U.S. patent application number 12/388403 was filed with the patent office on 2009-08-20 for apparatus for isolating a sensor from vibration.
This patent application is currently assigned to STEMCO LP. Invention is credited to Michael J. Massey.
Application Number | 20090206218 12/388403 |
Document ID | / |
Family ID | 40954217 |
Filed Date | 2009-08-20 |
United States Patent
Application |
20090206218 |
Kind Code |
A1 |
Massey; Michael J. |
August 20, 2009 |
Apparatus for Isolating a Sensor from Vibration
Abstract
A sensor bracket that isolates a sensor from mechanical
vibrations of an associated component extends the operational
lifetime, for example, of a wheel-mounted sensor on a vehicle. The
bracket includes a multi-legged bracket to decrease the dynamic
instability induced by using highly compliant isolating elements on
a rotating wheel. Multiple isolating elements provide a reduction
in the vibration impinging on a sensor while still maintaining
rotational stability of the assembly on the wheel. In some aspects,
an intrinsic, fail-safe feature is included in the sensor mounting
bracket and isolating element design.
Inventors: |
Massey; Michael J.;
(Longview, TX) |
Correspondence
Address: |
HOLLAND & HART, LLP
P.O BOX 8749
DENVER
CO
80201
US
|
Assignee: |
STEMCO LP
Longview
TX
|
Family ID: |
40954217 |
Appl. No.: |
12/388403 |
Filed: |
February 18, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61029414 |
Feb 18, 2008 |
|
|
|
Current U.S.
Class: |
248/220.21 ;
248/309.1 |
Current CPC
Class: |
F16F 2230/24 20130101;
B60B 7/02 20130101; B60B 7/068 20130101; F16F 1/324 20130101; B60B
7/14 20130101 |
Class at
Publication: |
248/220.21 ;
248/309.1 |
International
Class: |
A47B 96/06 20060101
A47B096/06 |
Claims
1. A bracket for isolating a sensor from vibration, comprising: a
sensor mount adapted to receive a sensor; a plurality of legs
extending from said sensor mount; and an isolating element that
engages with a distal end of each leg and adapted to receive an
attachment element that secures the respective leg, through said
isolating element, to a wheel hub.
2. The bracket of claim 1, wherein said sensor mount comprises a
plate having a mounting hole therein that is adapted to receive a
mounting element of a sensor.
3. The bracket of claim 1, wherein said sensor mount comprises a
plate and a plurality of tabs extending from said plate to at least
substantially cover a portion of a sensor when mounted to said
plate.
4. The bracket of claim 1, wherein said plurality of legs include
holes that receive said isolating elements.
5. The bracket of claim 1, wherein said isolating elements comprise
silicone rubber elements.
6. The bracket of claim 5, wherein said isolating elements are
substantially cylindrical and comprise a reduced diameter slot that
is captured by a matching hole a respective leg.
7. The bracket of claim 5, wherein said isolating elements further
comprise a spacer that is inserted into the center thereof.
8. The bracket of claim 5, wherein said isolating elements are
adapted to receive an attachment bolt thereby securing said leg to
a wheel hub.
9. The bracket of claim 1, wherein said isolating elements comprise
an elastomeric material and are molded directly onto said legs.
10. The bracket of claim 9 wherein said isolating elements further
comprise a spacer molded into said elastomeric material.
11. A bracket for isolating a sensor from vibration, comprising: a
sensor mount adapted to receive a sensor; a plurality of legs
extending from said sensor mount; and a dual stud isolator that
engages with a distal end of each leg and adapted secure each leg
to a vehicle wheel hub.
12. The bracket of claim 11, wherein said dual stud isolator
comprises a first threaded stud having an elastomeric element
bonded thereto and a second threaded stud bonded to said
elastomeric element opposite said first threaded stud.
13. The bracket of claim 12, wherein said studs comprise hex bolts
and said elastomeric element is bonded to the hex head of said hex
bolts.
14. The bracket of claim 12, further comprising a lanyard assembly
coupling said first and second threaded studs.
15. An apparatus for mounting a sensor to a vehicle, comprising: a
mounting plate that receives a sensor; a securement assembly that
secures said mounting plate to a vehicle; and an isolation element
coupled to said securement assembly between said securement
assembly and vehicle.
16. The apparatus of claim 15, wherein said securement assembly
comprises a plurality of legs that extend from said mounting
plate.
17. The apparatus of claim 15, wherein said mounting plate
comprises a plate and a plurality of tabs extending from said plate
to at least substantially cover a portion of a sensor when mounted
to said plate.
