WO2007098785A1

WO2007098785A1 - Appliances with battery packs

Info

Publication number: WO2007098785A1
Application number: PCT/EP2006/001989
Authority: WO
Inventors: Matthew White
Original assignee: B & Q Plc
Priority date: 2006-02-28
Filing date: 2006-02-28
Publication date: 2007-09-07

Abstract

A battery array comprising AA batteries is utilised in a battery pack for use with electrical appliances especially power tools. The battery array may also be used with a battery pack which comprises an actuated ejection mechanism associated with the terminal block of the battery pack and/or a battery pack housing which comprises a terminal post at an angle of between 5 and 95° in relation to the top surface of the battery pack.

Description

APPLIANCES WITH BATTERY PACKS

The present invention relates to appliances with battery packs and in particular to power tools with battery packs and to engagement and ejection mechanisms for such battery packs.

There is an increasing use of rechargeable batteries with appliances and in particular power tools. In the power tool field tradesmen and DIY enthusiasts are turning to battery operated tools. Rechargeable battery packs are used to provide the power for many different types of portable, electrically powered tools. The integration of the battery pack into this type of tool eliminates the need to provide the tool with a power cord that is connected to an external power source. A typical rechargeable battery pack includes a number of rechargeable battery cells, current storing cells that are used are Sub-C NiCd cells. These cells are connected together to form what is referred to as a cell cluster. The cell cluster is contained within a housing that forms the body of the battery pack and the housing has exposed contacts. The contacts serve as the conductive members through which current is stored in the cell cluster and drawn out of the cell cluster. These conventional battery packs lack versatility and are cumbersome to use.

With the greater use of battery operated tools, there is a growing desire for tools with increased power, extended battery life, longer durability and ease of use especially in the engagement and removal of the battery packs. However, as more power and extended battery life is required this has resulted in increase in battery size and weight making engagement and removal of battery packs increasingly more difficult.

Typically with hand held power tools the rechargeable battery pack is located on the base of the tool and is disengaged vertically from the base of the tool. Conventionally, in order to remove a battery pack from the tool it is normally necessary to press a catch release member in a direction generally perpendicular to the direction in which the battery pack is pulled to effect its removal from the tool appliance. The battery pack is then removed, usually with the assistance of gravity on the battery pack or by the user physically pulling the battery pack out of engagement with the tool. This type of catch release mechanism is used generally because it is thought to be easier to design and manufacture. However, it has the drawback than it generally renders the removal of the battery pack a moderately intricate manual procedure especially for

1 CONFIRMATION G⁽H₁ larger and heavier battery packs. Such an intricate procedure can be too difficult for some people, especially the elderly, the infirm or the disabled. Furthermore, such conventional release mechanisms generally require a two-step release procedure.

An example of such conventional battery packs and release mechanisms is described in United States Patent Application No. 5,213,913. Here, the latching mechanisms, when moved, allow gravity to drop the battery vertically from the housing. Thus, there was no need for a biasing force to remove the battery pack from the tool housing. However with this sort of mechanism the weight of the battery pack can make it difficult to remove the battery pack in a controlled fashion with one hand as the other hand is required to hold the body of the power tool.

An alternative arrangement to that described in United States Patent Application No. 5,213,913, is described in European Published Patent Application No. 1289032 A1. In this application a mechanism for engagement is described in which the battery pack is attached via sliding engagement with the base of the power tool in a horizontal fashion. The battery pack and base of the tool both have horizontal cooperating engagement surfaces. These battery packs are engaged and removed from engagement with the base by horizontal movement and without the aid of gravity. For larger battery packs it is necessary to use complicated ejection mechanisms.

In many of these prior art mechanisms easy alignment and engagement of the battery pack for engagement with the main body of the electrical appliance is problematic.

GB 2,380,761 describes a removable power source, in which removal is effected by an actuating mechanism that may be operated easily with one hand with the force required to disengage the mechanism being applied to the handle in the direction for removal of the power source. Although a relatively easy mechanism to operate further improvements are desirable.

