Note: Descriptions are shown in the official language in which they were submitted.
CA 02257521 2001-02-06
' 69905-89
1
ELECTROMECHANICAL SWITCHING DEVICE
RELATED APPLICATION
FIELD OF INVENTION
The present invention is directed to
electromechanical switches for automatically providing a
desired polarity connection between two sources of power.
Though not by way of limitation, the present invention finds
particular application in the automotive field in order to
properly interconnect like terminals of a pair of vehicle
batteries for recharging.
BACKGROUND OF THE INVENTION
Relays and switches are used in a variety of
industrial and commercial applications where there is a need to
control power. A relay may be either an electromechanical or
solid-state device to control other devices connected to an
output. Relays are generally associated with controlling the
transmission of electric current in a circuit.
Electromechanical relays are used as switches that
make or break a circuit by mechanical operation. Here, an
electromagnet moves an armature when current flows through the
electromagnet, and the armature acts as a switch. Where the
magnetic field produced by a current-carrying coil is used to
magnetize and move a plunger, the electromagnet may also be
referred to as a solenoid.
It is known to employ either electromechanical or
solid-state switches in order to ensure proper polarity
connection between two sources of power. One exemplary
application for such use is in the automotive field for the
purpose of interconnecting rechargeable batteries. It is not
uncommon for vehicles having rechargeable batteries, such as
CA 02257521 2001-02-06
' 69905-89
la
automobiles, busses, trucks, etc. and even watercraft to
require boosts on their batteries from external sources of DC
power. For example, in emergency situations, it may be
necessary to jump-start a vehicle by connecting one vehicle's
"dead" battery to another vehicle's "live" battery. Jumper
CA 02257521 1998-12-08
WO 98/01928 PCT/US97/12310
2
cables can be used for this purpose, but it is imperative to
connect the batteries with proper polarity, i.e. positive to
positive and negative to negative. Failure to do so can
potentially cause serious damage to either or both vehicles'
electrical systems.
In the past, a variety of techniques have been employed
by others to ensure proper interconnection between vehicle
batteries. For example, U.S. Patent No. 4,400,658 to Yates,
issued August 23, 1983, relates to a battery cable jumper
arrangement incorporating a plurality of solenoids and a
switching arrangement. A pair of double pole, double throw
(DPDT) switches are actuated by the solenoids to ensure
correct polarity of connection between the power source and
the battery, irrespective of the connected arrangement of the
cable pairs. In U.S. Patent No. 5,103,155 to Joannou, issued
April 7, 1992, a battery charging system utilizes solid-state
components interconnected between two pairs of booster cables.
Joannou's device incorporates an electronic polarity sensing,
monitoring and alarm circuit and a polarity sensing relay.
SUMMARY OF INVENTION
It is an object of the present invention to provide an
new and useful electromechanical switching device which is
adapted for interconnection between a pair of power sources
and operative to establish electrical communication between
desired terminals of the power sources, such as between like
terminals.
It is another object of the present invention to provide
an electromechanical switching device which utilizes either
electromagnetic or solenoid technology to ensure proper
interconnection between two power sources.
A further object of the present invention is to provide
a new and useful electromechanical switching device which is
relatively easy and inexpensive to manufacture.
Yet another object of the present invention is to provide
a new and useful methodology for ensuring automatic, desired
electrical interconnection between two sources of power.
T _ __ __ _...
CA 02257521 2001-02-06
' 69905-89
3
The present invention is particularly adapted to
interconnect like terminals of a pair of power sources. To
this end, the invention broadly includes a plurality of
current-carrying coils each adapted to electrically connect in
a selected connection state to the oppositely polarized
terminals associated with the respective one of the power
sources to produce an associated magnetic field so that a
composite magnetic field is established for the plurality of
coils. A switch is then magnetically coupled to the coils and
is operative when the coils are connected to the power sources
to interact with the composite magnetic field thereby to
interconnect the like terminals of the power sources
irrespective of the connection states of the coils.
