US2555707A - Tool rest for grinding machines - Google Patents

Description

June 5, 1951 H. T. SCOTT TOOL REST FOR GRINDING MACHINES Filed Oct. 6, 1947 INVENTOR. /2/ HAQQY 7. 56077 4 TTD/2N E Y (f/ MM Patented June 5, 1951 ASTATES `PAT EN T OFFICE TOOL REST FOR GRIND'ING MACHINES Harry T. Scott, Los Angeles, Calif.

Application Gotober 6, 1947, Serial N o. 778,180

SClams. l

This invention relates generally to tool grinding machines, and `more particularly to tool rests therefor.

An object o f this invention is to provide a tool rest which is structurally characterized in a manner to enable it to be readily applied to grinding machines at present being manufactured; which is particularly adapted for low cost production by modern, efficient and economical precision die cast methods; which is angularly adjustable about afixed Yaxis preferably in close proximity to the peripheral face of the grinding wheel and hence parallel to the axis of the grinding wheel, whereby to enable a tool bit to be hollow ground by using the `periphery of the wheel and thus reduce to a minimum the stoning of the bit required to produce a smooth, clean and sharp cutting edge.

Another .object of this invention is to provide a tool rest of the above described character whose fixed axis about which angular adjustment of the rest is effected, obviates any shifting of the rest towards or away from the grinding wheel, so as to insure proper relationship between the tool being ground and the grinding wheel, irrespective of angular adjustment `of the tool rest, all while maintaining the table of the tool rest free of projections which would interfere with the free manipulation `of the tool bit on the table.

A further object of this invention is to provide a tool rest, the table of which is suitably scribed or marked to guide the operator in grinding a tool bit to a predetermined angle; `whose table, when of die `cast metal, is provided with ahard metal insert to effectively resist the wear and tear to which the table is subjected by the tool bits; which, for angular adjustment of the table, i provided with journals `of `such construction that the rest can be made relatively compact so as to nt into a small space; and which is adapted to be angularly adjusted .about the axis of the journals and securely locked in a selected position vof adjustment with the utmost ease and dispatch.

With these and other objects in View, this invention resides in the combinations, arrangements and functional relationships of elements as set forth in the following specification and particularly pointed out in the appended claims.

In the accompanying drawings,

`Figure l is a plan View of the tool rest for grinding machines embodying this invention;

Figure 2 is a vertical sectional View of the tool` rest taken on the line 2-2 of Figure l;

`Figure 3 is a :vertical sectional View of the tool rest mounted on a conventional grinding machine, and taken on the line 3-3 of Figure 1;

Figure 4 is a vertical sectional view taken on the line ll--li of Figure 2;

Figure 5 is a Vertical sectional view taken on the line oi Figure l; and Figure G1 is a `View oi the tool rest in left side elevation.

Referring specifically to the drawings, this invention in `its illustrated embodiment, broadly comprises a base E anda table T mounted thereon for adjustment about a fixed axis a, the base and table being preferably die -cast of `suitable metal. The base is formed to provide a fiat bottom lli, side walls 1I, and a back wall I2, the central portion of which latter is inwardly offset to define `a recess I3 whose width closely receives the peripheral portion of the grinding wheel G of `a conventional grinding machine having a very elementary form of adjustable tool rest R. By means of two cap screws or bolts Ii passing freely through openings in the bottom li of the Vbase B, the latter may be rigidly secured on the top plate i5 of the rest R by screwing the screws lli into bores if which are suitably drilled and tapped in the plate.

The table T comprises a fiat rest plate 2G from which subtends side walls 21 and aback wall 22 within which the base B is received as shown in Figures 2, 4 and 5. The back .edge of ,the rest plate ZB is provided with a recess 23 corresponding to the recess i3 of the base B so as to receive the peripheral portion of the grinding wheel G. The rest plate 2li is further provided with a recess 2d extending from one side of the rest plate to `the other `and receiving a wear plate 25 of relatively hard metal whose top surface is flush with the surface of the rest plate. The wear plate is rigidly secured to the rest plate by screws 26, with the rear top edge of `the wear plate coinciding with the `fired axis a.

The fixed axis u is formed by segmental trunnions or journals Si!! on the inner sides of the walls 2|, which seat in segmental bearings il formed on the side walls il of the base As illustrative of one means for maintaining the journals 3l! against upward displacement from the `nee-rings 3i, coil springs 32 are connected under tension to anchor pins i3 and 34 seating in recesses inthe rest plate 2li of the table and in the bottom iii of the base, respectively, as shown in Figure 5, so as to hold the trunnions in contact with the bearings, yet permit free angular adjustment of the table on the base about the aX-is a.

