Metal valve of the clamp-in type for inflating tyres associable with a TPMS transducer

Abstract

Valves for inflating tires of tired wheels, in particular tires for vehicles, wherein the term “vehicles” refers to motor vehicles, vans, trucks, motorcycles or in general elements of locomotion on tires. More in detail, a metal valve (1) of the clamp-in type for inflating tires (2) associable with a TPMS transducer (3) by a locking screw (4) and arranged to be mounted, by a fixing system including a nut (5) adapted to screw onto a thread (18) provided on the stem (8) of the valve (1), on a rim (6) of a wheel, wherein the fixing system includes an element (7) that irreversibly yields when a preset tightening torque is reached for the locking nut (5), and wherein the element (7) that irreversibly yields is associated with the stem (8) of the valve (1).

Claims

1. A clamp-in metal valve system configured for inflating tyres associable with a tyre pressure monitoring system transducer, comprising: a stem terminating in a head configured to associate with a rim of a wheel; a thread provided on the stem; a locking nut adapted to screw onto the thread; a seat provided in the stem; and an annular element at least partially axially fitted in the seat, the annular element being configured to irreversibly yield when a preset tightening torque is reached for said locking nut, wherein a portion of the annular element that remains visible on the stem of the valve after a breakage of the annular element is adapted to act as an indicator, on an outside of the tyre, of a presence of the transducer on an inside of the tyre.

2. The clamp-in metal valve system according to claim 1, wherein said annular element is irreversibly yielding upon breakage.

3. The clamp-in metal valve system according to claim 2, wherein a broken portion of said annular element is adapted to cooperate with said nut and said stem of said valve to act as barrier against penetration of corrosive agents inside said nut.

4. The clamp-in metal valve system according to claim 1, wherein said annular element has a trapezoidal cross section.

5. The clamp-in metal valve system according to claim 1, wherein said annular element has a lobed shape.

6. The clamp-in metal valve system according to claim 1, wherein said element is obtained directly from a same material as the stem of said valve.

7. The clamp-in metal valve system according to claim 1, wherein said annular element is produced with material applied to the stem of said valve.

8. The clamp-in metal valve system according to claim 7, wherein said annular element is made from different materials corresponding to different tightening torques that can be predefined.

9. The clamp-in metal valve system according to claim 7, wherein said annular element is identified with different colors corresponding to different tightening torques that can be predefined.

10. A valve-transducer assembly which comprises the clamp in metal valve system according to claim 1.

11. A clamp-in metal valve system configured for inflating tyres associable with a tyre pressure monitoring system transducer, comprising: a stem terminating in a head configured to associate with a rim of a wheel; a thread provided on the stem; a locking nut adapted to screw onto the thread; a seat provided in the stem; and an annular element at least partially in the seat, the annular element being configured to irreversibly yield when a preset tightening torque is reached for said locking nut so that a broken portion of said annular element is located between said nut and said stem to act as barrier against penetration of corrosive agents inside said nut, wherein a portion of the annular element that remains visible on the stem of the valve after a breakage of the annular element is adapted to act as an indicator, on an outside of the tyre, of a presence of the transducer on an inside of the tyre.

12. The clamp-in metal valve system according to claim 11, wherein said annular element is irreversibly yielding upon breakage.

13. The clamp-in metal valve system according to claim 12, wherein a broken portion of said annular element is adapted to cooperate with said nut and said stem of said valve to act as barrier against penetration of corrosive agents inside said nut.

14. The clamp-in metal valve system according to claim 11, wherein said annular element has a trapezoidal cross section.

15. The clamp-in metal valve system according to claim 11, wherein said annular element has a lobed shape.

16. The clamp-in metal valve system according to claim 11, wherein said element is obtained directly from a same material as the stem of said valve.

17. The clamp-in metal valve system according to claim 11, wherein said annular element is produced with material applied to the stem of said valve.

18. The clamp-in metal valve system according to claim 17, wherein said annular element is made from different materials corresponding to different tightening torques that can be predefined.

