Note: Descriptions are shown in the official language in which they were submitted.
~3~ 533~
MOBI LE POW~'R TOO:L AND APE~LIANCE OPERATING SYSTE'M
Field of the ~n~ention:
The present inventiorl relates to a system for- operating bat-
tery powered, hand-held power tools and appliances, including
tools and appliances having a high direct current capacity.
Description of the ~rior Art:
In recent years, low-voltage, direct current le.q., 12 v~c)
hand held appliances and tools have proliferated for use in the
car and around the horne. Some appliances, such as the hand-held
car vacuum cleaners and car polishers, are intended for operation
using power supplied from the car battery~ These appliances,
which are relatively low current devices (~.e., 2-6 amps), typi-
cally employ a plug connector compatibl~ with the socket compo-
nent of a conventional, dash-mounted automotive cigarette
lighter, The necessity for use of these appliances in close
proximity to a vehicle having a lighter socket has restricted
somewhat the utilization of the same appliances around the home.
Many hand-held tools used around the home, in comparison, require
relatively high current levels ~l.e., 8-20 amps). These high
current tools include hedge trimmers, grass tri~ers, etc., which
can seriously tax the capacity of self-contained battery packs
which t~pically are of the NiCd variety.
An operating system ~sing a portable battery pack having in-
creased power capacity and longer operation times be-reen
3 ~ ~
charging would be highly desirable for these high ~irect current
tools. The system shoul~ enable th~ battery ,oack to be selec-
~ively connecta~le to a variety of different tools to maximize
utility. Moreover, because of the existence in the marketplace
of a variety of automotive appliances having cigarette lighter
socket-compati~le low current plug connectors, an ability to
accommodate existing low current plug connectors would further
extend the usefulness of the system.
13i~i3~
~UMM~RY OF THE I NVr,NT I ON
In accordancc with th~ preserlt invention, as embodied and
broadly described herein~ the system for op~r~ting one-at-a-time
a plurality of different hand-held, low-voltage, direct current
power ~ools and appliances of the present inventiorl comprises a
portable battery pack, and ~irst electrical connector rneans for
selectively connecting any one of the plurality of tools and
appliances to the battery pack, for mobile operation thereof.
The system also includes regulated charging means energizable by
standard 110 volt AC house current, the charging means including
a housing and charging circuit means including a transformer and
voltage regulator contained in the housing, and second electrical
connector means for selectively connecting the oattery pack to
the charging means.
Preferably, the battery pack includes at least one battery
of the lead acid type, and the ~irst electrical connector means
includes a high current connector assembly of the plug-and-socket
typ~. The plug component including safeguard means for pre-
venting insertion into an automotive cigarette lighter socket~
It is also preferred that the socket component is adapted
for also receiving, and electrically connecting to~ low-voltage
tool and appliance plugs intended for operation in an automotive
cigarette lighter socket, and that the socket component includes
loch.out means for preventin~ insertion of an automotive ~igarette
1 ig)lter plug ~
--3--
1315~5
Further in accordance with the preserlt invention, the
hand-held, low-voltage, hi~h direct current power tool operatin~
system of the present invention comprises a hand-held,
low voltage, high direct current power tool having an operational
end, a power cord, and cord control means for biasing the power
cord away from the ground and away from the operational end. The
system further includes a portable battery pack including a
lead-acid battery, and first high direct current electrical con-
nector means for selectively connecting the power cord to the
battery pack for mobile operation of the power tool; and requ-
lated charging means energizable by standard 110 volt AC house
current, the battery pack being selectively connectable to the
charging means.
Preferably, the high direct current power tool includes a
tool handl~ positioned distant from the operational end, the
power cord being self-retractably coiled and connected to the
tool at the handle.
~ till further in accordance with the invention, as embodied
and bro~dly described herein, the system for operating
one-at-~ time a plurality of different hand-held, low-voltage,
direct current power tools and appliances of the present inven-
tion comprises a portable battery pack, and electrical connector
means for selec~ively connecting ~ny one of the plurality of
tools and appliances to the ba~tery pack, for mobile operation
3 ~ ~
thereof, wherein the electrical conn~ctor ~eans includes a hiqh
current connector assembly of the plug-and-socket type, The
socket component of the plu9 and-socket ass~mbly is incorporated
in the battery pack, and the plug component is connected to ~he
one tool or appliance. The socket component is adapted Eor also
receivinq, and electrically connecting to, low-voltage tool and
appliance plugs intended for operation in an autornotive cigarette
lighter socket.
