Abstract:
An apparatus for detachably fastening an equipment housing to a profile rail, preferably a top-hat rail mounted on a wall or bottom surface, includes guide strips. At least one clamp part slides on the guide strips and engages the profile rail in a clamping position like a tong. The at least one clamp part is retained in a clamping position by spring force operating in a given direction and is displaceable into an open position counter to the given direction for loosening. At least one locking part is displaceable relative to an equipment housing and is coupled to the at least one clamp part. The at least one locking part and the at least one clamp part occupy at least two positions defining a mutual spacing. The at least one locking part blocks the at least one clamp part in one of the positions for preventing the at least one clamp part from being displaced into the open position for loosening the equipment housing from the profile rail.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to an apparatus for detachably fastening an equipment housing to a profile rail, preferably a top hat rail, which is mounted on a wall or bottom surface, having clamp parts sliding on guide strips and engaging the profile rail in tonglike fashion, the clamp parts being retained in a clamping position thereof by spring force and being displaceable into an open position counter to an operative direction of the spring force for loosening. 
     Profile rails that are mounted on a wall surface are preferably used to fasten equipment housings, for instance for measuring transducers or switchgear, to walls. The housings can be attached to them with the said of a clamp device. As a rule, the clamp parts belonging to the clamp device are secured to the bottom part of such housings in such a way that they can slide on guide rails, and they engage the profile rail like tongs. Spring means assure that the clamp parts are retained in their clamping position. 
     In order to release such a clamp device when the equipment housing is removed from the profile, at least one of the two clamp parts must be put in its opening position, counter to the direction in which the spring means act. In order to achieve secure fastening of the equipment housing that is independent of vibration, so that the equipment will not unintentionally fall out of its anchoring, a strong spring must be used. On the other hand, strong spring forces make loosening of the fastening more difficult. 
     It is accordingly an object of the invention to provide an apparatus for detachably fastening an equipment housing to a profile rail, which overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type, which is simple in structure and with which an especially secure yet easily released housing fastening is attained. 
     SUMMARY OF HE INVENTION 
     With the foregoing and other objects in view there is provided, in accordance with the invention, an apparatus for detachably fastening an equipment housing to a profile rail, preferably a top hat rail, comprising guide strips, at least one clamp part sliding on the guide strips and engaging a profile rail mounted on a wall or bottom surface in a clamping position like a tong, the at least one clamp part being retained in a clamping position by spring force operating in a given direction and being displaceable into an open position counter to the given direction for loosening, at least one locking part being displaceable relative to an equipment housing and being coupled to the at least one clamp part, the at least one locking part and the at least one clamp part occupying at least two positions defining a mutual spacing, the at least one locking part blocking the at least one clamp part in one of the positions for preventing the at least one clamp part from being displaced into the open position for loosening the equipment housing from the profile rail. 
     Locking at least one clamp part in its retaining position means that even strong counter forces cannot effect unintentional loosening. Particularly simple locking is achieved with a locking part that is displaceable relative to the equipment housing and is coupled to the clamp part in such a way that both parts can assume at least two positions that define the mutual spacing. In one of these two positions, the clamp part is blocked by the locking part in such a way that it cannot be displaced into the open position for loosening of the equipment housing from the profile rail. In the other of the two positions, opening of the clamp device must necessarily be possible. 
     According to an advantageous feature of the invention, the operating coupling between the locking part and the clamping part is constructed in such a way that the two parts are guided jointly in the displacement direction between two guide strips in guide grooves formed by them. In order to connect the locking part to the clamping part, at least one of these two parts has a gripper arm that engages a handle attachment of the other part in such a way that the maximum spacing between the two parts is defined thereby. However, the mutual spacing may be reduced by displacing the two parts toward one another, counter to the force of a spring, preferably a helical spring, that spreads them apart. 
     The various positions of the two parts relative to one another are defined by a plurality of stops, which are optionally formed by resilient detent means for changing position. In a first position, blocking the clamp part, the locking part is moved so close to the clamp part that it prevents its displacement into the opening position. This locking position of the fastening adaptor assures fastening of the housing to the profile rail in a manner that is secure against self-loosening, even under unfavorable conditions, such as strong vibrations. 
     In a second position, the spacing between the two parts is defined in such a way that the clamp part can be displaced into the opening position counter to the force of the spring that spreads the parts apart. This position thus corresponds in its action to known versions in which the housing must be pulled in one direction counter to the force of a spring in order to enable loosening of one of the two clamp parts from the top hat rail. However, that can be achieved only with the said of a pivoting motion and the housing must be swiveled about the engagement point of the other clamp part. 
