FLAT CABLE CONNECTOR
United States Patent 3702982
An electrical connector member having an insulated flat cable having conductors embedded therein. The electrical contacts have insulation piercing portions formed thereon with the contacts mounted in an insulator member. The contacts are connected to the flat cable conductors by the piercing portions which penetrate the cable insulation when a clip is secured to the insulator. A cover member may be interposed between the clip and the flat cable for positioning the cable in the connector. Also, a spring member allows the cover member and insulator member to be securely held together.
US Patent References:
Angular contact connector
Williams - August 1965 - 3201745
Cable and connector therefor
Elm - February 1966 - 3235833
Angular contact connector
Williams - August 1965 - 3201745
Cable and connector therefor
Elm - February 1966 - 3235833
Inventors:
Kelly, Joseph Francis (Phoenix, AZ)
Prow Jr., Harold James (Phoenix, AZ)
Prow Jr., Harold James (Phoenix, AZ)
Application Number:
05/113325
Publication Date:
11/14/1972
Filing Date:
02/08/1971
View Patent Images:
Export Citation:
Assignee:
International Telephone and Telegraph Corporation (New York, NY)
Primary Class:
Other Classes:
439/422, 439/492, 439/495
International Classes:
H01R43/00; H01R7/04
Field of Search:
339/97-99,176
Primary Examiner:
Moore, Richard E.
Claims:
What is claimed is
1. An electrical connector member for an insulated flat cable having conductors embedded therein comprising:
2. An electrical connector member in accordance with claim 1 and further comprising a cover member interposed between said clip member and said flat cable, said cover member having means for positioning said cable in said connector.
3. An electrical connector in accordance with claim 2 wherein said cover member positioning means comprising peripheral ribs formed on the bottom surface of said cover member.
4. An electrical connector in accordance with claim 1 wherein said contact piercing means are positioned on a leaf spring portion of said contacts for insuring electrical contact between said piercing means and said cable conductors.
5. An electrical connector in accordance with claim 1 wherein said contacts are formed of a leaf spring portion and a vertical portion, each of said leaf spring portions being mounted in channels formed in said insulator, with channels for one row of contacts being interspaced between channels for another row of contacts.
6. An electrical connector in accordance with claim 2 wherein said clip member contains shoulders for positioning said cover member therein prior to mounting said clip on said insulator.
7. An electrical connector member for an insulated flat cable having conductors embedded therein comprising:
8. An electrical connector member for an insulated flat cable having conductors embedded therein comprising:
9. An electrical connector member for an insulated flat cable having conductors embedded therein comprising:
10. An electrical connector in accordance with claim 9 wherein said cover member contains a dimpled positioning means for accurately positioning said spring member on said cover member.
1. An electrical connector member for an insulated flat cable having conductors embedded therein comprising:
2. An electrical connector member in accordance with claim 1 and further comprising a cover member interposed between said clip member and said flat cable, said cover member having means for positioning said cable in said connector.
3. An electrical connector in accordance with claim 2 wherein said cover member positioning means comprising peripheral ribs formed on the bottom surface of said cover member.
4. An electrical connector in accordance with claim 1 wherein said contact piercing means are positioned on a leaf spring portion of said contacts for insuring electrical contact between said piercing means and said cable conductors.
5. An electrical connector in accordance with claim 1 wherein said contacts are formed of a leaf spring portion and a vertical portion, each of said leaf spring portions being mounted in channels formed in said insulator, with channels for one row of contacts being interspaced between channels for another row of contacts.
6. An electrical connector in accordance with claim 2 wherein said clip member contains shoulders for positioning said cover member therein prior to mounting said clip on said insulator.
7. An electrical connector member for an insulated flat cable having conductors embedded therein comprising:
8. An electrical connector member for an insulated flat cable having conductors embedded therein comprising:
9. An electrical connector member for an insulated flat cable having conductors embedded therein comprising:
10. An electrical connector in accordance with claim 9 wherein said cover member contains a dimpled positioning means for accurately positioning said spring member on said cover member.
