U.S. patent application number 14/385529 was filed with the patent office on 2015-02-12 for power adapter for cordless power tools.
The applicant listed for this patent is Husqvarna AB. Invention is credited to Fritz Laible, Corinna Monch, Joachim Rief, Peter Rudolph, Tobias Zeller.
Application Number | 20150042280 14/385529 |
Document ID | / |
Family ID | 47901116 |
Filed Date | 2015-02-12 |
United States Patent
Application |
20150042280 |
Kind Code |
A1 |
Rief; Joachim ; et
al. |
February 12, 2015 |
POWER ADAPTER FOR CORDLESS POWER TOOLS
Abstract
The present application is directed in particular to a power
adapter, adapted to be connected on the one hand to a power
interface of a cordless power tool and adapted to be connected on
the other hand to an energy source, in particular mobile energy
source, for electrically power the power tool via the power
adapter.
Inventors: |
Rief; Joachim; (Biberach,
DE) ; Monch; Corinna; (Neu-Ulm, DE) ; Laible;
Fritz; (Asselfingen, DE) ; Rudolph; Peter;
(Senden, DE) ; Zeller; Tobias; (Neu-Ulm,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Husqvarna AB |
Huskvarna |
|
SE |
|
|
Family ID: |
47901116 |
Appl. No.: |
14/385529 |
Filed: |
March 19, 2013 |
PCT Filed: |
March 19, 2013 |
PCT NO: |
PCT/EP2013/055698 |
371 Date: |
September 16, 2014 |
Current U.S.
Class: |
320/113 |
Current CPC
Class: |
H01M 2/1022 20130101;
H02J 7/0044 20130101; Y02E 60/10 20130101; B25F 5/02 20130101; H02J
7/0048 20200101; H01M 10/488 20130101; H02J 7/0047 20130101 |
Class at
Publication: |
320/113 |
International
Class: |
H02J 7/00 20060101
H02J007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 19, 2012 |
EP |
PCT/EP2012/054847 |
Claims
1. Power adapter to be mounted in a cordless electrical power tool
for electrically powering the power tool, the power adapter
comprising an electrical interface to be electrically connected to
a power interface of the cordless power tool and another electrical
interface to be electrically connected to a battery assembly to be
carried such as a backpack battery assembly or a belt battery
assembly, wherein in an indirect powering operation no battery is
present in the power adapter or power tool itself, but the power
tool is powered by the battery assembly through the power
adapter.
2. Power adapter according to claim 1, further comprising at least
one balancing weight for weight balancing the power tool in the
indirect powering operation.
3. Power adapter according to claim 2, comprising a housing adapted
to accommodate, on an outer or inner side, the balancing weight in
the indirect powering operation.
4. Power adapter according to claim 2, comprising a fixture unit
into or onto which the balancing weight is fixed into a receiving
space enclosed by a side wall, wherein the fixture unit comprises a
first fixture sub-unit and a second fixture sub-unit connectable by
fastening elements to form the fixing unit and wherein the at least
one balancing weight is fixed to the first fixture sub-unit or
second fixture unit before connection of the two fixture sub-units
or arranged in an inner space between the first fixture sub-unit
and the second fixture sub-unit.
5. Power adapter according to claim 3, wherein the housing is
adapted to removably accommodate therein or thereon the fixture
unit with the balancing weight.
6. Power adapter according to claim 3, wherein the housing
comprises a base section and a cap or dome shaped cover configured
to be connected to the base section to establish a casing for
accommodating therein the balancing weight, wherein the balancing
weight is mounted to the base section.
7. Power adapter according to claim 6, wherein the base section
comprises a recess adapted to accommodate a printed circuit board,
and further comprising a support plate adapted to support the
balancing weight while bridging the recess, the support plate being
adapted to bridge the recess via flanges or webs supported
laterally adjacent to the recess.
8. Power adapter according to claim 6, comprising a retaining
bracket adapted and configured for bracket fastening the balancing
weight to or against the base section, wherein the retaining
bracket comprises support sections protruding from the retaining
bracket, and adapted to support the retaining bracket and balancing
weight against at least one inner wall of the housing, wherein the
support sections are further configured to act as cable support
bars or wherein the retaining bracket comprises an integrated cable
clamp section configured to clamp an electric supply cable of the
power adapter.
9. Power adapter according to claim 7, wherein the base section
comprises a cable bushing, which at the outer side of the base
section is shaped as a cone or funnel shaped deepening.
10. Power adapter according to claim 1, wherein in a direct
powering operation the power adapter comprises, instead of the at
least one balancing weight, at least one battery for powering the
power tool, wherein the weight of the battery is used for balancing
the power tool.
11. Power adapter according to claim 1, being adapted to
accommodate balancing weights of different mass in the indirect
powering operation, which different masses are adapted to different
battery masses in the direct powering operation.
12. Power adapter according to claim 1, further comprising a
slewable cable outlet for an electrical cable.
13. Power adapter according to claim 1, further comprising a
display unit adapted to display a charging condition or one or more
other parameters such as temperature of the energy source at least
in the electrically connected state.
14. Power tool assembly comprising a power tool with a power
interface to which a power adapter is removably coupled, the power
adapter comprising: an electrical interface to be electrically
connected to a power interface of the cordless power tool and
another electrical interface to be electrically connected to a
battery assembly to be carried such as a backpack battery assembly
or a belt battery assembly, wherein in an indirect powering
operation no battery is present in the power adapter or power tool
itself, but the power tool is powered by the battery assembly
through the power adapter.
