US2787872A

US2787872A - Adjustable worktable for grinding machine

Info

Publication number: US2787872A
Application number: US497652A
Authority: US
Inventors: Parker John William
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-03-29
Filing date: 1955-03-29
Publication date: 1957-04-09
Anticipated expiration: 1974-04-09

Description

'2 She ets-Sheet l I 'IIIIIII/ J. W. PARKER ADJUSTABLE WORKTABLE FOR GRINDING MACHINE Filed March 29. 1955 April 9, 1957 INVENTOR.

April 9, 1957 J. w. PARKER 2,787,372

' ADJUSTABLE WORKTABLE FOR GRINDING MACHINE Filed March 29, 1955 '2 Sheets-Sheet 2 INVENTOR. 2257/ 14/ )Z'rZe'f BY @144, 3 far/V1959,

United States Patent ADJUSTABLE WORKTABLE FOR GRINDING MACHINE John Parker, Grosse Pointe, Mich.

Application March 29, 1955, Serial No. 497,652

2 Claims. (Cl. 51125) the corresponding side of the way to effect a close fit therebetween. Setscrews 32 hold the gib 30 in a properly adjusted position.

A horizontal, rotatable, adjusting screw 34 carried by 2. depending flange 36 on the forward end of the slide 24 extends through and threadedly engages an upstanding lug 38 on the base 14 In the particular arrangement shown in the drawing, the screw 34 is rotatably supported by a bushing 40 which is disposed within a supporting sleeve 42, and the latter is formed with a radial flange 44 which overlies the flange 36 and is detachably fastened thereto by screws 46. A flange 48 formed integrally on the screw 34 at the outer side of the sleeve 42 and a collar 50 fastened to the screw by a pin 52 at the inner side of the sleeve hold the screw against longitudinal movement relative to the sleeve and the slide 24. As shown in Fig. 1

' the threaded portion of the screw 34 begins inwardly of factorily in this manner using a fixed horizontal work-supporting table; however, there also are many situations whereworkpieces can be ground more easily and efiiciently if the table is inclined either upwardly or downwardly from the normal horizontal position.

The instant invention provides a novel mounting for a Work-supporting table which permits the table to be tilted either upwardly or downwardly so as to position the work with respect to the grinding wheel for maximum efiiciency of operation. It is the purpose of this invention to provide a mechanically simple but efiicient mechanism for adjusting the table to the desired angle and for holding it securely in the selected adjusted position. Also, it is an important object of the invention to provide a mechanism of this type wherein parts which are subjected to the most wear are readily accessible for repair or replacement.

In the drawings forming a part of this specification and wherein like numerals are employed to designate like parts throughout the same:

' Fig. 1 is a vertical, sectional view showing an adjustable worktable embodying the invention in operative associa tion with a power-operated grinding wheel;

Fig. 2 is a side elevational view thereof; and

Fig. 3 is a fragmentary, vertical sectional view taken on the line 33 of Fig. 1.

In the drawing, wherein for the purpose of illustration is shown a preferred embodiment of the invention, the numeral 10 designates the base of a tool grinder. A vertical bore 12 at the rear of the base 10 receives a vertically adjustable shaft 13 having a head 14. A motor mounting bracket 15 carrying the motor 16 is fastened to the head 14 by bolts 17. As perhaps best shown in Fig. 1, the motor 16 is arranged with the drive shaft disposed generally horizontally and extending forwardly toward the front of the base 10. A grinding wheel 18 is mounted on the drive shaft so as to rotate in unison therewith, and the wheel is provided with the usual guard 19. Any suitable or conventional means (not shown) can be used to move the shaft 13 so as to adjust the grinding wheel 18 vertically, and a bellows 20 or other suitable seal is interposed between and connected to the base 10 and the head 14 to prevent dirt and grit from having access to the bore 12.

The front portion of the base 10 has a fiat top portion 22, and a slide 24 mounted thereon is formed with a guide 26 which travels in a way 28 provided in the top 22. The guide 26 and way 28 extend from front to back of the base 10 so that the slide 24 is free to move forwardly or rearwardly on the base and relative to the grinding wheel 18. As shown in Fig. 2, the guide 26 and way 28 are of the usual dovetail conformation, and a gib 30 is interposed between one side of the guide and the supporting sleeve 42, and the portion of the screw within the bearing 40 has a smooth surface which cooperates with the bushing to assure easy turning of the screw. The outer terminal portion of the screw 34 projects from the sleeve 42 and is formed with a square end 54. A wrench or other suitable tool can be fitted to the square end 54 to rotate the screw 34, and as the screw rotates it advances or retracts the slide 24, depending upon the direction of rotation.

Mounted on the front portion of the slide 24 is a table mounting plate 56 having upstanding bearing supports 58 and 60 at opposite sides thereof (Fig. 2). Screws 62 fasten the plate 56 detachably to the slide 24. Overlying the plate 56 is a work-supporting table 64 having depending lugs 66 and 68 which embrace the supports 58 and 60. Journals 7t and '72 carried by the supports 53 and 60 project outwardly therefrom through openings '74 and 76 in the lugs 66 and 68, and bushings 78 and 80 in the openings rotatably receive the journals. By reason of this construction the table 64 is free to rock or pivot on the journals 70 and 72. The pivot axes are disposed parallel to the face of the grinding wheel 18 so that pivotal movement of the table 64 inclines the latter either upwardly or downwardly with respect to the grinding Wheel. In this connection, it will be observed that the table 64 extends from the journals 70 and 72 in the direction of the grinding wheel 18 and that the inner portion thereof is provided with a recess 82 which receives the lower portion of the grinding wheel. In all adjusted positions of the table 64 the inner edge of the recess 82 is closely adjacent the outer vertical face of the grinding wheel 18 so that a workpiece (not shown) can be supported on the table 64 in close proximity to the wheel. In this connection it will be observed that the slide 24 and the table 64 can be adjusted horizontally by the screw 34 as required to maintain a proper or desired spacing between the table and the wheel.

