Abstract:
A handle ( 10 ) for controlling a machine, has a largely vertical shaft ( 12 ) forming a grip part ( 11 ) and has an upper end forming a receptacle ( 14 ) that holds switch units ( 15 - 17 ) and a lower end forming a hand rest ( 20 ). The hand rest can be adjusted along the shaft ( 12 ) and can be detachably clamped to the shaft. The hand rest ( 20 ) comprises front and rear rest part ( 26, 27 ) that are pivotally, or swivelably, connected to one another. To prevent unintentional opening of the hand rest ( 20 ) by axial pressure on the latter, the two rest parts ( 26, 27 ) can be moved relative to one another in the axial direction to effect a locking and unlocking of their relative pivotabilities.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    Applicant claims priority from German patent application DE 10 2006 0 22 967.3 filed May 11, 2006. 
       BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to a handle grip, preferably for driveable construction machines, agricultural machines and the like. In particular, the invention relates to a handle grip with a grip part, at the upper end of which is provided a receptacle for switch units, and which is provided with a hand rest which can be adjusted with respect to the receptacle. Such handle grips, on which the operator rests his hand and can at the same time actuate individual switch units, are provided with a hand rest for supporting the edge of the hand. Conveniently in such a hand rest, the distance from the rest to the switch units to be operated with the thumb and possibly with other fingers can be adapted to the size of the operator&#39;s hand. 
         [0003]    DE 101 27 515 Al discloses a handle grip having a one-piece rear rest part, which is pivotally, or swivelably coupled via diametrically opposite radially projecting bosses to the front non-swivelable remaining rest part in such a way as to produce a clamping-type connection of the two rest parts to the grip part in a self-locking manner. This self-locking clamping is released by moving the rear rest part in the radial direction. It has been found that this self-locking clamping of the two rest parts on the grip part can be released in the case of a high axial resting pressure on the rest parts, in particular the rear rest part, on account of the existing lever arm to the swivel axis, and thereby the hand rest can unintentionally open. The object of the present invention is to provide a handle grip of the type mentioned in the introduction in which an unintentional opening of the hand rest due to axial pressure on the latter is prevented. 
       SUMMARY OF THE INVENTION 
       [0004]    According to the invention, there is provided a handle grip for drivable construction machines, agricultural machines and the like, with a grip part, with an upper end forming a receptacle for switch units and with a hand rest. The hand rest position can be adjusted along a shaft of the grip part and can be detachably clamped to the latter. The hand rest has front and rear rest parts that are pivotally connected, wherein the two rest parts can be moved relative to one another in the axial direction so as to effect a locking and unlocking of their relative pivotability. 
         [0005]    By means of the measures according to the invention, for a swivelling movement of one of the rest parts, preferably the rear rest part, to occur, first of all a locking action acting in the radial direction between the two rest parts must be released before for example the rear rest part can be swivelled relative to the front rest part. This reliably prevents an unintentional release of the rest parts on the grip part, since due to the axially gripping and radially acting locking action, the rest parts cannot be unintentionally released simply by axial pressure on them. 
         [0006]    A preferred structural embodiment of the mutual locking action of the two rest parts is given by forming the swivelable rear rest part in two parts, a lower element being swivelably coupled to the front rest part and an upper element forming a region of a hand rest surface being axially movable with respect to the lower element. The rear rest part is designed as two parts, both of which can move relative to one another in the axial direction. This means that an active axial movement of the upper element of the rear rest part relative to its lower element, which remains in the preset swivel position, is necessary to release the locking action. 
         [0007]    A preferred structural embodiment of the locking action of the two rest parts in the axial direction to one another is given by providing the upper element of the swivelable rear rest part with axial lock bars that axially engage in undercuts on the front rest part. 
         [0008]    Further advantageous modifications, in particular also as regards the clamping of the rest parts on the grip part, are also provided. A left-hand/right-hand usability of the hand rest can also be provided. 
         [0009]    A structural configuration that is technically simple to implement is given by forming the grip part by two semishells. This gives a simple installation of the individual switch units. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    Further details of the invention are given in the following description, in which the invention is described and explained in more detail with the aid of the embodiment shown in drawings, in which: 
           [0011]      FIG. 1  is a front view of a handle grip according to a preferred embodiment of the present invention, 
           [0012]      FIG. 2  is a perspective rear view of the handle grip according to  FIG. 1 , 
           [0013]      FIG. 3  shows on an enlarged perspective and partially exploded view the lower region of the handle grip according to  FIG. 2  provided with the hand rest, and 
           [0014]      FIGS. 4A ,  4 B and  4 C show in the assembled state and in a perspective side view the lower region of the handle grip according to  FIG. 2  in various positions, namely in a locked clamped position and in an unlocked clamped position as well as in an unclamped swivelled position. 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0015]    The handle grip  10  shown in the drawings is intended in particular for installation and incorporation in driveable construction machines. The handle grip  10  is intended to be operated by the operator&#39;s thumb and/or fingers while the operating hand is supported in a resting manner. 