In accordance with the present invention, there is
provided an electromechanical switching device operative to
electrically interconnect a positive terminal of a first power
source to a selected one of a positive and negative terminal of
a second power source and a negative terminal of said first
power source to another one of the positive and negative
terminals of said second power source thereby to define a
selected coupled state for the first and second power sources,
comprising: (a) a switch including a first pair of contacts, a
second pair of contacts and a third pair of contacts, said
switch movable between a first state wherein each of said third
pair of contacts is electrically connected to a respective one
of said first pair of contacts and a second state wherein each
of said third pair of contacts is electrically connected to a
respective one of said second pair of contacts; (b) a first
pair of electrical leads having first ends each respectively
connected to a selected one of said first pair of contacts and
to a selected one of said second pair of contacts in a
configuration such that electrical connection between each of
said third electrical contacts and said first pair of
electrical leads is reversed when said switch moves from said
CA 02257521 2001-02-06
69905-89
3a
first state to said second state, said first pair of electrical
leads having second ends adapted to connect respectively to the
positive and negative terminals of one of said first and second
power sources; (c) a second pair of electrical leads having
first ends each respectively connected to a selected one of
said third contact and second ends adapted to connect
respectively to the positive and negative terminals of another
of said first and second power sources; and (d) a switch
controller including a plurality of current-carrying coils
electrically connected to said first and second pairs of
electrical leads and an actuator coupled to said switch, said
current carrying coils operative upon connection of the second
ends of said first and second pairs of leads to said first and
second power sources to produce a composite magnetic field,
said coils arranged such that said actuator interacts with said
composite magnetic field to automatically move said switch into
whichever one of said first and second states that
interconnects said first and second power sources in the
selected coupled state regardless of the respective connections
of the second ends of said first and second pairs of leads to
the positive and negative terminals of said first and second
power sources.
In accordance with the present invention, there is
provided an electromechanical switching device adapted for use
with a pair of power sources each including a positive terminal
and a negative terminal, said electromechanical switching
device operative to establish electrical communication between
like terminals of the power sources, comprising: (a) a
plurality of current-carrying coils each adapted to
electrically connect in a selected connection state to the
oppositely polarized terminals associated with a respective one
of said power sources to produce an associated magnetic field
so that a composite magnetic field is established; and (b) a
CA 02257521 2001-02-06
' 69905-89
3b
switch magnetically coupled to said coils and operative when
said coils are connected to the power sources to interact with
the composite magnetic field thereby to interconnect the like
terminals of the power sources irrespective of the selected
connection state of said coils.
In accordance with the present invention, there is
further provided a method of ensuring desired electrical
interconnection automatically between a pair of power sources,
wherein each of said power sources includes a positive terminal
and a negative terminal, comprising the steps of: (a)
producing a first magnetic field associated with a first one of
said power sources; (b) producing a pair of second magnetic
fields associated with a second one of said power sources; and
(c) actuating a switch in response to interaction between said
first magnetic field and second magnetic fields thereby to
establish electrical interconnection between the desired
terminals of said power sources.
In its basic forms, the invention provides an
electromechanical switch device that is operative to
electrically interconnect the positive terminal of the first
power source to a selected one of the positive and negative
terminals of the second power source and a negative terminal of
the first power source of the other one of the positive and
negative terminals of the second power source thereby to define
a selected coupled state. This switching device includes a
switch that has first, second and third pairs of contacts with
the switch being movable between a first state wherein each of
the third pair of contacts is placed in electrical
communication with respect to one of the second pair of
contacts and a second state wherein each of the third pair of
contacts is placed in electrical communication with respective
to one of the second pair of contacts.
CA 02257521 2001-02-06
' 69905-89
3c
A first pair of electrical leads have first ends
connected to the first pair of contacts and also to the second
pair of contacts in a configuration such that the electrical
communication between the third electrical contacts and the
first pair of the leads is reversed when the switch moves from
the first state to the second state. A second pair of
electrical leads have first ends connected to the third
contacts. Second ends of both the first and second ends of
CA 02257521 1998-12-08
WO 98/01928 PCT/US97/12310
4
electrical leads are then adapted to connect respectively to
the positive and negative terminals of the first and second
power sources.
