GB2057787A

GB2057787A - Contact member for jack socket

Info

Publication number: GB2057787A
Application number: GB8020632A
Authority: GB
Original assignee: IIZUKA ELECTRIC IND CO Ltd
Current assignee: IIZUKA ELECTRIC IND CO Ltd
Priority date: 1979-08-30
Filing date: 1980-06-24
Publication date: 1981-04-01
Also published as: GB2057787B; FR2464580A1; FR2464580B1; CA1136724A; DE3031800C2; DE3031800A1

Abstract

A jack plug contact member comprises a fixed leg (31) which is fixed to an inner wall of a jack housing, a movable leg (32) having an outwardly projecting contour (32a) for engaging a pin of a jack plug inserted into the jack, and a substantially U-shaped portion coupling (33) the fixed and movable legs to each other at one end, the fixed and movable legs extending substantially parallel with each other. The member is cut out of a thin metal plate in one piece and is formed so that the movable leg is displaceable in a resilient manner toward the fixed leg in the plane of the thin plate. <IMAGE>

Description

SPECIFICATION Jack plug contact members The present invention relates generally to an electrical jack for use in conjunction with a pin-plug, and more particularly to a resilient contact member which engages resiliently with a pin portion of the pin-plug inserted into the jack.

There have been proposed various kinds of jack. Fig. 1 is a cross section showing an embodiment of a known jack. A jack 1 comprises a resilient contact member 2 which is secured to an inner wall of a housing 3 made of electrically insulating material. The contact member 2 is formed by bending a metal strip of a relatively large width into a substantially U-shaped form. The contact member 2 comprises a fixed leg portion 8 and a movable leg portion 10 connected to the leg portion 8 by means of a U-shaped bent portion 6. When a pin-plug 4 is inserted into the jack 1, the movable leg portion 10 is displaced from a position illustrated in Fig. 1 by a chain line due to an engagement of the movable leg portion 10 with a pin portion 5 of the plug 4.

Each time the pin-plug 4 is inserted into and pulled out of the jack 1, the bent portion 6 of the contact member 2 is deformed and thus is fatigued. Therefore the resiliency or elasticity of the contact member 2 becomes gradually decreased. In an extreme case the bent portion 6 might be deformed beyond its elastic limit and could not return to its original position. In this manner the contact pressure of the contact member 2 with respect to the pin portion 5 becomes small and thus an electrical property of pin-plug and jack connection is deteriorated to a great extent.

In order to avoid the above mentioned drawback of the known jack there have been devised several other known jacks. Fig. 2a shows an embodiment of such a jack. In this jack 1 a projection 7 is formed on the inner wall of a housing 3 as shown in Fig. 2a and a fixed leg portion 8 of contact member 2 is provided with a hole 9 as illustrated in Fig.

2b. As shown in Fig. 2a the contact member 2 is secured to the housing 3, while the projection 7 is inserted into the hole 9. The projection 7 has such a length that it can limit the displacement of the movable leg portion 10 of the contact member 2.

Figs. 3a, 3b and 3c show other embodiments of the known contact member 2. In the contact member of Fig. 3a between a fixed leg portion 8 and a movable leg portion 10 is inserted a coiled spring 11. In the embodiment illustrated in Fig. 3b a resilient lead like strip 1 2 is formed integrally with a fixed leg portion 8 and a free end of the strip 1 2 is urged against a movable leg portion 10 in a resilient manner. In the contact member 2 shown in Fig. 3c a projection 1 3 made of insulating material is secured to a fixed leg portion 8.

The contact members illustrated in Figs. 2 and 3 can overcome the disadvantage of the contact member shown in Fig. 1 and the movable leg portion 10 can be effectively prevented from being deformed beyond its elastic limit. However it is rather difficult to manufacture such contact members. It is apparent that the manufacture of such contact members requires at least one additional step.

Particularly in the case of a jack of small size, the contact member could not be formed from a relatively wide metal strip, but has to be made of a thin metal strip such as a metal wire. In this case the measures adopted in Figs. 2 and 3 to improve the performance of the basic contact member 2 could not be applied at all.

