A REMOTE CONTROL APPARATUS FOR TRIPPING OFF SWITCHES

Abstract: An apparatus (1) with remote control features (3) for tripping off magnetothermal switches (2) comprises at least one switch (2) having a central core (5) supporting trip-off linkages (18) wherein a voltmeter coil (10) is housed with each switch (2) being connected to a respective one (4), e.g. a lamp, of user electric appliances. The apparatus also comprises a pushbutton control (3) connected to each voltmeter coil (10) in each magnetothermal switch (2) for remotely and simultaneously operating the trip-off linkages (18) to thus turn off simultaneously each electric appliance (4), while enabling function regaining by operating the corresponding switch (2) locally.

Description: This invention relates to a remote control apparatus for tripping off switches, of a type which comprises at least one of said switches having at least two contacts and a contacting means adapted to connect electrically said two contacts to one another, a central core supporting trip-off linkages adapted to operate said contacting means, a voltmeter coil housed within the switch central core for operating said trip-off linkages and a power supply circuit equipped with a pushbottom control for energizing said coil, said switch having an input terminal, connected both to one of said contacts and to a first voltage supply line, and an output terminal, connected both to the other of said contacts and to a second voltage supply line through a user electric appliance. As is known, switches of the kind referred to above are usually housed, as the so-called working cores, in flush mounted boxes of civil range electric appliances. Further, such switches are particularly, though not solely, used for turning on/off a light in an office or a dwelling space, and reference will be made in the ensuing description to such an application merely for simplicity of illustration. This invention fills a demand for an ability to turn off in a simultaneous and centralized manner plural user electric appliances, such as lights left on in a dwelling or in varius offices of a working site. That ability is specially useful on the emloyees leaving their place, or to save on power where the ambient illumination provided by natural light proves adequate. To meet such requirements, the prior art proposes two different approaches. A first approach consists of operating a power cut-out switch to put off all the lights. However, this approach has the serious drawback that it denies restoration of a light function by a possible user operating a nearby switch. Also, there are certain electric appliances which are to be kept alive on a continuos basis. A second prior approach, currently employed in industrial environments, consists of providing a lighting system comprising a set of cascade connected so-called sectional switches. In other words, a group of switches are provided which fit generally in a common panel and are each connected to a respective light which may be located in remote areas from the switch panel. Such a set of switches would be controlled by another switch placed upstream thereof, and so on to form power supply sections which are structurally independent of one another. However, this second approach has some serious disadvantages, especially as regards cost, due to the increased requirement for electric cables, and operating convenience, due to the impossibility of regaining local control of a light, just like the first approach. From US 3,860,910 is known a switch assembly comprising a relay switch that is held in closed position by a holding circuit, which is supplied with power through the same relay switch. The relay coil is energized by a low d.c. voltage supplied by a transformer and a rectifier. The swith assembly is used to connect an outlet to the electric distribution line. In order to turn-off the outlet from a remote position, the current in the electric distribution line is momentarily interrupted by operation of a master switch. According to this prior art approach, a separate d.c. voltage source is required and all the outlets connected to that particular distribution line are momentarily disconnected by the operation of the master switch. The problem underlying this invention is to provide a remote control apparatus for tripping off switches which has such constructional and operational feature as to overcome the prior art drawbacks noted above. The solutive idea underlying this invention is one of remotely operating the trip-off linkages of each switch while keeping the latter alive. This problem is solved by an apparatus as indicated being characterized in that said two contacts consist of a movable contact, supported by said contacting means, and a fixed contact, said coil has one end connected electrically to either of said input and output terminals, at least when the switch is closed, and the other end connected to an