BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is an exploded view of a low-voltage circuit breaker according to the invention;
FIG. 2 is a partial cross-sectional view of a rotating element of a low-voltage device according to the invention;
FIG. 3 is a perspective view of a first embodiment of a reinforcement element used in a low-voltage device according to the invention;
FIG. 4 is a further view of the element of FIG. 3;
FIG. 5 is a perspective view of a second embodiment of a reinforcement element used in a low-voltage device according to the invention;
FIG. 6 is a perspective view of a third embodiment of a reinforcement element used in a low-voltage device according to the invention;
FIG. 7 is a view of a portion of rotating element and of a corresponding reinforcement element according to the embodiment of FIG. 3;
FIG. 8 is a perspective view of a fourth embodiment of a reinforcement element used in a low-voltage device according to the invention;
FIG. 9 is a view of a portion of rotating element and of a corresponding reinforcement element according to the embodiment of FIG. 8;
FIG. 10 is a perspective view of a fifth embodiment of a reinforcement element used in a low-voltage device according to the invention; and
FIG. 11 is a view of a portion of rotating element and of a corresponding reinforcement element according to the embodiment of FIG. 10.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the attached figures, the device for low-voltage systems according to the invention, in this case a circuit breaker 1, comprises an outer casing that in the embodiment illustrated comprises two half-shells 2 and 2′. The half-shells house a plurality of poles, in this case three, each of said poles containing at least one fixed contact and at least one mobile contact 3 that can be coupled to/uncoupled from one another. The mobile contact 3 can be made of a single piece or else of a plurality of pieces adjacent to one another, as clearly illustrated in FIG. 2.
The circuit breaker moreover comprises a rotating element 4 that is defined by a shaped body 5. At each pole of the circuit breaker, the shaped body 5 comprises at least one seat 6 that is designed to house at least the mobile contact 3 of the corresponding pole. In order to enable movement of the rotating element 4, the circuit breaker 1 also comprises a control mechanism 7 that is operatively connected to said rotating element 4. Furthermore, a closing mask 9 is generally present; said mask 9 is usually applied on one of the half-shells 2′ and can if necessary be easily removed by an operator in order to gain access to the internal parts of the circuit breaker 1.
For a detailed description of an example of switch the reader is referred to the patent application No. BG2005A000026, the description of which is incorporated herein for reference.
The circuit breaker according to the invention moreover comprises reinforcement elements, which are positioned in the seat 6 of the mobile contact 3 made in the shaped body 5 of the rotating element 4. In the device according to the invention, the reinforcement elements are in general shaped and positioned in such a way as to favour the strength of the areas subject to stress of said shaped body 5.
With reference to FIGS. 2 and 7, said rotating element 4 usually comprises at least one driving pin 8 that passes through corresponding holes 80, defined in said shaped body 5. In this case, in practice, the reinforcement elements interact operatively with said driving pin 8 and with the shaped body 5, and distribute the action of thrust or of tugging on an extensive and not concentrated portion of the rotating element 4. With the expression “interact operatively with said driving pin 8 and with the shaped body 5” is meant that, thanks to the presence of the reinforcement elements, the stresses, instead of being concentrated in the proximity of the hole 80 for passage of the driving pin 8, are distributed over a relatively extensive region of the shaped body 5.
The shape, dimensions and location of the reinforcement elements can be different according to the needs. For example, with reference to FIGS. 3, 4 and 7 the reinforcement elements can substantially comprise a first shaped body 10, which has a hollow portion with substantially rectangular cross section 11. The outer surface of the portion 11 is shaped so as to substantially mate with the inner surface of the seat 6 made in the shaped body 5 of the rotating element (see FIG. 7). The shaped body 10 of the reinforcement element moreover comprises a first tab 12 and a second tab 13, which extend from the hollow portion 11 of the shaped body 10. With reference to FIG. 7, the tabs 12 and 13 preferably project from the width of the rectangular hollow portion 11 so as to engage, for example, by snap action, in corresponding housings 22 and 23, defined in the seat 6.
Preferably, defined on said first tab 12 and second tab 13 are a first hole 32 and second hole 33 for passage of said driving pin 8. In this way, the stresses and the twisting moments generated in a position corresponding to the driving pin 8, instead of being concentrated on a limited area adjacent to the hole 80, can be distributed over a far more extensive surface.
