TECHNICAL FIELD
The present disclosure generally relates to the field of electro-mechanical engineering.
Particularly, but not exclusively, the present disclosure relates to a motorized latch
assembly for a vehicle. Further, embodiments of the present disclosure disclose a
motorized latch assembly of a vehicle which can operate both electronically and
manually.
BACKGROUND
The information in this section merely provide background information related to the
present disclosure and may not constitute prior art(s).
Latch assemblies are known in the art for securing items, such as panels, doors, and
doorframes together. Further, latch assemblies have also been used for securing the
various elements in automobiles. Some of these applications include use of such latch
assemblies in doors, hood covers, bonnets etc. of a vehicle. Such latch mechanisms are
generally operated manually by the user by opening/closing a latch. However, one
major drawback of such latch mechanisms is that it is highly inconvenient for users to
operate the latch mechanism manually.
With the on-going efforts to provide a more convenient and technically advanced latch
mechanism, a number of arrangements have been proposed. One such arrangement
provides a latch mechanism comprising a motor, a catch means for releasably holding
a pawl of the latch mechanism. Further a cam is connected to the motor to actuate the
movement of the pawl. However, a major drawback of the said arrangement is the lack
of discrete locking/unlocking of the pawl due to overdrive of the cam. Additionally,
there is no provision for operating the latch mechanism manually in case of a
breakdown/failure of the electrical circuit. One more major drawback of the said latch
mechanism is that at many times, the latch is not locked properly due to application of
less force by the user. As a result, the panel member to which the latch is attached
remains unlocked and may open during operation of the vehicle/machinery, thereby
jeopardizing the safety of human lives.
3
In the light of the foregoing discussion, there is need to develop an improved motorized
latch mechanism having discrete locking/unlocking. More specifically, a latch
mechanism, that overcomes one or more limitations stated above.
SUMMARY OF THE INVENTION
One or more shortcomings of the prior art are overcome by a motorized latch assembly
as claimed and additional advantages are provided through the provision of assembly
as claimed in the present disclosure.
According to an aspect of the present disclosure, there is provided motorized latch
assembly comprising a body and a latch member. The latch member comprises at least
one elongated arm and is mounted rotatably about a pivot in the body, wherein the latch
member is rotatable between a locked position and an unlocked position. The motorized
latch assembly further comprises a drive mechanism comprising a cam having a
substantially helical profile and a lock sub assembly. The lock sub assembly comprises
a guide member comprising a plurality of guide tracks and a resiliently loaded slider
being movable transversely on the guide tracks for selectively engaging with the latch
member. The slider comprises a locking portion comprising at least one locking face
being engageable with the at least one elongated arm of the latch member. The slider
further comprises a pin being supported on the helical profile of the cam, wherein the
pin operates the slider transversely upon rotation of the cam.
In an embodiment of the present disclosure, a position sensing means is disposed in the
body for detecting a position of the latch member.
In another embodiment of the present disclosure, the position sensing means is
configured to regulate the drive mechanism depending on the position of the latch
member.
In yet another embodiment of the present disclosure, the sensing means is a microswitch.
4
In another embodiment of the present disclosure, the micro switch is in actuated
condition by an actuating face of the latch member in the locked position, and the micro
switch is in unactuated condition in the unlocked position of the latch member.
In a further embodiment of the present disclosure, the locking portion comprises a slant
face.
In a still further embodiment of the present disclosure, the elongated arm of the latch
member comprises a tapered face corresponding to the slant face of the locking portion
so as actuate the slider transversely.
In an embodiment of the present disclosure, the slider comprises an extended groove
being configured with a mechanical means for manual actuation of the slider to unlock
the latch assembly.
In another non-limiting embodiment of the present disclosure, there is provided a
motorized latch assembly comprising a body and a latch member. The latch member
comprises a first elongated arm and a second elongated arm. The latch member is
mounted rotatably about a pivot in the body, wherein the latch member is rotatable
between a primary locked position, a secondary locked position and an unlocked
position. The motorized latch assembly further comprises a drive mechanism
comprising a cam having a substantially helical profile and a lock sub assembly. The
lock sub assembly comprises a guide member comprising a plurality of guide tracks
and a resiliently loaded slider which is movable transversely on the guide tracks for
selectively engaging with the latch member. The slider comprises a locking portion
comprising a first locking face which is engageable with the first elongated arm and a
second locking face which is engageable with the second elongated arm of locking
member. The slider further comprises a pin being supported on the helical profile of the
cam. The pin operates the slider transversely upon rotation of the cam.
In an embodiment of the present disclosure, a position sensing means is disposed in the
body for detecting a position of the latch member.
5
In another embodiment of the present disclosure, the position sensing means is
configured to regulate the drive mechanism depending on the position of the latch
member.
BRIEF DESCRIPTION OF DRAWINGS
Further aspects and advantages of the present disclosure will be readily understood
from the following detailed description with reference to the accompanying drawings.
Reference numerals have been used to refer to identical or similar functionally similar
elements. The figures together with a detailed description below, are incorporated in
and form part of the specification, and serve to further illustrate the embodiments and
explain various principles and advantages, in accordance with the present disclosure
wherein:
Figure 1 illustrates an exploded view of the motorized latch assembly according to an
embodiment of the present disclosure.
Figures 2a-2b illustrates the top view and bottom view of the motorized latch assembly
respectively according to an embodiment of the present disclosure.
Figures 3a-3b illustrates the perspective views of the latch member of the motorized
latch assembly according to an embodiment of the present disclosure.
Figures 4a-4b illustrate the perspective views of the cam of the drive mechanism of the
motorized latch assembly according to an embodiment of the present disclosure.
Figures 5a-5b illustrate the perspective views of the slider of the lock sub assembly
according to an embodiment of the present disclosure.
Figures 6a-6b illustrate the perspective views of the guide member of the lock sub
assembly according to an embodiment of the present disclosure.
Figure 7a illustrates a sectional view of the motorized latch assembly whereby the latch
member is in the locked position according to an embodiment of the present disclosure.
6
Figure 7b illustrates a sectional view of the motorized latch assembly whereby the latch
member is in the unlocked position according to an embodiment of the present
disclosure.
Figures 8a-8b illustrate the perspective views of the latch member of the motorized
latch assembly in an alternate embodiment of the present disclosure.
Figure 9 depicts a perspective views of the slider of the lock sub assembly of Figure 8
according to an embodiment of the present disclosure.
Figure 10a illustrates a sectional view of the motorized latch assembly of Figure 8
whereby the latch member is in the unlocked position.
Figure 10b illustrates a sectional view of the motorized latch assembly of Figure 8
whereby the latch member is in the secondary locked position.
Figure 10c illustrates a sectional view of the motorized latch assembly of Figure 8
whereby the latch member is in the primary locked position.
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 structures and methods illustrated herein may be
employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION OF THE INVENTION
While the embodiments in the disclosure are subject to various modifications and
alternative forms, specific embodiments thereof have been shown by way of example
in the figures 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 scope of the disclosure.
It is to be noted that a person skilled in the art would be motivated from the present
disclosure and modify various constructions of a motorized latch assembly, which may
vary from vehicle to vehicle. However, such modifications should be construed within
7
the scope and spirit of the disclosure. Accordingly, the drawings show only those
specific details that are pertinent to understand the embodiments of the present
disclosure so as not to obscure the disclosure with details that will be readily apparent
to those of ordinary skill in the art having benefit of the description herein.
The terms “comprises”, “comprising”, or any other variations thereof used in the
disclosure, are intended to cover a non-exclusive inclusion, such that a device, system,
assembly that comprises a list of components does not include only those components
but may include other components not expressly listed or inherent to such system, or
assembly, or device. In other words, one or more elements in a system or device
proceeded by “comprises… a” does not, without more constraints, preclude the
existence of other elements or additional elements in the system or device.
Accordingly, it is an aim of the present disclosure to provide an improved motorized
latch mechanism having discrete locking/unlocking. More specifically, a latch
mechanism, that is user friendly and provides an intermediate locking position for
enhanced safety and efficient locking.
According to an aspect of the present disclosure, there is provided motorized latch
assembly comprising a body and a latch member. The latch member comprises at least
one elongated arm and is mounted rotatably about a pivot in the body, wherein the latch
member is rotatable between a locked position and an unlocked position. The motorized
latch assembly further comprises a drive mechanism comprising a cam having a
substantially helical profile and a lock sub assembly. The lock sub assembly comprises
a guide member comprising a plurality of guide tracks and a resiliently loaded slider
being movable transversely on the guide tracks for selectively engaging with the latch
member. The slider comprises a locking portion comprising at least one locking face
being engageable with the at least one elongated arm of the latch member. The slider
further comprises a pin being supported on the helical profile of the cam, wherein the
pin operates the slider transversely upon rotation of the cam. Further, a position sensing
means is disposed in the body for detecting a position of the latch member. The position
sensing means is configured to regulate the drive mechanism depending on the position
of the latch member. The sensing means is a micro-switch. The micro switch is in
actuated condition by an actuating face of the latch member in the locked position, and
8
the micro switch is in unactuated condition in the unlocked position of the latch
member. Further, the locking portion comprises a slant face. The elongated arm of the
latch member comprises a tapered face corresponding to the slant face of the locking
portion so as actuate the slider transversely. The slider comprises an extended groove
being configured with a mechanical means for manual actuation of the slider to unlock
the latch assembly.