In accordance with the present invention there is provided a jack plug contact member comprising a fixed leg for securing the member to a jack housing; a movable leg extending substantially parallel with the fixed leg and having an outwardly projecting contour for engaging the pin of a jack plug inserted into the housing; and a substantially U-shaped portion coupling the fixed and movable legs to one another at one end; the member being cut out of a metal plate in one piece and being formed such that the movable leg is displaceable in a resilient manner toward the fixed leg in the plane of the metal plate.

Either the fixed leg or the movable leg may include integral projections extending into the space between the two legs and thereby limiting the displacement of the movable leg toward the fixed leg. Resilient reinforcing members may also be provided between the two legs so that displacement of the movable leg is against the bias of the reinforcing member.

By way of example only, several embodiments of the invention will now be described with reference to the accompanying drawings in which: Figure I is a cross section showing a connection of a pin-plug and a jack having a known contact member; Figure 2a is a cross section of a known jack and Figure 2b is a perspective view illustrating a contact member of Fig. 2a; Figures 3a, 3b and 3c are perspective views showing another embodiments of a known contact member having means for limiting an excessive displacement of a movable leg portion; Figures 4a and 4b are perspective and plan views, respectively showing an embodiment of a contact member according to the invention; and Figures 5 and 6 are perspective views illustrating another embodiments of a contact member according to the invention; Figures 7a and 7b are perspective and plan views, respectively showing another embodiment of a contact member according to the invention; Figures 8, 9, and 10 are perspective views illustrating three embodiments of a contact member having a reinforcing member formed integrally according to the invention; Figures 11, 12 and 13 are perspective view and cross sectional views of another embodiment of the contact member according to the invention; Figures 14a and 14b are perspective and plan views illustrating another embodiment of the contact member according to the invention; and Figure 15 is a perspective view showing still another embodiment of the contact member according to the invention.

Figs. 4a and 4b show a first embodiment of a resilient contact member of a jack according to the present invention. The contact member of the invention can be easily manufactured by punching a thin metal plate having a thickness of, for example, 0.5 mm by means of a pressing machine. Fig. 4a shows the contact member 20 in a free condition, i.e. in such a condition that it does not engage with a pin-plug. The contact member 20 comprises a fixed leg portion 21, a movable leg portion 22 and a U-shaped portion 23 for coupling the leg portions 21 and 22 with each other.

The movable leg portion 22 has formed therein a semicircularly bent portion 22a which projects outwardly and is to be resiliently engaged with the pin portion 5 of the pin-plug 4 shown in Fig. 1. The fixed leg portion 21 has formed integrally therewith a semicircular sector projection 21a. As shown in Fig. 4b these semicircular portions 21a and 22a have corresponding contour configurations and thus the projection 21 a can serve as a stopper for limiting the displacement of the movable leg portion 22 beyond its elastic limit. Further the fixed leg portion 21 has formed therein a small projection 21 b for securing the contact member 20 to a housing of a jack and a terminal portion 21 c for connecting a lead wire to the contact member 20.Since the contact member 20 is formed by punching the thin metal plate and the movable leg portion operates or deforms in a plane of the metal plate, the elastic force of the movable leg portion is quite large and thus a mechanically and electrically good connection can be obtained between the jack and pin-plug.

Fig. 5 is a perspective view illustrating another embodiment of the resilient contact member according to the invention. A contact member 30 of this embodiment is similar to the previous embodiment shown in Figs. 4a and 4b except that a fixed leg portion 31 has formed integrally therewith a rod-shaped projection 31 a which extends toward a semicircularly bent portion 32a of a movable leg portion 32 connected to the fixed leg portion 31 by means of a U-shaped portion 33. As shown in Fig. 5 the fixed leg portion 31 has formed therein a projection 31b for securing the contact member 30 to a housing of a jack and a terminal portion 31 c for connecting a lead wire to the jack. This contact member 30 can be also simply manufactured by punching a thin metal plate.

Fig. 6 is a perspective view showing still another embodiment of the contact member according to the invention. A contact member 40 of this embodiment comprises a fixed leg portion 41 and a movable leg portion 42 coupled to the fixed leg portion 41 by means of a U-shaped portion 43. In this embodiment a rod-shaped projection 42b is integrally formed with a semicircularly bent portion 42a of the movable leg portion 42. At a free end of the movable leg portion 42 is integrally formed therewith a second projection 42c.

