Vibration proof electrical receptacle

Abstract: An electrical receptacle terminal (2) is comprised of an outer spring member (10) and an inner spring member. The inner spring member is axially moveable within the outer spring member (10) to compensate for vibration. The inner spring member includes a plurality of stacked box sections (34, 45, 58) interconnected by webs (24, 44, 56) thereby allowing the longitudinal movement. Base walls (50, 52; 62) of the upper spring portion are provided with slots (90, 98) which define spring strap portions which act as a secondary spring to the spring contact arms (70, 72).

Description: This invention relates to an electrical receptacle contact according to the preamble of claim 1. Electrical connectors often are situated in an environment where they are exposed to mechanical load caused by shaking or oscillating movement or vibrations and/or stress due to thermal changes. Examples are electrical connectors used in machines or motor vehicles. If such connectors are situated in the engine compartment of a motor vehicle, not only does heavy mechanical load of the above-mentioned kind occur but also high differences in temperature occur especially during wintertime between the motor vehicle at standstill and being driven. If the two connectors of a connector pair are attached to different parts or components moving relative to each other due to such mechanical and/or thermal stress, a corresponding relative motion between the connectors occurs, for example between contct pins or contact tabs of one connector and the receiving contacts, for example receiving sockets of the other connector of the connector pair. Such relative motion causes frictional corrosion leading to an impairment of the electrical contact between the pin contacts and the socket contacts. An electrical receptacle of the above-mentioned type is shown in EP-A-0 492 479, and is used in high vibration environments. This receptacle contact is mainly for use on a printed circuit board where a mating pin can be inserted through the top of the receptacle, or through the bottom of the receptacle, through the board. For this reason, the contact arms are elongate, to centralize the pin contact point within the length of the receptacle. It is desirable to use a similar terminal for connection to a wire, for use in automotive applications. It is the object of the invention to solve this problem, that is to avoid frictional corrosion even in those connector pairs whose connectors move relative to each other due to loads of the above mentioned kind. This object has been accomplished by providing a receptacle contact as defined in claim 1. The preferred embodiment of this invention will now be described in more detail with reference to the drawing Figures, whereby; Figure 1 is a top plan view of a receptacle contact in accordance with the invention. Figure 2 is a side plan view of the terminal shown in Figure 1; Figure 3 is a cross sectional view through lines 3-3 of Figure 2; Figure 4 is a cross sectional view similar to that of Figure 3 without the outer spring; Figure 5 is a side plan view of the terminal, similar to that shown in Figure 2 without the outer spring; and Figure 6 is a side plan view of the inner terminal. With respect first to Figure 1, an electrical receptacle is shown generally at 2 comprising a front mating section 4, a body or mounting portion 6, and a wire terminating section 8. An outer spring surrounds the receptacle front portion and is shown generally at 10. With respect now to Figures 4 and 5, the inner contact portion is shown as 12 and is generally box shaped in construction, where the base portion 6 includes a base wall 14, side walls 16 and 18 and top wall portions 20 and 22 (Figure 6). As shown in Figures 5 and 6, the cover wall portions 20 and 22 extend upwardly at a web portion 24 to form wall portions 26 and 28, leaving a peripheral slit at 30 thereby forming a moveable box portion 34 having side walls 36 and 38 and a base portion 40. The base portion 40 continues upwardly to form a base portion 42 interconnected by a medial web portion 44 to form a further box portion at 45 comprised of base portion 42, side walls 46 and 48 (Figure 4) and top cover portions 50 and 52. The box portion 34 is separated from the box portion 45 via the peripheral slit at 53. Finally top cover portions 50 and 52 are continuous to form top cover portion 54 and 55 via a web 56 thereby forming an upper box portion 58. The upper box portion 58 is separated from the box portion 45 at peripheral slit 60 thereby allowing the box portions 45 and 58 to be moveable relative thereto about the web portion 56. The upper box portion 58 is comprised of a base portion 62 side walls 66 and 68 and the top wall portions 54 and 55. Contact arms 70 and 72 (Figure 4) extend integrally from side wall portions 66 and 68 respectively about bight portions 74 and 76. The contact arms 70 and 72 have outward projections forming contact members 78 and 80 opposed from one another and are profiled to engage a mating tab member. The contact arms 70 and 72 are formed such that their ends 82 and 84 are positioned within the upper box portion 58. The contact arms 70 and 72 further include stop surfaces 86 and 88 which can abut the side walls 66 and 68 respectively to prevent over-stressing or plastically deforming the contact arms 70 and 72. The base wall 62 includes a slot 90 (Figure 4) and openings 92 which, as shown in Figures 4 and 5 extend around into the side wall 66. The slot 90 together with the openings 92 define strap portions 96, which will be described in greater detail herein. As shown in Figure 6, the top cover parts 54 and 55 are connected together by a spot weld at 97, and a second slot 98 is positioned above the weld 97. Two further openings are located at 99 which also extend into the side walls 66 and 68, as shown in Figure 5, thereby forming strap portions 100, between the slot 98 and openings 99. With respect now to Figures 1-3, the outer spring 10 will be described in greater detail. The outer spring 10 is generally box shaped in nature and overlies the receptacle portion of the inner spring member 12. The outer spring member 10 is comprised of a base portion 102 side walls 104, 106 and top cover parts 108, 110. Resilient locking lances 112 and 114 are stamped out of the side walls 104 and 106, respectively as shown in Figure 2 and 3. The outer spring member 10 is fixed to the inner contact 12 by way of tab portions 120 and 122 which are sheared from the side walls 104 and 106 and partly from the cover members 108 and 110, being crimped over the top edges of side wall portions 16 and 18, as best shown in Figures 1 and 2. The cover parts 108 and 110 are fixed to each other at the front end, for example by spot welding at 124, however this spot weld 124 does not retain the inner spring contact 12 to the outer cover 10. It should be appreciated that the box portions 34, 45 and 58 are moveable axially along center line C as shown in Figure 5 towards and away from the base portion 6, within the confines of the outer spring member 10. While the inner spring member 12 is allowed to move axially within the outer spring, stop means must be provided cooperatively between the inner spring member 12 and the outer spring member 10 to prevent over stressing the inner spring member 12. The outer spring member 10, and more particularly the side walls 104,106 include half moon shaped projections 125, as shown in Figures 2 and 3 which are formed by shearing lines at 126 (Figure 2), and thereafter moving the sheet metal into the interior of the outer spring, as viewed in Figure 3, thereby forming a stop surface at the shear line 126 to cooperate with an edge 128 (Figure 5) on the top box portion 58 to control the extremity of the downward movement of the top box portion 58. With reference to Figure 3, the outer spring 10 includes curved wing portions 130 and 132 overlying the bight portions 74 and 76, which controls the upper extreme movement of the box member 58. Advantageously then, the electrical terminal shown in Figures 1-5 can be crimped to a wire via the wire interconnection section 8 and used in an atmosphere containing high vibration, such as for use in an automobile. Due to the axial movement of the terminal contact portion 12 the pin and receptacle can undergo vibration without fear of fretting corrosion between the mating contact surfaces of the tab and contact portions 78 and 80. Also due to the short length of the contact arms 70 and 72, the contact arms are kept within the profile of the top box portion 58 thereby preventing any friction between the surfaces 86 and 88 of the contact arms 70 and 72 during the axial movement of the top box portion 58 during vibration. However due to the short length of the contact length portions 70 and 72, the base portion 62 is slotted at 90 thereby defining the strap portioned 96 which act as further spring members allowing spring action in the strap portions 96. Furthermore the terminal can be conventionally retained in the connector housing by way of the locking lances 112 and 114 as the primary lock, while the curved wing portions 130 and 132 (Figure 3) of the outer spring 10 provide a flared entry way for a mating tab member.

