Patent Abstract:
A plug-in nut has an outer body and an inner body which is mounted in the outer body such that it can be displaced in a rotationally fixed manner. On the inner body, rear-latching lugs are formed on spring arms, which rear-latching lugs fix an attachment component on a carrier part in a variable position of the inner body in relation to the outer body, which variable position is assumed so as to compensate for tolerances, as soon as a screw has been screwed into a screw receiving space of the inner body. This results in a secure hold with very simple handling.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. National Phase Patent Application based on International Application No. PCT/EP2012/055893 filed Mar. 30, 2012, which claims priority to German Patent Application No. 10 2011 017 154.1 filed Apr. 15, 2011 and German Patent Application No. 20 2011 102 954.2 filed Jul. 6, 2011, the entire disclosures of which are hereby explicitly incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a plug-in nut. 
     2. Description of the Related Art 
     A plug-in nut of this kind is known from DE 10 2005 032 699 A1. The prior plug-in nut has an outer body configured with a support plate and receiving slots. Also present is an inner body, which is mounted in the outer body such that it can be displaced over a displacement path. The inner body is formed with a screw receiving space into which a screw can be screwed, and comprises rear-locking catch lugs that protrude radially outward beyond the outer body and that in a final mounted arrangement, after the inner body has been rotated relative to the outer body from a preliminary mounted arrangement, are disposed in the receiving slots of the outer body. In the preliminary mounted position, the inner body is rotated relative to the outer body so that the rear-locking catch lugs are aligned with a base portion of the outer body, to enable the prior plug-in nut to be fitted into a receiving opening formed in a carrier part. The axial displaceability of the inner body relative to the outer body makes it possible to compensate for tolerances. 
     SUMMARY OF THE INVENTION 
     The present invention provides a plug-in nut which is distinguished by relatively simple, robust construction that makes for reliable handling in large-scale use. 
     Because the inner body is rotationally fixedly mounted in the outer body in the plug-in nut according to the invention, rotational movement of the inner body relative to the outer body is prevented. 
     Because the rear-locking catch lugs are formed on radially movable spring arms, the plug-in nut can be inserted, as the spring arms deflect, into a receiving opening of at least one carrier part and also optionally into a receiving opening of an add-on part, the rear-locking catch lugs themselves being guided in receiving slots for reasons of stability and thus being locked against being diverted in a circumferential direction, as a complement to the rotational locking of the inner body relative to the outer body, with commensurate reliability of handling in large-scale use. 
     In one form thereof, the present invention provides a plug-in nut having a support plate and an outer body that is provided with receiving slots, and having an inner body that is mounted in the outer body displaceably over a displacement path and is provided with a screw receiving space into which a screw can be screwed and is configured with rear-locking catch lugs that protrude radially outward beyond the outer body and in a final mounted arrangement are disposed in the receiving slots of the outer body, characterized in that the inner body is rotationally fixedly mounted in the outer body, each rear-locking catch lug being formed on a spring arm that is flexible in the radial direction and being disposed in an assigned guide slot over the entire displacement path. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of an exemplary embodiment of a plug-in nut according to the invention, having an outer body and an inner body, which is pushed partway into the outer body; 
         FIG. 2  is a longitudinal section of the exemplary embodiment according to  FIG. 1 , with an inner body pushed into the outer body to a final position; 
         FIG. 3  is a longitudinal section of the exemplary embodiment according to  FIG. 1  in a final mounted arrangement in which an add-on part is fastened to a carrier part; 
         FIG. 4  is a partially cut-away perspective view of a further exemplary embodiment of a plug-in nut according to the invention, comprising a sealing cap; 
         FIG. 5  is a longitudinal section of the further exemplary embodiment according to  FIG. 4  in a final mounted arrangement with a pressed sealing cap; 
         FIG. 6  is a perspective view of a further exemplary embodiment of a plug-in nut according to the invention, having an outer body and an inner body that is pushed into the outer body to a final position; 
         FIG. 7  is a longitudinal section of the further exemplary embodiment according to  FIG. 6  with the inner body arranged in the final position; and 
         FIG. 8  is a longitudinal section of the further exemplary embodiment according to  FIG. 6  with an inner body pushed into the outer body to a removal position. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. Although the exemplifications set out herein illustrate embodiments of the invention, in several forms, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed. 
