Lever type connector

Abstract: A c-shaped lever member 30 is attached and supported on a housing 20 by straddling it, plate springs 32e are formed on the inner side faces of wing members 32, and stoppers 22c are formed on the housing 20 so that they make contact with the plate springs 32e. As a result, the plate springs 32e do not protrude outwards and are less easily damaged by accident and moreover, a compact lever-type connector 10 is provided.

Description: TECHNICAL FIELD The present invention relates to a lever-type electrical connector, and specifically relates to a lever-type connector comprising a spring mechanism which makes a lever move in a specified direction with respect to a housing. BACKGROUND TO THE INVENTION A conventional lever-type connector of this kind is described in Laid-Open Publication JP-5-90843, and is shown in Figure 9 of this specification. A schematically rectangular shaped housing 1 has a hood 2 constituted by the anterior end portion thereof, and a terminal insertion member 3 constituted by the posterior end portion. The hood 2 has a C-shaped lever 4 provided thereon which grips the hood 2. The lever 4 comprises a transverse member 4a which extends in a parallel manner with respect to the upper face of the housing 1, and arms 4b which extend from both the ends of the transverse member 4a in a parallel manner with respect to the side faces of the housing 1. Supporting pins 2a formed on the external side faces of the hood 2 fit into axial holes 4b1 formed on the arms 4b, thereby pivotably supporting the arms 4b. The external side faces of the housing 1 have protecting walls 5 formed to support the arms 4b from the outside. These protecting walls 5 have resilient plastics spring members 5a formed so as to protrude towards the arms 4b. These spring members 5a make contact with the arms 4b and lightly apply a force thereon so as to pivot the arms 4b in a clockwise direction (as viewed). However, if the spring members were to be attached to the lever member 4 instead of to the housing 1, they would exposed, resulting in a possibility of damage occurring due to collision with an external object or the like. Such a construction is disclosed in JP-7-230850 which shows an electrical lever-type connector in which integral leaf springs on the lever arm urge the arm to an open condition. The springs are exposed, and are susceptible to contact damage. The present invention has been developed after taking the above problem into consideration, and aims to present a lever-type connector wherein a plastics spring that is difficult to damage is used in the lever member. According to the invention there is provided a lever-type electrical connector comprising a moulded plastics body and a moulded plastics lever arm pivotally mounted on the body, the lever arm having a transverse portion extending across the body and two side arms, one at each end of the transverse portion, each side arm being journalled in a respective side of the body, and having an inner surface adjacent the body, wherein an integrally moulded resilient member is provided on the inner surface of one of said side arms, the body having an abutment engageable with said resilient member to urge said transverse portion away from said body, characterised in that said resilient member is wholly located in a recess in the inner surface of said side arm, and said recess opens from said side arm in the arcuate direction of said closed condition to expose said resilient member to said abutment. BRIEF DESCRIPTION OF DRAWINGS Other features of the invention will be apparent from the following description of a preferred embodiment shown by way of example only in the accompanying drawings in which: FIGURE 1 is a side view of a lever-type connector related to an embodiment of the present invention; FIGURE 2 is a diagonal view of the inner side face of a wing member of the lever-type connector of Fig.1; FIGURE 3 is a see-through side view showing a spring member and a convex member in the lever-type connector of Fig. 1; FIGURE 4 is a graph showing the load required to be applied on the lever member for a given angular movement; FIGURE 5 is a diagram showing the bending of the plate spring; FIGURE 6 is a graph showing the load generated by the plate spring as the deflection angle increases; FIGURE 7 is a partially enlarged side view of the wing member showing an example of a variation of the plate spring; FIGURE 8 is a partially enlarged side view of the wing member showing an example of a variation of the plate spring; FIGURE 9 is a side view of a conventional lever-type connector. DESCRIPTION OF PREFERRED EMBODIMENT A lever-type connector 10 comprises a schematically angular tubular shaped housing 20 and a lever member 30 which straddle the housing 20. The housing 20 has a terminal insertion member 21 that allows the insertion of terminal fittings in the posterior end side thereof. A tubular hood member 22 is formed so as to widen from the anterior end of the housing 21. The hood member 22 allows the insertion therein of the anterior end portion of a corresponding connector. Side walls 22a of the hood member 22 have slots 22a1 formed in the centre so as to extend from the anterior end towards the posterior end, these slots 22a1 