         [0016]    The handle grip  10  comprises a grip part  11 , the shaft  12  of which is grasped and enclosed by the operator&#39;s hand and can be connected via a hollow holding rod  13  to the relevant machine. The holding rod  13  may in this connection be part of a joystick arrangement. The holding rod  13  and shaft  12  are fixedly connected to one another in a manner not shown in detail. The shaft  12  is provided at its upper end with a receptacle  14  for various switch units  15 ,  16 ,  17 . According to  FIG. 2  the receptacle  14  for the switch units  15  to  17  is inclined relative to the alignment of the shaft  12  and of the holding rod  13 . A hand rest  20  is arranged on the shaft  12  at its lower end facing towards the holding rod  13 . The shaft  12  and the receptacle  14  of the grip part  11  are formed by two, in each case single piece semi-shells  18 ,  19 , wherein the semi-shell  18  covers the front region and the semi-shell  19  covers the rear region of the handle grip  10  ( FIG. 2 ). The two semi-shells  18  and  19  are formed as one piece from plastics material. 
         [0017]    The hand rest  20  is in the embodiment shown symmetrical with respect to a longitudinal mid plane  21  ( FIG. 1 ), which is rotated by  904  relative to the separating plane  25  of the two semi-shells  18  and  19 . The hand rest  20  comprises a rest plate  22 , which is roughly elliptically shaped in the direction transverse to the longitudinal mid plane  21 , and the hand rest surface  23  of which in the lower region of the shaft  12  runs slightly inclined with respect to the separating plane  25  of the semi-shells  18  and  19 . The hand rest surface  23  is eccentric with respect to the shaft  12  in such a way that the front region of the rest surface  23  is somewhat wider than the rear region. The rest plate  22  covers a guide sleeve  24  which surrounds the shaft  12 . 
         [0018]    According to  FIG. 3  the hand rest  20  is designed in two parts, and comprises a front rest part  26  and a rear rest part  27  held thereon and which can swivel in the direction of the double arrow A (in  FIG. 4C ) , and which in turn is formed as two parts. The rest plate  22  is thus in two parts ( 22 ′ and  22 ″), while the radially inwardly displaced guide sleeve  24  is basically in three parts. The front rest part  26  consisting of the front rest plate part  22 ′ and guide sleeve part  24 ′ is, seen in the circumferential direction, the larger of the two rest parts, so that the rest plate part  22 ′ and guide sleeve part  24 ′ surround the shaft  12  over  180   s , and is enlarged by cheek portions  30  and  28  running tangentially to the shaft  12 . The rear swivelable rest part  27  fits into a roughly U-shaped and axially stepped recess of the front rest part  26  formed by the cheek portions, in such a way that a continuous internal and external circumferential surface is formed both on the internal circumferential side in the region of the guide sleeve  24  as well as on the external circumferential side in the region of the rest plate  22 . 
         [0019]    The swivelable rear rest part  27 , which as already mentioned is in two parts, comprises an upper element  53  which is axially movable with respect to a lower element  54  in the direction of the double arrow B ( FIG. 4B ). Whereas the upper element  53  with its rest plate part  22 ′ forms a region of the hand rest surface  23 , the lower element  54  with its side cheek portions  52  serves to effect the swivelability in the direction of the double arrow A ( FIG. 4C ) with respect to the front rest part  26 . For this purpose, holes for swivel axes  29  are made in the side cheek portions  52  of the lower element  54  and in the cheek portions  28  of the guide part  26 . The upper element  53  comprises a guide sleeve part  24 ″ and two diametrically oppositely facing axial side cheek portions  51  formed thereon. The two elements  53  and  54  are guided on one another in the axial direction on their side cheek portions  51  and  52  and are movably fixedly connected to one another in the swivelling direction according to the double arrow A. For this purpose the side cheek portions  51  of the upper element  53  comprise axial strips  56  ( FIG. 3 ) that are inserted into axial grooves  57  of oppositely facing outer surfaces of the side cheek portions  52  of the lower element  54  ( FIG. 3 ). The axial relative movement of the upper element  53  with respect to the lower element  54  is limited by an oblong hole  58  in the side cheek portions  51  of the upper element  53 , through which hole passes the respective swivel axis  29 . The arrangement is designed so that the side cheek portions  51  of the upper element  53  are arranged between the side cheek portions  52  of the lower element  54  and the guide sleeve part  24 ′ of the front rest part  26 . 
