DESC:Operating Mechanism for Modular Device

Field of the invention

The present invention relates generally to a modular device, and more particularly, to an operating mechanism for the modular device such as a modular changeover switch.

Background of the invention

The modular device such as a modular changeover switch comprises two incoming supplies, a source-I (S-I) and a source-II (S-II) and an outgoing terminal (L). The S-I is for connecting an incoming power supply and the S-II is for connecting a generator set. The outgoing terminal (L) is a common terminal for the sources (S-I and S-II) for connecting a load.

The modular changeover switches (herein after ‘the switch’) are generally used in distribution and building segments for isolation and transferring of the load from the source-I to the source-II with some delay. The switch has three distinct positions that include OFF, ON-I and ON-II. In OFF-state, current does not pass from the source to the load. Whereas in ON-I and ON-II positions, the current flows from the source to the load.

For example, power supply comes to the source-I from utility and to the source-II from the generator set. In general, the switch is always connected to the utility via the source-I. If there are any major fault/variations in the supply, the load is manually transferred (changeover) from the source-I (utility) to the source-II (the generator set). Transferring the load manually is called as a manual changeover switch and the changeover happening under load (supply) is called as an on-load changeover switch. After some time if utility power supply resumes, the load is required to be transferred from the source-II to the source-I. This entire process is carried out on three distinct positions that include OFF-state, source-I (ON-I state) and source-II (ON-II state). The prior switches achieve these stable positions (OFF, ON-I and ON-II) mainly by a knob or a complex mechanism that occupies more space within the switch.

Accordingly, there exists a need to provide an operating mechanism for a modular device that overcomes the above mentioned drawbacks.

Objects of the invention

An object of the present invention is to provide a compact mechanism for modular device for achieving three stable positions that are OFF, ON-I and ON-II.

Another object of the present invention is to reduce number of components for achieving the three stable positions that are OFF, ON-I and ON-II.

Summary of the invention

Accordingly, the present invention provides an operating mechanism for a modular device. The modular device includes a left housing, a right housing, a first terminal assembly, a second terminal assembly, a third terminal assembly, a left source separator, a right source separator and a pair of din clips.

The operating mechanism is adapted for achieving any of OFF, ON-I and ON-II positions of the modular device. The operating mechanism comprises a knob, a bridge assembly and a bridge pin. The knob is positioned on any of the housings and being capable of operating to and from the OFF, ON-I and ON-II positions. The knob includes a cam profile.

The bridge assembly includes a bridge, at least two stopper members, a contact system and a second spring. The bridge is positioned below the knob for being guided by the cam profile in any of the OFF, ON-I and ON-II positions. The at least two stopper members are positioned below the bridge. The at least two stopper members include a first spring loaded therebetween to lock the bridge in any one of the OFF, ON-I and ON-II positions.

The contact system is configured in communication with the bridge. The contact system includes at least two moving contacts and a pair of buttons for each moving contact of the at least two moving contacts. The second spring is configured between the at least two moving contacts. The bridge pin connects the knob to the bridge assembly.

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 a single pole modular device, in accordance with the present invention;

Figures 2a - 2b show exploded views of the single pole modular device of figure 1;

Figure 3a shows an inclined view of left and right housings of the single pole modular device of figure 1;

Figure 3b is a view of the left/right housing showing three stable positions of the single pole modular device of figure 1;

Figures 4a- 4c show a first terminal assembly, a second terminal assembly and a third terminal assembly of the single pole modular device of figure 1;

Figure 5 shows a din clip of the single pole modular device of figure 1;

Figure 6a shows a knob of an operating mechanism of the single pole modular device of figure 1;

Figure 6b shows a bridge assembly of the operating mechanism of the single pole modular device of figure 1;

Figure 6c shows a contact system of the bridge assembly of figure 6b;

Figures 6d and 6e show a stopper of the bridge assembly of figure 6b;

Figure 7 shows an assembled view of the housing of the single pole modular device of figure 1;

Figure 8a shows an assembled view of the of the single pole modular device of figure 1;

Figure 8b shows a cross-sectional (section B-B) view of the single pole modular device of figure 8a;

Figures 9a - 9b show the single pole modular device of figure 8b in OFF- condition;

Figures 10a - 10b show the single pole modular device of figure 8b in ON-I-condition; and

Figure 11a - 11b show the single pole modular device of figure 8b in ON-II-condition.

Detailed description of the invention

The foregoing objects of the present 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 an operating mechanism for a modular device such as a modular changeover switch. The operating mechanism of the present invention is compact and uses reduced number of components (only two components a housing and a stopper) for achieving three distinguished stable positions that are OFF, ON-I and ON-II of the modular changeover switch.

The present invention is illustrated with reference to the accompanying drawings, wherein numbers indicated in the bracket represent the components of the invention throughout the description.

Referring now to figures 1 to 11b, a modular device (100) in accordance with the present invention is shown. The modular device (100) is adapted to achieve OFF, ON-I and ON-II positions. Specifically, the modular device (100) is a modular changeover switch, particularly a single pole modular changeover switch having dimensions of width=17.5mm (1-Mod), height=100.6mm and depth=75.1mm. However, it is understood that any other modular devices such as a miniature circuit breaker (MCB), an isolator, an earth leakage miniature circuit breaker (EL-MCB) and an automatic changeover with a current limiter (ACCL) and the like having two or more number of poles and varying dimensions can be used in other alternative embodiments.

