DESC:TECHNICAL FIELD
[0001] The present disclosure relates generally to switching devices such as circuit breakers/MCCB. More particularly, the present disclosure relates to an arrangement for changing operational mode in direct drive mechanism for switching devices.
BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Existing switching devices/electrical power switchgear get mounted inside a board or panel board for added safety to the operator. At times they may be mounted at an elevated or isolated place such as overhead installations also. These devices are operated either by opening the enclosure/ panel or from outside when it is possible to access them. Alternatively they may have means to operate them remotely when direct access is not possible. As response time for switchover from one desired source to the other in an electrical switching system to is gaining importance, with a view of lesser operational time and also for other advantages such as remote operation and saving in space, direct driven type or stored energy type motor mechanisms for operating the switch gears are increasingly being used.
[0004] Motor operators are such mechanisms used widely for operating the switch gears and provide ease of operation. These motor operators are required to have a feature that permits manual operation of the switch in eventuality of motor failure or other such reasons. A variety of mechanisms with various features are available and provided with operators that permit manual switch operation. Some of them mechanically decouple the operator's drive system from the motor to allow manual operation. Decoupling itself can be done in a number of different ways. A motor operator is typically housed in an enclosure that also contains other power, control, and protection elements, including elements for initiating operation from a remote control station. In order to perform a manual switch operation with that system, a worker is typically required to remove a hand tool (e.g., a hand crank) from the enclosure wherein the act of removal opens a handle interlock switch that in turn opens the motor control circuit to ensure that the motor does not operate during manual operation. A decoupler pin, or other mechanical release element, is available for manual removal so that manual switch operation can be performed using the hand tool to apply force to move the mechanical linkage to the overhead switch.
[0005] United States Pat. No. 3,980,977 (Evans) discloses a system in which insertion of a specified hand tool at a particular location of a clutch mechanism in a motor operator disconnects the motor from the mechanism and allows manual rotation of a drive lever that recharges a wound spring operating mechanism.
[0006] U.S. Pat. No. 5,856,642 (Sanders) discloses an infinite engagement friction clutch coupled switch operator with selectable engagement and disengagement by a user to allow for manual operation.
[0007] U.S. Pat. No. 5,895,987 and U.S. Pat. No. 6,025,657 (Lo et al.) present a switchgear motor operator with a drive including a clutch with a hub and friction discs or an actuator-follower arrangement with opposing actuating and follower surfaces that is subject to an automated control means that responds to a switch operation to reverse the engaging elements to allow manual operation.
[0008] All these known arts, however useful each may be involve complicated mechanisms that are difficult to manufacture, install and operate with resultant cost implications. There is, therefore, a need in the art to provide a motor operator with positive coupling - decoupling characteristics.
[0009] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[0010] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0011] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0012] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0013] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

OBJECTS OF INVENTION
[0014] An object of the present disclosure is to provide a motor operator for Switch Gears in which motor can be decoupled at the time of manual operation.
[0015] Another object of the present disclosure is to provide a simple decoupling-coupling mechanism between motor and output shaft of a motor operator.
[0016] Yet another object of the present disclosure is to provide a decoupling-coupling mechanism that is easy to produce and operate.
[0017] Still another object of the present disclosure is to provide a simple decoupling-coupling mechanism that is based on dog clutch.

SUMMARY
[0018] Aspects of the present disclosure relate to a motor operator for switch gears. In particular it pertains to decoupling-coupling mechanism in the motor operator configured to disengage motor during manual operation of the Switch Gear.
[0019] In an aspect, the present disclosure provides the decoupling-coupling mechanism to be configured between motorized gear train and output member of the motor operator wherein the output member is operatively coupled to rack of the Switch Gear to drive the rack which eventually accommodates the operating knob of the Switch Gear. The output member can also incorporate means for manual operation such as a socket for insertion of a crank handle for manual rotation of the output member. Therefore decoupling the motorized gear train from the output member enables manual operation through the output member without drag of the motorized gear train.
[0020] In an aspect, means to couple-decouple the motorized gear train from the output member can be a sleeve configured with the output member so as to rotate along with the output member but has freedom to axially slide and engage-disengage with a concentrically located member of the motorized gear train.
