# Patent

## Title
Terminal fitting

## Abstract

A terminal fitting (10) includes a tubular connecting portion (11) and a resilient contact (14) in the form of a plate that is deflectably arranged in the connecting portion (11) and that resiliently contacts a male tab (90) inserted into the connecting portion (11). A contact (35) is provided in a range from a contact start position (37) with the male tab (90) to a contact end position (38) inside the resilient contact (14) in a plate width direction. Curved portions (31) recessed toward a center in the plate width direction are provided on outer edges of the resilient contact (14) in the plate width direction. Parts of the curved portions (31) most recessed toward the center in the plate width direction are arranged to face the contact start position (37) of the contact (35) in the plate width direction.

## Background
BACKGROUND
1. Field of the Invention
The invention relates to a terminal fitting.
2. Description of the Related Art
U.S. Pat. No. 6,171,155 discloses a terminal fitting that has a tubular connecting portion with a front end. A plate-shaped resiliently deflectable contact is formed separately from the connecting portion and extends in a front-back direction in the connecting portion. A tab of a mating male terminal fitting is inserted into the connecting portion from the front and contacts the resilient contact to connect the terminal fittings electrically.
The resilient contact is formed into an angled shape having an apex in a central part in a front-back direction. The apex of the resilient contact serves as a contact portion with the male tab. A front half of the resilient contact is provided at a front side of the apex and a rear half thereof is provided at a rear side of the apex. Two cuts are provided on opposite left and right edges of each of the front and rear halves of the resilient contact. Each cut is recessed in a curved manner toward a widthwise center of the resilient contact.
The apex of the above-described resilient contact is not arranged at a position corresponding to the cuts and a part corresponding to the apex has a maximum width of the resilient contact portion. As a result, resistance generated when the male tab contacts the apex is high and an inserting force may be increased. Thus, insertion feeling of the male tab is not good.
The invention was completed based on the above situation and aims to further improve insertion feeling of a male tab.
SUMMARY OF THE INVENTION
The invention is directed to a terminal fitting, including a tubular connecting portion into which a mating male tab is to be inserted. A resilient contact portion in the form of a deflectable plate piece is arranged in the connecting portion and resiliently contacts the male tab inserted into the connecting portion. A contact is provided in a range from a contact start position with the male tab to a contact end position inside the resilient contact portion in a plate width direction. A curved portion is provided on an outer edge of the resilient contact portion in the plate width direction and is recessed toward a center in the plate width direction. A part of the curved portion most recessed toward the center in the plate width direction is arranged to face the contact start position of the contact in the plate width direction.
The part of the resilient contact corresponding to the contact start position of the contact is narrowed by the curved portion. Thus, an inserting force of the male tab can be significantly reduced when the male tab inserted into the connecting portion contacts the contact start position of the contact. As a result, insertion feeling of the male tab can be improved.
The curved portion is disposed so as not to face the contact end position of the contact in the plate width direction. Thus, the male tab is held in contact with the contact portion with good contact pressure at the contact end position.
The resilient contact preferably is provided separately from the connecting portion, and extends in a front-back direction. The resilient contact includes a contact main body with a support as a deflection supporting point of the resilient contact on a rear end part, and the contact is located before the supporting point. Two receiving portions are arranged on opposite sides of the contact main body in the plate width direction and are fixed by caulking to the connecting portion. The contact main body is narrowed from a part on the contact end position of the contact toward the supporting point and is coupled integrally to the receiving portions on a side behind the supporting point. The receiving portions extend forward from coupled positions to the contact main body, thereby forming slits between the contact main body and the receiving portions. The contact main body is narrower at the supporting point than in the part on the contact end position of the contact. Thus, the inserting force of the male tab is reduced further and insertion feeling is improved. Further, wider of the receiving portions can be ensured by as much as the width of the supporting point is reduced, and hence space efficiency is improved. Additionally, the resilient contact portion is fixed stably to the connecting portion via the receiving portions.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a terminal fitting of one embodiment of the present invention.
FIG. 2 is a plan view of the terminal fitting.
FIG. 3 is a bottom view of the terminal fitting.
FIG. 4 is a front view of the terminal fitting.
FIG. 5 is a plan view in section showing the interior of a connecting portion.
FIG. 6 is a section along A-A of FIG. 5.
FIG. 7 is a side view in section showing the interior of the connecting portion.
FIG. 8 is a front view in section showing the interior of the connecting portion.
FIG. 9 is a side view of a resilient contact portion.
FIG. 10 is a front view of the resilient contact portion.
FIG. 11 is a plan view of the resilient contact portion.
FIG. 12 is a section of a part of the resilient contact portion corresponding to both receiving portions.
FIG. 13 is a side view partly in section of the terminal fitting inserted into a cavity of a connector housing.
