US3259873A - Terminals for flat electrical conductors - Google Patents

Description

July 5, 1966 P. K. PARKINSON ETAL 3,259,873

TERMINALS FOR FLAT ELECTRICAL CONDUCTORS Filed Oct. 21, 1963 g Sheets-Sheet 1 F I ya-R INVENTORS 1 404 K. Poem/v50 6424 .1 Ham/awa y 1966 P. K, PARKINSON ETAL 3,259,873

TERMINALS FOR FLAT ELECTRICAL GONDUCTORS Filed 001;. 21, 1963 2 Sheets-Sheet 2 m a s N s mi H mu m Wm M m a v k m e a. J m 2 y m 2 mm m 0 P 5 6 mm w a 6 H I a W K A i Q 4 H m 7/ L Mw mJ 4w a 4 4 y Am Z Z a 3,259,873 TERMINALS FOR FLAT ELECTRICAL CONDUCTORS Paul K. Parkinson, Monterey Park, and Carl H. Hemingway, La Puente, Calif., assignors, by mesne assignments, to International Telephone and Telegraph Corporation, New York, N.Y., a corporation of Maryland Filed Oct. 21, 1963, Ser. No. 317,683 10 Claims. (Cl. 339-97) The present invention relates to termination devices for electrical conductors, and it relates particularly to a novel terminal adapted to be attached to a flat electrical conductor and to a novel method of attaching the terminal to the flat conductor. The present invention has especial utility in the termination of the conductor ribbons of fiat electrical cables commonly known as strip cables.

Terminals for fiat electrical conductors such as the flat conductor ribbons of a strip cable may take various forms. For example, such terminals may comprise contact terminals of an electrical connector member which is adapted to be engaged with another connector member having mating contact terminals. In such a case, the terminals for the flat conductor ribbons will usually each have a terminal portion at one end adapted to be mechanically and electrically connected to a bared end of a respective conductor ribbon of the cable, and will at the other end have contacting means such as a pin or socket or other means which is mateable with another contact terminal member. The use of such pin or socket contact terminal members as terminations for the flat conductor ribbons of a strip cable may, for example, be for the purpose of providing a transition from the flat cable to round wires.

Regardless of the purpose for which the fiat conductor terminals are to be employed, it has been conventional prior art practice to attach the terminals to the flat conductor ribbons by soldering or welding. This is general- 15; difficult and time consuming and has the disadvantage that the terminals cannot readily be disconnected from the ends of the conductor ribbons for repair or circuit reconstitution.

Because of the foregoing difficulties, attempts have been made in the art to attach terminals to flat conductors by crimping spaced jaws of each terminal against opposite sides of a bared flat conductor. However, this procedure has not heretofore been satisfactory because of the fact that stress creep or relaxation would gradually occur after the crimp had been applied, causing the jaws to gradually release their grip on the conductor, thus diminishing or completely releasing the mechanical and electrical connection.

. In view of these and other problems in the art, it is an object of the present invention to provide a novel terminal adapted to be crimped to a flat electrical conductor, and to provide a novel method of crimping same to the flat conductor, wherein regions having opposing stresses are established in the crimped terminal such that stress creep or relaxation in one region of the terminal which tends to diminish the grip of the terminal on the flat conductor will be compensated at least in part by an opposing stress creep or relaxation in another region of the terminal which tends to increase or strengthen the grip of the terminal on the fiat conductor.

Another more specific object of the present invention is to provide a novel terminal for a flat electrical conductor such as a conductor ribbon of a flat electrical cable, wherein the terminal embodies a pair of spaced crimp jaws which are crimped together against opposite sides of the flat conductor, the jaws being so constructed and the crimp being applied in such a manner that the primary bend applied to the terminal for crimping the jaws to- United States Patent 3,259,873 Patented July 5, 1966 gether will occur generally proximate the roots of the jaws and a secondary bend will be applied in the opposite direction to at least one of the jaws in a region intermediate the root and free end of that jaw, whereby any tendency for stress creep or relaxation in said primary bend to cause a weakening of the grip of the jaws on the conductor will tend to be compensated for by an opposed stress creep or relaxation in the region of said secondary bend which will tend to urge the free ends of the jaws closer together.

