Patent Document

BACKGROUND OF THE INVENTION 
   The invention is based on a known laser distance measuring device. 
   The known laser distance measuring devices PD20 and PD25 made by HILTI make it possible to fasten a separate sighting telescope, by suspending a metal sheet, screwed to the sighting telescope, from the front of the housing of the laser distance measuring device and fastening it to the housing at the rear with a screw. 
   SUMMARY OF THE INVENTION 
   The invention includes the general technological teaching of securing an accessory to a device by means of a detent connection, which advantageously enables simple mounting and removal without using tools. 
   The device for fastening an accessory can for instance be a laser distance measuring device, but the invention can also be realized with other devices to which accessories can be mounted. Preferably, however, the device is a hand-held electronic device. 
   The accessory to be fastened can for instance be a sighting lens for a laser distance measuring device and/or a circular or tubular spirit level for determining position, but the invention can also be realized with other accessories. If a tubular and a circular spirit level are advantageously combined in one accessory, then the device can be oriented in multiple directions without having to re-chuck or replace the accessory. 
   In the preferred embodiment of the invention, the device has two mounts, each for receiving one accessory, and both mounts create a detent connection with the respective accessory. One mount can then for instance receive a sighting telescope, while a spirit level can be fastened to the other mount so that the spatial position of the device can be determined. 
   Preferably, the two mounts are disposed laterally side by side, but the two mounts can in principle also be disposed in arbitrary other positions. 
   However, it is advantageous if the two mounts are disposed such that the accessories to be fastened have the same spatial orientation in each mount. 
   This is especially important for fastening a sighting telescope or a spirit level, since in these cases a predetermined spatial orientation relative to the device must be adhered to. 
   However, alternatively it is also possible for the two mounts to be spatially oriented differently from one another. This is advantageous for instance in a laser distance measuring device which is capable of measuring vertical and horizontal distances. Then, the sighting telescope can be selectively mounted on the laser distance measuring device with vertical or horizontal orientation. The two mounts, in this variant of the invention, are therefore preferably oriented at right angles to one another. 
   Advantageously, the device of the invention has a device housing with which the mount for the accessory is integrated, which advantageously makes economical production possible. 
   The mount can for instance comprise two indentations or undercuts in the device housing, which are disposed at a predetermined spacing from one another. For instance, slitlike indentations can be provided in the device housing, which extend parallel to one another and engage the corresponding detent protrusions on the accessory to be fastened. 
   The detent connection between the accessory and the device of the invention is preferably made by providing that detent protrusions on the accessory snap into suitably adapted detent recesses on the device. However, it is conversely also possible for the accessory to have detent recesses, which suitably adapted detent protrusions on the device of the invention snap into. 
   The detent protrusions on the accessory can for instance be disposed on two brackets, which are elastic relative to one another. Then the accessory can simply be slipped onto the mount of the device of the invention, and the two brackets spread resiliently apart until the detent protrusions finally snap into corresponding detent recesses on the device and thereby fix the accessory. The detent protrusions can be shaped in such a way as to create a positive engagement that is designed for high mechanical loads. However, it is also possible to provide additional locking elements, such as a bayonet mount. 
   In one variant of the invention, both brackets of the accessory are elastic, so that they can spread resiliently apart on being slipped onto the mount of the invention. The two brackets are, however, preferably elastic in only the direction of motion in which they spread resiliently apart, while conversely in other possible directions of motion the two brackets are preferably rigid. 
   However, preferably one of the two brackets is extensively rigid while the other bracket is elastic. The resilience of one bracket, however, is preferably limited to the direction of motion in which the bracket is intended to spread resiliently apart upon being mounted. 
   The rigid bracket preferably has a hook, which can catch in a corresponding recess on the mount of the invention. When the accessory is being mounted, accordingly, first the rigid bracket of the accessory is suspended by the hook from the device mount according to the invention. Next, the accessory is then pressed onto the device, causing the elastic bracket to deflect resiliently outward, until finally the detent protrusion provided on the resilient bracket snaps into a corresponding detent recess on the device. 
   One possible way of defining the resilience of the brackets is to select a length of the brackets accordingly, since the resilience increases with the length. 
   In the preferred embodiment of the invention, for fastening the accessory to the device, the combination of a detent connection with a hook connection is accordingly employed. 
   The hook definition here preferably defines a pivot axis about which the accessory can be pivoted relative to the device of the invention upon mounting, until finally the detent connection fixes the accessory in its final position. 
