Patent Publication Number: US-4319797-A

Title: Electrical connector with terminal locking means

Description:
FIELD OF THE INVENTION 
     The present invention relates in general to an electrical connector and more particularly to an electrical connector of a type having a locking mechanism by which male and female plugs of the connector are locked to each other for assuring tight connection therebetween. 
     OBJECTS OF THE INVENTION 
     It is an object of the present invention to provide an improved electrical connector wherein undesired accidental disconnection of a male terminal from a female terminal and vice versa is assuredly prevented. 
     It is another object of the present invention to provide an improved electrical connector which has a locking mechanism by which the male and female terminals are locked upon completion of coupling therebetween. 
     It is still another object of the present invention to provide an improved electrical connector having a locking mechanism for the male and female terminals, in which disconnection of these terminals is easily made by applying a slight manual force to the locking mechanism. 
     It is a further object of the present invention to provide an improved electrical connection wherein the proper coupling between the male and female plugs can be recognized by a slight shock which is produced upon the proper coupling. 
     Other objects and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings which are outlined hereinafter. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a conventional electrical connector, the connector being shown as accompanied with a battery terminal connector; 
     FIG. 2 is a sectional view of an improved electrical connector embodying the invention, depicting a procedure for disconnecting a female plug from a male plug; 
     FIG. 3 is a plan view of the electrical connector of FIG. 2 with the male and female plugs being separated; 
     FIG. 4 is a sectional view of another improved electrical connector of the invention; 
     FIG. 5 is a plan view of the another improved electrical connector with the male and female plugs being coupled; and 
     FIG. 6 is a side view of the electrical connector of FIG. 4. 
    
