Abstract:
A module latching arrangement for mounting and dismounting on a generally U-shaped support rail at least two module base bodies arranged orthogonally above and extending transversely across the support rail, each of the base bodies having a pair of bottom corner portions arranged on opposite sides of the support rail. At least one foot member is connected for horizontal longitudinal sliding movement relative to one of the base body corner portions relative to the adjacent support rail horizontal flange portion. A lateral displacement arrangement on the foot member is operable, when the foot member is displaced from a locked position toward an unlocked position relative to the support rail, to displace the first base body laterally away from an adjacent second base body mounted on the support rail. The foot member is latched in either a locked or an unlocked position relative to the base member.

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application is a national stage application under 35 U.S.C. §371 of PCT International Application No. PCT/EP2011/063420 filed Aug. 4, 2011, claiming priority of German application No. 20 2010 008 319.2 filed Aug. 20, 2010. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     A module latching arrangement for mounting and dismounting on a generally U-shaped support rail at least two module base bodies arranged orthogonally above and extending transversely across the support rail, a foot member being connected with a first base body for horizontal longitudinal sliding movement between locked and unlocked positions relative to the adjacent support rail horizontal flange portion. A lateral displacement arrangement on the foot member is operable, when the foot member is displaced from a locked position toward an unlocked position relative to the support rail, to displace the first base body laterally away from an adjacent second base body mounted on the support rail. 
     2. Description of Related Art 
     For wiring electrical subassemblies, for example, electrical conductors and/or bus systems and/or modules of complex electronic equipment, one frequently provides panel boxes and switch cabinets in which one can align the electrical subassemblies next to each other on a mounting rail. Such electrical subassemblies, for example, are so-called connection modules or blocks that are used not only in production engineering but also for the interfacing of complex networks. By virtue of this modular alignment, the connection modules can be rearranged in many different ways despite their complexity even after installation with a comparatively minor effort and individual electrical subassemblies are exchangeable. 
     In such especially standardized panel boxes and switch cabinets, it is also necessary to displace the electrical subassemblies so that they will directly rest against each other. 
     In this connection, the electrical subassemblies should, on the one hand, be separable from each other as easily and as quickly as possible. On the other hand, they should not by themselves separate from each other, especially in a vibration-stressed environment such as it is often found, for example, in the field of production engineering. 
     The German patent No. DE 299 16 303 U1 discloses a connection module where the electrical subassemblies that are lined up parallel with respect to each other on the mounting rail can be separated from each other in that their mutual parallelism is canceled out. But it takes a lot of structural space to push these units apart from each other so that there must be a longer part of the mounting rail for the mutual separation of the electrical subassemblies, which means that no additional electrical subassemblies can be mounted there. 
     Furthermore, it is possibly advantageous in the mutually adjoining walls of mutually adjoining electrical subassemblies in each case to provide electrical contacts that contact with each other when the electrical subassemblies are arranged mutually resting against each other. The cancellation of parallelism and therefore an oblique separation of mutually adjoining electrical subassemblies from each other, however, depending on the particular model of the electrical contacts provided in mutually adjoining walls, for example, in the case of electrical contacts that are made in the form of plug and socket systems, is no longer readily possible. This is because, depending on the structural shape of the contacts, there is the danger that the electrical contacts might be jammed against each other, causing short-circuits, or that the electrical contacts in the process might be damaged or even destroyed. 
     The present invention was developed to create a subassembly, in particular, an electrical subassembly that can be mutually lined up on a mounting rail which, in a simple manner, quickly, without damage and using as little structural space as possible, can be separated from an adjoining subassembly even if on mutually adjoining side walls there are provided lined-up adjoining subassemblies, in particular, electrical contacts, whereby the subassembly facilitates a secure line-up, in particular, in vibration-stressed environments, so that there will be no danger of a self-actuated mutual separation of several lined-up subassemblies, and whereby the subassembly can be made at reasonable cost. 
