Abstract:
A moveable contact connector system provides easy lead insertion, lead retention, and reliable electrical connection for implantable devices. The connector system may be used with in-line leads commonly found in such applications. Moveable contacts are provided in the connector, which contacts are placed in a first position for easy lead insertion, and in a second position for lead retention. The second position also provides a good electrical connection between the moveable connector contacts and the lead contacts. Multiple means for moving said at least one moveable contact between the first and second positions are described. A first embodiment uses a rotatable cam which is rotated to align the cam lodes with said at least one moveable contact, pushing the movable contacts against the lead contacts. The second and third embodiments use a sliding key to force said at least one moveable contact against the lead contacts.

Description:
The present application claims the benefit of U. S. Provisional Application Serial No. 60/188,967, filed Mar. 10, 2000, which application is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to implantable electronic and electrochemical medical devices and systems, and more particularly to a movable contact locking connector system for use with such devices and systems. Such connector system provides easy lead insertion, a reliable means to retain an in-line lead in a connector and ensures effective electrical connection between lead and connector contacts. The connector system provides these features through a simple design avoiding complexity. 
     Implantable electronic medical devices and systems have been in use for the past 20 years or more. One of the earliest implantable medical devices to be implanted in a patient was the cardiac pacemaker. Other implantable electronic devices have included neurostimulators, i.e., electrical stimulators designed to stimulate nerves or other tissue, sensors for sensing various physiological parameters or physical status of a patient, and therapeutic-delivery devices, e.g., pumps for delivering controlled amounts of medication. In more recent years, a tiny implantable cochlear stimulator has been developed that allows patients who are profoundly deaf to experience the sensation of hearing. Other tiny implantable sensors and neuro-stimulators are under development that will enhance the ability of a patient who is a recipient of such sensors or stimulators to walk, or to see, or to experience the use of other lost or impaired body functions. 
     Most of the implantable medical devices and systems described above require that at least one electrical lead be connected thereto in order for the device or system to perform its intended function. Such lead typically includes a plurality of insulated conductors, or wires, through which electrical signals may be delivered or sensed. At an end distal from an implantable electronic device, each of the insulated conductors usually terminates in one or more electrodes designed to be in contact with body tissue. A Spinal Cord Stimulation (SCS) system, for example, has an electrode array adapted for insertion into the spinal column of the patient. Such electrode array typically employs a multiplicity of electrode contacts, each of which must be individually electrically connected to the pulse generator circuitry housed within an Implantable Pulse Generator (IPG). The lead associated with such spinal cord stimulator thus carries the individual conductors that electrically connect the respective electrodes, to the implantable pulse generator, thus making up the spinal cord stimulation system. 
     In-line leads are often chosen to connect an electrode array to an implantable electronic device. The contacts of an in-line lead are spaced-apart rings on one or more ends of the lead. An important benefit of such in-line lead is that when the lead is used with a ring type electrode array of similar diameter, the lead and array combination may be inserted into a patient&#39;s spinal column using a large gauge needle. However, the use of a lead with such in-line male connector with a simple push-in female connector is limited by the ability to push the lead into a female connector passageway. The problem of in-line lead insertion has been addressed by U.S. Pat. No. 5,843,141 issued Dec. 1, 1998 for “Medical Lead Connector System.” The &#39;141 patent uses a tool to pull the lead end into the connector. However, the requirement to provide good electrical contact between the contacts on the lead and the contacts in the connector, and the need to provide a means for retaining the lead in the connector once inserted, work against easy insertion, and results in a requirement that the lead be sufficiently strong to resist tearing or stretching during insertion and extraction. Damaging a lead during the implanting or replacement of an implantable electronic device increases the complexity and medical risks associated with the required surgery. But, adding strengthening structure to the lead may be difficult and result in undesirable stiffening of the section of the lead where the lead exits the connector. What is therefore needed is an improved in-line connector system that allows easy insertion of an in-line lead into a connector, good retention of the lead once inserted, and reliable contact between the lead&#39;s contacts and the connector&#39;s contacts. Further, it is desirable that an improved in-line connector system, having these qualities, not compromise the beneficial properties which the lead would otherwise have. 
