Double-ended conductor-in-slot connecting device
United States Patent 1 Doty et al.  
 [451 Apr. 15, 1975 DOUBLE-ENDED CONDUCTOR-IN-SLOT CONNECTING DEVICE [75] Inventors: Donald Judson Doty,  
 Winston-Salem; Robert Philmore Reavis, Jr., Statesville, both of NC.  
 [73] Assignee: AMP Incorporated, Harrisburg, Pa.  
 [22] Filed: Oct. 29, 1973 [21] Appl. No.: 410,946  
 FOREIGN PATENTS OR APPLICATIONS United Kingdom 339/97 P 1,963,313 6/1971 Germany 339/97 R Primary ExaminerJoseph l-l. McGlynn [5 7 ABSTRACT Tubular conductor-in-slot connecting device comprises a formed tubular member having an axially extending open seam which serves as a conductor receiving slot. The member is partially transversely severed intermediate its ends to form two or more separate spring systems. A conductor can be inserted into the slot from each end of the tubular member to electrically connect the conductors to each other. One embodiment is adapted to be mounted on a panel member and another embodiment is insulated and used as a dead end connector for wires. An improved strain relief means for tubular connecting devices is also disclosed.  
 5 Claims, 9 Drawing Figures PATENTEBAPR 1 5191s 3, 877.  
 DOUBLE-ENDED CONDUCTOR-lN-SLOT CONNECTING DEVICE BACKGROUND OF THE INVENTION Application Ser. No. 347,956 now Pat. No. 3,860,318 discloses and claims an improved conductor-in-slot connecting device comprising a formed tubular member which is transversely sheared along a shear line extending partially therearound intermediate its ends. The transverse shear line divides the tubular member into two separate spring systems so that a wire can be positioned on each side of this shear line and will not be effected by an adjacent wire on the other side of the shear line. The connecting device shown in application Ser. No. 347,956 is provided on the end of an electrical contact terminal contained in a multicontact electrical connector.  
  Tubular connecting devices of the type shown in the above-identified application have been found to be highly satisfactory for a number of reasons as set forth and described in that application. An improved tubular connecting device is disclosed in application Ser. No. 405,970 now U.S. Pat. No. 3,845,455 which incorporates a strain relief for tensile forces applied to an inserted wire.  
  The instant invention is directed to the achievement of a tubular connecting device of the general type disclosed in application Ser. No. 347,956 and which is double ended in that it is adapted to receive a wire from either end thereof. Such double ended tubular connecting devices can be used for example, on a panel-like member for connecting wires which are on opposite sides of the panel to each other and can be used with a suitable insulating means as a dead end connector.  
  The invention is also directed to the achievement of an improved strain relief for tubular conductor-in-slot connecting devices which retains an inserted conductor against movement laterally (rather than axially) out of the slot of the connecting device. This strain relief can be used in conventional single ended tubular connecting devices of the type under consideration as well as double ended devices.  
  It is accordingly an object of the invention to provide an improved eonductor-in-slot connecting device. A further object is to provide a double ended conductorin-slot connecting device. A still further object is to provide an improved strain relief for a conductor-inslot connecting device. A further object is to provide a suitable tubular conductor-in-slot connecting device which can be mounted in a panel-like member and to which wires or other conductors on either side of the panel can be connected. A further object is to provide an improved splice connector for connecting the ends of wires or other conductors.  
  These and other objects of the invention are achieved in preferred embodiments which are briefly described in the foregoing abstract, which are described in detail below, and which are shown in the accompanying drawing in which:  
  FIG. 1 is a perspective view of a connecting device for connecting the ends of wires in accordance with the invention.  
  FIG. 2 is an exploded perspective view of the component parts of the connecting device of FIG. 1.  
  FIG. 3 is a top plan view of the connecting device of FIG. 1 showing the positions of the parts prior to insertion of the wires into the slots of the device.  
  FIG. 4 is a view similar to FIG. 3 but showing the positions of the parts after insertion of the wires.  
 FIG. 5 is a view taken along the lines 5-5 of FIG. 4.  
 FIG. 6 is a view taken alongthe lines 66 of FIG. 5.  
  FIG. 7 is a perspective view of an alternative embodiment of the invention which is adapted to be mounted on a panel-like member.  
  FIG. 8 is a view showing a plurality of the connecting devices of the type shown in FIG. 7 mounted on a panel.  
  FIG. 9 is a view illustrating the principle of the strain relief means which is provided on the connecting device of FIG. 7.  
  FIG. 1 shows a connecting means 2 for connecting the ends of wires 4 to each other, this connecting means incorporating a double ended tubular conductor-in-slot connecting device in accordance with the invention. The connecting means 2 comprises a double ended formed tubular member 6 of suitable insulating conductive sheet metal, a tubular insulating sleeve 20, and two end caps 29 which are threaded onto the insulating member 20.  