There is a need for more easily adaptable and compact battery packs for use with power tools that are able to provide adequate power to the tool whilst at the same time being relatively easy to engage and remove from the power tool. The present invention in three aspects provides a new form of battery pack, a new battery pack ejection mechanism and a new battery pack engagement mechanism each of which may be used individually, in combination with each other or all together in a battery pack for use with appliances preferably power tools. This application discloses an improved battery pack arrangement of the rechargeable type, which avoids disadvantages of prior battery packs, while affording additional structural and operating advantages. In connection with the foregoing feature, another feature is the provision of a battery pack which can be directly and easily engaged and disengaged from an appliance preferably a cordless power tool.

The invention in all aspects is applicable generally to electrical appliances which have their own power source in addition to, or instead of, an external source of power (e.g. mains electricity). However, the invention has particularly utility for cordless electrical appliances, i.e. appliances which are powered by their own power source rather than an external power source. The invention is applicable to substantially any electrical appliance having a removable power source. However, the invention is particularly applicable to appliances such as power tools (e.g. drills, saws, sanders and the like), garden tools (e.g. hedge trimmers, lawn trimmers, and the like), domestic appliances (e.g. portable vacuum cleaners and the like), torches, and other miscellaneous appliances. This list of appliances is not intended to be exhaustive but merely illustrative of the broad applicability of the invention.

The present invention in a first aspect is concerned with a new form of rechargeable battery pack and therefore provides a rechargeable battery pack said battery pack comprising a housing adapted to engage with an electrical appliance and a cell cluster disposed within said housing, said cell cluster including a cell array formed from a plurality of AA rechargeable cells.

In relation to the first aspect in a preferred embodiment the electrical appliance is a power tool, more preferably a cordless power tool and even more preferably a handheld power tool. It is preferred that the battery pack delivers a voltage within the range of 7.2V to 48V, preferably within the range of 9.6V to 48V, more preferably 12V to 48V and most preferably 18V to 48V. In a further preferred embodiment the AA batteries are metal hydrid batteries and most preferably are NiMh batteries. In a preferred embodiment each AA battery is 1.2V. When the cluster has a voltage of 10V it comprises 8 AA batteries, when it has a voltage of 12V it comprises 10 AA batteries, when it has a voltage of 18V it comprises 15 AA batteries, when it has a voltage of 24V it comprises 20 AA batteries, when it has a voltage of 48V it comprises 40 AA batteries. In a further preferred embodiment it is preferred that the battery pack deliver at least 1500 mAh, more preferably at least 1800 mAh, even more preferably at least 2000 mAh and most preferably at least 2200 mAh. In a further embodiment when the battery pack is an 18V battery pack it preferably has a weight of 700 grams or less, preferably 600 grams or less and more preferably 550 grams or less. When the battery pack is a 7.2V battery pack, preferably it has a weight of 45Og or less, preferably 40Og or less and most preferably 35Og or less. When the battery pack is a 9.6V battery pack, preferably it has a weight of 55Og or less, preferably 50Og or less and most preferably 45Og or less. When the battery pack is a 12V battery pack, preferably it has a weight of 70Og or less, preferably 65Og or less and most preferably 50Og or less. When the battery pack is a 24V battery pack, preferably it has a weight of 1000g or less, preferably 90Og or less and most preferably 80Og or less. When the battery pack is a 48V battery pack, preferably it has a weight of 200Og or less, preferably 175Og or less and most preferably 160Og or less. In a further preferred embodiment the AA batteries are arranged in a battery cell cluster and are arranged in the body of the battery pack in a horizontal arrangement in relation to the direction of engagement with the tool base.

The battery packs according to the first aspect may be used in power tool battery housings that are of a significantly smaller size than those of the prior art. This results in the use of less material and packaging for the housing. The battery packs of the present invention in all aspects offer improved ergonomics through smaller overall tool package or design flexibility. The reduced mass of the battery packs enables improved tool design and balance and allows the use of more powerful battery packs e.g. 48V with hand held tools.