     SUMMARY OF THE INVENTION 
     The present invention addresses the above and other needs by providing a connector system with spaced-apart moveable contacts in the connector, and means for forcing the moveable connector contacts downward against spaced-apart lead contacts (for the purposes of this description, downward means toward the lead contacts, however, in actual use the connector may be arbitrarily rotated). The connector system may be integrated into the housing of an implanted device for the connection of a lead to the device. Advantageously, the connector system provides easy lead insertion, positive lead retention, and reliable electrical contact, without complexity. 
     In accordance with one aspect of the invention, there is provided a connector system including one or more spaced-apart moveable contacts in a connector, one or more spaced-apart lead contacts on an end of an in-line lead, and a means for applying downward force against the moveable contacts. When a lead in inserted fully into the connector passageway, the downward force causes the moveable contacts to move from a first position, wherein the moveable contacts are not pressing against the lead contacts, to a second position, wherein the moveable contacts are pressing against the lead contacts. When the movable contacts are in the second position, sufficient force is applied to the moveable contacts by the means for applying downward force, to both retain the lead in the connector, and to provide reliable electrical connection between the moveable contacts and the lead contacts. 
     It is also a feature of the present invention to provide a connector body made from a resilient material. One or more moveable contacts are molded into the resilient connector body so that, in the absence of force, the moveable contacts rest in a position which permits easy insertion and removal of the lead. When force is applied to the moveable contacts by the means for applying downward force, the moveable contacts press against the lead contacts, thus retaining the lead, and providing reliable electrical contact between the connector contacts and the lead contacts. When the downward force is no longer applied to the moveable contacts, the resilient nature of the connector body causes the moveable contacts to return to the first position, thus freeing the lead. 
     It is a further feature of the invention to provide a solid cam with solid lobes as a means for applying downward force. The cam may be rotated, and the solid lobes thereby apply force to the moveable contacts, which force results in the moveable contacts moving from the first position to the second position. A cam stop lug is provided on the cam that cooperates with a cam stop in the connector to limit the rotation of the cam. The positions of the cam lug and the cam stop are designed to allow the cam to rotate to a locked position slightly past centering the solid lobes on the moveable contacts. As the cam is rotated from an open position to a locked position, the cam solid lobe pushes down on the moveable contacts. As the cam solid lobes rotate downward and against the moveable contacts, the resisting force of the movable contacts against the cam solid lobes result in torque on the cam resisting the rotation from the open to the locked position. When the cam lobes are pointed directly down (i.e., towards the moveable contacts) the moveable contacts, the solid lobes, and the rotational axis of the cam are aligned. In this position there is no torque on the cam. When the cam is rotated slightly farther, the torque on the cam is reversed and is pushing the cam towards the locked position. A past center effect thus results that causes the cam to remain in the locked position until sufficient torque is applied to force the solid lobes past centering the solid lobes on the moveable contacts. In a preferred embodiment the cam is a straight shaft with solid lobes spaced along the shaft. In an alternative embodiment the cam is a simple wireform device. 
     In a first alternative embodiment of the means for applying downward force, a rod with bulged sections is inserted into the connector. When the rod is fully inserted, the bulged sections align with the moveable contacts, thus applying force to move the moveable contacts from the first position to the second position. Advantageously, the bulged sections may be radially symmetric which allows the rod to be inserted with arbitrary rotation. In a variation of this embodiment, the rod is captive with a first and second position, wherein the bulges are not aligned with the movable contacts in the first position, allowing easy lead insertion; and the bulges are aligned with the movable contacts in the second position, providing good lead retention. 
     In a second alternative embodiment of the means for applying downward force, a moveable actuator is captive within the connector. The actuator defines one or more bulges vertically aligned with the moveable contacts. The actuator is free to move vertically within the connector. A key is insertable into the connector through a key passageway above the actuator. When the key is inserted, a ramped surface on the bottom face of the key pushes downward against the actuator causing the actuator to move downward against the moveable contacts, and thus causing the moveable contacts to move from the first position downward to the second position. 
