Connector

This invention relates to a connector assembly for an electrical connector housing whose coupling completion can be visually confirmed.

Various types of connectors are widely used for connecting electrical and electronic circuits. When a pair of connector housings that forms a connector are coupled, there are cases where the coupling is incomplete even though they are coupled and electrically connected, in which cases the coupling may come apart and break the electrical connection, and may even lead to a dangerous situation. Therefore, what is needed is a connector whose coupling completeness can be confirmed by the operator at the point in time when it is coupled.

Japanese Patent Application 60-1774, as shown in prior art FIGS. 8 and 9, is directed to a visible coupling complete indicator. FIG. 8 is a cross-sectional view showing the pre-coupling status of one connector housing. As shown in FIG. 8, coupling complete indicator member 22's projection 22b is held in one connector housing 21, coupling complete indicator member 22 is pressed by spring 24, and coupling complete indicator member 22's rod-shaped member 22f is supported by arm 21b. As shown in FIG. 8, arm 21b's front end 21c has a narrowed shape that surrounds the front end of rod-shaped member 22f. Prior art FIG. 9 is a cross-sectional view showing the connector housing with the coupling in a completed state. As shown in FIG. 9, when another connector housing 25 is coupled with connector housing 21, connector housing 25 opposes the pressure of spring 24, and bottom 22a of coupling complete indicator member 22 is pushed upward, so coupling complete indicator member 22's rod-shaped member 22f opens connector housings 21's front end 21c and moves through that opening, and rod-shaped member 22f's front end 22e projects outside connector housing 21. This front end 22e has a color that differs from that of connector housing 21, for example, and complete coupling can be confirmed by looking at this front end 22e.

The prior technology of Japanese Utility Application 61-197672, as shown in FIGS. 10 and 11, is also concerned with the same sort of object. In connector housing 30 shown in FIG. 10, coupling complete indicator member 32's projection 32b is held in main body unit 33, and coupling complete indicator member 32's compressible front end 32e is inserted in hole 34d in indicator unit 34, and coupling complete indicator member 32 is pressed by spring 31 and is supported between connector housing 30's main body unit 33 and indicator unit 34.

In prior art FIG. 11, connector housing 33 is coupled with another connector housing 35, and this connector housing 35 opposes the pressure of spring 31, and pushes up bottom 32a of coupling complete indicator member 32. When coupled, coupling complete indicator member 32's front end 32e compresses and passes through hole 34d, and front end 32e projects outside indicator unit 34. The connector's coupling completeness can be confirmed by looking at this projection.

The two conventional technologies noted above have problems. With the conventional example shown in prior art FIGS. 8 and 9, even though arm 21b's front end 21c narrows, there are cases where gap 21d occurs, and even when the coupling is imperfect and coupling complete indicator member 22's front end 22e doesn't project outside, or the operator can see coupling complete indicator member 22's front end 22e through gap 21d and mistakenly decide the coupling is complete. Additionally, with the conventional example shown in prior art FIGS. 10-11, providing hole 34d further increases the possibility of an incomplete coupling situation.

In view of the above-noted circumstances, the object of this invention is to present a connector in which the operator can visually confirm the completion of the coupling of the connector housing without error.

In order to achieve the above-noted object, the instant connector is characterized by providing a pair of mutually coupling connector housings, and attaching a flexible arm for indicating coupling completion which is disposed in one of the pair of connector housings. Additionally, a coupling complete indicator window opening is formed through the inner wall and outer wall of the connector housing. Also, an engaging protrusion is formed on the inner wall to engage the flexible arm when coupling and elastically deforming the flexible arm to reach a position visible through the coupling complete indicator window from a position outside the coupling complete indicator window when coupling is complete.

The invention's connector has the above-noted coupling complete indicator window, and when coupled the above-noted engaging protrusion engages with the flexible arm, and the flexible arm is arranged such that it is elastically deformed to reach a position visible through the coupling complete indicator window from a position outside the coupling complete indicator window when coupling is complete. The operator, therefore, cannot see the flexible arm when coupling is incomplete, and the operator can visually confirm the flexible are through the coupling complete indicator window only when coupling is complete. In this way the connector housing's complete coupling can be visually confirmed with confidence and without error. Moreover, the instant invention uses the elasticity of the coupling complete indicator member, so the separate spring member in conventional technology is not required, and the number of parts is reduced and assembly costs are lowered.

FIG. 1 is a cross-sectional view of one embodiment of the invention showing the coupling status before coupling completion.

FIG. 2 is a plan view of the bolt housing shown in FIG. 1.

FIG. 3 is a cross-sectional view of the bolt housing of FIG. 1 taken along line A--A.

FIG. 4 is a cross-sectional view of the bolt housing of FIG. 1 taken along line B--B.

FIG. 5 is a cross-sectional view the embodiment of FIG. 1 showing the coupling status after coupling completion.

