Lever-type connector

Abstract: A lever-type electrical connector 10,20 has a lever 30 pivotable from open to closed conditions to draw the connector parts together. A resilient latch 33,14 holds the lever in the closed condition. When the lever 30 is unlatched by depressing an abutment 14b it is given an initial upward movement by virtue of a ramped abutment 14d1, 14b1, 34 or by a resilient spring formed e.g. by a waterproof ring seal 15. This initial movement permits the lever to be grasped for further movement. A separate wire spring is avoided.

Description: TECHNICAL FIELD The present invention relates to a lever-type connector, and particularly to a lever-type electrical connector. BACKGROUND TO THE INVENTION Figure 8 and Figure 9 of this specification show a conventional lever-type electrical connector in which a male connector 1 has a hood 2. A C-shaped pivoting lever 3 straddles the hood 2 from above and has arms 3a and 3b which engage the hood 2. Axial holes 3a1 are formed on the pivot axis of the lever 3. Axial pins 2a formed on the external face of the side wall of the hood 2 pass through the axial holes 3a1, thereby making the lever 3 pivotable. The internal side faces of the arms 3a have spiral-shaped cam grooves 3a2. The external-most portions of these cam grooves 3a2 form guiding apertures 3a3 which open in the direction of the open side of the hood 2. A female connector 4 is insertable into the hood 2. In the side walls of the female connector 4, cam pins 4a project outwards from slits 2b formed from the open side of the hood 2. After inserting these cam pins 4a into the slits 2b, the pins 4a engage the grooves 3a2 of the lever 3, and when the lever 3 is pivoted, the male and female connector are drawn together. One of the axial pins 2a has a helical spring 5 wound around it. One end of the spring 5 is fixed to the lever 3 and the other end is fixed to the hood 2 so as to bias the lever in the open direction. A bridge member 3b that connect the arms 3a has a latch member 3c that projects in the direction of the male connector 1 when the lever 3 is in the closed position. The latch member 3c has a projection 3c1 formed at an anterior end which protrudes in a posterior direction. Furthermore, the male connector 1 has a locking member 6 that has a latch hole 6a provided therein. The locking member 6 protrudes in the direction of the fitting member 3c, and the latch hole 6a allows the projection 3c1 to be engaged therein. The locking member 6 has a pressing-down member 6b. When the pressing-down member 6b is pressed down, the locking member 6 bends and, as shown in Figure 9, the projection 3c1 separates from the latch hole 6a. When the fitting is released the lever 3 pivots up slightly due to the helical spring and reaches a state in which it can be engaged by hand for movement to the open condition. In this conventional lever-type connector, the helical spring 5 causes the lever 3 to rise slightly after the release of the latch. Since a separate part must be attached, the production process becomes problematic, and production cost also rises. The present invention has been developed after taking the above problem into account, and aims at presenting a low cost lever-type connector wherein the lever is made to rise upwards after the release of the fitting, but without the helical spring 5. US-A-5344194 discloses a lever arm connector having a resilient wire or plate spring to urge the lever arm through a predetermined angle to a fully released condition. SUMMARY OF THE INVENTION According to the invention there is provided a connector having a body, and an arm pivotable on said body from an open to a latched position, the arm being releasably retainable in the latched position by a latch comprising a latch member of said arm and a latching member of said body, the connector further including disengagement means arranged to urge said arm from the latched position through a predetermined angle to a delatched position intermediate said latched and open positions when said arm is delatched, wherein said latching member is pivotable on a resilient foot, one of said arm and latching member having a ramp surface whereby resilient movement of the latching member about said foot releases the latch, and said ramp surface is operable by abutment to move said arm to the delatched position. Such a connector has an arm which can be urged to a delatched condition where it can be manually moved to the open position. Normally the resistance to movement of the connector cables means that greater force is required to fully separate the two parts of a connector. Accordingly there is no strain on the disengagement means whilst the arm is in the fully open position. The disengagement means may be a rigid abutment. The rigid abutment may be an integral part of a latching member. According to the invention the latching member has a resilient foot to permit movement from a latched to an unlatched condition. In this arrangement resilient movement of the latching member releases the latch and brings the disengagement means into contact with the arm, thereby to move the arm to the delatched position; removal of the delatching force permits the latching member to return to the rest position whilst leaving the arm in the delatched position for subsequent manual movement. This arrangement has the particular advantage that the disengagement means is not under load whilst the arm is in the latched position. The arm is preferably in the form of a stirrup and has a depending latch projection for engagement by the latching member. The disengagement means preferably acts directly on the latch projection. The rigid abutment may be made as part of a one piece connector body, for example a plastics moulding, thus eliminating entirely the need for a spring and the consequent assembly step. The latching member may be provided on the body of the connector or on the body of another component with which the connector is fitted in use. This invention is particularly useful for lever-type connectors in