     SUMMARY OF THE INVENTION 
     Accordingly, a primary object of the present invention is to provide a module latching arrangement for mounting and dismounting on a generally U-shaped support rail at least two module base bodies arranged orthogonally above and extending transversely across the support rail, a foot member being connected with a first base body for horizontal longitudinal sliding movement between locked and unlocked positions relative to the adjacent support rail horizontal flange portion. A lateral displacement arrangement on the foot member is operable, when the foot member is displaced from a locked position toward an unlocked position relative to the support rail, to displace the first base body laterally away from an adjacent second base body mounted on the support rail. 
     According to another object of the invention, first latching means are provided for latching the foot member in an unlocked condition. Unlatchting means serve to release the foot member for displacement to a locked condition when the associated base member is positioned adjacent a second base member. 
     A further object of the invention is to provide second latching means for latching the foot member in a locked condition relative to the mounting rail. 
     Another object is to provide an electrical subassembly which can be attached upon a mounting rail and which, by shifting in a given assembly direction along said mounting rail, can be positioned against an adjoining subassembly that is arranged on the mounting rail. A base member of a first subassembly is provided with a foot member that can be shifted in a shifting direction with relation to the base body, whereby the first subassembly can be separated from the adjoining subassembly by shifting the foot part in the shifting direction, whereby it is pushed away from the adjoining subassembly during the separation simultaneously, and in the direction opposite from the assembly direction. 
     Upon the separation of the subassembly from the adjoining subassembly, the latter therefore according to the invention is shoved away from the adjoining subassembly so that the subassembly is spaced apart from the adjoining subassembly. As a result, the operator can handle the subassembly in a very simple manner. Besides, the subassembly is pushed away from the adjoining subassembly in a defined manner so that parts, for example, electrical contacts that are arranged on mutually opposite side walls of the subassembly and adjoining subassembly, will not be damaged during the separation of the subassembly. 
     In order to shift the subassembly from the adjoining subassembly during separation, there is provided on the foot part preferably a shifting means, and on the base body, there is provided a ramp, whereby the shifting means during the separation of the subassembly from the adjoining subassembly slides along the ramp and pushes the subassembly against the assembly direction. 
     Likewise in a preferred manner, there is provided on the foot part a latching means that so cooperates with a counter-latching means arranged on the base body that the foot part, during the separation of the subassembly from the adjoining subassembly, will latch into an open position on the base body. In the open position, the subassembly is at least not latched upon the adjoining subassembly. Preferably, it is latched neither on the adjoining subassembly nor on the mounting rail so that it can be taken out of the arrangement. 
     In a preferred embodiment, the subassembly comprises a base body as well as a foot body, whereby by shifting the foot part, it can be arranged in a shifting direction with relation to the base body, both on the adjoining subassembly and also on the mounting rail. For the arrangement of the subassembly, both on the mounting rail and on the adjoining subassembly, one therefore merely needs a part, in other words, the foot part, so that the operator will find it as a result very simple to handle the subassembly during arrangement. 
     The mounting rail preferably extends parallel to a mounting rail plane whereby the adjoining subassembly, by shifting in a latch-on direction and/or by swinging into a latch-on pivotal direction, both of which in each case run parallel to the subassembly plane, can arranged upon the mounting rail and by shifting along a line-up direction, which runs parallel to the mounting rail plane, can be arranged against the adjoining subassembly. 
     Accordingly, the subassembly can be arranged on a mounting rail by shifting into a latch-on direction and/or swinging into a latch-on rotary direction, both of which in each case run parallel to a subassembly plane. In the process, the subassembly plane is the plane in which extends a subassembly arranged on the mounting rail. Subsequently, the subassembly can be arranged upon an adjoining subassembly in that it is pushed into an alignment direction that runs parallel to a mounting rail plane in which extends the mounting rail. As a result, for arranging a subassembly between two adjoining subassembly groups and for the separation and removal of the subassembly, one merely needs a structural space that is only slightly larger than the depth of the subassembly itself. Compared to a connection block with a traditional subassembly in the case of this particular connection block with inventive subassemblies, one therefore has available considerably more structural space along the mounting rail and/or such a connection block can be built correspondingly smaller. 
