Abstract:
A work machine handle device having a foldable handle is disclosed. As the handle is to be changed from a folded-up state to a use state, the handle is turned about a frame as a turning fulcrum. An actuating protuberance provided integrally to a turning member of a clamp body is pushed by a handle engaging/disengaging part provided to a front end of the handle, and the turning member is caused to turn. The handle engaging/disengaging part is held from either side and automatically restrained by a clamp mechanism. When the handle is changed from the use state to the folded-up state, a restraining mechanism is operated to release the engagement between the restraining mechanism and a distal end of the turning member. The turning member is turned by a return force of a spring provided to the clamp body, the handle engaging/disengaging part ceases to be restrained, and the handle can be folded up.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a handle device of a work machine, such as a power generator and a pump, having a frame provided with a foldable handle. 
     BACKGROUND OF THE INVENTION 
     Japanese Patent No. 4226404 B discloses a work machine comprising a handle device provided to a steel chassis frame, wherein the handle folds up during transportation or movement. The handle device has a handle bracket fastened to a plate-shaped bracket provided to the chassis frame, a supporting base plate held by a bolt passed through a disc spring and fastened to the handle bracket so as to not turn, and a handle fitted with the supporting base plate. A manual locking mechanism engages with the handle bracket when the handle is in its use position. 
     However, a problem is presented in the handle device described above in that its structure is complicated and it has a large number of components. 
     Japanese Patent Application Laid-Open Patent Publication No. 2007-115457 A (JP 2007-115457 A) discloses a handle device in which a handle, which is a rod bent into a foldable U shape, is connected at one end to a plate attached to a chassis frame composed of a steel pipe, the other end of the rod is fixed in place by being passed through the handle and the plate, and the rod can be removed and turned. 
     However, although the handle device disclosed in JP 2007-115457 A has a simple structure, a problem is presented in that since the handle turns of its own weight when the pin (rod) is removed, the handle must first be held in the use position and then the handle must be lowered while being supported, and both the force and direction with which the handle is turned are unstable. 
     Furthermore, another problem is that when the handle is fixed in place (locked) or turned, the pin must be removed and inserted, and the handling thereof is complicated. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a handle device of a work machine which has a simple structure for fixing (locking) the handle in a detachable manner in a use position, and which also has a simple operation for fixing (locking) the handle in the use position. 
     According to an aspect of the present invention, there is provided a handle device of a work machine, which device comprises: a frame for carrying a work device; a transportation/movement handle attached in a foldable manner to the frame, extending outwardly of the frame, and having left and right grip parts at distal ends; a handle turning mechanism for supporting attachment parts of the handle that intersect the frame in such a manner as to be turnable about the frame as a turning fulcrum; and a clamp mechanism for detachably fixing a handle engaging/disengaging part to the frame, the handle engaging/disengaging part continuing from the attachment parts, extending forwardly of the frame and positioned on a side opposite the grip parts, wherein the clamp mechanism comprises: a clamp body for clamping the handle engaging/disengaging part by closing; a spring of the clamp body, for holding the clamp body in an open standby state; a actuating protuberance which, when closed against a spring force of the spring, extends from a turning member of the clamp body toward the handle engaging/disengaging part so as to contact and be pushed by the handle engaging/disengaging part; and a restraining mechanism for automatically restraining a distal end of the clamp body by a spring force when the clamp body is closed due to the actuating protuberance being pushed further and brought nearer to the frame. 
     Therefore, the structure whereby the handle is detachably fixed (locked) in the use position is simplified. Only one clamp mechanism need be provided to the frame, and the structure whereby the handle is detachably fixed (locked) in the use position is simplified. 
     When the handle is turned form the folded up position to the use position and the handle engaging/disengaging part (the other end) facing the grip parts (the one end) of the handle is engaged with the clamp body which is opened in a standby state, the clamp body is also turned and automatically closed by the actuating protuberance pushed by the handle engaging/disengaging part, and the closed state is automatically restrained by the restraining mechanism. 
