Abstract:
A reciprocating saw includes a carrier operable to cooperate with a motor to translate rotational movement of the motor into reciprocal linear actuation of a saw blade. A carrier is slidably disposed within the housing and includes a first portion adapted to receive a saw blade and a second portion having a slot therethrough. A rotatable element is fixed for rotation about an output shaft of the motor. A follower operably interconnects the carrier and the rotatable element wherein rotation of the rotatable element provides reciprocal linear motion of the carrier whereby the follower follows a reciprocal linear path within the slot.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This is a continuation of an application filed Jan. 2, 2002 and assigned U.S. Ser. No. 10/162,535. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to reciprocating saws and more particularly to a reciprocating saw arrangement operable to translate rotational movement of a power source into reciprocal linear actuation of a saw blade. 
       BACKGROUND OF THE INVENTION 
       [0003]    Craftsman and builders have used reciprocating saws and jigsaws throughout the industry to perform various cutting operations. A conventional reciprocating saw or jigsaw generally consists of a housing having a motor, a drive mechanism for translating rotational motion of the motor into linear actuation of a carrier or drive shaft, and a saw blade releasably coupled to the drive shaft. Such conventional arrangements however present a few drawbacks which decrease usability and longevity of the tool. For example, during a cutting operation, woodchips or debris from the workpiece tend to collect around the clamping mechanism holding the saw to the tool. Furthermore, in some instances debris can be ingested into the drive mechanism of the saw. It would be desirable to provide a saw that created a positive pressure at the blade, clamping mechanism interface to inhibit debris from collecting in the area or travelling into the drive mechanism. 
         [0004]    In addition, conventional reciprocating saws generally include a handle extending at a 180 degree angle while jigsaws have a handle extending at 90 degrees. It would be an advantage to provide a handle greater than 90 and less than 180 degrees to allow for a comfortable grip of the tool for use in both jigsaw and reciprocating saw applications. 
         [0005]    Furthermore while conventional drive mechanisms associated with reciprocating saws are satisfactory for their intended purpose, a need exists to provide simpler, more durable alternatives that provide the desired function while advancing the art. 
       SUMMARY OF THE INVENTION 
       [0006]    It is a general object of the present invention to provide a reciprocating saw including a carrier operable to cooperate with a power source to translate rotational movement of the power source into reciprocal linear actuation of a saw blade. 
         [0007]    In one form, the present invention provides a reciprocating saw having a housing containing a motor. A carrier is slidably disposed within the housing and includes a first portion adapted to receive a saw blade and a second portion having a slot therethrough. A rotatable element is fixed for rotation about an output shaft of the motor. A follower operably interconnects the carrier and the rotatable element. Rotation of the rotatable element provides reciprocal linear motion of the carrier. The follower follows a reciprocal linear path within the slot. 
         [0008]    In another form, the present invention provides a reciprocating saw including a housing containing a motor. The saw further includes a saw blade having a cutting edge, a mounting edge and a side surface, the side surface defining a first plane. A carrier member is included having a first portion including a base defining a second plane, the base is adapted to receive the saw blade wherein the first plane is parallel to the second plane. The carrier includes a second portion in communication with the motor. The second portion includes a slot which defines a guide path. A rotatable element is fixed for rotation about an output shaft which extends from the motor. A follower operably interconnects the carrier and the rotatable element. Rotation of the rotatable element provides reciprocal linear motion of the carrier. The follower follows a reciprocal linear path within the guide path. 
         [0009]    In yet another form, the present invention provides a reciprocating saw including a housing containing a motor. A saw blade is included having a shank portion and a cutting portion. The reciprocating saw further includes a carrier having a first portion adapted to receive a saw blade and a second portion in communication with the motor. The first portion includes a pair of lateral walls and a base extending between the walls. A clamp extends from the lateral walls. The clamp engages the saw blade at an interface edge to retain a shank portion of the saw blade within the first portion of the carrier. A cam member extends between the lateral walls. The cam member is positioned away from the base portion forming a gap to receive the blade. The cam member is adjacent a portion of the blade between the interface edge and the cutting portion. 
