# US 2018/0323740 A1 · Trigger potentiometer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0323740 A1 - Document ID: US20180323740A1 - Status: Published application - Kind: A1 - Application number: 15/969,730 - Filed: 2018-05-02 - Published: 2018-11-08 - Earliest claimed: 2017-05-03 - Assignees: Blount, Inc. - Applicants: Blount, Inc. - Inventors: Noah Erickson; Stephen Jones; Thomas Pitts; Jonathan Ziring - Web page: https://patentgrep.com/patent/US20180323740A1 ## CPC - H02P 29/40: Regulating or controlling the amount of current drawn or delivered by the motor for controlling the mechanical load - B25F 5/00: Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for - B25F 5/02: Construction of casings, bodies or handles {(B25F5/006, B25F5/008 take precedence)} - G05G 1/015: Arrangements for indicating the position of a controlling member (means for continuously detecting pedal position G05G1/38; means for detecting position through tactile feedback G05G5/03) - H01C 10/00: Adjustable resistors - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - B25F: COMBINATION OR MULTI-PURPOSE TOOLS NOT OTHERWISE PROVIDED FOR; DETAILS OR COMPONENTS OF PORTABLE POWER-DRIVEN TOOLS NOT PARTICULARLY RELATED TO THE OPERATIONS PERFORMED AND NOT OTHERWISE PROVIDED FOR {(machines or arrangements of machines for performing specified combinations of different metal-working operations not covered by a single other subclass B23P23/00 and subgroups)} - G05G: CONTROL DEVICES OR SYSTEMS INSOFAR AS CHARACTERISED BY MECHANICAL FEATURES ONLY ("Bowden" or like mechanisms F16C1/10; gearings or mechanisms not peculiar to this purpose F16H; speed changing or reversing mechanisms for gearings conveying rotary motion F16H59/00 - F16H63/00) - H01C: RESISTORS ## Abstract An electric hand tool that includes an electric motor, an electrical position indicator for operation by a user, and a control unit for controlling power delivery from a power supply to an electric motor, based signals received from the electrical position indicator. The electrical position sensor may be coupled to a trigger operable by a user, and the electrical position sensor may be configured to detect the relative position of the trigger and to only operate in the middle of its possible range. The control unit may determine if the signals received from the electrical position indicator are out of a defined range. If the signals received from the electrical position indicator are out of a defined range, the control unit may register a fault, such as a fully open and/or fully short fault. ## Claims ### Claim 1 An electric hand tool, comprising: an electrical motor; an operating element comprising an actuation trigger and an electrical position indicator that reads a position of the actuation trigger; and a control unit for controlling power delivery to the electrical motor on the basis of the position of the actuation trigger, wherein: the electrical position indicator is configured to sense the position of the actuation trigger in a working range that is within and less than its possible range, and provide a signal of the position of the actuation trigger to the control unit, and the control unit is configured to detect signals from the electrical position indicator outside of the working range. ### Claim 2 (depends on 1) The tool of claim 1, wherein the control unit is configured to prevent power delivery to the electrical motor upon detection that the electrical position indicator is outside of the working range. ### Claim 3 (depends on 2) The tool of claim 2, wherein the control unit is further configured to provide a notification of an error condition upon detection that the electrical position indicator is outside of the working range. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the electrical position indicator is one of a microswitch, a spring contact, a sliding switch, a reed contact, a Hall effect sensor, a potentiometer, a photoelectric barrier, or an encoder. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the control unit comprises a microprocessor or microcontroller. ### Claim 6 A method for controlling an electric tool, comprising: sensing the position of an actuation trigger of the tool using an a electrical position indicator that reads a position of the actuation trigger; controlling power delivery to an electrical motor in response to the electrical position indicator indicating the position of the actuation trigger being within a working range of the electrical position indicator, the working range within the possible range of the electrical position indicator; and preventing power delivery to the electrical motor in response to the electrical position indicator indicating a position outside the working range. ### Claim 7 (depends on 6) The method of claim 6, further comprising indicating an error condition in response to the electrical position indicator indicating a position outside the working range. ### Claim 8 (depends on 6) The method of claim 6, wherein the method is performed by a control unit capable of controlling an electric hand tool. ### Claim 9 A non-transitory computer readable medium (CRM), comprising instructions that, when executed by a processor of an apparatus, cause the apparatus to: receive a position of an actuation trigger from an electrical position indicator; control a speed of an electrical motor in response to the received position when the received position is within a working range that is less than the possible range of the electrical position indicator; and prevent delivery of power to the electrical motor in response to the received position outside of the working range. ### Claim 10 (depends on 9) The CRM of claim 9, wherein the instructions are further to indicate an error condition in response to the electrical position indicator indicating a position outside the working range. ### Claim 11 (depends on 9) The CRM of claim 9, wherein the apparatus comprises a control unit. ### Claim 12 (depends on 11) The CRM of claim 11, wherein the control unit comprises a microprocessor or a microcontroller. ### Claim 13 (depends on 9) The CRM of claim 9, wherein the electrical position indicator is one of a microswitch, a spring contact, a sliding switch, a reed contact, a Hall effect sensor, a potentiometer, a photoelectric barrier, or an encoder.