Enhanced detent guide track with dog-leg

Abstract

An electrical connector having a receptacle including a receptacle shell and a plug including a plug housing, a coupling nut threaded on the plug housing and engaged with a coupling ring, the coupling nut having threaded engagement with the plug housing and the coupling ring having locking flanges engageable with cooperable locking lands on the receptacle shell, the plug and receptacle being adapted to be fully electrically mated and locked by rotation of the coupling ring through about 90 degrees. An arcuate detent member subtending an angle of about 180 degrees is keyed to the plug housing for relative axial movement of the plug housing, and is received within an annular groove in the coupling ring for resilient forcible selective engagement of opposite radially outwardly enlarged ends of the arcuate detent member with two sets of radially outwardly formed recesses in the coupling ring. When the coupling ring is rotated to the fully locked position of the plug and receptacle means, the ends of the arcuate member are forcibly snapped into one set of recesses to indicate attainment of the locked and fully mated position by sound and by feel. Rotation of the coupling ring in the opposite direction unlocks the plug and receptacle and the enlarged ends of the detent member are released from the first set of recesses to engage a second set of recesses in the coupling ring to audibly and tactilely indicate attainment of the unlocked position. The resilient arcuate member comprises an enlarged center portion forming a key which is designated to mate with and ride in a keyway on the plug housing with an enlarged portion of the keyway defining a dog-leg in the path of the axial travel of the plug housing. The key makes audible contact with a terminal wall of the dog leg momentarily moves out of contact with the plug housing on the key entering the dog-leg producing an intensified audible snap of the arcuate detent member into the coupling ring recesses when the fully mated and locked position of the connector is attained.

Description

BACKGROUND OF THE INVENTION

Electrical connectors for coupling cables having a bundle of wires are required to be operable under many adverse environmental conditions which include continual vibration, extreme changes in temperature and pressure, minimal space availability, and shock stresses. Various prior constructions of electrical connectors have been proposed utilizing various types of detent means for releasably locking or holding lock means in locked engagement to retain the plug and receptacle means in assembly in full mated electrical and mechanically locked condition.

Some of such prior detent devices have included indicators adapted to be seen, heard and/or felt. U.S. Pat. No. 3,609,632 shows a releasable electrical connector having a lock indicator in the form of a button forced outwardly of an outer shell so that it can be seen and felt. U.S. Pat. No. 3,601,764 shows a locking means for an electrical connector in which visual, audible and tacile indications are given when a locked condition is achieved. Such prior constructions were relatively structurally complex and were adapted to the construction of the particular electrical connector.

In some installations, available space is very limited for manipulation of a connector into coupled and uncoupled relation. Often whether or not the coupling is fully electrically mated and mechanically locked cannot be determined visually but can be determined best by an audible and/or tactile indicator. Awareness that a coupling is in full electrical and mechanically locked relation is obviously desirable to assure proper operation of an electrical system. It is also highly desirable to be aware of a fully unlocked and unmated condition of the coupling because if partially unlocked coupling parts are separated, damage to the parts may be caused by applying excessive force or overstressing of the parts may occur.

In an electrical connector in which mating rapidly occurs upon only a part turn of a coupling ring, audible and tactile indicating means must be immediately operable, must be reliable, and should be protected in operation from possible interference by adjacent parts of the connector.

In U.S. Pat. No. 4,066,315 an electrical connector construction which includes a novel means for audibly and tactilely indicating fully coupled (electrically and mechanically) and uncoupled conditions of the connector is disclosed. The invention therein particularly relates to an arctuate detent member carried by one of the shells of the connector and moveable relative to a coupling ring which is turned to bring plug and receptacle means into electrically mated and mechanically locked condition. Although this connector has proven to be extremely successful in its application, and has in fact proved to be a superior connector which visibly, audibly and tactilely reliably indicates a fully locked and mated position or an unlocked and unmated position after fairly substantial and extended use, it has been found that the audible indication, i.e., the snap generated by the connector upon attainment of the locked position, is found somewhat to diminish.

