US3780476A

US3780476A - Grinding wheel and mounting assembly

Info

Publication number: US3780476A
Application number: US00278768A
Authority: US
Inventors: T Sipe
Original assignee: General Motors Corp
Current assignee: Motors Liquidation Co
Priority date: 1972-08-08
Filing date: 1972-08-08
Publication date: 1973-12-25
Anticipated expiration: 1990-12-25

Abstract

A solid grinding wheel substantially in the form of a cloverleaf having equiangular spaced petals and the like spaced roots defined therebetween, the spaced roots receiving flanged retaining pins securing the grinding wheel to a rotatable drive shaft. The shanks of the flanged retaining pins include a portion of increased diameter including a tapered cam surface engaged by a like tapered cam surface on an adjustable nut of a chuck mounting assembly. The adjustable nut is internally threaded and received upon a sleeve in the chuck assembly and presents a tool receiving end through which the shanks of the retaining pins are received with the flanges engaging the outside surface of the grinding wheel. Tightening movement of the nut engages the mating tapered cam surfaces axially moving the retaining pins drawing the grinding wheel into engagement with an end of the driving shaft. A conical protuberance is provided on one surface of the grinding wheel and is received in a like recess in the end of the driving shaft thereby aligning the wheel on the shaft prior to firmly securing it by rotation of the adjustable nut. Coolant fluid passages are provided in the flanged retaining pins so that coolant fluid is directed onto work engaging surfaces of the grinding wheel beneath a wind barrier created when the wheel is rotated at high speeds. The adjustable nut can be formed to accommodate a fluid collector sleeve which is secured to the nut and extends away from the grinding wheel terminating in an arcuate portion receiving coolant discharged from a source under pressure, the fluid being received by the collector sleeve and directed through the passages in the flanged pins for discharge onto the grinding wheel work engaging surfaces.

Description

United States Patent [191 Sipe ' GRINDING WHEEL AND MOUNTING ASSEMBLY Therell L. Sipe, Sandusky, Ohio [73] Assignee: General Motors Corporation,

Detroit, Mich.

[22] Filed: Aug. 8, 1972 [21] Appl. No.: 278,768

[75] Inventor:

Peterson 51/168 X Herczeg 51/168 X Primary Examiner-Donald G. Kelly Att0rneyFrank J. Soucek et a1.

[57] ABSTRACT A solid grinding wheel substantially in the form of a cloverleaf having equiangular spaced petals and the like spaced roots defined therebetween, the spaced roots receiving flanged retaining pins securing the grinding wheel to a rotatable drive shaft. The shanks Dec. 25, 1973 of the flanged retaining pins include a portion of increased diameter including a tapered cam surface engaged by a like tapered cam surface on an adjustable nut of a chuck mounting assembly. The adjustable nut is internally threaded and received upon a sleeve in the chuck assembly and presents a tool receiving end through which the shanks of the retaining pins are received with the flanges engaging the outside surface of the grinding wheel. Tightening movement of the nut engages the mating tapered cam surfaces axially moving the retaining pins drawing the grinding wheel into engagement with an end of the driving shaft. A conical protuberance is provided on one surface of the grinding wheel and is received in a like recess in the end of the driving shaft thereby aligning the wheel on the shaft prior to firmly securing it by rotation of the adjustable nut. Coolant fluid passages are provided in the flanged retaining pins so that coolant fluid is directed onto work engaging surfaces of the grinding wheel beneath a wind barrier created when the wheel is rotated at high speeds. The adjustable nut can be formed to accommodate a fluid collector sleeve which is secured to the nut and extends away from the grinding wheel terminating in an arcuate portion receiving coolant discharged from a source under pressure, the fluid being received by the collector sleeve and directed through the passages in the flanged pins for discharge onto the grinding wheel work engaging surfaces.

