Muffler
    1.
    发明授权
    Muffler 失效
    围巾

    公开(公告)号:US5619020A

    公开(公告)日:1997-04-08

    申请号:US599642

    申请日:1996-02-09

    IPC分类号: F01N1/06 G10K11/178

    摘要: A muffler for muffling noise in a fluid flow, such as exhaust gases from an internal combustion engine comprises a chamber, loudspeakers for injecting anti-noise into the chamber under the control of processing circuitry in dependence upon residual noise detected by a microphone. The gas flows from an inflow pipe to an outflow pipe past a radial aperture that produces an acoustic coupling between the chamber and the gas flow, to allow the anti-noise to mix with noise in the gas flow and produce noise cancellation. The coupling is so arranged that the chamber becomes pressurized by the gas flow, in use, so as to restrict hot gas flow through the chamber and thereby provide an essentially benign environment for the loudspeaker.

    摘要翻译: 用于消除来自内燃机的废气的消声器的消音器包括一个室,用于根据麦克风检测到的残余噪声在处理电路的控制下将抗噪声注入到室内的扬声器。 气体从流入管道流过径流孔,径向孔径在腔室和气体流之间形成声耦合,以使抗噪声与气流中的噪声混合并产生噪声消除。 联接器被布置成使得室在使用中被气流加压,以便限制热气流通过室,从而为扬声器提供基本上良好的环境。

    Noise reduction system
    2.
    发明授权
    Noise reduction system 失效
    降噪系统

    公开(公告)号:US5638454A

    公开(公告)日:1997-06-10

    申请号:US190031

    申请日:1994-05-26

    IPC分类号: G10K11/178 A61F11/06

    摘要: A system for reducing periodic noise, which includes a plurality of harmonically related noise signals, comprises an actuator for producing a canceling acoustic signal, a sensor for detecting a residual noise signal, a synchronizing signal generator and processing circuitry. The processing circuitry comprises a plurality of tunable harmonically related band pass filters, a tuning signal generator and a summer which sums the outputs of the filters. The tuning signal generator receives the synchronizing signal from the synchronizing signal generator and outputs the tuning signals to the band pass filters. As the frequency of the synchronizing signal changes, the tuning signal generator causes the tunable filters to track harmonics of the noise to be canceled. After summing by the summer and suitable amplification, the outputs from the filters are used to drive the actuator so as to reduce the residual noise detected by the sensor.

    摘要翻译: PCT No.PCT / GB92 / 01399 Sec。 371日期:1994年5月26日 102(e)日期1994年5月26日PCT提交1992年7月28日PCT公布。 出版物WO93 / 03479 日期:1993年02月18日包括多个谐波相关噪声信号的减少周期性噪声的系统包括用于产生消除声信号的致动器,用于检测残余噪声信号的传感器,同步信号发生器和处理电路。 处理电路包括多个可调谐的谐波相关带通滤波器,调谐信号发生器和对滤波器的输出求和的加法器。 调谐信号发生器从同步信号发生器接收同步信号,并将调谐信号输出到带通滤波器。 随着同步信号的频率变化,调谐信号发生器使可调滤波器跟踪待消除的噪声的谐波。 在夏季求和和合适的放大后,滤波器的输出用于驱动执行器,以减少传感器检测到的残留噪声。

    Hydraulic lever actuator
    3.
    发明授权
    Hydraulic lever actuator 失效
    液压杠杆执行器

    公开(公告)号:US5676353A

    公开(公告)日:1997-10-14

    申请号:US969272

    申请日:1994-11-01

    摘要: An actuator having a linear current force characteristic comprises a moving coil transducer and a hydraulic lever. The moving coil is capable of producing only a relatively low force but with a relatively large displacement. The coil is formed on a piston which acts as an input piston to a hydraulic level. An output piston has a much larger area than the input piston. Thus, the long throw, low force input to the hydraulic lever is converted into a short throw, high force output at the second piston.

    摘要翻译: PCT No.PCT / GB91 / 01210 Sec。 371日期:1994年11月1日 102(e)1994年11月1日PCT PCT 1991年7月19日PCT公布。 出版物WO92 / 02107 日期1992年2月6日具有线性电流力特性的致动器包括运动线圈换能器和液压杆。 运动线圈只能产生相对较小的力但位移相对较大。 线圈形成在用作输入活塞至液压水平的活塞上。 输出活塞具有比输入活塞大得多的面积。 因此,输入到液压杆的长时间投入,低力被转换成在第二活塞处的短输出,高的力输出。

    Headphone assemblies
    4.
    发明授权
    Headphone assemblies 失效
    耳机组件

    公开(公告)号:US5361304A

    公开(公告)日:1994-11-01

    申请号:US565434

    申请日:1990-08-10

    CPC分类号: H04R1/1083 H04R9/047

    摘要: A headphone assembly for an active noise cancellation system has a rigid moulded plastics shell having a rigid baffle dividing the shell interior into a front volume and a closed rear volume, both of which may be filled with an acoustic foam. The baffle has a central opening in which is mounted a headphone transducer, and a seal cushion is disposed around the mouth of the shell, to effect an air-tight seal against the user's head. The headphone transducer has two effective sound radiating surfaces of different sizes, and may be constructed as a form of orthodynamic drive unit. In the latter case, the orthodynamic drive unit diaphragm may have two separate coils of different radial extents.

    摘要翻译: 用于主动噪声消除系统的耳机组件具有刚性模制塑料外壳,其具有将壳体内部分成前体积和闭合的后体积的刚性挡板,两者都可以填充声泡沫。 挡板具有中央开口,其中安装有耳机换能器,并且密封垫设置在壳体的嘴部周围,以对使用者的头部进行气密密封。 耳机换能器具有两个不同尺寸的有效的声辐射表面,并且可以被构造为一种形式的正弦驱动单元。 在后一种情况下,正弦驱动单元隔膜可以具有不同径向范围的两个单独的线圈。