The invention relates to a plug connector for cooperation with a socket connector and particularly to a squib connector for use in an automotive airbag restraint system.
Such vehicle airbag systems use an electrical connection system which comprises a receptacle or socket connector on the side of the airbag and a plug connector on the side of a control unit. These connectors have to be mated while fulfilling safety requirements relating to electrical safety and mechanical safety.
Electrical connectors for airbags are known from EP 0 591 948 B1 and include a socket connector having a shorting insert, and a plug connector having a safety leg for mechanically locking the connectors mated, and simultaneously breaking the shorting condition in the socket connector.
There are further developments in the electrical connection system with safety interlock which are termed “secondary locking device” or “CPA member” (connector position assurance). One of these developments can be found in U.S. Pat. No. 6,530,799 B2. The plug connector has a plug projection with locking arms fixed on the end of the plug projection and extending upwardly and forming a slot between locking arm and plug projection. The secondary locking device has several legs, among them a locking leg, a short circuit releasing leg and a spring arm with a step and a projection. The secondary locking device can be inserted into an upper face of the plug connector to take a pre-locked position wherein the step of the spring arm rests on a wedge-shaped crest projecting from the locking arm of the plug projection, and a locking projection formed on the plug connector housing. The locking arms of the plug connector which extend upwardly can be partly inserted into the socket connector to take a pre-mounted position of the plug connector and socket connector. When the plug connector is fully inserted into the socket connector, the spring arm is deflected by the locking projection acting against the step so that the spring arm bends, whereby the step is lifted from the locking projection. This allows a further depression of the secondary locking device where the projection of the spring arm slides in the socket connector, and the spring arm is bent and stays bent in the fully inserted position of the connectors. Such bent condition of the safety member is not desirable for certain applications. In terms of structural differences to invention, the plug projection does not comprise a pair of recesses that face the respective locking arms. Also a pair of cross ribs is not provided in the plug projection. The locking arms extend upwardly and have locking shoulders at half the length thereof and a wedge-shaped crest at the free end thereof. The locking leg of the secondary locking device extends downwardly and has a wedge-shaped projection at its free end and a step arranged in a small distance thereto. The plug connector housing has a locking projection which cooperates with the step and the projection of the spring arm for deflecting the spring arm and getting past the wedge-shaped crest projecting from the locking arm when the connectors are mated. There is no cooperation with inner walls of the socket connector for deflecting the spring arms of the secondary locking device.
With EP 2 026 421 A1 an airbag connector is known that avoids the bent condition of the safety member in the fully inserted position of the connectors. The plug connector has a housing being formed with a body portion, a cylindrical plug projection and a pair of latch arms. The latch arms extend downwardly and have a lug at its end for cooperation with a radial groove in the socket connector. The CPA member comprises a pair of locking legs which can block the latch arms of the plug connector when the same is fully inserted in the socket connector. The CPA member also comprises a pair of spring arms each with a free end that rests on a cross rib of the plug connector housing in the pre-locked position. Free end lugs of the spring arms are provided with camming surfaces which cooperate with inner walls of the socket connector when the plug connector is inserted into the socket connector so that the free end lugs of the spring arms get past the cross rib and snap into spaces behind the inner walls of the socket connector without any stresses remaining. Whereas the connector assembly described fulfill a great number of requirements on the market, there are still some improvements for the connectors in question. The plug connector has to be shipped, which is done in the pre-locked position of the CPA member, wherein the plug connector is separated from the socket connector. In view of the tendency to miniaturization, the plug connector includes tiny members as the spring arms of the CPA member. The connector could be subjected to forces in connection with shipping or handling that could lead to the spring arms being bent excessively so that correct mounting of the plug connector in the socket connector would be impaired.
It is an object of invention to design an electrical connector assembly for an automotive airbag restrained system which avoids the drawbacks discussed.
It is a further object of the invention wherein the CPA member can be held in the plug connector in a pre-locked position well in excess of mating forces.
It is another object of the invention to avoid damages on the CPA member, even if excessive forces act onto the CPA member.
It is still another object of the invention to have the latching or locking members in an essentially relaxed condition when the plug and the socket connectors are fully mated.
The plug connector of invention comprises a plug housing, terminal means in the plug housing, a cover and a CPA member. The plug housing is formed with a body portion, a cylindrical plug projection and a pair of latch arms. The CPA member comprises a pair of locking legs and a pair of spring arms, each of which has a free end formed with a lug, and a midway portion formed with a nose that projects inwardly of the device. The cylindrical plug portion has a hollow wherein the spring arms of the CPA member are accommodated, a pair of recesses facing the latch arms, and a pair of cross ribs. The latch arms which extend downwardly from the plug connector housing into the socket connector housing when the connectors are mated, each have a lug at its end for cooperation with an appropriate groove in the socket connector. The body portion of the plug housing also has a support portion for the nose at each spring arm of the CPA member. The nose has such a distance from the free end surface of the spring arm that, when the CPA member is inserted in the plug connector with the free end surface of the spring arms resting on the cross rib, the lower surface of the nose keeps a short distance to the support portion. This allows the spring arms to straddle and getting past the respective cross ribs, when the plug connector is inserted into the socket connector, without the nose getting in contact with the support portion of the plug connector. On the other hand, when the CPA member is inserted into the plug connector for taking the pre-locked position for shipment, the support portion may form a stop for the nose and therefore also for the CPA member when there is a load well in excess of the mating force onto the CPA member in a direction inwardly of the plug connector.
