Lever type connector
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a lever type connector used to reduce the force required for a male-female connection between mating connecters accommodating wire harnesses therein and, more particularly, to a lever type connector comprising a lever unit whose size is variable according to the size of the mating connector housings. 
     2. Description of the Prior Art 
     In a connector having mating plug and receptacle units, a lever is commonly used to reduce the connecting force required to fit the mating units together. One example of such a connector is shown in FIG. 6. 
     This connector includes a mating plug unit 200 for accommodating a plurality of first electrical wires with male terminals (not shown) therein and a receptacle unit 100 for accommodating a plurality of second electrical wires with female terminals (not shown) therein. The first and second electrical wires are electrically connected by engaging the male and female terminals of wires when the plug unit 200 is inserted into the receptacle unit 100. 
     The plug unit 200 has a plurality of first terminal chambers 203 extending between opposite sides of a generally rectangular shaped housing 201. Each of first wires is held in each of first terminal chambers 203, such that the female terminal locates on the one side. The plug unit 200 further has a pair of guide pins 204 separately formed on outer opposite side surfaces aligned in a line perpendicular to the longitudinal direction of first terminal chambers 203. A flange portion 205 is provided on the opposite side to the side on which the female terminal is held. 
     The receptacle unit 100 has a receptacle housing 101 for receiving the plug unit 200 and accommodating the second wires therein. The receptacle unit 100 further has a lever unit 104 for reducing the force to press the plug unit 200 into a receptacle opening 113 of the receptacle housing 101. The lever unit 104 is installed on the receptacle housing 101 by a fixture unit 105 such that pivot pins 104a on the lever unit 104 are captured by slots 105a of the fixture unit, as shown in FIG. 6. Thus, the lever unit 104 can pivot with respect to a line X. The housing 101 further has a plurality of second terminal chambers 115 extending therein, in a direction approximately parallel to the line X, and being opened to the opening 113. Each of second wires is held in each of second terminal chambers 115, such that the male terminal overhangs from the side facing the opening 113 by a predetermined length for the engagement with the female terminal. A pair of notches 117 are separately formed in the opening 113 side edges of the housing 101 for receiving the guide pins 204 of the plug unit 200. 
     The lever unit 104 is formed in a generally U-shaped configuration. On outer surface of the opposite side members of the lever unit 104, the pair of pivot pins 104a are separately formed in a position in alignment with the axis X. In each inner surface of side portions of the lever unit 104, a pair of guide grooves 104b are separately engraved from the edge portion by a predetermined depth. A pair of elongated guide channels 104c are also formed integrally with the guide grooves 104b in a curved line shape. A locking tab 104d is provided at the middle of the lever unit 104. 
     When the plug unit 200 is inserted into the opening 113, each of pivot pins 204 is guided into the notch 117 by the guide groove 104b and guide channels 104c. As the lever unit 104 rotates down in a direction of the arrow A from the position shown in FIG. 6, the guide pins 204 captured in the notches 117 are further pressed by the guide channels 104c. A further rotation of the lever unit 104 causes the guide pins 204 to travel along the slots 105a in the direction B. Thus, when the lever unit 104 is completely rotated, the female and male terminals of wires accommodated in the connector 100 and 200, respectively, are firmly engaged and an electrical connection is made therebetween. At the same time, the locking tab 104d and the flange portion 205 are also engaged to lock the lever unit 104 at the position to prevent the connected wires from accidentally disconnecting. 
     With this connector design, the required number of terminal chambers will vary according to the number of terminals to be connected in the connectors, and the width W of the receptacle housing 101 will vary accordingly. The width W of the housing 101 will also vary when the size of the terminals varies. 
     The lever unit 104 on the receptacle unit 100 must therefore be molded according to the width of the connector housing. This means a different lever unit must be manufactured when the housing width changes because of a difference in the number or size of terminals. Manufacturers have therefore produced a specific lever unit for each different width of connector housing, and this duplication of parts necessarily increases unit costs. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is therefore to provide a lever type connector device which solves these problems. 
     The present invention has been developed with a view to substantially solving the above described disadvantages and has for its essential object to provide an improved connector. 
