Abstract:
The present invention relates to a power tool comprising: a housing and a handle engaged with the housing, wherein the rear portion of the housing is provided with an arcuate track. The handle is provided with an engaging portion which is engageable with the arcuate track so that the engaging portion of said handle can slide along the track. In this manner, the position of the handle is adjustable relative to the housing. The handle is simple in construction and convenient to use.

Description:
RELATED APPLICATIONS 
   This application claims priority to Chinese Application No. 200410014373.0, filed Mar. 18, 2004 and Chinese Application No. 200410014439.6, filed Mar. 22, 2004. Both of these applications are incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a power tool with an adjustable handle. 
   2. Description of the Related Art 
   In order to improve the comfort of using a power tool in different operational states, it is known to make the handle of the power tool angularly adjustable. U.S. Pat. No. 6,588,112 discloses a handle which is adjustable relative to the housing for a circular saw but the handle is complicated constructionally and cannot be used widely. In addition, EP-A-1314518 discloses a power tool in which the housing can pivotally rotate relative to the handle. This is also complicated constructionally. 
   SUMMARY OF THE INVENTION 
   It is an object of this invention to provide a power tool with an adjustable handle to overcome certain disadvantages of prior art tools. 
   Viewed from a first aspect the present invention provides a power tool including:
     a housing for mechanical and electrical components of the power tool, wherein an exterior surface of the housing has an elongate mounting portion along which is an arcuate track; and   a handle having a distal gripping portion contiguous with a proximal non-gripping portion mounted on the elongate mounting portion of the housing, wherein an outer circumferential surface of the proximal non-gripping portion is provided with an elongate engaging portion arcuately engageable with the arcuate track so that the handle can slide along the arcuate track to allow the orientation of the handle and the housing to be angularly adjustable.   

   In accordance with an embodiment of the invention, the power tool comprises a housing, a handle engaged with the housing and an arcuate track disposed on a rear mounting portion of the housing. The handle is provided with an engaging portion which is engaged with the arcuate track. The engaging portion of the handle can slide along the track so that the position of the handle is adjustable relative to the housing. 
   The adjustability of the handle relative to the housing is provided in a simple manner and can be used conveniently. 
   In a preferred embodiment, the handle is substantially D-shaped and the elongate mounting portion is arcuate, wherein the outer circumferential surface of the proximal non-gripping portion is arcuate to generally match the elongate mounting portion. 
   Preferably the power tool further comprises:
     a locking assembly for selectively interlocking the handle and the housing.   

   In a preferred embodiment, the locking assembly includes:
         an inner hasp pivotally coupled to the elongate mounting portion of the housing at a first position; and   an outer hasp pivotally coupled to the elongate mounting portion of the housing at a second position, wherein the first position and second position are spaced apart along the elongate mounting portion and wherein the inner hasp and outer hasp are mutually pivotal between (A) a partially overlapping juxtapositional engagement with the inner circumferential surface of the proximal non-gripping portion whereby to interlock the housing and the handle and (B) a non-overlapping juxtapositional disengagement from the inner circumferential surface of the proximal non-gripping portion whereby the housing and the handle are not interlocked.       

   Preferably the inner hasp comprises:
     a first arcuate plate body terminating at a first end in a cylindrical barrel pivotally coupled to the elongate mounting portion of the housing at the first position by a first connecting pin and incorporating at a second end a laterally extending bore, wherein the cylindrical barrel has a radially projecting cam selectively engageable with a first one of a plurality of locking recesses on the inner circumferential surface of the proximal non-gripping portion of the handle,   and wherein the outer hasp comprises:   a second arcuate plate body terminating at a first end in a cylindrical sleeve pivotally coupled to the mounting portion of the housing in the second position by a second connecting pin, wherein the cylindrical sleeve has a second radially projecting cam which is selectively engageable with a second one of the plurality of locking recesses on the inner circumferential surface of the proximal non-gripping portion of the handle.   

