Device capable of signalling the inflating condition in the tires

• US RE41,058 E1
• Filed: 05/25/1999
• Issued: 12/29/2009
• Est. Priority Date: 05/28/1998
• Status: Expired due to Fees

• Current Assignee: Giovanni Barbanti
• Original Assignee: Giovanni Barbanti
• Inventors: Barbanti, Giovanni
• Primary Examiner(s): Allen; Andre J
• Assistant Examiner(s): JENKINS, JERMAINE L
• Application Number:
  US11/223,914
• Time in Patent Office: 3,871 Days
• Field of Search: 73146-1468, 340442-447
• US Class Current: 73/146.2
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: B60C 23/0496 Valve stem attachments positioned outside of the tyre chamber

Abstract

The inventor discloses and claims a device for signaling the inflation condition of tires, as externally visible or as may be registered by remote audio or visual cues. The device generally is adapted to be attached to the stem valve of a tire without causing substantial loss of air pressure in the tire. The device may be loaded to register the inflation condition of the tire, following which loading the device may continue to register the inflation condition, without causing substantial loss of pressure in the tire.

Claims

1. A device capable of signalling the inflating condition of a tire when screwed onto a jointing tube (5) of an inflating valve (6) that has a self-closing valve core (7) stressed for closure by a valve spring (8), the claimed device comprising:

a. an external envelope (1)

b. a threaded body (4) slidably mounted at least partially within and rotating together with the external envelope (1), which threaded body (4) is adapted to be screwed onto the jointing tube (5);

c. a plunger (11) fitted with a rod positioned to engage the self-closing valve core (7), and housing a lamina (18) that varies geometrical configuration from a resting configuration to a pressured configuration in response to a pressure greater than a first pre-established threshold value , which variation effects movement within the rod of a bistable valve fitted with a double closing member (22);

d. a movable sealing member (10) connected to the plunger (11), which movable sealing member (10) delimits, with respect to the envelope (1), at least a first chamber (15) located under the plunger (11), and at least a second chamber (16, 20) located over the plunger (11);

wherein the plunger (11) is movably positioned between the first chamber (15) and in the second chamber (16, 20) with a range of motion of a magnitude sufficient to cause the opening of the self-closing valve core (7) from a closed position, said range of motion being limited between;

i. a first limit stop position into which the plunger (11) is urged by the movable sealing member (10) in an absence of pressurization , and in which the plunger (11) does not cause the opening of the self-closing valve core (7), and

ii. a second limit stop position, in which the plunger (11) separates a third chamber (26) from the first chamber (15) by sealingly contacting a gasket (25) and causes the opening of the self-closing valve core (7);

wherein this second limit stop position is successively maintained only if the difference between;

1. the pressure in the second chamber (16, 20), the value of which reaches the value in of the tire during the loading phase of the device, and

2. the pressure in the first chamber (15), which is connectable to atmospheric pressure

 

is maintained higher than a first pre-established threshold value, so that a resultant thrust acting on the plunger (11) is higher than the forces of the valve spring (8) and the movable sealing member (10); and

e. means for used signalling the configuration of the lamina (18) or the position of the plunger (11), whereby the device indicates if the pressure in the tire exceeds or not said first pre-established threshold value.

2. Device as in claim 1, wherein the lamina (18) with variable geometrical configuration is a bistable valve acts on the bistable valve fitted with a double closing member (22), the lamina (18) presenting a first position of stability and a second position of stability;

in which first position of stability, the bistable valve (22) connects a first duct (12, 21) to a plunger housing (17) and closes the connection between the first duct (12) and a second duct (13); and

in which second position of stability, the bistable valve (22) connects the second duct (13) to the first duct (21, 12) and closes the connection between a the first duct (12, 21) and the housing (17).

3. Device as in claim 2, wherein the lamina (18) with variable geometrical configuration is a bimetal for which a the pressure threshold at which the commutation of the geometrical configuration occurs is a function of the temperature.

4. Device as in claim 1, wherein the movable sealing member (10) comprises a bellows (10) allowing the frictionless axial translation of the plunger (11) inside the device, and separates a first chamber (15) from a second chamber (16, 20), said first chamber (15) and second chamber (16, 20) being respectively located under and over the plunger (11).

5. Device as in claim 2 1, wherein an external axial force (P) applied to the external envelope (1)

a. causes the axial translation of the external housing of the device and moves the envelope (1) with respect to the threaded body (4) against a thrust of a spring (9), so that the envelope (1) passes

ii. from the first limit stop position which is in absence of said force maintained by the thrust of the spring (9),

iii. to a second limit stop position, in which the envelope (1) remains only until the external force (P) is released;

b. is transmitted from the wall (2) to the lamina (18), and

c. causes both

iv. the change of the geometrical configuration of the lamina (18) towards its second configuration of stability and

v. the motion of the plunger (11) towards the second limit stop position, in which the plunger (11) causes the opening of the self-closing valve core (7), and by interfering with the gasket (25), separates the third chamber (26) from the first chamber (15).

6. Device as in claim 1, wherein after the releasing of the force (P), the spring (9) and the thrust of the air pressure in the second chamber (16, 20) move the external envelope (1) towards the first stable limit stop position.

7. Device as in claim 1, wherein the position of the plunger (11) signals the exceeding or not of at least a first pre-established threshold pressure value, and wherein the wall (2) is transparent for displaying an indication selected from the group consisting of a chromatic change as a function of the position of the plunger (11), and the configuration of the lamina (18).