     Besides, the arrangement of the subassembly upon the adjoining subassembly in case of roughly mutually parallel arrangement will facilitate the supply of parts in mutually adjoining, especially mutually adjoining side walls of the subassembly and the adjoining subassembly. As a result, parts arranged on one of these side walls, which are elevated, in particular, with respect to the side walls upon which they are arranged during the arrangement of the subassembly against the adjoining subassembly are stuck into adjoining parts of the adjoining side wall without being damaged or without causing any damages. The inventive subassembly therefore facilitates the arrangement of, for example, electrical connections, such as plug-and-socket connections in the conventional model upon the side walls of the subassembly. 
     In a preferred embodiment, the subassembly, during line-up upon the adjoining subassembly, is latched upon the latter so that it will not by itself become separated from the adjoining subassembly in a vibration-stressed environment. 
     Preferably, the mounting rail plane runs at a right angle to the subassembly plane. Furthermore, it is preferred that a cutting line of the subassembly plane cutting the mounting rail plane should run at a right angle to a longitudinal extent of the mounting rail. 
     In a preferred embodiment, the subassembly has a subassembly latch means that is provided for latching the subassembly upon the adjoining subassembly, whereby the adjoining subassembly comprises an adjoining subassembly latch means that cooperates with the subassembly latch means during the latching action, whereby the subassembly latch means for the purpose of arranging the subassembly upon the adjoining subassembly can be shifted in the direction of shifting against the force of a power means and which, for the latching of the subassembly upon the adjoining subassembly, is provided in such a manner that it can be pushed back against the shifting direction in the direction of the force. 
     In this embodiment, the subassembly latch means, therefore during the arrangement of the subassembly against the adjoining subassembly, avoids the adjoining subassembly latch means so that the subassembly can be arranged upon the adjoining subassembly without any rotation or swinging in that it is shoved in the alignment direction preferably in a parallel arrangement with respect to the adjoining subassembly. The subassembly is retained upon the adjoining subassembly with the force of the power means because the subassembly latch means, due to the force against which it is pushed during the arrangement on the adjoining subassembly, is shoved back against the shifting direction. 
     As power means, one preferably use a compression spring. Therefore, one can also use other, for example, resilient parts, which cause a resetting force. 
     In a preferred embodiment, the subassembly furthermore has a mounting rail latch means that is provided for the purpose of latching the subassembly upon the mounting rail, whereby the mounting rail has an edge that, during the latching action, cooperates with the mounting rail latch means so that the mounting rail latch means can be pushed against the force of the power means for the arrangement of the subassembly upon the adjoining subassembly in the direction of shifting, and it is provided in such a manner that it can be pushed back in the direction of the force for latching the subassembly upon the mounting rail against the shifting direction. 
     The mounting rail latch means in this embodiment also avoids the edge of the mounting rail during the arrangement of the subassembly upon the mounting rail. Basically, the subassembly therefore can be arranged on the mounting rail also without any rotation or swinging in that it is shoved in the latch-on direction, preferably in a parallel arrangement with respect to the adjoining subassembly. Because the mounting rail latch means, likewise on the basis of the force against which it is shoved during arrangement upon the mounting rail, is shoved back against the shifting direction, the subassembly is also retained on the mounting rail likewise with the force of the power means. 
     In a preferred embodiment, the subassembly latch means and/or the mounting rail latch means are arranged on the foot part. When the foot part is shifted, the subassembly latch means and/or the mounting rail latch means is therefore shifted. 
     Here, the foot part can preferably be shifted against the force of the power means into the shifting direction and in the direction of the force against the shifting direction. In a further preferred manner, the foot part is arranged on the base body in a reversibly separable manner. In a furthermore preferred manner, it has a longitudinal extent with respect to which it is manufactured in a symmetrical mirror fashion. 
     In a likewise preferred manner, the subassembly is made in a symmetrical mirror fashion with respect to a midline so that the subassembly can be aligned against the adjoining subassembly also in an arrangement that is rotated by 180° with respect to the mounting rail. 
     Preferably, the subassembly can be latched upon the adjoining subassembly and the mounting rail by shifting the foot part against the shifting direction with relation to the base body. In a likewise preferred manner, it can be separated both from the adjoining subassembly and from the mounting rail by shifting the foot part in the shifting direction with relation to the base body. 