   Preferably the second arcuate plate body deflects along a lateral edge into an arcuate lip which is provided partly along its length with an arcuate sliding slot, wherein a third connecting pin is slidably received in the sliding slot and through the bore of the inner hasp so that the inner hasp is pivotally connected to the outer hasp. 
   In a preferred embodiment, the locking assembly includes:
     a first pressing member at a first position of the elongate mounting portion of the housing;   a second pressing member at a second position of the elongate mounting portion of the housing laterally opposed to the first position;   lateral connecting rods coupling the first pressing member and the second pressing member together so that a part of the proximal non-gripping portion of the handle is captivated by the elongate mounting portion of the housing; and   an actuating member adjacent to the surface of the first pressing member, wherein the actuating member is actuatable from (A) a first configuration relative to the first pressing member in which there is effective disengagement of the elongate mounting portion from the outer circumferential surface of the proximal non-gripping portion whereby the housing and the handle are not interlocked to (B) a second configuration relative to the first pressing member in which the first pressing member is inwardly displaced to cause effective engagement of the elongate mounting portion with the outer circumferential surface of the proximal non-gripping portion whereby the housing and the handle are interlocked.   

   Preferably the power tool further comprises:
     one or more coupling pins pivotally coupling the actuating member to a first end of the lateral connecting rods adjacent to the first pressing member,   wherein each end of the actuating member comprises an eccentric cam which when the actuating member is in the second configuration inwardly displaces the first pressing member to cause effective engagement of the elongate mounting portion with the outer circumferential surface of the proximal non-gripping portion.   

   Preferably a clearance is defined between the first pressing member and the second pressing member when the actuating member is in the first configuration. 
   Preferably the external surface of the eccentric cam lies against the external surface of the first pressing member and wherein the actuating member is actuatatable from the first configuration to the second configuration such that the eccentric cam is rotated eccentrically to push against the first pressing member whereby to cause the first pressing member and the second pressing member to rotate inwardly and distort. 
   In a preferred embodiment, a part of the inner circumferential surface of the proximal non-gripping portion of the handle is formed with a plurality of parallel mutually spaced apart locking teeth and the locking assembly includes:
     a first pressing member at a first position of the elongate mounting portion of the housing;   a second pressing member at a second position of the elongate mounting portion of the housing laterally opposed to the first position;   lateral connecting rods coupling the first pressing member and the second pressing member together so that a part of the proximal non-gripping portion of the handle is captivated by the elongate mounting portion of the housing;   a retractable coupling device fixed at a first end to the first pressing member and at a second end to the second pressing member, wherein the retractable coupling device is formed with a plurality of parallel mutually spaced apart locking bars selectively engageable with the locking teeth; and   an actuating member adjacent to the surface of the first pressing member, wherein the actuating member is actuatable from (A) a first configuration in which the retractable coupling device is unretracted so that the locking bars and locking teeth are disengaged whereby the housing and the handle are not interlocked to (B) a second configuration in which the retractable coupling device is retracted so that the locking bars and locking teeth are meshed whereby the housing and the handle are interlocked.   

   Preferably the power tool further comprises:
     one or more coupling pins pivotally coupling the actuating member to a first end of the lateral connecting rods adjacent to the first pressing member,   wherein the actuating member is rotational eccentrically from the first configuration to the second configuration so as to push against the retractable coupling device whereby to cause the retractable coupling device to be retracted laterally.   

   Preferably the retractable coupling device comprises:
     a locking block, wherein a first end of the retractable locking block is defined with an axially projecting finger received in and through a receiving slot of the first pressing member and a second end of the locking block opposite to the first end is defined with a receiving bore; and   a guiding pin, wherein a first end of the guiding pin is defined by two axially projecting fingers which are slotted in the receiving bore and a second end of the guiding pin is a lateral connecting member which connects the two axially projecting fingers and is captured in a recessed slot of the second pressing member.   

