Switch integrated controller for energizing an external electrical device

Information

  • Patent Grant
  • 6262497
  • Patent Number
    6,262,497
  • Date Filed
    Monday, September 28, 1998
    26 years ago
  • Date Issued
    Tuesday, July 17, 2001
    24 years ago
Abstract
A switch integrated controller capable of giving a wide variety of controllers at a reduced cost. The controller has a casing composed of a controller module and a terminal module which are separately formed from each other and detachably connected to each other. The controller module has an entry section for receiving a specific external condition and a signal generating section which generates a trigger signal when the specific condition is met by a predetermined reference. The terminal module includes at least one pair of terminals which are adapted to be connected through wires to the external electrical device and an associated external power source and further includes a relay switch which is connected between the terminals for selectively connecting and disconnecting the electric device to and from the electrical power source in response to the trigger signal. Thus, the terminal module including the relay switch can be made common to different kinds of the controller modules and can be assembled with the controller module into a single unit only at an expense of simple mechanical connection between enclosures of the respective modules and electrical connection between the switch relays and the signal generating section. With this result, a wide variety of controller units of different functions can be fabricated at a reduced cost.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention is directed to a switch integrated controller for energizing an external electrical device in a controlled manner.




2. Description of the Prior Art




U.S. Pat. No. 5,329,082 discloses a conventional timer controller for controlling an electrical device. The controller includes a mounting plate which is accommodated in a housing to mount thereon the timer with a rotary switch, in addition to an array of terminals which are adapted to be connected by way of wires to a power circuit including the electric device and a power source thereof. The switch is inserted in the power circuit to selectively energize and deenergize the electric device in response to a particular position of a time dial of the timer. In the meanwhile, there has been an increasing demand of providing a wide variety of sophisticated controllers which are designed specifically to have accessory functions in conformity with individual needs at various installation sites. Such controllers are different in their specific functions or components utilized, for example, different timing control schemes, different kinds of timers of either mechanical or electronic type, and so on. However, when the switch is provided in the form of a relay switch which is activated by a trigger signal from the timer, the relay switch as well as the terminals could be common components to these different controllers. This is also true when the controller is provided with a temperature control section other than the timer, which, for example, controls the electric device depending upon a temperature signal from an external temperature sensor. Therefore, it is highly desired to provide different kinds of controllers while using the common terminals and the relay switch in order to reduce a cost of manufacturing the individual controllers, and enable the use of molds which is of simpler configurations than otherwise for production of the controllers.




SUMMARY OF THE INVENTION




The present invention has been accomplished in view of the above and has a primary object of providing a switch integrated controller which is capable of giving a wide variety of controllers at a reduced cost. The switch integrated controller of the present invention has a casing composed of a controller module and a terminal module which are separately formed from each other and detachably connected to each other. The controller module has an entry section for receiving a specific external condition and a signal generating section which generates a trigger signal when the specific condition is met by a predetermined reference. The terminal module includes at least one pair of terminals which are adapted to be connected through wires to the external electrical device and an associated external power source and further includes a relay switch which is connected between the terminals for selectively connecting and disconnecting the electric device to and from the electrical power source in response to the trigger signal. Thus, the terminal module including the relay switch can be made common to different kinds of the controller modules and can be assembled with the controller module into a single unit only at an expense of simple mechanical connection between enclosures of the respective modules and electrical connection between the switch relays and the signal generating section and the like electrical connection as necessary. With this result, a wide variety of controller units of different functions can be fabricated at a reduced cost, with additional effects of simplifying configurations of molds for production of enclosures of the overall controller unit than when an enclosure of terminal module is formed as an integral part of an enclosure of the controller module, and of facilitating an inventory management of the parts utilized in the controller unit.




The terminal module has a terminal block which carries an array of terminals, a circuit board mounting thereon the relay switch, and electronic components forming a driver for activating the relay switch in response to the trigger signal. The relay switch is provided with input pins for soldering electrical connection with the circuit board to receive an activating signal from the driver and with output pins for direct soldering electrical connection with the terminals. Generally, the output pins of the relay switch are of reduced cross section and likely to produce a large amount of heat as a large current flows through the electric device. Because of the direct soldering connection of the output pins of the relay switch to the terminals, the heat given off at the output pin can be released through the terminals of generally large cross section for easy heat radiation from the relay switch.




