1、 MIL-DTL-70742A (AR) 6 May 2013 SUPERSEDING MIL-M-70742 (AR) 30 September 1988 DETAIL SPECIFICATION MOUNT, TELESCOPE AND QUADRANT - M187A1 This specification is approved for use by ARDEC and is available for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This s
2、pecification covers the Mount, Telescope and Quadrant: M187A1 which supports the Telescope, Panoramic: M137A2 for use on the M119 series of towed howitzers. The mount provides elevation adjustment and compensates for angles of cant when laying the guns for indirect fire. 2. APPLICABLE DOCUMENTS 2.1
3、General. The documents listed in this section are specified in sections 3 and 4 of this specification. This section does not include documents in other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the completeness
4、 of this list, document users are cautioned that they must meet all requirements of documents cited in sections 3 and 4 of this specification, whether or not documents are listed in this section. Comments, suggestions, or questions on this document should be addressed to: Commander, US Army ARDEC, A
5、TTN: RDAR-QES-E, Picatinny Arsenal, New Jersey 07806-5000 or emailed to usarmy.picatinny.ardec.list.ardec-stdzn-branchmail.mil Since contact information can change, you may want to verify the currency of this address information using the ASSIST online database at https:/assist.dla.mil. AMSC N/A FSC
6、 1240 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. INCH-POUND Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-70742A (AR) 2 2.2 Government documents. 2.2.1 Specifications, standards, and handbooks. The fol
7、lowing specifications, standards, and handbooks form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. DEPARTMENT OF DEFENSE SPECIFICATIONS MIL-F-13926 - Fire Control Materiel, Manufactur
8、e, and Inspection, General Specification for DEPARTMENT OF DEFENSE STANDARDS MIL-STD-1916 - DOD Preferred Methods for Acceptance of Product (Copies of federal and military specifications, standards, and handbooks are available online at https:/assist.dla.mil/quicksearch/ or from the Standardization
9、Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.) 2.2.2 Other Government documents, drawings, and publications. The following other Government documents, drawings, and publications form a part of this specification to the extent specified herein. Unless otherwise sp
10、ecified, the issues of these documents are those cited in the solicitation or contract. U.S. ARMY ARMAMENT RESEARCH, DEVELOPMENT AND ENGINEERING CENTER (ARDEC) DRAWINGS 8213745 - Adapter, Fixture for Mt. Telescope M137, Quad. Elevation M15 8565556 - Pressure Tester Two Station 8658940 - Inspection A
11、id 10555620 - Sighting Device 11747889 - Gage, Interchangeability Max 12984689 - Mount, Telescope and Quadrant: M187A1 12984713 - Telescope, Panoramic: M137A2 13020787 - Plate, Identification 13028309 - Adapter, Fixture (Copies of these drawings may be requested online at usarmy.picatinny.ardec.list
12、.drawing-request-help-deskmail.mil or from U.S. Army ARDEC, ATTN: RDAR-EIS-PE, Picatinny Arsenal, NJ 07806-5000) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-70742A (AR) 3 2.3 Order of precedence. Unless otherwise noted herein or in the co
13、ntract, in the event of a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 First art
14、icle. When specified (see 6.2), a sample shall be subjected to first article inspection in accordance with 4.2. 3.2 Conformance. A sample shall be subject to conformance inspection in accordance with 4.3. 3.3 Mount. The mount shall conform to drawing 12984689. 3.4 Environmental. 3.4.1 Storage temper
15、ature. While thermally stabilized at temperatures of +160 5F and -60 5F, the mount shall not exhibit any signs of physical failure or damage. Upon return to and stabilization at standard ambient temperature, +60F to +90F, the mount shall meet the requirements of 3.5 through 3.11 inclusive. 3.4.2 Ope
16、rating temperature. The mount shall meet the requirements of 3.7 while exposed to and thermally stabilized at temperatures of +145 5F and -50 5F. Upon return to and stabilization at standard ambient temperature, +60F to +90F, the mount shall meet the requirements of 3.5 through 3.11 inclusive. 3.4.3
17、 Shock. With a M137A2 panoramic telescope, 12984713, attached in the appropriate location, the mount shall withstand a total of 18 shock impulses along the 3 mutually perpendicular axes as defined in Figure 1. Each shock impulse shall be a half sine wave with a time duration of 0.010 0.001 seconds a
18、nd peak amplitude for each shock impulse as shown in Table I when measured at the face of the counterbox of the M137A2 telescope (see Figure 1). Subsequent to shock, the mount shall show no evidence of damage or physical failure and shall meet the requirements of 3.5 through 3.11 inclusive. TABLE I.