15. Energy source assembly comprising a backpack energy source,
wherein the energy source is connected via a cable connection to a
power adapter, the power adapter comprising: an electrical
interface to be electrically connected to a power interface of the
cordless power tool and another electrical interface to be
electrically connected to a battery assembly to be carried such as
a backpack battery assembly or a belt battery assembly, wherein in
an indirect powering operation no battery is present in the power
adapter or power tool itself, but the power tool is powered by the
battery assembly through the power adapter.
16. (canceled)
Description
[0001] The present invention relates to a power adapter for
cordless power tools.
[0002] Cordless electrically operated power tools such as hedge
trimmers, clearing saws, chain saws, brush cutters, trimmers,
blowers, screw drivers, drills, hammer drills, nailers, staplers,
polishing or grinding tools, need to be operated by batteries and
provide a wide operating range since no electrical cables are
provided.
[0003] Due to the increasing demand for elongated operating
intervals for cordless power tools, larger batteries with higher
capacities may be used. However, larger batteries having higher
weights adversely affect comfort and ergonomy of operating the
cordless tool, in particular power tool.
[0004] Therefore, in particular it is one object of the invention
to provide a possibility of operating cordless tools, in particular
cordless power tools, in a comfortable and/or ergonomic way even if
energy sources, in particular battery systems, with larger loading
or charging capacities are used. Further, an energy source
assembly, power tool assembly and energy source and power tool
assembly shall be provided.
[0005] This object is achieved by the subject-matter of claims 1
and 13 to 15. Advantageous and preferred embodiments in particular
result from the dependent claims.
[0006] According to claim 1, a power adapter is provided, which is
to be mounted in an electrical power tool for electrically powering
the power tool and comprises [0007] an electrical interface to be
electrically connected to a power interface of a cordless power
tool on the one hand and [0008] another electrical interface to be
electrically connected to an external electrical energy source, in
particular a battery assembly to be carried such as a backpack
battery assembly or a belt battery assembly, on the other hand,
[0009] wherein in an indirect powering operation no battery is
present in the power adapter and/or power tool itself, but the
power tool is powered by the external electrical energy source
through the power adapter.
[0010] The indirect powering operation shall comprise all
situations, in which the power tool is operable exclusively by an
external energy source, such as a battery pack and/or a power grid
or power network.
[0011] The fact that "no battery is present in the power adapter"
in particular shall mean, that the power adapter is not provided
with or at least temporarily does not incorporate, an independent
electrical power reservoir or source which would enable to
cordlessly operate the power tool.
[0012] A cordless power tool in particular shall be understood as a
power tool, which, for ordinary operation, does not require a cable
connection to a fixed or stationary electrical power source such as
an energy generator or an electrical network or grid.
[0013] Rather, cordless power tools, in particular cordless power
tools as rendered possible by the present invention, shall in
particular be understood as power tools that can be operated in a
stand-alone manner, in particular providing electric self-supply,
such as for example with a passive energy source, such as a
secondary battery or accumulator.
[0014] Note that a cordless power tool as rendered possible by the
present invention, and in the broader sense, shall be understood as
a stand-alone power tool or stand-alone power tool arrangement
comprising battery packs either attached directly or indirectly
thereto. Indirect connections may in particular comprise electrical
connections to backpack battery packs and the like. It shall be
stressed, that even in the event that the power tool is connected
to a portable backpack energy source or the like via a cable, a
respective power tool nevertheless is considered a cordless power
tool. This in particular is the case as providing a backpack energy
source does not require a fixed energy source or grid.
[0015] In embodiments, the power adapter may comprise at least one
balancing weight. The balancing weight is adapted and configured
for weight balancing the power tool in the indirect powering
operation.
[0016] In other words, the balancing weight may be provided for
acting as a counter weight for other operational components of the
power tool in cases where no secondary battery of considerable
weight is connected thereto. In particular, the counter weight may
be configured so as to imitate the presence, in particular weight,
of a conventional secondary battery, which hitherto is usual for
cordless electrical power tools.
[0017] In particular, the counter weight may be adapted to provide
the impression and to provide handling features comparable to the
direct powering operation in which a secondary battery is provided
and coupled to a respective interface of the power tool for
powering the same. The balancing weight may provide advantageous
weight distribution, and a favorable center of mass for the power
tool. Also, in some cases the balancing weight may be provided for
the reason to fulfill legal standards.
[0018] The proposed power adapter, either with or without balancing
weight, may be used, for example, to connect to any type of
cordless tool adapted to be powered by a network-independent energy
source, i.e. off the line or by a battery energy source, such as a
secondary battery, in particular a battery unit having enhanced
loading capacity. As already indicated, a respective battery unit
may for example be a backpack energy source, i.e. a mobile energy
source, in particular battery pack, specially adapted to be carried
on the back of the user, in particular via at least one shoulder
strap. Backpack energy sources are advantageous with respect to and
can be designed for high wear comfort and ergonomics. However, also
other types of energy sources, in particular battery packs, such as
single shoulder strap type mobile battery packs, are
conceivable.
[0019] Advantageously the power adapter comprises a housing adapted
to accommodate, in particular on an outer and/or inner side, the
balancing weight in the indirect powering operation. Furthermore,
the power adapter may comprise a fixture unit into or onto which
the balancing weight is fixed.
[0020] In an embodiment the fixture unit comprises a first fixture
sub-unit and a second fixture sub-unit which are or can be
connected by means of fastening elements to form the fixing unit.