     When the restraining mechanism is pushed against the spring force when the handle is folded up from the use state, the clamp body opens up. 
     Therefore, the clamp mechanism can be operated by a single pressing action, and the operation of fixing, or in other words clamping (locking) the handle is simplified, as is the operation of releasing the clamp (the lock) of fixing the handle. 
     It is preferred that the clamp body be comprised of a fixed member fixed to the frame and the turning member turnably attached to the fixed member and provided with the actuating protuberance, the fixed member have an open end with an inside surface being curved and in proximity to the handle engaging/disengaging part, and the turning member have a distal end with an inside surface being curved and in proximity to the handle engaging/disengaging part. 
     Therefore, when the handle engaging/disengaging part is turned and inserted into the clamp body which is opened in a standby state, interference between the handle engaging/disengaging part and the inside surface of the open end of the clamp body can be prevented. In other words, even if there is a comparatively large degree of variation in the precision of assembling the handle turning mechanism and the clamp mechanism, the variation can be absorbed and the structure of the handle device is effectively simplified. 
     It is preferred that the clamp body be comprised of a fixed member fixed to the frame and the turning member turnably attached to the fixed member and provided with the actuating protuberance, and the restraining mechanism be comprised of a fixed pawl formed on a distal end of the turning member and a movable pawl member turnably attached to the fixed member so as to engage the fixed pawl by a spring force of a return spring. 
     When the handle engaging/disengaging part is turned and fitted in the clamp body opened in a standby state, the movable pawl of the movable pawl member automatically engages with the fixed pawl part of the opened turning member. The operation of clamping the handle is thus simplified. 
     The spring may comprise a helical torsion spring, with a direction of the torsion load coinciding with a direction in which the clamp body opens. As a result, the helical torsion spring need only be inserted through the fulcrum axis of the clamp body, and the structure is simplified. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Certain preferred embodiments of the present invention will be described in detail below, by way of example only, with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view illustrating a work machine according to a first embodiment of the present invention; 
         FIG. 2  is a top plan view of the handle device shown in  FIG. 1 ; 
         FIG. 3  is an enlarged cross-sectional view taken along line  3 - 3  of  FIG. 2 ; 
         FIG. 4  is an enlarged cross-sectional view along line  4 - 4  of  FIG. 2 ; 
         FIG. 5  is an exploded view of the handle device shown in  FIG. 1 ; 
         FIG. 6  is an enlarged view showing area  6  of  FIG. 2 ; 
         FIG. 7  is a cross-sectional view taken along line  7 - 7  of  FIG. 6 ; 
         FIG. 8A  is a perspective view showing a fixed member of a clamp body shown in  FIG. 7 ; 
         FIG. 8B  is a top plan view showing the fixed member; 
         FIG. 8C  is a cross-sectional view taken along line c-c of  FIG. 8B ; 
         FIG. 9  is a perspective view showing a turning member of  FIG. 7 ; 
         FIG. 10A  is a front view showing the turning member of  FIG. 7 ; 
         FIG. 10B  is a side view of the turning member as seen in the direction of arrow b of  FIG. 10A ; 
         FIG. 10C  is a cross-sectional view taken along line c-c of  FIG. 10A ; 
         FIG. 10D  is a bottom view showing the turning member as seen in the direction of arrow d of  FIG. 10B ; 
         FIG. 11A  is a perspective view showing a movable pawl member of a restraining mechanism shown in  FIG. 7 ; 
         FIG. 11B  is a view showing the movable pawl member of  FIG. 11A , as seen in the direction of arrow b of  FIG. 11A ; 
         FIG. 11C  is a cross-sectional view taken along line c-c of  FIG. 11B ; 
         FIGS. 12A through 12C  are views illustrating locking engaging/disengaging actions of the handle of the handle device according to the first embodiment; and 
         FIG. 13  is an exploded perspective view of a crank mechanism according to a second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Embodiment 
     Reference is now made to  FIGS. 1 through 12  showing a work machine  11  according to a first embodiment. In the work machine  11  according to the present embodiment, a power generator is shown as an example. 
