Patent Publication Number: US-2015078811-A1

Title: Modular power tool

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is a Continuation of application Ser. No. 13/594,542 filed Aug. 24, 2012, which is a Continuation of International Application No. PCT/AU2011/000209 filed Feb. 25, 2011, claiming priority based on Australian Patent Application No. 2010905259 filed Nov. 29, 2010, Australian Patent Application No. 2010900831 filed Feb. 26, 2010, Australian Patent Application No. 2010900808 filed Feb. 25, 2010, Australian Patent Application No. 2010900807 filed Feb. 25, 2010, Australian Patent Application No. 2010900809 filed Feb. 25, 2010, the disclosures of which are incorporated herein in their entirety by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to the field of electro-mechanical devices such as domestic appliances. In particular, the present invention relates to the field of handheld power tools and to a modular handheld power tool arrangement wherein a power tool handle and switch assembly is capable of releasable attachment to, and for controlling power input to, any one of a number of different modular power tool devices. However, it is to be appreciated that the present invention may have broader application for electrically powered appliances other than handheld power tools. 
     BACKGROUND OF THE INVENTIONS 
     It is to be appreciated that any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the present invention. Further, the discussion throughout this specification comes about due to the realisation of the inventor and/or the identification of certain related art problems by the inventor. Moreover, any discussion of material such as documents, devices, acts or knowledge in this specification is included to explain the context of the invention in terms of the inventor&#39;s knowledge and experience and, accordingly, any such discussion should not be taken as an admission that any of the material forms part of the prior art base or the common general knowledge in the relevant art in Australia, or elsewhere, on or before the priority date of the disclosure and claims herein. 
     There are a wide variety of handheld power tools available for performing a variety of different functions. For example, there are drills for drilling, power drivers for driving screws, power saws for sawing work pieces, power grinders for grinding material from work pieces and a variety of other power tools for performing various other work. In order for a consumer to have a range of tools for performing any one or more required jobs it is necessary for the consumer to purchase a variety of power tools. Purchasing a wide variety of power tools can involve significant expense because each tool may include a variety of components including an electric motor, a switch, a handle assembly, a power cable or battery for supplying power to the tool that must be sourced by the manufacturer, assembled, packaged and transported. 
     In particular, tradesmen often own numerous handheld devices such as power drills, AC high speed drills, hammer drills, angle grinders, circular saw, jigsaws, sanders and so forth which may be connected to a power source or battery operated. Similarly, as the cost of power tools has diminished individuals in a domestic environment often possess a wide variety of power tools for DIY projects or hobbies. 
     In order to overcome the inconvenience and physical limitation of having a power cord attached to a power tool, cordless power tools adapted to receive non-rechargeable or rechargeable batteries were developed. Non-rechargeable batteries were typically loaded into a recess in the power tool handle and replaced when they were flat. Due to their need to be regularly replaced, some power tools have rechargeable batteries that are removably located in the power tool, or alternatively, the batteries can be plugged into a recharger while located in the handle. 
     Design of power tools (both those operating from a power source and those that are battery operated) has further progressed to include the use of a single handle that can be removably connected to a range of attachments for different applications. For example a single controller could be attached to a drill body, sander body, jigsaw body, grinder body and so forth. This modularity, particularly the ability to remove a handle from a power tool reduces the overall size of each unit, allowing more units to be stored in a given volume of space such as a shipping container (saving freight costs), or a retail shelf (allowing retailers to maximise stock and improve return on shelf or floor space cost) and simplifying inventory and reducing the amount of storage needed by users. Given that many people now live in apartments or town houses, the ability to more efficiently store tools in a small space in the home environment can be very appealing to home handymen and hobbyists. 
     For example U.S. Pat. No. 6,286,611 (Black &amp; Decker Inc) discloses a power tool including a motor mounted in a handle, the handle being adapted for connection to any one of a plurality of tool head attachments to form a tool dedicated for a particular job. Typically each tool head attachment has a drive mechanism that engages a spindle cog. The spindle has a male cog attachment for mesh engagement with a female cog of a drive mechanism on the power tool head. The tool head is kept in connection with the drive mechanism by a locking mechanism. 
     U.S. Pat. No. 6,796,389 (Snap-on Incorporated) teaches the use of a handle grip which slides over a handle of a tool body where it is retained by flanges that resiliently clip into grooves in the handle. 
     U.S. Pat. No. 6,181,032 (Black &amp; Decker Inc) relates to an interface for releasably connecting a power control module or battery pack to an electrical tool. A power control switch is located on the electrical tool and is actuated by a manual trigger on the power control module/handle. The interface is formed by sliding connection between the power control module and electrical tool via a pair of dovetail connections with interlocking flanges. The trigger operates a linkage that reaches through the interface plane into the tool to operate a switch located within the tool. 
     U.S. Pat. No. 7,414,211 (C Enterprise HK Ltd) relates to a cordless power tool having a handle that can house multiple rechargeable cylindrical batteries. Complementary female and male connectors provided respectively on the power handle and on the electrical tool permit sliding engagement and disengagement, the male connector having electrical contact means exposed thereon for engagement with the electrical contacts on the power handle. 
     U.S. Pat. No. 6,443,675 (Roto Zip Tool Corp) relates to a hand held power tool having a motor housing and detachable handle bearing a manually operable trigger switch. The trigger switch is coupled to a motor controller within the motor housing without use of a direct mechanical connection so as not to interfere with the easy and quick attachment and detachment of the handle to and from the housing. Fixed housing mounting structures such as housing apertures are formed in the tool housing and positioned therein for receiving extending tabs (preferably hook shaped to hook into the apertures) and a rotatable rod which extend from the ends of the handle. The end of the rod preferably includes one or more distal radially extending portions that fits through slots in the tool housing and can be oriented to resist removal of the handle from the power tool. 
     US patent application 2006/003776 (Gass &amp; D&#39;Ascenzo) relates to an electrically powered hand drill/driver having a housing containing a motor and a handle and a power control module to deliver power to the motor. The housing and power control module are connected by a ridge that fits in a slot, held in place by a locking member. 
     One of the problems associated with modular power tools of the prior art, or more particularly their connections, is that they permit a degree of movement between the parts. A user typically notices a ‘wobble’ between the parts. Any instability in the connection of an electro-mechanical device tends to cause concern in the mind of a user, particularly concerns relating to electric shock. This is particularly so with respect to alternating current (AC) devices which are of higher energy than direct current (DC) devices. Furthermore, any movement at electrical contacts between the parts can cause arcing, accelerated wear and concomitant decrease in efficiency. 
     Accordingly, it would be desirable to be able to provide a variety of power tools at less cost to the consumer. It would also be desirable to provide an improved connection between parts of an electro-mechanical device. 
     SUMMARY OF THE INVENTION 
     In a first aspect of embodiments described herein there is provided a connection for releasably connecting two parts of an electro-mechanical device, the connection including;
         (i) a first connecting portion associated with a first part, and a second connecting portion associated with a second part, such that engagement of the first and second connecting portions imparts bias between the two parts, and   (ii) a retention means suitable for maintaining the bias between the two parts.       

     Accordingly, the present invention provides, in a second aspect, a connection arrangement for releasably connecting an electrical device and a power control module, the electrical device including an electrically powered functional component, the power control module including a device for controlling the supply of electrical power to the functional component when the electrical device and the power control module are connected, the connection arrangement including:
         a first connecting portion associated with one of the electrical device or the power control module and configured to interengage with a second connecting portion associated with the other one of the electrical device and the power control module;   the first connecting portion including a first locking member and the second connecting portion including a second locking member, wherein when the first and second connection portions are engaged the first and second locking members are movable relative to each other between an unlocked position in which the first and second connection portions are separable and a locked position in which the first and second connection portions are locked together.       

