Adjustable disc sander

Abstract

An adjustable disc sander includes: a base defining an operating surface; a sanding device being mounted on the base having a sanding disc; and an adjustable support unit including a linkage unit and an adjustable positioning unit. The sanding disc and the operating surface include a working angle. The linkage unit connects between the sanding device and the adjustable positioning unit. The adjustable positioning unit includes an adjuster being mounted around a support bar along a move direction, and includes a retainer being arranged between the support bar and the adjuster to move between a fixing position and a releasing position in a direction perpendicular to the move direction. When the retainer is at the fixing position, the adjuster can slightly adjust the support bar to achieve fine adjustment of the working angle. When the retainer is at the releasing position, the support bar can move significantly to achieve coarse adjustment of the working angle.

What is claimed is: 
     
         1 . An adjustable disc sander, comprising:
 a base, being provided with a platform that defines an operating surface for a workpiece to be placed thereon;   a sanding device, being mounted on the base and having a sanding disc for sanding the workpiece, wherein the sanding disc and the operating surface include a working angle; and   an adjustable support unit, comprising a linkage unit, a support bar, and an adjustable positioning unit, wherein the linkage unit is connected to the sanding device, and the support bar passing through the platform along a move direction has an inner end connected to the linkage unit for support, and has an outer end exposed outside the platform and connected to the adjustable positioning unit, while the adjustable positioning unit has an adjuster and a retainer, in which the adjuster is mounted around the support bar along the move direction, and the retainer is arranged between the support bar and the adjuster, so that the retainer moves between a fixing position and a releasing position in a direction perpendicular to the move direction;   whereby when the retainer is at the fixing position, the adjuster is allowed to make the support bar to move slightly along the move direction, thereby achieving fine adjustment of the working angle, and when the retainer is at the releasing position, the support bar is allowed to move significantly along the move direction, thereby achieving coarse adjustment of the working angle.   
     
     
         2 . The adjustable disc sander of  claim 1 , wherein the adjuster has a first receiving hole extending in the move direction and a second receiving hole intersecting the first receiving hole, and the retainer has a limiting hole coaxial with the first receiving hole, in which the first receiving hole and the limiting hole are for the support bar to pass therethrough, while the second receiving hole is for the retainer to pass therethrough. 
     
     
         3 . The adjustable disc sander of  claim 2 , wherein the support bar has a periphery that is externally threaded, while the first receiving hole and the limiting hole are each defined by a wall that is internally threaded. 
     
     
         4 . The adjustable disc sander of  claim 2 , wherein the first receiving hole and the second receiving hole are perpendicular to each other. 
     
     
         5 . The adjustable disc sander of  claim 1 , wherein the adjustable positioning unit further comprises a positioner that is inserted into one side of the retainer to hold the retainer at the fixing position. 
     
     
         6 . The adjustable disc sander of  claim 5 , wherein the adjuster has a first fixing hole, and the retainer has a second fixing hole coaxial with the first fixing hole, in which the first fixing hole and the second fixing hole are for the positioner to pass therethrough. 
     
     
         7 . The adjustable disc sander of  claim 1 , wherein the adjustable positioning unit further comprises a spring member that is mounted around one end of the retainer to normally bias the retainer toward the fixing position. 
     
     
         8 . The adjustable disc sander of  claim 1 , wherein the outer end of the support bar is provided with a handle that is exposed outside the platform. 
     
     
         9 . The adjustable disc sander of  claim 1 , wherein the platform has each of two sides thereof provided with a first pivot portion, and the sanding device has each of two sides thereof provided with a second pivot portion, in which the first pivot portion and the second pivot portion are pivotally connected to each other so that the sanding device is allowed to pivotally swing with respect to the platform. 
     
     
         10 . The adjustable disc sander of  claim 1 , wherein the linkage unit has a first moving arm and a second moving arm, in which the first moving arm has one end thereof pivotally connected to the inner end of the support bar, and the second moving arm has two ends thereof pivotally connected to an opposite end of the first moving arm and the sanding device, respectively, so that the first and second moving arm are driven by the support bar to adjust the working angle. 
     
     
         11 . The adjustable disc sander of  claim 10 , wherein the first moving arm has each of two sides thereof provided with a first sliding portion near the support bar, and the base is formed with slide grooves aligned with the first sliding portions, so that the first sliding portions move along the slide grooves, and wherein the second moving arm has each of two sides thereof provided with a second sliding portion near the sanding device, and the base is formed with curved grooves aligned with the second sliding portions, so that the second sliding portions move along the curved grooves.