US 4,283,706 AGranted

Puncture detecting device

AssigneeHonda Giken Kogyo Kabushiki Kaisha

InventorsShigeo Kimura, Tadashi Kamiya, Kiyotaka Hayashi

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Abstract

A tire puncture detecting device having a pressure chamber defined by a flexible diaphragm and held in communication with the interior of the tire, an atmospheric chamber communicating with the atmosphere, and a spring plate member disposed in the pressure chamber and supporting on the front face thereof a magnet and on the rear face thereof a central portion of the flexible diaphragm. The spring plate member is normally maintained in a retracted position under the air pressure in the pressure chamber against the bias of a resilient member disposed rearwardly of the spring plate member. When a reduction in the air pressure in the pressure chamber exceeds a predetermined degree, the spring plate member buckles so as to quickly project forwardly under the force of the resilient member. In this manner, the magnet supported on the spring plate member is moved closer to an alarm circuit switch located in front of the device and energizable by magnetic force, thereby actuating the switch. Puncturing of the tire is thus detected rapidly and reliably.

Claims20

Dependent claims

A puncture detecting device comprising:

a body casing (3);
an alarm circuit switch (20) disposed forwardly of said body casing (3), said alarm circuit switch (20) being actuable by magnetic force;
a pressure chamber (A) formed in said body casing (3), said pressure chamber (A) communicating with the interior of a tire (15);
an atmospheric chamber (B) formed in said body casing (3), said atmospheric chamber (B) communicating with the atmosphere;
a flexible diaphragm (5) sealingly separating said pressure chamber (A) from said atmospheric chamber (B);
a snap-acting spring plate member (7) disposed in said pressure chamber (A) and rigidly connected at a central portion (7b) of said snap-acting spring plate member (7) to a central portion (5b) of said flexible diaphragm (5);
a magnet (8) supported on a front face of said snap-acting spring plate member (7);
said magnet (8) being secured to an outer surface of said central portion (7b) of said snap-acting spring plate member (7), and being connected to said central portion (5b) of said flexible diaphragm (5) by means of said snap-acting spring plate member (7);
resilient means (11) for resiliently urging said snap-acting spring plate member (7) from the rear side thereof;
said snap-acting spring plate member (7) being normally held in a rearward direction against said resilient means (11) by the air pressure in said pressure chamber (A) to permit said magnet (8) to be spaced from said alarm circuit switch (20);
and
said snap-acting spring plate member (7) being buckled under the force from said resilient means (11) to rapidly project forwardly when said air pressure in said pressure chamber (A) decreases below a predetermined amount, whereby said magnet (8) is moved closer to said alarm circuit switch (20) to actuate said alarm circuit switch (20).

9 more elements

Dependencies are inferred from the claim text.