A SWITCHING ARRANGEMENT COMPRISING A CONTACT-BEARING LAMINA APT TO BE INCLINED TOWARDS ONE OR MORE POSITIONS

Description

Technical Field

[0001] The present invention relates to a two or three position switch, in particular for controlling the two speeds of a number of different apparatus.

[0002] The invention finds particular application in two or three position switches, for example in a pendant pushbutton for controlling two different functions of an electric motor, especially for controlling an overhead travelling crane either in one direction or in an opposite direction, for raising and lowering a load, and so forth.

Background Art

[0003] Conventional prior switches for the above mentioned applications are invariably based on one and the same principle, i.e. that of providing a bridge consisting of a metal plate having two contacts which engage two other stationary contacts thereby creating an electrical connection between them in order to actuate a relay. If then an electric motor is to be controlled in order for it to provide two different speeds, then the number of the already numerous components is doubled. Document US 3 005 055 discloses a device according to the preamble of claim 1.

Disclosure of the Invention

[0004] Object of the invention is to provide a switch having a novel structure and arrangement of its components in such a manner as to drastically reduce be it the number of said components, be it the time for producing, assembling and wiring said switch.

[0005] Another object is to provide a novel switch maintaining the said advantages and features which can easily be employed to provide a two-position and tw-way switch, having either one or two control pushbuttons, in which each pushbutton can controll, for example, two relays connected to a two-speed electric motor.

[0006] A further object of the invention is to provide such a switch having a very simple and reliable structure, which can be used both in industrial and in civil applications.

Brief Description of Drawings

[0007] The above mentiond objects are all achieved by a switch according to the present invention, which will be described hereinafter with reference to the accompanying drawings, wherein:

Figure 1 is a schematic view of the novel operating principle on which is based the novel switching arrangement according to the instant invention for commutating a switch having two sequential closed conditions of its contacts;

Figures 2A, 2B and 2C are, respectively, a top plan view, a front elevation view and a side elevation view showing schematically the main construction of a double switching arrangement, having a biassing spring as shown in Figures 2B and 2C, for switching from an inactive or open condition to two active or closed conditions of different contacts, in accordance with the present invention;

Figure 3 is a front elevation view illustrating the double switching arrangement of Figures 2, in its inactive or open condition, the biassing spring not being shown in order to allow all the contacts to be seen;

Figure 4 is a front elevation view illustrating the double switching arrangement of Figure 3, in its first actuating condition, according to the present invention;

Figure 5 is a front elevation view illustrating the double switching arrangement of Figure 3, in its second actuating condition, according to the present invention;

Figure 6 is a side elevation view illustrating the double switching arrangement of Figure 3, in its inactive or open condition;

Figure 7 is a side elevation view illustrating the double switching arrangement of Figure 4, in its first actuating condition, according to the present invention;

Figure 8 is a side elevation view illustrating the double switching system according to Figure 5, in its second actuating condition, according to the present invention;

Figure 9 illustrates an electric locking function should two control pushbuttons, controlling two opposite functions, be pressed simultaneously;

Figures 10A to 10D illustrate an application of the switching arrangement to a safety switch in which the deactivation of an apparatus is achieved be it by releasing the control pushbutton, be it by applying an anomalous pressure to said control pushbutton;

Figures 11 and 12 are exploded perspective views, from the top and bottom, respectively, of a particular constructional embodiment of the switch as schematically shown in Figures 3 to 8;

Figure 13 is a top plan view of a preferred embodiment of a switch made according to the arrangement shown in Figures 3 to 9;

Figures 14A and 14B are cross-sectional views, taken along the lines V-V and R-R, respectively, of Figure 13, of the switch in its open condition corresponding to Figures 3 and 6;

Figures 15A and 15B are cross-sectional views, taken along the lines V-V and R-R, respectively, of Figure 13, of the switch in the first actuating position corresponding to Figures 4 and 7; and

Figures 16A and 16B are cross-sectional views, taken along the lines V-V and R-R, respectively, of Figure 13, of the switch in its second actuating position corresponding to Figures 5 and 8.

[0008] With reference to Figure 1, the novel basic concept of a switching arrangement providing the possibility of switching at two sequential connecting positions relying on a single pushbutton which can be lowered to two different lowered positions will be disclosed hereinafter.

