1、MIL-H-4 635 4A (MU) 21 October 1974 SUPERSEDING MIL-H-46354 (OW) 20 September 1962 MILITARY SPECIFICATION HEADRESTS, OPTICAL INSTRUMENT This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope.- The specification covers headrests, browre
2、srs, and crash pads for use with Fire Control Instruments. referred to in this specification as headrests. These items collectively are 1.2 Classification.- Headrests shall be of the following types: Type I - Encased mounting bracket Type II- Adhered mounting bracket 2. APPLICABLE DOCUMENTS 2.1 The
3、following documents, of the issue in effect on date of invita- tion for bids or request for proposal, form a part of this specification to the extent specified herein. SPECIFICATIONS Federal TT- S- 735 Standard Test Fluids; Hydrocarbon Military MIL-F-13926 MIL-P-14 23 2 MIL-F-45133 MIL-1-45607 Fire
4、Control Materiel: General Specifi- cation Governing the Manufacture and Inspection of Material, Packaging and Packing of Parts Equipment and Tools for Army Fire Control Components and Assemblies Inspection Equipment, Acquisition, Dis- position and Maintenance of Licensed by Information Handling Serv
5、icesMIL-H-4b354A 12 m 7977906 0311438 1 W MXL-II-46354A (MU) STANDARDS Federal FED- STD- 59 5 FED-STD-601 Military MIL-STD-105 MIL-STD-109 MIL-STD- 28 9 MIL-STD-293 MIL-STD-417 Colors, Requirements for Rubber Sampling and Testing Sampling Procedures and Tables for Quality Assurance Terms and Definit
6、ions Visual Inspection Guide for Rubber Sheet Inspection by Attributes Material Visual Inspection Guide for Cellular Rubber Items Rubber Com osition Vulcanized General Purpose, Eolid (Symbols and $ests) (Copies of specifications, standards, drawings and publications required by suppliers in connecti
7、on with specific procurement functions should be obtained from the processing activity or as directed by the contracting officer.) 3. REQUIREMENTS 3.1 Qualification.- Headrests furnished under this specification shall be products which are qualified for listing on the applicable qualified pro- ducts
8、 list at the time for opening of bids (see 4.2 and 6.2). 3.2 Materials.- Materials shall be as specified on the applicable draw- ing. Choice of elastomeric materials shall be at the option of the manufac- turer except that natural rubber shall not be used for portions of the assem- bly exposed direc
9、tly to the atmosphere. 3.3 Construction.- The headrests shall be either Type I or Type II, constructed to the form and dimensions specified on the drawing (see 6.1). 3.3.1 Type 1.- Type I headrests shall consist of a cellular elastomeric pad molded through and around a perforated mounting bracket an
10、d coated with a minimum 0. 02 inch thick elastomeric skin. 3.3.2 Type II.- Type II Headrests shall consist of a molded cellular elastomeric pad adhered to a steel plate and the entire assembly coated with a minimum 0.02 inch thick elastomeric skin. 3.3.3 Metal components.- Shall be in accordance wit
11、h the applicable drawings and Specification MIL-F-45133. 3.4 Flexibility.- The flexibility of the pad in terms of unit pressure required to produce a compression-deflection equal to 25 percent of the thick- ness of the pad, shall be 7 +- 3 pounds per square inch (psi) at room tempera- ture, 70F I 8O
12、F. 2 Licensed by Information Handling ServicesflIL-H-4b354A 32 777970b 0333437 3 W 3.5 Resilience.- The pad shall return to within 95% of its original shape within one minute following flexibility testing at room temperature. 3.6 Accelerated aging.- After exposure to a temperature of 158OF I 2OF for
13、 a period of 70 hours, the headrest shall not become tacky or deformed. Upon return to room temperature, flexibility of the pad shall be 7 2 4 psi for 25 percent compression deflection. 3.7 Low temperature flexibility. 3.7.1 Type 1.- Type I specimens previously subjected to the accelerated aging tes
14、t shall require a unit pressure of not more than 15 psi to attain 25 percent compression deflection at -40F 2 2OF after thermal stabilization at this temperature for 20 to 24 hours. 3.7.2 Type 11.- Type II specimens previously subjected to the accel- erated aging test shall require a unit pressure o
15、f not more than 20 psi to attain 25 percent compression deflection at 40F 2 2OF after thermal stabilization at this temperature for 20 to 24 hours. 3.8 Adhesive bond strength. 3.8.1 Coating to pad.- The adhesive strength of the bond between the coating and the pad shall be greater than the cohesive
16、strength of the pad or of the coating. 3.8.2 Pad to backplate.- Type II only. The adhesive strength of the bond between the pad and the backplate shall be greater than the cohesive strength of the pad. 3.9 Coating. 3.9.1 Tensile strength and elongation.- The coating material shall have a minimum ten
17、sile strength of 300 psi and a minimum ultimate elonga- tion of 200 percent. 3.9.2 Fungus resistance.- The coating material shall be fungistatic or suitably treated to retard fungus growth. 3.9.3 Oil resistance.- The coating material shall comply with the oil resistance requirements, percent volume
18、change or Type S, Class SC rubber in MIL-STD-417. 3.9.4 Color.- The color of the coating material shall be black com- parable to Color Chip No. 27038 or 37038 of FED-STD-595. 3.9.5 Toxicity and reactions with human skin.- All portions of the fabricated headrest shall be inert and inherently incapabl
19、e of causing a toxic or irritant effect as a result of contact with human skin. Licensed by Information Handling Services3.9.6 Woriaanship.- Workmanship shall be of a quality consistent with The coating shall the highest commercial standards. quality and condition, and free from structural defects.
