The invention relates to a board eraser including a compact structure and a light weight.

Typical board erasers comprise the following kinds:

• First, Taiwanese Patent Application No. 83213896 is entitled "disposable endless belt board eraser" and includes an endless rubbing cloth having an inner protruded rib extended therefrom, and each roller having a groove formed therein, for engaging with the inner protruded rib of the rubbing cloth, and for preventing the rubbing cloth from moving laterally when erasing the dust from the blackboard, and for increasing the frictional engagement between the rubbing cloth and the rear roller, and when forcing the board eraser onto the blackboard to move the rubbing cloth, the rear roller may be rotated by the rubbing cloth and the inner protruded rib, and the rear roller has two side transmission belts for rotating a dust loosening brush, and for forcing the dust loosening brush to move in a direction opposite to the rubbing cloth, and for removing the dust from the rubbing cloth and collected in a casing, however, the application has the following drawbacks:
  1. 1. the rollers include a curved structure and include a line-contact with the rubbing cloth and the rubbing cloth may be curved into the rollers such that the rubbing cloth may not be easily cleaned by the dust loosening brush.
  2. 2. the rubbing cloth may be curved and engaged into the curved rollers and may have a small contact area with the blackboard and thus may not suitably erase the dust from the blackboard.
  3. 3. the dust removed from the rubbing cloth will be collected in a casing, but the dust may flow into the air when moving the board eraser such that the dust may be breathed by people.
• Second, Taiwanese Patent Application No. 87206860 is entitled "vacuum board eraser" and includes a number of partitions disposed in a casing for positioning a rubbing cloth, and a spherical port for coupling to a joint of a vacuum device, and a remote control device disposed on the casing, however, the application has the following drawbacks:
  1. 1. the dust may be sticked onto the rubbing cloth such that the rubbing cloth may not be used to suitably erase the blackboard.
  2. 2. the dust may be sticked onto the rubbing cloth and may not be suitably vacuumed by the vacuum device unless the vacuum device includes a stronger power.
  3. 3. the vacuum device is coupled to the board eraser with a hose which may increase the weight of the board eraser and may interfere the erasing operation of the board eraser.
• Third, Taiwanese Patent Application No. 91221547 is entitled "improved board eraser" and includes the following drawbacks:
  1. 1. the dust may be sticked onto the rubbing cloth and may flow into the air when moving the board eraser such that the dust may be breathed by people.
  2. 2. the board eraser includes a vacuum device coupled to a hose for drawing and collecting the dust into the vacuum device, however, the hose may increase the weight of the board eraser and may interfere the erasing operation of the board eraser.

The inventor is to overcome the drawbacks and to develop the vacuum board eraser of the invention.

The invention is to provide a vacuum board eraser including a compact structure and a light weight.

The invention provides a vacuum board eraser comprising a receptacle including a chamber and a compartment formed on the upper portion and communicating with the chamber, a brush engaged into the chamber of the receptacle and disposed beside the communicating portion of the chamber and the compartment; a frame secured in the chamber of the receptacle, and including two rollers, and a rubbing cloth engaged around the rollers and engageable with the brush; a fan device engaged into the compartment and a motor coupled to the fan device for driving the fan device; a container attached to the receptacle and disposed between the chamber and the compartment, and the fan device draws the dust from the chamber of the receptacle into the container.

The receptacle includes two rails, the container includes two side tracks for engaging with the rails and for detachably attaching the container to the receptacle, and a dust net engaged into the container for collecting the dust. A cover is disposed on top of the compartment of the receptacle and a switch disposed on the cover, and a battery disposed in the compartment of the receptacle. One or more conductors are disposed on the receptacle and coupled to the battery for electrically coupling to a charging base. The frame includes two flaps each having an oblong hole for slidably receiving end blocks of spindles of the rollers, and a spring engaged with the end blocks of the spindles The receptacle includes a rim attached to the peripheral portion of the chamber of the receptacle and made of soft materials.

• FIGS. 1, 2 are partial exploded views of a board eraser;
• FIG. 3 is a perspective view of a roller supporting device,
• FIG. 4 is a bottom perspective view of the board eraser;
• FIG. 5 is a cross sectional view;
• FIG. 6 is a side plan view of the vacuum board eraser; and
• FIG. 7 is a partial exploded view of the vacuum board eraser.

