Abstract:
An angle impact tool includes a handle assembly extending along a first axis, a prime mover in the handle, an output shaft rotatable about the first axis, and a work attachment connected to the handle assembly. An output drive is supported in the work attachment for rotation about an output axis perpendicular to the first axis. A gear assembly including a spur gear is positioned within the work attachment to transfer torque from the prime mover about the first axis to the output drive about the output axis. An impact mechanism is positioned within the work attachment and includes a hammer and an anvil. The hammer rotates under the influence of the prime mover and is operable to periodically deliver an impact load to the anvil. The output drive rotates about the output axis under the influence of the impact load being transmitted to the output drive by the anvil.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 13/033,241, filed Feb. 23, 2011 (entitled “Right Angle Impact Tool”), the entire disclosure of which is incorporated by reference herein. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to angle impact tools. 
       SUMMARY 
       [0003]    In one embodiment, the present disclosure relates to an angle impact tool including a handle assembly extending along a first axis and graspable by a user. A prime mover is positioned in the handle and includes an output shaft rotatable about the first axis. A work attachment is connected to the handle assembly. An output drive is supported in the work attachment for rotation about an output axis perpendicular to the first axis. A gear assembly is positioned within the work attachment. The gear assembly includes at least one spur gear and is operable to transfer torque from the prime mover about the first axis to the output drive about the output axis. An impact mechanism is positioned within the work attachment. The impact mechanism includes a hammer and an anvil. The hammer rotates under the influence of the prime mover and is operable to periodically deliver an impact load to the anvil. The output drive rotates about the output axis under the influence of the impact load being transmitted to the output drive by the anvil. 
         [0004]    In another embodiment, the present disclosure relates to an angle impact tool including a handle assembly graspable by a user, and a prime mover at least partially contained within the handle assembly. The prime mover has a rotor rotatable about a first axis. An output drive is functionally coupled to the prime mover and selectively rotated in response to rotation of the rotor. The output drive defines an output axis about which the output drive rotates. The output axis is substantially perpendicular to the first axis. At least one bevel gear is functionally positioned between the rotor and the output drive. The at least one bevel gear is rotatable in response to rotation of the rotor. At least one spur gear is functionally positioned between the rotor and the output drive. The at least one spur gear is rotatable in response to rotation of the rotor. An impact mechanism is functionally positioned between the prime mover and the output drive. The impact mechanism selectively drives the output drive with impact forces in response to rotation of the rotor. 
         [0005]    In yet another embodiment, the present disclosure relates to an angle impact tool including a handle assembly extending generally along a first axis and graspable by a user, a prime mover having an output shaft rotatable about the first axis, and an output drive functionally coupled to the prime mover and selectively rotated in response to rotation of the output shaft. The output drive defines an output axis about which the output drive rotates. The output axis is substantially perpendicular to the first axis. A first spur gear is functionally positioned between the prime mover and the impact mechanism. The first spur gear is rotatable in response to rotation of the output shaft. A second spur gear meshes with the first spur gear for rotation in response to rotation of the first spur gear. A third spur gear meshes with the second spur gear for rotation in response to rotation of the first and second spur gears. A first bevel gear is connected to the output shaft for rotation with the output shaft about the first axis. A second bevel gear is functionally positioned between the first bevel gear and the first spur gear, such that rotation of the first bevel gear about the first axis causes rotation of the second bevel gear to rotate about a second axis and the first spur gear to rotate about a third axis. The second axis and the third axis are substantially perpendicular to the first axis. An impact mechanism is functionally positioned between the prime mover and the output drive. The impact mechanism selectively drives the output drive in response to rotation of the output shaft. The impact mechanism includes a hammer functionally coupled to the output shaft for rotation with the output shaft, and an anvil functionally coupled to the output drive. The hammer is operable to impact the anvil to drive the output drive with impact forces in response to rotation of the output shaft. 
         [0006]    Other aspects of the present disclosure will become apparent by consideration of the detailed description and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a perspective view of an angle impact tool. 
           [0008]      FIG. 2  is an exploded view of the tool of  FIG. 1 . 
           [0009]      FIG. 3  is an exploded view of an angle head of the tool of  FIG. 1 . 
           [0010]      FIG. 4  is a cross-sectional view taken along line  4 - 4  of  FIG. 1 . 
           [0011]      FIGS. 5A-5J  illustrate an impact cycle of the impact tool of  FIGS. 1-4 . 
           [0012]      FIG. 6  is an exploded view of another alternate embodiment of an angle head of an impact tool. 
