KINEMATIC SYSTEM FOR ACTUATING THE MOVABLE CONTACT OF AUTOMATIC ELECTRIC BREAKERS

Abstract: A kinematic system for actuating the movable contact of automatic electric breakers includes an actuation mechanism (5) which includes an external handle (9) which is pivoted to the body (3) of a breaker and is connected to the cross-member (13), which is in turn connected to an actuation lever (15) which is operatively associated with a reset spring (17) and with an actuation spring (19), both of which are coupled to a common pivot (21); a mushroom-shaped member (23) of a relay of the breaker acts on a reset lever (25) which is in turn kinematically associated with a hook (27) supported by a second common pivot (29); an engagement lever (31), retained by the hook, is suitable to act on the rear part of a traction lever (33).

Description: Kinematic system for actuating the movable contact of automatic electric breakers . The present invention relates to a kinematic system for ac tuat ing t he movab l e c ont ac t o f automat i c e l ect ri c breakers . Kinematic systems have long been used in automatic electric breakers and allow to open and close the movable contact both by actuating an external handle which can be accessed by the user and by virtue of the automatic intervention of the protection devices provided internally. The two constant problems in the design of these kinematic systems are the complexity of the mechanisms and the dimensions. There is a constantly felt need to simplify the kinematic system from the constructive point of view in order to achieve low-cost production, and in this regard it is very important to try to achieve simple and automatable assembly. The aim of the present invention is to provide a kinematic system for actuating the movable contact, particularly for automatic electric breakers, which has a simplified construction with respect to the known art. An object of the invention is to provide a kinematic system whose assembly is simplified. Another object is to provide a kinematic system which is more reliable than conventional ones. This aim, these objects and others which will become apparent hereinafter are achieved by a kinematic system for actuating the movable contact, particularly for automatic electric breakers, characterized in that it includes an actuation mechanism which includes an actuation means which is pivoted to the body of a breaker and is connected to the cross-member, which is in turn connected to an actuation lever which is operatively associated with a reset spring and with an actuation spring, both of which are coupled to a common pivot; a mushroom-shaped part of a relay of the breaker acting on a reset lever which is in turn kinematically associated with a hook supported by the common pivot; an engagement lever, retained by the hook, being suitable to act on the rear part of a traction lever. Further characteristics and advantages will become apparent from the description of a preferred but not exclusive embodiment of the invention, illustrated only by way of non- limitative example in the accompanying drawings, wherein: Fig. 1 is a schematic perspective view of the breaker with a wall of the box-like body removed in order to clearly show the components; Fig. 2 is an exploded perspective view of the kinematic system for the actuation of the residual current operated breaker; Figs. 3 and 4 are views, taken from opposite sides, of the kinematic actuation system of the residual current operated breaker in the open position; Figs. 5 and 6 are views, similar to the preceding ones, of the kinematic system for actuating the residual current operated breaker in the closed position; Figs. 7 and 8 are views, similar to the preceding ones, of the kinematic system in the tripped position, with the lever still in the closed position: Figs. 9 and 10 are views, similar to the preceding ones, of the kinematic system in the tripped position and with the contact open; Figs. 11 and 12 are views, taken from mutually opposite sides, of the mechanism of the test circuit with the breaker in closed position; Figs. 13 and 14 are views, similar to the preceding ones, of the mechanism of the test circuit with the breaker in tripped position; Figs. 15 and 16 are views, similar to the preceding ones, of the mechanism of the test circuit with the breaker in the open position. With reference to the above figures, a kinematic actuation system, particularly for electric breakers, according to the invention, generally designated by the reference numeral 1, includes a case body 3 which is constituted for example by the ordinary case body of a residual current operated breaker 100 which is adapted to be associated with conventional omega-shaped bars. The kinematic system 1 includes an actuation mechanism 5 for the residual current operated breaker, shown in Figs. 3-10, and a test circuit mechanism 7, shown in Figs. 11-16. The actuation mechanism includes an actuation means which is constituted for example by a conventional handle 9 which is pivoted to the body 3 and is connected to an actuation lever 11 by a U-shaped cross-member 13. The actuation lever 11 is connected to the kinematic system of the automatic breaker, shown schematically in Fig. 1. The cross-member 13 is connected to an actuation lever 15 which is operatively associated with a reset spring 17 and with an actuation spring 19 on a common pivot 21. A mushroom-shaped member 23 of the relay acts on a reset lever 25 which is in turn kinematically associated with a hook 27 which is supported by a second common pivot 29 and is provided with a return spring 47. An engagement lever 31, retained by the hook 27, is suitable to act on the rear part of a traction lever 33. The engagement lever 31 is connected to an indicator 35 which is pivoted to the handle 9 and is provided with a return spring 49. The mechanism 7 of the test circuit is shown in greater detail in Figs. 11-16 and includes a test button 37 which is suitable to act on a test strip 39 which acts on a contact spring 41. The fixed contact 43 is connected to the pivot 21 by means of the actuation spring 19 and to a resistor 45 by means of the contact spring 41. The resistor 45 is in turn connected to the terminal . The operation of the kinematic system is as follows. By turning the handle 9, the cross-member 13 is moved and turns the actuation lever 11, which acts on the kinematic system of the automatic breaker. The cross-member 13 is also rigidly coupled to the actuation lever 15, which in the closing action turns and loads the reset spring 17 and the actuation spring 19. The reset spring 17, by loading, releases the reset lever 25, which can thus be pushed by the mushroom-shaped member 23 of the relay in case of activation. In case of activation, the mushroom-shaped part of the relay pushes the reset lever 25, which by moving down shifts the hook 27. In this manner, the engagement lever 31 is released and turns; by striking the rear part of the traction lever 33, the engagement lever 31 allows the release of the kinematic system of the automatic breaker. The engagement lever 31 also disengages the indicator 35, which in the closed position was rigidly coupled to its rear part. Resetting occurs immediately after tripping: when the handle 9 returns, the actuation spring 19 turns the actuation lever 15 in the opposite direction with respect to the closure rotation. In this manner, the actuation lever repositions the engagement lever 31 by virtue of their physical coupling, returning its lower end into the seat of the hook 27, while the reset spring 17 repositions the reset lever 25, resetting the relay with a force which is linked to the return speed of the handle 9 and is therefore calibrated. It is noted that during resetting the indicator 35 is still active and is deactivated only after the first closure. The operation of the test circuit entails the simulation of a residual current in order to check the operation of the relay and of the breaker. When the test button 37 is raised, the circuit is open and the contact spring 41 in fact does not touch the pivot 21. By actuating the test button in the direction indicated by the arrows in the figures, the contact spring 41 is lowered, closing the circuit. It should be noted that when the differential kinematic system has tripped, the test circuit must not be usable, otherwise the resistor 45 would burn out. Disabling of the test circuit is achieved in two ways: either by lifting the contact spring 41 by means of the engagement lever 31, which by rotating lifts the lower part of the contact spring 41, or by virtue of the insulation of the pivot 21 obtained by the rotation of the seat of the pivot in the actuation lever 15, when the knob 9 is in the open position. In practice it has been found that the invention achieves the intended aim and objects. The kinematic actuation system of the movable contact, particularly for automatic electric breakers, according to the invention, is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept; all the details may furthermore be replaced with other technically equivalent parts. The materials used, as well as the dimensions, may of course be any according to the requirements and the state of the art. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

