Patents for B43L 21 - Blackboard or slate-cleaning devices (5,409) |
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05/12/1999 | CN2318051Y Blackboard brush |
05/05/1999 | CN2317098Y Electric dust collecting blockboard eraser |
04/28/1999 | CN2316147Y Dust-absorbing health-protecting blackboard eraser |
04/21/1999 | CN2314952Y Automatic eraser for black board |
04/21/1999 | CN2314949Y Automatic erasing dust-free black board |
03/31/1999 | CN2312134Y Dust-suction type blackboard eraser |
03/24/1999 | CN2311372Y Anti-dust wiper |
03/24/1999 | CN2311371Y Dustless chalk eraser |
03/10/1999 | CN2309960Y Dust-suction blackboard eraser |
03/10/1999 | CN2309959Y Light dust-proof blackboard traser |
03/03/1999 | CN2309238Y Dust-removing eraser |
02/24/1999 | CN2308517Y Rolling dust removing eraser |
02/24/1999 | CN2308516Y Dust absorbing eraser |
02/11/1999 | WO1999005939A1 Cleaning board |
02/10/1999 | CN2306893Y Sanitary blackboard eraser box |
01/27/1999 | CN2305299Y Dust absorption blackboard |
01/27/1999 | CN2305298Y Dustless blackboard |
01/20/1999 | EP0891880A1 Device for wet wipe off of blackboards |
01/19/1999 | CA2127143C Eraser system for stubborn dry erase marks |
01/13/1999 | CN1204587A Blackboard erasing machine capable of collecting chalk dust |
01/06/1999 | CN2302904Y Folding blackboard eraser |
01/06/1999 | CN2302903Y Device for absorbing chalk-dust |
01/06/1999 | CN2302902Y Dust-less blackboard wiper |
01/06/1999 | CN2302901Y Electrical blackboard wiper |
01/05/1999 | US5855442 Combined whiteboard marking pen and eraser |
12/30/1998 | CN2302138Y Dust-collecting chalk eraser |
12/23/1998 | CN2301333Y 无尘黑板擦 Clean eraser |
12/23/1998 | CN2301332Y Dust-removing blackboard eraser |
12/16/1998 | CN2300525Y 无尘黑板擦 Clean eraser |
12/09/1998 | CN2299727Y Eraser without chalk dust |
12/09/1998 | CN2299726Y Charging chalk dust absorbing eraser |
12/09/1998 | CN2299725Y Dust-proof eraser |
11/17/1998 | US5836038 Magnetic mount dry eraser |
11/11/1998 | CN2296828Y Chalk dust-proof blackboard eraser |
10/14/1998 | CN2294174Y Blackboard eraser with electrostatic dust absorbing means |
10/14/1998 | CN2294173Y Miniature and multi-function electric blackboard eraser with absorbing chalk dust means |
10/07/1998 | CN2293461Y Blackboard eraser with means for absorbing the chalk dust |
10/07/1998 | CN2293460Y Automatic cleaning chalk dust blackboard |
09/30/1998 | CN2292687Y Chalk dust removal blackboard eraser |
09/30/1998 | CN2292686Y Chalk dust absorbing blackboard eraser |
09/30/1998 | CN2292685Y Multifunctional chalk dust absorbing blackboard eraser |
09/23/1998 | CN2292032Y Dust-suction blackboard eraser |
09/23/1998 | CN2292031Y Electric brush for cleaning blackboard chalk dust |
09/16/1998 | CN2291317Y Rolling-type dust-removing eraser |
09/09/1998 | CN2290486Y Dust absorbing multi-hole eraser |
09/09/1998 | CN2290485Y Ash-proof eraser |
08/26/1998 | CN2288855Y Electric dust-removing, dust-absorption, filtering blackboard eraser |
08/26/1998 | CN2288854Y Electric dust absorption blackboard eraser |
08/26/1998 | CN1191181A Electric dust-proof blackboard eraser |
