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A control module for a walk behind trowel configured to detect and to prevent an uncontrolled or undesirable motion of the trowel. The trowel includes an engine configured to drive rotation of a rotor. The control module includes a gyroscope and a controller. The gyroscope is configured to provide a

A control module for a walk behind trowel configured to detect and to prevent an uncontrolled or undesirable motion of the trowel. The trowel includes an engine configured to drive rotation of a rotor. The control module includes a gyroscope and a controller. The gyroscope is configured to provide an electrical signal representative of an angular rate of motion of a reference structure on the walk behind trowel. The controller is configured to receive the electrical signal from the gyroscope and to determine when a change in the angular rate of motion of the trowel exceeds a threshold value, and in response, to prevent the engine from driving the rotor to rotate.

대표청구항 ▼

1. A walk behind trowel, comprising:(A) a frame having a reference structure; (B) a rotor positioned underneath the frame; (C) an engine configured to drive rotation of the rotor; and (D) a control module having: a gyroscope operable to provide an electrical signal representative of an angular rate

1. A walk behind trowel, comprising:(A) a frame having a reference structure; (B) a rotor positioned underneath the frame; (C) an engine configured to drive rotation of the rotor; and (D) a control module having: a gyroscope operable to provide an electrical signal representative of an angular rate of motion of the reference structure on the frame; and a controller configured to receive the electrical signal from the gyroscope and to determine when a change in the angular rate of motion exceeds a threshold value, and in response to prevent the engine from driving the rotor to rotate. 2. The walk behind trowel of claim 1, wherein the controller is operable to shut down the engine to prevent rotation of the rotor.3. The walk behind trowel of claim 1, wherein the engine includes an ignition coil configured to receive a plurality of electrical pulse to drive operation of the engine, and further comprisinga switch connected electrically to an electrical ground and in parallel to the ignition coil of the walk behind trowel. 4. The walk behind trowel of claim 3, wherein the controller prevents rotation of the trowel blades by activating the switch and electrically snubbing the plurality of electrical pulses to the ignition coil to shutdown the engine.5. The walk behind trowel of claim 4, wherein the controller is configured to electrically snub a portion of the electrical pulses to prevent the engine from driving rotation of the rotor.6. The walk behind trowel of claim 1, wherein the electrical signal from the gyroscope is a variable voltage value representative for every degree of rotation/second.7. The walk behind trowel of claim 6, wherein a reduction in the variable voltage value from the gyroscope represents an increase in the angular rate of motion of the frame of the walk behind trowel.8. The walk behind trowel of claim 7, wherein the controller determines the threshold value of the angular rate of motion by averaging a running average of variable voltage values with a baseline value.9. The walk behind trowel of claim 7, wherein the controller stores a histogram of variable voltage values generated by the gyroscope.10. The walk behind trowel of claim 7, wherein the controller is configured to shutdown the engine upon detecting the angular rate of motion exceeding 70 degrees/second.11. The walk behind trowel of claim 1, wherein the gyroscope is configured to be mounted on a handle connected to the frame of the walk behind trowel.12. The walk behind trowel of claim 1, wherein the controller is configured to determine an operating state outside of the designated range within at least 15 degrees rotation of the trowel.