Power leveling machine

Abstract

The utility model discloses a power leveler. The power leveler includes a handle, a housing, a blade assembly, a motor coupled to the blade assembly, a motion sensor, and a controller. The motion sensor is configured to provide an output signal indicative of motion of the power leveler. The output signal includes an orientation signal indicative of an orientation of the power leveler. The controller is connected to the motor and the motion sensor. The controller is configured to: receive an output signal from the motion sensor; determining whether the orientation of the power leveler is greater than or equal to an orientation threshold based on the orientation signal; and deactivating the motor in response to the angle of the powered leveler being greater than or equal to the orientation threshold.

Description

[0001] Related Applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 284,828, filed on December 1, 2021, the entire contents of which are incorporated herein by reference. Utility Model Content

[0003] The embodiments described herein provide systems and methods for determining and reacting to a kickback event or other uncontrolled condition of a battery-powered trowel. For example, a power trowel may begin to spin rapidly or generally out of operator control. In such an event, the proposed system and method assists the operator in regaining control of the power trowel.

[0004] The power trowel described herein includes a handle, a housing, a blade assembly, a motor coupled to the blade assembly, a motion sensor, and a controller. The motion sensor is configured to provide an output signal indicating the motion of the power trowel. The output signal includes an orientation signal indicating the orientation of the power trowel. The controller is connected to the motor and the motion sensor. The controller is configured to: receive the orientation signal from the motion sensor; determine whether the orientation of the power trowel is greater than or equal to an orientation threshold based on the orientation signal; and deactivate the motor in response to the orientation of the power trowel being greater than or equal to the orientation threshold.

[0005] In some aspects, the output signal includes a speed signal indicative of a speed of movement of the power trowel. The controller is further configured to determine whether the speed signal is greater than or equal to a speed threshold and deactivate the motor in response to the speed signal being greater than or equal to the speed threshold.

[0006] In some aspects, the motion sensor is located on the handle.

[0007] In some aspects, the orientation of the power trowel is the angle of the handle.

[0008] In some aspects, the motion sensor is located on the housing.

[0009] In some aspects, the power trowel further includes a battery pack and a switch, the battery pack connected to the motor, the switch connected to the controller, the battery pack and the motor. The controller is further configured to operate the switch to disconnect the battery pack from the motor in response to the orientation of the power trowel being greater than or equal to the orientation threshold.

[0010] In some aspects, the power trowel further includes a load sensor configured to provide a load signal indicative of a load condition of the motor. The controller is further configured to monitor the load condition of the motor and deactivate the motor in response to the load condition of the motor exceeding a predetermined load operating range.

[0011] In some aspects, the load condition is at least one selected from the group consisting of: current draw of the motor, power draw of the motor, revolutions per minute ("RPM") of the motor, and RPM of the blade assembly.

[0012] The power trowel described herein includes a handle, a housing, a blade assembly, a motor coupled to the blade assembly, a detector for detecting whether an operator is holding the handle, and a controller. The controller is connected to the motor and the detector. The controller is configured to: operate the motor to drive the blade assembly; determine whether the operator is holding the handle; and deactivate the motor in response to determining that the operator is not holding the handle.

[0013] In some aspects, the detector is a joystick operable to be actuated by an operator.The controller is further configured to determine that the operator is holding the handle when the joystick is actuated, and to determine that the operator is not holding the handle when the joystick is not actuated.

[0014] In some aspects, the power trowel further includes a battery pack configured to provide power to the motor. The controller is further configured to disconnect the battery pack from the motor in response to determining that the operator is not holding the handle.

[0015] In some aspects, the detector is a tether configured to be connected to a power trowel.The controller is further configured to determine whether the tether is connected to the power trowel and to deactivate the motor in response to determining that the tether is not connected to the power trowel.

[0016] In some aspects, the power trowel further includes a switch configured to deactivate the motor in response to being actuated.

[0017] In some aspects, the detector is a metal conductor integrated into the handle.The controller is further configured to monitor the resistance of the metal conductor and deactivate the motor in response to detecting a change in the resistance of the metal conductor.

[0018] The power trowel described herein includes a handle, a housing, a blade assembly, a motor coupled to the blade assembly, a battery pack configured to provide power to the motor, a motion sensor, and a controller. The motion sensor is configured to provide an output signal indicating the motion of the power trowel. The output signal includes an orientation signal indicating the orientation of the power trowel. The controller is connected to the motor and the motion sensor. The controller is configured to: receive the output signal from the motion sensor; determine whether the orientation of the power trowel is greater than or equal to an orientation threshold based on the orientation signal; and reduce the amount of power provided by the battery pack to the motor in response to the orientation of the power trowel being greater than or equal to the orientation threshold.

[0019] In some aspects, the amount of power provided by the battery pack to the electric machine is reduced to a non-zero value.