         [0010]    In another form, the present invention provides a reciprocating saw including a housing and a motor. A carrier is slidably disposed within the housing and includes a first portion adapted to receive a saw blade and a second portion adapted to communicate with a motor. A fan is disposed in a handle portion of the housing and configured to force air through the second portion of the carrier. Air flows from the second portion of the carrier to the first portion of the carrier creating a seal to prevent woodchips and debris from entering the tool. 
         [0011]    In still another form, the present invention provides a reciprocating saw including a housing and a motor. The housing includes a primary base having a planar surface for interfacing the workpiece. The primary base further includes an aperture providing a passageway for a saw blade. In addition, the primary base includes a first pair of lateral rails extending outwardly from opposite sides of the base. A secondary base is provided including a second pair of lateral rails oriented to slidably engage the first pair of lateral rails for selectively mounting to the primary base. The secondary base provides a greater planar surface area for increased stability during cutting. 
         [0012]    Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limited the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
           [0014]      FIG. 1  is a perspective view of the reciprocating saw of the present invention. 
           [0015]      FIG. 2  is a cutaway view of the reciprocating saw. 
           [0016]      FIG. 3  is a perspective view of the carrier removed from the saw. 
           [0017]      FIG. 4  is a cutaway view of the saw along line  4 - 4  of  FIG. 2 . 
           [0018]      FIG. 5A-5D  is a partial cutaway view of the carrier and drive assembly through one complete rotation of the output gear. 
           [0019]      FIG. 6  is a rear perspective view of the reciprocating saw shown with the secondary base attached. 
           [0020]      FIG. 7  is a perspective view of the reciprocating saw shown with the secondary base removed to illustrate the rails of the primary base. 
           [0021]      FIG. 8  is a perspective view of the secondary base. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0022]    The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
         [0023]    With initial reference to  FIGS. 1 and 2 , a reciprocating saw according to the teachings of the present invention is illustrated and generally identified by reference numeral  10 . Reciprocating saw  10  includes a motor  12  disposed within a housing  14 . Reciprocating saw  10  is configured to actuate saw blade  20 . Housing  14  includes a handle  94  extending at an angle greater than 90 degrees with respect to saw blade  20 . Handle  94  preferably extends at an angle between 105 and 125 degrees to allow for a comfortable grip for use in jigsaw and reciprocating saw applications. 
         [0024]    With continued reference to  FIG. 2 , and additional reference to  FIGS. 3 and 4 , the blade retaining mechanism  46  will be described in greater detail. A carrier or shaft  16  actuates a saw blade  20 . The carrier  16  is disposed within the housing  14 . The carrier  16  has a first portion  24  which receives the saw blade  20 , and a second portion  26  which is driven by drive assembly  30 . First portion  24  of carrier  16  incorporates the blade retaining mechanism  46 . The blade retaining mechanism  46  includes cam system  28  and base  42  as described in copending application “Saw Blade Clamp System” which is hereby incorporated by reference. The cam system  28  includes a rocker arm  32  having a lever end  34 , an intermediate pivot portion  36  and a clamp end  38 . The intermediate pivot portion  36  is adapted to receive a support shaft  40 . The rocker arm  32  rotates about the support shaft  40 . The lever end  34  is activated by a push button  108  mounted on the housing  14 . 
         [0025]    Rocker arm  32  is biased in a clockwise direction (arrow C) such that the clamp end  38  is influenced against the saw blade  20 . Spring  44  includes spring ends  48  fixedly attached to a first and second side wall  56 ,  58  of base  42 . An intermediate loop  50  of the spring  44  is adapted to communicate with an upper surface  54  of the rocker arm  32  to provide a biasing force. 
         [0026]    First and second side walls  56 ,  58  extend perpendicularly from floor  60  of base  42  to define channel  62 . Side walls  56 ,  58  are supported on opposite sides by ball bearings  64 ,  66  disposed on guide platform  164  in housing  14  for slidable movement. Ball bearings  64 ,  66  are preferably positioned at a location proximate to the rocker arm  32  and blade  20  interface point to reduce torquing on the carrier  16  and blade  20  during operation. The outside cross-section of the carrier  16  is substantially the same along the length of where the blade  20  is retained. This allows ball bearings  64 ,  66  to roll smoothly along surfaces  56  and  58 . Concurrently, ball bearings  64 ,  66  maintain a proximate relation to the cutting bias forces created during cutting which minimizes bearing load. Guide flanges  84 ,  86  retain bearings  64 ,  66  and allow the bearings  64 ,  66  to be closer to the cutting bias force. 
