Field of Search:
51/102,128,135,137,148,218A,173,238R,238S,239
Claims:
I claim
1. A work supporting mechanism for a sanding machine having an endless sanding belt at the top thereof, comprising a pair of work supporting plates arranged above said belt and diverging upwardly, the lower edges of said work supporting plates being arranged adjacent and parallel to said belt whereby a workpiece arranged on one plate will have its lower edge engageable with the belt to bevel the edges thereof while the other plate acts to limit downward movement of the workpiece to determine the degree of sanding cut of the lower edge of the workpiece, and means for adjusting the distance between said plates to adjust the degree of cut of the lower edge of the workpiece.
2. A mechanism according to claim 1 provided with means for bodily shifting said plates transversely of the belt to utilize different lines of cutting thereover.
3. A mechanism according to claim 1 provided with means for raising and lowering said plates relative to the sanding belt.
4. Apparatus according to claim 1 provided with outwardly extending horizontal shafts supporting each plate, and means for supporting each set of shafts for longitudinal movement to vary the distance between said plates to adjust the degree of cutting of the lower edge of the workpiece.
5. A mechanism according to claim 4 wherein the means for adjusting said shafts comprises horizontal supporting bearings for said shafts in which said shafts are slideable, and means for clamping each set of shafts to the bearings thereof.
6. Apparatus according to claim 5 provided with means for adjusting the height of said bearings to move said shafts vertically to adjust the height of said plates above said belt.
7. A mechanism according to claim 6 provided with arms pivotally connected to said plates and projecting outwardly respectively therefrom, vertical supports connected to the ends of said arms, and a bar connected between the lower ends of said supports free of said sanding machine whereby when said shafts are loosened from their bearings, said bearings, said supports and said arms may be bodily moved to bodily move said plates transversely of the sanding belt to utilize different portions thereof in the sanding operation.
8. The mechanism according to claim 7 wherein the lower ends of said supports are adjustable laterally of the sanding machine relative to said bar to provide for the adjustment of the spacing of said plates when said shafts are loosened in their bearings.
9. In combination with a sanding machine having an endless horizontal belt provided with upper and lower runs, a pair of work supporting plates extending longitudinally of said upper belt run and diverging upwardly with their lower edges arranged adjacent the upper run of said belt, the lower extremities of said plates being arranged in proximity whereby a workpiece arranged flat against one plate may contact with the upper run of a belt to bevel the lower edge of said workpiece with the other plate acting as a stop to limit downward movement of the workpiece to predetermine the depth of the sanding cut.
10. The combination defined in claim 9 wherein each work supporting plate is provided with a pair of horizontal shafts spaced longitudinally of the sanding machine and pivoted at their inner ends to said plates, and means for fixing said plates in adjusted positions relative to their pivots to predetermine the angle of the individual plates to determine the beveling angle cut in the lower edge of the workpiece.
11. The combination defined in claim 10 wherein each shaft is provided with a supporting bearing having releasable clamping means engaging the associated shaft whereby said shafts may be adjusted horizontally of the machine to determine the spacing between said plates.
12. The combination defined in claim 11 wherein each horizontal bearing is provided with a depending supporting shaft, a vertical bearing for each vertical shaft, and means for clamping each vertical bearing relative to its associated vertical shaft to determine the height of the latter shaft and thus the height of said plates above said sanding belt.
13. The combination defined in claim 12 wherein said sanding machine is provided with a base spaced below said sanding belt, and means connecting said plates to each other outwardly of said sanding machine and above the base thereof for bodily movement of said plates transversely of the upper run of the sanding belt to utilize different cutting portions of the sanding belt transversely of the width thereof.
14. The combination defined in claim 13 wherein said means for connecting said plates outwardly of and above said base of said sanding machine comprises horizontal arms pivotally connected at their inner ends to said plates, and depending arms outwardly of the sanding machine connected at their upper ends to the outer ends of said arms, and a bar arranged horizontally above the base of said sanding machine and extending transversely thereof, the outer ends of said bar being connected to the lower ends of said supports.
