Auxiliary contact mounting block

An auxiliary contact mounting block for electromagnetic switching devices, having a housing comprising two shells, a hook, which is able to mate with a marginal ledge of the switching device while facing the switching device during mounting, and a ratchet, which latches with parts of the switching device in the mounted condition. The ratchet and the hook are premolded as whole pieces on respective ones of the two shells. A bezelled crossbar is premolded in front of the entry slot for the supply leads on the shell with the ratchet so that the entry slot is divided into two entry slots for the supply leads.

BACKGROUND OF THE INVENTION 
The present invention relates to an auxiliary contact mounting block for 
electromagnetic switching devices, having a housing comprising two shells; 
a hook, which is able to mate with a marginal ledge of the switching 
device while facing the switching device during mounting; a ratchet, which 
latches with parts of the switching device in the mounted condition; and 
terminal screws for the stationary contacts with a gable-shaped clamping 
piece that permits the introduction of two supply leads. 
In a known switching device of the above type (EP 0 045 683), a separate 
part, which is rotatably supported by a journal, is used for the ratchet. 
The hook in this case is premolded in halves on both shells. 
SUMMARY OF THE INVENTION 
It is an object of the invention to provide an auxiliary contact mounting 
block for an electromagnetic switching device having a housing comprising 
two shells which is simple and inexpensive to produce. 
The objects of the invention are achieved in a simple manner in that the 
ratchet and the hook are premolded as whole pieces on respectively one of 
the two shells. In this manner, the further advantage results that only 
the one shell must be manufactured using cross slides, while the other 
shell is to be manufactured using a tool without cross slides. 
The above and other objects of the invention are achieved by an auxiliary 
contact mounting block for electromagnetic switching devices, having a 
housing, comprising two shells; a hook, which is able to mate with a 
marginal ledge of the switching device while facing the switching device 
during mounting; a ratchet which latches with parts of the switching 
device in the mounted condition; and terminal means for the stationary 
contacts with a gable-shaped clamping piece that permits the introduction 
of two supply leads, wherein the ratchet and the hook are premolded as 
whole pieces on one of the two shells, respectively. 
Since in any case cross slides are required for the one shell, it is 
further advantageous if a bezelled crossbar is premolded on this shell in 
front of the entry slot for the supply leads. In this manner, two supply 
leads are prevented from being introduced into the supply terminal on one 
side. In order to be able to substantially adjust the spring 
characteristic to the requirements, it is further advantageous if the 
ratchet is designed in a U shape between the premolded shape and notched 
edge. 
If very strong shocks are to be reckoned with, then it can be of further 
advantage if a spring is inserted between the U-legs. 
In order to prevent blocking the ratchet through the intrusion of foreign 
bodies while the auxiliary contact block is being removed, it is further 
advantageous if the open side of the U is covered by an actuating 
extension which is premolded on the one leg of the U. The fulcrum for the 
notched edge can be determined in a simple manner with regard to the 
spring if the one leg of the U is premolded on the one shell. An 
overloading of the premolded spring can be avoided if stop faces are 
provided in the one shell for the actuating extension in the resting and 
stressed conditions of the ratchet. The recognition as well as the 
operation of the actuating extension is facilitated when the actuating 
surface of the actuating extension is fluted over a large surface area. 
In order to prevent the ends of the supply leads from being able to be 
inserted into the arcing chamber, it is advantageous if the passage for 
the stationary contact points is designed to overlap from the terminal 
housing into the arcing chamber.

BRIEF DESCRIPTION OF THE DRAWINGS 
With reference now to the drawings, the contact bridge carrier 3 with the 
contact bridge 4 is held in a movable fashion, and the stationary contacts 
5 are held in a form locking manner between the housing shells 1 and 2. In 
FIG. 1, the left stationary contact is shown together with the contact 
bridge as a break contact and the right stationary contact is shown 
together with the contact bridge as a make contact. The stationary 
contacts are bent in a staircase shape. The passage is formed by the walls 
6 and 7 in an overlapping manner, i.e., in a labyrinth shape, so that no 
supply leads can be inserted into the arcing chamber. A chamber 30 is 
defined where the contacts 4 and 5 are positioned. Walls 6 and 7 prevent 
supply leads 31, 32 from being inserted into this chamber 30. Terminal 
screws 8 which are studded with gable-shaped clamping pieces 9 serve to 
connect the supply leads to the stationary contacts. As FIG. 2 shows, a 
bezelled crossbar 10, which shares the entry slot for the supply leads, is 
premolded onto the housing shell 1 so that one supply lead can be 
introduced to the left and to the right of the terminal screw, 
respectively. Furthermore, a ratchet 11, which is designed in a U shape as 
shown in FIG. 1, is premolded on the housing shell 1. The one leg 12 of 
the U is at least partially connected to the floor of the housing shell 1. 
The other leg 13 terminates in an actuating extension 14 which is shaped 
such that it shields the opening 15 so that no foreign bodies can intrude 
into the spring region of the ratchet and thus could interfere with the 
removal of the auxiliary contact block. The actuating extension 14 is 
fluted on the outside so that it is both more easily identified and 
operated as an actuator. Stops 16 and 17 serve to limit the positions of 
the actuating extension. If needed, a compression spring 18 can be 
inserted between the two legs 12,13 when the housing shells are separated. 
The notched edge of the ratchet is designated as 19. The hook 20 which is 
premolded on the housing shell 2 serves to anchor the auxiliary contact 
block onto the electromagnetic switching device. Crosspieces 21 are 
premolded on the side of the housing shells 1 and 2 opposite the hook 20, 
which can interact with projections on the housing of the electromagnetic 
switching device which are not shown more closely. In an equivalent 
manner, the contact bridge carrier 3 is also coupled to the contact bridge 
carrier of the electromagnetic switching device. 
By means of the invention, an auxiliary contact mounting block has been 
provided whose housing can be manufactured with an integrated ratchet and 
anchoring hook in a simple manner. Only for manufacturing housing shell 1 
is a tool with cross slides required. The housing shell 2 is able to be 
manufactured in a form without cross slides. 
In the foregoing specification, the invention has been described with 
reference to a specific exemplary embodiment thereof. It will, however, be 
evident that various modifications and changes may be made thereunto 
without departing from the broader spirit and scope of the invention as 
set forth in the appended claims. The specification and drawings are, 
accordingly, to be regarded in an illustrative rather than in a 
restrictive sense.