KINEMATIC DEVICE FOR ACTUATING THE MOVING CONTACT, PARTICULARLY FOR AUTOMATIC ELECTRIC BREAKERS

Abstract: A kinematic device for actuating the moving contact, particularly for automatic electric breakers, includes inside a box-like body, a motion lever (2) which is connected to a lever (10) for actuating the breaker and is pivoted to the box-like body by means of a first pivot (3). The motion lever (2) is articulated to linkages (11) which are pivoted, at the other end, to the first end (12) of a cross-member (13) which is operatively associated with a moving contact (15). The first end (12) of the cross-member (13) slidingly engages an engagement lever (21) which is pivoted to the box-like body by means of a second pivot (22) and is provided with a locking arm (30) of a control part (31) which is pivoted to the box-like body by means of a third pivot (32). The third pivot (32) constitutes the fulcrum of the moving contact (15).

Description: KINEMATIC DEVICE FOR ACTUATING THE MOVING CONTACT, PARTICULARLY FOR AUTOMATIC ELECTRIC BREAKERS The present invention relates to a kinematic device for actuating the moving contact, particularly for automatic electric breakers. Conventional automatic electric breakers use kinematic systems which allow to open and close the moving contact both by actuating the actuation lever, which can be accessed from outside the box-like casing which has the typical configuration for coupling to the omega-shaped rail, and by virtue of the automatic intervention of the protection devices provided internally. In conventional kinematic systems, all the lever systems have such dimensions as to occupy substantially all the space available inside the box-like body, so that the masses involved are relatively large and therefore it is not easy to achieve very fast opening of the moving contact, which would reduce all the problems related to the electric arc which is generated. Another drawback is constituted by the fact that the kinematic systems that are currently used are generally very complicated from a structural point of view and require relatively long assembly operations which affect production costs. An aim of the present invention is indeed to eliminate the above described drawbacks of the prior art. A further aim of the invention is to provide a kinematic system for actuating the moving contact, particularly for automatic electric breakers, which allows to significantly reduce the dimensions used, with consequent considerable advantages as regards the opening speed of the moving contact. An object of the invention is to provide a kinematic actuation system which can be produced with a limited number of components that can be easily assembled together. Further object of the present invention is to provide a kinematic system for actuating the moving contact which, by virtue of its particular constructive characteristics, is capable of giving the greatest assurances of reliability and safety in use. Still a further object of the present invention is to provide a kinematic actuation system which can be easily obtained starting from commonly commercially available parts and materials and is also competitive from a purely economic point of view. This aim, these objects and others which will become apparent hereinafter are achieved by a kinematic device as claimed in the appended claims. Further characteristics and advantages will become apparent from the description of a preferred but not exclusive embodiment of a kinematic system for actuating the moving contact, particularly for automatic electric breakers, illustrated only by way of non-limitative example in the accompanying drawings, wherein: Fig. 1 is a schematic exploded perspective view of the kinematic device for actuating the moving contact, according to the invention; Fig. 2 is a schematic view of the kinematic device in the position in which the contact is open; Fig. 3 is a view of the kinematic device in the position in which the contact is closed; Fig. 4 is a view of the kinematic device in the released position, with the contact open and the lever still arranged in closed position. Fig. 5 is a schematic exploded perspective view of the kinematic device for actuating two moving contacts, according to a second aspect of the invention; Fig. 6 is a schematic side partial view of the kinematic device of Fig. 5 wherein the right hand side contact is shown in the open position; Fig. 7 is a schematic side partial view of the kinematic device of Fig. 5 wherein the left hand side contact is shown in the open position; Fig. 8 is a schematic side perspective view of the kinematic device of Fig. 5, wherein the right hand side contact is shown in the closed position; Fig. 9 is a schematic side perspective view of the kinematic device of Fig. 5, wherein the left hand side contact is shown in the closed position. With reference to the above figures, the kinematic system for actuating the moving contact, particularly for automatic electric breakers, according to the invention, includes a box-like body which is generally designated by the reference numeral 1 and is constituted by a conventional box-like body provided for coupling to conventional omega-shaped bars. Inside the box-like body there is a motion lever, generally designated by the reference numeral 2, which is pivoted to the box-like body 1 by means of a first pivot 3. The motion lever 2 has a first arm 4 to which a bracket 5 is pivoted; the bracket is connected to the body 6 of an actuation lever or part, generally designated by the reference numeral 10, which can be accessed from the outside of the box-like body 1. The motion lever 2 has second arms, designated by the reference numeral 7, which are pivoted to the ends of linkages 11 which are articulated, at the other end, to the first end 12 of a cross-member 13 which is substantially U- shaped . The cross-member 13 is operatively connected, at its second end 14, to a moving contact 15 as will become apparent hereinafter. The first end 12 of the cross-member 13 slidingly engages the slots 20, which are formed on an engagement lever 21 which is substantially U-shaped and is pivoted at the free ends of its arms by means of a second pivot 22 which is rigidly coupled to the box-like body. In the connecting portion, the engagement lever has a locking tab 23 which interacts with the locking arm 30 of a control part 31, which by means of a third pivot 32 is mounted so that it can oscillate with respect to the boxlike body 1. A coiled wire spring biases control part 31 against engagement lever 21. The third pivot 32 also constitutes the fulcrum of the lever 15. The control part has, on the opposite side with respect to the locking arm, a protrusion 35 which constitutes the coupling point for the intervention of the thermal protection device. A hook-shaped body 36 is formed by the control part 31 inside the moving contact 15 and is U- shaped in transverse cross-section. The hook-shaped body 36 also provides the coupling point for the intervention of the magnetic protection device. The moving core of the magnetic protection device has a wider portion which