           [0013]      FIG. 7  is a cross-sectional view taken along line  7 - 7  of  FIG. 6 . 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Before any of the embodiments of the present disclosure are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
         [0015]      FIGS. 1 and 2  illustrate an angle impact tool  10  that includes a handle or motor assembly  12  and a work attachment  14 . The illustrated motor assembly  12  includes a motor  16 , a motor housing  18 , a motor bracket  20 , a first grip portion  22 , a second grip portion  24 , a trigger lever  26 , and a lock ring  28 . The lock ring  28  and a plurality of fasteners  30  retain the first and second grip portions  22  and  24  together. The motor housing  18  is coupled to the first and second grip portions  22  and  24  by a plurality of fasteners  32  and a U-shaped part  34 . A switch  36  is included in the motor assembly  12  between the first and second grip portions  22  and  24 . The switch  36  is coupled (mechanically and/or electrically) to the trigger lever  26 , such that actuation of the trigger lever  26  causes actuation of the switch  36  and, therefore, operation of the motor  16 . 
         [0016]    The motor bracket  20  is coupled to the motor  16  by a plurality of fasteners  38 . The motor  16  includes an output shaft, such as the illustrated rotor  40 , that is rotatable about a longitudinal handle axis  42 . The illustrated motor  16  is an electric motor, but any suitable prime mover, such as the pneumatic motor disclosed in U.S. Pat. No. 7,886,840, which is herein incorporated by reference, can be utilized. Although not specifically illustrated, a battery and a directional reverse switch are provided on the angle impact tool  10 . 
         [0017]    The illustrated work attachment  14  includes an angle housing  46  and an angle housing plate  48 . A plurality of fasteners  50  couple the angle housing plate  48  to the angle housing  46 . The motor housing  18  is coupled to the angle housing  46  with a plurality of fasteners  52 . The motor bracket  20  is coupled to the angle housing  46  by a plurality of fasteners  54 . 
         [0018]    The illustrated work attachment  14  houses a gear assembly  58  and an impact mechanism  60 . The gear assembly  58  includes a first bevel gear  62  coupled to the rotor  40  for rotation with the rotor  40  about the longitudinal handle axis  42 . A first bearing  64  is positioned between the first bevel gear  62  and the motor bracket  20 . The illustrated gear assembly  58  includes a second bevel gear  66  that meshingly engages the first bevel gear  62 . The second bevel gear  66  is coupled to a shaft  68  for rotation with the shaft  68 . The shaft  68  is supported in the work attachment  14  by bearings  70   a  and  70   b.  The shaft  68  includes a splined portion  72  near bearing  70   b.  The shaft  68  rotates about an axis  74  ( FIG. 4 ). The splined portion  72  functions as a spur gear and, in some embodiments, can be replaced with a spur gear. 
         [0019]    The splined portion  72  engages a gear, such as a first spur gear  76 , such that rotation of the splined portion  72  causes rotation of the first spur gear  76  about an axis  78  (FIG.  4 ). The first spur gear  76  is coupled to a second shaft  80  for rotation with the second shaft  80  ( FIG. 4 ) about the axis  78 . The second shaft  80  is supported for rotation with respect to the work attachment  14  by bearings  82   a,    82   b.    
         [0020]    The first spur gear  76  meshes with a second spur gear  84  to cause rotation of the second spur gear  84  about an axis  86  ( FIG. 4 ). The second spur gear  84  is coupled to a square drive  88  through the impact mechanism  60  for selectively rotating the square drive  88 . The second spur gear  84  and the square drive  88  are supported for rotation within the angle housing  46  by bearings  90   a,    90   b,    90   c  ( FIG. 4 ). The axes  74 ,  78 , and  86  are all substantially parallel to each other and are thus each substantially perpendicular to axis  42 . 
         [0021]    The square drive  88  is connectable to a socket or other fastener-driving output element. In some constructions, the work attachment  14  can be substantially any tool adapted to be driven by a rotating output shaft of the motor  16 , including but not limited to an impact wrench, gear reducer, and the like. 
         [0022]    With reference to  FIGS. 2-4 , the impact mechanism  60  can be a standard impact mechanism, such as a Potts mechanism or a Maurer mechanism. The illustrated impact mechanism  60  includes a cam shaft  94  coupled to the second spur gear  84  for rotation with the second spur gear  84  about the second axis  86 . The illustrated cam shaft  94  includes opposite cam grooves  96   a,    96   b  that define pathways for respective balls  98   a,    98   b.  The illustrated impact mechanism  60  further includes a hammer  100  that includes opposite cam grooves  102   a,    102   b  that are substantially mirror-images of cam grooves  96   a,    96   b.  The balls  98   a,    98   b  are retained between the respective cam grooves  96   a,    96   b,    102   a,    102   b.  The hammer  100  also includes first and second opposite jaws  104   a,    104   b.    