[0020] In some aspects, the output signal includes a speed signal indicating a speed of movement of the power trowel. The controller is further configured to determine whether the speed signal is greater than or equal to a speed threshold, and to reduce the amount of power provided by the battery pack to the motor in response to the speed signal being greater than or equal to the speed threshold.

[0021] In some aspects, the motion sensor is located on the handle.

[0022] In some aspects, the power trowel further includes a load sensor configured to provide a load signal indicative of a load condition of the motor. The controller is further configured to monitor the load condition of the motor and reduce the amount of power provided by the battery pack to the motor in response to the load condition of the motor exceeding a predetermined load operating range.

[0023] In some aspects, the load condition is at least one selected from the group consisting of: current draw of the motor, power draw of the motor, revolutions per minute ("RPM") of the motor, and RPM of the blade assembly.

[0024] A method of operating a power trowel described herein includes: operating a motor coupled to a blade assembly to drive the blade assembly; and receiving an orientation signal from a motion sensor. The orientation signal indicates an orientation of the power trowel. The method includes: determining whether the orientation of the power trowel is greater than or equal to an orientation threshold based on the orientation signal; and deactivating the motor in response to the orientation of the power trowel being greater than or equal to the orientation threshold.

[0025] In some aspects, the method further includes providing an output signal from the motion sensor indicating the motion of the power trowel. The output signal includes an orientation signal. The output signal includes a speed signal indicating the speed of motion of the power trowel. The method also includes: determining whether the speed signal is greater than or equal to a speed threshold; and deactivating the motor in response to the speed signal being greater than or equal to the speed threshold.

[0026] In some aspects, the motion sensor is located on the handle of the power trowel.

[0027] In some aspects, the orientation of the power trowel is the angle of the handle.

[0028] In some aspects, the motion sensor is located on the housing of the power trowel.

[0029] In some aspects, the method further includes operating a switch to disconnect the battery pack from the motor in response to the orientation of the power trowel being greater than or equal to the orientation threshold.

[0030] In some aspects, the method further includes: monitoring a load condition of the motor based on a load signal received from the load sensor; and deactivating the motor in response to the load condition of the motor exceeding a predetermined load operating range.

[0031] In some aspects, the load condition is at least one selected from the group consisting of: current draw of the motor, power draw of the motor, revolutions per minute ("RPM") of the motor, and RPM of the blade assembly.

[0032] The method of operating a power trowel described herein includes operating a motor coupled to a blade assembly to drive the blade assembly; determining via a detector device whether an operator is holding a handle of the power trowel; and deactivating the motor in response to determining that the operator is not holding the handle.

[0033] In some aspects, the detector device is a joystick operable to be actuated by an operator, and the method includes: determining that the operator is gripping the handle when the joystick is actuated; and determining that the operator is not gripping the handle when the joystick is not actuated.

[0034] In some aspects, the method includes disconnecting the battery pack from the motor in response to determining that the operator is not gripping the handle.

[0035] In some aspects, the detector device is a tether configured to connect to a power trowel, and the method includes: determining whether the tether is connected to the power trowel; and deactivating the motor in response to determining that the tether is not connected to the power trowel.

[0036] In some aspects, the method includes deactivating the motor in response to the switch being actuated.

[0037] In some aspects, the detector device is a metallic conductor integrated into the handle, and the method further includes: monitoring the resistance of the metallic conductor; and deactivating the motor in response to detecting a change in the resistance of the metallic conductor.

[0038] The method of operating a power trowel described herein includes: operating a motor coupled to a blade assembly to drive the blade assembly; and receiving an orientation signal from a motion sensor. The orientation signal indicates an orientation of the power trowel. The method includes: determining whether the orientation of the power trowel is greater than or equal to an orientation threshold based on the orientation signal; and reducing the amount of power provided by the battery pack to the motor in response to the orientation of the power trowel being greater than or equal to the orientation threshold.

[0039] In some aspects, the amount of power provided by the battery pack to the electric machine is reduced to a non-zero value.

[0040] In some aspects, the method further includes providing an output signal from the motion sensor indicating the motion of the power trowel. The output signal includes an orientation signal. The output signal includes a speed signal indicating the speed of motion of the power trowel. The method includes: determining whether the speed signal is greater than or equal to a speed threshold; and reducing the amount of power provided by the battery pack to the motor in response to the speed signal being greater than or equal to the speed threshold.

[0041] In some aspects, the motion sensor is located on the handle of the power trowel.

[0042] In some aspects, the method includes: monitoring a load condition of the motor based on a load signal received from a load sensor; and reducing an amount of power provided by the battery pack to the motor in response to the load condition of the motor exceeding a predetermined load operating range.

[0043] In some aspects, the load condition is at least one selected from the group consisting of: current draw of the motor, power draw of the motor, revolutions per minute ("RPM") of the motor, and RPM of the blade assembly.

