Patent Publication Number: US-2012036956-A1

Title: Control Lever Unit for a Construction Machine and Construction Machine Having Such a Control Lever Unit

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to foreign Patent Application DE 10 2010 007608.2, filed on Feb. 11, 2010, the disclosure of which is incorporated herein by reference in its entirety. 
     FIELD OF THE INVENTION 
     The invention relates to a control lever unit for controlling the driving and braking function of a construction machine, this control lever unit having at least one manual control lever that can be actuated by hand. Furthermore, the invention relates to a construction machine, in particular a material compaction device used in the fields of construction or refuse compaction, having at least one such control lever unit. 
     BACKGROUND OF THE INVENTION 
     Control levers are known in the art. 
     SUMMARY OF THE INVENTION 
     Embodiments of the present invention advantageously improve known control lever units, particularly from an ergonomic standpoint. 
     These advantages are achieved by a control lever unit having a manual control lever actuatable by hand, the manual control lever having a hand rest surface, which renders possible a passive resting of the hand, wherein the hand rest surface is configured as a saddle-shaped free-form surface adapted to the inner surface of hand, is inclined in space and has an angle of inclination between 20° and 40°, preferably between 25° and 35°, and particularly approximately 30° in relation to a horizontal plane, and merges into a pommel, which is used for thumb support, and a cantle, which makes it more difficult for the hand to slip off. Embodiments of the invention also refer to a construction machine having at least one control lever unit. Such a construction machine is a material compaction device such as e.g. a roller with a driver&#39;s cab. 
     To achieve the above advantages, a control lever unit for controlling the driving and braking functions of a construction machine is provided, the control lever unit having at least one manual control lever that can be actuated by hand, this manual control lever having a hand rest surface that renders possible the passive resting of the hand during operation. 
     “Passive resting” is understood to mean that the weight of the hand is essentially completely supported, i.e. the hand can rest on the hand rest surface in such a manner that the operator does not have to exert muscular strength to hold the lever, as is the case in the manual control levers known from the prior art without a corresponding hand rest surface. A hand rest surface is understood as a planar area on the manual control lever, on which the inner surface of the operator&#39;s hand, at least essentially the palm, can be placed so that its weight is supported. A hand rest surface in the sense of the invention is thus to be differentiated from a simple hand contact surface, which does not support of the weight of a hand. As a result, in particular a comfortable and fatigue-free operation of the control lever unit is rendered possible according to the invention. 
     The control lever unit according to embodiments of the invention can comprise further components such as e.g. switch elements and in particular buttons for controlling auxiliary functions or a transmitter unit for converting the control movements into control signals. Furthermore, it may comprise shock absorption elements, fastening means, seal elements, etc. 
     According to one preferred embodiment, the hand rest surface is designed as a saddle-shaped, free-form surface adapted to the inner surface of a hand. The saddle-shaped design is characterized by a ridge line, from both sides of which two surface areas slope away. The ridge line can be linear or curved. A free-form surface is understood as a complex surface with multiple curves in space. The adaptation to the inner surface of a hand is based in particular on a so-called standard hand. Additionally, the possibility of individual adaptation also exists. 
     According to one preferred embodiment, the hand rest surface is inclined in space and has an angle of inclination between 20° and 40°, preferably between 25° and 35° and in particular approximately 30° in relation to a horizontal plane. At the specified angles of inclination, outstanding weight support and anti-slip characteristics are ensured for the hand placed or resting on the lever. The angle of inclination can be specified in particular as an angle of inclination of a ridge line relative to a horizontal plane. The specified angle measurements are relative to a neutral position of the manual control lever. 
     According to one preferred embodiment, the saddle-shaped hand rest surface, which is also inclined in space, merges into (or is limited by) a pommel, which is adapted in particular as a knob-like elevation and which is used for thumb contact and in particular for thumb support. Furthermore, the saddle-shaped hand rest surface, which is inclined in space, merges into (or is limited by) a cantle, which is adapted in particular as a bulge-shaped elevation to prevent a hand resting on the lever from slipping off or at least in order to render this more difficult. The actual saddle-shaped hand rest surface extends between the pommel and the cantle. This design is approximately suggestive of a riding saddle. The operating hand can be placed in a relaxed and ergonomic manner between the pommel and the cantle. The terms “pommel” and “cantle” are also derived from the terms for the corresponding parts of a riding saddle. 
