VALVE INSERT AND AIR VENTING VALVE

Abstract

A valve insert (4) for use in an air venting valve (1) of a vulcanizing mould of a vehicle tyre, which valve insert (4) comprises a valve stem (6) arranged to be inserted into a valve sleeve (3) of the air venting valve (1), a first end of which valve stem (6) is provided with a valve disk (7) and a second end of which valve stem (6) is provided with an elastically compressible retainer member (8) for detachably attaching the valve insert (4) to the valve sleeve (3) and for limiting an opening stroke of the valve insert (4). The retainer member (8) comprises a stop surface (14) which is arranged to abut an end surface (16) of the valve sleeve (3) and thus limit the opening stroke of the valve insert (4).

Claims

1. A valve insert for use in an air venting valve of a vulcanizing mould of a vehicle tyre, which valve insert comprises a valve stem arranged to be inserted into a valve sleeve of the air venting valve, a first end of which valve stem is provided with a valve disk and a second end of which valve stem is provided with an elastically compressible retainer member for detachably attaching the valve insert to the valve sleeve and for limiting an opening stroke of the valve insert, and wherein the retainer member comprises a stop surface which is arranged to abut an end surface of the valve sleeve and thus limit the opening stroke of the valve insert.

2. The valve insert according to claim 1, wherein the stop surface is perpendicular to a longitudinal axis of the valve stem.

3. The valve insert according to claim 1, wherein the stop surface is straight.

4. The valve insert according to claim 1, wherein the elastically compressible retainer member comprises a slot for achieving the compression of the retainer member, which slot extends from the second end of the valve stem towards the first end of the valve stem.

5. The valve insert according to claim 1, wherein the elastically compressible retainer member comprises a slot for achieving the compression of the retainer member, which slot extends from the second end of the valve stem towards the first end of the valve stem and the slot extends through the valve stem in a radial direction.

6. The valve insert according to claim 1, wherein the valve stem 6) comprises at least one cutout for improving air removal from the valve sleeve.

7. The valve insert according to claim 1, wherein the valve stem comprises at least one cutout for improving air removal from the valve sleeve and the cutout extends from the retainer member towards the valve disk.

8. The valve insert according to claim 1, wherein the valve stem comprises at least one cutout for improving air removal from the valve sleeve and the diameter of the valve stem at the location of cutout is smaller than that at the location adjacent to the cutout.

9. The valve insert according to claim 1, wherein the valve stem comprises at least one cutout for improving air removal from the valve sleeve and the cutout surface is straight and/or parallel to the longitudinal axis of the valve stem.

10. A venting valve for removing air from a vulcanizing mould of a vehicle tyre, which air venting valve comprises a valve sleeve, and wherein the valve insert according to claim 1 is detachably attached to the valve sleeve.

11. The venting valve according to claim 10, wherein an end surface of the valve sleeve is parallel to the stop surface of the valve insert.

12. The venting valve according to claim 10, wherein the cutout of the valve stem extends through an outlet opening of the valve sleeve.

13. The venting valve according to claim 10, wherein a wall of the valve sleeve comprises hole or holes for improving air removal from the valve sleeve

14. The venting valve according to claim 10, wherein the wall of the valve sleeve comprises hole or holes for improving air removal from the valve sleeve, and the hole or holes are located in the lower portion of the valve sleeve that has a smaller outer diameter than the upper portion of the valve sleeve.

Description

[0013] In the following, the invention will be described in more detail by means of examples with reference to the attached drawings, wherein FIGS. 1 and 2 show an air venting valve according to an embodiment of the invention,

[0014] FIG. 3 shows a side view of a valve insert of the air venting valve of FIGS. 1 and 2,

[0015] FIG. 4 shows another side view of the insert of the air venting valve of FIGS. 1 and 2, rotated 90 degrees relative to the side view of FIG. 3, and

[0016] FIG. 5 shows the valve insert of FIGS. 1 and 2.

[0017] FIGS. 1 and 2 show a venting valve 1 for removing air from a vulcanizing mould, e.g. a vulcanizing mould of a vehicle tyre. Typically the vulcanizing mould comprises 1000-4000 venting valves 1. The venting valve 1 comprises a valve sleeve 3 and a valve insert 4 inserted into the valve sleeve 3. The valve sleeve 3 is attached to a venting bore of the vulcanizing mould e.g. by a press fit. The valve sleeve 3 is cylindrical. The outer diameter of the valve sleeve 3 is typically 1.5-4 mm. In FIG. 2 the valve sleeve 3 is shown as a cross section.

[0018] The valve insert 4 comprises a valve stem 6, the first end of which is provided with a valve disk 7 and the second end with a mechanism or means 8 for detachably attaching the valve insert 4 to the valve sleeve 3. The valve insert 4 is attached to the valve sleeve 3 by a detachable connection. The valve insert 4 is shown in more detail in FIGS. 3-5. The first end of the valve sleeve 3 comprises a conical seat surface 9 against which a conical surface 5 of the valve disk 7 is arranged in the closed position of the venting valve 1 as shown in FIGS. 1 and 2.

[0019] The venting valve 1 comprises a spring 2 for moving valve insert 4 towards an open position in which the conical surface 5 of the valve disk 7 is at a distance from the conical surface 9 of the valve sleeve 3. The spring 2 is a helical spring that is arranged around the valve stem 6. One end of the spring 2 is against the lower surface of the valve disk 7 and the other end against the support surface 15 of the valve sleeve 3.

