Claims:I/ We claim:
1. A drive mechanism (100) for a disconnector assembly in a switchgear, the drive mechanism (100) comprising:
a main access slot (102) formed on a profile plate (106);
an earth access slot (104) formed on the profile plate (106) at a pre-defined distance from the main access slot (102);
a locking arrangement (600), longitudinally extending from the profile plate (106) and operationally coupled to the main access slot (102) and the earth access slot (104), to engage with profile cut out (406) in an operating handle (400) to lock the operating handle (400) to one of: the main access slot (102) and the earth access slot (104), to enable toggling of the disconnector assembly between different operating states.
2. The drive mechanism (100) as claimed in claim 1, wherein the locking arrangement (600) includes:
two pairs of handle locks (108, 110) positioned in lock travel profiles (118, 120) formed on the profile plate (106), such that the two pairs of handle locks (108, 110) pass through the lock travel profiles (118, 120) to be perpendicular to the profile plate (106),
wherein a first pair of handle locks (108) extend longitudinally along the main access slot (102) and the second pair of handle locks (110) extend longitudinally along the earth access slot (104).
3. The drive mechanism (100) as claimed in claim 2, wherein each of the lock travel profiles (118, 120) is a curved cut-out on the profile plate (106) in shape of an inverted ‘U’ having couple of horizontal arms (704) separated by semi-circular vertical transition groove (702), further the main access slot (102) and the earth access slot (104) are formed around the lock travel profiles (118, 120), such that the two pairs of handle locks (108, 110) extend along the main access slot (102) and the earth access slot (104) to a predefined length after passing through the profile plate (106).
4. The drive mechanism (100) as claimed in claim 2, wherein each handle lock has a hook end (602) and a coupling end (604) separated by the length of the handle lock, further wherein the hook end (602) of the handle lock extends away from the profile plate (106) and the coupling end (604) extends towards a base plate (116) formed below the profile plate (106).
5. The drive mechanism (100) as claimed in claim 4, wherein each handle lock (108, 110) has a pivoting protrusion (606) formed between the hook end (602) and the coupling end (604) along the length of the handle lock (108, 110).
6. The drive mechanism (100) as claimed in claim 5, wherein each of the first pair of the handle locks (108) and the second pair of handle locks (110) are coupled to each other at the coupling end (604) via a spring (608), further wherein translation of the pivoting protrusion (606) under the impact of engagement and release of the operating handle (400) amounts to stretching and de-stretching of the spring (608) and variation in distance between each pair of the handle locks (108, 110) and enables movement of the handle locks (108, 110) in the lock travel profiles (118, 120) for toggling the disconnector assembly between different operating states upon rotation of the operating handle (400).
7. The drive mechanism (100) as claimed in claim 1, further comprising a base plate (116) formed below the profile plate (106), wherein the base plate (116) includes:
a main actuator (202) coupled to the main access slot (102) to rotate upon rotation of the main access slot (102) by the operating handle (400);
an earth actuator (204) coupled to the earth access slot (104) to rotate upon rotation of the earth access slot (104) by the operating handle (400);
a main actuator link (208) coupled at one end to the main actuator (202) and to a main shaft coupling (206) at the other end; and
an earth actuator link (210) coupled at one end to the earth actuator (204) and to the main shaft coupling (206) at the other end,
wherein the main actuator link (208) and the earth actuator link (210) move under the impact of rotation of their respective actuators and toggle the main shaft coupling (206) between switching device and earth connection.
8. The drive mechanism (100) as claimed in claim 7, further comprises an access block flap (212) is coupled with the main shaft coupling (206) and configured to be positioned in one of: main operating state, earth operating state and OFF operating state.
9. The drive mechanism (100) as claimed in claim 1, wherein the main access slot (102) and the earth access slot (104) have access receptacles (112, 114) that form a male-female coupling between the operating handle (400) and profile of the access receptacles (112, 114).
10. The drive mechanism (100) as claimed in claim 9, wherein the access receptacles (112, 114) are provided with a plurality of keyway pins (502) and the operating handle (400) is provided with a plurality of keyways, such that during the male-female coupling between the operating handle (400) and the access receptacles (112, 114) the keyway pins (502) are guided into the keyways to engage the operating handle (400) into the access receptacle.
11. The drive mechanism (100) as claimed in claims one of claims 1-10, wherein the drive mechanism (100) is arranged in main operating state when:
the operating handle (400) is pushed into the access receptacle (112) of the main access slot (102);
the pivoting protrusions (606) of the first pair of handle locks (108) move inwards in the direction of the profile plate (106) while rotating towards each other;
the coupling ends (604) of the first pair of handle locks (108) moves from independent ends (706) of the horizontal arms (704) to linking ends (708) of the transition groove (702) in their respective lock travel profile (118) to move away from each other amounting to stretching of the spring (608); and
the hook ends (602) of the first pair of handle locks (108) move towards each other and engage with profile cut out (406) of operating handle (400) for locking of the operating handle (400) to the main access slot (102).
12. The drive mechanism (100) as claimed in claim 11, wherein upon locking of the operating handle (400) to the main access slot (102), the operating handle (400) is rotated in counterclockwise direction to:
rotate the main actuator (202) to move the main actuator link (208) in a pre-defined orientation;
actuate the main shaft coupling (206) as a result of the rotation of the main actuator link (208) to connect the main shaft coupling (206) to the switching device; and
position the access block flap (212) over the earth access slot (104).
