US 3852701 A
A three-phase electrical power connector comprising a housing to which three outlets are secured. Each outlet typically includes three individually removable female contacts, each contact having a segmented one-piece design with a pair of garter springs surrounding the segmented portions. Resilient flexible bus bars are provided within the housing for electrically connecting the contacts of each phase. Each contact is constructed and arranged for mounting and securing to its respective bus bar in a manner which permits both resilient axial and radial movement of the contact by amounts which will allow for a relatively large misalignment with the contacts of the mating plug.
Claims available in
Description (OCR text may contain errors)
Unite States Patent initz Dec. 3, I974 POWER CONNECTION SYSTEM  Inventor: Lee Minitz, Granada Hills, Calif.
 Assignee: Bunker Ramo Corporation, Oak
 Filed: Oct. 10, 1972 ] Appl. No.: 296,417
 U.S. Cl. 339/64 M, 339/156 R, 339/259 R  Int. Cl. HOIt 13/62  Field ofSearch 339/18, 19, 22, 28, 29, 64,
. FOREIGN PATENTS OR APPLICATIONS Great Britain 339/64 M Primary Examiner-Joseph H. McGlynn Attorney, Agent, or Firm-Frederick M. Arbuckle; Nat Cass 57 ABSTRACT A three-phase electrical power connector comprising a housing to which three outlets are secured Each outlet typically includes three individually removable female contacts, each contact having a segmented onepiece design with a pair of garter springs surrounding the segmented portions. Resilient flexible bus bars are provided within the housing for electrically connecting the contacts of each phase. Each contact is constructed and arranged for mounting and securing to its respective bus bar in a manner which permits both resilient axial and radial movement of the contact by amounts which will allow for a relatively large misalignment with the contacts of the mating plug.
14 Claims, 4 Drawing Figures PATENTEL BEE 3 74 SIIEH 2 0F 3 ll POWER CONNECTION SYSTEM This invention relates generally to electrical connection systems, and more particularly to a system for supplying power at a plurality of outlets on a vehicle or at an installation or site presenting severe and/or hostile environmental conditions.
An example of an application for which the present invention is particularly well suited is for supplying power on a ship during power failure emergencies. Such a system is commonly referred to as a casualty power system and the connector assembly as a casualty power connector. 7
In a preferred embodiment in accordance with the invention, a casualty power connector typically provides three outlets or sockets to which cabled plug assemblies containing mating male contacts may rapidly and reliably be connected during a power failure emergency. Each outlet typically provides three individually removable contacts constructed and arranged so as to provide for'both axial and radial movement of each contact with respect to the outlet by amounts which will allow for a relatively large misalignment. Also, the design of each contact is such as to permit engagement and disengagement with the mating plug to be easily and reliably accomplished with a maximum required force of, for example, 2.5 pounds for individual connector and plug contacts, while at the same time providing a high quality, very lowcontact resistance electrical connection therebetween.
The construction and arrangement of this preferred embodiment in accordance with the invention ,is further such as to provide a simple, compact and economical design which minimizes electrical shock hazards and also provides for ease of servicing as well as for ease in making the required internal connections to external power leads.
The specific nature of the invention as well as other objects, features,-advantages and uses thereof will become apparent from thefollowing-detailed description of a specific embodiment of the invention taken in conjunction with the accompanying drawings in which:
FIG. 1 is an overall perspective view of a preferred embodiment of a casualty power connector system in accordance with the invention showing a three-outlet casualty power connector along with the three associated plugs to be respectively connected thereto;
FIG. 2 is a perspective view of the housing of the casualty power connector of FIG. 1 with the cover and contacts removed to illustrate details of the internal construction along with an exploded illustration of the contact and flexible bus construction and arrangement for a typical. oneof the three phases provided therein;
FIG. 3 is a front view with portions broken away of the casualty power connector illustrated in FIGS. 1 and 2; and
FIG. 4 is a longitudinal view showing details of a typical oneof thecontacts employed in the embodiment of FIGS. l-3.