At least one balancing weight is now fixed to the first fixture
sub-unit and/or the to the second fixture sub-unit before
connection with the other sub-unit, preferably into a receiving
space enclosed by a side wall of the sub-unit and/or is arranged in
an inner space between the first fixture sub-unit and the second
fixture sub-unit.
[0021] The housing is preferably adapted to removably, in
particular slidably, accommodate therein and/or thereon the fixture
unit with the balancing weight.
[0022] In embodiments, the housing may comprise a base section and
a cap or dome shaped cover. The base section and cover may be
adapted to be combined and/or connected with each other to
establish a casing, in particular an essentially closed housing,
for accommodating therein in particular the balancing weight and
other components of the power adapter.
[0023] In more general terms, the casing may provide an inner space
for accommodating therein electronics, cables, in particular the
balancing weight and/or other elements of the power adapter.
[0024] It is preferred, that the balancing weight is mounted to the
base. Here, in general any type of mounting connections may be
used, in particular clamping, screwing, snapping and the like.
[0025] Using the base section as a mounting base for the balancing
weight may provide advantages for mounting the overall power
adapter. In particular, the base section may be used and adapted
for mounting or preassembling all the essential components of the
adapter, and thereafter, the base section may be coupled to the
cover to finally enclose all essential elements preassembled to the
base.
[0026] In further embodiments, the base section comprises a recess
adapted to accommodate a printed circuit board or similar control
electronics, in particular for adequately controlling operation of
the power adapter and power tool.
[0027] The power adapter may further comprise a support plate
adapted to support the balancing weight while at the same time
bridging the recess. The support plate is adequate for avoiding or
preventing the balancing weight to exert mechanical loads to the
control electronics, in particular printed circuit board.
[0028] The support plate is preferably adapted to bridge the recess
in that flanges or webs are supported laterally adjacent to the
recess, in particular on or at respective ribs. The flanges or webs
may be implemented with or at the support plate or with or at the
base section.
[0029] It shall be noted, that the control electronics, preferably
a printed circuit board, which preferably is arranged below the
balancing weight, optionally separated therefrom by the support
plate, may be potted within the base section.
[0030] In embodiments, the power adapter may comprise a retaining
bracket adapted and configured for bracket or clamp fastening the
balancing weight to or against the base section.
[0031] Using a mounting or fastening bracket may be advantageous in
view of assembly efficiency. The bracket may be U-shaped and/or
pot-shaped and may in particular provide a rectangular clamping
volume for clamping rectangular balancing weights.
[0032] It shall be noted that the clamping volume may be of any
other shape. The balancing weight, by the way, may be any object or
body suitable for being attached to the base section, in particular
any metallic object of standardized shape having sufficient or
adequate shape and corrosion resistance and other relevant
characteristics.
[0033] In embodiments, the bracket comprises support sections or
jibs, preferably protruding from the retaining bracket, preferably
in a lateral direction. The support sections may be adapted to
support the support bracket and balancing weight against at least
one inner wall of the housing, in particular cover.
[0034] The support sections are advantageous for adequately fixing
and supporting the balancing weight within the housing, in
particular for protecting fastening elements and fixings against
high impact loads.
[0035] The support sections may in addition be used and configured
as cable support bars, which in particular shall mean that the
support bars may be used for cable routing functions within the
housing.
[0036] In further embodiments, the retaining bracket may comprise
an integrated cable clamp section configured to clamp an electric
supply cable of the power adapter, i.e. to be used for cable
routing within the housing. Here, a high level of integration can
be obtained, which may provide advantages during assembly. Further,
as the bracket is adapted for retaining the balancing weight and
therefore is comparatively robust, cables, such as supply cables,
can be safely fixed.
[0037] In embodiments, the base section comprises a cable bushing.
A cable bushing in particular shall mean a type of opening allowing
a cable, in particular an electric supply cable, to be guided
through the base section to the inner of the housing.
[0038] At the outer side, i.e. at the side external to the housing
interior, the bushing may be implemented as a cone or funnel shaped
deepening. Such a cone or funnel shaped deepening may comprise
bended walls, in particular convex walls, adapted to allow smooth
bending of the cable within the bushing, whilst avoiding sharp
bends of the cable.
[0039] The cone or funnel, i.e. deepening, may be of rotational
symmetric, i.e. isotropic, design. However, the cone or funnel may
also be implemented in an anisotropic design, in which walls of the
cone or funnel show different bending radii and ascent angles with
respect to different bending directions.
[0040] In a view from the outside of the housing, the deepening
comprises widening walls, which in particular shall mean that the
axial cross section of the deepening gradually widens or increases
towards the outside of the housing.
[0041] In an embodiment the power adapter comprises in or for a
direct powering operation, instead of the at least one balancing
weight, at least one battery for powering the power tool, wherein
the weight of the battery is used for balancing the power tool. The
power adapter in these cases may be adapted to the power tool, and
the power tool then implements a self-powered device.
[0042] In particular, the power adapter is adapted to accommodate
balancing weights of different mass in the indirect powering
operation, which different masses are preferably adapted to
different battery masses in the direct powering operation. The
balancing weight in particular may be from steel and/or aluminum,
and in particular any standard sized element or product suitable to
be accommodated and/or arranged and/or fixed to the power adapter,
in particular an inner interface of the power adapter, preferably
housing.