19、 Shock orientation and impulse at M137A2 counterbox. Orientation Shock impulse and direction Number of impulses Longitudinal -100 gs, +100 gs 3 each direction Vertical -100 gs, +100 gs 3 each direction Transverse -60 gs, +60 gs (See 6.7) 3 each direction Provided by IHSNot for ResaleNo reproduction
20、or networking permitted without license from IHS-,-,-MIL-DTL-70742A (AR) 4 FIGURE 1. Orientation of shock loads on M187A1 mount. 3.4.4 Vibration “A”. The mount shall withstand a total of 270 5 minutes of sweep-cycle vibration. The vibration shall be applied for 90 2 minutes along each of the three m
21、utually perpendicular major axes shown in Figure 1. A complete sweep-cycle shall consist of vibration from origin (5 Hz at 1 inch double amplitude) to mid-point (5 0.5 gs at 500 Hz) to origin, and shall have a duration of 15 1 minutes. Double amplitude shall be constant at 1 inch between 5 Hz and 10
22、 Hz, and varied with frequency to maintain a constant 5 0.5 gs acceleration between 10 Hz and 500 Hz. Upon completion of vibration, the mount shall exhibit no evidence of damage or physical failure and shall meet the requirements of 3.5 through 3.11 inclusive. 3.4.5 Vibration “B”. The mount shall be
23、 vibrated in the vertical plane shown in Figure 1 for a total of 15 1 minutes of sweep cycle vibration. A complete sweep-cycle shall consist of vibration from origin (5 Hz at 1 inch double amplitude) to mid-point (5 0.5 gs at 500 Hz) to origin, and shall have a duration of 15 1 minutes. Double ampli
24、tude shall be constant at 1 inch between 5 Hz and 10 Hz and varied with frequency to maintain a constant 5 0.5 gs acceleration between 10 Hz and 500 Hz. Upon completion of vibration, the mount shall exhibit no evidence of damage or physical failure and shall meet the requirements of 3.5 through 3.11
25、 inclusive. 3.5 Sealing. The counter box enclosure of the mount shall be capable of holding dry nitrogen at a minimum internal pressure of 2.0 psi for a minimum of 2 hours without the loss of pressure in excess of 0.2 psi for that 2 hour period. Provided by IHSNot for ResaleNo reproduction or networ
26、king permitted without license from IHS-,-,-MIL-DTL-70742A (AR) 5 3.6 Purging. The counter box enclosure of the mount shall be purged with dry nitrogen supplied at a pressure of 5.0 0.2 psig until the dew point of the emergent gas is no higher than -25F. Purging apparatus shall be removed when the r
27、elief valve is reseated and maintains a pressure between 0.25 and 0.5 psig. 3.7 Performance. 3.7.1 Elevation travel. From a level starting position, the mount shall be able to travel through a minimum excursion of 1333 mils in elevation and a minimum excursion of 89 mils in depression. 3.7.2 Elevati
28、on plumb travel. From a level starting position, the line of sight shall not deviate from a plumb line by more than 0.5 mil on either side and the cross level vial bubble shall remain level within the thickness of a graduation line, when the elevation knob is actuated through its full range of movem
29、ent. 3.7.3 Elevation error. Elevation error shall not exceed 0.5 mil, excluding backlash, at any elevation between -89 and +1333 mils. 3.7.4 Elevation backlash. Backlash in the elevation mechanism shall not exceed 0.5 mil. 3.7.5 Cross level (cant) travel. From a level starting position, the mount sh
30、all be able to cant a minimum of 356 mils to the right and a minimum of 356 mils to the left using the cross level knob. 3.7.6 Cross level (cant) backlash. Backlash in the cross level mechanism shall not exceed 0.5 mil. 3.7.7 Correction counter operation. The correction counter shall travel through
31、an excursion of +9 mils to -9 mils. Plus (+) values set on the correction counter shall subtract an equal number of mils from the elevation counter. Minus (-) values set on the correction counter shall add an equal number of mils to the elevation counter. 3.7.8 Correction counter accuracy. The angle
32、 of the level bar shall correspond to the value displayed on the correction counter within 0.2 mil throughout the full range of the correction counter (-9 mils through +9 mils, inclusive) when the mount is reoriented to the initial elevation reading. 3.7.9 Counter alignment. Variation in the alignme
33、nt of the number centerline in the elevation counter shall be within one sixteenth inch (1/16”). 3.7.10 Cant correction. The mount shall make left and right cant corrections at various elevations in accordance with the values in Table II. The elevation counter shall read within plus or minus 0.5 mil
34、s of the elevation angle of the level bar. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-70742A (AR) 6 TABLE II. Cant correction. Counter elevation (mils) Cant angle (mils) Correction (mils) Correction tolerance (mils) 500 177.8 0.5 96.1 0.