     The work machine  11  comprises a work device  12  mounted on a frame  13 , as shown in  FIG. 1 . This work device  12  includes a drive device (an engine)  15  and a power generation part  16 . A handle  22  held on a handle device  21  can be folded up. 
     Another possible example of the work device  12 , other than the power generator, is a pump device which deals with water or another fluid. 
     The handle device  21  is attached to the frame  13  so that the handle  22  can be folded up in the direction of arrow a 1  as shown in  FIGS. 1 and 2 . The use position of the handle  22  is shown by U, and the folded position of the handle  22  is shown by S. When the handle  22  is in the use position U, the work machine  11  is moved by grasping the handle  22  by hand and pushing using the wheels  23 . When the work machine is loaded onto an automobile, two people lift the machine by taking hold of the handle  22  and the frame  13 . 
     The frame  13  is formed into a substantial square and is composed of a bottom frame part  26 , four vertical frame parts  27  standing upright from the bottom frame part  26 , and a top frame part  28  spanning as a continuation between the vertical frame parts  27 . In other words, the frame  13  includes members, e.g., bottom cross base plates  31  and a top cross frame part  32  attached to a pipe frame. 
     The wheels  23  and the cross base plates  31 ,  31  are attached to the bottom frame part  26 . On the cross base plates  31 , the engine  15  and the power generation part  16  are carried on the cross base plates  31 ,  31 . 
     The top frame part  28  is composed of a first cross frame part  34  to which the handle  22  is attached, first and second side frame parts  35 ,  36  continuing from the first cross frame part  34 , a second cross frame part  37 , and the top cross frame part  32  which is in proximity to the first cross frame part  34 . The handle  22  is attached to a handle support part  41  of the first cross frame part  34 . 
     The handle  22  is created by bending a steel pipe. Specifically, a support part  44  supported on the frame  13  is plastically deformed into a U shape. A first arm part  45  is attached as a continuation to one end of this U-shaped support part  44 . A second arm part  46  is attached to the other end. Seen in a plan view, the first and second arm parts  45 ,  46  extend rearward out to the exterior of the work machine  11  so as to widen outward. The first and second arm parts  45 ,  46  have a first grip part  47  and a second grip part  48  at their respective ends. 
     Due to a 90° plastic deformation of a first bent part  51  and a second bent part  52 , the U-shaped support part  44  has a handle engaging/disengaging part (a stopper part)  53  extending in the vehicle width direction, and first and second attachment parts  54 ,  55  extending in parallel in the vehicle forward-backward direction. 
     The handle engaging/disengaging part  53  is engaged to and disengaged from a clamp mechanism  62  provided to the top cross frame part  32  when the handle  22  is turned to the use position U. 
     The first attachment part  54  and the second attachment part  55  are orthogonal to the first cross frame part  34  of the frame  13 , and are attached so as to be capable of turning relative to the first cross frame part  34  (in the direction of arrow a 1 ). 
     When the handle  22  is lifted up, causing the work machine  11  to be lifted up while the handle  22  is in the use position U, force is created in the handle engaging/disengaging part  53  as shown by arrow a 2  and transmitted to the top cross frame part  32  of the work machine  11 . 
     Next, the configuration of the handle device  21  of the work machine  11  according to the first embodiment will be described based on  FIGS. 1 through 7 . 
     The handle device  21  has a structure in which a handle  22  for transportation and movement, which has a first grip part  47  and a second grip part  48  extending to the rear of the vehicle body at the distal ends, is attached in a foldable manner to the frame  13  on which a power generator or another work device  12  is carried. 
     The handle device  21  comprises the first attachment part  54  and the second attachment part  55  which are attachment parts of the handle  22  that intersect the frame  13 , a handle turning mechanism  61  for supporting the frame  13  to be capable of turning about a turning fulcrum P, and the clamp mechanism  62  for detachably fixing the handle engaging/disengaging part  53  to the frame  13 . The handle engaging/disengaging part  53  continues from the first attachment part  54  and the second attachment part  55 , continuing as extending parts  45   a ,  46   a  extending into the frame  13  (in the direction of arrow a 3  shown in  FIGS. 2 and 3 ). 