The modular device (100) (refer figure 2a) comprises a left housing/ left cassette (5), a right housing/ right cassette (10), a first terminal assembly (20), a second terminal assembly (30), a third terminal assembly (40), a left source separator (50), a right source separator (52), a pair of din-clips (54) and an operating mechanism (not numbered).

The first terminal assembly (20) is housed in any one of the left housing (5) and the right housing (10). The first terminal assembly (20) (figure 4a) includes a first terminal (12), a first button (14), a first box clamp (16) and a first termination screw (18). This is used as a source-I incoming terminal. The second terminal assembly (30) is positioned in the same housing (5/10) in which the first terminal assembly (20) is housed.

The second terminal assembly (30) (figure 4b) includes a second terminal (22), a second button (24), a second box clamp (26) and a second termination screw (28). This is used as a source-II incoming terminal. The housings (5, 10) include supporting walls (indicated by ‘P’ in figure 3a) for the box clamps (16, 26). The first terminal assembly (20) and the second terminal assembly (30) are separated from each other by interface/ in-built inter-phase barriers (indicated as ‘Q’ in figure 3a) such as the left source separator (50) and the right source separator (52). The left source separator (50) is configured in the left housing (5) and the right source separator (52) is configured in the right housing (10).

The third terminal assembly (40) is positioned on top of the left source separator (50). The third terminal assembly (40) (figure 4c) includes a terminal (L) common outgoing terminal for the first terminal (12) and the second terminal (22), a pair of buttons (34), a box clamp (36) and a termination screw (38). The pair of din-clips (54) (figure 5) is a din rail locker that holds the assembled housings (5, 10) in a distribution board (DB)/ panel (not shown) with a din-rail (not shown).

The operating mechanism is guided in the housings (5, 10) and locked at respective OFF, ON-I and ON-II positions. The operating mechanism comprises a knob (60), a bridge assembly (70) and a bridge pin (80). The knob (60) is positioned on a supporting wall (indicated by ‘R’ in figure 3a) of any of the housings (5/10) so as to cover the bridge assembly (70). The knob (60) (figure 6a) includes a cam profile/ cam follower arrangement/ slot (58) (herein after ‘the cam profile (58)’). As the knob (60) operates to any of the three positions (OFF, ON-I, ON-II positions), the cam profile (58) guides the bridge assembly (70) in the housing (5/10) to that same position. The bridge pin (80) connects the knob (60) to the bridge assembly (70). In an embodiment, the knob (60) is manually operated to the three positions.

The bridge assembly (70) is positioned in a centre portion of the housing (5/10). The bridge assembly (70) includes a bridge (62), at least two stopper members (64), a contact system (68) and a second/ contact spring (69) as shown in figures 6b-6e. The bridge (62) is configured below the knob (60). The cam profile (58) of the knob (60) guides the bridge (62) to the OFF, ON-I and II positions. The at least two stopper members (64) are positioned below the bridge (62) in any one of the housings (5 or 10).

The at least two stopper members (64), the driving part of the operating mechanism are loaded with a first/ mechanism spring (63) therebetween. In an embodiment, the at least two stopper members (64) are of a triangular shape having defined dimensions and a specific angle of 86 degrees. Due to the triangular shape, the at least two stopper members (64) travel on the housing (5/10) from three stable positions: OFF-ONI-OFF-ONII-OFF (indicated by ‘S’ in figure 3a) till a specific distance and stop at an intended position (OFF/ON-I/ON-II). The at least two stopper members (64) stops to lock the bridge (62) therebetween in any one of the ON-I, ON-II and OFF positions. The bridge (62) remains locked unless an external manual force is applied to move the at least two stopper members (64).

The contact system (68) is configured in communication with the bridge (62). The contact system (68) includes at least two moving contacts (65) (herein after ‘the moving contacts (65)’) and a pair of buttons (66) configured on each moving contact of the at least two moving contacts (65). As the bridge (62) moves and gets locked in a particular position, the moving contacts (65) provide pressure at contact joints of the first terminal (12) and the second terminal (22). The contact pressure is provided to maintain low resistance of the current path that results in low temperature. The contact pressure, if insufficient, results in higher temperature. The second spring (69) is configured between the moving contacts (65) to maintain the pressure at the contact joints.

A single pole assembly of the modular device (100) is shown in figure 7 which is formed by placing all above mentioned components in any one of the housing (5/10) and then covering with the other housing (5/10). The left housing (5) and the right housing (10) are connected to each other by means of rivets (not shown). The rivets are guided inside the housings (5, 10) through a stacking male-female part (indicated by ‘T’ in figure 3a).

