(19)
(11) EP 1 073 145 A1

(12) EUROPEAN PATENT APPLICATION
published in accordance with Art. 158(3) EPC

(43) Date of publication:
31.01.2001 Bulletin 2001/05

(21) Application number: 99913640.1

(22) Date of filing: 12.04.1999
(51) International Patent Classification (IPC)7H01R 4/24
(86) International application number:
PCT/JP9901/949
(87) International publication number:
WO 9953/570 (21.10.1999 Gazette 1999/42)
(84) Designated Contracting States:
DE FR

(30) Priority: 14.04.1998 JP 10260398

(71) Applicant: Mirai Kogyo Kabushiki Kaisha
Anpachi-gun, Gifu 503-0201 (JP)

(72) Inventors:
  • KAWAMURA, Hirokazu, Mirai Kogyo, Co.
    Anpachi-gun, Gifu 503-0201 (JP)
  • SAKAI, Akihiro, Mirai Kogyo, Co.
    Anpachi-gun, Gifu 503-0201 (JP)

(74) Representative: Hamilton, Alistair 
Castles, 17 Lansdowne Road
Croydon CR0 2BX
Croydon CR0 2BX (GB)

   


(54) TERMINAL FITTING


(57) A terminal fitting for holding insulated wire and connecting it electrically with an object of connection easily and reliably without the need for a process of wire stripping. The terminal fitting is formed integrally of a conductive, metallic material, and has a terminal piece (10) to be connected electrically with an object of connection. Insulated wire (D) is pinched by plastic deformation of the metallic material to remove the coating from the insulated wire (D), and the exposed part of the wire is connected electrically.




Description

Background of the Invention


Technical Field:



[0001] This invention generally relates to an electric terminal fitting which provides electrical connection between an insulated electric wire and an electrical abject.

Background Art:



[0002] Various types of conventional electric terminal fittings for providing electrical connection between electrical objects and insulated electric wires exist, among which an electric terminal fitting 200 consisting of a cylindrical body 201 and an electric terminal as shown in Fig. 13 is widely utilized.

[0003] As is well known in the pertinent art, the coating or covering of a coated or insulated electric wire is first partially removed or stripped of its covering from an end portion of the electric wire such that a length of its conductive core wire is exposed at the end portion of the electric wire. Next the exposed core wire portion is inserted into the cylindrical body 201 of the electric terminal, fitting 200. Then the cylindrical body 201 is pinched with appropriate pinching means such that the cylindrical body 201 is deformed and the inserted core wire reliably contacts and is held by the cylindrical body 201 internally.

[0004] As is known to any electrician, it is often burdensome for electricians to use such electric terminal fittings 200 for it is required of them to adequately strip coverings from insulated electric wires one by one. Often the amount of removal of covering from an electric wire is insufficient or excessive, requiring additional removal work or leaving a short conductive core wire portion exposed outside the cylindrical body 201 of the terminal fitting 200.

[0005] Sometimes the deformation of the cylindrical body 201 is inadequate, possibly causing accidental slipping off of the electric wire from the cylindrical body 201 in use later.

[0006] An electric terminal fitting which eliminates separate covering stripping work has been proposed, shown in Fig. 14 (JP Patent Laid-Open Publication No. 54-39894), which is intended to provide electrical connection between two insulated electric wires.

[0007] This electric terminal fitting 300 made of a plastic material comprises a housing 304 provided with two wire receptacle grooves 301 formed side by side in a base 303 which respectively receive two insulated electric wires to be electrically interconnected (not shown). The fitting 300 further includes a conductive metal plate 302 having two open slots, which is mounted on these receptacle grooves 301 as shown in Fig. 14. Here and in the descriptions that follow, the term "open slot" signifies "slot whose one end is open". The cover grooves 304 separately formed are each provided with a socket groove having a wire press protrusion. Each cover groove 304 partially receives the metal plate 302 when pressed hard onto the corresponding receptacle groove 301 against the metal plate 302, and presses the electric wire laid along that receptacle groove 301 into the corresponding open slot.

[0008] The coverings of the insulated electric wires which contact the slots are peeled or stripped as the electric wires are forcedly pressed down through the slots whose gaps are substantially narrower than the diameters of the insulated electric wires. Those two electric wires are thus electrically connected via the conductive metal plate 302 that physically contacts the exposed core wires (not shown) of the electric wires.