FIG. 14 is a side view partly in section of the terminal fitting in which a mating male tab is inserted in the connecting portion.
FIG. 15 is a side view partly in section of the terminal fitting in which the male tab is properly inserted in the connecting portion.
FIG. 16 is a development of the terminal fitting.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
One embodiment of the invention is described with reference to FIGS. 1 to 16. A terminal fitting 10 of this embodiment is made of an electrically conductive metal plate material and is long and is narrow in a front-back direction. As shown in FIG. 13, the terminal fitting 10 is inserted into a cavity 61 of a connector housing 60 and is connected electrically to a male tab 90 of a mating connector, as shown in FIG. 15, as the housing 60 is connected to an unillustrated housing of the mating connector.
The terminal fitting 10 is shown in FIGS. 1 to 3 and includes a tubular connecting portion 11, a wire barrel 12 behind the connecting portion 11 and an insulation barrel 13 behind the wire barrel 12. A resilient contact 14 in the form of a plate is provided separately from the connecting portion 11 and is arranged in the connecting portion 11. The resilient contact 14 is made of copper alloy with high springiness and is formed of a material different from the connecting portion 11, which is made of brass.
As shown in FIG. 13, the wire barrel 12 is crimped and connected to a core 82 exposed by removing insulation coating 81 at an end of a wire 80 and the insulation barrel 13 is crimped and connected to the insulation coating 81 at the end part of the wire 80.
The connecting portion 11 is a long narrow rectangular tube extending in the front-back direction and includes, as shown in FIG. 4, a base wall 15 extending along a width direction, two side walls 16 erected from opposite sides of the base wall 15 and a facing wall 17 extending between upper ends of the side walls 16. As shown in FIG. 3, the base wall 15 extends over the entire length of the terminal fitting 10 and also defines bottom parts of the wire barrel 12 and the insulation barrel 13. A rectangular lance hole 18 is formed in the base wall 15 between the connecting portion 11 and the wire barrel 12. As shown in FIG. 13, when the terminal fitting 10 is inserted properly into the cavity 61, a tip of a locking lance 62 projecting from the inner wall of the cavity 61 is fit resiliently into the lance hole 18 of the base wall 15 and retains the terminal fitting 10 in the cavity 61.
As shown in FIG. 7, an excessive deflection preventing portion 19 projects into the connecting portion 11 on a part of the base wall 15 facing the resilient contact 14. As shown in FIG. 8, the excessive deflection preventing portion 19 is a rib extending along the width direction and formed by striking the base wall 15 up. The resilient contact 14 contacts the excessive deflection preventing portion 19 to prevent excessive deflection and deformation. Further, as shown in FIGS. 3 and 5, a projecting piece 21 projects forward in a widthwise central part of the front end of the base wall 15. The front end of the projecting piece 21 is at substantially the same position as the front ends of the side walls 16 and the facing wall 17.
As shown in FIG. 8, the facing wall 17 is composed of a lower wall 17A extending from the upper end of one side wall 16 to a locked engagement with an upper part of the other side wall 16 and an upper wall 17B extending from the upper end of the other side wall 16 toward the upper end of the one side wall 16 while being placed on the upper surface of the lower wall 17A. As shown in FIG. 7, the lower wall 17A is formed with a tab receiving portion 22 that projects into the connecting portion 11 at a position facing the resilient contact 14. The tab receiving portion 22 is a rib extending in the front-back direction and formed by striking the lower wall 17A down.
As shown in FIGS. 1 and 8, confirmation windows 23 are formed on lower parts of the side walls 16 and receive confirmation pieces 34 of the resilient contact 14. The confirmation windows 23 are open from the side walls 16 to the base wall 15 and the confirmation pieces 34 can be confirmed visually from lateral and lower sides through the confirmation windows 23 as shown in FIGS. 1 and 3.
As shown in FIGS. 1 and 5, locks 24 are provided on the lower parts of the side walls 16 behind the confirmation windows 23. The locks 24 are cut and erected from holes 25 that are open from the side walls 16 to the base wall 15 and are bent and deformed into the interior of the connecting portion 11 to be placed in close contact with receiving portions 41 of the resilient contact 14 from above. Specifically, as shown in FIG. 16, in a development state, each lock 24 is cantilevered laterally out from a base end 24A to a tip 24B. The base end 24A is on the base wall 15 and the tip 24B is on the side wall 16. As shown in FIG. 6, in a bent state, the locks 24 are folded toward the base wall 15B and the receiving portions 41 of the resilient contact 14 are sandwiched vertically (thickness direction of the resilient contact 14) between the tips 24B and the base wall 15. Further, the locks 24 are arranged so that the upper surfaces are lowered from the upper surface of the base wall 15 at the base ends 24A (see FIG. 16), and have a smaller thickness than other parts of the connecting portion 11 including the base wall 15.
The resilient contact 14 includes a contact main body 26 extending in the front-back direction and having an angled side view bent at an intermediate position in the extending direction, as shown in FIG. 9. The contact main body 26 includes an apex 27, a front portion 28 inclined down to the front from the apex 27 and a rear portion 29 inclined down to the back from the apex 27. When the resilient contact 14 is mounted in the connecting portion 11, the apex 27 is closest to the tab receiving portion 22 to form an insertion space 30 for the male tab 89 between the apex 27 and the tab receiving portion 22, as shown in FIG. 7. Additionally, the front end of the front portion 28 is in contact with the projecting piece 21 of the base wall 15 and the rear end of the rear portion 29 is arranged in contact with a position of the base wall 15 before the lance hole 18, as shown in FIG. 5.