3 Claims, 3 Drawing Figures GRINDING WHEEL AND MOUNTING ASSEMBLY This invention relates to a grinding wheel and mounting device therefor providing a means for securing a solid grinding wheel for high speed operation and more specifically to a solid grinding wheel, cloverleaf in form, having equiangular spaced petals and being retained by flanged pins having coolant fluid conducting passages therein.

In high speed operation, it is necessary to mount a grinding wheel composed of bonded abrasive particles in the most positive manner possible. An aperture through such a wheel for the purpose of receiving a fastening device necessarily results in a concentration of forces in the wheel in the area of the aperture. This concentration of forces frequently results in undesirable fracturing of the wheel. Also during high speed grinding operations it is desirable to supply a coolant fluid to the work engaging surfaces of the wheel so as to prevent generation of heat sufficient to create temperatures which may effect the bonding characteristics of the wheel. The supply of coolant fluid to the work engaging surfaces is difficult to accomplish because of a wind barrier, spaced from but conforming to the work engaging surfaces of the wheel, developing during high speed grinding operations.

In accordance with the disclosure of the present application, these objective are achieved in a structural combination of a chuck supporting a solid grinding wheel. The chuck is mounted on a drive shaft extending through the chuck into engagement with a side surface of the grinding wheel. The side surface of the wheel has an axially extending protuberance that is received in a recess in the end of the drive shaft positioning the wheel relative to the shaft. In preferred form, the solid grinding wheel resembles a cloverleaf including petals with roots therebetween. Pins having flanged or headed ends and containing coolant fluid conducting passages are disposed in the roots so that headed ends engage the exterior side surface of the solid grinding wheel. The shanks of the pins are received in the chuck adjacent the drive shaft. An adjustable nut associated with the chuck assembly includes cam surfaces engaging like surfaces on the retaining pins so that rotation of the nut moves the pins axially relative to the drive shaft. The engagement of the headed ends of the pins against the exterior side surface of the solid grinding wheel consequently draws the wheel into firm engagement with the end of the drive shaft providing a positive mouting arrangement.

A general object of this invention is to provide a solid grinding wheel and mounting means therefor capable of withstanding high speed grinding operations.

A further object of this invention is the provision of a solid grinding wheel, cloverleaf in form, defining roots receiving headed retaining pins, the shanks of which are firmly secured in a chuck assembly.

Another object of the subject invention is the provision of a cloverleaf form solid grinding wheel that is retained by flanged pins in a chuck mounting assembly, the retaining pins including an enlarged diametrical shank portion having a tapered surface thereon which is engaged by a like surface on the adjusting nut of the chuck assembly so that the pins are axially moved when the nut is rotated securely fastening the wheel against a driving shaft.

A still further object of the subject invention is the provision of coolant passages in the headed retaining pins for transmitting coolant fluid to the work engaging surfaces of a solid grinding wheel beneath a wind barrier created during high speed operation.

Another object of the subject invention is to provide coolant passages in headed retaining pins directing coolant fluid to work engaging surfaces of a solid grinding wheel and to secure a fluid collector sleeve to a chuck assembly securing the headed retaining pins so that the collector sleeve receives fluid from a pressurized source and directs it through the passages in the headed retaining pins.

The novel features which I believe to be characteristic of my invention are set forth with particularlity in the appended claims. My invention itself, however, both as to its organization and method of operation may be best understood by referring to the following description taken in conjunction with the accompanying drawing in which:

FIG. 1 is a side elevational view with portions broken away illustrating the grinding wheel and mounting assembly of the subject invention.

FIG. 2 is an end view taken in the direction of lines 22 in FIG. 1.

FIG. 3 is an exploded isometric view illustrating the specific elements of the grinding wheeland mounting assembly of the subject invention.