allowing cam pins formed on the side walls of the corresponding connector to be inserted therein and to thereby allow them to protrude outwards. Moreover, two parallel slots 22a2 are formed above and below the slots 22a1. Position-fixing ribs formed on the side wall faces of the corresponding connector fit into these slots members 22a2. The lever member 30 comprises a base member 31 that approximately corresponds to the width of the hood member 22, and wing members 32 that extend vertically from both ends of the base member 31. The wing members 32 grip the hood member 22. Moreover, the side walls 22a of the hood member 22 have supporting pins 22b projecting outwards and located more towards the posterior side than the slots 22a1. The wing members 32 of the lever member 30 have axial holes 32a that allow the insertion of supporting pins 22b. Consequently, the lever member 30 straddles the housing 20 and is supported so as to be pivotable within a specified range. As shown in Figure 2, the inner sides of the wing members 32 have partially spiral cam grooves 32c formed around the axial holes 32a. The extreme end of the outer portion of each cam groove 32c opens out to the side face of the wing member 32. This opening faces the slots 22a1 when the lever member 30 is at an angle corresponding to an initial position, having been rotated in an anti-clockwise direction with respect to the housing 20, as shown in Figure 1. From this position, when the lever member 30 rotates in a clockwise direction, the cam grooves 32c move sideways past the slots 22a1, and in the end the inner end portions of the cam grooves 32c come to face the inner side of the slots 22a1. At this stage, the cam pins of the corresponding connector are pulled towards the inner side of the cam grooves 32c within the slots 22a1. If the lever member 30 is rotated in the opposite direction, the cam pins are pulled out from the slots 22a1. Moreover, the outer face of the housing 20 is formed so as to be vertically symmetrical, and the lever member 30 can be attached either from above or from below. In the present embodiment, in the housing 20 having the hood member 22 and the terminal insertion member 21 provided as described above, although the lever member 30 with the cam grooves 32c is provided, as long as the housing 20 has an approximately tubular shape and a C-shaped lever member 30 straddles its anterior end and is rotatably supported thereon, the shape can be varied according to necessity. Consequently, it may be equally arranged so that, for example, it is the lever member 30 that has the pins and the corresponding connector that has the grooves, and the cross-sectional shape of the housing 20 can be changed so that the angular tubular shape is somewhat rounded. Moreover, the lever member 30 can be attached to the housing 20 either from above or below; although, it can equally be arranged so that attachment is allowed only from a specified direction. A cover 23 having a lock releasing member 23a is attached so as to cover the posterior face of the terminal insertion member 21. A locking member 31a is formed on the base member 31 of the lever member 30; this locking member 31a locks with the lock releasing member 23a when the cover 23 is attached. The locking member 31a has a protrusion 31a1 projecting from the posterior end thereof, and the lock releasing member 23a has a fitting protrusion 23a1 that fits with the protrusion 31a1. Consequently, when the lock releasing member 23a is bent so as to be inclined in a posterior direction, the lock is released. In the present embodiment, although the cover 23, provided with the lock releasing member 23a, is provided independently of the terminal insertion member 21, it may equally be formed uniformly with the terminal insertion member 21. Moreover, the lever member 30 may equally be such as to be fitted and fixed to the other connector. As shown in Figure 3, the inner side faces of the wing members 32 of the lever member 30 have concave recesses 32d formed on a portion facing the posterior face in the clockwise-rotated state. Inside these recesses 32d are formed flexible single-support plate springs 32e that are supported at one end; these plate springs 32e are formed in the circumferential direction with respect to the axial holes 32a. Moreover, the housing 20 has stoppers 22c formed thereon so as to be capable of making contact with the plate springs 32e. When the lever member 30 is rotated in a clockwise direction, the anterior end portions of the plate springs 32e are pushed against the stoppers 22c and bend. Furthermore, in correspondence with the fact that the lever member 30 can be attached from either above or below, the stoppers 22c are also formed in two places, above and below. That is, when the lever member 30 is pivoted, the plate springs 32e apply an opposing force against the lever 30 in a direction opposite to the direction of movement of the lever 30. Figure 4 shows the maximum load necessary to rotate the lever 30 in the anti-clockwise direction after it has been rotated maximally in the clockwise direction. After releasing the lock, in order to make the operation of the base member 31 easier, it is desirable that it rise up from 0 up to 15; the maximum load in this case