15. The combination defined in claim 14 wherein the connection between the outer ends of said bar and the lower ends of said vertical supports is adjustable laterally of the sanding machine to provide for the individual adjustment of said plates to vary the distance therebetween.
Description:
SUMMARY OF THE INVENTION
The apparatus is attached to a conventional power-driven belt sander including a supporting structure carrying the attachment. A pair of upwardly inclined guide plates are arranged slightly above the upper sanding surface and each is carried by a shaft with the shafts of opposite guide plates projecting in alignment horizontally away from each other. Horizontal guide bearings support the shafts which carry the plates and the shafts are individually adjustable in their bearings to vary the distance between the plates in accordance with the desired depth of the beveling cut. Each plate is provided therebeneath with a support plate each carrying a pair of ears pivotally connected to the adjacent end of one of the shafts by a bolt which may be loosened and tightened to adjust the angle of the associated plate according to the angle of the bevel which it is desired to cut.
Each horizontal bearing is carried by the upper end of a spaced vertical shaft vertically slidable in a guide bearing to which the vertical shaft may be clamped according to the desired height of the horizontal shafts and their plates. The vertical bearings are carried by bracket means supported on the body of the sanding apparatus.
In addition to their connection with the horizontal shafts, each guide plate is connected between the horizontal shafts to vertical arms at opposite sides of the apparatus and the lower ends of these vertical rods are connected to a transverse bar extending across the sanding apparatus. By loosening the connection of the horizontal shafts to their horizontal guide bearings, the vertical rods and their horizontal bars rigidly connected to the lower ends of the vertical rods may be moved laterally of the sanding belt to bodily move the guide plates so advantage may be taken of the sanding action of any portion of the sanding belt transversely thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the apparatus;
FIG. 2 is a side elevation of the same;
FIG. 3 is an end elevation of the apparatus looking from the left in FIG. 3; and
FIG. 4 is a vertical section on line 4--4 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, the numeral 10 designates a conventional belt sanding machine as a whole comprising a support 12 on which is mounted a base 14 having an upstanding stationary element 16 acting as a rest for the sanding table when the belt is horizontal. A horizontal bed 18 (FIG. 1) carries means for supporting the sanding belt including arms 20, bearings 22, shafts 24, pulleys 26 and a conventional sanding belt 28, the upper run of which is adapted to sand workpieces in contact therewith. One shaft 24 is belt driven as at 29.
The present apparatus is mounted to support workpieces in position to be beveled by the upper run of the sanding belt. This apparatus comprises a pair of guide plates 30 upwardly diverging as shown in FIGS. 3 and 4 and against one of which a board or other workpiece is adapted to rest so that its lower edge may be beveled by the upper run of the sanding belt 28. A workpiece, resting on one guide plate 30, will have its downward movement limited by contact with the other guide plate and obviously the further apart these plates are arranged, the deeper will be the beveling cut on the workpiece. These guide plates 30 are individually adjustable toward and away from each other to vary the beveling cut and are bodily movable transversely of the sanding belt to take advantage of the sanding surface at various points thereacross, all as described below.
Each guide plate 30 is supported by a pair of longitudinally spaced transverse shafts 32 slidable in guide bearings 34 spaced outwardly of opposite sides of the guide plates. Each shaft is provided with inner and outer collars 36 set-screwed thereon by means of screws 37. Each shaft 32 is pivoted as at 38 to the ears 40 of supporting plates 42 carried by the guide plates 30. Each pivot 38 is in the form of a bolt which may be loosened to change the inclination of the associated guide plate 30 whereupon such bolts may be tightened. Bearings 34 are supported by yokes 46, and each yoke 46 is supported on the upper end of a vertical shaft 48.
Each shaft 48 is slidable in a vertical guide bearing 52 and is adapted to be clamped in vertically adjusted position by a set screw 54 provided with a jamb nut 56. The lower ends of the guide bearings 52 have extending thereinto a screw 58 engageable with the lower end of the associated shaft 48. By loosening a jamb nut 60 each screw 58 may be turned to adjust the heights of the associated shaft 48 with the bottom of which the screw 58 contacts.