     In embodiments of the invention, in the locked position the first and second connection portions are compressed together. 
     In another embodiment, in the locked position the first and second locking members engage each other in an interference fit. 
     In yet another embodiment, the first connecting portion including a first connection member and the first locking member, the second connecting portion including a second connection member and the second locking member, the first and second connection members are connectable together such that the first and second locking members are movable relative to each other between a separated position and a locking position, wherein in the locking position the first and second locking members are movable relative to each other between the locked position and the unlocked position. 
     In a further embodiment, the first and second connection members are pivotally connectable so that when the first and second connection members are connected together the first and second locking members pivot relative to each other in an arc between separated and locking positions. Preferably, the first and second connection members are of complementary shape. 
     In yet a further embodiment, the first connection member and the first locking member are spaced apart in a direction along a first connecting axis, the second connection member and the second locking member are spaced apart in a direction along a second connecting axis, wherein connecting the first and second connecting portions involves orienting the first connecting portion relative to the second connecting portion so that the first connecting axis and the second connecting axis converge and moving the first and second connection members into engagement. Thus, for example, the first connection member/first locking member and the second connection member/second locking member form a hinge having a longitudinal axis substantially parallel to the direction of force applied to the device during use. 
     In preferred embodiments, the first and second connection members include a slot and ridge that is receivable within the slot to thereby connect the first and second connection members together. 
     In further preferred embodiments, the first and second locking members include an anchor and a movable catch, wherein when the first and second locking members are in the locking position the catch is movable between an unlocked position in which the anchor is free to move relative to the catch and a locked position in which the anchor is engaged by the catch in an interference fit. 
     In an embodiment of the invention, the catch includes a sloping surface that contacts with a surface adjacent to the anchor such that upon movement of the first and second locking members relative to each other between the separated position and the locking position the sloping surface slides against the surface adjacent to the anchor and is actuated between the locked and the unlocked positions. 
     In a preferred embodiment, the catch is at least partially actuated between the unlocked and the locked positions by a biasing mechanism. 
     In another preferred embodiment, the catch is at least partially manually actuated between the unlocked and the locked positions. 
     In further preferred embodiments, the first connecting portion includes a first electrical contact and the second connecting portion includes a second electrical contact, the first and second electrical contacts being configured to come into physical contact when the first connecting portion mates with the second connecting portion. 
     In another embodiment, the power control module includes a housing and the electrical contact of the connecting portion of the power control module is recessed within the housing for preventing user contact with the recessed electrical contact. 
     In yet another embodiment, the power control module includes a handle and a switch assembly for controlling the supply of electrical power to the functional component when the electrical device and the power control module are connected. 
     In still yet another embodiment, the power control module includes an electrical cable for connection to an alternating current power supply and facilitating the passage of electrical power to the power control module. 
     In another embodiment, the power control module includes a rechargeable power storage device. 
     In a preferred embodiment, the electrical device includes a power tool module. 
     In another aspect, the invention provides a power control module for releasable connection to an electrical device including an electrically powered functional component, the power control module including a device for controlling the supply of electrical power to the functional component when the electrical device and the power control module are connected, the power control module including:
         a housing including a connecting portion including a locking member,   the connecting portion being configured to interengage with the electrical device and when engaged the locking member includes a locked condition and an unlocked condition, wherein in the unlocked condition the power control module is separable from the electrical device and in the locked condition the connecting portion of the power control module is compressed together with the electrical device.       

     In embodiments of the invention, the connecting portion includes a connection member and the locking member, the connection member being configured for connection together with the electrical device and when connected the locking member is movable relative to the electrical device between a separated position and a locking position to thereby mate the connecting portion to the electrical device. 
     In an embodiment, the connection member includes a slot for receiving a ridge of the electrical device and to enable the connecting portion to pivot about the slot and the ridge between the separated position and the locking position. In a particularly preferred embodiment the slot and ridge are of complementary shape. 
     In another embodiment, the locking member includes a movable catch configured to interact with an anchor of the electrical device wherein in the locking position the catch is movable between an unlocked position in which the catch is free to move relative to the anchor and a locked position in which the anchor is engaged by the catch in an interference fit. 
     In yet another embodiment, the catch is at least partially actuated between the unlocked and the locked positions by a biasing mechanism. 
     In still yet another embodiment, the catch is at least partially manually actuated between the unlocked and the locked positions. 
     In an embodiment, the connecting portion includes an electrical contact recessed within the housing and configured to come into physical contact with a protruding electrical contact of the electrical device when the connecting portion mates with the electrical device. 
     In another embodiment, the power control module includes a handle and a switch assembly for controlling the supply of electrical power to the functional component when the electrical device and the power control module are connected. 
     In yet another embodiment, the power control module includes an electrical cable for connection to an alternating current power supply and facilitating the passage of electrical power to the power control module. 
     In another aspect, the invention provides an electrical device including an electrically powered functional component for releasable connection to a power control module, the power control module including a device for controlling the supply of electrical power to the functional component when the electrical device and the power control module are connected, the electrical device including:
         a housing including a connecting portion including a locking member,   the connecting portion being configured to interengage with the power control module and when engaged the locking member includes a locked condition and an unlocked condition, wherein in the unlocked condition the electrical device is separable from the power control module and in the locked condition the connecting portion of the electrical device is compressed together with the power control module.       

     In one embodiment, the connecting portion includes a connection member and the locking member, the connection member being configured for connection together with the electrical device and when connected the locking member is movable relative to the electrical device between a separated position and a locking position to thereby mate the connecting portion to the electrical device. 
     In one embodiment, the connection member includes a ridge for insertion into a slot of the power control module and to enable the connecting portion to pivot about the slot and the ridge between the separated position and the locking position. 
     In another embodiment, the locking member includes an anchor configured to interact with a movable catch of the power control module wherein in the locking position the catch is movable between an unlocked position in which the catch is free to move relative to the anchor and a locked position in which the anchor is held by the catch. 
     In still yet another embodiment, the connecting portion includes an electrical contact protruding from the housing and configured to come into physical contact with a recessed electrical contact of the power control module when the connecting portion mates with the power control module. 
     In a further embodiment, there is provided a method of connecting two parts of a power tool according to the present invention, including the steps of;
         (i) engaging the first connecting portion with the second connecting portion such that bias is imparted between the two parts, and   (ii) simultaneously or subsequently, applying the retention means to maintain bias between the two parts.       

     In one embodiment, the electrical device includes a power tool module. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will now be described in more detail with reference to the following Figures. The following Figures represent embodiments of the invention in the form of a power control module and a modular power tool, in the form of modular power drill, and for the sake of convenience the present invention will be described below in detail with reference to the modular power drill embodiment. It is to be appreciated, however, that the present invention may be suitable for use with other modular electrical devices including other forms of power tools such as handheld power saws, power screwdrivers, power percussion/hammer drills as well other electrical devices such as a light emitting device, radio, or a digital music player to name but a few. 
         FIG. 1  illustrates a perspective view of a modular electrical device and power control module arrangement including an electrical device in the form of a modular power drill and a power control module including a handle and switch assembly wherein the power tool and the power control module are in the assembled condition. 
         FIG. 2  illustrates a perspective view of the assembly of  FIG. 1  wherein the power tool and the power control module are in the partially assembled condition. 
         FIG. 3  illustrates a front view of the assembly of  FIG. 1  wherein the power drill and the power control module are in the partially assembled condition. 
         FIG. 4  illustrates a front view of the assembly of  FIG. 1  wherein the power drill and the power control module are in the assembled condition. 