A switch controller is provided which includes a
plurality of current-carrying coils which are in electrical
communication with the first and second pairs of electrical
leads and an actuator coupled to set switch. The current-
carrying coils, when connected to the power sources produce a
composite magnetic field with the coils being arranged such
that the actuator interacts with the composite magnetic field
to automatically move the switch into whichever one of the
first and second states results in the interconnection of the
first and second power sources in the selected couple state
regardless of the respective connections in the second ends of
the leads to the power sources.
Preferably, the switch is a double pole double throw
switch, and the switch controller includes an inner coil
interposed between a pair of outer coils. The inner and outer
coils are movable with respect to one another as a result of
the magnetic interaction when current f lows through the coils .
The actuator is then secured to one of the inner and outer
coils for common movement therewith thereby to throw the
switch. Preferably, the inner and outer coils are spiral
wound and axially aligned so that the actuator may move in an
axial direction internally of the coils. The actuator is
preferably secured to the inner coil while the outer coils are
fixed so that reciprocation of the inner coil reciprocates the
actuator between first and second positions. The first and
second coils are then wound in opposite directions relative to
the common coil axis and are electrically interconnected so
that, when current is passed therethrough, the first and
second coils produce magnetic fields having a common polarity
opposed to one another. The outer coils are, for convenience,
are wound with a common piece of wire.
Accordingly, the present invention is also directed to a
method of ensure proper electrical interconnection between a
CA 02257521 1998-12-08
WO 98/01928 PCT/US97/12310
pair of power sources. The method includes these steps of
producing a first magnetic field associated with a first one
of the power sources, and producing a pair of second magnetic
fields associate with a second one of the power sources. A
switch is then actuated in response to interaction between the
first and second magnetic fields thereby to establish
electrical interconnection between like terminals of the power
sources. This method accomplishes the step of producing the
magnetic fields by interconnecting a first power source to a
first current-carrying coil and the step of producing the
second magnetic field is accomplished by connecting the second
power source to a pair of second current-carrying coils in a
manner such that the second magnetic fields are oriented
oppositely with respect to one another.
These and other objects of the present invention will
become more readily appreciated and understood from a
consideration of the following detailed description of the
exemplary embodiments of the present invention when taken
together with the accompanying drawings, in which:
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 is a perspective view of a charging system
according to the present invention;
Figure 2 is a diagrammatic view of the charging system
shown in Figure 1;
Figure 3 is a circuit diagram showing the principal
features of the charging system, and its associated
electromechanical switching device, according to a first
exemplary embodiment of the present invention;
Figures 4(a) through 4(e) are diagrammatic views
illustrating the operation of the electromechanical switching
device of Figure 3 in response to various connected states of
the two power sources;
Figure 5 is a diagrammatic view illustrating the
operation of an electromechanical switching device according
to a second embodiment of the present invention;
CA 02257521 1998-12-08
WO 98/01928 PCT/US97/12310
6
Figure 6 is a circuit diagram showing the principal
features of the charging system, and its associated
electromechanical switching device, according to a third
exemplary embodiment of the present invention;
Figure 7 is a side view in elevation of the solenoid
component for the electromechanical switching device depicted
in Figure 6; and
Figure 8 is a cross-sectional view of the solenoid as
viewed about lines 8 - 8 in Figure 7.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
The present invention is directed to an electromechanical
switching device that automatically provides desired polarity
connection between two sources of power. For example, in the
vehicle industry, which includes automobiles, buses, etc. and
in the watercraft industry, rechargeable batteries are used to
start the vehicle's or boat's engine. Sometimes, it is
necessary to utilize the battery of one vehicle or craft to
boost-start the engine of another. The present invention
provides a means for automatically assuring that correct
polarity connections between the electrical systems of two
vehicles or water crafts are made. Thus, the present
invention is described with this application in mind; however,
it should be understood that other applications requiring
desired polarity interconnection could employ the technique
described herein.
With that in mind, a first exemplary embodiment of the
present invention is shown in Figure 1 wherein
electromechanical switching device 10 is shown interconnecting
two sources of power in the form of a first battery 12 and a
second battery 14. Switching device 10 includes a housing 20
and first and second electrical cables 22 and 28. Each of
cables 22 and 28 are formed by a pair of electrical leads.
