US2189015A - Grinder - Google Patents

Description

Feb. 6, 1940. H. A. MAURER 2,139,015

GRINDER Filed Jan. 11, 1937 ZSheets-Sheet 1 QWA/Z A 1 N VENT OR.

BY f/arm/ CZ. 777mg? y 1mm.

Feb. 6, 1940.

' H. A. MAURER GR INDER Filed Jan. 11, 1937 2 Sheets-Shet 2 uh I j INVENTOR. f/arrq dwaw'e' g ATTORNES- Patented Feb. 6,

. g I GRINDER Harry A. Mam, Noveltyrohimassignor mate 1 Oster Manufacturing Company, v Ohio, a corporation of Ohio Qleveland;

'Applicatiovn january 1 1, 1937, serialN o. 11$,9'76 v This invention,pertainsr'to a, zg'rinding machine \of universal-application within its I'field and comprising an arrangement of 'motive power,..

stand, and Wheels all particularly ad'aptedfor use therewith, and work-holding means also particu-x larly adapted to use therewith, such Work-holding means comprising a number. of .modificaticns of detail-within the-same principle, for-holding, for sharpening or dressing all mannerof threading or cutting dies or chasers.-'- A method 'of sharpen- --ing oz-"clressing a plurality of .chasers to uniform dimensions is also-included in the invention,- this method being adapted for, vbut notllimited to. performance by my improved machine.

" 'To the accomplishment i Qf the foregoing and related ends, said invention, then, consists; of

th'e'means hereinafter fully described; and par ticularly pointed out in the "claims. 1

The annexed drawings andt-he following description set forth in detail certain mechanism embodying the invention,- such disclosed means invention may be use'dlfi constituting, however, but j'one' c t various mechanical vforms in which the principle of the In the accompanying, drawings: l Fig. l is a side elevation showing apreferred embodiment of my improved grinder; Fig. 2 isa plan view of the same grinder, but showing a different grinding wheel attached thereto;

Fig.3 is a plan View of the work holding' chuck showing a grinding wheelin'relation thereto; ,Fig. 4 isanv enlarged diagrammatic vertical section illustrating the action of a grinding wheel on a chaserto produce the correct contour for working clearance; I I

Figs. 5 "to 11' inclusive are different types of chasers;

Fig. 12 is a face view of the movable jaw of the Work-holder, the point of view being the plane |2- l2, Fig. 5,--looking.in' the direction of the arrows and omitting-the work piece;

Fig. 13 is aface view of the movable jaw of the *workaholdenjthe point of-view' being the plane l3'-.-l' 3, 6,1ooking-in the direction of the arrows and'omitting the workpiece; and

Fig. 14 is a partial yertical section on plane |4- l4,.Fig."11.

comprises a base In and vertical standard H. The base carries a table 12 "slidable toward and away from the standard on ways 13 .bymeans of ascrew M manually operated 'by'crank I5. An

upper table IG issIidable longitudinallyof the rscrew 32.

some similar arrangement.

plan 1 views showing "several various arrangements of the holder for The machine, in its preferred "embodiment,

' table IZ ,-'that transversely of the ways 13.

On this" table it the work-holding chuck is the base. iii, forxrotat'ion about its own vertical axis, and can be clamped against-rotationbyset A unitary assembly of'mctor 33 and grinding wheel M is raised and lowered on the 'mounted, consisting in detail of a foundation j plate 26, a*turret he'ad'Zi and'positioningjaws22,

.213 respectively stationary and movable.