The terminal block includes a horizontally extending platform for supporting thereon the circuit board. The platform is formed with an opening or openings to allow the soldering connection between the relay switch and the circuit board as well as between the relay switch and the terminals, respectively from the bottom of the terminal module. Thus, the relay switch can be easily connected by soldering to the terminal block.




One of the controller module and the terminal module is provided with a hook which detachably engages with a catch formed in the other of the modules for easy mechanical assembly.




For easy electrical interconnection between the two modules, one of the terminal module and the controller module is equipped with a plug which is detachable to a socket provided on the other module.




The terminal is provided with a terminal screw extending through a front end portion of the terminal. The relay switch is fitted over rear end portions of the terminals and the circuit board with the output pins and the input pins projecting respectively through the rear end portions of the terminals and the circuit board. The terminal may be bent to make a step between the front end portion and the rear end portion which is in level with the circuit board for spatially arranging the relay switch and the electronic parts in an overlapping relation with the length of the terminal screw. This contributes to reduce a height of the terminal module including the relay switch and the associated electric components.




The casing or the controller unit is accommodated in a housing in a spaced relation from an inner bottom of the housing. The housing is formed on its inner bottom with studs which support the inner casing at portions immediately below to the terminal screws in order to reinforce the terminal block against a force applied when fastening the terminal screws for preventing otherwise warp or deformation of the terminal block.




The housing is provided in its wall with holes for passing therethrough the wires connected leading to terminals. The housing is also provided on its bottom with baffles which project towards the casing adjacent to the terminals for preventing the wires from entering a clearance between the inner casing and the inner bottom of the housing.




The controller module may be a timer having the entry section for setting a desired time as the specific external condition and having the signal generating section which generates the trigger signal when the desired time is coincident with the predetermined reference.




Further, the controller module may be arranged to make a temperature control based upon a temperature signal received at the entry section as the specific external condition from an external temperature sensor, the signal generating section generating the trigger signal when the temperature signal exceeds the predetermined reference.




These and still other objects and advantageous features of the present invention will become more apparent from the following description of the preferred embodiments when taken in conjunction with the attached drawings.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a perspective view of a switch integrated controller in accordance with a preferred embodiment of the present invention;





FIG. 2

is an exploded perspective view of a controller module and an associated terminal module utilized in the above controller;





FIG. 3

is a perspective view of a housing utilized in the above controller;





FIG. 4

is a schematic view illustrating an internal configuration of a combination of the controller module and the terminal module;





FIGS. 5 and 6

are exploded perspective views of the terminal module;





FIG. 7

is a perspective view illustrating a bottom of the terminal module;





FIG. 8

is a sectional view of the terminal module;





FIG. 9

is a sectional view similar to

FIG. 8

but of a modified terminal module;





FIG. 10

is a sectional view similar to

FIG. 8

but of another modified terminal module;





FIG. 11

is a perspective view of another switch integrated controller in accordance with a second embodiment of the present invention; and





FIG. 12

is a schematic view illustrating an internal configuration of a combination of the controller module and the terminal module of FIG.


11


.











DETAILED DESCRIPTION OF THE INVENTION




Referring now to

FIG. 1

, there is shown a switch integrated controller in accordance with a preferred embodiment of the present invention. The controller has a casing


20


in which a timer is mounted for controlling to energize and deenergize an external electric device or devices on a time basis. The casing


20


is accommodated within a housing


10


with a lid (not shown) for sealing the casing within the housing


10


. In most cases, the housing


10


is installed on a wall of a building or pole and is electrically connected to a power circuit including the external electric device and a power source thereof. For this purpose, the housing


10


is provided in its side walls with knockouts


11


which form openings for passing therethrough electrical wires into the interior of the housing


10


.




As best shown in

FIG. 2

, the casing


20


is composed of a control module


30


and a terminal module


50


which are detachably connected to each other to give a single unit. The terminal module


30


is physically connected to the controller module


50


in an end-to-end relation to make a top surface of the terminal module in flush with a top surface of the control module. Projecting from a front face of the controller module


30


is a flange


32


which fits into a rear opening of the terminal module


50


. The flange


32


has a pair of opposed legs each provided with a hook


34


for detachable engagement with corresponding catch recess


57


formed in each side wall


52


of the terminal module


50


. Formed along the legs of the flange


32


are a pair of opposed vertical guide groove


36


for slidably receiving corresponding vertical ribs


56


on the inner side walls of the terminal module


50


. A pair of tabs


38


project outwardly from the lower end of the legs of the flange


32


and is received in corresponding notches


58


in the side walls of the terminal module


50


.