FIG. 6 is a cross-sectional view of a second embodiment of the invention before coupling completion.

FIG. 7 is a cross-sectional view of a second embodiment of the invention after coupling completion.

FIG. 8 is a cross-sectional view of a conventional connector.

FIG. 9 is a cross sectional view of the connector of FIG. 8 after coupling completion.

FIG. 10 is a cross-sectional view of a conventional connector.

FIG. 11 is a cross sectional view of the connector of FIG. 10 after coupling completion.

FIG. 1 is a cross-sectional view showing one embodiment of the invention before coupling completion. FIG. 1 shows cap housing 7 imperfectly coupled in a distal position relative to bolt housing 1 and plug housing 3, which altogether form a unitary housing.

Coupling complete indicator member 9's flexible cantilever spring arm 9a engages with protrusion 1a formed on the inner wall of a cavity in bolt housing 1, and elliptical spring member 9b contacts contact member 1b projecting from the inner wall of bolt housing 1. Further, holding unit or projection 9c is held by bolt housing 1's projection 1e, and thus coupling complete indicator member 9 is supported by bolt housing 1. It is seen that coupling complete indicator member 9 is pressed downward in FIG. 1 by the engagement of bolt housing 1's protrusion la and contact member 1b. Additionally, bolt or joining mechanism 5 is inserted through bolt hole 1d (see FIG. 2) in bolt housing 1, and plug housing 3 is fitted onto bolt 5. Further, a unitary housing is formed from bolt housing 1 and plug housing 3.

FIG. 2 is a top view of bolt housing 1 shown in FIG. 1, FIG. 3 is a cross-section view along A--A in FIG. 2, and FIG. 4 is a cross-section view along B--B in FIG. 2. Referring to FIG. 2, coupling complete indicator window 1c is provided in the top of bolt housing 1 in order to confirm the complete coupling of connector housings 3 and 7. The cross-sectional view shown in FIG. 3 has protrusion 1a, which engages with coupling complete indicator member 9's flexible arm 9a (see FIG. 1), and contact member 1b, which contacts elliptical or O-shaped spring member 9b, around coupling complete indicator window 1c for confirming complete coupling. Additionally, the cross-sectional view shown in FIG. 4 has bolt hole 1d with bolt 5 inserted and bolt support protrusion 1f, which engages with bolt 5's notch.

FIG. 5 is a cross-sectional view of the embodiment in FIG. 1, but with the plug housing 3 and the cap housing 7 in a relatively proximal position, such that cap housing 7 is perfectly coupled with plug housing 3 (including bolt housing 1). Plug housing 3 has a plurality of electrical contacts (not shown) for mating engagement with electrical contacts in cap housing 7. Plug housing 3 and cap housing 7 are coupled by tightening bolt 5. Specifically, cap housing 7 presses upward on coupling complete indicator member 9 at downward projection 9e, as shown in FIG. 5, thereby displacing the coupling complete member 9, and thus flexible arm 9a is bent toward coupling complete indicator window 1c by protrusion 1a. Then, when coupling is complete, flexible arm 9a's tip 9d reaches the position of coupling complete indicator window 1c, and for the first time flexible ar 9a can be seen through coupling complete indicator window 1c. Further, a gap is formed between the coupling complete member 9 and the plug housing 3, and a gap is formed between the plug housing 3, holding unit 9c, and projection 1e. The coupling complete indicator member 9 has a color which is obviously different from the housing, so that by looking at this the operator can confidently confirm that the connector housing's coupling is complete.

FIGS. 6 and 7 are cross-sectional views of a second embodiment of this invention showing the start of coupling (FIG. 6), and complete coupling (FIG. 7.) In these Figures the same numbers are assigned to the same structural elements as in FIGS. 1-5 (see FIGS. 1-5), so that duplicate explanations are omitted. In this embodiment, as shown in FIG. 7, coupling complete indicator member 9's flexible arm 9a's tip 9d faces upward. When plug housing 3 and cap housing 7 are coupled from a relatively distal to proximal position by tightening bolt 5, coupling complete indicator member 9 is pushed upward, and thus flexible arm 9a engages with protrusion 1a and bends toward coupling complete indicator window 1c. Then, when coupling is complete, flexible arm 9a's tip 9d' is inserted into coupling complete indicator window 1c. In this way, the operator can visually confirm with all the more clarity that coupling is complete.

Furthermore, coupling complete indicator member 9 has elliptical spring member 9b in the above-noted embodiments, but flexible arm 9a itself has springiness, so elliptical spring member 9b can be eliminated by providing flexible arm 9a with appropriate elasticity. Moreover, each of the above-noted embodiments is furnished with a pair of flexible arms 9a, but there could also be a single or a plurality of flexible arms.

Finally, each of the above-noted embodiments is an example of this invention using a bolt-tightening type of connector, but this invention is not limited to a bolt-tightening type of connector, as it can be adopted in many types of connectors.