         FIG. 5  illustrates a perspective view of the power control module of the assembly of  FIG. 1 . 
         FIG. 6  illustrates a perspective view of the power drill of the assembly of  FIG. 1 . 
         FIG. 7  illustrates a side view of another embodiment of the modular electrical device and power control module of the invention wherein the power drill and the power control module are in the assembled condition. 
         FIG. 8  illustrates a rear view of the assembly of  FIG. 7  wherein the power drill and the power control module are in the assembled condition. 
         FIG. 9  illustrates a side view of the assembly of  FIG. 7  wherein the power drill and the power control module are in a partially assembled condition. 
         FIG. 10  illustrates a rear view of the assembly of  FIG. 7  wherein the power drill and the power control module are in the partially assembled condition. 
         FIG. 11  illustrates a side view of the assembly of  FIG. 7  wherein the power drill and the power control module are in a separated condition. 
         FIG. 12  illustrates a rear view of the assembly of  FIG. 7  wherein the power drill and the power control module are in the separated condition. 
         FIG. 13  illustrates a perspective view of the assembly of  FIG. 7  wherein the power drill and the power control module are in the separated condition. 
         FIG. 14  illustrates a perspective view of the assembly of  FIG. 7  wherein the power drill and the power control module are in the separated condition. 
         FIG. 15  illustrates a perspective view of the assembly of  FIG. 7  wherein the power drill and the power control module are in the partially assembled condition and part of the housing of the power drill and the power control module are hidden. 
         FIG. 16  illustrates a perspective view of the assembly of  FIG. 7  wherein the power drill and the power control module are in the assembled condition and part of the housing of the power drill and the power control module are hidden. 
         FIG. 17  illustrates a perspective view of a power control module arrangement in accordance with another embodiment of the invention with part of the housing of the module removed. 
         FIG. 18  illustrates a perspective view of an electrical device operable to be coupled to the power control module arrangement of  FIG. 17 , the electrical device being in the form of a modular power drill. 
         FIG. 19  illustrates another perspective view of the electrical device of  FIG. 18 . 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 to 16  illustrate preferred embodiments of the invention in the form of a modular assembly  10  including an electrical device  20  and a power control module  30 . The modular assembly  10  includes a connection arrangement  50  for releasably connecting the electrical device  20  and the power control module  30 . The electrical device  20  may include any form of electrical device including a handheld power drill, handheld power saw, power screwdriver, power percussion/hammer drill and any other power tool that utilises a drive means and a driven member for driving movement of a working element relative to the power tool body. The electrical device  20  may include other forms of electrical devices including a light emitting device, such as a torch, a radio or a digital audio playback device. Accordingly, the electrical device  20  may be any device including an electrically powered functional component (not shown) such as an electric motor, an electric light emitting device, a microprocessor device or any other electrically powered device. 
     The connection arrangement  50  between the power control module  30  and the electrical device  20  facilitates removal and connection of the power control module  30  to a variety of modular electrical devices  20  of which the power drill modules illustrated in  FIGS. 1 to 16  are only examples. 
     The power control module  30  includes a housing  32  including a handle portion  34 . The handle portion  34  extends between a bottom  37  and an opposite top  39 . The handle portion  34  also has a front end  36  and a rear end  35  and two opposite lateral sides  31 ,  33  extending between the front and rear ends  36 ,  35 . As shown in  FIGS. 7 to 16 , the front end  36  of the handle portion  34  provides a guard for protection of a user&#39;s fingers when holding the handle. The front end  36  of the handle portion  34  is also effective for reducing the likelihood of inadvertent operation of the trigger mechanism  38  and can also be used to wind the cable  52  thereon. As shown in FIGS.  15  and  16 , the housing  32  contains a switch assembly  41  mounted within the housing  32 . The housing  32  also includes an electric cable  52  extending from the housing  32  at the bottom  37  of the handle  34 . The cable  52  is suitable for connection to a power supply such as an alternating current power supply. The cable  52  is connected to the switch assembly which is operable for supplying electrical power to the electrically powered functional component of the electrical device  20  when the power control module  30  and the electrical device  20  are in the assembled condition as shown in  FIGS. 1 ,  4 ,  7 ,  8  and  16 . The power control module  30  includes a trigger mechanism  38  mounted to the front end  36  of the housing  32 . The trigger mechanism  38  is operated manually to actuate the switch assembly  41  between operative and inoperative conditions to respectively supply and cut the supply of electrical power to the electrically powered functional component of the electrical device  20 . 
     In another form, the housing  32  may contain an on board power supply such as a rechargeable battery. The battery may include an electrochemical cell, a supercapacitor or a hybrid capacitor or combinations thereof. The on board power supply can be connected to the switch assembly which is operable for supplying electrical power to the electrically powered functional component of the electrical device  20  when the power control module  30  and the electrical device  20  are in the assembled condition as shown in  FIGS. 1 ,  4 ,  7 ,  8  and  16 . 
     The connection arrangement  50  includes a first connecting portion  60  and second connecting portion  70 . The first connecting portion  60  may be associated with either the power control module  30  or the electrical device  20  and the second connecting portion  70  may be associated with the other one of the power control module  30  and the electrical device  20 . In the embodiment illustrated in the Figures, the first connecting portion  60  is associated with the power control module  30  and the second connecting portion  70  is associated with the electrical device  20 . 
     In general, the first connecting portion  60  includes at least one first locking member  65  and the second connecting portion  70  includes at least one second locking member  75 . As will be described in more detail below, the connection arrangement  50  facilitates connection of the power control module  30  and one of the modular electrical devices  20  by first moving the module  30  and the electrical device  20 , and the first connecting portion  60  and the second connecting portion  70 , towards each other so that the first and second connection portions  60 ,  70  come into engagement. Once the first and second connection portions  60 ,  70  come into engagement the first and second locking members  65 ,  75  are in a locking position. In the locking position, the first and second locking members  65 ,  75  are movable relative to each other between an unlocked position and a locked position. In the unlocked position, the first and second locking members  65 ,  75  are movable relative to each other such that the first and second connection portions  60 ,  70 , and the power control module  30  and the modular electrical device  20 , can be separated from each other. In the locked position, the first and second locking members  65 ,  75  are not movable relative to each other such that the first and second connection portions  60 ,  70 , and the power control module  30  and the modular electrical device  20 , are securely maintained in engagement with each other. Furthermore, the first and second locking members  65 ,  75  are configured such that in the locked position the first and second connection portions  60 ,  70  are compressed together. This can be achieved by configuring the first and second locking members  65 ,  75  to engage each other in an interference fit. 
     Thus, when the first and second locking members  65 ,  75  are in the locked position the power control module  30  and the modular electrical device  20  are compressed, or clamped, together so as to effectively render the power control module  30  and the modular electrical device  20  as a unitary, integrated assembly. Thus, an advantage of the power control module  30  and the modular electrical device  20  is that, when in use, the power control module  30  and the modular electrical device  20  have the feel of a unitary and integrated device in which any play between the power control module  30  and the modular electrical device  20  is substantially eliminated. Accordingly, in embodiments in which the power control module  30  includes a handle through which force is applied to the combined power control module  30  and the modular electrical device  20 , for example when applying pressure through the handle of the power control module  30  and the modular electrical device  20  upon a workpiece the feel that is provided to the user is one of a unitary and integrated device enabling precision work to be carried out on the workpiece. 