The controller module


30


has a rectangular bottom-open box


31


mounting the timer, while the terminal module


50


includes a terminal block


51


of dielectric material carrying an array of terminals


53


as well as relay switches


80


. The timer is of a conventional configuration, for example, as disclosed in Japanese Patent Publication No. 7-85379 and, as schematically shown in

FIG. 4

, has a synchronous clock motor


40


which is energized to drive a time dial


41


through a gear train


42


to rotate the dial one complete revolution per day. The time dial


41


is mounted within a recess in the top wall of the controller module box


31


and is manually rotatable in a clockwise direction for setting a time of day. Arranged around the time dial


41


are a number of set pins


43


which are pivotally supported to the periphery of the time dial to move between an upstanding ON-position and an inwardly inclined OFF-position. The set pins


43


corresponds to time markings on a 24 hour clock to set desired time periods at intervals of 15 minutes. A normally closed switch


44


is mounted interiorly of the box


31


and is caused to open by a cam wheel


45


which is in turn actuated by contact with the set pin


43


during the rotation of the time dial


30


. When the set pin


43


is in the ON-position, the cam wheel


45


is kept intact from the set pins


43


to thereby keep the contacts closed. When, on the other hand, the set pin


43


is moved to the inward OFF-position, the set pin


43


encounters the cam wheel


45


during the rotation of the time dial


30


, which in turn causes the switch


44


to open the contacts. Thus, so long as the contacts are closed, the switch


44


provides a trigger signal for energizing the external device in accordance with the desired time schedule determined by the set pins


36


. In this respect, the switch


44


defines a signal generating section which generates the trigger signal when a desired time period selected by the user as a specific external condition being met by an internal reference, say, a time of the day counted by the timer. The switch


44


includes a pair of conductor leads


45


for connection with the relay switches


80


of the terminal module


50


. Also, a pair of leads


47


extend from the motor


40


of the timer for connection with a pair of terminals


53


-


1


and


53


-


2


of the terminal block


50


to be energized by an external power source connected across the terminals.




As shown in

FIGS. 5

to


8


, the terminal module


50


is composed of the terminal block


51


and a top cover


66


which defines a top surface of the module. The terminal block


51


carries three pairs of the terminals, one pair


53


-


1


and


53


-


2


for connection with the power source to energize the motor


40


, the remaining two pairs of terminals


53


-


3


,


53


-


4


and


53


-


5


,


53


-


6


each for connection with the external electric device and the associated power sources thereof. The terminals


53


each provided with a terminal screw


54


are arranged in a row in the front end of the terminal block


51


and separated by partitions


55


. The terminal block


51


is molded to have an integral platform


60


which extends rearwards and horizontally for supporting thereon a circuit board


70


mounting electronic components


73


as well as rear portions of the switch relays


80


. The electronic components constitutes a driver


72


which actuates the relay switches


80


upon receiving the trigger signal from the switch


44


of the controller module


30


. The circuit board


70


gives conductor paths between the motor


40


and the corresponding pair of the terminals. As shown in

FIG. 4

, the relay driver


72


is connected to derive its power form the line leading to the motor


40


to activate an electromagnet of each relay switch


80


for contact closing and opening of the relay switch, and thereby closing and opening the power circuit of the electric device and the power source thereof each connected to the pair of terminals


533


,


53


-


4


and


53


-


5


,


53


-


6


. The relay switch


80


has a pair of input pins


81


for connection of the electromagnet with the driver


72


and a pair of output pins


82


for connection of the contacts to the corresponding terminals


53


.




