Control method and equipment for charging ready-mixed concrete additives batchwise

• US 4,008,093 A
• Filed: 07/08/1974
• Issued: 02/15/1977
• Est. Priority Date: 07/12/1973
• Status: Expired due to Term

• Current Assignee: Japanese National Railway, Kao Soap Co., Ltd. (KAO Corporation), Kayabakogyo-Kabushiki-Kaisha
• Original Assignee: Japanese National Railway, Kao Soap Co., Ltd. (KAO Corporation), Kayabakogyo-Kabushiki-Kaisha
• Inventors: Hattori, Kenichi, Nakagawa, Hiromi, Kitsuda, Toshiyuki, Matsuda, Tsunehisa, Wakao, Mitsuru
• Primary Examiner(s): Poer, J.
• Application Number:
  US05/486,348
• Time in Patent Office: 953 Days
• Field of Search: 106/90, 106/97, 106/89
• US Class Current: 106/638
• CPC Class Codes: B28C 7/026 by measuring data of the driving system, e.g. rotational speed, torque, consumed power

Abstract

A control method for charging ready-mixed concrete additives batchwise which aims at keeping the slump of ready-mixed concrete within a certain range and making longer transportation by truck mixer possible without degrading the quality, where the slump of ready-mixed concrete is detected electrically as a change in the mixing torque so that, when this detected value reaches a value set beforehand, a motor receives a control instruction to charge additives for adjusting slump into the ready-mixed concrete and so that the operating time of the motor for charging additives and the interval until control operation is reset may be adjusted with a timer.

Claims

1. A control method for the batchwise charging of ready-mixed concrete, comprising the steps of

mixing the concrete until a slump change occurs in the concrete;

detecting the occurrence of the slump change as a function of a change in the mixing torque required for effecting said mixing;

initiating a signal when said change in the mixing torque reaches a predetermined level; and

utilizing said signal to initiate dispensing of slump-adjusting additives into said concrete for a timed period.

2. A control method as defined in claim 1, the concrete being mixed by a motor;

and wherein the step of detecting comprises measuring changes in the motor torque.

3. A control method as defined in claim 1, the concrete being mixed by a hydraulic drive having a hydraulic working pressure;

and wherein the step of detecting comprises measuring changes in said working pressure.

4. A control method as defined in claim 3;

and further comprising the step of suppressing externally originating peaks and pulses of the working pressure so as to prevent them from influencing the initiation of said signal.