[0001] The present invention refers to an electronically driven mobile equipment comprising
a housing with a recess adapted for receiving at least one part of a battery pack.
The form of the recess corresponds to the form of the at least one part of the battery
pack, in order to allow insertion of the at least one part of the battery pack into
the recess for operating the mobile equipment by means of electric energy originating
from the battery pack.
[0002] Further, the invention refers to an electronic power supply unit, which can be connected
to an electronic mains power supply by means of an electric cable. The power supply
unit is adapted for use with an electronically driven mobile equipment of the above
mentioned kind.
[0003] Mobile equipment of the above identified kind is well known in the prior art. For
example, laptop computers are known which comprise a battery pack which can be inserted
into an external recess of the laptop's housing, thereby automatically establishing
an electronic connection between the electric contacts of the battery pack and the
corresponding electric contacts of the laptop. Laptop computers can be operated with
the electric energy originating from the battery pack for many hours.
[0004] If the battery has run down, an electric cable connected to the mains power supply
can be connected to a socket provided in the laptop's housing establishing a connection
between the mains power supply and the battery pack. An electric charging device is
located between the mains power supply and the battery pack for charging the battery
pack. The battery pack is located outside or inside the laptop's housing. While charging
the battery a laptop user can continue to use the laptop with the energy originating
from the battery pack. This is possible only because the laptop's power consumption
is less than the charging power provided by the charger allowing charging of the battery
contemporarily to a continuous use of the laptop.
[0005] In electronically driven mobile equipment which consumes more power than a laptop
computer, for example in electric power tools, in particular in hand guided electric
power tools such as grinders, polishers, sanders, planers, joining machines, edge
trimmers, vertical routers, saws, glazing machines, scouring machines, drills, screwdrivers,
mixers, and heat guns, it is at present not possible to connect the battery pack mounted
to the tool's housing to a mains power supply, for charging the battery pack when
the battery has run down and at the same time to continue to use the power tool. Therefore,
it is common practice in the field of electric power tools which can be operated with
the electric energy originating from a battery pack to simply replace an empty or
run-down battery pack by a fully or at least better loaded battery pack. Charging
of the battery packs is performed by means of separate external charging devices.
[0006] Furthermore, it is problematic with the laptop computers known from the prior art
that the battery pack remains in the recess and is electrically connected to the laptop's
electronic components, which provokes inevitably charging the battery pack each time
the laptop is connected to the mains power supply even though the battery might not
yet be fully run down. Each time the laptop is connected to the mains power supply
a charging cycle is initiated. This reduces the life cycle of the battery pack because
battery packs only endure a limited number of charging cycles.
[0007] The only way to avoid the automatic charging of the battery each time the laptop
is connected to the mains power supply is to remove the battery pack from the laptop.
However, this leaves an empty, unappealing recess in the laptop's housing which clearly
affects the aesthetic appearance and design of the laptop.
[0008] The same problems apply to other kinds of mobile equipment known from the prior art,
which can be electrically driven by means of electric energy from a battery pack as
well as with the electric energy originating from the mains power supply.
[0009] Therefore, it is an object of the present invention to provide for a mobile equipment
having a large power consumption, which can be operated by means of electric energy
originating from a battery pack and which can also be operated by means of electric
energy originating from a mains power supply without drawback for the battery pack
and the aesthetic appearance of the mobile equipment.
[0010] This object is solved by an electronically driven mobile equipment of the above identified
kind, characterized in that the mobile equipment comprises an electronic power supply
unit, which can be connected to an electronic mains power supply by means of an electric
cable. The power supply unit has a casing from which the cable emerges. The form of
at least one part of the casing corresponds to the form of the recess in order to
allow insertion of the at least one part of the power supply unit into the recess
after having removed the battery pack and to allow operation of the mobile equipment
by means of electric energy originating from the mains power supply.
[0011] The electronically driven mobile equipment according to the present invention has
the advantage that it can be operated with electric energy originating from a battery
pack as well as from a mains power supply. With other words, the mobile equipment
provides for a hybrid energy supply. The idea is to operate the mobile equipment in
a normal operation condition with electric energy originating from the mains power
supply. In that case the power supply unit would be neatly fitted inside the recess
located in the mobile equipment's housing. In this way the mobile equipment can be
easily operated for a longer period of time, even if the mobile equipment has a large
power consumption like, for example, a hand guided electric power tool. In case the
mobile equipment has to be used in a workspace with no mains power supply nearby or
in a narrow and difficult to access workspace, the electronic power supply unit can
be easily detached from the mobile equipment and removed from the mobile equipment's
housing. Then, the battery pack can be inserted into the recess provided externally
in the mobile equipment's housing. The battery pack provides for a safe power supply
for a restricted period of time. However, in practice this is not a real constraint,
because the mobile equipment is intended for use with the battery pack only in exceptional
cases from time to time. For the normal continuous operation of the mobile equipment
the electronic power supply unit is intended to be used.
[0012] It is further an advantage of the present invention that the design and the aesthetic
appearance of the mobile equipment is always appealing, no matter whether the mobile
equipment is operated with the battery pack or with the mains power supply. It does
not affect the design of the mobile equipment whether the power supply unit or the
battery pack is inserted into the recess of the mobile equipment's housing, because
both, the power supply unit as well as the battery pack, fit neatly into the recess
preferably leaving no gaps or free spaces between the housing on the one hand and
the casings of the inserted power supply unit and battery pack, respectively, on the
other hand. Preferably, the battery pack and the casing of the power supply unit have
similar designs so that the overall appearance and the design of the complete mobile
equipment comprising the power supply unit and the battery pack, respectively, is
essentially the same, no matter whether the power supply unit or the battery pack
is inserted into the housing's recess. In that preferred embodiment the only visible
difference between the power supply unit inserted into the recess and battery pack
into the recess is the electric cable emerging from the power supply unit's casing
and connecting the power supply unit to the mains power supply.
