US2798342A - Grinding wheels - Google Patents

Description

'July 9, 1957 A. A. MILLER GRINDING WHEELS 3 sheets-sheet 1 Filed July 25,- 1956 Fis. 2.1*

rrae/YE/ July 9,1957 v A. A. MILLER 2,798,342

. L Y l GRINDING WHEELS Filed .my 25. 195e 5 sheets-sheet s GRINDING WHEELS Arthur'v A. Miller, McHenry, lll., assigner to Lou C. Casanov, Waukegan, Ill., and himself Application July 25, 1956, Serial No. 600,019

3 Claims. (Cl. 51-192) My invention relates to improvements in grinding wheels.

My invention relates more particularly to a grinding wheel provided with an air cushioned tread portion.

Grinding wheels of the type to which this invention relates include a ring or band of abrasive such as sandpaper or the like mounted on the periphery or tread por tion of the Wheel, the tread portion being comparatively hard rubber, but so constructed that a certain amount of resiliency is given to the sanding surface of the Wheel.

One of the principal objects of the present invention is to provide a relatively simple and inexpensive wheel of this sort that is made of a relatively small number of parts that are easily assembled to form a strong and sturdy device.

During the use of a sanding wheel, the wheel is caused nited States arent l tightening the abrasive band B on the same.

to rotate at a relatively high velocity and the article to be sanded is applied against the sanding surface of the wheel. Due to the friction between the sanding surface of the wheel and the article applied thereto, there is a constant tendency for the abrasive band forming the surface of the wheel to creep or move circumferentially about the same. This movement is prevented in the device forming the subject matter of the present invention in a manner to be described hereinafter.

In one form of the invention the tread portion is mounted so that a comparatively high velocity the same is permitted to expand, thus tightening the abrasive band more effectively about the same. In another type of construction which forms part of this invention, the tread portion is provided with air under pressure to expand or move the same out sufficiently to effectively grip the abrasive band and prevent creeping or circumferential movement of the same on the wheel.

Another object of the invention is to 'so construct the mounting or supporting plates with air holes so that heat which is generated by a grinding action may be dissipated through the same during operation.

Other objects and advantages will be more apparent from the following description wherein reference is had to the accompanying drawings, upon which:

Fig. 1 is a plan View of an abrasive Wheel mounted in driving relation to an electric motor;

Fig. 2 is a front view thereof;

Fig. 3 is a cross-sectional view thereof taken on the line 3-3 of Fig. 2;

Fig. 4 is a similar cross-sectional view thereof showing a modified form of the invention; and

Fig. 5 is a cross-sectional View showing a further modified form.

In the embodiment of the invention which I have chosen to illustrate and describe the same, I provide a driving motor 10 which has a shaft hub 12 through which a driving shaft 14 extends, the shaft being screwthreaded at the end to receive a locking nut 16.

The grinding wheel may include a pair of mounting plates 18 and 20 generally similar to disc wheel members, having openings 23 therein to receive the shaft 14.

The mounting plates 18 and 20 are also provided with facing peripheral grooves 22 and 24 to clamp over circular ridges 26 and 28 formed in side Wall portions 30 and 32 of the tread member 34. The mounting plates 1S and Z0 are also provided with a circular row of openings 36 and 38 to receive fastening bolts 40 which also extend through aligned openings 42 in the side wall portions 30 and 32 of the tread 34.

The tread 34 which is made of rubber, has the inner faces of the jside walls 30 and 32 vulcanized together at 46 around the inner opening 48 in the same, so that when these walls are vulcanized together the air Within the same is trapped and sealed therein, forming in effect a low pressure tire construction.

In the embodiment of the invention shown in Fig. 3 I have also provided an annular ridge 50 in each of the side walls 30 and 32, so that when the grinding wheel is subjected to a comparatively high rotational speed, centrifugal force will tend to swing out the tread portion 52 thereof to a slightly larger diameter, thus effectively The side Walls 30 and 32 are contained Within the generally arcuate extensions 18a and 20a of the mounting plates 18 and 20 to a point adjacent the tread portion 52 thereof.

' In the embodiment of the invention shown in Fig. 4, I have provided the vulcanizing 46 between the inner surfaces of the side walls 30 and 32 of the tread portion of the wheel to a point beyond the bolt members 40, and provide an air valve 60 communicating with the chamber 62 therein, the air valve passing through one of a plurality of openings 66 in the mounting plate 20, the mounting plate 1S also having concentric rows of Openings 66 therein.