Like numerals refer to like elements throughout the figures of the drawings.
With reference to FIGS. 1-3 of the drawings, and primarily to the overall perspective view of FIG. 1, a preferred embodiment of a power connector system in accordance with the invention is illustrated which typically includes a three-phase power connector providing three outlets 12 located as shown with each outlet typically having three female contacts 13. Also shown in FIG. 1 are three cabled mating plugs 14, each having three pin contacts 17 for respective mating with the outlet contacts 13 when a plug 14 is plugged into an outlet 12. Appropriate polarizing elements 12a and 14a are provided on the outlets 12 and plugs 14 for orientation purposes.
As shown in FIG. 1, the power connector 10 basically comprises a generally U-shaped housing 15 to which the outlets 12 are affixed with the housing also including an integral triangular mounting plate 16 having mounting holes 16a along with rubber shock washers 16b for use in mounting the connector 10 to a suitable support, such as a panel or bulkhead.
FIG. 1 also generally illustrates a typical manner in which the three-wire input power cable 18 may enter the housing 15, via a hole 15b containing a rubber sealing grommet 15c provided in a removable housing cover 15a, for electrical connection of individual power cable wires with respective ones of the outlet contacts 13. FIG. 1 additionally illustrates the provision of an easily attachable and removable protective cover 19 for each outlet 12 to which it is retained against loss by a flexible cable 19d.
In the preferred embodiments of the invention described herein, housing 15 as well as the housings of the outlets 12, the-associated plugs 14, and the covers 19 arepreferably made by appropriate molding of a glass fiber, reinforced, phenolic-base, self-extinguishing material. Also, the various interfacial seals and shock washers employed are preferably made of an elastomeric compound and assembled under compression to provide an environmental seal. Attention is now directed to FIGS. 2-4 along with FIG. 1 for providing a more detailed understanding of the features and advantages of the preferred embodiment of the casualty power connector 10 being described herein.
As best shown in FIG. 3, internally threaded metal bushings 21 are incorporated into the housing 15 during molding for use in securing the outlets 12 thereto, an interfacial seal 22 being provided therebetween. Assembly of the outlets 12 to the housing 15 is typically accomplished using fasteners 23 each having an externally threaded end 23a and a larger diameter internally threaded opposite end 23b. Each fastener 23 is inserted into a counterbore 12c in the outlet 12 with its externally threaded-end 23a passing through bores 12d in the outlet and 15f in the housing-l5 for threading in a respective bushing 21 which may be accomplished, for
example, by rotating the fastener 23 using a screwdriver engaging a slot 23c provided in the fastener. The internally threaded opposite end 23b of each fastener 23 is used to permit securing to the outlet 12 either the associated plug 14 (FIG. 1) or the protective-cover 19 by manually turning the knurled portions of captive retaining screws 14b and 19b respectively provided therein. The plug 14 and protective cover 19 are also respectively provided with interfacial seals 14c and Still with primary reference to FIG. 2, it will be seen that the interior of the housing 15 provides a cavity 15d having three spaced, parallel grooves 15g extending along the inner housing wall between the three outlets 1 2. As will hereinafter become evident, an important feature of the invention resides in the provision of a resilient flexible bus bar 25 in each groove 15g having associated terminals 27 affixed thereto, each terminal having a mounting hole 27a. The flexible portions of each bus bar 25 may typically be made of braided copper. The terminals 27 on each flexible bus bar 25 are located so that when a bus bar 25 is disposed in its respective groove 15g, its terminal holes 270 will be adjacent corresponding contact receiving holes 15]: provided in the housing 15 which in turn are aligned with the outlet contact receiving holes 12e.
