Patent ID: 6370980
Filing Date: 2002-04-16
Classification: F16H,Y10T

Abstract:
Vehicle gearbox, comprising: a basic gearbox with an input shaft (2) mounted in a housing (1a), at least one lay shaft (3) driven by the input shaft; a main shaft (4); pairwise interengaging gears (7,12,8,13,9,14) carried by the lay shaft and the main shaft, of which at least one gear (12,13,14) in each pair is freely rotatably mounted on its shaft and is lockable on its shaft by means of an engaging sleeve (15,16) nonrotatably but axially displaceably disposed on the shaft, said engaging sleeve cooperating with synchronizing means; a shift control (21), the movement of which in one direction from a neutral position via motion-transmitting elements (17,18) produces displacement of one engaging sleeve (15) to an engaging position, and the movement of which from the neutral position in another direction produces a displacement of another engaging sleeve (16) to an engagement position; and a high-low range gearbox with an output shaft (34) and lock-out means comprising a blocking element with operating means, which under predetermined operating conditions holds the blocking element in a lockout position in which it inhibits movement of the shift control, characterized in that the operating means (73) of the blocking element (74) are coordinated with a first sensor (71) disposed to sense the speed of the output shaft (34) of the range gear-box, and a second sensor (70) disposed to sense the engaged range in the range gearbox, and that the operating means holds the blocking element in a lockout position which prevents movement of the shift control towards the position for the lowest synchronized gear in the basic gearbox, when said speed exceeds a predetermined speed in the low range of the range gearbox.