[0044] Before any embodiment is explained in detail, it should be understood that the embodiments are not limited in their application to the details of construction and arrangement of components set forth in the following description or shown in the accompanying drawings. The embodiments can be practiced or implemented in various ways. Moreover, it should be understood that the words and terms used herein are for descriptive purposes and should not be considered restrictive. The use of "including," "comprising," or "having" and variations thereof is intended to cover the items listed thereafter and their equivalents as well as additional items. Unless otherwise specified or limited, the terms "mount," "connect," "support," and "couple" and variations thereof are used broadly and cover both direct mounting, connection, support, and coupling as well as indirect mounting, connection, support, and coupling.

[0045] In addition, it should be understood that embodiments may include hardware, software, and electronic components or modules, which, for the purpose of discussion, may be shown and described as if most components are implemented only in hardware. However, those of ordinary skill in the art will recognize, based on reading this detailed description, that in at least one embodiment, electronic-based aspects may be implemented with software (e.g., stored on a non-transitory computer-readable medium) that may be executed by one or more processing units (e.g., microprocessors and / or application-specific integrated circuits ("ASICs")). Thus, it should be noted that embodiments may be implemented using a plurality of hardware- and software-based devices and a plurality of different structural components. For example, the "server" and "computing device" described in the specification may include one or more processing units, one or more computer-readable media modules, one or more input / output interfaces, and various connectors (e.g., a system bus) connecting the various components.

[0046] Other features and aspects will become apparent by consideration of the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A side view of a power trowel according to embodiments described herein is shown.

[0048] Figure 2 A front view of a power trowel according to embodiments described herein is shown.

[0049] Figure 3 A side view of a power trowel with a tether according to embodiments described herein is shown.

[0050] Figure 4A A front view of a power trowel having an emergency switch according to embodiments described herein is shown.

[0051] Figure 4B A side view of a power trowel having an emergency switch according to embodiments described herein is shown.

[0052] Figure 5 A front view of a power trowel with a charging handle according to embodiments described herein is shown.

[0053] Figure 6 The invention is shown in accordance with the embodiments described herein. Figures 1 to 5 Block diagram of a controller for a powered trowel.

[0054] Figure 7 The embodiment described herein is shown by Figure 6 A block diagram of a method for initiating a protection operation performed by a controller.

[0055] Figure 8The embodiment described herein is shown by Figure 6 A block diagram of another method of initiating a protection operation performed by a controller.

[0056] Fig. 9 The embodiment described herein is shown by Figure 6 A block diagram of another method of initiating a protection operation performed by a controller.

[0057] Fig.10 The embodiment described herein is shown by Figure 6 A block diagram of another method of initiating a protection operation performed by a controller. DETAILED DESCRIPTION

[0058] Figure 1 An example of a battery-powered trowel or power trowel 100 according to some embodiments is shown. The power trowel 100 includes a handle 105, a housing 110 (e.g., a motor housing), an axle 115, a blade housing (or blade barrier) 120, and a blade assembly 125. The handle 105 is coupled to the housing 110 via the axle 115. The handle 105 is composed of a first handle (or right handle) 105a and a second handle (or left handle) 105b. The housing 110 houses the motor 680 ( Figure 6 ). The motor 680 drives the blade assembly 125. The blade housing 120 surrounds the blade assembly 125 to protect an operator or bystander from the movement of the blade assembly 125.

[0059] The motor 680 may be powered from a battery pack 665 ( Figure 6 665 receives power from the motor 680. For example, the battery pack 665 provides direct current (DC) power to the motor 680. However, the power trowel 100 can be configured to operate via other types of power, such as, but not limited to, alternating current (AC) power from an AC power source. In some embodiments, the power trowel 100 includes a power cable (e.g., a power cord). In other embodiments, the motor 680 is a gas engine, and other electrical components of the power trowel 100 receive power directly or indirectly from the AC or DC power generated by the gas engine. Such electrical components may include, for example, emergency switches 150a-150f, a controller 600, an indicator 645, a load sensor 685, motion sensors 130a-130d, a secondary sensor 690, a tether detector 145, a handle resistance module 695, and Figure 6 Other parts shown.

[0060] In some embodiments, the power trowel 100 includes a motion sensor 130 (e.g., an accelerometer, a gyroscope, an angle sensor, etc.). The motion sensor 130 outputs a signal indicating the detected motion of the power trowel 100. In some embodiments, as Figure 1 As shown, the motion sensor 130 is disposed or located on the shaft 115. In some embodiments, the motion sensor 130 may be located at other locations on the power trowel 100. For example, Figure 2 As shown, the power trowel 100 may include a motion sensor 130a disposed on the handle 105. The motion sensor 130a may be located on the first handle 105a or the second handle 105b. In other embodiments, the power trowel 100 may include a motion sensor 130b disposed on the housing 110. The motion sensor 130b may be disposed at a location where the shaft 115 is coupled to the housing 110 or generally disposed on an upper portion of the housing 110. In some embodiments, the power trowel 100 includes a motion sensor 130c disposed on a lower portion of the housing 110. For example, the motion sensor 130c may be disposed at a location where the housing 110 is coupled to the blade housing 120. The motion sensor 130c may alternatively be disposed on an upper portion of the blade housing 120. In some embodiments, the power trowel 100 includes a motion sensor 130d disposed on a lower portion of the blade housing 120. While several locations of the motion sensor 130 are provided, the power trowel 100 may include multiple combinations of motion sensors 130. As one non-limiting example, the power trowel 100 may include both the motion sensor 130a and the motion sensor 130c.

