| Patents for B43L 21 - Blackboard or slate-cleaning devices (5,409) |
|---|
| 05/31/1995 | CN2199065Y Electric dust-absorbing blackboard eraser |
| 05/31/1995 | CN2199064Y Chalk brush |
| 05/17/1995 | CN2197232Y Duct-collecting blackboard eraser |
| 05/10/1995 | CN2196553Y Dustless high-efficiency blackboard eraser |
| 05/03/1995 | CN2196033Y Cover type ac blackboard wiper with dust adsorbing function |
| 04/26/1995 | CN2195451Y Blackboard eraser with absorbing chalk dust means |
| 04/19/1995 | CN2194825Y Automatic dust-reducing blackboard |
| 04/05/1995 | CN2193816Y Self-cleaning dust-proof blackboard |
| 03/29/1995 | CN2193262Y Enclosed dust collection eraser |
| 03/29/1995 | CN1100672A Method for mfg. dust adsorbing blackboard eraser, broom and curtain |
| 03/22/1995 | CN2192482Y Electric dust collecting eraser |
| 03/22/1995 | CN2192481Y Portable dust collecting eraser |
| 03/08/1995 | CN2191098Y Health teaching aid (health-type lift and fall Al alloy glass blackboard and health-type dusting blackboard eraser |
| 02/22/1995 | CN2190035Y Blackboard eraser |
| 02/15/1995 | CN2189540Y Electric-dusting eraser for blackboard |
| 01/25/1995 | CN2188040Y Centripetal rotary-brushing type dust-suction blackboard eraser |
| 01/04/1995 | CN2186670Y Electric dust-absorbing blackboard eraser |
| 01/04/1995 | CN2186669Y Convenient dust-absorbing blackboard brush |
| 12/28/1994 | CN2186169Y Dust catching eraser |
| 12/21/1994 | CN2185688Y Fully automatic dust-free blackboard eraser |
| 12/21/1994 | CN2185687Y Wet type blackboard eraser |
| 12/21/1994 | CN2185686Y Blackboard eraser with device for absorbing chalk dust |
| 12/14/1994 | CN2185209Y Dusting blackboard eraser |
| 12/07/1994 | CN2184576Y Dust collecting blackboard eraser |
| 12/07/1994 | CN2184575Y Dust collecting chalk eraser |
| 11/30/1994 | CN2183902Y Electric dust collecting blackboard eraser |
| 11/22/1994 | US5365631 Eraser carrier |
| 11/09/1994 | CN2182081Y Apparatus for cleaning board |
| 11/09/1994 | CN2182080Y Automatic eraser |
| 11/09/1994 | CN2182079Y Health eraser |
| 11/02/1994 | CN2181412Y Dust-proof blackboard eraser |
| 10/19/1994 | CN2179832Y Dust-collecting eraser |
| 10/04/1994 | US5351840 Combined chalk and eraser dispenser |
| 09/21/1994 | CN2177607Y Dust-obsorbing blackboard eraser |
| 09/21/1994 | CN2177602Y Automatic character-erazing blackboard |
| 09/07/1994 | CN2176264Y Automatic dust-removing blackboard eraser |
| 09/07/1994 | CN2176263Y Dust-free blackboard eraser |
| 09/07/1994 | CN2176262Y Automatic dust-removing blackboard eraser |
| 08/17/1994 | CN2174344Y Electric dust-absorbing wiper for blackboard |
| 08/10/1994 | CN2173714Y Dusting health blackboard eraser |
| 07/27/1994 | CN2172723Y Convenient blackboard eraser |
| 07/06/1994 | CN2170857Y Eraser with automatic dust catcher |
| 06/08/1994 | CN2167861Y Electric dust-collecting blackboard eracer |
| 05/25/1994 | CN2166020Y Magnetic wiper for chalk |
| 05/25/1994 | CN2166011Y Magnetic blackboard capable of scribbling & cleaning wantonly |
| 05/11/1994 | CN2164366Y Dustless blackboard eraser |
| 05/04/1994 | CN2163750Y Electric dust-absorbing eraser |
| 05/04/1994 | CN2163749Y Electric dust-absorbing eraser |
| 05/04/1994 | CN2163748Y Eraser-cleaning device |
| 04/27/1994 | CN2163083Y Dustless eraser |
| 04/20/1994 | CN2162366Y Automatic dust-collecting blackboard eraser |