SUMMARY OF THE INVENTION

The present invention relates to a novel electrical connector construction which includes a novel means for audibly and planerreceptable receptacle shell.

An insert retaining ring 158 may be made of a suitable compressible thermoplastic material, such as Torlon or Nylon. Ring 158 includes a cylindrical smooth inner surface 159 through which may be received, as by a clearance fit (a few thousandths of an inch), the back end portion of insert member 40. The outer cylindrical surface of ring 158 is provided with a thread 160 which has two leads, a left hand pitch and includes 25 turns per inch. The thread configuration, also or a buttress type, includes a generally triangular cross section having a width approximately one-third or one-quarter of the space between adjacent crests 161 as identified by the letter A, and an outwardly directed face 163 normal to flat root 162. The crest spacing A in this example may be about 0.020. The outer diameter of the insert retaining ring 158 is slightly larger than the inner diameter of the shell, the sharp corners 161 reaching into the root areas 154 of threads 152.

As shown in FIG. 20, the unique configuration of the threads 152 and 160; that is, one being a single lead right hand pitch of 50 threads per inch and the other being a left hand pitch two leads at 25 turns per inch, together with the specific cross sectional configuration of the two threads provides a unique thread interengagement in which mating or meshing thereof will occur at three points spaced approximately 120 degrees apart as indicated in FIG. 20 at 165, 166 and 167. The manner of such interengagement is now described.

In assembly, after the insert member 40 has been angularly oriented and axially positioned against reference shoulder 41a within receptacle shell 36, insert retaining ring 158 is sleeved over the end of the insert member 40 and moved axially toward back shell 39. When the sleeve member begins to enter intermediate portion 151 with threads 152, a cylindrical drive tool is employed to forcibly press the insert ring into the receptacle back shell 39 and axially along the shell threads 152. Because the threads are pitched in an opposite direction and are of non-threading non-mating characteristics, the forcing of the threads of the plastic ring along the threads of the metal back shell 39 places the insert ring under radial compression and causes the threads 160 to successively interengage and forcibly interfit with the threads 152 at three angularly spaced areas indicated in FIG. 20. Such radial pressure interfitting of the threads 152 and 160 during relative axial movement is facilitated by inclined faces 156 and 164. Restraint against opposite relative axial movement is positively restricted by the interabutment of faces 155 and 163 which are normal to the axis of the ring and shell. Such interengagement of compressible thermoplastic threads 160 with metal threads 152 successively and angularly progressively occurs at three angularly spaced places around back shell 39, the thermoplastic retainer ring 158 being deformed under radial compression into somewhat triangularly related locked or interfitting abutment areas 165, 166 and 167 provided by the opposed normal faces 155, 163 of the two different thread configurations.

The tapered configuration of the leading end 169 of ring 158 facilitates entry of the ring end 169 into the shell. The end face of the leading end 169 may be driven against a thrust shoulder 170 on the insert member or against a thrust ring provided on the back portion of an insert member so that the insert member is immovably locked between positioning shoulder 41a on the receptacle shell and the insert retainer ring pressed against shoulder 170 and threadably interlocked with the back shell. The compressible retainer ring is linearly pressure driven into engagement with and between the back shell and insert member. The insert retainer ring locks and meshes with the threaded shell to precisely position the insert member in the shell against reference shoulder 41a regardless of course coarse or loose tolerances between shoulder 41a and shoulder 170.

While the example describes the insert retaining member in relation to the receptacle shell, it will be understood that a similar insert retaining ring may be employed at the back portion of plug housing 60 to retain the plug insert member in fixed axial position relative to the plug housing in the same manner as above described.

While a present example of an insert retaining ring has been described with respect to an electrical connector having a cylindrical metal shell and a cylindrical dielectric insert member received within said shell and fixedly holding the insert member in immovable position with respect to the shell, it will be understood that such a compressible insert retaining ring may be employed to restrict to a minimum axial movement between two concentric members utilized in different environment.