Description:
The invention relates, in general, to an improved flat cable termination and, more particularly, to a connector for terminating a flat cable without removal of the cable insulation therefrom.
BACKGROUND OF THE INVENTION
In U.S. Pat. application Ser. No. 885,033, filed Dec. 15, 1969, there is depicted a flat cable termination wherein a plurality of contact spring members are mounted in a bore, each of the spring members terminating in a piercing surface. An actuating plate is inserted in the bore, causing the spring members piercing surfaces to pierce the insulation of the flat cable and thus make contact with the conductors of the cable. This flat cable termination device, while sufficient for certain uses, cannot provide the higher piercing force required for high temperature cables. Moreover, it has been found that movement can occur between the actuating plate and the cable insulation resulting in an unsatisfactory connection between the conductors and the spring members.
In order to overcome the attendant disadvantages of prior art flat cable terminating connectors, the present invention provides an electrical connector having a pair of connector halves which are snapped together over the end of the flat cable to insure a permanent and reliable termination. Moreover, the piercing forces are provided so as to allow the termination to readily operate with substantially all types of flat cables. Clip means are provided to lock the assembled connector halves together, while simultaneously spring loading the connector halves against the flat cable.
The advantages of the invention, both as to its construction and mode of operation, will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like referenced numerals designate like parts throughout the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts an exploded perspective view of the flat cable terminating connector in accordance with the invention;
FIG. 2 illustrates a top view of the flat cable connector of FIG. 1 assembled and partly in section;
FIG. 3 shows a sectional view of the flat cable connector of FIGS. 1 and 2 taken along the line 3--3 of FIG. 2;
FIG. 4 illustrates an end view of the connector of FIG. 2;
FIG. 5 depicts a sectional view of the connector taken along the line 5--5 of FIG. 2 prior to complete termination of the connector to the flat cable;
FIG. 6 depicts a sectional view of the connector of FIG. 5 with the flat cable fully terminated;
FIG. 7 illustrates the piercing of the flat cable by the electrical connector; and
FIG. 8 depicts a tool which may be utilized in assembling the connector of FIGS. 1 through 7.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, there is shown in FIG. 1 an exploded perspective view of a connector 12 used to terminate a flat cable 14 in accordance with the invention. The connector is formed of an insulator block 16 of generally rectangular shape having grooves or channels 18 extending diagonally across the top surface of the insulator block 16. Near alternate ends of adjacent channels openings 22 are formed which extend from the channel surface through to the bottom surface 24 of the insulator. As shown more clearly in FIGS. 3 and 4 the openings 22 may be chamfered at the top end 26 and a bore may be formed near the bottom surface 24 with a downwardly facing shoulder 28 formed by the bore.
At the opposite ends of the insulator block 16 a groove is formed defining a pair of side walls 32, 34. Adjacent the side walls inwardly extending sections are formed by a tapered top section 36 and a rectangular bottom block 38 which terminates prior to the bottom surface of the insulator to form a downwardly facing shoulder 42. Further, intermediate the inwardly extending sections a slot 44 is formed in a plane perpendicular to the side walls.
Contacts 52 which are generally L-shaped are positioned in the channels 18. The contacts are typically made from sheets of beryllium copper which have been stamped or formed and then heat treated. The contacts are constructed of a terminating portion 54 and a vertical portion 56. The terminating portion 54 is made in the form of a convex leaf spring portion 68 which is 58 positioned within the channels 18. At the center of the portion 58, the contact protrudes slightly above the top surface of the insulator 16 and formed therein are a pair of sharply pointed projections 62 which are designed to pierce the flat cable insulation. Although two projections 62 are depicted in the drawing, it should be understood that only one projection could be utilized or even a large number of projections could be used.
