Abstract:
A measuring device for measuring and inspecting various linear dimensional properties of a machined groove in a workpiece includes a fixing base, a measuring assembly, and first and second positioning members received through and protruding from the fixing base at right angles during the movement of the measuring assembly. The measuring assembly includes a measuring member, a shim, and an elastic member, the shim sleeves on an end of the measuring member, and the elastic member resists between the shim and the fixing base. The measuring assembly, together with the first positioning member and the second positioning member, enable the required depth and relative position of the machined groove to be accurately determined and inspected.

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure generally relates to measuring devices, and particularly to a measuring device for measuring and inspecting the distance or linear dimensional properties of a groove defined in a workpiece relative to a side wall of the workpiece to determine or assess whether the groove has been machined as desired. 
     2. Description of the Related Art 
     A groove with a bottom surface which is curved in three dimensions (3D), is usually defined in a workpiece for assembling with other structures. A side wall of the workpiece is positioned adjacent to the groove. A caliper is usually used to measure a depth of the groove and the distances between sidewalls of the groove and the side wall of the workpiece for measuring a position of the groove relative to the side wall to determine whether the groove has been machined as desired. However, the distance or linear measuring values may be inaccurate because the point of contact of the caliper to the 3D curved bottom surface of the groove may vary or be different in each measurement. A measuring device may include a fixing base and a measuring assembly positioned on the fixing base. A positioning surface fitting or matching to the 3D bottom surface of the groove is a bottom surface of the fixing base of the measuring device. The positioning surface of the fixing base of the measuring device resists against the 3D curved bottom surface of the groove during measuring. However, the measuring values greatly depend on a shape of the positioning surface of the fixing base. If a shape of the positioning surface is not exactly the same as a shape of the 3D curved bottom surface of the workpiece, a distance measuring value obtained is also inaccurate. 
     Therefore, there is room for improvement within the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  shows an assembled, isometric view of an embodiment of a measuring device. 
         FIG. 2  is similar to  FIG. 1 , but viewed from another aspect. 
         FIG. 3  shows an exploded, isometric view of the measuring device of  FIG. 1 . 
         FIG. 4  shows a work state of the measuring device of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean “at least one.” 
       FIGS. 1 to 4  show a measuring device  100  for measuring and inspecting various linear dimensional properties (relating to length, width, depth, etc.) of a groove  201  defined in a workpiece  200  relative to a side wall  205  of the workpiece  200 , to determine whether the groove  201  has been machined as desired. In the illustrated embodiment, the workpiece  200  further includes a bottom wall  203  connected to the side wall  205 . The groove  201  is formed in the bottom wall  203  and positioned adjacent to the side wall  205 . The bottom wall  203  includes a bottom surface  2011 , a first connecting surface  2013 , and a second connecting surface  2015 . The bottom surface  2011 , the first connecting surface  2013 , and the second connecting surface  2015  together define the groove  201 . The bottom surface  2011  is a 3D (three dimensional) curved surface. The second connecting surface  2015  is located oppositely to the first connecting surface  2013 , and the bottom surface  2011  connects the first connecting surface  2013  and the second connecting surface  2015 . The second connecting surface  2015  is positioned adjacent to the side wall  205 . The measuring device  100  includes a fixing base  10 , two measuring assemblies  30 , two first positioning members  50 , and a second positioning member  70 . The two measuring assemblies  30  are telescopically received through the fixing base  10  along a first direction in parallel. The first positioning members  50  and the second positioning member  70  are received through the fixing base  10  along a second direction substantially perpendicular to the first direction. 
     The fixing base  10  includes a first sidewall  11 , a second sidewall  13 , a third sidewall  15 , and a fourth sidewall  17  connected in that order. The first sidewall  11  and the third sidewall  15  are substantially parallel, and the second sidewall  13  and the fourth sidewall  17  are substantially parallel and positioned between the first sidewall  11  and the third sidewall  15 . Two through holes  113  are separately defined in the first sidewall  11  along the first direction. Two spaced first positioning holes  131  are defined in the second sidewall  13  along the second direction substantially perpendicular to the first direction, and are positioned adjacent to the first sidewall  11 . A second positioning hole  135  is defined in the second sidewall  13  along the second direction substantially perpendicular to the first direction and positioned adjacent to the third sidewall  15 . 
     Each measuring assembly  30  is telescopically received through one through hole  113 . The measuring assembly  30  includes a measuring member  31 , an elastic member  33 , a shim  35 , and a fastening member  37 . The measuring member  31  includes a connecting portion  311  and a measuring portion  313  protruding from the connecting portion  311 . The connecting portion  311  is received through the through hole  113 . Two ends of the connecting portion  311  protrude from the fixing base  10 . A locking hole  3113  is defined in an end surface of the connecting portion  311  away from the measuring portion  313 . The measuring portion  313  abuts the second sidewall  13  of the fixing base  10 . A size of the measuring portion  313  along the second direction is greater than that of the connecting portion  311 . The measuring member  31  further includes a benchmark shoulder  315  and a stop shoulder  317 . The benchmark shoulder  315  is formed in a bottom of the measuring portion  313  adjacent to the fourth sidewall  17 . A height of the benchmark shoulder  315  is predetermined according to an allowable error (tolerance) range of the workpiece  200 . The stop shoulder  317  is formed in the measuring portion  313  and located opposite to the benchmark shoulder  315  for preventing the measuring member  31  detaching from the fixing base  10 . The elastic member  33  is sleeved around an end of the connecting portion  311  exposed from the first sidewall  11 . The fastening member  37  passes through the shim  35  and is locked in the locking hole  3113 . The elastic member  33  resists the first sidewall  11  and the shim  35 , and is located between the first sidewall  11  and the shim  35 . The shim  35  is located between the fastening member  37  and the connecting portion  311 . 