     According to one preferred embodiment, at least one button for an auxiliary function of the construction machine is provided on the manual control lever, the at least one button being arranged on the pommel and actuatable by means of the thumb of the hand placed or resting on the lever. Such a button is preferably an electrical button such as a push button, a flip switch, or the like. Further diverse auxiliary functions that can be controlled by means of the button are named below. 
     According to one preferred embodiment, multiple buttons that can be actuated by means of the thumb, in particular four buttons, are provided for auxiliary functions. These buttons are arranged on the pommel along an arc section corresponding to the arc of motion of the thumb when a hand is resting on the lever. The control of multiple auxiliary functions can thus be effected in an ergonomically expedient manner. 
     According to one preferred embodiment, at least one button that can be actuated by means of a finger (not the thumb) is provided for an auxiliary function of the construction machine, the at least one button being arranged on the bottom side of the manual control lever. The above statements apply analogously to this button. This bottom side of the manual control lever can be accessed naturally by a finger as this area is designed to correspond to the natural curvature of a finger in e.g. a gripping motion. The relevant button is arranged so that it can be actuated by the actuating finger, the button being within the natural range of motion of a finger when a hand rests upon the lever. This is also in keeping with ergonomic principles. 
     According to one preferred embodiment, several buttons—in particular four buttons—that are actuatable by means of a finger (not the thumb) are provided for auxiliary functions, the several buttons being arranged on the bottom side of the manual control lever. The buttons are preferably arranged so that they are assigned to a specific finger (index finger, middle finger, ring finger and little finger) and, as they are respectively within an anatomical range of motion of the fingers when a hand is placed or resting on the lever, may readily be actuated by the individual fingers. The buttons are preferably situated along a straight line in this case. 
     According to one preferred embodiment, the control lever unit according to the invention is adapted for a right-handed operator or for a left-handed operator. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a front view of a control lever unit according to an embodiment of the invention, and 
         FIG. 2  shows a rear view of the control lever unit depicted in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. 
       FIG. 1  shows a control lever unit  1  for controlling the driving and braking functions of a construction machine according to the invention. The example shown is designed for a right-handed operator, i.e. the lever is designed for operation by means of a right hand. The control lever unit  1  comprises a manual control lever  2 , shown in a neutral position, and a transmission mechanism  3 , which is covered by a folding bellows, and an encapsulated transmitter unit  4 , for converting the manual control movements on the manual control lever  2  into corresponding control signals for the driving and braking functions. In a preferred arrangement inside the driver&#39;s cab of a construction machine, this control lever unit  1  is arranged to the right of the operator. In accordance with the illustration shown in  FIG. 1 , the manual control lever  2  can be operated directly by placing or resting the right hand on it. 
     The manual control lever  2  has a hand rest surface  21  adapted as a free-form surface that is adapted to the inner surface of a hand and extends in the shape of a saddle between an upper, knob-like pommel  22  and a lower, bulge-shaped cantle  23 . The lower, bulge-shaped cantle  23  runs into the lower front edge of the hand rest surface  21 . Designated by  24  and arching slightly upwards, the ridge line of the saddle-shaped hand rest surface  21  has an angle of inclination of approximately 30° in relation to the horizontal plane. 
     The hand rest surface  21  adapted between the pommel  22  and the cantle  23  renders possible the passive resting of the hand during operation, the weight of the hand being essentially completely supported. The thumb of the hand resting on the lever can touch or be placed or rested on the pommel  22 . The bulge-shaped cantle  23  prevents the hand from slipping off of the inclined hand rest surface  21 . The entire surface of the manual control lever  2 , at least the surface transitions in the area of the hand rest surface  21 , in particular toward the pommel  22  and the cantle  23 , are adapted with a constant and smooth curvature in an ergonomic manner. The surface of the manual control lever  2  is formed by a coating, for example, a plastic film with an underlying foam layer. 
