Abstract:
A connector which includes two components, hinges which connect the components together and which allow the relative movement of the components, and terminals on one connector to which at least a branch line conductor and a trunk line conductor are electrically connectable. The connector also has catch means which enables the two components to be secured to each other with a snap action with one component overlying the other component, and a tab for releasing the catch means which extend over the branch line when the components are secured to each other.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a connector which is suitable for use in making a branch connection to a trunk line for example in the manner which is required in a blasting system. The scope of the invention is however not confined to this application. 
     Connections to establish a blasting system are often made under difficult conditions. For example in an underground location lighting may be poor and accessibility may be limited. It is not always possible to make branch connections to a trunk line beforehand and in many instances such connections are made on site. The person making the connections may, in many cases, be guided more by feel than by sight and a connector which is usable in this way is therefore desirable. 
     A second factor which is important, particularly in poor lighting conditions, is the need to determine that a physical connection of the branch line to the trunk line has been made and that the connector has been correctly assembled. A connector which facilitates this determination is also desirable. 
     SUMMARY OF THE INVENTION 
     The invention provides a connector which includes a first component, conductive terminal means which is mounted to the first component and to which, in use of the connector, first conductor means which traverses the first component are connectable and second conductor means which extends from the first component at a defined location are connectable, a second component, hinge means which connects the first component to the second component so that the second component is movable from a first position at which the terminal means is exposed to a second position at which the second component overlies the first component and covers the terminal means, and catch means on the second component for releasibly securing the second component in the second position to the first component, wherein the catch means includes a tab which extends away from the second component and which is positioned so that in use it extends over the second conductor means at the defined location. 
     The catch means may be of any appropriate type and preferably has a flexible nature so that it is distorted as the second component is moved to the second position and, when the second component reaches the second position, the catch means is restored to its original non-distorted configuration due to its inherent resilience or memory. 
     The connector may be made from any suitable material and preferably is made from an appropriate plastics material with the desired qualities of toughness and resilience. 
     The tab may extend from a neck which projects from the second component and a hook formation may extend from the neck, preferably in an opposite direction to the direction in which the tab extends. 
     The second component may include any appropriate formation with which the hook formation is engageable. The first component may for example include an undercut formation such as a rib with which the hook is engageable. 
     The components may include respective surfaces which are brought into intimate abutting engagement with each other when the second component is moved to the second position. As has been indicated the second component is engaged with the first component at the second position preferably with a snap action which is generated by the catch means. This snap action ensures that the said surfaces are brought into abutting engagement with sufficient force to ensure that an audible sound is generated. To enhance this sound the invention, in a preferred embodiment, provides that at least one of the components includes at least one resonating chamber. The audible sound, which may be in the nature of a percussive click, is then generated and enhanced by the resonating or reverberating chamber. 
     Also according to the invention, there is provided a connector which includes two components, hinge means which connects the components together and which allows relative movement of the components, terminal means on one connector to which at least a branch line conductor and a trunk line conductor are electrically connectable, catch means which enables the components to be secured to each other with a snap action and with one component overlying the other component, and a tab, for releasing the catch means, which extends over the branch line conductor when the components are secured to each other. 
     The invention also provides a method of electrically connecting a trunk line conductor to a branch line conductor which includes the steps of electrically connecting the trunk and branch line conductors to a terminal, and enclosing the terminal inside two components which are interengageable with a snap action which simultaneously causes the generation of an audible sound. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is further described by way of example with reference to the accompanying drawings in which: 
     FIG. 1 is a plan view of a connector according to the invention, 
     FIG. 2 is a side view of the connector of FIG. 1 in an open position which is referred to herein as a first position, 
     FIG. 3 is a perspective view of the connector fully open i.e. in the first position, 
     FIG. 4 is a side view of the connector in a substantially closed configuration, 
     FIG. 5 is a side view of the connector fully closed i.e. in a position which is referred to herein as a second position, and 
     FIG. 6 is a perspective view of the connector in the said second position. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     The accompanying drawings illustrate a connector  10  according to the invention which is made from a suitable plastics material with desired qualities such as electrical resistivity, toughness, resilience and cost. The connector is manufactured using an injection moulding process by making use of techniques which are known in the art and which are consequently not further described herein. 
     The connector includes a first half-section or component  12 , a second half-section or component  14 , a hinge  16  which connects the second component to the first component, and two terminal posts  18  and  20  respectively. 
     The hinge  16  is constructed in a known manner essentially by forming a bridging section between the first and second components from relatively thinner and hence weakened material so that the bridging section is flexible. The hinge permits the second component  14  to be moved from a first position shown in FIG. 2 at which the connector is fully open and the terminal posts  18  and  20  are exposed to a second position, shown for example in FIG. 5, at which the second component overlies the first component and is securely engaged therewith. 
     Each terminal post  18 ,  20  is formed from suitable conductive sheet metal and for example has the shape shown in the inset drawing to FIG.  1 . Viewed in plan the terminal post has a U-shape and opposing limbs  22  and  24  are formed with insulation displacement slots  26 . A similar insulation displacement slot  28  is formed in a base  30  which extends between the limbs  22  and  24 . Insulation displacement slots of this type are known in the art and are not described in detail herein. It is pointed out though that an insulated electrical conductor of an appropriate size can be electrically connected to the terminal posts simply by pushing the connector into one or more of the slots. When this action takes place the insulation on the electrical conductor is displaced and the bared electrical conductor is thereby brought into electrical contact with the terminal posts. 
