US3455580A - Locking device in bayonet electrical connector - Google Patents

Description

LOCKING DEVICE IN A BAYONET ELECTRICAL CONNECTOR Filed April 7, 1967 2 Sheets-Sheet 1 /9- Pram 3/ F 54 if M 3 INVENTOR. Jay/v G. flow/1&0

BY @IW- A'ITOR NE YS y 15, 1969 J. G. HOWARD 3,

LOCKING DEVICE IN A BAYONET ELECTRICAL CONNECTOR Filed April 7, 19s"? 2 Sheets-Sheet 2 ifil N VEN TOR. Ja/m/ G. Armeo BY ATTORNEYS United States Patent O 3,455,580 LOCKING DEVICE IN A BAYONET ELECTRICAL CONNECTOR John G. Howard, Mount Prospect, Ill., assignor to The Pyle-National Company, Chicago, 11]., a corporation of New Jersey Filed Apr. 7, 1967, Ser. No. 629,229 Int. Cl. F16l 25/00, 55/00; H01r 7/32 U.S. Cl. 235-87 Claims ABSTRACT OF THE DISCLOSURE A bayonet connector consisting of a plug and receptacle which are mated to a metal bottom and locked or restrained by one or more bayonet pins and cam tracks in which a restraining spring imposes a counter force opposing the uncoupling of the plug and receptacle, but which can be overcome selectively by sufiicient reverse force applied by an operator.

BACKGROUND OF THE INVENTION Field of the invention This invention relates generally to connectors and more particularly to pin and slot couplings.

Description of the prior art Electrical connectors consisting of a mating plug and receptacle are generally coupled by some variation of friction, thread, tang or bayonet geometry. Designs of bayonet connections presently available generally are variations of a concept wherein a mating plug enters a receptacle beyond a detent point on the coupling mechanism and remote spring action returns it to a partially extracted position. A defect in this concept is that a space equal to the override on the detent exists between corresponding shoulders of the mating plug and receptacle. Heretofore only a connector assembly utilizing a threaded coupling concept could provide metal-to-metal bottoming at the corresponding shoulders.

Metal-to-metal bottoming is desirable for reasons of grounding, electromagnetic shielding and for reliability through closer control of functional characteristics of the connector at the interfacing surfaces.

SUMMARY OF THE INVENTION In accordance with this invention a cam track or ramp is provided having a curved trackway through which a pin is forced to travel by a transverse relative movement of the pin and cam track. The action imposes a component of force and motion in a direction at an angle to the transverse motion. A restraining spring is disposed in the cam track to provide a hump or interference to the passage of the pin. The restraining spring is deflected to let the pin pass, whereupon the spring loads the pin in a transverse direction to oppose uncoupling rotation.

It is an object of the present invention to provide a bayonet connector for electrical connector apparatus.

A further object of the present invention is to provide a smooth locking and unlocking means of restraining relative motion between a bayonet pin and cam track, for example, in a mating plug and a receptacle.

A further object of the present invention is to eliminate the necessity of an overriding detent and the housing clearances required and to eliminate an area of excessive wear which eventually causes ordinary detent locking arrangement to become inoperative as due to excessive wear.

A further object of the present invention is to eliminate overcompressing of the insert, where interfacial interference is to be retained in the coupled position.

3,455,580 Patented July 15, 1969 A further object of the present invention is to provide metal-to-metal, shoulder-to-shoulder, coupling of housings, for example, in a mating plug and receptacle.

A further object of the present invention is to provide a repetitive-type of locking arrangement that is durable.

Other objects, advantages and capabilities of the invention will become apparent from the following description taken in conjunction with the accompanying drawings showing an exemplification or embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is an elevational view partly in section showing an electrical connector embodying the invention;

FIGURES 2, 3 and 4 are cross-sectional views illustrating additional details of the invention and showing the parts in different positions of adjustment; and

FIGURE 5 is a fragmentary cross-sectional axial view illustrating the metal-to-metal relationship of the parts in the locked position along the line V--V of FIGURE 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGURES 1-4 an electrical connector is indicated generally at 10 and includes a pair of separable housing parts such as a mating receptacle housing 12 and plug housing 14 each having body portions with threaded ends 16 and 17, respectively.

At the forward end of the socket housing 12 is a stepped mating portion 18, 20 which is adapted to cooperate with a complementary mating portion 19 in the plug housing 14. A shoulder or wall 22 projects radially outwardly and serves as a mounting flange for the receptacle 12. The forwardly projecting mating portion 18, 20 has a hollow interior in which contact members are located.

The corresponding portion 19 is sized to be 'sufliciently smaller so that the portion 19 is received in mated telescoped relation with the portion 18, 20. A corresponding plurality of mating contact members are loacted in the interior of the plug housing 14.