     DETAILED DESCRIPTION 
       FIG. 1  is a perspective view of an exemplary embodiment of a plug-in nut  1  according to the invention, made from a hard-elastic synthetic material. The plug-in nut  1  comprises an outer body  2  having a support plate  3  and an elongate foot shaft  4  that is connected to the support plate  3  and is oriented substantially perpendicular to the support plate  3 , which extends radially outward, collar-like, beyond the foot shaft  4 . In this exemplary embodiment, the foot shaft  4  is formed with an essentially square outer cross section and tapers in a foot portion  5  remote from the support plate  3 . A middle portion  6  situated between the support plate  3  and the foot portion  5  has a cross section that is constant in the longitudinal direction and is configured in its region proximate the support plate  3  with compensating ribs  7  that extend in the longitudinal direction and protrude slightly beyond the outer wall of the outer body  2 . Provided in two opposite walls of the middle portion  6  are elongate receiving slots  8  extending in the longitudinal direction, which in their end portions  9  proximate the foot portion  5  are tapered relative to the rest of the width. 
     The plug-in nut  1  is also equipped with an elongate inner body  10  having a cross section that deviates from a circular shape, here formed with flat side faces oriented at angles to each other. The inner body  10  is provided with a screw receiving space  11  extending in the longitudinal direction. In the representation according to  FIG. 1 , the inner body  10  is inserted by a smooth-walled edge portion  12  into a receiving opening  13  provided in the support plate  3  and having a form-locking cross section complementary to the cross section of the inner body  10 . In the region of the edge portion  12 , the inner body  10  is configured with at least one, but preferably two mutually oppositely disposed fixing recesses  14 . 
     Disposed on the side of the fixing recesses  14  facing away from edge portion  12  are spring arms  16 , cut from a head portion  15  of inner body  10 , which are flexible in the radial direction and each of which carries a rear-locking catch lug  17  at its free end proximate the head portion  15 . In a relaxed arrangement, the rear-locking catch lugs  17  protrude radially outward beyond the outer wall of the inner body  10  and beyond the middle portion  6  of the outer body  2  and each comprise a respective axial stop face  18  that faces away from edge portion  12  and thus toward head portion  15 , together with a respective radial stop face  19  oriented at right angles to the axial stop face  18 . Formed on each spring arm  16  and each rear-locking catch lug  17 , on the side facing away from the axial stop face  18 , is a respective wedge-shaped rib  20  that is narrower than the rear-locking catch lug  17  and extends in the longitudinal direction, from an end proximate a fixing recess, with increasing radial distance from the respective spring arm  16 , toward the particular rear-locking catch lug  17 , and comprises a ramp face  21  that is disposed flush with the rear-locking catch lug  17 . Each rear-locking catch lug  17  has boundary surfaces  22  disposed on both sides of the wedge-shaped ribs  20 , oppositely from the particular axial stop face  18 . 
       FIG. 2  shows the exemplary embodiment according to  FIG. 1  in longitudinal section, with an inner body  10  pushed all the way into the outer body  2  to a final position. It is evident from the representation according to  FIG. 2  that in the final position, fixing projections  23  formed in the foot portion  5  of outer body  2  engage in the fixing recesses  14  of inner body  10  and form, together with the fixing recesses  14 , engaging means for fixing the inner body  10  in the outer body  2  so that it remains secure up to a preliminary mounting force that is smaller than the extraction force of the plug-in nut. It can also be seen from  FIG. 2  that in this arrangement of the inner body  10  where it is pushed farther into the outer body  2  than in the arrangement of  FIG. 1 , the rear-locking catch lugs  17  are now disposed in the receiving slots  8 ; to assume the arrangement according to  FIG. 2 , the rear-locking catch lugs  17 , on passing through the receiving opening  13  in the region of the support plate  3 , were deflected radially inward due to the flexibility of the spring arms  16  as the ramp faces  21  slid past the edge of the receiving opening  13 . In the arrangement according to  FIG. 2 , the wedge-shaped ribs  20  are inserted in the end portions  9  of the receiving slots  8 , whereupon the boundary surfaces  22  come into abutment against steps of the receiving slots  8  formed in the region of the end portions  9  and block further insertion of the inner body  10  into the outer body  2 . 