20、be free of runs, blisters, pock marks and surface voids or inclusions. All material shall be sound, of uniform 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for inspection.- Unless otherwise specified in the contract or purchase order, the supplier is responsibl for the performance of all inspe
21、ction requirements as specified herein. specified, the supplier may utilize his own facilities or any other facili- ties suitable for the performance of the inspection requirements specified herein, unless disapproved by the Government. The Government reserves the right to perform any of the inspect
22、ions set forth in the specification where such inspections are deemed necessary to assure supplies and services con- form to prescribed requirements. Except as otherwise 4.1.1 General provisions.- The component and subassembly inspection requirement of MIL-F-13926 form a part of the Quality Assuranc
23、e Pro,visions of this specification. Definitions of inspection terms shall be as listed in MIL-STD-109. 4.2 Classification of inspection.- Inspection requirements specified herein are classified as follows: 1. Qualification inspection 2. Acceptance inspection 4.3 Qualification inspection.- A qualifi
24、cation sample of eight test specimens of each type specified shall be submitted for qualification test- ing in compliance with 3.1. ance with Figure I. Test specimens for Type II shall be in accordance with Figure II. The samples shall be representative of the materials and con- struction of the hea
25、drest proposed to be furnished under contract. cation testing shall be conducted by the Government at a place designated by the Government and shall consist of an examination for the characteristics specified in Table I in the order listed. The eight test specimens shall conform to the requirements
26、specified for its type. Test specimens for Type I shall be in accord- Qualifi- TABLE I - SEQUENCE OF QUALIFICATION TESTING CHARACTERISTIC REQUIREMENT TEST PROCEDURE 1. Flexibility 3.4 4.6.3 2. Resilience 3.5 4.6.4 3. Accelerated aging 3.6 4.6.5 4. Low temperature flexibility 4 Licensed by Informatio
27、n Handling Services3.7.1 4.6.6 3.7.2 4.6.6 5. Adhesive bond strength (a) Coating to pad 3.8.1 4.6.7.1 (b) Pad to backplate (Type II only) 3.8.2 4.6.7.1 6. Coating (a) Tensile strength and elongation 3.9.1 4.6.8.1 (b) Fungus resistance 3.9.2 4.6.8.2 (c) Oil resistance 3.9.3 4.4.8.3 (d) Color 3.9.4 4.
28、6.8.4 (e) Toxicity 3.9.5 4.6.8.5 (f ) Workmanship 3.9.6 . 4.609 NOTE: Two specimens shall be selected for the fungus resistance test (see 4.6.8.2) from each of the eight specimens submitted. shall be the only test required for these two specimens. This 4.4 Acceptance inspection. 4.4.1 Submission of
29、product.- Unless otherwise specified by the con- . tracting officer, inspection lot size, lot formation and presentation of lots shall be in accordance with “Submission of Product“ provisions of MIL-STD-105. 4.4.2 Classification of examination and tests.- Examination, and tests related to Section 3
30、herein shall be performed on a single defect (individual characteristic) basis in accordance with MIL-STD-105 and the sampling plans specified in Table II herein. Examination and tests for packaging, packing, and marking shall be in accordance with MIL-P-14232 and Secti0n.V herein. shall constitute
31、the minimum inspection to be performed by the supplier after qualification approval and prior to Government acceptance or rejec- tion by item or lot. The tabulated classification of defects in Table II TABLE II - CLASSIFICATION OF DEFECTS Use Inspection Level II of Table I with Sampling Plan Table I
32、I-A of Standard MIL-STD-105. CRITICAL: None Defined MOR: AQL 1.0 Percent Defective 101. 102. 103. 104. CHARACTERISTIC Construction Flexibility Resilence Worhanship REQUIREMENT TEST PROCEDURE 3.3 4.6.2 3.4 4.6.3 3.5 4.6.4 3.9.6 4.6.9 5 Licensed by Information Handling ServicesMIL-H-4b354A 12 3777706
33、03LLLiLiZ 3 E MIL-H-4 63 54A (MU) MINOR: AQL 4. O Percent Defective 201. Color 202. Identification marking 3.9.4 4.6.8.4 3.3, Dwg. 4.6.2 NOTE: The above tests shall be conducted at 70F 2 8F temperature and in accordance with the test procedure paragraph listed. 4.4.3 Acceptance and rejection.- Rejec
34、ted lots shall be screened for all defective characteristics. and resubmittance of rejected lots shall be in accordance with “Acceptance and Rejection“ as specified in MIL-STD-105. Removal or correction of defective units 4.4.4 Certification.- Certification shall include test data and re- sults for
