Patent Publication Number: US-4647121-A

Title: Distributor strip comprising a plurality of double terminal posts allowing non-stripped connection of electrical conductors

Description:
RELATED APPLICATION 
     Attention is drawn to related applications, Ser. Nos. 719,30 and 719,342 copending herewith, and by the same inventors of the instant application. 
     BACKGROUND OF THE INVENTION 
     The invention relates to a distributor strip comprising a plurality of double terminal posts allowing the non-stripped connection of electrical conductors. The double terminal posts are held in sockets at the upper long sides of an insulating member having an approximately square cross-section. A plurality of upwardly open receptacle chambers are provided for surge arrestors. These chambers are separated by partitions and are provided in the upper part of the insulating member along a longitudinal direction of said insulating member. Contact springs connected to the terminal posts are provided at those side walls of the receptacle chambers proximate to the terminal posts. Parts of a grounding rail project into the receptacle chambers between two respective contact springs lying opposite one another. 
     Such a distributor strip can be employed exclusively as a terminal strip but it can also be subsequently arbitrarily equipped with surge arrestors. The disadvantage of this distributor strip is that the individual leads of the connecting lines can only be protected against overvoltages but not against overcurrents. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to specify a distributor strip of the type initially cited wherein it is possible to protect the individual leads against both overvoltages as well as overcurrents. 
     For a distributor strip of the type initially described, this object is achieved in that those parts of the contact springs projecting into the receptacle chambers are designed in right-angled fashion such that the free lag is resectively situated proximate to the floor, and wherein its outer edge is pressed against the grounding rail. A length of the free legs is dimensioned such that, after the insertion of an overvoltage arrestor and of a solder ring, the distance between its outer edge and the grounding rail is less than a thickness of the solder ring. 
     In the distributor strip of the invention, the outer edge of the contact spring respectively forms a grounding contact which connects the corresponding lead to ground potential after the solder ring has melted due to overcurrent. A protection against overcurrents is thus provided in a simple fashion, merely by modification of the contact springs lying in the receptacle chambers and by the additional insertion of a solder ring. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective, partial view of a distributor strip of the invention; 
     FIG. 2 is a partial plan view of the distributor strip of the invention; 
     FIG. 3 is a view of a partial section through the distributor strip of the invention; and 
     FIG. 4 is a perspective view of the grounding rail and of the contact springs with the corresponding terminal posts. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The distributor strip 1 shown partially iin perspective in FIG. 1 comprises receptacle chamber 2 at its upper part for the acceptance of overvoltage arrestors. Situated at the upper longitudinal sides of the distributor strip 1 in receptacles are a plurality of double terminal posts 3 which are connected to contact springs 4 which includes an inverted U-shaped portion projecting in at the neighboring side walls of the receptacle chambers 2. Parts of a grounding rail project into the receptacle chamber 2 between the contact springs 4. The individual receptable chambers are separated from one another by partitions 5. 
     The equipping of the receptacle chambers with overvoltage arrestors 7 and solder rings 8 may be derived from FIG. 2. The arrangement of the grounding rail 6 in the distributor strip 1 can be derived from FIG. 3. 
     The fashioning of the parts of the contact springs 4 projecting into the receptacle chambers can be derived from FIG. 4. As may be determined from this figure, the outer edge of the downwardly disposed, free leg of the contact spring 4 presses against the grounding rail 6 when the receptacle chamber is not equipped and forms a ground contact with this grounding rail 6. By inserting an overvoltage arrestor 7 and a solder ring 8, the outer edge of the free leg is forced away from the grounding rail 6 to such degree that a grounded contact no longer exits. This grounded contact is not reestablished until there is an overcurrent, when the solder ring 8 is melted. The distance between the outer edge of the contact spring 4 and the grounding rail 6 is therefore selected such that, given an inserted overvoltage arrestor 7 and solder ring 8, it is smaller than the thickness of the solder ring 8. After the solder ring has melted off, a reliable grounded contact between the contact spring 4 and the grounding rail 6 is guaranteed in this fashion. Although various minor changes and modifications might be proposed by those skilled in the art, it will be understood that we wish to include within the claims of the patent warranted hereon all such changes and modifications as reasonably come within our contribution to the art.