The battery packs according to the first aspect may also be utilised in conventional sized battery housings. When used in this way a number of advantages may be achieved. The spare room generated in the battery housing may allow for improved cooling of the battery pack during use through convective or forced cooling (e.g. through built in fan). The additional room may be used for additional functions such as tool holders and bolt on functions and/or built in functions such as charger packs, stud sensors, or laser levels etc. The additional storage may be used for materials such as screws etc, for use with the tool. In a further embodiment the battery pack of the first aspect may be used in conventionally sized battery housing and this will allow additional battery configurations. In one embodiment the housing contains more than one configuration such as for example a self configuring battery combination with intelligence capable of being a low drain/high capacity battery pack or a high drain/low capacity pack. This arrangement would allow one battery pack to be used for all voltages and loads. For example at a 24V setting the battery pack would deliver power from 20 of the 1.2V cells but would then be switched to lower power e.g. 12V using only 10 1.2V cells. Dual battery packs could be accommodated for different functions e.g. an 18V pack could be utilised for main tool power whilst a smaller 2.4V component of the pack or a separate pack could be accommodated for another function such as a laser level or torch etc.

In a second aspect the present invention is concerned with a new ejection mechanism for battery packs. Therefore according to a second aspect, the present invention provides an electrical appliance comprising a main body and a removable rechargeable battery pack having a housing and projecting from the housing, a post portion comprising battery pack terminals, the post portion being engaged with the main body during use of the appliance, the battery pack being removable from the main body by being forced in a desired direction of disengagement with respect to the main body, wherein the post portion further comprises a catch member that engages with the main body to retain the power source in attachment therewith and the battery pack also including a catch release member which, when actuated by the applied force, releases the catch member from the main body to allow removal of the battery pack there from, the force required for actuation being applied in substantially the same direction for removal of the battery pack from the main body.

In a further embodiment of the second aspect the invention provides a removable rechargeable battery pack for engagement with an electrical appliance having a housing and projecting from the housing a post portion comprising battery pack terminals and a catch member, and associated with the catch member a catch release member, the post portion being engaged with the main body during use of the appliance and locked in position by means of the catch member engaging with the main body of the appliance, the battery pack being removable from the main body by being forced in a desired direction of disengagement with respect to the main body, the application of force in the desired direction actuating the catch release member to release the catch member from the body of the tool. According to preferred embodiments of the second aspect of the present invention, the removal of the power source from the appliance is substantially a single step procedure i.e. pulling the catch release member and pulling the terminal lock of the power source out of and away from the main body of the electrical appliance are preferably carried out at one and the same time as part of one and the same pulling motion. In a further preferred embodiment of this aspect the catch member is retained in engagement with the main body via means of a resilient bias, preferably a spring. In a preferred embodiment of the second aspect the catch member emerges from the rear face of the post portion for contact and engagement with the main body. In a preferred embodiment the catch member comprises an extended portion for engagement with the catch release member and in a further preferred embodiment the catch member and extended portion are pivotally mounted within the housing, the disengagement of the catch member being achieved by actuation on the extended portion by the catch release member to cause pivotal rotation of the catch member out of engagement with the main body. In a preferred embodiment the catch release member protrudes from the rear of the battery pack. In one embodiment the catch release member is a piece of plastic, metal or rope or other flexible materials attached to the internal catch member and protruding from the rear of the battery pack. In a further embodiment the end of the catch release member remote from the catch member is attached to the rear of the battery pack to define a handle, which aids easy actuation and release of the battery pack from the main body.