[0009] The terminal fitting 300 is rather complicated in design, requiring considerable manufacturing cost and time for assembly, which is a great disadvantage with such an "adjunctive" type article. In addition, the cover grooves 304 may accidentally come off the receptacle grooves 301 in use.

[0010] Accordingly, it is an object of the present invention to provide an electric terminal fitting that eliminates preliminary wire covering removal work.

[0011] It is another object of the present invention to provide an electric terminal fitting that can easily as well as reliably and safely provide electrical connection between an insulated electric wire and an electrical object.

[0012] It is another object of the present invention to provide an electric terminal fitting that can be easily and commercially feasibly manufactured from a single conductive metal sheet piece.

[0013] Other objects of the present invention will become apparent from the following descriptions.

Summary of the Invention



[0014] An electric terminal, fitting according to the present invention is formed three-dimensionally in one piece from a single conductive metal sheet piece, greatly contributing in reducing manufacturing time and cost. The electric terminal, fitting of the present invention is provided with wire covering stripping means and electric terminal means, the former providing covering removal of an insulated electric wire and the latter providing electrical connection with an external electrical object.

[0015] Stripping of the covering of an insulated electric wire is physically provided by pressing the electric wire against the stripping means with pinching means, which is done by plastically deforming a portion of the terminal fitting. An exposed core wire portion of the electric wire physically contacts the conductive terminal fitting at the conductive stripping means, and the electric wire and the electrical object which is connected to the electric terminal means are electrically interconnected. The physical contact between the exposed core wire and the stripping means is reliably retained.

Brief Description of the Drawings



[0016] 

FIG.1 is a perspective view showing an electric terminal fitting according to a first embodiment of the present invention.

FIG.2 is a side view of the terminal fitting of Fig. 1 in use, a pinching device partially shown in broken lines.

FIG.3(a) is a rear view of the terminal fitting of Fig. 1 with an insulated wire received therein, and FIG.3(b) is a front view of the terminal fitting showing a pinched state.

FIG.4 is a perspective view showing another electric terminal fitting according to a second embodiment of the present invention.

FIG.5 is a side view of the terminal fitting of Fig. 4 in use.

FIG.6 is a perspective view showing another electric terminal fitting according to a third embodiment of the present invention.

FIG.7 is a side view of the terminal fitting of Fig. 6 in use.

FIG.8 is a perspective view showing another electric terminal fitting according to a fourth embodiment of the present invention.

FIG.9 is a side view of the terminal fitting of Fig. 8 in use, a pinching device partially shown in broken lines.

FIG.10 is a side view of the terminal fitting of Fig.8 with an insulated wire received therein, the terminal fitting pinched with the pinching device.

FIG.11 shows an alternative stripping slot according to an embodiment of the present invention.

FIG.12 shows another stripping slot according to another embodiment of the present invention.

FIG.13 shows a conventional electric terminal fitting.

FIG.14 shows another conventional electric terminal fitting.


Best Mode to Carry Out the Invention



[0017] The present invention is described in detail hereunder, first in connection with a first embodiment of the present invention depicted in Figs.1-3.

[0018] The electric terminal fitting 100 shown in Fig. 1 is made of a single metal sheet piece cut out from a larger conductive metal sheet. The terminal fitting 100 is provided with an electric terminal 10 and pinching means comprising paired pinching members 20a and 20b.

[0019] The electric terminal 10 is provided with a circular opening 11 to be used for electrically connecting an external electric object (not shown) therewith.

[0020] The lower pinching member 20a is formed by bending a middle portion of the metal piece in a deep U shape to receive the upper pinching member 20b within the U depression provided between two walls. Here and in the descriptions that follow, the expressions "upper" and "lower" are used just to help illustrate the features of the present invention as depicted in the accompanying drawings.

[0021] The pinching member 20a is provided with two open slots, a wire support slot 22a and a stripping slot 23, respectively provided on the dual walls of the pinching member 20a as shown in Fig.1, both of which open toward the pinching member 20b. The wire support slot 22a receives and supports an electric wire and is provided wider than the stripping slot 23 in this embodiment. The pinching member 20b is provided with a press depression or slot 24 which opens toward the pinching member 20a. The press depression or slot 24 is generally formed wider than the slots 22a and 23. The stripping slot 23 is provided with stripping corners 21 at its open mouth that will, strip an insulated electric wire "crosswise" or "across" as will be easily appreciated by a person skilled in the art. The stripping corners 21 also assist in introducing the electric wire placed thereon into the stripping slot 23. The press slot 24 is provided with a press end which presses an electric wire deep into the stripping slot 23.