As shown in FIG. 11, two arcuate curved portions 31 are recessed toward the widthwise center of the contact main body 26 at opposite lateral edges of the front portion 28 in the plate width direction so that the contact main body 26 is constricted toward a widthwise center of the contact main body 26 in a plan view. The front end of the front portion 28 is widened before the curved portions 31 and includes a contact piece 32 projecting forward in a widthwise central part. The contact piece 32 is slidable on the projecting piece 21 of the base wall 15 (see FIG. 5) while being held in contact with the projecting piece 21. Further, the upper surface of the contact piece 32 is pressed to thin the contact piece 32. Two cuts 33 are formed on opposite widthwise sides of the contact piece 32 on the front end of the front portion 28.
As shown in FIG. 11, the apex 27 of the contact main body 26 is wider than the front and rear portions 28 and 29, and confirmation pieces 34 are project toward opposite widthwise outer sides. Each confirmation piece 34 has a substantially rectangular plan view, and is in one of the confirmation windows 23 for visual confirmation when the resilient contact 14 is mounted in the connecting portion 11. The confirmation pieces 34 are in a lifted state without being held in contact with the opening edges of the confirmation windows 23, as shown in FIG. 1.
A widthwise central part of the apex 27 of the contact main body 26 is struck up to form an embossed contact 35, as shown in FIGS. 9 and 10. The embossed contact 35 extends from the apex 27 to the front portion 28 and has a gradually reduced width from the rear of the apex 27 toward the front portion 28, as shown in FIG. 11. A straight edge 36 having a straight side view is formed on the upper surface of the embossed contact 35, as shown in FIG. 9, and has substantially the same angle of inclination as the front portion 28.
A contact start position 37 is at the front of the straight edge 36 of the embossed contact 35 (see FIG. 14) and makes the first contact with the male tab 90 inserted into the connecting portion 11. A contact end position 38 is on a rear part of the straight edge 36 of the embossed contact 35 and contacts the male tab 90 that has been inserted completely into the connecting portion 11 (see FIG. 15). As shown in FIG. 11, the contact start position 37 of the embossed contact 35 is side by side with most recessed parts 39 of the curved portions 31 and hence is at the narrowest part of the front portion 28 of the contact main body 26. The contact end position 38 of the embossed contact 35 is behind the rear ends of the curved portions 31 and is arranged coaxially side by side with the confirmation pieces 34 in the width direction. Further, as shown in FIG. 7, the contact end position 38 is the uppermost part of the embossed contact 35 and is closest to the tab receiving portion 22 when the resilient contact 14 is mounted in the connecting portion 11.
As shown in FIG. 11, the rear portion 29 of the contact 26 gradually narrows from the apex 27 toward the back and is unitary with the receiving portions 41 on a rear part thereof. The receiving portions 41 protrude laterally out from opposite lateral edges of the rear end of the rear portion 29 so that the receiving portions 41 are at opposite widthwise sides of the rear portion 29 of the contact main body 26. Further, a support 42 extends along the width direction at a position immediately before a part of the rear portion 29 of the contact main body 26 coupled to the receiving portions 41. The resilient contact portion 14 is vertically resiliently deflectable with the supporting 42 as a fixed end.
The receiving portions 41 protrude laterally from the rear portion 29 of the contact main body 26 and then project forward, as shown in FIG. 11. Forwardly open slits 43 are formed between the opposite lateral edges of the contact main body 26 and the forward projecting parts of the receiving portions 41. The slits 43 extend obliquely out and forward in the front-back direction and are spaced farther from each other toward the front. Rear ends of the slits 43 are at substantially the same position as the support 42 in the front-back direction. In other words, the support 42 is arranged substantially on a straight line connecting rear ends of the slits 43.
The receiving portions 41 gradually widened from the front ends toward the back in reverse proportion to the rear portion 29 of the contact main body 26 gradually narrowing toward the back. As shown in FIGS. 11 and 12, a crimping surface 44 is formed on the upper surface of each receiving portion 41 and is held by one of the locks 24. The crimping surfaces 44 are lowered slightly from the upper surfaces of opposite front and rear sides of the receiving portions 41 by a press. Thus, the receiving portions 41 are thinned at the crimping surfaces 44. Further, as shown in FIG. 11, the crimping surfaces 44 extend farther back than the slits 43 while facing the slits 43 at inner sides and intersect with opposite widthwise ends of the support 42 at an intermediate position in the front-back direction. As shown in FIG. 6, the locks 24 closely contact the crimping surfaces 44 of the receiving portions 41, so that the receiving portions 41 are fixed by caulking to the connecting portion 11 and are sandwiched between the locks 24 and the base wall 15.
Outer lateral edges of the receiving portions 41 corresponding to the crimping surfaces 44 are recessed to form cuts 46, as shown in FIG. 11. The base end portions 24A of the locks 24 fit in the cuts 46 when the receiving portions 41 are fixed by caulking by the locks 24, thereby fixing the locks 24 in the front-back direction.