[0020] The means for detachably attaching the valve insert to the valve sleeve comprises an elastically compressible and/or elastically deformable retainer member 8 provided at the second end of the valve stem 6. The retainer member 8 is arranged to be compressed when the valve insert 4 is inserted into the valve sleeve 3 and the retainer member 8 is inserted through the outlet opening 12 of the valve sleeve 3.

[0021] The valve insert 4 comprises a slot 10 at the second end of the valve stem 6, by means of which the compression of the retainer member 8 is achieved. The slot 10 extends from the second end of the valve stem 6 towards the first end of the valve stem 6. The slot 10 extends through the valve stem 6 in the radial direction. The radial direction is perpendicular to a longitudinal axis 17 of the valve stem. Additionally, the retainer member 8 comprises a collar 11. The slot 10 extends through the collar 11.

[0022] The outer diameter of the collar 11 in the uncompressed state of the retainer member 8 is larger than the inner diameter of the outlet opening 12 of the valve sleeve 3. The collar 11 comprises a conical surface 13, which is arranged to abut the edge of the opening 12, when the valve insert 4 is inserted into the valve sleeve 3 and the collar 11 passes through the outlet opening 12.

[0023] Further, the retainer member 8 comprises a stop surface 14, which is arranged to abut the end surface 16 of the valve sleeve 3, when the valve insert 4 is moved towards the open position, and thus limit the opening stroke of the valve insert 4. The stop surface 14 faces the valve disk 7. The stop surface 14 is perpendicular to the longitudinal axis 17 of the valve insert. The stop surface 14 is parallel to the end surface 16 of the valve sleeve against which the stop surface 14 is arranged in the fully open position of the venting valve 1. The longitudinal axis 17 of the valve insert 4 is parallel to the direction of the opening and closing motion of the valve insert 4. When the valve disk 7 is against the seat surface 9, the stop surface 14 is at a distance from the end surface 16 of the valve sleeve 3. When the stop surface 14 is against the end surface 16 of the valve sleeve, the conical surface 5 of the valve disk is at a distance from the seat surface 9. The stop surface 14 is flat or straight. The end surface 16 of the valve sleeve is flat or straight.

[0024] The valve stem 6 comprises at least one cutout 18 for increasing air removal from the valve sleeve 3 through the outlet opening 12 and air flow rate through the valve sleeve 12. The cutout 18 extends from the second end of the valve stem 6 or from the retainer member 8 towards the valve disk 7. The cutout extends through the outlet opening 12 of the valve sleeve 3 when the valve insert 4 is in the open position. The diameter D1 of the valve stem 6 at the location of the cutout 18 is smaller than the diameter D2 of the valve stem 6 at a location adjacent to the cutout 18 in the circumferential direction of the valve stem 6. The diameter D1 of the retainer member 8 at the location of the cutout 18 is smaller than the diameter of the outlet opening 12. The diameter of the retainer member 8 at a location adjacent to the cutout 18 is larger than that of the outlet opening 12 when the retainer member 8 is in the uncompressed state. The surface of the cutout 18 is straight. The cutout 18 increases the cross-sectional air flow area through the venting valve 1. The cutout 18 extends to the level of the bottom of the slot 10.

[0025] In the embodiment shown in the drawings the valve stem 6 comprises two cutouts 18. The cutouts 18 are arranged on the opposite sides of the valve stem 6. The cutout surfaces on the opposite sides of the valve stem 6 are parallel. The cutouts are identical. Typically, the valve stem 6 comprises 1 to 4 cutouts 18 as described above.

[0026] The wall of the valve sleeve 3 comprises at least one hole 19, typically a plurality of holes 19, for increasing air removal from the valve sleeve 3. The hole 19 extends through the wall of the valve sleeve 3. The hole 19 extends from the inner surface of the valve sleeve 3 to the outer surface of the valve sleeve 3. The valve sleeve 3 comprises an upper portion 3.1 and a lower portion 3.2. The outer diameter of the lower portion 3.2 is smaller than that of the upper portion 3.1. The hole 19 or holes 19 are located in the lower portion 3.2 of the valve sleeve. Thus, air is discharged from the valve sleeve 3 through the hole(s) 19 and through the gap between the lower portion 3.2 and the venting bore of the vulcanizing mould. The holes 19 are arranged side by side in the circumferential direction of the valve sleeve 3 and/or one on the other.

[0027] The valve insert 4 and the spring 2 around the valve insert 4 are installed into the valve sleeve 3 such that the retainer member 8 is inserted into the valve sleeve 3 through the inlet opening of the first end of the valve sleeve 3. The conical surface 13 of the retainer member 8 abuts the edge of the outlet opening 12 of the second end of the valve sleeve 3 and is elastically compressed such that the retainer member 8 can be brought through the outlet opening 12.

[0028] The valve insert 4 is detached from the valve sleeve by compressing the retainer member 8 such that it can be brought inside the valve sleeve 3 through the outlet opening 12. The retainer member 8 is compressed e.g. by a tool having a conical opening or recess dimensioned to compress the retainer member 8. Thereafter, the valve insert 4 and the spring 2 can be removed from the valve sleeve 3.