US 3609637 A
Description (OCR text may contain errors)
United States Patent  lnventor Clyde C. Cole Primary ExaminerJoseph H. McGlynn 5298 Harvard St-., Ventura, Calif. 93003 Att0rneys-Richard S. Sciascia, Q. Baxter Warner and  Appl. No. 881,021 Howard J. Murray, Jr.  Filed Dec. 1, 1969  Patented Sept. 28, 1971 ABSTRACT: A plug for insertion into a socket of the type having a disk-shaped base member serving as a ground con-  ELECTRICAL CONNECTOR nection, such base member being formed with a central open- 1CMm4Dmwmg Figs. mg through whlch pro ects an electrically separate springloaded pln contact. The invention plug incorporates a  US. Cl 339/75 R, fl ti ground plate of annular configuration designed for 339/94 R engagement with the socket base member, and a spring-biased  lnt.Cl ..H01r 13/54 axial conductor in afignmem with the pin Contact f [he  Field of Search 339/45, 75, socket A f t f the plug design is that the necessity f 285/338, 346 screwing the plug into the socket is eliminated through the use [5 References Cited of a quick-connect-disconnect lever which is manually actuatable through a small angle to cause the radial extension of UNITED STATES PATENTS a deformable O-ring, thereby securing the plug in the socket 2,369,860 2/1945 Schroeder 339/75 after it has been linearly inserted thereinto. This precludes the 2,728,062 12/1955 Klostermann. 339/255 possibility of abrading small metal particles from the respec- 2,991,09l 7/1961 De Cenzo 285/83 tive contact surfaces, as may occur in conventional designs 3,345,604 10/1967 l-lenschen et a]. 339/186 when engagement therebetween is brought about by relative 3,521,909 7/1970 Brown 285/3 rotational movement of plug and socket.
cr m I T 60 62 m Ci ooo ELECTRICAL CONNECTOR STATEMENT OF GOVERNMENT INTEREST BACKGROUND OF THE INVENTION When a connection is desired between two electrical cables, one of which is terminated by a plug and the other of which is provided with a mating socket, it is necessary in many instances to screw the plug into the socket for as many as several complete revolutions before electrical engagement between the respective conductors is established Just prior to a tight fit, however, there is a short period when a lateral abrasive movement is present between the ends of the conductors to be electrically joined. This action often causes metal particles to rub off, and, over a period of time, these shavings can accumulate within the socket to a point where, in extreme cases, they create shoring problems or otherwise adversely affect the electrical characteristicsof the connector assembly.
A further disadvantage in standard connector assemblies of the type discussed above is the time required to screw the plug into the socket. For permanent or semipermanent connections this factor is normally of minor importance, but where the plug is to remain in any particular socket for only a few minutes (or even seconds) and then be transferred to another socket, the time expended in making the connection is difficult to justify. One example of such a situation is found in the checkout of electrical firing equipment on a missile-carrying aircraft. A test set having an output conductor terminating in a plug is sequentially connected to each breech cap (or socket) on the aircraft missile carriage assembly prior to loading of the missile thereon in order to determine the go-no go status of the aircraft firing circuitry. An indicator light on the test set is illuminated if such circuitry is in proper operating condition. It requires only a few seconds to make this test for each breech cap, but the necessity of screwing the test set plug into a number of caps in succession is very time consuming. A way of quickly and easily making such a connection is greatly to be desired.
SUMMARY OF THE INVENTION In accordance with a preferred embodiment of the present invention, both connector problems discussed above are concurrently solved by a unique plug design. Instead of screwing the plus into the socket by causing a relative rotational movement between these two members, the plug is fabricated to be of reduced diameter and not threaded, so that it can be inserted linearly into the socket with a straight-ahead motion until flrm contact between the respective conductors is established. Means are then prided 'on the plug in the form of a manually actuatable lever which can be turned through a small angle to cause the radial extension of a deformable O- ring the material of which this ring is composed frictionally engaging the innersurface of the socket to hold the plug securely in place therein. A subsequent small movement of this lever in the opposite direction releases the O-ring and permits the plug to be readily withdrawn after the desired test has been made, or when the electrical connection is no longer needed or desired. Such an operation requires only a fraction of the time formerly needed with standard connectors, and, since no rotational movement occurs between plug and socket, there is no danger of abrading the contacts or causing wear on the socket threads. Complete from from the presence of metal particles or shavings within the cap is thus achieved.