       FIG. 3  is a longitudinal section of the exemplary embodiment according to  FIG. 1  in a final mounted arrangement, showing the attachment of an add-on part  24  to a carrier part  25  by means of a screw  26 . To assume the final mounted arrangement according to  FIG. 3 , the plug-in nut  1  was inserted into a fastening opening  27  formed in the carrier part  25 ; as in the assumption of the final position described in connection with  FIG. 2 , during the insertion process the spring arms  16  are deflected radially inward sufficiently so that the rear-locking catch lugs  17  are sunk all the way into the receiving slots  8  as the edge of the fastening opening  27  slides up the ramp faces  21  of the wedge-shaped ribs  20 . Due to the engagement of the fixing recesses  14  and the fixing projections  23 , during the operation of inserting the plug-in nut  1  the inner body  10  remains in the arrangement of being inserted all the way into the outer body  2 , as illustrated in  FIG. 2 , up to a preliminary mounting force that is greater than the oppositely directed force exerted by the forcible deflection of the spring arms  16 . 
     Once the support plate  3  was in abutment with the carrier part  25 , the add-on part  24  was placed on the support plate  3 , on the side of the support plate  3  facing away from the carrier part  25 , and the screw  26  was pushed all the way through the receiving opening  13  into the outer body  2  until the end of a screw shaft  28  of the screw  26  was partway inside the screw receiving space  11  of the inner body  10 . After the screw  26  is turned by means of a tool not shown in  FIG. 3 , a thread of the screw shaft  28  comes into engagement with the inner wall of the inner body  10  and releases the engagement between the fixing recesses  14  and the fixing projections  23 . 
     As the operation of tightening the screw continues, the inner body  10 , by virtue of its displaceable mounting in the outer body  2 , moves over a displacement path until it comes into abutment with the axial stop faces  18  of the rear-locking catch lugs  17  on the side of the carrier part  25  facing away from the support plate  3 . In this arrangement, the spring arms  16  are blocked against deflecting inward by the screw shaft  28 , while the radial stop faces  19  prevent the spring arms  16  from moving radially outward by butting against the inner face of the fastening opening  27 . This ensures secure retention of the plug-in nut  1 , with a very high extraction force. 
       FIG. 4  is a partially cut-away view of a further exemplary embodiment of a plug-in nut according to the invention, having an outer body  2  and an inner body  10  shaped and constructed similarly to the exemplary embodiment described with reference to  FIGS. 1 to 3 . Thus, to avoid repetition, mutually corresponding elements in the exemplary embodiment according to  FIGS. 1 to 3  and the exemplary embodiment according to  FIG. 4  are provided with the same reference numerals and will not be described in more detail. In the further exemplary embodiment according to  FIG. 4 , the support plate  3  is configured at its edge side with a radially outwardly projecting plate collar  29 , which on its side facing toward the foot shaft  4  of the outer body  2  is configured with a chamfer  30  that slopes away from the radial outer face of the plate collar  29  toward the foot shaft  4 , and thus away from a top cover side  31  of the support plate  3 . At the radially inwardly disposed end of the chamfer  30 , the support plate  3  has an annular face  32  oriented parallel to the longitudinal direction of the foot shaft  4 . 