The invention according to the second aspect has the advantage that the actuation of the catch release member (which releases the catch member from the main body of the appliance to allow removal of the power source from the main body) is achieved by pulling the catch release member in substantially the same direction is the direction in which the power source is pulled with respect to the main body to effect its removal from the main body. This is advantageous because it makes removal of the power source from the main body of the appliance significantly easier than is the case with conventional power source removal systems. The location of the catch member within the post portion of the battery pack ensures that the engagement with the main body of the appliance is robust and secure. This advantage is further enhanced when the second aspect of the present invention is utilised in combination with the first aspect or the third aspect of the present invention or the first and third aspect of the present invention combined. In a third aspect the present invention provides for a new battery pack engagement mechanism, which ensures easy engagement and disengagement of the battery pack from an electrical appliance, preferably a power tool. In accordance with a third aspect of the present invention, there is provided a power tool with a main body having an engaging surface and a rechargeable battery pack having a contact surface in contact with the engagement surface of the main body, the main body comprising a cavity and the rechargeable battery pack comprising a post portion, both of which are configured to enable the post portion to engage with the cavity, characterised in that the post portion and cavity are configured, such that on insertion of the battery pack into the main body, they engage with each other in a plane that defines an angle of between 5 to 95° in relation to the plane of contact of the main body engaging surface and the battery pack contact surface.

In a preferred embodiment of the third aspect the post portion and cavity are configured in a plane which defines an angle of between 10 and 80°, more preferably 25 and 65°, even more preferably an angle of between 35 to 55°, in a most preferred embodiment the angle is substantially 45°.

In a further preferred embodiment of the third aspect the battery pack further comprises a secondary engagement means which co-operates with the post portion and cavity to enable engagement of the battery pack with the main body of the power tool. The secondary engagement means is located on the same surface of the battery pack as the post portion and preferably comprises one or more substantially planar blocks having a top surface that is in a plane substantially parallel with the plane of the contact surface of the battery pack. At least one of the edges of the block or blocks is at the same angle as the post portion and in a parallel plane to plane of engagement of the post portion and cavity. This edge engages with a corresponding surface within the main body when the battery pack is inserted into the main body. When the blocks are rectangular the other sides are substantially vertical with respect to the contact surface of the battery pack. The main body of the power tool has female engaging means that correspond to and co-operate with the secondary engaging means of the battery pack and in particular has an angled surface that is able to co-operate with and engage with the angled edge of the secondary engagement means. It is within the scope of the third embodiment that the battery pack has two or more e.g. three, post portions with corresponding cooperating cavities within the main body of the power tool. In a preferred embodiment the secondary engaging means is attached to the post portion. In a preferred embodiment the post portion is angled towards the front of the battery pack and the cavity is angled towards the front of the appliance. In this arrangement the battery pack is engaged with the main body of the power tool by engaging and pushing the battery pack in a generally forward motion, with disengagement being the reverse.

In a preferred embodiment of the third aspect the post portion further comprises terminals for engagement with corresponding contacts within the cavity of the main body. In a further preferred embodiment the plane of the contact surface of the battery pack is not horizontal with the plane of the base of the battery pack. In a preferred embodiment the plane of the contact surface is between 1 to 20°, more preferably 2 to 15°, even more preferably 2 to 10° and most preferably 3 to 8° from the horizontal with reference to the plane of the base of the battery pack. In a preferred embodiment the contact surface is angled towards the front of the battery pack. In a preferred embodiment of the third aspect the battery pack and main body further comprise the ejecting mechanism of the second aspect. In a further preferred embodiment of the third aspect it is preferred that the battery pack comprises the battery pack of the first aspect of the present invention.

It is in accordance with the present invention that any features as described in relation to any one or more aspects of the present invention may be combined with any of the features described in relation to one or more of the other aspects.

All aspects of the present invention will now be further described and illustrated with the following detailed description, taken in conjunction with the following figures and appended claims, other objects and advantages of the present invention will become apparent to those skilled in the art.

