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Title:
A MICROMOTOR OF A TIMEPIECE
Document Type and Number:
WIPO Patent Application WO/2019/043643
Kind Code:
A1
Abstract:
The present disclosure discloses a micromotor (100) for a timepiece. The micromotor (100) comprising: a base plate (106) configured to support components of the timepiece. A stator assembly (103) comprising a stator (103a) mounted on a base plate (106) of the timepiece, wherein, a cavity (103b) is defined in the stator (103a). The stator assembly (103) includes a first coil (101a) mounted on one side of the stator (103a), and a second coil (101b) mounted on other side of the stator (103a), wherein, profile of the first coil (101a) and the second coil (101b) are similar. A rotor (104) is disposed in the cavity (103b), and configured to generate bi- directional movement based on a flux generated by the first coil (101a) and the second coil (101b), and a wheel assembly (105) coupled to the rotor (104), is adapted to drive at least one movement of the timepiece.

Inventors:
RANGANATHAN RAJAGOPALAN (IN)
KRISHNAMURTHY SEENIVASAN (IN)
SUDA KRISHNAPPA (IN)
KANTAMANI SIVANANDHA JAYARAM (IN)
SINGARAVELU RAJAMANICKAM (IN)
Application Number:
PCT/IB2018/056678
Publication Date:
March 07, 2019
Filing Date:
August 31, 2018
Export Citation:
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Assignee:
TITAN COMPANY LTD (IN)
International Classes:
G04C13/00; G04C13/11; H02K37/00; H02K37/10; H02K37/12
Foreign References:
US5579290A1996-11-26
US6973010B12005-12-06
Attorney, Agent or Firm:
SIDDARA THIPPAPPA, Madhusudan et al. (Intellectual Property Attorneys4121/B, 6th Cross, 19A Main, HAL II Stage, Bangalore Karnataka 8, IN)
Download PDF:
Claims:
We claim: 1. A stator assembly (103) of a micromotor (100) of a timepiece, the stator assembly (103) comprising:

a stator (103 a) mounted on a base plate (106) of the timepiece, wherein, a cavity (103b) is defined in the stator (103) for accommodating a rotor (104);

a first coil (101a) mounted on one side of the stator (103a); and

a second coil (101b) mounted on other side of the stator (103a), wherein, profile of the first coil (101a) and the second coil (101b) are similar.

2. The stator assembly (103) as claimed in claim 1 comprises a coil end circuit (102a and 102b) integrated to a second end (108b and 108d) of each of the first coil (101a) and the second coil (101b).

3. The stator assembly (103) as claimed in claim 1, wherein the first coil (101a) and the second coil (101b) are arranged parallel to each other. 4. The stator assembly (103) as claimed in claim 1, wherein the stator (103a) comprises at least one stud (110a and 110b) on either sides to mount second ends (108b and 108d) of each of the first coil (101a) and the second coil (101b).

5. The stator assembly (103) as claimed in claim 1, wherein a first end (108a and 108c) of each of the first coil (101a) and the second coil (101b) is mounted on the stator (103a) through a fastener (109).

6. The stator assembly (103) as claimed in claim 1, wherein each of the first coil (101a) and the second coil (101b) includes:

a metal core (107); and

a winding wound on the metal core (107).

7. A micromotor (100) for a timepiece, the micromotor (100) comprising:

a base plate (106) configured to support components of the timepiece;

a stator assembly (103) comprising: a stator (103 a) mounted on a base plate (106) of the timepiece, wherein, a cavity (103b) is defined in the stator (103a);

a first coil (101a) mounted on one side of the stator (103a); and

a second coil (101b) mounted on other side of the stator (103a),

wherein, profile of the first coil (101a) and the second coil (101b) are similar; a rotor (104) disposed in the cavity (103b), and configured to generate bidirectional movement based on a flux generated by the first coil (101a) and the second coil (101b); and

a wheel assembly (105) coupled to the rotor (104), is adapted to drive at least one movement of the timepiece.

8. The micromotor (100) as claimed in claim 7 comprises a coil end circuit (102a and 102b) integrated to a second end (108b and 108d) of each of the first coil (101a) and the second coil (101b).

9. The micromotor (100) as claimed in claim 7, wherein the first coil (101a) and the second coil (101b) are arranged parallel to each other.