     In this embodiment, both the subassembly latch means and also the mounting rail latch means are arranged on the foot part so that by shifting the foot part, both the subassembly latch means and also the mounting rail latch means will be shifted. 
     In a particularly preferred manner, on the foot part, there is provided a slope that slides along the mounting rail during the arrangement of the subassembly upon the mounting rail. Here, the foot part and therefore simultaneously the mounting rail latch means will be shifted against the force in the shifting direction. 
     In a further preferred embodiment, there is provided on the foot part a handle, in particular, for actuation by means of a screwdriver for the separation of the subassembly from the adjoining subassembly and/or from the mounting rail so that the operator will find it very simple to separate the subassembly by means of the handle. 
     To facilitate the handling of the subassembly during the arrangement and latching on the mounting rail, there is provided an edge for the attachment of the subassembly upon the mounting rail, preferably bilaterally on the mounting rail, and preferably two mounting rail latch means are to be arranged on the subassembly, each of which cooperates with one of the edges of the mounting rail. The mounting rail latch means here are preferably provided in such a manner that the subassembly first of all is arranged parallel to the subassembly in a position swung with respect to the mounting rail plane with one of the mounting rail latch means upon an edge of the mounting rail in order subsequently to swing it into the latch-on direction so that the other mounting rail latch means will be arranged on the other edge of the mounting rail. In a likewise preferred manner, the subassembly can be arranged upon the mounting rail in that it is arranged parallel to the subassembly plane as well as parallel to the mounting rail plane and in that it is shifted in the latch-on direction. The mounting rail latch means therefore avoid the edges likewise initially and they are then, on the basis of the force of the power means, pushed back against the shifting direction, whereby the subassembly is latched upon the mounting rail. 
     In a likewise preferred manner, we provide two subassembly latch means that cooperate with two adjoining subassembly latch means in order, particularly in case of large-surface subassembly, to distribute the force that is to be applied for latching the subassembly upon the adjoining subassembly and/or to achieve a greater latching security. 
     To provide two mounting rail latch means and/or two subassembly latch means upon the subassembly, it is preferred to make the subassembly with two foot parts with in each case one mounting rail latch means and one subassembly latch means. In this embodiment, the subassembly can be taken out of the arrangement in that, first of all, one foot part and then the other foot part will be shoved into the open position. In a likewise preferred manner, the foot parts are so provided that both foot parts can be simultaneously separated from the mounting rail and/or the adjoining  11  subassembly. The problem is furthermore solved with a connection block with a mounting rail and at least one inventive subassembly that can be arranged upon the mounting rail. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects and advantages of the invention will become apparent from a study of the following specification, when viewed in the light of the accompanying drawing, in which: 
         FIG. 1  is a front perspective view illustrating the mounting on a support rail of a plurality of base member electrical components; 
         FIG. 2   a  is a perspective view of a foot member of  FIG. 1 , and  FIG. 2   b  is a bottom view of an electrical component of  FIG. 1 ; 
         FIG. 3   a  is an exploded side perspective view of an electrical component of  FIG. 1 , and  FIG. 3   b  is a corresponding bottom exploded perspective view; 
         FIG. 4   a  is a right side perspective view of an assembled electrical module, and  FIG. 4   b  is a detailed perspective view of the encircled area of  FIG. 4   a;    
         FIG. 5   a  is a left side perspective view of an assembled electrical module, and  FIG. 5   b  is a detailed perspective view of the encircled area of  FIG. 5   a;    
         FIG. 6  is a side elevation view illustrating the base member of  FIG. 1  mounted on a support rail; 
         FIGS. 7   a - 7   c  are sectional views taken along line C-C of  FIG. 6 , illustrating the operation of the latching means which locks the base members together, and the foot members in the locked position; 
         FIGS. 8   a  and  8   b  are sectional views taken along line C-C of  FIG. 6 , illustrating respectively the lateral displacement of a base member relative to another base member, and the latching of a base member in the unlocked condition, and  FIGS. 8   c  and  8   d  are detailed views of the encircled areas of  FIGS. 8   a  and  8   b , respectively; 
         FIGS. 9   a ,  9   b ,  9   d  and  9   e  are sectional views taken along line C-C of  FIG. 6 , illustrating the unlatching operation of the latch means, and  FIG. 9   c  is a detailed view of the encircled area Z of  FIG. 9   b ; and 
         FIGS. 10   a  and  10   b  are perspective views illustrating the manner of displacement of the foot members relative to the base member. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring first more particularly to  FIG. 1 , a plurality of module base members  11 ,  12  and  13  are arranged for mounting on a conventional top-hat type support rail  2  having a horizontal base portion  23 , a pair of upwardly extending vertical leg portions  24 , and a pair of outwardly extending flange portions  22 . Connection block  1  comprises two mutually adjoining subassemblies  12 ,  13 , which together are mounted on the support rail  2 , as well as a subassembly  11 , which is not yet mounted on the support rail. 
