Patent Publication Number: US-2022219251-A1

Title: Handheld punch tool

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a division of co-pending U.S. patent application Ser. No. 16/054,343, filed on Aug. 3, 2018, issued as U.S. Pat. No. 11,292,067, which claims priority to U.S. Provisional Patent Application No. 62/541,165, filed on Aug. 4, 2017, the entire content of each of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to power tools, and more specifically to handheld punch tools. 
     BACKGROUND OF THE INVENTION 
     Handheld reciprocating punch tools, also known as nibblers, operate by rapidly reciprocating a punch to cut through sheet metal, such as ductwork. Although nibblers are generally efficient and accurate tools for cutting through sheet metal, typical nibblers eject numerous small fragments during a cutting operation. These fragments can be sharp and difficult to clean up. In addition, typical nibblers are powered by an AC power source or compressed air, requiring a power cord or air hose that limits access and maneuverability. Finally, typical nibblers can only begin a cut on an edge. In other words, typical nibblers are not able to begin a cut in the middle of a sheet or on a closed duct, for example. 
     SUMMARY OF THE INVENTION 
     The present invention provides, in one aspect, a handheld punch tool including a housing defining a first axis, a motor contained within the housing, the motor having a motor shaft defining a second axis, and a head coupled to the housing. The head including a drive member reciprocable along a third axis in response to rotation of the motor shaft about the second axis, and a punch coupled to the drive member and reciprocable in response to reciprocation of the drive member along the third axis. The handheld punch tool further includes a debris collection container removably coupled to the head. The debris collection container configured to receive chips generated during operation of the handheld punch tool. 
     The present invention provides, in another aspect, a handheld punch tool including a housing defining a first axis, a motor contained within the housing, the motor having a motor shaft defining a second axis, and a head coupled to the housing. The head including a drive member reciprocable along a third axis in response to rotation of the motor shaft about the second axis, and a punch coupled to the drive member and reciprocable in response to reciprocation of the drive member along the third axis. The handheld punch tool further includes a debris collection configured to be removably coupled to the head in a first position and a second position, the debris collection container configured to receive chips generated during operation of the handheld punch tool in each of the first position and the second position. 
     The present invention provides, in yet another aspect, a handheld punch tool including a housing defining a first axis, a motor contained within the housing, the motor having a motor shaft defining a second axis, and a head coupled to the housing. The head including a drive member reciprocable along a third axis in response to rotation of the motor about the second axis, and a punch coupled to the drive member and reciprocable in response to reciprocation of the drive member along the third axis. The handheld punch tool further includes a debris collection container configured to receive chips generated during operation of the handheld punch tool. The head is rotatable relative to the housing about the third axis, and the debris collection container is rotatable with the head about the third axis. 
     Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a punch tool according to an embodiment of the invention. 
         FIG. 2  is a side view illustrating a head of the punch tool of  FIG. 1 . 
         FIG. 3  is a cross-sectional view, taken along line  3 - 3  in  FIG. 1 , illustrating a drive assembly of the punch tool. 
         FIG. 4  is a cross-sectional view of the head of the punch tool of  FIG. 1 . 
         FIG. 5  is an enlarged cross-sectional view illustrating a debris collection container coupled to the head of the punch tool of  FIG. 1 . 
     
    
    
     Before any embodiments of the invention 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. 
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a handheld punch tool or nibbler  10  including a housing  14 , an electric motor  16  supported within the housing  14 , a cutting head  18  coupled to a front portion of the housing  14 , and a battery pack  22  for supplying power to the motor  16  for operating the cutting head  18 . The illustrated battery pack  22  is a rechargeable battery pack with a plurality of lithium-based cells. The battery pack  22  may have a nominal output voltage of about 12 Volts. In other embodiments, the battery pack  22  may have other nominal output voltages (e.g., about 18 Volts or more). The features and advantages of the nibbler  10  according to the present disclosure may also be applied to corded nibblers or pneumatic nibblers, however. 
     With continued reference to  FIG. 1 , the housing  14  defines a first axis or housing axis  26 , which is a longitudinal axis that extends centrally through the housing  14  along its length. The battery pack  22  is partially insertable into a battery receptacle  30  located at a rear portion of the housing  14 , opposite the cutting head  18 . In the illustrated embodiment, the battery pack  22  is insertable into the battery receptacle  30  along the first axis  26  to couple the battery pack  22  to the battery receptacle  30 . This arrangement provides the nibbler  10  with a compact, in-line arrangement that facilitates use of the nibbler  10  in tight spaces. 