which the arm is flush with the connector body in the latched condition and thus difficult to grasp for delatching. BRIEF DESCRIPTION OF DRAWINGS Other features of the invention will be apparent from the following description of several preferred embodiments shown by way of example only in the accompanying drawings in which: Figure 1 is a side view of a first variant of a lever-type connector of the present invention. Figure 2 is a partial side view of a second variant of the lever-type connector. Figure 3 is a partial side view of a third variant of the lever-type connector. Figure 4 is an enlarged side view of the main parts of the lever-type connector relating to the first variant. Figure 5 is an enlarged side view of the main parts of the lever-type connector relating to the second variant. Figure 6 is an enlarged side view of the main parts of the lever-type connector relating to a fourth variant. Figure 7 is an enlarged side view of the main parts of the fourth variant in another position. Figure 8 is a side view of the conventional lever-type connector in a latched condition. Figure 9 is a side view of the conventional lever-type connector in an unlatched condition. DESCRIPTION OF PREFERRED EMBODIMENTS Figure 1 shows a male connector 10 that serves as a housing and comprises a terminal insertion member 11 and a hood 12. The terminal insertion member 11 is rectangularly box shaped and has a plurality of tubular terminal insertion chambers (not shown) which in use support conventional male terminal fittings. The hood 12 protrudes tubularly from the periphery of the open faces of the terminal insertion chambers. A female connector 20 is insertable into the hood 12. The hood 12 has retraction slits 12a1 formed towards the open sides of side walls 12a thereof. These retraction slits 12a1 correspond to retraction pins 21 projecting from the side wall faces of the female connector 20. A pivoting lever 30 is schematically C-shaped so as to straddle the hood 12 from above. The lever 30 comprises arms 31 that face the outer faces of the side walls 12a of the hood 12, and a base 32 that faces the upper face of a ceiling wall 12b of the hood 12. The outer faces of the side walls 12a have axial pins 12c that project outwards. The arms 31 have axial holes 31a that receive the axial pins 12c. Furthermore, it is arranged so that the arms 31 may be flexibly opened and made to straddle the hood 12, the axial pins 12c being inserted into the axial holes 31a, thereby allowing the lever 30 to be pivotably fitted. Spiral cam grooves 31b are formed on the inner side faces of the arm members 31. The outer extreme portions of the cam grooves 31b open towards the side faces of the arms 31 and form guiding apertures 31b1. When the lever 30 is rotated maximally in the counter-clockwise direction with respect to Figure 1 (this is the open condition), the guiding holes 31b1 coincide with the open end of the retraction slits 12a1. This makes it possible for the retraction cam pins 21 of the female connector 20 to enter into the cam grooves 31b. As the lever 30 is pivoted in the clock-wise direction, the spiral cam grooves 31b cause the retraction cam pins 21 to be drawn towards the direction of the axial pins 12c. As a result, the female connector 20 is drawn into the hood member 12. The position of the lever 30 whereby the female connector 20 is in a retracted state deep into the hood member 12 is known as the closed condition. The upper face of the terminal insertion member 11 has a locking member 14 formed so as to project upwards, and the lever 30 also has a latch member 33 formed so as to project towards the locking member 14. The latch member 33 is formed so as to approach the anterior end of the locking member 14 when the closed condition is reached. A wedge shaped fitting projection 33a is formed on the anterior end face of the latch member 33. This fitting projection 33a faces towards the locking member 14. In the closed condition, the projection 33a engages a fitting hole 14a formed in the locking member 14. The upper end of the locking member 14 has an operating member 14b that is offset towards the rear so as to avoid collision with the base 32. When the operating member 14b is pressed downwards, the locking member 14 itself inclines in a rearwards direction since the operating member 14b is offset towards the rear. This rearward inclination allows the locking member 14 to be released. The locking member 14 has a projection 14d formed so as to extend forwardly from somewhat below the fitting hole 14a and so as to curve around and upwards from the lower part of the latch member 33. This projection 14d has an inclined face 14d1 that faces the front lower end of the latch member 33. When the locking member 14 inclines posteriorly, this projection 14d moves approximately horizontally in a rearwards direction and causes the inclined face 14d1 to collide with the lower end of the latch member 33 (Fig. 4). As a result, the latch member 33 is pressed upwards along the inclined face 14d1, which in turn causes the lever 30 to be pushed backwards slightly from the closed condition in the direction of the open condition. In other words, the inclined face 14d1 of the projection 14d constitutes a movable abutment. In this first variant, although the locking member 14 is arranged to incline in a rearwards direction, all that is necessary is that it be inclinable. Consequently, as shown in Figures 2 and 5, in the case where the latch member 33 is to the rear of the locking member 14 and the fitting projection 33a protrudes in a forwards direction, the locking member 14 inclines in a forwards direction, and the latch member 33 is released by pressing the operating member 14b from a rear towards the front. Moreover, as shown in Figure 3, the inclining movement is not limited to a front/rear movement; a left-right movement is possible as well so that downwards and rightwards (as viewed) movement of the locking member 14b causes an upward engagement of the projection 14d on the latch member 