additional output terminal and said pushbutton control has one end connected to said additional output terminal and another end connected to said second voltage supply line. The inventive apparatus features and advantages will become apparent from the following detailed description of an exemplary embodiment, given by way of illustration and not of limitation with reference to the accompanying drawing figures. In the drawings: Figure 1 shows a schematical view of a switch tripping apparatus according to the invention; Figure 2 shows a perspective view of a switch mounted on the apparatus of Figure 1; Figure 3 shows a schematical view of a first variation of the inventive apparatus; Figure 4 shows a perspective view of a switch mounted on the apparatus of Figure 3; Figure 5 shows a schematical view of a second variation of the inventive apparatus; and Figure 6 shows a perspective view of a switch mounted on the apparatus of Figure 5. With reference to the drawing figures, and specifically to the embodiment shown in Figure 1, the numeral 1 generally designates an apparatus for tripping off switches, indicated at 2, by means of a remote control 3. The remote control 3 is a pushbutton type of control with an automatic spring bias, while the switches 2 are advantageously of the double-pole type with automatic magnetothermal protection. The switches 2 are adapted for mounting within a small frame, not shown, for flush-mounted boxes of civil range electric appliances. Further, such switches 2 would be connected to operate a respective user electric appliance such as a lamp 4 for lighting a civil enclosure. In the example of Figure 1, each switch 2 is connected serially to a corresponding lamp 4 across a respective live conductor or phase R, S or T of a three-phase system, and a neutral conductor N. The switch 2 comprises a central core 5 wherein a pole pair are accommodated, namely a protected pole 6 and a neutral pole 7. The protected pole 6 extends between an input terminal 11 and an output terminal 12. Provided along the pole 6 are a fixed contact 8 associated with the input terminal 11, and a moving contact 9 associated with the output terminal 12. The neutral pole 7 extends between an input terminal 13 and an output terminal 14. Provided along the pole 7 are a fixed contact 15 associated with the input terminal 13, and a moving contact 16 associated with the output terminal 14. The switch 2 further comprises trip-off linkages, generally designated 18, which are supported on the central core 5. The linkages 18 comprise a key 17 and a moving contact holder assembly 19. Between the key 17 and the moving contact holder assembly 19 there is provided a toggle mechanism, known per se, designated 20. The trip-off linkages 18 also comprise a springloaded lever 21 for clamping the moving contact holder assembly 19 in the switch make position. The lever 21 has two lugs, of which the lug 22 on the terminals 13 and 14 side is visible. The central core 5 of the switch 2 also accommodates a voltmeter coil 10 of thin wire, at the neutral pole 7. The voltmeter coil 10 has a respective pusher 23 adapted to become engaged with the lug 22 of the clamping lever 21 so as to release the moving contact holder assembly 19 and cause the switch to break on energizing the coil 10 electrically. One end 24 of the coil 10 is connected to the aforesaid moving contact 16, whereas the other end of the coil is connected to the output terminal 14 via a diode 27. One of the terminals of the pushbutton control 3, in particular the terminal 25, is connected to the output terminal 14, and the other terminal 26 of the pushbutton 3 is connected directly to the neutral conductor N. Thus, the moving contact 16 is connected in a power supply circuit 45 connecting the coil 10 serially with the pushbutton control 3. Advantageously, the diode 27 is connected serially to the coil 10, inside the switch 2, to avoid keeping the coil 10 alive as the swith makes to power the lamp 4 electrically. It may be appreciated that the pushbutton control 3 may be a programming device to enable turning off the lights at programmably set times of the day, or a so-called twilight device which becomes operative at a set evening time. With reference to the embodiment shown in Figure 3, a schematical view is shown therein of a first variation of the apparatus according to the invention. In this variation, items and cooperating parts which have the same construction and operate in the same way as the previously described embodiment are designated by the same reference numerals and no further explained herein. Where the lamp 4 is powered off the mains in the so-called single-phase mode, it will be sufficient to provide the switch with just the protected pole 6. A swith of this kind, i.e. having no neutral pole 7, is denoted by the numeral 41, the end 24 of the coil 10 being connected therein to the output terminal 12 of the protected