Now considering the preferred construction and mounting of the outlet contacts 13 in more detail with additional reference to FIG. 4, it will be understood that each contact 13 has a segmented one-piece construction with the segments 13:: being designed to provide smooth contact surfaces and minimal travel movement. Contact pressure is maintained at a desired level by the provision of two passivated garter springs 13b surrounding the segmented portion of the contact 13 and disposed in a groove 13c (FIG. 4). It is evident that these garter springs 13b will not come into contact with an inserted mating plug pin and will thus not form apart of the electrical circuit. Such a construction and arrangement for these outlet contacts 13 minimizes electrical contact losses between the mating contacts, while permitting engagement and disengagement to be accomplished with a maximum required force of, for example, 2.5 .pounds for individual connector and plug contacts.
As best shown in FIG. 4, proceeding rearwardly from the front end of the contact 13 (that is, the end containing the segments 13a), the contact 13 is provided with a hexagonal mounting flange 13d followed by a reduced diameter cylindrical portion Be, and lastly by a threaded portion 13f at the rear end of the contact. As will be evident from FIGS. 2 and 3, each contact is mounted in the connector by inserting it in its respective aligned contact receiving holes l2e and /1 in the outlet 12 and housing 15. The contact 13 is fully inserted when the rearward end of its hexagonal mounting flange 13d abuts against the shoulder provided by a hexagonal counterbore 151 formed at the outward end of the contact receiving hole 15/1 in the housing 15. The threaded end 13f of the contact 13 passes through the terminal hole 27a in the respective-bus bar terminal 27. If the connecting lug 18b of an input power lead 18a is also to be connected to the contact, as illustrated in H05. 2 and 3 for the lowermost outlet 12, then the threaded end 13f is also passed through the connecting lug hole 180 as shown. The contact 13 along with the bus bar terminal 27 (and also the connecting lug 18b if present), are then secured by a nut 13g and a locking washer I311, access thereto for this purpose being obtained by removing the housing cover 15a. Since both the counterbore 15: and the contact mounting flange 13d are hexagonal, the contact I3 is prevented from rotating during tightening by the nut 13g.
An important feature of the invention resides in choosing the size of the terminal hole 27a through which the threaded end 13f of the contact 13 passes so that, when the nut 133 is tightened, the terminal 27 will be tightened against the rearward shoulder provided by the reduced cylindrical portion l3e of the contact 13 I rather than against the inner wall of the housing 15. A
desired clearance is thus provided between the inner flexible material, such as copper braid, it will be understood that a desired amount of resilient axial movement may thus advantageously be provided for each contact 13 simply by appropriately locating the rearward shoulder of its reduced cylindrical portions Be.
A further feature of the invention resides in choosing the contact receiving holes 12e and 15/1 in the outlet 12 and housing 15 to be oversized with respect to the adjacent contact portions, thereby permitting the hexagonal flange 13d of the contact 13 to serve as a fulcrum about which the contact is able to pivot in any direction. It will be understood that the provision of such pivoting movement for each contact 13 in addition to axial contact movement, as previously described, results in a contact design which allows for a relatively large misalignment without damaging or otherwise detracting from the integrity of the contacts, and while also permitting the employment of a contact design requiring relatively low engagement and disengagement forces as well as providing low electrical contact losses.
Although the invention has been described with respect to a particular preferred embodiment, it is to be understood that many modifications and variations in construction, arrangement and use are possible within the scope of the invention. For example, it will be recognized that the features of the invention may be applied to a wide variety of other types of electrical connectors other than the particular casualty power connector embodiment described herein. Accordingly, the invention is to be considered as including all possible modifications and variations coming within the spirit and scope of the invention as defined by the appended claims.
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. In combination:
anelectrical contact supporting structure having a contact receiving hole,
an electrical terminal disposed adjacent said contact receiving hole,
a contact disposed in said contact receiving hole,
means for securing said contact to said terminal,
said contact and said means for securing being constructed and arranged in conjunction with said contact receiving hole in a manner so as to permit movement of the secured terminal and contact relative to said supporting structure, and
resilient means connected to said terminal for providing resiliency of said movement of the secured terminal and contact.