     In a third alternative embodiment of the means for applying downward force, the single actuator and moveable contacts combination is replaced by individual second actuators cooperating with each movable contact. When the key is inserted, the key&#39;s ramped bottom surface pushes against the second actuators, thus causing the second actuators to move downward and push downward on the moveable contacts. The force of the second actuators on the moveable contacts causes the moveable contacts to move from the first position to the second position. In an alterative to this embodiment, the second actuators and moveable contacts are combined to form second movable contacts. The base of the second movable contact is resiliently molded into the connector body to allow vertical movement of the second moveable contacts and to retain the second moveable contacts in the connector body. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein: 
     FIG. 1A shows a detailed view of a typical Spinal Cord Stimulation (SCS) system, the system comprising an electrical sensor/stimulator device connected to a lead having an electrical contact or an electrical array at its distal end; 
     FIG. 1B depicts the SCS system of FIG. 1 implanted in a patient; 
     FIG. 2 shows an in-line lead used with the present invention; 
     FIG. 3 illustrates a rotating lock connector system according to the present invention, integrated into an implantable device; 
     FIG. 3A provides a top view of a connector system; 
     FIG. 4 shows a cross-sectional view of the connector taken along line  4 A— 4 A of FIG. 3A, with moveable contacts in a first position; 
     FIG. 5 shows a second cross-sectional view of the connector taken along line  4 A— 4 A of FIG. 3A, with moveable contacts in a second position; 
     FIG. 6A shows a cross-sectional view of the connector taken along line  6 A— 6 A of FIG. 4; 
     FIG. 6B shows a cross-sectional view of the connector taken along line  6 B— 6 B of FIG. 5; 
     FIG. 6C shows a cross-sectional view of the connector taken along line  6 C— 6 C of FIG. 5; 
     FIG. 7 illustrates a second embodiment of a rotating lock, with a bent wire cam; 
     FIG. 8 depicts a first alternative embodiment of a means for applying a downward force; 
     FIG. 9 depicts a second alternative embodiment of a means for applying a downward force; 
     FIG. 10 depicts a third alternative embodiment of a means for applying a downward force; 
     FIG. 11A shows a cross-sectional view of the second alternative embodiment, taken along line  11 A— 11 A of FIG. 9; 
     FIG. 11B shows a cross-sectional view of the third alternative embodiment, taken along line  11 B— 11 B of FIG. 10; and 
     FIG. 11C shows a cross-sectional view of a variation of the third alternative embodiment, taken along line  11 B— 11 B of FIG.  10 . 
    
    
     Corresponding reference characters indicate corresponding components throughout the several views of the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims. 
     The connector system of the present invention provides a simple method for inserting, retaining, and ensuring reliable electrical contact for a multi-contact in-line lead and a connector. Such connector system is typically used in implanted medical devices, for example, in a Spinal Cord Stimulation (SCS) system  4  as shown in FIG.  1 A. An SCS system  4  typically includes an Implantable Pulse Generator  10 , a connector  12 , an in-line lead  14 , an in-line connector  16 , an electrode lead  20 , and an electrode array  18 . The IPG  10  generates stimulation current for implanted electrodes that make up the electrode array  18 . A connector  12  is either attached to the body of the IPG  10 , or integrated into the IPG  10 . The in-line lead  14  is removably connected to the connector  12  and either permanently or removably connected to the in-line connector  16 , at the end of the in-line connector  16  proximal to the IPG  10 , and the electrode lead  20  is removably connected to the end of the in-line connector  16  distal from the IPG  10 . The electrode array  18  is typically formed on an end of the electrode lead distal from the in-line connector  16 . The in-series combination of the in-line lead  14 , in-line connector  16 , and electrode lead  20 , carry the stimulation current from the IPG  10  to the electrode array  18 . 
     A view of the SCS system  4  described in FIG. 1A above is depicted implanted in a patient  6  in FIG.  1 B. The electrode array  18  (or sensors in other applications) is implanted at the site of nerves that is the target of stimulation, e.g., along the spinal column  8 . Due to the lack of space where the electrode lead  20  exits the spinal column, the IPG  10  is generally implanted in the abdomen or above the buttocks. The in-line lead  20  facilitates locating the IPG  10  distal from the electrode lead exit point. The connector system of the present invention is particularly well suited for use with an IPG  10  because a small diameter lead is easier to pull through tissue than a large diameter lead, and the present invention facilitates the use of such small diameter lead. 