Alternatively or additionally to providing the support portion of the connector housing, the cross ribs may be constructed in split shape in order to provide a frictional passage for the spring arms of the CPA member, when the CPA member is in the pre-locked position and an excessive force is placed upon the CPA member. If the CPA member has prior to mating been forced through the split between the cross ribs, the housing assembly can be prepared. In preparing for mating the plug connector and the socket connector, by withdrawing the CPA member outwardly to reach the pre-locked position of the plug connector, where the free end lugs of the spring arms get out of the frictional passage between the split in the cross ribs.
Thus, the invention keeps the possibility of fully inserting the plug connector and the CPA member into the socket connector, whereas in the pre-locked position of the CPA member and the plug connector during shipment, damaging of the spring arms of the CPA member due to excessive forces is prevented.
An embodiment of the present invention will be described by way of example with reference to the accompanying drawings in which
With reference to
The cylindrical plug projection 21 has a hollow 23 for accommodating the lower portions of the CPA member 5, and a pair of split cross ribs 26 which extend from parallel walls 27 extending vertically in the hollow 23. Each split cross rib 26 forms a gap 26a that offers a frictional passage for the respective end lug 54 of the respective spring arm 53.
The body portion 20 has an upper support surface 20a to which the nose 55 of the spring arm 53 keeps a short (vertical) distance d when the plug connector 1 together with the CPA member 5 takes the pre-locked position which is shown in
Furthermore, if the excessive forces placed upon the CPA member 5 are greater than what the nose 55 against the support surface 20a can support, the split cross ribs 26 prevent damage to the tiny spring arms 53. This is accomplished by the transfer of the excessive force on the CPA member 5 to the free end surface 54a which pushes against the split cross ribs 26, causing the parallel walls 27 to deflect outward, increasing the gap 26a between the cross ribs until the spring arms 53 can pass without damage through the passage so created. The CPA member 5 can still be used by being pulled up into the prelocked position without having been damaged. During the mating process, the cross ribs 26 do not separate due to the walls 27 being supported by a wall in the insert housing 92.
The stop surface 55a and the support surface 20a opposite the stop surface 55a are parallel to one another and may extend perpendicularly to the insert direction, or slope inwardly relative to the plug connector 1. This makes sure that the spring arm 53 does not move away from the body portion 20 when there is a force well in excess of mating forces onto the CPA member 5 from above, the nose 55 keeping the spring arm 53 closely to the body portion 20.
Final mating of the connectors 1, 9 is started from this situation of the pre-mounted position. As shown in relation of
For un-mating the connectors 1, 9, the CPA member 5 is gripped at the grip rims 58 and lifted. By doing so, the lugs 54 of the spring arms 53 slide along the slanting surfaces 97a and the spring arms 53 are spread apart. Simultaneously, the locking leg portions 50b leave their locking positions so that the lugs 29 are no more blocked. In this condition, the plug connector 1 can be drawn from the socket connector 9 against the latching force of the latch arms 22.
For reasons on electrical safety of the airbag, the socket connector 9 is short-circuited by a shorting clip 94 (
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2010/047513 | 9/1/2010 | WO | 00 | 5/9/2013 |
Publishing Document | Publishing Date | Country | Kind |
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WO2012/030335 | 3/8/2012 | WO | A |
Number | Name | Date | Kind |
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5616045 | Gauker | Apr 1997 | A |
6364683 | Kohno | Apr 2002 | B1 |
6530799 | Regnier et al. | Mar 2003 | B2 |
7108539 | Gunreben et al. | Sep 2006 | B2 |
7108542 | Ishiwa | Sep 2006 | B2 |
7556516 | Osada et al. | Jul 2009 | B2 |
7578694 | Takahashi et al. | Aug 2009 | B2 |
8317545 | Iida | Nov 2012 | B2 |
20040166715 | Parrish et al. | Aug 2004 | A1 |
Number | Date | Country |
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0 591 948 | Jan 1997 | EP |
1 006 621 | Jan 2005 | EP |
2 026 421 | Jun 2010 | EP |
Entry |
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International Search Report for PCT/US2010/047513. |
Number | Date | Country | |
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20150311633 A1 | Oct 2015 | US |