A still further object of the invention is to provide a crimp type terminal for a flat electrical conductor in which opposed jaws of the terminal are provided with a novel arrangement of gripping teeth wherein opposed teeth have longitudinally offset peaks which cause pinching or compressing of the flat conductor against flat, inclined portions of the teeth adjacent the peaks in such a manner that the teeth will not bite through or damage the conductor. Additionally, this novel arrangement of the teeth assists in the establishment of the double stress pattern which tends to compensate for stress creep or relaxation.

Further objects and advantages of this invention will appear in the course of the following part of the specification, wherein the details of construction, mode of operation and novel method steps of a preferred embodiment are described with reference to the accompanying draw ings, in which:

FIGURE 1 is a plan view, with a port-ion broken away, illustrating a plurality of socket contact terminals embodying the present invention crimped to the respective conductor ribbons of a flat electrical cable.

FIGURE 2 is an axial vertical section taken on the line 2-2 further illustrating the relationship of the contact terminal members to the flat electrical cable.

FIGURE 3 is a transverse vertical section taken on the line 33 in FIGURE 1.

FIGURE 4 is an enlarged, fragmentary transverse vertical section taken on the line 4-4 in FIGURE 2 illustrating two of the contact terminal members crimped to respective bared conductor ribbons of the flat cable.

FIGURES 5, 6 and 7 are sequential figures illustrating the method of crimping one of the terminals to the respective bared conductor ribbon of the flat cable;

FIGURE 5 illustrating the crimping jaws of the terminal in their initial, open position with the conductor ribbon operatively positioned therebetween for the crimp;

FIGURE 6 illustrating the jaws partially closed, with the forward gripping teeth having come into gripping engagement with the conductor ribbon; and

FIGURE 7 illustrating the jaws fully crimped together with the ribbon being gripped between all opposed pairs of gripping teeth.

Although the present invention is illustrated and will be particularly described herein in connection with the attachment of contact terminal members to conductor ribbons of a fiat electrical cable, it is to be understood that the invention is not limited to this particular use :but has general utility in the attachment of termination means to a flat electrical conductor.

Referring to the drawings, FIGURES 1 to 4 illustrate a plurality of contact terminal members 10 embodying crimping structure according to the present invention attached to a fiat cable 12 commonly known as 'a strip cable, the individual contact terminal members 10 being crimped to the bared end portions of the respective flat conductor ribbons 14 of cable 12.

The strip cable 12 comprises a sheet 16 of insulation material with the flat conductor ribbons 14 embedded therein in generally parallel, spaced, co-planar relationship. The conductor ribbons 14 are bared on both sides commencing at end edge 18 of the cable and extending back a sutlicient distance to permit crimping of the contact terminal members to the respective conductor ribbons 14. Although the conductor ribbons 14 may thus be bared on both sides of the cable 12 as best shown in FIG- URE 4, an alternative procedure is to bare the ribbons 14 on one side of the cable and then to double the end of the cable over so as to expose this one bared side of the ribbons on both sides of the end portion of the cable.

Each of the contact terminal members 10 includes a forward contacting portion 20 which is adapted for mating with an opposed contact member (not shown), and a rearward terminal portion 22 which is adapted for crimping to a respective conductor ribbon 14. For purposes of illustration only, the forward contacting portion 20 of each contact terminal member 10 has been shown as a socket contacting portion which is adapted to mate with an opposed pin contact member.

Each contact terminal member 10 includes a generally flat body 24 having an integral forwardly extending pin or rod 26 thereon which extends into the rearward portion of a socket tube 28, the forward portion of which constitutes the contacting portion of the socket. The socket tube may be crimped, soldered, brazed or welded to the pin or rod 26 so as to becom a permanent part of the contact terminal member 10.

A pair of opposed, spaced crimping jaws 30 and 32 extend rearwardly from the body portion 24 of the contact terminal member 10. Preferably, one of the jaws 30 extends rearwardly generally in alignment with the socket tube 28, while the other jaw 32 extends at an angle with respect to the jaw member 30 from an apex at the flat body 24 prior to the crimping operation, the jaws 30 and 32 being substantially parallel after the crimping operation.

The jaws 30 and 32 have respective free ends 34 and 36, the jaws defining a slot 38 therebetween which is adapted to receive one of the bared flat conductor ribbons 14.