The accompanying drawing which is incorporated in and con-
stitutes a part o this speclfication illustrates one emhodiment
of the invention and, together with the description, serves to
explain the principles of the invention.
~3~.~335
~RIEF DE~SC~IPTION OF T~E DR~ING
Fig. 1 is ~ schematiC representation of the mobile power
tool and appliance system of the present invention;
Figs. 2 and 3 are perspective and side views of the portable
battery pack preferred for use in th~ system of Fig~ l;
Fig. 4 is an illustration o~ the battery pack of Pigs. 2 and
3 to be worn by a user to power a high current capacity power
tool;
Fig. 5 is a schematic of a high current capacity
plug-and-socket connector assembly preferred for use in the sys-
tem of Fig. l;
Figs. 6 and 7 are top and side plan view schematics of a
charging base for use in recharging the hattery pack of the oper-
ating system depicted in Fig. 1
Fig. ~ is a schematic of the charging circuit used with the
charging base depicted in ~igs. 6 and 7
Fig~ 9 is a sc~.~rnatic of the power circuit used in the bat-
tery pack depicted in Figs. ~ ~nd 3;
Figs. 10 ~nd 11 show dctails of the socket component of ~he
connector assembly depicted ir. Fig. 5; and
Pig. 12 shows details of the plug component of the connector
assembly depicted in Fig. 5
3 3 ~
DF,SCR I PT I C)N Ol;` T~f:E PREFERRED EME~OD I ME~T
~ .
Reference will now be made in detail to the present pre-
ferred em.bodiment of the invention, an example of which is illus-
trated in the accornpanying drawing.
The pref erred embodiment of the mobile power tool and appli-
ance operating system is shown schematically in ~igure 1 and is
represented generally by the numeral 10. The s~stem is intended
for utilization with a number of different power tools and appli-
ances, such as the car vacuum, car polisher, power drill, etc.
devices listed in Figure 1. It should be noted that the listing
in Figure 1 is not intended to be inclusivet and one skilled ;n
the art would realize that the system of the present inYention
could be used with a greater number and variety of power tools
and appliances~
Importantly, however, the power toois and appliances listed
in Figure 1 include some that are relative~ low current devices,
such as those shown in Group I, as ~ell as the high current de-
mand tools listed in Group II. Again, one shilled in the art
would realize that certain of the tool or appliance types l;sted
in Pigure 1, such as the power drill, could encompass models
which more properly would belong in one or the other category de-
pending upon size and application. Therefo.~, the list. set forth
in Figure 1 is not intended to be restrictive in this sense.
However, the Figure 1 representation is intended to 5how that the
3 ~
pr~sent system can acco~ odate both low current tools and appli-
anc~s and tools and appliances dr~wi~g relatively high currents
It should be noted also th~t the present system contemplates
operation of the power tools and applian~es only one-at-a-time
In accordance with the present invention, the system for
operating one-at-a-time a plurality of different hand-held,
low~voltage, direct current power tools and appliances includes a
portable battery pack. As embodied herein, and with initial ref-
erenc~ to Figures 1-4, system 10 includes battery pack 12 which
is intended to be carried by an operator, .such as operator 14 in
~igure 4, such as by a combinatiorl of shoulder strap 16 and waist
strap 18. Battery pack 12 specifically includes housing 20 which
preferably can be formed from an impact resistent plastic in a
two-piece "clamshell" construction for ease of a5sembly. As best
seen in Fiqures 2 and 3, housing 20 includes an integrally formed
hand grip portion 22 and a battery patk side 24 inwardly curved
to conform to the rounded trunk of the operator. ~tteri pack
housing 20 also includes stud members 26, 28 for attachlng shoul~
der strap 14 and loop members 30, 32 for receiving wa;~t strap
18~ While battery pack 12 may be supported by operator 1~
through either shoulder strap 16 or waist strap 18 alon~, a more
co~fortable and secure attachment is provided through the use of
both shoulder strap 16 and waist strap la simultaneously.
~ 3 3L ~
With continued reference to Figure 3, portable battery
pack 12 includes a plurality of rechargeable batteries, such as
bat~eries 34 and 36 contained within housing 20 It ;s preferred
that batteries 34, 36 be of the lead~acid type which exhibit su-
perior voltag~current performance characteristics over extended
temperature ranges. This extended operating range is intended to
further increase the utility of the overall system.