The vertical portion 56 of the contact 52 is inserted into the openings 22 with the free end 64 thereof extending through the bottom surface of the insulator and acting as a mating pin contact or other terminating device. Further, a barb 66 in the vertical portion 56 of the contact is used to position the contact with respect to the insulator. The vertical portion of the contact 52, when inserted into opening 22 will emerge from the bottom surface of the insulator normally at a slight angle from the insulator's longitudinal axis. However, a slight twist is normally recommended to allow the top surface of the barb 66 to abut the insulator shoulder 28. Moreover, a twist is normally required to realign the mating portions 64 with respect to each other. The twist could be preformed at the proper location during fabrication of the contacts to provide snap-in self-retaining as well as self-aligning contacts. As can be seen, the channels for one row of contacts extend angularly across the insulator interspaced between the channels for another row of contacts, with the portion of the insulator between adjacent channels forming an insulator barrier.
A cover 72 is generally of the same rectangular dimensions as the insulator 16 and is made of insulating material also. A central recess 74 is formed longitudinally along the top surface of the cover with a dimpled surface 76 formed at the center of the recess and a tapered end surface 78 terminating the recess short of the end walls of the cover. The bottom surface of the cover is generally smooth and flat except for thin peripheral ribs 80 along one side and at both ends which serve to preposition the flat cable prior to termination while allowing the cable to extend outwardly from the connector side where there are no peripheral ribs.
Further, the bottom surface of the cover could be pre-coated with a pressure sensitive adhesive having a peel-off paper liner. The adhesive would aid in prepositioning of the flat cable for termination, as well as enhancing the cable retention capability of the terminated plug assembly.
A spring member 82 which is generally rectangular in shape fits in the recess 74 in the cover member. The spring member is shorter than the length of the recess. A downwardly extending dimple 84 formed therein is positioned in the cover dimple 76 to allow correct lengthwise positioning of the spring. The width of the spring is slightly smaller than the recess which allows the spring to move in a transverse direction. Further, the ends of the spring member are generally prestressed to bend upwardly when the dimple 84 is positioned in the cover dimple 76.
A retaining clip 86 is formed of generally U-shaped configuration and is formed of a top portion 88 which is slightly concave and a pair of side legs 92. At approximately the center of each of the legs 92 a coined inwardly extending tab 94 is formed. The ends of the legs 92 are folded back upon its inner surface to form retaining shoulders 96. The retaining clip 86 as well as the spring member 82 may be made from spring tempered sheet metal such as stainless steel.
To assemble the connector, the spring member 82 is inserted in the recess 74 of the cover member with the dimple 84 positioned in the dimple 76. Then the clip 86 is positioned in the recess so that the bottom edge of the end surface 78 is secured to the tabs 94 trapping the spring between the clip and the recess of the cover member as shown in FIG. 5. Then, the flat cable 14, having conductors 99, is inserted from the side where the peripheral ribs 80 have been removed from the cover 72. As previously pointed out, the bottom surface of the cover may have an adhesive covering to allow the flat cable to be secured thereto. Then the combined clip, spring, cover and flat cable are positioned on the insulator member so that the retaining shoulders 96 are adjacent the tapered top section 36 of the insulator 16.
A sufficient force is then applied to the top surface of the clip 86 as it is positioned in FIG. 5 of the drawings. The slight concave shape of the portion 88 of the clip is temporarily flattened out by the force, allowing the retaining shoulders 96 to grip to engage the downward facing shoulder 42 of the insulator. To allow for dimensional tolerances in the various parts of the connector, full flattening of the portion 88 of the retaining clip results in slight overtravel of the clip shoulders 96 past the insulator block shoulder 42. When the force applied to the top of the clip is removed, the spring force produced by the spring member 82 causes the locking shoulders 96 to engage securely and hold the cover 72 and insulator 16 together.