[0061] In some embodiments, Figure 3 As shown, the power trowel 100 includes a tether 140. A first end of the tether 140 is selectively coupled to the power trowel 100. A second end of the tether 140 is selectively coupled to an operator 300 of the power trowel 100. Although shown as being coupled to the handle 105, in other embodiments, the tether 140 is coupled to the shaft 115, the housing 110, or the blade housing 120. The power trowel 100 may include a tether detector 145 for detecting whether the tether 140 is coupled to the power trowel 100. For example, if the distance between the power trowel 100 and the operator 300 exceeds the length of the tether 140, the tether 140 will be disconnected from the power trowel 100.

[0062] In some embodiments, FIG. 4A to FIG. 4BAs shown, the power trowel 100 includes emergency switches 150a-150f. The emergency switches 150a-150f are configured to cut off or reduce the power to the motor 680 in response to being actuated. In some embodiments, the power trowel 100 includes an emergency switch 150a disposed on the first handle 105a. The power trowel 100 may include an emergency switch 150b disposed on the second handle 105b. In some embodiments, the emergency switch 150c is disposed at a position where the shaft 115 is coupled to the housing 110 or is generally disposed on an upper portion of the housing 110. In some embodiments, the power trowel 100 includes an emergency switch 150d disposed on a lower portion of the housing 110. For example, the emergency switch 150d may be disposed at a position where the housing 110 is coupled to the blade housing 120. The emergency switch 150d may alternatively be disposed on an upper portion of the blade housing 120. In some embodiments, the power trowel 100 includes an emergency switch 150e disposed on a lower portion of the blade housing 120. In some embodiments, the power trowel 100 includes an emergency switch 150f disposed on the shaft 115. Although several positions of the emergency switches 150a-150f are provided, the power trowel 100 may include multiple combinations of the emergency switches 150a-150f. As a non-limiting example, the power trowel 100 may include both the emergency switch 150a and the emergency switch 150c.

[0063] In some embodiments, Figure 4A As shown, the power trowel 100 includes a switch or lever (e.g., trigger) 108 configured to be actuated when the motor 680 is running. For example, the operator holds the lever when operating the power trowel 100. If the operator releases the lever, the motor 680 will be cut off.

[0064] In some embodiments, the handle 105 is charged with a low voltage or current, such as Figure 5 In such an embodiment, the handle 105 can be made of a metal material or include a metal conductor (e.g., a thin sheet) that provides a low current. In some embodiments, the metal conductor is integrated into the handle 105. When the operator places their hand on the handle 105, the corresponding resistance of the handle 105 will undergo a change.

[0065] Figure 6A controller 600 is shown for the power trowel 100. The controller 600 is electrically and / or communicatively connected to various modules or components of the power trowel 100. For example, the controller 600 is shown connected to an indicator 645, motion sensors 130a-130d, a tether detector 145, an emergency switch 150a-150f, an on switch or trigger 650 (via a trigger switch 658), a motor 680 (via a power switch network 675), a load sensor 685, a secondary sensor 690, a handle resistance module 695, and a power input unit 660. A battery pack 665 is connected to a battery pack interface 670 for mechanically and electrically connecting the battery pack 665 to the power trowel 100.

[0066] The controller 600 includes a plurality of electrical and electronic components that provide power, operational control, and protection to the components and modules within the controller 600 and / or the power trowel 100. For example, the controller 600 includes, among other things, a processing unit 605 (e.g., a microprocessor, an electronic processor, an electronic controller, a microcontroller, or other suitable programmable device), a memory 625, an input unit 630, and an output unit 635. The processing unit 605 includes, among other things, a control unit 610, an arithmetic logic unit ("ALU") 615, and a plurality of registers 620 (in Figure 6 600 is shown as a set of registers) and is implemented using a known computer architecture (e.g., a modified Harvard architecture, a von Neumann architecture, etc.). The processing unit 605, the memory 625, the input unit 630, the output unit 635, and various modules connected to the controller 600 are connected via one or more control buses and / or data buses (e.g., a common bus 640). For the purpose of illustration, the control bus and / or data bus are generally Figure 6 In view of the embodiments described herein, it is known to those skilled in the art to use one or more control buses and / or data buses for interconnection and communication between various modules and components.

