Abstract:
A height-adjustable carrying device with a parallelogram cranking mechanism has a self-locking pneumatic spring ( 6 ), with a valve for abolishing the blocking function. A release element ( 22 ), with which the valve ( 24 ) is actuated, is arranged according to the present invention at a handle ( 20 ) for swiveling the carrying device in one assembly unit.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of priority under 35 U.S.C. § 119 of German Patent Application 10 2006 052 803.4 filed Nov. 9, 2006, the entire contents of which are incorporated herein by reference. 
   FIELD OF THE INVENTION 
   The present invention pertains to a carrying device with a height-adjustable bracket that has two bracket legs arranged between two end-side head pieces to form a parallelogram rocker, with a device mount at one of the head pieces and a handle in the area of the device mount for swiveling the bracket. 
   BACKGROUND OF THE INVENTION 
   A carrying device of the type is known from U.S. Pat. No. 4,844,387. Two bracket legs, which are connected to the head pieces in an articulated manner, are arranged between two end-side head pieces in the form of a parallelogram cranking mechanism. To compensate the weight of an object being carried, an opposing force means in the form of a pneumatic spring is provided, which ensures that the height of the object being carried can be set in a predetermined position with the parallelogram cranking mechanism. The pneumatic spring is self-locking and has a valve, with which the self-locking can be abolished. This valve can be actuated via a pushbutton arranged laterally on the bracket. 
   The prior-art carrying device is designed such that one of the head pieces is attached to a table or desk with a cranking mechanism, while a device mount for a monitor is provided at the other head piece. The monitor can be set to the desired working height with a handle on the front side of the device mount. By actuating the pushbutton on the bracket, the self-locking of the pneumatic spring is abolished before the height adjustment. Such brackets are also used in medical treatment rooms to mount monitoring devices. The monitoring device can be positioned at the eye level of the user in a simple manner by means of the freely swiveling parallelogram cranking mechanism. 
   The drawback of the prior-art carrying device is that two hands are needed for the adjustment, one of which swivels the device mount while the other actuates the pushbutton. 
   A height-adjustable bracket with a parallelogram cranking mechanism between two head pieces and with a self-locking pneumatic spring, in which spring the self-locking can be abolished with a hydraulic system, is known from DE 10 2004 026 117 B3. The hydraulic system has a hydraulic release element at the pneumatic spring, a release button and a hydraulic line between the hydraulic release element and the release button. The release button is arranged at a head piece of the bracket. However, if a device mount for a monitor is additionally arranged at the head piece, one-hand operation is not yet solved in a satisfactory manner. 
   SUMMARY OF THE INVENTION 
   The basic object of the present invention is to improve a carrying device of the type mentioned in terms of simple operation. 
   According to the invention, a carrying device is provided with a height-adjustable bracket which has bracket legs arranged between two end-side head pieces in the form of a parallelogram rocker. A self-locking pneumatic spring is provided with a valve for abolishing (switching off) the blocking function of the pneumatic spring. A device mount is provided at one of the head pieces and a handle is provided in an area of the device mount for swiveling the bracket. A release element is provided with a transmission means for actuating the valve. The release element is present in the area of the handle. 
   The release element may be a pushbutton. The release element may be a gripping element pivotable about a joint in the area of the handle. The gripping element may be arranged on the underside of the handle, pivotable towards the handle. 
   The transmission means may advantageously be a bowden cable. A rocker arm, which is actuated by the bowden cable, may be provided for releasing the valve in the area of the valve. 
   The advantage of the present invention can be seen in the fact that the release element for the valve of the pneumatic spring is arranged directly in the region and preferably directly at the handle assigned to the device mount, so that when the bracket is swiveled with the release element, which is connected to the handle in one assembly unit, the valve of the pneumatic spring is opened. The release element is connected for this purpose to the valve of the pneumatic spring via the transmission means. Besides a bowden cable, other electric or mechanical components may be used for transmitting the actuation of the release element to the valve of the pneumatic spring, as transmission means. The release element is advantageously a pushbutton, which is arranged directly at the handle. 
