System for monitoring tire pressure and method for mounting a tire pressure monitoring system on a rim

1. A tire pressure monitoring system, comprising:

a tire valve; and

a tire pressure monitoring unit that comprises a plastic housing, in which a pressure sensor for measuring the tire pressure and a transmitter for wirelessly transmitting tire pressure data are arranged;

wherein the tire pressure monitoring unit is attached to a stem of the tire valve; and

wherein the stem comprises a row of latching recesses that are arranged behind one another, into which a latching element of the tire pressure monitoring unit engages at least one latching recess of the row of latching recesses;

wherein the latching element is realized integrally with a wall of the housing.

2. The system according to claim 1 , wherein the latching element forms part of a lever arm.

3. The system according to claim 2 , wherein the lever arm extends along the stem.

4. The system according to claim 1 , wherein the row of latching recesses are arranged on an upper side of the stem, which in the installed state faces away from the rim well.

5. The system according to claim 1 , wherein the row of latching recesses are a row of notches.

6. The system according to claim 5 , wherein the notches are defined by a first face on a first side and by a second face on the opposite side, wherein the first face has a steeper rise than the second face such that the tire pressure monitoring unit can be pushed further on the stem by engaging the second face, but an undesirable separation of the tire pressure monitoring unit from the stem is prevented by engaging the first face.

7. The system according to claim 5 , wherein the latching element engages with the notches in such a way that it disengages from the respective notch when the tire pressure monitoring unit is pushed further on the stem and prevents a displacement in the opposite direction.

8. The system according to claim 6 , wherein the latching element engages with the notches in such a way that it disengages from the respective notch when the tire pressure monitoring unit is pushed further on the stem and prevents a displacement in the opposite direction.

9. The system according to claim 1 , wherein the stem comprises at least five latching recesses which are arranged in the row.

10. The system according to claim 1 , wherein the stem comprises at least seven latching recesses which are arranged in the row.

11. The system according to claim 1 , wherein the stem comprises an opening, which extends in its longitudinal direction and allows the escape of air being pumped into the tire through the valve.

12. A tire pressure monitoring unit, comprising:

a plastic housing, wherein a pressure sensor for measuring the tire pressure and a transmitter for wirelessly transmitting tire pressure data are arranged;

an opening for being attached to a stem of a tire valve that comprises multiple latching recesses; and

a latching element for engaging into the latching recesses;

wherein the latching element is formed integrally with a wall of the housing and wherein the latching element forms part of a lever arm.

13. A method for installing a tire pressure monitoring system on a rim, in which a snap-in tire valve is inserted into a rim bore and a tire pressure monitoring unit is subsequently displaced toward the rim bore linearly along a stem of the tire valve, wherein a latching element of the tire pressure monitoring unit successively engages into a row of latching recesses of the stem.