     In order to achieve the aforementioned objective, a lever type connector which is used to connect at least one pair of first and second terminals comprises a first connector member for accommodating the first terminal therein and provided with a first engaging means and a second engaging means; a second connector member for accommodating the second terminal therein and provided with a third engaging means engageable to the first engaging means; and a substantially U-shaped lever unit pivotally provided on the second connector member having a center portion and two side portions connected to the opposite ends of the center portion. The center portion is contractible, and the side portions are provided with a fourth engaging means engageable to the second engaging means. When the lever unit pivots, the second engaging means engages with the fourth engaging means to force the first and second connector members into a firmly engaged state. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects and features of the present invention will become clear from the following description taken in conjunction with the preferred embodiment thereof with reference to the accompanying drawings throughout which like parts are designated by like reference numerals, and in which: 
     FIG. 1 is an exploded perspective view of a lever type connector according to a preferred embodiment of the present invention, 
     FIG. 2 is an exploded perspective view of a lever unit of the lever type connector set shown in FIG. 1, 
     FIG. 3 is a cross sectional view of the lever unit shown in FIG. 1, 
     FIG. 4 is an exploded perspective view of a lever type connector with an alternative lever unit according to the present invention, 
     FIG. 5 is an exploded perspective view of the lever unit shown in FIG. 4, and 
     FIG. 6 is an exploded perspective view of a conventional lever type connector. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, a preferred embodiment of a lever type connector according to the present invention is shown. 
     The connector includes a mating plug unit 20 for accommodating a plurality of first electrical wires W1 with male terminals and a receptacle unit 10 and a plurality of second electrical wires W2 with female terminals. (only one pair of wires W1 and W2 is shown in FIG. 1 for the sake of brevity). When the plug unit 20 and receptacle unit 10 are engaged with each other, the first and second electrical wires W1 and W2 are electrically connected by mating the male and female terminals of wires W1 and W2 accommodated therein. 
     The plug unit 20 has a plug housing 21, configured in a generally cubic shape defined by first and second end faces and four side walls extending between the first and second sides end faces. The plug housing 21 is provided with a plurality of first terminal chambers 23 extending between the first and second end faces. The first wire W1 is accommodated inside each of first terminal chambers 23 such that the female terminal is located at the second end face. The plug unit 20 further has a pair of guide pins 24 which are formed on opposite side walls in alignment with a line perpendicular a direction in which the first terminal chambers 23 extend. A flange portion 25 is provided on the first end face of the plug unit 20. 
     The receptacle unit 10 has a receptacle housing 11 for accommodating the second wires W2, a lever unit 30, and a lever fixture unit 19 for installing the lever unit 30 on the housing 11 pivotally. The receptacle housing 11 is formed in a generally rectangular box-like configuration defined by four peripheral sides walls and a top side portion, opening at one side opposed to the top side. Since the top side portion has a predetermined thickness, the inside of the housing 11 is divided into two portions. One is the top side portion thick enough to accommodate an electric terminal therein. The other is a receptacle space 13, wide and deep enough to accommodate the plug unit 20 therein. The receptacle opening 13 is shown on the left side of the housing in FIG. 1. The housing 11 further has a plurality of second terminal chambers 15 extending inside the top side portion approximately parallel to the peripheral side walls. The second wire W2 is accommodated in each of second terminal chambers 15 such that the male terminal protruding from the chamber 15 toward the receptacle space 13 by a predetermined length for engagement with the female terminal of the first wire W1. A pair of slots 17 are formed in the open edges of opposite side walls of the housing 11 in a configuration to receive the guide pins 24 of the plug unit 20 therein. 
     Referring to FIG. 2, an enlarged view of the lever unit 30 is shown. The lever unit 30 comprises a receptacle member 30a and a plug member 30b both formed in generally L-shaped configurations. The receptacle and plug members 30a and 30b fit together, as shown in FIG. 1, and operate as the single lever 30 formed in a generally U-shaped configuration. 
     The receptacle member 30a has a left side portion 32a almost in a plate-like form having first and second surfaces. A first arm portion 42 is integrally provided on one of end portions of the first surface of left side portion 32a. The first arm portion 42 is an elongated rectangular shape extends therefrom in a direction perpendicular to the left side portion 32a. A guide channel 46 with a top opening 44, having an inverted T-shape in cross section, is formed in the first arm portion 42, extending in the longitudinal direction thereof. The guide channel 46 is closed at one side by the left side portion 32a and is open at the end remote from the left side portion 32a. 
     On a bottom 48 of the guide channel 46, a series of wave-shaped claws 50 are formed parallel to the left side portion 32a. Each claw 50 has a serration-like configuration inclined toward the left side portion 32a, as best shown in FIG. 3. 
     The left side member 30a comprises a pivot pin 34a provided on one end corner, away from the first arm portion 42. 
     The left side member 30a further has a guide groove 38a engraved by a predetermined depth in the second surface and opened near an end corner 36a, far from both the pivot pin 34a and the first arm portion 42. The left side member 30a further has a guide channel hole 40a configured in a curved line shape. The guide groove 38a and the guide channel hole 40a are integrally connected and located such that the distance from the pivot pin 34a gradually changes from a maximum at the guide groove 38a to a minimum at the end of the guide channel hole 40 away from the guide groove 38a. 
