Safety release device for removable circuit breakers

Abstract

 A safety release device for removable circuit breakers, characterized in that it includes an actuation means which has an actuation head and is associated with the body of a circuit breaker so as to determine at least two positions: a retracted position, in which the actuation head lies inside the circuit breaker body, and an active position, in which the actuation head is external to the circuit breaker body and is suitable to be engaged by a surface of a fixed support with which the circuit breaker body is associated, the actuation means acting on the moving contact of the circuit breaker so that in the active position it forces the moving contact into an open-contact position, the actuation means automatically assuming the active position when the circuit breaker is moved away from the surface of the fixed support and assuming the retracted position when the circuit breaker is applied to the fixed support.

Description

[0001] The present invention relates to a safety release device for removable circuit breakers.

[0002] Enclosed circuit breakers and their accessories can be installed both in a fixed manner and in a removable manner.

[0003] In fixed installation, the unit is fastened to a support and is connected to the conductors by means of the appropriately provided terminals, in a per se known manner, and in this installation no provisions are made for frequent and rapid disassembly of the unit.

[0004] Other applications instead require the unit to be replaceable very rapidly and easily, even without shutting down the electric power supply.

[0005] A removable installation is generally achieved by installing receptacles on the connections of the circuit breaker. The receptacles provide the electrical connection with fixed bases installed in the electrical panels.

[0006] In a removable installation it is advisable to provide the unit with a safety device adapted to open the circuit breaker when the operator removes the unit in the closed position.

[0007] For that purpose, circuit breakers are usually provided with appropriate mechanical systems adapted to open the contacts when the operator removes the unit while the contacts are closed.

[0008] The safety systems known in the art are either constituted by accessories, to be applied to the unit when it is installed in a removable manner, or are constituted by mechanisms included within the unit but that can be activated by opening the unit.

[0009] The aim of the present invention is to provide a safety release device for removable circuit breakers that is more functional than the devices of the cited prior art.

[0010] An object of the invention is to provide a safety release device for removable circuit breakers that can be switched easily and rapidly depending on whether the unit is installed in a fixed or removable manner.

[0011] A further object of the invention is to provide a safety release device for removable circuit breakers that is constructively simple and economic from the point of view of production.

[0012] A further object is to provide a safety release device for removable circuit breakers that is reliable.

[0013] This aim, these objects and others which will become better apparent hereinafter are achieved by a safety release device, for removable circuit breakers, as claimed in the appended claims.

[0014] Further characteristics and advantages will become better apparent from the description of preferred but not exclusive embodiments of the invention, illustrated only by way of non-limitative example in the accompanying drawings, wherein:

Figure 1 is a schematic partial elevation view of a circuit breaker provided with the safety release device, shown in the fixed-installation position;

Figure 2 is a view, similar to Figure 1, of the circuit breaker provided with the safety release device, shown in the removable-installation position;

Figure 3 is a partial bottom view of the circuit breaker provided with the device according to the invention.

Figure 4 is a schematic partial elevation view of a circuit breaker provided with the safety release device, according to a further aspect of the invention, shown in the fixed-installation position;

Figure 5 is a perspective view of the actuation bar of the device of the preceding figure;

Figure 6 is a side view of the circuit breaker of figure 4, shown in the fixed-installation position;

Figure 7 is a side view of the circuit breaker of the preceding figure, shown in the process of disengaging the actuation bar;

Figure 8 is a front view of the circuit breaker of the preceding figure, shown with the actuation bar ready for the removable-installation position;

Figure 9 is a side view of the circuit breaker of the preceding figure, shown in the removable-installation position;

Figure 10 is a side view of the circuit breaker, according to a further aspect of the invention, shown in the process of disengaging the actuation bar;

Figure 11 is a perspective view of the actuation bar of the device of the preceding figure.

[0015] With reference to the above figures, the safety release device, according to the invention, is particularly useful in a circuit breaker, generally designated by the reference numeral 1, which can be installed both in a fixed manner and in a removable manner.

[0016] In the fixed installation, the circuit breaker 1 is fixed, for example by means of standard guides, in a rather removable manner to a support and is connected to the conductors by means of the appropriately provided terminals, in a per se known manner.

[0017] In a removable installation adapted receptacles are provided on the connections of the circuit breaker. The receptacles provide electrical connection to fixed bases installed in the electrical panels.

[0018] In the removable installation, it is advisable to provide the unit with a safety device adapted to open the contacts of the circuit breaker if the operator removes the unit in while the contacts are closed.

[0019] The safety release device according to the invention comprises a cylindrical body 3 associated with a body 5 of the circuit breaker and adapted to receive an actuation bar 7, which can slide within the cylindrical body 3.

