# US 10,245,663 B2 · Airflow management system for a power tool > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,245,663 B2 - Document ID: US10245663B2 - Status: Granted - Kind: B2 - Application number: 15/108,427 - Filed: 2014-12-17 - Published: 2016-11-03 - Granted: 2019-04-02 - Earliest claimed: 2013-12-30 - Assignees: Robert Bosch Tool Corporation; Robert Bosch GmbH - Applicants: Robert Bosch GmbH; Robert Bosch Tool Corporation; Jan Koegel - Inventors: Jan Koegel - Web page: https://patentgrep.com/patent/US10245663B2 ## CPC - B23D 59/0064: {by suction} - B23D 45/06: with a circular saw blade arranged underneath a stationary work-table - B23D 47/12: of drives for circular saw blades - B23D: PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR (making toothed gears or the like B23F; cutting metal by applying heat locally B23K; arrangements for copying or controlling B23Q) ## Abstract A table saw includes a lower guard assembly, a first airflow fan, a motor, and a drivetrain system. The lower guard assembly has a dust exhaust chute and is configured to at least partially enclose a lower portion of a saw blade. The first airflow fan is positioned in the lower guard assembly and is configured to produce a first airflow directed through the lower guard assembly toward the dust exhaust chute. The motor is configured to rotationally drive an output shaft, and the drivetrain system connects the output shaft to the first airflow fan and the saw blade to enable the motor to rotationally drive the first airflow fan and the saw blade simultaneously. ## Claims ### Claim 1 A table saw comprising: a lower guard assembly including a dust exhaust chute, the lower guard assembly being configured to at least partially enclose a lower portion of a saw blade; a first airflow fan positioned in the lower guard assembly and configured and arranged to produce a first airflow directed through the lower guard assembly toward the dust exhaust chute; a second airflow fan positioned in the lower guard assembly and configured to produce a second airflow directed through the lower guard assembly toward the dust exhaust chute, the first and second airflows forming a combined airflow directed toward the dust exhaust chute; a motor configured to rotationally drive an output shaft; and a drivetrain system connecting the output shaft to the first airflow fan and the saw blade to enable the motor to rotationally drive the first airflow fan, the second airflow fan, and the saw blade simultaneously. ### Claim 2 (depends on 1) The table saw of claim 1, wherein: the motor is positioned in the lower guard assembly and includes a motor casing in which a motor fan is positioned, and the motor fan is configured and arranged to produce a third airflow directed toward the dust exhaust chute, the first, second, and third airflows forming the combined airflow toward the dust exhaust chute. ### Claim 3 (depends on 2) The table saw of claim 2, wherein: the drivetrain system includes a drivetrain belt configured to transfer rotational energy from the output shaft to rotate the saw blade, the table saw further comprises an idler pulley roller fixed to the first airflow fan and rotatably connected to the drivetrain belt such that rotation of the drivetrain belt causes rotation of the idler pulley roller and the first airflow fan, and wherein the idler pulley roller is configured to be moved to adjust a tension of the drivetrain belt. ### Claim 4 (depends on 1) The table saw of claim 1, wherein: the second airflow fan is formed in one of a planar outer surface of the saw blade and a blade washer configured to fasten the saw blade to a drive shaft, and the second airflow fan is configured to produce the second airflow in at least one of an axial direction of the saw blade and a radial direction of the saw blade. ### Claim 5 (depends on 1) The table saw of claim 1, the drivetrain system further comprising: a first set of gears configured to transfer rotational energy from the motor to the first airflow fan, and a second set of gears configured to transfer rotational energy from the motor to the second airflow fan. ### Claim 6 (depends on 5) The table saw of claim 5, wherein the second airflow fan is integrally formed on a shaft rotationally fixed to one gear of the second set of gears. ### Claim 7 (depends on 6) The table saw of claim 6, wherein the lower guard assembly includes a dust rip defining an airflow channel configured to direct the first airflow and the second airflow downwardly toward the dust exhaust chute. ### Claim 8 (depends on 1) The table saw of claim 1, further comprising: a first blower assembly including the first airflow fan, which is configured to generate a suction in the lower guard assembly to produce the first airflow; and a second blower assembly including the second airflow fan, which is configured to produce the second airflow to blow air into the lower guard assembly. ### Claim 9 (depends on 1) The table saw of claim 1, further comprising: at least one airflow converter configured to accelerate and redirect a portion of the first airflow through gullets at an outer circumference of the saw blade in a direction transverse to a plane in which the saw blade is located. ### Claim 10 (depends on 1) The table saw of claim 1, wherein the first airflow is directed toward the saw blade, and the second airflow redirects the first airflow toward the dust exhaust chute. ### Claim 11 (depends on 2) The table saw of claim 2, wherein the motor fan is coaxial with the output shaft, and the first and second airflow fans have respective first and second rotational axes that are spaced apart from the output shaft. ### Claim 12 (depends on 3) The table saw of claim 3, wherein: the lower guard assembly further comprises a first dust rip and an idler housing; the idler pulley roller and first airflow fan are arranged in the idler housing; and the first dust rip and the idler housing define a first airflow channel through which the first airflow flows from the first airflow fan to the dust exhaust chute. ### Claim 13 (depends on 12) The table saw of claim 12, wherein: the lower guard assembly further comprises a second dust rip; and the first and second dust rips define a second airflow channel through which the second airflow flows from the second airflow fan to the dust exhaust chute. ### Claim 14 (depends on 13) The table saw of claim 13, wherein the lower guard assembly further comprises a saw blade housing in which the saw blade is at least partially enclosed, the first and second dust rips being positioned in the saw blade housing. ### Claim 15 (depends on 14) The table saw of claim 14, wherein the lower guard assembly further comprises a motor housing in which the motor and motor fan are arranged, the motor housing and the saw blade housing defining a third airflow channel through which the third airflow flows from the motor fan to the dust exhaust chute.