FIG. 1 is a perspective view of a rechargeable 18V battery pack according to the first aspect of the present invention;

FIG. 2 is a side elevation view of a rechargeable 18V battery pack according to the first aspect of the present invention;

FIG. 3 is sectional view of a battery pack according to the present invention incorporating all aspects of the present invention;

FIG. 4 is perspective view of a battery pack according to the present invention incorporating all aspects of the present invention;

FIG. 5 is a perspective view of a battery pack according to the present invention incorporating all aspects of the present invention;

FIG. 6 illustrates in side elevation a battery pack according to the present invention and incorporating all aspects of the present invention in engagement with a power tool main body and also in elevation a prior art power tool and battery pack;

FIG. 7 illustrates in side elevation a battery pack according to the present invention and incorporating all aspects of the present invention and also in elevation a prior art battery pack;

FIG. 8 illustrates in a partly-sectional elevation a battery pack according to the present invention and incorporating all aspects of the present invention and also a prior art battery pack;

FIG. 9 illustrates in plan view a battery pack according to the present invention and incorporating all aspects of the present invention and also a prior art battery pack; and

FIG. 10 illustrates in perspective view a battery pack according to the present invention and incorporating all aspects of the present invention and also a prior art battery pack.

With reference to Figure 1 there is shown a battery pack (1) according to the first aspect of the present invention. The battery pack (1) is an 18V battery pack comprising 15 1.2V AA NiMh cells (2) arranged in three horizontal rows, a configuration that is suitable for inclusion in a housing for engagement with an electrical appliance such as a power tool.

With reference to Figure 2 there is shown a battery pack (10) according to the first aspect of the present invention. The battery pack (10) is an 18V battery pack comprising 15 1.2V AA NiMh cells (20) arranged in horizontal rows. Also illustrated are arrangements of contacts between the cells (30), which enable the cells to be used as a cell array. Power is taken from the cell array via terminals (40) and (50). Figures 3 to 10 illustrates a battery pack incorporating all three aspects of the present invention. The battery pack (100) incorporates a cell array (101), which comprises 15 1.2V AA NiMh cells (102) to form an 18V cell array. The cell array (101) is enclosed within a battery pack housing (103). The housing (103) comprises a post portion (104) and secondary engagement means (105) in contact with the post portion (104). The post portion (104) is in a plane (A), which defines an angle of approximately 45° with the plane of the contact surface (106) of the battery pack (100). The front surface (107) of the secondary engagement means (105) is in a plane (B) which defines an angle of approximately 45° with reference to the plane of the contact surface (106) and is therefore in a parallel plane to the plane A of post portion (104). Also illustrated is the catch member (108) comprising an extended portion (109) and the combination being pivotally mounted in the housing (about point 110). The catch member (108) is rotatable about a pivot point (or fulcrum) (110). The extended portion (109) of the catch member (108) is in contact with the catch release member (116) which protrudes from the rear (111) of the battery pack (100). The end (112) of the catch release member (116) remote from the catch member (108) is attached to the rear and bottom (113) of the battery pack (100), thus defining a handle (114) which constitutes in combination with the internal parts of the mechanism the complete ejection release mechanism for the battery pack(100).

When the battery pack (100) is engaged with the main body of the power tool (not shown), the catch member (108) engages with the main body and prevents the battery pack (100) from disengaging from the power tool. In order to effect disengagement the handle (114) is grasped with one hand by the operative whilst the body of the tool is held with the other hand. Then the handle (114) is pulled in the direction indicated by arrow C in the figure; this pulling action causes the end of the handle (114) attached to the catch release member (116) to move towards the rear of the battery pack (111) and through attachment to the extended portion (109) of the catch member (108) causes the catch member (108) to rotate about the pivot point (110) to disengage from contact with the main body (not shown) and to be retracted within the post portion (104). In this position the battery pack (100) may now be easily removed form engagement with the power tool main body in a continuing and fluent single movement. On disengagement the battery pack (100) is easily retained in the hand of the operative because the catch release member (112) is in the form of a handle (114) which is being held by the operative to effect disengagement. The removal of the battery pack (100) is effected substantially in a single pulling manoeuvre in which the catch release member (112) is pulled in direction C and the whole battery pack (100) is pulled at substantially the same time. The catch member (108) is preferably retained in engagement with the main body of the power tool by a resilient means (115) e.g. in the form of a spring (as shown, a helical metal spring).