     In the embodiment illustrated in the Figures, and as can best be seen in  FIGS. 2 to 69 ,  10  and  12  to  15 , the first connecting portion  60  includes a first connection member  62  and the first locking member  65 . The first locking member  65  is spaced apart from the first connection member  62  along a first connecting axis X. The second connecting portion  70  includes a second connection member  72  and the second locking member  75  spaced apart from the second connection member  72  along a second connecting axis Y. As will be described in more detail below the connection arrangement  50  facilitates connection of the power control module  30  and one of the modular electrical devices  20  by first moving the module  30  and the electrical device  20 , and the first connecting portion  60  and the second connecting portion  70 , towards each other with the first connecting axis X converging with the second connecting axis Y so that the first and second connection members  62 ,  72  come into engagement as shown in  FIGS. 2 ,  3 ,  9 ,  10  and  15 . 
     When the first and second connection members  62 ,  72  are in engagement the power control module  30  and the modular electrical device  20  are then tilted relative to each other so that the first connecting axis X and the second connecting axis Y move in an arc or pivot relative to each other so that the first locking member  65  and the second locking member  75  also move in an arc or pivot relative to each other from a separated position until coming into engagement with each other in a locking position as shown in  FIGS. 1 ,  4 ,  7 ,  8  and  16 . In the locking position the first locking member  65  and the second locking member  75  are moveable relative to each other between a locked position and an unlocked position thereby providing a locked condition and an unlocked condition respectively. In the locked condition the first locking member  65  and the second locking member  75  are locked and compressed together and in the unlocked condition the first locking member  65  and the second locking member  75  are free to move relative to each other. 
     The connection arrangement  50  also facilitates separation of the power control module  30  and one of the modular electrical devices  20 . This is achieved by moving the first locking member  65  and the second locking member  75  relative to each other from the locked position to the unlocked position and thereby changing the condition of the first locking member  65  and the second locking member  75  from the locked condition to the unlocked condition. The power control module  30  and the modular electrical device  20  may then be tilted relative to each other so that the first connecting axis X and the second connecting axis Y move away from each other in an arc or pivoting motion to the position illustrated in  FIGS. 2 ,  3 ,  9 ,  10  and  15 . When the power control module  30  and the electrical device  20  are tilted so that the first connecting axis X and the second connecting axis Y move away from each other the first locking member  65  and the second locking member  75  also move in an arc or pivot away from each other. Then the module  30  and the electrical device  20  may be moved away from each other with the first connecting axis X converging with the second connecting axis Y so that the first and second connection members  62 ,  72  are moved out of engagement to the position illustrated in  FIGS. 11 to 14 . 
     In another form of the connection arrangement  50 , not illustrated, the first connecting portion  60  includes a pair of the first locking members  65 . The pair of first locking members  65  are spaced apart from each other along the first connecting axis X. The second connecting portion  70  includes a pair of the second locking members  75  spaced apart from each other along a second connecting axis Y. The connection arrangement  50  facilitates connection of the power control module  30  and one of the modular electrical devices  20  by first moving the module  30  and the electrical device  20 , and the first connecting portion  60  and the second connecting portion  70 , towards each other in a direction substantially perpendicular to the first connecting axis X and the second connecting axis Y so that the pairs of first and second locking members  65 ,  75  are in a locking position. In the locking position, when the first and second connection portions  60 ,  70  are mated together, the pairs of first and second locking members  65 ,  75  are movable relative to each other between a locked position and an unlocked position, wherein in the locked position the first and second connection  60 ,  70  portions are locked and compressed together and in the unlocked position the first and second connection portions  60 ,  70  are separable. 
     Preferred embodiments of the connection arrangement  50  will now be described in more detail below with reference to the embodiments illustrated in the Figures. As mentioned above, the first connecting portion  60  includes the first connection member  62  and the first locking member  65 . The first connecting portion  60  is arranged along an upper portion of the housing  32  at the top  39  of the handle  34 . Thus, the first connecting portion  60  is positioned distally from the bottom  37  of the handle  34  and the cable  52  extending therefrom. The first connecting portion  60  is also positioned immediately adjacent to the trigger  38 . 
     The first connection member  62  includes an elongate slot  64  extending generally in a direction Q from the rear  35  of the handle  34  to the front  36  of the handle  34 . The slot  64  of the first connection member  62  extends beyond and overhangs the front  36  of the handle  34 . The slot  64  also extends generally in a direction transverse to a direction A extending from the bottom  37  to the top  39  of the handle  34 . Accordingly, the power control module  30  is configured so that when a user grips the handle portion  34  the user&#39;s forefinger wraps around the trigger mechanism  38  and the base of the user&#39;s palm rests against the rear end  35  of the of the handle portion  34  and the direction Q in which the slot  64  generally extends is also generally in the direction from the base of the user&#39;s palm towards the user&#39;s forefinger when the user grips the handle  34 . 
     The first locking member  65  is spaced apart from the first connection member  62  along the first connecting axis X. In the embodiment illustrated in the figures the first connecting axis X is generally transverse to a direction of the axis A extending from the bottom  37  to the top  39  of the handle  34  and is generally transverse to the direction Q extending from the rear  35  to the front  36  of the handle  34 . In the illustrated embodiments, the axis X is substantially perpendicular to the direction A and is substantially perpendicular to the direction Q. The first connecting axis X also extends in a direction from one of the opposite lateral sides  31 ,  33  of the handle  34  to the other one of the opposite lateral sides  31 ,  33 . The first locking member  65  includes a catch  66  upstanding from a first connection face  61  of the first connecting portion  60  wherein the first connection face  61  extends in a plane aligned with the first connecting axis X and the direction Q from the rear  35  to the front  36  of the handle  34 . 
     The second connecting portion  70  is arranged on a housing  22  of the device  20 . In the embodiment illustrated in the Figures, in which the device  20  is a power drill, the housing  22  contains an electric motor assembly  19  connected to a driven member  21  in the form of a chuck. The driven member  21  projects from a forward end  23  of the housing  22 . Opposite the forward end  23  is a rear end  24  of the housing  22 . The housing  22  also includes a top end  25  and an opposite bottom end  26 . The housing  22  also includes a pair of opposite lateral sides  27 ,  28 . The top and bottom ends  25 ,  26  each extend between the forward end  23  and the rear end  24  of the housing  22 . The second connecting portion  70  is provided at the bottom end  26  of the housing  22 . As can be appreciated, in other embodiments in which the device  20  is a power drill module, or some other form of power tool or electrical device module, the second connecting portion  70  may not necessarily be located at a bottom end  26  of the housing  22  but may be located anywhere on the housing  22  such as the top end  25 , one of the lateral sides  27 ,  28  or may be positioned on any one or more of the top and bottom ends  25 ,  26  and the lateral sides  27 ,  28  of the housing  22 . 
     As mentioned above, the second connecting portion  70  includes the second connection member  72 . The second connection member  72  is in the form of a ridge  74  extending generally in a direction R from the forward end  23  to the rear end  24  of the housing  22 . Also as mentioned above, the second connecting portion  70  includes the second locking member  75  which is spaced apart from the second connection member  72  along the second connecting axis Y. The second connecting axis X is generally transverse to a direction B extending from the bottom end  26  to the top end  25  of the housing  22  and is generally transverse to the direction R extending from the forward end  23  to the rear end  24  of the housing  22 . In the embodiments illustrated, the axis Y is substantially perpendicular to the direction B and is substantially perpendicular to the direction R. 
     The second connecting axis Y also extends in a direction from one of the pair of opposite lateral sides  27 ,  28  to the other one of the pair of opposite lateral sides  27 ,  28  of the housing  22 . The second connecting portion  70  includes a second connection face  71  that extends in a plane aligned with the second connecting axis Y and the direction R from the forward end  23  to the rear end  24  of the housing  22 . 