[0022] The pinching members 20a and 20b are integrally connected through a bent portion 30, which is to be further bent to press the electric wire into the stripping slot 23. In this terminal fitting 100, the electric terminal 10 is provided on an end of the metal piece and the upper pinching member 20b is provided on the other end of the metal piece, with the lower pinching member 20a provided therebetween.

[0023] The bent portion 30 is formed with two parallel bent strips having a void 31b therethrough. An end portion of an insulated electric wire D is inserted through the void 31b to be laid on the stripping corners 21, which is pressed with the press end of the press slot 24 into the stripping slot 23 forcedly as the stripping members 20a and 20b are pinched with a pinching device 51 toward each other as depicted in Fig.2. The electric wire D is stripped crosswise or across of its covering as the distance between the stripping corners 21 (and the width of the stripping slot 23) are substantially smaller than the diameter of the insulated electric wire D. When the stripping of the covering by the stripping corners 21 alone is not sufficient, the edges of the stripping slot 23 will adequately complete the stripping. An exposed core wire portion of the electric wire D (not shown) reliably contacts the edges of the conductive stripping slot 23 and provides electrical connection therewith.

[0024] There is no need to preliminarily remove the covering from the electric wire D in a separate operation. What is required is simply mount an end portion of an insulated electric wire D on the mouths of the stripping slot 23 and the wire support slot 22a through the void 31b and pinch the terminal fitting 100 by the pinching members 20a and 20b with a pinching device 51 as shown in Fig.2 so that the pinching members 20a and 20b come closer toward each other, forcibly pushing down the electric wire D along the slot 23 as shown in Figs.3(a)and 3(b) as the pinching member 20b enters deep into the U depression of the pinching member 20a.

[0025] The electric wire D stripped across of its covering within the stripping slot 23 will be firmly held in the slot 23 as shown in Fig.3(b) since the deformed peeled portion of the covering of the electric wire D will reliably prevent slipping out of the electric wire D from the slot 23. The pinching members 20a and 20b will remain engaged.

[0026] Another terminal fitting according to a second embodiment is described hereunder utilizing Figs.4 and 5.

[0027] This terminal fitting 100 is somehow simpler in structure than the terminal fitting of the first embodiment. Its upper pinching member 20b is provided directly from its electric terminal 10, its lower pinching member 20a with a U-shape depression being provided at an end portion of a conductive metal piece. The bending or deformation of this terminal fitting 100 is provided through changing the "angle" of the upper pinching member 20b.

[0028] The pinching member 20b is located at a portion of the electric terminal 10 as shown in Fig.4, having a press slot 24 as indicated with a broken line which is used to press an insulated electric wire D laid on the pinching slot 23 and the support slot 22a into the pinching slot 23 and the support slot 22a.

[0029] The stripping slot 23 of the pinching member 20a is provided with stripping corners 21 as described in connection with the first embodiment.

[0030] An end portion of an electric wire D is placed between the upper and lower pinching members 20b and 20a and on the stripping slot 23 as shown in Fig. 5. The stripping member 20b is pressed onto the electric wire D and pushes the electric wire D into the slot 23 as the stripping member 20b is pressed into the U-shape depression of the stripping member 20a, when the electric wire D is stripped crosswise of its covering as described in connection with the first embodiment. The stripped wire D will be firmly retained in the slot 23, providing stable electrical connection with the terminal fitting 100 by securely contacting therewith at its conductive core wire (not shown). As with the first embodiment, there is no need to separately remove the covering of the electric wire D in an extra step.

[0031] Figs. 6 and 7 show an electric terminal fitting according to a third embodiment of the present invention.

[0032] This terminal fitting 100 is provided having an electric terminal 10, paired pinching members 20a and 20b and a bent portion 30 connecting the pinching members 20a and 20b.

[0033] The pinching member 20a with a U-shape depression is provided on an end portion of a conductive metal piece and the electric terminal 10 is provided on the opposite end of the metal piece with the pinching member 20b and the bent portion 30 provided inbetween.

[0034] The bent portion 30 is provided by two parallel strips as in the first embodiment giving a void 31b therethrough.