[0043] In a further embodiment the power adapter comprises a
slewable cable outlet for an electrical cable. The cable in
particular may be used for connecting the power adapter to and with
the energy source, in particular mobile energy source, in
particular battery pack. Providing slewable cable outlets and/or
connections adapted to connect cables to the power adapter in a
slewable manner, greatly improves freedom of operation of the power
tool, in particular as manual rotations or movements of the power
tool can be balanced by a slewable cable outlet provided at the
housing. In particular in operation, one advantage is that the
cable may always be brought best operational position, or position
to work.
[0044] In a preferred further embodiment the power adapter further
comprises a display unit adapted to display a charging condition
and/or other parameter such as temperature of the energy source at
least in the electrically connected state. Note, that if the power
connector itself comprises an additional battery, the display unit
may also be used to display the charging state of the additional
battery or battery unit. Displaying the charging state of the
energy source at the power tool, in particular power adapter is
advantageous, as such display is easily accessible and/or visible
to a user operating with the power tool. In particular, if the
energy source is a backpack energy source, checking the charging or
loading state of the backpack energy source does not require
removing the backpack energy source from the back.
[0045] Therefore, it is possible, that the power adapter itself may
comprise batteries, such as conventional battery packs to be
attached to the power tool. These batteries may in particular be
used as intermediate storage means, charged by an external mobile
energy source, such as a backpack energy battery pack.
[0046] However, it is also conceivable, and it is preferred that
the power adapter does not contain any batteries or accumulators.
In this case, the function of the power adapter is reduced to a
simple connector without any charging functions.
[0047] The housing of the power adapter is preferably designed such
that it complies with the design and dimensions of a respective
conventional battery pack, in particular rechargeable battery pack,
of the power tool. Here, the user of the power tool will not be
confronted and will not have to customize to different designs. As
in one configuration, such a housing may not contain any battery
units, such a power adapter may also be called a "dummy
battery".
[0048] The power adapter may have the same outside geometry and
interfaces as conventional batteries used with the power tools.
Note that using the proposed power tool does in general not require
any mechanical and/or electrical adaptations of respective power
tools. Conventional battery packs and the proposed power connector
preferably are fully compatible.
[0049] The balance weight thus can be used and preferably is
adapted such that an optimal center of gravity is obtained with the
power tool.
[0050] The fixture unit may be adapted to comprise recesses or
receiving spaces enclosed by side walls for accommodating therein
one or more balance weight bodies. In particular the fixture unit
may be adapted to clip or plug a balance weight body thereto.
[0051] In a further embodiment, the housing and/or fixture unit
is/are adapted to accommodate one or several, i.e. at least one,
balancing weight of the same or of different weight. If single
balance weights are used, the power adapter will correspondingly
have respective different weights. It is, however, also possible,
that several different balance weights can be accommodated, which
in particular means that the overall weight of the power adapter
can be tuned, in particular fine-tuned, in particular in accordance
with the weight distribution of the power tool to be used.
[0052] In cases, in which the housing is not fully filled with the
balance weight or balance weight units, the housing has free spaces
which may contribute to a more efficient cooling of the power tool,
in particular if cooling is provided via the housing.
[0053] However, the balance weight is of great advantage, as the
ordinary and usual weight distribution prevailing with conventional
battery packs attached to the power tool, can be obtained, in
particular simulated. It shall be noted, that the user in most of
the cases is used to conventional weight distributions, and often,
the weight distribution of the power tool is adapted under
consideration of the weight of the battery pack.
[0054] The balancing weight or balancing weights themselves may be
accommodated slidably within or on the housing. This may contribute
to easily removing/exchanging the balance weights, in particular to
adapt to different weight distribution requirements.
[0055] The power adapter may be connected, in particular fixedly or
removably connected, to or with a cable connected to the energy
source.
[0056] In a further preferred embodiment, the power adapter, in
particular the housing, is adapted to be coupled to a charging
device, adapted to charge the energy source, in particular mobile
energy source, such as a backpack energy source. In this way, the
benefit of the power adapter is two-fold. On the one hand, the
power adapter may be used to supply a power tool with energy of an
external, in particular mobile energy source, while simulating
battery-pack type conditions. On the other hand, the power adapter
may be plugged from the power tool and, without any further
actions, be plugged into the charging device. Here, time-saving
operations may be obtained, in particular if interfaces of the
power adapter, power tool and charging device are standardized.
[0057] The display may be any type of display, in particular
7-segment displays, digital displays, LED-displays and the like.
The advantages of a LED 7-Segment-indication are the bright
display, good visibility under working conditions, stable display
in a wide temperature range and in particular the UV-stability.
[0058] Advantages of the proposed power adapter in particular are
as follows.
[0059] The proposed power adapter allows to use bigger portable
battery-packs, in particular backpack batteries. In particular, the
power adapter opens the possibility to use such a backpack battery
for a variety of applications, in particular handheld power
equipment, i.e. power tools, or handheld power tools. Additionally,
different types of battery-packs can be used in the same
application, in particular handheld power equipment. For example,
the handheld power equipment may have an integrated battery-pack
(10S2P-type). Since the dummy-battery has the same size, in
particular outside geometry, and has the same interfaces, i.e.
interface geometry (like that of 10S2P-type), the backpack battery
can be used for respective handheld power equipment, too, leading
to elongated operational times.
[0060] According to claim 14, a power tool assembly is provided,
having a power tool with a power interface to which a power adapter
according to any of the above embodiments and variants is
coupled.