     The clamp mechanism  62  includes a clamp body  64  for engaging and disengaging the handle engaging/disengaging part  53 , as shown in  FIGS. 3 and 12 . The clamp body  64  has a fixed member  74  fixed to the frame  13 , and a turning member  66  attached to the fixed member  74  to be capable of turning in the direction of arrow a 4  shown in  FIG. 3 . P 1  shown in  FIG. 3  is the fulcrum of the turning member  66 . The turning member  66  is constantly being urged by a spring  65  to a standby state (an open standby position W) so as to be open relative to the fixed member  74 . When the turning member  66  closes against the force of the spring  65 , a actuating protuberance  67  pushed by the handle engaging/disengaging part  53  extends to the front of the work machine from the turning member  66 . A restraining mechanism  72  automatically restrains the distal end  71  of the turning member  66  with a spring force when the actuating protuberance  67  is pushed further by the handle engaging/disengaging part  53  and the turning member  66  closes (to the closed position K). 
     In the inside surface of an open end  78  of the fixed member  74 , a curved surface part  81  is formed in proximity to the handle engaging/disengaging part  53 , as shown in  FIGS. 7 and 8A  through  8 C. A curved surface part  82  in proximity to the handle engaging/disengaging part  53  is formed in the inside surface of the distal end  71  of the turning member  66 . The turning member  66  is coupled with the fixed member  74  by a coupling pin  84 . The coupling pin  84  is a fulcrum of the turning member  66  and is also a fulcrum of the clamp body  64 . 
     The restraining mechanism  72  comprises a fixed pawl  86  formed on the distal end  71  of the turning member  66 , and a movable pawl member  88  turnably (in the direction of arrow a 5 ) attached to the fixed member  74  so as to engage with the fixed pawl  86  due to the spring force of a return spring  87 . 
     The movable pawl member  88  interlocks with the fixed pawl  86  of the turning member  66 , and holds the turning member  66  in the closed position K of the clamp body  64  against the spring  65  which turns the turning member  66  in an opening direction. 
     The spring  65  used in the clamp body  64  is a helical torsion spring, and the direction of the torsion load (the direction of arrow a 6  in  FIG. 5 ) is made to coincide with the direction in which the clamp body  64  opens (the direction of arrow a 6 ). 
     Next, the clamp mechanism  62  of the first embodiment will be described. 
     The clamp mechanism  62  is composed of the previously described clamp body  64  (the fixed member  74 , the turning member  66 , the coupling pin  84 , and the spring  65 ), the actuating protuberance  67  formed on the clamp body  64 , and the restraining mechanism  72 . K is the closed position of the clamp mechanism  62 , the closed position of the clamp body  64 , and also the closed position of the turning member  66 . 
     The length of the clamp mechanism  62  is L as shown in  FIG. 2 , and this length L is approximately 2.3 times the outside diameter of both the handle  22  and the handle engaging/disengaging part  53 . The length L is also the length of the fixed member  74  ( FIG. 8B ). 
     The fixed member  74  has a base main body  105  fixed to the top cross frame part  32  of the frame  13  as shown in  FIGS. 7 and 8A . In the base main body  105 , a pressure-bearing groove  106  is formed into a shape that fits over the handle engaging/disengaging part  53 , and is also formed running along the handle engaging/disengaging part  53 . 
     In the longitudinal (widthwise) center of the pressure-bearing groove  106 , an accommodating part  107  is formed to a depth which accommodates the actuating protuberance  67 , and near the accommodating part  107  an engaging concavity  108  is formed into a shape which engages the end of the spring  65 . 
     In both dies of the pressure-bearing groove  106  in the width direction, holes  111  are formed through which fastening bolts  109  ( FIG. 5 ) are inserted. The longitudinal direction (the width direction) of the pressure-bearing groove  106  is made to coincide with the longitudinal direction (the width direction) of the handle engaging/disengaging part  53 . 