The resilient contact 14 is placed on the base wall 15 of the connecting portion 11 in a development state (see FIG. 16). More particularly, the locks 24 are placed in close contact with the crimping surfaces 44 of the receiving portions 41 of the resilient contact 14 by a press. As a result, the receiving portions 41 are fixed by caulking and are sandwiched between the locks 24 and the base wall 15 (see FIGS. 5 and 6). The slits 43 are between the receiving portions 41 and the contact main body 26. Additionally, the receiving portions 41 and the locks 24 are thinned. Thus, a caulking force received from the locks 24 by the receiving portions 41 does not affect the support 42 significantly and the support 42 does not deform.
Subsequently, in the development state, parts of the base wall 15 protruding toward opposite widthwise outer sides are successively bent to define the side walls 16 and the facing wall 17 and to form the connecting portion 11. Then, as shown in FIG. 13, the terminal fitting 10 is inserted into the cavity 61 of the connector housing 60 in a state connected to the end part of the wire 80, and held and retained by the locking lance 62.
The housing 60 is connected to the unillustrated mating housing so that the mating male tab 90 is inserted into the connecting portion 11 of the terminal fitting 10 from the front. As shown in FIG. 14, the male tab 90 first contacts the connection start position 37 of the embossed contact 35 and the contact main body 26 accordingly is deflected and deformed about the support 42. The embossed contact 35 is displaced down as the contact main body 26 is deflected and the contact piece 32 slides forward on the projecting piece 21. The support 42 is located behind the front ends of the receiving portions 41 and the entire longitudinal length of the contact main body 26 is ensured to be sufficiently long so that the contact main body 26 exhibits satisfactory springiness. Further, the part of the contact main body 26 corresponding to the connection start position 37 of the contact portion 35 is narrowed by the curved portions 31. Thus, resistance received by the male tab 90 at the connection start position 37 is reduced and insertion feeling is improved.
The male tab 90 is inserted to a proper depth in the connecting portion 11 when the housing 60 is connected properly to the mating housing. Thus, the male tab 90 is sandwiched resiliently between the connection end position 38 of the embossed contact 35 and the tab receiving portion 22, as shown in FIG. 15. The connection end position 38 of the embossed contact 35 at the apex 27 of the contact main body 26 is widened due to the protruding confirmation pieces 34. Therefore, the male tab 90 contacts the embossed contact 35 with proper contact pressure at the connection end position 38.
The connection start position 37 of the embossed contact 35 is aligned with the most recessed parts 39 of the curved portions 31. Thus, an inserting force of the male tab 90 is reduced significantly and insertion feeling is improved. On the other hand, the connection end position 38 of the embossed contact 35 is not aligned with the curved portions 31 and good contact pressure of the male tab 90 is ensured when connection is complete.
The rear portion 29 of the contact main body 26 gradually narrows toward the back and the support 42 is at the narrowest part. Thus, the insertion force of the male tab 90 is reduced and the insertion feeling is improved. Furthermore, the gradually narrowing of the rear portion 29 of the contact main body 26 toward the back forms empty spaces at opposite widthwise sides of the rear part of the rear portion 29 and the receiving portions 41 are arranged in these empty spaces. Therefore space efficiency is improved. Further, the widths of the rear ends of the receiving portions 41 can be increased in accordance with the narrow support 42 so that large crimping surfaces 44 to be locked by the locks 24 can be ensured. As a result, the resilient contact portion 14 is fixed stably to the connecting portion 11 via the receiving portions 41.
The support 42 is behind the front ends of the receiving portions 41 and the locks 24 are arranged within the range of the longitudinal length of a spring area of the resilient contact 14. Thus, the spring area of the resilient contact portion 14 is sufficiently long. As a result, the resilient contact 14 exhibits satisfactory springiness even if the connecting portion 11 is shortened with the miniaturization of the terminal fitting 10.
The support 42 is between the rear ends of the slits 43 on the rear part of the contact main body 26. Thus, the length of the spring area of the contact main body 26 is ensured to be even longer by the depth of the slits 43 and the springiness of the resilient contact portion 14 is improved further.
The receiving portions 41 are thinner than the other parts of the resilient contact 14. Thus, a caulking force exerted by the locks 24 on the receiving portions 41 is less likely to be transmitted to the supports 42 and the support 42 will not deform. As a result, the contact main body 26 deforms smoothly.
The confirmation windows 23 of the connecting portion 11 enable visual confirmation the confirmation pieces 34 of the resilient contact 14 from lateral and lower sides to confirm proper positioning of the resilient contact 14 in the connecting portion 11.
The invention is not limited to the above described and embodiment. For example, the following modes also are included in the scope of the invention.
The curved portion may be formed only on one lateral edge of the contact main body.
The contact start position of the contact need not be strictly arranged coaxially side by side with the most recessed parts of the curved portions in the width direction and has only to be arranged at a position substantially facing the most recessed parts of the curved portions in the width direction.
One lock may be provided on the connecting portion and only one receiving portion may be provided on the resilient contact.
The supporting point may be arranged behind the rear ends of the entire receiving portions.
The confirmation pieces may be configured to contact the opening edges of the confirmation windows in a state where the resilient contact is at least either in a natural state or in a deflected state.
The insulation barrel may be crimped and connected to a rubber plug mounted on the insulation coating of the end part of the wire.