pole 6. The diode 27 is connected serially to the coil 10 across the other end thereof and the output terminal 14. Connected to the terminal 14 is also the terminal 25 of the pushbutton control 3. In another embodiment, given with reference to Figure 5, both poles, i.e. the protected pole 6 and neutral pole 7, from a switch 28 are connected respectively across the phase line F and the lamp 4, and across the neutral conductor N and the lamp 4. This connection is referred to as single-plus-neutral pole. In this embodiment, the output terminal 12 of the protected pole 6 is connected to one end of the diode 27 whose other end is connected to the coil 10. Advantageously, to complete the connection between the other end of the coil 10 and the terminal 25 of the pushbutton control 3, there is provided an additional terminal 14 attached laterally of the metal frame 32 carrying the coil 10 and provided with a cable clamp screw 31. The end 24 of the coil 10 is connected to the aforesaid metal frame 32 to provide electric connection to said terminal 30. The greatest advantage shared by all the embodiments of this invention described hereinabove is that the inventive apparatus affords the ability to turn off simultaneously and in a centralized manner a plurality of electric appliances, while still enabling local regaining of the functions of each individual appliance by operating its respective switch, which will be kept alive because only its trip-off linkages are remotely controlled through the centralized pushbutton control connected to the voltmeter coil of each switch. Another advantage is that the voltmeter coil is connected in the very power supply circuit which it breaks by operating the trip-off linkages, thereby it will not be kept alive. The apparatus of this invention also affords a better than halved consumption of cable conductors compared to those required to make up a lighting system according to the pior art. Further, this apparatus may be connected and controlled by a programming device to centrally deactivate the functions of the various electric appliances for set periods of time to save on power consumption.

Claims: A remote control apparatus for tripping off switches, of a type which comprises at least one of said switches (2, 41,28) having at least two contacts and a contacting means adapted to connect electrically said two contacts to one another, a central core (5) supporting trip-off linkages (18) adapted to operate said contacting means, a voltmeter coil (10) housed within the switch central core (5) for operating said trip-off linkages and a power supply circuit (45) equipped with a remote pushbutton control (3) for energizing said coil (10), said switch (2) having an input terminal (11), connected both to one of said contacts and to a first voltage supply line (R, S, T), and an output terminal (12), connected both to the other of said contacts and to a second voltage supply line (N) through a user electric appliance (4), characterized in that said two contacts consist of a movable contact, supported by said contacting means (9), and a fixed contact (8), said coil (10) has one end connected electrically to either of said input (11) and output (12) terminals, at least when the switch (2) is closed, and the other end connected to an additional output terminal (14) and, said pushbutton control (3) has one end connected to said additional output terminal (14) and another end connected to said second voltage supply line (N). An apparatus according to claim 1, characterized in that it comprises a diode (27) connected serially to said voltmeter coil (10). An apparatus according to claim 1 or 2, wherein said switch is a double pole switch (2) characterized in that said switch (2) comprises an additional fixed contact (15), an additional movable contact and an additional contacting means (16) supporting said movable contact and being operable concurrently with said first cited contacting means (9), and in that said electrical connection of said one end of the coil (10) to either of said input (11) and output (12) terminals is effected through said additional contacting means (16). An apparatus according to claim 1 or 2, wherein said switch is a double pole switch (28) connected in the single-plus-neutral pole mode to said electric appliance (4), characterized in that, said switch (28) comprises an additional fixed contact (15), an additional movable contact and an additional contacting means (16) supporting said movable contact and being operable concurrently with said first cited contacting means (9) and in that, said conncetion of said output terminal (12) to a second supply voltage line through a user electric appliance (4) is effected through said additional contacting means (16).

Inventors: CALDERARA, ENNIO, FABRIZI, FABRIZIO
Applicants: BASSANI TICINO S.P.A.
Application year: 1988
Main classification: H02J13
IPC codes: G05B24, H05B37, H01H83, H02J13