     The connector system of the present invention may be employed with various other implantable devices. Sensing devices have similar electrodes, leads, and implantable electronics. Any medical device requiring leads to connect sensors or stimulators to implantable electronics may benefit from the improved connector system. 
     The present invention is directed to implantable connector systems using an in-line lead  14  as shown in greater detail in FIG.  2 . The in-line lead  14  typically has a constant diameter D, which enables the lead to be implanted through a large gauge needle. A constant or uniform diameter D is particularly useful for an electrode lead  20  attached to a ring type electrode array of an SCS system  4 . In such case, the entire electrode array and electrode lead assembly are the same diameter, thus permitting the entire assembly to be implanted through a large gauge needle. 
     As seen in FIG. 2, an in-line lead  14  comprises a lead body  22 , at least one conductor  26  carried within the lead body  22 , and at least one spaced-apart lead contact  24  on the lead body  22 . A lead end  23  in inserted into the connector  12  to electrically connect the in-line lead  14  to the connector  12 . It is through the lead contacts  24  that electrical connection is made between each of the conductors  26  that are carried within the in-line lead  14  and the electrical circuit in the IPG  10 , or with the conductors of the in-line connector  16 . The in-line lead  14  may have identical ends (only one of which is shown in FIG. 2) with spaced-apart lead contacts  24 , or may have one end as depicted in FIG. 2, and the opposite end may be a female connector. In other cases, as with the electrode lead  20 , one end is as depicted in FIG.  2  and the opposite end includes the electrode array/sensors. 
     While the implantable system depicted in FIGS. 1A and 1B comprises a separate lead  14  connecting the electrode lead  20  to the IPG  10 , a connector made according to the present invention would apply equally well to a system with an electrode lead connected directly to the IPG  10 . 
     The in-line lead  14  may be manufactured using conventional lead manufacturing techniques and materials, as are known and practiced in the implantable lead art. 
     Turning to FIG. 3, a connector according the present invention is shown integrated into the IPG  10 . The lead  14  is insertable through a connector port  30 . The rearward end of a solid cam  34 , which solid cam  34  serves as a means for locking the lead  14  into the connector  12 , protrudes from the connector  12  just above the connector port  30 . The solid cam  34  has a handle lug  36  attached to the rearward end, which handle lug  36  provides means to removably connect a key or handle to the solid cam  34  for the purpose of rotating the solid cam  34 , as indicated by the arrow  32 . 
     A top view of the connector  12  is shown in FIG. 3A for the purpose of defining cross-section  4 A— 4 A. 
     A cross-sectional view of the connector  12  taken at line  4 A— 4 A of FIG. 3A is shown in FIG.  4 . The in-line lead  14  is shown fully inserted through connector port  30 , shown in FIG. 3, into a cylindrically shaped passageway  44 . In the example shown, the in-line lead  14  has four spaced-apart lead contacts  24 . The actual number of contacts may vary and is not limited by this description. At least one spaced-apart movable contact as  48   a  is molded into the portion of a connector body  42   a  that forms the wall of the passageway  44 . The movable contacts  48   a  are vertically aligned with the respective lead contacts  24  with which each of the moveable contacts  48   a  cooperates. The connector body  42   a  is made from a resilient material, preferable epoxy. The first moveable contacts  48  are molded into the connector body  42   a  so that in the absence of a downward force (within this description “downward” means toward the lead contacts  24 ; however, in use, the connector may be arbitrarily rotated) upon the moveable contacts  48 , the in-line lead  14  may be easily inserted completely into the passageway  44 . When a downward force is applied to the moveable contacts  48 , the resilient connector body  42   a  allows the moveable contacts  48  to be pushed against the lead contacts  24 . The solid cam  34  comprises a substantially straight shaft  39  and at least one solid lobe  40 . The solid cam  34  shown in FIG. 4 has the at least one solid lobe  40  pointing away from the movable contacts  48   a.  As a result, the movable contacts  48   a  are in a relaxed position, wherein they are not pressing against the lead contacts  24 , thus permitting easy insertion of the in-line lead  14 . The handle lug  36  is also shown pointing up. In this embodiment the handle lug  36  is aligned with the solid lobes  40  to provide an intuitive indication of the direction of the solid lobes  40 . While this is an advantageous alignment, the handle lug  36  may be aligned arbitrarily without departing from the scope of the invention. 
