A filling device for an inflatable unit

Abstract

The invention provides a filling device for an inflatable unit, e.g., a pneumatic tire for a car. The device is connectable to a source of air pressure and to a valve for the inflatable unit. The valve has a whistle arranged to produce an audible signal based on a flow of air in the release outlet, and to enable improved handling and sound performance, the whistle comprises a flow-path forming a first leg extending radially from the passage, and a second leg extending about the passage.

Claims

1. A filling device (1) for an inflatable unit, the device comprising a body (4) having an inlet (5) connectable to a source of pressure and an outlet (6) connectable to a valve for the inflatable unit, a passage (7) extending axially between the inlet and outlet; an air-release path from the passage to a release outlet (13) for releasing air in the passage into an external space; a valve (14, 15) arranged between the passage and the air-release path and being configured to open at a predefined pressure; and a whistle (17) arranged to produce an audible signal based on a flow of air in the air-release path; wherein the whistle is configured not to provide the audible signal when the flow of air in the air-release path exceeds an upper flow limit.

2. The filling device according to claim 1, wherein the whistle forms a tone-chamber (18), and wherein the filling device further comprises a flow diverting structure (29) arranged between the release outlet (13) and the tone-chamber (18), the flow diverting structure being configured to change the direction of the flow of air after it has been released at the release outlet (13), the flow diverting structure being configured to establish the change of the direction when reaching the upper flow limit.

3. The device according to claim 2, wherein the configuration of the whistle not to provide the audible signal when the flow of air in the air-release path exceeds an upper flow limit is provided by an asymmetric airflow at the release outlet, the asymmetric airflow being created by the flow diverting structure.

4. The device according to claim 3, wherein the asymmetric airflow is defined by use of the Coanda effect.

5. The device according to claim 2, wherein the flow diverting structure forms an asymmetric wall section (26, 29B, 29C) at the release outlet.

6. The device according to claim 2, wherein the flow diverting structure forms a symmetric wall section (29A, 29C, 29D, 29E, 29F) at the release outlet.

7. The device according to claim 2, wherein the flow diverting structure forms a resilient wall section (29C, C).

8. The device according to claim 2, wherein the flow diverting structure forms a bleed opening in the passage (7) in the vicinity of the release outlet (13).

9. The device according to claim 1, wherein the whistle is configured not to provide the audible signal when the flow of air in the air-release path is below a lower flow limit.

10. The device according to claim 1, wherein the air-release path has a cross-sectional area which reduces in the flow direction of air being released into the external space through the air-release path.

11. The device according to claim 1, wherein the air-release path comprises a circumferential section extending about the passage.

12. The filling device according to claim 1, wherein the air-release path forms an initial section (25) extending radially away from the passage, the initial section being between the passage and the circumferential section in the flow direction of air being released into the external space through the air-release path.

13. The filling device according to claims 11 and 12, wherein the circumferential section is between the initial section and the release outlet in the flow direction of air being released into the external space through the air-release path.

14. The device according to claim 2, wherein the tone-chamber (18) extends about the passage (7).

15. The device according to claim 2, forming a lower chamber between the valve (14, 15) and the release outlet (13), and where the tone-chamber extends about the lower chamber.

16. The device according to claim 14 or 15, wherein the tone chamber forms an extension of the air-release path.

17. The device according to claim 14, where the release outlet is between the air-release path and the tone chamber.

18. The device according to claim 1 and forming part of or being configured for connection to a Schrader valve.

19. A method of filling an inflatable unit by use of a filling device capable of releasing air to an external space at a predetermined air pressure and to produce an audible signal as a consequence of the release of air, the method comprising repeating the steps of: filing air into the inflatable unit via the filling device; and stopping the filling while listening for the audible signal; until the audible signal begins when the filling is stopped.

20. A method according to claim 19, carried out by use of a filling device according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] FIG. 1 illustrates in a perspective view, a filling device according to the invention;

[0045] FIG. 2 illustrates the filling device from FIG. 1 in cross-section;

[0046] FIG. 3 illustrates an exploded view of the filling device;

[0047] FIG. 4 illustrates a filling device in an open configuration and seen from below,

[0048] FIG. 5 illustrates details of the filling device of FIGS. 1-4, and

[0049] FIGS. 6-14 illustrate different alternative embodiments of a filling device.

DETAILED DESCRIPTION OF AN EMBODIMENT

[0050] Further scope of applicability of the present invention will become apparent from the following detailed description and specific examples. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the scope of the invention will become apparent to those skilled in the art from this detailed description.

[0051] FIGS. 1 and 2 illustrate a filling device 1 which is made specifically for filling a pneumatic tire. The illustrated device is made particularly for an American valve, also called a Schrader valve 2. The Schrader valve consists of a valve stem 3 with a spring (not illustrated). Schrader valves are used on automobile tires, bicycle tires, in air conditioning systems, plumbing, fuel injection engines, suspension systems, SCUBA regulators, and in many other inflatable items.

[0052] The Schrader valve allows removal and attachment of the inflation hose while in use. When the inflatable item is being inflated, the stem is depressed and the air passage is opened. Otherwise, the stem is pressed upwards and seals the passage.