     The interaction between the first connecting portion  60  and the second connecting portion  70 , in the embodiment of the connection arrangement  50  illustrated in the Figures, will now be explained in more detail. In order to mate the first connecting portion  60  and the second connecting portion  70  a user must hold the power control module  30  and the device  20  relative to each other so that the front  36  of the module  30  faces towards the forward end  23  of the device  20  and the rear  35  of the module  30  is positioned substantially in alignment with the rear end  24  of the device  20 . In this orientation, the direction Q from the rear  35  to the front  36  of the handle  34  and the direction R from the forward end  23  to the rear end  24  of the housing  22  of the device  20  are substantially in alignment. The module  30  must also be held relative to the device  20  such that the first connecting axis X is angularly displaced and converges with the second connecting axis Y. In other words, the first connection face  61  is positioned at an angle to the second connection face  71 . The first and second connection members  62 ,  72  are then moved towards each other such that the ridge  74  fits within the slot  64 . The slot  64  has a curved profile and the ridge  74  also has a curved profile to enable a user to subsequently pivot the module  30  relative to the device  20  such that the first connection face  61  pivots towards the second connection face  71  such that the first locking member  65  also pivots in an arc towards the second locking member  75  until the first locking member  65  and the second locking member  75  come into engagement with each other. The user must then apply lateral force to the one of the sides  33  of the handle  34  opposite the side of the connection face  61  where the first locking member  65  is located in a direction towards the opposite side  31  of the handle  34  until the first and second locking members  65 ,  75  engage each other in a locked position. In this position, the first connection face  61  is positioned face to face with the second connection face  71 . 
     In the embodiment illustrated in  FIGS. 1 to 6 , the first locking member  65  is in the form of a catch  66  and the second locking member  75  is an anchor in the form of a rod  77 . The catch  66  is elongated in the direction of the axis Q and the rod is elongated in the direction of the axis R. The catch  66  has a hook shaped profile and includes an opening  67  that is elongated in the direction of the axis Q and is arranged to receive a rod  77  of the second locking member  75  when the first and second locking members  65 ,  75  are moved to the locking position wherein the first and second connection faces  61 ,  71  are face to face with each other. The catch  66  includes a biasing mechanism (not shown) that is operable to cause the catch  66  to move such that the rod  77  is received within the opening  67 . The catch  66  is also connected to a manually operated actuator (not shown) that is operable by a user to hold the catch  66  in position with the rod  77  received within the opening  67  to prevent separation of the rod  77  from the catch  66  and thereby prevent separation of the first and second locking members  65 ,  75 . 
     In the embodiment illustrated in  FIGS. 7 to 16 , the first locking member  65   a  includes a catch in the form of a plate  66   a  including a plurality of apertures  67   a  arranged in a row. The second locking member  75   a  includes an anchor in the form of a base  77   a  including a plurality of hook members  78   a  arranged in a row and extending from the base  77   a.  The hook members  78   a  each include an upright portion  79   a  extending from the base  77   a  and a transverse portion  80   a  extending forward from the upright portion  79   a.  The transverse portion  80   a  has a tapering edge  82   a  that faces towards the base  77   a . Thus, each of the hook members  78   a  defines a forwardly extending slot  81  a between the base  77   a  and the tapering edge  82   a  of the transverse portion  80   a.  The tapering edge  82   a  of the transverse portion  80   a  provides the slot  81  a with a tapered profile such that the slot  81  a has an open end  85   a  and an opposite closed end  86   a  wherein the open end  85   a  has a greater width dimension than the closed end  86   a.  The slot  81   a  tapers from the wider open end  85   a  to the narrower closed end  86   a.    
     Each of the hook members  78   a  of the second locking member  75   a  is configured to be received within a respective one of the apertures  67   a  in the sheet  66   a  of the second locking member  65   a.  However, the plate  66   a  and the plurality of apertures  67   a  of the first locking member  65   a  can move linearly in a fore and aft direction relative to the housing  22  of the device  20 . The plate  66   a  and the plurality of apertures  67   a  are biased by a biasing member  90   a,  which may be a helical spring or any other form of biasing member, towards a resting position that is in the aft direction in which the apertures  67   a  are not aligned with the hook members  78   a  and so cannot receive the hook members  78   a  therethrough. The first locking member  65   a  includes a pivoting detent  64   a  that is operable to pivot between a position in which the detent  64   a  abuts against an abutting surface  63   a  of the plate  66   a  and a position in which the detent  64   a  does not abut against the abutting surface  63   a.  When the detent  64   a  abuts the abutting surface  63   a  it maintains the plate  66   a  in a position that is forward of the resting position and counteracts the biasing force applied by the biasing member  78   a  so as to align the apertures  67   a  in the sheet  66   a  of the second locking member  65   a  with the hook members  78   a  of the second locking member  75   a.  When the hook members  78   a  are aligned with the apertures  67   a  they may be received through the apertures  67   a  in the sheet  66   a  of the second locking member  65   a.  When the hook members  78   a  are received through the apertures  67   a  one of the hook members  78   a  engages and moves the detent  64   a  out of abutment with the abutting surface  63   a  to allow the biasing member  78   a  to move the plate  66   a  to the aft resting position. 
     In another form (not shown) one of the hook members  78   a  can include a tapered surface that engages a surface of the plate  66   a  surrounding one of the apertures  67   a  to actuate the plate  66   a  against the biasing force applied by the biasing member  90   a  to a position in which the apertures  67   a  of the first locking member  65   a  are aligned with the hook members  78   a  to thereby receive the hook members  78   a  therethrough. 
     When the hook members  78   a  are initially received within the apertures  67   a  the first locking member  65   a  and the second locking member  75   a  and the plate  66   a  is in the forward position the first and second locking members  65   a,    75   a  are in the unlocked position relative to each other. After the hook members  78   a  are received within the apertures  67   a  the plate  66   a  and the plurality of apertures  67   a  can move linearly to the aft position and relative to the hook members  78   a  due to the biasing force applied by the biasing member  90   a.  When the plate  66   a  and the apertures  67   a  are in the aft position, as shown in  FIG. 16 , an edge region  68   a  adjacent to each of the apertures  67   a  is received within a respective one of the forwardly extending slots  81   a  of the hook members  78   a.  When the edge region  68   a  adjacent to each of the apertures  67   a  is received within a respective one of the slots  81   a  the first locking member  65   a  and the second locking member  75   a  are in the locked condition. When in the locked condition the first locking member  65   a  and the second locking member  75   a  are prevented from moving relative to each other thereby locking the first locking member  65   a  and the second locking member  75   a  together. 
     As the plate  66   a  begins to move to the aft position the edge regions  68   a  of the apertures  67   a  are initially received through the open ends  85   a  of the slots  81   a.  However, as the plate  66   a  continues to move further towards the aft position the tapering edge  82   a  begins to engage the edge region  68   a  of the aperture  67   a.  As the plate  66   a  moves yet further towards the aft position the tapering edge  82   a  engages the edge region  68   a  of the aperture  67   a  in a direction transverse to the direction of movement of the plate  66   a  relative to the hook members  78   a  with increasing force. In other words, the tapering edge  82   a  engages the edge region  68   a  of the aperture  67   a  in an interference fit. This is because the plate  66   a  is fixed to the first connecting portion  60  of the housing  22  of the electrical device  20  from movement transverse to the direction of movement of the plate  66   a  relative to the hook members  78   a  and the hook members  78   a  are fixed from relative to the second connecting portion  70  of the housing  32  of the power control module  30  from movement transverse to the direction of movement of the plate  66   a  relative to the hook members  78   a.    
