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United States Patent  [ii] Patent Number: 4,484,790
Scbildkraut et al.  Date of Patent: Nov. 27,1984
U.S. Patent Nov. 27, 1984 Sheet 1 of 2 4,484,790
U.S. Patent Nov. 27, 1984 Sheet 2 of 2 4,484,790
 ANTI DECOUPLING DEVICE FOR AN ELECTRICAL CONNECTOR
 Inventors: Alan L. Scbildkraut, Sidney; Dee A.
Werth, Bainbridge, both of N.Y.
 Assignee: The Bendix Corporation, Southfield, Mich.
 Appl. No.: 480,190
 Filed: Mar. 30, 1983
 Int. C1.3 H01R 13/623
 U.S. CI 339/89 M; 339/DIG. 2
 Field of Search 339/89 R, 89 C, 89 M,
339/90 R, 90 C, DIG. 2; 285/82, 87, 88, 92
 References Cited
U.S. PATENT DOCUMENTS
4,066,315 1/1978 Araeson 339/89 M
4,074,927 2/1978 Ball 339/89 M
4,109,990 8/1978 Waldron et al 339/89 M
4,165,910 8/1979 Anderson 339/89 M
4,183,605 1/1980 Arneson 339/89 M
4,268,103 5/1981 Schildkraut et al 339/89 M
Attorney, Agent, or Firm—C. D. Lacina
A compound coupling nut (60) mounted to a plug shell (10), first and second sets of detents (34, 84) arranged annularly and extending radially inward from one of the shell and/or the inner coupling sleeve, and a C-shaped detent spring (90) disposed radially-between the first and second detents, the detent spring having inwardly directed spring fingers (100) adapted to engage the ratchet teeth (34) and detent lugs (98) adapted to engage the arcuate detents (84), the detent spring (90) respectively, resisting and not resisting rotation of the coupling nut if rotated in one or the other directions, whereby as external coupling torques act on the coupling nut (60), the spring fingers (100) do not prevent rotation and as external uncoupling torques act on the coupling nut (60), the spring fingers (100) and the detent lugs (98) initially cooperate to resist rotation of the detent spring (90) and the coupling nut (60) until sufficient torque causes the detent lugs (98) to snap free, whereby uncoupling rotation of the coupling nut takes place.
Primary Examiner—John McQuade
13 Claims, 7 Drawing Figures
ANTI-DECOUPLING DEVICE FOR AN
This invention relates to an anti-decoupling device for an electrical connector.
Electrical connector assemblies are generally comprised of two separate connector members and a coupling member mounted to one of the connector members, each of the respective connector members supporting a plurality of electrical contacts for mating when the connector members are connected together by the coupling member engaging the other connector member. During mating and unmating the connector members must be easily coupled and decoupled with use of reasonable force. Once mated and in use, however, the connector assembly must remain connected despite vibrational and/or other forces which might be applied to the connector assembly and which might tend to uncouple the assembly.
Various anti-decoupling devices for resisting unwanted rotation are known. In U.S. Pat. No. 4,109,990 issuing Aug. 29, 1978 to Waldron et al and in U.S. Pat. No. 4,268,103 issuing May 19, 1981 to Schildkraut et al, each titled "Electrical Connector Assembly Having 25 Anti-Decoupling Mechanism," a straight spring beam is radially interposed between the coupling member and one of the connector members, the one connector member having a plurality of ratchet teeth arranged annularly and extending radially outward therefrom and the spring beam having a medial tooth arranged such that when the coupling member is rotated in either direction the medial tooth engages successive of the ratchet teeth to resist rotation. In these patents the anti-rotation spring beam is self-contained and protected during use but the term ratchet teeth is misused in that the spring beam allows two way rotation of the coupling riut.
However, while such a spring beam is suitable for use in many applications, in some vibration environments, the straight beam could bow upwardly and the medial 40 tooth removed from positive engagement with the ratchet teeth resulting in the coupling nut backing-bff from tightly coupled relation, such backing-off allowing the connector members to axially hammer against one another.
Oftentimes electrical circuitry must be protected from disruptions caused by electromagnetic interference (EMI) entering the system. Connectors are particularly susceptible to EMI energy because of numerous contact areas and openings for cable and external electrical contacts. One approach in preventing disruption from EMI is to ensure that metal-to-metal contact exist between end faces on each connector member. This requires that axial back-off be prevented.
Ratchets and pawls are known to allow movement in 55 one direction but prevent reverse movement in the other direction. However, since an electrical connector must be capable of being both coupled and uncoupled, a suitable anti-decoupling device must allow the coupling nut to rotate in opposite directions.
A desirable anti-rotation device for a separable electrical connector would be protectively enclosed and self-contained, combine the sureness of a ratchet without sacrifice of wanted uncoupling capability, would readily permit connection and/or disconnection and would provide increased resistance to uncoupling torques to resist unwanted uncoupling of the assembly formed.
Accordingly, the present invention is directed to an electrical connector having improved anti-decoupling which overcomes the difficulties and disadvantages associated with prior electrical connectors. An electrical connector assembly of the present invention generally comprises complementary plug and receptacle connector members, a coupling nut rotatably mounted to the plug connector and adapted to connect to the receptacle connector for axially drawing the connectors together upon rotation of the coupling nut in one direction and an anti-decoupling device for resisting unwanted uncoupling rotation of the coupling nut, each connector member comprising a generally cylindrical shell with the receptacle shell having thread formed on 15 a forward portion thereof and the coupling nut having thread formed on an interior portion thereof engagable with the exterior thread of the one connector member to hold the connector members together when in their fully mated assembly.
The anti-decoupling device is adapted to resist rotation of the coupling nut in one direction only relative to the connector member to which the nut is mounted and characterized by first and second sets of radially extending and annularly arranged detents and a detent spring radially interposed between the two sets of detents, one set of detents being disposed around the plug shell and including a plurality of abutment faces and the other set of detents being disposed around the inside surface of the coupling nut and including a plurality of first and second detent faces. The detent spring comprises a generally flat arcuate band including at least one spring finger and at least one detent lug, the spring" finger and detent lug extending radially from opposite surfaces of the arcuate band with the spring finger extending as a cantilever and having a free end adapted to seat within the one set of detents and against respective of the abutment faces and the detent lug being formed on the band and adapted to be seated within and between the first and second detent faces of the other set of detents, the spring finger and detent lug cooperating with their respective detents to allow unimpeded rotation of the coupling nut in the coupling direction but to resist rotation of the coupling nut in the uncoupling direction, whereby application of external coupling torque to the coupling nut constrains the detent spring to rotate with the coupling nut and the spring finger to deflect and advance from one abutment face to another abutment face but upon application of external uncoupling torque to the coupling nut the detent lug transmits force through the detent spring to the spring finger and the abutment face prevents rotation of the detent spring and thus the coupling nut, increased external uncoupling torques causing the detent lug to be cammed radially from engagement with its detent,: whereby the coupling nut breaks free to rotate in the uncoupling direction.
To increase resistance to uncoupling, the detent spring, includes two spring fingers and two detent lugs, the spring being generally C-shaped with opposite ends thereof subtending an angle greater than 180% one detent lug being disposed at each opposite end of the C-spring and the spring fingers being disposed between the ends.
In one embodiment, the one connector member includes an annular flange, the first set of detents are generally V-shaped and disposed annularly around the annular flange, the second set of detents are generally circular and disposed annularly around the coupling nut, the spring band is flat and rectangular in cross-sec