[0020] The actuation bar 7 has an actuation end 9 protruding out of the circuit breaker body 5 through an opening that connects the inside of the cylindrical body to the outside of the circuit breaker body, at the side 11 that faces the supporting surface, not shown in the figures, to which the circuit breaker body is applied.

[0021] The actuation bar 7 has an actuation end provided with a connecting means, a hook 15 in the specific case, which is operatively connected to a lever 17 acting on the moving contact, not shown, of the circuit breaker so as to define at least two positions: a closed-contact position, shown in Figure 1, and an open-contact position, shown in Figure 2.

[0022] The actuation bar 7 can slide within the cylindrical body 3 in contrast with an elastic means, which in the specific case is constituted by a helical spring 27 which is coaxial to the bar and has an end in contact with a fixed member of the circuit breaker body and another end in contact with a step of the actuation bar formed, in the specific case, by a recessed region of the bar.

[0023] The actuation bar 7 has a tooth 19 that can selectively engage a longitudinal slot 21 or an edge 23, through the rotation of the bar 7 about its own axis.

[0024] The longitudinal slot 21 and the edge 23 are formed in the cylindrical body 3.

[0025] When the bar 7 is turned so that the tooth 19 engages the edge 23, as shown in Figure 1, the bar 7 is prevented from sliding outward with respect to the cylindrical body 3, despite the action of the contrast spring 27, which would tend to push the bar 7 outward. In that condition, the hook 15 keeps the lever 17 in the closed-contact position and the circuit breaker is therefore in a fixed-installation condition.

[0026] If the circuit breaker has to be installed in a removable manner, the bar 7 will be turned until the tooth 19 is located at the slot 21, by acting on the actuation end 9 of the bar 7, for example by means of a tool such as a screwdriver.

[0027] In that position, shown in Figure 2, the bar can slide freely outward, pushed by the spring 27, and acts on the lever 17 by means of the hook 15, thereby opening the contact.

[0028] In that condition, by resting the unit on the surface of the mounting support, the actuation end 9 of the bar is made to retract into the cylindrical body 3, so that the hook 15 acts on the lever 17, moving it into the closed-contact condition.

[0029] If the operator removes the unit 1 from its seat, while the unit is in the closed position, the fixed surface ceases to abut the actuation end 9 of the bar 7 and the contrast spring 27 pushes the actuation bar outwards, thereby releasing the lever 17 which will open the contact.

[0030] The safety device may be switched from the fixed-installation condition to the removable one, and vice versa, in a very simple and rapid manner: it is in fact sufficient to act on the head of the bar with a screwdriver, or other suitable tool, in order to turn the bar into the intended position.

[0031] Figures 4 to 9 illustrate a circuit breaker, generally designated by the reference numeral 101, which can be installed both in a fixed manner and in a removable manner and is provided with a safety device according to a further aspect of the invention.

[0032] The safety release device according to the invention comprises an actuation bar 107 which can slide inside an elongated cavity 103 provided in the body 105 of the circuit breaker.

[0033] The actuation bar 107 has an actuation end 109 which is accessible from the outside of the circuit breaker body 105 through an opening 129 that connects the cavity 103 to the outside of the circuit breaker body, at the side 111 that faces the supporting surface 155, to which the circuit breaker body is applied.

[0034] The actuation bar 107 has an actuation end provided with a connecting means, a hook 115 in the specific case, which is operatively connected to a lever 117 acting on the moving contact, not shown, of the circuit breaker so as to define at least two positions: a closed-contact position, shown in Figures 4, 6, 7, and 9, and an open-contact position, shown in Figure 8.

[0035] The actuation bar 107 can slide within the cavity 103 in contrast with an elastic means, which in the specific case is constituted by a helical spring 127 which is coaxial to the bar and has an end in contact with a fixed member of the circuit breaker body and another end in contact with a step of the actuation bar formed, in the specific case, by a recessed region of the bar.

[0036] The actuation bar 107 has a tooth 119, provided at the tip of a blade 120, that can selectively engage an edge 123 provided on the wall of the cavity 103.

[0037] When the bar 107 has the tooth 119 engaged with the edge 123, as shown in Figures 4 and 6, the bar 107 is prevented from sliding outwards, despite the action of the contrast spring 127, which biases the bar 107 outwards. In such condition, the hook 115 keeps the lever 117 in the closed-contact position and the circuit breaker is therefore in a fixed-installation condition.

[0038] If the circuit breaker has to be installed in a removable manner, the bar 107 should be extracted partially from the cavity by acting with the tip 130 of a screw driver, or any other suitable tool, on the elastic blade 120 in order to disengage the tooth 119 from the edge 123, as visible in Figure 7.

[0039] In that position, shown in Figures 8 and 9, the bar 107 can slide freely outwards, pushed by the spring 127, and acts on the lever 117 by means of the hook 115, thereby opening the contact.

