US2857719A - Grinding wheels - Google Patents

Description

A. A. MILLER GRINDING WHEELS Oct; 28, 1958 4 Sheets-Sheet 1 Filed Aug. 5, 1957 ITTaA VEX Oct. 28, 1958 A. A. MILLER 2,857,719

GRINDING WHEELS Filed Aug. 5, .1957 v 4 Sheets-Sheet 2 INVENTOR.

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' GRINDING WHEELS Filed Aug. 5, 1957 4 Sheets-Sheet 3 HIHIIIIIIIIIIIIWF INVENTOR. Jan/we fl. Mame lrroz/vif Oct. 28, 1958 A, MlLLER 2,857,719

GRINDING WHEELS Filed Aug. 5, 1957 Y 4 Sheet sS hee t 4 a h i 5'3 i United States Patent GRINDING WHEELS Arthur A. Miller, McHenry, Ill., assignor to Arthur A. Miller, McHenry, and Lou C. Casanov, Waukegan,

Application August 5, 1957, Serial No. 676,257

11 Claims. (Cl. 51191) 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 portion 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 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 1 the same. This movement is prevented in the device forming the subject matter of the present invention in a manner to be described hereinafter.

The principal object of the present invention is to provide an improved construction of grinding wheel having a tread portion capable of guided movement during expansion and provided with pin members adapted to move in elongated slots in the disc wheel members or plates in which the same is mounted.

Patented Oct. 28, 1958 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 of a modified form of construction;

Fig. 5 is a side elevational view of a different form of the rubber tread member which I employ;

Fig. 6 is a cross-sectional view thereof taken generally on the line 66 of Fig. 5;

Fig. 7 is a side elevational view of one of the sheet metal side plates which I employ;

Fig. 8 is a side elevational view of the hub of the grinding wheel; and

Fig. 9 is a cross-sectional view similar to Figs. 3 and 4, showing a further modified form of the invention.

In the embodiment of the invention which I have chosen to illustrate and describe the same, Ihave shown a grinding wheel 10 which may be mounted upon the drive shaft 12 of an electric motor 14, the shaft 12 being screw-threaded at the end to receive a Washer and locking nut 16. The grinding wheel may consist of a minimum of partsa tread member upon which a sanding belt may be applied, a pair of side plates for generally supporting the side member, and a hub which provides a mounting for the grinding-wheel and also a means for attaching together the side plates and the tread member so that in its simplest design the grinding wheel is formed of only four parts.

The grinding wheel includes a pair of circular side plates 18 and 20, the plate 18 having the opening 22 to receive the shaft 12 and the side plate 20 having the opening 24 to permit access to the locking nut 16. The side plates or mounting plates 18 and 20 are provided with outwardly turned circular flanges 26 and '28 and a radial row of aligned elongated openings 30 and 32 to receive the ends of the pin members 34. Rivets 37 may extend through the circular ridges 26 and 28 to rigidly fasten the side plates, the side walls of the tread portion, and the hub together, as will be hereinafter described.

The tread member 36 may consist of a circular disclike member which has a comparatively hard rubber'outer peripheral portion 38, the side walls 40 and 42 of the A further object of the present invention is to provide I an improved construction of grinding wheel wherein the tread portion is mounted in a floating manner at radially spaced points throughout its circumference, the face of the same being maintained in exact alignment at low or high speeds of grinding, and the edges of the same being flexible within limits to permit the expansion or increase in the diameter of the wheel at such speed.

A further object is to provide a grinding wheel of the type described that is easily and simply constructed out of a minimum of parts, yet which when assembled provide an effective and highly efficient grinding wheel construction.

This application for patent shows an improvement on the construction of grinding wheels shown and described in my two issued United States Patents Nos. 2,795,902 issued June 18, 1957, and 2,798,342 issued July 9, 1957.

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

Fig. l is a plan view of a grinding or abrasive wheel Fig. 2 is a front elevational view of the same;

same extending inwardly and being provided adjacent their inner circular edges 44 and 46 with aligned circular ridges 48 and 50 that engage in the grooves of the mounting plates formed by the outwardly projecting ridges 26 and 28 of the mounting plates 18 and 20.

The inner sides of the side walls 40 and 42 are pressed against a circular shoulder 52 on the hub 54, the shoulder terminating in a pair of lateral ledges 56 and 58 of a diameter to receive the inner edges 44 and 46 of the side walls of the tread member. The pins 34, previously described, that engage in the elongated slots 30 and 32 in the side members 18 and 20, are firmly held in bores 60 in the tread portion 38 of the tread member 36.

Each of the side walls 40 and 42 of the tread member is provided with annular inwardly directed ridges 70 and 72 so that from centrifugal force the peripheral surface of the tread member may be expanded to a larger diameter, the extent of the same being controlled by the pin members 34 in the elongated slots 32 of the mounting plates. When the peripheral surface of the tread member is expanded, the abrasive band B which is used for sanding or grinding is thus efiectively tightened on the same.

I have also found that by directing the elongated openings 30 and 32 at a peak angle from the direction of rotation, 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 wall forming a, solid bracing for the expanded tread member at a high rate of speed.