[0061] Further, according to claim 15, an energy source assembly is
provided, comprising an energy source, in particular a mobile
energy source, in particular a backpack energy source, in
particular backpack battery or battery unit, wherein the energy
source is connected via a cable connection to a power adapter
according to one of the embodiments described further above and
below.
[0062] Further, according to claim 16, an energy source and power
tool assembly is provided, comprising an energy source, in
particular a movable or portable energy source, and a power tool,
and further comprising a power adapter according to any embodiment
described further above and below, wherein the power adapter on the
one hand is coupled to the power tool and on the other hand is
coupled to the energy source.
[0063] The power adapter according to the invention can be used
with or within any electrically operated handheld devices, in
particular within power tools such as hedge trimmers, clearing
saws, chain saws, brush cutters, trimmers, blowers, screw drivers,
drills, hammer drills, nailers, staplers, polishing or grinding
tools, etc.
[0064] Preferred embodiments will now be described in connection
with the annexed figures, in which:
[0065] FIG. 1 shows a perspective and partially broken-up view of a
power adapter;
[0066] FIG. 2 shows a fixture unit of the power adapter of FIG.
1;
[0067] FIG. 3 shows a fixture sub-unit of the fixture unit FIG. 2
with a balancing weight in a partially sectioned view;
[0068] FIG. 4 shows a perspective view of the power adapter;
[0069] FIG. 5 shows a front view of the power adapter;
[0070] FIG. 6 shows a system comprising a power tool, a backpack
battery pack assembly and a power adapter according to the
invention;
[0071] FIG. 7 shows an exploded view of a further embodiment of the
power adapter according to the invention;
[0072] FIG. 8 shows a base section of the power adapter according
to FIG. 7
[0073] FIG. 9 shows the base section with a printed circuit board
attached thereto;
[0074] FIG. 10 shows the base section together with a support plate
adapted to support the balancing weight;
[0075] FIG. 11 shows a balancing weight arranged on the support
plate;
[0076] FIG. 12 shows a bracket mounted to the base section and
fixing the balancing weight;
[0077] FIG. 13 shows the power adapter in a preassembled state;
[0078] FIG. 14 shows the power adapter in an advanced preassembled
state;
[0079] FIG. 15 shows the power adapter in an exploded view prior to
assembly,
[0080] FIG. 16 shows the power adapter in the assembled state
and
[0081] FIG. 17 shows a different perspective view of the power
adapter in FIG. 16.
[0082] FIG. 1 shows a perspective and partially broken up view of a
power adapter 1. The power adapter 1 is to be inserted into a
cordless hand-held power tool (not shown) and electrically and
mechanically coupled to the cordless power tool for electrical
supply of the power tool. The power adapter 1 comprises an adapter
housing 2 in which a fixture unit (or: insert) 3 is accommodated,
in particular inserted from above and slidably placed and/or
removed from the housing 2. When the fixture unit 3 is properly
mounted inside the adapter housing 2, the housing 2 is closed from
above by a housing lid 20 which is fixed to the main part of the
housing 2, e.g. by means of screws as shown in FIGS. 4 and 5.
[0083] The fixture unit 3 without or outside of the adapter housing
2 is shown in FIG. 2. Basically the fixture unit 3 comprises two
halves or two fixture sub-units 31 and 32, each preferably having a
plate-like base structure and a number, in particular four, of
fastening elements 5 and 15 respectively by which fastening
elements 5 and 15 the fixture sub-units 31 and 32 are fastened to
each other, in particular by snapping or shape-locking or also
screws. In the assembled or fastened state the two fixture
sub-units 31 and 32 and the fastening elements 5 and 15 form a
box-like or frame-like fixture unit 3 and enclose an inner space 36
of the fixture unit 3.
[0084] The power adapter 1 comprises a contact and coupling
electrical interface 6 adapted to be coupled to a respective
counter interface of a cordless power tool (not shown).
[0085] In the inner space 36 of the fixture unit 3 it is, in a
direct powering operation, possible to arrange battery cells (not
shown) to electrically power the power tool directly from the power
adapter 1 through the electrical interface 6 of the power adapter 1
being electrically coupled with a corresponding interface (not
shown) of the power tool when the power adapter 1 is mounted in the
power tool.
[0086] In order to insert or replace batteries the fixture unit 3
is dismounted from the housing 2 and the two fixture sub-units 31
and 32 are disassembled so that the batteries or new batteries can
be mounted in between the fixture sub-units 31 and 32 or first in
one of them. For this purpose a receiving space 35 (or 34) is
provided at one or both of the fixture sub-units 31 and 32 being
formed by a surrounding side wall 33 (or 37 [not indicated in the
figures]), so that the batteries are inserted into the receiving
space 35 (or 34) and held by the side wall 33 (or 37). The fixture
sub-units 31 and 32 can be re-assembled and fixed by means of the
fastening elements 5 and 15 again. Preferably, both side walls 33
and 37 of the receiving spaces 35 and 37 can hold or support the
batteries in the power adapter 1 and are, for this purpose,
opposing each other when the two fixture sub-units 31 and 32 are
mounted to form the fixture unit 3.
[0087] However, when external batteries such as backpack battery
assemblies to be carried on the back of the user of the power tool
are used for electric supply of the power tool the power adapter 1
does not need to comprise batteries by itself. Rather, the power
adapter 1 in this case is connected to the external batteries by
means of a cable 9 on one hand and by its electrical interface 6 to
the power tool 1 on the other hand. In this indirect powering
operation case the power adapter 1 has only the passive function of
electrically connecting the power tool with the external batteries,
in particular backpack batteries. For the user it is somewhat like
a dummy battery.
