US2944373A - Grinder with compensating trimming mechanism - Google Patents

Description

GRINDER WITH COMPENSATING TRIMMING MECHANISM Filed March .3, 1958 July 12, 1960 MENTLEY ETAL I5 Sheets-Sheet 1 INVENTORS MAX B.MENTLEY ZENON KOKORZYCKI AVID W. DANIEL ATTORNEYS July 12, 1960 Filed March 5, 1958 M. a. MENTLEY ETAL 2,944,373

GRINDER WITH COMPENSATING TRIMMING MECHANISM 3 Sheets-Sheet 2 INVENTORS MAX B.MENTLEY ZENON KOKORZYGKI BY DAVID W.DAN|EL GRINDER .WITH COMPENSATING TRIMMING MECHANISM Filed March 5, 1958 July 12, 1960 M. B. MENTLEY ETAL 3 Sheets-Sheet 3 ana INVENTORS MAX B.MENTLEY ZENON KOKORZYCKI AVID W. DANIEL ATTORNEYS GRINDER WITH COIVIPENSATING TRINIMIN MECHANISM Max B. Mentley, Zenon Kokorzycki, and David W. Daniel, all of Detroit, Mich., assignors to National Broach & Machine Company, Detroit, Mich., a corporation of Michigan Filed Mar. 3, 1958, Ser. No. 718,768

6 Claims. (Cl. 51-5) column, an adjusting nut-mounted for-rotation in a fixed position 'on a column supporting frame and selectively rotatable, a trimmer slide on said column, a nut fixed to said trimmer slide, and means for'selectivelyrotating said feed screw and said adjusting nut.

' Other objects and features of the invention will become apparent as-the description proceeds, especially when taken in conjunction with the accompanying drawings, illustrating a preferred embodiment of the invention, wherein: 2

- Figure 1 isa fragmentary elevationalview of a portion of the grinder.

' Figure 2 is a fragmentary vertical section through the mechanism shown in Figure 1 Figure 3 is a plan'view of the mechanism, partly in section. a a

Figure 4 is a composite sectional view taken in part on the line 4a4b of Figure 2, and in part on the line 4a-4c of Figure 2.

Referring now to the drawings, the grinder comprises a frame or base 10 having an upstanding hollow portion 12 in'which is received a vertically movable column 14. At its upper end the column 14 has fixedly secured thereto a table or plate 16 having T-slots 18 in which are movably secured the head of T-bolts 20 securing the grinder head 22 thereto. support portion 24 carrying the rotatable grinding wheel 26v which is adapted to be driven by suitable means such for example as the belts 28 connecting sheaves'30 driven by a motor 32, and sheaves 34 connected to the wheel The grinder head comprises a wheel 1 moved into accurately predetermined position by means of indicia indicated at 42 on a drum or disc secured to the shaft.

Referring now more particularly to Figures 2 and 4, it will be observed that the hollow vertically extending portion 12 of the frame. 10 is provided with a vertically extending open side as indicated at 44. The column 14 which is vertically movable in the frame portion 12 is also provided with a vertically extending opening as. indicated at 46 in Figure 4. In this figure it will be observed that sectional views on two different levels have been combined to avoid unnecessary duplication in the figures.

