US1873423A - Grinding machine - Google Patents

Description

F. M. KERN GRINDING MACHINE Aug. 23, 1932.

Filed Nov. 5, 1925 INVENTOR.

W M a.

ATTORNEY.

formly and continuously, markings the grinding zone.

Patented Aug. 23, 1932 UNITED STAT s PATENT OFFICE FRE D M. KERN, OF DETROIT, MICHIGAN,

CINCINNATI GRIND-ERS INCORPORATED, 013 CINCINNATI, OHIO, A CORPORATION OF OHIO ASSIGNOR, BY 'ivrnsivn ASSIGNMENTS, TO

GRINDING MACHINE Application filed November 5, 1923. Serial No. 672,773.

This invention relates to centerless grinding machines, and more particularly'to a niachineof this type adapted to grind to a cylindrical form various articles which are of such shapes or'sizes that it is difiicult for the wheels to rotate and feed the work unian'd detrimental tend to be formed thereon, and for grinding non-cylindrical bars especially substantially uniform cross which are of a section. It is an object of my invention to provide a centerless grinding machine which is'ad'apted to reduce objects of a non-cylindrical contour to a substantially true cylindrical form in a single operation.

It is a further object of .my invention to provide a two-wheeled centerless grinding lmachine with a work positioning member so arranged and constructed that the work will be maintained in correct axial position d'uring grinding and rotatedumformly' and fed continuously through the grinding zone.

Qther objects will be apparent in the following disclosure. i

In accordance with the invention, I provide a centerless grinding machine having a pair of abrasive wheels cooperating in such a manner as to rotate and grind the work and if desired to feed the work axially through 1 The wheels, preferably,

are rotated 1n the same direction at different speeds, one of the'wheels serving as a grinding wheel and rotating at a relatively high speed while the other acts as a regulating .wheel and rotates at a relatively slower rate.

. In order to reduce an article of non-cylindrical shape, such as a rod of square cross section, to substantially true cylindrical form, Iprovide a rotatable work positioning memher in operative association with the wheels which will permit the work to rotate continuously during the grinding operation. If the work is longer, than the width of the grinding wheel,-I utilize a rotatable bushing adapted to slidably engagethe work and ro tatively guide the same while permitting it to move in the direction of its axis of rotation. The bushingis preferably so mounted that it will be rotated by the work. The

2 2 of Fig.1

I active surfaces of the wheels may be tapered, ,if desired, to gradually Fig. 3 is a plan view of the wheels and work support, parts being removed and the inclination of one of the wheels being exaggerated for the sake of clarity of illustration; 1

Fig. 4 is a section, broken away, showing a bar in operative grinding contact with the two abrasive wheels.

While the invention use in connection with any well of centerless grinding machine, poses ofillustration, I have shown in the drawing, a grinding machine provided with a pair of'abrasive wheels mounted on axes which are in parallel planes, one of the axes being inclined to a third plane which is at right angles to passes through the other axis.

Attached to the frame 1 of this machine is a guide 2 on which a carriage 3 is slidable, being adjustable by means of the screw hand the vcarriage 3 is formed with guides for the vertical bracket 5 which may be moved up or down by means of a screw 6.

The upper end of this bracket 5 constitutes a bearing for a bushing 7 which is formed may-be adapted for known type with a longitudinal hole 8 to receive a rod or for the pur-- Y the work action. While v I and 13 of the two wheels in Contact with the character shown in the drawing,

' Fig. 2, the rodbeing on the usual paper making machines andimpregnated with phenol condensation prod- 7 note such as bakelite, the finished product being also known as Celeron, F ibrok and Bakelite-Micarta. These sheets are usually cut into rods of rectangular cross section, but the material need-not necessarily be formed into these sheets asit may be pressed into rods having square or any other desired cross section. These-rods have usually been finished by means of ordinary cutting tools, but this .material rapidly dulls even the hardest cutting tools and furthermore has a tendency to tear out and otherwse be damaged during the machining.

By the use of a grinding machine of the v rodsnia be introduced between the grinding "wheels 10 and 11 and as these. grinding wheels are formed with beveled or rounded edges 12 and 13, the pull of the inclined wheel '10 is suffi. cient to draw the work 9 inwardand through between the two grinding wheels. The width of the cylindrical portions of these wheels must be sufiicient to give enough friction on to move it endwise against the cutting pressure ofthe beveled or rounded portions. Thesewheels are beveled or rounded at the entrance ends to gradually reduce the work. These twofwheels rotate in the same direction, the wheel 11 rotating very-much inclined wheel 10 and perholdthe work in it alongon the support 15 against which the work is held by the wheel 11 because of its higher speed and also because of its cutting Fig. e'shows the cornerslQ flaring surfaces ofthe work 9, it is'not necessary that the corner 12 ofthe wheel should so contact as a slight'clearance is preferred.

When rods of this character are to be ground, a proper bushing 7 may be mounted in the bracket '5, the bushing being provided with a hole practically thecross section of the unfinished rods. 9.. I have found that good work can turned out by providing a cylindrical guide hole intheupper end of the bracket 5 in which hole the work isrotatable withoutlateral chatter. The operator passes the front end of the rod '9 through this bushing andfor ces it in between the two wheels so that the end will be ground asindicated in Fig. 4, but after the front end of the rod has been ground suflicientl to approach the rear side of the grinding w eels, theaction of the inclined wheel 10 becomes eflective'to move the rod longitudinally toward the right in supported on the guide 15 and moving forward toward the right in that" figure until entirely finished. The

wheels are preferably almost completelyenclosed in casings 16.