In order to rock the table 64 on the journals 70 and "i2 and then to hold the table in a selected, angularly adjusted position, an eccentric cam 84 is mounted at the inner side of the plate 56. The cam 84 is fixed to the inner end of a shaft 86 which is journaled for rotation in upstanding lugs 88 and 90 on the plate 56. As best shown in Fig. 1, the shaft 86 lies athwart at right angles to the pivot journals 7!} and 72, and the shaft extends between the supports 58 and 60 under the table 64. This arrangement positions the cam 84 substantially to one side of the axis on which the table 64 turns and at the inner side of the axis. A wear button 92 threaded in an embossment 94 on the underside of the table bears downwardly on the periphery of the cam 34. The weight of the table 64 maintains the wear button 92 in contact with the cam 84. At its forward end, the shaft 36 projects substantially beyond the supporting lug 90, and a square end 96 is formed thereon to receive a wrench or other a tool for turning the shaft. 'Manifestly, rotation of the shaft 86 also rotates the cam 84, and as the lobe of the cam moves toward or away from the table 64 it raises or lowers the table. The range in the angular adjustment of the table 64 by the'carn 84 may vary, depending upon the exigencies of the particular situation. In one tool grinder embodying the invention the cam 84 was adapted to move the table between a twenty-five degree positive angle and a seven'degree negative angle.

It should perhaps be noted at this point, however, that it usually it not necessary to turn the shaft 86 by means of a wrench or other tool, as in most instances this can be done manually. To this end, the slide 24 is formed with an upstanding flange 97 at the outer side of the shaft-supporting lug 90, and a base ring 98 extending through an opening 100 in the flange 96 and bearing against the outer side of the lug 90 is fastened securely to the lug by screws 102. The shaft 86 extends through a relatively large hole 104 in the ring 93,. ,A ,g iaduated knob or handwheel 1'66 is mountedon the shaft ,86 at the outer side of the ring 98. A key 1108 connects the haudwheel 106 for mutual rotation with the shaft, and a nut 110 threaded on the shaft holds the handwheel thereon. The handwheel 106 can be rotated manually to turn the shaft 86 and the cam 84.

In order to lock the cam .84 in a selected, rotatably adjusted position so as to hold the table 64 at a desired angle relative to the grinding wheel 18, I provide a T-bolt 112 which travels in a circular T slot 114 provided in the outer face of the ring 98. The T-bolt extends through an opening in the handwheel 106 and a thumb nut 116 is threaded on the outer end thereof. When the thumb nut 116 is loose on the T-bolt 112 the latter and the handwheel 106 are free to turn relative to the ring 98. However, when the thumb nut 116 is tightened it holds the handwheel 106 solidly against the ring 98 to prevent relative rotation therebetween. Thus, when the thumb nut 116 is loose the cam 84 and shaft 86 can be readily rotated by means of the handwheel 106 to rock the table 64 to a desired angular position relative to the grinding wheel 18, and when the thumb nut 116 is tightened it holds the part securely against rotation and in the selected, angularly adjusted position. If necessary or desirable, a wrench can be applied to the square end 96 of the shaft "86 to assist in turning the cam 84. Graduations (not shown) on the periphery of the handwheel 106 co-operate with a reference mark (also not shown) on the base ring 98 to indicate the degree of angular movement of the cam 84. Preferably, the graduations are correlated with the .angularposition of the table 64 to register directly the number of degrees the table is tilted either upwardly or downwardly from .a horizontal position.

Having thus described the invention, I claim:

1. A tool grinder having a grinding wheel, a worksupporting table disposed at one side of the wheel and pivotally mounted to rock about a horizontal axis arranged parallel to the face of said grinding wheel, a rotatable shaft lying athwart said pivot axis and below said table, an eccentric cam on and rotatable with said shaft supporting said table at one side of said pivot axis, manually operable means for rotating said shaft and said cam to incline the table relative to the grinding wheel either upwardly ordownwardly from a horizontal position, and means for detachably locking said shaft to hold said table in a selected, angularly adjusted position.

2. A tool grinder having a grinding wheel, a worksupporting table disposed at one side of the wheel and pivotally mounted to rock about a horizontal axis arranged parallel to the face of said grinding wheel, a rotatable shaft ilying .athwart said pivot axis and below said table, an eccentric cam on and rotatable with said shaft supporting said table at one side of said pivot axis, a 'haudwheel fixed to said shaft manually operable to rotate .the latter and said cam, and a manually operable locking device on said handwheel for holding the same in a selected, rotatably adjusted position.

References Gited in the tile of this patent UNITED STATES PATENTS 2,389,224 Wessman Nov. 20, 11945 FOREIGN PATENTS 16,699 France Jan. 23, 19:13

(1st addition to No. 432,438 528,982 Great Britain Nov. 12, 1940