U.S. patent application number 11/221819 was filed with the patent office on 2006-01-12 for torque angle sensing system and method with angle indication.
This patent application is currently assigned to SPX Corporation. Invention is credited to Robert Kochie, Phillip McGee, Durval Ribeiro.
Application Number | 20060009924 11/221819 |
Document ID | / |
Family ID | 25508569 |
Filed Date | 2006-01-12 |
United States Patent
Application |
20060009924 |
Kind Code |
A1 |
McGee; Phillip ; et
al. |
January 12, 2006 |
Torque angle sensing system and method with angle indication
Abstract
A device used for measuring the angle of torque beyond a
specific reference point. The device is comprised of a tool that
applies torque to a fastener, an adapter that is attached to the
fastener to transfer the torque from the tool, and an apparatus
that connects a first end to the tool and a second end to the
adapter. The apparatus comprises an angle selector that is
adjustable to the desired torque angle, an angle rate sensor that
measures the speed and direction of the torque applied, a processor
which calculates the current angle from the rate sensor
measurements, a zero point indicator that serves as the basis point
for the processor to calculate the selected angle, and an angle
indicator that indicates the current angle of rotation.
Inventors: |
McGee; Phillip; (Owatonna,
MN) ; Kochie; Robert; (Mantorville, MN) ;
Ribeiro; Durval; (Owatonna, MN) |
Correspondence
Address: |
BAKER & HOSTETLER LLP
WASHINGTON SQUARE, SUITE 1100
1050 CONNECTICUT AVE. N.W.
WASHINGTON
DC
20036-5304
US
|
Assignee: |
SPX Corporation
|
Family ID: |
25508569 |
Appl. No.: |
11/221819 |
Filed: |
September 9, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09964470 |
Sep 28, 2001 |
6965835 |
|
|
11221819 |
Sep 9, 2005 |
|
|
|
Current U.S.
Class: |
702/41 ;
702/145 |
Current CPC
Class: |
B25B 23/14 20130101;
G01L 5/24 20130101; B25B 23/1425 20130101 |
Class at
Publication: |
702/041 ;
702/145 |
International
Class: |
G01L 3/00 20060101
G01L003/00; G01P 3/00 20060101 G01P003/00 |
Claims
1. (canceled)
2. (canceled)
3. (canceled)
4. (canceled)
5. (canceled)
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8. (canceled)
9. (canceled)
10. (canceled)
11. (canceled)
12. (canceled)
13. (canceled)
14. (canceled)
15. (canceled)
16. (canceled)
17. (canceled)
18. (canceled)
19. (canceled)
20. (canceled)
21. (canceled)
22. (canceled)
23. (canceled)
24. (canceled)
25. An apparatus for measuring an angle of rotation beyond a
specific reference point comprising: a housing that is configured
to be located between a tool and a fastener; a shaft that is
configured to mate with the tool at a first end and a fastener at a
second end, wherein the shaft is located within the housing; an
angular rate sensor located within the housing and linked to the
shaft; a potentiometer that is configured to be adjustable to
differing degrees of torque angle, wherein the potentiometer is
located within the housing; a processor linked to the angular rate
sensor and the potentiometer, wherein the processor is located
within the housing.
26. The apparatus as in claim 25, wherein the potentiometer adjusts
the torque angle in 5 degree increments.
27. The apparatus as in claim 25, wherein the tool is a socket
wrench.
28. The apparatus as in claim 25, wherein the angular rate sensor
measures an output steady state voltage that is correlated to a
speed and direction of a torque applied to the fastener via the
shaft.
29. The apparatus as in claim 28, wherein the processor calculates
the torque angle.
30. The apparatus as in claim 29, wherein the processor determines
the torque angle by calculating an area underneath the measured
voltage.
31. The apparatus as in claim 25, further comprising a power source
located within the housing and linked to the microprocessor.
32. The apparatus as in claim 31, wherein the power source is a
battery.