[0009] Figure 1 schematically shows a contact-bearing plate P made of an electrically conductive material and having a pentagonal shape, to which plate a power supply conductor is directly coupled, and which bears two movable contacts C3, C4, on its bottom surface. Said plate P is suported by a spring M which at its bottom end is coupled to a fixed base B. As a force F is applied on the plate P at a point between the movable contact C3 and the spring, the plate P will be tilted leftwards to bring the movable contact C3 to engage with the stationary contact C1, thereby providing an electric contact between the conductor A and stationary contact C1 which will be suitably coupled to an apparatus to be controlled. By increasing the value of the force F, the mentioned contacts C3 and C1 will remain engaged one with the other and, moreover, also the contacts C4 and C2 remain engaged, since the right end of said plate will also be lowered to such an extent so as to bring the movable contact C4 in engagement with the stationary contact C2 suitably connected to a second apparatus.

[0010] At this point it becomes evident that the herein schematically disclosed arrangement is suitable for numerous applications, both of the industrial and civil type, for example for making switches for controlling two-speed motors in their two rotational directions.

[0011] Figures 2A, 2B and 2C show a subsequent development step of a switch of this type, again schematically shown for better illustrating its operating principle. Differently from what is illustrated in Figure 1, here is shown a plate P also of pentagonal shape, which can be operated by two pushbuttons P1 and P2, on which plate there are provided two top stationay contacts CF1 and CF3 which are electrically connected by a conductor K, and under which plate P there are provided three bottom stationary contacts CF4, CF6, CF5 substantially arranged at the vertices of a triangle. On and under said plate P are moreover provided double movable contacts CM1 and CM3 and a single movable contact CM2 (see Figure 2C), at a position vertically aligned with the respective top stationary contacts CF1, CF3 and bottom stationary contacts CF4, CF6, CF5, each double movable contact passing through the plate P; all the movable contacts CM1, CM2 and CM3 are electrically connected, for example by strips of an electroconductive material integral with said plate P which in this case serves exclusively as an insulating support.

[0012] From what above with respect to Figure 1, it is evident that a first lowering of the pushbutton P1 (Figure 2B) will cause the movable contact CM3 to become disengaged from the top stationary contact CF3, thereby engaging the bottom stationary contact CF6, while the movable contact CM1 will remain engaged with the top stationary contact CF1. By further lowering the pushbutton P1, the plate P will rotate around an axis passing through CM1 and CM3, to lower the opposite vertex so as to engage the movable contact CM2 with the stationary contact CF5, while the movable contact CM1 will remain in engagement with the stationary contact CF1, and the movable contact CM3, that had been shifted in engagement with the stationary contact CF6, will remain in engaged condition.

[0013] Likewise, a first lowering of the pushbutton P2 will cause the movable contact CM1 to disengage from the stationary top contact CF1 to engage the bottom stationary contact CF4, while the movable contact CM3 will remain in engagement with the top stationary contact CF3. By further lowering the pushbutton P2, also in this case the movable contact CM2 will engage the stationary contact CF5, while the movable contact CM3 will remain in engagement with the top stationary contact CF3, and the movable contact CM1, that had been shifted in engagement with the bottom stationary contact CF4, will remain in this engaged condition.

[0014] This can be more clearly seen in Figures 3 to 8, showing the shifting steps of the movable contacts and the circuity with the apparatus to be controlled, for example relays.

[0015] Figures 3 and 6 show a schematic view of the switching arrangement, in an open or inactive condition thereof, capable of controlling, for example, the two speeds of a motor, through relays: more specifically, a relay R3, figure 4, controlling a first function, for example, the first speed of the motor, for causing an apparatus, such as a movable crane, to advance; a relay R2, Figure 5, controlling a second function, for example the second speed of the motor, for causing the apparatus to advance or move backwards; a relay R1, indicated with its related circuit by dashed lines in figure 3, controlling a function alternative to that of the relay R3, for example the first speed of the motor for causing said apparatus to move backwards. In Figures 6, 7 and 8, in order to simplify the illustrations, the relays have not been shown.

[0016] As already stated, Figures 3 and 6 show the switching arrangement in its open condition, in which the movable contacts CM1, CM2 and CM3 are physically disconnected from the related stationary contacts CF4, CF5 and CF6, thus not feeding any of the relays R1, R2, R3, since the latter are fed by the power supply clamp M1.

[0017] As a first pressure F1 is applied to the pushbutton P1 (Figures 4 and 7), the movable contact CM3, Figures 4 and 7, becomes disengaged from the stationary contact CF3 and engeges the stationary contact CF6 thereby supplying power to the relay R3, i.e. causing an electric current to flow from the clamp M1 to the stationary contact CF6 and, consequently, to the relay R3, through the conductive strips connecting the movable contacts CM1, CM2 and CM3; thus, the so energized relay R3 will provide in this case, for example, the first advancing speed of the apparatus driven by said motor.

[0018] By subsequently applying to the pushbutton P1 a greater force F2 (Figures 5 and 8), the movable contact CM2 will become engaged with the stationary contact CF5, thereby creating a further closed circuit, simultaneously to the one defined above, shown in Figures 4 and 7, namely the relay R2 which energizes a second winding of the electric motor to provide a second speed to the apparatus driven by said motor.

