FIELD OF INVENTION:
The present subject matter described herein, relates to a heating5 ,
ventilation, and air conditioning (HVAC) control unit for a vehicle and, in
particular, to a knob structure of the HVAC control unit for absorbing impact
force to avoid injuries to occupant of the vehicle.
BACKGROUND AND PRIOR ART:
In general, a HVAC control unit is provided in the interior of a vehicle to
allow occupant of the vehicle to control temperature as per the comfort. The
HVAC control unit may have a plurality of knobs to control air direction, air flow
and temperature which helps in adjusting the speed, direction and temperature of
air flowing into passenger cabin.
15 [003] As seen in the figure 1, the knob has height that depends on two aspects,
such as styling of the part and ergonomics of the knob, i.e., the height should be
enough for the occupant to hold the knob properly. But, higher the height of the
knob, higher chance of causing injury to the occupant during collision., Currently,
knob assembly structure is designed to collapse and avoid injury to the occupant
20 during the collision. However, when the knob structure collapses, it may cause
rattle noise until it is refitted in its proper location and it may give inferior quality
perception to the customer. To repair this collapsed structure, many parts in the
vehicle have to be disassembled which increases the cost and assembly time.
[004] Referring to figure 2, which shows cross-sectional view of HVAC control
25 unit (200) with dial type knob 201 designed to absorb shocks and mitigate impact
force applied on the knob 201 to protect the driver or passengers in the event of a
vehicle collision. During application of impact force, the knob 201 sinks into the
control unit (200) upto a certain amount to protect the driver or passenger or both.
The knob 201 collapses at the snap fit region 202. The knob 201 has to be re-fitted
30 after removing HVAC Control Unit 200 from the vehicle. This will incur cost to
3
the customer and also, this safety feature in the vehicle is not appreciated by the
customer.
[005] Further, conventional structure of the HVAC control unit has a technical
problem that when a human impact is applied to the knob knowingly and by
mistake the knob sinks into the instrument panel and gets locked at the rear end 5 of
the HVAC control unit. To bring back the knob to original position for use, there
is requirement to un-assemble few other parts to complete HVAC control unit
knob re-fitment, which increases the assembly time and cost. Therefore, causing
inconvenience to the customer.
10 [006] Hence, there is a need in the art to modify the structure of the knob in the
HVAC control unit which allow retraction of knob after absorption of impact
force without manual intervention.
OBJECTS OF THE INVENTION:
[007] Some of the objects of the present disclosure, which at least one
15 embodiment herein satisfy, are listed hereinbelow.
[008] The principal object of the present invention is to provide a heating,
ventilation, and air conditioner (HVAC) control unit with impact absorbing
features.
[009] Another object of the present subject matter is to provide a knob with
20 spring to absorb impact force and retract to original position by restoring force of
the spring.
[0010] Another object of the present subject matter is to provide a HVAC control
unit in which knobs are protruded forward from the HVAC control unit and
supported by a spring at back end to absorb impact force applied on the protruded
25 portion.
[0011] These and other objects and advantages will become more apparent when
reference is made to the following description and accompanying drawings.
4
SUMMARY OF THE INVENTION:
[0012] This summary is provided to introduce concepts related to impact
absorbing structure of HVAC control unit. The concepts are further described
below in the detailed description. This summary is not intended to identify key
features or essential features of the claimed subject matter, nor is it intended to b5 e
used to limit the scope of the claimed subject matter.
In an embodiment, the present disclosure relates to a HVAC control unit having
impact absorbing structure. The HVAC control unit includes a knob rotatably
mounted on the HVAC control unit to control heating and ventilation components.
10 The knob has a front portion that protrudes away from front surface of the HVAC
control unit to define a handling portion. Further, the knob has a hollow cylinder
shaft which is fixedly connected with back surface of the knob. Further, the
HVAC control unit has a rotatory switch that is coupled with rear surface of the
HVAC control unit through snap locks. The rotatory switch has a spindle that
15 projects towards the rear surface of the HVAC control unit. The spindle is coupled
with the hollow cylinder shaft to transmit rotatory motion of the knob to the
rotatory switch for corresponding action. In the assembly of the spindle and the
hollow cylinder shaft, a spring is provided in between top surface of the spindle
and a spring fixture is provided in the hollow cylinder shaft to absorb impact
20 energy on the knob. During application of the impact force, the spring fixture
compresses the spring to allow inward movement of the knob to save the occupant
of the vehicle from any injury.