[0021] In an aspect, the engagement-disengagement of the sliding sleeve and the member of the motorized gear train can take place through a dog clutch arrangement. In an aspect the dog clutch arrangement can incorporate externally configured splines on the sleeve and internally configured splines on the member of the motorized gear train wherein the externally configured splines and the internally configured splines form two set of dog teeth of the dog clutch.
[0022] In an embodiment, the member of the motorized gear train configured with the internal splines can be last gear in the motor gear train and can be concentrically configured with the output member. Thus when the sleeve is in engagement with the gear, rotation of the gear is transferred to the output member through the sleeve and on the other hand when the sleeve is disengaged with the gear the output member is free to rotate without corresponding rotation of the gear and consequently without corresponding rotation of the motor gear train.
[0023] In an embodiment, the splines on the sleeve and the gear can be configured to allow easy engagement even when the splines are not in an aligned position. The means can be matching chamfers on the respective splines on both sides, such that they in combination work as cams to orient the sleeve and the gear in meshing position.
[0024] In an aspect, the mechanism can incorporate means to axially slide the sleeve on the output member in one or other direction to couple or decouple the motor gear train from the output member. The means can be a toggle arm one end of which engages in a circumferential groove in the sleeve and other end is accessible to user to operate and slide the sleeve from coupled to decoupled position or vice-versa.
[0025] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components

BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0027] FIG. 1 illustrates an exemplary representation of a direct drive type motor operator for a switch gear in accordance with an embodiment of the present disclosure.
[0028] FIG. 2 illustrates an exemplary representation of user interface of motor operator in accordance with an embodiment of the present disclosure.
[0029] FIG. 3 illustrates an exemplary representation of internal architecture of motor operator in accordance with an embodiment of the present disclosure.
[0030] FIG. 4 illustrates an exemplary representation of motorized gear train of the motor operator in accordance with an embodiment of the present disclosure.
[0031] FIG. 5 illustrates an exemplary representation of coupling-decoupling mechanism configured between the motorized gear train and output member in accordance with an embodiment of the present disclosure.
[0032] Fig. 6 illustrates an exemplary representation of the coupling-decoupling mechanism consisting of a splined sleeve and an internally splined gear in de-coupled condition in accordance with an embodiment of the present disclosure.
[0033] Fig. 7 illustrates an exemplary front view of the arrangement of FIG. 6 in accordance with an embodiment of the present disclosure.
[0034] Fig. 8 illustrates an exemplary construction of the internal splines in the gear in accordance with an embodiment of the present disclosure.
[0035] Fig. 9 illustrates exemplary meshing profiles of the splines of the sleeve and the splined gear in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0036] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0037] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0038] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[0039] The present disclosure relates generally to switch gear devices such as circuit breakers/MCCB. More particularly, the present disclosure relates to a motor operator typically provided in such switching devices for changing their operational mode. More specifically it pertains to decoupling-coupling mechanism in the motor operator configured to disengage motor during manual operation of the Switch Gear.
[0040] In an aspect, the present disclosure provides a positive decoupling-coupling mechanism to be configured between motorized gear train (or motor gear train) and output member of the motor operator wherein the output member is operatively coupled to rack of the Switch Gear to drive the rack which eventually accommodates the operating knob of the Switch Gear. The output member can also incorporate means for manual operation which can be a socket for insertion of a crank handle for manual rotation of the output member. Decoupling the motorized gear train from the output member can enable manual operation through the output member without drag of the motorized gear train.
[0041] In an aspect, means to couple-decouple the motorized gear train from the output member can be a sleeve configured with the output member so as to rotate along with the output member but has freedom to axially slide and engage-disengage with a concentrically located member of the motorized gear train wherein the member of the motorized gear train can be last gear (referred to simply as gear hereinafter) in the motor gear train. Thus when the sleeve is in engagement with the gear, rotation of the gear is transferred to the output member through the sleeve and on the other hand when the sleeve is disengaged with the gear the output member is free to rotate without corresponding rotation of the gear and consequently without corresponding rotation of the motor gear train.
