FUSE SWITCH MODULE

Abstract

The invention refers to a low-cost fuse switch module that comprises a pair of fixed contacts and a rotary contact rotatable about a rotation axis located in-between the fixed contacts. The rotary contact is rotatable between a closed position in which it is connected with the fixed contacts to enable current circulation, and an open position in which the rotary contact is electrically isolated from the pair of fixed contacts . An overcurrent protection fuse is provided for limiting maximum current circulation through the contacts in the closed position, and the fuse is rotatable about the axis and it is arranged to operate as the rotary contact of the switch, such as by rotating the fuse about the rotation axis, the switch reciprocally transit from the closed to the open position.

Claims

1. A fuse switch module comprising: a pair of fixed contacts and a rotary contact, wherein the rotary contact is rotatable about a rotation axis that extends through a point located between the fixed contacts, wherein the rotary contact is rotatable between a closed position, in which the rotary contact is electrically connected to both of the fixed contacts to enable current circulation between the fixed contacts, and an open position, in which the rotary contact is electrically isolated from the pair of fixed contacts to prevent current circulation between the fixed contacts; and.sub.; an overcurrent protection fuse configured to limit a maximum current circulation through the fixed and rotary contacts when the rotary contact is in the closed position, wherein the overcurrent protection fuse is rotatable about the rotation axis and is configured to operate as the rotary contact, such that rotating the overcurrent protection fuse about the rotation axis reciprocally transits the rotary contact between the closed position and to the open position.

2. The fuse switch module according to claim 1, further comprising an electrically insulating casing, and wherein the fuse switch module is configured such that the overcurrent protection fuse is enclosed within the casing when the rotary contact is in the open position and when the rotary contact is in the closed position.

3. The fuse switch module according to claim 1, wherein the overcurrent protection fuse has two connection terminals at opposite ends of the overcurrent protection fuse, and wherein the rotation axis extends transversally across the overcurrent protection fuse through a point located between the two connection terminals.

4. The fuse switch module according to claim 1, wherein the overcurrent protection fuse can rotate about the rotation axis by an angle within the range 45-90 from the closed position to the open position.

5. The fuse switch module according to claim 4, wherein the angle is 90.

6. The fuse switch module according to claim 2, further comprising a fuse cartridge made of an electrically insulating material, wherein the overcurrent protection fuse is attached to the fuse cartridge such that the fuse and the cartridge can rotate together.

7. The fuse switch module according to claim 6, wherein the fuse cartridge has at least one protrusion having a bore for receiving an actuation shaft for operating the fuse switch module wherein the protrusion is received within a circular aperture of a wall of the casing, and wherein the fuse cartridge is accessible from outside the casing, such that rotation of the fuse cartridge is guided by the aperture.

8. The fuse switch module according to claim 3, further comprising two conductive blades detachably fitted respectively to the two connection terminals and configured to contact the fixed contacts when the rotary contact is in the closed position.

9. The fuse switch module according to claim 2, further comprising a pair of switch terminals accessible from outside the casing for connection of the fuse switch module to an external circuit, and wherein the fixed contacts are enclosed within the casing and the switch terminals are respectively connected to the fixed contacts.

10. The fuse switch module according to claim 2, wherein the casing has an aperture and the fuse switch module further comprises a cover mounted on the casing for covering the aperture, and wherein the cover is movable to provide access to a casing interior through the aperture, and wherein the fuse switch module is configured such that the overcurrent protection fuse can be extracted out of the casing through the aperture when the rotary contact is in the open position.

11. The fuse switch module according to claim 10, further comprising a fuse carrier coupled with the overcurrent protection fuse, wherein the fuse carrier has an end configured to be gripped and configured to pull the overcurrent protection fuse axially out of the casing.

12. The fuse switch module according to claim 8, further comprising a fuse cartridge made of an electrically insulating material, wherein the overcurrent protection fuse is attached to the fuse cartridge such that the fuse and the cartridge can rotate together, wherein at least one of the blades protrudes outside the fuse cartridge, wherein each blade includes a generally Y-shaped portion, wherein each blade has a double-walled part that engages a respective one of the fixed contacts by elastic deformation of the double-walled part, and wherein each blade has a single-walled part that can be inserted into one of the fixed contacts.

13. The fuse switch module according to claim 10, wherein the overcurrent protection fuse has a cylindrical body, when the rotary contact is in the closed position, the overcurrent protection fuse is parallel to the aperture of the casing, and when the rotary contact is in the open position, the overcurrent protection fuse is orthogonal to the aperture.

14. The fuse switch module according to claim 10, wherein the cover is pivotally mounted to the casing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Preferred embodiments of the invention are henceforth described with reference to the accompanying drawings, wherein:

[0022] FIG. 1.shows a perspective view of a preferred embodiment of a switch module according to the invention.

[0023] FIG. 2.shows another perspective view with one of the casing walls represented in exploded view.

