US3871235A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Distance or speed measuring apparatus for land-vehicles
Assignee: Smiths Group PLC
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Filing: 1972-06-12
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Granted: 1975-03-18
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Expires: 1992-06-12
Abstract
Abstract A representation of the distance travelled by, or the speed of, a wheeled-vehicle and compensated for wheel-slip, is provided from signals derived in accordance with the speeds respectively of two driven wheels of the vehicle. Difference between the two signals arising from slip is detected to derive a difference signal that is subtracted from the sum of the two signals so as to derive thereby an output in accordance with the speed of the slower, non-slipping, wheel. Alternatively, the difference signal controls switches that supply the two signals to an adder to cause both to supply the slower-wheel signal to the adder when a predetermined threshold value of the speed-difference signal is detected. The sense of the speed-difference signal may instead be used to control selection for direct use of whichever of the two wheel-speed signals is representative of the slower wheel. The two speed signals may be in the form of mechanical or electrical manifestations and in the latter case may be of pulse form supplied to respective switching inputs of a bistable device to produce an output pulse train in accordance with the lower pulse frequency. Where two wheels are driven from a common drive-shaft through a differential, detected rotation of the planet wheels of the differential (arising from slip of one driven wheel relative to the other) may be used to reduce the engine speed so as to eliminate slip and ensure correct reading of speed or distance directly from the drive-shaft rotation.
Inventors
- 👤 Edward William Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:40
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/42; G01P3/50; G01P3/56
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
116 words
Apparatus for providing a representation of movement of a land-vehicle having a pair of driven traction members, comprising first means for providing first and second manifestations respectively dependent on the speeds of different driven traction members of the vehicle, second means responsive to said first and second manifestations for providing said representation in accordance with one of said manifestations, said second means comprising means responsive to a condition in which there is difference between said first and second manifestations for providing an output manifestation in accordance with whichever of said first and second manifestations is representative of the slower speed, and further means for providing said representation of vehicle movement in accordance with said output manifestation.
Claim 2
Dependent Claim
116 words
Apparatus for providing a representation of movement of a land-vehicle having a pair of driven traction members, comprising first means for providing first and second manifestations respectively dependent on the speeds of different driven traction members of the vehicle, second means responsive to said first and second manifestations for providing said representation in accordance with one of said manifestations, said second means comprising means responsive to a condition in which there is difference between said first and second manifestations for providing an output manifestation in accordance with whichever of said first and second manifestations is representative of the slower speed, and further means for providing said representation of vehicle movement in accordance with said output manifestation.
Claim 3
Dependent Claim
144 words
Apparatus according to claim 1, wherein said first and second manifestations are each in the form of a pulse train whose repetition frequency varies in accordance with the speed of the relevant traction member, and wherein said means responsive to a condition in which there is difference between said first and second manifestations comprises bistable means that is switchable between first and second stable states, means to apply pulses of one pulse train to the bistable means for switching it from said first state to its second state, and means to apply pulses of the other pulse train to said bistable means for switching it from said second state to the first state, so as thereby to cause the bistable means to switch at a frequency which is in accordance with whichever of the first and second manifestations has the lower pulse repetition frequency.
Claim 4
Dependent Claim
135 words
Apparatus according to claim 1, including summation means, a pair of switch means each of which is switchable between a first state in which it supplies said first manifestation to the sumMation means and a second state in which it supplies said second manifestation to the summation means, said summation means providing an output in accordance with the sum of the manifestations supplied thereto by the switch means, means responsive to a condition in which there is difference between said first and second manifestations, and means for controlling the said switch means in response to the said condition, said control means controlling the said switch means, in response to said condition, so that each switch means supplies to the summation means whichever of the first and second manifestations is representative of the slower-speed traction member.
Claim 5
Dependent Claim
146 words
Apparatus according to claim 1, including switch means which is switchable between first and second states, means connecting said switch means between said first means and said further means to supply said first manifestation to said further means as said output manifestation when said switch means is in said first state and to supply said second manifestation to said further means as said output manifestation when said switch means is in said second state, means responsive to a condition in which there is difference between said first and second manifestations, and means for controlling switching of said switch means between said first and second states in response to said condition to maintain said switch means in the state in which the manifestation supplied by the switch means to said further means is whichever of the first and second manifestations is representative of the slower-speed traction member.