19. The clamp-in metal valve system according to claim 17, wherein said annular element is identified with different colors corresponding to different tightening torques that can be predefined.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

(1) These and other advantages will become more apparent from the following description of preferred embodiments of the invention, provided by way of non-limiting example, and with the aid of the figures, wherein:

(2) FIGS. 1 and 2 show a perspective and plan view respectively of a valve-transducer assembly for TPMS systems mounted on a wheel rim;

(3) FIGS. 3-5 show a longitudinal section view of a metal valve of the clamp-in type associated with a transducer and fixed to the rim of a wheel, according to possible embodiments of the invention;

(4) FIG. 6 shows a longitudinal section of a detail of FIG. 4 during a valve fitting phase;

(5) FIGS. 7a and 7b show a longitudinal section view of a detail of the valve in the embodiment shown in FIG. 5, in two operational assembly phases.

DETAILED DESCRIPTION OF THE INVENTION

(6) With reference to the Figures, a metal valve of the clamp-in type 1 for inflating tyres 2 is shown, adapted to be stably associated with a transducer 3 using TPMS technology.

(7) With particular reference to FIGS. 1 and 2, a wheel rim 6 of a motor vehicle is shown, on which said valve 1 and said transducer 3 are fitted, assembled together to form a valve-transducer assembly 10.

(8) In relation to the cross-section view shown, the position of each component of the valve-transducer assembly 10 is apparent, especially with reference to the rim 6.

(9) The transducer 3 is positioned tangential to the rim 6, inside the air chamber 9 delimited by the relative tyre 2, while the valve 1 projects on the outside of the rim 6 and is stably fixed thereto by means of a locking nut 5.

(10) With reference to the cross-section views shown in FIGS. 3-5, possible embodiments of the valve 1 according to the invention are shown in more detail, wherein the valve 1 comprises a stem 8 and a head 11.

(11) Between the inner edge of the rim 6 and the head portion 11 of the valve 1 in contact with the rim, a seal gasket 12 is interposed. Said seal 12 can be elastic (O-Ring) or metallic (Grommet).

(12) Alternatively, the valve head may be in direct contact with the rim, without seals.

(13) Between the outer edge of the rim 6 and the locking nut 5, a washer 13 is usually interposed, made of metallic or plastic material.

(14) With reference to all the accompanying Figures, by way of example only, a particular type of valve 1 of the clamp-in type has been selected, provided with an axially perforated hemispherical head 11. Alternative variants of the valve 1 may comprise cylindrical heads 11, or so-called “hammer” heads, wherein the head-sensor coupling is achieved on two appropriately shaped, symmetrical supporting surfaces, always in accordance with the claims and achieving the same advantages.

(15) For its coupling to the transducer 3, the head 11 of the valve 1 has a specific seat 14 obtained in the transducer 3.

(16) In order to stably associate the two components, both the valve 1 and the transducer 3 are passed through by a perforated screw 4, the head 15 of which has a square or polygonal cross-section, or it may have different shapes for suitable couplings.

(17) The stem of the screw 4 screws onto a thread inside the body of the valve 1, while the square head 15 fits into a corresponding shaped housing in the transducer 3 so that the valve 1 can turn with respect to the screw 4 which, instead, remains stationary with respect to the transducer 3.

(18) This mutual rotation between the valve 1 and the screw 4 is achieved, during the phase of mounting the valve-transducer assembly onto the rim, by means of the nut 5 which rests on a striking element 7 on the stem 8 of the valve 1.

(19) With reference to the cross-section view shown in FIG. 3, said element 7 has annular shape and is obtained directly from the same material as the stem 8 of the valve 1, orthogonally projecting therefrom. In this embodiment, said annular element 7 is irreversibly yielding upon breakage: once the maximum tightening torque for the screw 4 joining the valve 1 to the transducer 3 is reached, said element 7 breaks.

(20) The thickness and shape of said element 7 determines its strength: a thin annular element 7 will break easily and can be used for valves that do not require high tightening torques for the coupling thereof to the transducer. Conversely, if the annular element 7 is thicker, it will break with greater difficulty: in this case, the valve will be stably fixed to its transducer only when a high tightening torque is reached.

(21) The cross-section view shown in FIG. 4 illustrates a possible alternative embodiment of the valve 1 shown in FIG. 3. In this case, the annular element 7 is irreversibly yielding upon deformation: its cross-section (for example trapezoidal) is shaped so that once the desired tightening torque is reached, the nut 5 irreversibly deforms said element 7, by bending it towards the stem 8 of the valve 1, and then continues screwing (FIG. 6).