   It is especially advantageous to arrange a gripping element on the underside of the handle, which can be swiveled in the direction of the handle and which is used to release the valve of the pneumatic spring. The bowden cable may be a bowden cable, which is known from other fields of application, and with which the necessary forces can be transmitted between the release element and the valve. A rocker arm, which is actuated by the bowden cable and acts on the valve lifter, is advantageously provided for actuating the valve. 
   An exemplary embodiment of the present invention is shown in the figures and will be explained in more detail below. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which the preferred embodiment of the invention is illustrated. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
       FIG. 1  is a longitudinal sectional view of a carrying device; 
       FIG. 2  is a detailed view A from  FIG. 1  showing aspects of the carrying device according to  FIG. 1 ; and 
       FIG. 3  is a detailed view B from  FIG. 1  showing aspects of the carrying device according to  FIG. 1 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to the drawings in particular,  FIG. 1  schematically shows a longitudinal section of a bracket  1 , which comprises a first head piece  2 , a second head piece  3 , a first bracket leg  4 , a second bracket leg  5 , and a pneumatic spring  6 . The bracket legs  4 ,  5  are connected to the head pieces  2 ,  3  in the form of a parallelogram cranking mechanism via pin joints  7 ,  8 ,  9 ,  10 . A piston sleeve  11  of the pneumatic spring  6  is attached via a pin joint  12  and a collet  13  to a threaded bolt  14  mounted within the first head piece  2 . A lifting rod  15  of the pneumatic spring  6  is connected to the first bracket leg  4  via a pin joint  16  and a bearing block  17 . The pneumatic spring  6  may be of the type disclosed in GB 2, 178, 508 A (which is incorporated by reference in its entirety) wherein the lifter  23  includes a valve  24  with a sealing cone and the spring arrangement presses the sealing cone on a valve seat of the valve  24 . As the pneumatic spring  6  is a self locking pneumatic spring, an additional pull back spring between handle  20  and gripping element  22  is not required. 
   A holder  18  with a device mount  19  for a monitor, not shown in more detail, is arranged at the second head piece  3  by means of a ball and socket joint, not shown in more detail. A handle  20  is provided defining a hand grasping region with which the device mount  19  can be brought into the desired position. The handle  20  is located on the front side of the device mount. On its underside, the handle  20  has a gripping element  22 , which can be swiveled against the handle  20  about a joint  21  to form a release element. 
     FIG. 2  shows detail A according to  FIG. 1 . Identical components are designated by the same reference numbers as in  FIG. 1 . 
   A lifter  23 , which actuates a valve  24  within the pneumatic spring  6 , with which valve the self-locking of the pneumatic spring can be abolished, is guided within the lifting rod  15  in such a way that it can perform strokes. 
   In addition to the pin joint  16 , a rocker arm  26 , which can be swiveled about a hinge  25 , is attached to the bearing block  17  for actuating the lifter  23 . A mount  27  for arranging a steel cable  28  of a bowden cable  29 , which is fixed in a mounting sleeve  30  at the lower end of the rocker arm  26 , is located at the lifting rod  15 . When the steel cable  28  is actuated, the rocker arm  26  is swiveled in the direction of the mount  27  and the valve  24  is thus opened via the lifter  23 . 
     FIG. 3  illustrates detail B according to  FIG. 1 . Identical components are provided with the same reference numbers as in  FIGS. 1 and 2 . 
   A mounting device  31  for the other end of the bowden cable  29  is located on the rear side of the handle  20 . The steel cable  28  of the bowden cable  29 , which steel cable is located inside, is hung into an eye  32  on the gripping element  22 . When the gripping element  22  is swiveled along arrow  33  in the direction of the handle  20 , the steel cable  28  is tensioned and the lifter  23  of the valve  24  is actuated with the rocker arm  26 . The self-locking of the pneumatic spring  6  is thus abolished and the bracket can be swiveled into the predetermined working position with the handle  20 . After releasing the handle  20 , the gripping element  22  resumes the starting position and the valve  24 ,  FIG. 2 , is closed. The pneumatic spring now holds the bracket  1  in the working position set previously by means of the self-locking. 
   While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.