Brushing – scrubbing – and general cleaning – Machines – With air blast or suction
Reexamination Certificate
2002-04-09
2004-08-10
Till, Terrence R. (Department: 1744)
Brushing, scrubbing, and general cleaning
Machines
With air blast or suction
C015S403000
Reexamination Certificate
active
06772472
ABSTRACT:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not applicable.
BACKGROUND OF THE INVENTION
Many schools provide chalkboards and chalk for teachers to use as educational tools. The teachers write on the blackboards with the chalk and erase the writings with cotton head erasers, causing particles of chalk dust or powder to drift into the air. The floating chalk dust is harmful to health of the teachers and students.
As an alternative to conventional erasers, teachers may use a wet cloth to clear the chalkboard in order to reduce the amount of chalk dust polluting the air. A consequent problem with this method is that the teacher must wait until the board is dry before writing on it again with chalk, which is inconvenient for both teachers and students. In recent years, new ideas in improving chalk to produce less chalk dust have come to light. While somewhat reducing chalk dust, such chalk usually provide lighter writing and make scratching noises when in contact with a chalkboard.
Attention also has been given to erasers with vacuum devices, including motor-driven fans, which act to more efficiently collect dust particles. While these devices represent an advance in the art, improvements to such devices continue to be sought.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to an eraser for collecting dust, i.e., chalk dust, released from a surface, i.e., a chalkboard. The eraser includes a housing having a front wall to which is attached an eraser head. Extending through the front wall are a matrix of apertures. A controller, consisting in part of a single panel or a series of panels, is provided to selectively open and close the apertures in response to the orientation of the eraser as it contacts the chalkboard. Within the housing is a cavity and a collection chamber assembly. Attached to the eraser housing is a selectively energizeable suction device. When the suction device is energized, the controller selectively opens and closes the apertures and airborne chalk dust is drawn through the open apertures through the cavity and into the collection chamber assembly. Inside the collection chamber assembly the air is filtered, the chalk dust remaining in the collection chamber of the assembly, while filtered air is exhausted by the suction device.
Also disclosed is a method for collecting dust, i.e. chalk dust, released from a surface, i.e., chalkboard. The method includes the steps of providing an eraser such as described above, energizing the suction device, and moving the eraser across a chalkboard to collect chalk dust.
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