[0019] With reference to Figure 9, it must be pointed out thanks to this specifically designed novel construction of the switch, by simultaneously pressing the two pushbuttons P1 and P2, and consequently applying two simultaneous forces F1 and F3, the power supply clamp M1 will become electrically disconnected, thereby opening the circuits connected to the relays R1, R2 and R3. Thus, this "electric locking" function will prevent two relays associated with opposite movements (R1, R3) from being simultaneously actuated, it not being possible to perform such opposite movements, for example in the case of a motor the two rotational directions of which are controlled by two relays.

[0020] What described above also holds good, in an analogous manner, when the pushbutton P2 is actuated through the force F1 to energize the relay R1 so as to provide a first driving speed, in a direction opposite to that provided by the relay R3 to the apparatus controlled by said motor, or through greater force F2 to energize the relay R2 so as to provide a second driving speed to the apparatus controlled by said motor.

[0021] For example, Figure 10A shows a top plan view of the same switch as that of Figure 2A which differs with regard to the operation points of the pushbuttons P1 and P2; and Figure 10B shows a schematic view of the switch in its open condition.

[0022] A first pressure F1 applied to the pushbutton P1 (Figure 10C) will cause the closure of the electric circuit of the relay R2 passing through the power supply clamps M1 and M2. A further pressure F2 applied to the pushbutton P1 (Figure 10D), having varied the application point of the driving force, i.e. by causing the pushbuttons P1 and P2 to move towards the spring M, will disengage the plate P from the clamp M1, thereby deactivating the relay R2.

[0023] Such a variation can find application in some safety switches, which serve to deactivate a given apparatus (in this specific case controlled by the relay R2) when the switch is released (as schematically shown in Figure 10B), or when an anomalous pressure is applied to the actuator (which case is schematically shown in Figure 10D).

[0024] Figures 11 and 12 show an exploded view of the switch, as seen from the top and from the bottom, respectively, made according to a preferred embodiment of the invention as shown in Figures 3 through 9, in which the pentagonal plate P is made, from the constructional view point, by using two components assembled one onto the other. More specifically, the switch consists of a base 10 having an inner cavity in which is fitted a cylindric coil spring M passing through a hole 11 of an intermediate cover element 12 projecting from the latter. On the top surface of the intermediate cover 12 are mounted: two bottom stationary contacts CF4, CF6, equal to each other, connected to clamps M1, M3; the stationary contact CF5 connected to clamp M3; as well as the clamp M4 into which will be inserted a terminal 29 of an element 28 forming a common top contact CF1 to CF3. Said common contact element CF1 to CF3 is housed on the bottom of the cavity of the top cap 13. A contact-bearing element 18 made of electroconductive metal having three arms 19, 20, 21 bearing, respectively, the movable contacts CM1, CM3, CM2 is provided. Said contact-bearing element 18 is supported by a plastic carrier element 16, having two arms 43 and 44 slightly radially offset with respect to the arms 19, 20, 21 of the contact-bearing element 18. Carrier 16 presents a central disc-like hub 17 integral with the two arms 43 and 44, said hub 17 supporting the spring M. Hub 17 is joined to the contact-bearing element 18 by means of a screw 45 engaged in a hole 46 of element 18. The contact-bearing element 18 and the carrier element 16 operate together acting as the plate P of the previous figures. On the ends of said arms 43 and 44 bear the bottom ends of two control pushbuttons P1 and P2 having two overlapping slots 38 and 39 so that the precision sliding of the pushbuttons through the holes 40 is contrasted by said slots 38 and 39, as well as by two springs 30 urging rollers 31 inserted in suitable recesses formed in the top cap 13, which rollers 31 laterally engage the slots of the pushbuttons P1 and P2 so that as the first hindering slot is engaged, the user will feel this as the reaching of a first operating position of the pushbuttons, whereas the reaching of the second hindering slot is perceived, as the reaching of the second operating position of the control pushbuttons. Above the top cap 13 a pressing plate 32 overlapped by a sealing rubber sleeve 52 is arranged.

[0025] In said control pushbuttons P1 and P2 are assembled springs 50 for optimizing the electric operation of the switch when the outer buttons 51 are actuated.

[0026] The force F1 is applied to the pushbutton P1 through the spring 50 inside said pushbutton, which spring is pressed by the outer button 51. The suitable selection of the dimensions of the spring 50 allows the plate P, bearing the movable contacts CM1, CM2 and CM3, to reach in a correct and stable manner the different operating positions of the switch, the reaching of any intermediate position being prevented. In order to complete and close the assembly of the switch, two screws 42 locking with one another the base 10, the intermediate cover 12 and the top cap 13 are used.