[0013] Finally, it is a further advantage of the present invention that the mobile equipment
can be operated by means of electric energy originating from the main power supply
for a long period of time without reducing the lifetime of the battery pack and without
provoking a deterioration of the capacity of the batteries, which could lead to a
damage and finally even to a complete failure of the battery pack. The reason for
this is that when the mobile equipment is operated by means of electric energy originating
from the mains power supply, the electronic power supply unit has to be inserted into
the recess and electronically connected to the electronic components of the mobile
equipment. In that case it is mandatory that the battery pack is detached from the
mobile equipment and removed from the recess and housing. Hence, repeating automatic
charging cycles or an overlong charging process of the batteries during operation
of the mobile equipment by means of electric energy originating from the mains power
supply is effectively avoided by removing the battery pack and replacing it with the
power supply unit.
[0014] According to a preferred embodiment of the present invention, it is suggested that
the power supply unit comprises power transformer means for transforming the energy
originating from the mains power supply into energy suitable for operating the mobile
equipment. The power transformer means located in the power supply unit's casing can
be, for example, but are not limited to: one or more printed circuit boards (PCBs),
coils of metal wire for realizing an inductive transformer, a programmable microprocessor,
electronic storage means, relays, electric switches, diodes, transistors, triacs and
other electronic components such as resistors, capacitors and inductances. All these
electronic components necessary for power transformation are located within the casing
of the power supply unit. Preferably, the power supply unit is adapted for receiving
an input voltage of 100 V to 380 V, preferably 110 V or 230 V, and an input frequency
of 50 Hz to 60 Hz. The output voltage preferably ranges between 12 V and 24 V, preferably
18 V. It is advantageous if the output voltage of the power supply unit corresponds
to the output voltage provided by the battery pack intended for use with the respective
mobile equipment. In that case the power supply unit can be simply replaced by the
battery pack without any electric transformation etc.
[0015] According to another preferred embodiment of the present invention, it is suggested
that the power supply unit is adapted to comply with the ATEX 95 equipment directive
94/9/EC. The directive 94/9/EC of the European Parliament and the Council of 23 March
1994 refers to the approximation of the laws of the Member States of the European
Union concerning equipment and protective systems intended for use in potentially
explosive atmospheres. For example, this directive stipulates that the electronic
power supply unit must not cause any sparks during its operation. With other words,
the power supply unit preferably used in the mobile equipment according to the present
invention is a so-called safety isolating transformer adapted for use in potentially
explosive atmospheres.
[0016] Preferably, the form of the casing of the power supply unit is such that the casing
resumes the form of the housing of the mobile equipment in the region of the recess,
when the electronic power supply unit is fully inserted into the recess. Similarly,
it is preferred that the form of the battery pack is such that it resumes the form
of the housing of the mobile equipment in the region of the recess, when the battery
pack is fully inserted into the recess. It is further preferred that the form of the
casing of the power supply unit conforms or is even identical to the form of the battery
pack. According to these preferred embodiments the design of the battery pack and
of the power supply unit's casing is such that - after insertion into the recess -
they nicely fit into the overall aesthetic appearance and design of the mobile equipment.
It is possible that at least part of the casing of the power supply unit or the battery
pack constitutes part of the mobile equipment's housing when the power supply unit
or the battery pack is fully inserted in the recess.
[0017] Depending on the type of mobile equipment, the power supply unit's casing and the
battery pack, respectively, can be formed to meet special needs of the mobile equipment.
For example, if the mobile equipment is a hand-guided electronic power tool, the power
supply unit's casing and the battery pack, respectively, can be formed like a handle
or grip in order to allow the user of the tool to easily grip and safely hold the
power tool during its operation. Similarly, if the mobile equipment was a laptop computer,
and if the recess for receiving the power supply unit and the battery pack, respectively,
was on the bottom of the laptop's housing, the power supply unit's casing and the
battery pack, respectively, could be provided with specially damped resting means
for safely placing the laptop onto a surface. If the recess was designed on the top
of the laptop's housing, the power supply unit's casing and the battery pack, respectively,
could be provided with some kind of input means for the laptop, for example a touchpad
and respective buttons. Furthermore, the casing of the power supply unit as well as
the battery pack could be provided with output means, such as a small display or colored
status lights, in order to provide a user of the mobile equipment with information
on the operation status of the mobile equipment and/or the power supply unit and the
battery pack, respectively, for example, with information on the battery's current
capacity and charge condition.
[0018] According to a preferred embodiment, the battery pack comprises at least one rechargeable
battery or battery cell. Depending on the number of batteries or battery cells used
in the battery pack and the way they are electrically interconnected with one another
(in series or parallel), the battery pack provides for different output voltages and
electric charges (ampere-hours, Ah). Of course, the more batteries or battery cells
the battery pack comprises, the heavier the mobile equipment with the inserted battery
pack will be. Therefore, for each mobile equipment driven by electric energy taken
from a battery pack inserted into the recess, a compromise has to be found between
the desired or requested minimum duration of operation with electric energy taken
from the battery pack on the one hand and a desired or required maximum weight and
size of the mobile equipment containing the battery pack inserted into the recess
on the other hand. For example, the battery pack of a hand-guided electronic power
tool should be adapted to operate the tool with electric energy from the battery pack
at maximum power temporarily in narrow and difficult-to-reach workspaces and/or where
no mains power supply socket is within reach.