13. The drive mechanism (100) as claimed in claims one of claims 1-10, wherein the drive mechanism (100) is arranged in earth operating state when:
the operating handle (400) is pushed into the access receptacle (114) of the earth access slot (104); and
the pivoting protrusions (606) of the second pair of handle locks (110) move inwards in the direction of the profile plate (106) while rotating towards each other;
the coupling ends (604) of the second pair of handle locks (110) moves from independent ends (706) of the horizontal arms (704) to linking ends (708) of the transition groove (702) in their respective lock travel profile (120) to move away from each other amounting to stretching of the spring (608);
the hook ends (602) of the second pair of handle locks (110) move towards each other and engage with profile cut out (406) of operating handle (400) for locking of the operating handle (400) to the earth access slot (104).
14. The drive mechanism (100) as claimed in claim 13, wherein upon locking of the operating handle (400) to the earth access slot (104), the operating handle (400) is rotated in clockwise direction to:
rotate the earth actuator (204) to move the earth actuator link (210) in a pre-defined orientation;
actuate the main shaft coupling (206) as a result of the rotation of the earth actuator link (210) to connect the main shaft coupling (206) to the earth connection; and
position the access block flap (212) over the main access slot (102).
15. The drive mechanism (100) as claimed in claims one of claims 1-10, wherein the drive mechanism (100) is arranged in OFF operating state when:
the operating handle (400) is pushed into the access receptacle (112) of the main access slot (102); and
the pivoting protrusions (606) of the first pair of handle locks (108) move inwards in the direction of the profile plate (106) while rotating towards each other;
the coupling ends (604) of the first pair of handle locks (108) moves from independent ends (706) of the horizontal arms (704) to linking ends (708) of the transition groove (702) in their respective lock travel profile (118) to move away from each other amounting to stretching of the spring (608);
the hook ends (602) of the first pair of handle locks (108) move towards each other and engage with profile cut out (406) of operating handle (400) for locking of the operating handle (400) to the main access slot (102).
16. The drive mechanism (100) as claimed in claim 15, wherein upon locking of the operating handle (400) to the main access slot (102), the operating handle (400) is rotated in clockwise direction to:
rotate the main actuator (202) to move the main actuator link (208) in a pre-defined orientation; and
actuate the main shaft coupling (206) as a result of the rotation of the main actuator link (208) to disconnect the main shaft coupling (206) from the switching device and earth connection; and
position the access block flap (212) between the earth access slot (104) and the main access slot (102).
17. The drive mechanism (100) as claimed in one of claims 11, 13 and 15, wherein the operating handle (400) is configured to be released from the locking arrangement (600) when the drive mechanism (100) is in one of: main operating state, earth operating state and OFF operating state.

18. The drive mechanism (100) as claimed in claim 17, wherein when the drive mechanism (100) is in one of: main operating state, earth operating state and OFF operating state the operating handle (400) is released by:
the operating handle (400) pulls away from the access receptacles (112, 114) to horizontally slide the hook ends (602) of one of: the first pair of handle locks (108) and the second pair of handle locks (110) in the profile cut out (406) of the operating handle (400);
the pivoting protrusions (606) of the one of: the first pair of handle locks (108) and the second pair of handle locks (110) move outwards in direction away from the profile plate (106) and rotate away from each other due to disengagement of the operating handle (400) from the pivoting protrusions (606) and impact of de-stretching of the spring (608); and
the coupling ends (604) of one of: the first pair of handle locks (108) and the second pair of handle locks (110) moves from linking ends (708) of the transition groove (702) towards independent ends (706) of the horizontal arms (704) in their respective lock travel profiles (118, 120) to move towards each other and to move the hook ends (602) away from each other and from the away from each other and away from the profile cut out (406) of the operating handle (400).
19. The drive mechanism (100) as claimed in claim 18, wherein when the coupling ends (604) are in the independent ends (706) of the horizontal arms (704) their horizontal and vertical movement is disabled till an operating handle is engaged.
20. The drive mechanism (100) as claimed in claim 17, wherein when the drive mechanism (100) is transitioning between operating states:
the coupling ends (604) of one of: the first pair of handle locks (108) and the second pair of handle locks (110) are in the transition groove (702) away from horizontal arms (704) of their respective lock travel profiles (118, 120), such that horizontal movement of the coupling ends (604) is restricted and the coupling ends (604) only move in the transition groove (702) so that the coupling ends (604) stay away from each other;
the hook ends (602) of one of: the first pair of handle locks (108) and the second pair of handle locks (110) remain engaged in the profile cut out (406) of the operating handle (400) to lock the operating handle (400) while the drive mechanism (100) is transitioning between operating states.
, Description:A DRIVE MECHANISM FOR A DISCONNECTOR ASSEMBLY
FIELD OF THE INVENTION
[0001] The present invention generally relates to a disconnector assembly. In particular, the present invention relates to a drive mechanism for the disconnector assembly.
BACKGROUND OF THE INVENTION
[0002] A disconnector assembly is a manually operated switching device which is used to provide safe isolation by de-energizing parts of an electrical apparatus, such as a switchgear, an overhead line, transformer and busbar. Further, the disconnector assembly serves as a visual indicator of whether an electrical connection between the electrical apparatus and power supply is open or closed. The visual indication informs network operators if the electrical apparatus is energised or de-energised.