   Preferably the base of the retractable locking block is formed with the plurality of parallel mutually spaced apart locking bars. 
   In a preferred embodiment, springs are mounted upon the two axially projecting fingers. 
   Preferably the outer circumferential surface of the proximal non-gripping portion is provided with an arcuate guiding slot slidably engageable with the arcuate track. 
   Preferably a part of the inner circumferential surface of the proximal non-gripping portion of the handle is formed with a plurality of parallel mutually spaced apart locking teeth. 
   Typically the elongate mounting portion and the housing lie in a common plane. Preferably the housing and the handle lie in a common plane. Particularly preferably the orientation of the handle and the housing is angularly adjustable in the common plane. 
   Preferably the inner circumferential surface of the proximal non-gripping portion has a plurality of locking recesses or teeth. Typically the locking recesses or teeth are parallel and mutually spaced apart. Typically the locking recesses or teeth extend laterally. 
   The power tool may be a power drill, a reciprocating saw or a planar. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features and advantages of preferred embodiments of the present invention may be better understood by reference to the accompanying Figures in which: 
       FIG. 1  is a perspective view of a part of a power tool in accordance with an embodiment of the invention; 
       FIG. 2  is an exploded perspective view of a part of the power tool in accordance with the embodiment of the invention; 
       FIG. 3  is an exploded perspective view of a power tool in accordance with an embodiment of the invention illustrating a first preferred locking assembly; 
       FIG. 4  is a perspective view of the first preferred locking assembly in a locked condition; 
       FIG. 5  is a schematic view of the first preferred locking assembly in an unlocked condition; 
       FIG. 6  is a schematic view of the first preferred locking assembly in a locked condition; 
       FIG. 7  is an exploded perspective view of a power tool in accordance with an embodiment of the invention illustrating a second preferred locking assembly; 
       FIG. 8  is a perspective view of the second preferred locking assembly in a locked condition; 
       FIG. 9  is a partial cross-sectional view of the second preferred locking assembly in an unlocked condition; 
       FIG. 10  is a partial cross-sectional view of the second preferred locking assembly in a locked condition; 
       FIG. 11  is an exploded perspective view of a power tool in accordance with an embodiment of the invention illustrating a third preferred locking assembly; 
       FIG. 12  is a perspective view of the third preferred locking assembly in a locked condition; 
       FIG. 13  is a partial cross-section view of the third preferred locking assembly in an unlocked condition; and 
       FIG. 14  is a partial cross-section view of the third preferred embodiment in a locked condition. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIGS. 1 and 2 , a power drill includes generally a housing  1  for the main mechanical and electrical components of the drill (not shown) and a handle  2  mounted on a rear elongate mounting portion of the housing  1  so as to be in a common plane with the housing  1 . The handle  2  is substantially D-shaped with a distal gripping portion contiguous with a proximal non-gripping portion. The outer circumferential surface of the proximal non-gripping portion has an arucate configuration which generally matches the arcuate configuration of the rear elongate mounting portion of the housing  1  on which it is mounted. 
   Each side face of the proximal non-gripping portion is provided with a guiding slot  21 . The guiding slot  21  slidably engages an arcuate track  11  defined along the rear elongate mounting portion of the housing  1 . The proximal non-gripping portion of the handle  2  can slide along the arcuate track  11  so that the handle  2  is adjustably mounted on the rear elongate mounting portion of the housing  1 . This allows the relative orientation of the distal gripping portion and the housing  1  to be angularly adjusted in the common plane for different operations and users. 
   A locking assembly interlocks the housing  1  to the handle  2  when the desired relative orientation of the distal gripping portion and the housing  1  is achieved. Embodiments of three preferred locking assemblies are described below in their locked and unlocked states. 
   Referring to  FIGS. 3 and 4 , the first preferred locking assembly includes an inner hasp  31  and an outer hasp  32  in juxtapositional overlap or non-overlap. The inner hasp  31  comprises an arcuate plate body  31   a  terminating at a first end in a cylindrical barrel  36  pivotally coupled to the rear mounting portion of the housing  1  perpendicular to the common plane by a first connecting pin  33   a  and incorporating at a second end a laterally extending bore  35 . The cylindrical barrel  36  has a radially projecting cam  311  which (in the locking state) selectively engages one of a plurality of locking recesses  22  on the inner circumferential surface of the proximal non-gripping portion of the handle  2 . The outer hasp  32  comprises an arcuate plate body  32   a  terminating at a first end in a cylindrical sleeve  37  pivotally coupled to the rear mounting portion of the housing  1  perpendicular to the common plane by a second connecting pin  33   b . The cylindrical sleeve  37  has a radially projecting cam  321  which (in the locking state) selectively engages one of the plurality of locking recesses  22  on the inner circumferential surface of the proximal non-gripping portion of the handle  2 . 