As best shown in

FIG. 8

, the terminals


53


-


3


,


53


-


4


and


53


-


5


,


53


-


6


have their respective rear end portions extending rearwards in an aligned relation with the circuit board


70


but in a spaced relation thereto. The relay switch


80


is mounted across the rear end portion of the terminal


53


and the circuit board


70


with the output pins


82


projecting directly through holes


59


in the adjacent terminals and with the input pins


81


projecting through holes


71


of the circuit board


70


. As best shown in

FIG. 7

, the platform


60


is formed with openings


61


through which the connections of the input pins


81


and the output pins


82


are exposed so that these pins can be soldered to the terminals


53


and the circuit board


70


from the bottom of the terminal module


50


. The platform


60


is also provided with sets of retainer arms


62


for retaining the relay switches


80


in position, which facilitates the soldering connection of the relay switches


80


. Since the output pins


82


of the relay switch


80


are directly soldered to the terminals


53


-


3


,


53


-


4


and


53


-


5


,


53


-


6


, resistive heat developed in the output pins


82


can be conducted to the terminals for successfully dissipating the heat. The resistive heat is likely to develop when a large current of, say


30


A, flows through the output pins


82


which is of generally small cross-section and therefore should be radiated quickly for protection of the relay switches. In this sense, the terminal may be provided additionally with radiator fins for expediting the heat radiation. Also formed on the circuit board


70


is sockets


78


(


79


) for detachable connection respectively with plugs


48


(


49


) at the ends of the conductor leads


46


and


47


respectively from the switch


44


and the motor


40


. Thus, the switch


44


is electrically connected to the driver


72


for transmitting the trigger signal thereto, and the motor


40


is electrically connected to the associated terminals


53


-


1


and


53


-


2


though conductor patterns on the circuit board


70


. When it is required to connect the conductor leads


46


and


47


directly by soldering to the circuit board without using the socket and plug combination, as shown in

FIG. 9

, the soldering from the bottom of the terminal block


51


can be made through additional openings


63


form in the rear end of the platform


60


. After mounting the relay switches


80


on the circuit board


70


and the terminals


53


, the top cover


66


is attached to the terminal block


51


to cover the relay switches and the circuit board. The top cover


66


includes a pair of resilient legs


67


for connection with corresponding recesses in the side walls of the terminal block and also includes a skirt


67


which closes rear ends of individual spaces formed between the partitions


55


.




As shown in

FIG. 3

, the housing


10


is provided with a plurality of stands


12


and


13


supporting thereon the terminal module


50


as well as the controller module


30


in a spaced relation from the inner bottom of the housing


10


for keeping the electrical components out of contact with rainwater possibly invading and staying in the bottom of the housing


10


. The stands include studs


13


projecting to abut against the terminal block


51


at portions corresponding to the terminal screws


54


to bear a force applied when fastening the terminal screw


54


for reinforcing the terminal block against deformation or breakage of the terminal block. Also formed on the bottom of the housing


10


are baffles


14


which project toward the front bottom of the terminal block


51


in order to block undesired entry of the wires into the space between the terminal module


50


and the inner bottom of the housing


10


, thus avoiding inconvenience of misleading the wires introduced into the housing for connection with terminals. A pair of latch arms


15


extend from the bottom of the housing


10


for retaining the inner casing


20


, i.e., the assembled combination of the controller module


30


and the terminal module


50


.





FIG. 10

shows a modification of the terminal block in which each terminal


53


is bent to have a step between the front end portion provided with the terminal screw


54


and a rear end portion receiving the front end of the relay switch


80


. The rear end portion of the terminal is horizontally aligned with the circuit board


70


so that major portions of the relay switch


80


and the components on the circuit board


70


are arranged within the height of terminal screw


54


, which contributes to reduce the overall height of the terminal module


50


. In this modification, the terminal


53


is provided additionally with radiator fins 150 for expediting radiation of heat transmitted to the terminal from the output pin of the relay switch, as discussed hereinbefore.




The controller module


30


can be modified in accordance with particular demands by the user. For example, the timer may be designed to operate in a cycle of one week. Also, the timer may additionally include a compensation circuit against power failure, a circuit breaker, or any other circuit of making accessory functions as desired. Further, instead of the above mechanical timer, the controller module


30


may be designed to include an electronic timer with an LED digital display, set buttons for adjusting the present time and desired time duration of energizing or deenergizing the external electrical device. The electronic timer includes the switch which generates the trigger signal as well as an electronic clock which is analogous to the motor of the mechanical timer and energized by electricity fed through the terminals


53


-


1


and


53


-


2


of the terminal module


50


. As such, it is desired to give different functions to the controller module. Since the controller module


30


of the present invention is detachably connected to the terminal block


50


which can be common to the controller units, the controller unit of different type can be realized simply by assembling the controller module having a specific function with the common terminal module


50


.