     In a preferred embodiment, the moveable contacts  48  are resiliently attached to the connector body  42   a  in a manner to cause the moveable contacts  48  to retreat from the lead contacts  24  when no downward force is acting on the moveable contacts  48 . In such cases, the moveable contacts rest in a first cam position when no force is applied to them. When the downward force is applied to the moveable contacts  48 , the moveable contacts  48  move to a second cam position where they contact the lead contacts  24 . In other embodiments, the absence of a downward force upon the moveable contacts  48  may result in the moveable contacts touching but applying negligible force to the lead contacts  24 . In either case, the absence of a downward force applied to the movable contacts  48   a  results in easy insertion and removal of the lead end  23  from the connector  12 . 
     In a preferred embodiment, the lead contacts  24  comprise rings that circle the lead body  22  as shown in FIG.  2 . The cross-sectional view of the lead contacts  24  shown in FIG. 4 shows the rectangular cross sections of the lead contacts  24  at the top and bottom of the in-line lead  14 . In other embodiments the cross-sectional view of the lead contacts  24  may be rounded or “D” shaped. These other cross-sections are intended to come within the scope of the present invention. Connector ridge seals  46  are molded into the passageway  44  to prevent conductive body fluids from readily passing between connectors and to thereby minimize current leakage between contacts. The connector seals  46  form a complete circle around the inner diameter of the passageway  44 , much like an o-ring, and make sufficient contact with the lead body  22  to prevent fluid and current leakage. 
     A second sectional view taken at line  4 A— 4 A of FIG. 3A is shown in FIG.  5 . This view is identical to the view in FIG. 4 with the exception that the solid cam  34  has been rotated approximately 180 degrees into a locking position. The handle lug  36  is in the down position. The solid lobes  40  are now pointing down and contacting the moveable contacts  48 . The moveable contacts  48  are pushed down and are contacting the lead contacts  24 . In this position, the in-line lead  14  is held in the passageway  44  by the friction resulting from the moveable contacts  48  pushing against the lead contacts  24 . A reliable electrical connection is created by the same cooperation of contacts. A cam stop lug  50  resides on the forward end of the solid cam  34 . 
     A cross sectional view taken at line  6 A— 6 A of FIG. 4 is shown in FIG.  6 A. The arced shape of the moveable contacts  48  is clearly visible. Additionally, the conductors  26  are shown within the lead body  22 . The solid lobes  40  are pointed up and are not in contact with the moveable contacts  48 . In the absence of downward force, the moveable contacts  48  are not touching the lead contacts  24 . 
     A cross sectional view taken at line  6 B— 6 B of FIG. 5 is shown in FIG.  6 B. The solid lobes  40  are pointed downward and are pushing the moveable contacts  48  firmly against the lead contacts  24 . 
     Another cross sectional view taken at line  6 C— 6 C of FIG. 5 is shown in FIG.  6 C. The solid cam  34  is depicted in the locked position (i.e., the solid lobes  40  are pointing downward towards the moveable contacts  48  as shown in FIG. 6B.) The cam stop lug  50 , on the forward end of the solid cam  34 , is resting against a second cam stop  60   b,  thus providing a second rotational stop for the solid cam  34  and a closed position for the connector  12 . The cam stop lug  50  and cam stop  60   b  are designed to allow the solid cam  34  to rotate slightly past the point where the solid lobes  40  are pointed directly at the moveable contacts  48 . By incorporating this “past center” position, the solid cam remains in the locked position once released. The solid cam  34  may be rotated so that the cam stop lug  50  cooperates with a first cam stop  60 a thus providing a first rotational stop for the solid cam  34  an open position for the connector  12 . While the cam stop lug  50  is shown at the forward end of the solid cam  34 , other locations for the cam stop lug  50  along the length of the solid cam  34  will provide an equivalent function, and are intended to come within the scope of the present invention. 
