Air Gage Fixture for Measurement of Work-piece Seating Location.

7/22/2019 Air Gage Fixture for Measurement of Work-piece Seating Location.

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01)/ R F P 1 0 9 ~ \y ~ fr M STER

AIR G GE FIXTURE FOR MEASUREMENT OFWORK PIECE SEATING LOCATION

THE DOW CHEMICAL COMPANYROCKY FLATS DIVISION

P. 0 . BOX 888GOLDEN COLORADO 80401

U. S ATOMIC ENERGY COMMISSIONCONTRACT AT 29-ll-1106


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DISCLAIMERThis report was prepared as an ccount of work sponsored by an

gency of the United States Government. Neither the United StatesGovernment nor ny agency Thereof nor ny of their employeesmakes ny warranty express or implied or assumes ny legalli bility or responsibility for the accuracy completeness orusefulness of ny information apparatus product or processdisclosed or represents th t its use would not infringe privatelyowned rights. Reference herein to ny specific commercial productprocess or service by trade name trademark manufacturer orotherwise does not necessarily constitute or imply its endorsementrecommendation or favoring by the United States Government or ny

gency thereof. The views and opinions of authors expressed hereindo not necessarily state or reflect those of the United StatesGovernment or ny gency thereof.


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LEG L NOT I EThis report was prepared as an account of Government sponsored work. Neither the UnitedStates, nor the Commission, nor any person acting on behalf of the Commission:A. Makes any warranty or representation, expressed or implied, with respect to the accu-racy, completeness, or usefulness of the information contained in this report, or that the useof any information, apparatus, method, or process disclosed in this report may not infringeprivately owned rights; or

B. Assumes any liabilities with respect to the use of or for damages resulting from theuse of any information, apparatus, method, or process disclosed in this report.

As used in the above person acting on behalf of the Commission includes any em-ployee or contractor of the Commission, or employee of such contractor, to the extent thatsuch employee or contractor of the Commission, or employee of such contractor prepares,disseminates, or provides access to any information pursuant to his employment or contractwith the Commission, or his employment with such contractor.

Printed in the United States of AmericaAvailable from

Clearinghouse for Federal Scientific and Technical InformationNutwnal llureau of Utandards, U S Devarlmeul uf Commerce

Springfield, Virginia 22151Price: Printed Copy $3.00; Microfiche $0.65


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May 9, 1968

AIR

RFP-1096UC 38 ENGINEERING

AND EQUIPMENTTID-4500

GAGEWORK-PIECE

FIXTURE FOR MEASUREMENTLOCATIONEATING

OF

r

R A arsonl

LEGAL NOTICETbJs report wna prepared ae an account of Go .States, nOr the Comm.l1 81on, nor any peraon ac; e =n ' : : ~ N ~ l t b e r ~ U n J

A. Makes nnywarranty orrepreeent4Uon,'expresaed or lm U 88 on.racy, completeness, or usefulneas of the In U P ed, wtth reapeet to the accuof liny tniormaUo n, apparo.tua method orma contained 1n th.Je report, or thnt thep r l ~ ~ ~ ~ o;nod rights: or ' . or process d l ~ c l o s e d In thJe report may DOt ln rl.nuae ofI.IJ; ~ : ~ ~ ~ ~ a : ; : . ~ : u : ~ r=ct o the uae of, or for da.UJ.agee resuiUng rom th

Ae used In the above, p e r ~ o n :eoceea dlacloaed .ta this r ~ ; p o r t .ployee or contractor of \he CommJaeloil b.al1 of the CommJsalon Includes 411y emIIUCb employee or conti-actor of the coO: olr elmployee of IIUCb coutractor . to the extent tbdlsscmJnatea, or provtdes acceae to an on, or employee of such coolrnctor p r e p ; : ~ . r ewttb,tbe CommtssloD, or hill e m p l o y ~ e D ~ M ~ r : ~ : : : : : : ~ to his employment or contra

~ ~

THE DOW CHEMICAL COMPANYROCKY FLATS DIVISION.

P. 0. BOX 888GOLDEN, COLORADO 80401u. s. ATOMIC ENERGY COMMISSIONCONTRACT AT 29-l)-1106


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RFP-1096AIR GAGE FIXTURE FOR MEASUREMENT OF WORK PIECE SEATING LOCATION

R A Larson

Abstract. An open air-jet mounted in a workholding fixture will Jleasure the work-piece seatinglocation prior to machining. Machine-tool compensations can then be made to eliminate finalproduct error due to inconsistent seating of partsas illustrated in Figure l DISCUSSIONFigure 2 illustrates a vacuum holding-fixturefitted with an air gage. The part locatio n (dimension A is measured for each part, and machinetool settings are changed as required to eliminatefinal-part errors either from a face or insidecontour machining operation. Dimension A shouldbe checked after the machining operation todetermine part-location changes which may haveoccurred, during the machining operation.The air-gage fixture uses a no contact, open,air-jet nozzle Figure 3) press-fitted into the baseof the fixture. The air-jet gaging surface is finishedto the contour of the work-holding fixture.

For gaps of zero to 0.0025 inches the accuracy ofthe system is compatible with open jet-nozzleapplications; that is, within 0.0001 inch accuracy.

The drift of the air-gage readout can be checkedon the machine by stopping the flow at the openjet, or at the air gage readout plug, either of whichwill give a 0.0001 inch lower reading than a partbottomed out in the fixture. The magnificationof the readout system should be checked (andoriginally set) off the machine using a calibra.tionfixture which is shown in Figure 4. The calibrationfixture can be used for size and shape of the workholding fixture so long as the detail dimensions' of the _air gage. Figure 3) are used in the fixturedesign.

Eight to ten additional man hours are required toadd the air gage feature to a new fixture. Thereadout system is cfl)ibrated in one hour, andon-the-machine readings of part location take 15seconds or less.

FIGURE 1. Work-holding fixture without air gage. Although the outside contour is within specifications,the seating variance is great enough to cause scrap during the i n s i d e c o n t o u ~ finishing operation.

WORKPIECE

SM LLER PARTSSEAT IN HU K

LARGER PARTS DO NOT SEAT INCHUCK. PART WILL BE CUT UNDER-SIZE IF MACHINE CORRECTIONS ARENOT MADC.


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RFP-1096

2

POT-CHUCK

PART

CHEVRONTYPE.SEAL

PLUG INTOPOT CHUCK _...,TO TAKE READING

NO CONTACT OPENJET NOZZLE

CONNECT TO .VACUUM PUMP

AIR GAGEREADOUTSYSTEM

\. l

.AIR~ s u P P L Y

. FIGURE 2. Work-holding fixture with air gage. The i n t e r a c t i ~ i i of the open air jet andthe part results in a back pressure proportional to dimension A, whic.h is then measuredin terms of. distance by a commercial readout system with adjustable magnification

.FIGURE 3. Detail drawing of air jet nozzle. All jets must. e made to .same dimensions to ensure correct calibration of air gage readout system

.CONTOUR FINISHEDAFTER PRESS FITINTQ POT. CHUCK .

0.128 0.136 m. DIA.

0.125 in. SLOT MATCHES/WITH AIR GAGE/ EXHAUST HOLEIN FIXTURE

0.0625 ;:in. DRILL


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b)

12680-7

a)

c)

FIGURE 4. Special fixture necessary to calibrate air gage system. a) Calibration part and fixture, b) plugging the output of the air gage readout systemyiP.lcls 0.0001 iuch lower reading than a fully se a ted part, c) when the calibration part is raised 0.001 inch, t hP readout system is set to read 0.001 inch.

RFP-1096

12680-2

12680-11

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Air Gage Fixture for Measurement of Work-piece Seating Location.

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