By having one of the jaws 30 substantially aligned with the contact socket 28 and the other jaws 32 offset from the axis of socket 28 where the jaw 32 commences at body 24, and then during the crimping by closing the jaw 32 toward the jaw 38 while maintaining the alignment between jaw 30 and socket tube 28, the result is that the socket tube 28 extends generally longitudinally from the end edge 18 of the cable 12 but offset to one side of the plane of cable 12. By staggering the contact terminal members 10, as best shown in FIGURES 2 and 3, with the socket tubes 28 of alternate contact terminal members 10 being disposed on opposite sides of the plane of the strip cable 12, greater spacing is provided between adjacent socket tubes 28, thereby decreasing the likelihood of electrical cross-over or leakage, and permitting greater voltages to be employed for a given spacing between adjacent fiat conductor ribbons 14 of the strip cable 12.

Referring in greater detail'to the construction of the jaws 30 and 32, the jaw 30 is provided on its inner edge facing the slot 38 with a plurality of teeth 40, 42, 44 and 46 commencing at the free end 34 of jaw 30 and extending rearwardly approximately half the length of the slot 38. Similarly, the jaw 32 has teeth 48, 50, 52 and 54 thereon which generally oppose the respective teeth 40, 42, 44 and 46 of jaw 38.

The jaws 30 and 32 have respective outer longitudinal edges 56 and 58 which are preferably but not necessarily generally straight, and the free ends of jaws 30 and 32 are provided with respective external chamfers 60 and 62. The chamfer 62 of jaw 32 intersects the outer longitudinal edge 58 of jaw 32 at an external corner 64.

The jaw 32 has an external notch 66 proximate the root of the jaw where it joins the body 24; Le. the notch 66 is generally at the forward end of the outer longitudinal edge 58 of jaw 32. This external notch 66 is for the purpose of reducing the rigidity of jaw 32 proximate its root so that during the crimping operation the primary bend will occur in this region.

An internal notch 68 is provided in jaw 32 facing the slot 38 between the jaws, this notch 68 being intermediate the root and free end of jaw 32. This internal notch 68 is for the purpose of providing secondary bending of the jaw 32 intermediate its ends during the crimping operation in the manner hereinafter described in detail for establishing a secondary stress area in jaw 32 which will tend to compensate for stress creep or relaxation in the region of the primary bend proximate the root of jaw 32.

The fulcrum about which the crimping force tends to bend the jaw 32 in its primary bend will be proximate the inner end 70 of the slot 38.

Referring now to FIGURES 5, 6 and 7, these figures illustrate a crimping sequence wherein the jaws 30 and 32 of one of the contact terminal members 18 are crimped about opposite sides of a conductor ribbon 14 between a pair of opposed die members 72 and 74 which are moved toward each other. With the jaws 30 and 32 constructed in the manner shown in the drawings and heretofore described in detail, the die members 72 and 74 may have fiat, generally parallel die faces which engage the respective outer edges 56 and 58 of jaws 30 and 32. While either or both of the die members 72 and 74 may be moved during the crimping operation, for the purpose of simplicity in the following explanation it will be assumed that the die member 72 is stationary and that the die member 74 is being moved downwardly toward the die member 72.

The outer longitudinal edge 56 of jaw 30 is set flat against the face of die 72, and the strip cable 12 is engaged in the slot 38 between the jaws 30 and 32, with the bared end portion of a conductor ribbon 14 registering with the jaws 30 and 32. As the upper die 74 commences to move downwardly it will first engage the outer corner 64 of jaw 32, and will bend the jaw 32 down into engagement against the conductor ribbon 14. Most of the bending will occur approximate the root of jaw 32 because of the external notch 66, and because this is the region of the greatest torque. However, because of the reduced structural rigidity of jaw 32 in the region of internal notch 68, there will be some bending proximate the internal notch 68, although this will normally be a relativly small amount of bending because of the much smaller torque at this point than that proximate the root of the jaw.

As the jaws 30 and 32 first come into gripping engage ment about the ribbon 14 as illustrated in FIGURE 6, the opposed teeth 42 and 50 will be the first to close down upon the ribbon 14. The principal reason why the opposed teeth 42 and 50 near the free ends of the jaw come together first is that the peaks of the teeth 50, 52 and 54 on jaw 32 are not aligned with one side of the general angle A defined between the jaws in the initial open position of the jaws as shown in FIGURE 5, but are arranged instead so that a line passing through the peaks of teeth 50, 52 and 54 is at a lesser angle B with respect to the peaks of the teeth 42, 44 and 46 of the other jaw 30 than the general jaw angle A. Thus, as seen in FIGURE 6, as the jaws are being brought toward the crimped position on opposite sides of the conductor ribbon 14, the rearwardmost sharp teeth 42 and 50 are the closest together and the first to engage the ribbon 14. The next pair of opposed teeth 44 and 52 are still slightly spaced when the teeth 42 and 50 engage the ribbon, and the next set of opposed teeth 46 and 54 are still further apart than the teeth 44 and 52.

