| 摘要 |
<p>1,139,890. Reversing; gearing. CATERPILLAR TRACTOR CO. 9 Jan., 1967 [1 Feb., 1966], No. 1131/67. Headings F2D and F2E. In a bevel forward-neutral-reverse gear, for raising and lowering the scraper blade of a roadgrading machine wherein a pair of continuously and oppositely-driven bevel wheels 12, 13 driving through spur gears 16, 17, are alternatively clutched to a driven shaft 11 by a pair of independently movable dog-toothed clutch members 22, 23 splined on the driven shaft 11 and arranged in a fixed cylinder 24 at the outer ends of two separate axially adjacent stacks of friction brake discs 28, 28a splined alternatively to the shaft 11 and cylinder 24, the clutch members 22, 23 are normally spring biased at 26, 27 out of engagement with the gears 16, 17 and compress the two separate stacks of brake discs to hold the driven shaft 11 stationary until fluid pressure, supplied from a pump 30 through ducts 32, is selectively directed by a manually operated valve 33 through ducts 39, 40 to one or other of the two piston-like clutch members 22, 23 releasing only one or other of the two brake stacks 28, 28a and connecting the driven shaft with either gear 16 or 17 for rotation in one or other direction, the remaining engagement of the other brake stack preventing uncontrolled movement of the output shaft and hence the scraper blade &c. during the interval between brake release and clutch engagement, after which the engaged brake stack slips during power transmission. The brake stacks 28, 28a are separated in the cylinder 24 by an annular plate 43 axially retained by four tongues (41), Fig. 3 (not shown), which engage a groove (42), Fig. 4 (not shown), in the cylinder, the plate 43 being assembled through channels (44) to the groove (42) in which it is turned out of register with the channels and retained by keys (45) fitted in the channels to prevent rotation of the plate, the keys being retained by the brake stacks.</p> |
