US 3818644 A
A cup grinding wheel assembly includes an abrasive wheel having a frustoconical central opening therethrough and a mating frustoconical shaped nut secured to the cup grinding wheel through a bayonet coupling. The grinding assembly is positioned on a spindle of a grinding tool.
Description (OCR text may contain errors)
United States Patent Walters 1 June 25, 1974 1 CUP GRINDING WHEEL ASSEMBLY  Inventor: Klemens C. Walters, Logan Rd.,
R.D. No. 1, Box 218, Gibsonia, Pa. 15044  Filed: May 3, 1973  App]. No.: 356,935
 US. Cl. 51/168, 51/209 R [51 Int. Cl B24b 45/00  Field of Search 51/168, 206 R, 209 R; 279/93, 103
 References Cited UNITED STATES PATENTS 2,266,604 12/1941 Murphy 279/93 2,278,301 3/1942 Bauer 51/209 R 2,486,078 10/1949 Tocci-Guilbert 51/168 2,806,331 9/1957 Hoye 51/168 3,716,951 2/1973 Walters 51/209 R FOREIGN PATENTS OR APPLICATIONS 87,300 6/1896 Germany 51/209 R Primary Examiner-Al Lawrence Smith Assistant Examinerl(. J Ramsey Attorney, Agent, or FirmWebb, Burden, Robinson & Webb  ABSTRACT A cup grinding wheel assembly includes an abrasive wheel having a frustoconical central opening therethrough and a mating frustoconical shaped nut secured to the cup grinding wheel through a bayonet coupling. The grinding assembly is positioned on a spindle of a grinding tool.
3 Claims, 5 Drawing Figures CUP GRINDING WHEEL ASSEMBLY FIELD OF THE INVENTION My invention relates to grinding equipment and, more particularly, to cup grinding wheels.
DESCRIPTION OF THE PRIOR ART In my US. Pat. No. 3,716,951, I disclosed a cup grinding wheel and frustoconical shaped nut therefor which eliminated the integral metal bushing and the resultant costly practice of discarding the unused abrasive portion which included the metal bushing. The frustoconical shaped nut contains tool engaging slots along the upper surface which are engageable by a special tool for tightening the assembly on a spindle.
My above described grinding assembly has proven effective but can be further improved by connecting the nut to the grinding wheel through a bayonet connection to form an integral unit. This improvement eliminates any slippage associated with the frustoconical shaped nut since it is held in place through its connection to the grinding wheel. In addition, the need for special wrenches is eliminated since my improved grinding assembly can be now positioned on the spindle by hand. In addition, the nut is locked to the cup grinding wheel by a simple hand manipulation.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross section taken along the center line of my grinding assembly;
FIG. 2 is an isometric of the nut;
FIG. 3 is a section through the bayonet slot of the cup grinding wheel;
FIG. 4 is a broken isometric of the bayonet slot; and
FIG. 5 is a cross section taken along the center line of a cup grinding wheel forming another embodiment of my invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT The grinding assembly, generally designated 10, includes an abrasive cup wheel 12 and a securing nut 14 attached thereto for securing the grinding assembly to a threaded spindle 16 of a grinding tool, not shown, FIG. 1. The abrasive cup grinding wheel 12 has a central opening 18 extending completely therethrough. Central opening 18 is defined by interior wall 20 and is frustoconical shaped. The outer periphery of cup grinding wheel 12 can be defined by any of the cup grinding wheel shapes and the flared sidewalls of FIG. 1 are exemplary. The actual grinding is conducted along the forward or top surface of the cup grinding wheel 12.
The nut 14 is also frustoconical shaped and the shape of the nut 14 includes the same angulation as wall of opening 18, FIG. 2. However, the nut 14 is dimensioned so that its smallest cross section or base is larger than the smallest cross section of the opening 18, FIG. 2. Nut 14 easily fits into the opening 18 but cannot extend through or reach the small base. Nut 18 includes oppositely directed lugs or bayonets 21 and 22 which are spaced 180 apart and are positioned slightly upward from the small base of the nut 14.
The cup grinding wheel 12 includes two bayonet slots 23 along the conical wall 20 which defines the central opening 18, FIG. 1. These bayonet slots 23 extend vertically through the wheel 12 and include an entry section 27 and a holding section 29 separated by a shoulder 28, FIGS. 3 and 4. Shoulder 28 and holding section 29 accommodate the lugs 21 and 22 in the assembled position.
My grinding assembly is assembled by placing the nut 14 into the central opening 18 so that the lugs 21 and 22 slip into the entry section 27 of bayonet slot 23. The nut is then given a slight turn so that the lugs 21 and 22 are moved into the holding section 29 beneath shoulder 28 of the bayonet slots 23. The grinding assembly is then placed on the spindle and merely rotated by hand so that the threaded hole 17 in the nut threadably engages the spindle 16 of the grinding tool. The nut 14 forces the cup grinding wheel 12 against the adapter plate 24 which can be an integral part of the grinding tool. Because of the dimensions of the nut 14 relative to the opening 18 in the cup grinding wheel 12, a space 25 is formed between the bottom of the nut 14 and the adapter plate 24, FIG. 1. 7
After use the remaining grinding assembly 10 is normally removed by merely striking the wheel 12 against a hard rigid object such as the workpiece being ground. The nut 14 is easily removed by hand through a slight turning movement and is then ready for reassembly with another cup grinding wheel.
The cup grinding wheel 12 can also be formed with a thin metal backing plate 30 secured thereto, FIG. 5. This backing plate is molded into mechanical securement with wheel 12 by means of a plurality of keys 32 punched outwardly from plate 30 at an angle of about and which extend upwardly into the abrasive wheel 12. Plate 30 includes a central opening 31 which loosely accommodates the spindle of a grinding tool. The inclusion of plate 30 in the grinding assembly avoids the necessity of an adapter plate since the plate 30 can be tightened against the standard grinding tool fitting which accommodates the metal bushings of the prior art.
1. A grinding assembly for securement on a grinding tool including a cup grinding wheel having a frustoconical central opening defined by an inner wall and extending therethrough and a nut, the sidewall of which is at the same angulation as said inner wall, the nut dimensioned so as to be wholly retained within the central opening and having at least one lug extending outwardly from the sidewall, said inner wall having at least one bayonet slot recessed therein to accommodate each lug and form a bayonet coupling therebetween.
2. The assembly of claim 1, each bayonet slot defined by a vertically extending receiving section and an adjacent holding section including a shoulder which accommodates the lug in a locked position.
3. The assembly of claim 1, said grinding wheel including an apertured bottom plate having a plurality of integral keys extending into and mechanically secured to said grinding wheel.