Patent Publication Number: US-2023149870-A1

Title: Mixer and power tool

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority to Japanese Patent Application No. 2021-186610, filed on Nov. 16, 2021, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a mixer for mixing fluid materials, such as paint and mortar, and non-fluid materials, such as sand and gravel, and to a power tool including an output shaft protruding downward from a body and to which a tip tool is connectable. 
     2. Description of the Background 
     A mixer has a spindle protruding from a body accommodating a motor, and a mixer shaft connectable to the spindle to receive rotation of the motor. A blade is attached to the mixer shaft. The mixer can mix a material such as paint with the blade rotating together with the mixer shaft. A handle is fixed to the body. An operator holds left and right grips on the handle to support the body (e.g., German Utility Application Publication No. 202010014783). 
     BRIEF SUMMARY 
     A known double-handled mixer has a handle protruding largely to the left and to the right from a body. The mixer with this structure uses much space for transportation and for storage. The same occurs to, for example, a power tool such as an earth auger including an output shaft protruding downward from a body with a handle and to which a tip tool such as an auger bit is connectable. 
     One or more aspects of the present disclosure are directed to a mixer and a power tool that are transportable and storable without using much space. 
     A first aspect of the present disclosure provides a mixer, including: 
     a body including a motor and an output shaft rotatable when driven by the motor, the output shaft extending downward and being connectable to a mixer shaft; 
     a handle attachable to the body; and 
     a lock unit located on the body, the lock unit being engageable with the handle at an attachment position of the handle to the body to lock the handle at the attachment position, the lock unit being operable to disengage from the handle to unlock the handle at the attachment position. 
     A second aspect of the present disclosure provides a mixer, including: 
     a body including a motor and an output shaft rotatable when driven by the motor, the output shaft extending downward and being connectable to a mixer shaft; 
     a handle attachable to the body; and 
     a lock unit located on the handle, the lock unit being engageable with the body at an attachment position of the handle to the body to lock the handle at the attachment position, the lock unit being operable to disengage from the body to unlock the handle at the attachment position. 
     A third aspect of the present disclosure provides a power tool, including: 
     a body including a motor and an output shaft rotatable when driven by the motor, the output shaft extending downward and being connectable to a tip tool; 
     a handle attachable to the body; and 
     a lock unit located on the body, the lock unit being engageable with the handle at an attachment position of the handle to the body to lock the handle at the attachment position, the lock unit being operable to disengage from the handle to unlock the handle at the attachment position. 
     The mixer and the power tool according to the above aspects of the present disclosure are transportable and storable without using much space. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is an overall perspective view of a mixer. 
         FIG.  2    is a perspective view of a body of the mixer. 
         FIG.  3    is a plan view of the body of the mixer. 
         FIG.  4    is a side view of the body of the mixer. 
         FIG.  5    is a cross-sectional view taken along line A-A in  FIG.  3   . 
         FIG.  6    is a diagram describing a male connector. 
         FIG.  7    is an exploded perspective view of a lock unit, with a handle removed. 
         FIG.  8 A  is an enlarged cross-sectional view taken along line B-B in  FIG.  3    with a lock pin at a protruding position. 
         FIG.  8 B  is an enlarged cross-sectional view taken along line B-B in  FIG.  3    with the lock pin at a retracted position, with the handle removed. 
         FIG.  9    is a perspective view of the body, with the handle removed. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments 
     Embodiments of the present disclosure will now be described with reference to the drawings. 
       FIG.  1    is an overall perspective view of a rechargeable mixer  1  as an example of a mixer.  FIG.  2    is a perspective view of a body.  FIG.  3    is a plan view of the body.  FIG.  4    is a side view of the body.  FIG.  5    is a cross-sectional view taken along line A-A in  FIG.  3   . 
     The mixer  1  includes a body  2  and a mixer shaft  3 . 
     The body  2  includes, as its housing, a motor housing  4  and a reducer housing  5 . The motor housing  4  accommodates a motor  6  in its rear portion and a controller  8  in its front portion. The motor  6  is supported with a rotational shaft  7  extending downward. The rotational shaft  7  has its lower end protruding in the reducer housing  5 . 
