US531817A

US531817A - Precision-index

Info

Publication number: US531817A
Authority: US
Publication date: 1895-01-01
Anticipated expiration: 1912-01-01

Description

TU e e .n s e e h S 2 NUL Emu R Rm AN Wo .Tl S ...m HUB .R HD.. n. 1u 0 M O w No. 531,817. Patented Jan, 1, 1895.

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H. U. WARREN.

PRECISION INDEX.

No. 531,817. Patented Jan. 1, 189.5.

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HERBERT C. VARREN, OF HARTFORD, CONNECTICUT.

PRECISION-INDEX.

SPECIFICATION forming part of Letters Patent No. 531,817, dated January 1, 1 895.

Application filed April 11, 1 894.

To all whom it may concern:

Be it known that I, HERBERT C. WARREN, a citizen of the United States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented certain new7 and useful improvements in Precision-Indexes',of which the following is a specification.

This invention relates to machines for the manufacture of precision-indexes, the object of the invention being to furnish an improved machine adapted for producing corrected or precision indexes of the class used on geareutting and graduating-machines, and for astronomical instruments and like purposes, with economy and rapidity and with the ntmost accuracy.

In the drawings accompanying and forming a part of this specification, Figure 1 is a plan view of one form of machine embodying my improvements and adapted for carrying out my invention. Fig. 2 is a side elevation of the saine, the cutter for graduating or cutting the index-blank being shown in an elevated position out of contact with said blank. Fig. 3 is a vertical longitudinal section taken inline 8-3, Fig. l. Fig. et is a horizontal cross-section of a portion of the machine, taken in line 4-4, Fig. 3, a portion of the master-index being broken away to more clearly illustrate certain of the details. Fig. 5 represents a table of determined errors, showing the ascertained differences in plus or minus as between the approximately correct divisions of the masterindex and the divisions of a correct, or precision, index.

Similar characters designate like parts in all the figures.

My improved machine for the manufacture of precision indexes, in the preferred embodiment thereof herein shown, comprises a bed or frame-Work for supporting the operative details of the mechanism, a Work-carrying spindle adapted for carrying a master-index and a blank from which a corrected or precisionindex is to be made, a master-index approximately divided into a given number of aliquot parts, each of which parts has a Working face, a normally fixed reference point or scale, and a reading indicator in position and adapted for being shifted from and into bearing engagement with the successive Working faces of the masterindex and adapted to be read in con- Serial No. 507,133. (No model.)

neetion with said reference point or scale, all of which Will be hereinafter more fully described.

In the drawings, the bed of the machine, which, in practice, may be of any suitable form adapted for carrying the operative parts, is designated in a general Way by B.

The Work-carrying spindle, designated by S, is shown supported in a bearing, 2, formed preferably integral with the bed or frame of the machine, aftera Well-known manner. The spindle S is shown provided with a Worinwheel, 3, rigidly fixed thereon in a manner hereinafter more fully described, whose teeth mesh with the threads of a Worm, 4, which is carried by a shaft, 5, that is supported in bearings, 6 and 6', upon the bed B of the machine. This worm-shaft is shown furnished with a hand-wheel, 7, whereby the same may be re- Volved for turning the Worm-Wheel, and through this the work-carrying spindle and parts carried thereby.

In the form thereof herein shown, the worm- Wheel is connected indirectly to the Workcarrying spindle, it being secured by means of screw-bolts to a master-index, C, which in turn is rmly secured to the Work-carrying spindle, preferably by being driven thereon. In this connection, it is desired to state that the master-index and the Worm-wheel secured thereto may be fitted to rotate upon the workcarrying spindle, and said spindle may be non-rotatively fixed in the bed or frame of the machine if desired, although the construction before described is preferable.