     The terminal posts  18  and  20  are mounted in the first component  12  with the respective slots  26  and  28  facing upwardly. 
     FIG. 1 illustrates a trunk line  32  and a branch line  34  connected to the terminal posts. The trunk line  32  includes two conductors  36  and  38  respectively which pass through opposed slots  40  and  42  in the side walls  44  and  46  of the first component. The conductors  36  and  38  are respectively engaged with the slots  28  in the terminal posts  18  and  20  and hence are thereby electrically connected to the terminal posts. The branch line  34  also includes two conductors which are designated  48  and  50 . These conductors are respectively connected to the terminal posts  18  and  20  by engaging the conductors with the two slots  26  in each respective terminal post. The conductors  48  and  50  are flared at a location  52  and then brought together so that they are positioned within opposing walls  54  of a channel  56 . The trunk line exits the first component  12  at a location  58  which is defined or formed by an opening  60  in an end wall of the first component. 
     Hollow chambers  64  and  66  are formed in the first component and are respectively positioned on opposing sides of the channel  56 . 
     The second component  14  has protrusions  68  and  70  which are shaped so that when the second component is engaged with the first component at the second position as shown in FIG. 5 the protrusions bear against upper surfaces of the conductors  36 ,  38 ,  48  and  50 , forcing the conductors downwardly into the first component, and providing a secure frictional lock between the conductors and the connector. 
     A relatively large hollow chamber  72  is formed in the second component to one side of the protrusions  68  and  70 . 
     A catch formation  74  is provided on the second component. The catch formation includes a relatively short neck  76 , a tab  78  which projects outwardly from the neck and a hook  80  which extends inwardly from the neck in an opposite direction to which the tab  78  extends. 
     As is evident particularly from FIG. 1 the first component  12  has an outwardly extending flange  82  which is formed in two sections located respectively on opposing sides of the location  58  and this flange provides a slightly flexible undercut formation with which the hook is engageable, as is shown in FIG.  5 . 
     The geometry and design of the connector are such that when the second component is engaged with the first component in the second position shown in FIG. 5 at least two opposing surfaces which are located respectively on the first and second components are brought into close abutting relationship. For example upper surfaces  82 A of the flange  82  are brought into close contact with opposing surfaces  84  on the second component. In a similar way a number of surfaces on the second component are brought into close abutting relationship with respective opposing surfaces on the first component. 
     In many cases the branch line  34  is connected to the connector prior to assembly of the connector on site. If this is not the case then the branch line is connected on site to the connector in the manner which has been described. 
     The electrical conductors  36  and  38  are passed through the slots  40  and  42 , as shown in FIG. 2, and are pushed downwardly so that they enter the slots  28  on the terminal posts  18  and  20 . The second component is then pivoted upwardly in the direction of an arrow  86 , see FIG. 2, relatively to the first component, with the pivotal movement taking place about the hinge  16 . 
     FIG. 4 illustrates the connector in a substantially closed configuration. The protrusions  68  and  70  bear against upper surfaces of the conductors inside the first component and urge the conductors downwardly deeper into the first component, thereby establishing a good frictional lock between the conductors and the connector. 
     As the second component is moved from the FIG. 4 position to the FIG. 5 position the hook  80  bears against outer upper corners of the sections of the flange  82 . The catch  74  is deflected outwardly and upwardly in the direction of an arrow  88 , see FIG. 4, with this movement being allowed for by flexing of the neck  76 . Once the upper surfaces of the flange  82  are in contact with the opposing surfaces  84  on the second component the neck, due to its inherent resilience, moves from its distorted position forcing the hook into engagement with the flange, as shown in FIG.  5 . 
     The neck  76 , when distorted, acts as a loaded spring. The hook  80  has an outermost tip  80 A, see FIG. 4, which passes over an outer edge  82 B of the flange  82 . When the tip reaches the lower side of the edge  80 B the neck  76  springs back to a non-distorted shape rapidly urging the two components together. 
     The engagement of the second component with the first component thus takes place with a snap action which arises due to the distortion, and then restoration to its original shape, of the catch  74 . The two components are thereby brought into the second position shown in FIG. 5 in an abrupt and quick manner and opposing surfaces of the components, e.g. the surfaces  82 A and  84 , are moved quickly into contact with each other. This action generates an audible sound in the nature of a percussive click and the sound is enhanced by the hollow chambers  64 ,  66  and  72  which act in the manner of reverberating or resonating chambers. A distinct audible click is thereby generated which acts as a notification to the operator that the connector has been securely closed. 
     As the connector closes flaps  90  on opposing sides of the component  14  partly overlie the slots  40  and  42  in the component  12  and thereby bend the projecting portions of the conductors  36  and  38  downwardly, increasing the mechanical fixing of the conductors to the connector. 
     The catch  74  extends outwardly from the second component and is positioned so that it overlies the branch line  34  at the location  58 . The operator is therefore able, acting only by touch, and by using a hand, to trace the branch line  34  to the connector. When the connector is reached the tab is simultaneously touched for the tab  78  extends over the conductor  34 . The tab may be flexed upwardly, relatively to the first component, to bend the neck  76  and move the hook out of engagement with the flange, if this is desired. 
     The positioning of the tab in the manner described and the audible percussive click which is generated when the two components of the connector are interengaged carry significant benefits in that they simplify the use of the connector on site particularly in difficult conditions for they enable an operator, substantially relying on touch only, to make a secure electrical connection between branch and trunk lines and, where necessary, to verify that such connections have, in fact, been made.