US 3073083 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Jan. 15, H c
BELT SANDING APPARATUS Filed NOV. 5, 1960 a i "L5 21 J1 2 H :g F.)- 13 9 Z5 INVEN TOR. FRA/Vf/J' H. Ailc/mer HTTDRNZ'Y 7 nite This invention relates to belt type polishing, buffing or sanding machines and more particularly to the type in which the abrasive treated belt oscillates.
One object of my invention is to provide an open end belt which may be used with surfaces which have no opening as for example the interior of a ring or the rung of an assembled chair.
Another object of my invention is to provide means for easily and quickly installing or removing the belt to replace it with a fresh one or of a different grade of abrasive.
Still another object of this invention is to provide simple means for changing the belt with one hand so that the other hand may be free to hold the machine in its working position.
A further object of my invention is to provide a light weight portable machine which may be attached to a convenient portable source of power such as an electric hand drill.
Also another object of my invention is to provide a light weight machine having its own source of power incorporated in the machine.
A still further object of my invention is to provide a unique attachable and detachable belt.
Other and further objects of this invention will appear from the specifications and from the claims hereto annexed and from the accompanying drawings.
In the drawings:
FIG. 1 shows, in perspective, the belt sander in position for sanding the rung of an assembled chair.
FIG. 2 shows a side View with one end portion of the belt attached to an oscillating mechanism member.
FIG. 3 is a plan view of the invention as shown in FIG. 2.
FIG. 4 is a vertical end View taken along the lines 44 of FIG. 3 with one end of the belt disengaged.
FIG. 5 is schematic view showing the belt in the position of its longest arc of contact with the convex surface of the specimen to be sanded.
FIG. 6 is schematic view showing the belt in the position of its shortest arc of contact with the specimen to be sanded.
In the following description and in the claims, various details Will be identified by specific names for convenience, but they are intended to be as generic in their application as the art will permit.
In the drawings where like reference characters denote like parts in the several figures and in this description, certain specific disclosure of the invention is made for purposes of explanation, but it will be understood the details may be modified in various respects without departure from the broader aspects of the invention.
Referring now more particularly to the drawings, reference numeral 10 denotes a housing (see FIG. 3) to which is perpendicularly attached a partition 11 terminating into a transverse safety shield 12. A pinion shaft 25 mounted in suitable bearings (not shown) in housing 10 extends into one direction through the wall of the housing 10 as 28 in FIG. 3 and at the other end carries pinion 21 within the housing 10. Power may be supplied to the apparatus by connecting an electric hand drill 29 to shaft extension 28 by means of chuck 30 forming part of the electric hand drill. In another embodiment, power may be obtained from an electric motor (not shown) incorporated in the housing 10.
atent Mounted in suitable bearings (not shown) in housing 10 (see FIG. 3) are two disc-gear shafts 24, each carrying a gear 23 located within the housing 10 and a disc 13 located outside of the housing 10 and between housing 10 and safety shield 12. Pinion 21 meshes with gears 23 to drive both gears in the same direction and at same speed.
A crank pin 14 is mounted on each disc 13 (see FIGS. 2 and 3) each pin 14 being located the same distance from disc-gear axis or shaft 24. The disc-gears 23 are meshed (see FIG. 3) so that the crank pins 14 are angularly displaced from each other which results in a minimum distance between the crank pins 14 when in one position as shown in FIG. 5 and conversely as shown in FIG. 6 a maximum distance along a straight line such as XY (FIGS. 5 and 6) drawn through the crank pins 14 and the centers of the disc shafts 24.
Also referring to FIG. 5, it will be observed that when the crank pins are spaced a minimum distance apart the belt has the maximum arc of contact between the belt and the surface of the work to be polished. Now referring to FIG. 6, it will be observed that when the crank pins are spaced at a maximum distance apart, the resulting effect is that the said are of contact is at its minimum. This enables the sawdust or loose material created by the sanding or polishing to be quickly discharged from the surface of the work and not clog up the belt.
