Patent JPS5979264A successfully refreshed from Google Patents.
US4866419A
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US
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Method for detecting an underinflated tire by monitoring a work vehicle suspension
Assignee: Caterpillar Inc
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Filing: 1987-10-13
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Granted: 1989-09-12
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Expires: 2007-10-13
Abstract
Abstract In the field of off-highway trucks, tires represent a significant portion of operating expenses. Underinflated tires wear more quickly than properly inflated tires. This invention pertains to an apparatus for detecting an underinflated tire of a work vehicle (12) and displaying the information to the operator or service personnel. The apparatus senses internal pressures of preselected struts (16,18), and converts these signals into an indication of relative inflation pressures of the associated tires (32). When a tire is underinflated relative to another tire by a preselected amount, an underinflation signal is transmitted to a display. The display indicates to the operator that a tire is underinflated.
Inventors
- 👤 Christos T. Kyrtsos
- 👤 Gregory E. Long
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:57
CPC Classifications
G; G01; G01M; G01M17/00; G01M17/007; G01M17/04; B; B60; B60C; B60C23/00; B60C23/001; B60C23/002; B60G; B60G17/00; B60G17/015; B60G17/018; B60G17/0185; B60G2300/00; B60G2300/02; B60G2300/026; B60G2300/07; B60G2400/00; B60G2400/20; B60G2400/204; B60G2400/50; B60G2400/51; B60G2400/52; B60G2400/60; B60G2600/00; B60G2600/02; B60G2600/04; B60G2600/08
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
143 words
A method (250) for detecting an underinflated tire of a work vehicle (12) having a plurality of left and right strut mounted wheels, comprising: periodically sensing the internal pressure of each of the struts (16, 18) and delivering a plurality of first signals each having a magnitude correlative to the internal pressure of each respective strut (16, 18); comparing consecutive first signals of each respecting strut and delivering a second signal having a magnitude correlative to the differential therebetween; counting the number of second signals exceeding a preselected setpoint during a preselected period of time; comparing the count for each strut (16, 18) to the count for another strut (16, 18) and delivering a third signal having a magnitude responsive to the count differential, and delivering a signal indicative of an underinflated tire in response to the count differential exceeding a preselected setpoint.
Claim 2
Independent Claim
143 words
A method (250) for detecting an underinflated tire of a work vehicle (12) having a plurality of left and right strut mounted wheels, comprising: periodically sensing the internal pressure of each of the struts (16, 18) and delivering a plurality of first signals each having a magnitude correlative to the internal pressure of each respective strut (16, 18); comparing consecutive first signals of each respecting strut and delivering a second signal having a magnitude correlative to the differential therebetween; counting the number of second signals exceeding a preselected setpoint during a preselected period of time; comparing the count for each strut (16, 18) to the count for another strut (16, 18) and delivering a third signal having a magnitude responsive to the count differential, and delivering a signal indicative of an underinflated tire in response to the count differential exceeding a preselected setpoint.
Claim 3
Dependent Claim
47 words
A method (250), as set forth in claim 1, wherein the step of comparing the count for each strut (16, 18) includes comparing the counts of the left (16L) and right (16R) front struts and comparing the counts of the left (18L) and right (18R) rear struts.
Claim 4
Independent Claim
176 words
A method for detecting an underinflated tire of a work vehicle having pneumatic tires mounted on a plurality of opposed wheels which are mounted on hydraulic struts, comprising: periodically sensing the internal pressure of preselected struts and delivering a plurality of first signals each having a value responsive to the internal pressure of a respective strut; converting said first signals to a plurality of second signals by the formula: .sub.Δ X=K(1/p(t)).sup.5/7 where: X is the linear displacement of the strut with respect to time; K is a constant related to strut configuration; and p(t) is strut pressure with respect to time; summing said plurality of second signals for each preselected strut; comparing said summed preselected second signals one with another; delivering a signal indicative of relative inflation pressures of associated tires in response to said compared second signals; and comparing said relative inflation pressure signal with a preselected setpoint signal, and delivering an underinflation signal in response to the difference between said relative inflation signal and said setpoint signal being greater than a preselected difference value.