With this construction sufficient air pressure can be pumped into the chamber 62 to securely lock the abrasive band B on the periphery of the tread portion of the grinding wheel so that the same may be used for grinding at comparatively low speeds if desired. With the provision of the concentric rows of openings 66 in both of the mounting plates 1S and 20, heat generated in the rubber of the grinding wheel can be dissipated to the atmosphere so that the grinding wheel is capable of longer use and will not become heated during operation.

In Fig. 5 I have shown a modified form of the invention wherein I employ a cylindrical adapter 15, the adapter being of the desired width for the desired width of the grinding wheel required for a particular job. For this purpose also longer bolts 40a are used as well as a longer shaft 14a from the motor 12. It can be seen that the mounting plates 1S and 20 are the same as those employed in the other embodiments of the invention, and the tread 34 also has the same type of side walls 30a and 32a with the tread portion 52a of the desired width required for the abrasive band B to be used. The side walls 30a and 32a are also preferably provided with one or more annular ridges 50a so that when the grinding wheel rotates at a comparatively high speed centrifugal force will tend to swing out the tread portion to effectively tighten the abrasive band upon the same. Thus for various widths of abrasive bands various Widths of adapters 15 may be employed, depending entirely upon the type work to be done thereby.

From the above and foregoing description it can be seen that I have provided a grinding wheel constructed of comparatively few parts; also by the use of the ridges 26 and 28 in the rubber side walls of the tread portion and their containment in circular grooves in the mounting plates, together with the circular row of bolt members 40, the complete assembly is effectively held together and can not be easily broken or become out of order.

While I have illustrated and described a preferred embodiment of the invention and modifications thereof,

it will be apparent to those skilled in the art that changes and modifications may be made in the exact details shown and I do not wish to be imited in any particular; rather what I desire to secure and protect by Letters Patent of the United States is:

1. An abrasive wheel of the class described comprising a mounting shaft, a pair of similarly shapedrmounting plates facing each other on said shaft, said plates each having a flat disc portion and an axially and radially turned curved portion terminating in a portion parallel to said at disc portion, a rubber tread member having a comparatively rigid peripheral edge, thin side walls transverse to said edge, said side walls having an axial opening therethrough and a circular ridge concentric to said axial opening and adjacent thereto, said side walls extending inwardly from said peripheral edge and adapted to flex to lie against and be positioned against the facing lsides of said mounting plates, each of said mounting plates having a circular groove therein to receivey a circular ridge of each of the side walls of saidV tread members, and an abrasive band secured about the peripheral edge of said tread member.

2. An abrasive wheel of the class described comprising a mounting shaft, a pair of similarly 'shaped mounting plates facing each other on said shaft, said plateseach having a flat disc portion and an axially and radially turned curved portion terminating in a portion parallel to said flat disc portion, a rubber tread member having a comparatively rigid' peripheral edge, thin side walls transverse to said edge, said side walls having an axial opening therethrough and a circular ridge concentric to said axial opening andadjacent thereto, said side walls extending inwardly from said peripheral edge and adapted to flex to lie against and be positioned against the facing sides of said mounting plates, each of 'said mounting plates having a circular groove therein to receive a circular ridge of each ofthe side walls of said tread members, and an abrasive band secured about the peripheral edge of said tread member, the inner edges of the thin side walls of 'said tread portion being vulcanized together to form an air-tight circular chamber.

3. An abrasive wheel of the class described comprising a mounting shaft, a pair of similarly shaped mounting plates facing each other on said shaft, said plates each having a flat disc portion and an axially and radially turned curved portion terminating in a portion parallel to said flat disc portion, a rubber tread member having a comparatively rigid peripheral edge, thin side walls transverse to said edge, said side walls having an axial opening therethrough and a circular ridge concentric to said axial opening and adjacent thereto, said side walls extending inwardly from said peripheral edge and adapted to flex to lie against and be positioned against the facing sides of said mounting plates,'each of said mounting plates having a circular groove therein to receive a circular ridge of each of the side walls of said tread members, and an abrasive band secured about the peripheral edge of said tread member, the inner edges of the thin side walls of said tread portion being vulcanized together to form an air-tight circular chamber, one of said side walls having an air valve by means of which air under pressure may be introduced into said chamber.

References Cited in the file of this patent UNITED STATES PATENTS

Images