[0003] Generally, the disconnector assembly is provided with a drive mechanism that enables the disconnector to switch between different operating states for the energizing and de-energizing of the electrical apparatus. In conventionally known disconnector assemblies, the drive mechanism has a single access point to toggle the switching device between different operating states by way of engaging an operating handle to the access point by way of one or more latches. However, the conventional access points lack a mechanism for locking the operating handle to the access point during the toggling of the switching device, to obviate a possibility of tampering of operation of the switching device. Thus, conventionally known disconnector assembly lack a fail-safe mechanism to lock the access point which the switching device is operating in a desired operating state.
[0004] Additionally, the generally known drive mechanisms are operated by means of a spring-load arrangement and include multiple components for operation of the drive mechanism. The presence of the multiple components amounts to increase in complexity of the drive mechanism and increase in dimensions of the overall drive mechanism. The increase in size of the drive mechanism amounts to increase in size of the disconnector assembly which makes the switching device and switchgear bulky.
[0005] In the light of the above, there is a need for a compact disconnector assembly with a compact and tamper-proof drive mechanism.
SUMMARY OF THE INVENTION
[0006] In an embodiment to the present invention a drive mechanism for a disconnector assembly is provided. The drive mechanism includes a main access slot formed on a profile plate, an earth access slot formed on the profile plate at a pre-defined distance from the main access slot and a locking arrangement, longitudinally extending from the profile plate and operationally coupled to the main access slot and the earth access slot, to engage with profile cut out in an operating handle to lock the operating handle to one of: the main access slot and the earth access slot, to enable toggling of the disconnector assembly between different operating states.
[0007] Further, the locking arrangement includes two pairs of handle locks positioned in lock travel profiles formed on the profile plate, such that the two pairs of handle locks pass through the lock travel profiles to be perpendicular to the profile plate. A first pair of handle locks extend longitudinally along the main access slot and the second pair of handle locks extend longitudinally along the earth access slot.
[0008] Further, each of the lock travel profiles is a curved cut-out on the profile plate in shape of an inverted ‘U’ having couple of horizontal arms separated by semi-circular vertical transition groove. Further the main access slot and the earth access slot are formed around the lock travel profiles, such that the two pairs of handle locks extend along the main access slot and the earth access slot to a predefined length after passing through the profile plate.
[0009] Further, each handle lock has a hook end and a coupling end separated by the length of the handle lock. The hook end of the handle lock extends away from the profile plate and the coupling end extends towards a base plate formed below the profile plate. Each handle lock has a pivoting protrusion formed between the hook end and the coupling end along the length of the handle lock.
[0010] Further, each of the first pair of the handle locks and the second pair of handle locks are coupled to each other at the coupling end via a spring. Further, translation of the pivoting protrusion under the impact of engagement and release of the operating handle amounts to stretching and de-stretching of the spring and variation in distance between each pair of the handle locks and enables movement of the handle locks in the lock travel profiles for toggling the disconnector assembly between different operating states upon rotation of the operating handle.
[0011] Further, a base plate formed below the profile plate, the base plate includes, a main actuator coupled to the main access slot to rotate upon rotation of the main access slot by the operating handle and an earth actuator coupled to the earth access slot to rotate upon rotation of the earth access slot by the operating handle, a main actuator link coupled at one end to the main actuator and to a main shaft coupling at the other end and an earth actuator link coupled at one end to the earth actuator and to the main shaft coupling at the other end.
[0012] Further, the main actuator link and the earth actuator link move under the impact of rotation of their respective actuators and toggle the main shaft coupling between switching device and earth connection. Furthermore, an access block flap is coupled with the main shaft coupling and configured to be positioned in one of: main operating state, earth operating state and OFF operating state.
[0013] Further, the main access slot and the earth access slot have access receptacles that form a male-female coupling between the operating handle and profile of the access receptacles. The access receptacles are provided with a plurality of keyway pins and the operating handle is provided with a plurality of keyways, such that during the male-female coupling between the operating handle and the access receptacles the keyway pins are guided into the keyways to engage the operating handle into the access receptacle.
[0014] Further, when the drive mechanism is arranged in main operating state when the operating handle is pushed into the access receptacles of the main access slot. The pivoting protrusions of the first pair of handle locks move inwards in the direction of the profile plate and rotate towards each other. The coupling ends of the first pair of handle locks moves from independent ends of the horizontal arms to linking ends of the transition groove in their respective lock travel profiles to move away from each other amounting to stretching of the spring and the hook end of the first pair of handle locks move towards each other and engage with profile cut out of operating handle for locking of the operating handle to the main access slot.
[0015] Further, upon locking of the operating handle to the main operating state, the operating handle is rotated in counter clockwise direction to: rotate the main actuator to move the main actuator link in a pre-defined orientation, actuate the main shaft coupling as a result of the rotation of the main actuator link to connect the main shaft coupling to the switching device and position the access block flap over the earth access slot.
[0016] Further, when the drive mechanism is arranged in earth operating state when the operating handle is pushed into the access receptacles of the earth access slot and the pivoting protrusions of the second pair of handle locks move inwards in the direction of the profile plate and rotate towards each other. Furthermore, the coupling ends of the second pair of handle locks moves from independent ends of the horizontal arms to linking ends of the transition groove in their respective lock travel profiles to move away from each other amounting to stretching of the spring. The hook end of the second pair of handle locks move towards each other and engage with profile cut out of operating handle for locking of the operating handle to the earth access slot.
