Abstract:
An electromagnetic hinged-armature relay comprises a contact spring (2) which is arranged on and attached to an armature (1). The contact spring serves as a switching contact spring and has a bounce dampener which is in the form of a swing element (3) made as one piece with the contact spring which greatly reduces bounces of contacts and contact wear resulting therefrom.

Description:
BACKGROUND OF THE INVENTION 
     This invention concerns an electromagnetic hinged-armature relay having a contact spring with a bounce retarder attached to an armature for reducing contact bounces. 
     Hinged-armature relays, for example for use in motor vehicles, typically bounce from one to four times upon closing of normally-open make contacts and three to ten times upon closing of normally-closed break contacts, whereby for each bounce, depending upon a load being switched, strong arcs are sometimes ignited which cause high contact wear, which, in turn, negatively affect the life of such a relay. 
     European Patent EP 0 281 384 B1 discloses an electromagnetic hinged-armature relay which has a miniature air cylinder dampener as a bounce dampener which, depending upon requirements, is provided to reduce noise production of the electromagnetic relay. 
     Aside from the facts that such a solution is quite expensive and, because electromagnetic hinged-armature relays are manufactured in such volume, represent a large costs factor, it is also questionable if such an arrangement sufficiently protects contacts against consumption by burning. 
     German Patent DE 26 02 362 A1 discloses an arrangement for suppressing bounces of a closing armature of flat relays, in which, a device is provided at an area of a free end of the relay for absorbing movement energy of the armature after its impact on the relay core. 
     One or more additional masses can be provided on the armature of the relay to serve as such a device. 
     Aside from the fact that the solution suggested here is also structurally quite expensive, a transfer of this solution from a flat relay, as disclosed, to a small-structured hinged armature relay is not possible without further changes because the mounting space to attach such an additional device is generally not available, at least not without a disadvantageous enlargement of the structural volume of the hinged-armature relay. 
     It is therefore, an object of this invention to provide an uncomplicatedly-constructed and cost effective hinged-armature relay in which contact bounce is substantially prevented by structural measures which are particularly uncomplicated. 
     SUMMARY OF THE INVENTION 
     According to principles of this invention, a bounce dampener is constructed as one piece with a contact spring as a swing element. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The invention is described and explained in more detail below using the embodiments shown in the drawings. The described and drawn features, in other embodiments of the invention, can be used individually or in preferred combinations. The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings in which reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating principles of the invention in a clear manner. 
     FIG. 1 is a plan view of an embodiment of a contact spring of this invention attached to an armature of a hinged-armature relay. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The single drawing shows an arrangement of a contact spring attached to an armature. Various other features of the hinged-armature relay are not shown on this drawing, because they are not necessary to an explanation of the invention. 
     The contact spring 2 has one or more switch contacts 4. Two end portions 5 of the contact spring extend about an end edge of an armature 1. A further end portion 6 of the contact spring 2 is bent to be perpendicular to the plane of the drawing and forms a return spring as one piece with the contact spring 2 for the armature 1. The contact spring is attached approximately in the middle of the armature 1 by means of a rivet attachment 7. 
     According to this invention, the contact spring 2 forms a swing element 3 which is formed on the contact spring 2 as one piece therewith by a cut-out, or recess, 8 which is made in the contact spring 2. 
     This swing element 3 extends from the contact spring edge 10 outwardly to be free to swing, relative to the armature 1, which it touches, or at least covers, with its free end portion 9 (that is, the end which is not attached to the contact spring). 
     When the normally-open make contacts (not shown) close, because of a deflection of the contact spring 2 and an inclination of its end 10 resulting therefrom, the swing element 3 which is formed at this end, is biased against the armature and carries out a movement relative to the armature 1. In this manner, the bounce energy of the contact is changed into a friction energy, whereby the bouncing, at least for suitably dimensioned swing elements 3, is completely eliminated. Thus, the swing element 3 is a bounce retarder. 
     Upon closing of a normally-closed break contacts (from which only the moveable contact 4 is shown in the drawing) the free end portion 9 of the swing element 3 swings over, during which a large portion of the swing, or bounce, energy of the spring contact is transmitted to the swing element 3. 
     When the swing element 3 swings back, it contacts the armature, which by this time is at rest, and bows, whereby a movement of the free end portion 9 of the swing element 3 relative to the armature 1 is created which converts the swing energy into friction energy to thereby significantly reduce contact bounce. 
     This, structurally-speaking, particularly uncomplicated inventive solution has the benefit that contact bounce is at least substantially reduced without the relay requiring additional individual parts, particularly no additional masses requiring increased structural volumes because this bounce dampener is constructed as one piece as a part of the contact spring. The swing element which acts as a bounce dampener can, in a beneficial manner, be formed in a particularly simple manner by placing the cut-out or slot, in the contact spring. Thus, this inventive solution can be carried out in a particularly uncomplicated and cost effective manner. 
     A particularly beneficial embodiment of a hinged-armature relay of this invention having the bounce dampener is produced by having the swing element extend outwardly from the area of the contact spring at the contacts, so as to be capable of swinging toward the armature, which it touches, or at least covers, with the end not attached to the contact spring. In this manner, a mechanical movement energy which otherwise would lead to contact bounce, is not only converted to a swing energy of the swing element, but also is particularly effectively absorbed by the end portion of the swing element contacting, or rubbing on, the armature so that is it is converted to heat energy. 
     While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.