08/19/1998 | CN2288081Y Teaching writing blackboard without generating dust |
08/12/1998 | CN2287577Y Multifunctional dust absorbing blackboard eraser |
08/05/1998 | CN2287090Y Dustless brackboard eraser |
07/15/1998 | CN2286110Y Dustproof-blackboard eraser |
07/08/1998 | CN2285719Y 无尘黑板擦 Clean eraser |
06/03/1998 | CN2282993Y Dust-collecting blackboard eraser capable of replacing hairbrush |
06/03/1998 | CN2282992Y Electric dust-absorption blackboard eraser |
05/20/1998 | CN2281903Y Eraser device for blackboard |
04/29/1998 | CN2280013Y Static electricity blackboard eraser |
04/23/1998 | DE19730566C1 Device for wet wiping of wall blackboards used in schools |
03/25/1998 | CN2276882Y Dusting blackboard eraser |
03/11/1998 | CN2275952Y Electric blackboard eraser |
03/11/1998 | CN1175509A Dust-proof self-erasing blackboard |
03/04/1998 | CN2275526Y Eraser for absorbing chalk dust |
02/11/1998 | CN2274140Y Slide-rail for blackboard eraser |
01/21/1998 | CN2272824Y Multifunctional dustless hand-operated blackboard cleaning machine |
01/21/1998 | CN2272823Y Multifunctional dustless motor-driven blackboard cleaning machine |
01/21/1998 | CN2272822Y 粉笔擦 Chalk rub |
01/14/1998 | CN2272376Y Dust-proof eraser for blackboard |
01/14/1998 | CN2272375Y High-effect convenient eraser for chalk |
12/31/1997 | CN2271449Y Dust collecting cover of eraser |
12/31/1997 | CN2271445Y Dustless writing training aid |
12/10/1997 | CN2269967Y Chalk dust absorbing blackboard eraser |
12/03/1997 | CN2269320Y Hard resin glue cotton blackboard eraser and blackboard eraser box |
11/26/1997 | CN2268638Y Dust collecting blackboard eraser |
11/19/1997 | CN2267953Y 黑板擦擦体装置 Blackboard wipe body apparatus |
11/19/1997 | CN1165499A Writing board |
11/12/1997 | CN2267169Y Dustless blackboard wiper |
11/05/1997 | CN2266522Y Blackboard erazer |
11/05/1997 | CN2266521Y Double-eraser type blackboard |
10/29/1997 | CN2265912Y Dustless blackboard eraser |
10/29/1997 | CN2265911Y 吸尘黑板擦 Vacuum eraser |
10/22/1997 | CN2265305Y 黑板擦 Eraser |
10/15/1997 | CN2264678Y Dust-proof eraser |
10/15/1997 | CN2264677Y Enclosed eraser |
10/01/1997 | CN2263591Y Electric eraser |
09/24/1997 | CN2263010Y Charging dust-absorption blackboard eraser |
09/17/1997 | CN2262500Y Blackboard without hand to clean |
09/10/1997 | CN2261943Y Dust-removing blackboard eraser |
08/27/1997 | CN2260723Y Blackboard eraser |
08/19/1997 | US5658635 Bulletin board and accessory attaching mechanism |
08/13/1997 | CN2259298Y Combined blackboard eraser with dust-absorbing device |
08/13/1997 | CN2259297Y Blackboard eraser with device for absorbing the chalk dust |
08/13/1997 | CN2259295Y Improved wear-resistant electric blackboard |
07/30/1997 | EP0786358A1 Writing board |
07/22/1997 | US5649828 Water tank filled with water for erasing and decoloring the marked ink; carbon-free, dustless |
07/16/1997 | CN2257769Y Eraser |
07/16/1997 | CN2257768Y 无尘黑板擦 Clean eraser |
07/02/1997 | CN2257251Y Eraser with means for absorbing chalk dust |
07/02/1997 | CN2257250Y Eraser with dust remover |
06/25/1997 | CN2256828Y Blackboard eraser with means for absorbing chalk dust |