[0088] Now, the mass distribution and weight of a power tool is
usually balanced for an optimum use and for this balancing the
considerable weight of the batteries inside the power tool is taken
into account.
[0089] However, in the indirect powering operation the power
adapter 1 has no batteries and thus lacks the weight it has in the
direct powering operation. This can lead to an unpleasant and
different behaviour of the power tool during indirect powering
operation as compared to direct powering operation.
[0090] To compensate this disadvantage a counter-weight or
balancing weight 4 is provided in the power adapter 1 to reach at
least approximately the same weight and balance of the power tool
as if batteries were present. So, preferably for each power tool
and battery set a corresponding set of balancing weights can be
provided.
[0091] Preferably, the balancing weight 4 is arranged in the same
region of the power adapter 2, i.e. here the inner space 36 of the
fixture unit 3, where in the direct powering operation the
batteries would be placed so as to emulate or produce the same
balancing behaviour as if the batteries were present in the same
place. In this case the balancing weight 4 can have basically the
same mass as the (missing, replaced) batteries.
[0092] A preferred embodiment of how to incorporate the balancing
weight 4 in the power adapter 1 is shown in FIG. 3. Here, the
balancing weight 4 which is shown only partly in a partially
sectioned view, is received within the receiving space 34
surrounded by the side wall 37 and the base plate at the bottom of
the first fixture sub-unit 31. For instance the balancing weight 4
can be a mineral body such as concrete or any other material such
as metal or a compound material of metal and mineral or plastic or
resin material which is heavy enough to reach the weight of the
missing batteries. The weight 4 can be produced in situ into the
receiving space 34 for instance poured into it or produced
separately and then fixed into the receiving space 34 for instance
by press-fitting or shape-locking or glueing or any other suitable
fastening means. By means of the density and the size of the weight
4 the weight of the missing batteries in the power adapter 1 can be
compensated.
[0093] This embodiment has the big advantage that only the first
fixture sub-unit 31 has to be changed or replaced when the power
adapter 1 is to be used in indirect powering operation instead of
direct powering operation. The second fixture sub-unit 32 and all
other components of the power adapter 1 as well as its dimensions
and mechanical interfaces and electrical interface 6 to the power
tool can basically stay the same.
[0094] In an alternative embodiment both fixture sub-units 31 and
32 have a balancing weight 4 and, thus, are both replaced in the
case of direct powering operation or, in other words, the whole
fixation unit 3 is replaced by a fixation unit having batteries
instead.
[0095] Balance weights 4 of different types, in particular
different weight can be attached to the fixture unit 3. Preferably,
the fixture unit 3 and balancing weight 4 of different types are
designed such that the outer geometry of the fixture unit 3 with
the balancing weight 4, is independent from the type of balancing
weight 4, and can in any case be inserted into the housing 2.
[0096] Providing the balancing weight 4, in particular with the
fixture unit 3, has the advantage that the weight of the power
adapter 1, as such being clearly lighter than conventional NiMH or
Li-Ion accumulator packs, can be adapted to match, in particular
approximately match, the weight of the conventional battery packs.
This in turn has the advantage that a favorable balance of weight
can be obtained, which is or will be familiar to a user experienced
in operating battery-pack driven tools. The power adapter 1
therefore simulates the presence of a conventional battery
pack.
[0097] However, as the power adapter 1 can be connected to a remote
battery pack, such as a backpack battery pack, as will be described
further below, a battery pack of comparatively high load capacity
can be used and the overall operational time can be raised.
[0098] As shown in FIGS. 4 and 5 the power adapter 1 also comprises
a display unit 7. The display unit 7 is adapted and attached in
such a way that, in an indirect powering operation, the loading or
charge status and/or temperature of a remote, movable energy
source, such as a backpack battery pack, can be displayed and
observed by a user during operation of the power tool. Such a
display unit 7 is of particular advantage for backpack battery
packs, as the loading status of the battery pack on the back of the
user in this way can be easily checked during operation of a tool
connected to the energy source and power adapter 1. Signals for
controlling the display unit may be outputted from an electronic
controller or the like of the energy source. Of course it is also
possible that the display unit 7 shows the charge status and/or
temperature of batteries inside the power adapter 1 in a direct
powering operation, in particular when the first fixture sub-unit
31 with the weight 4 is replaced by a sub-unit adapted for
batteries.
[0099] Furthermore, the power adapter 1 may comprise a slewable
cable outlet 8. The slewable cable outlet 8 has an outlet opening
9. The outlet opening 9 is adapted to guide through an electric
cable (shown in FIG. 6 only) for connecting the power adapter 1, in
particular electrical contacts of the coupling interface of the
power adapter 1, to a remote energy source, such as a backpack
battery pack.
[0100] The slewable cable outlet 8 may comprise or be constituted
by a slewable member attached and mounted to the housing 2 to be
slewable as indicated by the double arrow in FIG. 5. In FIG. 5, the
slewable member is slewable in a horizontal plane. However, it is
also or in the alternative possible to implement the slewable
member to be slewable in a vertical plane. Such a slewable member
will greatly ease operation of a tool or device connected to the
power adapter 1 since the cable has a slewing range of up to
180.degree. in a rotational movement. Of course also a spherical
movement is possible, i.e. a rotation about two orthogonal
axes.