18. The apparatus of claim 15, wherein said isolation element
comprises a silicone rubber element.
19. The apparatus of claim 18, wherein said isolation element is
substantially cylindrical and includes a reduced diameter slot that
is captured by a matching hole in said securement assembly.
20. The apparatus of claim 15, wherein said isolation element
comprises an elastomeric material that is molded directly onto said
securement assembly.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. provisional patent
application No. 61/029,414, filed on Feb. 18, 2008 entitled
"Apparatus for Isolating a Sensor From Vibration," the entire
disclosure of which is incorporated herein by reference.
FIELD
[0002] The present invention is related to mechanically isolating
vehicle sensors from vehicle vibrations, and, more specifically, an
isolation bracket that isolates a vehicle sensor from vibrations of
the vehicle.
BACKGROUND
[0003] Vehicle sensors are often mounted to vehicle components such
that information directly related to the associated component may
be relayed to an interested party. For example, odometers may be
placed on a wheel hub to measure the revolutions of the associated
wheel. The measured revolutions, along with information related to
the wheel diameter, may be used to calculate a distance traveled by
the associated wheel, and therefore a distance traveled by the
associated vehicle. Such a device is well known, and is commonly
referred to as a hubodometer. A hubodometer is one example of a
sensor that may be mounted to a vehicle. Other types of sensors or
devices may also be attached to a vehicle, such as, for example,
tire pressure sensors, weight sensors, temperature sensors,
location sensors, and communications devices, to name but a
few.
SUMMARY
[0004] Embodiments disclosed herein provide a sensor bracket that
isolates a sensor from mechanical vibrations of an associated
component. Mounting brackets of various embodiments extend the
operational lifetime, for example, of a wheel-mounted sensor on a
truck, trailer or bus. Mounting brackets of various aspects
accomplish this by protecting the mounted sensor from damaging
shock and vibration. The sensor could be an electronic mileage
counter such as an electronic hubodometer, a mechanical mileage
counter such as a mechanical hubodometer, a tire pressure monitor,
and/or a lubricant fluid sensor, to name a few. The shock and
vibration impinging on a wheel-mounted sensor may result from poor
road conditions such as potholes, washboard, gravel, expansion
joints, and/or dislocations associated with the roadway. The shock
and vibration impinging on a wheel-mounted sensor also may result
from poor driving skill, resulting in excessive encounters with
shoulder/centerline `rumble strip` cut outs/protrusions, curbs,
foreign objects, and the like. The shock and vibration impinging on
a wheel-mounted sensor also may result from poor vehicle
maintenance, resulting in, for example, excessive `wheel hop` on
braking. The shock and vibration impinging on a wheel-mounted
sensor further may be the result of high levels of vibration
generated by the internal gearing of the axle on which the sensor
is mounted. In other vehicles, such as rail vehicles, vibration may
result from axle gearing, track conditions, and the like. The
present disclosure provides isolating mounting brackets that reduce
the vibration transmitted to a vehicle sensor. In some embodiments,
provided is a provision of a `fail-safe` attachment method, which
prevents the bracket and sensor assembly from being launched from
the wheel during operation of the vehicle should a failure of
isolating elements occur.
[0005] Provided in various aspects of the present disclosure are: a
sensor-mounting system, designed for the purpose of extending the
operational life of a wheel-mounted sensor by protecting it from
harmful shock and vibration; use of a multi-legged bracket to
decrease the dynamic instability induced by using highly compliant
isolating elements on a rotating wheel; implementation of wide
temperature range, multiple isolating elements to provide a
reduction in the vibration impinging on a sensor while still
maintaining rotational stability of the assembly on the wheel;
and/or implementation of an intrinsic, fail-safe feature in the
sensor mounting bracket and isolating element design.
[0006] In one aspect this disclosure provides a bracket for
isolating a sensor from vibration, comprising: (a) a sensor mount
adapted to receive a sensor; (b) a plurality of legs extending from
the sensor mount; and (c) an isolating element that engages with a
distal end of each leg and adapted to receive an attachment element
that secures the respective leg, through the isolating element, to
a wheel hub. The sensor mount, in an embodiment, comprises a plate
having a mounting hole therein that is adapted to receive a sensor.