An additional factor which tends to bring the opposed teeth 42 and 50 together before the other opposed pairs of teeth is the slight downward bend of the free end portion of jaw 32 from the internal notch 68.

It will be noted from FIGURE 6 and particularly FIG- URE 7 that the peaks of teeth 50, 52 and 54 on jaw 32 are offset slightly forwardly relative to the peaks of the adjacent teeth 42, 44 and 46, respectively, on jaw 30.

This results in the ribbon 14 being pinched or compressed and bent between opposed inclined surfaces of the mating teeth in the manner best shown in FIGURE 7, so that the teeth will not bite through and cause permanent damage to the ribbon 14. This is important to provide optimum electrical continuity between the ribbon and the terminal, and is also important to permit disengagement of the terminal from the ribbon and subsequent reengagement of the same or a different terminal with the same ribbon without imparied electrical continuity. Thus, the present invention provides the feature of easy removability of the contact terminal member from the strip cable conductor and subsequent replacement for repair or circuit reconstitution.

In the final phase of the crimping stroke from the position shown in FIGURE 6 to that of FIGURE 7 further movement of the tooth 50 toward the tooth 42 will tightly compress the ribbon between the opposed inclined surfaces of these two teeth, and the peak portions of these teeth will give way and bend in a longitudinal direction as required. It is preferred that the material of the teeth be somewhat softer or more malleable than the material of the conductor ribbon 14 to facilitate this longitudinal shifting of the peaks of teeth 42 and 50 relative to each other and to avoid possible galling of the conductor ribbon.

The crimping action between the position of FIGURE 6 and that of FIGURE 7 will further result in straightening out of the jaw 32 in the region of internal notch 68, which actually is a reverse bending of the jaw 32 in this region. During this reverse bending the rearward portion of jaw 32 will pivot about the point where teeth 42 and 50 grip the conductor ribbon 14. At the same time the opposed teeth 44 and 52 will grip the ribbon 14 bein time after the crimp has been applied there will be a tendency for stress creep or relaxation to occur in this region, which will tend to relax the grip of the jaws on the conductor ribbon 14. However, since the final bending in the region of internal notch 68 intermediate the ends of jaw 32 was a reverse bend straightening. this jaw out from a slightly outwardly convexed condition, an opposite stress condition will occur in this intermediate region of jaw 32 and stress creep or relaxation in this region will be such that the free end portion of jaw 32 will tend to move toward the opposed jaw 30, thus tending to compensate for the stress creep proximate the root of jaw 32. Thus, despite the occurrence of stress creep, this compensation will result in the jaws maintaining a firm mechanical and electrical engagement of the conductor ribbon 14.

In addition to this compensating stress creep in the intermediate portion of jaw 32 proximate internal notch 68, it is believed that the application of the aforesaid reverse bending which generally straightens out the jaw 32 at the final part of the crimping stroke will result in some downward biasing of the free end of jaw 32 toward jaw 30, according to the amount of resiliency of the material of the jaws. Any such biasing would operate inthe correct direction to assist in holding the opposing teeth in crimping engagement with the conductor ribbon 14. A further possible assistance in the compensation also appears to result from the fact that when the final crimping movement is applied the opposed teeth, and particularly teeth 42 and 50, are cammed so as to bend in a longitudinal direction relative to the cable and contact member, the tooth 4-2 tending a bend rearwardly or to the right in FIGURE 7, and the tooth 52 tending to bend forwardly or to the left in FIGURE 7. A similar but lesser etfect tends to occur between the opposing teeth 44 and 52 and the opposing teeth 46 and 54. Any

stress creep or relaxation occurring in the teeth will tend to move the peaks of the opposing teeth closer together, thus tending to tighten their grips on the conductor ribbon.

It will be noted that the opposed teeth 40 and 48 proximate the free ends of jaw- s 30 and 32, respectively, are rounded and do not come into gripping engagement with the conductor ribbon. These rounded teeth 40 and 48 act as a strain relief entrance for the conductor ribbon into the terminal to minimize wear of the conductor ribbon' at this point.

