CA1059272A - Electronic way to rapidly erase a blackboard - Google Patents

Abstract

ABSTRACT.

The advantages offered by the invention hereby applied for and enti-tled "An electronic way to rapidly erase a black-board" are the fol-lowing;
1)-It makes it possible to erase a blck-board mechanically instead of manually, which implies a considerable saving of time for the per-son who is using it and...
2)- It represents a large saving of funds for the School, Commission, University, Institution etc, which presently must hire a special staff whose duty is to make the turn of all the class rooms, in order to erase, at the end of each school day, all the black-boards.

Description

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The inventive idea which the new process embodies,c~ercomes and eli-m.nates the high cost and losa of time which were a'~ays present in the past,when a black-board har to be erased.The three attached dra-wings are illustrating it.In fast..
Sheet No.3.is an elevation in section of it.
Sheet No.~.is a pla~ view of this invention while..
Sheet No.5.illustrates in a larger scale,the details of what is shown on sheet No.3.
What is illustrated by the drawings can be described this wayj 10-,~ motor driven erasin~device comprisin~a_vertically elon~ated ,brush means _(l~)_of a_rectan~ular prism sha~e~vertically mounted for ,motion across the_width of and in contact_with a_black-board _(l~) ,with drive~ meanQ havin~an endless_belt ( 21J driven ,by a_r,eversible ,motor (l9~_and switch control means_(15~_b~ which t~e_reversib1e ,motor is switched off when the brush means ap~roaches_ one side_ed~e ,of the_black-board To make sure that the endless belt (21) is at all times tight enough to prevent it from slipping on the pulleys (22~) and not transmit-tind the motion to the brush means (13),the axle supporting the 20-pulley located at the extreme right end of the upper panel (22~) is permitted to move laterally being connected to a solid spring (24) which,if necessary can be tightened by turning clockwise the flange (2~ t the end of each run the brush means (13) which is put in motion just by putting a finger on the switch (27) and activa-ting the motor,will hit the switch control means (15)and stop the Page 1.

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motor which will reverse itself an~ make the brush means (13) go in the opposite ~irection,as soon as the switch (27) is once again pressed by a finger.
The brush means (13) is resting on springs (11) which are located 30-in the square casing (10) ~rhich forms part of the wheels means (~).
Said wheel means (~) which is resting on the track (9) supports the brush means (13) which moves horizontally back and forth,rub-bing against the black-board,when the motor (19) is activated.
To make sure that the pressure exercised by the brush means (13) against the black-board (lLi) is sufficient to erase rapidly what is written or illustrated on it,the track support (5) and the track (9~ which is bolted to it (and consequently the brush means (13~ ) can be made to move nearer said black-board,just by turning clock-wise the two fl-~nges (7).
40-The grease cups (25) are ment to eliminate the friction which may develop between the lateral outside part of the track (-9) and the casing ~10) due to the pressure caused by (6) means. ;
The wheels means (~) can,if required, be extracted from the track (9) for upkeeping,by moving it to nne of the two ends of said track which are open.
When one side of a brush after ha~ing been used repeatedly is too full of chalk and does not erase properly,it can be replaced by ano-ther clean side or face of the same brush,by pressing down on it (as made possible by the springs (llJ~getting it out of the upper 50-carriage (231,lifting it out of the square casing (10) and putting it back in its original position after rotating it 90 degrees.
When the brush means (13) is not in use,it will r6~; behind the side panels or casings (1~) where it is out of sight.
The upper panel or casing (1~) will hide at all time~ the upper mechanical parts.~ fluorescent (ne~n)electric tube (17) will illumi-nate the black-board when in use.
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The inventive idea described above may be used or put into opera-tion in two other ways providing that all parts composing it are made to be contained by a portable steel frame which should stand on wheels so that the whole unit can easily be mo~ed laterally and or in depth,as desired. In fact if the brushes instead of being li-ned wqth a soft cloth,a deep pile rug etc,are lined with sand pa-per,emery cloth etc,.the same inventive idea can be used for san-ding any flat surface.
.~190 if the brushes instead of being of a rectangular~rismatic sha-pe are made to be cylindrical,with some small alterations the same inventive idea can be used for painting any flat surface.

Page 3.

Claims (8)

1. CLAIMS.
   The embodiment of the invention in which an exclusive property or privilage is claimed, are defined as follows;
   
   I-A device for automatically erasing a black-board, comprising an elongated brushing means having two ends, one end being mounted on a carriage, said carriage being rigidly secured to an endless drive means, a fixed motor means engaging said endless drive means to pro-duce a movement of said carriage means, and limit switch means to li-mit said movement of said carriage means and the direction of rota-tion of said motor means, said device further comprising track means, said other end of said brushing means being slidably supported by said track means.
2. 2-A device for authomatically erasing a black-board as described in claim No.I above, by which the actual erasing is done by a vertically mounted brush means, the brushes being of a rectangular prism shape.
3. 3-A device for authomatically erasing a black-board as described in claim No.1 above, in which when the face or side of a brush which is in direct contanct with the black-board, get to be too full of chalk and does not erase properly any more, it can rapidly and promptly be replaced by another clean side or face of same brush, by pressing gently downward on it (as made possible by the fact that each brush rest on a biasing spring which can be compressed), extracting it from the upper carriage means and lifting it out of the track means which embodies a square casing which contains said biasing spring.
4. 4)-The device of claim No.I, wherein said drive means is a cable sup-ported on a plurality of pulleys.
5. 5- The device of claim No.4 wherein said drive means further compri-ses tensioning means to mantain tension in said cable.
6. 6-The device of claim No.I wherein said device is fixedly attached to said black-board.
7. 7-The device of claim No.1, wherein said device is supported in working relationship with said black-board.
8. 8-The device of claim No.1 wherein said device further comprises lighting means to illustrate said black-board.