Rigidly secured to the front of the portion 12 of the frame 10 is a housing 48, a connection of the housing beingindicated by the assembly screw 50. Within the housing 48 is a shaft 52 having a worm 54 fixed thereto and having a hand wheel 56 fixed to its outer end. Journaled to the housing is a shaft 58 carrying a worm gear 60 which is rigidly secured to a drive gear 6 2. The housing 48 includes an inwardly extending portion 64 received within an inwardly shaped-portion 66 of the column, and the inwardly extending portion 64 supports a nut 68 having a gear portion 70 in mesh with thegear Rotatably carried by the table or plate 16 is a compound screw 72, the screw being mounted for free rotation but being held against endwise movement. .At its lower. end the screw 72 includes a threaded. portion 74 in which the threads are of a predetermined hand such for example as left hand. The upper portion of the screw as indicated at 76, is of the opposite hand as for example right hand. The hand of the threaded portions is immaterial except that it is essential that the threaded portions be of .dilferent hand. Mounted on the column 14 in Ways indicated at 78 is a trimmer slide 88 carrying suitable trimming mechanism. The nature of the trim- .ming mechanism will of course depend upon the particu- .lar form to be imparted to the periphery of the wheel. In general, it includes a pivotally mounted diamond and may include templates for. producing a, required form. The detailed construction of the trimmer is immaterial to the present invention and the trimmer is indicated diagrammatically at 82 in Figure 2.

Fixedly secured as by a pin 84 to the upper end 'of the compound screw shaft 72 is a worm gear 86 which is in mesh with a worm 88 carried by a shaft 90 extending outwardly of the column 14 where it is connected to a hand wheel 92. The shaft 90is received in suitable supporting and housing structure 94 fixedly connected as by screws 96 to the column so that the hand wheel 92, worm S8,v

worm gear 86, and compound screw shaft-72 all move vertical-1y when the screw shaft is rotated relative to the stationary nut 68.

supporting spindle 3-6. When the T'bolts 20 are loosened 1 thehead .22 is movable transversely or in a direction parallelto the axis of the spindle to position the; grinding wheel 26 either on-center or off-center with respect to a work piece '(not shown) suitably mounted on the machine. The transverse movement of the grinder head permits the wheel to be mounted off-center with respect to a gear so as to perform an exceptionally eflicient gear tooth grinding operation known as off-center grinding. It also permits the grinding wheel to be shifted to a cen- .Inasmuch as the nut 68 is connected through gearing 62' and 70 and through the worm and worm gear combination 60, 54,-.it will be apparent that unless the hand wheel 561's rotated,' the nut 68 is fixed against rotation. Accordingly, when the hand wheel 56 is rotated, rotation is impartedtothe nut, 68. At timetheworm and worm gear 86, T88 and accordingly, the compound shaft72 is thus elevated or lowered with respect to the nut 68,

tral-ized position for trimming so that the trimmer may be fixedly mounted, and errors attributable to movement of the trimmer to different trimming positions are thus completely eliminated. The transverse adjustment of the head 22 is accomplished by a feed screw 38 associated with a nut, the feed screw being rotatable by a squared end section 40 exterior of thehead. The head mayrbe thereby raising or lowering the column and all mechanism connected thereto.

The trimmer slide includes a stationary nut 98 which is in threaded engagement with the upper end portion 76 of the compound screw shaft 72. It will be apparent that when the hand wheel 92 is rotated rotation is imparted V 7 directly to the compound screw shaft 72. Rotation of the associated therewith including the column 14 and the table or plate 16. However at this time rotation of the screw shaft also results in a separate independent and superimposed movement of the trimmer slide 80. The pitch of the threads of the upper and lower threaded portions of the compound screw shaft 72 are equal As a result of this upward movement of the column 14 and hence of the grinding Wheel 26 in any amount is accompanied by an equal upward movement of the trimmer slide. Thus for example, if the wheel requires trimming and if the hand wheel 92 is moved to feed the wheel 26 upwardly by .0001", thetrimmer 82 moves upwardly relative to the wheel by an equal amount and is thus positioned to remove from the periphery of the wheel an amount of stock exactly equal to the amount by which v the wheel was fed upwardly. Thus, if it is assumed that the Work piece such as a gear, is in working position locate directly above the center of the wheel, it will be appreciated that repeated trimming of the wheel may be accomplished as desired without regard to the amount of 1 stock removal, and the repositioning and trimming of the Wheel is carried out in such a way that its operating portion remains in precisely the same position.