[0101] Also the housing 2 comprises air vents 10 which allow a flow
of air through the housing 2 which is not completely, in particular
only slightly, filled. As can be seen, despite of the balance
weight 4 and fixture unit 3 accommodated in the housing 2, the
housing 2 still comprises a dead volume. This dead volume may
contribute to enhanced air flow which may be used to cool the tool
or device operated via the power adapter 1. So the cooling of the
electronic components in the power adapter 1 and of the power tool
1 is improved.
[0102] In FIG. 6 an embodiment of the whole system including a
power tool 16 with a power adapter 1 and an external battery
supply, here a backpack battery assembly 14, is shown. The power
adapter 1 has an electrical cable 11 exiting from its cable outlet
9 which electrical cable 11 is electrically connected through an
electrical connector 12, in particular a magnetic or a
plug-socket-connector, to an electrical cable 13 of a backpack
battery assembly 14 to be carried on the back of a user while the
user holds the power tool 16 in his hands. The power adapter 1 is
for illustration purposes not yet inserted into the power tool 16.
Although the power adapter 1 has a cord or cable for connection to
the batteries, the power tool 16 itself remains a cordless power
tool. In particular the cable will be carried by the user and not
fall on the ground, nor and more important will the length of the
cables 11 and 13 restrict the range of the power tool 16 thus
maintaining the mobility of a cordless battery powered power
tool.
[0103] FIG. 7 shows an exploded view of a further embodiment of the
power adapter 1 according to the invention. The power adapter 1 in
this configuration comprises a base section 38 and a corresponding
dome shaped cover 39. The base section 38 and cover 39 can be
connected to each other, in the present case via screws 40, to
establish a casing or housing adapted for accommodating elements or
components of the power adapter 1.
[0104] Elements or components accommodated within the casing are as
follows: a support plate 42 adapted for supporting a balancing
weight 4 on the base section 38, and a retaining bracket 43 adapted
for retaining and holding the balancing weight 4 on the base
section 38. The bracket 43 at least partially embraces the
balancing weight 4 and is adapted to be fixed to the base section
38, presently via further screws 44, optionally via shape-locking
elements or connections and the like.
[0105] As can be seen from FIG. 7, the bracket 43 comprises on a
side averted from the support plate 42 a cable clamp arrangement 45
adapted to tightly clamp cables such as for example a cable 46 for
electric power supply.
[0106] The cable 46 is guided through the base section 38, through
the inner of the casing and finally ends in a connector interface
47 adapted to establish electric contact and others to
corresponding counter contacts of the cordless power tool.
[0107] As already becomes obvious from FIG. 7, the power adapter 1
in this configuration enables comparatively compact arrangements
and designs of the elements arranged or accommodated within the
casing. In particular beyond the balancing weight 4 and bracket 43
there is still room left for guiding cables, such as cable 46, and
air ventilation through the casing.
[0108] As can also be seen from FIG. 7, the base section 38
comprises a cable bushing 48. The cable bushing 48 is implemented
as a funnel shaped element extending from the base section 38 to
the inner volume of the casing. As will become more obvious further
below, the outer walls of the bushing 48 are designed to implement
a funnel or cone having increasing cross sections in a direction
from the inside of the casing towards its outside. Using such a
funnel shaped cable bushing 48 has the advantage that the cable
bending radii of the cable 46 can be kept at moderate values during
operation or use of the power adapter 1. In particular too small
bending radii probably causing cable damages may be avoided, at
least at the cable bushing 48. Also, less space is needed to align
the cable along the outside surface of the adapter or
powertool.
[0109] FIG. 8 shows the base section 38 of the power adapter 1 in
more detail. The base section 38 has an essentially rectangular
shape and provides several elements for fixing the cover 39,
bracket 43 and others. Further, the base section 38 may comprise at
its inner side several reinforcement elements or ribs. However, the
base section 38 of the present embodiment comprises a recess 49
which is adapted to accommodate a printed circuit board, in
particular in a press-locking, shape-locking and/or snap-locking
manner. The PCB may also be fastened by means of screws for
example. Several support elements for supporting the printed
circuit board are arranged in the recess 49.
[0110] FIG. 9 shows the base section 38 with the printed circuit
board arranged within the recess 49, wherein the printed circuit
board is designated with reference number 50. Mounting the printed
circuit board within the base section 38 has the advantage that it
can be protected against outer mechanical impacts, as the base
section 38 is of comparative robust construction. Further, display
and/or operating elements 51 (FIG. 8) or signs related to the
printed circuit board 50 may be viewed through the base section 38,
which in general is visible even if the power adapter 1 is coupled
to a cordless power tool.
[0111] As has been described in connection with FIG. 7, the
balancing weight is also mounted or fixed to the base section 38.
As becomes clear from a combination of FIG. 7 to FIG. 9, the
location of the printed circuit board 50 in the base section 38 at
least overlaps with the mounting location of the balancing weight
4. In order to avoid the balancing weight 4 to directly rest on the
printed circuit board 50, the base section 38 comprises several
support ribs 52 adjacent to the recess 49. The support ribs 52 are
adapted and configured such that they can support the support plate
42, and in particular can engage corresponding grooves or notches
or ribs provided with the support plate 42.
[0112] Reference is now made to FIG. 10 showing the base section 38
together with the support plate 42 in a configuration suitable for
supporting the balancing weight 4. It shall be noted, that the
printed circuit board 50 is not visible in FIG. 10. This is due to
the fact, that in the present embodiment, the recess 49
accommodating the printed circuit board 50 is potted or sealed with
a potting or sealing compound 53, which is provided for protecting
the printed circuit board 50 from outer influences.