[0019] According to a further preferred embodiment of the invention it is suggested that
the mobile equipment comprises means for securing the battery pack and the power supply
unit in the recess and for releasing them from the recess. Similarly, it is suggested
that the battery pack and the power supply unit comprise means for securing the battery
pack and the power supply unit in the recess and for releasing them from the recess.
Preferably, insertion and removal of the battery pack and the electronic power supply
unit should be easy and fast. Nonetheless, the battery pack and the power supply unit,
respectively, should be adapted to be connected safely to the housing of the mobile
equipment. In particular, a merely partial insertion of the battery pack and the power
supply unit, respectively, into the recess should be avoided. At the same time, it
should be avoided that a battery pack or a power supply unit inserted into the recess
undesirably falls out of the recess during operation of the mobile equipment, for
example, caused by a shock or vibrations. For this reason it is suggested that the
mobile equipment and/or the power supply unit and the battery pack are equipped with
means for securing the battery pack and the power supply unit in the recess and for
releasing them from the recess upon a defined user activity and not just upon shock
or vibrations.
[0020] The securing means could comprise, for example, a permanent magnet located in the
recess or in the power supply unit and the battery pack. The respective corresponding
part, i.e. the power supply unit and the battery pack, respectively, (with the permanent
magnet located in the recess) or the recess (with the permanent magnet located in
the power supply unit or the battery pack), are provided with corresponding magnetic
elements, for example a metal plate, which is magnetically attracted by the permanent
magnet, thereby securing the battery pack and the power supply unit, respectively,
in the recess.
[0021] Alternatively, the securing means could comprise a mechanical slider provided at
the outside of the mobile equipment's housing or the battery pack and the power supply
unit, respectively. After fully inserting the battery pack and the power supply unit,
respectively, into the recess, the slider can be sled into a locking position in order
to secure the battery pack or the power supply unit in the recess. Before removing
the battery pack or the power supply unit the slider can be sled into an unlocked
position, thereby releasing the battery pack and the power supply unit, respectively,
from the recess. Preferably, the battery pack and the power supply unit, respectively,
are automatically electronically connected to the electronic components of the mobile
equipment upon completed insertion of the battery pack or the power supply unit into
the recess. No additional user activity for establishing an electronic connection
between the battery pack and the power supply unit, respectively, on the one hand
and the mobile equipment on the other hand is required.
[0022] According to another preferred embodiment of the invention it is suggested that the
mobile equipment and/or the battery pack and the power supply unit comprise coding
means for assuring that the mobile equipment can only be operated with such a battery
pack and such a power supply unit which is actually intended and approved for use
with the mobile equipment. The same or different coding means could be provided for
assuring that the battery pack and the power supply unit, respectively, are correctly
(in particular fully) inserted into the recess. The coding means suggested here could
be of the mechanical type or of the electronic type.
[0023] Mechanical coding means could inhibit the insertion of the battery pack and the power
supply unit, respectively, into the recess of the mobile equipment's housing due to
a mismatch in the form of the recess and the form of the power supply unit and the
battery pack, respectively. Electronic coding means could electronically determine,
whether the mechanically inserted battery pack or power supply unit is actually intended
and approved for use with the mobile equipment and following this determination could
allow operation of the mobile equipment (if the correct battery pack or power supply
unit has been inserted) or inhibit operation of the mobile equipment (if the battery
pack or the power supply unit is not of the type intended or approved for use with
the mobile equipment). For example, an electronic read switch, a Hall-sensor or a
micro-switch could be provided in the recess, in the battery pack and/or in the power
supply unit. Only a correct and approved power supply unit or battery pack will activate
the switch or sensor, thereby allowing operation of the mobile equipment.
[0024] The same or different coding means could be provided and adapted for assuring that
the battery pack or the power supply unit is correctly (fully) inserted into the recess.
For example, it is possible that the coding means activate the mobile equipment only
after the battery pack or the power supply unit has been completely inserted into
the recess, even though the battery pack and the power supply unit, respectively,
are already electronically connected to the electronic components of the mobile equipment
before the battery pack or the power supply unit are completely inserted into the
recess. These coding means could comprise for example, but not limited to, an electronic
read switch, a Hall-sensor or a micro-switch could be provided in the recess, in the
battery pack and/or in the power supply unit.
[0025] It is particularly advantageous if the mobile equipment comprises a hand guided electric
power tool. In particular, the mobile equipment could comprise one of, but not limited
to, a grinder, a polisher, a sander, a planer, a joining machine, an edge trimmer,
a vertical router, a saw, a glazing machine, a scouring machine, a drill, a screwdriver,
a mixer, a heat gun and a vacuum cleaner. In more detail, the hand-guided power tool
could be one of, but not limited to, a straight grinder, an angular grinder, a vertical
grinder, an angular polisher, a random orbital polisher, an angular sander, an orbital
sander, a random orbital sander, a planetary sander, a jigsaw, a plunge circular saw,
a percussion drill, a rotary hammer drill and a drill-screwdriver. The advantages
of the present invention are particularly apparent, if the mobile equipment is an
electric power tool. Electric power tools tend to have a rather high power consumption
and, hence, benefit from the present invention a lot. Until now a hybrid power supply
for electronic power tools is not known. The present invention gives the user the
opportunity to have only a single power tool which can be operated both by electric
energy from a battery pack and by electric energy from the mains power supply. Up
to now the user had to have two separate tools, one driven with a battery pack and
the other driven with the mains power supply, for example a drill driven by the mains
power supply and an electric screwdriver driven by a battery pack. Now the user only
needs a single tool, for example a drill, which can be driven both with the electric
energy from a battery pack and with the electric energy from the mains power supply.