10. The micromotor (100) as claimed in claim 7, wherein the wheel assembly (105) is a gear train including a plurality of gears (105a, 105b and 105c).

11. The micromotor (100) as claimed in claim 7, wherein the stator (103a) comprises at least one stud (110a and 110b) on either sides of the stator (103a) to mount second ends (108b and 108d) of each of the first coil (101a) and the second coil (101b).

12. The micromotor (100) as claimed in claim 7, wherein each of the first coil (101a) and the second coil (101b) includes:

a metal core (107); and

a winding wound on the metal core (107).

13. A timepiece comprising a micromotor (100) as claimed in claim 7.

Description:
A MICROMOTOR OF A TIMEPIECE

This application is a combination of two Indian provisional patent applications bearing application numbers 201741030865 and 201741030942, filed on 31-08-2017. TECHNICAL FIELD

Present disclosure in general relates to the field of horology. Particularly but not exclusively, the present disclosure relates to an analog timepiece. Further embodiments of the present disclosure disclose a micromotor for the timepiece.

BACKGROUND OF THE DISCLOSURE

Watches or timepiece may be of various types including but not limited to, mechanical windup watches, self-winding or "automatic" mechanical watches, electric or electronic (i.e., battery- powered) analog watches, battery-powered watches with digital time displays (LED (light emitting diode) and constant-display, LCD (liquid crystal display) and analog quartz timing devices.

Conventionally, analog watches are employed with a stepper motor for operation of one or more movements such as for hands of the watch. The stepper motor is an electromechanical device, which converts electrical power into mechanical power. The stepper motor can divide a single rotation into a number of equal steps. Stepper motors consist of a rotor (rotating part) which may be a permanent magnet and a stator (stationary part) which may be an electromagnet. Stepper motors work on the principle of electromagnetism. In conventional stepper motors, a coil wound on the stator, carries current to energize the stator. The stator, being an electromagnet creates a north and south pole. When the stator is energized, the rotor being a permanent magnet, rotates to align itself to the opposite pole of the stator. For instance, the rotor aligns its south pole with the north pole of the stator and its north pole with the south pole of the stator. When the excitation (current flowing through the coil) is reversed, the polarity of the stator would be reversed and the rotor continues to rotate in the same direction to align its poles with corresponding poles of the stator. This way the stators are energized in a sequence to rotate the rotor of the stepper motor.

With advancements in technology, the analog timepieces or watches such as wrist watches are employed with micromotor. In the micromotor with a single coil, change of direction of current does not take place instantaneously. Thus, a lag may be observed when direction of rotation of the rotor is changed. However, in a motor with the twin coils , each coil may be used to rotate the rotor in a predefined direction. FIG.l shows stator assembly of conventional micromotor (1). The conventional stator assembly may include a stator plate which accommodates, a left coil (2 A) and a right coil (2B). In such conventional arrangement, the left coil (2 A) creates a flux in one direction and the rotor will rotate in one direction, for example clockwise direction. Similarly, when the right coil (2B) is connected, it may produce a flux in an opposite direction to that of the flux created by the left coil, and hence the rotor rotates in anticlockwise direction. The twin coil (the left coil and the right coil) are integrated and sub assembled with the Coil End Circuit (CEC) (3), fixed and heat sealed with pillars as a single unit. The unit may then assembled to motor.

Further, in the conventional micromotor (1), the left and right coil profiles may be different. The left coil (2A) is supposed to be placed in the left side and the right coil (2B) is supposed to be placed in the right side. They cannot be used interchangeably. Since the two coils are assembled to a single core, damage caused to any one of the coils, may result in replacing the entire twin coil set. Hence, conventional micromotors may not be economical. As the two coils are wound to the common core, the winding tool operation is complicated and needs skilled operators and very high precision tools to perform the operation. Thus, the manufacturing cost also increases.

The present disclosure is proposed to overcome one or more limitations stated above or any such limitations associated with the prior arts.

SUMMARY OF THE DISCLOSURE

One or more shortcomings of conventional system and method are overcome, and additional advantages are provided through the system as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In one non-limiting embodiment of the disclosure, a stator assembly of a micromotor of a timepiece is disclosed. The stator assembly comprising a stator mounted on a base plate of the timepiece, wherein, a cavity is defined in the stator for accommodating a rotor. There is a first coil mounted on one side of the stator and a second coil mounted on other side of the stator. The profile of the first coil and the second coil are similar.

In an embodiment of the disclosure, the stator assembly comprises a coil end circuit integrated to a second end of each of the first coil and the second coil.

In an embodiment of the disclosure, the first coil and the second coil are arranged parallel to each other.

In an embodiment of the disclosure, the stator comprises at least one stud on either sides to mount second ends of each of the first coil and the second coil.

In an embodiment of the disclosure, a first end of each of the first coil and the second coil is mounted on the stator through a fastener. In an embodiment of the disclosure, each of the first coil and the second coil includes a metal core and a winding wound on the metal core.

In another non-limiting embodiment of the disclosure, a micromotor for a timepiece is disclosed. The micromotor comprises a base plate configured to support components of the timepiece, and a stator assembly. The stator assembly in turn comprises a stator mounted on a base plate of the timepiece, wherein, a cavity is defined in the stator. There is a first coil mounted on one side of the stator and a second coil mounted on other side of the stator. The profile of the first coil and the second coil are similar. The micromotor further comprises a rotor disposed in the cavity and configured to generate bi-directional movement based on a flux generated by the first coil and the second coil. Further there is a wheel assembly coupled to the rotor and is adapted to drive at least one movement of the timepiece.

In an embodiment of the disclosure, the micromotor comprises a coil end circuit integrated to a second end of each of the first coil and the second coil.

In an embodiment of the disclosure, the wheel assembly is a gear train including a plurality of gears.

It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure. The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following description.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES

The above-mentioned aspects, other features and advantages of the disclosure will be better understood and will become more apparent by referring to the exemplary embodiments of the disclosure, as illustrated in the accompanying drawings.

FIG.l illustrates a micromotor with a conventional coil arrangement;

FIG.2 illustrates top view of the micromotor assembly=, in accordance with an embodiment of the present disclosure; and

FIG.3 illustrates perspective view of a coil of the micromotor assembly of FIG.2, in accordance with an embodiment of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the system illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other devices for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the scope of the disclosure. The novel features which are believed to be characteristic of the disclosure, as to its organization, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described below. It should be understood, however that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the disclosure.

The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a mechanism that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such mechanism. In other words, one or more elements in the device or mechanism proceeded by "comprises... a" does not, without more constraints, preclude the existence of other elements or additional elements in the mechanism.

Embodiments of the present disclosure disclose a micromotor with an arrangement of the coil. In the conventionally known micromotors, the coils of a particular profile may be placed or arranged in a particular configuration in the micromotor. In these micromotors, two coils were generally wound a single core. However, in these micromotors if one of the coils failed in function, both the coils along with the core had to be replaced which increased complexity.

In the present disclosure, the coils i.e. a first coil and a second coil may be of same profile. In an embodiment, the same profile of coils may imply similar shape and structure and may be used interchangeably. Further, similar profile may also imply that the coils may require same amount of power required to drive a rotor of the micromotor. Thus, with the provision of coils of similar profile, the coils may be interchangeably used and also in case of any damage to either of the coils, only that coil may be replaced. Henceforth, the present disclosure is explained with the help of one or more figures of exemplary embodiments. However, such exemplary embodiments should not be construed as limitations of the present disclosure.

FIG.2 is an exemplary embodiment of the present disclosure illustrating micromotor (100). The micromotor (100) comprises a base plate (106), a stator assembly (103) and a rotor (104). The stator assembly includes a stator (103a) mounted on the base plate (106). The stator (103a) is defined with a cavity (103b) to accommodate a rotor (104). In an embodiment, the cavity (103b) may be circular in shape, and may be defined with one or more notches in the inner circumference. The stator assembly (103) further comprises at least two coils - which may be referred to herein as a first coil (101a) and a second coil (101b), coil end circuits (CECs) (102a and 102b) corresponding to the first coil (101a) and the second coil (101b). The CECs (102a and 102b) may be mounted on a stud (110a and 110b) provided in the stator assembly (103). In an embodiment, the stud (110a and 110b) may be integrally formed in the base plate (106) and may co-operate with a hole or a provision defined in the corresponding coil end circuits (CECs) (102a and 102b) to hold the coil end circuits (CECs) (102a and 102b) in place.