The secondary engagement means (105) also has a top surface (117) that is in a plane substantially parallel to the plane of the contact surface (106) of the battery pack (100). The catch member (108) protrudes from the rear surface (118) of the post portion (104). The post portion (104) preferably also comprises terminals (119), which are illustrated in figure 5.

Additional illustrated in figure 8 are the corresponding features of the power tool main body that are required to co-operate with the features of the battery pack (100) to enable secure engagement with the two components. The main body (130) has a cavity (124) that is in alignment with the post portion (104) of the battery pack (100). At the end of the cavity are electrical contacts (123) that engage with the terminals (119) of the battery pack (100). Also shown is the engaging surface (120) of the main body (130) that co-operates with the catch member (108) of the battery pack (100) to effect locking of the battery pack (100) into the main body (130) after engagement. Also shown is the female engaging means (121) designed to accommodate the secondary engagement means (105) of the battery pack (100). Also illustrated is the angled surface (122) of the female engaging means (121) that contacts with the front edge (107) of the battery pack (100) when inserted into and interlocked with the main body (130). The combination of the angled post portion (104) and the interlocking combination (107/122) and the catch member/engaging surface (108/120) results in a robust engagement and disengagement mechanism for a battery pack (100) for a power tool. The actuation of the catch member (108) via the handle (114) provides easy release, whilst the angled insertion of the battery pack (100) through angled post portion (104) is significantly easier than the prior art methods of engagement as the need for accurate alignment is less critical. This is enhanced further via the location of a curved region (131) between the post portion (104) and the secondary engagement means (105).

Claims

1. A rechargeable battery pack said battery pack comprising a housing adapted to engage with an electrical appliance and a cell cluster disposed within said housing, said cell cluster including a cell array formed from a plurality of AA rechargeable cells.

2. A battery pack according to claim 1 configured for use with a power tool.

3. A battery pack according to claim 2 wherein the power tool is a cordless hand held power tool.

4. An electrical appliance comprising a main body and a removable rechargeable battery pack having a housing and projecting from the housing, a post portion comprising battery pack terminals, the post portion being engaged with the main body during use of the appliance, the battery pack being removable from the main body by being forced in a desired direction of disengagement with respect to the main body, wherein the post portion further comprises a catch member that engages with the main body to retain the power source in attachment therewith and the battery pack also including a catch release member which, when actuated by the applied force, releases the catch member from the main body to allow removal of the battery pack there from, the force required for actuation being applied in substantially the same direction for removal of the battery pack from the main body.

5. A removable rechargeable battery pack for engagement with an electrical appliance having a housing and projecting from the housing a post portion comprising battery pack terminals and a catch member, and associated with the catch member a catch release member, the post portion being engaged with the main body during use of the appliance and locked in position by means of the catch member engaging with the main body of the appliance, the battery pack being removable from the main body by being forced in a desired direction of disengagement with respect to the main body, the application of force in the desired direction actuating the catch release member to release the catch member from the body of the tool.

6. A removable rechargeable battery pack according to claim 5 wherein the battery housing comprises a cell cluster disposed within said housing, said cell cluster including a cell array formed from a plurality of AA rechargeable cells

7. An electrical appliance preferably a power tool with a main body having an engaging surface and a rechargeable battery pack having a contact surface in contact with the engagement surface of the main body, the main body comprising a cavity and the rechargeable battery pack comprising a post portion, both of which are configured to enable the post portion to engage with the cavity, characterised in that the post portion and cavity are configured, such that on insertion of the battery pack into the main body, they engage with each other in a plane that defines an angle of between 5 to 95° in relation to the plane of contact of the main body engaging surface and the battery pack contact surface.

8. An electrical appliance according to claim 7 which comprises a battery pack according to claim 5 or 6.

9. An electrical appliance according to claim 4 or claim 7 which comprises a removable rechargeable battery pack according to any one of claims 1 to 3.