is 0.4N. In contrast, as shown in Figure 6, when the plate springs 32e are bent as shown in Figure 5, in the maximally bent state of 0, a load of 1.74N is generated, and even in the state corresponding to 15 where the bending gradually decreases, a load of 0.72N is generated, which is enough to cause the lever member 30 to rise up. In the present embodiment, although the plate springs 32e are formed as spring members in the recesses 32d opening towards the side faces of the wing members 32, the spring members need not directly face the circumferential direction and may be diagonal as long as they have at least a bending component in at least the circumferential direction. Moreover, although the spring members are formed by means of the single-support plate springs 32e supported at one end, in the case where this is insufficient to generate a specified load, twin-support plate springs supported at both ends can be provided, as shown in Figure 7. In the case of the plate springs supported at both ends, a larger opposing force can be maintained for a longer time. Of course, apart from this, the shape of the plate spring can be changed as required to a curved shape, for example, as shown in Figure 8. Moreover, in the case of the present embodiment 1 although it is arranged that during the release of the lock the rotation is limited to making the lever member rise, it may equally be arranged so that the stroke is increased as necessary. However, it is more effective to have an arrangement so that the extent of movement of the rising up is kept short when a plastics spring is formed in a unified manner on to the lever member 30. Furthermore, although the recess 32d is formed on the wing member 32, it may be formed either on the interior side face of the lever member 30 or on the inner side face of the base member 31. Of course, in this case the location of the stopper must be altered so that it is located in a corresponding position. Next, the operation of the embodiment, configured as described above, is explained. The lever member 30 is attached so as to straddle the hood member 22 of the housing 20, and, with the lever member in a pivoted state in the anti-clockwise direction, the corresponding connector is fitted thereto, and gradually the lever member 30 is rotated in the clockwise direction. As the lever member 30 is rotated, the corresponding connector is pulled in, and in the maximally rotated position the two connectors fit and connect, and the locking member 31a formed on the base member 31 fits and is fixed firmly with the lock releasing member 23a formed on the cover 23. Just before this final position is reached, the plate spring 32e makes contact with the stopper 22c and bends, and in the fitted and fixed state the plate spring 32e experiences an opposing recovery force. Consequently when the operator inclines backwardly the lock releasing member 23a and thereby releases the fitting with the locking member 31a, due to the opposing force the wing members 32 rotate slightly. When this happens, the base member 31 reaches a state whereby it is raised from the housing 20, and it becomes easy to raise it with a finger. Moreover, since the plate spring 32e is housed in the concave member 32d, it cannot easily collide with an external object, and therefore is not damaged easily. Furthermore, a compact lever-type connector 10 is provided.

Claims: A lever-type electrical connector (10) comprising a moulded plastics body (20) and a moulded plastics lever arm (30) pivotally mounted on the body (20) for arcuate movement between an open and a closed condition, the lever arm (30) having a transverse portion (31) extending across the body and two side arms (32), one at each end of the transverse portion (31), each side arm (32) being journalled in a respective side of the body (20), and having an inner surface adjacent the body (20), wherein an integrally moulded resilient member (32e) is provided on the inner surface of one of said side arms (32), the body (20) having an abutment (22c) engageable with said resilient member (32e) to urge said transverse portion (31) away from said body (20) towards the open condition, characterised in that said resilient member (32e) is wholly located in a recess (32d) in the inner surface of said side arm (32), and said recess (32d) opens from said side arm in the arcuate direction of said closed condition to expose said resilient member (32e) to said abutment (22c). The connector of claim 1 wherein the resilient member has one free end. The connector of claim 1 wherein the resilient member (32e)is supported at both ends on the side arm (32), a camming surface being defined substantially between said ends for contact with said abutment (22c). The connector of claim 1 or claim 2 wherein the resilient member (32e) is convoluted. The connector of claim 4 wherein the resilient member (32e) is helical. The connector of any preceding claim wherein a respective resilient member (32e) is provided on each side arm (32). The connector of any preceding claim wherein the abutment (22c) comprises a projection of said body (20).

Inventors: KATSUMA TAKATOSHI, KATSUMA, TAKATOSHI
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1997
Main classification: H01R13
IPC codes: H01R13