     Mounting rail  2  extends along a longitudinal axis  202  and has a U-shaped cross-section, with the flange portions  24  defining a horizontal mounting rail plane  200 . 
     The adjoining subassembly arranged on mounting rail  2 , which adjoins the subassembly  11  that is to be arranged on mounting rail  2 , extends parallel to a subassembly plane  100 .  FIG. 1  further shows a second subassembly plane  100 ′ that is parallel to subassembly plane  100  in which extends the subassembly  11  that is not yet arranged on mounting rail  2 .  FIG. 1  shows that the mounting rail plane  200  as well as the subassembly plane  100  in the embodiment illustrated here are arranged at a right angle  99  with respect to each other. Besides, an intersection cutting the mounting rail plane  200 , here shown on cutting line  103 ′, runs with the second subassembly plane  100 ′ at a right angle with respect to the longitudinal extent  202  of mounting rail  2 . 
     Subassembly  11  can be arranged on mounting rail  2  by displacement in a downward latching direction  101  and/or swinging in a latching pivotal direction  102 , both of which in each case extend parallel to the subassembly plane  100 . Furthermore, subassembly  11  can be arranged upon the adjoining subassembly  12  by displacement in a longitudinal assembly direction  201  that extends parallel to the mounting rail plane  200 . For arrangement upon the adjoining subassembly  12 , subassembly  11  is first of all arranged in a vertical direction upon mounting rail  2 , and is then pushed along the latter in the longitudinal direction  201 . 
     In the illustrated embodiment, each of subassemblies  11 ,  12 ,  13  includes two foot members  3 ,  3 ″ that cooperate with the edges  22  of mounting rail  2 , respectively, for the purpose of latching the subassemblies  11 ,  12 ,  13  upon mounting rail  2 . Subassemblies  11 ,  12 ,  13  furthermore in each case include a base member  4  upon which are arranged foot members  3 ,  3 ″. 
     The two foot members  3 ,  3 ″, arranged on subassemblies  11 ,  12  and  13 , in each case can be shifted in a shifting direction  301 ,  301 ″. Because the edges  22  of mounting rail  2  provided here are aligned in a manner directed away from each other, the shifting direction  301 ,  301 ″ of the two foot parts  3  is provided in a manner directed away from each other. The directional changes that result by the alignment of the edges that mutually point away from each other are characterized in the illustration of  FIG. 1  by the quotation marks on references  301 ,  301 ″,  102 ,  102 ″. 
     Referring now to  FIG. 2   a , each foot member  3  is generally rectangular, being symmetrical relative to its longitudinal axis  38 , and with a generally U-shaped cross-sectional configuration defining bottom and side walls. At one end, the foot member side walls include inclined surfaces  33  that terminate in projections  32  that are adapted to extend in locking engagement under the associated support rail flange portion  22 , and a first pair of resilient horizontal latching arms  36  that are provided at their free ends with outwardly directed projections  361 . At its other end, the foot member  3  is provided with an operating opening  34 , and a second pair of upwardly extending rigid vertical latching arms  31 . The side walls of the foot member are provided with a pair of integral resilient displacement arms  35  provided at their ends with inwardly directed projections  351 . A transverse bridge wall  37  extends between the side walls of the foot member. 
     Referring to  FIG. 2   b , it will be seen that the bottom portion  113  of the base member  4  is provided symmetrically on each side of the center line  104  with a pair of ramps  45  arranged for engagement by the projections  351  on the shifting arms  35  of the foot members, respectively, a pair of laterally extending latch projections  41 , and a pair of unlatching projections  46 , the purposes of which will be described in greater detail below. 