[0035] A wire support slot 22a, a stripping slot 23 and a press slot 24 having a press end as well as stripping corners 21 are provided as set forth earlier in connection with the foregoing embodiments.

[0036] An insulated electric wire D is inserted through the void 31b between the pinching members 20a and 20b onto the stripping slot 23 and the support slot 22a to be pressed with the press end of the press slot 24 into the stripping slot 23 as shown in Fig. 7 as the pinching member 20b enters the U-shape depression of the pinching member 20a. The insulated electric wire D is stripped across.

[0037] The terminal 10 is provided with a partially circular part which is used to electrically connect with an external electrical object (not shown).

[0038] The electric wire D stripped crosswise of its covering is securely held within the stripping slot 23, providing electrical connection between its exposed core wire and the conductive edges of the stripping slot 23 as explained earlier in connection with the previous embodiments.

[0039] Another terminal fitting prepared according to a fourth embodiment of the present invention is described hereunder in connection with Figs.8-10.

[0040] As shown in Fig.8 this terminal fitting 100 is the most complicated among the four embodiments of the present invention illustrated herein, and substantially differs in structure from the previous three embodiments. However, this terminal fitting 100 is also prepared from a single conductive metal sheet piece as the foregoing embodiments, having common features.

[0041] This terminal fitting 100 includes an annular electric terminal 10 having a circular opening 11 to be used for electrically connecting with an electrical object (not shown), a lower dual protrusion 20a, another lower dual protrusion 20b, an upper dual protrusion 20c, a hook protrusion 42, and a bent portion 30 consisting of two parallel bar members.

[0042] The dual protrusion 20a is provided with an open stripping slot 21a and stripping edges 23a. The dual protrusion 20b is provided with an open stripping slot 21b and stripping edges 23b. The dual protrusion 20c is also provided with an open stripping slot 21c and stripping edges 23c.

[0043] The terminal, fitting 100 further includes a rectangular opening 41 which is provided in the terminal 10 and receives the hook protrusion 42 therethrough. The rectangular opening 41 and the hook protrusion 42 together provide deformation retaining means. Between the dual protrusion 20a and the dual protrusion 20b is provided a bottom opening 40c which receives an end portion of the upper dual protrusion 20c. End portions of the dual protrusion 20a and the dual protrusion 20b are respectively received in an upper opening 40a and another upper opening 40b provided in front and rear of the upper dual protrusion 20c. The terminal fitting 100 further includes a wire void 31b formed between and through the parallel bar members of the bent portion 30 to receive an end portion of an insulated electric wire.

[0044] This electric terminal fitting 100 is used to strip covering of an insulated electric wire at three places, namely in the slots 21a, 21b and 21c, and can provide highly reliable and stable electrical connection between the electric wire and the terminal fitting 100 or the terminal 10. The electric wire can be held very securely by the terminal fitting 100 as the wire is held firmly at three places.

[0045] This electric terminal fitting 100 is utilized in the following manners and provides electrical connection between an insulated electric wire and an electrical object through the conductive electric terminal 10 without need to strip the covering of the electric wire in a separate operation.

[0046] As shown in Fig.9, an insulated electric wire D is inserted into the electric fitting 100 through the void 31b onto the open mouths of the dual protrusions 20a and 20b.

[0047] The terminal fitting 100 is pinched with a pinching device 51 indicated in broken lines in Fig. 9 as described earlier such that the bent portion 30 is further bent and the upper dual protrusion 20c and the lower dual protrusions 20a and 20b come closer with the electric wire D placed inbetween until an end portion of the upper dual protrusion 20c comes in the bottom opening 23b and end portions of the lower dual protrusions 20a and 20b are respectively received in the upper openings 40a and 40b. The hook protrusion 42 which is formed substantially longer than the dual protrusions 20a, 20b and 20c is received through the rectangular opening 41 with its end portion then bent as shown in Fig. 10 so as to securely retain the deformation of the fitting 100 as depicted in Fig.10. The book protrusion 42 helps control bending or deformation of the fitting 100 by preventing the pinching performance of the fitting 100 from going astray.