[0040] In that condition, by resting the unit on the surface 155 of the mounting support, the actuation end 109 of the bar 107 is made to retract into the cavity 103, so that the hook 115 acts on the lever 117, moving it into the closed-contact condition.

[0041] If the operator removes the unit 101 from its seat, while the contacts are closed, the fixed surface 155 ceases to abut the actuation end 109 of the bar 107 and the contrast spring 127 pushes the actuation bar outwards, thereby releasing the lever 117 which will open the contact, as shown in Figure 8.

[0042] The safety device may be switched from the removable condition back to the fixed-installation condition, in a very simple and rapid manner, by simply pushing the head 109 of the bar 107 inside the cavity 103, possibly with the aid of the tip 130 of a tool such as a screwdriver, until the tooth 119 engages the edge 123, thereby locking the bar 107 into the fixed installation condition.

[0043] The embodiment shown in figures 10 and 11 is substantially similar to the embodiment illustrated in figures 4-9, except that the bar 207 is constructed in a slightly different manner.

[0044] The bar 207 can slide inside an elongated cavity 203 provided in the body 205 of the circuit breaker.

[0045] The actuation bar 207 has an actuation end 209 which is accessible from the outside of the circuit breaker body 205 through an opening 229 that connects the cavity 203 to the outside of the circuit breaker body, at the side 211 that faces the supporting surface 255, to which the circuit breaker body is applied.

[0046] The actuation bar 207 has an actuation end provided with a connecting means, a hook 215 in the specific case, which is operatively connected to a lever 217 acting on the moving contact, not shown, of the circuit breaker so as to define a closed-contact position and an open-contact position, as described above.

[0047] The actuation bar 207 can slide within the cavity 203 in contrast with an elastic means, which in the specific case is constituted by a helical spring 227 which is coaxial to the bar and has an end in contact with a fixed member of the circuit breaker body and another end in contact with a step of the actuation bar formed, in the specific case, by a recessed region of the bar.

[0048] The actuation bar 207 has a tooth 219, provided at a median portion of a blade 220, that can selectively engage an edge 223 provided on the wall of the cavity 203.

[0049] When the bar 207 has the tooth 219 engaged with the edge 223, the bar 207 is prevented from sliding outwards, despite the action of the contrast spring 227, which biases the bar 207 outwards. In such condition, the hook 215 keeps the lever 217 in the closed-contact position and the circuit breaker is therefore in a fixed-installation condition.

[0050] If the circuit breaker has to be installed in a removable manner, the bar 207 should be extracted partially from the cavity by acting with the tip 130 of a screw driver, or any other suitable tool, on the elastic blade 220 in order to disengage the tooth 219 from the edge 223, as visible in Figure 10.

[0051] In that position, the bar 207 can slide freely outwards, pushed by the spring 227, and acts on the lever 217 by means of the hook 215, thereby opening the contact.

[0052] In that condition, by resting the unit on the surface of the mounting support, the actuation end 209 of the bar 207 is made to retract into the cavity 203, so that the hook 215 acts on the lever 217, moving it into the closed-contact condition.

[0053] If the operator removes the unit 201 from its seat, while the contacts are closed, the fixed surface ceases to abut the actuation end 209 of the bar 207 and the contrast spring 227 pushes the actuation bar outwards, thereby releasing the lever 217 which will open the contact.

[0054] The safety device may be switched from the removable condition back to the fixed-installation condition, in a very simple and rapid manner, by simply pushing the head 209 of the bar 207 inside the cavity 203, possibly with the aid of the tip 130 of a tool such as a screwdriver, until the tooth 219 engages the edge 223, thereby locking the bar 207 into the fixed installation condition.

[0055] In practice it has been observed that the invention achieves the intended aim and objects, providing a safety device that can be switched easily and rapidly depending on whether the unit has to be installed in a fixed or removable manner.

[0056] The device according to the invention is extremely simple from the constructive point of view, fully to the advantage of low manufacturing costs and operating reliability.

[0057] Another functional advantage of the device is the fact that it is not necessary to open the unit in order to activate or deactivate the safety function.

[0058] The device according to the invention is susceptible of numerous modifications and variations, within the scope of the appended claims. All the details may be replaced with technically equivalent elements.

[0059] The materials used, as well as the dimensions, may of course be any according to requirements and to the state of the art.

Claims

1. A safety release device for removable circuit breakers, characterized in that it comprises an actuation means (7, 107, 207) having an actuation head (9, 109, 209) and associated with the body (5, 105, 205) of a circuit breaker (1, 101, 201) so as to determine at least two positions: a retracted position, in which said actuation head lies inside said circuit breaker body, and an active position, in which said actuation head is external to the circuit breaker body and is adapted to be engaged by a surface (155) of a fixed support with which the circuit breaker body is associated, said actuation means acting on the moving contact of the circuit breaker so that in said active position it forces the moving contact into an open-contact position, said actuation means automatically assuming said active position when the circuit breaker is moved away from the surface of the fixed support and assuming said retracted position when the circuit breaker is applied to said fixed support.

