Abstract:
A jigsaw with the functions of blade scrolling and blade pendulum movement comprises a housing, a motor, a reciprocating rod and a motor transmission system. The motor transmission system transfers the rotation of the motor to an up-and-down movement of the reciprocating rod to drive the blade to make an up-and-down cutting operation. The jigsaw still comprises a control device used to control the blade scrolling and the blade pendulum movement and control device comprises a blade button, a set of link rods and a pendulum axis. The rotation of the blade button drives the reciprocating rod to rotate so as to rotate the blade. The pendulum axis is a cam mechanism used to control the rang of the pendulum movement of the blade. The rotation of the pendulum axis will drive the set of link rods so as to control the blade button.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of Chinese Patent Application No. 200420027477.0, filed Jun. 1, 2004 which is incorporated herein by reference. 
   FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not applicable. 
   TECHNICAL FIELD 
   The present invention relates to an improved power tool, and particularly to a reciprocating saw with a detachable handle. 
   BACKGROUND OF THE INVENTION 
   A conventional reciprocating saw generally comprises a leading portion perpendicular to the cutting surface, which mainly comprising gear driven means and a reciprocating shaft inside a leading housing, and a motor portion parallel to the cutting surface. A person typically operates a reciprocating saw by grasping the motor housing, or by grasping an extra handle disposed on the motor housing. To maintain a firm grip and precise control, such a reciprocating saw is preferably operated by grasping the motor housing. 
   However, with extended and continuous operation, the motor housing can become warm, and cutting vibrations may cause an operator&#39;s hands and arms to become fatigued. As such, the operating can become uncomfortable, reducing the ability of the operator to precisely control the cut being made. Otherwise, operate a reciprocating saw by grasping a handle is much more comfortable. But when the saw is to be used in tight quarters wherein the handle might become an obstacle to precise control of the cutting tool. When the cutting to be done on the ceiling or some other position which is not horizontal, grasping the motor housing will provide a firm grip and precise control of the cutting. 
   U.S. Pat. No. 6,443,675 to Kopras et al. discloses a spiral cutting tool with a detachable handle which includes a trigger switch for operating the cutting tool motor. The cutting tool includes a multiple-position power on/off switch mounted on the tool housing. While cutting tools such as those in Kopras et al. address some of the issues described above, there still exist limitations inherent to such systems. For example, the operation of the trigger switch of the device in Kopras et al. depends on three different operating position of the multiple-position power on/off switch. Accordingly, the system is complex, and subject to mechanical malfunctions. 
   The present invention is provided to solve the problems discussed above and other problems, and to provide advantages and aspects not previously provided. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings. 
   SUMMARY OF THE INVENTION 
   The present invention provides a power tool, especially a reciprocating saw, with a detachable handle, which can be easily, quickly and securely mounted to the housing and removed therefrom with one hand. Therefore, users can operate the tool with or without the handle optionally. 
   The reciprocating saw of the present invention comprises a housing which can comprise a leading housing and a motor housing wherein a motor is positioned for driving a gear system, a saw blade, a sole plate and a handle detachably mounted to the housing. The detachable handle preferably has two ends, wherein a lug positioned within the front end and can be inserted into a corresponding aperture of the housing for connecting. The rear end of the handle includes a pair of grooves and a pair of connector each of which comprises a push button and a protruding portion extends under the bottom of the rear end. At the upper portion of the rear end of the motor housing is a connecting platform which comprises a pair of wedging pieces and a pair of key bosses. To mount the handle, a person should guide the wedging pieces in the grooves until the key bosses are matched with the protruding portion. 
   The reciprocating saw of the present invention also comprises a first switch, a pole, a frame and a first switch trigger for activating the first switch. The reciprocating saw can further comprise a second switch and a trigging pole. The handle comprises a second trigger switch for activating the second switch, a cylindrical shaft fixed in the handle, and a lever pivot through the cylindrical shaft. 
   The frame mentioned hereinbefore preferably comprises a hole, wherein a locking pole can selectively insert. When the first switch trigger is in its OFF position, the handle can be mounted to the housing. During the mounting of the handle, one of the protruding portions of the connector pushes the locking pole down into the hole of the frame, such that the frame is secured, and the first switch trigger is locked. Conversely, when detaching the handle from the housing, the locking pole escapes from the hole, and the first switch trigger is enabled. 