Thus, it may be seen that first cable 22 includes a lead 23
that terminates in an alligator clamp 24 that is connected to
the positive terminal 15 of first battery 12. Lead 25 of
first cable 22 also terminates in an alligator connector 26
CA 02257521 1998-12-08
WO 98/01928 PCT/US97112310
7
that is connected to negative terminal 16 of first battery 12.
Second cable 28 likewise has a pair of leads 29 and 31. Lead
29 terminates in an alligator connector 30 that is connected
to the positive terminal 17 of second battery 14. Similarly,
lead 31 terminates in an alligator clamp 32 that is releasably
connected to negative terminal 18 of second battery 14.
Housing 20 contains electromechanical switching circuitry that
ensures proper interconnection of the two power sources and,
to this end, electrical leads 23, 25, 29 and 31 are
electrically connected to this circuitry at ends opposite the
respective alligator clamps. With reference to Figure 2,
it may be seen that housing 20 includes a switch 34 and a
switch control device 36 which determines the condition of
switch 34. Switch 34 is preferably a double-pole double-throw
(DPDT) switch which has its center contacts 38 and 40
connected to the positive and negative terminals of Power
Source "A" (in the form of battery 12). A first set of throw
contacts 42 and 44 of switch 34 are connected respectively to
the positive and negative terminals of Power Source "B" (in
the form of battery 12) while a second set of throw contacts
46 and 48 are cross- connected to first ends of leads 29 and
31. This reverses the electrical communication between the
third contacts and the electrical leads 29 and 31 which the
switch is moved between switching states. Switch control
device 36 is provided to control which pair of throw contacts
42, 44 or 46, 48 are placed respectively in contact with the
third set of contacts, designated as center contacts 38 and 40
to define a first and second state for switch 34. That is,
a switch control device 36 determines movement or the "throw"
of switch 34 and accomplishes it in a manner that
automatically puts the desired polarity in a connection
between the two power sources . This condition may be referred
to as the "coupled state" for the two power sources. '
Where electromechanical device 10 is employed as a jumper
cable for vehicle or watercraft use, it is desired that the
two power sources, such as batteries 12 and 14 be
CA 02257521 1998-12-08
WO 98/01928 PCT/US97/12310
8
interconnected so that like polarities are in electrical
communication to one another. Accordingly, for sake of
explanation, a first exemplary embodiment of the present
invention is shown in Figure 3 for connection to two power
sources in the form of batteries 12 and 14 so that like
polarities are interconnected as the coupled state. In Figure
3, it may be seen that switch control device 36 is in the form
of a plurality of current carrying coils which each produce
associated magnetic fields so that the array of coils
establishes a composite magnetic field that controls a
position of an actuator for switch 34.
In the first exemplary embodiment, a center coil 50 is
wound counterclockwise and is in electrical communication with
leads 23 and 25 respectively by way of leads 53 and 55.
Center coil 50 is interposed in spaced relation between a pair
of outer coils 60 and 62 with first outer coil 60 being wound
counterclockwise and second outer coil 62 being wound
clockwise. Coils 60 and 62 are electrically interconnected to
one another by electrical lead 64 and may preferably be wound
from a common strand of wire. Coils 60 and 62 are in turn
interconnected to leads 29 and 31, respectively, by leads 63
and 65. As noted above, leads 23 and 25 have first ends that
are connected, respectively, to contacts 38 and 40 of switch
34. Lead 63 is connected to contacts 42 and 4B of switch 34,
and lead 65 is connected to contacts 44 and 46 of switch 34.
Preferably, coils 50, 60 and 62 are formed by spools
which have hollow cores and about which a spiral winding of
wire is supported. For example, center or inner coil 50
includes a spool 52 having a longitudinally extending central
bore 54 therethrough. Outer coil 60 includes a spool 66
having a longitudinally extending bore 67 extending
therethrough while coil 62 includes a spool 68 having a
longitudinally extending bore 69 extending therethrough.
Coils 50, 60 and 62 are preferably longitudinally aligned with
one another along a common coil axis "X" so that bores 54, 67
and 69 are aligned with one another.