33. The apparatus as in claim 31, further comprising a zero point
device that is located in the housing and linked to the
microprocessor.
34. The apparatus as in claim 33, further comprising a first angle
indicator that is configured to activate upon reaching a derived
torque angle.
35. The apparatus as in claim 34, wherein the first angle indicator
is a light emitting diode.
36. The apparatus as in claim 35, wherein the angle indicator is
configured to alert an operator when a current torque angle is
within a specified range of the desired torque angle.
37. The apparatus as in claim 36, wherein the specific range is ten
degrees.
38. The apparatus as in claim 35, further comprising an audio
indicator that is configured to activate upon reaching the desired
torque angle.
39. The apparatus as in claim 39, further comprising a second angle
indicator that is electrically connected at a distance to the
apparatus such that the apparatus is not structurally attached.
40. The apparatus as in claim 30, wherein the angular rate sensor
transmits data to the microprocessor via wireless
communications.
41. The apparatus as in claim 29, wherein the wireless
communications is infrared.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to a torque angle
measuring device. More particularly, the present invention relates
to a torque angle sensor that measures the current angle of
rotation applied beyond a point of reference.
BACKGROUND OF THE INVENTION
[0002] The importance of accurately and consistently controlling
tension or preload applied to threaded fasteners increases with
precision or criticality of parameters and tolerances of the
assembly as a whole. This is particularly true in mass production
of precision-designed equipment which may later be subjected to
maintenance or repair, following which load applied to the assembly
fasteners must be substantially the same as that applied during
original manufacture. For example, in the manufacture of internal
combustion engines designed for high performance and fuel economy,
the head is fastened to the engine block with a plurality of bolts
prior to final machining of various block/cylinder critical
surfaces. In the event that the head is later removed for repair or
replacement, it is important that the same be precisely reassembled
to the block so as to restore relationships of critical surfaces
obtained during the original manufacturing machining
operations.
[0003] Conventionally, preloading of threaded fasteners in engine
and other assembly applications is controlled by monitoring torque
applied to the assembly tool, such as with a mechanical or
electrical torque wrench. Fastener preload control through
monitoring of fastener torque alone, however, yields unpredictable
and inconsistent results due in part to varying friction between
the mating threads and beneath the fastener head. Where it has been
attempted to obtain greater uniformity through use of lubricants or
the like, results have continued to be unsatisfactory.
[0004] Another approach has been to monitor torque as a function of
angle of rotation, determine rate of change of torque, and compare
the resulting data during the manufacturing operation to
empirically determine data prestored in a computer memory. Such
arrangements still do not directly measure fastener tension, and in
addition require expensive assembly and control hardware.
[0005] A third approach has been to tighten the fastener to a point
at which the fastener material yields and the fastener head
separates from the threaded body. Arrangements of this type suffer
from the same inherent drawbacks as the torque wrench technique
described above due to varying friction between the fastener and
the assembly, and also increases the cost of both manufacture and
repair due to requirement for special double-headed fasteners.
[0006] A further technique for controlling fastener preload has
been found to yield particularly consistent results. This
technique, termed "torque-turn" or "torque-angle," involves
initially tightening the fastener to a specified torque, and
thereafter tightening the fastener through an additional
prespecified angle. The initial tightening torque is empirically
predetermined to be one at which the fastener is tightened in
assembly but has not yet been substantially elastically stretched.
By thereafter tightening the fastener through an additional angle
or fraction of a turn, advantage is taken of the precision
machining of the fastener threads so as to obtain predetermined
elastic stretching of the fastener within the assembly. For
example, a torque-turn or torque-angle fastening specification may
call for initial tightening to a torque of twenty-five
Newton-meters, followed by an additional one-half turn or a one
hundred and eighty-degree rotation in three equal steps.
[0007] The following is an example of torque instructions that
accompany a service manual and the need for torque angle
measurements.
