US3671922A - Push-on connector - Google Patents

Abstract

A locking push-on, pull-off connector which maintains good electrical contact even under conditions where there is movement in the connector. The contact elements of one of the mating connector members are mounted for axial movement in the member and are normally biased by a resilient means to a forward-most position. Leading surfaces of mating contact elements in the two members are adapted to bear against each other to make electrical contact when the members are mated with the elements which are mounted for movement being adapted to be moved back to a predetermined position in their member by the force applied to them by the other contact element. This movement is against the force of the resilient means. A means is provided for locking the contact members together with the moveable element in the predetermined position. The locking means includes a bore in one of the mating members which is sized to accept a leading portion of the other member, said bore having an enlarged internal counterbore, and a wrap spring mounted on the leading portion of the first member. The wrap spring has tabs projecting at an angle to the connector axis which tabs are adapted to be compressed by the walls of the bore as a leading portion of the member is fitted into the bore and to expand into the enlarged counterbore to lock the members together. A sleeve is mounted for movement in an axial direction on the spring-containing member. This sleeve has openings through which the tabs normally project, the walls of the sleeve being moved over the tabs to compress them and unlock the members as the sleeve is moved in a rearward direction.

Description

United States Patent Zerlin et al.

[ 1 June 20, 1972 [54] PUSH-ON CONNECTOR [72] inventors: William Max Erich Zerlin, Newtown; Roger Peter Avery, Bethe]; David Hugh Royce, Brookfield, all of Conn.

[73] Assignee: The Bunker-Ramo Corporation, Oak

Brook, 11].

[22] Filed: Aug. 7, 1970 21 Appl.No.: 61,923

Primary Examiner-Joseph H. McGlynn Attorney-Frederick M. Arbuckle 57 ABSTRACT A locking push-on, pull-off connector which maintains good electrical contact even under conditions where there is movement in the connector. The contact elements of one of the mating connector members are mounted for axial movement in the member and are normally biased by a resilient means to a forward-most position. Leading surfaces of mating contact elements in the two members are adapted to bear against each other to make electrical contact when the members are mated with the elements which are mounted for movement being adapted to be moved back to a predetermined position in their member by the force applied to them by the other contact element. This movement is against the force of the resilient means. A means is provided for locking the contact members together with the moveable element in the predetermined position. The locking means includes a bore in one of the mating members which is sized to accept a leading portion of the other member, said bore having an enlarged internal counterbore, and a wrap spring mounted on the leading portion of the first member. The wrap spring has tabs projecting at an angle to the connector axis which tabs are adapted to be compressed by the walls of the bore as a leading portion of the member is fitted into the bore andto expand into the enlarged counterbore to lock the members together. A sleeve is mounted for movement in an axial direction on the spring-containing member. This sleeve has openings through which the tabs normally project, the walls of the sleeve being moved over the tabs to compress them and unlock the members as the sleeve is moved in a rearward direction.

6 Claims, 3 Drawing Figures l0 I4 I I8 PUSH-N CONNECTOR This invention relates to push-on connectors and more particularly to a locking push-on, pull-off connector which maintains good electrical contact even under conditions where there is movement in the connector.

A push-on connector of the type which this invention is concerned with is generally utilized to connect awire or cable to a panel such as that found on electrical instruments. Since such connections are normally temporary, it is important that both the connect and disconnect operations be fast and simple. These operations should, of course, also be nondestructive so that the connector may be reused. Another requirement which frequently exists is that the connection be locking so that stress on the cable will not cause the connection to open.

In the past, cam type and screw type connections have been employed in order to achieve the desired locking feature. However, the making and breaking of such a connection is more difficult and time consuming than a simple push-on, pull-off operation. A requirement therefore exists for a locking panel connector which may be pushed-on and pulledofi, but which will not be disconnected by a force applied to the cable. An existing device which fulfills the above requirement is both bulky and expensive. More specifically, a need therefore exists for a smaller, simpler, and less expensive connector of the type indicated above.