Claim 6
Dependent Claim
143 words
Apparatus for providing an output manifestation representative of movement of a land-vehicle having a pair of driven traction members, comprising first means for providing first and second manifestations respectively dependent on the speeds of different driven traction members of the vehicle, and second means for providing said output manifestation in accordance with at least one of said first and second output manifestations, said second means comprising means responsive to both of said manifestations to derive said output manifestation at least in part in accordance with the sum of said first and second manifestations, means for sensing a difference in speed between the two traction members representative of slip or either of the traction members, and means for responding to said difference to effect a reduction of said sum in accordance with said difference to relate said output manifestation to the slower-speed traction member.
Claim 7
Dependent Claim
143 words
Apparatus for providing an output manifestation representative of movement of a land-vehicle having a pair of driven traction members, comprising first means for providing first and second manifestations respectively dependent on the speeds of different driven traction members of the vehicle, and second means for providing said output manifestation in accordance with at least one of said first and second output manifestations, said second means comprising means responsive to both of said manifestations to derive said output manifestation at least in part in accordance with the sum of said first and second manifestations, means for sensing a difference in speed between the two traction members representative of slip or either of the traction members, and means for responding to said difference to effect a reduction of said sum in accordance with said difference to relate said output manifestation to the slower-speed traction member.
Claim 8
Dependent Claim
101 words
Apparatus according to claim 5, wherein said second means further comprises means responsive to said first and second manifestations for deriving a third manifestation in accordance with a difference between said first and second manifestations representative of slip of either of the two traction members, means for deriving a fourth manifestation representative of the sum of said first and second manifestations, and means for deriving said representation in accordance with the difference between said third and fourth manifestations so as thereby to relate said output manifestation to the slower-speed traction member whenever there is slip of either of the traction members.
Claim 9
Dependent Claim
228 words
Apparatus for providing a manifestation representative of movement of a land-vehicle of the type having two traction members comprising, a source of motive power for driving both said traction members, and a differential for conveying drive from said source to said traction members, said differential including an input shaft coupled to said source, two output shafts that are coupled respectively to said traction members, and means rotatable in accordance with any difference between the speeds of rotation of said two output shafts, the apparatus further including: a first speed sensor responsive to the speed of rotation of said input shaft of the differential to provide a first manifestation in accordance with said speed, A second speed sensor responsive to rotation of said rotatable means of the differential to provide a second manifestation dependent upon the difference in speed between the two output shafts arising from slip of either of said traction members, and output means for providing a representation of movement of the vehicle in accordance with the speed of the slower of the two traction members in the presence of said slip, said output means being responsive to said first manifestation to provide said representation and being also responsive to said second manifestation to effect a reduction on said representation in accordance with said difference so as thereby to relate said representation to the slower-speed traction member.
Claim 10
Dependent Claim
228 words
Apparatus for providing a manifestation representative of movement of a land-vehicle of the type having two traction members comprising, a source of motive power for driving both said traction members, and a differential for conveying drive from said source to said traction members, said differential including an input shaft coupled to said source, two output shafts that are coupled respectively to said traction members, and means rotatable in accordance with any difference between the speeds of rotation of said two output shafts, the apparatus further including: a first speed sensor responsive to the speed of rotation of said input shaft of the differential to provide a first manifestation in accordance with said speed, A second speed sensor responsive to rotation of said rotatable means of the differential to provide a second manifestation dependent upon the difference in speed between the two output shafts arising from slip of either of said traction members, and output means for providing a representation of movement of the vehicle in accordance with the speed of the slower of the two traction members in the presence of said slip, said output means being responsive to said first manifestation to provide said representation and being also responsive to said second manifestation to effect a reduction on said representation in accordance with said difference so as thereby to relate said representation to the slower-speed traction member.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |