1、MIL-S-347526 APRIL 1951SUPERSEDINGSpecification FXS-71912 July 1948MILITARY SPECIFICATIONSIGHT, M6This specification was approved by the Departments of the Army, the Navy, andthe Air Force for use Of Procurement services Of the respective Departments.1. SCOPE1.1 This specification covers one type of
2、sight known as Sight M6, for use on 81-mm.Mortars.2. APPLICABLE SPECIFICATIONSAND DRAWINGS2.1 Specifications.-The following specifi-cations and specifications referenced on draw-ings in 2.2, of the issue in effect on date ofinvitation for bids, form a part of this speci-fication:U. S. ARMY SPECIFiCA
3、Tions51-7 Instruments, Fire - Control;General Specification Governing theManufacture, and Inspection of.51-70-2-Optical Components for Fire-Control Instruments; General Specifi-cation Governing the Manufacture,Assembly, and Inspection of.(Army.Copies of specifications should be ob-tained from the pr
4、ocuring agency or as directed bythat agency. Both the title and identifying numberor symbol should be stipulated when requestingcopies.)(Navy.-Copies of Military specifications may beobtained upon application to the Bureau of Suppliesand Accounts, Navy Department, Washington 25,D. C., except that ac
5、tivities of the Armed Forcesshould make application to the Commanding Officer,Naval Supply Depot, Scotia 2, N. Y. Both the titleand identifying number or symbol should be stipu-lated when requesting copies.)2.2 Drawings. The following drawing,and all drawings referenced thereon, on theissue in effec
6、t on date of invitation for bids,forms a part of this specification:U. S. ARMY ORDNANCE CORPS DRAWING91-205-l-Sight M6.(Copies of drawings should be obtained from theprocuring agency or as directed by that agency.Both the title and the identifying number should bestipulated when requesting copies.)3
7、. REQUIREMENTS3.1 General. General requirements andassociated tests common to all fire controlinstruments as contained in Specifications51-7 and 51-70-2 shall be mandatory in sofar as they are applicable.3.2 Materials.-Materials shall be in ac-cordance with the drawings, general specifi-cations and
8、material specifications formingpart of this specification.3.3 Accuracy.-With the sight mountedin a suitable testing fixture: so that the verti-cal axis of the bracket d dovetail is inclined -to the rear 15 degrees, the fiat back surfaceof the dovetail is in a vertical plane, theelevation level bubbl
9、e centered, and the de-flection scale and micrometer set at zero,the following requirements shall be met:3.3.1 Index. The elevation index shallcoincide with the 60 degree graduaton andProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-3475the zero
10、 graduation on the elevation microm-eter shall be opposite its index.3.3.2 Collimator.-The line of sight of thecollimator shall be parallel with the flat backsurface of the dovetail with + 3 mils.3.3.3 Open sight.The line of sight of theopen sight shall be parallel with the line ofsight of the colli
11、mate within + 5 mils.3.3.4 Plumb travel.3.3.4.1 The line of sight of the collimatorshall not deviate from a plumb line by morethan 1.75 mils, when rotated from 40 to 90degrees by means of the elevation knob.3.3.4.2 The line of sight of the collimatorshall not deviate from a plumb line by morethan 3
12、roils when the collimator assembly isrotated throughout its limits of motion aboutthe pivoting axis.3.3.5 The error in any elevation settingbetween 40 and 90 degrees shall not exceed10 minutes.3.3.6 The error in any deflection settingshall not exceed 3 mils. .3.3.7 Backlash.-Backlash in the elevatio
13、nmechanism shall not exceed 5 minutes and inthe deflection mechanism it shall-not exceed1 mils.3.3.8 Vertical displacement of the line ofsight due to reversing the azimuth move-ment by means of the azimuth knob shall notexceed 0.5 mil.3.4 Temperature. The temperature re-quirements specified in Speci
14、fication 51-7 fortype III instruments shall apply.3.5 Workmanship. Workmanship shallbe in accordance with Specification 51-7.4. SAMPLING, INSPECTION, AND TESTPROCEDURES4.1 Inspection. fied, each sight and2Unless otherwise speci-spare part shall be in-spected for conformance with this specifica-tion
15、and as specified in 51-7and 61-70-2.4.2 Tests.4.2.1 ACCUracy test.Each sight shall betested for accuracy of elevation at not lessthan six different settings between 40 and90 degrees and for accuracy of deflection atnot less than eight settings throughout thedeflection movement.4.2.2 Temperature test
16、.The temperaturetest specified in Specification 51-7 for typeIII instruments shall apply.5. PREPARATION FOR DELIVERY5.1 Packaging, packing and marking shallbe in accordance with approved specificationsfurnished by the procuring agency.6. NOTES6.1 Ordering data. Procurement docu-ments should specify
17、the following:a.b.Title, number, and date of this speci-fication.Whether domestic or overseas pack-aging is required (see 5.1).Notice.This specification, together with speci-fications and drawings pertaining to it and bearing a“NOTICE” of similar restrictions, is intended foruse only in connection w
18、ith procumbent by theUnited States Government; and shall not be repro-duced either wholly or in part except when author-ized in connection with Government procurement,nor be used for any other purpose except whenspecifically y authorized by the Chief of Ordnance.Custodian:Army-Ordnance CorpsOther interest:Navy-O.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