   Preferably, the hook connection is disposed on the underside, while the detent connection is disposed on the top. In this variant of the invention, the accessory is accordingly made first to catch on the underside and then is pivoted with the top in the direction of the device until the detent connection snaps into place. 
   However, it is alternatively also possible for the hook connection to be disposed on the top while the detent connection is located on the underside. In this variant, the accessory will first catch on the top and then be pivoted with its underside toward the device until the detent connection snaps into place. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further advantages will become apparent from the ensuing description of the drawings. In the drawings, one exemplary embodiment of the invention is shown. The drawing, description and claims include numerous characteristics in combination. One skilled in the art will expediently consider the characteristics individually as well and put them together to make useful further combinations. 
     Shown are: 
       FIG. 1 , a perspective view of a laser distance measuring device and of a tubular spirit level that can be mounted as an accessory; 
       FIG. 2 , the laser distance measuring device of  FIG. 1  with the tubular spirit level in the mounted state; 
       FIG. 3 , a more-detailed view of the tubular spirit level of  FIGS. 1 and 2 ; 
       FIG. 4 , a perspective view of a sighting telescope which can be mounted on the laser distance measuring device of  FIG. 1 ; and 
       FIG. 5 , a view of the laser distance measuring device of  FIGS. 1 and 2  from below. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The perspective view in  FIGS. 1 and 2  shows a laser distance measuring device  10 , which is constructed largely in conventional fashion, so that to supplement this description, reference may be made to the relevant professional knowledge. 
   The laser distance measuring device  10  is accommodated in a substantially rectangular plastic housing  12 ; a keypad  14  and a display  16  are disposed on the top of the housing  12 , making simple operation of the laser distance measuring device  10  possible. 
   The laser distance measuring device  10  furthermore has two mounts, on which a tubular spirit level  18 , for instance, as shown in more detail in  FIG. 3  can be secured as an accessory. In addition, a sighting telescope  20 , as shown in more detail in  FIG. 4 , can also be fastened to one of the two mounts. 
   The two mounts are each disposed laterally beside the display  16  and each have a respective slitlike indentation  22 . 1 ,  22 . 2  on the top of the housing  12 ; the indentations  22 . 1 ,  22 . 2  extend parallel to the long edge of the housing  12 . On the underside of the housing  12 , below the slitlike indentations  22 . 1 ,  22 . 2 , is a respective further slitlike indentation  24 . 1 ,  24 . 2 , which is oriented parallel to the upper indentation  22 . 1 ,  22 . 2 . The two mounts for accessories thus each comprise the upper indentation  22 . 1 ,  22 . 2  and the lower indentation  24 . 1 ,  24 . 2 , respectively. 
   For being fastened to these mounts, the tubular spirit level  18  has two hooks  26 . 1 ,  26 . 2  on its underside, which in the mounted state of the tubular spirit level  18  are suspended in the lower indentation  24 . 2 . 
   The tubular spirit level  18  further has a connecting wall  28 , which in the mounted state of the tubular spirit level  18  has a spacing of approximately 0.5 mm laterally from the side wall of the housing  12  of the laser distance measuring device  10 , so that it can sag upon being unlatched. 
   The connecting wall  28  connects the two hooks  26 . 1 ,  26 . 2 , disposed on the underside, to a measuring body  30  disposed on the top; it is in this device that the actual position measurement is made in the conventional way by means of a spirit level. 
   The measuring body  30  protrudes inward from the connecting wall  28  and on its underside has two detent elements  32 . 1 ,  32 . 2 , which in the mounted state of the tubular spirit level  18  snap into the slitlike indentations  22 . 1 ,  22 . 2 , respectively, on the top of the laser distance measuring device  10 . 
   For mounting the tubular spirit level  18  on the laser distance measuring device  10 , first the two hooks  26 . 1 ,  26 . 2  of the tubular spirit level  18  are suspended into the slitlike indentation  24 . 1  or  24 . 2  on the underside of the housing  12  of the laser distance measuring device  10 . Next, the tubular spirit level  18  is pivoted in the direction of the laser distance measuring device  10  until the detent elements  32 . 1 ,  32 . 2  rest on the outside of the housing  12  of the laser distance measuring device  10 ; the hooks  26 . 1 ,  26 . 2  suspended in the indentation  24 . 1  or  24 . 2  define a pivot axis. The tubular spirit level  18  is then pressed farther inward by the user with lateral pressure on the measuring body  30 , until the detent elements  32 . 1 ,  32 . 2  of the tubular spirit level  18  finally snap into the slitlike indentation  22 . 1  or  22 . 2  on the top of the housing  12  of the laser distance measuring device  10 . The mounting of the tubular spirit level  18  is facilitated by the provision that the measuring body  30 , with the detent elements  32 . 1 ,  32 . 2  provided on it can spread slightly apart resiliently relative to the connecting wall  28 . 