Further in accordance with the present invention, the system
includes an electrical connector means for selectively connectinq
any one of the plurality o tools and aypliances to the ~attery
pack for mobile operation. As embodied herein, and with initial
reference to Figure 1, the sys~em 10 includes connector means 40
depicted schematically in the figure. In the present preferred
embodiment, and as best seen in Figure 5, connector means 40 spe-
ci~ically includes a high current density plug-and-socket con-
nector assembly including plug component 42 and socket component
44. Socket component 4~ is incorporated in battery pack housing
20 while a plurality of plug components 42 are attached via po~-e~
cord ~6 to respecti~e power tools and appliances. It is specifi-
cally contemplated that each power tool and appliance have a plug
42 permanently attached to a respective power cord 46, and that
the connection betwe~n battery pack 12 and the respective power
tool or appliance be achieved by insertion of the respective plug
component 42 into the socket component 44 carried by battery pack
12.
_9_
';f"~
13~33~
The constructional details of the preferred high current
plug-and-socket connector assembly 40, including plug component
42 and socket component 44, are set forth in Bailey et al.
Canadian Application 546,217 entitled "Low-Voltage, ,.
High Current Capacity Connector Assembly".
As is discuss~d in Canadian Application 546,217
socket component ~4 is also specific~lly designed to accept
conventional low current plug components, such as those typically
used in automotive ciqarette lighter sockets. Such a low-voltage
plug component is depicted in broken line representation in Pig-
ure 5 and is designated qenerally by the numeral 4a. The ability
of the present ~ystem to accommodate existing power tools and
appliances having low current plug components of the type de-
picted in Fig. 5 is expected to further enhance the utility of
the present operating system invention.
~ ecause of the intended compabi:Lity with conventional
low-voltage, low current plugs, the socket component used in the
operating system of the present invention preferably has means
for preventing insertion of an automotive cigarette lighter plug.
As embodied here;n, and as depicted schematically in Figs. 10 and
11, socket component 44 includes a boss 90 integrally formed with
soch~t housing 9~ of non-conductive material. ~oss 90 is sized
to intercept axial face 94 of ligher plug 96 (shown in broken
-10
~,
~3~ ~33~
lines) and space ~ace 94 ~rom socket electrical contact element
9~ to prevent an electric~l connection. ~lso, socket component
housing extension 100 inlcudes lip portion 102 sized to intercept
flange 104 of lighter plugs 56' so equipped to prevent an elec-
trical connection. See Fig. 11. The heat generated by
activiation of lighter plug 9G otherwise could damage socket com-
ponent ~q and degrade the performance of operating system 10.
It is also preferred that the plug components used with the
operating system of the present invention inlcude means for pre-
venting electrical connection when inserted in a standard automo-
tive lighter socket~ Such standard sockets are often fused for
relatively low current (~., 6 amps) and such fusing could be
blown or the lighter circuit damaqed if an operator attempted to
po~er high current tools from the lighter socket As embodied
herein, and wi~h reference to Fig. 12 plug 4~ includes electrical
contact memb~r 110 recessed in axial ~ace 112 of plug housing
114~ The recess prevents electrical contact between contact me.~-
ber 110 and contact face 116 of lighter socket 118 (shown in bro-
ken lines),
The de.~ils of the a~ove described safeguard means and lock-
out means ~re ~et for~h in Canadian Application 546~217.
One skilled i~ the art would appreciate that oth~r safegua~d and
lockout means could be provided in the plug component and the
socket ccmponent, respectively, of the present operating system
invention.
~3:~ ~3~.~
Further in accordance with t!le pres~nt illvention, the mobile
power tool and applianee operating system i~lcludes re9ulated
chcll-ging means energi~ahle by standard AC house current ~or use
with the battery pack. The chargirlg rneans specifically includes
a housing and a chargin~ circuit including a transformer and
voltage regulator components contained in the housin~. As
embod;ed herein and with reference to Figures 6 and 7, system 10
further includes a charging unit designated generally by the nu
meral 50 in Figure 1 andt as best seen in Figures 6 and 7,
including housing S2 which also can serve as a stand for
receiving battery pack 12 during charging operations. Housing 52
can be optionally rested on a hori~.ontal surface such as
surface 54 as depicted in Figure 7 or can be mounted on a verti-
cal surface such as surface 56 as depicted in ~igure 6, The
exact shape of housinq 52 is not considered important to the
present invention beyond the fact that it contain the charging
circuit means to be discussed henceforth. Thus, while the charg-
ing circuit is shown schematically located in the bottom portion
of housing 52 in the Figure 7 representation, and designated gen-
erally by the numeral 5a~ it is not critical that the charging
circuit be so located, and a variety of diEferent charging unit
housing configurations and charging circuit locations would occur
to one skilled in the art.
