EP0076679A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Control of motor vehicle transmission
Assignee: GKN Technology Ltd
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Filing: 1982-10-04
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Granted: —
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Expires: 2002-10-04
Abstract
Abstract A vehicle transmission, particularly an overdrive unit, is controlled by a micro-processor control circuit which responds to operating parameters including speed and torque being transmitted by the unit to determine whether a change in gear ratio of the unit is to be effected. The control circuit is also responsive to engine speed, operation of an accelerator controlled kick-down switch, and operation of a clutch associated with a conventional manual gearbox of the vehicle.
Inventors
- 👤 Brian Michael Forster
- 👤 John Stuart Renowden
- 👤 Geoffrey James Howell
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 14:31
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/70; F16H61/702; F16H59/00; F16H59/14; F16H59/16; B; B60; B60W; B60W2510/00; B60W2510/10; B60W2510/105; F16H2059/148; F16H37/00; F16H37/02; F16H37/04; F16H37/042; F16H37/046; F16H59/18; F16H59/20; F16H59/50; F16H59/56; F16H61/68; F16H61/684; F16H61/686
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
52 words
A motor vehicle transmission unit including a control circuit responsive to operating parameters of the unit and operative to effect a change in gear ratio of the transmission unit upon predetermined conditions and values of said parameters being achieved, characterised in that said parameters include torque and speed measured in the unit.
Claim 2
Dependent Claim
52 words
A motor vehicle transmission unit including a control circuit responsive to operating parameters of the unit and operative to effect a change in gear ratio of the transmission unit upon predetermined conditions and values of said parameters being achieved, characterised in that said parameters include torque and speed measured in the unit.
Claim 3
Dependent Claim
12 words
A transmission according to Claim 1 which is an over- drive unit.
Claim 4
Dependent Claim
32 words
A transmission according to Claim 1 or Claim 2 further characterised in that said parameter of torque is measured directly by a sensor (D) at an output shaft (3) of the unit.
Claim 5
Dependent Claim
55 words
A transmission according to Claim 1, 2 or 3 further characterised in that said operating parameters further comprise vehicle engine speed, and the condition of operation of a kick-down switch (F) operated from the vehicle's accelerator control and a switch (G) controlled by operation of a clutch associated with a manual gearbox of the vehicle.
Claim 6
Dependent Claim
49 words
A transmission according to Claim 4 further characterised in that said control circuit includes a micro- processor, arranged to carry out at pre-set intervals a program which includes determination of said operational conditions and measurements of said parameters to determine whether to effect a change in said gear ratio.
Claim 7
Dependent Claim
75 words
A transmission according to Claim 5 which is an overdrive unit and further characterised in that said control circuit includes means for storing a table (table A) of values of torque related to overdrive input speed and gear ratio, below which values the overdrive unit can be brought into operation, and a table (table B) of values of torque related to overdrive input speed and gear ratio, above which values the overdrive should be disengaged.
Claim 8
Dependent Claim
32 words
An overdrive unit according to Claim 6 further characterised in that said control circuit includes means for preventing said overdrive disengagement if the vehicle's engine speed exceeds a predetermined allowable maximum speed.
Claim 9
Dependent Claim
73 words
An overdrive unit according to any one of Claims 3 to 7 further characterised in that said torque is measured by means (118, 116, 218) for inducing a magnetic field in a surface region of said output shaft, and at least one sensor (122-125, 222-225) positioned adjacent said surface region to detect changes in said magnetic field due to torque in said shaft and provide an electrical output signal representative of said torque.
Claim 10
Dependent Claim
141 words
An overdrive unit according to Claim 8 further characterised by a ferro-magnetic core structure (111) having four poles (113-115) positioned adjacent the surface of the shaft, with a first pair of poles spaced axially and circumferentially of the shaft, a second pair of poles spaced axially and circumferentially of the shaft in a different orientation from said first pair, a sensor associated with each of said poles to measure the magnetic field therein and producing an electrical output signal representing said magnetic field, means (128, 229) for adding the output signals from said sensors of said first pair of poles, means (-, 232) for adding the output signals from said sensors of the second pair of poles, and means (129, 333) for subtracting the added signals thus derived from one another to produce an output signal representing torque in the shaft.
Claim 11
Dependent Claim
23 words
1 0. An overdrive unit according to Claim 9 further characterised in that said sensors (122 - 125)comprise coils carried by said poles.
Claim 12
Dependent Claim
24 words
An overdrive unit according to Claim 8 or Claim 9 further characterised in that the or each said sensor (222-225) comprises a Hall-effect sensor.
References Cited (Backward Citations)
No citation records indexed.
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