[0113] Further, the support plate 42 connected to the base section
38 comprises or provides support bars 54 adapted to support the
balancing weight 4 placed on the support plate 42. A respective
arrangement of the balancing weight 4 on the support plate 42 can
be seen in FIG. 11. From FIG. 11 it can in particular be seen that
the support plate 42 fully supports the load of the balancing
weight 4 and thereby prevents the load of the balancing weight 4
from acting on the printed circuit board 50 and/or potting or
sealing compound 53.
[0114] Reference is now made to FIG. 12 showing the balancing
weight 4 attached or fixed to the base section 38 via the retaining
bracket 43. The retaining bracket 43 in the present case is
screw-mounted to the base section 38. Further, the retaining
bracket 43 comprises stiffening elements, such as stiffening ribs,
configured to firmly fix the balancing weight 4 to the base section
38 in particular in extreme situations, in particular in situations
in which the power adapter crashes, unintentionally, to the ground
and the like.
[0115] In FIG. 12 it can be seen that the retaining bracket 43
comprises at lateral sides, in the present case at two lateral
sides averted from each other, a respective support jib 55. The
support jibs 55 are designed such that the retaining bracket 43 is
and will be supported against the inner walls of the cover 39 in
case that the base section 38 and the cover 39 are connected to
each other. The support jibs 55 may be effective in preventing
cracking or rupturing the retaining bracket 43 and balancing weight
4 from the base section 38 under extreme loads, such for example
occurring in instances where the power adapter, unintentionally, or
in drop tests, crashes or is crashed to the ground.
[0116] As can be seen in more detail from FIG. 13, the support jigs
55 can have a secondary function in which the support jigs 55 are
used for cable routing, as a cable holder and/or a cable retainer
for the cable 46 or cables or other elements within the casing
which is assembled from the base section 38 and cover 39 connected
thereto.
[0117] FIG. 13 further shows that there is still room left within
the casing which in particular is advantageous for allowing an air
flow through the casing, in particular for cooling respective
components accommodated therein.
[0118] FIG. 14 shows the power adapter 1 in an advanced
preassembled state in which the printed circuit board 50 is potted
to the base section 38 and the balancing weight 4 is fixed to the
base section 38 via the retaining bracket 43. Further, the cable 46
or parts thereof are fixed to respective retaining elements, in
particular to the cable clamp arrangement 45 and support jib 55.
The connector interface 47 is adequately mounted to the base
section 38, and the snap locking elements 41 are connected to the
base section 38.
[0119] In this state of assembly, the cover 39 can be imposed or
put on the base section 38 and all elements assembled thereto, and
the cover 39 can be fixed to the base section 38.
[0120] Here, it can in particular be seen that the proposed
embodiment allows a great deal of preassembly work on the basis of
the base section 38. In a final assembly step only the cover 39 may
be connected, which in particular is indicated in FIG. 15 by
arrows.
[0121] FIG. 16 shows the power adapter in the assembled state. From
FIG. 16 it can be seen that the cover 39 comprises air vents 56
allowing a cooling airflow through the casing. Further, it can be
seen that the display and/or operating element or unit 51 is freely
accessible and visible even if the power adapter 1 should be
connected to a power tool.
[0122] It can also be seen from FIG. 16, that the base section 38
may be screw mounted to the cover 39.
[0123] Reference is now made to FIG. 17 showing a different
perspective view of the power adapter 1 in FIG. 16. As can be seen
from a combination of FIG. 16 and FIG. 17, the cable bushing 48 is
implemented as a funnel or cone shaped deepening providing convex
outer walls for reducing or restricting the bending radii of the
cable 46 during operation to moderate values. The bending radii in
particular are selected such that damages to the cable 46 as a
result of sharp bends at the cable bushing 48 can be avoided, and
such that bending of the cable in a certain direction is
facilitated.
[0124] As can be seen, the power adapter as proposed herein greatly
improves operation of cordless tools, in particular cordless power
tools, in cases in which comparatively heavy energy sources, i.e.
battery pack with comparatively high load capacities are used.
REFERENCE SIGNS
[0125] 1 power adapter [0126] 2 adapter housing [0127] 3 fixture
unit [0128] 4 balance weight [0129] 5 fastening element [0130] 6
coupling interface [0131] 7 display unit [0132] 8 slewable cable
outlet [0133] 9 outlet opening [0134] 10 air vent [0135] 11
electrical cable [0136] 12 electrical connector [0137] 13
electrical cable [0138] 14 backpack battery assembly [0139] 15
fastening elements [0140] 16 power tool [0141] 20 housing lid
[0142] 31 first fixture sub-unit [0143] 32 second fixture sub unit
[0144] 33 side wall [0145] 34 receiving space [0146] 35 receiving
space [0147] 36 inner space [0148] 37 side wall [0149] 38 base
section [0150] 39 cover [0151] 40 screw [0152] 41 snap locking
element [0153] 42 support plate [0154] 43 retaining bracket [0155]
44 further screws [0156] 45 cable clamp arrangement [0157] 46 cable
[0158] 47 connector interface [0159] 48 cable bushing [0160] 49
recess [0161] 50 printed circuit board [0162] 51 display and/or
operating element [0163] 52 support rib [0164] 53 potting or
sealing compound [0165] 54 support bar [0166] 55 support jib [0167]
56 air vent
* * * * *