Vacuum board eraser

Abstract

A board eraser includes a receptacle having two side walls and two end walls and an oblong hole formed in each of the side walls, a roller rotatably attached to the receptacle with a spindle, another roller having a shaft slidably attached to the receptacle, an endless rubbing cloth member engaged around the rollers, and one or more spring members for biasing the rollers away from each other to straighten the rubbing cloth member, a backing device may be used for backing the rubbing cloth member, and a brush device may scrub the dust from the rubbing cloth member, a resilient peripheral rim may be attached to the receptacle for softly engaging with the blackboard.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a board eraser, and more particularly to a vacuum board eraser including an improved structure for straightening the rubbing cloth member and for allowing the rubbing cloth member to suitably erase the blackboard and for preventing the rubbing cloth member from becoming loose relative to the supporting receptacle.

2. Description of the Prior Art

Typical board erasers comprise a dust loosening brush for engaging onto the blackboard and for erasing and removing the dust from the blackboard on which the exercises are written by means of chalk.

For example, U.S. Pat. No. 1,552,713 to Leary discloses one of the typical blackboard erasing devices also comprising a dust loosening brush including one or more longitudinal strips and one or more lateral strips attached to a supporting plate for engaging onto the blackboard and for erasing and cleaning the blackboard, and an air exhausting device is further provided and coupled to the strips for vacuuming and removing the dust from the blackboard.

However, the strips may not be moved relative to the blackboard such that the dust may not effectively or easily flow through the intervening passages formed between the strips and may not be effectively drawn by the air exhausting device. In addition, the air exhausting device includes a complicated structure having a great volume such that the typical blackboard erasing device may not be easily carried or operated by the users.

U.S. Pat. No. 1,801,620 to Bettman discloses another typical vacuum board eraser comprising a set of felt strips attached to a rotary shaft with a drum for erasing and cleaning the blackboard, and a fan device coupled to a motor for drawing and collecting the dust into a dust bag. However, the felt strips may not be easily operated to remove the dust from the blackboard. In addition, the dust may be drawn through the fan device and the motor such that the fan device and the motor may be easily contaminated and may be easily damaged.

U.S. Pat. No. 4,941,225 to Liao discloses a further typical automatic chalk-powder collecting device for a board eraser comprising a rubbing cloth engaged around two rollers for engaging onto the blackboard and for erasing and cleaning the blackboard, and a bristle device biased to engage with the rubbing cloth with several springs. However, the rubbing cloth may not be suitably straightened, in addition, the bristle device may be forced against the rubbing cloth by the springs such that the rubbing cloth may be quickly rubbed or scraped and damaged by the bristle device and the springs.

U.S. Pat. No. 5,537,711 to Tseng discloses a still further typical electric board cleaner comprising an absorbing head having a cleaning pad for engaging onto the blackboard and for erasing and cleaning the blackboard, and a fan device coupled to a motor for drawing and collecting the dust into a dust net. However, the cleaning pad may not be moved relative to the supporting and absorbing head such that the dust may not effectively or easily flow into the absorbing head and may not be effectively drawn by the motor-powered fan device.

The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional vacuum board erasers.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to provide a vacuum board eraser including an improved structure for straightening the rubbing cloth member and for allowing the rubbing cloth member to suitably erase the blackboard and for preventing the rubbing cloth member from becoming loose relative to the supporting receptacle.

The other objective of the present invention is to provide a vacuum board eraser including an improved structure for preventing the rubbing cloth member from being forcefully rubbed or scraped and damaged by the bristle or brush device.