FIGS. 11

to


12


show another embodiment of the present invention. A controller module


30


A in this embodiment is designed for control of the electric device in response to a temperature signal from an external temperature sensor (not shown). The controller module


30


A has a like box


31


A incorporating therein electronic components which form a power circuit


90


, a control circuit


91


energized by the power circuit, a display-and-setting section


92


, a signal converter


93


, and a switch


94


. The power circuit


90


is connected to an external power source to drive the control circuit


91


for controlling the display-and-setting section


92


which is composed of a display for a temperature being monitored and a reference temperature, and buttons for manually setting the reference temperature. The signal converter


93


is connected to receive a temperature signal from the temperature sensor to give a digital data indicative of the temperature being monitored to the control circuit


91


for comparison with the reference temperature. When the monitored temperature exceeds the reference temperature, the control circuit


91


causes the switch


94


to give the trigger signal.




In the same manner as in the previous embodiment, the controller module


30


A is detachably connected to a complimentary terminal module


50


A which has three pairs of terminals. One pair of the terminals


53


A-


1


,


53


A-


2


are provided for connection to the external power source for supplying electricity to the power circuit


90


, another pair of terminals


53


A-


3


,


53


A-


3


for connection with the external electric device, and the remaining one pair for connection to the temperature sensor. Also, as in the previous embodiment, the terminal module


50


A carries a relay switch


80


A and a circuit board


70


A mounting electronic components forming a driver


72


A of the relay switch


80


A. Further, the circuit board


70


A gives conductor paths between the power circuit


90


and the corresponding pair of the terminals and between the signal converter


93


and the corresponding pair of the terminals. The relay driver


72


A is connected to derive its power form the line leading to the power circuit


90


to activate an electromagnet of the relay switch


80


A for contact closing and opening of the relay switch in response to the trigger signal, and thereby closing and opening the power circuit of the electric device and the power source thereof connected to the pair of terminals


53


A-


3


and


53


A-


4


.




The terminal module


50


A includes a terminal block


51


A which is of substantially the identical configuration to the terminal block


51


of the previous embodiment and is detachably connected to the box


31


A of the controller module


30


A also of substantially the identical configuration to that of the previous embodiment. That is, the mechanical connection between the controller module and the terminal module is achieved by the identical structures to those adopted in the previous embodiment. Also, the electrical connection between the controller module


30


A and the terminal module


50


A is achieved by the identical manners as explained in the previous embodiment. Further, the assembly of the controller module


30


A and the terminal module


50


A is accommodated in the same housing


10


. Therefore, no duplicate explanation as to these features is deemed necessary. Like parts are designated by like reference numerals with a suffix letter of “A”.




In order to assemble the controller module and the terminally module, it is equally possible to form the flange


32


on the terminal module


50


rather than on the controller module


30


and form corresponding members on the side of the controller module for receiving the flange and the associate members. Likewise, the socket and the plug may be formed respectively on the side of the controller module and the terminal module for electrical interconnection between the modules


30


and


50


.




LIST OF REFERENCE NUMERALS






10


housing






11


knockout






12


stand






13


stand (stud)






14


baffle






15


latch arm






20


inner casing






30


controller module






31


box






32


flange






34


hook






36


vertical groove






38


tab






40


motor






41


time dial






42


gear train






43


set pin






44


switch






45


cam wheel






46


conductor lead (from switch)






47


conductor lead (from motor)