     The motor housing  4  has a battery mount  9  on its upper portion. The battery mount  9  includes a terminal base  10 . A battery pack  11  is slid on and attached to the terminal base  10  from the rear. A battery cover  12  is attached to the upper portion of the motor housing  4 . The battery cover  12  covers the battery pack  11  and the battery mount  9  from above. 
     The reducer housing  5  accommodates a reducer  15 . The reducer  15  includes a spindle  16 . The spindle  16  protrudes downward from the lower end of the reducer housing  5 . The spindle  16  has a thread  17  on its lower end. The reducer  15  reduces rotation of the rotational shaft  7  and transmits the reduced rotation to the spindle  16 . A switching lever  18  is located on a right side surface of the reducer housing  5 . The rotational speed of the spindle  16  is switchable between two levels, or specifically, high and low, in response to an operation on the switching lever  18 . 
     The mixer shaft  3  is coaxially connectable with the thread  17  on the spindle  16 . A blade  19  is attached to a lower end of the mixer shaft  3 . 
     A handle  20  is attached to the body  2 . The handle  20  includes a fixture  21 , a pair of left and right front arms  22 , a pair of left and right rear arms  23 , a left grip  24 , and a right grip  25 . 
     The fixture  21  is attached to the motor housing  4 . The fixture  21  is U-shaped as viewed in plan and surrounds left and right portions and a rear portion of the body  2  and is open at the front. The fixture  21  is a vertically thin metal sheet. 
     The front arms  22  are integral with the fixture  21 . The pair of left and right front arms  22  extend from the front end of the fixture  21  outward to the left and to the right. The rear arms  23  are integral with the fixture  21 . The pair of left and right rear arms  23  extend from a rear portion of the fixture  21  outward to the left and to the right. 
     The left grip  24  and the right grip  25  extend across the ends of the front arms  22  and the rear arms  23  in the front-rear direction. The left grip  24  and the right grip  25  have their front ends fastened to the ends of the front arms  22  with rear ends screwed and fastened to the ends of the rear arms  23 . 
     The right grip  25  accommodates a switch  26  ( FIG.  4   ). The switch  26  includes a trigger  27 . The trigger  27  protrudes from a lower surface of the right grip  25 . A lock button (not shown) is located on a left side surface of the right grip  25 . The lock button locks the trigger  27  being pressed. A lock lever  28  is located in front of the switch  26 . The lock lever  28  can slide between a position at which the trigger  27  is locked and cannot be pressed and a position at which the trigger  27  is allowed to be pressed. 
     The lock lever  28  includes an adjustment dial  29  on its front portion. The rotational speed of the motor  6  can be adjusted by rotating the adjustment dial  29 . The adjustment dial  29  is exposed on an upper surface of the right grip  25 . 
     A flange  30  is located at the outer peripheral surface of the motor housing  4 . The flange  30  supports the fixture  21  from below. Above the flange  30 , multiple guide ribs  31  are located on the left and right side surfaces of the motor housing  4 . The guide ribs  31  extend parallel to the flange  30  in the front-rear direction. The vertical distance between the flange  30  and each of the guide ribs  31  is the distance that allows the fixture  21  to be fitted and inserted from the front. The degree by which each of the guide ribs  31  protrudes to the left or to the right is smaller than the degree by which the flange  30  protrudes. 
     The fixture  21  can be inserted and removed from the rear of the body  2  between the flange  30  and each of the left and the right guide ribs  31 . When inserted between the flange  30  and the left and right guide ribs  31 , the fixture  21  is restricted from moving forward any further at the position shown in  FIG.  5    at which the rear portion of the fixture  21  is in contact with the rear surface of the body  2 . This position is the attachment position of the handle  20 . A pair of engagement holes  32  are formed in substantially the middle in the front-rear direction on the left and the right of the fixture  21 . 