2. The device according to claim 1, characterized in that said actuation means (7, 107, 207) can be selectively locked in said retracted position independently of whether the circuit breaker is associated or not with the fixed support.

3. The device according to claim 1 or 2, characterized in that said actuation means comprises a cylindrical body (3) associated with the body of the circuit breaker and adapted to receive an actuation bar (7), said actuation bar being adapted to slide inside said cylindrical body and having an actuation end (9) which protrudes out of the circuit breaker body through an opening that connects the inside of the cylindrical body to the outside of the circuit breaker body at the side that faces the fixed supporting surface to which the circuit breaker body is applied, said actuation bar further having an actuation end (15) provided with a connection means, which is operatively connected to a lever (17) which acts on the moving contact of the circuit breaker; actuation bar sliding within the cylindrical body in contrast with an elastic means constituted by a helical spring (27) which is coaxial to said bar and having one end in contact with a fixed member of the circuit breaker body and another end in contact with a step of the actuation bar formed by a recessed region of the bar; said actuation bar having a tooth (19) adapted to selectively engage a longitudinal slot (21) and an edge (23), through the rotation of the bar about its own axis; when said bar is turned so that the tooth engages said edge, said bar being prevented from sliding outward; said longitudinal slot and said edge being formed in said cylindrical body.

4. The device according to one or more of the preceding claims, characterized in that said actuation head or end of said bar (7, 107, 207) has an engagement means for a tool (130), said means being accessible from the outside in order to act on said bar without opening said circuit breaker body.

5. The device according to claim 1 or 2, characterized in that said actuation bar (107, 207) can slide inside an elongated cavity (103, 203) provided in the body (105, 205) of the circuit breaker.

6. The device according to one or more of the preceding claims, characterized in that said actuation bar (107, 207) has an actuation end (109, 209) which is accessible from the outside of the circuit breaker body (105, 205) through an opening (129, 229) that connects the cavity (103, 203) to the outside of the circuit breaker body, at the side (111, 211) that faces the supporting surface (155), to which the circuit breaker body is applied.

7. The device according to one or more of the preceding claims, characterized in that said actuation bar (107, 207) has an actuation end, constituted by a hook member (115, 215), which is operatively connected to a lever (117, 217) acting on the moving contact of the circuit breaker, so as to define at least two positions: a closed-contact position and an open-contact position.

8. The device according to one or more of the preceding claims, characterized in that said actuation bar (107, 207) can slide within the cavity (103, 203) in contrast with an elastic means, constituted by a helical spring (127, 227) which is coaxial to the bar and has an end in contact with a fixed member of the circuit breaker body and another end in contact with a step of the actuation bar formed by a recessed region of the bar.

9. The device according to one or more of the preceding claims, characterized in that said actuation bar (107) has a tooth (119), provided at the tip of a blade (120), that can selectively engage an edge (123) provided on the wall of the cavity (103).

10. The device according to one or more of the preceding claims, characterized in that said actuation bar (207) has a tooth (219), provided at a median portion of a blade (220), that can selectively engage an edge (223) provided on the wall of the cavity (203).

11. The device according to one or more of the preceding claims, characterized in that when said actuation bar (107, 207) has its tooth (119, 219) engaged with said edge (123, 223), said bar (107, 207) is prevented from sliding outwards, despite the action of said contrast spring (127, 227), which biases said bar (107, 207) outwards; in such condition, said hook (115, 215) keeping said lever (117, 217) in the closed-contact position and said circuit breaker being in a fixed-installation condition.

12. The device according to one or more of the preceding claims, characterized in that, when the circuit breaker has to be installed in a removable manner, said bar (107, 207) being partially extracted from said cavity by acting with the tip (130) of a screw driver, or any other suitable tool, on said elastic blade (120, 220) in order to disengage said tooth (119, 219) from said edge (123, 223); in such condition, said actuation bar (107, 207) being able to slide freely outwards, biased by said spring (127, 227), and acting on said lever (117, 217) by means of said hook (115, 215), thereby opening the contact; in such condition, by resting the unit on the surface of the mounting support, said actuation end (109, 209) of said bar (107, 207) being made to retract into said cavity (103, 203), so that said hook member (115, 215) acts on said lever (117, 217), moving it into the closed-contact condition; if an operator removes the unit (101, 201) from its seat, while the contacts are closed, the fixed surface ceases to abut the actuation end (109, 209) of said bar (107, 207) and said contrast spring (127, 227) pushes said actuation bar outwards, thereby releasing said lever (117, 217) which will open the contact.

Drawing