[0017] Further, upon locking of the operating handle to the earth access slot, the operating handle is rotated in clockwise direction to rotate the earth actuator to move the earth actuator link in a pre-defined orientation actuate the main shaft coupling as a result of the rotation of the earth actuator link to connect the main shaft coupling to the earth connection and position the access block flap over the main access slot.
[0018] Further the drive mechanism is arranged in OFF operating state when the operating handle is pushed into the access receptacles of the main access slot and the pivoting protrusions of the first pair of handle locks move inwards in the direction of the profile plate and rotate towards each other. Furthermore, the coupling ends of the first pair of handle locks moves from independent ends of the horizontal arms to linking ends of the transition groove in their respective lock travel profiles to move away from each other amounting to stretching of the spring. The hook end of the first pair of handle locks move towards each other and engage with profile cut out of operating handle for locking of the operating handle to the main access slot.
[0019] Further, upon locking of the operating handle to the main access slot, the operating handle is rotated in clockwise direction to: rotate the main actuator to move the main actuator link in a pre-defined orientation and actuate the main shaft coupling as a result of the rotation of the main actuator link to disconnect the main shaft coupling from the switching device and earth connection and position the access block flap between the earth access slot and the main access slot.
[0020] Further, the operating handle is configured to be released from the locking arrangement when the drive mechanism is in one of: main operating state, earth operating state and OFF operating state.
[0021] When the drive mechanism is in one of: main operating state, earth operating state and OFF operating state the operating handle is released by: the operating handle pulls away from the access receptacles to horizontally slide the hook ends of one of the first pair of handle locks and the second pair of handle locks in the profile cut out of the operating handle.
[0022] Further, the pivoting protrusions of the one of the first pair of handle locks and the second pair of handle locks move outwards in direction away from the profile plate and rotate away from each other due to disengagement of the operating handle from the pivoting protrusions and impact of de-stretching of the spring and the coupling ends of one of the first pair of handle locks and the second pair of handle locks moves from linking ends of the transition groove towards independent ends of the horizontal arms in their respective lock travel profiles to move towards each other and to move the hook ends away from each other and from the away from each other and away from the profile cut out of the operating handle.
[0023] In an embodiment, when the coupling ends are in the independent ends of the horizontal arms their horizontal and vertical movement is disabled till an operating handle is engaged.
[0024] Further, when the drive mechanism is transitioning between operating states: the coupling ends of one of the first pair of handle locks and the second pair of handle locks are in the transition groove away from horizontal arms of their respective lock travel profiles, such that horizontal movement of the coupling ends is restricted and the coupling ends only move in the transition groove so that the coupling ends stay away from each other.
[0025] Further, the hook ends of one of the first pair of handle locks and the second pair of handle locks remain engaged in the profile cut out of the operating handle to lock the operating handle while the drive mechanism is transitioning between operating states.
[0026] Other aspects, advantages, and salient features of the present invention will become apparent to those skilled in the art from the following detailed description read in conjunction with the drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0027] The following drawings are illustrative of preferred embodiments for enabling the present invention and are not intended to limit the scope of the invention. The drawings are not to scale (unless so stated) and are intended for use in conjunction with the explanations in the following detailed description.
[0028] Figure 1 illustrates an isometric view of the drive mechanism in accordance with an embodiment of the present invention;
[0029] Figure 2 illustrate another isometric view of the drive mechanism in accordance with an embodiment of the present invention;
[0030] Figure 3 illustrates an exploded view of the drive mechanism in accordance with an embodiment of the present invention;
[0031] Figure 4 illustrates an isometric view of a handle arrangement in the drive mechanism in accordance with an embodiment of the present invention;
[0032] Figures 5(a) and 5(b) illustrate top view of an engagement key mechanism in the drive mechanism in accordance with an embodiment of the present invention;
[0033] Figure 6(a) illustrates a sectional view of a locking arrangement in accordance with an embodiment of the present invention;
[0034] Figure 6(b) illustrate a side view of a handle lock in accordance with an embodiment of the present invention;
[0035] Figure 7 illustrates a top view of a lock travel profile in accordance with an embodiment of the present invention;
[0036] Figures 8(a) and 8(b) illustrate a sectional view and an isometric view of the operating handle and the locking arrangement in a non-engaged orientation thereof, respectively in accordance with an embodiment of the present invention;
[0037] Figure 9 illustrates a sectional view of the operating handle during transition state before engagement or disengagement with the locking arrangement in accordance with an embodiment of the present invention;
[0038] Figures 10(a) and 10(b) illustrate a sectional view and an isometric view of the operating handle after engagement with the locking arrangement, respectively in accordance with an embodiment of the present invention;
[0039] Figures 11(a) – 11(d) illustrate different views of the drive mechanism in main operating state in accordance with an embodiment of the present invention;
[0040] Figures 12(a) and 12(b) illustrate different views of the drive mechanism in OFF operating state in accordance with an embodiment of the present invention; and
[0041] Figures 13(a) – 13(d) illustrate different views of the drive mechanism in earth operating state in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF DRAWINGS
[0042] The following disclosure is provided in order to enable a person having ordinary skill in the art to practice the invention. Exemplary embodiments are provided only for illustrative purposes and various modifications will be readily apparent to persons skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Also, the terminology and phraseology used is for the purpose of describing exemplary embodiments and should not be considered limiting. Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed. For the purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention.
