Resilient tires and wheels – Tires – resilient – Inflating devices
Patent
1995-06-07
1997-10-07
Ball, Michael W.
Resilient tires and wheels
Tires, resilient
Inflating devices
36442403, B60C 2300
Patent
active
056743327
DESCRIPTION:
BRIEF SUMMARY
The subject of the present invention is a method of adjusting the pressure of the tires on a vehicle; more precisely, it relates to vehicles equipped with a centralized inflating installation which can operate even while the vehicle is being used, and it also makes it possible to avoid employing the normal inflating or deflating mode.
It is known that the optimum inflation pressure of tires depends on the conditions of use of the vehicle and especially the load, speed and nature of the ground. This is the reason why systems have been developed which are capable of modifying the pressure, even when running, so that it always has this optimum value; these systems include a source or reserve of compressed air installed on board the vehicle, lines connecting this source to the tires via rotary seals and a selector enabling the source to be connected up to each of the tires: Patents FR 884,598 and EP 297,837 may be mentioned.
The normal mode of operating these installations consists in periodically measuring the pressure of each tire and in correcting it, as the case may be, by inflating or deflating the tire in question.
When double-acting valves are used, such as the one described in Patent FR 884,598 for example, hereinafter called "isolating valve", it is possible to open the usual valve by means of a piston which acts on this valve and is actuated by compressed air; by virtue of the differential operation of this piston--which comprises two faces of different cross sections--it is possible to keep the usual valve open even if the control pressure is slightly less than the internal pressure of the tire.
In order to check the pressure of each tire, the compressed-air source is connected up, this having the effect of opening the usual valve, then, after a short time, the air supply line is isolated, this having the effect of equilibrating the pressure in the line to the tire pressure and thus enabling the pressure to be measured. Inflating or deflating is then carried out, if necessary. Finally, the line is vented to atmosphere, this having the effect of closing the isolating valve again.
SUMMARY OF THE INVENTION
Now, the applicant has surprisingly discovered that, whatever the initial pressure of a tire, if the checking operation is repeated a few times, connecting up the tire to the compressed-air source for very short times of equal durations t.sub.i, the pressure finally tends towards a value p.sub.i which depends only on this duration t.sub.i and on the pressure of the compressed-air reserve, but absolutely not on the initial pressure of the tire before the pressure checks. In other words, there corresponds to a pulse duration t.sub.i a constant difference between the pressure prevailing in the compressed-air source and the asymptotic value of the pressure in the tire. Therefore, if the pressure in the compressed-air source is constant, the pressure (asymptotic value) of the tire depends only on t.sub.i.
In accordance with the invention, a method of adjusting the pressure of the tires on a vehicle equipped with a centralized inflating installation which includes a compressed-air source, a selector and lines, a rotary seal as well as an isolating valve between the selector and each tire, said method including, successively for each tire, the following steps controlled by the selector: connecting the compressed-air source to the tire via the line and rotary seal associated with the respective tire, this having the effect of opening the isolating valve, after a very short time closing the compressed-air inlet to the line, then measuring the pressure in the line which has become the same as the pressure in the tire, and then venting said line to atmosphere, this having the effect of closing the isolating valve again, is characterized in that the duration of said very short time is determined as a function of the set pressure to be obtained in the tire in question, and in that the operation is repeated at least until said set pressure has been obtained.
This iterative type of operating mode may advantageou
REFERENCES:
patent: 4333491 (1982-06-01), Knubley
patent: 4498515 (1985-02-01), Holtzhauser et al.
patent: 4510979 (1985-04-01), Hjorth-Hansen
patent: 4583566 (1986-04-01), Kalavitz et al.
patent: 4640331 (1987-02-01), Braun et al.
patent: 4708184 (1987-11-01), Pechar
patent: 4782879 (1988-11-01), Le Chatelier et al.
patent: 4862938 (1989-09-01), Mittal
patent: 4893664 (1990-01-01), Oltean
patent: 4917163 (1990-04-01), Schultz
patent: 5141589 (1992-08-01), Mittal
patent: 5249609 (1993-10-01), Walker et al.
patent: 5313995 (1994-05-01), Schultz
Ball Michael W.
Compagnie Generale des Etablissements Michelin - Michelin & Cie
Lorin Francis J.
LandOfFree
Method of adjusting the pressure of the tires on a vehicle does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of adjusting the pressure of the tires on a vehicle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of adjusting the pressure of the tires on a vehicle will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2353676