   The reciprocating saw of the present invention also comprises a blade clamping device which can be operated without any aid of a tool. The blade clamping device comprises a fixing element, a sleeve, a pair of springs, and a pair of rollers. The fixing element comprises a cavity for receiving the end of a saw blade, a reverse-V-shaped groove and a cylindrical bore on the top of the cavity, and a V-shaped groove through the fixing element for receiving the rollers. The inside of the sleeve has a pair of elongate grooves for receiving and guiding two ends of the rollers. 
   The reciprocating saw may further comprise a sole plate with a plurality of dust channels. The sole plate includes a base, a sole and a pipe, wherein a groove is positioned in a bottom side of the base. When the sole is mounted to the base, two channels are formed thereby. The dust channels open near the saw blade and connect to the pipe at their respective opposed ends. 
   According to one aspect of the present invention, the reciprocating saw with detachable handle comprises two switch triggers positioned on the motor housing and the detachable handle respectively for activating the motor. 
   According to another aspect of the present invention, the reciprocating saw with detachable handle, wherein once the detachable handle is mounted to the housing, the switch trigger on the motor housing will be locked and only the one on the handle is operable. So that the two switch triggers can&#39;t be operated simultaneously, and unexpected accident is avoided. 
   According to another aspect of the present invention, the reciprocating saw with detachable handle comprises a sole plate which includes at least one dust channels which opens near the saw blade and which connect to a pipe at the other end. When in operation, a dust absorption device is connected to the pipe so that sawdust will be absorbed through the dust channels then. 
   According to still another aspect of the present invention, the reciprocating saw is provided, wherein the saw includes a laser alignment device. 
   According to yet another aspect of the present invention, the reciprocating saw is provided, wherein the saw includes an illumination system. 
   According to still another aspect of the present invention a pendulum scrolling reciprocating saw is provided. 
   Other features and advantages of the invention will be apparent from the following specification taken in conjunction with the following drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     To understand the present invention, it will now be described by way of example, with reference to the accompanying drawings in which: 
       FIG. 1  is a partial cross-sectional front view of a reciprocating saw with the detachable handle mounted on the housing according to the present invention; 
       FIG. 2  is a perspective view of a reciprocating saw with the laser alignment device projecting a laser beam according to the present invention; 
       FIG. 3  is a partial cross-sectional perspective view of a reciprocating saw according to the present invention shown with the detachable handle mounted on the housing; 
       FIG. 4  is a perspective view of a preferred detachable handle according to the present invention; 
       FIG. 5  illustrates the inner structure of the detachable handle according to the present invention; 
       FIG. 6  is a perspective view of a reciprocating saw according to the present invention shown with the handle removed; 
       FIG. 7  is a top view of the reciprocating saw of  FIG. 6 ; 
       FIG. 8  is a schematic cross-sectional view taken along line K-K in  FIG. 7 ; 
       FIG. 9  is a front sectional view of a preferred blade clamping device according to the present invention; 
       FIG. 10  is a perspective view of the blade clamping device of  FIG. 9  shown with a blade; 
       FIG. 11A  is a perspective view of a sole plate according to the present invention; 
       FIG. 11B  is another perspective view of a sole plate according to the present invention; 
       FIG. 11C  is a another perspective view of a sole plate according to the present invention; 
       FIG. 12A  is a cross-sectional view of a another embodiment of the present invention; and 
       FIG. 12B  illustrates two possible positions of the components shown in the dot line circle of  FIG. 12A . 
   

   DETAILED DESCRIPTION 
   While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated. 
   Referring to  FIGS. 1 and 2 , a preferred reciprocating saw of the present invention comprises a housing  1 . The housing  1  has a leading housing  7 , a motor housing  2 , a motor  6  and a blade  3 . The saw also includes a first switch  103  contained within the motor housing  2 . A gear system  71  is positioned within the leading housing  7  for transmitting and altering the rotation of the motor shaft to reciprocation of the blade  3 . The saw is also comprised of a detachable handle  10 , a laser alignment device  4 , an illuminating device  5 , a blade clamping means  30 , and a sole plate  30 . 
