US 5,636,120 A · Direct drive autoshift transmission control

Abstract

An electronic autoshift control is provided for a transmission and engine to help reduce demands on the operator. Part of the autoshift feature is an auto/manual switch which is a two-position rocker switch controlled by the operator. The switch determines whether the transmission is being operated in the manual or the automatic mode. In the manual mode, all shifting is performed by the operator by moving the shift lever. Once in the automatic mode, the transmission controller takes over with the autoshift feature. When switched to the automatic mode, an auto/manual lamp is lit indicating the transmission's automatic mode of operation. The rocker switch also functions as a hold switch. If traction conditions are poor and the operator wants to stay in the present gear, the rocker switch can be toggled to the manual mode. This locks the transmission in its present gear and causes the auto/manual lamp to flash if the shift lever selection and the present transmission selection do not coincide. Once the operator is out of the poor conditions, the switch can be returned to auto thus resuming the autoshift functions.

Claims12

Dependent claims

A method for controlling shifting of an electronic transmission having an output shaft, a plurality of forward and reverse gears to rotate said output shaft in forward and reverse directions, a neutral gear and an operator controlled shift lever for requesting a gear from said forward, neutral and reverse gears, said method comprising the steps of:

monitoring transmission output shaft speed;
operating an auto/manual switch to
respective auto and manual positions to select a corresponding one of auto and manual modes of operation for an electronic shift control of the transmission;
operating said shift lever to request a gear from said forward, reverse and neutral gears;
shifting said transmission to said requested gear when said transmission shift control is operating in said manual mode and automatically selecting a present gear on the basis of said transmission shaft output speed when said shift control is operating in said auto mode;
setting the transmission shift control to the manual mode when the requested gear coincides with the present gear and said auto/manual switch is moved to the manual position;
and
automatically holding said transmission in the present gear, when the auto/manual switch is moved from the auto position to the manual position, until the requested gear coincides with the present gear.

5 more elements

An electronic autoshift control for a transmission having an output shaft and being electronically shiftable between forward and reverse gear to rotate said output shaft in forward and reverse directions and a neutral gear, said electronic autoshift control comprising:

electronic shift control means operable in a manual mode for shifting said transmission between said forward, reverse and neutral gears responsive to operator shift requests, and operable in an automatic mode for shifting said transmission responsive to stored transmission speed shift points;
an operator actuated gear shift lever operable to request a gear from said forward reverse and neutral gears;
and
a switch operable between a manual position and an automatic position, for selecting between said automatic and said manual modes, said shift control means holding said transmission in the present gear until the gear requested by said shift lever coincides with the present gear when said switch is moved from the automatic position to the manual position and thereafter shifting said transmission responsive to operator shift requests.

1 more element

Dependencies are inferred from the claim text.

Direct drive autoshift transmission control

Life of this patent

Direct drive autoshift transmission control

Life of this patent

Abstract

Claims12