US2791870A

US2791870A - Centerless grinding machine

Info

Publication number: US2791870A
Application number: US386760A
Authority: US
Inventors: Earl L Horton
Original assignee: S & E Machine Products Inc
Current assignee: S & E Machine Products Inc
Priority date: 1953-10-19
Filing date: 1953-10-19
Publication date: 1957-05-14
Anticipated expiration: 1974-05-14

Description

May '14, 1957 E. L. HORTON 2,791,870

CENTERLESS GRINDING MACHINE Filed Oct. 19, 19 53- I 20 Z7 /5 .I

. f /A H IIENTOR an al on. 7 BY y l3 AUOQNEYS United States Patent CENTERLESS GRINDING MACHINE Earl L. Horton, Saginaw, Mich., assignor to S. & E.

Machine Products, Inc., Bridgeport, Mich., a corporation of Michigan Application October 19, 1953, Serial No. 386,760

3 Claims. (Cl. 51-103) This invention relates to grinding apparatus and more particularly to a centerless grinding attachment for conventional external grinding machines.

One of the prime objects of my invention is to provide a practical and effective centerless grinding attachment for external grinding machines which will substantially broaden the field of use of such machines.

A further object of the invention is to design a highly efficient and reliable centerless grinding attachment of simple construction which can be economically manufactured and mounted on conventional external grinding machines of all kinds without necessitating extensive changeovers or adaptations.

patented May 14, 1957 12, which may be an emery wheel or the like, removably mounted on an arbor 13 as shown, the one end of the arbor being reduced and threaded as at 14 to accommodate a nut 15 which clamps the wheel 12 between the washer 16 and the shoulder 17 formed by reducing the 'arbor 13. The ends of the arbor 13 are bored with tapered openings as at 18 to accommodate the head and

tail stock centers

19 and 20 respectively with which most external grinding machines are commonly provided, and

. a dog 21 is clamped to the head end of the arbor 13 to accommodate a lug 22 projecting from the drive spindle of the machine which also supports the center 19 and is mounted in the head stock (not shown) of the machine.

The center 19, of course, is a so-called live center and I the center 20 a dead center, and the spindle is driven Another object of the invention is to design a centerless grinding attachment of the type described which is readily and accurately adjustable to permit the grind- 7 ing of various work diameters within an extended range and which is particularly well suited to the precision grinding of extremely small parts of all kinds.

A further object of the invention is to design a centerless grinding attachment which may be simply and readily adjusted to govern the rate at which the work passes between the grinding and regulatory wheels.

Another object of the invention is to provide a centerless grinding attachment capable of high speed production operations which can be driven from the head stock of conventional center-type external grinders.

A still further object of the invention is to provide an attachment of the type described which when incorporated with a conventional grinding machine, increases its speed of operation and rate of production.

A still further object of the invention is to design a centerless grinding attachment which can be very quickly mounted on a grinding machine and removed therefrom,

and which can be very rapidly set in position, thus per mitting a change of grinding wheels or a change in position to grind work of a different size with a minimum of down time.

With the above and other objects in view, the present invention consists in the combination and arrangement of-parts, hereinafter more fully described, illustrated in the accompanying drawing, and more particularly pointed out in the appended claims, it being understood that changes may be made in the form, size, proportion, and minor details of construction, without departing from the spirit, or sacrificing any of the advantages of the invention.

in the drawing:

Fig. 1 is an end elevational view of my grinding attachment mounted on a conventional external grinding machine, fragmentary portions of the grinding wheel and bed of the machine only being shown.

Fig. 2 is a top plan view thereof showing also the centers and spindle of the grinding machine.

Fig. 3 is an end elevational view of the adjustable work support member only.

Fig. 4 is a reduced sectional view through the regulating wheel which forms a portion of my novel attachment.

at variable speeds in a clockwise direction as usual so that the speed of the regulating wheel 12 can be varied to suit the operation.

Slidably supported on the ways 10 is a carriage 24 which is provided with guides 25, and it will be seen that a transversely disposed work supporting member 26 is adjustably mounted on the carriage 24, slots 27 in one end of the member 26 accommodating bolts 28 on the carrier 24 which can be tightened down to clamp the member 26 in adjusted position. The opposite end of the member 26 is recessed as at 29 to accommodate the peripheral edge of the grinding wheel 11 which extends therein, and support blocks 30 are provided adjacent the sides of the recess as shown.

The work W which is fed between the

wheels

11 and 12 in any suitable manner is peripherally supported on a tilted work rest blade 31 which includes an inclined supporting surface with a carbide tipped edge. Fixed to the blade 31 are laterally extending bolts 33 which are adjustably accommodated in the slots 34 provided in the blocks 30, and it will be clear that the blade 31 can be clamped in position by tightening down of the nuts 35 I on the ends of the bolts 33.

In operation, both the regulating wheel 12 and the grinding wheel 11 are driven in a clockwise direction, the peripheral speed of the wheel 12 being slightly in excess of the peripheral speed of the Wheel 11 so that the wheel 12 in frictionally engaging the work and retaining it in contact with the wheel 11 controls its rotation andeliminates chatter and slippage.

