# US 12,759,182 B2 · Handheld power tool > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,759,182 B2 - Document ID: US12759182B2 - Status: Granted - Kind: B2 - Application number: 19/159,052 - Filed: 2024-01-12 - Published: 2026-07-30 - Granted: 2026-10-13 - Earliest claimed: 2023-02-23 - Assignees: Husqvarna AB - Applicants: Husqvarna AB - Inventors: Carl Rudenstam; Joakim Samefors; Kevin Sundin - Web page: https://patentgrep.com/patent/US12759182B2 ## CPC - B27B 17/12: Lubricating devices specially designed for chain saws - B27B: SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR (saws specially adapted for pruning or debranching A01G3/08; sawing apparatus specially adapted for felling trees A01G23/091; features not restricted to a particular type of wood saw B23D, e.g. attaching saw blades B23D51/00; machine tool frames, beds, pillars or like members, in general B23Q1/01) ## Abstract A handheld power tool (40) is disclosed comprising a power source (38) configured to power a tool (30) of the handheld power tool (40) and a lubrication pump (1). The lubrication pump (1) comprises a pump chamber unit (4) comprising a pump chamber (4′) with an inlet (11) connected to the lubricant tank (2) and an outlet (12) connected to the lubrication portion (3), a pump member (5′) arranged inside the pump chamber unit (4), and an electric motor unit (6) configured to rotate the pump member (5′) relative to the pump chamber unit (4) such that the pump member (5′) pumps lubricant from the inlet (11) to the outlet (12). The handheld power tool (40) further comprises a sensor assembly (7) configured to provide data indicative of the rotational position of the pump member (5′) relative to the pump chamber unit (4). ## Claims ### Claim 1 A handheld power tool comprising a power source configured to power a tool of the handheld power tool and a lubrication system, wherein the lubrication system comprises a lubricant tank and lubrication pump configured to pump lubricant from the lubricant tank to a lubrication portion to lubricate the tool, and wherein the lubrication pump comprises: a pump chamber unit comprising a pump chamber with an inlet connected to the lubricant tank and an outlet connected to the lubrication portion, a pump member arranged inside the pump chamber unit, and an electric motor unit configured to rotate the pump member relative to the pump chamber unit such that the pump member pumps lubricant from the inlet to the outlet, and wherein the handheld power tool further comprises a sensor assembly configured to provide data indicative of the rotational position of the pump member relative to the pump chamber unit. ### Claim 2 (depends on 1) The handheld power tool according to claim 1, wherein the handheld power tool further comprises a control arrangement connected to the sensor assembly and to the electric motor unit, and wherein the control arrangement is configured to control operation of the electric motor unit based on the data from the sensor assembly. ### Claim 3 (depends on 2) The handheld power tool according to claim 2, wherein the control arrangement is configured to: determine a current rotational speed of the pump member using the data from the sensor assembly upon rotation of the pump member, obtain a desired rotational speed of the pump member, and control a power output of the electric motor unit such that the rotational speed of the pump member is controlled towards the desired rotational speed of the pump member. ### Claim 4 (depends on 3) The handheld power tool according to claim 3, wherein the control arrangement is configured to increase the power output of the electric motor unit in case the current rotational speed is below the desired rotational speed and is configured to reduce the power output of the electric motor unit in case the current rotational speed is above the desired rotational speed. ### Claim 5 (depends on 3) The handheld power tool according to claim 3, wherein the control arrangement is configured to: obtain at least one parameter indicative of a current lubrication need of the tool, and determine the desired rotational speed of the pump member based on the obtained at least one parameter. ### Claim 6 (depends on 5) The handheld power tool according to claim 5, wherein the at least one parameter is indicative of a current operational condition of the power source of the handheld power tool. ### Claim 7 (depends on 2) The handheld power tool according to claim 2, wherein the control arrangement is configured to, upon receipt of a stop demand of the lubrication pump, control the electric motor unit to rotate the pump member to assume an angle relative to the pump chamber unit being within a predetermined angle interval. ### Claim 8 (depends on 7) The handheld power tool according to claim 7, wherein the pump chamber unit comprises an inlet port connected to the inlet and an outlet port connected to the outlet, and wherein the pump member comprises a mantle surface configured to cover and uncover the inlet port and the outlet port respectively upon rotation of the pump member. ### Claim 9 (depends on 8) The handheld power tool according to claim 8, wherein the mantle surface of the pump member is configured to cover the inlet port when the pump member is at an angle relative to the pump chamber unit being within the predetermined angle interval. ### Claim 10 (depends on 1) The handheld power tool according to claim 1, wherein the lubrication pump comprises a plunger unit comprising the pump member, and wherein the plunger unit is rotationally arranged relative to the pump chamber unit around a rotation axis, and wherein the lubrication pump comprises a mechanism configured to force the plunger unit to reciprocate relative to the pump chamber unit along directions coinciding with the rotation axis upon rotation of the plunger unit relative to the pump chamber unit. ### Claim 11 (depends on 10) The handheld power tool according to claim 10, wherein the mechanism is formed by a groove on one of the plunger unit and the pump chamber unit and a protrusion arranged on the other of the plunger unit and the pump chamber unit, wherein the protrusion protrudes into the groove, and wherein the groove is angled relative to a plane perpendicular to the rotation axis. ### Claim 12 (depends on 10) The handheld power tool according to claim 10, wherein the lubrication pump comprises a connector connecting an output shaft of the electric motor unit and the plunger unit. ### Claim 13 (depends on 12) The handheld power tool according to claim 12, wherein an end section of the plunger unit protrudes into an aperture of the connector, and wherein the aperture and the end section together form an interface rotationally locking the plunger unit to the connector while allowing movement of the plunger unit relative to the connector along directions coinciding with the rotation axis of the plunger unit. ### Claim 14 (depends on 13) The handheld power tool according to claim 13, wherein the sensor assembly comprises a sensor configured to sense the magnitude of a magnetic field and a magnet arranged on a portion of the lubrication pump, and wherein the portion of the lubrication pump is arranged to rotate with the pump member. ### Claim 15 (depends on 14) The handheld power tool according to claim 14, wherein the portion of the lubrication pump is a portion of the connector. ### Claim 16 (depends on 14) The handheld power tool according to claim 14, wherein the sensor is a Hall effect sensor. ### Claim 17 (depends on 1) The handheld power tool according to claim 1, wherein the electric motor unit comprises an electric motor and a gearbox, and wherein the gearbox connects an output shaft of the electric motor and an output shaft of the electric motor unit. ### Claim 18 (depends on 1) The handheld power tool according to claim 1, wherein the handheld power tool is a chainsaw or a hedge trimmer.