35、the characteristics specified below. certification shall be pro- vided prior to performing final acceptance inspection, and remain in effect throughout the contract for Government acceptance. the contractor from inspection throughout the contract production, includ- ing recording data and results th
36、erefrom. Recorded data and results shall be made available to the Government upon request. be required should any changes occur in materials, manufacturing processes and techniques previously certified. This does not relieve A new certification will CHARACTERISTIC Mat er ials Accelerated aging Low t
37、emperature flexibility Fungus resistance Toxicity REQUIREMENT TEST PROCDURE 3.2 4.6.1 3.6 4.6.5 3.7 4.6.6 3.9.2 4.6.8.2 3.9.5 4.6.8.5 4.5 Inspection equipment.- Except as otherwise provided for by the contract, the contractor shall supply equipment in accordance with the applicable requirements of M
38、IL-1-45607. 4.5.1 Government furnished inspection equipment.- Where the contract provides for Government furnished test equipment, care and maintenance of test equipment shall be in accordance with the applicable requirements specified in MIL-1-45607. 4.5.2 Contractor furnished inspection equipment.
39、 4.5.2.1 Government design.- Unless otherwise specified in the con- tract, all inspection equipment specified by drawing number in specifica- tions forming a part of the contract shall be supplied by the contractor in accordance with technical data listed in the List of Inspection Docu- ments when p
40、rovided with the technical data package (TDP). Licensed by Information Handling ServicesMIL-H-46354A(MU) . 4.5.2.2 Contractor design.- The contractor shall design and supply inspection equipment compatible with the “Test Methods and Procedures“ specified in 4.6 of this specification and with the com
41、ponent inspection procedures specified in “Examination“ and “Test Facilities“ requirements of MIL-F-13926. Since tolerance of test equipment is normally considered to be within 10% of the product tolerance for which it is intended, this inherent error in the test equipment design must be considered
42、as part of the prescribed product tolerance limit. .Thus, concept, construction, ma- terials, dimensions and tolerance used in the design of test equipment shall be so selected and controlled as to insure that the test equipment will reliably indicate acceptability of a product which does not exceed
43、 90% of the prescribed tolerance limit, and permit positive rejection when non-conforming. bration of test equipment. Construction shall be such as to facilitate routine cali- 4.6 Test methods and procedures. 4.6.1 Materials.- The headrest shall be visually examined for com- pliance with 3.2. chemic
44、al analysis of materials or certification thereof, to insure quality of material in accordance with respective drawing or specification require- ments specified herein. The Government shall reserve the right to require a 4.6.2 Construction.- The headrest shall be subjected to a visual, tactile and d
45、imensional inspection for conformance with the construction and configuration requirements of 3.3. shall be used for dimensional inspections. Standard measuring equipment 4.6.3 Flexibility.- The load applied to the specimen or headrest to determine compliance with 3.4 shall be made with a compressio
46、n testing de- vice. surface contact area of 1.0 square inch. For contact areas that do not have this size of flat area, a pressure foot with an area of 0.5 square inch minimum shall be used. The device shall be capable of exerting a force of 7 i 3 pounds per square inch (psi) on the specimen through
47、 a force gage with a minimum range of 10 psi, with an accuracy of 1/2 psi of full scale. The largest flat area of uniform thickness on the specimen shall be used as the test location. Apply the pressure gradually and in a perpendicular plane until the pressure foot has traveled 25 i 2 percent of the
48、 free height of the specimen or headrest. be read from the force gage and shall not exceed the value specified. . Force readings shall be taken 15 to 30 seconds after initial application of the force. The device shall be equipped with a circular pressure foot with a The force required for this compr
49、ession shall 4.6.4 Resilience.- This test shall be conducted concurrent with the flexibility test. rest shall return to within 95 time limit specified. measuring equipment. Upon removal of the applied load the specimen or head- percent of its original shape within the Any deformation shall be measured with standard 7 Licensed by Information Handling ServicesL i MIL-H-46354A 12 E 9999906 0311444 7 E MIL-H-46354AW) 4.6.5 Accelerated aging.- The aging test shall be performed in a heating chamber equipped with automatic temperature controls capable of maintaining the chamber at the operati