. The standard I l is rotatable in asocket 3! of.

etandard i by the crank 35 operating a threaded shaft 3% with, whichthe framettl of the assem-l \blyislconnected through a slot in the standardaii by the usualarrange nent of a traveling nut, not I shown, or other suitablemechanism. The set screw 38 clamps the frame 3'31 against movement on the standard? t loads, and thusmsafeguard against, bursting the wheel whenv idle a resistance coil is carried im- Jnediatelyf-upon the motor case, covered by Ventilated shield ti). ,"Ihe arrangements for fastening various sizes of .grindingwheels, suchas 3t or 34A, to; the motor spindle are conventional and not shown in detail. The grinding wheel is Fo-r convenient portability a flexible card 42 with the usual plug 43 and switch guarded as at 39'.

it. are provided. It; is contemplated that the grinder" will ordinarilybemade in a bench size, and may be moved from place to place, being carried for example ona wheeled Workbench or :Thechuck includes the base piaceflzo and top To hold the motor to uniform speed atvaryi'ng 1 plate f2! vertically pivoted thereto and capable of being fastened by alock nut 53in any l'angular position within its range "of motion, as indicated by 'the index 5 I. The positioning jaws,-bothof which: are ordinarily flat plates of about or :less than,1.the'thickness'0f a chaser, on the-order of one-half inch more or less, and. horizontally placed,.Garried on thepupper plate, comprises a segmental-jaw 22 movable as-in Fig-3 and with clamping means 55-for, jaw 22 including" a-En-ut and a bolt the head of which travels in an underout slot 55, andanother movablejaw 23:with adjustment transverse to the movement of -22,:=by

slots :56, and clampedf-by nuts 51. :Where the .j aw

vforms are modifiedythey are designated inthe Qdrawingsas 23A and 2333;,

Asshown in" Figs. 12. and 13; the inner surface dearth of these jaws-contains a seriesof horizontal holes; '16 and H threaded andpilotedgfor I the insertion of pins whereby the work can be set according to critical surfaces and dimensions,

although,'to- .avoid complication of :the drawings,

long wide shank and a scroll-cam recess 75 at the side. In this type of chaser, the forward edge.

only the holes which are in use are shown in Figs. 5 to 11 inclusive.

Further details and modifications of the chuck In Figs. 2 and 3 a chaser C. is shown having a 16 of the recess I5 is the base with referenceto which feed of the cutters is regulated. Consequentlythis is the datum for grinding work, and the cutter C is held thereto by a pin. in e I lip grindi g, the feed between successive cutsis appropriate one of the holes ll]. The preferred form of pin is screw threadedand piloted, with I I a3ll, while in throat grinding .the feed'is by the, handle I5 and screw I4, as'already mentioneds a projecting head it, all asshownin Fig. 5,

; but other forms of pin may be used. I

Further setting, if necessary, is by sliding the plate.22 and locking the fastening 55 in theslot 55. Thereafter, feed across the face of, the grinding wheel is accomplished bytraversing the slide I6 by hand. Feed against the-wheel for throat grinding, Fig. 2, is obtained by the feed screw M, but feed against the wheel for lip grinding is by the handle 35 and vertical feed screw 36, moving the wheel downfto the -work, as in Fig. 1.. I I i Fig. 5 shows the set-up for a small shortshanked chaser C. Here the datum surface-is the outer end of the chaser, which is established. against the head 18 of the pin H in the app'ropriate hole 10 in the plate 22. In'Figg, 6 the arrangement is similar to that. of Fig.3 but reg versed, with the front edge of thescroll-icam recess 80 of the chaser C positioned against a screw in one of the holes i l in the jaw 23.

Fig shows a set-up for awide short chaser C Here a long pin 8! is used in the proper hole,

70. The jaw plate 22 is here shown slightly offset from concentricity with the plate 2|, to 'adjust the chaser C3 position an amount less than the distance between successive holes it. The

opposite chuck plate 23A is modified, having eral support to the inset side of this chaser.

In Fig. 10 the chaser C is a modification of that shown in Fig. 6, and is positioned for depth by the'pin T! and held laterally by the widehead of pin 82. I I V In Fig. 11 the chaser C is longer than the chuck diameter and also. is of a type in which i the feed scroll engagement is by a side stud .90.

cutting chasers areon the lip: and on the throat. The former is shown in Fig. 1, where B indicates the lipangle and the latter by Fig. 2 whereD indicates the throat angle. It will be observed that the lip angle B is established by inclination of the face of the grinding wheel 34, shown in Figs. 1 and 3, whereas the throat angle" D is established by the inclination of the face plane the axis. of rotation.

of the chaser teeth with the he, of the grindingi wheel, inthis instance 34A. i Various sizesand shapes oflgrindirig wheels maybe employed asq required.