35、5 800 177.8 0.5 180.5 1.0 1000 177.8 0.5 271.9 2.0 3.7.11 Knob torque. The running torque required to operate the knobs shall conform to the values in Table III at the corresponding temperatures. TABLE III. Knob torque. Knob Torque between +60F to +90F and at +145 5F Torque at F -50 5F Cross level 4
36、 to 12 inch pounds 25 inch pounds maximum Elevation level 4 to 14 inch pounds 25 inch pounds maximum Correction 2 to 4 inch pounds 8 inch pounds maximum 3.8 Mount rigidity. With the mount secured by the mounting points and with a telescope attached, the total lateral movement when a 20 pound load is
37、 applied and released from one side of the telescope mounting flange and then applied and released from the opposing side shall not exceed the values of Table IV at each of the specified elevations. TABLE IV. Mount rigidity. Elevation (mils) Cant angle (mils) Total lateral movement (mils) 0 0 0.25 8
38、00 0 0.75 1100 0 1.75 1333 0 3.50 3.9 Illumination. When illuminated using the mounts power and lighting system, the level vial bubbles, graduation lines, and two counters shall be clearly distinguishable when observed in ambient light conditions ranging from dusk into darkness with and without the
39、use of a 50% neutral density filter. 3.10 Interchangeability. The mounting surface on the M187A1 mount for the M137A2 telescope shall be able to accept a M137A2 telescope with its mounting surfaces at maximum material condition. 3.11 Workmanship. Workmanship of the M187A1 mount shall be in accordanc
40、e with the requirements of MIL-F-13926. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-70742A (AR) 7 4. VERIFICATION TABLE V. Requirement/verification cross reference matrix. Method of Verification Class of Verification A - First Article B -
41、 Conformance 1 - Analysis 2 - Demonstration 3 - Examination 4 Test Section 3 Requirements Description Verification Method Verification Class Section 4 Verification 1 2 3 4 A B 3.1 First article X X X 4.2 3.2 Conformance X X X 4.3 3.3 Mount X X X X 4.3.2.4 3.4.1 Storage temperature X X X 4.4.1 3.4.2
42、Operating temperature X X X 4.4.2 3.4.3 Shock X X X 4.4.3 3.4.4 Vibration “A” X X 4.4.4 3.4.5 Vibration “B” X X 4.4.5 3.5 Sealing X X X 4.5 3.6 Purging X X X 4.6 3.7.1 Elevation travel X X X 4.7.1 3.7.2 Elevation plumb travel X X X 4.7.2 3.7.3 Elevation error X X X 4.7.3 3.7.4 Elevation backlash X X
43、 X 4.7.4 3.7.5 Cross level (cant) travel X X X 4.7.5 3.7.6 Cross level (cant) backlash X X X 4.7.6 3.7.7 Correction counter operation X X X 4.7.7 3.7.8 Correction counter accuracy X X X 4.7.8 3.7.9 Counter alignment X X X 4.7.9 3.7.10 Cant correction X X X 4.7.10 3.7.11 Knob torque X X X 4.7.11 3.8
44、Mount rigidity X X X 4.8 3.9 Illumination X X X 4.9 3.10 Interchangeability X X X 4.10 3.11 Workmanship X X X 4.11 4.1 Classification of inspection. The inspection requirements specified herein are classified as follows: a. First article inspection (see 4.2) b. Conformance inspection (see 4.3) 4.2 F
45、irst article. When specified, a sample shall be subjected to first article verification in accordance with Table VI. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-70742A (AR) 8 TABLE VI. First article inspection. Examination or Test 1/ Sect
46、ion 3 Requirement Section 4 Verification Mount 3.3 Visual Storage temperature 3.4.1 4.4.1 Operating temperature 3.4.2 4.4.2 Shock 3.4.3 4.4.3 Vibration “A” 3.4.4 4.4.4 Sealing 3.5 4.5 Purging 3.6 4.6 Elevation travel 3.7.1 4.7.1 Elevation plumb travel 3.7.2 4.7.2 Elevation error 3.7.3 4.7.3 Elevatio
47、n backlash 3.7.4 4.7.4 Cross level (cant) travel 3.7.5 4.7.5 Cross level (cant) backlash 3.7.6 4.7.6 Correction counter operation 3.7.7 4.7.7 Correction counter accuracy 3.7.8 4.7.8 Counter alignment 3.7.9 4.7.9 Cant correction 3.7.10 4.7.10 Knob torque 3.7.11 4.7.11 Mount rigidity 3.8 4.8 Illuminat
48、ion 3.9 4.9 Interchangeability 3.10 4.10 Workmanship 3.11 4.11 1/ With the exception of the verifications that are required to be completed at the operating temperatures during the verification of the operating temperature requirement, the verification of requirements 3.5 through 3.11 inclusive do not have to be confirmed after each of the required environmental tests; if preferred by the personnel conducting the testing and in an effort to reduce verification time, the verification of requirements 3.5 through 3.11 inclusive may be conducted af