   The arcuate plate body  32   a  deflects along a lateral edge into an arcuate lip  38  which is provided partly along its length with an arcuate sliding slot  322 . A second connecting pin  34  is slidably received in the sliding slot  322  and through the bore  35  of the inner hasp  31  so that the inner hasp  31  is pivotally connected to the outer hasp  32 . The connecting pin  34  can slide along the axis of the sliding slot  322 . 
   Referring to  FIG. 5 , in the unlocked state the connecting pin  34  is located at a first end of the sliding slot  322 . The cams  311  and  321  are disengaged from the locking recesses  22  and so the handle  2  is free to slide along the arcuate track  11 . To achieve the locked state (see  FIG. 6 ), the outer hasp  31  is depressed to cause the second connecting pin  34  to slide towards a second end of the sliding slot  322  and to pivot the inner hasp  31 . Simultaneously the cam  311  and  321  are rotated into engagement with the locking recesses  22  to interlock the handle  2  and the housing  1 . 
   Referring to  FIGS. 7 and 8 , the second preferred locking assembly includes generally an actuating member  41 , connecting rods  42 , a first pressing member  43  on a first portion of the housing  1  and a second pressing member  44  on a second portion of the housing  1  opposite to the first portion. The first pressing member  43  is provided with first bores  431  and the second pressing member  44  is provided with second bores  441  which are collinear with the first bores  431 . The connecting rods  42  extend through the first bores  431  and the second bores  441  so that the first pressing member  43  and the second pressing member  44  together with the remainder of the housing  1  encapsulate a receiving space for captivating a part of the proximal non-gripping portion of the handle  2 . Coupling pins  46  pivotally couple the actuating member  41  to the first ends of the connecting rods  42  adjacent to the first pressing member  43  and the second ends of the connecting rods  42  are fastened to the second pressing member  44  by the nuts  47 . Each end of the actuating member  41  is provided with an eccentric cam  411  and  412  respectively. 
   Referring to  FIG. 9 , in an unlocked state a portion of the handle  2  is snugly captivated by the housing  1  and a clearance  45  is defined between the first pressing member  43  and the second pressing member  44  so that the housing  1  and handle  2  are not interlocked. The external surface of the eccentric cam  411  lies against the external surface of the first pressing member  43 . To achieve a locked state (see  FIG. 10 ), the actuating member  41  is actuated so that the eccentric cam  411  is rotated eccentrically to displace the first pressing member  43 . The first pressing member  43  and the second pressing member  44  rotate inwardly and distort so that the handle  2  is pressed downwardly against the housing  1 . This means that the clearance  45  is closed and the handle  2  and the housing  1  are interlocked. 
   Referring to  FIGS. 11 and 12 , the third preferred locking assembly includes generally an actuating member  51 , connecting rods  52 , a first pressing member  53  on a first portion of the housing  1 , a second pressing member  54  on a second portion of the housing  1  opposite to the first portion, a retractable locking block  55 , a guiding pin  553  and springs  554 . The first pressing member  53  is provided with first bores  531  and the second pressing member  54  is provided with second bores  541  which are collinear with the first bores  531 . The connecting rods  52  extend through the first bores  531  and the second bores  541  so that the first pressing member  53  and the second pressing member  54  together with the remainder of the housing  1  encapsulate a receiving space for captivating a part of the proximal non-gripping portion of the handle  2 . Coupling pins  56  pivotally couple the actuating member  51  to the first ends of the connecting rods  52  adjacent to the first pressing member  53  and the second ends of the connecting rods  52  are fastened to the second pressing member  54  by the nuts  58 . The middle of the actuating member  51  defines a recessed portion  511 . An embossed portion  512  extends from the base of the recessed portion  511 . 
   A first end of the retractable locking block  55  is defined with an axially projecting finger  551  received in a receiving slot  532  between the first bores  531  of the first pressing member  53  and a second end of the locking block  55  opposite to the first end is defined with a receiving bore  552 . A first end of the guiding pin  553  is defined by two axially projecting fingers  553   a ,  553   b  upon which are mounted springs  554  and which are slotted in the receiving bore  552 . A second end of the guiding pin  553  is a lateral connecting member  553   c  which connects the two axially projecting fingers  553   a ,  553   b  and is captured in a recessed slot (not shown) of the second pressing member  54 . 
   The base of the retractable locking block  55  is formed with a plurality of parallel mutually spaced apart locking bars  555  (as shown in  FIG. 13 ). The opposing part of the proximal non-gripping portion of the handle  2  is formed with a plurality of parallel mutually spaced apart locking teeth  23  with which the locking bars  555  are selectively engageable. 
   Referring to  FIG. 13 , in an unlocked state the recessed portion  511  is seated adjacent the receiving slot  532  and the locking bars  555  are disengaged from the locking teeth  23 . To achieve a locked state (see  FIG. 14 ), the actuating member  51  is rotated so that the embossed member  512  engages and retracts the axially projecting finger  551  against the action of the springs  554  so that the locking bars  555  mesh with the locking recesses  23  to interlock the housing  1  and the handle  2 .