     Movement of the plate  66   a  of the first locking member  65   a  in the aft direction relative to the hook members  78   a  of the second locking member  75   a  results in abutment between the edge region  68   a  of the aperture  67   a  of the plate  66   a  and the tapering edge  82   a  of the hook member  78   a.  Abutment between the edge region  68   a  of the aperture  67   a  of the plate  66   a  and the tapering edge  82   a  of the hook member  78   a  results in preventing relative movement of the first and second locking members  65   a,    75   a . Because the edge  82   a  of the hook member  78   a  is tapered it is possible, by applying force to move the plate  66   a  in the aft direction, to impart an increasing amount of force of engagement of the edge  82   a  of the hook member  78   a  and the edge region  68   a  of the aperture  67   a  of the plate  66   a  and thereby impart a compression force between the first connecting portion  60  of the housing  22  of the electrical device  20  and the second connecting portion  70  of the housing  32  of the power control module  30 . Thus, the first and second locking members  65   a,    75   a  are configured to compress the first connecting portion  60  of the housing  22  of the electrical device  20  and the second connecting portion  70  of the housing  32  of the power control module  30  together. Thus, when the first and second locking members  65   a,    75   a  are in the locked position the power control module  30  and the modular electrical device  20  are compressed, or clamped, together so as to effectively render the power control module  30  and the modular electrical device  20  as a unitary, integrated assembly. 
     When it is required to separate the power control module  30  and the device  20  from each other the first connecting portion  60  and the second connecting portion  70  must be separated. A button  97   a  on the rear end  35  of the of the handle portion  34  which is mechanically coupled to the plate  66   a  and the plurality of apertures  67   a  of the first locking member  65   a.  Depressing the button  97   a  actuates the plate  66   a  and the plurality of apertures  67   a  in the forward direction to the position in which the apertures  67   a  of the first locking member  65   a  are aligned with the hook members  78   a.  When the apertures  67   a  of the first locking member  65   a  are aligned with the hook members  78   a  the power control module  30  and the device  20  may be tilted relative to each other such that the first and second locking members  65 ,  75  pivot about the first and second connection members  62 ,  72  to the separated position illustrated in  FIGS. 9 and 10 . When the hook members  78   a  are removed from within the apertures  67   a  in the sheet  66   a  of the second locking member  65   a  the hook members  78   a  disengages the detent  64   a.  The detent  64   a  is biased into abutment with the abutting surface  63   a  of the sheet  66   a  to maintain the plate  66   a  in the forward position ready for another reinsertion of the hook members  78   a  into the apertures  67   a  in the sheet  66   a  of the second locking member  65   a.    
     In another form of the connection arrangement  50 , not illustrated, the first connecting portion  60  includes a pair of the first locking members  65   a  in the form of a pair of the plates  66   a  each including a plurality of apertures  67   a  arranged in a row. The pair of first locking members  65   a  are spaced apart from each other along the first connecting axis X. The second connecting portion  70  includes a pair of the second locking members  75   a  in the form of a pair of the bases  77   a  each including a plurality of hook members  78   a  arranged in a row and extending from each of the bases  77   a.  The second locking members  75   a  are spaced apart from each other along a second connecting axis Y. The connection arrangement  50  facilitates connection of the power control module  30  and one of the modular electrical devices  20  by first moving the module  30  and the electrical device  20 , and the first connecting portion  60  and the second connecting portion  70 , towards each other in a direction substantially perpendicular to the first connecting axis X and the second connecting axis Y so that the pairs of first and second locking members  65   a,    75   a  are in a locking position. The pairs of first and second locking members  65   a,    75   a  operate substantially the same as the locking members  65   a ,  75   a  described above. In the locking position, when the first and second connection portions  60 ,  70  are mated together, the pairs of first and second locking members  65   a ,  75   a  are movable relative to each other between a locked position and an unlocked position, wherein in the locked position the first and second connection portions  60 ,  70  are locked and compressed together and in the unlocked position the first and second connection portions  60 ,  70  are separable. 
     In the embodiment illustrated in  FIGS. 17 to 19 , the modular assembly includes a connection arrangement for releasably connecting the electrical device  20  and the power control module  30 . The connection arrangement includes the first connecting portion  60  and the second connecting portion  70 . The first connecting portion  60  includes a first connection member  62  and the first locking member  65   b.  The first locking member  65   b  is spaced apart from the first connection member  62  along the first connecting axis X. The second connecting portion  70  includes a second connection member  72  and the second locking member  75   b  spaced apart from the second connection member  72  along the second connecting axis Y. The connection arrangement facilitates connection of the power control module  30  and one of the modular electrical devices  20  by first moving the module  30  and the electrical device  20 , and the first connecting portion  60  and the second connecting portion  70 , towards each other with the first connecting axis X converging with the second connecting axis Y so that the first and second connection members  62 ,  72  come into engagement in the same manner as illustrated in the embodiment shown in  FIGS. 2 ,  3 ,  9 ,  10  and  15 . 
     When the first and second connection members  62 ,  72  are in engagement the power control module  30  and the modular electrical device  20  are then tilted relative to each other so that the first connecting axis X and the second connecting axis Y move in an arc or pivot relative to each other so that the first locking member  65   b  and the second locking member  75   b  also move in an arc or pivot relative to each other from a separated position until coming into engagement with each other in a locking position in the same manner as illustrated in the embodiment shown in  FIGS. 1 ,  4 ,  7 ,  8  and  16 . In the locking position the first locking member  65   b  and the second locking member  75   b  are moveable relative to each other between a locked position and an unlocked position thereby providing a locked condition and an unlocked condition respectively. In the locked condition the first locking member  65   b  and the second locking member  75   b  are locked and compressed together and in the unlocked condition the first locking member  65   b  and the second locking member  75   b  are free to move relative to each other. 
     The connection arrangement  50   b  also facilitates separation of the power control module  30  and one of the modular electrical devices  20 . This is achieved by moving the first locking member  65   b  and the second locking member  75   b  relative to each other from the locked position to the unlocked position and thereby changing the condition of the first locking member  65   b  and the second locking member  75   b  from the locked condition to the unlocked condition. The power control module  30  and the modular electrical device  20  may then be tilted relative to each other so that the first connecting axis X and the second connecting axis Y move away from each other in an arc or pivoting motion to the position illustrated in  FIGS. 2 ,  3 ,  9 ,  10  and  15 . When the power control module  30  and the electrical device  20  are tilted so that the first connecting axis X and the second connecting axis Y move away from each other the first locking member  65   b  and the second locking member  75   b  also move in an arc or pivot away from each other. Then the module  30  and the electrical device  20  may be moved away from each other with the first connecting axis X converging with the second connecting axis Y so that the first and second connection members  62 ,  72  are moved out of engagement. 
     In the embodiment illustrated in  FIGS. 17 to 19 , the first locking member  65   b  includes a catch  66   b  upstanding from the first connection face  61  of the first connecting portion  60 . The catch  66   b  includes an upright portion  63   b  and a transverse portion  68   b  in the form of an elongated ridge depending from the upright portion  63   b.  The transverse portion  68   b  has a first abutting surface  64   b  that faces towards, and is substantially parallel to, the first connection face  61 . The first abutting surface  64   b  may be parallel or may slope relative to the first connection face  61 . A groove  67   b  is defined between the transverse portion  68   b  and the first connection face  61 . The transverse portion  68   b  also has a tapering or sloping edge  69   b  that faces away from, and is sloped relative to, the first connection face  61 . The second locking member  75   b  of the second connection portion  70  includes an anchor in the form of an elongated ridge  74   b  defining an elongated recess  77   b  within the second connection face  71 . The elongated recess  77   b  includes an upright recess portion  78   b  and a transverse recess portion  79   b  depending from the upright recess portion  78   b.  The transverse recess portion  79   b  has a second abutting surface  80   b  located below and facing away from the second connection face  71 . 