         [0027]    The first and second side walls  56 ,  58  include first and second spring mounting passages  70 ,  72 . The passages  70 ,  72  fixedly secure the spring ends  48 . Similarly, support shaft  40  is retained through apertures  74 ,  76  disposed in walls  56 ,  58 , respectively. The ends  80 ,  82  of first and second side walls  56 ,  58  are contoured outwardly creating first and second guide flanges  84 ,  86 . A cam member or pin  90  extends between walls  56 ,  58 . The pin  90  provides additional support to blade  20  which discourages blade breakage within the carrier  16  during operation. The guides  84 ,  86  serve to help direct the blade  20  into the channel  62 . The floor  60  of the base  42  includes a stop  92 . Stop  92  is oriented at an angle toward the cam system  28 . 
         [0028]    Referencing now all Figures, the operation of retaining mechanism  46  will now be described. To install blade  20  in the retaining mechanism  46 , the blade  20  is inserted into channel  62  until the outer edge  52  of the blade  20  abuts the angled contact surface  68  of stop  92 . Accordingly, the body or major side surface  22  of blade  20  is oriented so that the planar surfaces  22  and  60  are in a parallel or in-line relationship. Thus, as the blade  20  cuts through a workpiece, the material width of the carrier  16  as well as the blade  20  are in the line of cut. This increases the blade strength during operation. 
         [0029]    Tail section  78  of blade  20  extends between stop  92  and the first side wall  56  to provide the blade  20  with additional stability. Side surface  98  of stop  92  provides a bias against surface of tail section  78  of blade  20 . Once the blade  20  is fully inserted, spring  44  biases the clamp end  38  against the aperture wall  18  of the blade  20 . The force influences surface  52  against surface  68  of stop  92  to secure the blade  20  to the blade retaining mechanism  46 . Stop  92  cams blade  20  down against base  42  which minimizes side to side clearances making the cut more accurate and efficient. To remove the blade  20 , a push button  108  on housing  14  is pressed against the lever end  34  of rocker arm  32  to disengage the clamp end  38  from the aperture wall  18  of the blade  20 . 
         [0030]    The second portion  26  of the carrier  16  includes an outer flange  100  extending from first and second walls  56 ,  58  around the perimeter of first portion  24 . Likewise, base  42  of first portion  24  extends to second portion  26  and is bordered by flange  100 . Slot  102  is integrated into base  42 . Slot  102  is defined by a first and second pair of lateral walls  104 ,  106  extending from opposing edges of the slot  102 . Lateral wall sections  104 ,  106  define a guide path  110 . Slot  102  further includes opposing channels  114 ,  116  formed in base  42  of carrier  16 . The channels  114 ,  116  are formed between first and second pair of lateral wall sections  104 ,  106 . As will be described in detail, opposing channels  114 ,  116  are configured to accommodate gear support shaft  120 . The opposite ends of guide path  110  are defined by grooves  122 ,  124 . 
         [0031]    Turning now to  FIGS. 2-4 , the drive assembly  30  will be further described. The drive assembly  30  is initiated by actuation of trigger  96  extending from housing  14 . Motor  12  includes drive gear  88  which is splined for rotation with output gear  124 . Drive assembly  30  includes gear support shaft  120  supported at opposite ends by bearings  140 ,  142 . Gear noise and wear are reduced by supporting shaft  120  at opposite ends. Output gear  124  is disposed on support shaft  120 . An offset output shaft  130  is coupled to output gear  124 . The output shaft  130  is arranged to orbit drive shaft  130 . A follower  134  is rotatably coupled to offset output shaft  130 . Follower  134  includes roller  136  and slider  138  which are received within guide path  110  of slot  102 . As such, translation of follower  134  along guide path  110  encourages concurrent rotatable engagement of roller  136  and slidable engagement of slider  138  along the face of the corresponding lateral walls  104 ,  106 . The advantage of using follower  134  including roller  136  and slider  138  is that it provides reduced gear noise and wear while providing low output shaft  130  losses. 