Simultaneous with the application of the force to the retaining clip 86, the contacts 52 are terminated to the conductors 99 of the cable 14. The force applied to the clip causes the insulator 16 and cover 72 to be pressed together tightly against the flat cable 98. The flat cable, in turn, compresses the convex leaf spring portions 58 of the contacts into their respective channels 18. However, when the bottom of the contact leaf spring flattens against the bottom of the channel, the sharp terminating projections 62 still protrude above the top surface of the insulator 16 and will penetrate the flat cable insulation.
Since the flat cable is backed on its side opposite the projection 62 by the smooth flat bottom surface of the cover 72, the cable is fixed in its position and the termination point 62 penetrates the cable insulation sufficiently to impinge against the conductor 99 of the cable, thus establishing electrical contact. When the force applied to the cover 86 is removed, the compressive force holding the insulator 16 and cover 72 together is reduced to that provided by the spring 82 and the retaining clip 86. The spring force exerted by the flattened leaf spring portion 58 of the contact 52 insures that electrical contact is maintained permanently between the contact 52 and the flat cable 14. This inherent contact spring force also is used to compensate for dimensional tolerance variations in the parts of the connector, for surface irregularities in the insulator 16 and cover 72, as well as for cold-flow of the flat cable insulation above the termination points 62.
Referring now to FIG. 8, there is depicted a typical fixed tool 102 which can be utilized to impart a uniform force to the retaining clip 86. The tool contains a rotatable arm 104 whose rotation causes linear movement of a lever 106. Mounted at the end of the lever is a block of metal 108 which upon operation of the tool is forced against the retaining clip correctly positioning the clip in place.
Alternatively, a special pliers-type tool could be employed to assemble the two connector halves together on the flat cable. Such a tool would have a special seating block for the connector assembly in its lower jaw. The seating block would have clearance holes to accept the protruding ends 64 of the contacts of the assembly to protect them from damage during termination. The seating block would also include features to position and support the insulator during the termination operation.
With the insulator assembly positioned properly in its seating block in the tool, the cover 72 would be positioned upon the insulator 16 with the flat cable in position, and with the protruding ends of the clip positioned as in FIG. 5. The handles of the tool would then be compressed together to complete the termination assembly.
BACKGROUND OF THE INVENTION
In U.S. Pat. application Ser. No. 885,033, filed Dec. 15, 1969, there is depicted a flat cable termination wherein a plurality of contact spring members are mounted in a bore, each of the spring members terminating in a piercing surface. An actuating plate is inserted in the bore, causing the spring members piercing surfaces to pierce the insulation of the flat cable and thus make contact with the conductors of the cable. This flat cable termination device, while sufficient for certain uses, cannot provide the higher piercing force required for high temperature cables. Moreover, it has been found that movement can occur between the actuating plate and the cable insulation resulting in an unsatisfactory connection between the conductors and the spring members.
In order to overcome the attendant disadvantages of prior art flat cable terminating connectors, the present invention provides an electrical connector having a pair of connector halves which are snapped together over the end of the flat cable to insure a permanent and reliable termination. Moreover, the piercing forces are provided so as to allow the termination to readily operate with substantially all types of flat cables. Clip means are provided to lock the assembled connector halves together, while simultaneously spring loading the connector halves against the flat cable.
The advantages of the invention, both as to its construction and mode of operation, will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like referenced numerals designate like parts throughout the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts an exploded perspective view of the flat cable terminating connector in accordance with the invention;
FIG. 2 illustrates a top view of the flat cable connector of FIG. 1 assembled and partly in section;
FIG. 3 shows a sectional view of the flat cable connector of FIGS. 1 and 2 taken along the line 3--3 of FIG. 2;
FIG. 4 illustrates an end view of the connector of FIG. 2;
FIG. 5 depicts a sectional view of the connector taken along the line 5--5 of FIG. 2 prior to complete termination of the connector to the flat cable;
FIG. 6 depicts a sectional view of the connector of FIG. 5 with the flat cable fully terminated;
FIG. 7 illustrates the piercing of the flat cable by the electrical connector; and
FIG. 8 depicts a tool which may be utilized in assembling the connector of FIGS. 1 through 7.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, there is shown in FIG. 1 an exploded perspective view of a connector 12 used to terminate a flat cable 14 in accordance with the invention. The connector is formed of an insulator block 16 of generally rectangular shape having grooves or channels 18 extending diagonally across the top surface of the insulator block 16. Near alternate ends of adjacent channels openings 22 are formed which extend from the channel surface through to the bottom surface 24 of the insulator. As shown more clearly in FIGS. 3 and 4 the openings 22 may be chamfered at the top end 26 and a bore may be formed near the bottom surface 24 with a downwardly facing shoulder 28 formed by the bore.