[0026] The object of the present invention is also solved by an electronic power supply
unit of the above identified kind, characterized in that the power supply unit has
a casing from which the cable emerges, the form of the casing being adapted to the
form of the recess of the mobile equipment in order to fit at least part of the power
supply unit into the recess after having removed the battery pack, in order to operate
the mobile equipment by means of electric energy originating from the mains power
supply.
[0027] Hence, an electrical power supply unit is proposed for any type and kind of battery
driven electric mobile equipment. According to the invention the casing of the power
supply unit is formed such that it neatly fits into the recess originally adapted
for receiving the equipment's battery pack. This means that depending on the type
and kind of electric mobile equipment to be equipped with the power supply unit according
to the present invention, the electric characteristics and the mechanical characteristics
of the power supply unit have to be adapted in order to fit the electric mobile equipment
from an electrical point of view as well as from a mechanical point of view. With
other words, the power supply unit's mechanical interface as well as its electrical
interface towards the mobile equipment has to correspond the corresponding interfaces
of the battery pack towards the mobile equipment.
[0028] For example the electric characteristics to be adapted can be one or more of an input
and an output voltage, an input and an output frequency and a maximum output current.
For example the mechanical characteristics to be adapted can be one or more of the
external form of the casing, type and position of securing means (for holding the
casing in the recess) and type and form of coding means (for assuring that only power
supply units adapted and approved for use with the intended electric mobile equipment
can be used). Summing up, the power supply unit constitutes a kind of fake battery
pack, mechanically and electrically corresponding to the real battery pack with the
main difference that the power supply unit drives the mobile equipment with energy
from a mains power supply, which after transformation is directly fed to the mobile
equipment.
[0029] Further features and advantages of the present invention will be explained in more
detail in the following specification taking into consideration the drawings. These
show:
- Figure 1
- an electric power tool according to a preferred embodiment of the present invention
equipped with a power supply unit inserted into a recess of the tool's housing;
- Figure 2
- a battery pack adapted for being inserted into the recess of the housing of the power
tool according to figure 1 after having removed the power supply unit;
- Figure 3
- the electric power tool according to figure 1 in a more detailed, partially sectional
view;
- Figure 4
- the battery pack of figure 2 in a more detailed, partially sectional view;
- Figure 5
- the tool according to figure 3 with a battery pack inserted into the recess of the
tool's housing instead of the power supply unit;
- Figure 6
- the housing of the power tool according to figures 3 and 5 without a power supply
unit and a battery pack inserted into the recess of the tool's housing;
- Figure 7
- the power supply unit adapted for being inserted into the recess of the housing of
the tool of figures 1 and 6, in a more detailed, partially sectional view;
- Figure 8
- an electric power tool according to another preferred embodiment of the present invention
equipped with a battery pack to be inserted into a recess of the tool's housing;
- Figure 9
- a top view of the power supply unit adapted for being inserted into the recess of
the housing of the tool of figure 8; and
- Figure 10
- a side view of the power supply unit adapted for being inserted into the recess of
the housing of the tool of figure 8.
[0030] Figures 1 and 2 show an example of an electronically driven mobile equipment according
to the present invention. In this embodiment the mobile equipment comprises an electronic
power tool, in particular a hand guided electronic power tool, for example a polisher.
In figure 1 the polisher in its entirety is designated with reference sign 1. The
following description is directed to the preferred embodiment of figure 1, that is
to a polisher 1, its construction and its functioning. Of course, the following description
refers to any other type of electronically driven mobile equipment according to the
present invention just the same.
[0031] The polisher 1 comprises a housing 2, preferably made of a plastic material. Of course,
at least part of the housing 2 could be made of any other material than plastic, too,
for example metal or carbon fiber. Furthermore, it comprises a power supply unit 4
(see figure 1) and a battery pack 6 (see figure 2). The power supply unit 4 or the
battery pack 6 can be releasably connected to the housing 2, thereby providing power
supply to the polisher 1 and its electric components either from a mains power supply
or from the battery pack 6.
[0032] The housing 2 comprises an electric motor in its inside, preferably a brushless electric
motor (not shown in the figures). The electric motor has a motor shaft, which performs
a rotational movement about its longitudinal axis if electric supply energy is provided
to the motor. Furthermore, the polisher 1 comprises a working element 3 which performs
a rotational, an orbital or a random orbital movement. Transmission means (not shown
in the figures) are provided in the housing 2 located between the electric motor and
the working element 3 in order to transform the rotational movement of the motor shaft
into the desired movement of the working element 3.
[0033] The polisher 1 can be operated with electric energy originating from a power supply
unit 4 connected to a mains power supply by means of an electric cable 5. At its distal
end the cable 5 has a plug 5a which can be inserted into a corresponding socket (not
shown) of the mains power supply. Depending on the country the polisher 1 is to be
used, the type of plug 5a can vary significantly. Alternatively, the polisher 1 can
be operated with electric energy originating from a battery pack 6 (see figure 2).
Therefore, the polisher 1 can be alternatively equipped with the power supply unit
4 or with the battery pack 6. The power supply unit 4 as well as the battery pack
6 can be releasably connected to the housing 2 of the polisher 1, thereby providing
power supply to the polisher 1 and its electric components either from a mains power
supply or from the battery pack 6.
