Method of overriding ratio matching feature in power shift transmissions

Patent · Tue Apr 16 04:00:00 EDT 1991

OSTI ID:5062788

Bulgrien, G H

This patent describes a method of controlling the operation of a vehicle transmission operably connected to an engine and having clutches for selectively interconnecting an engine driven input drive shaft, an output drive shaft operatively coupled to ground engaging wheels of the vehicle to effect movement thereof over the ground, and gears rotatably housed in output drive shafts such that a selective engagement of the clutches will effect a varying of the speed of operation of the output shaft for a given speed of operation of the input shaft, the transmission further having en electrical control system including a microprocessor responsive to switches actuated by manual movement of a gearshift means between positions, including forward, reverse, and neutral positions, for controlling the clutches in the transmission, the microprocessor being operable to engage a ratio matching routine when the gearshift means is placed in the neutral position to select a gear having a gear ratio substantially equivalent to the ratio derived from the respective speeds of rotation of the input and output shafts. It comprises signaling the microprocessor for an upshift or a downshift of the transmission while engaged in the ratio matching routine; and exiting the ratio matching routine and entering a gear selection routine in the microprocessor while the gearshift remains in the neutral position to effect a selection of an alternative gear other than the gear selected by the ratio matching routine.

• Assignee: Ford New Holland, Inc., New Holland, PA (USA)
• Patent Number(s): US 5007299; A
• Application Number: PPN: US 7-521630
• OSTI ID: 5062788
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330602* -- Vehicle Design Factors-- Engine-Transmission Matching
AUTOMATION
COMPUTERIZED CONTROL SYSTEMS
COMPUTERS
CONTROL SYSTEMS
ELECTRONIC CIRCUITS
GEARS
MACHINE PARTS
MECHANICAL TRANSMISSIONS
MICROELECTRONIC CIRCUITS
MICROPROCESSORS
ON-LINE CONTROL SYSTEMS
ON-LINE SYSTEMS
OPERATION