[0008] Tighten the cylinder head bolts. [0009] a. Tighten the
cylinder head bolts a first pass in sequence to 30 N.cndot.m (22 lb
ft). [0010] b. Tighten the cylinder head bolts a second pass in
sequence to 70 degrees. [0011] c. Tighten the cylinder head bolts
(1, 2, 3, 4, 5, 6, 7, 8) to 70 degrees and the cylinder head bolts
(9 and 10) to 60 degrees a final pass in sequence.
[0012] Computer-based equipment has been proposed for implementing
such fastener preloading technique in mass production operations.
However, as previously noted, control during maintenance and repair
is as important as control during original assembly.
[0013] There remains a need in the art for inexpensive equipment
which may be employed by maintenance and repair technicians in the
field for obtaining the same precision control of fastener
preloading as is done during the original manufacturing operation.
Additionally, the products on the market that perform such a
function are large and cumbersome. These products use torque angle
detection techniques that inhibit their ability as well as for the
operability in constrained spaces.
[0014] Accordingly, it is desirable to provide a device that is
capable of determining the angle of rotation applied to a fastener
as well as display the current angle of rotation.
SUMMARY OF THE INVENTION
[0015] It is therefore an object of the present invention to
provide an apparatus that measures and displays the current angle
of rotation at which a fastener is rotated.
[0016] It is another aspect of the present invention to provide an
apparatus that measures the angle of rotation after a specified
torque is applied to a fastener with an apparatus compactly sized
to function in confining areas.
[0017] The above and other aspects are achieved through the use of
a novel combination of features as herein disclosed. In accordance
with one embodiment of the present invention, an apparatus measures
the angle of rotation beyond a specific reference point and an
angle indicator linked to the apparatus indicates the current angle
of rotation.
[0018] In a preferred embodiment, the apparatus comprises an angle
selector that is adjustable to the desired angle of rotation, an
angle rate sensor that measures the speed and direction of the
rotation applied, a processor which calculates the current angle
from the rate sensor measurements and a zero point indicator that
serves as the basis point for the processor to calculate the
selected angle of rotation.
[0019] In accordance with another embodiment of the present
invention, a device for measuring the angle of rotation beyond a
specific reference point is comprised of a means for measuring an
angle of rotation of the fastener from a fixed reference point and
a means for displaying the current angle of rotation. In this
alternate embodiment, the means for measuring an angle of rotation
is comprised of means for applying an angle of rotation to a
fastener, and a means for measuring the angle of rotation as
applied to the fastener from a fixed reference point. The means for
measuring comprises a means for selecting the desired angle of
rotation angle, a means for sensing data from the rate and speed of
the rotation being applied to a fastener, a means for calculating
the torque angle from the data and a means for indicating a zero
point from which the means for calculating bases its angle of
rotation measurement.
[0020] In accordance with another embodiment of the present
invention, a method for determining the angle of rotation is
comprised of measuring the angle of rotation as applied to a
fastener and displaying the current angle of rotation. In this
embodiment, the step of measuring the current angle of rotation is
comprised of selecting the desired angle of rotation with an angle
selector located on an apparatus. Further steps to the method are
indicating the zero point to processor as to the basis point to
determine the angle of rotation, applying torque to a fastener with
a tool to which the apparatus is attached, measuring the rate and
speed of the angle of rotation with the angle rate sensor starting
from the zero point and calculating the area from the rate and
speed to arrive at the torque angle, the area.
[0021] In accordance with another embodiment of the present
invention, a system is used to determine the angle of rotation
beyond a specific reference point. The system is comprised of an
apparatus that measures the angle of rotation beyond a specific
reference point and an angle indicator linked to the apparatus that
indicates the current angle of rotation. In this preferred
embodiment, the apparatus is comprised of an angle selector
adjustable to the desired angle of rotation, an angle rate sensor
that measures the speed and direction of the torque applied, a
processor which calculates the current angle from the rate sensor
measurements and a zero point indicator that instructs the
processor as to the basis point to calculate the selected
angle.