[0034] As can be seen in figure 6, the polisher 1 is provided with an external recess 7
in its housing 2. The recess 7 has an opens to the outside and can be accessed with
the power supply unit 4 or the battery pack 6 from the outside. It is not necessary
to open the housing 2 in order to insert the power supply unit 4 or the battery pack
6 into the recess 7. The recess 7 is adapted for receiving at least part of the power
supply unit 4 or the battery pack 6. That part of the power supply unit 4 that is
received in the recess 7 of the polisher's housing 2 is designated with reference
sign 8 (see figures 3 and 7). Similarly, that part of the battery pack 6 that is received
by the recess 7 is designated with reference sign 9 (see figures 4 and 5). That part
of the power supply unit 4 which remains outside the recess 7 when the power supply
unit 4 is fully inserted into the recess 7 is designated with reference sign 10. Similarly,
that part of the battery pack 6, which remains outside the recess 7 when the battery
pack 6 is fully inserted into the recess 7 is designated with reference sign 11. The
regions 8 and 10 of the power supply unit 4 and the regions 9 and 11 of the batter
pack 6, respectively, are separated by a dashed line in figures 3, 4, 5 and 7.
[0035] The polisher 1 is provided with electrical contacts 12 (see figures 3, 5 and 6) extending
into the recess 7. The contacts 12 are located at the bottom of the recess 7. They
are connected to the electronic components of the polisher 1, in particular to a control
unit of the tool and the electric motor. The contacts 12 are preferably embodied as
longitudinal pins made of a conductive material, for example metal, in particular
copper. The longitudinal axis of the contact pins 12 extends essentially parallel
to a direction 13 of insertion (see figure 6) in which the power supply unit 4 and
the battery pack 6 are inserted into the recess 7 from outside. When the power supply
unit 4 or the battery pack 6 is fully inserted into the recess 7 an electric connection
is automatically established between the electronic components of the polisher 1 on
the one hand and the power supply unit 4 or the battery pack 6 on the other hand.
The power supply unit 4 and the battery pack 6 are provided with a corresponding socket
element 14 (schematically shown in figures 3, 4, 5 and 7), which is adapted for receiving
the contact pins 12 and for establishing the electric connection between the electronic
components of the polisher 1 on the one hand and the power supply unit 4 or the battery
pack 6 on the other hand.
[0036] Of course, it would also be possible that the polisher 1 is provided with a socket
similar to socket element 14 and that the power supply unit 4 and the battery pack
6, respectively, are provided with connecting means such as the connection pins 12,
for cooperation with the socket in order to establish the electric connection.
[0037] The power supply unit 4 comprises a casing 15 (see figure 7) comprising a first part
8 within the region, which is inserted into the recess 7, and a second part 10 within
the region, which remains outside the recess 7 if the power supply unit 4 is fully
inserted into the recess 7. In this connection "fully inserted" does not mean that
the entire power supply unit 4 is inserted into recess 7 but rather that the power
supply unit 4 is inserted into the recess 7 as far as possible, which means that the
entire part 8 of the power supply unit 4 is inserted into the recess 7 and the socket
element 14 has entered into electric connection with the contact pins 12. The casing
15 is preferably made of a plastic material. Within the casing 15 the power supply
unit 4 comprises electronic components for performing a power transmission. These
can comprise a printed circuit board (PCB) 16, which has conducting paths (not shown)
and numerous other electronic components mounted thereon. The electronic components
mounted on the PCB 16, for example, comprise coils 17 adapted for transforming the
energy originating from the mains power supply (e.g. 230 V) into energy suitable for
operating the polisher 1 (e.g. 12 V or 18 V). Furthermore, the power supply unit 4
comprises a safety fuse 18 which is accessible from outside the casing 15. The electronic
power supply unit 4 is preferably adapted to comply with the ATEX 95 equipment directive
94/9/EC. Hence, the power supply unit 4 is a safety isolating transformer, which can
be used in potentially explosive atmospheres.
[0038] The battery pack 6 also comprises a casing 19 preferably made of plastic material
(see figure 4). The casing 19 comprises a first part 9 in the region of the battery
pack 6, which is completely inserted into the recess 7. Further, the casing 19 comprises
a second part 11 in the region, which remains outside the recess 7 and the housing
2 of the polisher 1, when the battery pack 6 is fully inserted into the recess 7.
Again, the term "fully inserted" does not mean that the entire battery pack 6 is inserted
into the recess 7. Rather, only the entire part 9 of the casing 19 is inserted into
the recess 7, while the part 11 remains outside the housing 2 and the recess 7. Inside
the casing 19 a plurality of batteries or battery cells 20 are provided. For charging
the battery pack 6 it is inserted into a separate external charging device connected
to the mains power supply. The charging device comprises a connector similar to the
connector pins 12 of the polisher 1 in order to establish an electronic connection
with the socket element 14 when the battery pack 6 is inserted into the charging device.
[0039] It can be clearly seen from figures 3 that the external form of the casing 15 of
the electronic power supply unit 4 is such that the casing 15 resumes the form of
the housing 2 of the mobile equipment 1 in the region of the recess 7, when the power
supply unit 4 is fully inserted into the recess 7. Hence, the form of the housing
2 is continued by the form of the part 10 of the casing 15, which remains outside
of the recess 7 when the power supply unit 4 is fully inserted into the recess 7.
This means that the casing 15 of the power supply unit 4 and the housing 2 both influence
the polisher's design. Both the housing 2 as well as the casing 15 provide for the
appealing design of the polisher 1, when the power supply unit 4 is inserted into
the polisher 1.
[0040] Similarly it is suggested that the form of the casing 19 of the battery pack 6 is
such that the casing 19 resumes the form of the housing 2 of the mobile equipment
1 in the region of the recess 7, when the battery pack 6 is fully inserted into the
recess 7 (see figure 5). Again both the housing 2 as well as the casing 19 influence
the overall design of the polisher 1. The appealing design of the polisher 1 is obtained
by means of a cooperation of the housing 2 and the external part 11 of the casing
19 of the battery pack 6.
