GB2108434A - Electric blackboard eraser - Google Patents

Abstract

A blackboard cleaning device comprises a sponge eraser pad 21, a filter 31 covered with fabric 32, and a turbine fan 422 driven by an electric motor to create a suction force whereby chalk powder or particles are collected on the surface of the fabric to be accumulated in a lower transparent chamber 14. <IMAGE>

Description

SPECIFICATION Electric blackboard eraser A problem that has long been noticed, but still exists is the health of thousands and thousands of students and teachers in all schools being jeopardized with the chalk powder flying in the classroom; as a result, the learning interesting has badly been affected, and the learning efficiency has considerably be reduced.

In considering all the teachers who are working for educating our young generations on a long range plan of over one hundred yars, and in considering the students, the future leaders in the generations to come, we should definitely not overlook the problem of their being suffered from the chalk powder without doing something to improve it.

In view of the aforesaid fact, the inventor with a heart of serving our society has, thru repeated studies for years, developed the present invention, an electric blackboard eraser, which is so effective in solving the aforesaid problem.

Summary of the invention The object of this invention is to improve the defect of the general blackboard eraser, which causes many chalkpowder flying around during erasing, by providing a new electric blackboard eraser that can absorb and store the chalkpowder in said device to eliminate the powderfying around and to save the steps of cleaning the chalkpowder so as to maintain a clean environment, and to maintain the health of the teachers and the students as well.

The appearance of this invention is designed in a handle shape, which is conforming to the human engineering principle, for erasing convenience.

Since the sponge surface is designed in an arc shape, the absorbing scope has been increased considerably.

During erasing, the chalk powder will smoothly be sucked up by the absorbing force generated with the well-designed turbine type fan and the air passage.

Since the chalk powder is blocked by the sieve and the napped fabric, it will be fell into the chalk powder chamberforfurther handling.

Brief description of the drawings Figure 1 shows the isometric view of this invention.

Figure 2 shows a sectional view of this invention.

Figure 3 shows the isometric and exploded view of the tubine type fan in this invention.

Detailed description This invention, an electric blackboard eraser, comprises five major components, ie., a main body, the erasing means, the filter means, the driving means, and the powder supply means.

(1) Main Body: The main body comprises a body cover (11) and a handle (12), and has been designed in a shape conforming with the principle of human engineering for easily handling. During erasing, the chalkpowder will be absorbed into the fine pores (211) in the sponge eraser (21) by a sucking force generated by the driving means. When hitting the filter means, the chalkpowderwill be detained and accumulated in the powder storing space (13), while the air is sucked to pass thru the exhausting hole (15), and is filtered adequately. When the transparent powder chamber (14) is full with chalk powder, remove the chamber and clean it.

(2) Erasing Means: The erasing means comprises a sponge eraser (21) and a plastic panel (22). Said sponge eraser (21) is specially processed for wear and tear resistance, and for absorbing more chalkpowder with the fine pores (211). Said plastic panel (22) is used for supporting said sponge eraser (21), and is also furnished with many absorbing holes (221) as one of the air passages.

Since said eraser is designed in arc shape, it has a perfect and more contact area with the blackboard during erasing without leaving any powder on the surface of the blackboard, and without repelling the chalkpowder around the contact surface of said eraser (21) so as to have all powder being sucked into the powder chamber (14) thru the absorbing hole (221).

(3) FilterMeans: The filter means in the present invention comprises a filter sieve (31) having many meshes (311), and a piece of napped fabric (32) covering said sieve.

Since said napped fabric (32) is a thick and fine material, the absorbing force cannot let the powder pass thru said napped fabric (32) to reach to the area of the fan (42) and the motor (41); then,the powder being blocked ouside the napped fabric (32) will fall into the powder storing space (13). As soon as said space (13) is full with powder, pull out the powder chamber (14) and discard the powder.

(4) Driving Means: The driving means comprises a turbine type fan (42) and a motor (41) of series excitation type with carbon brushes. Said turbine type fan (42) is mounted on the motor axle (411) of said motor (41), and is covered with a shock absorbing rubber (421) for shock proof during operation so as to have the driving means being tightly attached to the body cover (11). Since the shock absorbing rubber (421) tightly covers the body (422) which has damping piece (424) and ventitation aperture (423), the air being exhausted would not be changed into a turbulent current within said body (422) before being smoothly exhausted thru the ventilation aperture (423) and the exhausting hole (15). Between said air fin (426) and said damping piece (424), a basin pad (425) is provided for the purposes of preventing from contact friction, and of better air concentration.

Since the motor (1) rotates under a rather light load state, a series-exciation-type motor with carbon brush is used for the purpose of generating high absorbing force under high speed rotation; therefore, the motor has the advantages of definitely absorbing powder, and of convenient operation.

(5) Power Supply Means: The power supply means comprises a switch (51), a power cord (52), and a power cord plug. Said switch (51) can set said eraser either in "ON" state (using) or in "OFF" state (not use). The power cord (52) and plug are used for conducting power; between the main body (1) and the power cord (52), an insulating rubber sleeve (53) is furnished to prevent from electric leak and damaging the power cord (52).

Finally, the features of the present invention are further described in detail as follows: (1) The erasing means is made of special sponge, and is an acr shape for a better absorbing and covering a larger area.

(2) The powder storing space is rather large so as to save the user from cleaning it quite often.

(3) The motor being in small size, a series excitation type with carbon brushes, 45-60 watts, 16000- 20000rpm, consumes less power.

(4) The turbine type fan with a thick and bigger slanting angle fins can generate an absorbing force so powerful that five-dollar coin may be sucked up.

(5) The ventilation means is perfect; for example, the motor is provided with an excellent air cooling system, it can always operate in an excellent condition.

(6) Lightweight, easily assembling and disassembling, an appearance conform to human engineering principle, and easily and conveniently operating are also the good features of the present invention.

Claims (7)

1. An electric eraser for erasing chalk from a blackboard comprising a body, an erasing means, a filter means, a driving means, means for absorbing chalk powder with an absorbing body generated by electric power and power supply means.

2. An eraser according to Claim 1 wherein the main body includes a handle, a cover and a chamber at least a part of which is made from a transparent material for housing erased chalk powder and an exhaust aperture.

3. An eraser according to Claim 1 or Claim 2 wherein the erasing means includes an arcuate sponge eraser and a supporting panel and an array of apertures passing through the eraser and the panel.

4. An eraser according to any preceding claim wherein the filter comprises a sieve and a filter cloth overlying the sieve.

5. An eraser according to Claim 1 wherein the driving means is a turbine.

6. An eraser according to Claim 5 wherein the turbine includes a fan having resilient blades, a basin pad, damping pieces and a body formed with ventilation apertures.

7. An electric eraser constructed as hereinbefore described and with reference to and as shown in the accompanying drawings.