[0042] The sliding sleeve and the gear of the motorized gear train can incorporate a dog clutch arrangement between them to enable engagement-disengagement of the sliding sleeve and the gear.
[0043] In an aspect the dog clutch arrangement can comprise externally configured splines on the sleeve and internally configured splines on the gear wherein the externally configured splines and the internally configured splines form two set of dog teeth of the dog clutch.
[0044] In an embodiment, the splines on the sleeve and the gear can be configured to allow easy engagement even when the splines are not in an aligned position/meshing condition. The means can be matching chamfers on the respective splines on both sides, such that they in combination work as cams to orient the sleeve and the gear in meshing position.
[0045] In an aspect, the mechanism can incorporate means to axially slide the sleeve on the output member in one or other direction to couple or decouple the motor gear train from the output member. The means can be a toggle arm, one end of which engages in a circumferential groove in the sleeve and other end is accessible to user to operate and slide the sleeve from coupled to decoupled position or vice-versa.
[0046] Referring now to FIG. 1 where a motor operator assembly 100 that incorporates a motor operator 102, a cover 104, a bezel/rim 106, a padlock arrangement 108 and a key-lock 110. Further, FIG. 2 illustrates interface means provided on the motor operator assembly 100 that include an auto-manual toggle switch 112 and an access 114 for inserting a crank handle for manual operation. Furthermore, as shown in FIG. 3 and FIG. 4 the motor operator 102 can include a motorized gearing mechanism 116 comprising a gear train as shown and a motor (not shown) operatively coupled to the gear train to rotate the gear train in one direction or other.
[0047] In an embodiment, the motor operator 102 can comprise an output member configured to be driven by the motorized gear train wherein the output member is operatively coupled to rack of the Switch Gear to drive the rack which eventually accommodates the operating knob of the Switch Gear. In embodiment the disclosure provides means to couple-decouple the motorized gear train with the output member which can enable manual operation through the output member without drag of the motorized gear train by decoupling the two and on the other hand enable operation by the motor when the two are coupled..
[0048] In an aspect, means to couple-decouple the motorized gear train from the output member can be a sleeve configured with the output member so as to rotate along with the output member but has freedom to axially slide and engage-disengage with a concentrically located member of the motorized gear train wherein the member of the motorized gear train can be last gear (referred to simply as gear herein after) in the motor gear train. Thus when the sleeve is in engagement with the gear, rotation of the gear is transferred to the output member through the sleeve and on the other hand when the sleeve is disengaged with the gear the output member is free to rotate without corresponding rotation of the gear and consequently without corresponding rotation of the motor gear train.
[0049] FIG. 5 illustrates an exemplary arrangement of the sleeve 124 and the gear 122 that is the last gear in the gear train and gets drive from the motor through other gears of the gear train. Also shown therein is an output gear 126 which gets the drive from the sleeve 124 through the output shaft (not shown here) on which the sleeve 125 is free to slide. the output gear 126 further transfers the drive to an output idle gear 128, which eventually transfers the power to rack and operating knob of switching device. In an aspect the output gear 126 and the output idle gear 128 can get drive from the motor through the gear train, the sleeve and the output member during a motorized operation or directly from the output member which can be operated manually during manual operation. There can be a toggle arm 130 to slide the sleeve 124 from a position of engagement with the gear 122 to other position of disengagement. One end of the toggle arm 130 can be coupled to a circumferential or cylindrical groove in the sleeve 124 to move the sleeve from the first position to the second position. The other end can be accessible to user as auto-manual toggle switch 112 (fig. 2). Thus a user can use the auto-manual toggle switch 112 to shift the sleeve 124 from one position to the other to affect a corresponding change in status of the motor operator.
[0050] In an aspect, the present disclosure provides the sleeve 124 configured with the output member so as to rotate along with the output member but have freedom to axially slide from a first position to a second position wherein the sleeve 124 and the gear 122 incorporate engagement means such that when the sleeve 124 is in the first position the sleeve 124 and the gear 122 rotate together resulting in transfer of drive from the motorized gear train to the output member and that when the sleeve 124 is in the second position the sleeve 124 and the gear 122 are free to rotate independently enabling manual operation through means for manual operation on the output shaft without drag of the motorized gear train. To change tha status of the motor operator a user can use the auto-manual toggle switch 112 to shift the sleeve 124 from the first position to the second position and vice versa to affect a corresponding change in status of the motor operator.