It will be understood that when the terms "thread means", "thread configuration" and "threaded interengagement" are used therein, that "threads" include the usual helical type thread shown as well as non-helical annular rings pitched at a desired angle to the axis of the shell and retainer ring. Either or both cooperable threads may be helical or non-helical. The selected pitch of each thread should provide for crossing of the interengaging threads at at least three abutment areas with the insert ring under radial compression.

It will be noted that use of insert retainer ring 158 and such a cooperable back shell 39 provides quick fullproof assembly of the insert member within the receptacle shell and no additional adjustments are required to positively seat and hold insert member 40 against positioning shoulder 41a.

Breech Holdoff Merchanism

In some prior electrical connectors relative axial movement of plug and receptacle sections were permitted under desirable conditions which could result in damage to the connector and failure to properly mate electrical contacts. Such undesirable conditions include relative axial movement with a bent contact pin, attempting to mate connector sections in which both sections include protruding contact pins, jamming or cross-starting of the coupling means, and permitting relative axial movement under axial misalignment conditions.

The present construction embodies features which obviate the undesirable conditions mentioned above. It should be noted that breech flange 81 on the coupling housing ring includes two radially inwardly projecting keys 85 located about 120 degrees apart and approximately the same angular distance with respect to keyway 84. Keyway 84, as mentioned above, receives master key 50 on the receptacle shell for orienting the two shells with respect to polarization or axial alignment of mating pin and socket electrical contacts. In the present electrical connector, visible reference indicia are provided on the coupling housing and on the shell in linear alignment with the key 50 and keyway 84 so that the coupling ring plug housing and receptacle shell are properly angularly oriented for mating of the pin and socket contacts. Before the plug means can be advanced axially with respect to the receptacle shell in such visually aided alignment, it will be apparent that the keys 85 must be oriented with the keyways 85a on the receptacle shell to permit further axial movement.

In the event proper visual orientation of master key 50 and keyway 84 is made, but the receptacle shell and plug shell are not compatible for mating as by a difference in number of pin contacts, the orientation of the keys 85 and keyways 85a on such noncompatible shells will cause keys 85 to bear against the front faces 48b and 49b of the locking lands 48, 49 on a noncompatible shell. Such spaced bearing at faces 48b and 49b provide balanced holding off of the plug means; that is, any axial misalignment of the plug and receptacle means is resisted and minimized so that damage to pin contacts will not occur. Further axial advance of the coupling ring and of a mismatched plug housing and insert member is prevented. As noted in FIG. 4, the tips of the pin contacts 45 are in spaced relation to the socket contacts in the plug insert member. Damage to pin contacts is thereby prevented in the event noncompatible plug and receptacle means are attempted to be coupled together.

It should be noted that the two keys 85 provide such holding off function at two spaced points approximately 120 degrees apart. Cocking or attempting to mate noncompatible plug and receptacle means by manipulation of the plug means in three dimensions is prevented. The use of at least two spaced keys in spaced relation to a master keyway 84 on the coupling ring provides variation in key and keyway patterns so that a wide range of different keying may be made for connectors of the same shell size but with different members of electrical contacts and arrangements thereof.