The work W can be fed from either direction and in the instant application is fed to the left end of the blade 31 (see Fig. 3) by hand or by employment of a chute or other feed mechanism (not shown), and it will be observed that the blade 31 is tilted so that the work feeds from left to right, and finally is discharged into a suitable receptacle (not shown) adjacent the right end of the blade. The rate of feed of the work is controlled by variation of the tilt of the blade 31 and variation of the speed of travel of the regulating wheel 12.

The device can be readily adjusted to grind cylindrical work to extremely fine tolerances by setting of the grinding wheel 11 relative to the axis of the regulating wheel 12, so that the minimum distance between their opposed peripheral surfaces is slightly less than the diameter to the ground; then by approximate setting of the position of the support member 26 relative to the

wheels

11 and 12, and finally by adjustment of the vertical position of the blade 13 relative to the slots 34 and variance of the position of the grinding wheel 11 until the correct position of these elements is determined. Sincethe heads of the bolts 33 for clamping the blade 31 in position are located on the face of the blocks 30 remote from the regulating wheel 12, it will be clear that they are readily accessible to the operator for setting the position of the blade 31. Further, since the slots 34 are open to the tops of the blocks 30, it will be apparent that a replacement blade 31 can be readily substituted for one which has become worn without disturbing the adjusted position of the other elements.

Thus, for high speed grinding of cylindrical work surfaces to extremely close tolerances, it will be apparent that by employing the novel attachment which I have perfected, I can adapt a conventional, center type external grinding machine so that production centerless grinding operations can be performed thereon. The difierence in the cost of providing such attachments in lieu of purchasing a cen terless grinding machine will be readily appreciated.

By provision of an individual motor drive for the regulating wheel, it also will be possible to employ the attachment with surface and cutter grinders. It is to be understood that the carriage 24 for the support, member can be modified or eliminated if necessary to adapt to various types of external grinders and that various equivalent changes may be made in the various elements of the device without departing from the spirit of the invention or the scope of the subjoined claims.

What I claim is:

1. In an attachment for an external grinding machine. including a grinding wheel adapted to be driven in a predetermined direction, and having center means, including a live center, in axial parallelism with the axis of the grinding wheel and rearward thereof; a plate for relative movement with the periphery of said wheel provided for mounting on said machine; means for securing said last mentioned plate in position; a regulating wheel for mounting in axially parallel relation with said grinding wheel a spaced distance rearward therefrom on said centers; said regulating wheel being at least twice the width of the grinding wheel and extending axially beyond said grinding wheel on at least one side thereof a predetermined distance greater than the width of the grinding wheel; the front of said plate extending under said regulating wheel; blocks on said plate on either side of the grinding wheel opposite the side faces thereof with rear faces in near alignment with the periphery of the grinding wheel; a work supporting blade, having an inclined face adjacent the regulating wheel, of. at least twice the Width. of the grinding wheel; said blade being mounted on the said faces of said blocks between said regulatory wheel and, grinding wheel and extending beyond said grindingwheel; on at leastone side thereof opposite the extending side of the regulating wheel so as to be disposed opposite said blocks and wheel to provide, with said wheel, work feeding surfaces on which a workpiece is revolved prior to reaching said grinding wheel by the regulating wheel, and clamping means to secure the blade to said blocks.

2. The combination defined in claim 1 in which lateral openings parallel to the grinding wheel are provided through said blocks and posts extend from said blade through said openings in a manner so as not to project outward of the rear faces of said blocks and securing means on the ends of the posts clamping said blade to the blocks.

3. In combination with an external grinding machine including a grinding wheel adapted to be driven in a predetermined direction, a work supporting surface rearward of the wheel and opposite the peripheral edge of the wheel, means mounted on said work supporting surface including a guide plate having guides formed thereon movable with relation to said support surface toward and away from the periphery of said grinding wheel, means securing said guide plate in position relative to said support surface, a regulating wheel mounted in axially parallel relation with said grinding wheel a spaced distance therefrom, means supporting and driving the regulating wheel, said regulating wheel extending substantially beyond said grinding wheel on both sides thereof, the front of said guide plate extending under said regulating wheel and being recessed to receive the edge of said grinding wheel, an upstanding block on the front of said guide plate on each side of the grinding wheel having a lateral slot therethrough open to the top face thereof. the blocks having rear faces substantially aligned with the peripheral edge of the grinding wheel, a tilted work support blade having an upper surface sloping upwardly away from said regulating wheel mounted directly on the rear faces of said blocks adjacent the regulating wheel, said regulating Wheel being of sufi'icient length to extend out from said grinding wheel opposite said blocks and blade to provide surface for feeding the workpiece to the grinding wheel and revolving it prior to the time it reaches the grinding Wheel, threaded means extending laterally from the front face of the blade forwardly through the slots in the blocks, and clamping means thereon. forwardly of the blocks to secure the blade in adjusted position.

References Cited in the file of this patent UNITED STATES PATENTS 1,456,462 Reeves; May 22, 1923 11,579,934 Heim Apr. 6, 1926 1,585,983 Heim May 25, I926 1,733,087 Heim Oct. 22, 1929 1,737,852 Kern Dec. 3, 1929 1,814,431. Caster July 14, 1931 1,987,850, Heim Jan. 15, 1935 2,,l5l,365 Winkler Mar. 21, 1939 2,375,396 K'aplin May 8, 1945 2,559,430 I-Iollengreen et a1. July 3, 1951 FOREIGN PATENTS 306,177 Great Britain Feb. 18, 1929