In accordance with the principles of the present invention a pin and cam track locking means is located relative to the telescoping parts 18, 19, 20.

On the forwardly projecting portion 18 inwardly of its end extremity 15 is a bayonet pin 26 disposed to lie on a diametral axis and having a portion thereof projecting radially outwardly for engagement with an outwardly circumjacent coupling nut 30. The coupling nut 38 is a ring-shaped member having an inwardly extending flange 31 and which assists in forming an annular internal recess in which is received an annular shoulder 33 provided on the external peripheral surface of the plug housing 14. Thus, the coupling nut 30 is retained in relatively rotatable assembly on the plug housing 14. The shoulder 33 on the plug 14 is urged into metal-to-metal relationship with the end extremity 15 of the receptacle 12, FIGURE 5.

A ramp or cam track 32 is formed within the coupling nut 30 and is engaged by the bayonet pin 26. The cam track 32 is formed as a trough-shaped groove having a bottom wall 50 and side walls 51 and 52. At one edge of the coupling nut shown at 35, the track 32 opens through the edge 35 to form an inlet 37 for receiving the pin 26. At the inlet 37 the walls 51 and 52 are spaced apart just sufliciently to receive the pin 26 in sliding relation. The walls 51 and 52 extend away from the groove on a curvilinear path, thereby to form curved camming surfaces.

The coupling nut 30 also has formed therein axially inwardly of the flange 31 an annular circumferentially extending groove 53 having a wall 54 and a wall spaced parallel thereto at 55.

The wall 51 of the cam track 32 intersects the wall 55 at 56. The wall 52 curves to form with the wall 54 an enlarged recess area 57 adjacent the intersection point 56, Thereafter, the wall 52 extends circumferentially and axially until it blends in with the wall 55. Although only one pin 26 and one cam track 32 is shown in detail, it will be understood that a lurality of pins 26 and tracks 32 may be provided on a single fixture, for example, three at equal 120 circumferential spacing dimensions.

The bayonet pin 26 is adapted to move along track 32 during transverse motion of the coupling nut. The configuration of the cam track 32 thereby urges the plug 14 into axial engagement with the receptacle 12. Comating keys (not shown) on the plug and receptacle prevent relative rotation or transverse motion. The restraining of the coupling nut 30 at the end of transverse motion is provided by a leaf spring 34 with a V-shaped projection hump 42.

More specifically, the spring 34 comprises a ring made of spring metal which extends circumferentially through the groove 53. At each respective locking portion 40 of the groove 53 corresponding to a so-called inlet slot prescribed by the parts 50, 51, 52, etc., there is formed an offset lug comprising a triangularly shaped projection forming the hump 42. The lug or hump 42 has a first leg 42a which overlies the intersection point 56 and extends into the slot for engagement with the pin 26 upon entry of the pin 26 into the slot.

A second leg 42b extends angularly in the same general direction as the slot and forms a wedging cam with the adjoining slot wall 52, thereby to engage the pin 26 after entry.

Between the legs 42:; and 42!) there is formed an apical portion 420 which is spaced from the wall 52 by a spacing dimension less than the diameter of the pin 26. However, the lug 42 is resiliently or elastically yieldable or displaceable from the full line position to the dotted line position of FIGURE 2, thereby permitting the pin to enter the slot.

The portion of the cam surface X within the transverse distance 4215 of the spring 34 is inclined two degrees to four degrees with respect to a transverse plane perpendicular to the axis of the coupling nut 30, FIG- URE 4. This inclined plane provides a wedging action to maintain the lug and receptacle locked in a metalto-metal relationship by the coupling nut 30 acting on the pin 26 of the receptacle 12 at one face 52 of the cam track 32 and by a shoulder 31 on a corresponding shoulder 33 of the plug 14. The forward face 52 of the cam track 32 is used to bring the plug and receptacle to the mated position. The rear face 51 is used to unlock and separate the plug and receptacle.

The spring 34 interposed in the cam track 32 performs the function of preventing the coupling nut 30 from rotating from the locked to an unlocked position. In addition, the hump 42 in the spring 34 is designed to create an audible click as the spring 34 passes the bayonet pin 26. The purpose of the click is to provide an indication of complete and correct coupling Once the pin has passed the apex 420 it is confined by the spring leg 42b and the camming surface afforded by the wall 52, thereby preventing counter-rotation or reverse of the coupling nut 30 and thereby resulting in a loss of fully coupled relationship of the shells. Yet, if manual force is supplied, the restraining force applied by the spring can be overcome to separate the parts.

Additional means such as a pin 36 may be used to secure the leaf spring or spring ring 34 in the groove 53.