[0043] Figure 1 illustrates an isometric view of the drive mechanism 100 in accordance with an embodiment of the present invention. Figure 2 illustrate another isometric view of the drive mechanism 100 in accordance with an embodiment of the present invention. Figure 3 illustrates an exploded view of the drive mechanism 100 in accordance with an embodiment of the present invention. Figure 4 illustrates an isometric view of a handle arrangement in the drive mechanism 100 in accordance with an embodiment of the present invention. For the sake of brevity Figures 1, 2, 3 and 4 are described together.
[0044] A drive mechanism 100 is a manually operated switching device used in a disconnector assembly to provide safe isolation by de-energising parts of an electrical apparatus. In an embodiment of the present invention, the drive mechanism 100 may be employed in a disconnector assembly for a cable fed distribution network such as a Ring Main unit (RMU). The drive mechanism 100 may be understood as a manually operated switching device for connecting and isolating electrical apparatus from a power source associated with the disconnector assembly. Further, to connect and isolate the electrical apparatus, the drive mechanism 100 may have different operating states, such as a main operating state, an earth operating state and an OFF operating state.
[0045] In the main operating state, the drive mechanism 100 may maintain the electrical apparatus in service by energizing the electrical circuit from a power source. In the OFF operating state, the drive mechanism 100 may switch-off the service of the electrical apparatus by de-energising the electrical circuit from the power source. Further, in the earth operating state, the drive mechanism 100 may ground the residual charge from the power source after disconnecting from the electrical circuit of the electrical apparatus. It may understood that when the drive mechanism 100 is in OFF operating state some residual charge remains in the electrical circuit and the earth operating state facilitates in discharging any residual charges which may have accumulated in the electrical circuit. The function, operation and working mechanism of the various operating states of the drive mechanism 100 have been elaborated in subsequent paragraphs of the present description.
[0046] In an embodiment of the present invention, the drive mechanism 100 may include a profile plate 106 and a base plate 116. The profile plate 106 and the base plate 116 may have similar shape and dimensions. Further, the profile plate 106 and the base plate 116 may be coupled symmetrically in parallel to each other via one or more connectors, such that when viewed from outside of the disconnector assembly, the base plate 116 may be formed behind or below the profile plate 106, depending on whether the drive mechanism 100 is placed horizontally or vertically. The one or more connectors may, without any limitation, include connectors known in the art, such as nuts and bolts.
[0047] In an embodiment of the present invention, a main access slot 102, an earth access slot 104 and a locking arrangement may be formed on the profile plate 106. In an exemplary embodiment of the present invention the earth access slot 104 may be formed on the profile plate 106 at a pre-defined distance from the main access slot 102. It may be understood that the pre-defined distance between the main access slot 102 and the earth access slot 104 may be based on the dimension of the drive mechanism 100.
[0048] In an exemplary embodiment of the present invention, an operating handle 400 may be configured to engage with the main access slot 102 and the earth access slot 104. Further, upon rotation of the engaged operating handle 400 the drive mechanism 100 may operate in one of the operating states. The operating handle 400 may include a plurality of keyways 408 and a couple of profile cut outs 406. In an embodiment of the present invention, the profile cut outs 406 may be through grooves in the operating handle 400 with a predefined length along the length of the operating handle 400. The predefined length may correspond to length of the plurality keyways 408. In another embodiment of the present invention, the profile cut outs 406 may be a cavity of depth corresponding to the locking arrangement component engaging in the profile cut out 406.
[0049] Further, the operating handle 400 may also include a handle shaft 404 and a handle crossbar 402. The handle shaft 404 may include the handle crossbar 402 at one end and plurality of keyways 408 at the opposite end, separated by a length of the operating handle 400. In an embodiment of the present invention, each of the main access slot 102 and the earth access slot 104 may include access receptacles 112, 114 that form a male-female coupling between the operating handle 400 and profile of the access receptacles 112, 114, by way of engagement of the handle shaft 404 with the main access slot 102 and the earth access slot 104, depending on the operating state. Further, the access receptacles 112, 114 may be provided with a plurality of keyway pins 502. Further, during the male-female coupling between the operating handle 400 and the access receptacles 112, 114 the keyway pins 502 are guided into the plurality of keyways 408 to engage the operating handle 400 into the access receptacles 112, 114.
[0050] Further, the locking arrangement may longitudinally extend from the profile plate 106. The locking arrangement may be operationally coupled to the main access slot 102 and the earth access slot 104, to engage with the profile cut out 406 in the operating handle 400 to lock the operating handle 400 to the main access slot 102 or the earth access slot 104. Upon locking of the operating handle 400 to the main access slot 102 or the earth access slot 104 the operating handle 400 may enable toggling of the disconnector assembly between different operating states, by way of rotation of the operating handle 400 using the handle crossbar 402.
[0051] In an embodiment of the present invention, the base plate 116 may include an actuation mechanism having a main actuator 202, an earth actuator 204, a main actuator link 208, an earth actuator link 210 and a main shaft coupling 206. The main actuator 202 may be coupled to the main access slot 102 to rotate upon rotation of the main access slot 102 by the operating handle 400 and the earth actuator 204 may be coupled to the earth access 104 slot to rotate upon rotation of the earth access slot 104 by the operating handle 400. Further, the main actuator link 208 may be coupled at one end to the main actuator 202 and to a main shaft coupling 206 at the other end and the earth actuator link 210 may be coupled at one end to the earth actuator 204 and to the main shaft coupling 206 at the other end. The main actuator link 208 and the earth actuator link 210 may move under the impact of rotation of their respective actuators and toggle the main shaft coupling 206 between switching device and earth connection.
