CN1138224A - 电气插接件 - Google Patents

电气插接件 Download PDF

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CN1138224A
CN1138224A CN96104424A CN96104424A CN1138224A CN 1138224 A CN1138224 A CN 1138224A CN 96104424 A CN96104424 A CN 96104424A CN 96104424 A CN96104424 A CN 96104424A CN 1138224 A CN1138224 A CN 1138224A
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corresponding plug
receiving compartment
plug
plug receiving
housing
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W·S·戴维斯
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Whitaker LLC
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Whitaker LLC
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    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01RELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R13/00Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
    • H01R13/02Contact members
    • H01R13/26Pin or blade contacts for sliding co-operation on one side only
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01RELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R24/00Two-part coupling devices, or either of their cooperating parts, characterised by their overall structure
    • H01R24/60Contacts spaced along planar side wall transverse to longitudinal axis of engagement
    • H01R24/62Sliding engagements with one side only, e.g. modular jack coupling devices
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01RELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R13/00Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
    • H01R13/40Securing contact members in or to a base or case; Insulating of contact members
    • H01R13/42Securing in a demountable manner
    • H01R13/428Securing in a demountable manner by resilient locking means on the contact members; by locking means on resilient contact members
    • H01R13/432Securing in a demountable manner by resilient locking means on the contact members; by locking means on resilient contact members by stamped-out resilient tongue snapping behind shoulder in base or case
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01RELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R13/00Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
    • H01R13/648Protective earth or shield arrangements on coupling devices, e.g. anti-static shielding  
    • H01R13/658High frequency shielding arrangements, e.g. against EMI [Electro-Magnetic Interference] or EMP [Electro-Magnetic Pulse]
    • H01R13/6581Shield structure
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01RELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R2107/00Four or more poles
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01RELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R4/00Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation
    • H01R4/10Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation effected solely by twisting, wrapping, bending, crimping, or other permanent deformation
    • H01R4/18Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation effected solely by twisting, wrapping, bending, crimping, or other permanent deformation by crimping
    • H01R4/183Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation effected solely by twisting, wrapping, bending, crimping, or other permanent deformation by crimping for cylindrical elongated bodies, e.g. cables having circular cross-section
    • H01R4/184Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation effected solely by twisting, wrapping, bending, crimping, or other permanent deformation by crimping for cylindrical elongated bodies, e.g. cables having circular cross-section comprising a U-shaped wire-receiving portion
    • H01R4/185Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation effected solely by twisting, wrapping, bending, crimping, or other permanent deformation by crimping for cylindrical elongated bodies, e.g. cables having circular cross-section comprising a U-shaped wire-receiving portion combined with a U-shaped insulation-receiving portion

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  • Connector Housings Or Holding Contact Members (AREA)
  • Details Of Connecting Devices For Male And Female Coupling (AREA)

Abstract

一种电气插接件,包括:在相应插头接纳腔中的多个电气插头,每个相应腔在壳体中,沿着每个腔的侧壁的悬伸部分,每个插头包括一个长插头部分,该长插头部分形成有沿着每个相应插头的由悬伸部分限界的弧部和侧边,弧部在该悬伸部分之间伸出,用于与另外一个匹配的电气插接件的插头配合接触。