In FIGURE 3, the bayonet pin 26 has passed the hump 42 in the spring 34 and is in a locked position. The spring 34 is deflected as the pin passes the spring hump 42 within the space 40. The hump 42 is contemplated to be of sufficient strength to prevent uncoupling until a suitable reverse force is applied.

In the locked position, the mating plug 12 and receptacle 14 are in metal-to-metal contact with a smooth locking as the bayonet pin 26 passes the spring hump 42.

Although minor modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.

1. A mating plug and receptacle comprising:

first and second separable parts adapted to mate telescopically on an axis of separation,

rotatable means to mate and lock said first and second parts,

one of said parts having a pin and the other of said parts mounting said rotatable means,

said rotatable means having a cam. track comprising a groove having an inlet Opening axially to receive said pin,

said groove extending axially and circumferentially, said rotatable means having a spring receiving groove intersected by said cam track, and spring means in said spring receiving groove including a resiliently yieldable portion projecting in said groove of said cam track to admit and release said pin with an interference fit relationship.

2. A mating plug and receptacle comprising:

male and female parts telescopically separable and a coupling nut having groove means,

said receptacle having pin means,

said pin and groove means more specifically comprising an annular recess extending circumferentially in one of said parts and having a plurality of intersecting slots extending out of said recess in circumferential and axial direction,

each of said slots forming a cam track terminating in an axial inlet disposed to receive a corresponding pin, and a circumferentially extending spring in said annular recess,

said spring being made of a ring of spring metal and narrower in width than the width of said recess, thereby to be received and seated in said recess,

said spring having an offset lug portion formed at each corresponding slot comprising a triangularly shaped projection including a first leg extending into the slot for interference engagement with the pin at a first position upon entry and a second leg engageable with the pin at a second position after entry and forming with the adjoining wall of said slot 9. wedging cam, said first and second legs having an apical portion therebetween spaced from the adjoining wall of said slot less than the thickness of the pin but being displaceable in response to relative movement of the parts, said second leg loading said pin to prevent rotation of said coupling nut.

3. A coupling connection for separable male and female parts of an electrical connector comprising:

means on one of said parts forming (a) a circumferentially extending groove disposed concentrically to the axis of separation of the parts and (b) at least one cam track angularly intersecting said groove at a junction area and extending circumferentially and axially relative thereto,

a pin on the other of said parts movable through said cam track and into said groove upon relative axis and rotational movement between said parts, and

a spring in 'said groove having a detent projecting into said junction area of said cam track and said groove to form a deflectable obstruction in the path of said pin as it moves from said cam track into said groove,

whereupon said pin will deformably displace said detent for snap-in retention to retain said parts in mated relationship.

4. In an electrical connector having axially separable male and female parts,

a system of grooves on one of said parts including a groove disposed concentrically relative to the axis of separation of the parts,

said groove having a first side wall extending circumferentially continuously and a second side wall spaced axially therefrom, said second side wall having a curved portion extending axially and circumferentially to form one wall of a cam track on said one of said parts,

said second side wall having a reentrant portion extending generally parallel to said one wall of said cam track,

said groove in said cam track together with one another forming an area of intersection between said cam track and said groove, and

a spring in said groove having a detent portion projecting into said area of intersection for an interference relationship with a pin on the other of said parts moving through said cam track,

whereby the cam track operates with the pin upon rotational advance of the parts to bring the parts into fully mated position and the spring prevents inadvertent relative rotation to an unlocked position after deformably passing the pin.

5. In an electrical connector having axially separable male and female parts, a system of grooves on one of said parts including a groove disposed concentrically relative to the axis of separation of the parts, said groove having a first side wall extending circumferentially continuously and a second side wall spaced axially therefrom, said second side wall having a curved portion extending axially and circumferentially to form one wall of a cam track on said one of said parts, said second side wall having a reentrant portion extending generally parallel to said one wall of said cam track, said groove and said cam track together with one another forming an area of intersection between said cam track and said groove, and a spring in said groove having a detent portion projecting into said area of intersection for an interference relationship with a pin on the other of said parts moving through said cam track, said spring comprising a leaf spring and said detent comprising a V-shaped projection on said leaf spring having one leg passing adjacent said reentrant portion and having the apical portion thereof disposed to reduce the width of the cam track to less than the thickness of the pin for establishing the inter- References Cited UNITED STATES PATENTS 828,243 8/1906 Polmann 285376 X 1,089,650 3/1914 Kile 285-361 X 1,871,421 8/1932 Muhlhauser et a1. 285-361 X FOREIGN PATENTS 1,297,925 5/1962 France. 1,383,119 11/1964 France.

CARL W. TOMLIN, Primary Examiner W. L. SHEDD, Assistant Examiner US. Cl. X.R. 285396; 339

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