     A lead wire cover  33  is screwed on an upper surface of the right rear arm  23  and an upper surface of the fixture  21 . The lead wire cover  33  contains lead wires (not shown) that are routed and connected to the switch  26  in the right grip  25  and to the board in the adjustment dial  29 . As shown in  FIG.  6   , each lead wire is connected to a terminal plate in a male connector  34  located on a right upper surface of the rear portion of the fixture  21 . The male connector  34  has two slits  35  for the switch  26  and one slit  36  for the adjustment dial  29  in the front-rear direction. The slits  35  and the slit  36  receive terminal plates (not shown). 
     As shown in  FIG.  7   , a receptacle  37  for the male connector  34  is located on the rear surface of the motor housing  4 . The male connector  34  can be inserted into the receptacle  37  when the handle  20  is at the attachment position. The receptacle  37  accommodates a female connector  38 . The female connector  38  includes two terminal plates  39  for the switch  26  and one terminal plate  40  for the adjustment dial  29  extending in the front-rear direction. The terminal plates  39  for the switch  26  are connected to the controller  8  and to the terminal base  10  with lead wires (not shown) inside the motor housing  4 . The terminal plate  40  for the adjustment dial  29  is connected to the controller  8  with a lead wire (not shown) inside the motor housing  4 . 
     The flange  30  has, on its left and right portions, blind holes  41  each with an open upper end. The blind holes  41  are immediately below the engagement holes  32  in the handle  20  at the attachment position. The blind holes  41  receive lock units  45  for the handle  20 . The lock units  45  will be described in detail below. To represent the left and right lock units  45  that are symmetrical to each other, the right lock unit  45  alone will be described. 
     As shown in  FIG.  7   , the lock unit  45  includes a lock pin  46 , a coil spring  47 , and a retainer pin  48 . 
     The lock pin  46  is a cylindrical rod. The lock pin  46  is fitted in the blind hole  41  and is movable in the vertical direction. A smaller-diameter portion  49  coaxially protrudes downward from the lock pin  46 . The lock pin  46  has, on its upper end, an engagement groove  50  extending across the diameter. The lock pin  46  has a through-hole  51  extending through the lock pin  46  across the diameter. The through-hole  51  includes a guide hole  52  and a pair of engagement holes  53 . The guide hole  52  is elongated vertically in a direction orthogonal to the engagement groove  50  as viewed in plan. The engagement holes  53  extend circumferentially from upper ends of the guide hole  52  in a manner point-symmetrical with respect to the axis of the lock pin  46 . 
     As shown in  FIG.  8 A , the coil spring  47  is located on the bottom of the blind hole  41  below the lock pin  46 . The coil spring  47  has an upper portion externally mounted on the smaller-diameter portion  49 . 
     The retainer pin  48  is inserted from the right outside into a lateral hole  42  in the flange  30  laterally at the position of the blind hole  41 . This allows the retainer pin  48  to extend orthogonally through the blind hole  41  and also through the through-hole  51  in the lock pin  46 . 
     The lock pin  46  is thus urged upward by the coil spring  47  in a direction in which the lock pin  46  protrudes. However, the lock pin  46  is restricted from protruding by the retainer pin  48  that extends through the through-hole  51  at the position at which the retainer pin  48  is in contact with the lower end of the guide hole  52  in the through-hole  51 . At this protruding position, as shown in  FIG.  8 A , the lock pin  46  has its upper portion partially protruding from the blind hole  41 . The degree by which the lock pin  46  protrudes is substantially equal to the thickness of the fixture  21 . 
     The lock pin  46  is then pushed further into the blind hole  41  to move the retainer pin  48  relatively to the upper end of the guide hole  52 . In this state, the lock pin  46  is rotated to the left as viewed in plan (to be at a first rotational position). As shown in  FIG.  8 B , the engagement holes  53  then rotate and are engaged with the retainer pin  48 . The lock pin  46  is restricted from moving at the retracted position at which the lock pin  46  is retracted in the blind hole  41 . The lock pin  46  is rotated with a tool, such as a screwdriver, that is engaged in the engagement groove  50 . 
     The lock pin  46  at the retracted position is rotated to the right as viewed in plan from the first rotational position (to be at a second rotational position). The engagement holes  53  then rotate backward and are disengaged from the retainer pin  48 . Thus, the lock pin  46  moves to the protruding position shown in  FIG.  8 A  as it is urged by the coil spring  47 . 