____ ..~.. __.__ .___-_.
CA 02257521 1998-12-08
WO 98/01928 PCT/US97/12310
9
Switch 34 includes an actuator 70 that extends through
bores 54, 67 and 69. In the first exemplary embodiment,
actuator 70 is secured to spool 52 so that movement of coil 50
to the left or right as shown in Figure 3 causes actuator 70
to move to the left or right respectively. Coils~60 and 62
are fixed with respect to the housing 20, in any convenient
manner, and actuator 70 is spring biased by means of centering
springs 72 and 74 acting, for example, against sidewall 21 of
housing 20 so as to maintain actuator 70 in a neutral position
wherein there is no electrical communication between contacts
38, 40 and any of contacts 42, 44, 46 and 48. Electrical
communication only occurs when a connection is made to the
power sources.
This neutral position is diagramed in Figure 4 ( a ) . Here,
it may be seen that center coil 50 is equidistantly positioned
between outer coils 60 and 62 such that actuator 70 is in a
neutral position. When actuator 70 is in the neutral
position, it may be seen that the poles associated with pole
contacts 38 and 40 do not make electrical communication with
any of contacts 42, 44, 46 or 48. Electromechanical switch
device 10 is thus in a neutral state prior to interconnection
with a power source.
However, with reference to Figures 4(b)-4(e), it may be
seen that, when electromechanical switching device 10 is
connected between two power sources, it automatically operates
to establish electrical communication between like terminals
of the power sources. Thus, for example, in Figure 4{a), the
connection of leads 23 and 25 to the positive and negative
terminals of a power source creates a circuit through center
coil 50 so that it has a north and south magnetic poles, with
these poles being respectively designated as "N" and "S".
Correspondingly, contact 40 is negatively biased while contact
42 is positively biased. When leads 29 and 31 are
respectively connected to the positive and negative terminals
of a second power source an electrical circuit is established
between outer coils 60 and 62 which generate associated
CA 02257521 1998-12-08
WO 98/01928 PCTIUS97/12310
magnetic poles. Here, due to their opposite winding, coils 60
and 62 have south poles opposed to or facing one another and
north poles outwardly opposite one another. As a result, coil
50 is repelled from coil 60 and attracted to coil 62. Coil 50
thus moves to the right as is shown in Figure 4(b), and
actuator 70 toggles switch 34 so that contact 40 is placed in
electrical communication with contacts 44 and 46 while contact
38 is placed in electrical communication with contact 42.
Thus, the positive terminals of the two power sources are in
electrical communication with one another and the negative
terminals of the two power sources are in electrical
communication with one another. Correspondingly, contact 42 is
positive while contacts 44, 46 are negatively biased.
If the connection to each of the power sources is
reversed, as is shown in Figure 4(c), a similar circuit
configuration results. Here, leads 23 and 25 are respectively
connected to the negative and positive terminals of the first
power source while leads 29 and 31 are respectively connected
to the negative and positive terminals of the second power
source. This reverses the magnetic poles for each of coils
50, 60 and 62. However, due to this reversal, coil 50 still
shifts to the right by being attracted to coil 62 and being
repelled from coil 60. Actuator 70 again moves to the right
placing electrical contact 38 in communication with electrical
contact 42 and electrical contact 40 in communication with
contacts 44 and 46. However, since the electrical bias of
each of the contacts is reversed, once again the positive
terminals of the two power sources are in communication as are
the negative terminals.
With reference to Figure 4(d), the electrical connection
to the first power source by leads 23 and 25 are the same as
that shown in Figure 4(b). Here, however, the electrical
connection of leads 29 and 31 are reversed so that lead 29 is
connected to the negative terminal of the second power source
and lead 31 is connected to the positive terminal. When so
connected, coil 50 has its magnetic polarity the same as that
CA 02257521 1998-12-08
WO 98/01928 PCT/US97/12310
11
shown in Figure 4(d). However, each of coils 60 and 62 are
reversed so that now the north poles face one another with the
south poles opposite one another. Accordingly, coil 50 will
be attracted to coil 60 and repelled by coil 62. Coil 50 and
actuator 70 thus move to the left as is shown in Figure 4(d).
