Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS3509644 A
Publication typeGrant
Publication date5 May 1970
Filing date28 Jun 1968
Priority date28 Jun 1968
Publication numberUS 3509644 A, US 3509644A, US-A-3509644, US3509644 A, US3509644A
InventorsClaus Steven F, Powers Richard E, Santell Michael P
Original AssigneeSantell Michael P, Powers Richard E, Claus Steven F
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Self-cleaning blackboard
US 3509644 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)


M/a/ma 1. 5.4117644 E/cH/azoE.Pan draws F. 6420 9 QMAMPQLQM Bv ATTORNEY United States Patent SELF-CLEANIN G BLACKBOARD Michael P. Santell, 5545 S. 106th St., Hales Corners, Wis. 53130; Richard E. Powers, 6098 N. Hopkins St., Milwaukee, Wis. 53209; and Steven F. Claus, 1509 Manitowoc St., South Milwaukee, Wis. 53172 Filed June 28, 1968, Ser. No. 741,037

Int. Cl. B43] 1/00; G091? 7/04 US. Cl. 35-66 2 Claims ABSTRACT OF THE DISCLOSURE An immobile blackboard writing surface and a magnetic sheet on a top hinged panel behind it, whereby a ferrous material can be applied in writing on said writing surface and will remain thereon until the magnetic sheet is pulled out of magnetic range, whereupon the ferrous writing material will fall into a receptacle from which it may be reclaimed.

BRIEF SUMMARY OF THE INVENTION A fixed vertical writing surface of a plastic material has a backing of any suitable material, and behind said backing is a sheet of magnetic material such as Koroseal adhesively fixed to a top hinged sheet of rigid material. Ferrous material is applied to the writing surface by a writing implement and is retained in written form by the adjacent magnetic attraction, and when erasure is desired a lever or cord is used to move the magnetic sheet away from the writing surface. Removal of the magnetic attraction thus drops the ferrous material into a trough under the writing surface for reclamation and subsequent use.

FIG. 1 is a vertical cross-sectional view taken from the side of a board assembly embodying the invention.

FIG. 2 is a view in perspective of a self-erasing board assembly.

FIG. 3 is an enlarged fragmentary vertical cross-sectional view of the board elements in writing position.

FIG. 4 is a similar view of the rear panel in retracted position.

DETAILED DESORIPTION In FIG. 1, a back panel is shown, 10, attached to wall 11, with a bottom 12 and top 13 fronted by the frame element 14 and a plastic writing surface 15 adhesively or otherwise attached to the fixed panel 16. A rear panel 3,509,644 Patented May 5, 1970 17 is hinged at 18 of the top element 13 and is frontally covered by the magnetic sheet of Koroseal 19. The writing implement 20 applies ferrous material or shredded magnetic tape 21 to the writing surface where it is retained in form by the magnetic force of the Koroseal 19. To erase, a handle 22 attached to cord 23, in turn engaged about the pulley 24 and tethered at 25 to the lower portion at the rear of panel 17 may be pulled to remove the magnetic force by withdrawing the Koroseal from proximity to the Writing surface 15, allowing the material 21 to drop into a trough 26 from which it may be reclaimed for subsequent use.

It will be understood that the device is capable of many modifications in structure and design, without departing from the spirit of the invention, within the scope of the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent of the United States is:

1. A self-erasing blackboard including a fixed writing surface, a panel coextensive in area with said surface disposed behind said writing surface and hinged at its top to lie in close proximity with and to be displaced away from said writing surface, a magnetic sheet on the frontal surface of said hinged panel, means for writing with ferrous material on the writing surface, and means for withdrawing the hinged panel and magnetic sheet from proximity to said writing surface to free the ferrous material for subsequent use.

2. A device as in claim 1, including a backing fixed rearwardly of said writing surface sheet, and said means for withdrawing the hinged panel and attached magnetic sheet is a cord puller.

References Cited UNITED STATES PATENTS 1,881,140 10/1932 Settel 66 2,746,172 5/1956 Crow -1 35-19 3,093,919 6/1963 Holtz 142 EUGENE R. CAPOZIO, Primary Examiner H. S. SKOGQUIST, Assistant Examiner

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1881140 *23 Nov 19294 Oct 1932Benjamin SettelMemorandum pad
US2746172 *22 Jan 195422 May 1956Crow Leonard RMagnet holding block
US3093919 *6 Nov 195818 Jun 1963Hermann J HoltzMagnetic display arrangement
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4172333 *30 Aug 197730 Oct 1979Towsend Marvin SWriting and display apparatus
US4288936 *11 Oct 197915 Sep 1981Pilot Man-Nen-Hitsu Kabushiki KaishaWall-hanging type magnetic displaying device
US5018979 *16 Nov 198928 May 1991The Ohio Art CompanyMagnetic visual display
US5112229 *13 Mar 199112 May 1992The Ohio Art CompanyMagnetic visual display
US5295837 *7 May 199222 Mar 1994The Ohio Art CompanyMagnetic visual display
US5419706 *22 Jun 199330 May 1995Levy; Richard C.Apparatus for forming images of non-visible elements underlying an opaque surface
US6416329 *8 Aug 20009 Jul 2002Kyowa Electric And Chemical Co., Ltd.Writing device for practice in writing characters
U.S. Classification434/409, 40/621
International ClassificationB43L1/00
Cooperative ClassificationB43L1/008
European ClassificationB43L1/00M