[0022] There has thus been outlined, rather broadly, the more
important features of the invention in order that the detailed
description thereof that follows may be better understood, and in
order that the present contribution to the art may be better
appreciated. There are, of course, additional features of the
invention that will be described below and which will form the
subject matter of the claims appended hereto.
[0023] In this respect, before explaining at least one embodiment
of the invention in detail, it is to be understood that the
invention is not limited in its application to the details of
construction and to the arrangements of the components set forth in
the following description or illustrated in the drawings. The
invention is capable of other embodiments and of being practiced
and carried out in various ways. Also, it is to be understood that
the phraseology and terminology employed herein, as well as the
abstract, is for the purpose of description and should not be
regarded as limiting.
[0024] As such, those skilled in the art will appreciate that the
conception upon which this disclosure is based may readily be
utilized as a basis for the designing of other structures, methods
and systems for carrying out the several purposes of the present
invention. It is important, therefore, that the claims be regarded
as including such equivalent constructions insofar as they do not
depart from the spirit and scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 provides an exploded perspective view of the
preferred embodiment.
[0026] FIG. 2 provides a block diagram of the preferred
embodiment.
[0027] FIG. 3 is a view of the preferred embodiment incorporated
with a ratchet and socket.
[0028] FIG. 4 is a flowchart illustrating the steps that may be
followed in accordance with one embodiment of the present inventive
method or process.
[0029] FIG. 5 provides a view of an alternate embodiment.
[0030] FIG. 6 is a view of the alternate embodiment incorporated
with a ratchet and socket.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
[0031] A preferred embodiment of the present invention provides a
device that measures an angle of rotation of a fastener after a
specified torque has been applied to the fastener. As illustrated
in FIG. 1, a preferred embodiment includes a shaft 10 is inserted
between a socket and torque wrench. The wrench end 12 is connected
to the torque wrench. The socket end 14 is connected to a socket
that is chosen for the appropriate fastener. The shaft 10 is linked
to an angular rate sensor 16 such as a gyroscope. Additionally, the
apparatus contains an angle selector 18. The angle selector 18 can
be a potentiometer, which allows for angle selection in about five
degree increments, or a resistance ladder, which allows for finer
angle selection. The angle selector 18 varies the voltage and
resistance. Any other suitable resistance adjuster can be used in
place of either the ladder or the potentiometer.
[0032] The shaft 18 does not need to be a separate component
between a socket and wrench. The shaft 18 itself can be
incorporated either with the socket itself, the wrench itself, or
be constructed as part of a combined socket and wrench.
[0033] Both the angular rate sensor 16 and the potentiometer 18 are
linked to a microcontroller or processor 20. The angular rate
sensor 16 measures the output steady state voltage that deviates
depending on the speed and direction of the torque, using the
Corolis effect. The processor then takes these measurements and
calculates the area underneath the measured voltage curve to arrive
at the torque angle.
[0034] A housing 22, 24, 26 encases the shaft 10 and all the other
components of the apparatus. The housing 22, 24, 26 contains a door
28 for insertion of a power source, which in the preferred
embodiment includes batteries 30.
[0035] The following is an example of how the device is used. After
inserting the apparatus between the ratchet and socket, the user
adjusts the angle selector 18 to the desired angle. At the time of
selection of the angle, the processor 20 notes the voltage. Torque
is then applied to the fastener until the desired torque is
reached. At this time, the zero point is set. After setting the
zero point, the wrench is rotated further. The angular rate sensor
16 measures the output steady state voltage and its deviation based
upon the speed and direction of the torque. From these
measurements, the processor 20 calculates the torque angle.