This places electrical contact 38 in communication with
contacts 44, 46 and electrical contact 40 in communication
with electrical contact 48. Since electrical contacts 44 and
46 are positively biased, and since electrical contact 48 is
negatively biased, with respect to the second power source,
the positive polarities of each of the power sources are again
in communication as are the negative terminals.
Finally, in Figure 4(e), the electrical connection of
leads 29 and 31 to the second power source are the same as
shown in Figure 4(b). Here, however, the electrical
connection of leads 23 and 25 are reversed with respect to the
first power source with lead 23 being connected to the
negative terminal and lead 25 being connected to the positive
terminal. Accordingly, in comparison with Figure 4(b), the
magnetic polarity of coil 60 and 62 remains the same while the
magnetic polarity of coil 50 is reversed. In this
configuration, coil 50 is attracted to coil 60 and repelled by
coil 62, thus causing it and actuator 70 to move to the left.
Again, contact 38 is placed in electrical communication with
contacts 44, 46 while contact 40 is electrically in
communication with contact 48. Since leads 23 and 25 are
reversed, however, contact 38 is negatively biased and contact
40 is positively biased with respect to the second power
source. Accordingly, matching polarity is again achieved.
While the present invention has been described with
respect to an electromechanical switching device that is
operative to automatically ensure that like terminals of two
power sources are placed in communication, such as would be
desirable for an automobile "jumper cable", the ordinarily
skilled person in this field would recognize that the
exemplary embodiments shown in Figures 1-4 could be modified
CA 02257521 1998-12-08
WO 98/01928 PCT/iJS97/12310
12
to ensure that opposite polarity terminals of two power
sources are automatically placed in communication. Thus, with
reference to Figure 5, it may be seen that merely the
reversing of the winding of coil 50 is all that is required to
accomplish this task. Figure 5 may readily be compared to
Figure 4(b) to determine that an opposite result occurs by
this reverse winding of coil 50. Here, when leads 23 and 25
are respectively connected to the positive and negative
terminals of a first power source, the magnetic polarity of
coil 50 is reversed so that its north pole is located on the
left side and the south pole is located on the right side.
When leads 29 and 31 are connected, a polarity of coil 60 and
62 are the same as that shown in Figure 4(b). As a result of
reversing the polarity of coil 50, though, coil 50 is
attracted to coil 60 and repelled by coil 62. Thus, coil 50
and actuator 70 move to the left. This toggles switch 34 so
that contact 38 is placed in electrical communication with
contacts 44 and 46 while contact 40 is placed in communication
with contact 48. Thus, in a positive terminal of the first
power source is connected to the negative terminal of the
second power source and the negative terminal of the first
power source is connected to the positive terminal of the
second power source. A similar result of connecting opposite
polarities would occur for the other possible connection
states, as well.
Moreover, it should be appreciated that, in the
embodiment shown in Figures 1-5, coils 60 and 62 are held
stationary, while coil 50 and actuator 70 translate between
coils 60 and 62. It should be understood, though, that coil
50 could be stationary and the structure provided so that
coils 60 and 62 translate along with the actuator 70. Also,
as described below, it is possible that all three coils 50, 60
and 62 be held stationary while translating only the actuator
70.
A third alternate embodiment of the present invention is
shown in Figures 6-8 where an electromechanical switching
CA 02257521 1998-12-08
WO 98/01928 PCT/US97/12310
13
device 110 employs a solenoid 135 as switch control device
136. Here again, electromechanical switching device 110
includes a pair of leads 123, 125 which are adapted to
interconnect to a first power source such as battery 112. A
second pair of leads 129 and 131 are likewise provided to
connect to a second power source such as battery 114. Leads
123, 125 connect to a central winding 150 of solenoid 135 by
means of leads 153 and 155. Leads 123 and 125 are also
connected to contacts 138 and 140 respective of switch 134.
Lead 129 is connected by lead 163 to a first outer winding 160
of solenoid 135, and outer winding 160 is connected to a
second outer winding 162 of solenoid 135 by means of a lead
164. Electrical connection is then made by lead 131 to coil
162 by way of lead 165. Lead 129 also establishes electrical
communication to contacts 142 and 148 of switch 134 while lead
131 is in electrical communication with contacts 144 and 146
of switch 134. Centering springs 172 and 174 maintain
actuator 170 in a neutral position, for example, against
sidewall 121 of the housing for electromechanical switch 110.
