Electromagnetic flat relay

An electromagnetic flat relay has an elongated carrier element which is disposed inside of the hollow coil spool and parallel to the longitudinal axis thereof. The carrier element consists of non-ferromagnetic material and supports the yoke and the pole piece and is directly or indirectly connected to one or more contact elements. The base of the carrier element rests on the yoke and the pole piece opposite the armature and has laterally depending flanks which at least partially surround the yoke and the pole piece.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to electromagnetic relays, and in particular 
to electromagnetic flat relays having the operative components of the 
relay disposed in the hollow interior of the coil spool. 
2. Description of the Prior Art 
Electromagnetic flat relays are known, for example, from German 
Auslegeschrift 16 39 417 and German Offenlegungsschrift 25 02 078. Such 
flat relays have a hollow central portion in the interior of the coil 
spool in which is disposed a contact carrier consisting of insulating 
material which, in addition to the contact elements, also carries the 
operative magnetic components and is axially inserted into the coil spool. 
A plastic carrier of this type because of space limitations does not have 
a large cross-section and thus presents the problem that the operative 
magnetic components and the contact elements which are secured to the 
carrier exhibit relatively unstable tolerance values between the 
components. Even if the contacts are accurately adjusted as to position 
before insertion of the carrier in the coil spool, twisting and other 
distortions of the carrier may still occur following insertion as a result 
of the poor mechanical stability of the plastic carrier so that the 
adjusted values change by an unknown amount. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a flat relay having the 
operative magnetic components carried and supported on a carrier element 
in the hollow interior of the coil spool in which the contact elements are 
firmly secured in their respective positions so that the relative 
positions of the contact elements is not changed by insertion of the 
carrier and components attached thereto into the coil former. 
The above object is inventively achieved in a flat relay in which the 
carrier consists of a non-ferromagnetic metal and has a U-shaped profile 
or cross-section and has a base which rests on the yoke and the pole piece 
opposite the armature. The carrier further has lateral flanks which at 
least partially enclose the yoke and the pole piece. 
A carrier for a flat relay constructed as described above, in the form of a 
metal bar having a U-shaped cross-section, exhibits considerably improved 
stability compared to conventional plastic carriers. A metal bar of this 
type requires only a small thickness to achieve sufficient mechanical 
stability, so that the overall height of the relay can be reduced. 
Moreover, the mechanical stability of the metallic carrier insures a high 
resistance to bending and distortion so that a plurality of contact 
carriers can be arranged adjacent to one another with the relative 
dimensions between contacts remaining stable so that the contact elements 
and associated contacts can be actuated by a common armature. 
The mechanical stability of the carrier is insured by relatively short 
laterally depending flanks of the carrier forming the U-profile. The 
lateral flanks may partially or entirely surround the yoke and the pole 
piece on which the carrier rests. The contact elements which are held in 
an insulating body and face the carrier are secured on the yoke and on the 
pole piece and are thus indirectly connected to the carrier. A further 
embodiment employing the inventive concept disclosed herein exhibits 
lateral flanks of the carrier which also surround the contact elements and 
carry the elements directly by means of laterally engaging supporting 
elements. The armature disposed between the carrier and the contact 
elements is flat and is designed in a known manner and fixed on the yoke, 
for example, by means of a biasing spring. The insulating material body 
which carries the contact elements may have a stop for limiting the 
movement of the free end of the armature. 
In order to enclose the magnetic circuit a further embodiment of the 
invention employs a yoke and/or a pole piece which are angled outside of 
the coil spool so that the angled portions thereof abut against a 
ferromagnetic housing cap. The angled portions of those elements 
preferably are directed upward or downward depending upon the type of 
arrangement of contact spring terminals which is employed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A flat relay constructed in accordance with the principles of the present 
invention is shown in various sectional views in FIGS. 1, 2 and 3. The 
relay has a coil spool 1 on which the coil or winding 2 is wound and which 
has a hollow interior 3. Within the interior 3 is disposed the magnetic 
system for the relay comprising a yoke 4, an overlying flat armature 5 and 
a pole piece 6. The interior 3 further contains one or more contact 
elements, and in the embodiment shown in FIGS. 1, 2 and 3 contains four 
switching contacts mounted on a stationary center contact element 7 and 
two opposing movable contact elements 8 and 9, in the form of leaf 
springs, which are operated by means of an actuation element 10 which is 
attached to or integrally formed on the armature 5. The center contact 
element 7 is held in an insulating material body 11 by embedding or other 
means, whereas the movable contact elements 8 and 9 are fixed in a 
one-part or multi-part insulating material body 12. The insulating 
material body 11 is secured to the pole piece 6 by means of screws, 
rivets, or other suitable means known to those skilled in the art and the 
insulating material body 12 is similarly secured to the yoke 4. 
All elements arranged inside the coil spool 1 are secured on a common 
carrier element 13 which consists of non-ferromagnetic material such as, 
for example, nickel silver, and exhibits a U-shaped cross-section or 
profile as shown in FIG. 7 before insertion. FIGS. 4 and 5 illustrate a 
first embodiment of the carrier 13 and FIG. 6 shows a second embodiment 
for the carrier element designated 13'. 
The carrier 13 shown in FIGS. 4 and 5 possesses relatively short lateral 
flanks 14 having a length which corresponds approximately to the thickness 
of the yoke 4 and the pole piece 6, and may be slightly less than those 
thicknesses. When in place in conjunction with the pole piece 6 and the 
yoke 4, the flanks 14 partially or completely embrace the lateral portions 
of those elements. 
In the embodiment shown in FIG. 6, the common carrier element 13' is 
provided with longer lateral flanks 15. In this embodiment, the lateral 
flanks 15 embrace the insulating material bodies 11 and 12 for the contact 
elements as well as surrounding the yoke 4 and the pole piece 6. The 
insulating material bodies can then be directly connected to the carrier 
13' by means of engagement in correspondingly shaped recesses 16. 
In order to assemble the relay all components of the magnetic system and 
the stationary the movable contact springs are first connected to the 
carrier 13, or the carrier 13', and the dimensions are appropriately 
adjusted between elements outside of the coil spool 1. The connection pins 
7a of the center contact element is not yet angled at this time. The 
assembled and adjusted switching elements together with the carrier 13 as 
shown in FIG. 7 can then be inserted into the wound coil spool 1. As shown 
in FIG. 1, insertion of the carrier 13 and the elements attached thereto 
is effected from the right side of the relay. After insertion of the 
carrier 13 and the associated magnetic system the connection pins 7a are 
bent downward. The interior 3 and the entire relay can be subsequently 
sealed by bonded foils 18 or similar means known to those skilled in the 
art on both front sides. A ferromagnetic cap 17, which may be filled with 
a sealing compound, is put over the relay components. In order to improve 
the magnetic transition the outer end 4a of the yoke 4 and the outer end 
6a of the pole piece 6 are angled at right angles to the portions of those 
elements in the interior of the spool 1 so as to abut against the cap 17. 
Although modificatins and changes may be suggested by those skilled in the 
art it is the intention of the inventor to embody within the patent 
warranted hereon all changes and modifications as reasonably and properly 
come within the scope of his contribution to the art.