Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Background of the Invention
The present invention relates to a switching
mechanism that has an actuator for manually setting
in-to operation, in an at least pariodically limited
manner, electrical devices in motor vehicles,
especially an electric heater or defroster ~or a
rear window.
Switching meehanisms of this general type are
provided, for example, in motor vehicles for setting
into operation windshield washers in conformity with
a prescribed interval of time (interval operation).
Thus, for example, a windshield washer is switched
on during such interval operation for a prescribed
period of time, and is also switched off for a
prescribed period of time, whereby the switehed-on
and the switched-off state ean be repeated or
interrupted in conformity with the construction of
the switching mechanism. Switching mechanisms of
this type have a manually operable actuator
(controller) that is disposed either in the
dashboard or directly in the steering column,
whereby with the latter embodiment an ex-tension
lever that eooperates with -the actuator makes it
possible to undertake a direct aetuation from the
steering wheel of the motor vehiele.
The actual control circuitry for the
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periodically adjustable operation of the electrical
device is disposed at suitable locations in the
vehicle and is connected with the aforementioned
triggering switch via separate electrical control
and power supply lines.
Due to the extremely high cost pressures in the
motor vehicle industry, manual operations during
vehicle assembly must be kept to a minimum, with the
number thereof being reduced even further where
possible.
Furthermore, with many motor vehicles the space
available for the installation of devices and
control mechanisms is very limited due to the number
of such devices. Finally, similarly due to the
general cost situation, the manufacturing costs for
tools for producing switches and switching
mechanisms and the like, i.e. for each individual
component therefor, become increasingly higher, in
addition to which the installation of all of these
individual components into the vehicle, as
previously mentioned, requires an increased manual
effort, and is therefore cost intensive.
It is therefore an object of the present
invention to provide a switching mechanism that can
be produced more economically than the heretofore
known switching mechanisms, requires considerably
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less in the way of tools for its manufacture, can be
easily installed, and requires less space for
installation in a vehicle than do the heretofore
known switching mechanisms.
Brief Description of the Drawings
This object, and other objects and advantages
of the present invention, will appear more clearly
from the following specification in conjunction with
the accompanying schematic drawings, in which:
Fig. 1 is a side view of one exemplary
embodiment of a complete inventive
switching mechanism with a housing
and an end member of the housing,
and shows the actuator in an
inoperative end position;
Fig. 2 is a view of the switching
mechanism of Fig. 1 with the
housing and the actuator removed;
Fig. 3 shows the electric circuitry of an
electronic embodiment for the
switching mechanism of the present
invention;
Fig. 4 is a block circuit diagram of the
electrical components of the
switching mechanism; and
Fig. 5 showæ one possible signal diagram
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of the inventive switchlng
mechanism in an embodiment
corresponding to the electronic
switching mechanism of Fig. 3.
Summary of the Invention
The switching mechanism of the present
invention is characterized primarily by a time
control unit that is adapted to be switched-on
directly by the actuator and is physically connected
therewith, with the tima control unit switching on
an electrical device for a predetermined interval of
time after actuation of the time control unit by the
actuator.
The advantage of the inventive switching
mechanism is essentially that it can be a compact
unit that can be installed directly in the dashboard
or in some other suitable location in the motor
vehicle, with separate manufacturing costs for the
actuator (controller) and the time control unit
being eliminated, so that also the tool costs for
manufacturing the switchi~g mechanisms are cut
nearly in half. A further advantage of the
inventive switching mechanism is that assembly costs
are also cut nearly in half, and no separate control
lines are any longer required between the actuator
and the time control unit, which in turn saves
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material as well as assembly and installation costs.
Finally, the space required by the inventive
switching mechanism is considerably less than that
required by heretofore known devices, so that the
space that has been gained can be used for other
purposes.
Pursuant to one advantageous specific
embodiment of the present invention, the time
control unit, and a switching element that is
adapted to be activated by the actuator, are
disposed on a carrier plate, i.e. the carrier plate
as such can include all electrical and possibly
electronic components, so that at least one
essential portion of the inventive switching
mechanism can be manufactured in a greatly automatic
manner.
Pursuant to a further advantageous specific
embodiment of the present invention, that end of the
carrier plate that faces the actuator is provided
with a support plate that extends essentially
perpendicularly from the carrier plate. Spring
means are preferably disposed on the support plate
for holding the actuator, in a relieved state, in an
inoperative end position. In this connection, the
support plate is provided with at least one hole
through which extends a rod-like projection that is
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provided on the back side of the actuator and that
contacts the switching element. Operation of the
actuator effects activation of the switching element
via the projection.
The switching mechanism is advantageously
surrounded by a preferably one-piece housing that is
provided on its inner walls with guide means for the
actuator. The housing is embodied in such a way
that no separate guide means are required for the
actuator, which in turn leads to a reduction in
manufacturing costs. That end of the carrier plate
that is essentially opposite from the actuator is
advantageously provided with plug means that are
preferably the customary tongue-like flat plugs that
are used in the motor vehicle industry, whereby
those ends that are connected with the carrier plate
engage, for example, on one or both sides of a
printed circuit board, where they can be soldered or
can be electrically connected in some other suitable
manner.