Referring now to the drawing, in FIG. 1 a solid grinding wheel of the subject invention is shown mounted against end 12 of a drive shaft 14. A plurality of headed pins 16 are received within a chuck assembly 18 to retain the wheel 10 against drive shaft end 12. The pins 16 include a flanged head 20 which engages an exterior side surface 22 of the grinding wheel 10 as shown. The pins 16 also have a shank portion 24 which is enlarged in diameter relative to

shank portions

26 and 28 of the pin and includes a tapered cam surface 30. The pins 16 terminate in a second enlarged shank portion 32 for a purpose later described.

The chuck assembly 18 is secured to drive shaft 14 in a conventional manner not shown. It includes an externally threaded sleeve 34 which is positioned relative to a slightly enlarged section 36 of the drive shaft 14 so that the internal surface 38 of the sleeve 34 and the external surface 40 of the drive shaft cooperate to define an aperture guiding axial movement of the pin 16 therebetween as the enlarged shank portion 32 engages both surfaces. The aforementioned enlarged shank portion 24 includes a circumferential surface 42 engaging a slightly reduced diameterical surface 44 of the drive shaft 14 to also guide axial movement of the pin 16 within the chuck assembly 18. The chuck assembly 18 further includes an adjustable nut 46 which is threadably received upon sleeve 34 and is formed to include a tapered cam surface 48 matingly engaging like surface 30 of pin 16. The adjustable nut 46 can be provided with a relieved portion 49 fixedly mounting a fluid collector sleeve 50 which in turn includes a rearwardly and inwardly extending arcuate portion 52 which receives coolant fluid from a source under pressure such as shown at a nozzle 54 for purposes of illustration only.

As more specifically shown in FIGS. 2 and 3, the solid grinding wheel 10 is cloverleaf in form including petals 56 with roots 58 therebetween. The grinding wheel 10 further includes, in preferred form, a conical protuberance 60 which extends from side surface 62 rearwardly for engagement with a mating aperture 64 formed in the end 12 of drive shaft 14. These figures clearly illustrate that the flanged heads of pins 16 are received within the roots 58 of the solid grinding wheel so that the flanges engage the external side surface 22 of the grinding wheel.

In operation, the solid grinding wheel 10 with its protuberance 60 positioned within aperture 64 of the drive shaft 14 is centrally aligned on the end 12 of the drive shaft. The pins 16, with their headed flanges 20 engaging side surface 22 of the grinding wheel, are received within the chuck assembly 18 when the adjustable nut 46 has been sufficiently rotated to expand the chuck assembly. As this time the enlarged shank portion 24 with its tapered cam surface 30 is positioned adjacent the mating cam surface 48 of the adjustable nut 46. Likewise, the enlarged shank portion 32 of the pins 16 are received between the interior surface 38 of sleeve 34 and the exterior surface 40 of the enlarged portion 36 of shaft 14. Also the circumferential surface 42 of the enlarged shank portion 24 engages exterior surface 44 of the drive shaft 14 so that the pins are positively positioned but yet loosely retained within the chuck assembly 18 for axial movement therein when the nut 46 is rotated in a tightening direction. Tightening movement of the nut 46 engages cam surface 48 with cam surface 30 of the pins 16 slidably moving the engaging surfaces of the enlarged shank portions along exterior surfaces 40 and 44 of the drive shaft 14 as well as along interior surface 38 of sleeve 34. The guiding axial movement of the pins continues until the headed flanges 20 are drawn tightly against side surface 32 of the grinding wheel 10 so that the interior surface 62 of the wheel is in rigid contact with end surface 12 of drive shaft 14 thereby positively retaining the wheel 10 upon the end 12 of shaft 14 for use during high speed grinding operations.

Ifit is desired to supply a coolant fluid to work engaging surfaces 11 of the solid grinding wheel 10, the fluid is supplied through nozzle 54 adjacent the arcuate portion 52 of collector sleeve 50. The arcuate portion 52 catches the coolant fluid and supplies it to passages 27 in the pins 16 from which it exits laterally extending passages 17 for distribution about the periphery about the grinding wheel 10 and more specifically to the work engaging surfaces 11. The supplying of the coolant fluid through pin passages 27 and the lateral passages 17 results in the fluid being discharged beneath a wind barrier that develops around the wheel during high speed operation. Obviously the supplying of the fluid in this manner eliminates the problem of attempting to pass the coolant fluid through the wind barrier during rotation of the grinding wheel 10.