     When the handle  20  is locked to the mixer  1 , the lock pins  46  on the left and right lock units  45  are at their protruding positions. Each lock pin  46  at the protruding position is engaged with the engagement hole  32  in the fixture  21 . Thus, the handle  20  is restricted by the lock pins  46  from sliding backward at the attachment position. 
     The male connector  34  is inserted into the receptacle  37  and is connected with the female connector  38 . Thus, the terminal plates  39  and  40  in the female connector  38  are inserted into the slits  35  and  36  in the male connector  34  for electrical connection between the terminal plates. 
     In this state, the operator holds the left grip  24  and the right grip  25  on the handle  20 . The mixer  1  is thus supported with the mixer shaft  3  protruding downward. In this state, the operator presses the trigger  27  on the right grip  25  to turn on the switch  26 . The motor  6  is thus driven to rotate the rotational shaft  7 . The rotation of the rotational shaft  7  is reduced by the reducer  15  in either a high speed mode or a variable speed mode selected with the switching lever  18  and is transmitted to the spindle  16 . The mixer shaft  3  connected to the spindle  16  rotates to allow mixing of a material such as paint with the blade  19  rotating together with the mixer shaft  3 . 
     During the operation, the operator holding the left and right grips  24  and  25  to support the mixer  1  views, from above the motor housing  4  and the battery cover  12 , the blade  19  on the lower end of the mixer shaft  3 , the mixer shaft  3 , and the material being mixed. In this state, the fixture  21  in the handle  20  is not in front of the motor housing  4  and the battery cover  12  and thus can avoid obstructing the field of view of the operator. The operator can thus reliably view, for example, the blade  19 . 
     When removing the handle  20  after the operation, the lock pin  46  in each lock unit  45  is pushed in to retract the lock pin  46  from the engagement hole  32  into the blind hole  41 . Each lock pin  46  is then rotated to the first rotational position. Each lock pin  46  is then restricted from moving at the retracted position and is disengaged from the engagement hole  32 . As shown in  FIG.  9   , the handle  20  can be slid backward at the attachment position and removed from the body  2 . 
     When the handle  20  is removed, the male connector  34  is also removed from the receptacle  37 . This disconnects the male connector  34  from the female connector  38  to disconnect electrical connection between the terminal plates. 
     To attach the handle  20  again, the handle  20  can be slid from the rear of the body  2  forward with the lock pins  46  being each at the retracted position, and the fixture  21  is then inserted between the flange  30  and the guide ribs  31 . The handle  20  stops being slid at the attachment position at which the rear portion of the fixture  21  comes in contact with the rear surface of the body  2 . At the attachment position of the handle  20 , each lock pin  46  is rotated from above to the second rotational position. Each lock pin  46 , which is disengaged from the retainer pin  48 , moves to the protruding position under an urging force from the coil spring  47  and is engaged with the engagement hole  32  to lock the handle  20 . 
     The mixer  1  according to the present embodiment includes the body  2  including the motor  6  and the spindle  16  (an example of an output shaft) rotatable when driven by the motor  6 , protruding downward, and being connectable to the mixer shaft  3 . The mixer  1  includes the handle  20  attachable to the body  2 . The body  2  includes the lock units  45  engageable with the handle  20  at the attachment position of the handle  20  to the body  2  to lock the handle  20  at the attachment position. The lock units  45  are operable to disengage from the handle  20  to unlock the handle  20  at the attachment position. 
     In this structure, the handle  20  can be easily locked or unlocked at the attachment position by operating the lock units  45 . With the handle  20  being removed, the mixer  1  is transportable and storable without using much space. 
     The handle  20  can be slid (an example of movement) from the rear (an example of a predetermined direction) relative to the body  2  and be set at the attachment position. The lock units  45  are engageable with the handle  20  attached to the body  2  and set at the attachment position. 
     Thus, the lock units  45  in the body  2  facilitate attachment and removal of the handle  20 . The handle  20  can be simplified and be lighter. 
