensing conductive mark representing response
360  DF  .~.~ Means sensing aperture representing response
361  DF  .~.~ Means perforating response form at correct answer location
362  DF  .~ Electrical means for recording examinee's response
363  DF  .~ Card or sheet for receiving examinee's written, marked, or punched response
364  DF  .~.~ With apertured overlay
365  DF  MEANS FOR DEMONSTRATING APPARATUS, PRODUCT, OR SURFACE CONFIGURATION, OR FOR DISPLAYING EDUCATION MATERIAL OR STUDENT'S WORK
366  DF  .~ Means for simulating abnormal condition
367  DF  .~ Means for comparing characteristics of plural articles or materials
368  DF  .~ Superposed indicia bearing sheets, one depicting interior view
369  DF  .~ Means for displaying article at various stages of manufacture or treatment
370  DF  .~ Transparent means permitting interior view
371  DF  .~ Mirror for displaying something (e.g., apparel, hair style, etc.) as it would appear when associated with viewer
372  DF  .~ Aircraft, spacecraft, or component thereof
373  DF  .~ Land or water vehicle (e.g., automobile, boat, etc.) or component thereof
374  DF  .~.~ Servicing aid (e.g., lubrication chart, etc.)
375  DF  .~.~ Shock absorber or spring
376  DF  .~.~ Tire, wheel, or brake
377  DF  .~ Beauty aid or perfume
378  DF  .~ Burial means or grave maker
379  DF  .~ Demonstration or display of electrical apparatus or component
380  DF  .~.~ Motor or generator
381  DF  .~ Fluid filter
382  DF  .~ Household equipment
383  DF  .~.~ Refrigerator or air conditioner
384  DF  .~.~ Vacuum cleaner
385  DF  .~ Insulation
386  DF  .~ Jewelry or monogram
387  DF  .~ Lock or safe
388  DF  .~ Lubricant or lubrication
389  DF  .~ Mechanical power source (e.g., engine, windmill, etc.)
390  DF  .~ Mining
391  DF  .~ Pen or pencil
392  DF  .~ Sport equipment
393  DF  .~ Toy
394  DF  .~ Timepiece or component thereof
395  DF  .~ Wearing apparel
396  DF  .~.~ Displayed on doll or manikin
397  DF  .~.~ Footwear
398  DF  .~.~.~ Hose
399  DF  .~.~ Headwear
400  DF  .~.~ Neckwear
401  DF  .~ Machine mechanism
402  DF  .~ Rotatable element having indicia or picture on perimeter thereof
403  DF  .~ Block or like manually manipulatable object having indicia or picture on face thereof, or three-dimensional form for demonstrating shape
404  DF  .~ Plaque (e.g., disk, etc.) turnable relative to index (e.g., window in card, etc.) to selectively align different points on plaque therewith
405  DF  .~ Plaque slidable relative to index (e.g., window in card, etc.) to selectively align different points on plaque therewith
406  DF  .~ Jigsaw elements having indicia thereon
407  DF  .~ Manually manipulated pin or peg inserted into display board
408  DF  .~ Chalkboard or equivalent means having easily erasable surface
409  DF  .~.~ Mark formed by magnetic attraction between materials (e.g., particles in sheet made visible by movement of magnet over sheet, etc.)
410  DF  .~.~ Mark formed by bonding sheet to underlying surface with pressure-applying stylus (e.g., Magic Slate, etc.)
411  DF  .~.~ Erasable surface on endless belt
412  DF  .~.~ Erasable surface on reel-mounted sheet
413  DF  .~.~ Separate elements having erasable surfaces
414  DF  .~.~.~ Relatively swingable
415  DF  .~.~ With pencil holder or sharpener
416  DF  .~.~ With chart, illustration, or indicia
417  DF  .~.~ Chalkboard cleaning means, chalk or eraser holder, or chalk dust receiver
418  DF  .~.~ With ruler, straight edge, or holder therefor
419  DF  .~.~ Pivotal about horizontal axis
420  DF  .~.~ Vertically adjustable
421  DF  .~.~ Attached to wall
422  DF  .~.~ Hand-carried school slate
423  DF  .~.~.~ With rigid corner cap or separate means holding slate frame elements together
424  DF  .~.~.~ With cushion or noise muffler attached to slate frame
425  DF  .~.~ Artificial slate formed of plural constituents
426  DF  .~ Endless belt or reel-mounted strip having indicia thereon
427  DF  .~ Apertured mask placed over information bearing surface
428  DF  .~ Pictorial demonstration or display
429  DF  .~ Demonstration or display means combined with storage or collection means (e.g., receptacle, scoop, etc.)
430  DF  .~ Display panel, chart, or graph
431  DF  .~.~ Showing seat or desk location
432  DF  DESK, TABLE, OR STUDY BOOTH
433  DF  MISCELLANEOUS