     The further exemplary embodiment according to  FIG. 4  is also provided with a top cover  33  made of a soft-elastic synthetic material, which is preferably fabricated as a separate component and is mounted on the support plate  3 , as illustrated in  FIG. 4 , in an assembly step. The top cover  33  comprises a top cover plate  34  whose base area corresponds to the base area of the support plate  3 . At the radial outer side of the top cover plate  34 , the top cover  33  is configured with an inwardly directed collar  35  having an edge portion  36  that radially outwardly surrounds the plate collar  29 , and an inner portion  37  that extends radially inwardly from the end of the edge portion  36  remote from the top cover plate  34 . The distance between the top cover plate  34  and inner portion  37  is so adapted that, as can be clearly seen in  FIG. 4 , the plate collar  29  of the support plate  3  fits form-lockingly therein. As a result, the inner side of inner portion  37 , facing toward the top cover plate  34 , rests against the chamfer  30 . The dimension of inner portion  37  in the radial direction is so adapted that the radially inwardly directed end of inner portion  37  rests against the annular face  32  of the support plate  3 . The top cover  33  thus surrounds the support plate  3  on the side thereof facing away from foot shaft  4  and in the region of the radial outer side. It can also be understood from the representation of  FIG. 4  that in the relaxed arrangement of the top cover  33 , as depicted in  FIG. 4 , inner portion  37  extends past the support plate  3  in the axial direction, toward the foot shaft  4 . 
     In the exemplary embodiment according to  FIG. 4 , the top cover plate  34  is configured with a central well  38  that extends into the receiving opening  13 . In the further exemplary embodiment depicted in  FIG. 4 , the well  38  is formed with an opening  39  whose diameter is dimensioned to be approximately half the nominal diameter of a screw shaft  28  of a screw  26  that is to be used with the plug-in nut  1 . 
       FIG. 5  is a longitudinal section of the further exemplary embodiment according to  FIG. 4  in a final mounted arrangement in which the top cover  33  is pressed, particularly by its inner portion  37 , between an add-on part  24  and a carrier part  25  by the tightening of a screw  26 , the inner body  10  simultaneously being pressed against the carrier part  25  as explained in connection with  FIG. 3  concerning the exemplary embodiment of  FIG. 1 . The pressing of the top cover  33  and the surrounding of the screw shaft  28  in the region of the well  38  results in extremely high leak-tightness, particularly to water or other liquid materials. 
       FIG. 6  is a perspective view of a further exemplary embodiment of a plug-in nut  1  according to the invention, it being noted that, to avoid repetition, mutually corresponding elements of the exemplary embodiment according to  FIG. 1  and the exemplary embodiment according to  FIG. 6  are provided with the same reference numerals and will not all be described in more detail below. The foot shaft  4  of the exemplary embodiment according to  FIG. 6  is formed as oval-shaped. It can also be understood from  FIG. 6  that in the exemplary embodiment according to  FIG. 6  the rear-locking catch lugs  17  each have an oblique surface  40  that is offset in the radial direction from the particular ramp face  21 , and that extends radially inwardly from the respective boundary surface  22 . Facing the oblique surfaces  40  in both the axial and the radial direction, the outer body  2  has a ramp edge  41  extending in the circumferential direction, disposed in the region of those ends of the end portions  9  of the receiving slots  8  which are proximate the support plate  3 . 
       FIG. 7  is a longitudinal section of the exemplary embodiment according to  FIG. 6  with the inner body  10  in the final position. It is evident from  FIG. 7  that in the final position, the ramp edge  41  of each rear-locking catch lug  17  abuts the inner body  10  at the end of oblique surface  40  remote from the boundary surface  22 , in which arrangement the rear-locking catch lugs  17  nevertheless protrude radially outward to the maximum extent. It can further be understood from the representation according to  FIG. 7  that the inner body  10  has, on the side of the fixing recesses  14  facing toward the latching lugs  17 , locking recesses  42  whose shape is complementary to that of the fixing projections  23 . 
       FIG. 8  is a longitudinal section of the further exemplary embodiment according to  FIG. 6  with the inner body  10  pushed into the outer body  2 , in the axial direction of the plug-in nut  1 , past the final position illustrated in  FIG. 7  until the locking recesses  42  engage with the fixing projections  23 . When the inner body  10  is moved from the final position according to  FIG. 7  into the locked position according to  FIG. 8 , the oblique surfaces  40 , after overcoming a certain resistance, slide over the ramp edges  41 . The boundary surfaces  22  form a stop for this movement. In the locked position, therefore, the inner body  10  is fixed with its rear-locking catch lugs  17  deflected radially inward, so that the plug-in nut  1  can be removed. 
     While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

Technology Classification (CPC): 5