Other bearings 4l] are provided on the side walls Il of the base B to rotatably mount a shaft 4| whose ends'project through arcuate slots 42 and 43 in the side walls 2i of the top T. Fixed to one end of the shaft 4| by a set screw 44, is an actuating member orknob 45 whose hub is formed to provide a driving gear 46 projecting into the slot 42 and constantly meshing with curved rack teeth or segmental rack 41 on one wall of the slot. Thus, upon rotating the member 45 in the l0 clockwise direction of the arrow in Figure 6, the gear 46 will co-act with the rack 4l to angularly adjust the table T about the axis a from the full line position in Figure 8 towards the broken line position in this figure. 15

The other end of the shaft 4I is threaded at 48 to receive a clamp nut 49 in the form of a lever by which the table T can be clamped to the base B in any selected position of angular adjustment, by simply tightening the nut. The front of the o table T is closed by a curved cover or name plate '5U whose lower edge is curled inwardly as indicated at I to provide a finger grip adapted to be grasped by the operator to effect a quick, rough adjustment of the table. .25

The periphery of the actuating member 45, which is provided with a dial having graduations 60 numbered in degrees of angles, is of such curvature that the periphery will remain in tangential relationship to the top surface of the rest plate irrespective of the position of adjustment of the table, for co-action with a fixed graduation 6I on the rest plate (Figure l) in indicating the angle to which the table T is adjusted.

The top of the rest plate 20 is provided with Y angle indicating lines 62 and appropriate indicia for indicating tool angles, and is further providedwith lines 63 and appropriate indicia for indicating back rake, all in the operation of the invention which is as follows:

With the tool rest embodying this invention applied to the grinding machine as shown in Figure 3, the top surface of the rest plate 20 is horizontally disposed at the level of the axis of the grinding wheel G, and the iixed axis a is in close proximity to the peripheral surface of the grinding' wheel and parallel to the axis of the latter, to thus locate the table T symmetrically about the peripheral portion of the grinding wheel for use of the periphery of the wheel in the hollow grindo ing of tool bits, as well as the sides of the wheel for various other grinding operations upon the bits.

The table T is now adjusted by rotating the member 45, and is then locked in a selected position by the nut 49, for grinding of a predetermined front or side clearance upon the tool bity when placed on the rest plate ZIJ and fed over the hard wear plate against the periphery of the grinding wheel. A predetermined tool angle or back rake may be accurately ground on the toolI bit by utilizing the corresponding angle indicating line B2 or 63 as a guide in feeding the bit to the wheel.

, I claim:

1. A tool rest for grinding machines comprising: a base adapted to be rigidly mounted on a support of the grinding machine; a table; said base and table having means co-acting to provide 7 a xed axis in close proximity to a surface of said wheel, forangular adjustment of the table relative to the base; a shaft journaled on said base about an axis in spaced parallel relationship to .saidxed axis; means on the shaft and table 7 co-acting to angularly adjust the table about said fixed axis in response to rotation of said shaft; an actuating member fixed to the shaft and having a dial graduated in degrees of angles for coaction with a fixed graduation on the table in indicating the positions of angular adjustment of the table; and means for releasably retaining the table in selected positions of adjustment.

2. A tool rest for grinding machines comprising: a base adapted to be rigidly mounted on a support of the grinding machine; a table having a iiat work supporting surface; said base and table having means co-acting to provide a fixed axis in close proximity to a surface of said wheel, for

. angular adjustment of the table relative to the base; a shaft journaled on said base about an axis in spaced parallel relation to said fixed axis; means on the shaft and table co-acting to angularly adjust the table about nsaid iixed axis in response to rotation of said shaft; a member iixed to said shaft at a location beyond one end of said table and having a peripheral dial graduated in degrees of angles for alinement with a fixed graduation on said work supporting surface of the table in indicating the position of angular adjustment of the table;v the peripheral contour of said member being such as to maintain a tangential relationship between the peripheral surface of said member and said work supporting surface of the table at said fixed graduation thereof, irrespective of the position of adjustment of the table.

3. A tool rest forgrinding machines comprising: a base adapted to be rigidly mounted on a support of the grinding machine; a table having a fiat rest plate and arcuately slotted sidewalls subtending therefrom at opposite sides of the base; the table having alined, downwardly facing segmental journals beneath said rest plate, whose centers are coincident to the top surface of the. plate; the base having upwardly open, segmental bearings in which said journals are seated to mount the table for angular adjustment relativel to the base; a shaft rotatably mounted on said base parallel to the axis of said journals and projecting through said slots of said side walls; a gear fixed to said shaft; a segmental rack iixed to said table ,and with which said gear meshes, to angularly adjust the table about said fixed axis in response to rotation of the shaft; a member fixed to one projecting end of said shaft and having a dial graduated in degrees of angles for co-action with a fixed graduation on said rest plate, in indicating the position of angular adjustment of the table; and means at the other projecting end of said shaft, co-acting with said member to releasably retain the table in a selected position of adjustment.