In another non-limiting embodiment of the present disclosure, there is provided a
motorized latch assembly comprising a body and a latch member. The latch member
comprises a first elongated arm and a second elongated arm. The latch member is
mounted rotatably about a pivot in the body, wherein the latch member is rotatable
between a primary locked position, a secondary locked position and an unlocked
position. The motorized latch assembly further comprises a drive mechanism
comprising a cam having a substantially helical profile and a lock sub assembly. The
lock sub assembly comprises a guide member comprising a plurality of guide tracks
and a resiliently loaded slider which is movable transversely on the guide tracks for
selectively engaging with the latch member. The slider comprises a locking portion
comprising a first locking face which is engageable with the first elongated arm and a
second locking face which is engageable with the second elongated arm of locking
member. The slider further comprises a pin being supported on the helical profile of the
cam. The pin operates the slider transversely upon rotation of the cam. Further, a
position sensing means is disposed in the body for detecting a position of the latch
member. The position sensing means is configured to regulate the drive mechanism
depending on the position of the latch member.
Now referring to figures 1 to 10, in which the figures 1 is an exemplary embodiment of
the disclosure illustrating an exploded view of the motorized latch assembly (100). As
shown in figures 1 to 7, the motorized latch assembly (100) comprises a body (1) being
configured with a cover (2) so as to define a hollow encapsulation therebetween. In a
non-limiting and facile manner, as shown in figure 2, the cover (2) is secured coaxially
with the body (1) by means of rivet pins (15, 16). A mounting screw (17), a plurality of
grommets (18, 19, 20) and a plurality of POP rivets (23) cover cavities are present in
the body (1) and the cover (2).
9
Referring to figures 1 and 3, the motorized latch assembly (100) further comprises a
latch member (3) being mounted pivotably in the body (1) at pivot (3a). The latch
member (3) is energized resiliently by means of torsion spring (9) which is supported
on the body (1) such that the latch member (3) is rotatable between a locked position
and an unlocked position corresponding to the locked and unlocked conditions of the
motorized latch assembly (100). The latch member comprises a U-shaped slot (3e) for
accommodating a locking member of the vehicle. The latch member (3) further
comprises at least one elongated arm (3b) extending linearly inwardly in the
encapsulation formed between the body (1) and cover (2). The elongated arm (3b) has
a tapered face (3d). Further, the latch member (3) comprises an actuating face (3c).
Disposed in the encapsulation is a position sensing means which is configured to detect
the position of the latch member (3), i.e. whether the latch member (3) is in the locked
position or unlocked position. Accordingly, the position sensing means may be
configured to regulate a drive mechanism (6) of the motorized latch assembly (100).
The drive mechanism (6) comprises a cam (8) having a helical profile (8a).
Referring to figure 4, the cam (8) has a cylindrical configuration having a substantially
helical profile (8a). The helical profile (8a) has an apex point (A) and a bottom point
(B) adjacent to the apex point (A) so as to define a gradual helix between the bottom
point (B) and apex point (A). The cam (8) further comprises a mounting slot (8b) for
being mounted on the drive shaft of a motor (13) such that the cam (8) is rotatable with
the drive shaft of the motor (13). In an embodiment, the cam (8) is connected with
motor shaft secured in a plastic enclosure (12) with an O-ring (22) slotted in between
them. The plastic enclosure (12) has a first end (12a) and a second end (12b). The first
end (12a) of the plastic enclosure (12) is secured with the cam (8). The second end
(12b) of the plastic enclosure (12) is secured with the motor (13). The motor is operably
configured with a PCB (14). The plastic enclosure (12) covers the geared motor (13)
and the PCB (14) and restricts the entry of moisture and water.