The lower ends of each guide bearing 52 is secured to a bracket 66 of right-angular form as shown in FIG. 3, screw 58 threadedly engaging bracket 66. The brackets 66 (FIG. 4) have their vertical flange welded at one end to the upstanding ends 68 of a horizontal support 70 bolted as at 72 to the top of the base 14. The other ends of brackets 66 (FIG. 3) are welded to the upstanding ends 74 of brackets 75 having lower horizontal ends 76 bolted as at 78 to the top of the base 14. As shown in FIG. 3, the inner ends of brackets 75 are spaced from each other so that the entire mechanism of the present invention may be withdrawn, as described below, endwise of the apparatus to clear the vertical support 16.
Between each pair of bearings 34, the respective guide plates 30 are pivotally connected as at 80 (FIG. 4) to oppositely extending arms 82 welded at their outer ends to vertical supports 84. The lower ends of these supports are bolted as at 86 to angle brackets 88 and the lower ends of these brackets are attached by screws 90 to a rigid transverse bar 92 which is free of all portions of the sanding machine so as to be movable transversely thereof to adjust the positions of the guide plates 30 transversely of the sanding belt 28. The screws 90 are threaded in the transverse bar 92 and operate in slots 94 (FIG. 3) in the lower ends of the brackets 88.
Bolts 86 are screwed into tapped holes in angle brackets 88 after first being inserted into elongated slots in the lower portion of supports 84. Slots 85 are necessary in the event a rather long set of guide plates 30 are employed on industrial sanding machines having a far longer belt than the home craftsman uses. In this case bolts 86 are loosened and the vertical supports 84 automatically raise up to coincide with the adjusted height of shaft 48 and related components. Guide bearings 52 on a long machine may be spaced a considerable distance from vertical supports 84. By moving 84 with shafts 48 there is less likelihood of binding or load strain in the center of plates 30.
OPERATION
The apparatus is attached to a conventional sanding machine as described. When it is desired to bevel one edge of a board, for example, the board will be placed flat against one of the guide plates 30 with its lower edge contacting with the upper run of the sanding belt and with its downward movement limited by engagement with the other guide plate 30. The bolts at pivot points 38 are loosened to adjust the lateral positions of the lower edges of guide plates 30 and this also tilts plates 30 to obtain the angle of the bevel cut desired on the lower end of the workpiece. If the workpiece was a rather thick piece of material, then in order to get some degree of bevel, the plates would have to be moved farther apart by loosening bolts 90. The height of the guide plates 30 above the belt may be adjusted by loosening the jamb nuts 56 and 60 and set screws 54, turning the screws 58, and then tightening the jamb nuts. This adjusts the vertical positions of either pair of shafts 48 and consequently adjusts the height of either guide plate 30 above the work.
Shafts 32 move in bearings 34 freely, and plates 30 and all related mechanism may instantly be moved right or left by the workman to a different spot on the belt so that no particular grinding area of the sanding belt becomes prematurely worn. Also the belts on the machine can be changed when finally worn out without disturbing any setting on the device or having to remove the device from the machine because the belt can be slid off one side of the machine naturally passing under plates 30.
To remove the apparatus from the sanding machine, all of the bolts 72 and 78 in the lower horizontal ends 76 of brackets 75 and horizontal support 70 are removed, whereupon the entire apparatus bodily may be moved longitudinally of the apparatus. This removal will be from the end of the apparatus on which the integral bar 70 (FIG. 4) is arranged, and the spacing of the inner ends of the bracket ends 76 from each other will permit them to clear the vertical support 16. This will be the removal of the apparatus from the left end of the machine as viewed in FIG. 2, that is, the end opposite the drive belt 27.
From the foregoing it will now be seen that there is herein provided an improved beveling attachment for belt sanders which accomplishes all of the objects of this invention and others, including many advantages of great practical utility and commercial importance.
As various embodiments may be made of this inventive concept, and as many modifications may be made in the embodiment hereinabove shown and described, it is to be understood that all matter herein is to be interpreted merely as illustrative, and not in a limiting sense.