The hub 54 is a comparatively simple casting or turned member which includes the medial bore 74 to receive the shaft 12, the circular shoulder 52 extending from the body portion of the same and the enlarged bore 76 in the front end of the same to receive the locking nut 16. The openings .78 are drilled thercthrough to receive the fastening rivets 37.

In Fig. 4 I have shown a modification of the structure of the hub 54 providing in the ledge 52 thereof a pair of semi-circular grooves 80 to receive a pair of circular ledges 82 and 84 upon the inner faces of the side walls 40 and 42 of the tread member 36. The side walls 18 and are held together by a plurality of rivets 83 that extend through the ledges 82 and 84 and through suitable holes 85 in the side walls 18 and 20, thereby fastening together the hub, the side walls and the tread member solely by these rivets. In this construction it will also be noted that the inwardly directed expansion ledges 70 and 72 of the construction shown in Fig. 3 have been omitted, it having been discovered that. under certain conditions and speeds there is sufiicient elasticity in the walls and 42 to permit the desired expansion of the circumference of the tread member and abrasive band.

In the embodiment of the invention shown in Fig. 9 I have provided both of the side plates 18 and 20 with an axial bore 22 to receive the drive shaft 12 of a motor, the locking nut 16 in this construction being fastened directly against the side plate 20 and the side plate 22 bearing against the shoulder 13 of the motor 14 through which the shaft 12 extends. The side plates 20 and 22 may be fastened directly to the hub 54 by means of two sets of screw members 53 and extending inwardly from opposite sides of the hub and being secured in bevelled openings in the side plates. In this construction the entire assembly, consisting of the hub, side plates and the tread member, are thus assembled and locked together by the simple expedient of fastening four screw members.

As a further variation in the design and construction of the grinding wheels, I mount the pin members 34a rigidly in aligned openings 35 in the side walls 18 and 20, the pins extending through elongated openings 90 in the solid peripheral portion 38 of the tread member 36.

B to a slightly larger diameter, the same being controlled generally throughout the circumference of the grinding wheel by the provision of the circular row of elongated openings through which the solidly mounted pin members project.

With this construction and the comparatively large number of pressure resistant points about the periphery or diameter of the grinding wheel, I have found that effective straight grinding may be done across the entire face of the abrasive band B, as contrasted with those constructions in which the effect of pressure upon the surface tends to belly in the abrasive band and thus no elongated surface can be effectively ground in a straight line. With the construction shown in this application this type of grinding is easily effected and can be done with such eificiency that a larger number of grinding operations per minute can be effected with this grinding wheel.

From the above and foregoing description it can be seen that I have provided a highly improved construction of grinding wheel, one in which in effect under centrifu'gal force a self-balancing wheel is obtained, a wheel at the angle shown, solid supportis afforded the grinding s rface at a ura t f ga ns throughout h P I PhEF of the grinding wheel.

While in the construction shown eight supporting pins are provided on a 7-inch diameter grinding wheel, naturally a larger number of pins would be required for a wheel of a larger diameter, the amount depending entirely upon the size of the grinding wheel and the nature of the grinding operations to be performed by the same. The tread member as shown is a single molded rubber structure including the comparatively solid tread portion and the side walls together with their fastening ridges, the side walls being elastic due to the reduction in the thickness of their walls, thus providing in a single tread unit a highly eflicient member which is not only capable of long and hard usage without becoming broken or worn out, but which, due to its construction, provides a simple and quick assembly with the side plates and the huh.

I contemplate that changes and modifications may be made in the various details shown and I 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. A circular abrasive wheel of the class described comprising a circular hub adapted to be mounted on a motor shaft, said hub having a pair of reduced shoulders and a central flange, a pair of circular side plates attached thereto, a rubber tread member having a peripheral flange, said tread member having inwardly extending side walls secured between said side plates and said hub, and a pin and slot connection between said side plates and said tread member for permitting uni form expansion of the diameter of the same at a high rate of speed, each of said tread member side walls being comparatively thin and having a central opening to fit over said hub flange and a circular ridge concentric to said opening, said side plates having a groove in the facing walls of each side plate to receive said ridges.

2. A circular abrasive wheel of the class described comprising a circular hub adapted to be mounted on a motor shaft, said hub having a pair of reduced shoulders and a central flange, a pair of circular side plates attatched thereto, a rubber tread member having a peripheral flange, said tread member having inwardly extending side walls secured between said side plates and said hub, a pin and slot connection between said side plates and said tread member for permitting uniform expansion of the diameter of the same at a high rate of speed, each of said tread member side walls being comparatively thin and having a central opening to fit over said hub flange and a circular ridge concentric to said opening, said side plates having a groove in the facing walls of each side plate to receive said ridges, and rivets passing through said side plates, tread member, side walls and the central flange of said hub for assembling said abrasive wheel together.