     As shown in  FIGS. 3   a  and  3   b , each base member  4  is generally U-shaped and includes a first side wall  112  provided at each end with first latch openings  43  adjacent the ramp surfaces  45 , and a second side wall  121  is provided at each end with corresponding first latch projections  41 . The intermediate portion of side wall  112  contains a pair of unlatching openings  49 , and the intermediate portion of side wall  121  includes a pair of corresponding unlatching projections  46 . The intermediate portion of side wall  112  also contains a third pair of openings  493 . 
     The parts that are arranged symmetrically with respect to midline  104  on base body  4  as well as the parts that are arranged symmetrically with respect to the longitudinal extent  38  on foot member  3  make it possible to arrange subassembly  11  on mounting rail  2  also in a position rotated by 180° with respect to mounting rail  2 . 
     When subassembly  11  is first latched upon mounting rail  2 , slope surface  33  of foot member  3 , during the shifting into the latch-on direction  101  and/or during swinging into the latch-on rotation direction  102 , comes to rest upon edge  22  of mounting rail  2 . During further shifting in the latch-on direction  101  and/or during swinging into the latch-on rotation direction  102 , slope  33  slides along edge  22 , whereby foot part  3  is shifted against the resilient force of a compression spring  6  (see  FIG. 3 ) with relation to base body  4  into the shifting direction  301  until edge  22  engages the mounting rail projection  32 . The mounting rail projection  32  is here provided in the form of an edge. Additional embodiments could be provided, for example, a mounting rail latch means  32  in the form of a recess. 
     The subassembly latch means includes a pair of integral latch arms  31  on the foot member  3  that extend upwardly at least partly into the base body  4 , opposite the latch-on direction  101 , for cooperation with the latch projection  41  of an adjacent base member, as will be described below. 
     The particular function of the other parts will be described on the basis of the following figures, more particularly, on the basis of  FIGS. 6-9 . Here, the function of the severally provided parts  31 ,  32 ,  35 ,  36 ,  37 ,  41 ,  43 ,  45 ,  46 ,  47 ,  49 ,  493  will in each case be illustrated and described relative to a foot member  3 . But it also applies to the other severally provided parts, in each case in an analogous fashion. 
       FIGS. 3   a  and  3   b  show two perspective views of subassemblies  11 ,  12 ,  13  from  FIG. 1 , whereby foot member  3  and a biasing compression spring or power means  6  are shown in an exploded fashion. Visible in  FIG. 3   a  is a side wall  112  of subassembly  11  in a position arranged in the arrangement show in  FIG. 1  in mounting rail  2  resting against an adjoining side wall  121  of adjoining subassembly  12 . In  FIG. 3   b , the position arranged in  FIG. 1  on mounting rail  2  is on the adjoining side wall  121  of adjoining subassembly  12  resting against side wall  112  of subassembly  11 . 
     In this arrangement, it can be seen that latching projections are provided on adjoining side wall  121 , including the adjoining subassembly latch projection  41 , the unlatching projection  46 , and the electrical connections  48 , which are made as female contacts. 
     Each of the subassemblies  11 ,  12 ,  13  in this embodiment is an electrical subassembly. Basically, the invention at hand can also be used for subassemblies that are not electrical subassemblies (not shown). In particular, as shown in  FIG. 4   a , it can be used for a subassembly into which one can arrange an electronic module  422  and/or an electrical connection bar  44 . 
       FIG. 3  shows an embodiment in which the power means  6  is a compression spring arranged in a structural space of base body  4  (see  FIG. 3   b ) between transverse wall  37  of foot part  3  and transverse wall  47  of base body  4 . 
       FIG. 4   a  shows a perspective view of the subassemblies  11 ,  12 ,  13  of  FIG. 1 , wherein subassembly  11  includes the electronic module  442  as well as the connection bar  44 . In  FIG. 1 , one can see side wall  121  arranged to engage the side wall  112  of the adjacent subassembly. 