  The conductive tubular member 6 is cylindrical throughout the major portion of its length and has an axially extending open seam 8 which serves as a conductor receiving slot. The tubular body is transversely sheared as shown at 10 midway between its ends and partially around its circumference. The shear lines 10 extend to punched holes 12 which serve to prevent propagation of the cracks from the ends of the shear lines. Openings 14 are provided at each end of the tubular member 6 for the reception of the wires as will be described below and the edges of these openings extend convergently to the ends 16 of the slots 8. A pair of radially extending ears 18 are formed on each side of the openings 14 to retain the metallic tubular member 6 in the insulating tubular member 20 as shown in FIG. 6.  
  The insulating member 20 has an open seam or gap 22 which is somewhat wider than the seam 8 and has external threads 24 on its surface which extend partially inwardly from each end to outwardly facing stop shoulders 27. The edges of the seam or gap 22 are notched at each end of the insulating member as shown .at 26, these notches being adapted to receive the previously described ears 18.  
  The end caps or end covers 29 are in the form of cuplike cylindrical members having internal threads 28 which engage with the threads 24 and have axially extending centrally located cylindrical ram or wire stuffer 30 members integral therewith.  
  The conductive tubular member 6 may be formed of any suitable conductive metal such as phosphorbronze, beryllium copper etc. Good results are obtained with a No. 4 hard cartridge brass having a thickness of about 0.012 inches and the plastic parts 20, 29 may be molded of any suitable plastic material which is relatively firm and rigid in thick sections but which should have some flexibility. The conductive tubular member 6 is assembled to the insulating sleeve member 20 by merely moving these two members laterally towards each other from the positions shown in FIG. 2. The conductive member can be forced through the gap 22 of the insulating member if the insulating member is capable of flexing to a slight degree and after assembly, the ears 18 will be seated in the recesses 26 as shown in FIG. 6 to prevent rotation of either member with respect to the other.  
  In use, the cap members are assembled to the insulating sleeve and the wires are inserted into the open ings 14 as shown in FIG. 3. The cap members are then merely moved inwardly and towards each other until the faces 32 of the cap members are against the shoulders 27. Such movement of the cap members 29 force the wires into the slot 8 so that the edges of the slot penetrate the insulation of the wires and establish electrical contact with the conducting core thereof.  
  As noted above, the cap or cover members 29 and the insulating sleeve 20 are advantageously formed of a material which has some flexibility and depending upon the degree of flexibility on this material, the cap members may be simply passed inwardly from the posi&#39; tion of FIG. 3 to the positions of FIG. 4 and the teeth will flex while they move over each other. The cap members can be removed by unthreading and the device can be reused if desired. Suitable materials for the plastic parts are poly carbonate and nylon, the latter material being glass-filled to the extent necessary to achieve the desired combination of hardness or firmness and flexibility FIGS. 7-9 show an alternative form of double ending connecting device 34 which is adapted to be mounted in a panel-like member 34 for connecting wires 38 on the upper side of the panel to wires 40 on the lower side. The connecting device 36 comprises a formed tubular member 42 having an axially extending seam 44 which serves as a conductor receiving slot. Mid-way between its ends, the tubular member is partially transversely sheared as shown at 46, the shear lines extending to punched holes 48 for reasons previously discussed. Opposed spaced apart tangs 50 are struck from the tubular member on each side of the shear line 46 for retaining the member in the panel-like member. The connecting device is mounted in the panel by merely inserting it into a circular hole in the panel and the tangs 50 will bear against the opposite sides of the panel as shown.  
  The embodiment of FIGS. 79 has an improved strain relief at each end to impede or prevent movement of the wires laterally of their axes from the slot.  
 This strain relief means is provided adjacent to the con-.  
 ductor receiving openings 52 at the ends of the connecting device and is formed by shearing the tubular member adjacent to the openings 52 transversely as shown at 56, the shear lines extending partially around the circumference to punched holes 58. The portions 60 of the tubular member which lie between the shear lines 56 and the edges 59 of the openings are formed inwardly towards the axis of the tubular member so that the retaining portion 62 of the slot 44 is relatively more narrow than the central conductor receiving portion of the slot. The axial seam thus has a retaining portion of restricted width which extends from a first location (the intersection of the edges 59 and the axially extending edges of the portion 62 of the seam) to a second location defined by the intersection of the shear lines 56 with the seam. The first and second locations define an entrance portion, a contact slot portion, and a retaining portion of the seam. The entrance portion is bounded by the end of the tubular member and the first location and is coincident with the opening edges 59. The retaining portion 62 is between the first and second locations. The second location defines the outermost extent of the contact or conductor receiving slot portion, 44. The slot may, in fact, be completely closed although there will usually be a narrow gap at 62 because of spring back effects in the metal. By virtue of the fact that the tubular member is sheared at 56, proportions 60 can be flexed towards or away from the axis of the tubular member and the slot portion 62 will be opened to the extent necessary to admit the wire.  