As shown in figures 1, 5 and 6, the motorized latch assembly (100) comprises a lock
sub assembly being disposed in the encapsulation. The lock sub assembly is configured
to selectively lock/unlock the latch member (3) by engaging/disengaging with the
elongated arm (3b) of the latch member (3). The lock sub assembly comprises a guide
member (5) and a slider (4). As shown in figure 5, the guide member (5) has a rigid
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configuration and is fixed to the body (1). The guide member (5) comprises a plurality
of guide tracks (5a) being defined in the transverse direction. The term transverse
direction herein refers to a direction along axis XX. The guide channel (5a) is formed
so as to accommodate the slider (4) movably along the transverse direction. As shown
in figures 1 and 6, the slider (4) comprises wing like projections (4c) extending
vertically, perpendicular to axis XX. The projections (4d) are receivable in the guide
tracks (5a) so as to support the slider (4) in the transverse direction, thereby limiting
lateral movement. In the mounted condition, the slider (4) is resiliently loaded by means
of a compression spring (10). The slider (4) comprises locking portion (4a) formed
towards the latch member (3). The locking portion (4a) comprises a slant face (4c)
corresponding to the tapered face (3d) of the latch member (3) such that the slider (4)
is actuated transversely by the elongated arm (3b) of the latch member (3). Further, the
slider (4) comprises a pin (4b) being formed laterally towards the cam (8). The pin (4b)
is supported on the helical profile (8a) of the cam (8) such that the pin (4b) operates the
slider (4) transversely upon rotation of the cam (8).
Referring to figures 7 (a) and (b), in an embodiment of the present disclosure, a micro
switch (7) is provided in the encapsulation. The micro switch (7) is connected with the
PCB (14) so as to regulate the motor (13). As shown in figure 7 (a), in locked position
of the latch member (3), the elongated arm (3b) is engaged with a horizontal flat face
(4a) of the slider (4), thereby preventing rotation of the latch member (3). This position
of the latch member (3) corresponds to the locked condition of the motorized latch
assembly (100) and the locking member/hinge of the vehicle is held fixedly in the Ushaped
slot (3e). Under this condition, the micro switch (7) is in actuated condition by
the actuating face (3c) of the latch member (3). In an embodiment, an extended groove
(4e) of the slider (4) is configured with a mechanical means such as wire, cable or the
like for manual actuation of the slider to unlock the latch assembly (100). When the
user actuates the motor (13) electronically, the cam (8) is rotated. The rotation of the
cam (8) results in the pin (4b) moving on the helical profile to reach the apex position
(A) of the cam (8). In this position, the slider (4) moves away from the elongated arm
(3b) and the elongated arm (3b) gets disengaged. Due to resilient action of the torsion
spring (9), the latch member (3) swings into the unlocked position. This movement of
the latch member (3) results in deactivation of the micro switch (7) by the actuating
face (3c). In turn, the PCB (14) which is configured with the micro switch (7) stops
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rotation of the motor (13), thereby holding the pin in the bottom position (B) of the
helical profile (8a) and the slider (4) reaches back to the unactuated position. In this
condition, the latch member (3) is said to have reached the unlocked position as shown
in figure 7 (b). In this condition, the locking member/hinge of the vehicle is released
from the U-shaped slot (3e) and the door/bonnet panel member can be opened and the
motorized latch assembly is said to be in unlocked condition.
As shown in figures 8 to 10, in a non-limiting embodiment of the present disclosure the
latch member (103) can alternatively be provided with a first elongated arm (103b) and
a second elongated arm (103c). Correspondingly, the lock sub assembly comprises a
guide member (5) having a plurality of guide tracks (5a) for supporting a slider (104)
in the transverse direction. The slider (104) comprises a locking portion (104a) having
a first locking face (104c) being engageable with the first elongated arm (103b) of the
latch member (103) and a second locking face (104d) being engageable with the second
elongated arm (103c) of locking member (103). During operation of the latch member
(103) from the unlocked to the locked condition, in case of inadequate locking force,
the second elongated arm (103c) gets engaged with the second locking face (104d),
thereby preventing opening of the panel member. This is termed as a secondary locked
position of the latch member (103). Upon further application of the locking force, the
first elongated arm (103b) gets engaged with the first locking face (104c), thereby
providing complete locking of the panel member. This is termed as a primary locked
position of the latch member (103).
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
12
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 the invention has been described with reference to a preferred embodiment, it is
apparent that variations and modifications will occur without departing the spirit and
13
scope of the invention. It is therefore contemplated that the present disclosure covers
any and all modifications, variations or equivalents that fall within the scope of the
basic underlying principles disclosed above and claimed therein.
