BRIEF DESCRIPTION OF DRAWINGS
This invention is better understood by referring to the accompanying drawings, wherein:
FIG. 1 is a perspective view of a conventional roller belt sander;
FIG. 2 is a perspective view of a roller belt sander in the present invention;
FIG. 3 is an exploded perspective view of a first preferred embodiment of an adjustment device for adjusting a level difference between rollers of a roller belt sander in the present invention;
FIG. 4 is a side view of the first preferred embodiment of an adjustment device for adjusting a level difference between rollers of a roller belt sander in the present invention, showing it being working;
FIG. 5 is a front cross-sectional view of the first preferred embodiment of an adjustment device for adjusting a level difference between rollers of a roller belt sander in the present invention, showing it being positioned;
FIG. 6 is a front view of a graduation ruler of a second preferred embodiment of an adjustment device for adjusting a level difference between rollers of a roller belt sander in the present invention; and
FIG. 7 is a cross-sectional view of a third preferred embodiment of an adjustment device for adjusting a level difference between rollers of a roller belt sander in the present invention, showing it being assembled.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 2 and 3 show a first preferred embodiment of an adjustment device 70 for adjusting a level difference between rollers of a roller belt sander 3 in the present invention. The roller belt sander 3 is composed of a main body 30, a front belt sanding roller 40, a rear belt sanding roller 50, and a conveying table 60 installed under the front belt sanding roller 40 and the rear belt sanding roller 50 for carrying a work to be ground via passing underneath the front belt sanding roller 40 and the rear belt sanding roller 50. Each of the adjustment devices 70, which is set between a bearing 51, provided respectively at two ends of the rear belt sanding roller 50, and a wall edge of the main body 30 to adjust the level of the rear belt sanding roller 50, is composed of a base 71, an eccentric shaft 72, a rotating rod 73, a restricting knob 74, a bearing base 75 and two locking rings 76.
The base 71 is fixed on an interior wall of the main body 30 corresponding to each end of the rear belt sanding roller 50, provided with a penetrating opening 711 bored axially, a threaded hole 712 bored in its top center, a hole 715 bored at a preset sidewise location for accommodating a locking ball 713 and a compression spring 714 in order, and a tightening bolt 716 screwed on the top of the hole 715 to squeeze the compression spring 714 to restrict the locking ball 713. The rear end of the hole 715 is tapered to a smaller diameter, so that the locking ball 713 is to be stopped therein with a part of it extruded outside the hole 715.
The eccentric shaft 72 inserted in the penetrating opening 711 of the base 71 has a rear end portion 721 and bored with a threaded hole 7211 on its top, a front-end engaging portion 722 to have an opening 7221 cut near around its edge for pivotally receiving the bearing 51 of the rear belt sanding roller 50, and a preset number of ball recesses 723 concaved around its annular rim. The opening 7221 formed to rotate eccentrically is pivotally positioned in the penetrating opening 711 of the base 70, and a locking ring 76 is to fit tightly around the bearing base 75.
The rotating rod 73 consists of a grip 731 set at its top for a user to grab easily, and a threaded bar 732 located at its lower portion for engaging in the threaded hole 7211 of the eccentric shaft 72 so that the rotating rod 73 is able to keep the eccentric shaft 72 whirling eccentrically up and down.
The restricting knob 74 is provided with a threaded portion 741 located at its lower portion for engaging with the threaded hole 712 of the base 71 so as to fix deadly the eccentric shaft 72 in the penetrating opening 711 of the base 71 after having the eccentric shaft 72 being adjusted to a desired position.
The bearing base 75 mounted by the locking ring 76 and pivotally inserted in the opening 7221 of the eccentric shaft 72 is provided with an axial hole 751 bored axially for accommodating the bearing 51 of the rear belt sanding roller 50.
In using, as shown in FIGS. 4 and 5, when the level of the rear belt sanding roller 50 is to be adjusted, the restricting knob 74 has to be first turned loosely to loosen the base 71 and the eccentric shaft 72, and then rotate the rotating rod 73 according to numbers matched between the front belt sanding roller 40 and the rear belt sanding roller 50, so as to enable the eccentric shaft 72 to whirl eccentrically to keep the rear belt sanding roller 50 moved up or down. It should be noted that the locking ball 713 can be trapped in any of the ball recesses 723 to get restricted when the rotating rod 73 drives the eccentric shaft 72 to rotate, enabling the adjustment device 70 to move the rear belt sanding roller 50 up and down with various segmented levels, achieving a preferable grinding effect in conjunction with the front belt sanding roller 40.
As shown in FIG. 6, a second preferred embodiment of an adjustment device 70 for adjusting a level difference between rollers of a roller belt sander 3 in the present invention has the same parts as the first embodiment does, except that a graduation ruler 717 is additionally provided in the base 71 located at a top arc of one side of the base 71 facing to the rotating rod 73. The eccentric shaft 72 is additionally provided with a pointer 724 set at a preset position corresponding to the graduation ruler 717 so as to indicate a scope the eccentric shaft 72 rotates. Therefore, the rotating rod 73 can be turned according to an indication the pointer 74 points at the graduation ruler 717, so that the rear belt sanding roller 50 can be moved up or down to a desired level.
As shown in FIG. 7, a third preferred embodiment of two adjustment devices 70 for adjusting a level difference between rollers of a roller belt sander 3 in the present invention has the same parts as the first embodiment does, except that the eccentric shaft 72 is provided with a sleeve 725, which, fixed at one side of the eccentric shaft 72 facing to the rear belt sanding roller 50, is composed of an axial hole 7251 cut axially for pivotally fitting with the bearing 51 of the rear belt sanding roller 50, so that the sleeve 725 can be driven by the engaging portion 722 to rotate eccentrically to drive the rear belt sanding roller 50 to move up and down.
The invention has the following advantages as can be seen from the foresaid description.
1. The engaging portion 722 of the eccentric shaft 72 can be provided with an eccentric opening or an eccentric outer diameter to drive the rear belt sanding roller 50 to move up and down.
2. With the locking ball 713 squeezed to match restrictively with any of the ball recesses 723 of the eccentric shaft 72, the eccentric shaft 72 can rotate eccentrically with various steps for changing the level of the rear belt sanding roller 50.
3. It needs only to grab the rotating rod 73 to operate the adjustment device 70 in the present invention for quickly and conveniently carrying out adjustment.
4. The adjustment device 70 in the present invention has so less components that it can be assembled easily for saving its manufacturing cost.
While the preferred embodiment of the invention has been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications that may fall within the spirit and scope of the invention.
Patent Application
20080090492