OBJECTS OF THE INVENTION One object of the present invention, therefore, is to provide an improved form of electrical plug designed for quick connection to a threaded socket without having to be screwed thereinto.
Another object of the invention is to provide an electrical plug designed for linear insertion into a threaded socket without introducing relative rotary motion therebetween.
A further object of the invention is to provide means for securing in a threaded socket an electrical plug which has been linearly inserted thereinto, such securing means taking the form of a deformable member which is expanded radially outwardly from the plug body into contact with the inner wall of the socket.
Other objects, advantages, and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of an electrical plug designed in accordance with a preferred embodiment of the present invention, together with a conventional socket of one type into which the plug is receivalbe;
FIG. 2a is a sectional view of the plug of FIG. 1 taken along the line 2a-2a FIG. 2b is a sectional view of the socket of FIG. 1 taken along the line 2b2b; and
FIG. 3 is a view showing the plug of FIG. 2a inserted into and secured within the socket of FIG. 2b.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, there is shown an electrical plug made up of a tubular body member 10 having a flanged forward edge 12 and a rear portion 14 of restricted diameter relative to the main body portion, as illustrated. Within body member 10 is disposed a centrally apertured cylindrical insulator I6 resting on a shoulder 17 (FIG. 2a and serving both as a base and as a guide for an outer coil spring 18 and also as a base for an inner coil spring 20 the function of which will be set forth hereinafter. Spring element 18 lies in an annular chamber between insulator 16 and the inner surface of body member 10, as illustrated.
The electrical connectors or the plug being described comprise a center contact 22 and a grounding disk 24, these two elements being separated by the insulating flanged collar 26 as best shown in FIG. 2a. The disk 24 is held in place by a press fit lockring 28.
Spring 18 acts to load the grounding disk 24 and bias it forwardly away from the plane of the body flange 12. A shoulder 30 on disk 24 limits its forward extension by engaging lock ring 28.
The center contact 22 is in the form of a pin extending axially of the plug. It has a flange 32 intermediate its ends, such flange being cup shaped to receive one end of spring 20, the other end of this spring resting on a planar portion 34 of the insulator 16. The remaining surface of flange 32 abuts the flanged collar 26 so as to limit the forward extension of pin contact 22 to a degree where it is slightly beyond the plane of disk 24, as shown both in FIG. I and FIG. 2a. It will now be recognized that pin contact 22 and grounding disk 24 are both spring biased forwardly by their respective springs 20 and I8. The arrangement is such that inward pressure only on center contact 22 to depress the mine does not result in movement of disk 24, but an inward pressure on the latter does cause concurrent movement of the inner contact since it rides along" therewith.
A feature of the present concept lies in the provision of means for securing the plug in a conventional socket (such as that illustrated in the drawing) without the necessity of producing any relative rotational movement therebetween. This means includes a compressor sleeve 36 overlying the body member 10, this sleeve being shown in both FIG. I and FIG. 2a of the drawings. Sleeve 36 is designed to move axially of member I0 in the direction indicated by the arrow following insertion of the plug into a socket and when a temporary electrical connection therebetween is desired.
Disposed between the forward edge of compressor sleeve 36 and the flange 12 on member is an O-ring 38 composed of some deformable material. The rearward edge of compressor sleeve 36 abuts a pair of cammed surfaces 40 formed on a pair of oppositely disposed laminated disks or washers 42 only one of which is visible in FIG. I. These disks 42 are pivoted on an axis extending transversely of the plug body (FIG. 2a and are respectively carried on a pair of pivot pins 44 joumaled by member 10. These pins 44 serve the dual function of supporting the disks 42 and also limiting the axial forward movement of body member 16 by abutting a shoulder 45 formed on the latter. This construction is clearly brought out in FIG. 2a of the drawings. From each of disks 42 extends a manually actuatable lever arm 46 (only one of which can be seen in FIG. 1 connected together and carry an optional thumb or finger pressure plate 48.