These projections 42b and 42c extend toward the fixed leg portion 41 and thus serve as a stopper for limiting the displacement of the movable leg portion 42 beyond an elastic limit of the U-shaped portion 43. The contact member 40 of this embodiment can be also formed by simply punching a thin metal plate.

Figs. 7a and 7b show another embodiment of a resilient contact member of a jack according to the present invention. The contact member 50 comprises a fixed leg portion 51, a movable leg portion 52 and a U-shaped portion 53 for coupling the leg portions 51 and 52 with each other. The movable leg portion 52 has formed therein a semicircularly bent portion 52a which is resiliently engaged with a top of a pin portion 5 of a pin-plug 4 shown in Fig. 1. The fixed leg portion 51 has formed integrally therewith a small projection 51a for securing the contact member 50 to a housing of a jack and a terminal portion 51 b for connecting a lead wire to the contact member 50.

The contact member 50 has further formed integrally therewith a curved projection 54 which extends from the fixed leg portion 51 in a space between the fixed leg portion 51 and the movable leg portion 52 and serves as a reinforcing member.

When the pin portion 5 of pin plug 4 is inserted into the jack in which the contact member 50 has been installed, the movable leg portion 52 is moved toward the fixed leg portion 51 and is engaged with the projection 54 as illustrated in Fig. 7b. Then the movable leg portion 52 moves together with the projection 54 in a resilient manner toward the fixed leg portion 51 due to the resilience of the movable leg portion 52 and the projection 54. Therefore the movable leg portion 52 could not be bent beyond its elastic limit, and thus the U-shaped portion 53 does scarecely wear and is not deformed beyond its elastic limit. Further the movable leg portion 52 is urged against the pin portion 5 with the great spring force produced by the projection 54 as well as the movable leg portion 52 and thus the pin portion 5 is hardly fallen off the jack.

Fig. 8 is a prespective view illustrating another embodiment of the resilient contact member according to the invention. A contact member 60 of this embodiment is similar to the previous embodiment shown in Figs. 7a and 7b. The contact member 60 comprises a fixed leg portion 61 having a projection 61a and a terminal portion 61 b, a movable leg portion 62 having a semicircularly bent portion 62a, and a U-shaped portion 63. In this embodiment the fixed leg portion 61 has formed integrally therewith a reinforcing projection 64 extending between the fixed and movable leg portions substantially in parallel therewith. The projection 64 serves to allow the resilient displacement of the movable leg portion 62 toward the fixed leg portion 61.

Fig. 9 shows another embodiment of the contact member according to the invention. A contact member 70 of this embodiment comprises a fixed leg portion 71 with projections 71a and 71b, a movable leg portion 72 and a U-shaped portion 73. In this embodiment a reinforcing member 74 is formed by extending the movable leg portion 72 and bending the extension into a space between the fixed and movable leg portions. The reinforcing member 74 extends substantially in parallel with the leg portions 71 and 72. A free end 74a of the reinforcing member 74 is further bent toward a semicircular portion 72a of the movable leg portion 72. At first the reinforcing portion 74 is urged against the fixed leg portion 71 and the movable leg portion 72 is allowed to move toward the fixed leg portion 71.After the free end 74a has been made in contact with the portion 72a the movable leg portion 72 cannot move toward the fixed leg portion any more.

Fig. 10 illustrates another embodiment of the contact member of the invention. A contact member 80 comprises a fixed leg portion 81, a movable leg portion 82 and a U-shaped portion 83. The contact member 80 has formed integrally therewith a reinforcing leg portion 84 which extends from the U-shaped portion 83 in a space between the fixed.and movable leg portions. The fixed leg portion 81 has formed integrally therewith projections 81a and 81b and the movable leg portion 82 has formed therein a semicircularly bent portion 82a and a small projection 82b. The reinforcing leg portion 84 has formed therewith a small projection 84a. At first the projection 82b is made in contact with the reinforcing leg portion 84 and then can move in a resilient manner together with the reinforcing leg portion 84 untill the projection 84a is made in contact with the fixed leg portion 81.

