The Yokohama Rubber Co., Ltd.

Suga Test Instruments Co., Ltd.

Fuji Telecasting Co., Ltd.

Kenhachi Mitsuhashi

Shigeru Suga

Akira Yamada

Hiroyuki Itoh

Tuneo Morikawa

Yoshinobu Ohashi

Tadanobu Nagumo

Hajime Tomoda

Shohei Nakayama

Hiromitsu Akashi

Takuji Nishi

A method of measuring or controlling ozone concentration by ultraviolet ray absorptiometry, includes charging air into a testing tank with its temperature controlled, measuring the disturbing gases generated from testpieces such as rubber samples inside the testing tank by regarding them as ozone, subtracting a value representative of the disturbing gases with a calculation circuit from a value indicative of the preexisting state in the tank to set the ozone concentration at zero, generating a necessary quantity of ozone with an ozonizer by using the zero ozone concentration as a reference point, suspending the generation of ozone after the passage of a predetermined time, measuring once again to obtain a new ozone concentration zero value, adjusting the ozone concentration zero value to the new value if there has been a change in the amount of disturbing gases generated, and repeating at least once the operation described above to regulate the ozone concentration to a desired ozone concentration.

Method of measuring and controlling ozone concentration

A test oven wherein heated air having a predetermined temperature is supplied and the oxygen concentration in the supplied air is controlled. The test oven has a test oven body having an air supply port and an air discharge port, a blower connected to the air supply port for blowing air thereinto, an oxygen concentration detector connected to the test oven body, an oxygen concentration setting control unit connected to the oxygen concentration detecting detector and including an oxygen concentration setter for setting a desired level of oxygen, and an oxygen concentration controller constantly comparing a reference output level generated on the basis of a concentration level set in advance in the oxygen concentration setter with an output level outputted from the oxygen concentration detector and for controling the actual output level to a set level, and at least one oxygen concentration adjusting device. This can be an oxygen and nitrogen supply unit controlled by the oxygen concentration setting control unit for supplying an amount of oxygen and/or nitrogen to an air circulating passage upstream of the blower for regulating the concentration of the oxygen in response to the actual output level of the oxygen concentration setting control, or it can be a blower speed control for controlling the speed of the blower in accordance with such actual output level to blow air from outside into the oven body.

Oven provided with oxygen concentration controls

A ventilation regulated hot air supplied constant temperature oven used for heat aging testing. Heated air of a predetermined temperature is supplied to a test oven body through an air supply port. Ventilation of the test oven is carried out through the air discharge port at a predetermined rate at predetermined time intervals. A discharge cylinder is provided at the discharge port, a blower is connected to the air supply port, a differential pressure detector is connected to the discharge cylinder and adapted to detect a differential pressure corresponding to the air flow rate on the basis of the data obtained in advance on the relation between a difference between the pressure at an outlet port of the blower and that at the discharge cylinder and the air flow rate, and a blower speed regulator is provided between the blower and the differential pressure detector and adapted to control the speed of the blower in accordance with an output level of a signal corresponding to a differential pressure measured by the differential pressure detector.

Ventilation regulated hot air supplied constant temperature oven

A tension tester in which a specimen marked with at least one measuring marking whose optical characteristic is different from that of the specimen's ground color is held by chucks at the ends and subjected to a tensile load by moving one of the chucks; in which, while the specimen is being stretched, the marking is scanned by a scanner to detect a positional change of the marking in the tensile direction; and in which electric signals which are produced due to the difference in the optical characteristic between the marking and the specimen's ground color are processed to determine the tensile characteristic of the specimen. In this tension tester, the scanner consists of a first scanner with its field of view set to the entire elongation range of the specimen; and at least one second scanner having its field of view set only to a low elongation range of the specimen, the second scanner either having a greater number of elements than the first scanner or being adapted to perform a magnified scanning with greater magnification than that of the first scanner.

Tension tester

A tensile testing system for use with a specimen of rubber or other material having a test region defined on its reduced midportion by a marking or markings of, for example, higher lightness than the other specimen surface. The system comprises a scanning device for repeatedly translating the optical characteristics of the specimen or specimens into an electrical signal as the specimen or specimens are subjected to increasing tensile stress, and a gate circuit for deriving from the output signal of the scanning device its portions corresponding to the test region or regions. The varying length of the test region or regions can be represented either by pulse durations or by pulse numbers. The scanning device can be either an 'area scanner' such as a television camera or a 'line scanner' such as a solid-state line image sensor. Various embodiments are disclosed.

Opto-electronic tensile testing system

A radial ply pneumatic tire, having a high durability, comprising an improved bead portion thereof which comprises a bead wire bundle, a carcass ply of a metal tire cord fabric and a reinforcing ply, all embedded in a rubber matrix, the reinforcing ply having a portion thereof located in the outside surface layer in the bead portion and comprising a woven multifilament fabric consisting of multifilament warps in a density of 20 to 65 yarns/50 mm and multifilament wefts in a density of 20 to 65 yarns/50 mm and an endmost point of the portion of the reinforcing ply in the outside surface layer of the bead portion is located farther from the bead wire bundle than the endmost point of the carcass ply.

Radial ply pneumatic tire having woven multifilament fabric reinforcing

A pneumatic tire provided with a plurality of slots which are provided in tread grooves and extend in the transverse direction of the grooves but at a suitable spacing from each other for the purpose of confining between the slots the growth of cracks produced in the grooves, so that each crack is prevented from growing up to an extent exceeding the spacing between the slots.

Growing community of inventors

Kanagawa, Japan

Kenhachi Mitsuhashi