     The body  2  includes the flange  30  and the guide ribs  31  (each being an example of a guide) to guide the sliding of the handle  20 . The lock units  45  are located on the flange  30 . 
     The handle  20  can thus slide stably. The lock units  45  can easily be located on the flange  30 . 
     Each lock unit  45  includes the lock pin  46  (an example of a lock member) movable between the protruding position at which the lock pin  46  protrudes from the flange  30  and the retracted position at which the lock pin  46  is retracted in the flange  30 , and the coil spring  47  (an example of an urging member) that urges the lock pin  46  to the protruding position. The handle  20  has the engagement holes  32  (each being an example of an engagement portion) engageable with the lock pins  46  at the protruding positions. 
     Thus, the handle  20  is reliably locked with the lock pins  46 . 
     Each lock unit  45  further includes the retainer pin  48  (an example of a retainer member) that restricts movement of the lock pin  46  at the protruding position. Each lock pin  46  has the engagement holes  53  (each being an example of an engagement portion) engageable with the retainer pin  48  at the retracted position. Each lock pin  46  is selectively operable between the first rotational position (an example of a first orientation) at which the engagement holes  53  are engaged with the retainer pin  48  at the retracted position to restrict movement to the protruding position and the second rotational position (an example of a second orientation) at which the engagement holes  53  are disengaged from the retainer pin  48  at the retracted position to allow movement to the protruding position. 
     Thus, each lock pin  46  can be maintained at the retracted position. The handle  20  can be slid on the body  2  for attachment or removal without interfering with the lock pins  46 . The handle  20  can thus be attached and removed smoothly. 
     Each lock pin  46  is a rod. The flange  30  has the blind holes  41  to receive the lock pins  46 . Each urging member is the coil spring between the bottom of the blind hole  41  and the lock pin  46 . 
     The lock units  45  can thus be formed in a space-efficient manner. 
     The body  2  includes the controller  8  that controls the motor  6 . The handle  20  includes the switch  26  (an example of an operation member) that outputs electric signals to the controller  8  in response to an operation and the adjustment dial  29  (an example of an operation member). The body  2  and the handle  20  include the male connector  34  and the female connector  38  (each being an example of a connector) that electrically connect the controller  8  to the switch  26  and to the adjustment dial  29  through contact at the attachment position of the handle  20  and that electrically disconnect the controller  8  from the switch  26  and from the adjustment dial  29  through being out of contact in response to the handle  20  being removed. 
     Any operation members on the handle  20  can be electrically connected and disconnected when the handle  20  is attached or removed. 
     The operation members are the switch  26  that turns on or off the motor  6  and the adjustment dial  29  that changes the rotational speed of the motor  6 . 
     These operation members can be electrically connected and disconnected easily using the male connector  34  and the female connector  38 . 
     The handle  20  includes the fixture  21  attachable to the body  2 , the front and rear arms  22  and  23  (each being an example of an arm) extending from the fixture  21  outward to the left and to the right, and the left and right grips  24  and  25  (each being an example of a grip) attached to the front and rear arms  22  and  23 . 
     The body  2  can thus be supported in a balanced manner on the left and the right. 
     The fixture  21  and the front and rear arms  22  and  23  are included in an integral metal sheet. 
     The handle  20  can thus be manufactured easily. 
     The fixture  21  is U-shaped as viewed in plan and surrounds the left and right portions and the rear portion of the body  2  and is open at the front. 
     This structure allows the operator to view the blade  19  and other components reliably, without the field of view being obstructed by the fixture  21 , and thus can have improved workability. 
     The same number of lock units  45  are located on each of the left and the right of the fixture  21  (a single lock unit  45  on each side in this example). 
     The handle  20  can be locked to the body  2  in a well-balanced manner. 
     Modifications will now be described. 
     Each lock pin may be restricted from moving at the protruding position or at the retracting position with a structure other than the retainer pin and the through-hole described above. For example, each lock pin may be integral with a retainer pin that is engaged in a guide groove on the inner surface of the blind hole. A rotational operation of the lock pin may then cause the retainer pin to be engaged at a selected position in the guide groove to move to the protruding position or to the retracted position. 