[0024] FIG. 3.shows another exploded view of the switch module.

[0025] FIG. 4.shows a perspective view of the fuse cartridge and the fuse coupled together.

[0026] FIG. 5.shows a side elevational view in the open position of the switch, and with the fuse cartridge removed for the sake of the illustration.

[0027] FIG. 6.shows a similar representation than FIG. 5 but in the closed position of the switch.

[0028] FIG. 7.shows another side elevational view with the fuse partially extracted out of the casing.

PREFERRED EMBODIMENT OF THE INVENTION

[0029] FIG. 1 shows a preferred embodiment of a fuse switch module (1) according to the invention, comprising an electrically insulating casing (2) formed by two coupled parts (2a,2b) that form together an enclose within which fixed contacts (5,6) and a fuse (8) of the switch are housed during the normal use of the switch. The casing (2) has an aperture (3) in a front wall of the casing, and a cover (4) covering the aperture (3). The cover (4) is pivotally mounted on the casing (2) so when the cover (4) is open (as shown in FIG. 7), the casing interior is accessible through the aperture (3) for extracting the fuse (8) out of the casing.

[0030] The switch module (1) further comprises a pair of fixed contacts (5,6) in the form of tweezers, and a rotary contact (7) rotatable about a rotation axis (X) located in-between the fixed contacts (5,6), as shown more clearly in FIGS. 5-7. The switch module (1) has an overcurrent protection fuse (8) that is part of the rotary contact (7), so that the fuse (8) is rotatable about the axis (X) between a closed position (FIG. 6) in which it is connected with the fixed contacts (5,6) to enable current circulation, and an open position (FIG. 5) in which the fuse (8) is electrically isolated from the pair of fixed contact (5,6) to prevent current circulation.

[0031] Therefore, the fuse (8) operates as the rotary contact (7), so by rotating the fuse (8) about the rotation axis (X), the switch transit from the closed to the open position and vice-versa.

[0032] The fuse (8) is an elongated body and has two connection terminals (9,10) at opposite ends of the fuse. The rotation axis (X) runs transversally across the fuse (8) (transversal to the longitudinal direction of the fuse), and it is located in-between the two connection terminals (9,10), so that, the fuse is rotatable on a plane. The switch is configured such the fuse (8) rotates about the rotation axis (X) an angle () between the open position (FIG. 5) and closed position (FIG. 6). The angle () is within the range (45-90), and preferably the angle () is 90 as represented in the figures.

[0033] The switch module (1) has a fuse cartridge (11) made of an electrically insulating material, such as the fuse (8) is fitted inside the cartridge (11) during the normal use of the switch, so both components cartridge (11) and fuse (8) can rotate together about the axis (XS). For that, the fuse cartridge (11) has two lateral protrusions (12,13) with circular configuration and having respective bores (14,15) for receiving an actuation shaft (not shown) for rotating the fuse cartridge (11) to operate the switch. These circular protrusions (12,13) are received respectively within circular windows (16,17) formed in the lateral walls of the casing (2), so that the rotation of the cartridge (11) is guided by the windows (16,17).

[0034] The switch module (1) further comprises a pair of switch terminals (18,19) enclosed within the casing (2) respectively connected with the fixed contacts (5,6) by means of connections (20,21) as shown more clearly in FIG. 3. These terminals (18,19) are accessible through upper and lower windows (22,23) provided at the casing, for their connection with an external electric circuit (not-shown), for example for their connection with wires that can be secured by means of screws (24,25) in known manner accessible through openings (29,20).

[0035] The fuse cartridge (11) is represented in FIG. 4 in more detail, and it is configured to receive the fuse (8) such as, in use, the two connection terminals (9,10) can be connected with the fixed contacts (5,6) by means of a pair of blades (26,27) detachably coupled respectively with fuse terminals (9,10). The blades (26,27) protrude outside the fuse cartridge (11), and are configured for contacting with the fixed contacts (5,6) in the closed position of the switch module.

[0036] Each blade (26,27) has generally an Y shape in a cross-sectional view of the same, and it is configured such as its double-walled part embraces one of the fuse contacts (9,10) by elastic deformation as shown in FIG. 4, and the single-wall part of the blade can be inserted into one of the fixed contacts (5,6) as shown in FIG. 6.

[0037] A fuse carrier (28) is provided for extracting the fuse (8) out of the casing (2) for its replacement or for inspection purposes. The fuse carrier (28) is coupled with the fuse (8), and it is configured to pull the fuse (8) axially out of the casing (2) as shown in FIG. 7, by pulling one end (29) of the fuse carrier (28), either by hand or with the aid of a proper tool.

[0038] A switch can be formed in a known manner by stacking axially several switch modules (1) as the one described above, together with an actuation mechanism (not shown) having a shaft coupled axially with respect the axis (X) and with the with fuse cartridge (11).

[0039] Other preferred embodiments of the present invention are described in the appended dependent claims and the multiple combinations of those claims.