| Patents for B43L 21 - Blackboard or slate-cleaning devices (5,409) |
|---|
| 06/04/1997 | CN2255370Y Closed dust-proof blackboard eraser |
| 06/04/1997 | CN2255369Y Dust-less blackboard eraser |
| 05/28/1997 | CN2254834Y DC/AC two purpose electric wiper with means for absorbing chalk dust |
| 05/14/1997 | CN2254044Y Dustless blackboard eraser |
| 05/07/1997 | CN2253701Y Chalk powder suction blackboard eraser |
| 04/30/1997 | CN2253300Y Automatic eraser |
| 04/16/1997 | CN2252119Y Self-erasing non-dust blackboard |
| 04/09/1997 | CN2251497Y Dust-removing eraser |
| 04/02/1997 | CN2250868Y Special duster for chalk brush |
| 03/26/1997 | CN2250265Y Electric dustless chalk brush |
| 03/26/1997 | CN2250261Y Fixed seat for white board pen and eraser |
| 03/04/1997 | US5607312 Writing board with an automatic erase device |
| 02/27/1997 | WO1997006963A1 Writing board |
| 02/26/1997 | CN2248134Y Rolling self dust-removing health blackboard |
| 02/05/1997 | CN2246588Y Automatic dust-absorbing eraser |
| 02/05/1997 | CN2246587Y Electric dust-absorbing eraser |
| 02/05/1997 | CN1141855A 自动黑板擦 Automatic eraser |
| 01/22/1997 | CN2245541Y No-dust eraser |
| 01/22/1997 | CN2245536Y Multipurpose automatic dust removing blackboard |
| 01/15/1997 | CN2245002Y Non-electric dust-absorbing blackboard eraser |
| 01/01/1997 | CN2243992Y Fully automatic dust absorption blackboard eraser |
| 01/01/1997 | CN2243991Y Health blackboard eraser |
| 01/01/1997 | CN2243990Y Adjustable dust collector |
| 01/01/1997 | CN2243989Y Drop-free blackboard eraser |
| 12/25/1996 | CN2243399Y Dustless chalk eraser |
| 12/25/1996 | CN2243398Y Rolling dust collecting blackboard eraser |
| 12/25/1996 | CN2243391Y Pore absorbing dustless blackboard |
| 12/18/1996 | CN2242799Y Electric dustless blackboard eraser |
| 12/11/1996 | CN1137452A Blackboard cleaning machine with automatic selector |
| 11/27/1996 | CN2241068Y Multipurpose moving blackboard eraser |
| 11/27/1996 | CN2241067Y Dust-removing blackboard eraser |
| 11/27/1996 | CN2241066Y Magnetic eraser |
| 11/20/1996 | CN2240444Y Dust-suction eraser for blackboard |
| 11/13/1996 | CN2239896Y Dust-collecting eraser |
| 11/06/1996 | CN2239356Y Dust collecting eraser |
| 10/30/1996 | CN2238748Y Eraser cleaner cabable of feeling chalk dust capacity |
| 10/23/1996 | CN2238150Y Writing board with eraser |
| 10/09/1996 | CN2236955Y Dust-proof chalk eraser |
| 09/25/1996 | EP0733491A1 Eraser system for stubborn, dry erase marks |
| 09/25/1996 | CN2235906Y Electric dust-collecting blackboard eraser |
| 09/25/1996 | CN2235905Y Dust-collecting blackboard eraser |
| 09/25/1996 | CN2235904Y Dust-collecting blackboard eraser |
| 09/11/1996 | CN2234868Y Sound-deadening blackboard dust-collector |
| 09/11/1996 | CN2234867Y Dust-proofing eraser |
| 09/04/1996 | CN2234361Y Chalk dust collecting box |
| 08/21/1996 | CN2233325Y Wet-type dust-absorbing eraser |
| 08/21/1996 | CN2233323Y Chalk dust ledge with dust-collecting cup |
| 08/14/1996 | CN2232850Y Electric dust-proof eraser |
| 08/07/1996 | CN2232359Y Eraser without storing chalk powder |
| 07/23/1996 | US5537711 Electric board cleaner |