     The pin integral with the lock pin may protrude outward through a slit in the flange. In this case, the pin may be moved to the protruding position or to the retracted position with an operation to cause the pin to be engaged at a selected position in the slit. 
     The lock members may not be rods such as the lock pins. The lock members may be plates that can be engaged with and disengaged from the handle. The lock member may have another shape and may be selectively at the protruding position or the retracted position with a method other than a rotational operation. For example, a lock member may be movable with a swinging operation to select from two orientations. 
     An urging member other than the coil spring may also be used. The lock member may be operable to move between the protruding position and the retracted position without the use of the urging member. 
     The number and arrangement of lock units may be changed as appropriate. 
     Multiple lock units may be located on each of the left and the right of the fixture, and a lock unit may also be located at the rear of the fixture. Lock units may be located on guide ribs, instead of being on the flange, and lock pins protruding downward may be engaged with the handle. Thus, each engagement portion may not be the engagement hole, but may be a recess. 
     The lock units may be located on the handle, instead of being located on the body. Lock members may protrude from the handle and be engaged with engagement portions located on the body. 
     The handle may be slid relative to the body from the front, instead of from the rear. The handle may have another shape and may be moved in the lateral direction for attachment. The handle may be attached in the vertical direction. 
     The guides for the handle may not be the ribs on the housing as described above. The guides may be grooves recessed in the housing. 
     The handle is not limited to the handle including the front and rear arms as described above. For example, the handle may include front arms alone on the left and the right and may include left and right grips. The fixture may not be U-shaped as viewed in plan, but may be a ring surrounding the entire periphery of the body. 
     The operation members are not limited to the switch and the adjustment dial. The connection between each operation member and the controller is not limited to the connection described above. For example, the male connector and the female connector may be located reversely from the above example. The shape of each connector and the number of terminal plates may be changed as appropriate. A separate connector may be provided for each terminal. The connectors may be eliminated from the handle that has no operation members. 
     The shape of the body, the arrangement of the motor inside, and the position of the controller may be changed as appropriate. 
     The battery mount may be located differently, rather than being located on the upper portion of the motor housing. The battery mount may be on a side surface or a rear surface of the motor housing. 
     The power supply is not limited to batteries. The motor may receive utility power (alternating current or AC) with a power cable. 
     The length of the mixer shaft, the attaching structure for the mixer shaft attached to the spindle, as well as the shape of the blade are not limited to those described above. 
     The present disclosure is not limited to the mixer. The present disclosure is also applicable to a power tool including an output shaft protruding downward from the body to which the handle is attached, and to which a tip tool such as an auger bit or a drill bit is connectable. Examples of such a power tool include an earth auger and an electric hammer. More specifically, the power tool according to one or more embodiments of the present disclosure includes the body including the motor and the output shaft rotatable when driven by the motor, protruding downward, and being connectable to a tip tool, and the handle attachable to the body. The power tool includes the lock units attached to the body. The lock units are engaged with the handle at the attachment position of the handle to the body to lock the handle at the attachment position. An operation to disengage the handle using the lock units then allows the handle to be unlocked at the attachment position. 
     The components including the body, the handle, and the lock units may have the same structures as the corresponding components of the mixer according to the above embodiments (and the modifications). 
     REFERENCE SIGNS LIST 
     
         
           1  mixer 
           2  body 
           3  mixer shaft 
           4  motor housing 
           5  reducer housing 
           6  motor 
           7  rotational shaft 
           8  controller 
           15  reducer 
           16  spindle 
           19  blade 
           20  handle 
           21  fixture 
           22  front arm 
           23  rear arm 
           24  left grip 
           25  right grip 
           26  switch 
           27  trigger 
           29  adjustment dial 
           30  flange 
           31  guide rib 
           32  engagement hole 
           33  lead wire cover 
           34  male connector 
           35 ,  36  slit 
           37  receptacle 
           38  female connector 
           39 ,  40  terminal plate 
           41  blind hole 
           45  lock unit 
           46  lock pin 
           47  coil spring 
           48  retainer pin 
           50  engagement groove 
           51  through-hole 
           52  guide hole 
           53  engagement hole