In designing a push-on, pull-off connector, it is diflicult to completely eliminate movement inside the connector when one of the connected elements is subjected to vibration, stress or the like. However, such movement does not cause a serious problem so long as good electrical contact can be maintained. A need therefore exists for a means to maintain good electrical contact in a connector of this type in spite of limited movement inside the connector caused by external forces.

It is therefore a primary object of this invention to provide an improved push-on connector.

A more specific object of this invention is to provide a relatively simple, compact, and inexpensive locking, push-on, pull-off connector.

A further object of this invention is to provide a connector of the type indicated above which permits good electrical contact to be maintained in the connector in spite of limited movement in the connector resulting from externally applied forces.

In accordance with these objects this invention provides a push-on connector having first and second mating members. There is a first contact element in the first member and a second contact element in the second member, each of the contact elements having a substantially flat leading surface at an angle substantially perpendicular to the axis of the connector. An electrical conductor is physically and electrically connected to the first contact element. The second contact element is mounted in the second member in a manner such that it may move in a direction parallel to the axis of the connector. The second contact element is normally bias by a resilient means to its forward-most position, the leading surfaces being adapted to bear against each other to make electrical contact when the members are mated and the first contact element being adapted to bear against the second contact element to move the second contact element back into the second member against the force of the resilient means to a predetermined position as the members are mated. A locking means is provided for locking the members in the predetermined position. The locking means includes an internal counterbore in the second member and a wrap spring mounted on a leading portion of the first member, the spring having tabs projecting at an angle to the connector axis. The tabs are adapted to be compressed by the walls of a bore in the second member as the leading portion of the first member is fitted into the bore and to expand into the counterbore to lock the members together. An unlocking means for compressing the tabs out of the counterbore includes a sleeve mounted for movement in an axial direction on the first member. The sleeve has openings through which the tabs normally project, the walls of the sleeve being moved over the tabs to compress them as the sleeve is moved in a rearward direction. A locking, push-on pull ofi" connector is thus provided which permits electrical contact to be maintained between contact elements in spite of element movement within the connector.

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a cut-away axial view of the connector of a preferred embodiment of the invention showing the members of the connector in an unmated condition.

FIG. 2 is a cut-away axial view of the connector of FIG. 1 showing the members in a mated condition.

FIG. 3 is a perspective view of a wrap spring suitable for use in the embodiment of the invention shown in FIGS. 1 and 2.

Referring now to FIG. 1, it is seen that the connector of this invention includes a male member 10 and a female member 12. Male member 10 consists of a body 14 having an axial bore 16, an internally threadedcounter bore 18, and a substantially flat leading surface 20. The exterior of body 14 has a grove 22 in which is seated a wrap spring 24. This spring, which is shown in greater detail in FIG. 3, has an opening 26 so that it may be spread apart for easy assembly on body 14. Spring 24 has two resilient outwardly projecting tabs 28 each of which terminates in a formed over end 30 having a relatively flat leading surface. A sleeve 32 is fit over body 14 and spring 24. Sleeve 32 has openings 34 through which tabs 28 normally project. Sleeve 32 is free to move between a position where ends 30 of tabs 28 bear against the rear edge of opening 34 and a position where shoulder 36 of sleeve 32 bears against shoulder 38 of body 14. Outer surface 40 of sleeve 32 may be knurled to facilitate gripping of the sleeve. The function of sleeve 32 will be described shortly.

A rear body 42 having an externally threaded projection 44 is connected to body 14 by screwing projection 44 into counterbore 18. Body 42 has a tapered rear projection which is adapted to fit between outer conductor 46 and insulator 48 of a coaxial cable 50. A crimp ferrule 52 secures the cable to body 42 and causes good electrical contact to be made between the body and outer conductor 46. The outer conductor is thus connected through body 42 and body 14 to leading contact surface 20. A dielectric insert 54 is provided in projection 44 which insert coacts with a dielectric insert 56 in bore 16 of body 14 to captivate a male contact element 58. Contact 58 is connected to inner conductor 60 as by a drop of solder 62.