Description

电气插接件
本发明涉及一种电气插接件,具体来说涉及有强度特别高并且保持在壳体中的薄片插头的电气插接件。
美国专利5017156的电气插接件公开了一薄的并且有水平部分的电气插头,它沿着它们的整个扁平长度由在绝缘壳体中的各个台阶槽所支承。因此,水平部分适于承受当其与另外一个匹配的电气插接件的插头相接触时所产生的接触压力。
本发明的一个特征在于有加强强度的弧形的电气插头。
本发明的另外一个特征在于绝缘壳体,在壳体中的插头接纳腔,该腔有将电气插头的侧边限界在腔中的悬伸部分。
根据本发明的一个实施例,电气插接件包括,一个绝缘壳体,插头接纳腔,在相应腔中的多个电气插头,沿着每个相应腔的侧壁的悬伸部分,每个插头构成有由悬伸部分限界的侧边,并且每个插头构成有从一个侧边延伸到另外一个侧边的弧部,在相应腔的悬伸部分之间伸出的每个弧部的长顶部,每个顶部提供一个接触表面,用于与另外一个匹配的电气插接件匹配接触。
现在参照列举的附图介绍本发明的实施例,其中:
图1是连在电缆上的包括壳体和屏蔽总成的电气插接件的等角图;
图2是图1所示插接件的绝缘壳体的等角图;
图3是图2所示壳体的剖视图以及图1所示插接件的导电屏蔽;
图4是通过图2所示壳体的部分所取的剖视图;
图5是通过图2所示壳体的部分所取的剖视图;
图6是图1所示插接件电气插头的等角图;
图7是四个电气插头的顶视图;
图8是图7所示电气插头之一的侧视图;
图9是图7所示电气插头之一的侧视图;
图10是图1所示插接件的一部分壳体和两个电气插头的前视图;
图11和12是图1所示插接件的壳体和屏蔽总成的剖视图。
请主要参阅图1-5,电气插接件1包括一个绝缘壳体2,在壳体2中的插头接纳腔3,和在相应的腔3中的多个电气插头4(见图11和12)。现在参阅图2-5,壳体2是例如整体模塑结构,并且包括一个前部分5和一个后部分6。参阅图10,悬伸部分7沿着每个相应腔3的侧壁8延伸。每个相应腔3的横剖面是燕尾槽。每个相应腔3的悬伸部分7包括开始于腔3的较宽底部9并且彼此向悬伸部分7之间的较窄的长开口10倾斜的侧壁8。
参阅图6-10,每个相应的插头4例如可由冲压成形的整体薄的金属坯料制成。插头3的前部分11是薄刀口结构,并且有由相应腔3的悬伸部分7限界的长侧边12。每个插头3构成得带有从一个侧边12延伸到另外一个侧边12的弧部13。弧部13可以使否则便是弱而薄的刀口形状加强,并且还提供限界在相应的悬伸部分7之下的侧边12。每个弧部13的长顶部伸在相应腔3的悬伸部分7之间的开口10中。每个顶部向外伸在悬伸部分7之上,并且提供光滑的,长的,摩擦闭合接触表面。每个顶部提供一个摩擦闭合接触表面,用于与另一个匹配的电气插接件(未示出)匹配啮合。在顶部向外伸出相应的插头接纳腔3之处,弧部13的顶部的前棱边14(图6)从后向前倾斜成一个坡度。倾斜的前棱边14可以防止插头4在插接件1与另外一个匹配的电气插接件(未示出)匹配连接时碰绊另外一个匹配的电气插接件。相应插头4的每个相应后部15包括一个第一连接件,该第一连接件是一个由第一对翼板17形成一个敞开桶的束桶16,用于束接电缆20(图1)的绝缘线19的导体部分18(图11,12),第二连接件是一个由第二对翼板22形成一个敞开桶的第二束桶21,用于束接绝缘线19的绝缘部分。
参阅图2-5,每个相应插头接纳腔3向后部6加宽,以便接纳插头3的不同尺寸的后部15。后部15的尺寸和材料量可以不同,以便传导不同量的电能而无过分的传导阻力。例如,大尺寸和大质量可以比小尺寸和小质量提供较小的电能传导阻力。小尺寸的插头4不贵,容许腔3在壳体2中有较紧凑的空间,并且要求较少的围绕插头4的绝缘。
悬伸部分7沿着相应的插头接纳腔3在长度方向延伸相等的长度,较小尺寸的插头4的长插头部分11构形相同,每个该插头部分11的该弧部13沿着长插头部分11从一个侧边12延伸到沿着长插头部分11的另一个侧边12,以便可以互换地安装在任何一个插头接纳腔3中。
参阅图1,11和12,导电屏蔽23包围着壳体2。一个通道24在屏蔽23的前端有一个开口25。该通道24沿着屏蔽23的内部从壳体2的前部延伸到壳体2的后部6。通道24将屏蔽23的内部与每个相应插头4的顶部隔开。从屏蔽23伸出的突耳26(图12)向下弯曲并且伸入在壳体2前端的突耳接纳凹槽27中,以便阻止壳体2相对于屏蔽23向前运动。凹槽27从壳体2的靠着屏蔽23的外缘延伸。
参阅图11和12。在壳体2上的倾斜前缘28在每个相应腔3的前方和在每个相应腔3中的插头4的前方伸出。倾斜前缘28提供一个使匹配的电气插头(未示出)偏入通道24的缩口,用于与相应的插头4的每个相应顶部摩擦闭合接触。每个相应腔3与在前缘28中的相应槽29相沟通。每个相应槽29与在相应腔3中的相应插头4的顶部对齐。当前缘28使匹配的电气插头(未示出)偏置时,前缘28会擦拭匹配的电气插头的绝缘材料。希望防止匹配的插头擦去前缘28的绝缘材料,特别是在插头4与匹配的插头啮合的相同部位。这种对绝缘材料的擦拭会将绝缘材料涂覆在匹配的插头上,特别是在插头4和匹配的插头之间。在匹配其间,在插头4和匹配的插头彼此啮合部位,所涂覆的绝缘材料的存在会降低导电性,这是不希望的。因此,在结合插头4的相应顶部前,槽29容许匹配的电气插头4的未擦拭部位沿着槽29横贯。
在所选定的那些相应插头接纳腔3的前方的前缘28的第一部分30长于在所选定的其它那些相应插头接纳腔3的前方的前缘28的第二部分32。所选定的那些相应插头接纳腔3从壳体2的前端开始得比所选定的其它那些相应插头接纳腔3较远。在腔3中的插头4按照顺序与匹配电气插接件(未示出)的匹配插头匹配是有利的,这取决于它们在腔3中距壳体2的前端的相应空间。
参阅图3-12。相应的突出部33在每个相应插头接纳腔3的相应内壁34上。相应的内斜壁35在每个相应突出部33的后部,使相应插头4上的前棱边14偏置。相应的朝前的肩部36在每个相应的突出部33上。每个相应的插头4有面朝相应的朝前肩部36的后突的弹性叉37。当插头4横贯相应腔3的前部11时,叉37可弹性偏转地通过突出部分33。叉37向外弹出并且面朝肩部36,以阻止每个相应插头4相对于壳体2向后移动。与突出部分33对直并且在其前方的窄通道38与后部6的前方沟通。通道38的壁由通道38的宽度隔开。隔开的壁宽得可以侧面支承在叉38的对置侧上,以便阻止插头4绕其纵向轴线旋转。
在每个相应插头接纳腔3上的斜壁35从后向前倾斜并且面朝腔3的内底壁9。在每个相应腔3中的内底壁9从内斜壁35和悬伸部分7跨过相应腔3。相应的插头4从后部6插入腔3中。插头4沿腔3横贯。插头4的侧边12必须靠着底壁9横过,以便沿着在壳体2的后部6和前部5中的腔3正确对中。底壁9将插头4的侧边12引导在相应的悬伸部分7之下。斜壁35和底壁9将插头4的对置侧偏向相应腔3的前部。插头4的顶部13对着斜壁35。对着相应插头4的顶部13的斜壁35使顶部13上的倾斜前边14偏置,在悬伸部分17上的后端40之下穿过。后端40从后向前倾斜并且使插头4汇聚成与相应腔3的前部轴向对中。
本发明的优点在于,电气插接件包括,在绝缘壳体中的插头接纳腔,和沿着腔边的悬伸部分阻挡限界在悬伸部分之下的电气插头的运动。
本发明的另外一个优点在于,电气插接件包括带有薄刀片和在每个薄刀片上的弧部的电气插头,其使插头加强并且提供插头摩擦闭合表面。