4. A tool rest for grinding machines comprising: a base adapted to be rigidly mounted on a support of the grinding machine; a table having a flat rest plate and arcuately slotted sidewalls subtending therefrom at opposite sides of the base; the table having alined, downwardly facing segmental journals beneath said rest plate, whose centers are coincident to the top surface of the rest plate; the base having upwardly open, segmental bearings in which said journals are seated to mount the table for angular adjustment rela` tive to the base; a shaft rotatably mounted on said base parallel to the axis of said journals and 0 projecting through said slots of said side walls;

a gear ilxed to said shaft; a segmental rack formed in one of said slots and with which said gear meshesto angularly adjust the table about said iixed axis in response to rotation of the shaft; an actuating knob iixed torone end of said'shaft exteriorly of one side wall of said table and having a dial graduated in degrees of angles for coaction with a fixed graduation on said rest plate, in indicating the position of angular adjustment of the table; and a locking knob threadedly mounted on the other end of said shaft exteriorly of the other side wall of said table for co-action of said knobs with the respective side walls in binding same against the base when the locking knob is tightened, whereby to releasably retain the table in a selected position of adjustment.

5. A tool rest for grinding machines comprising: a base adapted to be rigidly mounted on a support of the grinding machine; a table having a flat rest plate and arcuately slotted sidewalls subtending therefrom at opposite sides of the base; the table having alined, downwardly facing segmental journals beneath said rest plate, whose centers are coincident to the top surface of the rest plate; the base having upwardly open, segmental bearings in which said journals are seated to mount the table for angular adjustment relative to the base; a shaft rotatably mounted cn said base parallel to the axis of said journals and projecting through said slots of said side walls; a gear xed to said shaft; a segmental rack xed to said table and with which said gear meshes, to angularly adjust the table about said fixed axis in response to rotation of the shaft; an actuating knob fixed to one end of said shaft exteriorly of one side wall of said table and having a dial graduated in degrees of angles for coaction with a fixed graduation on said rest plate, in indicating the position of angular adjustment of the table; and a locking knob threadedly mounted on the other end of said shaft exteriorly of the other side wall of said table for coaction of said knobs with the respective side walls in binding same against the base when the locking knob is tightened, whereby to releasably retain the table in a selected position of adjustment; said dial being arranged on the peripheral surface of said actuating knob, whose contour is such as to maintain a tangential relationship between said surface and said rest plate at the fixed graduation thereon, irrespective of the position of adjustment of the table.

6. A tool rest for grinding machines as embodied in claim 5, wherein said table is provided with a finger grip along the front thereof, adapted to be gripped to effect a rough adjustment of the table; and said rest plate is provided with a relatively hard metal insert removably fitted in a recess in close proximity to the grinding surface of the grinding wheel and flush with the top surface of the rest plate.

7. A grinding machine having a grinding wheel and a tool rest support; a base rigidly mounted on said support at the periphery of the grinding wheel; a table having a fiat Work supporting surface; said base having alined, upwardly open segmental bearings whose centers define a fixed axis co-incident and parallel to said surface of said table and in parallel relationship to the periphery of the grinding wheel in close proximity thereto; the table having segmental journals mounted in said bearings for angular adjustment of the table on the base about said fixed axis; and spring means operatively connected to said base and table to yieldingly maintain said journals in working engagement with said bearings against displacing forces incident to a tool grinding operation, yet render the table readily adjustable angularly on the base as aforestated; and means for releasably retaining the table in selected po sitions of adjustment.

8. A tool rest for grinding machines comprising: a base adapted to be rigidly mounted on a support of the grinding machine; a table; said base and table having means co-acting to provide a fixed axis in close proximity to the periphery of said wheel; a shaft journaled on said base about an axis in spaced parallelism to said fixed axis; a member xed to said shaft and having a dial graduated to co-act with a xed graduation on the table in indicating positions of angular adjustment of the table; said table being adapted to be grasped and manually moved directly about saidL xed axis to effect a quick angular adjustment of the table; and means on said shaft and table co-acting to rotate the shaft in accordance with the aforesaid manual movement of the table, for co-action of said member graduations with said table graduation in indicating the position to which the table is moved.

HARRY T. SCOTT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 134,296 Libbey Dec. 24, 1872 565,644 Taylor Aug. 11, 1896 876,372 Matthews Jan. 14, 1908 957,978 Meyers May 17, 1910 1,259,494 Downer 1 Mar. 19, 1918 1,277,377 Carter Sept. 3, 1918 2,176,726 Shepherd Oct. 17, 1939 2,374,716 Wiken May 1, 1945

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