Claims

1. An electric switching arrangement, comprising two bottom stationary contacts (C1, C2), an electroconductive plate (P), bearing two movable contacts (C3, C4) and being supported by a spring (M) at an intermediate position between said two movable contacts (C3, C4), and a control pushbutton adapted to apply a driving force (F) to said plate (P) at a position variable between a point substantially aligned with one (C3) of said movable contacts and said spring (M), whereby said movable contact (C3), upon said pushbutton being lowered by a force (F) into a first position, is brought into contact with one of said bottom stationary contacts (C1) characterised in that, upon a further lowering of said pushbutton, the other movable contact (C4) is brought into contact with the second bottom stationary contact (C2).

2. An electric switching arrangement according to Claim 1, characterized in that it comprises at least two top stationary contacts (CF1, CF3), arranged on at least two vertices of an isosceles triangle; three intermediate movable double contacts (CM1, CM2, CM3), arranged at the vertices of said isosceles triangle, supported by at least one plate (P) bearing said movable contacts,plate (P) being urged by a spring (M); three bottom stationary contacts (CF4, CF5, CF6), arranged at the vertices of said isosceles triangle; and two control pushbuttons (P1, P2) for applying a lowering force (F) at a point substantially aligned, on a single axis, with two respective movable contacts (CM1 and CM3), respectively, each of said two control pushbuttons (P1, P2) being able to apply a pressure to said plate (P), bearing said movable contacts (CM1, CM2, CM3), at a position between said spring (M) and one of said side movable contacts (CM1, CM3), arranged on the base of said triangle, one or said two side movable contacts (CM1 or CM3), upon the lowering of either one or the other of said control pushbuttons (P1 or P2) to a first position, holding at the same time a first top stationary contact (CF1 or CF3) in engagement with a corresponding first movable contact (CM1 or CM3) and bringing a second opposite movable contact (CM3 or CM1) in engagement with a second bottom stationary contact (CF6 or CF4), whilst, upon a further lowering of said control pushbutton (P1 or P2) to a second position, a third movable contact (CM2) is moved in engagement with a third bottom stationary contact (CF5), holding at the same time said stationary top contact (CF1) in engagement with the first movable contact (CM1), whilst a simultaneous application of forces (F1 and F3) to the two control pushbuttons (P1 and P2) causes the electric circuit to be opened.

3. An electric switching arrangement according to Claim 1, characterized in that it comprises at least two top stationary contacts (CF1, CF3), arranged on at least two vertices of an isosceles triangle; three intermediate movable double contacts (CM1, CM2, CM3), arranged at the vertices of said isosceles triangle, and supported by at least one plate (P) bearing said movable contacts, plate (P) being urged by a spring (M); three bottom stationary contacts (CF4, CF5, CF6), arranged at the vertices of said isosceles triangle; and two control pushbuttons (P1, P2) for applying a first lowering force (F1) at a point between the spring (M) and a respective movable contact (CM1 and CM3), each said control pushbutton (P1, P2) being able to apply a pressure to said plate (P), bearing said movable contacts (CM1, CM2, CM3), at a position between said spring (M) and one of said side movable contacts (CM1, CM3), arranged on the base of said triangle, one of said two side movable contacts (CM1 or CM3), upon the lowering of either one or the other of said control pushbuttons (P1 or P2) to a first position, holding at the same time a first top stationary contact (CF1 or CF3) in engagement with a corresponding first movable contact (CM1 or CM3) and biassing a second opposite movable contact (CM1 or CM3) to become in engagement with a second bottom stationary contact (CF6 or CF4), whereas, by a further lowering of said control pushbutton (P1 or P2) due to a greater force (F2) into a second lowering position, both said movable contacts (CM1 and CM3) are disengaged from the top stationary contacts (CF1 and CF3), opening at the same time the electric circuit.

