The circuit breaker constitutes a contact switching unit capable to switch on, to conduct and to switch off currents under normal conditions in circuits, and also to switch on, to conduct during preset normalized period, and to switch off currents under abnormal conditions in circuits such as short- circuit event.

The automatic circuit breaker is known comprising a contact system, placed in insulating body that consists of two half bodies. The body has conjugated flat front, top, bottom and back walls, command push button located in the window embodied in the front wall of a turret and clamping contacts with openings in the top and bottom base walls. (1) The disadvantages of this analogue are low assembly manufacturability, insufficient strength during transporting and

storing, impractical layout due to limited volume of the body, and insufficient surface of heat dissipation.

Another automatic circuit breaker is known comprising a contact system, placed in an insulated body, consisting of two half part bodies attached by edges and fastened by top and bottom rivets, forming a body base and protruding turrets possessing conjugated front, top, bottom, side and back walls, a command push button located in a window embodied in the front wall of the turret between convex collars adjoining the side walls and displaced with respect to the middle of the turret front wall, and clamping contacts with openings in top and bottom base walls. (2).

The disadvantages of this circuit breaker type are low assembly manufacturability, insufficient strength during transporting and storing and insufficient surface of heat dissipation.

The technological purpose of this invention is to create an effective and manufacturable automatic circuit breaker and also expanding the range of automatic circuit breaker.

The technological result providing for solution of the problem constitutes in increased body strength, due to most part of its walls being embodied as curved shells, useful internal volume increased to the maximum possible value within the limits of feasible overall and connecting dimensions, increased reliability due to locating the push button in its extreme positions in the special deepenings, which reduces the risk of accidental switching, high manufacturability of contact assembling in the body, and enlarged heat dissipation surface.

The essence of this invention is that this circuit breaker comprises a contact system placed in a body consisting of two half part bodies fastened by top and bottom rivets, forming a body base and a protruding turret possessing conjugated front, top, bottom, side and back walls, a command push button located in a window embodied in the front wall of the, and clamping contacts with openings in top and bottom base walls. At that, the top and bottom walls of the base and the front walls of the base and the turret are embodied smoothly

convex, while the base is embodied expanding between top and bottom walls towards the turret.

Preferably, the top and the bottom base walls and turret collars are embodied cylindrical, with top and bottom walls of the turret being flat, cylindrical front walls of the base and the turret are concentric to one another, turret collars are deepened at the edges forming two transversal deepenings with curved profiles, and edges of half bodies have staged shape in the transversal direction their junction line being of the staged profile in the transversal direction, clamping contacts possess wells located along the axes perpendicular to the back wall, while bottom rivets are situated under the clamping contact wells and top rivets are situated at the turret corners.

The circuit breaker is equipped with the latch placed in one of the supports on the back wall of the base, and the button is equipped with knurling attachment with the width larger than the button width and less (or equal) than the width of front turret wall.

The drawing in Fig. 1 shows the general view of the circuit breaker in the isometric view, and Fig. 2 shows the circuit breaker cross section.

The circuit breaker comprises a contact system (shown schematically in the Fig. 2), placed in an insulating body made from incombustible insulating plastic consisting of two half bodies (not shown) conjugated by edges and fastened with top rivets 1,2 and bottom rivets 3,4 forming the body base and the protruding turret is tapered with respect to the base of the body. The base of the body has conjugated front (face) walls 5,6, top wall 7, bottom wall 8, parallel flat side walls, out of which only side wall 9 and back wall 10 are shown in the drawings. The protruding turret has conjugated front (face) wall 11, top wall 12, bottom wall 13 and flat side walls (not shown due to being extensions of the base side walls 9). The command button 14 is located in the rectangular window (not shown) embodied in the front wall of the turret 11 between convex cylindrical collars 15,16, adjoining side walls and displaced downside from the middle of the front turret wall 11. The top and bottom walls of a base

7,8 and the front walls of a base and a turret 5,6, 11 are embodied smoothly convex, for example cylindrical, concentric to one another, with the base embodied tapered between top and bottom walls 7,8 expanding towards the turret. Top and bottom walls 12,13 are embodied flat.