While the instant invention has been shown and described herein in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is therefore not to be limited to the details disclosed herein, but is to be accorded the full scope of the claims.

Having described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A terminal for a flat electrical conductor comprising a forward body having a pair of jaws extending rearwardly therefrom and adapted to receive a flat electrical conductor therebetween, a first pair of opposed internal gripping teeth generally rearwardly disposed on the jaws, and a second pair of opposed internal gripping teeth on the jaws intermediate the first teeth and the body, the jaws having a first relative position wherein they diverge rearw-ardly from the body toward their free ends for insertion of a flat electrical conductor therebetween, a second relative position wherein the jaws are partially closed and said first teeth are initially engaged against opposite sides of the fiat conductor, and a third relative position wherein said jaws are fully closed with both of said pairs of opposed teeth tightly engaged against opposite sides of the flat conductor, at least one of the jaws being bendable at a primary bend region proximate the body to allow partial closing of the jaws from their said first relative position to their said second relative position, said first opposed teeth projecting further toward each other than said second opposed teeth so that in said second relative position of the jaws with said first opposed teeth engaged against opposite sides of the flat conductor there is a clearance between said second opposed teeth that is materially greater than the thickness of the flat conductor, at least one of said jaws being bendable at a secondary bend region intermediate said first teeth and the body, whereby during the final closing movement of the jaws from said second relative position to said third relative position the engagement of said first teeth against the conductor will oppose relative closing movement between the free end portions of the jaws and closure of said second teeth against opposite sides of the conductor will result in generally oppositely directed bending movements in said primary and secondary bend regions and hence gene-rally oppositely directed stress patterns in said primary and secondary bend regions.

2. A terminal as defined in claim 1 wherein said terminal comprises a contact terminal of an electrical connector, said contact terminal having a forward contacting portion extending forwardly from said body and adapted to mate with another contact terminal.

3. A terminal as defined in claim 1 wheri-n said primary and secondary bend regions are each defined by a narrowed place in the respective jaw between its inner and outer surfaces.

4. A terminal as defined in claim -1 wherein said primary bend region is ldefi-ned by an external notch in the respective jaw proximate the body and said secondary bend region is defined by an internal notch in the respective jaw intermediate said first teeth and the body.

5. A terminal as defined in claim 4 wherein said notches are in the same jaw.

6. A terminal as defined in claim 1, wherein said 7 body andjaws are generally flat and coplanar, with the plane of the body and jaws generally perpendicular to the plane of the flat conductor that is engaged between the jaws.

7. A terminal as defined in claim 6 wherein the peaks of the opposed teeth are voifset relative to each other -in a direction .logitudinally of the jaws, the .flatconductor being gripped between opposed inclined surfaces of the opposed teeth adjacent the offset peaks of .the opposed teethand ,theflat conductor being deformed to a generally serpentine pattern in the region of the teeth.

v.8. A terminal for a vflat electrical conductor comprising a generally flat forward body having a ,pair of generally :flat jaws extending .rearwardly therefrom and ,gen-

-erally coplanar therewith, thejijaws being initially diverg- .ing and open to receive .a flat electrical conductor there- .between with the plane of the conductor generally .perpendicular to the plane of the body .and jaws, at least one of the jaws being bendable in .its plane at a primary bend region proximate the body .for closing the inner edges of the jaws against opposite sides of the conductor upon the application of crimping force to the outer edges of the jaws, the jaws having first opposed gripping teeth generally 'rear-wa-rdly disposed on their inner edges and second opposed gripping teeth on their inner edges between the first teeth and the body, said teeth being so arranged that as the jaws approach the closed position said first teeth will close against the .flatconduetor ahead of said second teeth, at least one .of the jaws being bendable in its plane at a secondary .bend region intermediate said first teeth .and the body to close said second teeth against theiiat conductor .as the jaws are moved to the .fully closed position, the peaks of the opposed teeth being oifset relative .to each other vin a :direction longi- I tudinally of the jaws, the flat conductor being gripped between opposed inclined surfaces of the opposed teeth adjacent the offset peaks of the opposed teeth with the flat conductor being deformed to a generally serpentine .pattern in the region of the teeth, and at least said first opposed teeth being deform-able in a direction longitudinally of the jaws so that said first teeth will deform longitudinally relative to the jaws as said first teeth are compressed against opposite sides of the conductor during movement of the jaws to the fully closed position in order to minimize damage to the conductor by said first teeth.