     The plug member 30b is formed in a configuration very similar and symmetrical to the receptacle member 30a. The plug member 30b has a right side portion 32b provided with an end corner 36b, pivot pin 34b, guide channel 38b, guide groove channel 40b, and second arm portion 52. 
     The second arm portion 52 extends in a direction perpendicular to the right side portion 32b by a predetermined length, in a similar manner to the first arm portion 42. However, the second arm portion 52 has no guide groove therein, but has a plug portion having an inverted T-shaped cross section. This plug portion is defined by a top block 54 and a base block 56 each corresponding to the top opening 42 and the guide groove 46, respectively. Thus, the plug portion 54 and 56 of second arm portion 52 can be inserted into the guide channel 46 with top opening 44 and held stably therein. 
     A series of wave-shaped claws 58 is formed on the bottom surface of the base block 56 (shown in FIG. 3), running in a direction parallel to the right side portion 32b. Each claw 58 has a serration-like configuration inclined toward the right side portion 32a, as best shown in FIG. 3. Thus, the claws 50 and 52 are inclined to the directions opposed to each other when the second arm portion 52 is inserted into the first arm portion 42. 
     Because of this construction, the plug arm 52 inserted in the guide channel 46 is fixed by the engagement between wave-shaped claws 50 and 58 formed on the receptacle and plug members 42 and 52, respectively. The distance between the receptacle member 30a and the plug member 30b can thus be adjusted. It is therefore possible to adjust the inner width, distance between the left and right side members 32a and 32b, of the lever unit 30 to the width of the receptacle unit 10 housing 11. Therefore, it is not necessary to prepare different sizes of lever units according to those of connector housings, resulting in reduction of variation and manufacturing cost of lever units. It is to be noted that wave-shaped claws 50 and 58 can be designed as any other profile and orientation which functions to engage each other to position and hold the plug member 30b in the guide channel 46. 
     The receptacle unit 10 further comprises a fixture unit 19 provided on the opposite peripheral sides of the housing 11, proximal to the receptacle space 13 end, with a predetermined clearance therebetween. A pair of elongated slots 19a are provided approximately at a middle of the fixture 19, such that each elongated slot 19a extends in a direction approximately parallel to the second wire accommodating chambers 15 and opens at the end side thereof. 
     The lever unit 30, thus assembled as described above, is installed in the predetermined clearance between the housing 11 and the fixture unit 19 such that each of pivot pins 34a, 34b is captured by elongated slots 19a and the guide grooves 30b face on the opening space 13 end. Thus, the lever unit 30 can pivot freely in the direction shown by the arrow A, with respect to the axis X and can slide along the elongated slots 19a. When the lever unit 30 is turned up to locate at a stable position over the housing 11, the guide grooves 38a and 38b almost overlaps the slots 17. 
     The operation features of the lever type connector according to the present invention, described above, are described herebelow. 
     When connecting the receptacle and plug units 10 and 20, the lever unit 30 is first turned back to the open position shown in FIG. 1. Then, the plug unit 20 is inserted in the receptacle space 13 of the receptacle unit 10 in the direction of arrow B. The guide pins 24 of the plug unit 20 will be guided into the slots 17 and guide channel holes 40a and 40b by the guide groove 38a. 
     Then, the lever unit 30 arms are lifted up and rotated in the direction of arrow A, the guide channel holes 40a and 40b capture and press the guide pins 24 along the elongated slot 19a. This is because the distance between the pivot pins 34a and 34b and the guide channel holes 40a and 40b becomes short as the lever unit 30 rotates in the direction A, as described the above. This pulls the plug unit 20 into the receptacle unit 10, creating a positive contact between the female and male terminals of wires held in the chambers 23 and 15. 
     Because the force is applied to the arms of a lever unit 30 which turns on pivot pins 34a and 34b, the principle of a lever and fulcrum works to reduce the force required to establish a positive connection between the plug and receptacle units 20 and 10. 
     Referring to FIGS. 4 and 5, an alternative of lever unit 30 according to the above described embodiment is shown. In this alternative, a lever unit 60 comprises a first receptacle member 60a, a second receptacle member 60b, and a plug arm 60c inserted therebetween. This alternative lever unit 60 is installed on a receptacle unit 10&#39;, as shown in FIG. 4. 
     As best shown in FIG. 5, the first receptacle member 60a has a construction very similar to that of the receptacle member 30a such that left side portion 32a, end corner 36a, guide channel 38a, guide channel hole 40a, first receptacle arm portion 42, top opening 44, guide channel 46, bottom 48, and wave-shaped claws 50 of the receptacle member 30a are replaced by a first left side member 62a, a first end corner 66a, a first guide groove 68a, a first guide channel hole 70a, a first receptacle arm 72a, a first top opening 74a, a first guide channel 76a, a first bottom 78a, and first wave-shaped claws 80a, respectively, in the first receptacle member 60a. The guide channel 70a is opened at both ends, as shown in FIG. 5, but can be closed by the left side member 62a such as in the receptacle member 30a. 
