US2881572A - Grinding wheels - Google Patents

Description

April 14, 1959 A. A. MILLER GRINDING WHEELS Filed Jan. 24, 195s 4 sheets-sheet 1 Ffa/ H6. 2.

April 14, 195,9

Filed Jan. 24, 1958 A. A. MILLER GRINDING WHEELS F/ca. i,

4 Sheets-Sheet 2 INVENTOR. Aer/fw@ fi /V/LEL frag N15/ April 14, A1959 A. @MILLER 2,881,572v

GRINDING WHEELS Filed Jan. 24, 1958 4 Sheets-Sheet 3 INVENTOR. l www? /u if@ v qUnited tates Patat v2,881,572 Patented Apr- 14, 1.95.9

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GRINDING WHEELS Arthur A. Miller, McHenry, Ill., assignor to Arthur A. Miller and Lou C. Casanov, Waukegan, lll.

Application January 24, 1958, Serial No. 710,904

8 Claims. (Cl. 51191) My invention relates to improvements in grinding Wheels.

My invention relates more particularly to grinding wheels of the type which may include a band or ring of abrasive such as sandpaper or the like mounted on the periphery or tread portion of the grinding wheel, the tread portion being comparatively hard rubber so constructed that a certain amount of resiliency is given to the sanding surface of the Wheel, and due to the r.p.rn. of the grinding wheel, it will expand within limits as required by the work for which it is intended.

In the accompanying description, by way of example, I am describing generally three constructions of grinding wheels, all of which are designed according to the same general principles, but which are constructed for use at different rates of speed or revolutions per minute.

The principal object of the present invention is to provide an improved construction of grinding wheels, each one of which has a tread portion capable of guided movement during expansion, said movement being limited according to the construction of the wheel, and each of the wheels being provided with pin members adapted to move in elongated slots in side plates of the assembly in which the tread portion of the wheel is mounted.

A further object of the invention is to provide a con struction of grinding wheels of the same general type, yet which are modified in the exact details of construction to meet requirements of operation at various degrees of speed as has been found by trial and experience in designing and constructing the grinding wheels herein referred to.

A further object of the invention is to provide a grinding wheel of the type described that is easily and simply constructed, is made of a minimum of parts, and is capable of an eicient and long life as a grinding Wheel without becoming broken or out of order.

For a more comprehensive understanding of the details of construction and the manner in which the structure and assembly is provided, reference is had to the following description and accompanying drawings, upon which:

Fig. 1 is a side elevational view of a comparatively small type of grinding wheel, generally for use in grinding inside castings, under fenders., and various other types of grinding in which a comparatively small grinding unit is required;

Fig. 2 is a ,front View thereof;

Fig. 3 is a vertical sectional View therethrough taken on the line 3-3 of Fig. l;

Fig. 4 is a side elevational view of the tread member;

Fig. 5 is a side elevational view of a modified form of construction of grinding wheel adapted generally for work at the comparatively slow speed of 1725 r.p.m.;

Fig. 6 is a crossrsectional view therethrough taken generally on the line 6-6 of Fig. 5;

Fig. 7 is a side elevational Iview of the tread member;

Fig. 8 is a `side `elevational view of the hub to which it is attached;

construction designed for use at a speed of 3450 rpm.;

and

Fig. l0 is a cross-sectional view thereof taken on the line 10-10 of Fig. 9.

In the embodiment of the invention which I have chosen to illustrate and describe the same, in Figs. l to 4 I have shown a comparatively small type of grinding wheel in which the tread member 10 may have a cylindrical peripheral edge 12 about which an abrasive band 13 is positioned. The tread member y10, as shown, is cylindrical in shape and is provided with an axial bore 14 for the reception of a spacer 15. The treadmember 10 also has circular recesses 20 and 22 for the reception of side plates 24 and 26 positioned against both ends of the spacer 15. The side plates 24 and 26 hav axial openings 28 and 30 to receive the drive shaft 16, the grinding wheel being mounted on the drive shaft and fastened by a nut member 32.

The side plates 24 and 26 may both be provided with elongated slots 34 positioned at a point adjacent their peripheral edge, and the slots being directed at an angle back from a center line through the inner edge of the slot and the axis o f the plate.

The tread member l0 is provided with rods 36 which extend parallel with the bore 14 for the reception of the drive shaft, the ends of the rods being received in the elongated slots 34 in the plates 24 and ,26, the ends of the rods being headed as shown at 36a and 36b to aS- semble together the side plates, the pins and the tread member.

