Claims:We claim:

1. A modular fuse switch (150) for screw less termination, the modular fuse switch (150) being mounted on DIN rails (not shown) using at least two DIN clips (160), the modular fuse switch (150) having a first end (120) and a second end (140), the modular fuse switch (150) comprising of:
a housing having,
• a left housing (20), the left housing (20) being configured with a knob (10),
• a right housing (40), and
• rivets (60) for fastening and securing the left housing (20) and the right housing (40) to each other thereby creating a space therebetween;
a first termination assembly (80A) configured within the space created between the left housing (20) and the right housing (40), the first termination assembly (80A) comprising,
• a fuse holder (68A) having a fuse holder spring (62A),
• a box clamp (78A) being in operable connection with the fuse holder (68A), the box clamp (78A) having a top box clamp supporter (74A) and a bottom box clamp supporter (76A), and
• a box clamp spring (72A) being configured below the box clamp (78A) using the bottom box clamp supporter (76A);
a second termination assembly (80B) configured within the space created between the left housing (20) and the right housing (40), the second termination assembly (80B) comprising,
• a fuse holder (68B) having a fuse holder spring (62B),
• a box clamp (78B) being in operable connection with the fuse holder (68B), the box clamp (78B) having a top box clamp supporter (74B) and a bottom box clamp supporter (76B), and
• a box clamp spring (72B) being configured below the box clamp (78B) using the bottom box clamp supporter (76B);
a fuse (100) being removably inserted between the fuse holders (68A, 68B) using the fuse holder springs (62A, 62B) the fuse (100) being held in position by the knob (10);
wherein, the first termination assembly (80A) and the second termination assembly (80B) are pressed by inserting the screwdriver (170) within the top box clamp supporters (74A, 74B) of the box clamps (78A, 78B), thereby compressing the box clamp springs (72A, 72B) to create gaps between the box clamps (78A, 78B) and the fuse holders (68A, 68B) for facilitating insertion of cables (180A, 180B) therein.

2. The modular fuse switch (150) for screw less termination as claimed in claim 1, wherein the first termination assembly (80A) and the second termination assembly (80B) are positioned parallelly such that the fuse holders (68A, 68B) face each other creating a space therebetween for accommodating the fuse (100) therein, whereas the box clamps (78A, 78B) lie at peripheral edge, facing each other, relative to the fuse (100).

3. The modular fuse switch (150) for screw less termination as claimed in claim 1, wherein the box clamps (78A, 78B) and the fuse holder (68A, 68B) are adapted for pulling and simultaneously holding and locking the cables (180A, 180B ) in between the box clamps (78A, 78B) and the fuse holders (68A, 68B) respectively thereby facilitating insertion of the cables (180A, 180B) therein and establishing a screw less termination at the first end (120) and the second end (140) of the modular fuse switch (150).

4. The modular fuse switch (150) for screw less termination as claimed in claim 1, wherein the top box clamp supporters (74A, 74B) and the bottom box clamp supporters (76A, 76B) are made up of plastic.

5. The modular fuse switch (150) for screw less termination as claimed in claim 1, wherein the top box clamp supporters ( 74A, 74B) are configured for receiving the screwdriver (170) for pressing the first termination assembly (80A) and the second termination assembly (80B), whereas the bottom box clamp supporters (76A, 76B) are configured for providing support to the box clamp springs (72A, 72B).

6. A method for establishing a screw less termination using the modular fuse switch (150), the method comprising the steps of:
• inserting the screwdriver (170) within the top box clamp supporter (74A) of the box clamp (78A) of the first termination assembly (80A);
• pressing the first termination assembly (80A) using the screwdriver (170) thereby compressing the box clamp spring (72A) to create a gap between the box clamp (78A) and the fuse holder (68A);
• inserting the cable (180A) into the gap created between the box clamp (78A) and the fuse holder (68A) of the first termination assembly (80A) for establishing a screw less termination at the first end (120) of the modular fuse switch (150); and
• repeating the above steps for establishing a screw less termination at the second end (140) of the modular fuse switch (150);

wherein the box clamps (78A, 78B) and the fuse holders (68A, 68B) are adapted for pulling and simultaneously holding and locking the cables (180A, 180B) therebetween, thereby establishing a screw less termination at the first end (120) and the second end (140) of the modular fuse switch (150).
, Description:A MODULAR FUSE SWITCH FOR SCREW LESS TERMINATION AND METHOD THEREOF

Field of the invention

The present invention relates to a modular fuse switches and more particularly provides a modular fuse switch having screw less termination, and a method thereof for establishing a screw less termination, allowing quick installation and removal of the modular fuse switches from an external conductors.