4. An electric switch arrangement according to Claim 2, characterized in that it comprises a base (10) having an inner hollow in which is arranged a cylindric coil spring (M) passing through a hole (11) of an intermediate cover (12) and projecting therefrom, on the top surface of the intermediate cover (12) being mounted two bottom side stationary contacts (CF4, CF6), each ending with clamps (M1, M3); a stationary contact (CF5) connected to a related clamp (M3); and a clamp (M4) in which is inserted a terminal (29) of an element (28) forming a top common contact (CF1 - CF3), said common contact element (CF1 - CF3) being housed on the bottom of the cavity of a top cap (13); a contact-bearing element (18), made of electroconductive metal having three arms (19, 20, 21) and bearing the respective movable contacts (CM1, CM3, CM2), being provided, said contact-bearing element (18) being supported by a plastic carrier element (16) having two arms (43 and 44) slightly radially offset with respect to the arms (19, 20 and 21) of the contact-bearing element (18); said carrier element (16) having a central disc-like hub (17) integral with the arms (43 and 44) and supporting the spring (M) and operating as a joining element through a screw (45) engaged in a hole (46) of the contact-bearing element (18), said screw (45) engaging itself in the disc-like hub (17) of the carrier element (15), the ends of said two arms (43 and 44) supporting the bottom ends of two control pushbuttons (P1 and P2) having two overlapping slots (38, 39), the precision sliding of said pushbuttons through the holes (40) being contrasted by the slots (38, 39) and by two springs (30) urging suitable rollers (31), inserted in suitable recesses formed in the top cap (13), which rollers laterally engage the slots (38, 39)of the pushbuttons (P1, P2) for contrasting a displacement of said control pushbutton so that, as a first hindering slot is engaged, a user will feel this as the reaching of a first operating position of the pushbuttons, whereas the reaching of the second hindering slot is perceived as the reaching of the second operating position of the control pushbuttons, a press plaque (32) overlapped by a sealing rubber sleeve (52) being arranged above the top cap (13), the assembly being closed by two screws (42) locking with one another said base (10), the intermediate cover (12) and the top cap (13).

Ansprüche

1. Elektrische Schaltanordnung, mit zwei unteren stationären Kontakten (C1,C2), einer elektrisch leitenden Platte (P), die zwei bewegbare Kontakte (C3,C4) trägt und an einer zwischen den beiden bewegbaren Kontakten (C3,C4) gelegenen Position von einer Feder (M) abgestützt ist, und einem Steuer-Druckknopf, der geeignet ist zum Aufbringen einer Antriebskraft (F) auf die Platte (P) an einer Position, die zwischen einem im Wesentlichen mit einem (C3) der bewegbaren Kontakte ausgerichteten Punkt und der Feder (M) variierbar ist, wobei der bewegbare Kontakt (C3), wenn der Druckknopf durch eine Kraft (F) in eine erste Position nach unten bewegt wird, in Kontakt mit einem der unteren stationären Kontakte (C1) gebracht wird,
dadurch gekennzeichnet, dass bei einer weiteren Abwärtsbewegung des Druckknopfs der andere bewegbare Kontakt (C4) in Kontakt mit dem zweiten unteren stationären Kontakt (C2) gebracht wird.

2. Elektrische Schaltanordnung nach Anspruch 1, gekennzeichnet durch mindestens zwei obere stationäre Kontakte (CF1,CF3), die an mindestens zwei Spitzen eines gleichschenkligen Dreiecks angeordnet sind; drei mittlere bewegbare Doppelkontakte (CM1,CM2,CM3), die an den Spitzen des gleichschenkligen Dreiecks angeordnet sind und die an mindestens einer Platte (P) gehalten sind, welche die bewegbaren Kontakte trägt, wobei die Platte (P) von einer Feder (M) druckbeaufschlagt ist; drei untere stationäre Kontakte (CF4,CF5, CF6), die an den Spitzen des gleichschenkligen Dreiecks angeordnet sind; und zwei Steuer-Druckknöpfe (P1,P2) zum Aufbringen einer Abwärtsbewegungskraft (F) an einem Punkt, der an einer einzigen Achse mit zwei jeweiligen bewegbaren Kontakten (CM1 und CM3) im Wesentlichen ausgerichtet ist, wobei jeder der beiden Steuer-Druckknöpfe (P1,P2) in der Lage ist, einen Druck auf die die bewegbaren Kontakte (CM1, CM2,CM3) tragende Platte (P) an einer Position aufzubringen, die zwischen der Feder (M) und einem der an der Basis des Dreiecks angeordneten seitlichen bewegbaren Kontakte (CM1,CM3) gelegen ist, wobei einer der beiden seitlichen bewegbaren Kontakte (CM1 oder CM3) bei der Abwärtsbewegung des einen oder des anderen der Steuer-Druckknöpfe (P1 oder P2) in eine erste Position gleichzeitig einen ersten oberen stationären Kontakt (CF1 oder CF3) in Zusammengriff mit einem entsprechenden ersten bewegbaren Kontakt (CM1 oder CM3) hält und einen zweiten, gegenüberliegenden bewegbaren Kontakt (CM3 oder CM1) in Zusammengriff mit einem zweiten unteren stationären Kontakt (CF6 oder CF4) bringt, während bei einer weiteren Abwärtsbewegung des Steuer-Druckknopfs (P1 oder P2) in eine zweite Position ein dritter beweglicher Kontakt (CM2) in Zusammengriff mit einem dritten unteren stationären Kontakt (CF5) gebracht wird, wobei gleichzeitig der stationäre obere Kontakt (CF1) in Zusammengriff mit dem ersten bewegbaren Kontakt (CM1) gehalten wird, während eine gleichzeitige Aufbringung von Kräften (F1 und F3) auf die beiden Steuer-Druckknöpfe (P1 und P2) ein Öffnen der elektrischen Schaltung verursacht.