As shown in FIG. 2 rotatively mounted on each crank pin 14 is a link 18 carrying belt hooks 17 in spaced relation for cooperating with openings or eyelets 16 in belt 15 to secure belt 15 in its desired rotary relation to crank pins 14.
Instead of a disc carrying a crank pin I may use a simple crank (not shown) attached to each disc shaft 24 with the crank pins 14 mounted on the cranks with equal radii of revolution in which case the cranks are positioned on their respective shafts 24 so that in each complete revolution of the cranks the crank pins 14 are at a minimum distance apart and at a maximum distance apart respectively on a straight line (such as XY FIGS. 5 and 6) drawn through the crank pins and centers of the disc shafts 24.
In another embodiment, I may omit the pinion 21 and pinion shaft 28 and connect my electric hand drill or other power source directly to shaft 24 and mesh disc gears 24 directly with each other with a 1 to 1 ratio in which case the discs will revolute in opposite directions. Also in this case my crank pins 14 will be so positioned that when each crank is in a vertical position, they will have an angular displacement of 180 with each other.
Referring now to FIG. 2 it will be noticed that the handle 31 is mounted underneath the housing which not only tends to balance the apparatus by being more in line with its center of gravity but it is offset from the center line of the belt when the latter is held in a vertical position as shown clearly in FIG. 1. This offset gives clearance to the operators hand and also allows the operator to regulate the pressure of the belt on the work.
The belt 15 may be impregnated with sand or other abrasive grains as desired. The belt may also be of material suitable for polishing or buffing. The belt may be of any suitable flexible material as for example woven or non-woven fabric capable of holding abrasive material of the desired fineness. At each end of the belt and for a short distance therefrom, reinforcing material 26 is secured to the belt to strengthen the belt Where the holes or eyelets 16 are inserted for receiving the belt books 17.
The safety shield 12 comes into use (see FIG. 1) to prevent injury by the cranks to objects at the end of the work piece as for example chair leg 32.
The partition 11 is necessary to prevent the belt hooks 17 from tangling with each other in case the tension on the belt loop is slackened while the discs are revolving 3 i (see FIG. 5 for example) and also to hold the link in a stationary and receptive position to easily engage and disengage the belt (see FIG. 4);
In operating this apparatus in a situation similar to that disclosed in FIG. 1, the operator places both links 18 against the partition 11 to hold the links 13 so that the eyelets 16 may be easily engaged with corresponding hooks 17. One end of the belt 15, of course, is not attached until after the belt 15 has been looped over the work 27. The apparatus is now ready for operation.
While certain novel features of the invention have been disclosed herein, and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art Without'departure from the spirit of the invention.
What is claimed is:
1. In a belt polishing device portable to the work to be polished; an open end abrasive belt; means for reciprocating said belt in a substantially single plane perpendicular to the axis or the work area to be polished comprising a pair of cranks rotating in the said plane and synchronized with each other to give a reciprocating movement to said belt attached respectively thereto; means for detachably securing said belt to said reciprocating means; and shield means adjacent to said reciprocating means to prevent outside interference with said reciprocating means.
2. In the device of claim 1 means for detachably securing said belt to said cranks comprising a crank pin mounted on said crank; a link rotatable at one end on said pin and companion hook and eyelet members of which one member is carried by the other end of said link and the other member by said belt.
3. The combination in a device as set forth in claim 2 which further comprises, a housing for mounting said cranks; a member attached to said housing and extending between said cranks to support said shield means and located in reference thereto so as to provide a rest for one of said links when it is desired to connect said belt.
4. In the device of claim 1 whereby said cranks rotate at the same speed and in the same direction; and said cranks angularly displaced from each other.
References Qited in the file of this patent UNITED STATES PATENTS 1,912,016 Sittner May 30, 1933 2,498,947 Fielding Feb. 28, 1950 2,556,041 Pick June 5, 1951 2,751,728 Pctit June 26, 1956 FOREIGN PATENTS 573,143 Germany Mar. 27, 1933