[0041] Preferably, the external form of the casing 15 of the power supply unit 4 and of
the casing 19 of the battery pack 6 are near to identical in order to provide for
a similar or even the same aesthetic appearance of the polisher 1 irrespective of
whether the power supply unit 4 or the battery pack 6 is inserted into the recess
7.
[0042] Preferably, the polisher 1 comprises means 21 (see figure 6) for securing the power
supply unit 4 and the battery pack 6, respectively, in the recess 7 after insertion
and for releasing them from the recess 7. In the embodiment of figure 6 the securing
means 21 are only schematically shown and comprise an elastically resilient finger,
which is connected to the housing 2 at one end and comprises a protrusion extending
towards the inserted power supply unit 4 and battery pack 6, respectively, on its
other end. When the power supply unit 4 or the battery pack 6 is inserted into the
recess 7 in the direction 13 the protrusion of the securing means 21 is forced out
of the way by the power supply unit 4 or the battery packs 6 and moves away from the
inserted power supply unit 4 or the battery pack 6 in the direction of the lower wall
of the housing 2. When the power supply unit 4 or the battery pack 6 is fully inserted
in the recess 7, a cavity or a hole in the housing 15 of the power supply unit 4 or
in the housing 19 of the battery pack 6 is located at a position corresponding to
the position of the protrusion of the securing means 21. Hence, the securing means
21 can elastically move back into its original position (before the power supply unit
4 or the battery pack 6 was inserted into the recess 7), whereby the protrusions enters
into the cavity or hole. The protrusion interacts with the cavity or hole in the casing
15 or the casing 19. By means of this interaction the power supply unit 4 or the battery
pack 6 is mechanically secured in its fully inserted position in the recess 7.
[0043] For removing the power supply unit 4 or the battery pack 6 the securing means 21
can be disabled or released. Preferably, this is effected from outside of the housing
2 by a certain user activity, for example by pressing a release button (not shown
in the figures). Of course, it is possible that the securing means similar to the
securing means 21 are located at or in the casing 15 of the power supply unit 4 or
the casing 19 of the battery pack 6 and that the corresponding cavity or hole is located
in the housing 2 of the polisher 1.
[0044] Preferably, the external form of the casing 15 of the power supply unit 4 and of
the casing 19 of the battery pack 6 is adapted to the form of the recess 7 so that
the power supply unit 4 and the battery pack 6 neatly fit into the recess 7 leaving
almost no gaps or clearances between the housing 2 and the casing 15; 19. If the form
of the casing 15 of the power supply unit 4 and of the casing 19 of the battery pack
6 was significantly different than the form of the recess 7, then the power supply
unit 4 and the battery pack 6 would not fit into the recess 7. Therefore, the external
form of the casings 15, 19 in co-operation with the form of the recess 7 can be regarded
as coding means for assuring that only such a battery pack 6 and such a power supply
unit 4 can be inserted into the recess 7 which is actually intended and approved for
use with the mobile equipment 1.
[0045] Further it is preferred that if the power supply unit 4 and the battery pack 6 are
not fully inserted into the recess 7 the socket element 14 at the front end of the
inserted power supply unit 4 and battery pack 6, respectively, will not come into
electric contact with the contact pins 12. Only if the power supply unit 4 and the
battery pack 6 are fully inserted into the recess 7 the contact between the socket
member 14 and the contact pins 12 is established. Therefore, the location and the
co-operation of the contact pins 12 and the socket member 14 can be regarded as coding
means for assuring that the battery pack 6 and the power supply unit 4, respectively,
are correctly and in particular fully inserted into the recess 7.
[0046] As already mentioned, the present invention refers to any kind of electrically driven
mobile equipment. Preferably, the mobile equipment comprises a hand guided electric
power tool. Besides the polisher 1 shown in the figures, the electric power tool could
also be one of but not limited to a grinder, a polisher, a planner, a joining machine,
an edge trimmer, a vertical router, a saw, a glazing machine, a scaring machine, a
drill, a screw driver, a mixer, a heat gun and a vacuum cleaner.
[0047] Figure 8 shows a further preferred embodiment of an electric power tool according
to the present invention. In this embodiment the tool 1 is embodied as a portable
electric drill or cordless electric screwdriver equipped with a battery pack 6 to
be inserted into the recess 7 of the tool's housing 2. The recess 7 is embodied at
the bottom end of a grip portion 22 of the housing 2. There are guiding rails 23 extending
along opposite sidewalls of the recess 7. The battery pack 6 comprises corresponding
guiding rails 24 located at a top wall of the battery pack's casing 19. The rails
24 of the battery pack 6 are adapted to interact with the rails 23 of the recess 7,
when the battery pack 6 is inserted into the recess 7. The battery pack 6 is inserted
sideways (in respect to a longitudinal extension of the grip portion 22 of the housing
2) into the recess 7 in the insertion direction 13 represented by an arrow.