     However, in the case of profile rails secured directly to a wall, such swiveling motion cannot be carried out, so that according to a further feature of the invention, a third position is provided, in which the spacing between the two parts equals the maximum spacing defined by at least one gripper arm, so that by joint displacement of the two parts, the clamp part can be displaced into the opening position without overcoming a spring force. The clamp parts retracted on both sides then enable pivot-free removal of the housing from the profile rail. 
     According to a suitable feature of the invention, the clamp part has a V-beam which forms a clamping edge that engages the profile rail and a clamp body past which the V-beam protrudes on both sides, so that the beam shoulders located on the back side of the V-beam form a stop, which strikes the guide strip in the opening position. 
     A second stop, defining the closing position of the clamp part, can suitably form at least one slide hook, which engages an associated detent hole of the base plate of the rail holder when the clamp part is inserted into the guide grooves and in the clamping direction prevents the clamp part from undesirably sliding out of the guide grooves. The slide hooks rest in hook slots, which in turn are recessed out of the clamp body of the clamp part. A spring hole which is also provided in the clamp body serves the purpose of unilaterally supporting the spring disposed between the clamp part and the locking part. 
     It is advantageous to construct the locking part in uch a way that it is slideably movable in the guide grooves with guide rails, in a manner corresponding to the clamp part, and it has the gripper arms needed for coupling to the clamp part. The gripper arms have an end secured to the slide body, on which they are provided with gripper arm shoulders, that prevent the locking part from sliding out of the guide groove in the opening direction, together with a groove stop formed in each guide groove. 
     In order to enable anchoring of the locking part in different detent positions, the locking part has a resilient locking tab that is disposed in a manner capable of oscillating in a tab slot. The locking tab is provided with at least one detent tooth, which engages a detent depression and strikes a stop edge. On the free end of the locking tab, an actuating rib is provided, which enables access of such a type that the locking tab is freedfrom its stop position, counter to its spring force, and thus enables displacement of the locking part. 
     It is especially advantageous for the locking part also to be constructed in such a way that in the third position of the two parts, it protrudes with its free end past the end of the rail holder and thus past the bottom surface of the housing body as well and in this position offers the possibility of performing a screw fastening of the housing, through suitable holes provided in the locking part. 
     A very substantial improvement provided by the subject of the invention is that the clamp part and the locking part are secured on a rail holder, in such a way that an interchangeable fastening adaptor is created, which is detachably secured on the outside of a bottom part of the equipment housing, that is equipped with retaining tangs. The fastening adaptor can be adapted to the type of wall or bottom fastening being provided and can easily be attached to the housing. This makes it possible to construct the housing, including its bottom plate, completely independently of the type of fastening it will have later, and also for the entire piece of equipment to be on consignment or in inventory so that a selection of a fastening apparatus can be made later. Even a later change, such as a system conversion, presents no difficulties because all that needs to be procured is the correct adaptor. 
     Advantageously, the bottom part holding the fastening adaptor should be constructed in such a way that it can be slipped onto the housing body from at least one side. To that end, intermeshing slide rails and slide grooves are respectively provided on the housing body and on the bottom part. As a result, very simple, fast opening and closing of the housing is attained without means for screwing them together. 
     It is especially advantageous if the bottom part includes two bottom halves, that are preferably constructed identically, which can be slipped onto the housing body from two opposite sides and which meet one another with their abutting edges in the middle of the housing. 
     To this end, the bottom part preferably has the form or shape of a flat shell, which is open on one side for being slipped on, because of its separation into the two bottom halves. The slide elements that are needed in any case for slipping on the two bottom halves act as a meandering seal, so that the housing is also well-protected against dust. 
     Two additional guide rails disposed on the bottom halves parallel to the two housing side walls in the sliding direction, form a running groove for the ends of the housing walls engaging them there, and assure adequate lateral stability of the housing walls. 
     In order to achieve good sealing from the outside in the region of the abutting edge of the two bottom halves as well, each bottom wall is provided in the region of its abutting edge with an overlapping tongue, which has half the width and half the wall thickness of the remaining bottom wall and is offset in stages in such a way that two overlapping tongues that meet, which are halved in their wall thickness, add together by overlapping to make the wall thickness of the remaining bottom wall. 
     A secure connection of the two bottom halves to make a common bottom part is attained by providing one detent hook and one detent bearing surface anchoring the detent hooks, each being disposed in the region of a respective abutting edge, the detent elements interlocking when the two bottom halves meet. 