     The second receptacle member 60b is in a form substantially symmetrical to that of the first receptacle member 60a, resulting in comprising a second left side member 62b, a second end corner 66b, a second guide groove 68b, a second guide channel hole 70b, a second receptacle arm 72b, a second top opening 74b, a second guide channel 76b, a second bottom 78b, and second wave-shaped claws 80b. 
     The plug arm 60c is formed in a flat plate-like configuration having a cross sectional shape, enabling insertion in the guide channels 76a and 76b. A series of wave-shaped claws 80c is formed on the bottom of the plug arm 60c for the engagement with the wave-shaped claws 80a and 80b in the guide channels 76a and 76b. The first and second receptacle members 60a and 60b are formed substantially symmetrical to each other, as described above. Therefore, the claws 80a and 80b are inclined to the opposite directions when the first and second receptacle members 60a and 60b are installed on the receptacle housing 11. 
     In this case, the third claws 80c on the bottom of plug member 60c are divided in two groups with respect to the inclined direction thereof. The claws 80c in the first group is inclined to a direction to engage with the first claws 80a. The claws 80c in the second group inclined to an opposite direction in which those in the first group is inclined. The plug arm 60c can be fixed by the each group of third claws 80c  engaged with the first and second claws 80a and 80b, respectively, when inserted into them. 
     However, the third claws 80c all can be inclined in a single direction. For example, the third claws 80c can be inclined in a direction to engage with the first claws 80a, when the second claws 80b is inclined to an opposite direction from the direction in which the second claws 80b is originally inclined. The third claws 80c also can be inclined in a direction to engage with the second claws 80b, when the first claws 80a is inclined to an opposite direction from the direction in which the first claws 80a is originally inclined. 
     The lever unit 60 is further provided with a flexible locking tab 61 at approximately middle portion of one of side edges of the plug portion 60c. This locking tab 61 engages with a locking slot 25 provided in the housing 21 of the plug unit 20. 
     Because of this construction, the length of plug arm 60c inserted in the guide channels 76a and 76b of the first and second receptacle arms 72a and 72b can be changed. The effective length of each of arms 72a, 72b, and 72c can thus be controlled to adjust the distance between the left and right side members 62a and 62b. It is therefore possible to adjust the inner width of the lever unit 60 equal to the width of the housing 11 of the receptacle unit 10&#39;. Thus, a single lever unit 60 can be used with connector housings of different sizes. 
     In addition, when the lever unit 60 is lifted in the direction of the arrow A to connect the plug and receptacle units 20 and 10&#39;, the plug unit 20 is pulled into the receptacle space 13 of the unit 10&#39;. Thus, electrical terminals therein are mated for establishment of electrical connection therebetween. Furthermore, the locking tab 61 engages with the locking slot 25. This locks the connection between the plug and receptor units 20 and 10&#39;, and prevents accidental disconnection. 
     It will be known to those skilled in the art that the present invention can be varied in many ways. For example, in the alternative lever unit 60 described above, a rectangular guide channel can be provided in the plug arm 60c. In this case, the first and second receptacle arms 60a and 60b can be rectangularly shaped, enabling themselves to insert in the guide channel of the plug arm 60c. The wave-shaped positioning claws can also be provided in any form and in any position suitable for fixing the arms by the means of mutual engagement of claws. 
     In addition, the positioning means used to adjust and hold the length of the lever arm members shall not be limited to the described wave-shaped claw construction, and may be of various known designs. 
     In a lever type connector according to the present invention, the following benefits are obtained with the construction thereof, as described above. 
     First, because the arm length of the lever unit is adjustable, a single lever unit can be used with connector housings of varying widths. This eliminates the need to mold levers for each size of connector housing, and thus reduces production costs. 
     Specifically, when the lever is composed of two parts (receptacle member and plug member), the arm of the plug member is inserted to the guide channel in the arm of the receptacle member, and a wave-shaped or other type of positioning means is provided, the arm length of the plug member inserted to the guide channel can be adjusted, and the overall arm length of the lever until can thus be adjusted. 
     In addition, when the lever unit is composed of three parts such that the third part is inserted into the guide channels provided in the arm member of each of the other two parts, the arm length of the lever unit can be adjusted to the width of the connector housing by varying the length by which the third part is inserted into the guide channels. 
     Furthermore, the connection between the receptacle and plug units can be locked by a locking tab which is provided on this third part, such that the locking tab engages with a locking slot provided in the plug unit housing. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. 
     Although the present invention has been fully described in connection with the preferred embodiment thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.