Patent Publication Number: US-2023132829-A1

Title: Blocking device camera holder with blocking device

Description:
The invention relates to a blocking device and a camera holder. 
     For mounting cameras on holders, for example on a tripod, so-called dovetail plates are frequently used. To this end, the dovetail plate is fastened to the camera and for mounting the camera the dovetail plate is flush-mounted in a track of the blocking device and blocked therein. The blocking device is fastened to the holder. 
     In known solutions, problems frequently arise when flush-mounting the dovetail plate in the track of the blocking device, for example due to tilting or due to the dimensions of the track, on the one hand, and the dovetail plate, on the other hand, not exactly matching one another. 
     The object of the present invention is to propose a blocking device for blocking a dovetail plate which is flush-mounted in a track of the blocking device, which, on the one hand, permits a simple flush-mounting of the dovetail plate and, on the other hand, ensures a secure blocking. 
     Proceeding therefrom, the blocking device of the independent Claim 1 is proposed. Features of several exemplary embodiments described herein by way of example are specified in the subclaims. Additionally, a camera holder with such a blocking device is proposed. 
    
    
     
       Further details and advantages of the invention will become apparent in the following description of several exemplary embodiments with reference to the figures. 
       In which: 
         FIG.  1    shows by way of example and schematically a camera holder; 
         FIG.  2    shows by way of example and schematically four perspective views (A) to (D) of a blocking device according to one embodiment; and 
         FIG.  3    shows by way of example and schematically three perspective views (A) to (C) of a blocking device according to one embodiment. 
     
    
    