Since the angle does not change eXcept 'by; I changingthe wheel 3d; and since the angle D can be fixedby clamping the turret- 2| (index 5l it I may begracluated intennsof thisang le) it will,

be seen that to! grind .aqset'of 'chasers uniformly I I to any required. angle and depthall that is necessary is to'setup the grinder and make successive passesor cuts. by traversing the carriage lffi'.

accomplished by the handle-35 and vertical screw Consequently, to grind all fourchasersof a set the pinsy afford afumI'locatingfit. I

After the turret-chuck is set up for the-chasers, chaser No. 1 of theset is placed in the chuck,

and passed oncea'crossthe wheel by sliding the table it by hand. With the other hand the operator maintainsa lightrpressure' on the chaser,

keeping it positioned. in the chuck. After one pass across the face of the grinding wheel he lays it to one side, returns: the table to starting. position, inserts chaser l \.T o. 2 of thesame'isletin the chuck, passes it across the wheel, removes vit, and so on, as beforefalways picking up his chasersin the same order and making only one pass at a. time with each chaser of the series, until the requisite amount of grinding has been Theimethod of grinding the lip is-indi i cated by Figs. '3 and. 1, and'throat grinding by 7 i done.

Fig. 2.'

. It .will be. understoodfby those. skilled in the art thatfor. throat grinding the wheel 34A must I I be of the same .radius'as'thei'curvatur'ei of thek chaser threads. Fig; 4. illustrates. the pra-ctice in grinding the chaser' throat," where the grind ing wheersiA, ,indicated'by a solid circumfer- J.

ential-line, is centeredfa't E, and-thenoncave throat curvature exactlyflts the'whee'l circ1'1rn.-'v

i'erence, since it is ground in by the. wheel; The

broken circle P indicates the circumference 0fa"v pipe or a rod Wbichthe chase r C- is. intended: to 1 thus apparent that only thefront'edge G of. the.

throat (more strictly'speaking," the point of each thread, this circle being centered. at It 15 tooth) will contact the pipe. 1 The divergenceof the clearance betWeenIchaser and'work in thread cutting.

circle P from the solid circle below'G indicates I I I It will likewise J be. apparent .to those Ski1Ied:

in the-art that myz improved"tool can alsof b'eused for dressing the, grinding wheels by insert? ing a dressing stickinto the chuck instead "of Ta chaser, and bringing the stick into proper rela tion with the wheel; For dressing a. cylindrical,

wheel, the stick will be arranged square-to the" wheel, that isywith the 'dr'essing'edge' parallel" to For dressing a conical wheel, the standard iii carrying the grinding unit will .be'turned through ahorizontatangle,

the Wheel edge at the ap'propriateangle. 1'- This angle can be made entirely by; turning the stand". I ard i l, or .partly-byturning thefstandard .H and partly by turning the chuck turret 2!." While the wheel is in rotation the stick is traversed across the face by sliding the carriage 5.

To maintain nearly uniform speed under both working and idle conditions, thus avoiding excessive idling speed with consequent danger of wheel explosion, I provide a resistance coil in the armature circuit of the motor. The preferred motor is a constant speed universal type,

of suitable voltage for use on lighting circuits.

This resistor, a permanent part of the apparatus, is housed by the shield 40, perforated for ventilation. The action of the resistor in maintaining uniform speed does not impair the efficiency ofthe motor under load. This constant speed feature is not in itself a part of my invention, since the resistor is provided by the motor manufacturer.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a chaser grinding machine comprising a; wheel and a horizontal traversing table, the' combination with said table of a pair of relatively movable plates thereon, said plates in-- cluding vertical inner edges defining between .them the walls of a groove whereof the table inner edges defining between them the walls ofa groove whereof the table forms the bottom, a chaser-positioning element, and a plurality of positive engaging means between said groove and said chaser-positioning element for holding the latter in said groove, said edges and said chaserpositioning element being adapted to establish positioning contact with controlling surfaces of a chaser laid on said table in said groove.

HARRY A. MAURER.

Images