[0013] In an aspect of the present subject matter, the hollow cylinder shaft is snap
fitted with the spindle to restrict popping out of the knob from the spindle during
25 spring restoration effect.
[0014] In an aspect of the present subject matter, internal diameter (D) of the
hollow cylinder shaft is more than external diameter (d) of the spindle to allow up
and down motion.
5
[0015] To further understand the characteristics and technical contents of the
present subject matter, a description relating thereto will be made with reference
to the accompanying drawings. However, the drawings are illustrative only but
not used to limit scope of the present subject matter.
BRIEF DESCRIPTION OF 5 THE DRAWINGS
[0016] It is to be noted, however, that the appended drawings illustrate only
typical embodiments of the present subject matter and are therefore not to be
considered for limiting of its scope, for the invention may admit to other equally
effective embodiments. The detailed description is described with reference to the
10 accompanying figures. In the figures, the left-most digit(s) of a reference number
identifies the figure in which the reference number first appears. The same
numbers are used throughout the figures to reference like features and
components. Some embodiments of system or methods in accordance with
embodiments of the present subject matter are now described, by way of example,
15 and with reference to the accompanying figures, in which:
[0017] Fig. 1 illustrates front view of heating, ventilation, and air conditioning
(HVAC) control unit;
[0018] Fig. 2 illustrates cross section view along AA of figure 1, in accordance
with existing structure of the HVAC control unit; and
20 [0019] Fig. 3 illustrates cross section view along AA of the figure 1, in
accordance with an embodiment of the present subject matter.
[0020] The figures depict embodiments of the present subject matter for the
purposes of illustration only. A person skilled in the art will easily recognize from
the following description that alternative embodiments of the structures and
25 methods illustrated herein may be employed without departing from the principles
of the disclosure described herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0021] The detailed description of various exemplary embodiments of the
disclosure is described herein with reference to the accompanying drawings. It
6
should be noted that the embodiments are described herein in such details as to
clearly communicate the disclosure. However, the amount of details provided
herein 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 scope of the present disclosure as defined by the appe5 nded
claims.
[0022] It is also to be understood that various arrangements may be devised that,
although not explicitly described or shown herein, embody the principles of the
present disclosure. Moreover, all statements herein reciting principles, aspects,
10 and embodiments of the present disclosure, as well as specific examples, are
intended to encompass equivalents thereof.
[0023] The terminology used herein is for the purpose of describing particular
embodiments only and is not intended to be limiting of example embodiments. As
used herein, the singular forms “a",” “an” and “the” are intended to include the
15 plural forms as well, unless the context clearly indicates otherwise. It will be
further understood that the terms “comprises,” “comprising,” “includes” and/or
“including,” when used herein, specify the presence of stated features, integers,
steps, operations, elements and/or components, but do not preclude the presence
or addition of one or more other features, integers, steps, operations, elements,
20 components and/or groups thereof.
[0024] It should also be noted that in some alternative implementations, the
functions/acts noted may occur out of the order noted in the figures. For example,
two figures shown in succession may, in fact, be executed concurrently or may
sometimes be executed in the reverse order, depending upon the functionality/acts
25 involved.
[0025] Unless otherwise defined, all terms (including technical and scientific
terms) used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which example embodiments belong. It will be further
understood that terms, e.g., those defined in commonly used dictionaries, should
30 be interpreted as having a meaning that is consistent with their meaning in the
7
context of the relevant art and will not be interpreted in an idealized or overly
formal sense unless expressly so defined herein.
[0026] These and other advantages of the present subject matter would be
described in greater detail with reference to the following figures. It should be
noted that the description merely illustrates the principles of the present 5 sent subject
matter. It will thus be appreciated that those skilled in the art will be able to devise
various arrangements that, although not explicitly described herein, embody the
principles of the present subject matter and are included within its scope.
[0027] In the present subject matter, HVAC control unit is described with impact
10 absorbing knob structure. In the present subject matter, the knob is assembled
with the switch with a spring that absorbs the impact force and restores the
original position of the knob when there is no impact force on the knob front
surface.
[0028] Figure 1 illustrates front view of HVAC control unit. The HVAC control
15 unit 100 includes a plurality of knobs and switches on front surface to control
temperature of the vehicle cabin. For example, the HVAC control unit has a fan
speed controller knob, a fan direction controller knob, and a hot air controller
knob. The knob structure may be same or different to each other. Further, each
knob structure can implement the present invention to absorb the impact force.
