Vacuum board eraser

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.