     Once the first and second connection portions  60 ,  70  come into engagement the first and second locking members  65   b,    75   b  are in the locking position. In the locking position, the catch  66   b  of the first locking member  65   b  is positioned within the recess  77   b  of the second locking member  75   b.  In the locking position the first and second locking members  65   b,    75   b  are movable relative to each other between an unlocked position and a locked position. In the unlocked position the upright portion  63   b  and the transverse portion  68   b  of the first locking member  65   b  are located within the upright recess portion  78   b  of the second locking member  75   b.  In the locked position, the upright portion  63   b  of the first locking member  65   b  is located within the upright recess portion  78   b  of the second locking member  75   b  and the transverse portion  68   b  of the first locking member  65   b  is located within the transverse recess portion  79   b  of the second locking member  65   b  such that the first and second abutting surfaces  64   b,    80   b  are in face to face contact and abut each other. The first abutting surface  64   b  may be sloped relative to the first connection face  61  such that when in abutment with the second abutting surface  80   b  a compression force, or a greater compression force, is applied between the first and second connection faces  61 ,  71 . In the unlocked position, the first and second locking members  65   b,    75   b  are movable relative to each other such that the first and second connection portions  60 ,  70 , and the power control module  30  and the modular electrical device  20 , can be separated from each other. In the locked position, the first and second locking members  65   b,    75   b  are not movable relative to each other such that the first and second connection portions  60 ,  70 , and the power control module  30  and the modular electrical device  20 , are securely maintained in engagement with each other. Furthermore, the first and second locking members  65   b,    75   b  are configured such that in the locked position the first and second connection portions  60 ,  70  are compressed together. 
     The first locking member  65   b  is biased by a spring or like biasing means towards a position in which when the first and second connection members  62 ,  72  are in engagement and the power control module  30  and the modular electrical device  20  are tilted relative to each other so that the first locking member  65   b  and the second locking member  75   b  are moved towards each other the contact surface  81   b  is engaged by the sloping edge  69   b  of the catch  66   b.  The second connection face  71  includes a sloping contact surface  81   b  located adjacent to the upright recess portion  78   b.  Continuing to move the first locking member  65   b  and the second locking member  75   b  towards each other causes the sloping edge  69   b  of the catch to slide over the sloping contact surface  81   b  and to be actuated against the biasing force acting on the first locking member  65   b  such that the sloping edge  69   b  of the catch clears the sloping contact surface  81   b.  When the sloping edge  69   b  clears the sloping contact surface  81   b  the upright portion  63   b  and the transverse portion  68   b  of the first locking member  65   b  can enter the upright recess portion  78   b  of the second locking member  75   b.  Continuing to move the first locking member  65   b  and the second locking member  75   b  towards each other causes the upright portion  63   b  and the transverse portion  68   b  of the first locking member  65   b  to enter the upright recess portion  78   b  to an extent that the transverse portion  68   b  of the first locking member  65   b  reaches the transverse recess portion  79   b  of the second locking member  75   b.  The transverse portion  68   b  of the first locking member  65   b  is then biased by the biasing force into the transverse recess portion  79   b  of the second locking member  75   b  such that the first and second abutting surfaces  64   b,    80   b  are in face to face contact and abut each other. As a result, the first locking member  65   b  and the second locking member  75   b  are in the locking position and, more particularly, are in the locked position in which the first locking member  65   b  and the second locking member  75   b  are locked together. 
     When it is required to separate the power control module  30  and the device  20  from each other the first connecting portion  60  and the second connecting portion  70  must be separated. A button  97   b  on one of the lateral sides  31 ,  33  of the handle  34  is mechanically coupled to the first locking member  65   b.  Depressing the button  97   b  actuates the first locking member  65   b  against the biasing force acting on the first locking member  65   b  such that the first locking member  65   b  is moved from the locked position to the unlocked position. The power control module  30  and the modular electrical device  20  can then be tilted relative to each other so that the first locking member  65   b  and the second locking member  75   b  also move in an arc or pivot relative to each other from the locking position to the separated position. The first and second connection members  62 ,  72  can then be moved out of engagement such that the power control module  30  and the modular electrical device  20  are thereby completely separated. 
     The power control module  30  also includes a trigger lock for preventing operation of the trigger  38  unless the first connecting portion  60  and the second connecting portion  70  are mated together and the first locking member  65  and the second locking member  75  are locked together. The trigger lock is also operable for preventing operation of the trigger  38  when the button  97   a,    97   b  is depressed to separate the power control module  30  and the device  20  from each other. The trigger lock for preventing operation of the trigger  38  may take any suitable form. In the embodiment illustrated in  FIGS. 7 to 16  the trigger lock for preventing operation of the trigger  38  is in the form of a pivoting member  95   a  that pivots fore and aft as the plate  66   a  including the plurality of apertures  67   a  moves fore and aft. When the plate  66   a  is in the forward position the pivoting member  95   a  abuts against a rearward surface of the trigger  38  to prevent depression of the trigger  38  and transmission of electrical current from the electrical power source via the cable  52  to the motor  19  or other electrically powered functional component of the device  20 . When the plate  66   a  is in the rearward position, such as when the first locking member  65   a  and the second locking member  75   a  are in the locked condition, the pivoting member  95   a  does not abut against a rearward surface of the trigger  38  to enable depression of the trigger  38  and transmission of electrical current from the electrical power source via the cable  52  to the motor  19  or other electrically powered functional component of the device  20 . In the embodiment in  FIGS. 17 to 19  the trigger lock is in the form of a depressable member  95   b  in the first connecting face  61  of the power control module  30  that is engaged by a protuberance  96   b  on the second connecting face  71  of the electrical device  20  when the first connecting portion  60  and the second connecting portion  70  are engaged. The trigger  38  can only be operated when the depressable member  95   b  is depressed by the protuberance  96   b  when the power control module  30  and the electrical device  20  are engaged together. Furthermore, the power control module includes a second trigger lock (not shown) that is engaged when the button  97   b  for releasing or disengaging the first and second locking members  65   b,    75   b  is depressed to prevent operation of the trigger  38 . The second trigger lock is also operable for preventing the button  97   b  for releasing or disengaging the first and second locking members  65   b,    75   b  from being depressed when the trigger  38  is in operation, namely when the trigger  38  is being depressed by a user&#39;s finger. 
     In each of the embodiments illustrated in the Figures, the first connecting portion  60  also includes a first electrical contact  69  that is positioned within a recess  68  within the first connection face  61  of the housing  32  of the module  30 . The contact  69  is positioned within the recess  68  such that when the module  30  is separated from the device  20  a user cannot access the contact  69  or at least inadvertently touch the contact  69 . The second connecting portion  70  also includes a second electrical contact  79  that projects from and is upstanding from the second connection face  71 . The second contact  69  is arranged so as to fit within the recess  68  and to engage the first electrical contact  69  when the first connecting portion  60  mates with the second connecting portion  70  in the manner described above. The first electrical contact  69  of the module  30  is in electrical contact with the switch assembly of the module  30  and the second electrical contact  69  is in electrical contact with the motor  19  or any other electrically powered functional component of the device  20 . Thus, when the first and second electrical contacts  69 ,  79  are in engagement with each other manual operation of the trigger  38  actuates the switch assembly to facilitate the transmission of electrical current from the electrical power source via the cable  52  to the motor  19  or other electrically powered functional component of the device  20  to thereby operate the device  20 . 