Claims (6)

1.一种电气插接件包括,多个电气插头,每个插头在相应的插头接纳腔中,每个相应的插头接纳腔在一个壳体中,其特征在于,沿着每个相应插头接纳腔的侧壁的悬伸部分,每个插头包括,形成有弧部的长插头部分,该弧部从沿着长插头部分的一个侧边延伸到沿着长插头部分的另一个侧边,沿着每个相应插头的该侧边由悬伸部分限界在相应的插头接纳腔中,弧部的长顶部在相应的插头接纳腔上的该悬伸部分之间伸出,并且每个顶部提供一个长插头表面,用于与另外一个匹配的电气插接件的插头匹配接触。
2.如权利要求1所述的电气插接件,其特征在于,每个相应插头接纳腔的横剖面是燕尾槽,并且在每个相应的插头接纳腔上的悬伸部分包括彼此相向倾斜的侧壁。
3.如权利要求1所述的电气插接件,其特征在于,它还包括:在顶部向外伸出相应插头接纳腔的部位倾斜成从后向前的坡度的在弧部之顶部上的前棱边。
4.如权利要求1所述的电气插接件,其特征在于,它还包括:壳体后部,每个相应插头接纳腔穿过壳体后部,并且每个相应插头接纳腔有与相应插头的顶部对置的内斜壁,使弧部顶部上的前棱边偏置在悬伸部分之下。
5.如权利要求1所述的电气插接件,其特征在于,它还包括:选定的一些相应的插头接纳腔从壳体的前端开始得比选定的其它一些相应插头接纳腔较远,壳体的前缘在每个相应插头接纳腔的前方伸出,在该选定的一些相应插头接纳腔的前方的前缘的第一部分比在选定的其它一些相应插头接纳腔前方的前缘的第二部分长。
6.如权利要求1所述的电气插接件,其特征在于,它还包括:壳体的后部,每个相应插头接纳腔穿过壳体后部,在每个相应插头接纳腔的相应内壁上的一个相应突出部分,在每个相应突出部分的后部上的一个相应的内斜壁使相应插头的前棱边偏置,在每个相应突出部分上的一个相应的朝前的肩部,并且每个相应插头有面朝相应的朝前肩部的后突叉,以阻挡每个相应插头相对于壳体的向后运动。
CN96104424A 1995-03-27 1996-03-26 电气插接件 Pending CN1138224A (zh)