       FIG.  1    shows by way of example and schematically a camera holder with a tripod  1  and a joint arrangement  2 . A blocking device  100 ′ for blocking a dovetail plate  3  which has been flush-mounted in a track of the blocking device  100 ′, for example by being inserted from the side, is located on the joint arrangement  2 . A clamping element  110 ′ is provided for blocking the dovetail plate  3 , said clamping element being able to be manually actuated and blocking the flush-mounted dovetail plate  3  by preventing a movement of the dovetail plate  3  along the longitudinal extent of the track. The blocking is released by the push button  112 ′ being actuated. 
     The blocking device  100 ′ shown in  FIG.  1    has proved to be unsafe and impracticable: firstly it is possible for the dovetail plate  3  to slide out by inadvertent actuation of the push button  112 ′ and secondly the dovetail plate has to be flush-mounted in the track with a “precise fit”. 
       FIG.  2    shows four views (A) to (D) of an embodiment of a blocking device  100  according to the invention which remedies these drawbacks. Reference is made hereinafter to  FIG.  3   : 
     The blocking device  100  for blocking a dovetail plate  3 , which is flush-mounted in a track  11  of the blocking device  100 , comprises a base  12  defining a side of the track  11 . The other side of the track  11  is defined by an oblique side wall  19 , the angle thereof relative to the base of the track  11  being selected so as to correspond to the dovetail plate  3 . 
     The term “track” which is used herein is not intended to imply that the dovetail plate  3  may only be flush-mounted in the blocking device  100  from the side (so-called “back loader” or “front loader”). Whilst this is possible, an insertion of the dovetail plate  3  from above (“top loader”) may also be possible. 
     A housing part  150  may define a first track width B1 on a first end portion  111  of the track  11  with the opposing side wall  19  (see  FIG.  2 (D) ) A second housing part  152  may define a second track width B2 on a second end portion  112  of the track  11  with the opposing side wall  19 , said second track width being larger than the first track width B1. This may facilitate the insertion of the dovetail plate  3  from the side, on the second end portion  112  of the track  11 . 
     The blocking device  100  further comprises a clamping block  13  which is arranged so as to be laterally displaceable on the base  12 , said clamping block having a blocking side  131  facing the track  11  and a clamping side  132  opposing the blocking side  131 . A spacing between the blocking side  131  and the clamping side  132  varies in a direction parallel to the longitudinal extent of the track  11 . For example, to this end the clamping side  132  is curved, as shown, which additionally saves space. The blocking side  131  for blocking the dovetail plate  3  acts on a side surface of the dovetail plate  3  and may be arranged, as is the side wall  19 , at a corresponding angle to the surface of the track  11 . For improved blocking of the dovetail plate  3 , the blocking side  131  which is configured to be flat, for example, may be provided with a friction pad, for example a rubber pad. 
     The blocking device  100  also comprises a clamping lever  14  which is rotatably arranged on the base  12  and which has a handpiece  141  and an eccentric part  142 , wherein the eccentric part  142  acts on the clamping side  132  for displacing the clamping block  13 . The handpiece  141  and the eccentric part  142  are coupled together, for example, via a pivot pin  143 . The rotation of the handpiece  141  about the pivot pin  143  brings about the action of the eccentric part  142  on the clamping side  132 . This brings about the displacement of the clamping block  13  in the direction of the track  11  and thus the action of a clamping force on the dovetail plate (not shown in  FIGS.  2  and  3   ). In this manner, the dovetail plate  3  is blocked. 
     A defining surface  144  (see dashed line in  FIG.  3 (A) ) which is defined by the contact between the eccentric part  142  and the clamping side  132  is not located parallel to the blocking side  131  when the clamping lever  14  is positioned for blocking the dovetail plate  3  ( FIGS.  2 (A) to (D)  and  FIGS.  3 (A) and (C) ) To this end, the eccentric part  142  is designed, for example, to be conically convex and the clamping side  132  is designed to be conically concave. 
     In one embodiment, the base  12  and the clamping block  13  are displaceably arranged parallel to the longitudinal extent of the track  11  and relative to the pivot pin  143  of the eccentric part  142 . Additionally or alternatively, the pivot pin  143  of the eccentric part  142  may also be arranged so as to be displaceable parallel to the longitudinal extent of the track  11 . Due to the variable spacing between the clamping side  132  and the blocking side  131 , the spacing between the defining surface  144  and the pivot pin  143  may be adjusted in a variable manner. Thus the track width defined by the clamping block  13  and the side wall  19  is also adjustable in a variable manner, or the clamping force (or the contact pressure) exerted by the clamping block on the dovetail plate  3 . In this manner, the blocking device  100  may receive dovetail plates of different widths, in particular even those dovetail plates which have a smaller width than the track  11 , as is defined by the housing parts  150  and  152 , on the one hand, and the side wall  19 , on the other hand. 
     Instead of a curved clamping side  132 , a clamping side  132  which runs in a linear manner could also be provided, said clamping side being arranged at an angle to the blocking side  131  in order to achieve the variable spacing between the clamping side  132  and the blocking side  131 . 
     The blocking device comprises an adjusting means  15 , for example an adjusting screw, in order to bring about the longitudinal displacement of the base  12 . The adjusting means  15  may be provided in the housing part  150  which, on the one hand, forms a side wall portion opposing the side wall  19  and, on the other hand, adjoins the base  12 , as shown. Due to the geometric shapes of the eccentric part  142  and the clamping side  132 , therefore, the adjusting means  15  permits the adjustment of the clamping force. Additionally, a counter pressure means  16 , for example a compression spring, which counteracts the longitudinal displacement of the base  12  may be provided. The counter pressure means  16  is accommodated, for example, in the further housing part  152  which, on the one hand, forms a further side wall portion opposing the side wall  19  and, on the other hand, adjoins the base  12 . 
     The clamping lever  14  and, in particular, the pivot pin  143  thereof are preferably fixedly arranged and are not displaced by the actuation of the adjusting means  15 . 
     The clamping block  13  may be floatingly mounted. To this end, the base is configured, for example, as a slide in which the clamping block  13  is arranged so as to be laterally displaceable. For example, the clamping block  13  is mounted so as to be displaceable between two end portions  121 ,  122  of the base, perpendicular to the longitudinal extent of the track  11 . The slide which is located, for example, in a U-shaped manner below the clamping block  13  ensures that when the clamping is released, the clamping block  13  is moved away uniformly and parallel from the side edge of the dovetail plate and thus is fully opened. Compression springs  171  and  172 , which push the clamping block  13  in the direction of the eccentric part  142 , may also be provided (see  FIGS.  3 (B) and (C) ). 
     In one embodiment, the blocking device comprises a securing element  18  which is movably mounted between a first position and a second position, wherein the rotatability of the clamping lever  14  is blocked when the securing element  18  is in the first position (see  FIGS.  3 (A) and (C) ). The securing element  18  is mounted in the first position, for example, by pretensioning. 
     The securing element is arranged on the handpiece  141  and has to be manually transferred into the second position, for example by displacement, in order to actuate the clamping lever  14  ( FIG.  3 (B) ). 
     In one embodiment, the blocking device  100  is configured to function both as a top loader, front loader and back loader, i.e. to permit the dovetail plate  3  to be flush-mounted from above, and also by insertion starting from the two end portions  111  and  112 . 
     Due to the displaceability of the clamping block  13  along the longitudinal extent of the track  11 , the extent of the lateral displacement of the clamping block  14  and thus the clamping force may be adjusted. Thus it is possible for different dovetail plates to be blocked or for tolerances in the geometric dimensions of the dovetail plate to be accepted. 
     The base of the track  11  may be configured to be entirely planar and does not necessarily have to have securing elements for securing the blocking of the dovetail plate. 
     The handpiece  141  may be rotated, for example, by 90°. In the non-blocked state, the handpiece  141  is located approximately at a 90° angle to the longitudinal extent of the track  11  ( FIG.  3 (B) ). In the blocked state, the handpiece  141  is located flat and flush with the further housing part  152 . In a central position, not shown here, the handpiece  141  is located approximately at a 90° angle to the longitudinal extent of the track  11 ; then the flush-mounted dovetail plate  3  may still be pushed forward and back, but no longer pivoted out of the track.