192 clutches and power-stop control – Clutch and brake – Vehicle type
Patent
1981-06-22
1984-01-31
Krizmanich, George H.
192 clutches and power-stop control
Clutch and brake
Vehicle type
B60K 4124
Patent
active
044284683
DESCRIPTION:
BRIEF SUMMARY
The present application relates to clutch-clutch-brake mechanism for use in vehicles which are steered-by-driving. More particularly, the application relates to the left and right clutch-clutch-brake steering units for a crawler tractor. Left and right clutch-brake steering units are disclosed in the co-assigned U.S.A. crawler tractor patents noted, U.S. Pat. Nos. 4,015,619 and 4,164,276, which have only steering-brake turns with no geared steering; whereas the second clutch of the clutch-clutch-brake mechanism hereof superimposes the geared-steer option affording, along with other versatility of significance hereinafter emphasized, the rub-free type of full power turns, left and right, with no rubbing and friction losses in the friction clutches which are not allowed to slip and no rubbing and friction losses in the steering brakes which are not allowed to drag, while steering with gearing.
Background patents further include but are not limited to U.S. Pat. Nos. 1,835,790, 2,323,115, 2,447,920, 2,974,639, 2,984,213, 3,215,044, 3,220,318, 3,221,770, 3,460,577, 3,540,559, 3,677,362, 3,693,503, 3,706,322, 3,757,915, 3,843,205 and particularly Bidwell U.S. Pat. No. 3,018,041.
It is an object in connection with steering mechanism according to my invention, to provide an alternately acting hydraulically actuated clutch-clutch-brake unit so arranged that braking is automatic (spring applied) upon failure of hydraulic pressure, thus affording fail-safe braking.
An object in line with the preceding objective is to provide a clutch-clutch-brake unit in which one clutch and brake are siamese-connected for pressure actuation of same, and in which a single signal is therefore usable for clutch-brake control pressure both for the one clutch and for the brake in the unit; provision is made in the same way for clutch-brake control pressure both for the other clutch and for the brake in the unit. One such clutch constitutes the hi speed clutch providing for a high gear drive, and the other such clutch constitutes a lo speed clutch providing for a low ratio gear drive through the steering unit.
A further object is to provide a metering valve for controlling clutch-brake pressure, also provide an inlet-outlet port to which the lo clutch and brake cylinders are connected in common and controlled by the metering valve as the clutch-brake control pressure is applied or released, and additionally provide correlated sets of springs on the lo clutch and brake causing engagement of each cylinder to be cushioned by delayed pressure-change owing to the fact that the volume of the cylinder of the other is undergoing a metered change because of the metering valve's restrictive control over the common inlet-outlet port.
Also, even though the gear ratio is fixed in high gear, and fixed in low gear, and the high gear clutch is unmodulated, there is an additional object in connection with the lo clutch and brake cylinders. Pressure to their aforesaid inlet-outlet port is modulated with the object to slip the lo speed clutch for controlled speeds in the upper half of the low speed range and to drag the brake for controlled speeds in the lower half of the low speed range.
Another object of the invention, in line with the foregoing objective because similarly in connection with the lo clutch and brake cylinders, is the provision of a hydropotentiometer type steering valve spool having, among others, two well defined Br and Lo positions in order to select for operation the cylinders concerned for full braking and for full lo clutching, respectively, and utilizing a bore core standpipe effect to provide its own dashpot effect in being positioned. More particularly, there is no spool overshoot as the steering valve spool advances at its leading end in a bore and reaches Lo position, because the hydropotentiometer provides a restrictive connection between the end-displaced fluid and a standpipe reservoir maintained with a level above the spool; conversely, there is no cavitation or air-bubbled-in as the steering valve spool withdraws that leadin
REFERENCES:
patent: 3378119 (1968-04-01), Schaefer
patent: 4164276 (1979-08-01), Shore et al.
Dresser Industries Inc.
Krizmanich George H.
Van Winkle Roy L.
LandOfFree
Clutch-clutch brake steering mechanism for tractors does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Clutch-clutch brake steering mechanism for tractors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Clutch-clutch brake steering mechanism for tractors will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2341902