Turret collars 15,16 are deepened at the edges forming two transversal deepenings (not shown). The edges of half bodies have staged shape in the transversal direction and are jointed forming the joint line staged in the transversal direction. Clamping contacts have wells 17,18 located along the axes perpendicular to the back wall 10 and cable inlets into the wells 17,18 embodied in top and bottom base walls 7,8. Bottom rivets 3,4 are situated under the clamping contact wells 17,18, while top rivets 1,2 are at the top corners of the turret. Mutually perpendicular axis of the well 17,18 of every contact and bottom rivet 3 or 4 axis, respectively, intersect, i. e. these are situated in the same plain.

The circuit breaker is provided with spring latch 19 (Fig. 2) located in the top one of the supports 20,21 on the back wall

10 of the base, while a trapezoidal shape protrusion 22 (Fig. 1) can be embodied in the middle part of the back wall 10.

The button 14 is equipped with the knurling attachment 23 with the width larger than the button 14 width and less or equal to the width of front turret wall 11. The button 14 and the attachment 23 are colored contrasting to the other surfaces.

The circuit breaker mechanism comprises the contact system and consists of the following component parts: a push control mechanism with a button 14 and an attachment 23 on a swivel block (drum) provided with labels"ON" (I) and"OFF" (0), displayed alternatively in the window in extreme position of the button 14, an electromagnetic solenoid with the core, a <BR> <BR> bimetallic plate, an arc control device, etc. , shown as contours in the Fig. 2. Various circuit breaker embodiments comprising these units are widely known from technological and patent literature, for example from the analog comprising the three- dimensional drawing of the assembled switch, and from the prototype. Due to growth of the internal volume of the body and its shape advantageous for assembly due to the adopted novel wall geometry and rational rivet positioning, the capabilities for

optimum arrangement all units in the circuit breaker body are enlarged.

The circuit breaker is used as follows.

The operating position of the circuit breaker is vertical, in accordance with notation of front, top, bottom, side and back walls 5-13 of the base and the turret, with the angle tolerance with respect to the vertical plane 5.

Before mounting the circuit breaker it is necessary to check it for external damages and to switch it several times manually from"OFF"or"BbIKJI" (0) position to the opposite position"ON"or"BKI1" (I) and backwards to be sure that moving mechanism works smoothly without sticking.

By means of support 20,21 and latch 19, the circuit breaker (one or more) is mounted on the standard rack DIN 35 x 7,5 mm (standard EH 50022). The cables (not shown) of the protected electric circuit are passed to wells 17,18 from above and/or from below through holes and are clamped by threaded parts of clamping contacts. While mounting the position of

pushbutton 14 is adjusted so as the label"OFF"on the swivel block be visible in the window of the turret.

The turning of the pushbutton 14 provides circuit closing to feed the equipment connected to power supply.

In the case of overloading in protected circuit, the overcurrent (in accordance to the rating value, for example 16 Amps) forces the bimetallic plate to bend, which in turn pushes the lever of release mechanism. The moving contact separates from the stationary one, performing the circuit protection from overloading.

Should a short current appear in the protected circuit, the core of the electromagnetic release is drawn back and pulls the lever, which act on the release mechanism. The moving contact separates from the stationary one, performing the circuit protection from short-circuit current influence.

Simultaneously with breaking the electric circuit, the pushbutton 14 returns to the bottom position. The intrinsic time of circuit breaker tripping is not more than 0.02 sec.

To disconnect the voltage, for example during repair works, the pushbutton 14 could be switched manually. In extreme positions the attachment 23 is partly recessed in the wells on the surface 11 along collar edges 15,16.

The circuit breaker is practically not heated, as the internal body volume is sufficient for loose arrangement of the components, with the heat dissipation surface enlarged. The curved convex body walls possess adequate strength, ruling out mechanical damages of the internal components under the high forces acting during transporting or mounting.

Manufacturing of the half bodies with the curved shells on standard equipment is quite straightforward.

Thus, an efficient and manufacturable circuit breaker is designed, and the range of circuit breakers has been expanded.

Therewith, the strength of the body the most part of the walls of which are embodied as curved shells is increased, the useful internal volume is enlarged to the maximum possible extent within the limits of feasible overall and connecting dimensions, the reliability has been increased due to locating

the push button in its extreme positions in the special deepenings, which reduces the risk of accidental switching, high manufacturability of contact assembling in the body has been provided for, and the heat dissipation surface has been enlarged.

References 1. Booklet'W3K@" (DEC@), DEC Corporation, Moscow, Nauchniy proezd, 12,2001, p. 2, photo 1, 3 (circuit breaker).

2. Patent application PCT WO 01/37304, ICL H01H73/48, 2001, prototype.