[0052] In an exemplary embodiment of the present invention, the drive mechanism 100 may further include an access block flap 212. The access block flap 212 may be coupled with the main shaft coupling 206 and configured to be positioned in main operating state, earth operating state and OFF operating state, by placement over the main access slot 102, the earth access slot 104 and in between the main access slot 102 and the earth access slot 104, respectively. The actuating mechanism may change the external configuration of the drive mechanism 100 for each operating state during rotation of the operating handle 400. The external configuration may be changed by changing the position of an access block flap 212 with respect to the operating states. The access block flap 212 provides a fail-safe mechanism by restricting access to the access slots 102, 104 with respect to the operating states. For example, during the main operating state, the access to the earth access slot 104 may be restricted and during the earth operating state, the access to the main access slot 102 may be restricted providing a fail-safe mechanism. Further, during the OFF operating state, the access block flap 212 may not restrict access to either of the access slots 102, 104, providing access to both the access slots 102, 104.
[0053] Figures 5(a) and 5(b) illustrate top view of an engagement key mechanism in the disconnector assembly in accordance with an embodiment of the present invention. Figure 6(a) illustrates a sectional view of a locking arrangement in accordance with an embodiment of the present invention. Figure 6(b) illustrates a side view of a handle lock in accordance with an embodiment of the present invention. For the sake of brevity Figures 5(a), 5(b), 6(a) and 6(b) are described together. The engagement and disengagement of the operating handle 400 with the access slots 102, 104 are described further.
[0054] The locking arrangement 600 may be provided with two pairs of handle locks 108, 110 for the access slots 102, 104. The two pairs of handle locks 108, 110 may be positioned in lock travel profiles 118 formed on the profile plate 106. The two pairs of handle locks 108, 110 pass through the lock travel profiles 118, 120 to be perpendicular to the profile plate 106. The handle locks 108, 110 are locking mechanism that engage and disengage with the operating handle 400 to hold the handle shaft 404 in position after coupling with the access slots 102, 104. In an embodiment of the present invention, the main access slot 102 is provided with a first pair of handle locks 108 and the earth access slot 104 is provided with a second pair of handle locks 110. The first pair of handle locks 108 extend longitudinally along the main access slot 102 and the second pair of handle locks 110 extend longitudinally along the earth access slot 104.
[0055] Further, each handle lock may have a hook end 602, a coupling end 604 and a pivoting protrusion 606. The hook end 602 may be in shape of an inward facing hook, such that hook end 602 of a pair of the handle locks 108, 110 face each other. Further, each of the coupling ends 604 may include a groove for engaging with an end of a spring 608, such that a spring 608 is held between a pair of handle locks 108, 110. Furthermore, the pivoting protrusion 606 may be understood as curved protrusion resting obliquely on the access slots 102, 104.
[0056] In an embodiment of the present invention, the hook end 602 and the coupling end 604 may be separated by the length of the handle lock. Further, the hook end 602 of the handle lock may extend away from the profile plate 106 and the coupling end 604 may extend towards a base plate 116 formed below the profile plate 106. Further, the pivoting protrusion 606 in each pair of the handle locks 108, 110 may be formed between the hook end 602 and the coupling end 604 along the length of the handle lock.
[0057] Figure 7 illustrates a top view of a lock travel profile 702 in accordance with an embodiment of the present invention. Further, the profile plate 106 may be provided with lock travel profiles 118, 120. The lock travel profiles 118, 120 may be understood as a curved cut-out on the profile plate 106. In an exemplary embodiment of the present invention, each lock travel profile may be in shape of an inverted “U” having a couple of arms 704 separated by a semi-circular transition groove 702. In an embodiment of the present invention, the arms 704 may be bent inwards at the linking end 708 of the arms 704 with the transition groove 702, such that the independent ends 706 of the arms 704 partially point towards each other. The lock travel profiles 118 may enable the movement of the handle locks 108, 110 after the handle locks 108, 110 lock the operating handle 400 to the access slots 102, 104.
[0058] Further, the handle locks 108, 110 may pass through their respective the lock travel profiles 118, 120. It may be understood that the main access slot 102 and the earth access slot 104 may be formed around the lock travel profiles 118, 120 respectively. The two pairs of handle locks 108, 110 extend along the main access slot 102 and the earth access slot 104 to a predefined length after passing through the profile plate 106. In an exemplary embodiment of the present invention, the predefined length of the extension of the handle locks 108, 110 may be based on the length at which profile cut-outs 406 in the operating handle 400 may be formed as the hook ends 602 of the handle locks 108, 110 engage with the profile cut-outs 406 to lock the operating handle 400 to the access slots 102, 104. Accordingly, the main access slot 102 may be provided with a first pair of lock travel profile 118 and the first pair of handle locks 108. Similarly, the earth access slot 104 may be provided with a second pair of lock travel profile 120 and a second pair of handle locks 110. The lock travel profiles 118, 120 are provided opposite to each other around the access slots 102, 104 in the profile plate 106.