     The illustrated housing  14  includes first and second cooperating clamshell halves  38   a ,  38   b  that define a handle portion  42  (i.e. a portion of the housing  14  configured to be grasped by an operator during operation of the nibbler  10 ) having a generally cylindrical shape. The housing axis  26  extends centrally through the handle portion  42 . However, the housing  14  may have a variety of other constructions such that the housing axis  26  may not extend through the handle portion  42 . For example, the housing  14  may be generally  1 ′ or ‘T’ shaped with the handle portion  42  formed as a pistol grip. In such embodiments, the housing axis  26  may not extend through the handle portion  42  but rather may extend through another portion of the housing  14  containing the motor  16 . 
     In the illustrated embodiment, an on/off switch  46  is located on the handle portion  42  for selectively electrically connecting the motor  16  and the battery pack  22  to provide DC power to the motor  16 . In some embodiments, the on/off switch  46  may be a variable speed switch. The motor  16  has a motor shaft  50  that is rotatable about a second axis or motor axis  54 . The motor  16  is preferably oriented such that the motor axis  54  is coaxial with the housing axis  26 . As such, relationships described herein with reference to the motor axis  54  are equally applicable to the housing axis  26 , and vice versa. However, it is contemplated that in other embodiments, the motor axis  54  and the housing axis  26  may not be coaxial. 
     Referring to  FIG. 3 , the nibbler  10  also includes a drive assembly  58  positioned between the motor  16  ( FIG. 1 ) and the cutting head  18  along the housing axis  26 . The drive assembly  58  is at least partially contained within a drive housing portion  60  of the housing  14 . The drive assembly  58  includes an input member or input shaft  62  that receives torque from the motor shaft  50 , an intermediate member or intermediate shaft  66  driven by the input shaft  62 , and an output member or output shaft  70  driven by the intermediate shaft  66 . The input shaft  62  and the output shaft  70  are coaxial with the motor axis  54  in the illustrated embodiment; however, in other embodiments, the input shaft  62  and the output shaft  70  may be parallel to the motor axis  54 . The intermediate shaft  66  extends transverse to the motor axis  54 . 
     The input shaft  62  may be coupled to the motor shaft  50  via a transmission (e.g., a single or multi-stage planetary transmission; not shown) or gear reduction, or the input shaft  62  may be directly driven by the motor shaft  50 . Alternatively, the input shaft  62  and the motor shaft  50  may be integrally formed together as a single component. The input shaft  62  includes an input pinion  74  meshed with an intermediate ring gear  78  that is supported on the intermediate shaft  66 . The output shaft  70  includes an output pinion  82  meshed with the intermediate ring gear  78 . The intermediate ring gear  78  is thus disposed between the input pinion  74  and the output pinion  82  to transmit torque from the input pinion  74  to the output pinion  82 . 
     With continued reference to  FIG. 3 , the illustrated drive assembly  58  further includes an eccentric  86  for providing a reciprocating input to the cutting head  18 . The eccentric  86  includes a yoke  90  pivotally coupled to the output shaft  70  by an eccentric pin  94 . The opposite end of the yoke  90  is pivotally coupled to a drive member or drive rod  98  of the cutting head  18 . Rotation of the output shaft  70  thus causes reciprocation of the drive rod  98  along a third axis  102 . In the illustrated embodiment, the third axis  102  is transverse to the first and second axes  26 ,  54 ; however, the orientation of the third axis  102  may vary in other embodiments. A counterweight  104  is fixed to the output shaft  70  to balance radial forces on the output shaft  70  generated by the reciprocating drive rod  98 . The counterweight  104  thus reduces vibration in the drive assembly  58 . 
     With reference to  FIGS. 2 and 3 , the cutting head  18  is coupled to the housing  14  by a swivel joint  106  to permit adjustment of the orientation of the cutting head  18  relative to the housing  14  about the third (swivel) axis  102 , thereby making the cutting head  18  omnidirectional. In other words, the orientation of the cutting head  18  may be adjusted, while maintaining the position of the housing  14 , to change the cutting direction of the cutting head  18 . The perpendicular orientation of the swivel axis  102  relative to the housing axis  26  and the omnidirectional cutting head  18  advantageously allow the nibbler  10  to make more precise cuts in smaller spaces compared to typical nibblers. In addition, the nibbler  10  advantageously allows an operator to make cuts in spaces with limited access. 
