# US 12,759,125 B2 · Powered fastener driver > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,759,125 B2 - Document ID: US12759125B2 - Status: Granted - Kind: B2 - Application number: 19/214,199 - Filed: 2025-05-21 - Published: 2025-09-11 - Granted: 2026-10-13 - Earliest claimed: 2023-01-27 - Assignees: Milwaukee Electric Tool Corporation - Applicants: Milwaukee Electric Tool Corporation - Inventors: Arik A. Miller; Kirat S. Mokha; Mitchell A. Ellena; Marcus M. Wechselberger; David C. Graf - Web page: https://patentgrep.com/patent/US12759125B2 ## CPC - B25C 1/041: {with fixed main cylinder} - B25C 1/047: {Mechanical details} - B25C 1/06: operated by electric power - B25C 7/00: Accessories for nailing or stapling tools, e.g. supports (for tools operated by detonation of a cartridge B25C1/18) - B23Q 11/0092: {actuating braking or stopping means} - B25C 1/008: {Safety devices} - B25D 11/00: Portable percussive tools with electromotor {or other motor} drive - B25F 5/00: Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for - H02P 29/0027: {Controlling a clutch between the prime mover and the load} - B25C: HAND-HELD NAILING OR STAPLING TOOLS; MANUALLY OPERATED PORTABLE STAPLING TOOLS (for shoemaking A43D) - B23Q: DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING (tools of the kind used in lathes or boring machines B23B27/00); MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT - B25D: PERCUSSIVE TOOLS {(percussive machines for forging B21J; hand-held drilling machines, in general B23B45/00, for wood B27C3/08; drilling machines, used for mining or quarrying, with reciprocating tool which is turned intermittently when out of contact with the working face E21B1/00)} - 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)} - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract A powered fastener driver includes a housing, a cylinder within the housing, the cylinder containing a pressurized gas, a piston within the cylinder and movable from a top-dead-center position to a bottom-dead-center position, a driver blade movably coupled to the piston, a lifter, a drive unit configured to provide torque to the lifter, and a sensor. The driver blade has a plurality of teeth. The sensor is configured to detect one or more of the plurality of teeth and a controller in communication with the drive unit and the sensor. The controller is configured to count a number of the plurality of teeth detected by the sensor, compare the number of detected teeth to a predetermined number of teeth, and stop the drive unit when the number of detected teeth is less than the predetermined number of teeth. ## Claims ### Claim 1 A powered fastener driver comprising: a housing; a cylinder within the housing, the cylinder containing a pressurized gas; a piston within the cylinder and moveable from a top-dead-center position to a bottom-dead-center position; a driver blade moveably coupled to the piston for driving a fastener into a workpiece, the driver blade having a plurality of teeth; a lifter configured to engage the plurality of teeth for returning the driver blade from the bottom-dead-center position toward the top-dead-center position; a drive unit configured to provide torque to the lifter, causing it to rotate; a sensor configured to detect one or more of the plurality of teeth; and a controller in communication with the drive unit and the sensor, the controller configured to: count a number of the plurality of teeth detected by the sensor, compare the number of detected teeth to a predetermined number of teeth, and stop the drive unit when the number of detected teeth is less than the predetermined number of teeth. ### Claim 2 (depends on 1) The powered fastener driver of claim 1, further comprising a lifter sensor configured to detect a position of the lifter, and wherein the controller is configured to activate a timer and a counter once the lifter sensor detects that the lifter moves through a nominal driver blade drop position. ### Claim 3 (depends on 2) The powered fastener driver of claim 2, wherein the controller is configured to execute an interrupt service routine when the number of detected teeth is equal to the predetermined number of teeth. ### Claim 4 (depends on 3) The powered fastener driver of claim 3, wherein the interrupt service routine disables the controller from counting the plurality of teeth until a subsequent fire-reload cycle. ### Claim 5 (depends on 2) The powered fastener driver of claim 2, wherein the controller is configured to determine whether the driver blade reaches a ready position within a predetermined amount of time. ### Claim 6 (depends on 1) The powered fastener driver of claim 1, wherein the controller is configured to determine whether the driver blade reaches the bottom-dead-center position within a predetermined amount of time. ### Claim 7 (depends on 6) The powered fastener driver of claim 6, wherein the controller includes a memory, and when the controller determines that the driver blade reached the bottom-dead-center position within the predetermined amount of time, the controller is configured to move data for the number of detected teeth to an array in the memory. ### Claim 8 (depends on 6) The powered fastener driver of claim 6, wherein the controller is configured to execute an interrupt service routine when the controller determines that the driver blade reached the bottom-dead-center position within the predetermined amount of time. ### Claim 9 (depends on 8) The powered fastener driver of claim 8, wherein the interrupt service routine disables the controller from counting the plurality of teeth until a subsequent fire-reload cycle. ### Claim 10 (depends on 1) The powered fastener driver of claim 1, wherein the sensor is an optical sensor having a phototransistor positioned on a first side of the driver blade and an infrared emitter located on an opposite side of the driver blade. ### Claim 11 (depends on 1) The powered fastener driver of claim 1, wherein the predetermined number of teeth are all the plurality of teeth or a portion of the plurality of teeth. ### Claim 12 A powered fastener driver comprising: a housing; a cylinder within the housing, the cylinder containing a pressurized gas; a piston within the cylinder and moveable from a top-dead-center position to a bottom-dead-center position; a driver blade moveably coupled to the piston for driving a fastener into a workpiece, the driver blade having a plurality of teeth; a frame supported within the housing; a lifter supported within the housing by the frame and configured to engage the plurality of teeth for returning the driver blade from the bottom-dead-center position toward the top-dead-center position; a drive unit configured to provide torque to the lifter, causing it to rotate; a lifter position sensing assembly configured to detect an angular position of the lifter at an end of a fastener driving cycle, the lifter position sensing assembly including a sensor coupled to the frame and a sensor target coupled for co-rotation with the lifter; and a controller in communication with the drive unit and the lifter position sensing assembly, the controller configured to stop the drive unit in response to the lifter position sensing assembly not detecting the angular position of the lifter at the end of the fastener driving cycle. ### Claim 13 (depends on 12) The powered fastener driver of claim 12, wherein the lifter is formed of a first material and the sensor target is formed of a second material different than the first material. ### Claim 14 (depends on 12) The powered fastener driver of claim 12, wherein the sensor target is separate from and coupled to the lifter. ### Claim 15 (depends on 12) The powered fastener driver of claim 12, wherein the sensor target is integrally formed with the lifter. ### Claim 16 (depends on 12) The powered fastener driver of claim 12, wherein the drive unit includes a motor, and wherein the sensor is positioned between the motor and the lifter. ### Claim 17 (depends on 12) The powered fastener driver of claim 12, wherein the sensor is coupled to the frame by a sensor housing at a position below the lifter. ### Claim 18 (depends on 12) The powered fastener driver of claim 12, further comprising a timer configured to be activated in response to a beginning controller of the fastener driving cycle, and wherein the controller is configured to deactivate the drive unit when the controller does not receive an output from the sensor before expiration of the timer. ### Claim 19 (depends on 18) The powered fastener driver of claim 18, wherein the controller is configured to determine whether the lifter rotated 360 degrees before the expiration of the timer. ### Claim 20 (depends on 18) The powered fastener driver of claim 18, wherein the controller is configured to activate an indicator to alert an operator that maintenance is required when the controller does not receive the output from the sensor before expiration of the timer.