3. Elektrische Schaltanordnung nach Anspruch 1, gekennzeichnet durch mindestens zwei obere stationäre Kontakte (CF1,CF3), die an mindestens zwei Spitzen eines gleichschenkligen Dreiecks angeordnet sind; drei mittlere bewegbare Doppelkontakte (CM1,CM2,CM3), die an den Spitzen des gleichschenkligen Dreiecks angeordnet sind und die an mindestens einer Platte (P) gehalten sind, welche die bewegbaren Kontakte trägt, wobei die Platte (P) von einer Feder (M) druckbeaufschlagt ist; drei untere stationäre Kontakte (CF4,CF5,CF6), die an den Spitzen des gleichschenkligen Dreiecks angeordnet sind; und zwei Steuer-Druckknöpfe (P1,P2) zum Aufbringen einer ersten Abwärtsbewegungskraft (F) an einem zwischen der Feder (M) und einem jeweiligen bewegbaren Kontakt (CM1 und CM3) gelegenen Punkt, wobei jeder Steuer-Druckknopf (P1,P2) in der Lage ist, einen Druck auf die die bewegbaren Kontakte (CM1, CM2,CM3) tragende Platte (P) an einer Position aufzubringen, die zwischen der Feder (M) und einem der an der Basis des Dreiecks angeordneten seitlichen bewegbaren Kontakte (CM1, CM3) gelegen ist, wobei einer der beiden seitlichen bewegbaren Kontakte (CM1 oder CM3) bei der Abwärtsbewegung des einen oder des anderen der Steuer-Druckknöpfe (P1 oder P2) in eine erste Position gleichzeitig einen ersten oberen stationären Kontakt (CF1 oder CF3) in Zusammengriff mit einem entsprechenden ersten bewegbaren Kontakt (CM1 oder CM3) hält und einen zweiten, gegenüberliegenden bewegbaren Kontakt (CM1 oder CM3) in Zusammengriff mit einem zweiten unteren stationären Kontakt (CF6 oder CF4) bringt, während bei einer durch eine größere Kraft (F2) bewirkten weiteren Abwärtsbewegung des Steuer-Druckknopfs (P1 oder P2) in eine zweite Abwärtsbewegungs-Position beide bewegbaren Kontakte (CM1 und CM3) von den oberen stationären Kontakten (CF1 und CF3) abrücken und gleichzeitig die elektrische Schaltung öffnen.

4. Elektrische Schaltanordnung nach Anspruch 2, gekennzeichnet durch eine Basis (10) mit einem inneren Hohlraum, in dem eine zylindrische Schraubenfeder (M) angeordnet ist, die durch ein Loch (11) einer Zwischen-Abdeckung (12) verläuft und von dieser absteht, wobei an der oberen Fläche der Zwischen-Abdeckung (12) zwei untere seitliche stationäre Kontakte (CF4,CF6) angeordnet sind, die jeweils mit Klemmen (M1,M3) enden; einen stationären Kontakt (CF5), der mit einer zugehörigen Klemme (M3) verbunden ist; und eine Klemme (M4), in die ein Anschluss (29) eines Elements (28) eingeführt ist, das einen oberen gemeinsamen Kontakt (CF1-CF3) bildet, wobei das gemeinsame Kontaktelement (CF1-CF3) an der Unterseite des Hohlraums einer oberen Kappe (13) angeordnet ist; wobei ein aus elektrisch leitendem Metall ausgebildetes kontakttragendes Element (18) vorgesehen ist, das drei Arme (19,20,21) aufweist und die jeweiligen bewegbaren Kontakte (CM1,CM2,CM3) trägt, wobei das kontakttragende Element (18) von einem Plastik-Trägerelement (16) gehalten ist, das zwei Arme (43 und 44) aufweist, die relativ zu den Armen (19,20,21) des kontakttragenden Elements (18) radial leicht versetzt sind; wobei das Trägerelement (16) eine zentrale scheibenartige Nabe (17) aufweist, die einstückig mit den Armen (43 und 44) ausgebildet ist und die Feder (M) trägt und durch eine mit einem Loch (46) des kontakttragenden Elements (18) zusammengreifende Schraube (45) als Verbindungselement wirkt, wobei die Schraube (45) selbst mit der scheibenartige Nabe (17) des Trägerelements (16) zusammengreift, die Enden der beiden Arme (43 und 44) die unteren Enden zweier Steuer-Druckknöpfe (P1 und P2) tragen, die zwei überlappende Schlitze (38,39) aufweisen, wobei der durch die Löcher (40) hindurch erfolgenden Präzisions-Gleitbewegung der Druckknöpfe von den Schlitzen (38,39) und von zwei Federn (30) entgegengewirkt wird, die auf geeignete Rollen (31) drücken, welche in in der oberen Kappe (13) ausgebildete geeignete Vertiefungen eingeführt sind, wobei die Rollen seitlich in die Schlitze (38,39) der Druckknöpfe (P1,P2) eingreifen, um einer Verschiebung des Steuer-Druckknopfs derart entgegenzuwirken, dass, wenn ein Eingriff in einen ersten Hinderungs-Schlitz erfolgt, der Benutzer dadurch wahrnimmt, dass eine erste Betriebsposition der Druckknöpfe erreicht worden ist, während durch das Erreichen des zweiten Hinderungs-Schlitzes das Erreichen der zweiten Betriebsposition der Druckknöpfe wahrgenommen wird, wobei über der oberen Kappe (13) eine von einer dichtenden GummiManschette (52) überlappend bedeckte Druck-Platte (32) angeordnet ist und die Anordnung durch zwei Schrauben (42) geschlossen ist, mittels derer die Basis (10), die Zwischen-Abdeckung (12) und die obere Kappe (13) miteinander verriegelt sind.