[0067] The memory 625 is a non-transient computer readable medium and includes, for example, a program storage area and a data storage area. The program storage area and the data storage area may include a combination of different types of memory, such as ROM, RAM (e.g., DRAM, SDRAM, etc.), EEPROM, flash memory, hard disk, SD card or other suitable magnetic, optical, physical or electronic memory devices. The processing unit 605 is connected to the memory 625 and executes software instructions, which can be stored in the RAM of the memory 625 (e.g., during execution), the ROM of the memory 625 (e.g., on a generally permanent basis) or another non-transient computer readable medium such as another memory or disk. The software included in the implementation of the power trowel 100 can be stored in the memory 625 of the controller 600. The software includes, for example, firmware, one or more applications, program data, filters, rules, one or more program modules and other executable instructions. The controller 600 is configured to retrieve from the memory 625 and execute instructions related to the control process and method described herein, in particular. In other embodiments, the controller 600 includes additional components, fewer components or different components.

[0068] The controller 600 drives the motor 680 to rotate the blade assembly 125 in response to the user's actuation of the trigger 650. The blade assembly 125 can be directly coupled to the motor 680 via an output shaft. In other embodiments, the blade assembly 125 is coupled to the motor 680 via a gearbox. Pressing the trigger 650 actuates the trigger switch 658, which outputs a signal to the controller 600 to drive the motor 680, and thus drives the blade assembly 125. In some embodiments, the controller 600 drives the power switch network 675 (e.g., a FET switch bridge) to drive the motor 680. For example, the power switch network 675 may include a plurality of high-side switch elements (e.g., FETs) and a plurality of low-side switch elements. The controller 600 may control each FET in the plurality of high-side switch elements and the plurality of low-side switch elements to drive each phase of the motor 680. When the trigger 650 is released, the controller 600 may apply a braking force to the motor 680. For example, the power switch network 675 may be controlled to decelerate the motor 680 faster.

[0069] The indicator 645 is also connected to the controller 600 and receives control signals from the controller 600 to turn on and off or otherwise communicate information based on different states of the power trowel 100. The indicator 645 includes, for example, one or more light emitting diodes (LEDs) or a display screen. The indicator 645 can be configured to display the status of the power trowel 100 or information associated with the power trowel. For example, the indicator 645 can display information related to the operating state of the power trowel 100 or the battery pack 665, such as the charging capacity of the battery pack 665. The indicator 645 can also display information related to a fault condition or other abnormality of the power trowel 100. In addition to or in lieu of the visual indicator, the indicator 645 can also include a speaker or a tactile feedback mechanism to convey information to the user through an auditory or tactile output. In some embodiments, the indicator 645 displays information related to an uncontrolled condition or state (e.g., a winding condition, a recoil condition, etc.) of the power trowel 100. For example, when an uncontrolled state of the power trowel 100 is detected, one or more LEDs are enabled.

[0070] The motion sensor 130 senses the motion of the power trowel 100. In some embodiments, the motion sensor 130 provides one or more motion signals (e.g., output signals) to the controller 600 indicating the motion of the power trowel 100. The controller 600 can determine the position of the power trowel 100 based on the motion signals, such as the orientation of the power trowel 100 or the angle at which the shaft 115 is tilted. In some embodiments, the controller 600 determines the angular displacement, angular velocity, or angular acceleration of the movement of the power trowel 100 (e.g., relative to a vertical axis or z-axis with respect to the ground) based on the motion signals.

[0071] The tether detector 145 provides a signal to the controller 600 indicating whether the tether 140 is coupled to the power trowel 100. In some embodiments, the signal from the tether detector 145 is a binary signal ("1" or "ON" when the tether 140 is coupled to the power trowel 100 and "0" or "OFF" when the tether 140 is not coupled to the power trowel 100).

[0072] The load sensor 685 provides a load signal to the controller 600 indicating the load condition of the power trowel 100. The controller 600 can determine the current consumption of the motor 680, the power consumption of the motor 680, the revolutions per minute (RPM) of the motor 680, the RPM of the blade assembly 125, etc. based on the load signal. Accordingly, the load sensor 685 can include a current sensor, a voltage sensor, a Hall sensor, etc. Additional sensors (such as voltage sensors, temperature sensors, etc.) can be included in the secondary sensor 690 to detect additional conditions of the power trowel 100.

[0073] The emergency switches 150a-150f output signals to the controller 600 to stop the operation of the motor 680. For example, when the emergency switches 150a-150f are actuated, the controller 600 initiates a braking operation of the motor 680 using the power switch network 675. In some embodiments, when the emergency switches 150a-150f are actuated, the controller 600 electrically disconnects the battery pack 665 from the power switch network 675, and thus disconnects the battery pack 665 from the motor 680.

[0074] The controller 600 also monitors the handle resistance module 695 of the handle 105. In some embodiments, the controller 600 determines the resistance of the handle 105 based on the current value flowing through the handle 105 and / or the voltage value of the handle 105. For example, the user's hand adds a series or parallel resistance to the user detection circuit (e.g., the handle resistance module 695). The inclusion of a series or parallel resistance will increase or decrease the total resistance of the circuit. The change in resistance can be detected by detecting the change in the voltage across the resistance of the circuit. Similarly, when the user's hand is removed from the handle, the resistance of the circuit changes again. If the change in resistance of the circuit exceeds a threshold, the power trowel 100 determines that one or both hands of the user have been removed from the handle. In some embodiments, a first threshold is used to determine whether one hand of the user has been removed, and a second threshold is used to determine whether both hands of the user have been removed.