[0059] In an embodiment of the present invention, each of the first pair of the handle locks 108 and the second pair of handle locks 110 may be coupled to each other at the coupling end 604 via the spring 608. The spring 608 provides tension between the pairs of the handle locks 108, 110 and pulls the pair of handle locks 108, 110 away from each other. Further, translation of the pivoting protrusion 606 under the impact of engagement and release of the operating handle 400 may amount to stretching and de-stretching of the spring 608 and variation in distance between handle locks of each pair of the handle locks 108, 110. Additionally, movement of the handle locks 108, 110 in the lock travel profiles 118, 120 for toggling the disconnector assembly between different operating states may be enabled only upon engagement of the operating handle 400 with the locking arrangement 600. When the operating handle 400 is not engaged in the locking arrangement 600, the spring 608 de-stretches and pulls the coupling ends 604 of the handle locks 108, 110 into the horizontal arms 704 of the respective travel access profiles 118, 120. Further, until the engagement of the operating handle 400, the handle locks 108, 110 are held in the horizontal arms 704 by the spring 608, disabling the movement of the handle locks 108, 110 in the respective lock travel profiles 118, 120. Thus, the disengagement or release of the operating handle 400 with the locking arrangement 600 disables the movement of the handle locks 108, 110 in the respective lock travel profiles 118, 120 for toggling the disconnector assembly between different operating states. The orientation of the components of the locking arrangement 600 in different operating states has been elaborated in subsequent paragraphs of the present description.
[0060] Figures 8(a) and 8(b) illustrate a sectional view and an isometric view of the operating handle 400 and the locking arrangement 600 in a non-engaged orientation thereof, respectively in accordance with an embodiment of the present invention. Further, Figure 9 illustrates a sectional view of the operating handle 400 during transition state before engagement or disengagement with the locking arrangement 600 in accordance with an embodiment of the present invention. Furthermore, Figures 10(a) and 10(b) illustrate a sectional view and an isometric view of the operating handle 400 and the locking arrangement 600 in engaged orientation, respectively, in accordance with an embodiment of the present invention. For the sake of brevity Figures 8(a), 8(b), 9, 10(a) and 10(b) have been described together.
[0061] The non-engaged orientation of the drive mechanism 100 may be understood as a state in which the operating handle 400 and the locking arrangement 600 is completely separated from each other physically, as illustrated in Figures 8(a) and 8(b). In the non-engaged orientation, the locking arrangement 600 may be in its default orientation. In the default orientation of the locking arrangement 600, only force acting on the handle locks 108, 110 may be tension caused by the spring 608 attached between the coupling ends 604 of the handle locks 108, 110. The tension in the spring 608 may pull the coupling ends 604 towards each other, such that the handle locks 108, 110 rest in independent end 706 of the arm 704 of the lock travel profile 118 in the profile plate 106. Further, the pivoting protrusions 606 may be oriented at a pre-defined angle with respect to the access slots 102, 104 and the hook ends 602 of the handle locks 108, 110 may be pulled away from each other.
[0062] To operate the drive mechanism 100, the operating handle 400 may be inserted into the access slots 102, 104 via the access receptacles 112, 114, to achieve the engaged orientation of the drive mechanism 100. During the male-female coupling between the operating handle 400 and the access slots 102, 104, the keyway pins 502 may be guided into the keyway 408 to engage the operating handle 400 into the access slots 102, 104.
[0063] Further during the insertion into the access slots 102, 104, the handle shaft 404 may be pushed inside the access receptacles 112, 114 making contact with the pivoting protrusions 606 in the handle locks 108, 110. Upon pushing further, the handle shaft 404 may push the pivoting protrusions 606 to translate them towards the profile plate and rotating them towards each other, such that they are oriented perpendicular to the access slots 102, 104. The translation provided due to the push of the operating handle 400 may be understood as a force greater than the tension of the spring 608 and thus, the spring 608 stretches. Thus, the coupling ends 604 of the handle locks 108, 110 move away from each other, and the handle lock moves from the independent end 706 of the arm 704 in lock travel profiles 118, 120 to the linking end 708 of the arm 704 with the transition groove 702. Further, the hook end 602 of the handle locks 108, 110 may pivot towards each other and engage with the profile cut out 406 in the operating handle 400.
[0064] Once locked to the access slot via the handle locks 108, 110, the operating handle 400 may be rotated in clockwise and counterclockwise direction. The operating handle 400 may be rotated by the handle crossbar 402 and the rotational force is transmitted via the plurality of keyway pins 502 in the access receptacles 118, 120. In an embodiment of the present invention, the operating handle 400 may be configured to be released from the locking arrangement 600 when the drive mechanism 100 is in main operating state, earth operating state or OFF operating state only. Further, when the drive mechanism 100 is in main operating state, earth operating state or OFF operating state the operating handle 400 may be released pulling away of the operating handle 400 from the access receptacles 118, 120 to horizontally slide the hook ends 602 of one of the handle locks 108, 110 in the profile cut out 406 of the operating handle 400. As a result of sliding off of the hook ends 602, the contact between the surface of the operating handle 400 and the pivoting protrusions 606 may be removed and the pivoting protrusions 606 may move outwards in direction away from the profile plate 106 and rotate away from each other due to disengagement of the operating handle 400 from the pivoting protrusions 606. Upon removal of the operating handle 400, the only force acting on the handle locks 108, 110 may be tension of the spring 608, thus the spring 608 de-stretches. Further, the coupling ends 604 of handle locks 108, 110 may move from linking ends 708 of the transition groove 702 towards independent ends 706 of the horizontal arms 704 in their respective lock travel profiles 118, 120 to move towards each other and to move the hook ends 602 away from each other and away from the profile cut out 406 of the operating handle 400.
