cause electrical contact between plug and 

 receptacle is not possible prior to proper 

 alignment and mechanical locking. For this 

 reason, this type of connector is vulnerable 

 to electrical mismating and contact damage. 



The materials most often used in fabricat- 

 ing this connector are neoprene for pressure 

 molding and polyurethane for cast molding. 

 The neoprene molded connector is superior 

 in several design areas. However, the inabil- 

 ity to properly control movement of the con- 

 ductor during the pressure molding process 

 can lead to electrical opens and shorts that 

 very often don't appear until after the con- 

 nector sees the operating environment. 

 Thus, reliability is seriously affected. 



The all rubber type of connector, not hav- 

 ing a rigid internal or external structure, 

 does not provide for positive and controlled 

 compression of interfacial seals. For the 

 same reason, most coupling and mounting 

 devices are marginal because the material is 

 subject to compression set. Seal failure can 

 also occur when the connector is mated in a 

 low temperature environment, due to loss of 

 elasticity. Most designs have little or no pro- 

 tection for pin contacts. 



This type of connector construction is not 

 without certain advantages. Among these 

 are low cost, light weight, capability of with- 

 standing considerable abuse and, because it 

 is integrally molded, a need for fewer seals. 

 Both plug and receptacle withstand open 

 face pressure equally well. No material cor- 

 rosion problem exists and the material being 

 a dielectric does not contribute to galvanic 

 corrosion of adjacent areas. No separate in- 

 sulating parts are required and the resilient 

 material provides for a void-free interface 

 between mated plug and receptacle. 



Underwater Disconnectable Connectors: 



Underwater disconnectable, or make and 

 break, connectors are a definite requirement 

 for submersible applications. For instance, it 

 is advantageous for divers to be able to dis- 

 connect camera and light housings while the 

 vehicle is still in the water. This allows re- 

 placement of film and lights on a routine 

 basis without the need to haul the vehicle 

 from the water. Another disconnectable con- 

 nector requirement is the one-time electrical 

 disconnect that is required when emergency 



drops are made of outboard mounted equip- 

 ment such as batteries and manipulators. 

 These equipments would be disconnected 

 from the vehicle under conditions of emer- 

 gency surfacing; it may also be necessary to 

 drop the manipulators should they become 

 entangled during underwater operations. 



Electro Oceanics has developed and pat- 

 ented an underwater make and break con- 

 nector wherein both the male plug and fe- 

 male receptacle are molded of a nonwetting 

 elastomer, neoprene, to which the metallic 

 contacts are bonded (Fig. 7.27). An interfer- 

 ence fit between plug and receptacle causes 

 a wiping action as connection is made. By 

 slightly constricting the front face of the 

 female opening and slightly flaring the end 

 of the male, the entire male surface is wiped 

 clean as is the interior of the female with 

 excess water or salt film being ejected to the 

 rear. The purging action is so effective that 

 the connector can be plugged and unplugged 

 in salt water with a resultant leakage resist- 

 ance exceeding 100 megohms. 



As one part of the DOT Program, the 

 Crouse-Hinds Company of Syracuse, New 

 York, developed an underwater make-break 

 connector capable of operation at depths to 

 1,000 feet. A flexible bladder provides volume 

 compensation for changes due to pressure or 

 temperature, and a method employing one 

 active and one dummy rod maintains zero 

 displacement when connection is made. Tests 

 to 15,000 psi show no damage to the connec- 

 tor and subsequent development is aimed at 

 multicircuit use. A complete description of 

 this novel approach and its advantages are 

 presented by Small and Weaver (37). 



Prior to completion of the DOT Program's 

 Connector, Cable and Harness Handbook, 

 several manufacturers and users published 

 state-of-the-art reports of these components 

 which included recommendations for the fu- 

 ture and described the techniques employed 

 on a few specific vehicles. These reports and 

 articles are included in references (38) 

 through (42) and are mentioned herein, not 

 only for historical reasons, but also to give 

 the views of both users and manufacturers. 

 A more recent development in penetrators in 

 Figure 7.28 shows Electro Oceanics' titanium 

 penetrator for the 12,000-foot titanium hull 

 of ALVm. 



350 