         [0032]    Turning to  FIGS. 5A-5D , during operation, carrier  16  makes a generally reciprocal up and down linear motion as designated by arrow “A”.  FIG. 5A  represents the follower  134  in a top dead center position with respect to slot  102 .  FIG. 5B  shows the follower at 90 degrees fully extended in the horizontal position.  FIG. 5C  represents the follower in a bottom dead center position at 180 degrees.  FIG. 5D  shows the follower at 270 degrees in a fully extended horizontal position. 
         [0033]    The rotational motion of drive gear  88  is transmitted through output gear  124  and associated orbit drive shaft  130  to follower  134 . Rotational movement of output gear  124  is designated by arrow “B”. Slot  102  within carrier  16  converts the vertical component of the circular path of the orbit drive shaft  130  into up and down linear motion of carrier  16 . The horizontal component of the circular path is expended as the orbit drive shaft  130  moves in the direction of guide path  110 . The opposing channels  114 ,  116  integrated on carrier  16  provide a passage to accommodate gear support shaft  120  as the follower  134  transmits through the horizontal component of the circular path ( FIGS. 5A and 5C ). Accordingly, slider  138  has a width “W”, which extends in the direction of guide path  110 , a distance greater than the width “X” of channels  114 ,  116 . Such a relationship minimizes momentum loss of the follower  134  while travelling past channels  114 ,  116  to provide smooth transition in the horizontal direction. In addition, roller  136  increases efficiency of the reciprocating movement of follower  134 . This is due to the fact that the majority of the movement is accomplished by the roller  136  rolling on the lateral walls  104 ,  106 . 
         [0034]    Returning to  FIGS. 2 and 3 , the reciprocating saw  10  includes a fan  17  disposed within the handle  94  and oriented to force air around motor  12  to second portion  26  of carrier  16 . The fan  17  is arranged to provide cooling to motor  12  and inhibit debris from collecting around cam system  28  and drive assembly  30 . A portion of the air escapes the housing  14  through vents  150  incorporated on opposite sides of the housing  14 . The remaining airflow is directed from second portion  26  to first portion  24  through channel  62  of carrier  16 . The airflow through channel  62  acts as a seal to inhibit woodchips and other debris from settling around retaining mechanism  46 . The residual air flowing through channel  62  clears debris away from the blade  20 , workpiece interface which improves visibility. The airflow also creates a positive pressure away from second portion  26  of carrier  16  to discourage debris from settling around the drive assembly  30 . 
         [0035]    Turning to  FIGS. 6-8 , the reciprocating saw  10  includes a primary and secondary base  144 ,  154 . Primary base  144  includes heal portions  146  and lateral rails  148  extending from opposite edges to provide stability during operation. Secondary base  154  includes a second pair of lateral rails  156  inwardly extending from outer walls  158 . Secondary base  154  is selectively attachable to primary base  144  to provide greater surface area and stability during operation. A latch  160  is mounted to primary base  144  and provided for coupling the secondary base  154  with the primary base  144  in an engaged position. A button  162  of the latch  160  is configured to extend through an opening  166  in the housing  14  to improve accessibility. The latch  160  maintains a static position in the tool assembly by a compression spring (not shown). The spring acts along its axis between sidewall  174  of button  162  on one end and an interior wall (not shown) of primary base  144  on the opposite end which forces the latch  160  into engagement with the contact wall  182  of stop  172 . 
         [0036]    To install secondary base  154  onto primary base  144 , the first pair of rails  148  of the primary base  144  are aligned with the second pair of rails  156  on the secondary base  154 . The secondary base  154  is moved forward in a direction parallel to the axis of the rails  156 . The button  162  of latch  160  is depressed until wall  172  of stop  170  extending from the secondary base  154  engages wall  176  of the primary base  144 . The button  162  of latch  160  is then released causing arm  178  of latch  160  to be received through passage  184  in stop  170 . Engagement of arm  178  with lip  182  of stop  170  ensures secondary base  154  is locked into position. 
         [0037]    While the invention has been described in the specification and Illustrated in the drawings with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention as defined in the claims. Accordingly, it is intended that the invention not be limited to the particular embodiment illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out this invention, but that the invention will include any embodiments falling within the description of the appended claims.