With the construction shown, and at a comparatively high rate of speed, such as about 10,000 r.p.m., `the tread member is expanded outwardly until the pins 36 reach a point where they are generally directly aligned with the surface of the abrasive belt and the axis of the tread member so that each pin is a rm backing or support for the tread member and abrasive belt at this point. Further, at the high rate of speed mentioned, the entire body of the tread member may be made of a ,comparatively hard rubber, or a short thick web 17 as -shown may connect hub portion 19 and rim portion 21.

In Figs. 5 and 6 I have shown a form of the invention wherein the grinding wheel 40 may have la circular ymetal hub 42 having an axial bore 44 to receive the drive shaft 46 of the motor 48. The tread member of the grinding wheel may be a right-angle member 50 having the at outer surface 52 upon which the abrasive belt 54 is positioned, the annular peripheral shoulders 56 and 5S, and the body portion 60. Side plates in the form of metal discs 62 and 64 are seated in the shallow recesses 65 formed by the annular shoulders 56 and 58, the same being fastened together and -to the hub 42 by means of a peripheral row of rivets 68.

The side plates 62 and 64 may be provided with elongated openings 70 in the plate 62, and 72 in the plate 64, all of the elongated openings being disposed at an obtuse angle from a radial line through the axis ofthe plates. The four elongated openings l70 are adapted to receive the extended ends of pin members 474 which have lan enlarged head 76 set into a suitable opening in the side of the body portion 60 of the tread member, the pin 74 extending through the other endv of the tread member and engaging the opening 70. In a similar manner, the pin members 78 extend from the opposite side of the tread member through the same, having a head 80 embedded in a suitable opening in the tread member 60 and with the ends of the pins engaging in the slots 72 of the side plate 64.

The grinding wheel which I have provided in' the embodiment herein described thus may .consist of a-tread member made of comparatively hard rubber, the same being mounted only upon the pin members 74 and 78 which are mounted in the elongated slots in the side plates. The consistency of the rubber is such that with this type of mounting and in grinding wheels of approximately 7 inches diameter, the wheel will operate with high efcieney at a comparatively low speed. The grinding wheel has been found to expand satisfactorily and effectively support the abrasive band at 1725 r.p.rn., or any speeds from approximately 1200 r.p.m. to 2250 r.p.m.

In the embodiment of the invention shown in Figs. 9 and 10, I have shown a grinding wheel 82 which may include acylindrically shaped hub member 84, side plates 86 and 88 and a tread member 90. The hub member 84 is provided with an axial bore 92 to receive the drive shaft 94 of a motor 96, the side plates 86 and 88 having the axial openings 87 and 89 therethrough for the same purpose.

The tread member 90 may comprise a peripheral ring member 100 having the outer surface 102 to receive an abrasive band 104, the ring member 100 being connected by -a medial web 106 with a hub portion 108 of the tread member that has a bore 110 to receive the metal hub 84. The hub of the tread member may be fastened by means of a plurality of pin members 112 to the side plates 86 and 88, the portion 108 also having a peripheral ridge 114 through which the pins pass and the side plates 86 and 88 having outwardly turned circular anges 116 to receive the ridges 114.

I provide a peripheral row of pin members 120 extending through both sides of the peripheral ring member 100 and engaging in elongated slots 122 in the side plates 86 and 88. Here again the elongated openings are directed at a peak angle from the direction of rotation, so that when pressure is applied to the abrasive band as by grinding a casting or other work piece, there is no tendency to compress the expanded tread for the reason that the pin member in effect is backed up against a side wall of the elongated opening, the side wall forming a solid bracing for the expanded tread member at a comparatively high rate of speed.

The web 16 which connects the hub of the tread member to the peripheral ring member of the same is of :a thickness such that the elasticity of the same permits the expansion of the grinding wheel by reason of centrifugal force, the expansion generally being absorbed in the web provided.

While I have illustrated and described several modiications of the grinding wheel capable of operating eflicently at different rates of speed ranging from 1200 r.p.m. to a maximum of 10,000 r.p.m., depending upon the size and the solidity of the rubber tread member, it is apparent that the general principles of engineering involved are similar throughout the various constructions. The extremely high rate of speed of the smaller wheel of necessity requires a denser rubber body portion than that in either of the modifications shown in Fig. 6 or Fig. 10, one of which is designed for a comparatively low rate of speed, and the embodiment shown in Fig. 10 being designed for a speed in the neighborhood of 3500 rpm. Both of the latter designs are of a type which are readily capable of use with the ordinary quarter-inch drill motors and other types of motors found in the home and home work shops, and thus present a grinding wheel for home use for a variety of purposes.