Background of the invention

Modular fuse switches are suitable for protection against overloads and short circuits and are used in any applications where need of electrical protection, isolation and switching under load of inductive or resistive loads is required. Particularly, the modular fuse switches are used in commercial, distribution and building segments to isolate and protect the equipments. Modular fuse switch, act like a switch, for connecting and disconnecting electrical circuit parts without load or at full load, wherein the modular fuse switches forms a moving contact, that is capable of making, carrying and breaking currents under normal circuit conditions, and is also capable of carrying currents for a specified time under certain abnormal circuit conditions such as those of over-load and short-circuits.

Conventionally, for all the modular fuse switches, a screw-type termination is established for connecting the modular fuse switches to the external conductors or external electrical circuit parts, wherein a cable or a wire is wrapped around a screw and the screw is then tightened to secure the connection. The termination is done using a conventional screwdriver or a torque screw driver having a specified torque. However, there are certain drawbacks associated with the conventional screw-type termination for connecting the modular fuse switches with the external conductors. For establishing a screw-type termination, the process involves loosening the screw to create a gap/cavity in the box clamp of the modular fuse switch for inserting the cable/wire therein, which is then tightened by tightening the screw, the process which consumes a lot of time and efforts. Also establishing a firm electrical connection between the terminals of the modular fuse switch and the external conductors using cables or wires requires tightening of the screw beyond the electrical contact which leads to frequent terminal screw threads and screw head damage. Additionally, for achieving zero resistance at the termination joints, one needs to be very careful to avoid thermal damages. Thus, the process makes it very time consuming and involves a lot of efforts to be taken. In addition, there is a chance/possibility of insufficient loosing of termination over period of time due to vibrations or other connections.

Therefore, there exist a need to provide a modular fuse switch with screw less type termination that overcomes the above mentioned drawbacks of the prior art. Accordingly, there is a need for a method for establishing a screw less termination that allows quick installation and removal of the modular fuse switches from external conductors.

Objects of the invention

An object of the present invention is to provide a screw less terminal which can be operated easily utilizing minimum efforts and less time, without requiring the application of high force for establishing a firm electrical connection between the terminals of a modular fuse switch and the external conductors.
Another object of present invention is to provide a screw less terminal which is easy and economical to manufacture and assemble, thereby reducing the manufacturing cost.

Yet another object of present invention is to allow quick connection of cable or wire during installation and quick removal of cable or wire during maintenance, thereby making the operation simple and robust.

Summary of the invention

The present invention provides a modular fuse switch for screw less termination between the terminals of a modular fuse switch and an external conductor. The modular fuse switch comprises of housing having a left housing and a right housing secured to each other using rivets thereby creating a space therebetween, a first termination assembly and a second termination assembly enclosed in the space created within the housing, and a fuse being operatively configured between the first termination assembly and the second termination assembly. The first termination assembly and the second termination assembly each comprises of a fuse holder having a fuse holder spring, a box clamp operatively connected to the fuse holder, and a box clamp spring positioned below the box clamp. The box clamp is further provided with a top box clamp supporter, and a bottom box clamp supporter providing support to the box clamp spring. The fuse is removably inserted between the fuse holders of the first and the second termination assembly using the fuse holder springs, and is held in position using a knob provided on the left housing. The first termination assembly and the second termination assembly is assembled parallelly within the housing such that the respective fuse holders face each other configuring a fuse therebetween, whereas the respective box clamps face each other and lie at the peripheral edges relative to the fuse.
In another aspect, the present invention discloses a method for establishing a screw less termination using the modular fuse switch. Accordingly, the first termination assembly and the second termination assembly is pressed by inserting a screwdriver within the respective top box clamp supporters of the box clamps, thereby compressing the respective box clamp springs. Compression of the box clamp springs creates a gap between the respective box clamps and the fuse holders thereby facilitating insertion of the cables or wires therein. Particularly, the box clamps and the fuse holders are adapted for pulling and simultaneously holding and locking the cables therein for facilitating insertion of the cable for establishing a screw less termination at the first end and the second end of the modular fuse switch respectively.