[0048] During its insertion the battery pack 6 performs a sliding movement of the guiding
rails 24 relative to the guiding rails 23. After fully inserting the battery pack
6 into the recess 7, a front wall of the housing 2 or the grip portion 22, respectively,
may abut against a corresponding wall of the battery pack 6 facing backwards towards
the housing 2 and the grip portion 22, respectively, thereby limiting the insertion
movement and bringing it to an end. Additionally or alternatively, snapping means
are provided within the recess 7, which interact with corresponding cavities 5 located
in the battery pack 6 or its casing 19, respectively, as soon as the battery pack
6 is fully inserted into the recess 7. The snapping means in co-operation with the
cavities 25 provide for a safe and secure fixation of the battery pack 6 within the
recess 7. The snapping means can be adopted to automatically move out of the cavities
25 and to release the battery pack 6 from the recess 7, if a force is exerted on the
battery pack 6 into a direction opposition to arrow 13. This force could be applied
by a user of the tool 1. Possibly, additional securing means (not shown in figure
8) would have to be pressed by the user before the snapping means leave the cavities
25 and the battery pack 6 is released from the recess 7.
[0049] When the battery pack 6 is inserted into the recess 7, a socket element 14 provided
on the top wall of the casing 19 and comprising a plurality of electric contact elements
interacts with corresponding contact pins 12 (not shown in figure 8) located inside
the recess 7. The electrical contacts established between the contact elements of
the socket element 14 and the contact pins 12 serve for transmitting electric energy
from the battery pack 6 to the tool 1, in particular to its electric motor and the
tool's other electrical components. Furthermore, the electrical contacts may serve
for transmitting status and/or control information between the tool 1 and the battery
pack 6.
[0050] Figures 9 and 10 show a power supply unit 4 adapted for being inserted into the recess
7 of the housing 2 of the tool 1 of figure 8, after the battery pack 6 has been removed.
Figure 9 shows a top view and figure 10 a side view of the power supply unit 4. The
power supply unit 4 comprises a casing 15 which comprises a first part 8, which is
inserted in the recess 7, and a second part 10, which remains outside the recess 7,
if the power supply unit 4 is fully inserted into the recess 7. A dashed line is drawn
in figure 10 in order to separate the part 8 to be inserted into the recess 7 from
the part 10 remaining outside of the recess 7 when the power supply unit 4 is fully
inserted into the recess 7. The dashed line is not straight (like in figures 3, 4,
5 and 7) but rather comprises a sharp bend of approximately 45°.
[0051] A top wall of the casing 15 comprises guiding rails 24 similar or identical to those
of the battery pack 6. The guiding rails 24 of the casing 15 are adapted to cooperate
with the recess' guiding rails 23 when the power supply unit 4 is sled into the recess
7. The guiding rails 24 of the power supply unit 4 form part of a sledge which slides
along the corresponding guiding rails 23 of the recess 7. Furthermore, the power supply
unit 4 also comprises cavities 25 for receiving the tool's snapping means when the
power supply unit 4 is fully inserted into the recess 7. Additionally or alternatively,
the power supply unit 4 can comprise additional securing means (not shown in figures
9 or 10) which have to be actuated, for example by pressing, by the user before the
snapping means leave the cavities 25 and the power supply unit 4 is released from
the recess 7. Also the position and the design of the contact elements of the power
supply unit's socket element 14 are identical to those of the battery pack 6, allowing
the automatic establishment of electronic contacts between the contact pins 12 of
the tool 1 and the contact elements of the socket element 14, when the power supply
unit 4 is fully inserted into the recess 7.
[0052] Hence, the external form of the power supply unit 4 and in particular of the part
8 of the casing 15 is identical to that of the battery pack 6 and of part 9 of its
casing 19, respectively. The power supply unit 4 is inserted into the recess 7 just
the same way as a battery pack 6 would be inserted therein. Just the same, the electronic
contact between the power supply unit 4 and the tool 1 is established the same way
as it would be established between a battery pack 6 and the tool 1. Hence, the power
supply unit's mechanical interface towards the tool 1 is identical to that of a battery
pack 6 adapted for being inserted into and held within the recess 7 of the tool 1.
[0053] Additionally, also the electronic characteristics of the power supply unit 4 correspond
to those of the battery pack 6, in particular in respect to input and output voltage,
input and output frequencies, maximum output current, etc. The main difference is
that the power supply unit 4 transforms energy from a mains power supply into energy
(voltage and/or current) adapted for driving the tool 1 and its electric motor and
other electronic components, respectively, and directly operates the tool 1 with that
transformed energy, without storing it in storing means, like a battery. Hence, also
the power supply unit's electrical interface towards the tool 1 is identical to that
of a battery pack 6 adapted for driving the tool 1 with an appropriate electric signal.
Preferably, the power supply unit 4 provides for the same electrical driving signal
that a battery pack 6 adapted for use with the tool 1 would.
[0054] Of course, form and dimensions of that part 10 of the casing 15, which remains outside
the recess 7, when the power supply unit 4 is fully inserted into the recess 7, may
slightly differ from the form and dimensions of the corresponding part 11 of the battery
pack's casing 19. The form and dimensions of the part 8 of the casing 15 of the power
supply unit 4 must correspond to the form and dimensions of the corresponding part
9 of the casing 19 of the battery pack 6 only insofar as proper insertion and fixation
of the power supply unit 4 inside the recess 7 is assured.
[0055] For example, the casing 15 of the power supply unit 4 may be provided with additional
ventilation openings 26 which allow warm air created during energy transformation
operation in the power supply unit 4 to escape from the inside of the casing 19 to
the environment. Furthermore, additional venting means (not shown in the figures)
like a fan or ventilator could be provided in the casing 19. The venting means could
be adapted for actively conveying the warm air to the environment through the ventilation
openings 26. The additional venting means could be coupled to and controlled by a
temperature control circuit comprising a temperature sensor for determining the current
temperature inside the casing 19 and means for activating/deactivating the venting
means if the inside temperature exceeds a predefined threshold value. The energy for
driving the temperature control circuit and the additional venting means could also
be provided from the mains power supply, preferably only after transforming the energy
form the mains power supply into the energy for driving the tool 1. The cable 5 exits
the casing 15 of the power supply unit 4 at a rear wall in the insertion direction
13. Of course, the cable 5 could exit the casing 15 through any other part 10 of the
casing 15, too, except for that part 8 of the casing 15, which is received by the
recess 7, when the power supply unit 4 is fully inserted in the recess 7.