20 Apart from the plurality of knobs, the HVAC control unit may have a plurality of
switches or buttons to ON and OFF various components, such as AC, heater, and
circulation of vehicle air with atmospheric air.
[0029] Referring to figure 2 illustrating cross section view along AA of figure 1,
after installation of the HVAC control unit 100 into the vehicle instrument panel.
25 The surface which is visible to the occupant of the vehicle can be referred as front
surface 100a and opposite to the front surface 100a there is a back surface 100b
which may have internal mechanism to operate the switches. The knobs are
protruded away from the front surface 100a to define a handling portion for
occupant to operate the knobs as per requirement. During impact, the protruded
30 portion may cause injuries to the occupant which includes driver and other
8
passenger. Therefore, during impact, the protruded portion must go inside the
HVAC control unit to avoid any injuries to the occupant. Further, when there is no
impact force on the protruded portion, the protruded portion must retain its
original position without any manual intervention.
[0030] To achieve the above technical objective, the present HVAC control 5 unit
100 includes a knob 101 that is rotatably mounted on the HVAC control unit 100.
The knob 101 has a front portion 102 that protrudes away from front surface 100a
of the HVAC control unit 100 to define a handling portion. Further, a hollow
cylinder shaft 103 is fixedly connected with back surface 101b of the knob 101.
10 The knob 101 receives impact force on a front surface 101a that is present in the
vehicle cabin. The HVAC control unit 100 further has a rotatory switch 104 that is
coupled with rear surface 100b of the HVAC control unit 100 with a fixing
means. The fixing means can be snap fit, screw fit, interference fit, welding
means, etc. The rotatory switch 104 has a spindle 105 that projects towards the
15 rear surface 100b of the HVAC control unit 100 to have connection or coupling
with the hollow cylinder shaft 103 of the knob 101. Further, the hollow cylinder
shaft 103 may be integrated with the back surface 101b of the knob. In another
embodiment, the hollow cylinder shaft 103 may be fixed with the back surface
101b of the knob 101 by known fixing means, such as pasting, welding, and
20 interference fit. The hollow cylinder shaft 103 is snap fitted with the spindle 105.
The snap fit mechanism in the hollow cylinder shaft 103 and the spindle 105
restrict popping out of the knob. As shown in the figure 2, internal diameter ‘D’ of
the hollow cylinder shaft 103 is more than external diameter ‘d’ of the spindle
105.
25 [0031] Not shown in the figures, the hollow cylinder shaft 103 may have a
plurality of guide protrusions which extend internally towards internal center of
the hollow cylinder shaft 103. On the other hand, the spindle 105 may have a
plurality of grooves corresponding to the plurality of guide protrusions of the
hollow cylinder shaft 103. The plurality of grooves engaged with the plurality of
30 guide protrusions to guide up and down movement of the knob 101 and transfer
9
rotatory motion of the knob 101 to the rotatory switch 104 for controlling the
operation of the rotatory switch 104.
[0032] In another embodiment, the hollow cylinder shaft 103 may have a plurality
of grooves. On the other hand, the spindle 105 may have a plurality of guide
protrusion which protrudes forwardly away from the spindle corresponding to th5 e
plurality of grooves of the hollow cylinder shaft 103. The plurality of grooves
engaged with the plurality of guide protrusions to guide up and down movement
of the knob 101 and transfer rotatory motion of the knob 101 to the rotatory
switch 104 for controlling the operation of the rotatory switch 104.
10 [0033] A spring 106 having a spring constant ‘K’ is provided in between top
surface 105a of the spindle 105 and a spring fixture 101c provided in the hollow
cylinder shaft 103 to absorb impact energy on the knob 101. The spring 106 rests
on the top surface 105a of the spindle 105 and fixes with the hollow cylinder shaft
103. During application of impact force, the knob 101 pushes the connected
15 cylinder shaft 103 which pushes the spring 106 in inward direction to absorb the
impact force. The spring 106 stores the impact force and sends back the hollow
cylinder shaft 103 and knob 101 to original position due to restored spring force
after release of the impact force. Further, the spring constant ‘K’ of the spring 106
depends on the below mentioned Hooke’s law equation:
20 [0034] F=(-)Kx
K= (-) F/x
Where K is spring constant, F is force applied, and x is distance moved.
[0035] Based on the above equation, spring can be decided based upon the
applied force and distance x by which spring has to compress. In the present
25 application, F is the threshold impact force and ‘x’ is distance which the knob 101
has to move inside during impact.