     In order to attain a secure connection of the fastening adaptor to the bottom part, retaining tangs are formed onto the outside of the bottom halves along their sliding direction, and retaining grooves are located between these tangs and the bottom wall. Slide cams, which are formed onto a rail holder and belong to a fastening adaptor, fit into these retaining grooves. 
     Convenient mounting of the fastening adaptor on the bottom part is achieved due to the fact that the retaining tangs and the slide cams are each disposed at such a distance from one another that the slide cams find space between the retaining tangs, so that the two intermesh in toothlike fashion, and the slide cams can slide inside the retaining grooves up to a stop by a short displacement parallel to the plane of the bottom wall. 
     Locking of the fastening adaptor to the bottom part is attained with the aid of a spring tab that is exposed in a base plate of the rail holder by a recess. The spring tab has an indentation, into which retaining cams dip, each retaining cam being formed onto a respective bottom half in the region of the abutting edge and protruding past the plane of the bottom wall. Since the indentation engages both retaining cams, the two bottom halves are simultaneously held together as well. 
     Other features which are considered as characteristic for the invention are set forth in the appended claims. 
     Although the invention is illustrated and described herein as embodied in an apparatus for detachably fastening an equipment housing to a profile rail, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
     The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a fragmentary diagrammatic lateral-sectional view of a housing with a fastening apparatus; 
     FIG. 2 is fragmentary, bottom-plan view of the housing of FIG. 1, with a view of the fastening apparatus; 
     FIG. 3 is another fragmentary, lateral-sectional view of the housing of FIG. 1; 
     FIG. 4 is a lateral-sectional view of a housing body without the fastening apparatus; 
     FIG. 5 is a bottom-plan view of the housing body of FIG. 4; 
     FIG. 6 is another lateral-sectional view the housing body; 
     FIG. 7 is a plan view of the outside of a bottom half; 
     FIG. 8 is a lateral view of the bottom half of FIG. 7, which is pivoted by 90°; 
     FIG. 9 is another lateral view in a section taken along the line IX--IX of FIG. 7, in the direction of the arrows; 
     FIG. 10 is a plan view of the outside of a bottom half; 
     FIG. 11 is a lateral-sectional view of the bottom half, taken along the line XI--XI of FIG. 10, in the direction of the arrows; 
     FIG. 12 is a plan view of a completely assembled fastening adaptor; 
     FIG. 13 is a lateral-sectional view of the fastening adaptor; 
     FIG. 14 is another lateral-sectional view of the fastening adaptor; 
     FIG. 15 is a side-elevational view of a rail holder; 
     FIG. 16 is a plan view of the inside of the rail holder facing toward the housing; 
     FIG. 17 is a lateral-sectional view of the rail holder taken along the line XVII--XVII of FIG. 16, in the direction of the arrows; 
     FIG. 18 is another lateral-sectional view of the rail holder taken along the line XVIII--XVIII of FIG. 16, in the direction of the arrows; 
     FIG. 19 is a lateral view of a locking part; 
     FIG. 20 is a plan view of the inside of the locking part facing toward the housing; 
     FIG. 21 is another lateral view of the locking part; 
     FIG. 22 is a further lateral-sectional view of the locking part; 
     FIG. 23 is a lateral view of a clamp part; 
     FIG. 24 is a plan view of the inside of the clamp part facing toward the housing; and 
     FIG. 25 is a lateral-sectional view of the clamp part taken along the line XXV--XXV of FIG. 24, in the direction of the arrows. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the figures of the drawing in and first, particularly, to FIGS. 1-3 thereof, there is seen an equipment housing 1, 2, including a housing body 1 and a bottom part 2, which is equipped with a fastening adaptor 3-6, that is adapted to the type of wall or bottom fastening intended for the equipment housing 1, 2. In the present example, the fastening adaptor 3-6 is constructed in such a way that the equipment housing 1, 2 can be secured to a profile rail 7, which in this case is constructed as a top hat rail. 
     The housing body 1 serves to receive inserted printed wiring boards 8 and connection terminals 9, which require no further description herein because these details have no significance for the invention. An opening that makes it possible to insert the printed wiring boards 8 is located in the bottom region of the housing body 1, which is provided with one slide rail 11 shown in FIGS. 4-6 that points outward on each of the free ends of two opposed housing walls 12, and which enables two identical parts or halves 2a and 2b of the bottom part 2 to be slipped on. 