Figs. 11, 12, and 1 3 show another embodiment of the contact member according to the invention. A contact member 90 of the present embodiment comprises a fixed leg portion 91, a movable leg portion 92 and a Ushaped portion 93. The movable leg portion 92 has formed therein a semicircularly bent portion 92a and the fixed leg portion 91 has formed therewith projections 91 a and 91 b.

The contact member 90 is installed in a housing 94 made of electrically insulating material such as resin. The housing comprises a pair of projections 94a and 94b and a ring 95 for inserting a pin portion 5 of a pin-plug 4. When the pin portion 5 is not inserted into the jack as shown in Fig. 12, the movable leg portion 92 is urged against the projection 94a. When the pin portion 5 is inserted into the jack as illustrated in Fig. 13, the movable leg portion 92 is moved toward the fixed leg portion 91 untill it is made in contact with the other projection 94b. After that the bent portion 92a of movable leg portion 92 can be shifted toward the leg portion 91.

Figs. 14a and 14b show another embodiment of the contact member according to the invention. A contact member 100 of the present embodiment comprises a fixed leg portion 101 with a projection 101a, a terminal portion and a projection 101c, a movable leg portion 102 with a semicircularly bent portion 102a and a U-shaped portion 103. Between the free ends of the fixed and movable leg portions 101 and 102 is arranged a leaf spring 104 which pushes the movable leg portion 102 apart from the fixed leg portion 101.When a pin portion 5 of a pin-plug 4 is inserted in a jack in which the contact member 100 is installed as illustrated in Fig. 14b, the movable leg portion is moved toward the fixed leg portion against the resilient force of the movable leg portion 102 and the spring 1 04. When the bent portion 1 02a is made in contact with the projection 101 c, the movable leg portion 102 does not move toward the leg portion 101 any more.

Fig. 1 5 shows still another embodiment of the contact member according to the invention. A contact member 110 of the present embodiment comprises a fixed leg portion 111 with projections 111 a, 111 b and 111 c, a movable leg portion 11 2 with a semicircularly bent portion 11 2a and projections 11 2b and 112c. Between the projections 111 c and 11 2c is arranged a coiled spring 11 4 which makes the movable leg portion 11 2 apart from the fixed leg portion 111.When the pin portion of plug is inserted, the movable leg portion 11 2 is moved toward the fixed leg portion 111 against the resilient force of the leg portion 11 2 and the spring 114 until the projection 11 2b is made in contact with the fixed leg portion 111.

When the contact member according to the invention is installed in a housing of a jack for use in conjunction with a pin-plug and a pin portion of the pin-plug is inserted into the jack, the movable leg portion is displaced in a resilient manner toward the fixed leg portion by means of an engagement of the semicircularly bent portion of the movable leg portion with a pin portion of the pin-plug. Therefore the movable leg portion could not be displaced over a necessary amount and thus the U-shaped portion could not be deformed beyond its elastic limit. Further a contact pressure between the movable leg portion and the pin portion of the pin-plug can be maintained sufficiently high for a very long time and thus the electrical property of the pin-plug and jack connection can be improved to a great extent.

Moreover since the contact member according to the invention can be formed by punching a thin metal plate into a desired shape, the rigidity of the movable and U-shaped portions is very high and thus the contact pressure is further increased. Therefore the pin-plug is hardly drawn out of the jack. Further the contact member according to the invention can be easily manufactured by a single punching operation, so that any additional manufacturing step is not required.

Claims

1. A jack plug contact member comprising: a fixed leg for securing the member to a jack housing; a movable leg extending substantially parallel with the fixed leg and having an outwardly projecting contour for engaging the pin of a jack plug inserted into the housing; and a substantially U-shaped portion coupling the fixed and movable legs to one another at one end; the member being cut out from a metal plate in one piece and being formed such that the movable leg is displacable in a resilient manner toward the fixed leg in the plane of the metal plate.

2. A resilient contact member according to Claim 1, further comprising at least one integral projection extending in the space between the fixed and movable legs, the projection having such a length that displacement of the movable leg toward the fixed leg is limited by engagement of the projection with the movable leg.