[0053] The filling device 1 comprises a body 4 which has an inlet 5. The inlet is connectable to a compressor via a threaded connection. At its axially opposite end, the filling device forms an outlet 6 (c.f. FIGS. 3 and 4) which has an internal threading for connection to an external threading on the Schrader valve.

[0054] A main passage 7 extends axially within the inner conduit wall 8 and connects the inlet and the outlet. A filling device stem 9 with a flat head 10 and an elongated body towards a tip 11 is movable in the main passage. The filling device stem is arranged such that the tip is adjacent the valve stem when the filling device is attached to the valve. In that way, the valve stem can be operated by use of the filling device stem when a compressor is attached to the inlet 4. The filling device stem is biased upwards by the first spring 12.

[0055] The filling device further comprises an air-release path extending from the main passage to a release outlet 13. The air-release path enables release of air from the passage into the surrounding external space.

[0056] The filling device further comprises an internal valve with a seat 14 and a valve element 15 movable relative to the seat to open and close for the air-release path and thereby to control the flow of air to the external space.

[0057] The valve is biased towards a closed configuration by the second spring 16 and it is configured to open at a predefined pressure, i.e. when the pressure provides an opening force exceeding the closing force provided by the second spring 16.

[0058] The filling device may particularly form a lower chamber 27 between the valve 2 of the inflatable item and the valve seat 14, and an upper chamber 28 above the valve seat 14. From the upper chamber, the air-release path extends towards the ambient space.

[0059] To provide a clear whistling sound, the filling device comprises a tone chamber 18 forming an extension of the air-release path. The tone chamber may extend about the main passage and about the aforementioned upper chamber, or about the main passage and about the aforementioned lower chamber.

[0060] The filling device comprises a whistle 17 arranged to produce an audible signal based on a flow of air in the air-release path. The whistle is more clearly seen in FIGS. 3 and 4. The whistle is constituted by the tone chamber 18 in combination with the lateral opening 19 and the forward edge 20 on the sidewall 21 of the tone chamber 18. When air escapes through the air-release path, the air passes a constriction 22 which reduces the cross section of the air-release path in the flow direction of air being released into the external space. The constriction increases the flow speed through the air-release path and focuses the air stream which leaves the constriction.

[0061] After the constriction 22, the air flows across the forward edge and thereby generates a whistling sound.

[0062] The tone chamber 18 has a circular shape and extends about the passage 7. This enables a relatively long tone chamber with a short axial length of the filling device.

[0063] FIG. 3 illustrates an exploded view of the filling device. The filling device comprises a lower basis member 23 forming the air-release path, the outlet 6, the seat 14, the lateral opening 19, and the tone chamber 18.

[0064] The upper basis member 24 forms a closure for the air-release path and forms an upper part of the main passage including an upper part of the inner conduit wall 7, and the inlet 5.

[0065] Additionally, the filling device comprises the filling device stem 9, the first spring 12, the second spring 16 and the valve element 15 movable in a space between the lower and upper basis members.

[0066] At the lateral opening 19, the air-release path is asymmetrically shaped and forms a widened-out section defined by the asymmetric wall section 26 immediately after the constriction 22. The widened-out section promotes the Coanda-effect and configures the whistle not to provide the audible whistling signal when the flow of air in the air-release path exceeds an upper flow limit. At the upper flow limit, the airflow will deflect radially outwards and away from the forward edge 20 thereby stopping whistling. When the flow speed is below the upper limit, it is insufficient to uphold the Coanda effect, and the radial outwards deflection of the airflow stops. The airflow thereby moves towards the forward edge 20 and the whistling sound starts.

[0067] Due to the increased airflow speed which is caused by the constriction 22, the effect becomes amplified and the limit between whistling and non-whistling becomes sharpi.e. the whistling starts and stops precisely at a certain flow speed.

[0068] FIG. 4 illustrates that the air-release path forms an initial section 25 extending radially away from the main passage, the initial section being between the passage and the circumferential section in the flow direction of air being released into the external space through the air-release path.

[0069] FIG. 5 illustrates details of the filling device 1 of FIGS. 1-4. The letters A-M, cf. column 1 in Table 1 below, refers to the dimensions indicated in FIG. 5. These dimensions are particularly suitable for a filling device to be attached to a valve of a car or truck tire, typically a Schrader valve. The dimensions are preferably within maximum +/20 percent of the indicated dimensions, more preferably within +/10 percent.

[0070] Column 3 specifies technical effects of the filling device. It should be understood, that these effects are relative to a filling device suitable for inflating a tire for a car or a truck. The skilled person would understand that the invention is not limited to these dimensions and that other dimension would also fall within the scope of the invention.