     The base main body  105  has a first base hinge part  113  formed in the side of a first divided end  112 , and a second base hinge part  115  formed in the side of a second divided end  114  (the open end  78 ). 
     The top surface of the second divided end  114  substantially coincides with a line E passing through the center of the radius r 1  of the handle engaging/disengaging part  53  as shown in  FIG. 7 . The depth of the pressure-bearing groove  106  substantially coincides with the external peripheral radius r 1  of the handle engaging/disengaging part  53 . The peripheral length of the pressure-bearing groove  106  is approximately 50% of the external peripheral length of the handle engaging/disengaging part  53 . The turning member  66  is coupled with the first base hinge part  113  by a coupling pin (including a retaining ring). 
     The turning member  66  has a pressing groove  122  formed in a turning main body  121  so as to face the pressure-bearing groove  106 , as shown in  FIGS. 7 ,  9 , and  10 B. The pressing groove  122  is formed into a curved shape along the longitudinal direction of the handle engaging/disengaging part  53  so that the handle engaging/disengaging part  53  fits therein. 
     In the longitudinal center of the turning main body  121 , a concave part  123  is formed for engaging the end of the spring  65 . A third divided end  125  and a fourth divided end (a distal end  71 ) are formed in the turning main body  121 . The third divided end  125  is formed so that a first hinge part  127  is coupled with the first base hinge part  113  by the coupling pin  84 . 
     A push surface  128  is formed as a continuation of the fourth divided end (the distal end  71 ) so as to push on the movable pawl member  88 . The fixed pawl  86  is formed as a continuation of the push surface  128 . The actuating protuberance  67  is formed as a continuation of the third divided end  125 . 
     The actuating protuberance  67  extends toward the handle engaging/disengaging part  53  in a state in which the clamp body  64  (the turning member  66 ) of the clamp mechanism  62  has been opened (the open standby position W). When the actuating protuberance  67  is pushed by the handle engaging/disengaging part  53 , the actuating protuberance  67  turns and pushes on the movable pawl member  88  via the push surface  128  provided to the fourth divided end (the distal end  71 ). 
     A movable pawl  132  of the movable pawl member  88  is formed on one end of a main body  131  as shown in  FIGS. 11A and 11C . A contact surface  133  is formed as a continuation of the movable pawl  132 . In the other end side of the main body  131 , an operating part  134  is formed so that it can be pushed by hand. 
     A second hinge part  135 , which is formed in the center of the main body  131  between the movable pawl  132  and the operating part  134 , is coupled with the second base hinge part  115  by a coupling pint  136 . A concave part  137 , which engages one end of the return spring  87 , is formed in proximity to the second hinge part  135 . The other end of the return spring  87  is in contact with the base main body  105  of the fixed member  74 . The return spring  87  is a helical torsion spring. 
     Next, the action of the handle device  21  of the work machine  11  according to the first embodiment will be described. 
     With this handle device  21 , when the handle  22  is turned from the folded position S to the use position U as shown by arrow b 1  in  FIG. 1 , the handle engaging/disengaging part (the stopper part)  53  of the handle  22  is automatically locked by the clamp mechanism  62 . 
     Specifically, when the handle  22  is folded up as shown in  FIG. 12A , the clamp mechanism  62  is opened and kept in the open standby position W by the spring  65 . To bring the handle  22  to the use state, the handle  22  turns in the direction shown by arrow b 1 . 
     The handle engaging/disengaging part  53  then comes in contact with the actuating protuberance  67  of the turning member  66  of the clamp mechanism  62 , as shown in  FIG. 12B . 
     When the handle  22  is turned further, the handle engaging/disengaging part  53  pushes on the actuating protuberance  67 , and the actuating protuberance  67  therefore begins the turn about a hinge (the first base hinge part  113  and the first hinge part  127 ) against the spring  65  as shown by arrow b 3  in  FIG. 12C . At the same time, the turning member  66  also begins to turn in the direction shown by arrow b 3 . 