In accordance with one aspect of the invention, there is provided a board eraser comprising a receptacle including a chamber formed therein, and including two side walls and two end walls for forming the chamber of the receptacle, and including an oblong hole formed in each of the side walls and located at a first end portion of the receptacle, and the receptacle including a second end portion, a first roller rotatably engaged in the chamber of the receptacle and attached to the receptacle with a spindle, and located at the second end portion of the receptacle, a second roller rotatably engaged in the chamber of the receptacle with a shaft, and the shaft including two end portions slidably engaged through the oblong holes of the side walls of the receptacle for allowing the shaft and the second roller to be moved and adjusted relative to the receptacle, an endless rubbing cloth member rotatably engaged around the first and the second rollers and partially extended out of the receptacle for engaging with a blackboard and for erasing a dust from the blackboard, at least one spring member coupled between the receptacle and the shaft for biasing and moving the shaft and the second roller away from the spindle and the first roller and for straightening the rubbing cloth member, a backing device engaged into the chamber of the receptacle and secured to the receptacle, and including a board for engaging with the rubbing cloth member and for allowing the rubbing cloth member to engage with the blackboard, and a brush device engaged into the chamber of the receptacle and attached to the receptacle and arranged for engaging with the rubbing cloth member and for scrubbing and removing the dust from the rubbing cloth member. The rubbing cloth member may be suitably straightened for allowing the rubbing cloth member to suitably erase the blackboard and for preventing the rubbing cloth member from becoming loose relative to the receptacle, and the rubbing cloth member may be prevented from being forcefully rubbed or scraped and damaged by the bristle or brush device.

The receptacle includes a stud extended outwardly therefrom and coupled to the spring member. The backing device includes two flaps extended from the board and secured to the receptacle with at least one fastener.

The receptacle includes a peripheral rim attached to the side walls and the end walls of the receptacle for engaging with the blackboard. The receptacle includes an outlet port formed in a first end wall of the end walls, and a nozzle coupled to the outlet port for coupling to a vacuuming device.

The receptacle includes a ball socket attached to the first end wall of the receptacle and located around the outlet port of the receptacle, and the nozzle includes a spherical member rotatably coupled to the ball socket. The ball socket preferably includes two half members to be secured together.

Further objectives and advantages of the present invention will become apparent from a careful reading of the detailed description provided hereinbelow, with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan schematic view illustrating an application of a vacuum board eraser in accordance with the present invention for a blackboard;

FIG. 2 is a partial side plan schematic view illustrating the operation of the vacuum board eraser for erasing and cleaning the blackboard;

FIG. 3 is a partial exploded view of the vacuum board eraser;

FIG. 4 is a bottom perspective view of the vacuum board eraser, in which a portion of the vacuum board eraser has been cut off for showing an inner structure of the vacuum board eraser;

FIG. 5 is a bottom perspective view illustrating a rubbing device of the vacuum board eraser,

FIG. 6 is another bottom perspective view of the rubbing device of the vacuum board eraser in which a portion of the rubbing device has been cut off for showing an inner structure of the rubbing device;

FIG. 7 is a partial exploded view similar to FIG. 3, illustrating the other arrangement of the vacuum board eraser; and

FIG. 8 is a partial exploded view similar to FIGS. 3 and 7, illustrating the further arrangement of the vacuum board eraser.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings, and initially to FIGS. 1 and 2, a vacuum board eraser 1 in accordance with the present invention is provided for being engaged with the blackboard 8 and for erasing and removing the dust from the blackboard 8 on which the exercises are written by means of chalk, and comprises an outer supporting receptacle 10 including a chamber 11 formed therein and formed or defined by two side walls 12 and two end walls 13, and including an oblong hole 14 formed in each of the side walls 12 and located at one end portion 15 of the receptacle 10, and the oblong holes 14 of the two side walls 12 of the receptacle 10 are preferably arranged parallel to each other.

One or more (such as two) pegs or studs 16 are extended outwardly from the receptacle 10, such as extended outwardly from the side walls 12 and also located at the end portion 15 of the receptacle 10, and preferably but not necessarily parallel or aligned with the oblong holes 14 of the side walls 12. The receptacle 10 further includes an outlet port 17 formed in the receptacle 10, such as formed in one of the end walls 13 of the receptacle 10 and located at the other end portion 18 of the receptacle 10. A ball socket 20 includes such as two half members 21 attached or secured to the end wall 13 of the receptacle 10 and located around the outlet port 17 of the receptacle 10.

For example, the two half members 21 of the ball socket 20 each include a substantially semi-spherical recess 22 formed therein for rotatably or pivotally receiving a ball or spherical member 23 of a nozzle 24 and for allowing the nozzle 24 to be rotated or pivoted relative to the receptacle 10. The nozzle 24 may be provided and coupled to an air exhausting device or vacuuming device 80 with such as a hose 81 for vacuuming and removing the dust collected within the chamber 11 of the receptacle 10 and removed from the blackboard 8 and then for allowing the dust to be collected within a dust bag, a dust net (not shown) or the like, and thus for preventing the dust from flowing out of the receptacle 10.