9. A terminal as defined in claim 8 wherein said primary and secondary bend regions are in the same jaw,

.said primary bend region being defined by a notch in the outer edge of that jaw and said secondary bend region bending defined by a notch in the inner edge of that jaw.

10. A terminal as defined in claim 9 wherein the teeth on said jaw having the bend regions therein are offset toward the body with respect to the opposedteeth ion the other jaw.

References Cited by the Examiner UNITED STATES PATENTS 2,962,692 '1 l/ 1960 White 339-220 2,965 6-99 12/ 1960 lBollmeier 174 84 3,140,907 7/1964 Davies 339- 17 3,156,514 11/1964 Wing et a1. 33917 PATRIC-KA. CLIFFORD, Primary Examiner.

W. DONALD MILLER, Examiner.

Claims (1)

1. A TERMINAL FOR A FLAT ELECTRICAL CONDUCTOR COMPRISING A FORWARD BODY HAVING A PAIR OF JAWS EXTENDING REARWARDLY THEREFROM AND ADAPTED TO RECEIVE A FLAT ELECTRICAL CONDUCTOR THEREBETWEEN, A FIRST PAIR OF OPPOSED INTERNAL GRIPPING TEETH GENERALLY REARWARDLY DISPOSED ON THE JAWS, AND A SECOND PAIR OF OPPOSED INTERNAL GRIPPING TEETH ON THE JAWS INTERMEDIATE THE FIRST TEETH AND THE BODY, THE JAWS HAVING A FIRST RELATIVE POSITION WHEREIN THEY DIVERGE REARWARDLY FROM THE BODY TOWARD THEIR FREE ENDS FOR INSERTION OF A FLAT ELECTRICAL CONDUCTOR THEREBETWEEN, A SECOND RELATIVE POSITION WHEREIN THE JAWS ARE PARTIALLY CLOSED AND SAID FIRST TEETH ARE INITIALLY ENGAGED AGAINST OPPOSITE SIDES OF THE FLAT CONDUCTOR, AND A THIRD RELATIVE POSITION WHEREIN SAID JAWS ARE FULLY CLOSED WITH BOTH OF SAID PAIRS OF OPPOSED TEETH TIGHTLY ENGAGED AGAINST OPPOSITE SIDES OF THE FLAT CONDUCTOR, AT LEAST ONE OF THE JAWS BEING BENDABLE AT A PRIMARY BEND REGION PROXIMATE THE BODY TO ALLOW PARTIAL CLOSING OF THE JAWS FROM THEIR SAID FIRST RELATIVE POSITION TO THEIR SAID SECOND RELATIVE POSITION, SAID FIRST OPPOSED TEETH PROJECTING FURTHER TOWARD EACH OTHER THAN SAID SECOND OPPOSED TEETH SO THAT IN SAID SECOND RELATIVE POSITION OF THE JAWS WITH SAID FIRST OPPOSED TEETH ENGAGED AGAINST OPPOSITE SIDES OF THE FLAT CONDUCTOR THERE IS A CLEARANCE BETWEEN SAID SECOND OPPOSED TEETH THAT IS MATERIALLY GREATER THAN THE THICKNESS OF THE FLAT CONDUCTOR, AT LEAST ONE OF SAID JAWS BEING BENDABLE AT A SECONDARY BEND REGION INTERMEDIATE SAID FIRST TEETH AND THE BODY, WHEREBY DURING THE FINAL CLOSING MOVEMENT OF THE JAWS FROM SAID SECOND RELATIVE POSITION TO SAID THIRD RELATIVE POSITION THE ENGAGEMENT OF SAID FIRST TEETH AGAINST THE CONDUCTOR WILL OPPOSE RELATIVE CLOSING MOVEMENT BETWEEN THE FREE END PORTIONS OF THE JAWS AND CLOSURE OF SAID SECOND TEETH AGAINST OPPOSITE SIDES OF THE CONDUCTOR WILL RESULT IN GENERALLY OPPOSITELY DIRECTED BENDING MOVEMENTS IN SAID PRIMARY AND SECONDARY BEND REGIONS AND HENCE GENERALLY OPPOSITELY DIRECTED STRESS PATTERNS IN SAID PRIMARY AND SECONDARY BEND REGIONS.

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