   Referring to  FIG. 4 , a lug  14  is positioned within the front end of the handle  10 . The lug  14  may be inserted into a corresponding aperture  140  on the housing  1  for connecting as shown in  FIG. 6 . The rear end of the handle  10  includes a pair of connectors  18  biased away from each other by a spring  182  connected therebetween as shown in  FIG. 5 . Each connector  18  comprises a push button  180  and a protruding portion  184  which includes a slant  186  and a groove  188  and extends under the bottom of the rear end of the handle  10 . The handle  10  further comprises a pair of elongate grooves  48  on the bottom of the rear end. Further referring to  FIG. 6 , at the rear end of the motor housing  2  is a platform  40  which comprises a pair of opposite wedging pieces  46  and a pair of key bosses  42  each of which comprises a slant  44 . 
   In mounting the handle  10 , a user will grasp and push the handle  10  so that the grooves  48  are guided along wedging pieces  46  and the lug  14  is inserted into, and received by, the aperture  140  until the slants  186  of the protruding portions  184  slide over the slants  44  of the key bosses  42  and are locked within the grooves  188 . At that time, the lug  14  is thoroughly inserted into the aperture  140 , and the handle  10  is fixedly mounted to the housing  1 . 
   To remove the handle  10 , a user will first depress the two push buttons  180  of the connectors  18 . This will cause the connectors  18  to retract inwards together with the compression of the spring  182 . Accordingly, the key bosses  42  disengage from the grooves  188 . The user may then pull the handle  10  until the wedging pieces  46  become disengaged from the grooves  48  and the lug  14  is released from the aperture  140 . 
   Referring to  FIGS. 1 and 2 , the reciprocating saw comprises a first switch  103 , a pole  102 , a frame  104  and a first switch trigger  100  for activating the first switch  103 . When the first switch trigger  100  is moved to a first position as shown in  FIG. 2 , the triggering surface  1041  of the frame  104  act a force on the trigger  1031  of the first switch  103  and thus the first switch  103  is switched on and the motor  6  is powered. Conversely, moving the first switch trigger  100  to a second position wherein the triggering surface  1041  disengages the trigger  1031 , causes the first switch  103  to be shut off and the motor  6  to stop rotating. 
   It will be appreciated that a second switch trigger  12  operatively positioned on the handle  10  may be provided. This second switch trigger  12  provides for convenient operation of the tool when the handle  10  is attached. The handle  10  further comprises a lever  16  fixed with a roller  160  proximate a front end. The roller  160  is movable within a pair of elongate apertures  120  of the second switch trigger  12 . The handle  10  also includes a cylindrical shaft  162  fixed in the handle for pivotally supporting the lever  16 . 
   The reciprocating saw may also comprises a second switch  101  as shown in  FIG. 3 . As shown in  FIGS. 7 and 8 , the second switch  101  comprises a trigger  1011 , above which is disposed a triggering pole  130  disposed with its top end slightly exposed on the platform  40 . When the detachable handle  10  is mounted to the tool housing  1  with the second switch trigger  12  on its OFF position, the trailing end  164  of the lever  16  is situated above the top end of the triggering pole  130  leaving the spring  131  free. By depressing the second switch trigger  12 , a roller  160  will then be raised, and the lever  16  will pivot clockwise around the cylindrical shaft  162  accordingly. This will cause the trailing end  164  to decline and push the triggering pole  130  to switch the second switch  101  to an ON setting. 
   In one embodiment of the present invention the reciprocating saw does not include a triggering pole  130 . Accordingly, when the second switch trigger  12  is depressed, the trailing end  164  pushes directly on the trigger  1011  of the second switch  101 . 
   It one embodiment of the invention the reciprocating saw does not include the second switch  101 . Referring to  FIG. 12A , the tool instead further comprises an active pole  130 ′ whose bottom end has a sharp slant  132 , and a resilient piece  133  with one end fixed.  FIG. 12B  is a schematic view showing two relative positions of the active pole  130 ′ and the resilient piece  133 . According to this embodiment, the active pole  130 ′ and the resilient piece  133  are in their first position when no force is applied to the active pole  130 ′. Conversely, when the second switch trigger  12  is pressed, the tailing end  164  of the lever pushes the active pole  130 ′ downwards such that the slant  132  slides on and pushes the resilient piece  133  to its second position (illustrated in phantom), wherein the trigger  1031  is pushed by the resilient piece  133  and thus the switch  103  is triggered to an ON position. If, however, the handle  10  is not attached, when the first switch trigger  100  is depressed, the frame  104  will follow to push the resilient piece  133  and activate the switch. 