48


plug






49


plug






50


terminal module






51


terminal block






52


side wall






53


terminal






54


terminal screw






55


partition






56


vertical rib






57


recess






58


notch






59


hole






62


retainer arm






63


opening






66


top cover






67


leg






68


skirt






70


circuit board






71


hole






72


driver






73


component






78


socket






79


socket






80


relay switch






81


input pin






82


output pin






90


power circuit






91


control circuit






92


display-and-setting section






93


signal converter






94


switch






150


radiator fin



Claims
  • 1. A switch integrated controller for powering an external electrical device in a controlled manner, said switch integrated controller comprising:a controller module with a first housing; a terminal module with a second housing, said second housing being separately formed from said first housing and detachably connected to said first housing in a direct engagement relation therewith so as to form a single complete casing, said controller module having an entry section for receiving a specific external condition and a signal generating section which generates a trigger signal when the specific condition is met by a predetermined reference, said terminal module having at least one pair of terminals for connection through wires with said external electrical device and an associated external power source, and having a relay switch which is connected between said terminals for selectively connecting and disconnecting said electrical device to and from said power source in response to said trigger signal.
  • 2. The switch integrated controller as set forth in claim 1, whereinsaid terminal module includes a terminal block carrying said terminals, a circuit board mounting thereon said relay switch and electronic components forming a driver for activating said relay switch in response to said trigger signal, said relay switch having input pins for soldering electrical connection with said circuit board to receive an activating signal from said driver and output pins for direct soldering electrical connection with said terminals.
  • 3. The switch integrated controller as set forth in claim 2, whereinsaid terminal block includes a horizontally extending platform for supporting thereon said circuit board, said platform being formed with an opening to allow the soldering connection between said relay switch and said circuit board as well as between said relay switch and said terminals, respectively from the bottom of said terminal module.
  • 4. The switch integrated controller as set forth in claim 1, whereinone of said controller module and said terminal module is provided with a hook which detachably engages with a catch recess formed in the other of said controller module and said terminal module.
  • 5. The switch integrated controller as set forth in claim 4, whereinsaid terminal module is physically connected to said controller module in an end-to-end relation to make a top surface of said terminal module in flush with a top surface of said control module.
  • 6. The switch integrated controller as set forth in claim 4, whereinone of said controller module and said terminal module is formed with vertical guide slots for slidably receiving corresponding vertical ribs formed on the other of said controller module and said terminal module.
  • 7. The switch integrated controller as set forth in claim 4, whereinone of said terminal module and said controller module is equipped with a plug which is detachable to a socket provided on the other of said terminal module and said controller for electrical interconnection between said driver on said circuit board of said terminal module with said signal generating section of said controller module.
  • 8. The switch integrated controller as set forth in claim 3, whereinsaid controller module includes a set of conductor leads extending from said signal generating section for soldering connection to said circuit board of said terminal module, said platform being formed with additional openings for allowing the soldering connection between said conductor leads and said circuit board from the bottom of said terminal module.
  • 9. The switch integrated controller as set forth in claim 1, whereinsaid terminal module includes a terminal block carrying said terminals each being in the form of a plate and each provided with a terminal screw extending through a front end portion of the terminal, said terminal block also carrying a circuit board mounting thereon electronic parts forming a driver for activating said relay switch in response to said trigger signal, said relay switch having output pins for electrical connection with said terminals and input pins for electrical connection with said circuit board to receive an activating signal from said driver, said relay switch being fitted over rear end portions of said terminals and said circuit board with said output pins and said input pins projecting respectively through said rear end portions of said terminals and said circuit board for soldering connection thereto respectively behind said terminals and said circuit board, said terminal being bent to make a step between the front end portion and the rear end portion which is in level with said circuit board for spatially arranging said relay switch and said electronic parts in an overlapping relation with the length of said terminal screw.
  • 10. The switch integrated controller as set forth in claim 1, whereinsaid casing is accommodated in a housing having a plurality of stands which project on an inner bottom of said housing to space the bottom of said casing from the inner bottom of the housing, said terminal module including a terminal block carrying said terminals and said relay switch, said terminals being provided respectively with terminal screws for securing said wires to said terminals, and said housing being formed on its inner bottom with studs which support said terminal block at portions immediately below to said terminal screws.
  • 11. The switch integrated controller as set forth in claim 10, whereinsaid housing is provided in its wall with holes for passing therethrough the wires connected to said terminals, said housing being provided on its bottom with baffles which project towards said terminal block adjacent to said terminals for preventing said wires from entering a clearance between the inner casing and the inner bottom of said housing.
  • 12. The switch integrated controller as set forth in claim 1, whereinsaid controller module comprises a timer having said entry section for setting a desired time as said specific external condition and having said signal generating section which generates said trigger signal when said desired time is coincident with said predetermined reference.
  • 13. The switch integrated controller as set forth in claim 1, whereinsaid controller module is arranged to make a temperature control based upon a temperature signal received at said entry section as said specific external condition from an external temperature sensor, said signal generating section generating said trigger signal when said temperature signal exceeds said predetermined reference.
Priority Claims (1)
Number Date Country Kind
9-299123 Oct 1997 JP
US Referenced Citations (5)
Number Name Date Kind
4012607 Graesslin et al. Mar 1977
4090093 Thompson May 1978
5329082 Saarem Jul 1994
5479785 Novak Jan 1996
5483212 Lankuttis Jan 1996
Foreign Referenced Citations (1)
Number Date Country
2088989 Dec 1992 CA