    
     DESCRIPTION OF PRIOR ART ELECTRICAL CONNECTOR 
     Prior to describing in detail the construction of the electrical connector of the invention, outlined explanation of a conventionally used electrical connector of a type accompanied with a battery terminal connector will be made with reference to FIG. 1 in order to clarify the invention. It should be noted that such type connector is particularly used in a case wherein the current transmittance by a cable (22) leading from the battery terminal connector is not sufficient in normally operating an electrical device because of a certain voltage drop due to the internal resistance of the cable. 
     Referring to FIG. 1 of the drawings, there is shown a conventional electrical connector 10 of a type accompanied with a battery terminal connector 12. The battery terminal connector 12 hereinshown comprises a clamp member 14 which is disposed at its circularly turned section about a terminal pin 16 of a battery (not shown). A bolt 18 passes through holes (no numeral) formed in leg portions of the clamp 14 and is tightened by a nut 20 to cause the clamp 14 to tightly clamp the pin 16. Designated by numeral 22 is the cable or wire 22 which extends from one of the leg portions of the clamp 14 to high power consumption electrical devices, such as a starter motor (not shown). 
     The electrical connector 10 shown as accompanied with the battery terminal connector 12 comprises a male plug or terminal 24 which is fixed to one of the leg portions of the clamp 14 by means of the bolt 18 and the nut 20. As shown, the male terminal 24 is formed like a tongue. A female plug 26 comprises a female terminal 28 and an insulating housing 30 in which the female terminal 28 is housed. The insulating housing 30 is formed at its right side in FIG. 1 with an opening into which the male terminal is inserted when coupling of the male and female terminals 24 and 28 is required for electrical connection therebetween. Designated by numeral 32 is a cable which connects the female terminal 28 with another electrical device (not shown). 
     Hitherto, however, the above-mentioned type connector 10 lacks a so-called locking means which assures a locking connection between the male and female terminals 24 and 28. Thus, it often happens that the female terminal 28 is accidentally disconnected from the fixed male terminal 24 when the cable 32 is inadvertently pulled away with only a small force. 
     It is accordingly an essential object of the present invention to provide an electrical connector which is free of the above-mentioned problem. 
     DESCRIPTION OF THE EMBODIMENT 
     Referring to FIGS. 2 and 3, particularly FIG. 2, there is illustrated a first preferred embodiment of the present invention. The electrical connector 34 shown in FIG. 2 assumes a coupling condition wherein the male and female terminals are coupled with each other. The connector 34 of this embodiment comprises a tongue-shaped male plug or terminal 24 which is constructed of an electrically conductive material. Although not shown, the male terminal 24 is fixed to a battery terminal connector in substantially the same manner as in the case of FIG. 1. As shown in FIG. 3, the male terminal 24 is formed with a rectangular opening 24a for the reason which will be described hereinafter. The leading end section of the male terminal 24 is somewhat reduced in width for facilitating insertion of the male terminal 24 into a female plug 36 which will be explained hereinnext. 
     The female plug 36 comprises a female terminal 38 which is housed in an insulating housing 40 of a plastic. The female terminal 38 is formed at its mating section 38a with a lug 38b which is inclined backwardly as shown, so that when the female terminal 38 is properly received in the housing 40, the lug 38b engages at its free end with a right-positioned wall of a recess 44 which is merged with a passage 42 of the housing 40. With this, rightward displacement of the female terminal 38 relative to the housing 40 is prevented. The female terminal 38 is formed with a gripping section 38c by which an end of the cable 32 is gripped. As will become clear as the description proceeds, the male terminal 24 is inserted into the passage 42 from the left entrance 42a of the same and is locked in a place, engaging the mating section of the male terminal 24 with the mating section 38a of the female terminal 38, as is shown in FIG. 2 
     According to the present invention, next-mentioned locking mechanism is provided to the connector 34. As is best shown in FIG. 2, a seesaw like locking arm 46 is formed on the housing 40 at a position near the left opening 42a to assure locking connection between the male and female terminals 24 and 38. The locking arm 46 and the housing 40 are molded as a one piece article. The locking arm 46 is united at its generally middle section with the housing 40 so that it can be pivotable about the united portion 46a upon application of a certain degree of force to the locking arm 46. The right section of the locking arm 46 with respect to the united portion 46a constitutes a handle 46b which is used for manually operating the locking arm 46. As shown, the handle 46b is shaped to have a generally triangular cross section to be permitted to pivot in a clockwise direction, in FIG. 2, about the united portion 46a. Further, the locking arm 46 is formed at its left end with a hook portion 46 c which is reinforced by several ribs 46d. It should be now noted that the locking arm 46 is formed to be biased to pivot in a counterclockwise direction in FIG. 2 about the united portion 46a. 
     Accordingly, for coupling between the male and female terminals or plugs 24 and 38, when the male terminal 24 is inserted into the housing 40 from the left opening 42a and is moved axially to the right, the hook portion 46c of the locking arm 46 is depressed in an upward direction by the leading end section or mating section of the male terminal 24. As the male terminal 24 continues to be moved to the right and finally the mating section of the male terminal 24 is tightly received in the mating section of the female terminal 38, the opening 24a of the male terminal 24 is finally disposed directly over the hook portion 46c, allowing the hook portion 46c to return toward its original generally undepressed position. Thus, the hook portion 46c enters the opening 24a of the male terminal 24 and the terminal 24 is now locked in place. Thus, further axial movement of the male terminal 24 to the right or the left is prevented. 
     When disconnection of the male terminal 24 from the female terminal 38 is required, the handle 46b of the locking arm 46 is depressed downward to cause the hook portion 46c to be lifted and disengaged from the opening 24a. With the hook portion 46c lifted, the male terminal 24 is axially withdrawn from the housing 40 of the female plug 36, disengaging from the female terminal 38. 
     Referring to FIGS. 4 to 6, there is illustrated a second preferred embodiment of the invention. The electrical connector 48 of this embodiment is similar in construction to the above-mentioned first embodiment, and comprises substantially the same parts or elements as those in the first embodiment except for the locking mechanism. For facilitation of description, explanation of such same parts will be omitted from the following, but such parts are designated by the same numerals in the drawing. 
     The locking mechanism according to the second embodiment comprises a seasaw like locking arm 50. Similarly to the first embodiment, the locking arm 50 is formed on the housing 40 near the left opening 42a, and the locking arm 50 and the housing 40 are molded as a one piece article. The locking arm 50 has a handle 50b and a hook portion 50c both of which have generally the same functions as in the case of the first embodiment. As will be understood from FIGS. 4 and 6, the locking arm 50 is united to the housing 40 by a pair of bridge sections 50a and 50a&#39; each extending from the generally middle section of the locking arm 50 to the front end of the hook portion 50c (that is the leftmost end of the locking arm 50 as viewed in FIG. 4). Preferably, each of the bridge sections 50a and 50a&#39; is constructed to have a semicircular cross section to cause the locking arm 50 to have a large pivoting range. Also in this embodiment, the locking arm 50 is constructed to be biased in a counterclockwise direction for the same reason which has been mentioned in the item of the first embodiment. If desired, in addition to the bridge sections 50a and 50a&#39;, the locking arm 50 may be provided with another pivotting section 50a&#34; in substantially the same manner as the united portion 46a of the locking arm 46 of the first embodiment. 
     From the above, it will be appreciated that, according to the present invention, the undesired accidental disengagement of the male and female terminals or plugs is assuredly prevented, while, disconnection of them is easily made by pulling the female plug away from the male plug with the handle of the locking arm being pressed. 
     Further, it will be appreciated that the proper coupling between the male and female plugs can be recognized by a slight shock which will be produced when the hook portion enters the opening of the male terminal.