The single pole assembly of the modular device (100) is achieved by first placing the first terminal assembly (20) in any one of the housing (5/10), followed by the third terminal assembly (40). After this, the source separators (50, 52) are placed separately. The second terminal assembly (30) is placed on top of the left source separator (50) followed by placing one stopper member from the at least two stopper members (64) in any of the housing (5/10). Then, the bridge (62) is placed on top of the stopper member, followed by the first spring (63) and another stopper from the at least two stopper members (64). Next, the knob (60) is placed in a way to cover the bridge (62) and the housing (5/10), followed by the bridge pin (80). After this, the other housing (5/10) is placed on the top. The housings (5, 10) are made with features like the knob supporting wall (R), the three stable positions (S), the inter-phase barriers (Q), the box clamp supporting wall (P) and the stacking male-female part (T) that eliminate the need of poka-yoke and make the assembly procedure easy.

Referring now to figures 9a-11b, an operation of the operating mechanism to cause the modular device (100) to achieve the three positions (OFF, ON-I, ON-II) in accordance with the present invention is illustrated. The middle position in the housing (5/10) indicates the OFF-position and the extreme positions indicate the ON-I and ON-II positions. Initially, when a switch (not shown) of the modular device (100) is in the OFF position, the knob (60) and the bridge assembly (70) are held in the middle position of the housing (5/10) as shown in figures 9a – 9b. Specifically, the angular dimension of the housing (5/10) and the at least two stopper members (64) in the OFF position is 90 degrees. In the OFF position, the at least two moving contacts (65) of the terminal-1 (12) and the terminal-2 (22) are isolated by a same distance by the inbuilt inter-phase barriers (Q). In an embodiment, the at least two moving contacts (65) of the terminal-1 (12) and the terminal-2 (22) are isolated by the distance of 3+3 = 6mm each side.

For the switch to occupy the ON-I and the ON-II positions, the knob (60) is operated from the OFF position to the ON-I and the ON-II positions such that the cam profile (58) guides the bridge (62) of the bridge assembly (70) to move from the OFF position to the ON-I and the ON-II positions. The bridge (62) is locked in the ON-I (figures 10a - 10b) and the ON-II positions (figures 11a -11b) by the at least two stopper members (64). The bridge (62) travels a total of 4mm distance from the OFF position to the ON-I/ON-II position. The bridge (62) travels first 1.5 mm distance with a manual force, followed by 2.5 mm travel independently. Since the operation happens independently after 1.5 mm hence the operation is a quick make mechanism.

In the ON-I position, the current flow through the terminal-1 (12) and the terminal-2 (22) is isolated by a distance of 8mm (4+4 =8mm, 1mm is over travel) and the terminal-2 (22) is speared by the inbuilt inter-phase barriers (Q). In the ON-II position, the current flow through the terminal-2 (22) and the terminal-1 (12) is isolated by 8mm distance (4+4 =8mm, 1mm is over travel) and the terminal-1 (12) is speared by the inbuilt inter-phase barriers (Q).

The angular dimension of the housing (5/10) and the at least two stopper members (64) in the ON-I and the ON-II positions is 45+62.4 = 107.4 degrees and 86 degrees, respectively. The profile angle on each side is different (one side 45 degrees and other side 62.4 degrees) to provide smooth travel from the OFF to the ON positions using lesser amount of operating force. However, it is understood that the angular dimension and the profile angle varies as per the construction of the modular device (100).

Advantages of the present invention:

1. The operating mechanism is very compact and occupies only 2% volume in the modular device (100).
2. The fixed contact and the cam profile (58) rests on the same housing (5/10). This reduces number of components involved between the mechanism position and the fixed contact.
3. The operating mechanism achieves the three stable positions by means of only two components namely the housing (5/10) and the at least two stopper members (64).
4. The cam profile (58) on the housing (5/ 10) is symmetric about X as well as Y axis, facilitating face to face assembly of the same housing to form the single pole assembly of the modular device (100).
5. The operating mechanism is quick make as the bridge (62) travels independently after a distance of 1.5 mm.
6. The first spring (63) is very easy to design and has a common load value at the OFF, the ON-I and the ON-II positions.

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.

,CLAIMS:We claim:

1. An operating mechanism for a modular device (100) having a left housing (5), a right housing (10), a first terminal assembly (20), a second terminal assembly (30), a third terminal assembly (40), a left source separator (50), a right source separator (52) and a pair of din clips (54), the operating mechanism adapted for achieving any of OFF, ON-I and ON-II positions of the modular device (100), the operating mechanism comprising:
• a knob (60) positioned on any of the housings (5/10) and being capable of
operating to and from the OFF, ON-I and ON-II positions, the knob (60) having a cam profile (58);
• a bridge assembly (70) having
a bridge (62) positioned below the knob (60) for being guided by the
cam profile (58) in any of the OFF, ON-I and ON-II positions,
at least two stopper members (64) positioned below the bridge (62),
the at least two stopper members (64) having a first spring (63) loaded therebetween to lock the bridge (62) in any one of the OFF, ON-I and ON-II positions,
a contact system (68) configured in communication with the bridge
(62), the contact system (68) having at least two moving contacts (65) and a pair of buttons (66) for each moving contact of the at least two moving contacts (65), and
a second spring (69) configured between the at least two moving
contacts (65); and
• a bridge pin (80) connecting the knob (60) to the bridge assembly (70).