Claim 5
Independent Claim
176 words
A method for detecting an underinflated tire of a work vehicle having pneumatic tires mounted on a plurality of opposed wheels which are mounted on hydraulic struts, comprising: periodically sensing the internal pressure of preselected struts and delivering a plurality of first signals each having a value responsive to the internal pressure of a respective strut; converting said first signals to a plurality of second signals by the formula: .sub.Δ X=K(1/p(t)).sup.5/7 where: X is the linear displacement of the strut with respect to time; K is a constant related to strut configuration; and p(t) is strut pressure with respect to time; summing said plurality of second signals for each preselected strut; comparing said summed preselected second signals one with another; delivering a signal indicative of relative inflation pressures of associated tires in response to said compared second signals; and comparing said relative inflation pressure signal with a preselected setpoint signal, and delivering an underinflation signal in response to the difference between said relative inflation signal and said setpoint signal being greater than a preselected difference value.
Claim 6
Dependent Claim
66 words
A method, as set forth in claim 3, wherein the steps of comparing said second signals and delivering said relative inflation pressures include: multiplying preselected second signals by scale factors; comparing preselected scaled second signals with preselected unscaled second signals; and delivering a signal indicative of relative inflation pressures of preselected tires in response to a difference between said scaled second signals and unscaled second signals.
Claim 7
Independent Claim
150 words
A method (130) for detecting an underinflated tire of a work vehicle (12) having pneumatic tires (32) mounted on a plurality of opposed wheels which are mounted on hydraulic struts (16,18), comprising: sensing the internal pressure of preselected struts (16,18) and delivering a plurality of first signals each having a value responsive to the internal pressure of a respective strut (16,18); converting said first signals to second signals, each of said second signals being responsive to a kinetic energy transfer from a tire (32) to an associated strut (16,18); comparing preselected second signals one with another and delivering a signal in response to said comparison, said signal being responsive to relative inflation pressures of preselected tires (32); and comparing said relative inflation pressure signal with a preselected setpoint and delivering an underinflation signal in response to a preselected difference between said relative inflation pressure signal and said preselected setpoint signal.
Claim 8
Independent Claim
150 words
A method (130) for detecting an underinflated tire of a work vehicle (12) having pneumatic tires (32) mounted on a plurality of opposed wheels which are mounted on hydraulic struts (16,18), comprising: sensing the internal pressure of preselected struts (16,18) and delivering a plurality of first signals each having a value responsive to the internal pressure of a respective strut (16,18); converting said first signals to second signals, each of said second signals being responsive to a kinetic energy transfer from a tire (32) to an associated strut (16,18); comparing preselected second signals one with another and delivering a signal in response to said comparison, said signal being responsive to relative inflation pressures of preselected tires (32); and comparing said relative inflation pressure signal with a preselected setpoint and delivering an underinflation signal in response to a preselected difference between said relative inflation pressure signal and said preselected setpoint signal.
Claim 9
Dependent Claim
62 words
A method (130), as set forth in claim 5, wherein the step of comparing said second signals includes: multiplying preselected second signals by scale factors; comparing preselected scaled second signals with preselected unscaled second signals; and delivering a signal indicative of relative inflation pressures of preselected tires (32) in response to a difference between said scaled second signals and unscaled second signals.
Claim 10
Dependent Claim
66 words
A method (130), as set forth in claim 5, wherein the step of comparing preselected second signals includes: repeating the steps of claim 5 a plurality of times; storing said second signals in a summation of like second signals from said previous sensing steps; and calculating a ratio of a pair of summed second signals and delivering a relative pressure signal in response to said calculation.
Claim 11
Dependent Claim
28 words
A method (130), as set forth in claim 5, wherein the step of comparing preselected second signals includes calculating a ratio of a pair of preselected second signals.
Claim 12
Dependent Claim
54 words
A method, as set forth in claim 5, wherein the step of comparing said preselected second signals includes: calculating the ratio of the kinetic energy transmitted to the left front (16L) and right rear struts (18R); calculating the ratio of the kinetic energy transmitted to the right front (16R) and left rear struts (18L).
Claim 13
Dependent Claim
98 words
A method, as set forth in claim 9, wherein the step of comparing preselected second signals includes: comparing the ratio of the kinetic energy transferred to the left front strut (16L) and the right front strut (16R) with a ratio of the kinetic energy transferred to the left front strut (16L) and the left rear strut (18L), and comparing a ratio of the kinetic energy transferred to the right front strut (16R) and the left rear strut (18L) with a ratio of the kinetic energy transferred to the right front strut (16R) and the right rear strut (18R).