The sensor mount may also include tabs extending from the plate
that cover a portion of a sensor when mounted to said plate and
provide a shield for the sensor. The plurality of legs, in an
embodiment, include holes that receive said isolating elements. The
isolating elements may be formed of silicone rubber elements that
are substantially cylindrical and include a reduced diameter slot
that is captured by a matching hole a respective leg. The isolating
elements also include, in some embodiments, a spacer that is
inserted into the center thereof. The isolating elements are
adapted to receive an attachment bolt used for securing the leg to
a wheel hub. The isolating elements may also be molded directly
onto said legs, and may include a spacer molded into the material
of the isolating element.
[0007] In another aspect, provided is a bracket for isolating a
sensor from vibration, comprising: (a) a sensor mount adapted to
receive a sensor; (b) a plurality of legs extending from the sensor
mount; and (c) a dual stud isolator that engages with a distal end
of each leg and adapted secure each leg to a vehicle wheel hub. The
dual stud isolator may comprise a first threaded stud having an
elastomeric element bonded thereto and a second threaded stud
bonded to the elastomeric element opposite the first stud. The
studs, in an embodiment, comprise hex bolts with the elastomeric
element bonded to the hex head of the hex bolts. The bracket may
also include a lanyard assembly coupling the first and second
threaded studs of each dual stud isolator.
[0008] A further aspect of the disclosure provides an apparatus for
mounting a sensor to a vehicle, comprising: (a) a mounting plate
that receives a sensor; (b) a securement assembly that secures the
mounting plate to a vehicle; and (c) an isolation element coupled
to the securement assembly between the securement assembly and
vehicle. The securement assembly, in some embodiments, includes a
plurality of legs that extend from said mounting plate. The
mounting plate may comprise a plate and a plurality of tabs
extending from the plate to at least substantially cover a portion
of a sensor when mounted to the plate. The isolation element, in
some embodiments, is substantially cylindrical and includes a
reduced diameter slot that is captured by a matching hole in the
securement assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of a vehicle of one
embodiment;
[0010] FIG. 2 is a perspective view of an exploded mounting bracket
assembly of an embodiment;
[0011] FIG. 3 is a perspective view of an assembled mounting
bracket assembly of the embodiment of FIG. 2;
[0012] FIG. 4 is a perspective view of an exploded mounting bracket
assembly of another embodiment;
[0013] FIG. 5 is a perspective view of an assembled mounting
bracket assembly of the embodiment of FIG. 4; and
[0014] FIG. 6 is a perspective view of a mounting bracket of
another embodiment.
DETAILED DESCRIPTION
[0015] For a more complete understanding of this invention,
reference is now made to the following detailed description of
several embodiments as illustrated in the drawing figures, in which
like numbers represent the same or similar elements. Various
embodiments are described herein, with specific examples provided
in many instances to serve to illustrate and discuss various
concepts included in the present disclosure. The specific
embodiments and examples provided are not necessarily to be
construed as preferred or advantageous over other embodiments
and/or examples.
[0016] With reference to FIG. 1, a vehicle 20 is illustrated for
one embodiment as a bus that may be used in public transit. While
the vehicle 20 of FIG. 1 is illustrated as a public transit bus, it
will be readily understood that this example is for purposes of
illustration and discussion, and that methods, systems and
apparatuses of the present disclosure may be used for any type of
vehicle, including, for example, automobiles, trucks, semi
tractor/trailers, and school buses. Furthermore, the systems and
apparatuses of the present disclosure may also be used with other
types of vehicles, including rail vehicles, aircraft, and/or
watercraft. In the embodiment of FIG. 1, an odometer 24 is mounted
to a wheel hub 28 of a set of rear wheel 32. Typically wheel 32
includes a set of dual wheels, although the present disclosure is
equally applicable to any wheel configuration. Such an odometer 24
is often referred to as a "hubodometer," and these devices are
commonly used in situations where the mileage of the wheel 32 may
not necessarily be tracked by an odometer within the vehicle 20
itself, and/or in situations where it is convenient to view a
mileage reading without having to access an interior of the vehicle
20. For example, in the example of buses used in public transit, it
may be more efficient for personnel to view the mileage of a bus on
such a hubodometer 24 rather than having to open a door to the bus,
climb into the bus, read a mileage from an odometer on the interior
instrument panel, exit the bus, and close the door. Furthermore, in
many cases digital odometers on the instrument panel may not be
active unless the vehicle is turned on, thus making such checking
of mileage even more inefficient. The odometer 24 of the embodiment
of FIG. 1 includes a display 36 that displays the distance
traveled, such as total miles since the odometer's 24 installation,
of the vehicle 20. Such an odometer 24 may record and output on
display 36 the distance traveled since a particular event, such as
vehicle 20 maintenance or wheel 32 replacement, instead of or in
addition to the total distance recorded since the installation of
the odometer. In the embodiment of FIG. 1, the odometer 24 is an
electronic hubodometer that measures distance traveled according to
a number of revolutions detected by an accelerometer within the
hubodometer and a size of the wheel 32 that is programmed into the
hubodometer. The odometer 24 may also include an RF circuit that
operates to transmit an information signal modulated onto an RF
signal that includes an identification for the odometer 24 and the
current value of the distance that has been measured by the
odometer 24.