     Four buttons  31  to  34  that are actuatable by means of the thumb of the hand resting on the lever are adapted as push buttons and arranged along an arc section arranged on the pommel  22 , the arc section corresponding to the arc of motion of the thumb. Each of these buttons  31  to  34  can be actuated comfortably by means of the thumb of the hand resting on the hand rest surface  21 . Diverse auxiliary functions of the construction machine may be controlled via the buttons  31  to  34 , as explained in greater detail below. 
       FIG. 2  shows a rear view of the control lever unit  1 . As is evident from this rear view, the manual control lever  2  has a bottom side  26 , which is accessible for the fingers of the (right) hand resting on the lever in an anatomically normal gripping motion. The pommel  22  continues on the bottom side  26  of the manual control lever  2 ; this continuation is adapted as a finger guide  25  for the index finger (of the right hand resting on the lever). Four buttons  36  to  39  that can each be actuated by means of a finger (index finger, middle finger, ring finger and little finger) are arranged on the bottom side  26 ; these buttons are also adapted as push buttons and can be actuated by means of the individual fingers in their respective anatomical direction of motion when the hand is resting on the lever. The buttons  36  to  39  are arranged along a straight line, which is not evident in the illustration shown. Diverse auxiliary functions may be controlled by means of the buttons  35  to  39 , as explained in greater detail below. 
     Buttons  31  to  34 , which can be actuated by the thumb of the resting hand, and buttons  36  to  39 , which can be actuated by the fingers of the resting hand, render possible the execution of additional control functions (auxiliary functions) of the construction machine without the position of the resting hand having to be changed relative to the manual control lever  2 . 
     Preferably, each of the buttons  31  to  34  and  36  to  39  has a specific auxiliary function assigned to it. The button configuration is selected here so that an intuitive actuation is possible, whereby greater safety and a reduction of incorrect operations are achieved. The buttons  31  to  34  and  36  to  39  may additionally be coded by different colors. All buttons  31  to  34  and  36  to  39  are adapted to correspond to the range of motion of the fingers (including the thumb). 
     For example, a particularly preferred configuration for the buttons  31  to  34  and  36  to  39  shown in the Table 1 can be selected for a tandem roller. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 Button 
                   
                 Actuation 
                   
               
               
                 Number 
                 Color 
                 by Means of 
                 Auxiliary Function 
               
               
                   
               
             
            
               
                 31 
                 red 
                 thumb 
                 vibration 
               
               
                 32 
                 green 
                 thumb 
                 edge pressing and cutting 
               
               
                   
                   
                   
                 equipment/chip spreader up 
               
               
                 33 
                 green 
                 thumb 
                 edge pressing and cutting 
               
               
                   
                   
                   
                 equipment/chip spreader down 
               
               
                 34 
                 orange 
                 thumb 
                 signal horn 
               
               
                 36 
                 blue 
                 index finger 
                 chip spreader left/ 
               
               
                   
                   
                   
                 crab steering left 
               
               
                 37 
                 blue 
                 middle finger 
                 chip spreader right/ 
               
               
                   
                   
                   
                 crab steering right 
               
               
                 38 
                 yellow 
                 ring finger 
                 LCD software maneuvering 
               
               
                 39 
                 yellow 
                 little finger 
                 LCD software maneuvering 
               
               
                   
               
            
           
         
       
     
     The many features and advantages of the invention are apparent from the detailed specification, and, thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and, accordingly, all suitable modifications and equivalents may be resorted to that fall within the scope of the invention.