     In the embodiments illustrated in  FIGS. 1 to 6  and  17  to  19 , the first connection member  62  includes an elongate slot  64  extending in the direction Q and the second connection member  72  is in the form of ridge  74  extending generally in the direction R. Also, the first locking member  65 ,  65   b  is in the form of a catch  66 ,  66   b  having an opening or groove  67 ,  67   b  that is elongated in the direction of the axis Q and the second locking member  75 ,  75   b  is an anchor in the form of a rod  77  or ridge  74   b  defining a recess  77   b  elongated in the direction of the axis R. When the first connecting portion  60  and the second connecting portion  70  mate with each other the first connection member  62  and the second connection member  72  come into engagement with each other as a result of the ridge  74  fitting within the slot  64  and the first and second locking members  65 ,  65   b,    75 ,  75   b  engage each other such that the elongated opening or groove  67 ,  67   b  of the catch  66 ,  66   b  receives the rod  77  or ridge  74   b  of the second locking member  75 ,  75   b  when the first and second locking members  65 ,  65   b,    75 ,  75   b  are moved to the locking position. In this position, the first connection face  61  is positioned face to face with the second connection face  71 . 
     An advantage of the embodiments of the invention described above is that the first connection member  62  and the second connection member  72  contact and engage each other along an elongated length in the directions Q and R, which when the first connection member  62  and the second connection member  72  are in contact, the directions Q and R are in the same direction. Also, the first and second locking members  65 ,  65   a,    65   b,    75 ,  75   a,    75   b  contact and engage each other along an elongated length in the directions Q and R. Thus, when a user operates the assembled electrical device  20  and power control module  30  by gripping the handle  34  and applies a force to the handle  34  in a direction from the rear of the handle  35  towards the front of the handle  36  that force is transmitted to the device  20  along the connection between the first connection member  62  and the second connection member  72  and the first and second locking members  65 ,  65   a,    65   b,    75 ,  75   a,    75   b  along an elongated length in the directions Q and R. In so doing, the load is spread between the first connection member  62  and the second connection member  72  and the first and second locking members  65 ,  65   a,    65   b,    75 ,  75   a,    75   b  and is spread along the respective elongated lengths thereof. Also, any load applied in a lateral direction to the handle  35  in a direction along the axis X will result in a load being transferred to or from the handle  34  from or to the device  20  which load is spread along the respective elongated lengths of the first connection member  62  and the second connection member  72  and the first and second locking members  65 ,  65   a,    65   b,    75 ,  75   a,    75   b.    
     As shown in  FIGS. 1 to 5 ,  7 ,  9 ,  11 ,  15  and  16  the trigger mechanism  38  includes a dial  38   a  that is operably connected to a device that varies the current and/or voltage flow from the power supply to the electrically powered functional component of the electrical device  20  when the power control module  30  and the electrical device  20  are in the assembled condition as shown in  FIGS. 1 ,  4 ,  7 ,  8  and  16 . The device that varies the current and or voltage from the power supply to the electrical device  20  may be any device suitable for this purpose and may include a resistor constructed so that its resistance value may be changed without interrupting the circuit to which it is connected, also known as variable resistor. The dial  38   a  is operable by a user to adjust the variable resistor to vary the flow of current from the power supply to the electrical device  20 . 
     The first electrical contact  69  includes three separate contacts that are positioned within the recess  68  within the first connection face  61  of the housing  32  of the power control module  30 . One electrical contact is a negative terminal and the other two are positive terminals. One positive terminal receives current in an on or off fashion whereas the other positive terminal receives variable current and/or voltage from the trigger mechanism  38 . The second connecting portion  70  also includes a second electrical contact  79 . However, the second electrical contact  79  includes two electrical contacts, one for contacting the negative terminal and the other for contacting either one of the positive terminals so as to receive current in an on or off fashion or to receive a variable current or voltage. The aforementioned arrangement enables the power control module  30  to mate with a variety of modular electrical devices  20  and to enable the trigger mechanism  38  to supply power either in an on or off fashion or in a variable fashion as appropriate for the electrical device  20 . 
     In another form of the power control module (not shown) which includes either and integral or a removal power supply battery providing DC power, as opposed to AC power in the previous embodiments, the first electrical contact includes five separate contacts that are positioned within the recess within the first connection face of the housing of the power control module. Two electrical contacts reversibly act as positive and negative terminals for reversibly providing power to the tool module to provide, for example, forward and reverse modes of operation of the tool module. Another, two terminals act as positive and negative terminals for another electrically powered device module for connection to the power control module, such as a light emitting device. Another terminal acts as a means for providing sensor signals to a charger when the power control module is mounted to a charger for charging the battery. The terminal feeds information to the charger about the amount of charge in the battery. The terminal may be connected to the battery to provide information about the voltage in the battery or to provide information about the resistance in the battery. Alternatively, the terminal may be connected to a sensor, such as a temperature sensor, to provide information about the charge in the battery. One positive terminal receives current in an on or off fashion whereas the other positive terminal receives variable current and/or voltage from the trigger mechanism  38 . The second connecting portion  70  also includes a second electrical contact  79 . However, the second electrical contact  79  includes two electrical contacts, one for contacting the negative terminal and the other for contacting either one of the positive terminals so as to receive current in an on or off fashion or to receive a variable current or voltage. The aforementioned arrangement enables the power control module  30  to mate with a variety of modular electrical devices  20  and to enable the trigger mechanism  38  to supply power either in an on or off fashion or in a variable fashion as appropriate for the electrical device  20 . 
     Various forms of electrical device  20  that are connectable to the power control module  30  may include an electrically powered functional component that is capable of, or suited to, receiving a variable flow of current from the power supply. Examples of such electrical devices include power drills, angle grinders, disc or belt sanders, light emitting devices to name but a few. In such cases adjustment of the variable resistor by operation of the dial  38   a  in conjunction with manual operation of the trigger  38  results in varying the amount of the power supplied to the electrically powered functional component. In the case of electrically powered functional components that are electric motors adjustment of the variable resistor by operation of the dial  38   a  will result in adjustment of the speed of rotation of the motor and/or adjustment of the amount of torque supplied by the motor. In the case of electrically powered functional components that are light emitting device or other static electrically powered devices adjustment of the variable resistor by operation of the dial  38   a  will result in adjustment of the intensity of light emitted by the device or adjustment of the intensity of whatever output is associated with the electrically powered functional component. 
     Not all forms of electrical device  20  that are connectable to the power control module  30  may include an electrically powered functional component that is capable of, or suited to, a variable flow of current from the power supply and in such cases the power control module  30  and the electrical device  20  may include a device or mechanism for preventing the adjustment of the variable resistor and/or operation of the dial  38   a.    
     As can be appreciated, an advantage of the fact that the power control module  30  includes a device that varies the current flow from the power supply to the electrically powered functional component of the electrical device  20  when the power control module  30  and the electrical device  20  are in the assembled condition is that each electrical device  20  capable of connection to the power control module  30  need not include such a device. Thus, by including the device that varies the current flow from the power supply to the electrically powered functional component of the electrical device  20  in the power control module  30  this component need not be included in each electrical device  20  which means that the cost of manufacturing the electrical devices  20  is reduced. 
     Although in the embodiments illustrated in the Figures, the device  20  is in a form of a power drill, it is to be appreciated that the device  20  may be any other device requiring electrical power to perform a function, such as any other handheld power tool such as a power saw, power screwdriver, power percussion or hammer drill, angle grinder, belt sander or disc sander, electrically powered gardening tool, such as a garden trimmer, edge trimmer, hedge trimmer. Alternatively, the device  20  may be of a type which does not include an electrically powered motor but may include another electrically powered functional component such as a light source, a radio or a digital sound recording playback device, to name but a few. 
     Finally, it is to be understood that various alterations, modifications and/or additions may be introduced into the constructions and arrangements of the parts previously described without departing from the spirit or ambit of the invention.