Claims: An electrical receptacle contact (2), comprising a body portion (6) having a conductor connecting section (8) extending from one end thereof, a receptacle section (4) extending from the other end thereof and including an upper box section (58) and resilient contact arms (70, 72) being formed from said upper box section (58) and being reversely bent into said upper box section 58), said upper box section (58) being longitudinally movable with respect to said body portion (6) characterized in that said contact arms (70,72) have a length no longer than a length of said upper box section (58), and that said receptacle section (4) is longitudinally guided by way of an outer spring body (10). An electrical receptacle contact (2) to claim 1, characterized in that the receptacle section (4) is provided with a plurality of longitudinally spaced, transversely extending spring slots (30,53,60) extending in alternating manner from opposing sidewalls (20, 22; 40; 50, 52) and extending to the respective opposing sidewall (26,28;42;54,52). An electrical receptacle contact (2) according to claim 1 or 2, characterized in that said receptacle section (4) is formed with a plurality of box shape members (34,45,58), adjacent box members being interconnected by way of webs of material (24,44,56), where said webs are alternating form side-to-side. An electrical receptacle contact (2) according to any of claims 1 - 2, wherein a further spring portion is formed by a slot (90,98), on at least one wall (54,55,62) of said upper box section (58), not containing a contact arm. An electrical receptacle contact (2) according to claim 4, characterized in that opposing walls (54,55,62) not containing said contact arms, have a longitudinal slot (92,99) forming strap portions flanking said slot (90,98). An electrical receptacle contact (2) according to any of claims 1 - 5, characterized in that stop members (125,126; 130,132) are provided on said receptacle portion or said outer spring body, or cooperatively on both, to limit the longitudinal movement of said receptacle section (4) in both directions. An electrical receptacle contact (2) according to claim 1 - 6, characterized in that said outer spring body (10) includes curved wing portions (130,132) which overlie bight portions (74,76) of said reversely bent spring contact arms (70,72), and are longitudinally spaced therefrom.

Inventors: HOTEA GHEORGHE, HOTEA, GHEORGHE
Applicants: WHITAKER CORP, THE WHITAKER CORPORATION
Application year: 1993
Main classification: H01R13
IPC codes: H01R13