Inner contact 22 is connected in conventional fashion to an output lead 50. Body member 10 is soldered or otherwise joined to a further output lead 52.
The socket shown sectionally in FIG. 2b may be of conventional design, with a threaded inner surface 54. The outer diameter of the plug sleeve 36 (and flange 12) is such that the plug is directly receivable in the socket with a straight linear motion, without any rotational engagement being necessary with the threads of the socket. A spring-loaded contact pin 56 is axially disposed within the socket body and is encircled by an electrically separate ground connector collar 58 having a flanged portion 60 adapted to lie in face-to-face relationship with the ground disk 24 of the plug. A plurality of projections 62 extend outwardly from the face of the flanged collar portion 60 so as to engage the plug ground disk 24 and ensure good electrical contact therewith. The pin 56 is soldered to an insulated output conductor 64, while the socket body is grounded through an adapter 66 carrying the conductor 64 therethrough.
When the plug of FIG. 2a is fully inserted into the socket of FIG. 2b, the various components assume relative positions as shown in FIG. 3 of the drawings. Pin contact 56 of the socket engages pin contact 22 of the plug, and, since each contact is spring loaded, firm electrical engagement therebetween is established, the spring 20 becoming partially compressed. In addition, projections 62 on socket flange 60 engage the ground disk 24 of the plug and force it inwardly against the tension of spring 18. This establishes a finn ground contact.
To maintain the electrical relationships thus brought about, the joined levers 46 are then manually actuated (as by pressure on plate 48) to rotate disks 42 about their respective pivot pins 44. This change in position of levers 46 from their position shown in solid lines in FIG. 1 to a position as illustrated by the broken lines causes the cam surface 40 to force compression sleeve forwardly, or to the right as indicated by the arrows in the drawings. Such movement compresses the deformable material of which O-ring 38 is composed, forcing the O-ring to assume a somewhat oval cross-sectional configuration in which shape it frictionally engages the inner threaded surface of the socket and precludes any further relative axial movement of these members until the levers 46 are subsequently returned to their original position.
The time required to linearly insert the plug into the socket and rotate the levers 46 is only a small fraction of that conventionally required to completely screw a standard plug into the same socket. Furthermore, since no rotational movement between plug and socket occurs, there is no chance that small metal particles will abraded from the mating contact surfaces.
The plug of the present invention is usable with many types of standard sockets, the only requirement being that the socket inner diameter be large enough to receive the compression sleeve 36.
Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.
I claim: 1. An electrical plug designed for linear insertion into'a socket in situations where a relative rotary movement between plug and socket is ordinarily required in order to establish an electrical connection, said plug comprising:
a tubular body member having an outwardly flanged forward edge,
a sleeve encircling said body member and slidable theralong, the outer diameter of said sleeve being less than the inner diameter of said socket,
an oO-ring composed of deformable material lying between the forward edge of said sleeve and the flange on said body member,
means manually actuatable following a linear insertion of said plug into said socket for moving said sleeve toward said flange,
thereby compressing said O-ring and defonning the material of which it is composed radially outwardly and into frictional engagement with the inner surface of said socket, thus precluding any relative axial displacement between said socket and said plug until subseguent manual actuation of said means,
said manually actuatable means including at least one lever mounted on said body member and rotatable about an axis extending transversely of the longitudinal axis of said P s.
one end of said lever being in the form of a rotatable disk having a peripheral cam surface engaging the rearward edge of said sleeve, and
an additional contact of annular configuration carried by said plug concentrically with said center contact, and means for spring loading said additional contact independently of the means for spring loading said center contact.