         [0023]    The first bevel gear  62  actuates the gear assembly  58  and the impact mechanism  60  to functionally drive an output, such as the square drive  88 , as shown in the illustrated embodiment. The square drive  88  is rotated about the axis  86  which is non-parallel to the axis  42 . In the illustrated embodiment, the axis  86  is perpendicular to the axis  42 . In other embodiments (not shown), the axis  86  is at an acute or obtuse non-parallel angle to the axis  42 . 
         [0024]    A biasing member, such as an axial compression spring  106  is positioned between the second spur gear  84  and the hammer  100  to bias the hammer  100  away from the second spur gear  84 . In the illustrated embodiment, the spring  106  rotates with the second spur gear  84  and the bearing  90   c  permits the hammer  100  to rotate with respect to the spring  106 . Other configurations are possible, and the illustrated configuration is given by way of example only. 
         [0025]    The illustrated square drive  88  is formed as a single unitary, monolithic piece with first and second jaws  108   a,    108   b  to create an anvil  110 . The anvil  110  is supported for rotation within the angle housing  46  by the bearing  90   a.  The jaws  104   a,    104   b  impact respective jaws  108   a,    108   b  to functionally drive the square drive  88  in response to rotation of the second spur gear  84 . The term “functionally drive” is herein defined as a relationship in which the jaws  104   a,    104   b  rotate to impact the respective jaws  108   a,    108   b  and, thereby, cause intermittent rotation of the square drive  88 , in response to the impact of jaws  104   a,    104   b  on the respective jaws  108   a,    108   b.  The jaws  104   a,    104   b  intermittently impact the jaws  108   a,    108   b,  and therefore the jaws  104   a,    104   b  functionally drive rotation of the square drive  88 . Further, any element that directly or indirectly drives rotation of the hammer to impact the anvil may be said to “functionally drive” any element that is rotated by the anvil as a result of such impact. 
         [0026]    The impact cycle is repeated twice every rotation and is illustrated in  FIGS. 5A-5J  in which the jaws  104   a,    104   b  impact the jaws  108   a,    108   b.  The spring  106  permits the hammer  100  to rebound after impact, and balls  98   a,    98   b  guide the hammer  100  to ride up around the cam shaft  94 , such that jaws  104   a,    104   b  are spaced axially from jaws  108   a,    108   b.  The jaws  104   a ,  104   b  are permitted to rotate past the jaws  108   a,    108   b  after the rebound.  FIGS. 5A-5J  illustrate an impact cycle of the impact tool of  FIGS. 1-4 . Two such impact cycles occur per rotation of the hammer  100 . 
         [0027]    A head height dimension  114  of the work attachment  14  is illustrated in  FIG. 4 . The head height dimension  114  is the axial distance from the top of the angle housing plate  48  to the bottom of the angle housing  46 . The head height dimension  114  is reduced so that the work attachment  14  can fit into small spaces. The motor housing  18  defines a motor housing height dimension  118 , as shown in  FIG. 4 . The head height dimension  114  is smaller than or substantially equal to the motor housing height dimension  118 . Such a configuration permits insertion of the tool  10  into smaller spaces than has previously been achievable without compromising torque. In one embodiment, the head height dimension  114  is less than two inches, and the angle impact tool 10 has a maximum torque of about 180 foot-pounds and a rate of rotation of about 7,100 rotations-per-minute. 
         [0028]      FIGS. 6 and 7  illustrate an alternate embodiment of an angle head work attachment  214  for an angle impact tool. The angle head work attachment  214  is coupled to a handle and motor  216  having a rotor  240 . The motor  216  is supported by a motor housing  218 . The illustrated motor  216  is an electric motor, but any suitable prime mover, such as the pneumatic motor disclosed in U.S. Pat. No. 7,886,840, which is herein incorporated by reference, can be utilized. Although not specifically illustrated, a battery and a directional reverse switch are provided on the angle impact tool. 
         [0029]    The angle head work attachment  214  includes an angle housing  246  and an angle housing plate  248  that support a gear assembly  258  and an impact mechanism  260 . The rotor  240  rotates about a longitudinal handle axis  242 . A first bevel gear  262  is coupled to the rotor  240  for rotation with the rotor  240  about the longitudinal handle axis  242 . A first bearing  264  is positioned between the first bevel gear  262  and the motor housing  218 . The illustrated gear assembly  258  includes a second bevel gear  266  that meshingly engages the first bevel gear  262 . The second bevel gear  266  is coupled to a shaft  268  for rotation with the shaft  268 . The shaft  268  is supported in the work attachment  214  by bearings  270   a  and  270   b.  The shaft  268  includes a splined portion  272  near bearing  270   b.  The shaft  268  rotates about an axis  274 . The splined portion  272  functions as a spur gear and, in some embodiments, can be replaced with a spur gear. 