The female member, or receptacle, 12 of the connector consists of a body having an axial bore 72. Bore 72 has an internal counterbore 74 the function of which will be described shortly. A contact assembly 75 consisting of a slide contact 76, insulating inserts 78 and 80, and female contact 82 is mounted in a second counterbore 84 of bore 72. The assembly is normally biased by spring 86 to the position shown in FIG. 1, but is free to move in an axial direction along the wall of counterbore 84 against the resistance of the spring. A retaining spacer 88 is provided to hold the contact assembly in body 70. A nut 90 and lock washer 92 are provided on an externally threaded outside wall of body 70 to secure the member 12 to the wall of a panel shown dotted in the figure. The wall is pinched between lock washer 92 and forward flange 94 of body 70. Electrical contact may be made with receptacle 12 by connecting wires to contacts 76 and 82.

When a connection between members 10 and 12 is desired, all that is required is that the leading portion of member 10 be pushed into bore 72 of receptacle 12. When tabs 28 enter bore 72, they are forced down into openings 34 in sleeve 32 by the action of the walls of the bore against the angled surface of the tabs. The various elements of the connector are dimensioned such that male contact 58 is fully seated in female contact 82 and leading surface 20 of contact body 14 is in contact with leading surface of slide contact 76 before edge 30 of tab 28 clears bore 72. Further movement of member into receptacle 12 causes contact assembly 75 to be slid back in counterbore 84 against the force of retaining spring 86. When assembly 75 has been moved backa predetemtined. distance, edge 30 clears bore 72 and expands into counterbore 74 as shown in FIG. 2 thus firmly locking the connector members together. When the connector is fully mated and locked as shown in FIG. 2, no amount of force applied to cable 50 will separate the elements although, of course, if sufficient force is applied either the cable or the connector could be broken. However, because of the snap type connection, a certain amount of movement is possible between members 10 and 12. But, since contact assembly 75 is biased by spring 86 toward member 10, the contact assembly will tend to move with any movement of member 10, permitting good electrical contact to be maintained in spite of such movement.

. When it is desired to disconnect members 10 and 12, member 10 is grasped by surface 40 of sleeve 32 and pulled backwards. The initial pulling on sleeve 32 will cause the sleeve to move back on body 14. This results in the forward end of holes 34 camming tabs 28 down into the space between the sleeve and spring 24 thus removing tabs 28 from counterbore 74. When the tabs have been lowered by the action of sleeve 32 to a height where they no longer project beyond the walls of bore 72, continued rearward pressure on sleeve 32 causes member 10 to be easily removed from member 12.

A relatively simple, compact, relatively easy to fabricate, and relatively inexpensive locking push-on, pull-ofl connector has thus been provided. In particular, the use of a wrap spring as the locking element significantly reduces both the material and assembly labor costs of the connector over that of prior art devices. The connector includes a means for maintaining good electrical contact between the members even when relative movement is induced between the members by external forces.

While in the preferred embodiment of the invention, receptacle 12 has been shown as panel mounted, it is of course possible to practice the teachings of the invention with both contact members being attached to cables. Spring 86 is the resilient means utilized in the preferred embodiment of the invention to provide the desired biasing force to the contact assembly 75; however, other equivalent means could be utilized for this function. Other similar modification could be made in the specific elements employed.

Thus, while the invention has been particularly shown and described with reference to a preferred embodiment thereof, the foregoing and other changes in form and details may be made by those skilled in the art without departing from the spirit or scope of the invention.

What is claimed is:

l. A push-on connector for a coaxial cable having an inner and an outer conductor, said connector having first and second mating members, comprising:

an inner and an outer contact element in each of said members, each of said outer contact elements having a substantially flat leading surface at an angle substantially perpendicular to the axis of said connector;

means for physically and electrically connecting the inner and outer conductor to the inner and outer contact elements respectively of said first member;

a contact assembly having the inner and outer contact elements of said second member secured together therein, said contact assembly being mounted in said second second member to move said contact assembl back in said second member, against the force of sar resilient means, to a predetermined position as said members are mated; and

means for locking said members with said contact assembly in said predetermined position.

2. A connector of the type described in claim 1 wherein said contact assembly includes insulating means for separating the inner and outer contact elements of the assembly;

wherein said second member includes a counterbore in which said assembly is mounted for restrained axial movement; and

wherein said resilient means normally biases said assembly to the forward most position in said counterbore.