[0065] In an embodiment of the present invention, when the drive mechanism 100 may be transitioning between operating states, the coupling ends 604 of one of the first pair of handle locks 108 and the second pair of handle locks 110 may be in the transition groove 702 away from horizontal arms 704 of their respective lock travel profiles 118, 120. Thus, horizontal movement of the coupling ends 604 is restricted and the coupling ends 604 may only move in the transition groove 702 so that the coupling ends 604 stay away from each other. Further, the hook ends 602 of the handle locks 108, 110 may remain engaged in the profile cut out 406 of the operating handle 400 to lock the operating handle 400 while the drive mechanism 100 is transitioning between operating states.
[0066] Figures 11(a) –11(d) illustrate different views of the drive mechanism 100 in main operating state in accordance with an embodiment of the present invention. The drive mechanism 100 may be arranged in main operating state when the operating handle 400 may be pushed into the access receptacle 112 of the main access slot 102 and the pivoting protrusions 606 of the first pair of handle locks 108 may move inwards in the direction of the profile plate 106 and rotate towards each other. Further, the coupling ends 604 of the first pair of handle locks 108 may move from independent ends 706 of the horizontal arms 704 to linking ends 708 of the transition groove 702 in their respective lock travel profile 118 to move away from each other amounting to stretching of the spring 608. The hook end 602 of the first pair of handle locks 108 may move towards each other and engage with profile cut out 406 of operating handle 400 for locking of the operating handle 400 to the main access slot 102.
[0067] Further, upon locking of the operating handle 400 to the main access slot 102, the operating handle 400 may be rotated in counter clockwise direction to rotate the main actuator 202 to move the main actuator link 208 in a pre-defined orientation and actuate the main shaft coupling 206 as a result of the rotation of the main actuator link 208 to connect the main shaft coupling 206 to the switching device. Further, the access block flap 212 may be poisoned over the earth access slot 104.
[0068] Figures 12(a) and 12(b) illustrate different views of the drive mechanism 100 in OFF operating state in accordance with an embodiment of the present invention. The drive mechanism 100 may be arranged in OFF operating state when the operating handle 400 may be pushed into the access receptacle 112 of the main access slot 102 and the pivoting protrusion 606 of the first pair of handle locks 108 may move inwards in the direction of the profile plate 106 and rotate towards each other. Further, the coupling ends 604 of the first pair of handle locks 108 may move from independent ends 706 of the horizontal arms 704 to linking ends 708 of the transition groove 702 in their respective lock travel profile 118 to move away from each other amounting to stretching of the spring 608. The hook end 602 of the first pair of handle locks 108 may move towards each other and engage with profile cut out 406 of operating handle 400 for locking of the operating handle 400 to the main access slot 102.
[0069] Upon locking of the operating handle 400 to the main access slot 102, the operating handle 400 may be rotated in clockwise direction to rotate the main actuator 202 to move the main actuator link 208 in a pre-defined orientation and actuate the main shaft coupling 206 as a result of the rotation of the main actuator link 208 to disconnect the main shaft coupling 206 from the switching device and earth connection. Further, the access block flap 212 may be positioned between the earth access slot 104 and the main access slot 102.
[0070] Figures 13(a) – 13(d) illustrate different views of the disconnector assembly in earth operating state in accordance with an embodiment of the present invention. The drive mechanism 100 may be arranged in earth operating state when the operating handle 400 may be pushed into the access receptacle 114 of the earth access slot 104 and the pivoting protrusions 606 of the second pair of handle locks 110 may move inwards in the direction of the profile plate 106 and rotate towards each other. Further, the coupling ends 604 of the second pair of handle locks 110 may move from independent ends 706 of the horizontal arms 704 to linking ends 708 of the transition groove 702 in their respective lock travel profile 120 to move away from each other amounting to stretching of the spring 608. The hook end 602 of the second pair of handle locks 110 may move towards each other and engage with profile cut out 406 of operating handle 400 for locking of the operating handle 400 to the earth access slot 104.
[0071] Upon locking of the operating handle 400 to the earth access slot 104, the operating handle 400 may be rotated in clockwise direction to rotate the earth actuator 204 to move the earth actuator link 210 in a pre-defined orientation and actuate the main shaft coupling 206 as a result of the rotation of the earth actuator link 210 to connect the main shaft coupling 206 to the earth connection. Further, the access block flap 212 may be positioned over the main access slot 102.
[0072] Accordingly, the present invention provides the following effects or advantages. The present invention discloses a mechanical drive mechanism 100 for the switching device having an isolation capability and toggle between different operating states. The drive mechanism 100 is provided with separate access points for main and earth operating states. Further, the drive mechanism 100 is provided with an actuating mechanism that provides a fail-safe mechanism for the operator. The operators can confirm the operating state of the circuit/equipment as the drive mechanism 100 provides a visual indication during the inspections, maintenance, and repairs, without unnecessary risk. Further, as there are two separate access slots 102, 104 provided, the risk of mal operation especially during working of the equipment is greatly reduced.
[0073] Further, the switching device architecture, space and assembly conditions are improved with the engagement mechanism. In general, if an assembly possesses more components, controlling the operating limits of many components in operation conditions will be difficult. The present invention solves this problem by providing a unique constructional aspect in the assembly members of the drive mechanism 100 to keep the simplicity and symmetricity of the arrangements of the mechanical and contact members.
[0074] While the exemplary embodiments of the present invention are described and illustrated herein, it will be appreciated that they are merely illustrative. It will be understood by those skilled in the art that various modifications in form and detail may be made therein without departing from or offending the spirit and scope of the invention as defined by the appended claims.