     The bottom part shown in FIGS. 7-11 creates a prerequisite for assuring that on one hand the fastening adaptor 3-6 needed to fasten the equipment housing 1, 2 can be easily attached to the equipment housing 1, 2, and on the other hand that the housing 1, 2 can be opened simply. Corresponding to the slide rails 11 on the housing body 1, the shell-like bottom part 2 is provided with one slide groove 21 in the inner surface of each of two opposed side wall parts 24a, 24b of a side wall 24. A guide rail 25 is disposed on a bottom wall 23 parallel to each side wall 24 and between these side walls. The guide rail 25 provides good lateral stability of the side walls that slide in a running groove 26 of the housing body 1, so that the side walls cannot be pressed inward. Due to the inter-engagement of grooves and rails, a meandering sealing edge is created between the housing body 1 and the bottom part 2, which assures good sealing against the entry of dust. 
     In the region of an abutting edge 22 of the two bottom parts 2 with which they meet the housing body 1 upon being slipped on, they have two overlapping tongues 27, which are offset relative to one another and extend as far as the middle of the bottom part 2. When the tongues 27 meet, they overlap one another and together make up a wall thickness equivalent to that of the remaining bottom wall 23. In the region of the abutting edge 22, each of the bottom parts 2 also has one detent hook 28 and one detent bearing surface 29 serving to anchor it. When the two bottom parts 2 are joined, these detent elements intermesh and hold the bottom parts together. 
     In order to mount the fastening adaptor 3-6 on the joined bottom parts 2, retaining tangs 201 are provided on both sides of the outside of these bottom parts facing away from the housing body 1, as seen in FIGS. 7 and 11. These tangs serve to form opposed retaining grooves 202, for receiving slide cams 31 shown in FIG. 12, which are part of the fastening adaptor 3-6. Like the retaining tangs 201, the slide cams 31 are spaced apart from one another on a base plate 32 shown in FIG. 16, which is part of a rail holder 3, so that they can find space in remaining gaps in a complementary part formed of the bottom part 2 and the rail holder 3. Upon connection of the fastening adaptor 3-6 to the bottom parts 2, the adaptor is first mounted vertically on the bottom parts 2. Retaining cams 203 and the slide cams 31 enter the respective gaps and are then displaced toward one another parallel to the plane of the bottom parts 2 in such a way that the slide cams 31 slide into the associated retaining grooves 202. 
     In the base plate 32 of the rail holder 3 of FIGS. 1-3, which is shown in more detail in FIGS. 15-18, a recess 34 is provided in which a spring tab 33 rests. Upon insertion of the fastening adaptor 3-6, the spring tab 33 locks into place with an indentation 35 thereof on the retaining cams 203, one of which is formed onto each abutting edge 22 of the bottom part 2. Since the indentation 35 engages the retaining cams 203 of both bottom parts 2, there is additional security in terms of the bottom parts being held together. The detent latching of the retaining cams 203 is made easier because the indentation 35 is preceded by a slide depression 37, in which the retaining cams 203 first find space as the fastening adaptor 3-6 is slipped on, and out of which they slide to the indentation 35 by raising of the spring tab 33. The spring tab 33, which is locked into place in detent fashion, can also be unlocked by being raised with a tool, in order to loosen the rail holder 3. 
     The thus conveniently interchangeable, or replaceable, fastening adaptor 3-6, in its present embodiment for profile rail fastening, not only has the rail holder 3 but also two opposed locking parts 5, two opposed clamp parts 4 and a spring 6 disposed between the two parts 4, 5, which are shown in FIGS. 1-3. The two opposed locking parts 5 are shown in more detail in FIGS. 19-22 and the two opposed clamp parts 4 are shown in more detail in FIGS. 23-25. In order to fasten the two parts 4, 5 to the rail holder 3, two guide strips 38 are formed onto the outer surface of the rail holder 3 facing away from the housing body 1, which are located on both sides facing one another in the region of the two ends of the rail holder 3. Guide grooves 39 are recessed into the guide strips and in turn receive first guide rails 46 of the clamp part 4 and second guide rails 501 of the locking part 5. 
     The clamp part 4 shown in FIGS. 23-25 have a clamp body 43, on both sides of which the first guide rails 46 are provided, and the clamp body is preceded in the clamping direction by a V-beam 41, which engages the profile rail 7 with a clamping edge 402 thereof that has a recess 401. The V-beam 41, which protrudes past the clamp body 43 on both sides, has beam shoulders 42 on its back which act as a stop against the guide strips 38, to limit the opening spacing between the two clamp parts 4. A closing spacing that defines the closing and sealing position of the two clamp parts 4 is limited by a further stop that is brought about by two slide hooks 44 which rest inside a hook slot 45 recessed in the clamp body 43. These slide hooks 44 engage detent holes 302 in the rail holder 3 that have a length which determines the maximum sliding travel of the clamp part 4 in the clamping direction. Two guide tangs 48 formed onto the V-beam 41 fit into tang grooves 307 in the rail holder 3 and serve to stabilize guidance. 