TABLE-US-00001 TABLE 1 A Nozzle slit length. Square Longer slit increases power of sound generation 3.1 mm resonance chamber profile height B Nozzle slit width Chosen to have laminar flow in desired flow range 0.2 mm C Resonance camber width Chosen for stable resonance generation D Tone edge alignment with Distance from perfect alignment defines at which 0.1 mm nozzle flow direction flow the tone generation begins, the higher value the lower flow for onset E Tone edge wall thickness May not be too large - other the tone generation 0.8 mm would be inhibited F Angle of attack between Defines at which flow the tone generation begins, 40 nozzle flow direction and tone the greater angle the lower flow for onset edge G Distance from nozzle flow Defines at which flow rates the flow is diverted 0.7 mm path to Coanda wall fillet transverse to flow H Length of Coanda wall along Defines at which flow rates the flow is diverted 1 mm nozzle flow I Distance from nozzle to tone- Keep long enough to allow diverted flow to pass 3.3 mm edge along flow direction clear of tone edge and low to prevent wind to disturb the normal flow path J Coanda wall fillet at flow Secures the diverted adhere to wall. Size also 0.1 mm intervention determines the flow rate at which the stream is diverted K Length of flow acceleration Secures laminar flow in the desired flow range. 2.7 mm path Shorter will cause turbulent at lower flow rates L Start width of flow Secures laminar flow in the desired flow range. 0.8 mm acceleration path Wider will cause turbulent at lower flow rates M Resonance camber length Length defines frequency of tone. The longer the 30 mm and lower pitch of tone. Too short makes high pitch 2.500 Hz unpleasant sound K/(L B) Rate of acceleration Low ratios cause turbulence, which inhibits tone 4.5 generation. A * B Nozzle area Defines general flow rate versus pressure drop 0.62 mm{circumflex over ()}2 A/C Squareness of resonance The closer to 1, the more true square, which 1.6 chamber profile improves stability of tone generation and reduces the powers of the harmonics H, G and J In correlation defining at which flow rates the flow is diverted H/I Relative distance for diverted 3.3 flow to pass clear of tone edge

[0071] FIGS. 6-13 illustrate different alternative embodiments of a filling device 1, where the Coanda effect is triggered in different ways to achieve that the whistle 17 does not to provide an audible signal when the flow of air in the air-release path 13a exceeds an upper flow limit. For each of the different embodiments, an audible signal is present when a laminar air flow is present in the air release path 13a. When the Coanda effect occurs, the direction of the air flow is changed sufficiently to ensure that the audible signal is no longer provided.

[0072] The whistle 17 forms a tone-chamber 18 and a whistle mouth 17a. The air flows via the air-release path 13a to the release outlet 13 to release air towards the whistle mouth 17a. The flow diverting structure 29 is configured to change the direction of the flow of air after it has been released at the release outlet 13 by utilisation of the Coanda effect, whereby the flow diverting structure 29 establishes the change of the direction of the flow of air when reaching the upper flow limit. Consequently, the whistle 17 does not to provide the audible signal when the flow of air in the air-release path 13a exceeds the upper flow limit.

[0073] In FIGS. 6 and 7, the flow diverting structure 29A is formed as a symmetric narrowing of the air release path 13a, i.e. the release outlet 13 itself constitutes the flow diverting structure. In FIG. 6, the tone-chamber 18 has a circular cross-section, whereas the tone-chamber in FIG. 7 has a cross-section being square-shaped. In both embodiments, the release outlet 13 has a cross-section being square-shaped.

[0074] In the embodiment illustrated in FIG. 8, the flow diverting structure 29B is formed as an asymmetric wall section at the release outlet 13. The tone-chamber 17 is similar to the tone-chamber illustrated in FIG. 6.

[0075] In FIG. 9, the flow diverting structure 29 is formed as a resilient wall section 29C, whereas the embodiment of a filling device illustrated in FIG. 10 comprises two resilient wall sections 29C on opposite sides of the release outlet 13. The symmetric resilient wall sections 29C will cause the air flow to change direction towards one of the two sections 29C. In both embodiments, the tone-chamber 17 is similar to the tone-chamber illustrated in FIG. 7.

[0076] In the embodiment illustrated in FIG. 11, the flow diverting structure 29D is formed as two wall sections arranged on opposite sides of the release outlet 13. The symmetric wall sections 29D will cause the air flow to change direction towards one of the two sections 29D. The tone-chamber 17 is similar to the tone-chamber illustrated in FIGS. 6 and 8.

[0077] FIGS. 12 and 13 illustrate two different embodiments of a filling device comprising a rotational symmetric flow diverting structure 29E, 29F. In FIG. 12, the flow diverting structure 29E is narrowing down towards the release outlet 13 along its full length, whereas the flow diverting structure 29F illustrated in FIG. 13 comprises a section having a cross-section narrowing down followed by a section having a cross-section being uniform. The flow diverting structure 29F illustrated in FIG. 13, will change the air flow from a concentrated jet to a soft diffuse vane at higher air flows.

[0078] FIG. 14 illustrates a further alternative embodiment of a filling device 1. The filling device 1 comprises a flow disturbing structure 30 in the form of a bleed opening 30 in the air release path 13a in the vicinity of the release outlet 13. The flow disturbing structure 30 causes a change of the flow of air from a laminar flow to a turbulent flow after it has been released at the release outlet, whereby the whistle 17 does not to provide the audible signal when the flow of air in the air-release path 13a exceeds the upper flow limit.