     Referring to  FIG. 4 , the cutting head  18  includes a main body  108  that houses a clamp assembly  110 . The clamp assembly  110  is coupled to the drive rod  98  opposite the eccentric  86 . In the illustrated embodiment, the clamp assembly  110  is coupled to the drive rod  98  via a C-shaped clip  114 , which is seated in a groove  118  proximate a distal end of the drive rod  98 . The engagement between the C-shaped clip  114  and the groove  118  axially secures the clamp assembly  110  to the drive rod  98  while permitting the clamp assembly  110  to rotate about the drive rod  98  when the cutting head  18  is rotated relative to the housing  14  about the swivel joint  106 . In the illustrated embodiment, a first set screw  122  bears against the C-shaped clip  114  to maintain the clip  114  in the groove  118 . In other embodiments, the clamp assembly  110  may be coupled for reciprocation with the drive rod  98  in other ways that permit rotation of the clamp assembly  110  about the drive rod  98 . 
     With continued reference to  FIG. 4 , the clamp assembly  110  includes a clamping recess  126  that receives a punch  130 . A second set screw  134  secures the punch  130  within the recess  126  to removably couple the punch  130  to the clamp assembly  110 . The punch  130  can thus be conveniently removed and replaced when worn, or to substitute the punch  130  for a punch having a different size or geometry. The cutting head  18  also includes a die  138  removably coupled to the main body  108  by a third set screw  142 . Thus, the die  138 , like the punch  130 , can be conveniently removed and replaced when worn, or to substitute the die  138  for a die having a different size or geometry. The die  138  defines a passageway  146  through which the punch  130  reciprocates in response to reciprocation of the drive rod  98  and clamp assembly  110 . The punch  130  is reciprocable along a fourth axis or punch axis  150  which, in the illustrated embodiment, is parallel to the third axis  102 . Thus, the position of the punch axis  150  relative to the housing  14  can be adjusted by rotating the cutting head  18  about the swivel joint  106 . 
     In some embodiments, the entirety of the clamp assembly  110  may not reciprocate with the drive rod  98 . For example, the clamp assembly  110  may include a motion transfer mechanism that reciprocates the punch  130  in response to reciprocation of the drive rod  98 . The motion transfer mechanism may include, for example, a first rack gear coupled to the drive rod  98 , a second rack gear coupled to the punch  130 , and a pinion meshed with the first rack gear and the second rack gear. In such embodiments, reciprocation of the first rack gear rotates the pinion, which in turn reciprocates the second rack gear (and the punch  130 ). In other embodiments, the drive rod  98  may not reciprocate but rather provide a rotational input to the cutting head  18 . In such embodiments, the drive rod  98  may be driven by the output shaft  70  for rotation about the axis  102 , and a reciprocation mechanism (e.g., a wobble-plate mechanism) may provided between the drive rod  98  and the punch  130 . 
     With reference to  FIGS. 4 and 5 , the illustrated die  138  includes a first opening  154  in communication with the passageway  146  and a second opening  158  in communication with the passageway  146 . Debris or chips generated during operation of the nibbler  10  can thus be ejected through either or both the first opening  154  or the second opening  158 . The first and second openings  154 ,  158  are located on opposite sides of the die  138  in the illustrated embodiment. In other embodiments, the relative positions of the first and second openings  154 ,  158  may vary, one of the openings (e.g., the second opening  158 ) may be omitted, or more than two openings may be provided. 
     The nibbler  10  includes a debris collection container  162  that can be coupled to the cutting head  18  in a first position in which the debris collection container  162  receives chips ejected through the first opening  154  ( FIG. 5 ). A removable plug  166  can be positioned in the second opening  158  to direct chips only through the first opening  154  and into the container  162 . In some embodiments, the debris collection container  162  may also be coupled to the cutting head  18  in a second position (not shown) in which the debris collection container  162  receives chips ejected through the second opening  158 . The plug  166  can then be positioned in the first opening  154  to direct chips only through the second opening  158 . When the container  162  is coupled to the die  138  in either the first position or the second position, the container  162  swivels with the cutting head  18  about the third axis  102 . In some embodiments, the container  162  can be coupled to the housing  14  rather than the cutting head  18 . In some embodiments, the container  162  may include one or more magnets to attract chips into the container  162 . 