1. Electronically driven mobile equipment (1) comprising a housing (2) with a recess
(7) adapted for receiving at least one part (9) of a battery pack (6), the form of
the recess (7) corresponding to the form of the at least one part (9) of the battery
pack (6), in order to allow insertion of the at least one part (9) of the battery
pack (6) into the recess (7) and operation of the mobile equipment (1) by means of
electric energy originating from the battery pack (6), characterized in that the mobile equipment (1) comprises an electronic power supply unit (4) connectable
to an electronic mains power supply by means of an electric cable (5), the power supply
unit (4) having a casing (15) from which the cable (5) emerges, the form of at least
one part (8) of the casing (15) corresponds to the form of the recess (7) in order
to allow insertion of the at least one part (8) of the power supply unit (4) into
the recess (7) after having removed the battery pack (6) and operation of the mobile
equipment (1) by means of electric energy originating from the mains power supply.
2. Mobile equipment (1) according to claim 1, characterized in that the power supply unit (4) adapted for use with a certain mobile equipment (1) has
a mechanical interface towards the recess (7) and an electric interface towards electronic
components of the mobile equipment (1), wherein the mechanical and electric interfaces
correspond to the mechanical and electric interfaces of a battery pack (4), which
is adapted and intended for use with the mobile equipment (1), towards the recess
(7) and the mobile equipment (1), respectively.
3. Mobile equipment (1) according to claim 1 or 2, characterized in that the power supply unit (4) adapted for use with a certain mobile equipment (1) has
a mechanical interface towards the recess (7) and an electric interface towards electronic
components of the mobile equipment (1), wherein the mechanical interface is adapted
to the form and design of the recess (7) and the electric interface is adapted to
the electronic characteristics of the mobile equipment's electronic components.
4. Mobile equipment (1) according to one of the preceding claims, characterized in that the power supply unit (4) comprises power transformer means (17) for transforming
the energy originating from the mains power supply into energy suitable for operating
the mobile equipment (1).
5. Mobile equipment (1) according to one of the preceding claims, characterized in that the power supply unit (4) is adapted to comply with the ATEX 95 equipment directive
94/9/EC.
6. Mobile equipment (1) according to one of the preceding claims, characterized in that the form of the casing (15) of the power supply unit (4) conforms to the form of
a battery pack (6) adapted and intended for use with the mobile equipment (1).
7. Mobile equipment (1) according to one of the preceding claims, characterized in that the battery pack (6) comprises at least one rechargeable battery or battery cell
(20).
8. Mobile equipment (1) according to one of the preceding claims, characterized in that the mobile equipment (1) comprises means (21) for securing the battery pack (6) and
the power supply unit (4) in the recess (7) and for releasing them from the recess
(7).
9. Mobile equipment (1) according to one of the preceding claims, characterized in that the battery pack (6) and the power supply unit (4) comprise means for securing the
battery pack (6) and the power supply unit (4) in the recess (7) and for releasing
them from the recess (7) .
10. Mobile equipment (1) according to one of the preceding claims, characterized in that the mobile equipment (1) and/or the battery pack (6) and the power supply unit (4)
comprise coding means for assuring that only such a battery pack (6) and such a power
supply unit (4) can be inserted into the recess (7) which is intended for use with
the mobile equipment (1) and/or for assuring that the battery pack (6) and the power
supply unit (4), respectively, are correctly inserted into the recess (7).
11. Mobile equipment (1) according to one of the preceding claims, characterized in that the mobile equipment (1) comprises a hand guided electric tool.
12. Mobile equipment (1) according to one of the preceding claims, characterized in that the mobile equipment (1) comprises one of a grinder, a polisher, a sander, a planer,
a joining machine, an edge trimmer, a vertical router, a saw, a glazing machine, a
scouring machine, a drill, a screwdriver, a mixer, a heat gun and a vacuum cleaner.
13. Mobile equipment (1) according to claim 12, characterized in that the mobile equipment (1) comprises one of a straight grinder, an angular grinder,
a vertical grinder, an angular polisher, a random orbital polisher, an angular sander,
an orbital sander, a random orbital sander, a planetary sander, a jigsaw, a plunge
circular saw, a percussion drill, a rotary hammer drill and a drill-screwdriver.
14. Electronic power supply unit (4) connectable to an electronic mains power supply by
means of an electric cable (5) and adapted for use with an electronically driven mobile
equipment (1) comprising a housing (2) and an external recess (7) located in the housing
(2) for receiving a battery pack (6), the form of the battery pack (6) being adapted
to the form of the recess (7) in order to fit at least part (9) of the battery pack
(6) into the recess (7), in order to operate the mobile equipment (1) by means of
electric energy originating from the battery pack (6), characterized in that the electronic power supply unit (4) has a casing (15) from which the cable (5) emerges,
the form of the casing (15) being adapted to the form of the recess (7) of the mobile
equipment in order to fit at least part (8) of the power supply unit (4) into the
recess (7) after having removed the battery pack (6), in order to operate the mobile
equipment (1) by means of electric energy originating from the mains power supply.
15. Power supply unit (4) according to claim 14, characterized in that the power supply unit (4) is adapted for use with an electronically driven mobile
equipment (1) according to one of the claims 2 to 13.