Preferably, the shaped body 10 of the reinforcement element also comprises plane regions 60 substantially perpendicular to the development of the rectangular hollow portion 11, designed to co-operate bearing upon corresponding plane regions 70 of the seats 6. In this way, the stresses generated in a position corresponding to the driving pin 8 can be discharged in particular on particularly massive areas of the shaped body 5.
With reference to FIG. 5, in order to improve further the distribution of the stresses over the rotating element, at least one part of the outer perimeter of said hollow portion 21 of the reinforcement element 20 has a bent-over edge 25 designed to co-operate with a corresponding coupling surface, defined on the shaped body 5. The term “outer perimeter” is intended to indicate the area of hollow portion 21 of the element 20 closer to the mouth of the seat 6, once the reinforcement element 20 has been inserted in said seat 6 according to the modalities illustrated in FIG. 7.
The reinforcement element illustrated in FIGS. 3 to 5 can advantageously be made of a single piece, appropriately shaped and bent. Once inserted in the seat 6, the reinforcement element easily remains in position thanks to the interaction between the tabs 12, 13 and the corresponding seats 22, 23, as well as thanks to the interaction between the outer surface of the hollow portion 11, 21 and the inner surface of the seat 6.
According to an alternative embodiment, illustrated in FIG. 6, the reinforcement element 30 can advantageously comprise crimping means 300, designed to favour coupling of the reinforcement element itself and the shaped body 5. This is particularly advantageous in the case where the positioning of the reinforcement element within the seat 6 is obtained by co-moulding, via insertion of the element 30 in the mould of the shaped body 5 of the rotating element 4.
An alternative embodiment, illustrated in FIGS. 8 and 9, envisages that the reinforcement elements 40 comprise a second shaped body 42 and a third shaped body 43. Each of said second and third shaped bodies 42, 43 has a first hollow portion 44 with substantially U-shaped cross section, defined by a first wall 45, a second wall 46 and a third wall 47 substantially perpendicular to one another. The outer surface of the hollow portion 44 is made so as to mate substantially with the inner surface of said seat 6. A third tab 48 extends from said second wall 46 and engages, for example, by snap action, in corresponding housings 480, defined in the seat 6 of the shaped body 5. As illustrated in FIG. 9, the second and third shaped bodies 42, 43 are inserted in the seat 6 so that the respective hollow portions 44 face one another.
Preferably, defined on said third tab 48 is a third hole 49 for passage of said driving pin 8. Like the embodiment previously described, the stresses and in particular the actions of thrust and of tugging generated in a position corresponding to the driving pin 8, instead of being concentrated on a limited area adjacent to the hole 80, can thus be distributed over a far more extensive surface.
In order to improve the ease of positioning in the seat 6, the second and third shaped bodies 42, 43 can advantageously have engagement means 401 designed to engage in corresponding housings 400, defined on said shaped body 5 of said rotating element.
A further alternative embodiment, illustrated in FIGS. 10 and 11, envisages that the reinforcement elements 50 comprise a fourth plate-shaped body 51 that has a surface 52 substantially mating with an inner surface of said seat 6. As illustrated in the figures, it is preferable for the reinforcement elements to comprise two plate-shaped bodies 51, positioned on two opposed sides of the seat 6. In order to improve the ease of positioning in the seat 6, the plate-shaped bodies 51 moreover comprise engagement means 521 designed to engage in corresponding housings 520, defined on the shaped body 5 of said rotating element.
Preferably, in order to optimize the distribution of the stresses over a surface that is as extensive as possible, defined on said fourth plate-shaped body 51 is a fourth hole 53 for passage of said driving pin 8. Furthermore, once again in order to improve further the distribution of the stresses over the rotating element, the fourth shaped body 51 has at least one portion of bent-over edge 55, designed to co-operate with a corresponding coupling surface 550, defined on said shaped body 5.
Preferably said reinforcement elements (10, 20, 30, 40, 50) are made of metal material, most preferably steel.
On the basis of what has been described above, it may be seen that the single-pole or multi-pole device for low-voltage systems, in particular a circuit breaker or a disconnector, according to the invention, enables the problems typically present in switches of the known art to be solved in so far as it makes available a rotating element in which the distribution of the stresses and the strength are optimized.
On the basis of the description provided, other characteristics, modifications or improvements are possible and evident to the average person skilled in the branch. Said characteristics, modifications and improvements are hence to be considered part of the present invention. In practice, the materials used, as well as the contingent dimensions and shapes, may be any whatsoever according to the needs and the state of the art.
Patent Application
20080087536