Reference Numerals
100 Motorized latch assembly
1 Body
2 Cover
3 Latch Member
3a Pivot of the Latch Member
3b Elongated Arm of the Latch Member
3c Actuating Face of the Latch Member
3d Tapered Face of the Elongated Arm of the Latch Member
3e U shaped Slot of the Latch Member
4 Slider
4a Locking Portion of the Slider
4b Pin
4c Slant Face of the Locking Portion
4d Projections of the Slider
4e Extended Groove of Slider
5 Guide Member
5a Guide Tracks of the Guide Member
6 Drive Mechanism
7 Micro-switch
8 Cam
8a Helical Profile of Cam
8b Mounting slot of Cam
9 Torsion spring
12 Plastic Enclosure
12a First side of Plastic Enclosure
12b Second side of Plastic Enclosure
13 Motor
14
14 PCB
15, 16 Rivet Pins
A Apex point of Helical Profile of Cam
B Bottom point of Helical Profile of Cam

We claim:
1. A motorized latch assembly (100) comprising:
a body (1);
a latch member (3) comprising at least one elongated arm (3b);
and being mounted rotatably about pivot (3a) in the body (1), wherein
the latch member (3) is rotatable between a locked position and an
unlocked position;
a drive mechanism comprising a cam (8) having a substantially
helical profile (8a); and
a lock sub assembly comprising:
a guide member (5) comprising a plurality of guide tracks
(5a); and
a resiliently loaded slider (4) being movable transversely
on the guide tracks (5a) for selectively engaging with the latch
member (3); wherein the slider comprises a locking portion (4a)
comprising at least one locking face being engageable with the
at least one elongated arm (3b) of the latch member (3); and a
pin (4b) of the slider (4) being operationally engaged with the
helical profile (8a) of the cam (8); wherein the pin (4b) of the
slider (4) operates the slider (4) transversely upon rotation of the
cam (8).
2. The motorized latch assembly (100) as claimed in claim 1, wherein a position
sensing means is disposed in the body (1) for detecting a position of the latch
member (3).
3. The motorized latch assembly (100) as claimed in claim 1, wherein the position
sensing means is configured to regulate the drive mechanism.
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4. The motorized latch assembly (100) as claimed in claim 1, wherein the sensing
means is a micro-switch (7).
5. The motorized latch assembly as claimed in claim 1, wherein the micro switch
(7) is in actuated condition by an actuating face (3c) of the latch member (3) in
the locked position; and the micro switch (7) is in unactuated condition in the
unlocked position of the latch member (3).
6. The motorized latch assembly as claimed in claim 1, wherein the locking portion
(4a) comprises a slant face (4c).
7. The motorized latch assembly as claimed in claim 1, wherein the elongated arm
(3b) of the latch member (3) comprises a tapered face (3d) corresponding to the
slant face (4c) of the locking portion (4a) so as actuate the slider (4) transversely.
8. The motorized latch assembly as claimed in claim 1, wherein the slider (4)
comprises an extended groove (4e) being configured with a mechanical means
for manual actuation of the slider to unlock the latch assembly (100).
9. A motorized latch assembly (100) comprising:
a body (1);
a latch member (103) comprising a first elongated arm (103b)
and a second elongated arm (103c); and being mounted rotatably about
pivot (103a) in the body (1), wherein the latch member (103) is rotatable
between a primary locked position, a secondary locked position and an
unlocked position;
a drive mechanism comprising a cam (8) having a substantially
helical profile (8a); and
a lock sub assembly comprising:
17
a guide member (5) comprising a plurality of guide tracks
(5a); and
a resiliently loaded slider (104) being movable
transversely on the guide tracks (5a) for selectively engaging
with the latch member (103); wherein the slider (104) comprises
a locking portion (104a) comprising a first locking face (104c)
being engageable with the first elongated arm (103b) and a
second locking face (104d) being engageable with the second
elongated arm (103c) of locking member (103); and a pin (104b)
being supported on the helical profile (8a) of the cam (8);
wherein the pin (104b) operates the slider (4) transversely upon
rotation of the cam (8).
10. The motorized latch assembly (100) as claimed in claim 1, wherein a position
sensing means is disposed in the body (1) for detecting a position of the latch
member (103), the position sensing means being configured to regulate the drive
mechanism.