3. A resilient contact member according to Claim 2, wherein said projection is integral with the fixed leg.

4. A resilient contact member according to Claim 3, wherein said projection is formed as a semicircular sector and said movable leg has a corresponding semicircularly bent portion for receiving the sector, the bent portion projecting in a direction opposite to the fixed leg and forming said outwardly projecting contour.

5. A resilient contact member according to Claim 2, wherein said projection is a rod-like projection integral with the movable leg.

6. A resilient contact member according to Claim 5, wherein said movable leg has a semicircularly bent portion projecting in a direction opposite to the fixed leg and constituting the outwardly projecting contour, and the rod-like projection is formed at the semicircularly bent portion.

7. A resilient contact member according to Claim 6, wherein a second rod-shaped projection is formed integrally with the movable leg at its free end.

8. A resilient contact member according to Claim 2, wherein said projection is a rod-like projection integral with the fixed leg.

9. A resilient contact member according to Claim 8 wherein said movable leg has a semicircularly bent portion projecting in a direction opposite to the fixed leg portion and forming the outwardly projecting contour and said rod-like projection is engageable with the semicircularly bent portion.

1 0. A resilient contact member according to Claim 1, further comprising a resilient reinforcing member for engaging the movable leg so as to allow a displacement of the movable leg against the resilient bias of the reinforcing member toward the fixed leg.

11. A resilient contact member according to Claim 10, wherein said reinforcing member is formed integrally with the fixed and movable legs and the U-shaped portion as a resilient leg extending in the space between the fixed and movable legs.

1 2. A resilient contact member according to Claim 11, wherein the resilient leg extends from the fixed leg.

13. A resilient contact member according to Claim 11, wherein the resilient leg extends from the U-shaped portion.

14. A resilient contact member according to Claim 11, wherein the resilient leg is formed as an extension of the movable leg, the extension being bent into the space between the fixed and movable legs.

15. A resilient contact member according to Claim 14, wherein a free end of the extension is further bent toward the movable leg.

16. A resilient contact member according to Claim 1 wherein a spring is arranged between the fixed and movable legs such that displacement of the movable leg toward the fixed leg is against the bias of the spring.

1 7. A resilient contact member according to Claim 16, wherein the fixed leg has an integral projection extending toward the movable leg.

1 8. A resilient contact member according to Claim 16, wherein the movable leg has an integral projection which extends toward the fixed leg.

1 9. A resilient contact member according to Claim 10, wherein said outwardly projecting contour is formed by a semicircularly bent portion of the movable leg which pro jects in a direction opposite to the fixed leg for engaging the pin of the pin-plug.

20. A resilient contact member according to any one of the Claims 1 to 19, wherein the fixed leg has a lug for securing the fixed leg to the housing of the jack.

21. A resilient contact member according to one of the Claims 1 to 19, wherein the fixed leg has a terminal for connecting a lead wire to the contact member.

22. A jack for use with a pin-plug, the jack comprising a housing adapted to receive a pin-plug, and a resilient contact member disposed within the housing for engaging the pin of a pin-plug inserted in the housing, the contact member being a member according to any one of the preceding claims.

23. A jack according to Claim 22 in which the housing includes a pair of internal projections disposed such that the free end of the movable leg moves between the two projections during displacement of the movable leg toward the fixed leg.

24. A resilient contact member substantially as herein described with reference to Fig. 4 of the accompanying drawings.

25. A resilient contact member substantially as herein described with reference to Fig. 5 of the accompanying drawings.

26. A resilient contact member substantially as herein described with reference to Fig. 6 of the accompanying drawings.

27. A resilient contact member substantially as herein described with reference to Fig. 7 of the accompanying drawings.

28. A resilient contact member substantially as herein described with reference to Fig. 8 of the accompanying drawings.

29. A resilient contact member substantially as herein described with reference to Fig. 9 of the accompanying drawings.

30. A resilient contact member substantially as herein described with reference to Fig. 10 of the accompanying drawings.

31. A resilient contact member substantially as herein described with reference to Figs. 11 to 1 3 of the accompanying drawings.

32. A resilient contact member substantially as herein described with reference to Fig. 14 of the accompanying drawings.

33. A resilient contact member substantially as herein described with reference to Fig. 1 5 of the accompanying drawings.