[0036] At some point, the apparatus indicates to the user when the
currently calculated torque angle approaches and/or equals the
desired angle. The alert can include a constant display of the
angle through the use of a display such as a light emitting diode
display or can include a single emitting diode to indicate when the
angle has been reached. In the preferred embodiment, the invention
contains light emitting diodes 32, 34 that provide indication to
the user. The first diode 32 alerts the user that the fastener is
within ten degrees of the specified angle. The second diode 34
alerts the user that the fastener is within one degree of the
specified angle. Additionally, a sounding indicator 36 or a sound
device activates concurrently with light emitting diode 34. The
sound device 36 in the preferred embodiment is a buzzer. The sound
indicator 36 is not limited to the use of a buzzer. It will be
readily apparent to one skilled in the art the available
replacements for this device.
[0037] FIG. 2 is a block diagram of the preferred embodiment. At
the center of the diagram is a microcontroller 20. Feeding into the
micorcontroller 20 is a potentiometer or other angle selector 18.
The user of the apparatus uses the angle selector 18 to select the
desired torque angle. The selection is fed into the microcontroller
20. From this point, the microcontroller 20 monitors the voltage.
The point of selection is used as a reference to calculate the
measured torque angle. The output of the gyroscope or angular rate
sensor 16 is inputted into the microcontroller or processor 20. The
angular rate sensor 16 measures the output steady state voltage.
The output deviates depending on the speed and direction of the
torque. These measurements are fed into the microcontroller 20 to
where a calculation takes place. The calculation is the area
underneath the curve of all the measurements obtained from the
angular rate sensor 16. With this calculation, the torque angle can
be detected.
[0038] The processor 20 controls the light emitting diodes 32, 34,
40. The first diode 40 is activated when the zero point is selected
subsequent to the depression of button 42. The button instructs the
processor 20 that the current location is the zero-point or
reference point from which to calculate the torque angle. When the
processor 20 acknowledges the zero point, the light emitting diode
40 is activated.
[0039] The other diodes are used to alert the user of the currently
calculated torque angle. This ranges from a constant display of the
angle through the use of a display such as a light emitting diode
display or a liquid crystal display to a single emitting diode that
alerts as to when the angle is reached. In the preferred
embodiment, the invention contains the light emitting diodes, 32,
34, which warn the user. The first diode 32 alerts the user that
they are within ten degrees of the specified angle. The second
diode 34 alerts the user that they are within one degree of the
specified angle. Additionally, a sounding indicator 36 or a sound
device activates concurrently with light emitting diode 34.
[0040] A switch 44 is also incorporated on the apparatus. The
switch 44 controls the power used by the gyroscope 16, the angle
selector 18 and the light emitting diodes 32, 34, 40. The switch 44
serves as a power conservation device when the device is not being
used to determine the torque angle.
[0041] FIG. 3 shows the preferred embodiment of the torque angle
sensor 46 with a ratchet handle and socket. The sensor 46 is placed
between the ratchet 48 and the socket 50. The ratchet 48 is used to
generate the torque to turn a fastener. The torque is transferred
to the sensor 46 and then onto the socket 50. The sensor 46
measures the speed and directions of the torque and uses these
calculations to arrive at the angle of rotation.
[0042] FIG. 4 is a flowchart illustrating the steps that may be
followed in accordance with one embodiment of the present inventive
method or process. The first step 52 in the process is selecting
the desired angle of torque with an angle selector 18. The
preferred embodiment uses a resistance ladder to achieve this
method. However a potentiometer as well as other devices are
interchangeable with that used in the preferred embodiment. The
resistance ladder has a finer angle selection than the
potentiometer.
[0043] The next step 54 is indicating the zero point to the
processor in order to determine the angle of torque. The preferred
embodiment accomplishes this function with the use of a button or
switch 42. The button or switch 42 instructs the processor to mark
this as the origination point from where to measure the torque
angle. The processor responds with illuminating a light emitting
diode. The illumination is a signal that the processor has indeed
received the instruction and has marked it as a reference
point.
[0044] The next step 56 is applying torque to rotate a fastener
with a tool. The tool can be a ratchet or socket or any other
device that is capable of applying torque. The tool can actually be
the device incorporated or built into a torque-generating device.