   To avoid multiple operations of the two switch triggers, and thus prevent unexpected accidents, the reciprocating saw preferably has a function, wherein when the handle  10  is attached to the housing  1 , the first switch trigger  100  on the motor housing  2  will be locked in its OFF position and only the second switch trigger  12  on the handle  10  is operable. As shown in  FIG. 3 , to achieve such an object, the frame  104  preferably comprises a hole  106  in which a locking pole  110  may be selectively inserted. 
   When the handle  10  is not mounted on the tool, a spring  111  remains free, and the locking pole  110  is released above the hole  106  as shown in  FIG. 8 , and the frame  104  can be moved freely to switch ON or OFF the motor  6 . When the first switch trigger  100  is in its OFF position, the handle  10 , may be mounted to the housing  1 . As illustrated in  FIGS. 1 and 3 , During the mounting of the handle  10  a bottom slant  187  of one of the protruding portions  184  pushes the locking pole  110  down into the hole  106  such that the frame  104  is hold from moving, and the first switch trigger  100  is locked in its OFF position. Conversely, when the handle  10  is detached from the housing  1 , the locking pole  110  escapes from the hole  106 , and the first switch trigger  100  is enabled. 
   In one embodiment, the reciprocating saw of the present invention preferably comprises a blade clamping device  30  which can be operated without the aid of a tool. Referring to  FIG. 9  and  FIG. 10 , the blade clamping device comprises a fixing element  32 , a sleeve  31 , a pair of springs  33  and a pair of rollers  34 . The fixing element  32  comprises a cavity  320  for receiving an end of the saw blade  3 , a reverse-V-shaped groove  324  and a cylindrical bore  322  on the top of the cavity  320  such that the top end  300  of the blade  3  can be fixedly received. The blade clamping device  30  further comprises a V-shaped groove  326  through the fixing element  32  for receiving the rollers  34  therein. The sleeve  31  includes a pair of elongate grooves  310  for receiving and guiding two ends of the rollers  34 . 
   The blade clamping device  30  shown in  FIG. 9  is free for receiving a blade. To clamp a blade, a user pushes the sleeve  31  upwards causing the roller  34  to run aslant along the V-shaped groove  326 . The blade  3  is then inserted through the gap of the two rollers  34  until the top end  300  reaches and is received in the cylindrical bore  322 . The sleeve  31  is then released. Under the biasing force of the springs  33 , the sleeve  31  will run down together with the roller  34  therein. The rollers  34  slide along the slant of the V-shaped groove  326  towards the blade  3 , and apply a force to the blade  3  thereby to fixedly clamping the blade  3 . 
   In one embodiment of the present invention, the reciprocating saw further comprises a sole plate  20  with a pair of dust channels  25 ′. Referring to  FIGS. 11A-11C , the sole plate  20  includes a base  23 , a sole  22  and a pipe  21 , wherein a pair of groove  25  is positioned on the bottom side of the base  23 . When the sole plate  22  is mounted to the base  23 , two channels  25 ′ are formed thereby. Each of the dust channels  25 ′ has at least one opening  24  disposed proximate the saw blade  3 . By connecting a dust collector to the pipe  21 , the sawdust may be absorbed along the channels  25 ′ into the dust collector. 
   According to one embodiment of the present invention shown in  FIG. 2 , the reciprocating saw comprises an illumination system  5  to illuminate the cutting area. The reciprocating saw may also include a laser alignment device  4  to project a fan-shaped laser beam  400  which can reflect a visible line on the work piece as a cutting reference, referring to  FIG. 2 . For example the alignment device  4  may be of the type described in China Patent No. ZL02220128.9. 
   According to the present invention, it is preferable that the reciprocating saw include a saw blade capable of scrolling and pendular movement as described in China Application No. 200420024532.0 which is hereby incorporated by reference. 
   When in practice use, a user can grasp the knob  8  with one hand and held the motor housing  2  with the other hand. Alternatively, the user can also mount the handle  10  to the housing  1  and operate with one hand held on the handle. 
   While the invention has been described in the specification and illustrated in the drawings with reference to preferred embodiments, 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 scope of the accompanying Claims.