[0048] The electric wire D is adequately stripped of its covering crosswise by means of the stripping edges 21a, 21b and 21c respectively provided on the stripping slots 20a, 20b and 20c as the wire D is forcedly pressed deep into the respective slots 23a, 23b and 23c which are tapered towards the bottom. The exposed core wire (not shown) of the electric wire D thus securely contacts the conductive edges of the dual protrusions 20a, 20b and 20c and is securely held in the slots 23a, 23b and 23c as described earlier in connection with the foregoing embodiments.

[0049] Figs.11 and 12 show alternative stripping slots. In Fig.11, a stripping slot 23d of a pinching member 20d is a triangular configuration whose open mouth "L" is wider than the diameter of an insulated electric wire D. The covering of the wire D will be removed across at stripping portions 21d of the stripping slot 23d as will be appreciated by a person skilled in the pertinent art.

[0050] Fig.12 shows another stripping slot 23e of a pinching member 20e, which is provided with stripping protrusions 21e as shown. As will be easily appreciated by a person skilled in the pertinent art, the stripping protrusions 21e provided as such will strip the covering of an insulated electric wire D crosswise to expose its core wire when the electric wire D passes between the stripping protrusions 21e. The exposed core wire (not shown) of the electric wire D will provide electrical connection with the slot 23e when the electric wire D substantially reaches the bottom of the slot 23e.

[0051] It is to be understood that the foregoing embodiments of the present invention are provided for the purpose of illustrating the present invention only. Accordingly, various modifications, alterations and changes can readily be made to those embodiments by persons skilled in the art within the scope of the accompanying claims. Therefore, those modifications, alterations and changes are intended to fall within the scope of the present invention.


Claims

1. An electric terminal fitting having an electric terminal to be electrically connected with an electrical object, which is formed in one piece of a conductive metallic material,

the electric terminal fitting providing electrical connection between an insulated electric wire and an electrical object by way of plastically deforming a predetermined portion of the electric terminal fitting against the electric wire to strip the electric wire of its covering crosswise and expose its core wire so that the exposed core wire physically contacts the conductive terminal fitting.


 
2. An electric terminal fitting of claim 1, wherein the terminal fitting is provided with oppositely positioned pinching members to pinch said electric wire therebetween and electrically conductive portions to be electrically connected with said exposed core wire.
 
3. An electric terminal fitting of claim 2, wherein said oppositely positioned pinching members are provided with covering stripping portions and said conductive portions.
 
4. An electric terminal fitting of claim 2 or 3, wherein said conductive portions are provided on stripping slot means which provides said covering stripping.
 
5. An electric terminal fitting of claim 4, wherein said stripping slot means forcibly receives and securely retains said electric wire.
 
6. An electric terminal fitting of claim 4 or 5, wherein said covering stripping portions are provided at the mouth of said stripping slot means.
 
7. An electric terminal fitting of any one of claims 1-6, wherein said conductive metallic material is a single metal sheet piece.
 
8. An electric terminal fitting of any one of claims 1-7, wherein said plastic deformation of the terminal fitting is provided at a bent portion.
 


Amended claims under Art. 19.1 PCT


1. An electric terminal fitting formed in one piece of a conductive metallic material, having a bending portion and paired pinching means which together pinch an insulated electric wire placed therebetween, further comprising:

an electric terminal provided at an end portion of the terminal fitting which is used to electrically connect with an electrical object; and

an access to said paired pinching means to facilitate easy placement of an insulated electric wire therebetween,

whereby said electric wire is stripped of its covering across by force provided by said paired pinching means as the pinching means are pinched with a pinching device toward each other such that a core wire portion of the electric wire is exposed and electrically contacts the pinching means to provide electrical connection between the electric terminal and the electric wire.

2. An electric terminal, fitting of claim 1, wherein the terminal fitting is provided with oppositely positioned pinching members to pinch said electric wire therebetween and electrically conductive portions to be electrically connected with said exposed core wire.

3. An electric terminal fitting of claim 2, wherein said oppositely positioned pinching members are provided with covering stripping portions and said conductive portions.

4. An electric terminal fitting of claim 2 or 3, wherein said conductive portions are provided on stripping slot means which provides said covering stripping.

5. An electric terminal fitting of claim 4, wherein said stripping slot means forcibly receives and securely retains said electric wire.

6. An electric terminal fitting of claim 4 or 5, wherein said covering stripping portions are provided at the mouth of said stripping slot means.

7. An electric terminal fitting of any one of claims 1-6, wherein said conductive metallic material is a single metal sheet piece.

8. (cancelled)


 




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