3. A connector of the type described in claim 1 wherein said second member includes a bore sized to accept a leading portion of said first member; and

wherein said locking means includes an internal counterbore in the bore of said second member, a wrap spring mounted on said leading portion, said spring having tabs projecting at an angle to the connector axis, said tabs being adapted to be compressed by the walls of said bore as said leading portion is fitted into said bore and to expand into said counterbore to lock said members together.

4. A connector of the type described in claim 3 including means for compressing said tabs out of said counterbore tounlock said members.

5. A connector of the type described' in claim 4 wherein said. compressing means includes a sleeve mounted for movement in an axial direction on said first member, said sleeve having openings through which said tabs normally project, the walls of said sleeve being'moved over said tabs to compress them as said sleeve is moved in a rearward direction.

6. A lockin push-on connector having first and second mating members comprising: v

contact means in each of said members, said contact means being adapted to make physical and electrical contact with each other when said members are matedj a bore in said second member sized to accept a leading portion of said first member, said bore having an internal counterbore;

a wrap spring mounted on said leading portion, said spring having tabs projecting at an angle to the connector axis, said tabs being adapted to be compressed by the walls of said bore as said leading portion is fitted into said bore and to expand into said counterbore to lock said members together; and

a sleeve mounted for movement in an axial direction on said first member, said sleeve having openings through which said tabs normally project, the walls of said sleeve being moved over said tabs when said sleeve is moved in a rearward direction to unlock said members.

I! k I! I i

Claims (6)

1. A push-on connector for a coaxial cable having an inner and an outer conductor, said connector having first and second mating members, comprising: an inner and an outer contact element in each of said members, each of said outer contact elements having a substantially flat leading surface at an angle substantially perpendicular to the axis of said connector; means for physically and electrically connecting the inner and outer conductor to the inner and outer contact elements respectively of said first member; a contact assembly having the inner and outer contact elements of said second member secured together therein, said contact assembly being mounted in said second member in a manner such that it may move in said member in a direction parallel to the axis of the connector; resilient means for normally biasing said contact assembly to its forward-most position; the outer contact leading surfaces being adapted to bear against each other to make electrical contact when said members are mated, the outer contact of the first member being adapted to bear against the outer contact of the second member to move said contact assembly back in said second member, against the force of said resilient means, to a predetermined position as said members are mated; and means for locking said members with said contact assembly in said predetermined position.

2. A connector of the type described in claim 1 wherein said contact assembly includes insulating means for separating the inner and outer contact elements of the assembly; wherein said second member includes a counterbore in which said assembly is mounted for restrained axial movement; and wherein said resilient means normally biases said assembly to the forward most position in said counterbore.

3. A connector of the type described in claim 1 wherein said second member includes a bore sized to accept a leading portion of said first member; and wherein said locking means includes an internal counterbore in the bore of said second member, a wrap spring mounted on said leading portion, said spring having tabs projecting at an angle to the connector axis, said tabs being adapted to be compressed by the walls of said bore as said leading portion is fitted into said bore and to expand into said counterbore to lock said membeRs together.

4. A connector of the type described in claim 3 including means for compressing said tabs out of said counterbore to unlock said members.

5. A connector of the type described in claim 4 wherein said compressing means includes a sleeve mounted for movement in an axial direction on said first member, said sleeve having openings through which said tabs normally project, the walls of said sleeve being moved over said tabs to compress them as said sleeve is moved in a rearward direction.

6. A lockin push-on connector having first and second mating members comprising: contact means in each of said members, said contact means being adapted to make physical and electrical contact with each other when said members are mated; a bore in said second member sized to accept a leading portion of said first member, said bore having an internal counterbore; a wrap spring mounted on said leading portion, said spring having tabs projecting at an angle to the connector axis, said tabs being adapted to be compressed by the walls of said bore as said leading portion is fitted into said bore and to expand into said counterbore to lock said members together; and a sleeve mounted for movement in an axial direction on said first member, said sleeve having openings through which said tabs normally project, the walls of said sleeve being moved over said tabs when said sleeve is moved in a rearward direction to unlock said members.

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