A roller 30 is rotatably attached or engaged into the chamber 11 of the receptacle 10 with a spindle 31, and preferably located at the other end portion 18 of the receptacle 10 and the spindle 31 and the roller 30 are preferably arranged in parallel to the end walls 13 and the lateral direction or Y-direction of the receptacle 10, and perpendicular to the side walls 12 and the longitudinal direction or X-direction of the receptacle 10, another roller 32 is rotatably attached or engaged into the chamber 11 of the receptacle 10 with a shaft 33 which includes two end portions 34 slidably engaged through the oblong holes 14 of the two side walls 12 of the receptacle 10, best shown in FIG. 4 for allowing the shaft 33 to be moved or adjusted relative to the receptacle 10.

An endless rubbing cloth member 35 is engaged onto or around the rollers 30, 32 and partially extended out of the receptacle 10 (FIG. 2) for engaging onto the blackboard 8 and for erasing and cleaning the blackboard 8. One or more (such as two) spring members 36 are further provided and attached or engaged onto the end portions 34 of the shaft 33 and attached or engaged or coupled to the pegs or studs 16 for applying a spring biasing force against the shaft 33 and the roller 32 to move or force the shaft 33 and the roller 32 away from the spindle 31 and the roller 30, and for suitably straightening the rubbing cloth member 35 and for allowing the rubbing cloth member 35 to suitably engage with the blackboard 8 and to suitably erase the blackboard 8 and thus for preventing the rubbing cloth member 35 from becoming loose relative to the receptacle 10.

An anvil or backing device 40 is further provided and attached or engaged into the chamber 11 of the receptacle 10 and secured to the receptacle 10 with one or more fasteners 41, for example, the backing device 40 includes a base board 42 for engaging with the rubbing cloth member 35 and for allowing the rubbing cloth member 35 to suitably engage with the blackboard 8 and to suitably erase the blackboard 8, and includes two flaps 43 extended from the base board 42 for securing to the receptacle 10 with the fasteners 41, and arranged for allowing the board 42 to suitably engage with or to anchor or to support the rubbing cloth member 35, best shown in FIGS. 4-6.

A bristle or brush device 50 is attached or engaged into the chamber 11 of the receptacle 10 and secured to the receptacle 10 with one or more fasteners or latches (not shown), or with adhesive materials or by welding processes, and arranged for engaging with the rubbing cloth member 35 (FIG. 2), and arranged for allowing the rubbing cloth member 35 to be suitably scrubbed by the bristle or brush device 50 in order to suitably scrub or scrape and remove the dust from the rubbing cloth member 35. The rubbing cloth member 35 and the rollers 30, 32 may thus be formed or acted as a rubbing means or device 35 for erasing and removing the dust from the blackboard 8.

One or more soft peripheral flanges or beads or rims 60 may further be provided and selectively or changeably attached or engaged onto the bottom peripheral portion of the side walls 12 and the end walls 13 of the receptacle 10, and arranged for determining or for changing the outwardly extending distance “d” of the rubbing cloth member 35 form the receptacle 10 (FIG. 2), and for allowing the air to be suitably drawn into the chamber 11 of the receptacle 10. The rims 60 are preferably made of rubber or plastic or other soft or resilient materials for softly engaging with the blackboard 8 and for preventing the blackboard 8 from being scrubbed or scraped or damaged by the receptacle 10.

As shown in FIG. 1, the receptacle 10 may further include a control switch 19 disposed thereon for allowing the users to easily actuate or operate the vacuuming device 80 with the switch 19. In operation, as also shown in FIG. 1, the receptacle 10 may be moved relative to the blackboard 8 laterally along the Y-direction of the receptacle 10 in order to engage with the blackboard 8 and to erase and remove the dust from the blackboard 8. In this moment, the rubbing cloth member 35 will not be rotated relative to the receptacle 10. After the dust has been erased with the rubbing cloth member 35, the receptacle 10 may then be moved relative to the blackboard 8 longitudinally along the X-direction to force the rubbing cloth member 35 to rotate or move relative to the receptacle 10.