     Turning to FIG. 7, and alternative embodiment of a cam serving as a means for applying downward force on the moveable contacts is shown. A wireform cam  74  is inexpensively formed from wire. Wireform lobes  76  press down on the moveable contacts  48  to provide downward force. At least one cam support  72  in a second connector body  42   b  is provided to rotatably support at least one straight section of the wireform cam  74 . The support provided by the at least one cam support  72  allows the wireform cam to be rotated about an axis substantially parallel with the passageway  44 . The handle lug  36  provides a means to turn the wireform cam  74  in the same manner as the handle lug  36  in FIG. 3. A cam stop lug  50  provides a positive rotational stop for the second solid cam as in the case of the solid cam  34  illustrated in FIG.  6 C. The wireform cam  74  functions substantially the same as the solid cam  34  described in FIGS. 4,  5 , and  6 . 
     An alternative to the solid cam  34  of FIG. 4 is shown in FIG. 8. A removable rod  84  is inserted into a rod passageway  82  in a third connector body  42 c as a means for applying downward force on the moveable contacts  48 . In a preferred embodiment, the removable rod  84  defines radially symmetric bulges  86  at the same spacing as the spaced-apart moveable contacts  48 . Advantageously, the symmetry of the bulges permits the removable rod to be inserted with an arbitrary rotation. Alternative embodiments may include asymmetric bulges, with a key way, or equivalent means, to align the asymmetric bulges with the moveable contacts  48   a.  When the removable rod  84  is fully inserted into the rod passageway  82 , the symmetric bulges  86  are aligned with the moveable contacts  48 , and push the moveable contacts  48  downward against the lead contacts  24 . The resulting cooperation between contacts both retains the in-line lead  14  in the passageway  44 , and provides a reliable electronic connection between the contacts. A rod latch  88  is provided on a forward rod end opposite the exposed rearward end of the removable rod  84 . A cooperating latch receptacle  89 , constructed from the resilient connector body  42   c  material, is molded into the rod passageway  82 . When the removable rod  84  is pushed fully into the rod passageway  82 , the rod latch  88  snaps into the latch receptacle  89  to latch the removable rod  82  into the connector body  42   c.  A hook hole  87  is provided on an exposed rearward end of the removable rod  84  to provide means to pull the removable rod from the connector body  42   c.  The latch described in FIG. 8 is one example of many equivalent means for providing retention of a rod in a rod cavity. 
     In another variation, the rod may be captive within the connector. The rod would require sufficient freedom to be moved from a first rod position where the bulges are not aligned with the moveable contacts, to a second rod position where the bulges are aligned with the moveable contacts. Such variations will be apparent to those skilled in the art and are intended to fall within the scope of the present invention. 
     A second alternative embodiment of the connector is shown in FIG. 9. A fourth connector body  42   d  comprises the passageway  44  as shown in previously described embodiments, but further comprises an actuator cavity  92  and a key passageway  95 . A captive actuator  93  is positioned in the actuator cavity  92  above the moveable contacts  48  as a means for applying downward force on the moveable contacts. The captive actuator  93  defines bottom bulges  94  which are vertically aligned with the movable contacts  48   a.  The captive actuator  93  is limited to vertical motion only. A removable key  96  is removably insertable into the key passageway  95  above the captive actuator  93 . A fully inserted removable key  96  has a rearward end that protrudes from the connector body  42   d,  and a forward end opposite the rearward end. The bottom of the removable key  96  defines a short downward ramp  91  at the forward end followed by a straight section. When the forward end of the removable key  96  is first inserted into the key passageway  95 , the downward ramp  91  makes contact with the captive actuator  93 , and the captive actuator  93  is pushed down against the moveable contacts  48 . The resulting downward force of the moveable contacts  48  against the lead contacts  24  retains the in-line lead  14  in the passageway  44 , and provides a reliable electronic connection between the contacts. When the removable key  96  is fully inserted into the key passageway  95 , a key latch  98  on the forward end of the removable key  96 , snaps into a latch receptacle  99  to retain the removable key  96  in the key passageway  95 . A hook hole  97  is provided in the rearward end of the removable key  96  to facilitate the removal of the removable key. 