13~3~
With ~pecific reference to Figure ~, ther~ is shown a sche
rn~tic representatiOrl of th~ details of the preferred charging
circuit means 5~. SpeciEically, chargillg circuit 5~ includes a
transformer 60 the input o which is shown operationally con-
nected to a source 6~ of standard house AC current, such as s~an
dard 120 VAC as is used in the United States or 2~0 VAC as is
used in Europe. Source 62, of course, can be a standar~ wall
outlet (not shown) and the charging means 50 shown in Pigures 6
and 7 can include a standard p].ug and cord ~4 for utilization
with such an outlet. Returning again to Figure H, charging cir-
cuit means sa also includes voltage regulator 66 which is opera--
tionally connected to transformer 60 through a full wave rectifi-
er 6a. Suitable commercially available products for use in
circuit means 5~ intended for 120 VAC power input include a ~odel
6050 trans~ormer manufactured by Coils, Incorporated, Huntley,
Illinois, A model WO2M rectifier manufactured by General Instru
ments; and a Model ~L 780-15C voltage regulator manufactu~ed by
Texas Instruments.
Further in accordance with the present invention, the oper-
ating system of the present invention includes electrically con-
nector means for selectively connecting the battery pack to the
regu1ated charginy means. As embodied herein and with reference
to Figures 6 and 7, the charging means/bat~.ery pack electrical
connector means is designated generally by l:he numeral 6~ and
~3~ ~3~
includes a pair of pin contacts 70, 72 mounted in housing 52 and
operationally connected to the output of charyirl~ circuit means
58. Mounted in housing 20 of battery pack 12 are a pair of rivet
contacts 74, 76 which are po5itioned to form an abutting contact
with pin contact 70, 7~ when battery pack 12 is received in hous-
ing 52 of charging unit 50. As depicted in the circuit schematic
in Figure 9, rivet contacts 7~, 76 are electrically connected
across the batteries of battery pack 12, such as batteries 3~,
36. LED 7a, shown schematically in Figure 9 with associated re-
sistor 79, is disposed on the outside of battery pack housing 20
(se~ Fi~ure 7) and provide~ a visual indication of power flow to
batteries 3~, 36 during charging operation. The LED is rated at
50 milliamps and the resistor at 660 ohms, 0.5 watts, 10~ ~at-
tery pack 12 also includes circuit breaker 80 connected ;n series
between batteries 34, 36 and socket component 4~ to provide pro-
tection against excessively high current flow in the battery cir-
cuit. A circuit breaker rated at 20 amps can be used. With ref-
erence to Figure 3, circuit breaker 80 can be positioned
conveniently in hand grip portioll 22 oE housing 20. Diode al in
the Figure 9 circuit schematic is a type 4002, 50 volt PIV.
Further in accordance with the present invention, eac~ of
the power tools and appliances intended for operation with the
operating system is intended to include a power cord and a cord
control means for biasing the power cord away from the ground an~
-14-
:~?~L~3~
away from the o~erational end of the respe ctive power tool or
appliance~ ~s embodied herein, and with specific reference to
Fiqure 4, power tool 380 which is a weed trimmer having an opera-
tional end (trimming head) 82 and a handle 84 includes power cord
~6 which is spirally coiled to be self-retractable along its
length. One end of coiled cord 86 is permanently connected to
the tool 3~0at handle 84 while a plug component ~2 is attached to
the other end of cord 86 and, in turn, is inserted into socket
component 44 in battery pack 12. The retractably coiled power
cord 86 prevents entanglement with the user's feet and arms while
providing a full range of motion of power tool 380. The re-
tractably coiled power cord ~ also prevents ~amage to the power
cord caused by inadvertent engagement with operational end 82 of
power ~ool380.
It will be apparent to those skilled in the art that various
modifica~ions and variations can be made in the mobile power tool
~nd appliance operating system of the present invention without
departing from the scope or spirit of the invention. Thus, it is
intended that the present invention cover the modifications and
v~riations of this invention provided they come within the scope
of the appended claims and their equivalents.
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