(22) In a preferred embodiment, said element 7 may be obtained by modifying the thread 18, provided on the stem 8 of the valve 1, onto which the nut 5 screws.

(23) By dimensionally modifying said thread 18, a zone is created with a different pitch or modified coupling tolerance with the nut, adapted to define differentiated tightening torques: a torque in said zone to definitively fix the valve 1 to the transducer 3, after which the operation can proceed with a torque required to fix the valve-transducer assembly onto the rim 6.

(24) The modified thread, indeed, brakes the advancement of the nut 5 on the stem 8 of the valve 1 until it is stably fixed to the transducer 3, and once the resistance torque has been overcome by breaking or deforming the modified thread, the nut 5 proceeds to screw onto the remaining standard thread, until the valve 1 is stably fixed onto the rim 6.

(25) With reference to the cross-section view shown in FIG. 5, said element 7 is not directly obtained on the valve 1, but is instead fitted, i.e. applied, to its stem 8. Said element 7 is configured as a ring adapted to be axially fitted onto the stem 8 of the valve and then held in position by a specific seat 16 also obtained along the stem 8 of the valve 1, and substantially adapted to avoid the involuntary slippage of the annular element 7 while screwing the nut 5 (FIG. 7a). Said seat 16 can be alternatively replaced by a “nose” or projecting tooth having the same retention function.

(26) In the embodiment illustrated, the applied element 7 is irreversibly yielding upon breakage, but in alternative embodiments a type that is irreversibly yielding upon deformation may be selected.

(27) The version of the valve wherein the element 7 is produced using applied material appears very advantageous since the element itself, an indicator of a predefined tightening torque being reached, can be made of different materials, rather than the metal from which the nut and the entire valve are made, depending on the predefined resistance value that one wants to give said tightening torque.

(28) Even more advantageously, the annular element 7 can be characterized by a specific color that can serve to distinguish it, based once again on the predefined resistance value that one wants to give it.

(29) Even the shape of the element 7 can vary: FIG. 5 illustrates an element with an annular shape, but alternatively, the shape may be lobed and may therefore have more projecting pointed teeth that can be broken (or deformed by bending towards the valve body in the variant wherein the element is yielding upon deformation).

(30) With reference to the detail shown in FIG. 7b, the broken portion 17 of the element 7 is dragged by the nut 5 as it screws: the broken portion 17 is interposed between the nut 5 and the stem 8 of the valve so as to prevent the penetration of corrosive agents between the two threads and to ensure that the coupling lasts longer.

(31) In some particularly preferred embodiments of the invention, the portion 19 of the element 7 that remains on the stem 8 of the valve after its breakage (or the portion deformed by said element in the case that it is yielding upon deformation) remains visible on the outside after the nut is fully tightened, and serves to indicate the presence of a TPMS sensor inside the tyre.

(32) The method of mounting the metal valve 1 onto the rim 6 according to the invention, in association with a transducer 3 for TPMS technology, is described below.

(33) The valve 1 is coupled to the transducer 3 and held in position by means of the screw with a square cross-section 4: in this manner the valve 1 and the transducer 3 are free to mutually rotate while still remaining coupled to one another.

(34) The valve-transducer assembly 10 is then positioned on the rim 6, taking care to place the transducer 3 tangential with the inner edge of the rim 6, and with the stem 8 of the valve 1 projecting outside the rim. This operation is carried out when the valve still does not have a nut.

(35) At this point it is necessary first of all to mutually fix the valve 1 to the transducer 3, and then to tighten the assembly 10 onto the rim 6 by screwing the nut 5.

(36) By acting on the locking nut 5, coaxially with the stem 8 of the valve 1, a first rotation is imparted to said valve, which rotates with respect to the transducer 3, which is instead held tangential to the rim 6.

(37) The valve 1 rotates in unison with the nut 5 until the breakage of the annular element 7 and then until the correct tightening torque is reached, by which the valve 1 and the transducer 3 are stably coupled to one another with no further risk of mutual rotations.

(38) If one continues to rotate the nut 5, the valve 1 now remains stationary and the nut 5 turns on the thread 18 provided on the stem 8 of the valve until it comes into contact with the rim 6, with an interposed washer 13. At this point, all the components are stably coupled to one another and no further mutual rotation is possible.