     The electronic element  442  can be pushed into the base member  4  of subassembly and can be electrically connected with the connection bar  44  that carries the electrical connections  441  for the wiring of subassembly  11 . Subassembly  11  is latched upon mounting rail  2  by means of two foot parts  3 ,  3 ″ that are arranged symmetrically with respect to its midline  104  (see  FIG. 2 ). 
     The detail view of  FIG. 4   b  shows the adjoining subassembly latch means  41 , the unlatching means  46 , the subassembly lateral displacement means  35 , as well as the operating opening  34 . 
       FIG. 5   a  shows one of the subassemblies  11 ,  12 ,  13  of  FIG. 1  with connection part  44 , and in the detailed view of  FIG. 5   b , one can see the side wall  112  that rests against adjoining side wall  121 . This side wall contains a subassembly displacing arm  35 , a first recess  43  arranged for cooperation with a projection  41  on the adjacent subassembly, a second recess  49  arranged for cooperation with an unlatching projection on the adjacent subassembly, as well as a third recess  493 . 
     Referring now to  FIGS. 6 and 7   a , in order to connect a first subassembly  11  to a row of subassemblies  12  and  13  mounted on the support rail, the first subassembly  11  is initially displaced downwardly relative to the support rail (for example, in the direction  101  of  FIG. 1 ), thereby to cause the foot projections  32  to extend under the edges of the support rail flanges  22 . The first subassembly is then laterally displaced longitudinally of the support rail  2  toward the subassembly  12  as shown by the arrow  201 , thereby causing the latching projections  41  on the subassembly  12  to extend into the latching openings  43  of the first subassembly  11 . Owing to the cooperation between the inclined surfaces  411  on the latching projection  41  with the latching arms  31  on the foot members, the foot members of the first subassembly  11  are displaced outwardly relative to the base member, as shown in  FIG. 7   b . When the tips of the projections  412  clear the latch arm  31 , the foot members are biased together by the associated springs  6  toward the locked position of  FIG. 7   c . The subassembly  11  is now locked to the support rail  2 , and to the next subassembly  12 . Preferably, side wall  112  of subassembly  11  then essentially rests on the adjoining side wall  121 . 
     Latch means  36  has a hook-shaped end  361  with an oblique side  362  and is arranged in the third recess  493 . During the latching action, the unlatching projection  46  extends into the unlatching opening  49 . 
     Referring now to  FIG. 8 , in order to unlock subassembly  11  from the assembled components on the support rail, foot member  3 , with the help of a screwdriver  5  (see  FIG. 10 ), is displaced as far as possible in the shifting direction  301 . The shifting arms  35  defined in the side walls of the foot member  3  of the first subassembly  11  are in the form of a hook with an oblique side  351 , with its oblique side  351  comes to rest against a ramp  45  that is arranged on base body  4  of subassembly  11 , and then slides along ramp  45 , whereupon shifting means  35  is pushed in the assembling direction  201  until it rests against the adjoining subassembly  12 , thereby pushing subassembly  11  slightly in the direction opposite from the assembling direction  201  ( FIG. 8   a ). 
     Simultaneously, the subassembly latch means  31  is pushed into the shifting direction  301 ,  301 ″ so that it no longer engages with catch corner  412  of adjoining subassembly latch projection  41 . During the lateral shifting of subassembly  11  opposite to the assembling direction  201 , the adjoining subassembly latch projection  41  in the process moves at least partly out of the first recess  43  (as shown in  FIG. 8   c ). 
     During the outward displacement of the foot member relative to the base member, the inclined surface  362  of the latch projection  361  on the resilient latch arm  36  slides along transverse wall  494  ( FIG. 8   c ) and enters the unlatching opening  49 . Because subassembly  11 , while shifting against the assembly direction  201  by means of a shifting means  35 , is shifted with relation to the adjoining subassembly  12  and therefore is spaced apart from the latter, the unlatching means  46  extends only partially into the unlatching opening  49 , so that projection  361  of latch arm  36  engages opening  49 . 