In order in general to be able to hermetically
seal the switching mechanism from dust, moisture,
and fuel or oil vapors, it is proposed pursuant to
another advantageous specific embodiment of the
present invention to provide the switching mechanism
with an end member of the housing that has openings
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through which can extend the plug means, with this
end member of the housing being disposed on that end
of the carrier plate remote from the actuator.
In order to be able to interconnect the housing
and the end member of the housing, any suitable
connecting means can be provided. However, it is
advantageous to interconnect the housing and the end
member thereof via latching or arresting means that
during manufacture can be integrally embodied with
the respective housing part, so that here also
assembly costs can be reduced.
The switching mechanism itself is provided on
the housing, i.e. on the outer surface thereof, with
at least one detachable securement means, which can
be embodied as a clip device, in order in a
straightforward manner to be able to secure the
switching mechanism in the dashboard or in some
other suitable location in the motor vehicle. The
securement means or clip device is embodied in such
a way that during introduction of the switching
mechanism into a designated mounting hole, the
securement means resiliently conforms closely to the
housing, and in the final assembled position again
spreads, in which connection it engages behind a
suitable mounting support or plate. No screws or
other such securing means are needed.
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The time control unit is advantageously formed
by an electronic switching device, although in
principle every suitable non-electronic time control
unit would also be conceivable pursuant to the
present invention. However, in contrast to other
embodiments, an electronic switching device has the
advantage that the manufacturing costs are
relatively low, since standardized electronic
components can be used that are considerably more
economical to provide than are mechanical or
electro-mechanical components. Furthermore, the
electronic embodiment of the switching device has
the further advantage of requiring mllch less space,
and is very operationally reliable while at the same
time requiring little power.
With a switching mschanism of this type, it is
advantageous for the electronic switching device to
include a relay, via the operating contacts of which
the electrical device is switched on, and to also
include an electronic switching member that
activates the relay for a prescribed period of time,
at least after being triggered by the switching
element or the actuator that cooperates therewith.
By a suitable selection of control elements, such
as resistors, capacitors, and the like, the duration
of the desired triggering of the switching mechanism
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can be adjusted. Depending upon the application of
the switching mechanism, for example as a switching
device for operating electrically heated rear
windows in motor vehicles, the triggering of the
switching mechanism can be selected for nearly any
length of time.
Finally, it is advantageous for the switching
mechanism to be provided with indicator means for
indicating the operational state, and/or indicator
means for making it possible to recognize the
switching mechanism as such in the darkness.
In this connection, it is advantageous for the
indicator means to be visible in the operative state
through the actuator, with at least the actuator
being made of suitable material, such as plastic,
which in the region of the indicator means is at
least light-transparent for the passage of light
from the indicator means to the outside when either
the indicator means for tha operating state and/or
the indicating means for recognition of the
switching mechanism in darkness is operative, i.e.
emits light.
Further specific features of the present
invention will b~ described in detail subsequently.
Description of Pr0ferr~d Embodiments
Referring now to the drawings in datail, the
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entire inventive switching mechanism 10 is
illustrated as a compact component in Fig. 1, and
essentially comprises an actuator 11, which can be
moved manually in the direction of the arrow 31 to
trigger the switching process, and also comprises a
carrier plate 15 that is surrounded by a housing 20.
The electrical and electronic components that
are disposed on the carrier plate 15, which can also
be a printed circuit board, will be explained in
detail subsequently.
The important thing for the inventive switching
mechanism lO is that the actuator 11 be in direct
physical connection with the time control unit 12,
an electronic embodiment of which is illustrated in
Figs. 3 and 4. The time control unit 12 is formed
by electrical and electronic components that are
disposed on the aforementioned carrier plate 15, and
will be described in detail subsequently. The
direct physical structural connection between the
actuator 11 and the time control unit 12 makes it
possible to considerably reduce manufacturing costs,
costs for installing the mechanism in a vehicle, as
well as assembly costs, whereby pursuant to the
present invention the space required for the
switching mechanism lO is on the whole similarly
less than the space required for previously known
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switching mechanisms of this general type.
Disposed on the carrier plate 15 is a switching
element 14 that is generally a mechanical switch
which is triggered by actuating the actuator 11 in
the direction of the arrow 31. In particular, the
switching element 14 is triggered by a non-
illustrated rod-li~e projection that is disposed on
the back side of the actuator 11 and extends through
a support plate 18, which extends essentially
perpendicularly at that end 16 of the carrier plate
15 that is closest to the actuator 11. Furthermore,
spring means 19 are disposed on the support plate
18; these spring means 19 hold the actuator 11 in an
inactive or inoperative end position, as is
basically illustrated in Fig. 1.