     The locking part 5 shown in FIGS. 19-22 is slidingly joined to the clamp part 4 by means of two gripper arms 53 formed onto both sides of a slide body 51. Located on the free end of each gripper arm 53 is one gripper hook 54, which holds onto a handle attachment 49 of the clamp part 4 and as a result determines the maximum spacing between the two parts 4, 5. The locking part 5, which is inserted from the middle of the rail holder 3 between the guide strips 38 counter to the clamping direction, has a gripper arm shoulder 55 on the other end of each gripper arm 53. With these shoulders 55, the gripper arms 53 strike a groove stop 301, so that it cannot slide out of the slide rails 11 at the end of the rail holder 3. 
     A tab slot 58 is recessed in the slide body 51 of the locking part 5, and resilient detent means in the form of a locking tab 52 rests in this slot with a first detent tooth 56 and a second detent tooth 57. With the aid of the two detent teeth 56, 57, which engage an associated detent depression 303 recessed in the base plate 32 of the rail holder 3 and which are supported on a stop edge 306, the locking parts 5 can assume three different positions with respect to the clamp part 4. 
     In a first position, which is shown in the lower part of FIGS. 12 and 14, the locking part 5 is moved so close to the clamp part 4 that the latter is locked in its clamping position. The first detent tooth 56 in this position has become anchored on the stop edge 306, and the spring 6 located between the two parts 4, 5, which is in a spring hole 47 of the clamp part 4 and in a spring chamber 59 of the locking part 5, is compressed to its maximum extent. The locking assures that the clamping apparatus of the fastening adaptor 3-6 cannot open even in the presence of severe vibration, for instance originating in a system, and thus that the equipment housing 1, 2 remains securely joined to the profile rail 7. 
     In a second non-illustrated position, the second detent tooth 57 has become anchored on the stop edge 306. In this case the spring 6 is only partly compressed, so that the possibility exists of removing the equipment housing 1, 2 from the profile rail 7, by pulling on the housing 1, 2 in the opening direction of a first part of the clamp part 4, counter to the force of the spring 6 of a second part of the clamp part 4, and by means of a swiveling motion of the housing 1, 2. 
     However, if a top hat rail is secured directly to a wall, this cannot be done successfully, because there is no space for the requisite pivoting motion of the equipment housing 1, 2. 
     A third position of the locking part 5, which is shown in the upper part of FIGS. 12 and 14, is therefore provided. In that position, the locking part 5 can be pulled out of the guide strips 38 until it strikes the gripper arm shoulder 55, so that the two parts 4, 5 attain their maximum spacing from one another, which is defined by the location where they meet the gripper hooks 54. The spring 6 assures that the two parts 4, 5 are kept spaced apart and can be pulled jointly into the open position, so that without overcoming a spring force, the equipment housing 1, 2, in this open position, can be removed from the top hat rail perpendicularly to the wall. 
     In the open position, the two locking parts 5 protrude beyond the equipment housing 1, 2 far enough to ensure that since they are provided with corresponding holes 502, 503, they afford the possibility of a screw fastening. The hole 502 is a larger head hole that is recessed from the locking tab 52 and allows the passage of a screw head through it, which rests above the hole 503 which is a smaller screw hole in the side body 51. In order to release the locking tab 52 from one of its clamping positions, this tab can be lifted by a suitable tool, such as a screwdriver, which is made easier by an actuation opening 304 and an actuation rib 504. In order to remove the locking part 5, this part can be pulled out of the guide strips 38 in the clamping direction, in the course of which the detent teeth 56, 57 slide out of the detent depression 303 over slide edge 305. 
     The same fastening adaptor 3-6 can be used in combination with housings having widths that are approximately that of the fastening adaptor 3-6, as well as with those that are substantially wider. In order to prevent wider housings, which only partly rest on the fastening adaptor 3-6, from being torn out of their anchoring by laterally exerted forces, the associated bottom parts 2 are provided on both sides with support ribs 204, with which they can be supported on the corresponding wall or bottom surface. If the equipment housing 1, 2 is mounted on a wall, the rail holder 3 is also provided on its lower end with retaining feet 36, on which the applicable bottom part 2 can be supported with the retaining tangs 201. As a result, the weight of the equipment housing 1, 2 need not be supported by the spring tab 33.