[0075] When operating the power trowel 100, the user may lose control of the power trowel 100, causing the power trowel 100 to begin to spin or experience other undesirable movements. In order to protect the power trowel 100 and the user of the power trowel 100 when an uncontrolled condition occurs, the controller 600 performs a protective operation in response to a detected uncontrolled condition. For example, Figure 7 is a flow chart of an example method 700 for controlling a power trowel 100 in response to a detected uncontrolled state. The method 700 may be performed by the controller 600. At block 705, the controller 600 operates the motor 680 to drive the blade assembly 125. For example, a user of the power trowel 100 actuates the trigger 650. Upon detecting actuation of the trigger 650, the controller 600 controls the power switch network 675 to supply power to the motor 680.

[0076] At box 710, the controller 600 receives one or more motion signals from the motion sensors 130a-130d. At box 715, the controller 600 determines whether the motion parameters (e.g., angular displacement, angular velocity, angular acceleration, etc.) of the power trowel 100 are greater than or equal to a threshold value based on the motion signals from the motion sensors 130a-130d. For example, the controller 600 determines the speed or angular velocity of the power trowel 100 based on the one or more motion signals (e.g., velocity signals). The angular velocity is compared with an angular velocity threshold (e.g., velocity threshold) stored in the memory 625. If the angular velocity is not greater than or equal to the angular velocity threshold (i.e., a controlled state), the controller 600 returns to box 705 and continues to operate the motor 680 to drive the blade assembly 125. Accordingly, in some embodiments, the controller 600 continuously monitors the angular velocity of the power trowel 100. If the angular velocity is greater than or equal to the angular velocity threshold (i.e., an uncontrolled state), then at box 720, the controller 600 adjusts the operation of the motor 680. In some embodiments, the controller 600 deactivates the motor 680 or otherwise stops the operation of the motor. The controller 600 can disconnect the battery pack 665 from the power switch network 675 so that the motor 680 no longer receives power. In some embodiments, the controller 600 reduces the amount of power provided to the motor 680. For example, the amount of power provided to the motor 680 is reduced to a non-zero value to allow the user to regain control of the power trowel 100.

[0077] Figure 8 8 is a flow chart of another example method 800 for controlling a power trowel 100 in response to a detected uncontrolled state. The method 800 may be performed by a controller 600. At box 805, the controller 600 operates the motor 680 to drive the blade assembly 125, as previously described with respect to box 705. At box 810, the controller 600 receives one or more motion signals from the motion sensors 130a-130d. At box 815, the controller 600 determines whether the position of the power trowel 100 is greater than or equal to a position threshold based on the motion signals from the motion sensors 130. For example, the controller 600 may determine the orientation of the power trowel 100 based on the motion signals. The controller 600 compares the orientation of the power trowel 100 with an orientation threshold. In some embodiments, the orientation of the power trowel 100 includes an angle of the power trowel 100, such as an angle of the shaft 115 (e.g., relative to gravity). Accordingly, the controller 600 may compare the angle of the shaft 115 with an angle threshold.

[0078] If the position of the power trowel 100 is not greater than or equal to the position threshold (i.e., a controlled state), the controller 600 returns to box 805 and continues to operate the motor 680 to drive the blade assembly 125. If the position of the power trowel 100 is greater than or equal to the position threshold (i.e., an uncontrolled state), at box 820, the controller 600 adjusts the operation of the motor 680. In some embodiments, the controller 600 deactivates the motor 680 or otherwise stops the operation of the motor. The controller 600 can disconnect the battery pack 665 from the power switch network 675 so that the motor 680 no longer receives power. In some embodiments, the controller 600 reduces the amount of power provided to the motor 680. For example, the amount of power provided to the motor 680 is reduced to a non-zero value to allow the user to regain control of the power trowel 100.

[0079] Fig. 9 is a flow chart of another example method 900 for controlling a power trowel 100 in response to a detected uncontrolled state. The method 900 may be performed by a controller 600. At box 905, the controller 600 operates the motor 680 to drive the blade assembly 125, as previously described with respect to box 705. At box 910, the controller 600 receives a load signal from the load sensor 685. At box 915, the controller 600 determines whether the load on the motor 680 (e.g., the load condition of the motor 680) is greater than or equal to a load threshold based on the load signal from the load sensor 685. For example, the controller 600 may determine the current consumption of the motor 680 based on the load signal. Then, the controller 600 compares the current consumption of the motor 680 with the current threshold. In some embodiments, the controller 600 determines the power consumption of the motor 680 based on the load signal. Then, the controller 600 compares the power consumption of the motor 680 with the power threshold. In some embodiments, the controller 600 determines the RPM of the motor 680 based on the load signal. The controller 600 then compares the RPM of the motor 680 to a rotational speed threshold.