3. A circular abrasive wheel of the class described comprising a circular hub adapted to be mounted on a motor shaft, said hub having a pair of reduced shoulders and a central flange, a pair of circular side plates attached thereto, a rubber tread member having a peripheral flange, said tread member having inwardly extending side walls secured between said side plates and said hub, a pin and slot connection between said side plates and said tread member for permitting uniform expansion of the diameter of the same at a high rate of speed, each of said tread member side walls being comparatively thin and having a central opening to fit over said hub flange and a circular ridge concentric to said opening, said side plates having a groove in the facing walls of each side plate to receive said ridges, and rivets passing through said side plates, tread member, side walls and the central flange of said hub for assembling said abrasive wheel together, said pin and slot connection comprising a circular row of pins connected between said side plates extending through elongated slots in said hard rubber flange.

4. A circular abrasive wheel of the class described comprising a circular hub adapted to be mounted on a motor shaft, said hub having a pair of reduced shoulders and a central flange, a pair of circular side plates attached thereto, a rubber tread member having a peripheral flange, said tread member also having inwardly extending side walls secured between said side plates and said hub, a pin and slot connection between said side plates and said tread member for permitting uniform expansion of the diameter of the same at a high rate of speed, each of said tread member side walls being comparatively thin and having a central opening to fit over said hub flange and a circular ridge concentric to said opening, each of said side plates having a groove in the facing walls of each side plate to receive said ridges, and rivets passing through said side plates, tread member, side walls and the central flange of said hub for assembling said abrasive wheel together, said pin and slot connection comprising a circular row of pins connected between said side plates extending through elongated slots in said hard rubber flange, said slots being at an angle biased outwardly and away from the direction of rotation.

5. A grinding wheel comprising a solid hub that is in the form of a flat cylinder having a pair of outstanding lateral ledges and a medial concentric shoulder therebetween, a pair of disc-shaped side plates, each having a circular peripheral groove at a point adjacent the lateral ledge of said hub, and a tread member, said tread member having a solid peripheral edge and comparatively thin flexible side walls, said side walls having an axial bore to receive said hub and each having a lateral ridge to fasten the same between the side plates and said hub.

6. A grinding wheel comprising a solid hub that is in the form of a flat cylinder having a pair of outstanding lateral ledges and a medial concentric shoulder therebetween, a pair of disc-shaped side plates, each having a circular peripheral groove at a point adjacent the lateral ledge of said hub, and a tread member, said tread member having a solid peripheral edge and comparatively thin flexible side Walls, said side walls having an axial bore to receive said hub and each having a lateral ridge to fasten the same between the side plates and said hub, said side plate being fastened to said hub by screw members from each of said side plates, whereby said side plates, said tread member and said hub are integrally connected together.

7. An abrasive wheel 'of the class described comprising a circular hub adapted to be mounted on a motor shaft, a pair of circular shoulders on the sides of said hub, said hub having a pair of circular side plates attached thereto over said shoulders, a rubber tread member having a peripheral flange and inwardly extending side walls, said side walls secured between said side plates and said hub, and a pin and slot connection between said side plates and said tread member for permitting uniform expansion of the diameter of the same at a high rate of speed.

8. An abrasive wheel of the class described comprising a hub adapted to be mounted on a motor shaft, a pair of circular shoulders in the sides of said hub, said hub having a pair of circular side plates attached thereto over said shoulders, a rubber tread member having a peripheral flange and inwardly extending side walls, said side walls secured between said side plates and said hub, and a pin and slot connection between said side plates and said tread member for permitting uniform expansion of the diameter of the same at a high rate of speed, said pin and slot connection consisting of a circular row of pins fastened in said peripheral. flange and extending through slots in said side plates.

9. An abrasive wheel of the class described comprising a hub adapted to be mounted on a motor shaft, said hub having a pair of circular side plates attached thereto, a circular rubber tread member having a pair of side flanges, one flange secured between one of said side plates and one side of said hub, and a pin and slot connection between said side plates and said tread member for permitting uniform expansion of the diameter of the same at a high rate of speed, said pin and slotconnection consisting of a circular row of pins fastened in said tread member and extending through slots in said side plates, said slots being elongated and at an angle backwardly and outwardly from the direction of rotation.

10. A circular abrasive wheel of the class described comprising a circular hub adapted to be mounted on a motor shaft, said hub having reduced side shoulders and an enlarged central flange, a pair of circular side plates attached to said hub, a rubber tread member having a peripheral flange, said flange having inwardly extending side walls secured between said side plates and the shoulders of said hub, and a pin and slot connection between said side plates and said tread member for permitting uniform expansion of the diameter of the same at a high rate of speed.

11. A grinding wheel comprising a solid hub that is in the form of a flat cylinder having a pair of outstanding lateral ledges and a medial concentric shoulder therebetween, a pair of disc-shaped side plates, each having a circular peripheral groove at a point adjacent the lateral ledge of said hub, and a tread member, said tread member having a solid peripheral edge and comparatively thin flexible side walls, said side walls having an axial here to receive said hub and each having a lateral ridge on both sides of the same to fasten the same between the side plates and said hub, said side plates and both side walls of said hub having grooves therein to receive the ridges on said side walls.

References Cited in the file-0f this patent UNITED STATES PATENTS 540,828 Casgrain June 11, 1895 2,264,589 Rydquist Dec. 2, 1941 2,410,536 Vonnegut Nov. 5, 1946 2,795,902 Miller June 18, 1957

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