[0036] In another embodiment of the present subject matter, the present knob
structure with spring is not limited to the HVAC control unit. It can be applied to
any other control unit also like music system. Accordingly, the impact absorbing
10
knob assembly includes a knob 101 having a front portion 102 that protrudes
forward to define a handling portion. Further, the knob assembly has a hollow
cylinder shaft 103 that is fixedly connected with a back surface 101b of the knob
101. Further, the knob assembly has a rotatory switch 104 having a spindle 105
projecting towards the hollow cylinder shaft 103 for coupling. Additionally, 5 a
spring 106 is provided in between top surface 105a of the spindle 105 and a spring
fixture 101c which is provided in the hollow cylinder shaft 103 to absorb impact
energy on the knob 101.
[0037] In an aspect, the hollow cylinder shaft 103 is snap fitted with the spindle
10 105. Further, internal diameter (D) of the hollow cylinder shaft 103 is more than
external diameter (d) of the spindle 105.
[0038] In an aspect, the present subject matter can be applied to different types of
knobs like normal knob, tapered knob, conical knob, trapezoidal knob, star knob,
splined knob, hemispherical knob, etc., Further, application of the present subject
15 matter is not limited to material of knobs, it can be applied on any knob which is
made of plastic of different grades, resins, rubber, metal etc.,
[0039] 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
20 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
25 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
30 introduced claim recitation to inventions containing only one such recitation, even
11
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 recit5 ed,
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
10 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.).
15 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,
20 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
25 possibilities of “A” or “B” or “A and B.”
[0040] 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
30 or examples, which are included to enable a person having ordinary skill in the art
12
to make and use the invention when combined with information and knowledge
available to the person having ordinary skill in the art.

We claim:
1. A heating, ventilation, and air conditioning (HVAC) control unit (100)
comprising:
a knob (101) rotatably mounted on the HVAC control unit 5 it (100)
and having a front portion (102) protruding away from a front surface
(100a) of the HVAC control unit (100);
a hollow cylinder shaft (103) fixedly connected with a back surface
(101b) of the knob (101);
10 a rotatory switch (104) coupled with rear surface (100b) of the
HVAC control unit (100) and having a spindle (105) projecting towards
the rear surface (100b) of the HVAC control unit (100),
the spindle (105) coupled with the hollow cylinder shaft (103); and
characterized in that
15 a spring (106) provided in between top surface (105a) of the
spindle (105) and a spring fixture (101c) provided in the hollow cylinder
shaft (103) to absorb impact energy on the knob (101).
2. The HVAC control unit (100) as claimed in claim 1, wherein the hollow
20 cylinder shaft (103) is snap fitted with the spindle (105).
3. The HVAC control unit (100) as claimed in claim 1, wherein internal
diameter (D) of the hollow cylinder shaft (103) is more than external diameter (d)
of the spindle (105).
25
4. The HVAC control unit (100) as claimed in claim 1, wherein the spring
fixture (101c) compress the spring (106) during inward movement of the knob
(101) upon impact force.
30 5. The HVAC control unit (100) as claimed in claim 1, wherein a plurality of
guide protrusions is provided on the hollow cylinder shaft (103) and a plurality of
14
grooves is provided on the spindle (105) corresponding to the plurality of guide
protrusions.
6. The HVAC control unit (100) as claimed in claim 1, wherein a plurality of
grooves is provided on the hollow cylinder shaft (103) and a plurality of guide
protrusions is provided on the spindle (105) corresponding to the plurality 5 of
grooves.
7. The HVAC control unit (100) as claimed in claim 1, wherein the knob
(101) is positioned back to original position by restoring force of the spring (106).
10 8. An impact absorbing knob assembly comprising:
a front portion (102) protruding forward from a front surface
(100a) to define a handling portion;
a hollow cylinder shaft (103) fixedly connected with a back surface
(101b) of the knob (101);
15 a rotatory switch (104) having a spindle (105) projecting towards
the hollow cylinder shaft (103) for coupling; and
characterized in that
a spring (106) provided in between top surface (105a) of the
spindle (105) and a spring fixture (101c) provided in the hollow cylinder
20 shaft (103) to absorb impact energy on the knob (101).
9. The impact absorbing knob assembly as claimed in claim 8, wherein the
hollow cylinder shaft (103) is snap fitted with the spindle (105).
25 10. The impact absorbing knob assembly as claimed in claim 8, wherein
internal diameter (D) of the hollow cylinder shaft (103) is more than external
diameter (d) of the spindle (105).