  FIG. 9 illustrates the principle of this strain relief feature and shows a wire located against the edges 59 of the opening 52, the position it would occupy. immediately prior to being moved into the central portion 44 of the slot. If a downward force F (which represents the insertion forces) is applied to the wire in FIG. 9, it will be transmitted to the tubular member as two components each of which has a magnitude of F /2 and which is directed substantially normally of the portion of the edges 59 against which the wire bears. Each force F /2 is a resultant of a vertical component and a horizontal component as indicated and the horizonal component force will tend to flex the associated portion 60 in one direction or another (outwardly or inwardly) so that the slot section 62 will be opened. Whilethe wire is being moved through the section 62 of the slot, there will ordinarily be some penetration of the insulation and this section of the slot will not be opened to a width which is equal to the diameter of the insulation of the wire.  
  After the wire moves past the shear lines 56, the portions 60 of the tubular member return to theirnormal positions and the wire will be prevented from moving upwardly by the constricted slot portion 62. It willbe apparent that an upward force applied to the shoulders 64 between the restricted slot portion 62 and the portion 44 of the slot will not tend to open the constricted portion of the slot since there is no horizonal force component developed. This upward force would be applied if one of the upwardly extending wires in FIG. 8 were pulled or tensioned.  
  A strain relief means as described above can beused in single ended connecting devices of the type shown in application Ser. No. 347,956 and the principle is equally applicable and can be used with connecting devices of the type shown in application Ser. No. 405,970 now US. Pat. No. 3,845,455. In the latter case, the strain relief can be provided on the strain relief slot rather than the electrical contact slot of the connecting device.  
  While the disclosed embodiment has a single shear line on each side of the open seam to providetwo separate spring systems, it will be apparent that an additional number of shears can be provided to form an additional number of spring systems, for example, two separate spring systems can be provided on each side of the middle of the connecting device so that a total of four wires can be electrically connected to each other.  
  Double-ended metallic connecting devices in accordance with the inventioncan be used under circum stances other than those disclosed above where it isexpedient to insert the wires from opposite ends of the connecting device rather than from only one end. For example, in multi-contact electrical connectors having a plurality of contact terminals therein. In a multicontact connector of this type, the individual tubular connecting device would ordinarily have a contact means for disengageably contacting a complementary contact terminal in a complementary multi-contact electrical connector.  
  Change in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the inventionl The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only.  
 What is claimed is:  
  l. A conductor-in-slot electrical connecting device comprising:  
 a formed metallic tubular member of conductive sheet metal, said member having an axially extending open seam extending from one end thereof to the other end thereof, said seam serving as a conductor-receiving slot and having edges which are adapted to engage a conductor inserted into said said member being partially transversely severed intermediate the ends thereof from said edges partially around the circumference of said member whereby said member is divided into two separate spring systems, for reception of at least two conductors,  
 conductor-receiving means at each end of said member, each of said conductor receiving means comprising an opening in the wall of said member adjacent to said ends, each of said openings intersecting said edges of said conductor-receiving slot a tubular insulating member in surrounding relationship to said metallic member, said insulating memher having an axially extending open seam which is in alignment with said open seam of said metallic member, and  
 insulating cover means each end of said tubular insulating member, said cover means being movable relatively towards each other on said tubular insulating member whereby,  
 upon locating a conductor in each of said openings with the axes of said conductors extending laterally of the axis of said member, and upon moving said cover means towards each other said conductors are moved laterally of their axes and towards each other, and said conductors will be moved into said conductor-receiving slot and said edges will engage, and establish electrical contact with, said conductors.  
  2. A connecting device as set forth in claim 1, said insulating cover means having internal threads and said tubular insulating member having external threads.  
 3. A connecting device as, set forth in claim 2, said tubular insulating member and said cover means being of a stiffly flexible material whereby, said cover means can be pushed inwardly on said tubular member with accompanying flexing of said screw threads and without destruction of said screw threads.  
 4. A conductor-in-slot electrical connecting device comprising:  
 a formed metallic tubular member of conductive sheet metal, said member having an axially extending open seam extending from one end thereof to the other end thereof,  
 said member being partially transversely severed intermediate the ends thereof from the edges of said seam partially around the circumference of said member by severance lines which are in alignment on opposite sides of said seam, whereby said member is divided into two separate spring systems forreception of at least two conductors,  
 conductor-receiving means at each end of said member, each of said conductor receiving means comprising an opening in the wall of said member adjacent to said ends;  
 contact slot portions of said seam on both sides of said severance lines and extending inwardly from each of said openings to said severance lines for the reception of a conductor on each side of said severance lines, said contact slot portions having opposed edges spaced apart by a distance which is less than that of the conductor for which said device is intended,  
 a tubular insulating member in surrounding relationship to said metallic member, and  
 an insulating cover means at each end of said tubular insulating member, said cover means being movable relatively towards each other, whereby upon locating a conductor in each of said openings with the axis of said conductors extending laterally of the axis of said member, and upon movement of said cover means towards each other, said conductors are moved by said cover means laterally of their axes towards said severance lines, and into said contact slot portions whereby said edges engage, and establish electrical contact with said conductors.  
  5. A device as set forth in claim 4, said cover means at each end having internal ram means movable along the axis of said tubular member and inside said tubular member, so that when said cover means are moved relatively towards each other said ram means push the portions of said conductors inside said tubular member towards each other.