     Upon release, foot member  3  is returned by the force of compression spring  6  inwardly in the direction opposite the shifting direction  301 . In the process, shifting means  35  with its oblique side  351  slides back along ramp  45  ( FIG. 8   d ). Furthermore, latching means  36  is shifted against shifting direction  301  until it rests on a surface  491  of wall  494  that faces toward unlatching opening  49 , thereby locking foot member  3  in the open position OS. 
       FIG. 9  shows the line-up of a subassembly  11 , which is in the open position OS, upon adjoining subassembly  12 . When foot part  3  is in the open position OS, then during the shifting of subassembly  11  in the assembling direction  301 , the unlatching projection  46  is pushed into the opening  49  and pushes the latch means  36  opposite the assembly direction  201  out of the opening  49 . Then foot member  3  can again be displaced inwardly by spring  6  all the way toward the latched position V. 
     At the same time, the latch projection  41  of the adjoining subassembly  12  is again pushed into the first recess  43 , whereby with its oblique side  411 , it slides in an analogy to the description in  FIG. 7  along the subassembly latch means  31  until the latter engages the latch corner  412  of the adjoining subassembly latch means  41  and rests against it. In this state, subassembly  11  is again latched upon mounting rail  2  as well as adjoining subassembly  12 , and it is in the latched position V. 
     Subassembly  11  can be delivered both in the open position OS and in the latched locked position V. 
       FIG. 10  demonstrates the separation of subassembly  11  with connection bar  44  and electronic element  442  from  FIGS. 4 and 5  from mounting rail  2  by means of actuation means  5 , which here is done by means of a screwdriver  5 . The subassembly  11 , shown here, has two foot members  3  that cooperate with two edges  22  of mounting rail  2  that point away from each other. As shown in  FIG. 1 , this again causes directional changes that are characterized by the quotation marks on references  301 ,  301 ″,  51 ,  51 ″. 
     Screwdriver  5  is inserted into operating opening  34  of foot member  3 , which here is made as a fourth recess and is pivoted in the separation direction  51 . Here, it rests against base body  4  of subassembly  11  and pushes foot member  3  into shifting direction  301  according to the mechanism explained in  FIGS. 7-9 . Here, foot member  3  is slightly shifted against assembly direction  201  (see  FIG. 1 ) on the basis of shifting arm  35 . During its return against shifting direction  201 , foot member  3  is latched in the open position OS, see  FIG. 9(   a ). The adjoining subassembly latch means  41 , which cooperates with the subassembly latch means  31  of the foot part  3  that is latched in the open position OS, is therefore separated from subassembly  11  and can be taken out of the first recess  43 . Besides, foot member  3  is no longer latched upon edge  22  of mounting rail  2 . 
     This process is then repeated for the other foot member  3  of subassembly  11 , so that the adjoining subassembly latch means  41  (see  FIGS. 7-9 ) of the other foot part  3  is also separated. Subsequently, subassembly  11  can be taken off mounting rail  2  in that it is shifted against the assembly direction  201 , and in that it is subsequently shifted against the assembling direction  101  and/or that it is pivoted against the assembling rotation direction  102 . 
     In the separation of subassembly  11  explained here, the foot members  3  of subassembly  11  are separated one after the other; therefore, subassembly  11  is first of all slightly adjusted by means of shifting means  35  of the first separated foot member  3  with respect to the subassembly level  100  of the adjoining subassembly  12 . The adjustment, however, first of all, is very slight. Besides, a simultaneous separation of the two foot members  3  is also possible here, and that brings about a parallel shifting of subassembly  11  with respect to adjoining subassembly  12 . Furthermore, the foot members  3  can also be so coupled together with each other that by means of the separation of a foot member  3 , simultaneously the other foot member  3  is also separated, so that subassembly  11 , during separation, is likewise pushed parallel to the adjoining subassembly  12 . Finally, one can also make an inventive arrangement with only one foot part  3 , which, during the separation, facilitates a parallel shifting of subassembly  11  with respect to adjoining subassembly  12 . In these embodiments, subassembly  11  can be arranged not only by pure parallel shifting with respect to the adjoining subassembly  12  upon the latter, but can also be separated from the adjoining subassembly  12  by means of a parallel shifting action. 
     While in accordance with the provisions of the Patent Statutes the preferred forms and embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that changes may be made without deviating from the invention described above.