[0051] According to one embodiment, the proposed disclosure relates to use of a dog clutch arrangement between the sleeve 124 and the gear 122 to enable engagement-disengagement of the sliding sleeve and the gear. The dog clutch arrangement can incorporate matching splines configured on the sleeve and the gear.
[0052] FIG. 6, FIG. 7, FIG. 8 and FIG. 9 illustrate different views of the sleeve 124, the gear 122 and the output member such as output shaft 132 clearly bringing out the configuration of the dog clutch arrangement between the sleeve 124 and the gear 122. In an aspect the dog clutch arrangement can comprise matching splines on the sleeve 124 and the gear 122 wherein the matching splines are externally configured splines on the sleeve 124 and internally configured splines on the gear 122. The externally configured splines and the internally configured splines form two sets of dog teeth of the dog clutch. There can be equally spaced splines on the two, configured to have an easy slide fit so that sleeve 124 when moved from one position to other, slides along with engagement-disengagement of its externally configured splines with the internally configured splines of the gear 122.
[0053] In an embodiment, the external splines on the sleeve 124 and the internal splines on the gear 122 can be configured to allow easy engagement even when the splines are not in an aligned position. The means can be matching double sided chamfers on leading apex of the respective splines, such that they in combination work as cams to orient the sleeve 124 and the gear 122 in meshing position. Upon the lateral movement of the sleeve 124, the corresponding chamfered cam surfaces of the respective splines on the sleeve 124 and the gear 122 can engage and cause to push and radially deflect either the sleeve124 or the gear 122, to bring the splines in alignment so as to allow the two splines to engage with each other.
[0054] As can be appreciated by those skilled in art, the disclosed coupling-decoupling arrangement is cheap and easy to manufacture, install and operate and therefore can be cost effective compared to conventional arrangements for coupling- decoupling the motoring mechanism.
[0055] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art

ADVANTAGES OF INVENTION
[0056] The present disclosure provides a motor operator for Switch Gears in which motor can be decoupled at the time of manual operation.
[0057] The present disclosure provides a simple decoupling-coupling mechanism between motor and output shaft of a motor operator.
[0058] The present disclosure provides a decoupling-coupling mechanism that is easy to produce and operate.
[0059] The present disclosure provides a simple decoupling-coupling mechanism that is based on dog clutch.
,CLAIMS:1. A motor operator for a switching device, the motor operator comprising:
an output member operatively coupled to rack of the switching device to drive the rack and operating knob of the switching device and configured with means for manual operation;
a motorized gear train having a gear configured concentrically with the output member wherein the gear is last gear of the motorized gear train; and
a sleeve configured with the output member so as to rotate along with the output member but has freedom to axially slide from a first position to a second position;
wherein the sleeve and the gear incorporate engagement mean such that when the sleeve is in the first position the sleeve and the gear rotate together resulting in transfer of drive from the motorized gear train to the output member and when the sleeve is in the second position the sleeve and the gear are free to rotate independently enabling manual operation through means for manual operation without drag of the motorized gear train.
2. The motor operator of claim 1, wherein the engagement mean is a dog clutch.
3. The motor operator of claim 2, wherein the dog clutch comprises matching splines configured on the sleeve and the gear.
4. The motor operator of claim 3, wherein the matching splines are external splines on the sleeve and internal splines on the gear.
5. The motor operator of claim 3, wherein the matching splines are configured with matching double sided chamfers on leading apex of the respective splines.
6. The motor operator of claim 1, wherein the motor operator further comprises a toggle arm to shift the sleeve from the first position to the second position and vice versa.
7. The motor operator of claim 6, wherein one end of the toggle arm is configured in a cylindrical groove in the sleeve to move the sleeve from the first position to the second position.
8. The motor operator of claim 7, wherein second end of the toggle arm is configured as auto-manual toggle switch.