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US41113795A 1995-03-27 1995-03-27
US411,137 1995-03-27

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EP (1) EP0735617B1 (zh)
JP (1) JPH08273731A (zh)
KR (1) KR960036205A (zh)
CN (1) CN1138224A (zh)
BR (1) BR9600832A (zh)
DE (1) DE69602669T2 (zh)

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US5683269A (en) * 1995-03-27 1997-11-04 The Whitaker Corporation Shielded electrical connector with cable strain relief
WO1997040551A1 (de) * 1996-04-22 1997-10-30 Siemens Aktiengesellschaft Steckverbinder mit kontaktflächenschutz im stecköffnungsbereich
SG79956A1 (en) * 1996-12-18 2001-04-17 Thomson & Betts Corp Electrical connector with pin retention
US6004160A (en) * 1997-03-25 1999-12-21 The Whitaker Corporation Electrical connector with insert molded housing
US5993263A (en) * 1997-08-15 1999-11-30 Molex Incorporated Reduced mating force electrical connector
US6908324B1 (en) * 2000-09-08 2005-06-21 3Com Corporation Connector scheme to allow physical orientation of a computer peripheral
JP3801889B2 (ja) * 2001-09-07 2006-07-26 住友電装株式会社 端子金具
JP3996067B2 (ja) * 2003-01-30 2007-10-24 第一電子工業株式会社 電気コネクタに対するケーブルの接続構造
CN101373864A (zh) * 2007-08-24 2009-02-25 鹏智科技(深圳)有限公司 低厚度usb插头连接器及利用该usb插头连接器的usb连接器
DE102018121239A1 (de) * 2018-08-30 2020-03-05 Rosenberger Hochfrequenztechnik Gmbh & Co. Kg Mehradriges kabel

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL256110A (zh) * 1959-10-09
US3582863A (en) * 1969-03-12 1971-06-01 Tektronix Inc Electrical terminal housing having hinge and adjacent lock projection
JPS52134681U (zh) * 1976-04-05 1977-10-13
JPS61201283U (zh) * 1985-06-07 1986-12-17
US4682836A (en) * 1985-10-07 1987-07-28 Thomas & Betts Corporation Electrical connector and cable termination apparatus therefor
US4740177A (en) * 1987-02-09 1988-04-26 Standex International Corporation Cluster assembly with locking tabs
JPH0716312Y2 (ja) * 1989-02-28 1995-04-12 ホシデン株式会社 コネクタ
JPH0722064Y2 (ja) * 1989-12-04 1995-05-17 ホシデン株式会社 コネクタ
JP2513945Y2 (ja) * 1991-06-26 1996-10-09 ホシデン株式会社 コネクタ
JP2513946Y2 (ja) * 1991-06-26 1996-10-09 ホシデン株式会社 コネクタ
JP2700117B2 (ja) * 1992-07-28 1998-01-19 矢崎総業株式会社 コネクタの端子挿入構造
US5267882A (en) * 1992-12-10 1993-12-07 The Whitaker Corporation Set of keyed electrical connectors
US5295843A (en) * 1993-01-19 1994-03-22 The Whitaker Corporation Electrical connector for power and signal contacts

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102640361A (zh) * 2009-12-15 2012-08-15 罗伯特·博世有限公司 用于插接连接装置的电触头
US8777677B2 (en) 2009-12-15 2014-07-15 Robert Bosch Gmbh Electrical contact for plug-in connections
CN102640361B (zh) * 2009-12-15 2016-05-11 罗伯特·博世有限公司 用于插接连接装置的电触头
CN105322327A (zh) * 2014-07-31 2016-02-10 诠欣股份有限公司 连接器端子、连接器及连接器的制造方法

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EP0735617A1 (en) 1996-10-02
DE69602669D1 (de) 1999-07-08
DE69602669T2 (de) 1999-11-11
US5766025A (en) 1998-06-16
KR960036205A (ko) 1996-10-28
EP0735617B1 (en) 1999-06-02
JPH08273731A (ja) 1996-10-18
BR9600832A (pt) 1997-12-30

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