Claim 14
Independent Claim
127 words
A method (200) for detecting an underinflated tire of a work vehicle (12) having pneumatic tires (32) mounted on a plurality of opposed wheels which are mounted on hydraulic struts (16,18), comprising: sensing the internal pressure of preselected struts (16,18) and delivering a plurality of first signals each having a value responsive to the internal pressure of a respective strut (16,18); determining the slopes of selected portions of preselected first signals; comparing said slopes one with another; delivering a signal indicative of relative inflation pressures of preselected tires in response to said comparison; and comparing said relative inflation pressure signal with a preselected setpoint signal, and delivering an underinflation signal in response to a preselected difference between said relative inflation pressure signal and said preselected setpoint signal.
Claim 15
Independent Claim
127 words
A method (200) for detecting an underinflated tire of a work vehicle (12) having pneumatic tires (32) mounted on a plurality of opposed wheels which are mounted on hydraulic struts (16,18), comprising: sensing the internal pressure of preselected struts (16,18) and delivering a plurality of first signals each having a value responsive to the internal pressure of a respective strut (16,18); determining the slopes of selected portions of preselected first signals; comparing said slopes one with another; delivering a signal indicative of relative inflation pressures of preselected tires in response to said comparison; and comparing said relative inflation pressure signal with a preselected setpoint signal, and delivering an underinflation signal in response to a preselected difference between said relative inflation pressure signal and said preselected setpoint signal.
Claim 16
Dependent Claim
97 words
A method (200), as set forth in claim 11, wherein the step of determining includes: monitoring each of said first signals and determining points responsive to relative low pressure points of each respective strut (16,18); calculating the slope of each of said first signals from said relative low pressure points to respective relative high pressure points; summing each of said calculated slopes of a respective strut for a preselected period of time; calculating ratios of a pair of said summed slopes; and delivering signals indicative of relative inflation pressures of preselected tires in response to said calculation.
Claim 17
Independent Claim
130 words
A method (160) for detecting an underinflated tire of a work vehicle (12) having pneumatic tires (32) mounted on a plurality of opposed wheels which are mounted on hydraulic struts (16,18), comprising: sensing the internal pressure of preselected struts (16,18) and delivering a plurality of first signals each having a value responsive to the internal pressure of a respective strut (16,18); determining maximums and minimums of selected portions of preselected first signals; comparing said maximums and minimums with each other; delivering a signal indicative of relative inflation pressures of preselected tires in response to said comparison; and comparing said relative inflation pressure signal with a preselected setpoint signal, and delivering an underinflation signal in response to a preselected difference between said relative inflation pressure signal and said preselected setpoint signal.
Claim 18
Independent Claim
130 words
A method (160) for detecting an underinflated tire of a work vehicle (12) having pneumatic tires (32) mounted on a plurality of opposed wheels which are mounted on hydraulic struts (16,18), comprising: sensing the internal pressure of preselected struts (16,18) and delivering a plurality of first signals each having a value responsive to the internal pressure of a respective strut (16,18); determining maximums and minimums of selected portions of preselected first signals; comparing said maximums and minimums with each other; delivering a signal indicative of relative inflation pressures of preselected tires in response to said comparison; and comparing said relative inflation pressure signal with a preselected setpoint signal, and delivering an underinflation signal in response to a preselected difference between said relative inflation pressure signal and said preselected setpoint signal.
Claim 19
Dependent Claim
40 words
A method (160), as set forth in claim 13, wherein said step of comparing said maximums and minimums includes: counting the number of maximums and minimums exceeding a preselected range; and comparing the counts from preselected struts one with another.
Claim 20
Dependent Claim
41 words
A method (160), as set forth is claim 13, wherein said step of comparing said maximums and minimums includes: calculating a difference between a maximum and a minimum of a preselected first signal; and comparing said difference to a preselected range.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-11 | 1993-03-13 | 1993-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-11 | 1997-03-13 | 1997-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-11 | 2001-03-13 | 2001-09-12 | $7700.00 | Window Closed / Lapsed |