Apparatus for determining the shrinkage temperature of leather, hides, skins and thelike

摘要

714,111. Testing physical qualities of leather. WACHTEL, K. April 15, 1953 [April 29, 1952], No. 10769/52. Class 106 (2) An apparatus for determining the temperature at which a hide commences to shrink comprises means for supporting a specimen strip of leather under slight tension in a body of liquid, means for heating the liquid, a maximum reading thermometer responsive to the temperature of the liquid, a solenoid-operated valve or switch for controlling the heating means and means operatively associated with the specimen strip and adapted immediately said strip commences to shrink, to break the control circuit of the solenoid and thereby cut off the supply of heat to the liquid. The leather strip 7 may be tensioned by a spring 37, a screw 38 being adjusted to engage the spring. On heating a liquid surrounding the strip 7 any shrinkage of the strip will cause the spring 37 to break contact with the screw 38, this action affecting an electrical control circuit to cut the supply of heat to the liquid. A maximum reading thermometer immersed in the liquid will indicate the temperature at which this occurs. As shown in Fig. 2, shrinkage of the strip 7 may be used to raise a' weight 29 acting as one switch contact in a solenoid circuit 33, 34, 36 adapted to cut off the gas supply to a burner 4a immediately the strip 7 commences to shrink. A motor operated peddle 13a may be immersed in the 'liquid body. The mercury switch 36 is adapted to cut off the supply to the motor 13a at the same instant that the heat supply is cut off According to a further modification, shrinkage of the strip 7 may be used to tilt a mercury switch cutting off a current supply to a solenoid which holds open a gas supply valve to the heating means.