Whilelhave shown a square rod being machine and thus stop plane, but I do not wish ground to cylindrical form, the original rods may be of any other desired cross section, but it is necessary in grinding a square rod to a cylindrical shape, for example, for the grinding wheels 10 and 11 to have their corners 12 and 18 rounded to such an extent that nosquare shoulders will-be formed on the rods, for otherwise such shoulders would prevent the rods from moving its automatic action.

The axes of the two grinding wheels shown in Fig. "1 are in substantially. a horizontal to be limited thereto as such wheels may be so arranged with relation to each other that their axes may be in any otherdesired planes.

Inthe grinding of rods of fibre desirable eitheralone or in combination with other non-aqueous fluids, which'has the'efi'ect of forward through the it is very. to use a solution of crudepet-roleum or one of itsdistillates, such as kerosene,

:eeping the abrasive wheel from becoming clogged with the particles of fibre removed from the work and italso serves to carry away the ground might have a tendency to be carriedaround' by the grinding wheel and pass between the work and the grinding surface, thus causing scratching and tearing of the surface of the work. By using a liquid of this character a very fine high polish maybe imparted to the work and the work may be ground with unusual. accuracy.

The details tions of the parts of this machine may all be varied by those skilled in the art withoi lt departing from the spirit of my invention as setforth in the following claims.

I claim 1. In a grinding machine, in combinatiomi a grinding wheel adapted to be rotated at a relatively high speed, a regulating wheel adapted to be rotated at a'relativel y lowspeed, said wheels being adapted to present operative surfaces travelin in o osite directions means between-said wheels for supporting work for movement axially therebetween and particles of fibre Whichof construction .and jproporioo to be rotated by said regulating wheel and ground by said grinding :wheel, the path of travel of the work being inclined with re- .spect to the path of travel of the operative surface of the regulating wheel whereby the regulating wheel movesthe work axially as it is rotated and ground, and means for holding 'a work piece initially in the form of a rod of non-circular cross-section as it is fed along said work support between said wheels and is rotated and ground to a substantially circular cross-section comprising a rotatable 1;

bushing having a non-cylindrical opening shaped to the contour of said non-cylindrical rod and through which the rod passes as it enters into grinding position, the axis of said bushing being substantially alined with the to be rotated by said axis of the rod portion being reduced to cylindrical shape between the wheels.

2. In a grinding machine, in combination, a grinding wheel adapted to be rotated at a relatively high speed, a regulating wheel adapted to be rotated at a relatively low speed, said wheels being adapted to present operative surfaces traveling in opposite directions, means between said wheels for supporting work for movement axially therebetween and regulating wheel and ground by said grinding wheel, the path of travel of the work being inclined with re-' spect to the path of travel of the operative surface of the regulating wheel whereby the regulating wheel moves the work axially as it is rotated and ground, and means for holding a work piece initially in the form of a rod of non-circular cross-section as it is fed along said work support between said wheels and is rotated and ground to a substantially circular cross-section comprising rotatable means exterior of said wheels adapted to hold an unground portion of the non-cylindrical rod with its axis in substantial alinement with the axis of the rod portion being reduced to cylindrical shape between said wheels, said rotatable means being rotated by said rod as the latter is rotated and fed by said regulating wheel and being arranged to (permit said axial feeding movement of the ro 3. In a grinding machine for reducing a work piece of polygonal cross-section to round cross-section, in combination, a grinding wheel adapted to be rotated at a relatively high speed, a regulating wheel adapted to be rotated at a relatively low speed, said wheels being adapted to present operative surfaces traveling in opposite directions, means between said wheels for supporting work for movement axially therebetween and to be rotated by said regulating wheel and ground by said grinding wheel, the path of travel of the work being inclined with respect to the path of travel of the operative surface of the regulating wheel whereby the regulating wheel moves the work axially as it is rotated and ground, and means for holding a work piece initially in the form of a rod of polygonal cross-section as it is fed along said work support between said wheels and is rotated and ground to a substantially circular cross-section comprising means exterior of said wheels for engaging an unground portion of the non-cylindrical rod and holding its axis in substantial alinement with the axis of the rod portion being reduced to cylindrical shape between the wheels, said means permitting said rotation and axial feeding movement of the rod.

4. In a grinding machine, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon work to reduce the work to substantially cylindrical form and comprising three means, one of which means is in the form of a grinding wheel adapted to be rotated at a relatively high speed, another of which means is in the form of a regulating wheel adapted to be rotatedat a relatively low speed and in a direction to present an operative surface traveling in a direction opposite from that of the adj acent surface of said grinding wheel, and the third of which means includes a member for holding the work in operative relationto said two wheels, the operative surfaces of said three means being tapered off at the entrance end of said grinding throat thereby to reduce the work gradually as it is fed into the grinding throat.

5. In a grinding machine for reducing a work piece of polygonal cross-section to round cross-section, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon work to reduce the work to substantially cylindrical form and comprising three means, one of which means is in the form of 'a grinding wheel adapted to be rotated at a relatively high speed, another of which means is in the form of a regulating wheel adapted to be rotated at a relatively low speed and in a direction to present an operative surface traveling in a direction opposite from that of the adjacent surface of said grinding wheel, and the third of which means includes a member for holding the work in operative relation to said two wheels, said three means being related and arranged so that said grinding throat is flared at the entrance end thereof to permit feeding thereinto and grinding down to substantially cylindrical shape a work piece of polygonal cross-section.

s FRED M. KERN;

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