         [0020]    In the region of the two diametrically opposite swivel axes  29  the rear semi-shell  19  of the shaft  12  is provided with two identical diametrically opposite running recesses  36 . The axial length of the recesses  36  defines via their upper and lower boundary edges  37 ,  38  the extent of the axial adjustability of the hand rest  20  with respect to the shaft  12 . In the circumferential direction each recess  36  is bounded by a clamping edge  41  running parallel to and roughly in the separating plane  25  of the two semi-shells  18  and  19  in the lower shaft region, which edge is provided with a transversely running toothed section  42 . The oppositely facing edge  43  in each case has a torsionally rigid surface running parallel to the longitudinal mid plane  21 , the plane of the said surface running in the region of the inside of the clamping edge  41 . 
         [0021]    In the region of the swivel axes  29  the side cheek portions  52  of the lower element  54  of the rear rest part  27  in each case include a boss  32  through which the hole for the swivel axis  29  radially passes and which abuts with its inner surface  33  against the edge  43  of the recess  36 . In this way, the hand rest cannot swivel with respect to the shaft  12 . Perpendicular to the inner surface  33  and facing towards the toothed clamping edge  41 , the boss  52  has on the front side an eccentric edge  34  that is provided with a complementary toothed section  59  running transversely to the toothed section  42 , and which after a swivelling movement of the rear rest part  27  and its lower element  54  to the front rest part  26  according to the arrow A, abuts in a clamping manner against the clamping edge  41 . In this connection the eccentric contour of the surface of the eccentric edge  34  with respect to the swivel axis  29  is such as to produce a self-retaining clamping of the hand rest  20  on and around the shaft  12 . This clamping also produces an interengagement of the toothed section  42  of the clamping edge  41  and the toothed section  59  of the boss  30  of the side cheek portions  52 . At the same time the gap between the front rest part  26  and the circumferential region of the shaft  12  becomes practically zero. In this way a practically continuous adjustment, corresponding to the very small width of the toothed section, is achieved in the self-locking retention of the hand rest  20  along the shaft  12  of the order of magnitude of the axial length of the recess  36 . 
         [0022]      FIGS. 4A ,  48  and  4 C illustrate a release of the clamping and locking retention of the hand rest  20  on the shaft  12 .  FIG. 4A  shows the clamping situation, in which the rest surface regions  23 ′ and  23 ″ of the rest plate parts  22 ′ and  22 ″ lie in one plane. If the upper element  53  of the rear rest part  27  is moved axially upwardly in the direction of the arrow B, then diametrically oppositely facing stop lugs  61  ( FIGS. 3 and 4C ) on the lower side  47  of the rest plate part  22 ″ disengage from axial stop lugs  62  ( FIG. 4C ) of the upper edge  48  of the guide sleeve  24 ′ of the front rest part  26 , which hitherto (in the position of  FIG. 4A ) in the catch-type locked state have ensured a non-swivelability of the rear rest part  27  with respect to the front rest part  26 , by means of an axial engagement. In the position shown in  FIG. 4B , the upper element  53  is axially lifted from the lower element  54 , so that a gap S is formed therebetween; also, the rear rest part  27  is swivelable in the direction of the arrow A, in that the upper element  53  can be swivelled for example on a lower gripping strip  63  outwardly around the swivel axes  29 . Due to the strip/groove locking engagement  56 ,  57  between the upper element  53  and the lower element  54 , the lower element  54  is entrained by the swivelling movement of the upper element  53  so that the position according to  FIG. 4C  results. The hand rest  20  can thereby be moved and adjusted in the axial direction with respect to the shaft  12 . The clamping retention of the hand rest  20  on the shaft  12  takes place in the reverse order to that described hereinbefore, in other words the upper element  53  is swivelled together with the lower element  54  in the direction of the arrow A to the shaft  12 , until the lower element  54  abuts against the shaft  12  and a clamping is thereby effected. The upper element  53 , which is not involved in the clamping, can then be displaced axially downwardly with respect to the lower element  54  in the direction of the arrow B until the stop lugs  61  of the upper element  53  engage in stop grooves  62  of the front rest part  26 . 
         [0023]    It is understood that in the self-locking and clamping retention of the lower element  54  of the rear rest part  27  and overall of the front rest part  26  on and with respect to the shaft  12 , an axial mobility of the upper element  53  with respect to the lower clamping element  54  and the shaft  12  is still retained.