engages a fold 37 to accelerate the opening of the moving contact 15. A rivetable pivot 40 is provided on the moving contact and provides the pivoting of a spring guide 41, which forms a recess 42 in which the end of the U-shaped part 13 is coupled; a spring 50 for the contact pressure that biases the moving contact closed is provided around the rivetable pivot 40. A driving lever 60 interacts with a connecting arm 61, formed by the control part and has the function of achieving simultaneous disengagement if two separate automatic breakers are inserted in the same box-like body; optionally, the lever 60 can interact with the components of a laterally adjacent box-like body. In practical operation, starting from the condition in which the contact is open, as shown in Fig. 2, by turning the actuation part 10 one causes the oscillation of the motion lever 2, with a consequent rotation of the linkages 11 which, by interacting with the end 12 of the cross- member 13 arranged on the engagement lever 21, pushes to the left, relative to the drawings, the moving contact 15, consequently positioning the engagement arm 30 of the control part 31 so as to couple to the locking tab 23; at the same time, a thrust is applied to the spring guide 41 and causes the moving contact to close against the fixed contact 70. In case of automatic release, as shown in Fig. 4, the oscillation of the control part 31 causes the disengagement of the engagement tab, with the consequent rotation of the engagement lever, which is no longer retained by the tab 23, and with the consequent opening of the moving contact. When automatic disengagement occurs, the tab 23 slides against the locking arm 30, causing the oscillation of the control part 31, which by virtue of the driving lever 60 also causes the disengagement of the other contact or of the component of the laterally adjacent box-like part. It should of course be noted that the actuation part 10 then also changes position; this part is shown while still in the closed condition in Fig. 4 and returns by means of an elastic return system. Likewise, when opening is performed by means of the actuation part, it is the actuation part that causes the rotation of the control part, consequently opening the moving contact. In the described arrangement of the kinematic device, it is evident that the kinematic device is provided by means of very compact and small-size parts, so that it is possible to obtain very quick disengagements, with a consequent significant reduction of arcing problems. The device according to the invention is susceptible of numerous modifications and variations, within the scope of the appended claims. Figs. 5-7 show a double kinematic device 100 and 200, for actuating two moving contacts in an automatic electric breaker, according to a second aspect of the invention. The double device will be described with reference to one side mainly, and like reference characters, added by 100 or 200, denote similar features to those of FIGs 1-4. An actuation lever 110, which can be accessed from the outside of the box-like body (not illustrated) has a body 106 connected to two motion levers 102 and 202 through a bracket 105. Each motion lever 102,202 is pivoted to cross-member 113,213 which is substantially U-shaped. Cross-member 113,213 is operatively connected to moving contact 115,215 as will become apparent hereinafter. Cross-member 113,213 engages an engagement lever 121,221 pivoted to the box-like body by means of a second pivot 122,222. Engagement lever 121,221 interacts with locking arm 130,230 of control part 131,231, which is mounted so that it can oscillate with respect to the box-like body, by means of third pivot 132, 232. A coiled wire spring 171,271 biases control part 131,231 against engagement lever 121,221. Third pivot 132,232 also constitutes the fulcrum of lever 115,215. Control part 131,231 has protrusion 135,235 which constitutes the coupling point for the intervention of a thermal protection device (not illustrated in the drawings). A hook-shaped body 136,236 is formed by the control part 131,231 inside moving contact 115,215. Hook- shaped body 136,236 also provides the coupling point for the intervention of a magnetic protection device (not illustrated in the drawings). A contact spring 150,250 biases the moving contact in the closed position. The kinematic device according to this second aspect of the invention operates as follows. Action on actuation lever 110, charges spring 172 and moves bracket 105 which is associated with lever 110 and with the two motion levers 102,202. The rotation of motion levers 102,202 actuates engagement levers 121,221 by means of cross-members 113,213 which are associated with the levers through contact springs 150,250. In this manner, engagement levers 121,221 may rotate about pivot 122,222. The motion of moving contacts 115,215 is transferred by means of link-rods 173,273 which are associated both with the moving contacts and with the cross-members. Control part 131 and drive control part 231 are inserted in the contacts and, by rotating about pivot 132, release engagement levers 121,221 in the case of intervention of the magnetic or thermal breaker (not illustrated), both acting on the control parts. Namely, the magnetic breaker acts on the control part through the magnetic bracket 174,274. Magnetic bracket 174,274 slides inside a slot 175,275 provided on moving contact 115,215. In this manner the magnetic bracket has two functions: it releases control part 131,231, at the start of its motion and then drives the moving contact to the open position (illustrated in FIGs. 6 and 7) . Control parts 131,231 are connected to control springs 171,271 which are adapted to re-cock engagement levers 121,221 in the case of intervention. Control parts 131,231 are also mutually connected so that one of the engagement levers disengages from one of the control parts, the other control part is released too. In case of intervention, a tooth on the front part of the engagement lever slides on the upper portion of the control part causing the control part to rotate. The mutual connection between the control part is ensured because the control parts are joined by a gear-like system, as can be observed on the inside ends of the control parts. The connecting system is designed to provide a delay in the release times, based on the play between the elements. Furthermore, drive control part 231 allows to interface the release motion with other possible joined modules or devices, by means of pivot 276 and is therefore capable to receive or transmit motion. Moving contacts 115,215 are also associated with drive springs 177,277 that ensure the opening of the contacts. When moving contacts 115,215 close, as shown in FIGs. 8 and 9, they rest on fixed contacts 170,270. The contact strength is guaranteed by the pressure generated between cross-members 113,213 and contact springs 150,250. All the details may be replaced with other technically equivalent items. In practice, the materials used, as well as the contingent shapes and dimensions, may be any according to the requirements.