When the rubbing cloth member 35 is caused to be rotated or moved relative to the receptacle 10, the dust engaged onto the rubbing cloth member 35 may be scrubbed or scraped or removed from the rubbing cloth member 35 by the brush device 50. The vacuuming device 80 may then be actuated or operated with such as the control switch 19 in order to vacuum and remove the dust disengaged from the rubbing cloth member 35 and collected within the chamber 11 of the receptacle 10 and/or removed from the blackboard 8. It is to be noted that the rubbing cloth member 35 may be suitably straightened by the spring members 36 in order to suitably engage with the blackboard 8 and to suitably erase the blackboard 8 and the dust may be suitably vacuumed and removed and disengaged from the rubbing cloth member 35 and collected by the vacuuming device 80.

As shown in FIG. 7, alternatively, the rollers 30, 32 may also be directly and rotatably attached or secured to the flaps 43 of the backing device 40, and the backing device 40 may include one or more (such as two) pegs or studs 44 extended outwardly from the flaps 43 of the backing device 40 for engaging with or coupling to the spring members 36 in order to suitably straighten the rubbing cloth member 35 and for allowing the rubbing cloth member 35 to suitably engage with the blackboard 8. Further alternatively, as shown in FIG. 8, the receptacle 10 may include one or more (such as two) rails 71 attached to one of the end walls 13 of the receptacle 10, and a container 72 coupled to the receptacle 10 with the rails 71 for closing the outlet port 17 of the receptacle 10 and for receiving and collecting the dust removed from the rubbing cloth member 35 by the brush device 50.

Accordingly, the vacuum board eraser in accordance with the present invention includes an improved structure for straightening the rubbing cloth member and for allowing the rubbing cloth member to suitably erase the blackboard and for preventing the rubbing cloth member from becoming loose relative to the supporting receptacle, and for preventing the rubbing cloth member from being forcefully rubbed or scraped and damaged by the bristle or brush device.

Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the detailed construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.

Claims

1. A board eraser comprising: a receptacle including a chamber formed therein, and including two side walls and two end walls for forming said chamber of said receptacle, and including an oblong hole formed in each of said side walls and located at a first end portion of said receptacle, and said receptacle including a second end portion, a first roller rotatably engaged in said chamber of said receptacle and attached to said receptacle with a spindle, and located at said second end portion of said receptacle, a second roller rotatably engaged in said chamber of said receptacle with a shaft, and said shaft including two end portions slidably engaged through said oblong holes of said side walls of said receptacle for allowing said shaft and said second roller to be moved and adjusted relative to said receptacle, an endless rubbing cloth member rotatably engaged around said first and said second rollers and partially extended out of said receptacle for engaging with a blackboard and for erasing a dust from said blackboard, at least one spring member coupled between said receptacle and said shaft for biasing and moving said shaft and said second roller away from said spindle and said first roller and for straightening said rubbing cloth member, a backing device engaged into said chamber of said receptacle and secured to said receptacle, and including a board for engaging with said rubbing cloth member and for allowing said rubbing cloth member to engage with said blackboard, and a brush device engaged into said chamber of said receptacle and attached to said receptacle and arranged for engaging with said rubbing cloth member and for scrubbing and removing the dust from said rubbing cloth member.

2. The board eraser as claimed in claim 1, wherein said receptacle includes a stud extended outwardly therefrom and coupled to said at least one spring member.

3. The board eraser as claimed in claim 1, wherein said backing device includes two flaps extended from said board and secured to said receptacle with at least one fastener.

4. The board eraser as claimed in claim 1, wherein said receptacle includes a peripheral rim attached to said side walls and said end walls of said receptacle for engaging with said blackboard.

5. The board eraser as claimed in claim 1, wherein said receptacle includes an outlet port formed in a first end wall of said end walls, and a nozzle coupled to said outlet port for coupling to a vacuuming device.

6. The board eraser as claimed in claim 5, wherein said receptacle includes a ball socket attached to said first end wall of said receptacle and located around said outlet port of said receptacle, and said nozzle includes a spherical member rotatably coupled to said ball socket.

7. The board eraser as claimed in claim 6, wherein said ball socket includes two half members.