   For removal of the tubular spirit level  18 , the user pulls the measuring body  30  outward away from the laser distance measuring device  10  until the detent elements  32 . 1 ,  32 . 2  come unlatched from the slitlike indentation  22 . 2 . Next, the user moves the tubular spirit level  18  downward relative to the laser distance measuring device  10 , causing the hooks  26 . 1 ,  26 . 2  to be released from the lower indentation  24 . 2 . 
   The sighting telescope  20  shown in  FIG. 4  has, in addition to an optical element  34 , a plastic housing  36 . 
   The fastening of the sighting telescope  20  to the laser distance measuring device  10  is effected essentially in the same way as the fastening, described above, of the tubular spirit level  18 . 
   To that end, the sighting telescope  20  has two brackets  38 . 1 ,  38 . 2 , which protrude laterally inward from the housing  36  of the sighting telescope  20 . 
   The upper bracket  38 . 1  here is integrally formed onto the top of the housing  36  and thus is likewise of plastic; the length of the bracket  38 . 1  is essentially equal to the width of the housing  36 , so that the upper bracket  38 . 1  can spread apart resiliently toward the top, because of the given elasticity of the plastic material used. On its free end, the bracket  38 . 1  has a downward-protruding detent protrusion  40 , which in the mounted state snaps into the slitlike indentation  22 . 2  on the top of the laser distance measuring device  10 . 
   Conversely, the lower bracket  38 . 2  is integrally formed onto the inner edge of the housing  36  of the sighting telescope  20  and is relatively short, so that the bracket  38 . 2  has only relatively slight resilience. Once again, two hooks  42 . 1 ,  42 . 2  are integrally formed onto the free end of the bracket  38 . 2 ; in the mounted state, they are suspended in the slitlike indentation  24 . 2  on the underside of the laser distance measuring device  10 . 
   For mounting the sighting telescope  20 , accordingly first the hooks  42 . 1 ,  42 . 2  are suspended into the slitlike indentation  24 . 2  on the underside of the laser distance measuring device  10 . Next, the user then presses on the housing  36  of the sighting telescope  20  from outside, so that the sighting telescope  20  is pivoted toward the laser distance measuring device  10 , and in the process the hooks  42 . 1 ,  42 . 2  suspended in the indentation  24 . 2  on the laser distance measuring device  10  define a pivot axis. This pivoting motion initially ends when the bracket  38 . 1  rests with the detent protrusion  40  on the outside of the housing  12  of the laser distance measuring device  10 . By pressing again on the outside, this pressure point is overcome, and the bracket  38 . 1  briefly spreads apart resiliently upward, until the detent protrusion  40  finally snaps into the slitlike indentation  22 . 2  on the top of the laser distance measuring device  10  and thereby fixes the sighting telescope  20 . 
   For removal of the sighting telescope  20 , the user grasps the free end of the upper bracket  38 . 1  and pulls it slightly upward, until the detent protrusion  40  is no longer held in the slitlike indentation  22 . 2  of the laser distance measuring device  10 . Next, the user pivots the sighting telescope  20  outward away from the laser distance measuring device  10 , in which process the two hooks  42 . 1 ,  42 . 2  once again define a pivot axis. Finally, the user moves the sighting telescope  20  downward, in order to release the hooks  42 . 1 ,  42 . 2  from the slitlike indentation  24 . 1  on the underside of the laser distance measuring device  10 . 
   The invention is not limited to the preferred exemplary embodiments described above. On the contrary, many variants and modifications that likewise make use of the concept of the invention and are therefore within the scope of the invention are conceivable. 
   LIST OF REFERENCE NUMERALS 
     10  Laser distance measuring device 
     12  Housing 
     14  Keypad 
     16  Display 
     18  Tubular spirit level 
     20  Sighting telescope 
     22 . 1 ,  22 . 2  Indentation 
     24 . 1 ,  24 . 2  Indentation 
     26 . 1 ,  26 . 2  Hook 
     28  Connecting wall 
     30  Measuring body 
     32 . 1 ,  32 . 2  Detent elements 
     34  Lens 
     36  Housing 
     38 . 1 ,  38 . 2  Brackets 
     40  Detent protrusion 
     42 . 1 ,  42 . 2  Hook

Technology Category: 3