Brief description of the drawings

The objectives and advantages of the present invention will become apparent from the following description read in accordance with the accompanying drawings wherein,

Figure 1 shows different views of a modular fuse switch for screw less termination, in accordance with the present invention; wherein
Figure 1A shows a front view of the modular fuse switch;
Figure 1B shows a top view of the modular fuse switch; and
Figure 1C shows a side view of the modular fuse switch;

Figure 2 shows a sectional front view of the modular fuse switch of figure 1;

Figure 3 shows an exploded view of the modular fuse switch of figure 1;

Figure 4 shows different perspective views of a fuse holder;
Figure 5 shows a perspective view of box clamps;
Figure 6 shows a perspective view of a fuse;
Figure 7 shows a perspective view of a knob;
Figure 8 shows a perspective of top and bottom box clamp supporters;
Figure 9 shows a perspective view of a DIN clip;

Figure 10 shows a perspective view showing the box clamp and the fuse holder being in operable connection with each other, in accordance with the present invention;

Figure 11A, 11B and 11C shows a sectional front view of the steps involved in assembling various components to form the modular fuse switch of the present invention;

Figure 12A and 12B shows a sectional front view of the steps involved in establishing a screw less termination at the ends of the modular fuse switch, in accordance with the present invention;

Figure 13 shows a perspective view showing the screw less termination established at the first end of the modular fuse switch, in accordance with the present invention; and

Figure 14A and 14B shows ingress protection and IP20 finger proof protection of the user establishing a screw less termination using the modular fuse switch of the present invention.

Detailed description of the invention

The foregoing objects of the invention are accomplished and the problems and shortcomings associated with the prior art techniques and approaches are overcome by the present invention as described below in the preferred embodiment.

The present invention provides a modular fuse switch for screw less termination and a method for establishing a screw less termination during electrically connecting the modular fuse switch with an external conductor. The method allows in quick installation and removal of the modular fuse switches from the external conductors without requiring the application of high force for establishing a firm electrical connection between the terminals of the modular fuse switch and the external conductors.

The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.

Referring now to figures 1-10, in an aspect, there is shown a modular fuse switch (150) for screw less termination in accordance with the present invention. In an embodiment, the modular fuse switch (150) is a single pole modular fuse switch (150). In another embodiment, the modular fuse switch (150) has a width of 17.5mm (1-Mod), height of 100.6mm and a depth of 60.7mm. The modular fuse switch (150) is mounted on DIN rails (not numbered) using at least two DIN clips (160). The modular fuse switch (150) comprises of a housing having a left housing (20) and a right housing (40), a first termination assembly (80A) and a second termination assembly (80B) enclosed within the left housing (20) and the right housing (40), and a fuse (100) being operatively configured between the first termination assembly (80A) and the second termination assembly (80B).

The housing comprises of a left housing (20) and a right housing (40) fastened and secured to each other using rivets (60). The left housing (20) is further configured with a knob (10) for operatively holding the fuse (100). The first termination assembly (80A) and the second termination assembly (80B) is enclosed within the space created in between the left housing (20) and the right housing (40).

The first termination assembly (80A) further comprises of a fuse holder (68A) having a fuse holder spring (62A); a box clamp (78A) being operatively connected to the fuse holder (68A) and having a top box clamp supporter (74A) and a bottom box clamp supporter (76A); and a box clamp spring (72A) positioned below the box clamp (78A) using the bottom box clamp supporter (76A).

The second termination assembly (80B) further comprises of a fuse holder (68B) having a fuse holder spring (62B); a box clamp (78B) being operatively connected to the fuse holder (68B) and having a top box clamp supporter (74B) and a bottom box clamp supporter (76B); and a box clamp spring (72B) positioned below the box clamp (78B) using the bottom box clamp supporter (76B).

The fuse (100) is operatively configured between the first termination assembly (80A) and the second termination assembly (80B). In an embodiment, the fuse (100) is removably inserted between the fuse holders (68A, 68B) using the fuse holder springs (62A, 62B) and is held in position using the knob (10) provided by the left housing (20).