8. Device as in claim 7, wherein the activity selected from the group consisting of displacement of the plunger (11), and the change in the geometrical configuration of the lamina (18) sets at work an electrical circuit causing the emission of optical and/or acoustic signals.

9. Device as in claim 2, wherein the lamina (18) with variable geometrical configuration is connected to a housing (17) by a sealing member (19);

and wherein further the bistable valve (22), through a channel (21), alternatively connects a first duct (12) to a second duct (13), or to the housing (17) according to the configuration of stability reached by the lamina (18), such that when the device is unloaded, the lamina (18) maintains a first configuration in which the plunger (11) does not cause the opening of the self-closing valve core (7), and the chambers (15, 16, 20, 17, 26), the ducts and the channels (12, 13, 21) communicate with the atmosphere (27).

10. Device as in claim 2 1, wherein the force necessary to move the plunger (11) from the first to the second limit stop position is transmitted by said envelope (1) and wall (2) to plunger (11) through the wall (2), which directly acts on the lamina (18) with variable geometrical configuration and causes the deformation of the lamina (18) to the second configuration;

in this configuration the plunger (11) is located at the second limit stop position, the bistable valve fitted with a double closing member (22) connects the second duct (13) to the first duct (12), so that pressure of the tire exists in the third chamber (26), the second duct (13), the first duct (12) and the second chamber (16, 20), while the atmospheric pressure exists in the housing (17), a third duct (14) and the first chamber (15);

in which position said second configuration of lamina (18) is maintained only if the difference between the pressure in the second chamber (16, 20) and in the housing (17) exceeds at least a first pre-established threshold value;

in said condition the difference between the pressure in second chamber (16, 20) and first chamber (15) is the same as the difference between the pressure in second chamber (16, 20) and housing (17);

until said difference in pressure is sufficient to maintain the second configuration of the lamina (18) the resultant force on the plunger (11) is sufficient to assure that the plunger (11) is maintained in the second limit stop position, so that the device remains loaded;

if said difference in pressure is, or soon after decreases, until a value lower than a second and lower pre-established threshold value, the lamina (18) instantaneously moves again towards the first configuration;

in such a way, the bistable valve fitted with a double closing member (22) intercepts the communication between the first duct (12) and the second duct (13) and connects the first duct (12) to the housing (17) which, in its turn, through third duct (14), the first chamber (15) and the channels (28, 29), is connected to the atmosphere (27);

this causes the quick falling of the pressure in the second chamber (16, 20) to the atmospheric value;

for this reason the plunger (11) moves again towards the first stable limit stop position;

therefore, the lamina (18) indicates if the pressure in the tire exceeds or not at least a higher pre-established threshold value and causes the recovery of the plunger (11) to the first limit stop position (unloading condition) in which the plunger (11) does not cause the opening of the self-closing valve core (7) which closes again the communication with the internal part of the tire.

11. Device as in claim 9, wherein the force necessary to move the plunger (11) from the first to the second limit stop position during the loading phase is applied to the envelope (1) and wall (2) integral with the envelope (1), said force is transmitted by said envelope (1) and wall (2) to plunger (11) through the wall (2), which directly acts on the lamina (18) with variable geometrical configuration and causes the deformation of the lamina (18) to a second configuration;

in this configuration the plunger (11) is located at the second limit stop position, the bistable double closing member (22) connects the second duct (13) to the first duct (12), so that pressure of the tire exists in second chamber (26), second duct (13), first duct (12) and second chamber (16, 20), while the atmospheric pressure exists in the housing (17), a third duct (14) and in first chamber (15);

said second configuration of the lamina (18) can be maintained only if the difference between the pressure in second chamber (16, 20) and housing (17) exceeds at least a first pre-established threshold value;

in said condition the difference between the pressure in second chamber (16, 20) and first chamber (15) is the same as the difference between the pressure in second chamber (16, 20) and housing (17);

until said difference in pressure is sufficient to maintain the second configuration of the lamina (18) the resultant on the plunger (11) is sufficient to assure that the plunger (11) is maintained in the second limit stop position, so that the device remains loaded;

if said difference in pressure is, or soon after decreases, until a value lower than a second and lower pre-established threshold value, the lamina (18) instantaneously moves again towards the first configuration;

in such a way, the bistable valve fitted with a double closing member (22) intercepts the communication between the first duct (12) and the second duct (13) and connects the first duct (12) to the housing (17) , which, in its turn, through the third duct (14), the first chamber (15) and the channels (28, 29), is connected to the atmosphere (27);

this causes the quick falling of the pressure in the second chamber (16, 20) to the atmospheric value, for this reason the plunger (11) moves again towards the first limit stop position;

therefore, the lamina (18) indicates if the pressure in the tire exceeds or not at least a higher pre-established threshold value and causes the recovery of the plunger (11) to the first limit stop position (unloading condition) in which the plunger (11) does not cause the opening of the self-closing valve core (7) which closes again the communication with the internal part of the tire.

12. Device as in claim 9, wherein the lamina (18) with variable geometrical configuration is a bimetal (18) allowing to change the pressure threshold which causes the commutation of the configuration in function of the temperature.

13. Device as in claim 5, wherein after the releasing of the force (P), the spring (9) and the thrust of the air pressure existing in the second chamber (16, 20) move again the external envelope (1) towards the first stable limit stop position.

14. Device as in claim 1, wherein the displacement of the plunger (11) or the change in geometrical configuration of the lamina (18) set at work an electrical circuitry by means of which the emission of optical and/or acoustic signals is obtained to be transmitted via electromagnetic waves.