The electrical connector 32 described above provides many advantages of construction and operation of which some have been particularly emphasized. In the general concept of the electrical connector, it is important to note that the coupling ring serves as a single component part which is constructed to perform a number of important functions. First, the coupling ring 71 has a breech flange 81 which locks the plug and receptacle against axial movement by interlocking abutment with the locking lands, 48, 49 on the receptacle shell. Such locking lands provide a substantial abutment area so that the loading per square inch is reduced. Second, the coupling ring 71 provides in breech flange 81, keys 85 which perform the holdoff function described above to prevent mating of noncompatible plug and receptacle means. Thus, the locking flange 81 provides a key means in which the keys 85 may be varied in spacing so that positive means is provided for preventing attempted coupling of noncompatible plug and receptacle; and such mating prevention occurs without damage to pin and socket contact members. Third, the coupling ring housing with its locking flange 81 provides a visual and a nonchangeable orientation of the plug with the receptacle by the alignment of the keyway 84 with the key 50 on a receptacle shell. Thus, positive orientation or polarization of the contact element of compatible mating plug and receptacle is assured. Fourth, the coupling ring housing provides an annular partcircular internal channel or groove for housing the detent spring 87, the detent spring being positively oriented with the plug housing and coupling ring through the central key 110 which is movable in an axial direction in the keyway 111 on the plug housing. Fifth, the coupling ring housing provides an annular shoulder 89 for abutment of one end of the coupling nut 72 and also provides the full lock breech recess 140 which secures the annular lock ring 92, which serves as a seat for the springs 91 which bias the coupling nut against the shoulder 89. It will thus be apparent that the specific construction of the coupling ring housing of the electrical connector 32 combines many features which provide an electrical connector which is reliable and in which there are safeguards against damage to connector parts in the event mismatching or attempted coupling of noncompatible connector parts is attempted.

Various changes and modifications may be made in the above described electrical connector and all such changes and modifications coming within the scope of the appended claims are embraced thereby.

Claims

1. In an electrical connector having receptacle means including a receptacle shell; a plug means including a plug housing; a coupling nut threaded onto said plug housing, a coupling ring keyed to said coupling nut; electrical contact elements carried within said receptacle shell and said plug housing for electrical mating and unmating; lock means on said coupling ring and said receptacle shell for releasably holding said contact elements in mating relation; means for audibly indicating fully mated and locked relationship of said receptacle means and plug means, said indicating means including an annular groove in said coupling ring, a keyway on said plug housing, and an arcuate spring detent in said annular groove and having a key engaged in said keyway, said detent having radially outwardly directed end portions carried by resilient arcuate arms which are bent when the end portions thereof are between spaced sets of radially outwardly directed recesses in said annular groove during turning of said coupling housing, whereby said end portions snap into a set of recesses to produce an audible sound to indicate fully locked or unlocked position of the receptacle means and plug means, the improvement comprising: an enlarged portion defining a dog-leg in said keyway in the path of axial travel of said plug housing whereby said key makes audible contact with a terminating wall of said dog-leg is released from contact with the plug housing so as to produce an intensified audible snap of the detent end portions indicating attainment of the fully mated and locked position of the connector.

2. The improvement according to claim 1, wherein said detent subtends an angle of about 180 degrees, and said recesses in each of said spaced sets of recesses are angularly displaced from one another in said annular groove by about 180 degrees.

3. The improvement according to claim 2, wherein said spaced sets of recesses are angularly displaced from one another by about 90 degrees.

4. The improvement according to claim 3, wherein said annular groove subtends an angle of about 270 degrees.

5. The improvement according to claim 1, wherein said coupling ring and said receptacle shell include locking means operative, when engaged, to secure said plug means and said receptacle means against relative axial movement, said plug housing being axially advanced to mate said electrical contact elements after initial engagement of said locking means, and being fully axially withdrawn to unmate said electrical contact elements before complete disengagement of said locking means.

6. The improvement according to claim 5, wherein the threaded connection between said coupling nut and said plug housing is by means of a fast thread adapted to axially advance the plug housing to fully mate said electrical contact elements by turning said coupling ring through about 90 degrees.

7. The improvement according to claim 8, wherein said fast thread is a four-lead stub thread.

8. The improvement according to claim 1, wherein said key is accelerated from one side of the keyway across the enlarged keyway to a point spaced from said terminal wall of said dogleg by the engagement of said detent end portions with said second set of recesses, thereby producing an intensified audible indication of attainment of the fully mated and locked condition of the connector.