Gearshift method and apparatus

US4360092A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Alfred Muller · Krefeld, DE
• Joseph Sauer · Strullendorf, DE

Key dates

• Filing date: Mar 10, 1980
• Grant date: Nov 23, 1982
• Expiry date: Mar 10, 2000

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16D49/12
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

In first gear, a brake band prevents one gear of the planetary gearing of an automatic transmission from rotating. In second gear, a clutch causes this gear to rotate as a unit with the drive and driven shaft of the transmission. For an upshift under load, the clutch is engaged slowly, thereby decreasing the required brake torque. The brake force is therefore decreased at a corresponding rate. A switch having a movable contact is mounted so that the contact is moved in response to the reactive force created between the brake band and the gear box. This reactive force varies as a function of the brake force and also depends upon the direction of movement of the braked member. The switch is set to a threshold value which is substantially less than the brake force applied in first gear. At the freewheel point, that is the point at which the moment of the brake member changes direction, the brake force has been decreased sufficiently that the change in direction of the moment will cause the switch to pass the threshold value thereby generating a signal. This signal is processed to cause full disengagement of the brake. The switch will also pass the threshold value when, after complete …