At the opposite ends of the insulator block 16 a groove is formed defining a pair of side walls 32, 34. Adjacent the side walls inwardly extending sections are formed by a tapered top section 36 and a rectangular bottom block 38 which terminates prior to the bottom surface of the insulator to form a downwardly facing shoulder 42. Further, intermediate the inwardly extending sections a slot 44 is formed in a plane perpendicular to the side walls.
Contacts 52 which are generally L-shaped are positioned in the channels 18. The contacts are typically made from sheets of beryllium copper which have been stamped or formed and then heat treated. The contacts are constructed of a terminating portion 54 and a vertical portion 56. The terminating portion 54 is made in the form of a convex leaf spring portion 68 which is 58 positioned within the channels 18. At the center of the portion 58, the contact protrudes slightly above the top surface of the insulator 16 and formed therein are a pair of sharply pointed projections 62 which are designed to pierce the flat cable insulation. Although two projections 62 are depicted in the drawing, it should be understood that only one projection could be utilized or even a large number of projections could be used.
The vertical portion 56 of the contact 52 is inserted into the openings 22 with the free end 64 thereof extending through the bottom surface of the insulator and acting as a mating pin contact or other terminating device. Further, a barb 66 in the vertical portion 56 of the contact is used to position the contact with respect to the insulator. The vertical portion of the contact 52, when inserted into opening 22 will emerge from the bottom surface of the insulator normally at a slight angle from the insulator's longitudinal axis. However, a slight twist is normally recommended to allow the top surface of the barb 66 to abut the insulator shoulder 28. Moreover, a twist is normally required to realign the mating portions 64 with respect to each other. The twist could be preformed at the proper location during fabrication of the contacts to provide snap-in self-retaining as well as self-aligning contacts. As can be seen, the channels for one row of contacts extend angularly across the insulator interspaced between the channels for another row of contacts, with the portion of the insulator between adjacent channels forming an insulator barrier.
A cover 72 is generally of the same rectangular dimensions as the insulator 16 and is made of insulating material also. A central recess 74 is formed longitudinally along the top surface of the cover with a dimpled surface 76 formed at the center of the recess and a tapered end surface 78 terminating the recess short of the end walls of the cover. The bottom surface of the cover is generally smooth and flat except for thin peripheral ribs 80 along one side and at both ends which serve to preposition the flat cable prior to termination while allowing the cable to extend outwardly from the connector side where there are no peripheral ribs.
Further, the bottom surface of the cover could be pre-coated with a pressure sensitive adhesive having a peel-off paper liner. The adhesive would aid in prepositioning of the flat cable for termination, as well as enhancing the cable retention capability of the terminated plug assembly.
A spring member 82 which is generally rectangular in shape fits in the recess 74 in the cover member. The spring member is shorter than the length of the recess. A downwardly extending dimple 84 formed therein is positioned in the cover dimple 76 to allow correct lengthwise positioning of the spring. The width of the spring is slightly smaller than the recess which allows the spring to move in a transverse direction. Further, the ends of the spring member are generally prestressed to bend upwardly when the dimple 84 is positioned in the cover dimple 76.
A retaining clip 86 is formed of generally U-shaped configuration and is formed of a top portion 88 which is slightly concave and a pair of side legs 92. At approximately the center of each of the legs 92 a coined inwardly extending tab 94 is formed. The ends of the legs 92 are folded back upon its inner surface to form retaining shoulders 96. The retaining clip 86 as well as the spring member 82 may be made from spring tempered sheet metal such as stainless steel.
To assemble the connector, the spring member 82 is inserted in the recess 74 of the cover member with the dimple 84 positioned in the dimple 76. Then the clip 86 is positioned in the recess so that the bottom edge of the end surface 78 is secured to the tabs 94 trapping the spring between the clip and the recess of the cover member as shown in FIG. 5. Then, the flat cable 14, having conductors 99, is inserted from the side where the peripheral ribs 80 have been removed from the cover 72. As previously pointed out, the bottom surface of the cover may have an adhesive covering to allow the flat cable to be secured thereto. Then the combined clip, spring, cover and flat cable are positioned on the insulator member so that the retaining shoulders 96 are adjacent the tapered top section 36 of the insulator 16.
A sufficient force is then applied to the top surface of the clip 86 as it is positioned in FIG. 5 of the drawings. The slight concave shape of the portion 88 of the clip is temporarily flattened out by the force, allowing the retaining shoulders 96 to grip to engage the downward facing shoulder 42 of the insulator. To allow for dimensional tolerances in the various parts of the connector, full flattening of the portion 88 of the retaining clip results in slight overtravel of the clip shoulders 96 past the insulator block shoulder 42. When the force applied to the top of the clip is removed, the spring force produced by the spring member 82 causes the locking shoulders 96 to engage securely and hold the cover 72 and insulator 16 together.
Simultaneous with the application of the force to the retaining clip 86, the contacts 52 are terminated to the conductors 99 of the cable 14. The force applied to the clip causes the insulator 16 and cover 72 to be pressed together tightly against the flat cable 98. The flat cable, in turn, compresses the convex leaf spring portions 58 of the contacts into their respective channels 18. However, when the bottom of the contact leaf spring flattens against the bottom of the channel, the sharp terminating projections 62 still protrude above the top surface of the insulator 16 and will penetrate the flat cable insulation.
Since the flat cable is backed on its side opposite the projection 62 by the smooth flat bottom surface of the cover 72, the cable is fixed in its position and the termination point 62 penetrates the cable insulation sufficiently to impinge against the conductor 99 of the cable, thus establishing electrical contact. When the force applied to the cover 86 is removed, the compressive force holding the insulator 16 and cover 72 together is reduced to that provided by the spring 82 and the retaining clip 86. The spring force exerted by the flattened leaf spring portion 58 of the contact 52 insures that electrical contact is maintained permanently between the contact 52 and the flat cable 14. This inherent contact spring force also is used to compensate for dimensional tolerance variations in the parts of the connector, for surface irregularities in the insulator 16 and cover 72, as well as for cold-flow of the flat cable insulation above the termination points 62.
Referring now to FIG. 8, there is depicted a typical fixed tool 102 which can be utilized to impart a uniform force to the retaining clip 86. The tool contains a rotatable arm 104 whose rotation causes linear movement of a lever 106. Mounted at the end of the lever is a block of metal 108 which upon operation of the tool is forced against the retaining clip correctly positioning the clip in place.
Alternatively, a special pliers-type tool could be employed to assemble the two connector halves together on the flat cable. Such a tool would have a special seating block for the connector assembly in its lower jaw. The seating block would have clearance holes to accept the protruding ends 64 of the contacts of the assembly to protect them from damage during termination. The seating block would also include features to position and support the insulator during the termination operation.
With the insulator assembly positioned properly in its seating block in the tool, the cover 72 would be positioned upon the insulator 16 with the flat cable in position, and with the protruding ends of the clip positioned as in FIG. 5. The handles of the tool would then be compressed together to complete the termination assembly.