Revendications

1. Dispositif de commutation électrique comprenant deux contacts fixes inférieurs (C1, C2), une plaque électroconductrice (P), supportant deux contacts mobiles (C3, C4) et supportée par un ressort (M) en une position intermédiaire entre lesdits deux contacts mobiles (C3, C4), et un bouton-poussoir de commande adapté à appliquer une force d'entraînement (F) à ladite plaque (P) à une position variable entre un point sensiblement aligné avec l'un (C3) desdits contacts mobiles et avec ledit ressort (M), moyennant quoi ledit contact mobile (C3), lorsque ledit bouton-poussoir est abaissé par une force (F) dans une première position, est mis en contact avec l'un desdits contacts fixes inférieurs (C1), caractérisé en ce que, lors d'un abaissement supplémentaire dudit bouton-poussoir, l'autre contact mobile (C4) est mis en contact avec le deuxième contact fixe inférieur (C2).

2. Dispositif de commutation électrique selon la revendication 1, caractérisé en ce qu'il comprend au moins deux contacts fixes supérieurs (CF1, CF3) disposés sur au moins deux sommets d'un triangle isocèle; trois doubles contacts mobiles intermédiaires (CM1, CM2, CM3) disposés sur les sommets dudit triangle isocèle et supportés par au moins une plaque (P) supportant lesdits contacts mobiles, la plaque (P) étant poussée par un ressort (M); trois contacts fixes inférieurs (CF4, CF5, CF6) disposés aux sommets dudit triangle isocèle; et deux boutons-poussoirs de commande (P1, P2) permettant d'appliquer une force d'abaissement (F) en un point sensiblement aligné sur un seul axe avec deux contacts mobiles respectifs (CM1 et CM3), respectivement, chacun desdits deux boutons-poussoirs de commande (P1, P2) étant capable d'appliquer une pression sur ladite plaque (P), supportant lesdits contacts mobiles (CM1, CM2, CM3), à une position située entre ledit ressort (M) et l'un desdits contacts mobiles latéraux (CM1, CM3) disposés sur la base dudit triangle, l'un desdits deux contacts mobiles latéraux (CM1 ou CM3), lors de l'abaissement de l'un ou l'autre desdits boutons-poussoirs de commande (P1 ou P2) vers une première position, maintenant en même temps un premier contact fixe supérieur (CF1 ou CF3) en contact avec un premier contact mobile correspondant (CM1 ou CM3) et amenant un deuxième contact mobile opposé (CM3 ou CM1) en contact avec un deuxième contact fixe inférieur (CF6 ou CF4), tandis que, lors d'un d'abaissement supplémentaire dudit bouton-poussoir de commande (P1 ou P2) vers une deuxième position, un troisième contact mobile (CM2) est déplacé en contact avec un troisième contact fixe inférieur (CF5), maintenant en même temps ledit contact fixe supérieur (CF1) en contact avec le premier contact mobile (CM1), alors qu'une application simultanée de forces (F1 et F3) aux deux boutons-poussoirs de commande (P1 et P2) entraîne l'ouverture du circuit électrique.