     With reference to  FIG. 3 , in the illustrated embodiment, the nibbler  10  includes an auxiliary cutting mechanism  170  for cutting holes in sheet metal (e.g., an enclosed duct) or other workpieces through which the punch  130  may then be inserted. The auxiliary cutting mechanism  170  is driven by the motor  16  via the intermediate shaft  66 , and the auxiliary cutting mechanism  170  is operable either in tandem with or independently from the cutting head  18 . In the illustrated embodiment, the auxiliary cutting mechanism  170  extends from the handle portion  42  of the housing (between the head  18  and the battery receptacle  30 ;  FIG. 1 ) and along an auxiliary cutting axis  174  that is transverse to the second axis  54  ( FIG. 3 ). In other embodiments, the auxiliary cutting mechanism  170  may be located elsewhere on the nibbler  10 . For example, the auxiliary cutting mechanism  170  may be located on the cutting head  18  (e.g., on a side opposite the punch  130  and die  138 ) or in front of the cutting head  18 . In some embodiments, the auxiliary cutting mechanism  170  may extend from a rear portion of the housing  14  behind the motor  16 . In such embodiments, the auxiliary cutting axis  174  may be coaxial with the motor axis  54  or perpendicular to the motor axis  54 . In addition, the auxiliary cutting mechanism  170  may be positioned such that the auxiliary cutting axis  174  does not intersect the motor axis  54 . 
     The auxiliary cutting mechanism  170  includes an integral or replaceable bit  178  (e.g., a stepped drill bit) having a nominal diameter larger than that of the punch  130  to create a pilot hole for the punch  130 , which can then be used to create an elongated cut in the sheet metal or other workpiece. In some embodiments, a clutch mechanism (not shown) may be provided between the intermediate ring gear  78  and the intermediate shaft  66  to selectively couple the intermediate shaft  66  for co-rotation with the intermediate ring gear  78 . The clutch mechanism can thus be actuated to enable or disable rotation of the auxiliary cutting mechanism  170 . 
     In operation of the nibbler  10  in a first mode, an operator depresses the switch  46  to activate the motor  16 , which continuously supplies torque to the drive assembly  58  via the motor shaft  50  and the input shaft  62  ( FIGS. 1 and 3 ). The input pinion  74  drives the intermediate ring gear  78  for rotation about the auxiliary cutting axis  174 , which in turn drives the output pinion  82  for rotation about the second axis  54  ( FIG. 3 ). In embodiments with a clutch mechanism, the clutch mechanism is disabled in the first mode, such that rotation of the intermediate ring gear  78  is not transmitted to the intermediate shaft  66 . 
     As the output shaft  70  rotates, the drive rod  98  of the cutting head  18  reciprocates along the third axis  102  due to the motion of the eccentric  86 . The drive rod  98  reciprocates the clamp assembly  110 , which in turn reciprocates the punch  130  along the punch axis  150 . The operator may then guide the cutting head  18  onto a piece of sheet metal or another workpiece to be cut. As the workpiece enters a space  180  in the die  138 , the reciprocating punch  130  repeatedly and incrementally shears small pieces of the workpiece against the die  138  to create an elongated cut. This generates debris or chips, which are discharged through the first opening  154  and into the debris collection container  162 . By containing the chips within the collection container  162 , the nibbler  10  can advantageously make cuts with less cleanup required compared to typical nibblers. If desired, the operator can rotate the cutting head  18  about the swivel axis  102  to reorient the cutting head  18 . This enhances the usability of the nibbler  10  in confined spaces. 
     The nibbler  10  is also operable in a second mode in which the motor  16  drives the auxiliary cutting mechanism  170 . In the second mode, the operator depresses the switch  46  to activate the motor  16 , which continuously supplies torque to the drive assembly  58  via the motor shaft  50  and the input shaft  62  ( FIGS. 1 and 3 ). The input pinion  74  drives the intermediate gear  78  for rotation about the auxiliary cutting axis  174 . In embodiments with a clutch mechanism, the clutch mechanism is enabled in the second mode, such that rotation of the intermediate ring gear  78  is transmitted to the intermediate shaft  66 . The bit  178  of the auxiliary cutting mechanism  170  co-rotates with the intermediate shaft  66 . The user can then engage the rotating bit  178  with a workpiece to create a pilot hole in the workpiece. The user may then insert the cutting head  18  into the hole and operate the nibbler  10  in the first mode, as described above, to create an elongated cut from the position of the pilot hole. 
     Various features of the invention are set forth in the following claims.