[0080] If the load of the motor 680 is not greater than or equal to the load threshold (i.e., uncontrolled state), the controller 600 returns to box 905 and continues to operate the motor 680 to drive the blade assembly 125. If the load of the motor 680 is greater than or equal to the load threshold (i.e., uncontrolled state), then at box 920, the controller 600 adjusts the operation of the motor 680. In some embodiments, the controller 600 deactivates the motor 680 or otherwise stops the operation of the motor. The controller 600 can disconnect the battery pack 665 from the power switch network 675 so that the motor 680 no longer receives power. In some embodiments, the controller 600 reduces the amount of power provided to the motor 680. For example, the amount of power provided to the motor 680 is reduced to a non-zero value to allow the user to regain control of the power trowel 100.

[0081] In some embodiments, the controller 600 determines whether the load on the motor 680 is within a predetermined load operating range (e.g., between an upper load threshold and a lower load threshold) based on the load signal from the load sensor 685. If the load of the motor 680 is within the predetermined load operating range, the controller 600 returns to block 905 and continues to operate the motor 680 to drive the blade assembly 125. If the load of the motor 680 is outside the predetermined load operating range, the controller 600 adjusts the operation of the motor 680 at block 920.

[0082] Sometimes, the operator may let go of the handle 105, causing the power trowel 100 to be in an uncontrolled state. Fig.10 is a flow chart of an example method 1000 for detecting whether an operator is holding the handle 105 of the power trowel 100. The method 1000 may be performed by the controller 600. At block 1005, the controller 600 operates the motor 680 to drive the blade assembly 125, as previously described with respect to block 705.

[0083] At box 1010, the controller 600 determines whether the operator is holding the handle 105. For example, the controller 600 can monitor the resistance of the handle 105. If the change in the resistance of the handle 105 is greater than a threshold, the controller 600 determines that the operator is not holding the handle 105. In some embodiments, the controller 600 receives a signal from the tether detector 145. If the signal from the tether detector 145 indicates that the tether 140 is not connected to the power trowel 100, the controller 600 determines that the operator is not holding the handle 105. In some embodiments, the controller 600 determines whether the switch 108 (or trigger 650) is actuated. If the switch 108 is not actuated, the controller 600 determines that the operator is not holding the handle 105.

[0084] If the operator is holding the handle 105 (i.e., the controlled state), the controller 600 returns to box 1005 and continues to operate the motor 680 to drive the blade assembly 125. If the controller 600 determines that the operator is not holding the handle 105 (i.e., the uncontrolled state), the controller 600 continues to box 1015 and adjusts the operation of the motor 680. In some embodiments, the controller 600 deactivates the motor 680 or otherwise stops the operation of the motor. The controller 600 can disconnect the battery pack 665 from the power switch network 675 so that the motor 680 no longer receives power. In some embodiments, the controller 600 reduces the amount of power provided to the motor 680. For example, the amount of power provided to the motor 680 is reduced to a non-zero value to allow the user to regain control of the power trowel 100.

[0085] Accordingly, implementations of the methods 700 , 800 , 900 , and / or 1000 may assist an operator of the power trowel 100 in regaining control of the power trowel when the controller 600 determines that the power trowel 100 is in an uncontrolled state.

[0086] Thus, the embodiments provided herein describe, among other things, systems and methods for determining and reacting to a kickback event or other uncontrolled condition of a power trowel. Various features and advantages are set forth in the appended claims.

Claims

1. A power trowel (100), characterized in that: include: Handle (105); Housing (110); Blade assembly (125); a motor (680) coupled to the blade assembly (125); a motion sensor (130) configured to provide an output signal indicative of the motion of the power trowel (100), wherein the output signal includes an orientation signal indicative of the orientation of the power trowel (100); and A controller (600) is connected to the motor (680) and the motion sensor (130), and the controller (600) is configured to: receiving the orientation signal from the motion sensor (130), determining, based on the orientation signal, whether the orientation of the power trowel (100) is greater than or equal to an orientation threshold, and The motor (680) is deactivated in response to the orientation of the power trowel (100) being greater than or equal to the orientation threshold.

2. The power trowel (100) according to claim 1, characterized in that: The output signal includes a speed signal indicating the movement speed of the power trowel (100); and The controller (600) is further configured to: Determine whether the speed signal is greater than or equal to a speed threshold, and The motor is deactivated (680) in response to the speed signal being greater than or equal to the speed threshold.

3. The power trowel (100) according to claim 1, characterized in that: The motion sensor (130) is located on the handle (105).

4. The power trowel (100) according to claim 3, characterized in that: The orientation of the power trowel (100) is the angle of the handle (105).

5. The power trowel (100) according to claim 1, characterized in that: The motion sensor (130) is located on the housing (110).