## Claims

1. A terminal fitting, comprising:
a tubular connecting portion into which a mating male tab is to be inserted; and a resilient contact in the form of a plate being arranged deflectably in the connecting portion and resiliently contacting the male tab inserted into the connecting portion, the resilient contact including a contact portion provided in a range from a contact start position with the male tab to a contact end position inside the tubular connecting portion, at least one curved portion provided on an outer edge of the resilient contact in a plate width direction and being recessed toward a center in the plate width direction, a part of the curved portion most recessed toward the center in the plate width direction being arranged to face the contact start position of the contact portion in the plate width direction, two receiving portions arranged on opposite sides of the contact main body in the plate width direction and being fixed by caulking to the connecting portion, the contact main body being narrowed from a part on the contact end position of the contact portion toward the support and integrally coupled to the receiving portions at positions behind the support, and the two receiving portions extending forward from coupled positions to the contact main body, thereby forming slits between the contact main body and the receiving portions.

2. The terminal fitting of claim 1, wherein the curved portion is disposed so as not to face the contact end position of the contact portion in the plate width direction.

3. The terminal fitting of claim 1, wherein the resilient contact is provided separately from the connecting portion and extends in a front-back direction, the resilient contact includes a contact main body with a support on a rear end part and defining a deflection support for the resilient contact, the contact portion being located before the support.

4. The terminal fitting of claim 1, wherein the receiving portions are thinner than other parts of the resilient contact.

5. The terminal fitting of claim 1, wherein the at least one curved portion comprises two curved portions disposed symmetrically on opposite sides of the resilient contact.

6. The terminal fitting of claim 1, wherein the resilient contact defines a maximum width at the contact end position.