Each of the first coil (101 A) and the second coil (10 IB) of the at least two coils consist of a metal core (107) on which the windings may be wound. In an embodiment, the windings of the first coil (101a) may be wound on one metal core (107) and the windings of the second coil (101b) may be wound on a separate metal core (107). In an embodiment, the metal core (107) may be an iron core and the windings may be made of copper material. The coils - first coil (101a) and second coil (101b) are designed such that, each of these coils have similar profile. Therefore, the first coil (101a) and the second coil (101b) may be interchangeably used in each other's position. This allows easier assembling of the coils (101a and 101b) in the micromotor (100). Each of the first coil (101a) and the second coil (101b) may consist of two ends where a second end (108b and 108d) of each of these coils (101a and 101b) may be connected to the studs (110a and 110b). In an embodiment, the first coil (101a) may be connected to a first stud (110a) and the second coil (101b) may be connected to a second stud (110b). Further, a first end (108a and 108c) of each of the at least two coils (101a and 101b) may be fastened to the stator (103a) of the stator assembly (103) by means of fasteners (109). In an embodiment, the metal core (107) of the first coil (101a) and the second coil (101b) may have provisions and the stator (103 a) consists of provisions corresponding to the provisions of the metal core (107) for fastening. Fastening facilitates easy attachment and detachment of the coils (101a and 101b) as per the requirement. For instance, if one of the coils (101a or 101b) is damaged, the damaged coil may be detached from the micromotor (100) and may be replaced with a new coil unlike the conventional micromotors, where the entire coil assembly has to be replaced.

In an embodiment, the micromotor (100) may be used to control the movement of hands of the watch. The electric pulses to the first coil (101A) and the second coil (101B) are provided by the CEC which is connected to the Complementary Metal-Oxide-Semiconductor (CMOS) Integrated Circuit (IC) [not shown] . Each of the CEC receives voltage signals from the CMOS IC and provides electric pulses to the respective coil. The micromotor (100) may be configured to produce bi-directional rotation of hands in the watch. The electric pulses are fed to the first coil (101A) and the second coil (101B) by respective CECs. Accordingly, the first coil (101 A) may create flux in one direction and energizes the stator assembly (103). A magnetic field between the stator assembly (103) and the rotor (104) may be created which causes the rotor (104) to rotate in a particular direction, for example clockwise direction. The rotor (104) in turn may cause movement of the watch ot timepiece, as an example, hand of the watch to rotate in clockwise direction through wheel assembly (105A, 105B and 105C). In an embodiment, when the second coil (101B) is energized, the second coil (101B) may create flux in opposite direction and energizes the stator

(103) . A magnetic field between the stator assembly (103) and the rotor (104) causes the rotor (104) to rotate in a particular direction, for example anticlockwise direction. Thus, the rotor

(104) causes movement of the watch, as an example, hand of the clock to rotate in anticlockwise direction through the wheel assembly (105a, 105b and 105c). In an embodiment, the wheel assembly may be a gear train including gears (105a, 105b and 105c). In an embodiment, individual gear may be provided for individual hand movements of the timepiece such as minute hand, second hand and hour hand.

FIG.3 is an exemplary embodiment of the present disclosure illustrating perspective view of a coil (101a or 101b) used in the micromotor (100). In the present disclosure, the micromotor (100) may have at least two coils (101a and 101b) configured parallel to each other. In the exemplary embodiment, a single coil (101a) is depicted, and the other coil is designed to have similar constructional features as well as the profile. As shown in FIG.3, the coil (101A) consists of a metal core (107), a coil winding and a CEC terminal. The coil winding may be wound on the metal core (107) and a second end (108b and 108d) of the coil winding may be soldered to the CEC terminal. Further, the metal core (107) may comprise provision such as hole, groove, slot etc at first end (108a and 108c) of the coil. This provision facilitates fastening of the coil (101a and 101b) to the stator assembly (103). Also, the second end (108b and 108d) of the coil (101a and 101b) includes a provision or hole to receive the stud (110a and 110b) provided on the stator assembly (103). In an embodiment of the disclosure, the micromotor includes a first and second coil of same profile, which enables easy replacement of a coil in case of failure or damage. This also facilitates use of same coil in either ends of the stator.

In an embodiment of the disclosure, the micromotor is simple in construction and easy to assemble.

Equivalents:

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B." While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

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