The tool can be manual-driven or power driven.
[0045] The next step 58 is measuring the rate and speed of the
applied torque rotation with the angle rate sensor 16 starting from
the zero point. The angle sensor 16 or gyroscope does this by
measuring the Corolis effect of the torque.
[0046] From these measurements, the next step 60 of calculating the
area is arrived at to determine the torque angle. The mathematical
computations are completed by the processor. The output steady
state voltage deviates depending on the speed and direction of the
torque. This deviation enables the processor to calculate the
torque angle.
[0047] The next step 62 is indicating the rotation angle of torque
applied beyond the zero point using the angle indicator 32, 34. The
preferred embodiment uses two angle indicators. The first
indicator, a light emitting diode 32, is illuminated when the
torque angle is within ten degrees of the pre-selected desired
torque angle. The second indicator, a light emitting diode 34, is
illuminated when the torque angle is within one degree of the
specified angle. Concurrently with the second indicator, the
apparatus uses a sound indicator 36. When the emitting diode 34 is
activated, the sound indicator is triggered. In the preferred
embodiment, the apparatus is a buzzer.
[0048] The indicating step 62 can use any number of devices. For
example, the indicator 34, 36 can range from a graduated display
that can be used to indicate the current angle calculated to a
plurality of diodes as in the preferred embodiment. Additional
indicating devices will be readily apparent to those of ordinary
skill in the art.
[0049] FIG. 5 provides a view of an alternate embodiment. In this
embodiment, the indicator of torque angle is a display 64 of a
digital multimeter 66. In this embodiment, the current angle of
rotation is constantly displayed throughout the angle of rotation.
A shaft 70 is placed between a fastener and a torque-generating
device such as a ratchet 48. The speed and direction of rotation of
the shaft 70 is monitored by an adapter 72, which uses these
measurements to arrive at the angle of rotation. The angle of
rotation is transferred to the digital multimeter 64. The angle of
rotation is shown on the display 66, which is based from the zero
point and continues to show the current angle of rotation.
[0050] The speed and direction of the angle of rotation applied to
the shaft 70 is transmitted to the adapter 72 via the hard wire 74.
The shaft 70 need not be hard wired to the adapter 72. The
transmission can be accomplished by an infrared transmission or
over a radio frequency, so that the data from the shaft 70 is
transmitted in a non-hard wired configuration. The data is
transmitted to a receiver on the adapter 72. The receiver captures
the data to calculate the current angle and transmits this a signal
to the multimeter 66.
[0051] In addition to a visual display, the preferred embodiment
contains a sound generating device 78 on the adapter 72. When the
desired angle of rotation has been reached, the sound device 78 is
activated. In the preferred embodiment, the sound device 78 is
audible to the human ear with an adequate distance from operation
of the invention.
[0052] FIG. 6 shows an alternate preferred embodiment of the torque
angle adapter with a ratchet 48 handle and socket 50. The shaft 70
is placed between the ratchet 48 and the socket 50. The ratchet 48
is used to generate the torque to turn a fastener. The torque is
transferred to the shaft 70 and then onto the socket 50. The shaft
70 is monitored by the angular rate sensor 16 to measure the speed
and directions of the angle of rotation and uses these calculations
to arrive at the angle of rotation. The angle of rotation is
calculated by the microcontroller 20. The result of this
calculation is transformed into a signal by the microcontroller 20
and transmitted to the digital multimeter 66 where is seen on the
display 76.
[0053] The many features and advantages of the invention are
apparent from the detailed specification, and thus, it is intended
by the appended claims to cover all such features and advantages of
the invention which fall within the true spirits and scope of the
invention. Further, since numerous modifications and variations
will readily occur to those skilled in the art, it is not desired
to limit the invention to the exact construction and operation
illustrated and described, and accordingly, all suitable
modifications and equivalents may be resorted to, falling within
the scope of the invention.
* * * * *