Non-illustrated guide means are formed on the
inner wall of the housing 20 to guide the actuator
11 in the direction of the arrow 31 during actuation
thereof. Provided on the carrier plate 15 are plug
means 21 via which the switching mechanism lO can be
connected not only with a power supply of the motor
vehicle, but also with the electrical device 13 that
is to b0 activated and controlled. In the
illustrated embodiment, the plug means 21 is in the
form of flat plugs, and in particular tongue-like
plug tabs, as are used throughout the motor vehicle
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industry. However, it should be noted that in
principle any other suitable plug means 21 could
also be provided.
At the end 17 of the carrier plate 15 where in
the illustrated embodiment the plug means 21 are
disposed, there is provided an end member 22 of the
housing 20. The end member 22 has openings through
which the plug means 21 extend, and serves to keep
dust, moisture~ and oil or fuel vapors from entering
into the housing 20.
It is also posslble to dispose on the end
member 22 of the housing 20 guide and twist-
prevention means 32 that pro;ect essentially at
right angles from the end member 22, with the means
32 being provided for positioning a non-illustrated
socket, which is to be connected with the plug means
21, in a well-defined manner relative thereto, so
that defective connections caused by twisting of the
non-illustrated socket are avoided.
The housing 20 and the end member 22 thereof
are interconnected via latching or arresting means
23 that can be integrally embodied with these two
components during the manufacture thereof, thereby
providing a straightforward possibility for
connecting these two components without additional
securement or connection means.
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As shown in Fig. l, with an essentially
rectangular cross-sectional configuration o~ the
housing 20, the two oppositely disposed outsr
surfaces 30 thereof are provided with securement
means 24 that in the illustrated embodiment ars
preferabl~ formed by resilient clip means. In the
relaxed state (see Fig. 1), the securement means 24
engage a surface 33 of a securement member or plate
after the switching mechanism 10 has been inserted
throu~h a mounting hole (not shown in detail here),
for example in the dashboard of a motor vehicle.
Fig. 4 is a block circuit diagram of the
switching mechanism 10, whereby via the actuator 11,
the time control unit 12 can be started in any
desired manner, for example via a switching pulse.
As a result of the activation of the time control
unit 12, a relay 25 that is a part thereof is also
activated. After this activation, the operating
contacts 26 of the relay 25 are closed, so that the
circuit between the terminals [6] and [5] is closed.
As a result, an electrical device 13 in the motor
vehicle is appropriately activated for a prescribed
period of time.
One possible embodiment for the time control
unit 12 is illustrated in the complete circuit
diagram of Fig. 3. The timing member in the time
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control unit 12 is formed by an electronic switching
member 27, which is formed by a single integrated
module, for example of -the type TYA 0298 produced by
Motorola. In the described embodiment, the
electronic switching member 27 is set with regard to
its oscillator frequency via the resistor 34 and the
capacitor 35, with the common connection of the
resistor 34 and the capacitor 35 being provided at
the frequency setting input 273 of the electronic
switching device 27. In addition, the electronic
switching device 27 has an input 271 to which is
delivered, via the actuator 11, an input signal
(positive voltage pulse); see S in ~ig. 5. In
conformity with the time that is adjustable as a
consequence of the resistor 34 and the capacitor 35,
after a triggering operation via the actuator 11, a
positive signal is delivered at the output 272; this
signal is delivered to the relay 25, thereby
activating the relay and closing the operating
contacts 26. The electrical device 13 is
consequently supplied with power for the prescribed
period of time; see R in Fig. 5.
The time control unit 12 can also be embodied
in such a way that the switching mechanism 10 is
always first actuated for a predetermined period of
time when, for example, the electrical power of a
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motor vehicle is switched on (by turning the
ignition key), i.e. the relay 25 is always activated
for a predetermined period of time when the motor
vehicle is turned on, for example by turning the
ignition key, etc. This function during start-up of
the motor vehicle can, as m0ntioned, signify an
additional possibility for starting the ele¢trical
device 13 that is to be placed into operation,
whereby in principle, however, the placement of the
switching mechanism 10 into operation by actuation
of the actuator 11 for triggering a previously
described starting pulse for the electronic
switching device 27 remains unaffected; see the
pulse graph of Fig. 5.
At the same time that the relay 25 is
triggered, an indicator means 28 in the form of a
bulb or luminous diode can be provided, so that the
active state of operation can be indicated.
Furthermore, the switching mechanism 10 can be
provided with an indicator means 29 for recognition
of the switching mechanism 10 as such when it is
dark outside. In the operative state, the indicator
means 28, 29 are preferably visible through the
actuator 11.
If the inventive switching mechanism 10 is
provided for the activation of a rear window heater
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or defroster in a motor vehicle, means are provided
to prevent the battery of the vehicle from becoming
inadvertently discharged. After being activated by
the actuator 11, the rear window defroster is
switched on for only a predetermined period of time,
for example ten minutes. This period of time is
generally sufficient to defrost even a heavily
frosted-up window.
The present invention is, of course, in no way
restricted to the specific disclosure of the
specification and drawings, but also encompasses any
modifications within the scope of the appended
claims.
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