Claims: CLAIMS 1. Kinematic device for actuating the moving contact, particularly for automatic electric breakers, characterized in that it comprises, inside a box-like body (1), a motion lever (2) which is connected to a lever (10) for actuating the breaker and is pivoted to said box-like body by means of a first pivot (3), said motion lever (2) being articulated to linkages (11) which are pivoted, at their other end, to the first end (12) of a cross-member (13) which is operatively associated with a moving contact (15), said first end (12) of said cross-member (13) slidingly engaging an engagement lever (21) which is pivoted to said box-like body (1) by means of a second pivot (22) and is provided with a locking tab (23) which interacts with the locking arm (30) of a control part (31) which is pivoted to said box-like body (1) by means of a third pivot (32) which constitutes the fulcrum of said moving contact. 2. Kinematic device for actuating the moving contact, according to claim 1, characterized in that said motion lever (2) comprises a first arm (4) to which a bracket (5) is pivoted, said bracket being connected to the body of said actuation lever. 3. Kinematic system for actuating the moving contact, according to the preceding claims, characterized in that said motion lever (2) has second arms (7) for pivoting said linkages ( 11 ) . 4. Kinematic system for actuating the moving contact, according to one or more of the preceding claims, characterized in that said first ends (12) of said cross- member (13) slidingly engage slots (20) formed in said engagement lever (21), said engagement lever being U-shaped and having said locking tab (23) at the connecting portion. 5. Kinematic system for actuating the moving contact, according to one or more of the preceding claims, characterized in that said control part (31) has a protrusion (35) which constitutes the coupling point for the thermal protection device, a hook-shaped body (36) being provided laterally to said third pivot (32) which constitutes the region for coupling to the magnetic protection device, said hook-shaped body interacting with said moving contact (15), an expansion of the moving core of the magnetic protection device being provided which interacts with a fold (37) of said moving contact (15) in O >r] der to accelerate its opening action. 6. Kinematic system for actuating the moving contact, according to one or more of the preceding claims, characterized in that it comprises a spring guide (41) , which is pivoted by means of a pivot (40) which can be riveted to said moving contact and has a recess (42) in which the other end of said cross-member couples, a spring (50) being provided for the closing contact pressure of said moving contact. 7. Kinematic system for actuating the moving contact, according to one or more of the preceding claims, characterized in that it comprises a driving lever (60) which interacts between a connecting arm (61) of said control part and is suitable to simultaneously disengage two kinematic systems provided in the same box-like casing or optionally the components of a laterally adjacent boxlike casing. 8. Kinematic system for actuating the moving contact, according to one or more of the preceding claims, characterized in that it affects substantially half of the useful volume formed inside said box-like casing. 9. Kinematic device for actuating the moving contact, particularly for automatic electric breakers, according to one or more of the preceding claims, characterized in that, in case of automatic breaker intervention, a tooth on a front part of said engagement lever slides on an upper portion of said control part causing said control part to rotate . 10. Kinematic device for actuating the moving contact, particularly for automatic electric breakers, according to one or more of the preceding claims, characterized in that, said control parts are joined by a gear-like system provided on the inside ends of said control parts. 11. Kinematic device for actuating the moving contact, particularly for automatic electric breakers, according to one or more of the preceding claims, characterized in that, said control parts are joined to provide a delay in the release times, based on the play between the associated elements . 12. Kinematic device for actuating the moving contact, particularly for automatic electric breakers, according to one or more of the preceding claims, characterized in that, said control part is adapted to interface the release motion with other possible joined modules or devices. 13. Kinematic device for actuating the moving contact, particularly for automatic electric breakers, according to one or more of the preceding claims, characterized in that, said control part is adapted to interface the release motion with other possible joined modules or devices, by means of a pivot, and is capable to receive or transmit motion.

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: 1997
Main classification: H01H71
IPC codes: H01H71