The master-index is herein shown as a discous plate radially divided peripherally by a series of notches, S, to form a plurality of radially disposed workingfaces, 9, herein shown as twenty-four in number, the difference between successive bearing-faces representin g approximately fifteen degrees and being designated, respectively, by the numerals l to 24 inclusive. Said master-index has a hub, IO, of considerable length, which engages the Work-carrying spindle S and has a bearing at its lower end upon the upper end of the journal-bearinlr 2. The master-index, which practically constitutes the pattern by means of which to approximately position the index-blank for graduating or dividing, may be constructed in any well-known man- 1 ner, and may .be divided into any number of i laliquot parts, which will depend upon the,

f- After the master-index has been divided, as; justdescribedfto approximate precision, saidy form of precision-index Ait is'desired'to make'.y

index is measured yor surveyedl to accurately ascertain theerrorsin division with relation l to aftrue standard,zwhich errors are then reg istered or tabulated in proper order with re#A lation to successivedivisions of theindex to i designate'the/degree oreXtent ofl error, plus orminus, as compared with the precise divisi ion, Awhich will be'y thoroughly understood by reference to'FigsAand offtheidrawings'.;

AThe method per se of surveying the index,- plate so as to obtain a true correction of rthe approximate divisions, is: well known in thel art to which this kinvention appertains, and it is therefore deemed unnecessary to enter into a detailed description of ythis method,

which, itmay be observed, is sometimesdes ignated lby inechanicians as ,Troughtons methodl" 1 f' In practice, the indexdolank, designateiiy by D, will :preferably be: secured to the spindle' S abovetbe master-index, as illustrated lmosty clearlyin Fign of thedrawings, the said in- .manner to prevent accidental movement of lone part with relation to the other, the mas'-,

ter-index and worm-wheel being either keyed to or driven upon the spindle S, and the pre i n fcision-indexblanlr' rbeing fitted io rthe uppery yS5 i f by means of anut ..11, at the upper end thereof,

end of the spindleand securely held in place said index-blank D being supported at a suitable distance above the master-index by the hub 10 of the said master-index; or, these parts may be firmly fixed to the Work-carrying spindle by any well-known means for lixing wheels on shafts.

In connection with the foregoing, it is desired to state that the positions of the masterindex and index-blank with relation to the spindle might be reversed, a corresponding re-arrangement of reading and dividing apparatuses being in such case made. The two plates or wheels, viz: the master-index and index-blank, should, of course, be rigidly fixed or connected together preparatory to the operation of dividing or cutting said blank. This may be done by forming said two plates or wheels integral, by making them separate and rigidly fixing them together, or by making them separate and separately iixingeach one to the spindle.

As a means for dividing, cutting or graduating the periphery of the index-blank, especially when this is to have teeth cut therein after the manner represented in the drawings, I have provided a milling-cutter, l2, of a form suitable for cutting the required tooth-space; which cutter is shown mounted upon an ordinary cutter-spindle, 13, that is carried ina bearing, 14, upon a slide, 15, that is mounted upon vertical slide-ways,`16, formed upon a carriage, 17, which lis tittedfor lhorizontal l movement in slide-ways, 18, formed upon the k'bed of the machine, as will be clearly understood by reference toFigs. 1y toy/i ofthe draw-l ings.

said spindle may be driven through/the in'- tervention ofgearing after a well-known man `nerftor driving the cuttersof dividing-engines and gear-cutting machines. l l f For the purpose'of imparting to the cutter- Wheels the required kmovement laterally ofthe index-blank, the cutter-slide is yshown rpro- .vided with La screw-threaded projection or A pulley, 19may be fixed on said cutfter-spindle'asy shown in Figs. l, 2 and 3; or,

nut,; 20, engaging with a screw, 21,15hat is can.

ried in a suitable bearing at the upper end of the. carriage i7',-as iliustratedmost clearly in Fig. 3, whiclfrscrevvl may be loperatedaby hand by means'y of the hand-wheel 22 secured y'to-said screw 2l;y and asa means for impartl inga movementgto the cutter toward and from: f

l2t? being provided. y.at-its outer Aendfwith a the axis of said blank, vI have provided a I screw, 23,-fjournaled at its outerend in a suit-l able bearing, 24:, upon the bed ofthe machine, I f f and having its inner end Afitted in a screw.-

threaded opening, A25, in the. carriage 17, after l the well-knownl mannery ofk connecting feed; ing-devices with sliding carriages, said screw hand-Wheel, 26, rbymeans of which the screw l' may be revolved to feed thecarriage toward orfro1n-thefwork.-f f l l f. f

As a means for supporting and holding the index-blank 'duringthe cutting operation,the

outeredge ofsaidwblank, :adjacent tothe point where the cutting .isdone, is lmade to bear upon a rigid support, 27, suitably ixed to a convenient part of the machine,a clamp (not shown) being usually provided in connection with said support -for clamping the blank thereon.

