초록 ▼

Rapid shaft stop devices and transmissions are described that utilize permanent magnets for coupling and/or braking and are useful for electronic propeller guards and other equipment. In an embodiment, one or more capacitive discharge pulses are used to rapidly stop a shaft. A magnetic transmission

Rapid shaft stop devices and transmissions are described that utilize permanent magnets for coupling and/or braking and are useful for electronic propeller guards and other equipment. In an embodiment, one or more capacitive discharge pulses are used to rapidly stop a shaft. A magnetic transmission is provided having axially oriented magnets on each side of an air space junction that transmit torque across the junction with a torque/speed profile that particularly suits boat propellers. The junction may include a bearing and allows slippage when the propeller resistance exceeds a given value. This slippage acts as a variable gear reduction. One or more electromagnets may be energized and thereby add to or subtract from one or more magnetic fields and provide electronic control of torque and of gear reduction ratio for devices such as watercraft drive systems.

대표청구항 ▼

1. An electrical control system for suddenly stopping a propeller in a motor driven watercraft, comprising at least one sensor that detects an object near the propeller and a control circuit that can stop or slow the propeller to less than 10 rpm within one second, wherein the at least one sensor tr

1. An electrical control system for suddenly stopping a propeller in a motor driven watercraft, comprising at least one sensor that detects an object near the propeller and a control circuit that can stop or slow the propeller to less than 10 rpm within one second, wherein the at least one sensor triggers the control circuit upon sensing the object, and the control circuit stops a motor connected to the propeller.2. An electrical control system as described in claim 1, wherein the at least one sensor is a piezoelectric device.3. An electrical control system as described in claim 1, comprising at least 2 piezoelectric sensors.4. An electrical control system as described in claim 1, comprising at least 3 piezoelectric sensors.5. An electrical control system as described in claim 1, comprising at least one continuously emitting sonic transmitter.6. An electrical control system for suddenly stopping a propeller in a motor driven watercraft in proximity to an object, comprising at least one sensor, a propeller, a motor connected to the propeller, and a control circuit that can stop or slow the propeller to less than 10 rpm within one second, wherein the sensor triggers the control circuit upon sensing the object.7. The electrical control system of claim 6, wherein the at least one sensor is a piezoelectric transmitter that transmits ultrasonic energy continuously.8. The electrical control system of claim 6, wherein the at least one sensor comprises at least two piezoelectric transmitters that emit two frequencies or pulse types simultaneously.9. The electrical control system of claim 6, wherein the control circuit comprises a capacitor discharge circuit for rapidly pulsing an electromagnet.10. The electrical control system of claim 6, wherein at least one motor of the motor driven watercraft is an internal combustion motor.11. The electrical control system of claim 10, wherein the control circuit comprises a capacitor discharge circuit for rapidly energizing an electromagnet.12. The electrical control system of claim 11, wherein the capacitor discharge circuit comprises a capacitor with a capacity rating of at least 10,000 microfarads and a voltage rating of at least 100 volts.13. The electrical control system of claim 9, further comprising at least one silicon controlled rectifier, IGPT or MOSFET for discharging the capacitor.14. The electrical control system of claim 6, further comprising at least one electromagnet and at least one permanent magnet arranged to disengage the propeller from the motor upon activation.15. The electrical control system of claim 6, further comprising a friction brake for slowing the propeller upon activation.16. An electrical control system for suddenly stopping a propeller in a motor driven watercraft, comprising at least one propeller that is connected to a motor, at least one sensor selected from the group consisting of an infrared sensor, an ultrasonic sensor and a tactile switch sensor, and a control circuit connected to the sensor that pulses into one or more electromagnets upon activation by the sensor, and wherein the one or more electromagnets act to at least slow or disconnect the propeller from the motor upon activation.17. The electrical control system of claim 16, wherein the electricity that is pulsed into one or more electromagnets is from one or more capacitors.18. The electrical control system of claim 17, wherein the capacitor has a rating of at least 10,000 microfarad and at least 100 volts.19. The electrical control system of claim 17, comprising at least two capacitors that are separately discharged into one or more electromagnets with different time constants upon activation by the control circuit.20. The electrical control system of claim 16, wherein the sensor comprises at least one piezoelectric transducer.21. The electrical control system of claim 16, wherein the at least one sensor comprises at least two piezoelectric devices oriented in different directions.22. The electrical control system of claim 16, wherein the one or more electromagnets are fixed and exert a magnetic field against one or more permanent magnets located on a spinning shaft attached to the propeller.23. The electrical control system of claim 22, wherein the spinning shaft comprises a first flange with one or more magnets that exert a field upon a second flange that comprises one or more magnets of opposite polarity, wherein the first and two flanges are held together by magnetic attraction but spaced apart via a bearing.24. The electrical control system of claim 16, wherein the one or more electromagnets are part of an electric motor that drives the propeller.25. An electrical control system for suddenly stopping a spinning shaft, comprising at least one sensor and a control circuit that comprises a capacitor stored charge of electricity that is pulsed into one or more electromagnets upon activation by the at least one sensor, the at least one sensor comprises at least one infrared sensor or ultrasonic sensor and wherein the one or more electromagnets act to at least slow or disconnect the shaft from a motor upon activation.26. The electrical control system of claim 25, wherein the spinning shaft is connected to a propeller.27. The electrical control system of claim 25, wherein the capacitor has a rating of at least 10,000 microfarad and at least 100 volts.28. The electrical control system of claim 25, comprising at least two capacitors that are separately discharged into one or more electromagnets with different time constants upon activation by the control circuit.29. The electrical control system of claim 28, wherein a first capacitor discharge circuit has a time constant of less than 100 milliseconds and a second capacitor discharge circuit has a time constant of less than 500 milliseconds.30. The electrical control system of claim 25, wherein the one or more electromagnets are fixed and exert a magnetic field against one or more permanent magnets located on the spinning shaft.31. The electrical control system of claim 30, wherein the spinning shaft comprises a first flange with one or more magnets that exert a field upon a second flange that comprises one or more magnets of opposite polarity, and wherein the first and two flanges can rotate together on the same rotational axis by magnetic attraction between them but are spaced apart via a bearing.