     Furthermore, when the handle  22  is turned, the push surface  128  connected to the distal end  71  of the turning member  66  pushes on the contact surface  133  of the movable pawl member  88 , and the movable pawl member  88  therefore begins to turn about a hinge (the second base hinge part  115  and the second hinge part  135 ) in the direction shown by arrow b 4  against the return spring  87 , as shown by the double-dashed lines. As a result, interference between the movable pawl member  88  and the distal end  71  of the turning member  66  can be prevented. 
     When the actuating protuberance  67  is then pushed by the handle engaging/disengaging part  53  and the actuating protuberance  67  and the turning member  66  (the turning main body  121 ) turn further, the actuating protuberance  67  moves into the accommodating part  107  of the fixed member  74 . The distal end  71  of the turning member  66  then comes in contact with or draws near to the second divided end  114  (the open end  78 ) of the fixed member  74  (the base main body  105 ). 
     The turning member  66  reaches the closed position K as shown in  FIG. 7  and the push surface  128  therefore separates from the contact surface  133 . The movable pawl member  88  turns in the direction of arrow b 5  shown in  FIG. 12C , and the fixed pawl  86  of the turning member  66  engages with the movable pawl  132 . 
     Therefore the handle engaging/disengaging part  53  is automatically fixed (locked) to the frame  13  in the use position U. 
     Conversely, when the handle  22  is folded up, when the operating part  134  of the movable pawl member  88  of the clamp mechanism  62  is pushed against the return spring  87  as shown by arrow b 6  in  FIG. 7 , the movable pawl member  88  turns as shown by the double-dashed line, and the movable pawl  132  separates from the fixed pawl  86 . 
     When the handle  22  is then turned to the folded position S ( FIG. 1 ), the turning member  66  of the clamp mechanism  62  turns as shown by arrow b 7  due to the spring  65 , and opens as shown by the double-dashed lines (the open standby position W). Specifically, the turning member  66  of the clamp body  64  turns in synchronization with the movement of the handle engaging/disengaging part  53 , and is thereafter held in the open standby position W by the spring  65 . 
     Thus, since the handle device  21  according to the first embodiment comprises the clamp mechanism  62 , it is easy to fix the handle  22  in the use position U. Furthermore, since the clamp mechanism  62  is composed of the clamp body  64 , the actuating protuberance  67 , and the restraining mechanism  72 , the structure is simplified. 
     Since a long distance is integrally set from the fulcrum (the handle turning mechanism  61 ) of the handle  22  to the handle engaging/disengaging part (the stopper part)  53 , the load imposed on the handle engaging/disengaging part  53  can be lessened without compromising the simplicity of the structure. 
     Second Embodiment 
     Next, the handle device of the work machine according to a second embodiment will be described based on  FIG. 13 . Components similar to those of the first embodiment are denoted by the same symbols and are not described. 
     A handle device  21 B according to the second embodiment comprises a clamp mechanism  62 B. The clamp mechanism  62 B is composed of a clamp body  64 B (a fixed member  74 B, a turning member  66 B, and a spring  65  (FIG.  7 )), a actuating protuberance  67 B formed on the clamp body  64 B, and a restraining mechanism  72 B. 
     The clamp mechanism  62 B has a width LB that is shorter than the width L of the clamp mechanism  62  of the first embodiment. The width LB of the clamp mechanism  62 B is about 30% of the length of the clamp mechanism  62  according to the first embodiment. 
     The handle device  21 B according to the second embodiment exhibits the same actions and effects as the handle device  21  according to the first embodiment. 
     Since the handle device  21 B according to the second embodiment is shorter in width than the clamp mechanism  62  of the first embodiment, the weight of the clamp mechanism  62 B can be reduced, and the weight of the work machine  11  can be effectively reduced. 
     The handle device of the work machine according to the present invention is suitable for mobile power generators and pumps. 
     Obviously, various minor changes and modifications of the present invention are possible in light of the above teaching. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.