Patent ID: 6986704

Claim:
A sand belt-tensioning device comprising: a drive roller adapted to permit a sand belt to be wound therearound, said drive roller including a roller body having opposite first and second end surfaces, and aligned first and second rotating shafts extending respectively and axially from said first and second end surfaces of said roller body; a fixing member sleeved fixedly on said first rotating shaft and adjacent to said first end surface of said drive roller, said fixing member being adapted to be connected fixedly to an end of the sand belt; a pulling member sleeved rotatably on said second rotating shaft and adjacent to said second end surface of said drive roller, said pulling member being adapted to be connected fixedly to the other end of the sand belt at an eccentric position; a resilient member for biasing said pulling member to rotate about said second rotating shaft in a direction so as to tauten the sand belt on said drive roller; and said pulling member has a slot formed therethrough and extending along a circumferential direction of said pulling member, said slot having opposite first and second ends, said resilient member being disposed within said slot in said pulling member and being configured as a coiled tension spring that has a first end located at said first end of said slot in said pulling member and fastened to said second end surface of said roller body of said drive roller, and a second end fastened to a wall of said pulling member defining said second end of said slot so as to bias the wall in a direction toward said first end of said resilient member, thereby providing a biasing force to said pulling member to rotate about said second rotating shaft in the direction.