| 04/20/1994 | CN2162365Y Electric dust-collecting blackboard eraser |
| 04/20/1994 | CN2162364Y Automatic blackboard eraser with dust collecting |
| 04/06/1994 | CN2160556Y Portable electric dust absorption bolackboard eraser |
| 04/06/1994 | CN2160555Y Dust-free blackboard eraser |
| 03/30/1994 | CN2159885Y Electric dust sucting blackboard eraser |
| 03/23/1994 | CN2159319Y Dust absorbing blackboard eraser |
| 03/23/1994 | CN2159318Y Dust absorbing blackboard eraser |
| 03/23/1994 | CN2159317Y Dust absorbing blackboard eraser |
| 03/23/1994 | CN2159316Y Dustless blackboard eraser |
| 03/23/1994 | CN2159315Y Dustless blackboard eraser |
| 03/16/1994 | CN2158794Y Quick-acting, light-weight and dustless eraser for blackboard |
| 03/09/1994 | CN2158347Y Magnetic dust-adsorption black board eraser |
| 02/23/1994 | CN2157051Y Chalk-dust collecting blackboard eraser |
| 02/23/1994 | CN2157050Y Water absorbing chalk dust cleaning blackboard eraser |
| 02/16/1994 | CN2156055Y 吸尘黑板擦 Eraser dust |
| 02/16/1994 | CN2156054Y Wet dustless blackboard eraser |
| 02/02/1994 | CN2154790Y Adjustable dust-collecting eraser |
| 02/02/1994 | CN2154789Y Dustless eraser |
| 01/26/1994 | CN2154183Y 电动清洁板擦 Electric cleaning eraser |
| 01/26/1994 | CN2154182Y Electric dust removing blackboard eraser |
| 01/26/1994 | CN2154181Y Electrostatic dust removing blackboard eraser |
| 01/26/1994 | CN2154180Y Blackboard eraser with collecting dust |
| 01/19/1994 | CN2153476Y Eraser with device for absorbing chalk dust |
| 01/12/1994 | CN2152688Y Dust-free blackboard eraser |
| 01/05/1994 | CN2151874Y Dust suction blackboard eraser |
| 01/05/1994 | CN2151873Y Static dust suction blackboard eraser |
| 01/05/1994 | CN2151816Y Electric dust cleaning brush |
| 01/04/1994 | US5274869 Automatic chalk ash cleaner |
| 12/29/1993 | CN2151020Y Dust collecting eraser |
| 12/29/1993 | CN2151019Y Dust self-absorbing eraser |
| 12/29/1993 | CN2151018Y Electric dust-absorbing eraser |
| 12/22/1993 | CN2150075Y Roller type blackboard-eraser with automatic dust collector |
| 12/15/1993 | CN2149301Y Black-board cleaner with function of absorbing chalk dust |
| 12/15/1993 | CN1079435A Electric dustless eraser |
| 12/08/1993 | CN2148688Y Blackboard eraser with means of absorbing chalk dust |
| 12/08/1993 | CN2148687Y Dust-reducing blackboard eraser |
| 12/01/1993 | CN2147974Y Dust-collecting blackboard eraser |
| 11/24/1993 | CN2147127Y Dust suction blackboard eraser |
| 11/17/1993 | CN2146380Y Health eraser |
| 11/17/1993 | CN2146379Y Dust collector for erasers |
| 11/10/1993 | CN2145715Y Long handle chalk powder brush |
| 11/04/1993 | DE4214682A1 Foldable partitioned container for storing writing and cleaning implements for blackboards - has stationary part fixed to wall and foldable part with insertable shell with partitions and ability to store water in closed or open positions |
| 11/03/1993 | CN2145123Y Purifying, dust-remove, light apparatus for blackboard |
| 10/20/1993 | CN2144064Y Non-electric dust-proof chalk eraser |
| 10/20/1993 | CN2144063Y Blackboard groove for collecting chalk dust |
| 10/13/1993 | CN2143562Y Dust absorption blackboard eraser |
| 09/30/1993 | WO1993018927A1 Tool for erasing black boards |
| 09/29/1993 | CN2142793Y Dust-collecting eraser for blackboard |
| 09/22/1993 | CN2142401Y Dust-removing blackboard eraser |