The drawings and the foregoing specification constitute a description of the improved grinder with compensating trimming mechanism in such full, clear, concise and exact terms as to'enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What we claim as our invention is:

1. A grinder comprising a frame, a grinding wheel support movable on said frame toward and away from the path of movement of a work piece, a compound screw mounted on said movable support for rotation but prevented from endwise movement relative to said support, an adjustment nut carried by said frame for rotation but prevented from endwise movement relative thereto, and threadedly engaged with a first portion of said screw, a wheel trimmer device mounted on said wheel support for movement parallel to the axis of said screw, a nut fixedly carried by said device and threadedly engaged with a second portion of said screw, said portions of said screw having threads of opposite hand, and means for selectively rotating said adjustment nut and said screw.

' 2. A grinder comprising a frame, a grinding wheel support movable on said frame toward and away from the path of movement of a work piece, a compound screw mounted on said movable support for rotation but prevented from endwise movement relative to said support, an adjustment nut carried by said frame for rotation but prevented from endwise movement relative thereto, and

threadedly engaged with a first portion of said screw, a wheel trimmer device mounted on said wheel support for movement parallel to the axis 'of said screw, a nut fixedly carried by said device and threadedly engaged with a second portion of said screw, said portions of said screw having threads of opposite hand, and drive means for selectively rotating said adjustment nut and said screw, said means being irreversible to selectively lock said. adjustment nut and screw against rotation except when operated by said drive means.

3. A grinder comprising a frame, a grinding wheel support movable on said frame toward and away from the path of movement of a work piece, a compound screw mounted on said movable support for rotation but prevented from endwise movement relative to said support,

an adjustment nut carried by said frame for rotation but prevented from endwise movement relative thereto, and threadedly engaged with a first portion of'said screw, a Wheel trimmer device mounted on said wheel support for movement parallel to the axis of said screw, a nut fixedly carried by said deviceiand threadedly engaged with a second portion of said screw, said portions of said screw having threads of opposite hand, and means for selectively rotating said adjustment nut and said screw, said means comprising irreversible worm and worm gear means. j

4. A grinder comprising a frame, a grinding wheel support movable on said frame toward and away from the path of movement of a work piece, a plate on said wheel support on which is mounted a grinding wheel and drive means therefor, and means for adjusting said plate in a direction perpendicularto the direction of movement of said wheel support, a compound screw mounted on said movable support for rotation but prevented from endwise movement relative to said support, an adjustment nut carried by said frame for rotation but prevented from endwise movement relative thereto, and threadedly engaged with a first portion of said screw, a

wheel trimmer device mounted on said wheel support for movement parallel to the axis of said screw, a nut fixedly carried by said device and threadedly engaged with a second portion of said screw, said portions of said screw having threads of opposite hand, first drive means for rotating said adjustment nut, and second drive means for rotating said screw. I

5. A grinder comprising a frame, a column movable on said frame, a wheel trimmer movable longitudinally on said column, a plate on said column movable thereon transversely of said column,,a grinding wheel and drive means therefor on said plate, means for effecting equal increments of adjustment of said column on said frame and of said trimmer on said column, said last means comprising a screw carried by said column, a first nut threaded on said screw and fixed to said frame and a second nut threaded to said screw and fixed toySaid trimmer, and selectively operable drive means for said screw and for said first nut.

6. A grinder comprising a frame, a column movable on said frame, a wheel trimmer movable longitudinally on said column, a plate on said column movable thereon transversely of said column, a grinding wheel and drive means therefor on said plate, means for eifeoting equal increments of adjustment of said column on saidframe and of said trimmer on said column, said last means comprising a screw carried by said column, a first nut threaded on said screw and fixed to said frame and a second nut threaded to said screw and fixed to said trimmer, and selectively operable drive means for said screw and for said first nut, said drive means being irreversible to lock said screw and first nut against rotation except when actuated by said drive means.

References Cited in the file of this patent UNITED STATES PATENTS Babbitt Sept, 9,' 1958

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