In the drawings, the master-index and its rotating-mechanism are shown protected by a cover, 28, secured to thebed of the machine by suitable screws; a supplemental cover or cap, 29, secured to the hub l0 of the masterindex, being provided to cover the slight opening at the top of the cover 28 and prevent admission ot' dust and dirt.

As a means for determining the position of the master-index, and as a means for enabling the operator to bring the same'accurately to the required position for making the graduations, I employ, in connection With the master-index and its operating means, a graduated reading indicator adapted for engaging the working-faces of the master-index and thereby showing with precision the location thereof. The graduated scale ot' said indicator, which will usually be a Vernier scale, constitutes the reading-scale of the machine, the mode ot' usingwhich will be hereinafter more full-y explained.

In the form thereof herein shown,the indicator, which is vdesignated ina general way by L, is in the nature of a lever Vshown mounted upon a pivot or stud, 30, fixed on IIO IZO

the bed of the machine. This lever has a tooth, or actuating-arm, 3l, located at one sidethereof in position and adapted for bearing against the working-face, as, for instance, the face designated by l, of the master-index.

In the construction shown in the drawings, the indicator is actuated and controlled in its movements by the rotation of the master-index through the medium of the feeding-means in connection `with said index; but it is desired to state that said indicator might, with practicability, constitute a feed-lever for actuating or feeding the master-index, in which case the Worm-Wheel and Worm constituting the feed-mechanism hereinbefore described will be dispensed with, the indicator or feedlever in this case being reciprocated to feed the master-index, together with the indexblank connected therewith, the requisite distance for making the graduation. This reading indicator` will have its indicating-end beveled to a knife-edge and provided with graduations after the manner of a Vernier; a reading-scale, 35, being employed in connection with said indicator to indicate the position of the master-index, as will be fully understood by reference to Figs. l and 4t of the drawings. The graduated scale 35 is shown as adjustably supported in a slide-Way formed in a block, 36, upon the bed of the machine, and as provided with adjusting-screws, 37, by means of which the position of the scale may be changed as desired.

In operating the machine, assuming the actuating-arm 3l to be in working-contact with a Working-face, as l, of the master-index, as shown in full lines in Fig. 4, the index is turned forward in the direction of the arrow in said figure, by means of the feeding-mechanism hereinbefore described, which swings the indicator to the position shown in dotted lines in said ligure, with its actuating-arm in position to engage the next succeeding working-face, 2, of said master-index; said indicator being retracted or thrown into engagement with the successive Working-faces by means of a spring, 38, secured at one end to an arm, 39, oppositely disposed with relation to the actuating-arm 31, and secured at its opposite end to the block 36 or bed of the machine. Said spring tends to normally retain the indicator with its operating-arm in constant bearing-contact with a working-face of the master-index, and is of such a nature as to maintain a bearing-contact which will be of uniform pressure, so as not to affect the precision of the reading, which might vary to some slight extent if the pressure of the actuating-arm 31 against the Working-face of the master-index should vary. This retraction of the indicator, it Will be understood, might be accomplished to secure the same results bya weight or other suitable retracting-device.

In ascertaining the correct position of the master-index for marking the graduations, the said index is moved until the reading of the indicator coincides with the required correctiondesignated by the Working-table T of the respective working-face with which the actuating-arm of the indicator is engaged,

which working-faces are designated in the Working-table by the numerals 1 to 24, inclusive, to coincide with the like designations in connection with the Working-faces of the master-index. For instance, in positioning the master-indexv for making the first graduation, which is designated, alike in the working-table and upon the index, as l, the indicator is set with its operating-arm in contact with the Working-face l. Reference is then made to the Working-table to ascertain the correction for the rst graduation. In said table the iirst graduation is tabulated as 1-.OOO1, which indicates that the correct position for the iirst graduation is one tenthousandth of an inch less than that rst indicated by the position of the indicator as determined by the reading-scale. Therefore the indicator Will be moved until the reading thereof will coincide with the registered correction on the working-table, which brings the master-index to the corrected position for graduating or marking the index-blank; which will be readily understood by those skilled in the art to which this invention appertains.