     Each first positioning member  50  is mounted in one of the first positioning holes  131 . Each first positioning member  50  includes a first mounting portion  51  and a first positioning portion  53  connected to the first mounting portion  51 . The first mounting portion  51  is received through the first positioning hole  131 . The first positioning portion  53  is positioned outside of the fixing base  10  and abuts the fourth sidewall  17 . A width of the first positioning portion  53  is greater than a width of the first mounting portion  51 . A first positioning shoulder  530  is formed at an end of the first positioning portion  53  adjacent to the first mounting portion  51 , and resists against the fourth sidewall  17  of the fixing base  10 . A first resisting end portion  531  is formed at one end of the first positioning portion  53  away from the first mounting portion  51 , and is being positioned resisting against the bottom surface  2011  and the first connecting surface  2013  of the groove  201 . In the illustrated embodiment, an end surface of the resisting end portion  531  away from the first mounting portion  51  is an arc-shaped surface. A shape of the end surface of the first resisting end portion  531  fits over the bottom surface  2011  and the first connecting surface  2013 . 
     Each second positioning member  70  is detachably received through the second positioning hole  135 . Each second positioning member  70  includes a second mounting portion  71  and a second positioning portion  73  connected to the second mounting portion  71 . The second mounting portion  71  is received through the second positioning hole  135 . The second positioning portion  73  is positioned outside of the fixing base  10  and abuts the fourth sidewall  17 . The width of the second positioning portion  73  is greater than that of the second mounting portion  71 . A second positioning shoulder  730  is formed in an end portion of the second positioning portion  73  adjacent to the second mounting portion  71 , and resists against the fourth sidewall  17 . A second resisting end portion  731  is formed in one end of the second positioning portion  73  away from the second mounting portion  71  and when being positioned, to be resisting against the bottom surface  2011  and the second connecting surface  2015  of the groove  201 . In the illustrated embodiment, an end surface of the second resisting end portion  731  away from the second mounting portion  71  is a curved surface. The second resisting end portion  731  includes two arc-shaped curved surface segments and a flat surface segment interconnecting the two arc-shaped curved surface segments. A number of the arc-shaped curved surfaces of the second resisting end portion  731  is not limited to two, and there may be one, or three, or more for multi-point contacts in an alternative embodiment. 
     In assembly, the connecting portion  311  of the measuring member  31  is inserted the through hole  113 , the elastic member  33  is sleeved on the connecting portion  311 , and the fastening member  37  passes through the shim  35  and is locked in the locking hole  3113 , such that one measuring assembly  30  is assembled to the fixing base  10 . Another measuring assembly  30  is assembled to the fixing base  10  in similar fashion. The two first positioning members  50  are respectively mounted in the two first positioning holes  131 . The second positioning member  70  is mounted in the second positioning hole  135 . 
     In use, the first resisting end portion  531  resists against the bottom surface  2011  and the first connecting surface  2013 , the second resisting end portion  731  resists against the bottom surface  2011 , and the measuring portion  313  is positioned towards the side wall  205 . A gap exists between the measuring portion  313  and the side wall  205 . The measuring member  31  is forced to move along the through hole  113 . When the benchmark shoulder  315  attaches to the side wall  205  or a bottom of the measuring portion  313  attaches to a top of the side wall  205 , then the position of the groove  201  in the workpiece  200  relative to the side wall  205  can be deemed to have been machined as desired or that of desired or adequate machining quality. When a bottom of the benchmark shoulder  315  is above the top of the side wall  205 ; in other words, when a gap is formed between the bottom of the benchmark shoulder  315  and the top of the side wall  205 , then the position of the groove  201  is deemed to be too close relative to the side wall  205 , and the groove  201  can be deemed unsatisfactory. It means that the position of the groove  201  is out of place or too far away relative to the side wall  205 , when a front surface of the measuring portion  313  away from the connecting portion  311  resists against the side wall  205 . 
     As described above, the first resisting end portion  531  resists against the first connecting surface  2013  and the bottom surface  2011  of the groove  201 , and the second resisting end portion  731  resists against the bottom surface  2011 , thereby the measuring device  100  contacts the bottom surface  2011  and the groove  201  at multiple points. As a result, the profile surface processing requirements of the first resisting end portions  531 , and the second resisting end portions  731  contacting with the bottom surface  2011  are lowered. In addition, operation of the measuring device  100  is simpler and quicker. 
     In other embodiments, a number of the first positioning member  50  and the second positioning member  70  is at least one. The positions and lengths of the first positioning member  50  and the second positioning member  70  are positioned as required. The elastic member  33 , the shim  35 , and the fastening member  37  of the measuring assembly  30  can be omitted, and the measuring member  31  is movably received through the through hole  113 . The benchmark shoulder  315  may be deleted, and the position of the groove  201  in the workpiece  200  relative to the side wall  205  can be deemed to have been machined as desired, when the bottom of the measuring portion  313  attaches to the top of the side wall  205 . 
     While the present disclosure has been described with reference to particular embodiments, the description is illustrative of the disclosure and is not to be construed as limiting the disclosure. Therefore, various modifications can be made to the embodiments by those of ordinary skill in the art without departing from the true spirit and scope of the disclosure, as defined by the appended claims.