While I have shown and described a specific embodiment of the present invention it will, of course, be understood that various modifications and alternative constructions may be made without departing from its true spirit and scope. In particular, it is possible to vary the specific configuration of the cloverleaf form of the solid grinding wheel 10 so as to present a work engaging surface 11 of different form than that illustrated in FIGS. 2 and 3. Further, it is possible to vary the configuration of collector sleeve 50 which is provided to collect the coolant fluid and supply it to the passages 27 in the retaining pins 16. With these possibilities in mind, therefore, I intend by the appended claims to cover all modifications of the subject invention which fall within their true spirit and scope.

I claim:

1. In a solid grinding wheel and chuck assembly secured to a drive shaft, a sleeve defining a tool receiving opening and including an adjustable nut threadably mounted on the sleeve, the nut having a tapered cam surface on the inner periphery thereof adjacent an axial opening registering with the opening in said sleeve, comprising in combination; a grinding wheel proper defined by a generally cloverleaf disk-like body of grinding material having equiangular spaced petals defining roots therebetween in axial alignment with the tool receiving opening in said sleeve, said drive shaft having a grinding wheel aligning cavity in an end surface, a centering protuberance on said solid grinding wheel received in the shaft aligning cavity, a pin having a flanged headed end received in each of the roots and in the tool receiving cavity of said chuck sleeve as well as within the axial opening in said adjustable nut, and a tapered cam surface on said headed pin engaged by said tapered cam surface on said adjustable nut so that tightening movement of said nut axially moves said pins engaging their heads with a side surface of said grinding wheel adjacent said roots drawing the wheel tightly against the end of said shaft for high speed rotation.

2. In a solid grinding wheel and chuck mounting assembly adapted to be secured to a drive shaft, a sleeve in said chuck defining a tool receiving opening and an adjustable nut coaxially threadably mounted on said sleeve and having an axial opening in alignment with the opening in said sleeve, the adjustable nut also having a tapered cam surface adjacent the axial opening, the combination comprising; a grinding wheel proper defined by a generally cloverleaf disk-like body of grinding material having spaced petals and roots therebetween, the roots being in axial alignment with the tool receiving cavity in said sleeve, said drive shaft extending through said chuck assembly and having an end surface with a grinding wheel aligning cavity therein, a centering protuberance on a side surface of said grinding wheel received in said shaft aligning cavity, a retaining pin having a headed end and a shank portion, the headed end of a pin each being positioned in a respective root of the grinding wheel while the shank portions are received within the aligned openings in said chuck, an enlarged portion on said shank engaging the exterior surface of said drive shaft, a tapered cam surface on said enlarged chuck portion adjacent said cam surface on said adjustable nut, rotation of said adjustable nut in a tightening direction axially moving said pins by the engagement of the said nut and said pin shank portion cam surfaces drawing their heads against a side surface of said solid grinding wheel adjacent each root therein and further tightening movement of said adjustable nut tightly engaging a side surface of said grinding wheel with the end surface of said drive shaft for high speed rotation thereof, said pins each containing an axial passage connecting with a lateral discharge passage adjacent the peripheral edge of said solid grinding wheel, and a collector sleeve secured to said chuck assembly and configured to receive and collect coolant fluid supplied under pressure from an external source for direction through the axial passages and discharge onto the peripheral surface and consequently the work engaging surfaces of said solid grinding wheel.

3. The combination as described in claim 2 wherein said headed retaining pins further comprise a second enlarged shank portion adjacent their ends opposite from said heads, the enlarged portion being received between the exterior surface of said drive shaft and an internal surface of said chuck sleeve for guiding said pins during their axial movement in a grinding wheel tightening direction.