The indicator or feed-lever L herein shown and described is in the nature of a multiplier; and it is desired to state in this connection that I may substitute therefor any other Well-known fOrm of mechanical multiplier adapted for multiplying the indications of the apparatus.

Having thus described my invention, I claiml. In a machine for the manufacture of precision-indexes, in combination, a master-index approximately divided into a given number of parts, which parts each have a Workingface, a normallyr fixed reference-point or scale, and a readingindicator in position and adapted for being shifted from and into bearing engagement with the successive Workingfaces, of the master-index and adapted to be read in connection with said reference point or scale, substantially as described.

2. In a machine for the manufacture of precision-indexes, a master-index approximately divided into a given number of aliquot parts, each part having a Working-face, in combination with an indicator in position and adapted for operatively engaging the successive Working-faces and having a reading-scale, and means for changing the position of said master-index, substantially as described and for the purpose set forth.

3. In a machine for the manufacture of precision-indexes, a revolubly-supported masterindex radially divided peripherally into a given number of approximately aliquot parts, each parthaving a working-face, a multiplier or indicator in position and adapted for successively engaging said Working-faces, a reading-scale in' connection with said multiplier,

IOO

IIO

and means for rotating the master-indexand for simultaneously changing the reading-position of the multiplier, substantially as described and for the purpose set forth.

4. In a machine for the manufacture of precision-indexes, in combination, a masterindex divided into a given number of approximately aliquot parts, each part having a working-face, an index-blank in rigid connection with said master-index, a multiplier or indicator in position and adapted for'successivel y engaging the Working-faces of the masterindex and having a reading-scale, means for shifting the position of the master-index and the index-blank, and means for marking or cutting the grad nations or divisions upon the index-blank, substantially as described and for the purpose set forth.

5. In a machine for the manufacture of pre cision-indexes, the combination with the framework, of a revoluble spindle, a masten index secured to said spindle and divided into a given number of approximately aliquot r parts, each part' havinga Working-face, anindex-blank in rigid connection with said spindle and master-index, feeding-mechanism in` connection with said master-index, an indiw cater in position and adapted for successivelyY engaging the Workingfaces 0f the masterindex, a reading-scale in connection with the free end of said indicator, and means substantially as described for cutting or marking the graduations in the index-blank, substan ially as described and for the purpose set forth..

6. In a machine for the manufacture of precision-indexes, a revolubly-supported masterindex radially divided peripherally into a given numberof approximately aliquot parte and having a precision index-blank xedly connected therewith, in combination with a pivotally-supported indicating-lever having an actuating-arm in position and adapted for operatively engaging the successive Workingfaces of the master-index, a reading-scale in connection with the indicating-end of said lever, means for rotating the master-index to bring successive Working-faces into engagement withthe actuating-arm of the indicatorlever, a shiftablysupported cutter or marker in position and adapted for cutting or niarking the index-blank, and means for bringing said cutter into Working position with relation to said blank, substantially as described and for the purpose set forth.

7. In a machine'for the manufacture of pre cision-indexes, the combination with the frame-Work, .of a master-index divided into a given number of, approximately, aliquot parts, each having a workiugface, an indexblank iixedly connected with said master-index and secured to a revcluble spindle, a Worm-Wheel secured to said master-index, a Worm meshing with said Worm-Wheel, means for rotating said Worm, a reading-indicator adapted for successively engaging the Working-faces of said master-index, a cutter or marker revoluhly carried upon a slide in position for cutting or marking the index-blank, and means for operating said cutter or marker, substantially as described and for the purpose set forth.

` HERBERT C. WARREN.

Witnesses:

FRED. J. DOLE, FREDERICK A. ROLAND.