6. The power trowel (100) according to claim 1, characterized in that: Further including: A battery pack (665), the battery pack (665) being connected to the motor (680); as well as a switch (150), the switch (150) being connected to the controller (600), the battery pack (665) and the motor (680), The controller (600) is further configured to: The switch (150) is operated to disconnect the battery pack (665) from the motor (680) in response to the orientation of the power trowel (100) being greater than or equal to the orientation threshold.

7. The power trowel (100) according to claim 1, characterized in that: Further including: a load sensor (685) configured to provide a load signal indicative of a load condition of the motor (680), The controller (600) is further configured to: monitoring the load condition of the motor (680), and The motor (680) is deactivated in response to a load condition of the motor (680) exceeding a predetermined load operating range.

8. The power trowel (100) according to claim 7, characterized in that: The load condition is at least one selected from the group consisting of: current consumption of the motor (680), power consumption of the motor (680), revolutions per minute of the motor (680), and revolutions per minute of the blade assembly (125).

9. A power trowel (100), characterized in that: include: handle(105); Housing (110); Blade assembly (125); a motor (680) coupled to the blade assembly (125); A detector (145, 108, 650, 695) for detecting whether an operator is holding the handle (105); and A controller (600) is connected to the motor (680) and the detector (145, 108, 650, 695), and the controller (600) is configured to: operating the motor (680) to drive the blade assembly (125), determining whether the operator is holding the handle (105), and The motor (680) is deactivated in response to determining that the operator is not gripping the handle (105).

10. The power trowel (100) according to claim 9, characterized in that: The detector (145, 108, 650, 695) is a joystick (108, 650) operable to be actuated by the operator; and The controller (600) is further configured to: determining that the operator is holding the handle (105) when the joystick (108, 650) is actuated, and The operator is determined not to be holding the handle (105) when the joystick (108, 650) is not actuated.

11. The power trowel (100) according to claim 9, characterized in that: Further including: a battery pack (665) configured to provide power to the motor (680), and The controller (600) is further configured to: The battery pack (665) is disconnected from the motor (680) in response to determining that the operator is not holding the handle (105).

12. The power trowel (100) according to claim 9, characterized in that: The detector (145, 108, 650, 695) is configured to be connected to a tether (140) of the power trowel (100); and The controller (600) is further configured to: determining whether the tether (140) is connected to the power trowel (100); and The motor (680) is deactivated in response to determining that the tether (140) is not connected to the power trowel (100).

13. The power trowel (100) according to claim 9, characterized in that: Further included is a switch (150) configured to deactivate the motor (680) in response to being actuated.

14. The power trowel (100) according to claim 9, characterized in that: The detector (145, 108, 650, 695) is a metal conductor (695) integrated into the handle (105); and The controller (600) is further configured to: monitoring the resistance of the metal conductor (695), and The motor (680) is deactivated in response to detecting a change in the resistance of the metallic conductor (695).

15. A power trowel (100), characterized in that: include: handle(105); Housing (110); Blade assembly (125); a motor (680) coupled to the blade assembly (125); a battery pack (665), the battery pack (665) being configured to provide power to the motor (680); a motion sensor (130) configured to provide an output signal indicative of movement of the housing (110), wherein the output signal includes an orientation signal indicative of an orientation of the power trowel (100); and A controller (600) is connected to the motor (680) and the motion sensor (130), and the controller (600) is configured to: receiving the orientation signal from the motion sensor (130), determining, based on the orientation signal, whether the orientation of the power trowel (100) is greater than or equal to an orientation threshold, and The amount of power provided by the battery pack (665) to the motor (680) is reduced in response to the orientation of the power trowel (100) being greater than or equal to the orientation threshold.

16. The power trowel (100) according to claim 15, characterized in that: The amount of power provided by the battery pack (665) to the motor (680) is reduced to a non-zero value.

17. The power trowel (100) according to claim 15, characterized in that: The output signal includes a speed signal indicating the movement speed of the power trowel (100); and The controller (600) is further configured to: Determine whether the speed signal is greater than or equal to a speed threshold, and The amount of power provided by the battery pack (665) to the motor (680) is reduced in response to the speed signal being greater than or equal to the speed threshold.

18. The power trowel (100) according to claim 15, characterized in that: The motion sensor (130) is located on the handle (105).

19. The power trowel (100) according to claim 15, characterized in that: Further including: a load sensor (685) configured to provide a load signal indicative of a load condition of the motor (680), The controller (600) is further configured to: monitoring the load condition of the motor (680), and The amount of power provided by the battery pack (665) to the motor (680) is reduced in response to a load condition of the motor (680) exceeding a predetermined load operating range.

20. The power trowel (100) according to claim 19, characterized in that: The load condition is at least one selected from the group consisting of: current consumption of the motor (680), power consumption of the motor (680), revolutions per minute of the motor (680), and revolutions per minute of the blade assembly (125).

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