         [0030]    The splined portion  272  engages a gear, such as a first spur gear  276 , such that rotation of the splined portion  272  causes rotation of the first spur gear  276  about an axis  278 . The first spur gear  276  is coupled to a second shaft  280  for rotation with the second shaft  280  about the axis  278 . The second shaft  280  is supported for rotation with respect to the work attachment  214  by bearings  282   a,    282   b.    
         [0031]    The first spur gear  276  meshes with a second spur gear  284  to cause rotation of the second spur gear  284  about an axis  286 . The second spur gear  284  is coupled to a square drive  288  through the impact mechanism  260  for selectively rotating the square drive  288 . The second spur gear  284  and the square drive  288  are supported for rotation with respect to the work attachment  214  by bushing  290   a  and bearings  290   b,    290   c.  The axes  274 ,  278  and  286  are all substantially parallel to each other and are thus each substantially perpendicular to axis  242 . 
         [0032]    The square drive  288  is connectable to a socket or other fastener-driving output element. In some constructions, the work attachment  214  can be substantially any tool adapted to be driven by a rotating output shaft of the motor  216 , including but not limited to an impact wrench, gear reducer, and the like. 
         [0033]    The impact mechanism  260  can be a standard impact mechanism, such as a Potts mechanism or a Maurer mechanism. The illustrated impact mechanism  260  includes a cam shaft  294  coupled to the second spur gear  284  for rotation with the second spur gear  284  about the second axis  286 . The illustrated cam shaft  294  includes opposite cam grooves  296   a,    296   b  that define pathways for respective balls  298   a,    298   b.  The illustrated impact mechanism  260  further includes a hammer  300  that includes opposite cam grooves  302   a,    302   b  that are substantially mirror-images of cam grooves  296   a,    296   b.  The balls  298   a,    298   b  are retained between the respective cam grooves  296   a,    296   b,    302   a,    302   b.  The hammer  300  also includes first and second opposite jaws  304   a,    304   b.    
         [0034]    The first bevel gear  262  actuates the gear assembly  258  and the impact mechanism  260  to functionally drive an output, such as the square drive  288 , as shown in the illustrated embodiment. The square drive  288  is rotated about the axis  286  which is non-parallel to the axis  242 . In the illustrated embodiment, the axis  286  is perpendicular to the axis  242 . In other embodiments (not shown), the axis  286  is at an acute or obtuse non-parallel angle to the axis  242 . 
         [0035]    A biasing member, such as an axial compression spring  306  is positioned between the second spur gear  284  and the hammer  300  to bias the hammer  300  away from the second spur gear  284 . In the illustrated embodiment, the spring  306  rotates with the hammer  100  and the bearing  290   c  permits the second spur gear  284  to rotate with respect to the spring  106 . Other configurations are possible, and the illustrated configuration is given by way of example only. 
         [0036]    The illustrated square drive  288  is formed as a single unitary, monolithic piece with first and second jaws  308   a,    308   b  to create an anvil  310 . The anvil  310  is supported for rotation within the work attachment  214  by the bushing  290   a.  The jaws  304   a,    304   b  impact respective jaws  308   a,    308   b  to functionally drive the square drive  288  in response to rotation of the second spur gear  284 . The impact cycle is repeated twice every rotation and is similar to the impact cycled illustrated in  FIGS. 5A-5J . During the impact cycle, the jaws  304   a,    304   b  impact the jaws  308   a,    308   b.  The spring  306  permits the hammer  300  to rebound after impact and balls  298   a,    298   b  guide the hammer  300  to ride up around the cam shaft  294 , such that jaws  304   a,    304   b  are spaced axially from jaws  308   a,    308   b.  The jaws  304   a,    304   b  are permitted to rotate past the jaws  308   a,    308   b  after the rebound. 
         [0037]    A head height dimension  314  of the work attachment  214  is illustrated in  FIG. 7 . The head height dimension  314  is the axial distance from the top of the angle housing  246  to the bottom of the angle housing  246 . The head height dimension  314  is reduced so that the work attachment  214  can fit into small spaces. The motor housing  218  defines a motor housing height dimension  318 , as shown in  FIG. 7 . The head height dimension  314  is smaller than or substantially equal to the motor housing height dimension  318 . Such a configuration permits insertion of the tool and the work attachment  214  into smaller spaces than has previously been achievable without compromising torque.