10

receptacle

11

chamber

110

opening

12

space

120

rail

13

compartment

130

entrance

14

conductor

15

orifice

16

cover

17

switch

20

brush

30

rubbing cloth

40

roller

50

spindle

500

end block

51

spring

52

fastener

60

frame

61

gap

62

flap

63

oblong hole

70

rim

80

fan deice

81

motor

82

battery

90

container

900

side track

901

space

902

inlet

903

open end

91

dust bag or net

910

coupler

A

charging base

The invention is to improve the Chinese Patent Application No. ZL03236805.X , entitled "board eraser".

Referring to FIGS. 1-4, a vacuum board eraser comprises a receptacle 10, a brush 20, four rollers 40, a frame 60, a rubbing cloth 30, a rim 70, a fan device 80 and a container 90, wherein:

• the receptacle 10 includes a chamber 11 opened downwardly, a space 12 and a compartment 13 formed on the upper portion, an opening 110 communicating with the space 12, two sets of orifices 15 formed in two sides, two rails 120 disposed on two sides of the space 12, an entrance 130 communicating the compartment 13 with the space 12, conductors 14 disposed on one side of the compartment 13, a cover 16 disposed on top of the receptacle 10 and having a switch 17;
• the brush 20 is planar and attached in the chamber 11 of the receptacle 10 and disposed beside the opening 110 for contacting with one side of the rubbing cloth 30;
• the rollers 40 are rotatably disposed in the frame 60 with spindles 50, and the outer spindle 50 has two end blocks 500 each engaged with a spring 51;
• the frame 60 includes two flaps 62 for securing to the orifices 15 of the receptacle 10 with fasteners 52, and four gaps 61 for receiving the rollers 40, the flaps 62 each include an oblong hole 63 for slidably receiving the end blocks 500 of the outer spindle 50 and for receiving the spring 51;
• the rubbing cloth 30 is engaged around the rollers 40 and confined between the flaps 62 of the frame 60 for preventing the rubbing cloth 30 from being disengaged from the rollers 40;
• the rim 70 is made of soft materials for attaching to the peripheral portion of the chamber 11 of the receptacle 10, and the rim 70 may prevent the blackboard from being scratched by the board eraser;
• the fan device 80 is disposed in the compartment 13 and coupled to a motor 81 which may actuate the fan device 80 to draw the air and the dust through the entrance 130, four batteries 82 disposed in the compartment 13 for energizing the motor 81 and coupled to the conductors 14 for electrically coupling to a charging base A (FIG. 7);
• the container 90 includes two side tracks 900 for engaging with the rails 120 and for detachably attaching the container 90 to the receptacle 10, and includes a space 901 and an inlet 902 communicating with the opening 110 of the receptacle 10 for communicating with the chamber 11 of the receptacle 10, and includes an open end 903 for communicating with the entrance 130 of the receptacle 10, a dust bag or net 91 is engaged into the space 901 of the container 90 and includes a coupler 910 secured to the open end 903 of the space 901 of the container 90.

The rollers 40 and the spindles 50 may then be assembled and engaged into the frame 60 as shown in FIG. 3.

As shown in FIG. 4, the rubbing cloth 30 may erase the dust from the blackboard and may be moved into the chamber 11 of the receptacle 10, and the brush 20 may scrub the rubbing cloth 30 to remove the dust.

The switch 24 may be actuated to operate the fan device 80 which may draw the air and the dust through the opening 110 of the receptacle 10 and into the container 90, and the dust net 91 may block the dust to allow the dust to be collected in the container 90, and the container 90 may be easily disengaged from the receptacle 10 for dumping the dust.

As shown in FIGS. 5 and 6, the springs 51 may bias the end blocks 500 of the outer spindle 50 of the roller 40 at one end of the frame 60 to allow the roller 40 to be moved to straighten the rubbing cloth 30.

As shown in FIG. 7, the board eraser may be engaged into the charging base A which may charge the batteries 82 that are engaged in the compartment 13 of the receptacle 10.

The cover 16 may be disposed on top of the compartment 13 of the receptacle 10, and the batteries 82 may be changed with the new ones by opening the cover 16, after the batteries 82 have been consumed.

The receptacle 10 may include an electric cable coupled to the batteries 82 for energizing the batteries 82.

The invention has the following advantages:

1. 1. the rubbing cloth 30 is supported by the frame 60 and engageable with the brush 20 for allowing the rubbing cloth 30 to have a greater contact area with the blackboard.
2. 2. the dust removed from the rubbing cloth 30 by the brush 20 may be collected within the container 90 by the fan device 80.
3. 3. the fan device 80 is disposed in the receptacle 10 and will not interfere the operation of the board eraser.

The board eraser is not limited to the embodiment as shown in the drawings, but include the changing of the invention.