Claims: CLAIMS 1. Kinematic system for actuating the movable contact of automatic electric breakers, characterized in that it comprises an actuation mechanism (5) which comprises an actuation means (9) which is pivoted to the body of a breaker (100) and is connected to a cross-member (13), which is in turn connected to an actuation lever (15) which is operatively associated with a reset spring (17) and with an actuation spring (19), both of which are coupled to a first common pivot (21); a mushroom-shaped member (23) of a relay of the breaker acting on a reset lever (25) which is in turn kinematically associated with a hook (27) supported by a second common pivot (29); an engagement lever (31), retained by the hook, being suitable to act on the rear part of a traction lever (33). 2. Kinematic system for actuating the movable contact, according to claim 1, characterized in that said engagement lever (31) is connected to an indicator which is pivoted to said actuation means. 3. Kinematic system for actuating the movable contact, according to claim 1 or 2, characterized in that it comprises a test circuit mechanism which comprises a test button (37) which is suitable to act on a contact spring (41), and a fixed contact (43) which is coupled to said first common pivot (21) by said actuation spring (19) and to a resistor (45) by means of said contact spring (41), said resistor being connected to a terminal of the breaker.

Inventors: BOSATELLI DOMENICO, CONTARDI AUGUSTO, PIANEZZOLA SERGIO, BOSATELLI, DOMENICO, CONTARDI, AUGUSTO, PIANEZZOLA, SERGIO
Applicants: BOSATELLI DOMENICO, CONTARDI AUGUSTO, GEWISS SPA, PIANEZZOLA SERGIO, BOSATELLI, DOMENICO, CONTARDI, AUGUSTO, GEWISS S.P.A., PIANEZZOLA, SERGIO
Application year: 1998
Main classification: H01H71
IPC codes: H01H71, H01H83