2. The invention in accordance with claim 1, wherein said contact and said contact receiving hole are constructed and arranged to permit both axial and radial resilient movement of said contact.
3. The invention in accordance with claim 1, wherein said contact is provided with a shoulder projecting beyond said supporting structure and against which shoulder said terminal abuts when secured to said contact, said shoulder being located on said contact so as to per- .mit a desired amount of axial movement of said contact in said contact receiving hole.
4. The invention in accordance with claim 3, wherein said contact includes a flange for abutting against a stop shoulder provided in said contact receiving hole, and wherein said contact receiving hole is oversized relative to adjacent contact portions on both sides of said stop shoulder so that said flange serves as a fulcrum about which the contact can pivot to thereby also permit radial movement of said contact.
5. The invention in accordance with claim 4,- wherein said contact has a front end forreceiving a mating contact and a threaded rear end on which said terminal is mounted via a terminal hold provided therein, said terminal hole being smaller than the shoulder provided by said contact so that the secured terminal abuts thereagainst rather than against said supporting structure.
6. The invention in accordance with claim 5, wherein said contact is of the female type having a segmented front end, and wherein at least one ring-shaped garter spring is provided surrounding the segmented portion of said contact for providing a desired level of contact pressure for a mating male contact inserted therein.
7. In combination: I
an electrical contact supporting structure having first and second contact receiving holes at spaced locations thereof, I
a first terminal disposed adjacent said first contact receiving hole,
a first contact disposed in said first contact receiving hole and secured to said first terminal,
a second terminal disposed adjacent said second contact receiving hole,
a second contact disposed in said second contact re ceiving hole and secured to said second terminal,
a resilient flexible bus bar electrically connecting said first and second terminals,
each contact and its respective terminal being constructed and arranged in conjunction with said bus bar so as to permit resilient movement of each contact and secured terminal relative to said supporting structure.
8. The invention in accordance with claim 7, wherein each contact is provided with a shoulder projecting beyond said supporting structure and against which shoulder its respective terminal abuts when secured so as to provide clearance for movement of each contact and secured terminal relative to said supporting structure.
9. The invention in accordance with claim 8, wherein each contact also'includes a flange for abutting against a stop shoulder provided in its respective contact receiving hole, and wherein each contact receiving hole is oversized relative to adjacent contact portions on both sides of saidstop shoulder so that said flange serves as a fulcrum about which its contact can pivot to thereby also permit radial movement thereof.
10. An electrical connector comprising:
prevent rotation of a housing providing a plurality of outlets at spaced locations thereof,
each outlet containing a plurality of electrical.
each contact having a front end for receiving a mating contact and a rear end to which its respective bus bar terminal is secured,
each contact also providing a shoulder intermediate said ends and projecting from said housing when the contact is inserted therein so that the respective secured terminal abuts thereagainst rather than against said housing so as to permit a desired amount of axial movement of each contact in its contact receiving hole determined by the location of said shoulder,
said flexible and resilient conducting members of each bus bar being chosen to provide resiliency of said axial'movementf 11. The invention in accordance with claim 10, wherein each contact also includes a flange located intermediate'the shoulder and front end thereof and located so as to abut against a stop shoulder provided in said housing when the contact is fully inserted therein, and wherein each, contact receiving hole is oversized relative to adjacent portions of its respective contact on both sides of said stop shoulder so as to permit said flange to serve as a fulcrum about which the contact can pivot. I
12. The invention in accordance with claim 11, wherein each terminal is provided with a terminal mounting hole through which the rear end of its respective contact passes, said terminal mounting hole being smaller than the projecting contact shoulder so that the secured terminal is secured thereagainst rather than against said housing. I
13. The invention in accordance with claim 12, wherein the rear end of each contact is externally threaded, and wherein an internally threaded securing means is provided threaded on the contact rear end to secure the respective terminal thereon.
14. The invention in accordance with claim 13, wherein said flange and the adjacent portion of said contact receiving hole are provided with shapes which the contact therein.