[0017] Traditionally, a solid metallic flat or formed (commercial
steel with rust resistant treatment or stainless steel) bracket is
used to attach an odometer to the wheel end of the vehicle or
trailer. This bracket is rigidly mounted to the wheel, utilizing
the existing hubcap bolts, drive axle cover-plate retainer bolts,
or, in some cases, the actual lug nuts that attach the wheel to
hub. The present disclosure recognizes that the mounting techniques
just described provide little, if any, attenuation of the
shock/vibration transmitted from the wheel to an odometer. It is
recognized that such shock/vibration may have a detrimental effect
on a hubodometer, or any other type of sensor associated with a
wheel end, including failure of the component. The present
disclosure provides for the shock/vibration transmitted to the
sensor to be reduced to a level that is within a sensor's fragility
limit. To achieve reduced shock and vibration impinging on the
sensor, a bracket, as will be described in more detail for some
exemplary embodiments, is mounted to the wheel end utilizing
isolating elements such as elastomeric (elastomeric refers to a
relatively highly pliable material or rubber-like substance, such
as neoprene or silicone-based rubber) elements. The assembly is
designed so that the vibration from the hub to the bracket and
sensor must be transmitted through the isolating element to the
sensor and bracket. The isolating elements and bracket combination
is designed, in various embodiments, to tailor the mechanical
resonances so that they do not occur in close proximity (in the
frequency domain) to the operational vibration frequencies in the
axle.
[0018] As mentioned above, vehicles, as they travel over roadways,
rails, etc. may experience a variety of different vibrations. Such
vibrations may be caused by roadway surfaces, environmental factors
such as wind, and/or by the vehicle itself as different mechanical
components of the vehicle operate and generate vibration. For
example, some vehicles have planetary gearing that is located at
the end of a vehicle axle, which may cause vibrations in the wheel
hub. Other drive train components may cause vibration as well, such
as the engine and transmission. Various embodiments disclosed
herein provide an isolation bracket that operates to isolate
vibrations from a sensor.
[0019] In one embodiment, illustrated in FIGS. 2 and 3, a
hubodometer (not shown) may be mounted to a bracket 100 via a
sensor mount 104 that in the embodiment of FIGS. 2 and 3 is a
center, 1/2 inch diameter hole, using a standard washer and locknut
(not shown). The bracket 100 is mounted to a axle hub cover plate
108, the cover plate 108 being associated with a wheel hub of a
vehicle (not shown). The bracket 100 is isolated from vibrations of
the wheel hub through isolating elements 112, which in the
embodiment of FIGS. 2 and 3 are four silicone rubber, single-piece,
elastomeric elements 112 that are inserted into associated holes
116 in the bracket 100. A spacer 120 is inserted into the center of
each of the isolating elements 112. The assembly is secured to the
cover plate 108 using an attachment bolt 124 and a washer 128. In
the embodiment of FIGS. 2 and 3, four, longer length bolts 124 and
larger OD washers 128, the assembly is mounted in the specified
manner on the cover plate 108. The associated wheel hub may be
associated, for example, with a MAN planetary gear reduction axle,
which is used in a large percentage of New Flyer, 40 foot transit
buses. In an exemplary embodiment, the elastomeric element 112 is a
single-piece design, molded from silicone or neoprene rubber. The
element 112 has a reduced diameter slot that is captured by a
matching hole 116 in the bracket 100. In other embodiments,
isolating elements may be molded directly onto the bracket, thereby
becoming an integral part of the bracket. Additionally, other
embodiments may have the steel spacer molded into such an isolating
element when the isolating element is molded directly onto the
bracket, thereby forming a bracket assembly that would require
fewer individual parts to assemble when mounted to a vehicle.