     A third alternative embodiment of the connector is shown in FIG. 10. A fifth connector body  42   e  comprises the passageway  44  and the key passageway  95  as shown in FIG. 9, but further comprises at least one actuator guide  102 . At least one multi actuator  104  slidably resides in the actuator guides  102 . The multi actuators  104  preferably have a round or rectangular horizontal cross section, but variations of the cross section will be apparent to those skilled in the art and fall within the scope of the present invention. The actuator guides  102  allows vertical movement of the multi actuators  104  but limit horizontal movement. The multi actuators  104  are positioned directly above the movable contacts  48   a.  The removable key  96  as described in FIG. 9 or equivalent, is insertable into the key passageway  95  above the multi actuators  104  as a means for applying a downward force on the multi actuators  104 . The bottom of the removable key  96  defines the downward ramp  91  followed by a straight section. The straight section is sufficiently long to cover all of the multi actuators  104  when the removable key  96  is fully inserted into the key passageway  95 . When the downward ramp  91  on the bottom of the removable key  96  makes contact with the multi actuators  104 , the multi actuators  104  are pushed down against the moveable contacts  48 . The moveable contacts  48  then are pushed down against the lead contacts  24 . The resulting downward force both retains the in-line lead  14  in the passageway  44 , and provides a reliable electronic connection between the contacts. 
     FIGS. 11A and 11B are cross sectional views taken along the lines  11 A— 1 A of FIG.  9  and the lines  11 B— 11 B of FIG. 10, respectively. FIG. 11A shows a second cross section of the second alternative embodiment of the means for applying downward force on the moveable contacts  48 . In this view, the removable key  96  is seen in the key passageway  95 . The captive actuator  93 , in the actuator cavity  92 , is just below the removable key  96 , and is forced downward by the removable key. The captive activator  93  forces the moveable contacts  48  downward. The moveable contacts  48  are thus pushed against the lead contacts  24 . The resulting downward force both retains the in-line lead  14  in the passageway  44 , and provides a reliable electronic connection between the contacts. 
     FIG. 11B is nearly identical to FIG. 11A with the exception that the captive actuator  93  in the actuator cavity  92  of FIG. 11A is replaced by the multi actuators  104  in the actuator guides  102  in FIG.  11 B. The actuator guides  102  position the multi actuators  104  above the movable contacts  48   a  and limit the multi actuators  104  to vertical movement. The removably insertable removable key  96  applies a downward force on the multi actuators  104 . The multi actuators  104  push down on the moveable contacts  48 . The moveable contacts  48  are thus pushed against the lead contacts  24 . The resulting downward force both retains the in-line lead  14  in the passageway  44 , and provides a reliable electronic connection between the contacts. 
     A connector with a second at least one spaced-apart moveable contact  48   b  is shown in FIG.  11 C. The moveable contacts  48   b  replace both the multi actuators  104  and first moveable contacts  48   a  shown in FIG. 11B described above. The moveable contacts  48   b  are movably contained in contact guides  112 . The contact guides  112  are vertically aligned with the lead contacts  24  of a fully inserted lead end  23 . The moveable contacts  48   b  are resiliently molded into a sixth connector body  42   f  at the base of the moveable contacts  48   b . Such resilient molding allows the movable contacts  48   b  to be pushed against the lead contact  24  by the insertion of the removable key  96  into the key passageway  95 , wherein the bottom key surface presses against at least one contact top surface, thereby retaining the lead end  23  in the connector body  42   f.  The same resilience causes the moveable contacts  48   b  to pull away from the lead end  23  when the removable key  96  is removed from the key passageway  95 , allowing easy removal of the lead end  23  from the connector body  42   f.    
     It is this seen that in each embodiment of the connector described herein, the moveable contacts are molded into the resilient connector body material to provide the correct positioning for the moveable contacts. A downward force moves the moveable contacts against the in-line lead. A resilient force moves the moveable contacts away from the in-line lead when no other force is acting upon the moveable contacts. This advantageously provides a simple connector, but alternative designs, for example using springs, would obtain the same functionality as that described here. Other means for positioning and restoring the moveable contacts will be apparent to those skilled in the art, and are intended to be within the scope of the present invention. 
     While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.