While I have illustrated and described a specific embodiment of the invention and various modifications thereof, it will be apparent to those skilled in the art that changes and modications may be made in the exact details shown and I do not wish to be limited 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 cylindrical hub adapted to be mounted on a motor shaft, a pair of circular side plates attached to the sides of said hub, each of said side plates having elongated slots therein adjacent their outer periphery, a .rubber tread member in the form of a ring having shallow bores on the sides of the same to receive said side plates and pin members extending beyond the side Walls of said ring member and received in said elongated slots for controlling the position of said tread member, said slots directed back at an angle from the `direction of rotation and said side plates being in planar alignment with the outer edges of said tread member.

2. An abrasive wheel of the class described comprising a cylindrical hub adapted to be mounted on a motor shaft, a pair of circular side plates attached to the sides of said hub, each of said side plates having a peripheral row of spaced elongated slots therein adjacent their outer peripheries, a rubber tread member in the form of a ring positioned between said side plates, a peripheral row of pin members therein extending beyond each of the side walls of said ring member and received in the elongated slots of said side plates for controlling the position of said tread member.

3. A circular abrasive wheel of the class described comprising a circular hub adapted to be mounted on a motor shaft, a pair of circular side plates attached to said hub, each of said side plates having an outwardly turned circular flange and a row of elongated slots near the peripheral edge of the same, a rubber tread member comprising a hub portion adapted to 'it over said first mentioned hub, the hub portion of said tread member having a circular ridge on each side of the same received in the circular flange of said side plates, said tread member having a medial web extending outwardly from said hub and a peripheral ring portion on the outer edge of said web, said peripheral ring portion having pins extending therethrough for engagement in the elongated slots of said side plates.

4. A circular abrasive wheel of the class described comprising a circular hub adapted to be mounted on a motor shaft, a pair of circular side plates attached to said hub, each of said side plates having a row of elongated slots near the peripheral edge of the same, a rubber tread member comprising a hub portion adapted to it over said first mentioned hub, means fastening the hub portion of said tread member between said side plates, said tread member having a medial web extending outwardly from said hub and a peripheral ring portion on the outer edge of said web, said peripheral ring portion having pins extending therethrough for engagement in the elongated slots of said side plates.

5. A circular abrasive wheel of the class described comprising a circular hub adapted to be mounted on a motor shaft, a pair of circular side plates attached to said hub, each of said side plates having a row of elongated slots near the peripheral edge of the same, a rubber tread member comprising a hub portion adapted to t over said first mentioned hub, means fastening the hub portion of said tread member between said side plates, said tread member having a medial web extending outwardly from said hub and a peripheral ring portion on the outer edge of said web, said peripheral ring portion having pins extending therethrough for engagement in the elongated slots of said side plates, said slots directed back at an angle from the direction of rotation.

6. An abrasive wheel of the class described comprising a solid cylindrically shaped rubber tread member having a peripheral edge for reception of an abrasive band, a plurality of pins spaced about said tread member near its peripheral edge and extending beyond both side edges of said tread member, a drive shaft, a spacer on said shaft, a medial bore through said tread member for reception of said spacer and disc-like side plates on each side of said tread member mounted on said drive shaft and fastened thereon against the ends of said spacer, and a plurality of elongated openings in said side plates near their peripheral edges for receiving the ends of said pins for driving said wheel, said tread member having shallow side bores therein and said side plates positioned in said side bores whereby the side edges of said tread member and the sides of said side plates are in planar alignment.

7. An abrasive wheel of the class described comprising a solid cylindrically shaped rubber tread member having a peripheral edge for reception of an abrasive band, a plurality of pins spaced about said tread member near its peripheral edge and extending beyond both side edges of said tread member, a drive shaft, a spacer on said shaft, a medial bore through said tread member for reception of said spacer and disc-like side plates on each side of said tread member mounted on said drive shaft and fastened thereon against the ends of said spacer, and a plurality of elongated openings in said side plates near their peripheral edges for receiving the ends of said pins for driving said Wheel, said elongated openings eX- tending outwardly from the axis of said wheel at an angle back from the direction of rotation, said tread member having shallow side bores therein and said side plates positioned in said side bores whereby the side edges of said tread member and the sides of said side plates are in planar alignment.

8. An abrasive wheel of the class described comprising a cylindrical hub 'adapted to be mounted on a motor shaft, a pair of circular side plates attached to the sides of said hub, each of said side plates having a peripheral row of spaced elongated slots therein adjacent their outer peripheries, a rubber tread member in the form of a ring positioned between said side plates, a peripheral row of pin members therein extending beyond each of the side walls of said ring member and received in the elongated slots of said side plates for controlling the position of said tread member, said tread member having shallow circular recesses in opposed side walls to receive said side plates, said recesses being as deep as the thickness of said plates.

References Cited in the le of this patent UNITED STATES PATENTS 1,186,058 Woods June 6, 1916 2,236,709 Hillix Apr. l, 1941 2,410,536 Vonnegut Nov. 5, 1946 2,795,902 Miller June 18, 1957

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