Thus, it should be appreciated that the structure of the
third exemplary embodiment shown in Figure 6 is identical with
respect to the embodiment shown in Figures 1-4 except that a
single solenoid 135 having multiple windings replaces coils
50, 60 and 62. Here, also, it should be appreciated that
actuator 170 includes as a portion thereof a magnetic
permeable material such that actuator 170 translates axially
within solenoid 135. Thus, solenoid 135 remains stationary
within the housing while actuator 170 interacts with switch
134 to change to the electrical state thereof.
The structure of solenoid 135 may best be seen in
reference to Figures 7 and 8. Solenoid 135 is preferably
about 2.5-3.0 inches (6.3-7.6 cm) long and 1.0-1.25 inches
(2.5-3.2 cm) in diameter. Here, it may be seen that coil 150
is wound on an insulated spool 178 while coils 160 and 162 are
respectively wound on insulating spools 180 and 182. Spools
178, 180 and 182 are preferably formed of an insulating
CA 02257521 1998-12-08
WO 98J01928 PCT/US97J12310
14
material, such as plastic. Spool 178 is separated from each
of spools 180 and 182 by means of a spacer or washer 184
preferably formed of a magnetic permeable material such as
soft iron. A pair of end caps 186 and 188 enclose opposite
ends of solenoid 135 with the end caps formed of a magnetic
permeable material, again such as soft iron. With this
construction, end caps 186 and 188 get polarized,
respectively, by coils 160 and 162. End caps 186 and 188 have
inwardly facing conic surfaces 187 and 189.
Actuator 170 includes an elongated rod 172 which extends
axially through solenoid 135 and is in the form of a
cylindrical rod made from metallic material, such as stainless
steel. A core 190 is positioned centrally in cavity 192
formed between end caps 186, 188 and spools 178, 180 and 182.
Core 190 is formed of a magnetic permeable material, such as
soft iron that reacts to the magnetic fields generated by
solenoid 135, and has opposite frastoconical ends 197 and 199
configured similarly to surfaces 187 and 189. Rod 172 is
secured to core 190 by means of suitable clips 194 so that rod
172 and core 190 translate together as a single unit.
From this description, it should be appreciated that
coils 150, 160 and 162 perform a similar function as coils 50,
60 and 62. Here, however, the shifting of actuator 170 to the
left or right occurs as a result of the interaction of the
magnetic permeability of core 190. Actuator 170 thus actuates
switch 134 similarly to that described with respect to switch
34.
From the foregoing, it should be appreciated that the
present invention also includes a method having shown desired
electrical interconnection automatically between a pair of
power sources where each of the power sources includes a
positive terminal and a negative terminal. This method is
accomplished by the structure described above, but broadly
includes the first step of producing a first magnetic field
associated with a first one of the power sources and producing
a pair of second magnetic fields associated with a second one
CA 02257521 1998-12-08
WO 98/01928 PCT/US97/12310
of the power sources. Finally, the broad method includes
actuating a switch in response interaction between the first
magnetic field and the second magnet fields thereby to
establish electrical interconnection between the desired
terminals of the power sources.
This method preferably includes the step of actuating the
switch so as to establish electrical interconnection between
the like terminals of the power sources. The step of
producing the first and second magnetic fields is accomplished
by electrically interconnecting the positive terminal and
negative terminal associated with a first one of the power
sources to a first current-carrying coil and electrical
interconnecting the oppositely polarized terminals associated
with a separate one of the power sources to a pair second
current-carrying coils in a manner such that the second
magnetic fields are oriented oppositely with respect to one
another. The method then includes interposing the first
current-carrying coil between the second current-carrying
coils in spaced relation and actuating the switch in response
to relative movement between the first and second coils.
Accordingly, the present invention has been described
with some degree of particularity directed to the exemplary
embodiment of the present invention. It should be
appreciated, though, that the present invention is defined by
the following claims construed in light of the prior art so
that modifications or changes may be made to the exemplary
embodiments of the present invention without departing from
the inventive concepts contained herein.