| 07/17/1996 | CN2231186Y Closed dust-proof blackboard eraser |
| 07/10/1996 | CN2230668Y Closed dust collecting blackboard eraser |
| 07/03/1996 | CN2230239Y Dust-collected blackboard eraser |
| 07/03/1996 | CN1125665A Writing board device |
| 06/12/1996 | CN2228850Y Blackboard eraser |
| 05/22/1996 | CN2227677Y Indoor static pressure pile rack |
| 05/08/1996 | CN2226636Y Automatic tracking screen window for sliding window |
| 05/01/1996 | CN2225975Y Electroless health teaching brush |
| 04/10/1996 | CN2224100Y Ashless convenient eraser for blackboard |
| 03/27/1996 | CN2223201Y Electric cleaning and dust absorbing eraser |
| 03/20/1996 | CN2222626Y Motor-driven dust-collecting blackboard eraser |
| 03/06/1996 | CN2221502Y Dust-collecting eraser |
| 03/06/1996 | CN2221501Y Whole-plate fixed automatic dustless eraser |
| 02/14/1996 | CN2219799Y Dust-collecting blackboard eraser |
| 02/14/1996 | CN2219798Y Multifunctional electric dust-collecting blockboard eraser |
| 02/14/1996 | CN2219797Y 无尘黑板擦 Clean eraser |
| 02/07/1996 | CN2219217Y Electric eraser capable of absorbing chalk dust |
| 02/07/1996 | CN2219216Y Blackboard eraser with means for absorbing chalk dust |
| 02/07/1996 | CN2219215Y 黑板清洁器 Blackboard cleaner |
| 01/31/1996 | CN2218660Y Dust-proof chalk brush and chalk box |
| 01/24/1996 | CN2218090Y Blackboard eraser with dust collector |
| 01/17/1996 | CN2217523Y Dust-proof chalk eraser |
| 01/10/1996 | CN2216933Y Wiper for blackboard |
| 01/03/1996 | EP0689942A1 Writing board device |
| 12/27/1995 | CN2215999Y Chalk dust-catching blackboard eraser |
| 12/06/1995 | CN2214304Y Eraser |
| 12/06/1995 | CN2214303Y Dust removing eraser |
| 11/29/1995 | CN2213644Y Anti-dust eraser |
| 11/22/1995 | CN2213082Y Eraser cleaner |
| 11/01/1995 | CN2211370Y Dust collecting blackboard eraser |
| 10/18/1995 | CN2210107Y Blackboard wiper and chock dust remover |
| 10/18/1995 | CN2210106Y Dust-proof blackboard wiper |
| 10/18/1995 | CN1110224A Blackboard eraser with dust-absorbing function |
| 10/11/1995 | CN2209606Y Blackboard cleaning device |
| 10/10/1995 | US5455976 Apparatus for automatically brushing chalk powder off from a blackboard eraser |
| 10/04/1995 | CN2209054Y Double dust-collecting brush |
| 10/04/1995 | CN2209053Y Healthy blackboard eraser |
| 08/29/1995 | US5445420 Footprint configuration sponge and base novelty device |
| 08/09/1995 | CN2204728Y Blackboard eraser with telescopic handle |
| 08/02/1995 | CN2204243Y Electric dust-collecting blackboard eraser |
| 07/26/1995 | CN2203933Y Blackboard eraser with means for adsorbing chalk dust |
| 07/18/1995 | US5432973 Eraser system for stubborn dry erase marks |
| 07/12/1995 | CN2203230Y Dedusting blackboard eraser |
| 07/05/1995 | CN2202653Y Electric erasing dust suction device |
| 07/05/1995 | CN2202652Y Suction type electric blackboard eraser |
| 07/05/1995 | CN2202651Y Dustless blackboard eraser |
| 07/05/1995 | CN2202650Y Blackboard eraser |
| 06/28/1995 | CN2201831Y Multi-purpose scrubbing brush |
| 06/21/1995 | CN2201263Y Dust-collecting eraser |
| 06/21/1995 | CN2201262Y Enclosed dustless eraser |