33. Furthermore, the lever 30 and the locking member 14 need only fit together; there are no limitations regarding the basic concave-convex fitting shapes of the lever 30 and the locking member 14. In the present embodiment, although a configuration is assumed whereby the locking member 14 inclines in a posterior direction, as shown in Figure 2, in the case where the locking member 14 inclines in an anterior direction, it may equally be arranged that an inclined face 14b1 be formed on the lower anterior face of the operating member 14b, and that during the pressing down operation the inclined face 14b1 collide with the lower end of a latch member 33 when it is pushed, thereby pushing the latch member 33 back. That is, all that is required is that there be a direct or indirect way of causing the lever 30 to be pushed back towards the open condition by means of the inclining operation of the locking member. Consequently, it may equally be arranged that an inclined face be formed on the lever 30. In the configuration shown in Figure 6 and Figure 7, an inclined face 34 is formed on the lever 30 so as to face the operating member 14b. This is in contrast to the pressing-down type configuration shown in Figure 2. As a result, if the operating member 14b is pushed forwards (as viewed), it collides with the inclined face 34 causing it to be pushed upwards. The shape etc. of the inclined face 34 formed towards the rotating lever 30 can be varied as necessary to give desired release characteristics. These inclined faces may be advantageously located in positions where it is easy to change the shapes thereof as necessary, so as to correspond with the shapes of peripheral members, and so on. Next, the operation of the first variant is explained. The lever 30 is pivoted up to the initial position and the female connector 20 is inserted into the hood member 12. The retraction cam pins 21 of the female connector 20 enter the cam grooves 31 via the guiding holes 31b1 of the arm members 31. Then, the rotating lever 30 is rotated in the clock-wise direction from the initial position to the final position. Accordingly, the female connector 20 is pulled deep into the hood member 20. The latch member 33 is pushed so as to brush against the anterior face of the locking member 14, and the fitting projection 33a enters and fits with the fitting hole 14a. Accordingly, the lever is firmly latched. When it becomes necessary to separate the male connector 10 and the female connector 20, the operating member 14b located at the upper end of the locking member 14 is pushed downwards. When this is done, the locking member 14 inclines in a posterior direction due to the lowering of the operating member 14b that is in an offset position. As a result, the latch member 33 is released. Moreover, since the projecting member 14d moves in a posterior direction, the inclined face 14d1 abuts with the lower end of the latch member 33, thereby pushing it upwards a little. Since the lever 30 is now in a floating state, having been pushed back slightly towards the open condition, the lever 30 can be grasped and easily moved to the fully open condition despite resistance of associated terminals cables and the like. Positive lifting of the latch member overcomes another prior problem that the internal spring may stick or jam. In the present invention, although a terminal insertion member 11 and the hood 12 are provided, there is no particular restriction in this regard. Moreover, although application to the male connector 10 is described above, the description is equally applicable if the side which houses the female terminal fittings is considered instead. Although the lever-type connector was originally developed to prevent deterioration in operability that accompanies the increase in fitting force due to multiple terminals, the lever-type connector is not necessarily limited to multiple terminal use and is also applicable for other purposes such as preventing disconnection, by means of a cam structure. In the present invention, it is not necessary for the lever 30 to straddle the hood 12 as long as it is pivotably supported and can retract the corresponding connector. Moreover, it is not necessary to have the cam grooves formed on the side of the lever 30; the locations of the cam pins and the cam grooves can be reversed. Furthermore, for convenience and depending on the pivoting operation, a retractable concave-convex shape can be provided apart from the fitting configuration comprising the cam pins and the cam grooves.

Claims: A connector having a body (10), and an arm (30) pivotable on said body (10) from an open to a latched position, the arm (30) being releasably retainable in the latched position by a latch comprising a latch member (33) of said arm and a latching member (14) of said body, the connector further including disengagement means (14d;14b1;34) arranged to urge said arm (30) from the latched position through a predetermined angle to a delatched position intermediate said latched and open positions when said arm is delatched, wherein said latching member (14) is pivotable on a resilient foot, one of said arm (30) and latching member (14) having a ramp surface whereby resilient movement of the latching member (14) about said foot releases the latch, and said ramp surface is operable by abutment to move said arm (30) to the delatched position. A connector according to claim 1 wherein the disengagement means comprises a rigid disengagement abutment (14d;14b1;34) for contact with said arm (30). A connector according ot claim 2 wherein said rigid disengagement abutment (14d; 14b1; 34) is moulded as a single part with said body (10). A connector according to any preceding claim wherein said arm (30) is in the form of a stirrup, from which projects said latch member (33) for engagement by said latching member (14).

Inventors: WAKATA SHIGEKAZU, WAKATA, SHIGEKAZU, Wakata, Shigekazu, Sumitomo Wiring Systems, Ltd.
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1996
Main classification: H01R13
IPC codes: H01R13