Now referring to figure 11A, 11B and 11C, for assembling the modular fuse switch (150), the first termination assembly (80A) is initially placed in the right housing (40), followed by the second termination assembly (80B), the knob (10) and the fuse (100). The left housing (20) is then placed on the top and is fastened and secured to the right housing (40) using the rivets (60). In an embodiment, the first termination assembly (80A) and the second termination assembly (80B) is assembled parallelly within the left housing (20) and the right housing (40) such that the fuse holders (68A, 68B) face each other configuring a fuse (100) therebetween, whereas the box clamps (78A, 78B) face each other but lie at the peripheral edges relative to the fuse holders (68A, 68B) and the fuse (100). The fuse (100) is removably placed between the fuse holders (68A, 68B) using the fuse holder springs (62A, 62B) and is operatively held in its position by the knob (10) configured on the left housing (20).

Referring to figure 12A, figure 12B shown is a sectional front view of the steps involved in establishing a screw less termination at the first end (120) and the second end (140) of the modular fuse switch (150).
The ‘first end’ refers to the end of the modular fuse switch (150) adjacent to the first termination assembly (80A).
The ‘second end’ refers to the end of the modular fuse switch (150) adjacent to the second termination assembly (80B).

In accordance with the present invention, establishing a screw less termination at the first end (120) of the modular fuse switch (150) involves inserting a screw driver (170) within the top box clamp supporter (74A) of the box clamp (78A) of the first termination assembly (80A), and pressing the first termination assembly (80A) thereby compressing the box clamp spring (72A). Compression of the box clamp spring (72A) creates a gap between the box clamp (78A) and the fuse holder (68A) for insertion of the cable (180A), alternatively referred to as ‘the wire’, therein.
Alternatively, inserting a cable (180B) within the second termination assembly (80B) for establishing a screw less termination at the second end (140) of the modular fuse switch (150) involves inserting a screw driver (170) within the top box clamp supporter (74B) of the box clamp (78B) of the second termination assembly (80B), and pressing the second termination assembly (80B) thereby compressing the box clamp spring (72B). Compression of the box clamp spring (72B) creates a gap between the box clamp (78B) and the fuse holder (68B) facilitating insertion of the cable (180B) therein. In a preferred embodiment, the cable (180A, 180B) is a 6 square meters copper cable.

Referring to figure 13 shown is a perspective view of the screw less termination established at the first end (120) of the modular fuse switch (150). Specifically, the box clamps (78A, 78B) and the fuse holders (68A, 68B) are adapted for pulling and simultaneously holding and locking the respective cables (180A, 180B) therebetween, thereby establishing a screw less termination at the first end (120) and the second end (140) of the modular fuse switch (150) respectively. More specifically, the top box clamp supporters (74A, 74B) are placed at the top position of the box clamps (78A, 78B) respectively and are exposed to an external body including, but not limited to, a screw driver (170); whereas the bottom box clamp supporters (76A, 76B) are placed at the bottom position of the respective box clamps (78A, 78B) and provides support to the box clamp springs (72A, 72B) respectively. In a preferred embodiment, the top box clamp supporters (74A, 74B) and the bottom box clamp supporters (76A, 76B) are made up of plastic body, thereby eliminating the possibility of shocks to the user while inserting the screw driver (170) within the top box clamp supporters (74A, 74B) and giving an IP20 finger proof protection, as shown in figure 14A and 14B, while establishing a screw less termination using the modular fuse switch (150).

Advantages of the invention

• The modular fuse switch (150) helps in establishing a simple, quick and secured screw less fixing or termination even with larger cross-section of the conductors to be connected (suitable for currents up to 32A).
• The modular fuse switch (150) helps in quick screw less connection of cable/wire during installation and quick removal of cable/wire during maintenance.
• The modular fuse switch (150) is easy and economical to manufacture and assemble.
• The modular fuse switch (150) provides dual state operation enabling user to use both the hands for cable/wire insertion effectively.
• The modular fuse switch (150) consumes less time and efforts in establishing a secure screw less termination with minimum chances of insufficient loosing of termination over period due to vibrations.

The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiment. Detailed descriptions of the preferred embodiment are provided herein; however, it is to be understood that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure, or matter. The embodiments of the invention as described above and the methods disclosed herein will suggest further modification and alterations to those skilled in the art. Such further modifications and alterations may be made without departing from the spirit and scope of the invention.