[0020] Another embodiment of an isolating bracket is illustrated in
FIGS. 4 and 5. In this embodiment, as will be described in more
detail, an elastomeric element is created by bonding rubber
directly to threaded studs. As illustrated in FIGS. 4 and 5, a
hubodometer (not shown) may mounted to a bracket 200 via a sensor
mount 204 that in the embodiment of FIGS. 4 and 5 is a center,
1/2'' diameter hole, using the standard washer and locknut (not
shown). The bracket 200 is mounted to a axle hub cover plate 208,
the cover plate 208 being associated with a wheel hub of a vehicle
(not shown). The bracket 200 is isolated from vibrations of the
wheel hub through a dual stud isolator 212. In this embodiment
elastomeric element 216 is created by bonding rubber directly to
threaded studs. The studs may be, for example, off-the-shelf hex
bolts. The hex head has the advantage of providing an easy method
of tightening the fastener into the wheel hub on one end and then
providing for nut attachment to the bracket 200 on the other end.
This system is made fail-safe by adding a lanyard assembly 220 made
from steel end pieces 224 and a lanyard 228 of Nylon or Kevlar, for
example, that connects the end pieces 224. The dual stud isolator
212 is assembled with the lanyard assembly 220 and the bracket 200
is secured with locknut 232 inserted into associated holes in the
bracket 200. The associated wheel hub may be associated, for
example, with a MAN planetary gear reduction axle, which is used in
a large percentage of New Flyer, 40 foot transit buses.
[0021] Another embodiment of an isolating bracket is illustrated in
FIG. 6. In this embodiment, a sensor such as a hubodometer (not
shown) may mounted to a bracket 300 via a sensor mount 304 that in
the embodiment of FIG. 6 is a center, 1/2'' diameter hole, using
the standard washer and locknut (not shown). The bracket 300,
similarly as described above, may be mounted to a axle hub cover
plate associated with a wheel hub of a vehicle (not shown). The
bracket 300 may be isolated from vibrations in a manner similar as
described above, such as through elastomeric isolating elements
that are inserted into associated holes 308 in the bracket 300. In
the embodiment of FIG. 6, tabs 312 are provided that provide
protection to the sensor from foreign objects and/or road debris
when the vehicle is in motion. The height of the tabs 312 is
selected such that each tab 312 is higher than the height of the
mounted sensor or hubodometer. In such a manner, any flying rocks,
sticks, small and medium-sized mammals, etc. may be deflected by
the tabs 312 and provide an additional degree of protection to the
sensor. In this embodiment, the elastomeric isolating elements
provide shock protection to the sensor in a similar manner as
described above in that they provide isolation to the sensor from
axle-borne shocks due to pot-holes and the other road hazards.
[0022] In a still further embodiment, sensor vibration isolation is
obtained by manufacturing the actual bracket from a high-damping
material or laminate composite that substantially reduces the
vibration transmitted to the sensor due to the energy absorbing
damping in the bracket construction. Elastomeric elements need not
be used in this embodiment, and the bracket is bolted directly to
the hub. For example, the bracket material is made from Constrained
Layer Damping (CLD) steel. This is a sandwich-type (laminated)
construction where two layers of steel are bonded together with an
high damping elastomeric layer in the center (similar to automotive
windshield construction). The laminate, in other embodiments, may
also be formed with multiple layers of steel and damping layers
thereby creating more damping and higher structural rigidity. In
yet another embodiments, the bracket is fabricated from aluminum,
magnesium, injection molded plastic or carbon fiber-reinforced
polymer that may be substituted for the steel components in the
laminate construction. Bracket construction using a high damping
material that has been described here would be inherently
fail-safe, as separate isolating elements such as elastomeric
elements are not required.
[0023] While embodiments described herein are described with
respect to a four-legged bracket that may be affixed to a vehicle
wheel of an over the road vehicle, it will be understood that
numerous other configurations and applications are within the scope
of this disclosure. For example, as briefly mentioned above,
isolation devices may be used in rail vehicle applications. In such
applications, it may be desirable to provide vibration isolation in
order to extend the lifetime of a sensor. In certain embodiments, a
three-legged bracket with isolating elements for each leg may be
affixed to a rail vehicle wheel in a similar manner as described
above. Numerous other applications and configurations of brackets
will be readily recognized by one of skill in the art.
[0024] The previous description of the disclosed embodiments is
provided to enable a person skilled in the art to make or use the
present invention. Various modifications to these embodiments will
be readily apparent to those skilled in the art, and the generic
principles defined herein may be applied to other embodiments
without departing from the spirit or scope of the invention. Thus,
the present invention is not intended to be limited to the
embodiments shown herein but is to be accorded the widest scope
consistent with the principles and novel features disclosed
herein.
* * * * *