3. Dispositif de commutation électrique selon la revendication 1, caractérisé en ce qu'il comprend au moins deux contacts fixes supérieurs (CF1, CF3) disposés sur au moins deux sommets d'un triangle isocèle ; trois doubles contacts mobiles intermédiaires (CM1, CM2, CM3) disposés aux sommets dudit triangle isocèle et supportés par au moins une plaque (P) supportant lesdits contacts mobiles, la plaque (P) étant poussée par un ressort (M); trois contacts fixes inférieurs (CF4, CF5, CF6) disposés aux sommets dudit triangle isocèle; et deux boutons-poussoirs de commande (P1, P2) permettant d'appliquer une première force d'abaissement (F1) en un point situé entre le ressort (M) et un contact mobile respectif (CM1 et CM3), chacun desdits boutons-poussoirs (P1, P2) étant capable d'appliquer une pression sur ladite plaque (P), supportant lesdits contacts mobiles (CM1, CM2, CM3), à une position située entre ledit ressort (M) et l'un desdits contacts mobiles latéraux (CM1, CM3) disposés sur la base dudit triangle, l'un desdits deux contacts mobiles latéraux (CM1 ou CM3), lors de l'abaissement de l'un ou l'autre desdits boutons-poussoirs de commande (P1 ou P2) vers une première position, maintenant en même temps un premier contact fixe supérieur (CF1 ou CF3) en contact avec un premier contact mobile correspondant (CM1 ou CM3) et poussant un deuxième contact mobile opposé (CM1 ou CM3) à entrer en contact avec un deuxième contact fixe inférieur (CF6 ou CF4), tandis que, lors d'un abaissement supplémentaire dudit bouton-poussoir de commande (P1 ou P2) vers une deuxième position d'abaissement à la suite de l'application d'une force supérieure (F2), lesdits deux contacts mobiles (CM1 et CM3) sont désengagés des contacts fixes supérieurs (CF1 et CF3), ouvrant en même temps le circuit électrique.

4. Dispositif de commutation électrique selon la revendication 2, caractérisé en ce qu'il comprend une base (10) présentant un volume intérieur creux dans lequel est arrangé un ressort hélicoïdal cylindrique (M) passant à travers un trou (11) d'un couvercle intermédiaire (12) et en saillie de celui-ci, deux contacts fixes inférieurs latéraux (CF4, CF6) étant montés sur la surface supérieure du couvercle intermédiaire (12), chacun de ces contacts se terminant par des pinces (Ml, M3); un contact fixe (CF5) connecté à une pince associée (M3); et une pince (M4) dans laquelle une borne (29) d'un élément (28) formant un contact supérieur commun (CF1 - CF3) est insérée, ledit élément de contact commun (CF1 - CF3) étant logé sur le fond de la cavité d'un couvercle supérieur (13); un élément de support de contacts (18), constitué d'un métal électroconducteur comportant trois bras (19, 20, 21) et supportant les contacts mobiles respectifs (CM1, CM3, CM2), étant prévu, ledit élément de support de contacts (18) étant supporté par un élément de support en plastique (16) comportant deux bras (43 et 44) légèrement décalés radialement par rapport aux bras (19, 20 et 21) de l'élément de support de contacts (18); ledit élément de support (16) comprenant un moyeu central en forme de disque (17) monobloc avec les bras (43 et 44) et supportant le ressort (M) et agissant comme un élément de jonction par l'intermédiaire d'une vis (45) engagée dans un trou (46) de l'élément de support de contacts (18), ladite vis (45) s'engageant elle-même dans le moyeu en forme de disque (17) de l'élément de support (16), les extrémités desdits deux bras (43 et 44) supportant les extrémités inférieures de deux boutons-poussoirs de commande (P1 et P2) comportant deux fentes superposées (38, 39), le coulissement précis desdits boutons-poussoirs à travers les trous (40) étant gêné par les fentes (38, 39) et par deux ressorts (30) poussant des rouleaux appropriés (31), insérés dans des évidements adéquats formés dans le couvercle supérieur (13), lesdits rouleaux s'engageant latéralement dans les fentes (38, 39) des boutons-poussoirs (P1, P2) pour gêner un déplacement dudit bouton-poussoir de commande de telle sorte que, lorsqu'une première fente d'obstruction est engagée, un utilisateur aura la sensation d'avoir atteint une première position des boutons-poussoirs, alors que le fait d'atteindre la deuxième fente d'obstruction est perçu comme la sensation d'avoir atteint la deuxième position opérationnelle des boutons-poussoirs de commande, une plaque de serrage (32) recouverte par un manchon isolant en caoutchouc (52) étant prévue au-dessus du couvercle supérieur (13), l'ensemble étant fermé par deux vis (42) verrouillant les uns avec les autres ladite base (10), le couvercle intermédiaire (12) et le couvercle supérieur (13).

Drawing