# US 12,005,542 B2 · Hand-held power tool for sending or polishing a workpiece > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,005,542 B2 - Document ID: US12005542B2 - Status: Granted - Kind: B2 - Application number: 16/852,778 - Filed: 2020-04-20 - Published: 2020-12-10 - Granted: 2024-06-11 - Earliest claimed: 2019-05-07 - Applicants: Guido Valentini - Inventors: Guido Valentini - Web page: https://patentgrep.com/patent/US12005542B2 ## CPC - B24B 23/022: {Spindle-locking devices, e.g. for mounting or removing the tool} - B24B 23/04: with oscillating grinding tools; Accessories therefor - B24B 23/03: the tool being driven in a combined movement - B24B 47/12: by mechanical gearing or electric power (B24B47/16 takes precedence) - B24D 9/08: Circular back-plates for carrying flexible material - B24B: MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING (grinding of gear teeth B23F, of screw-threads B23G1/36; by electro-erosion B23H; abrasive or related blasting B24C; tools for grinding, buffing or sharpening B24D; polishing compositions C09G1/00; abrasives C09K3/14; electrolytic etching or polishing C25F3/00; grinding arrangements for use on assembled railway tracks E01B31/17); DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS - B24D: TOOLS FOR GRINDING, BUFFING OR SHARPENING (abrading-bodies specially designed for tumbling apparatus, e.g. abrading-balls B24B31/14; honing tools B24B33/08; lapping tools B24B37/11) ## Abstract A hand-held power tool for sanding or polishing a working surface of a workpiece features a backing pad supported in respect to a housing in a manner freely rotatable about a longitudinal axis extending perpendicular to an extension plane of the backing pad. The housing or backing pad includes first magnetic elements spaced apart from each other in a direction extending parallel to the extension plane, and includes a second magnetic element located in a space between the first magnetic elements in such a manner that the second magnetic element is held at a distance to the first magnetic elements by a magnetic force when a motor of the power tool is running and the power tool is in an idle state, thereby limiting the movement of the backing pad to an orbital movement. ## Claims ### Claim 1 Hand-held power tool (1) for sanding or polishing a working surface (30) of a workpiece, the hand-held power tool (1) comprising a housing (2) and a backing pad (3) adapted for performing an orbital or a random orbital movement in an extension plane (25) of the backing pad (3) in respect to the housing (2) during use of the hand-held power tool (1), and the hand-held power tool (1) further comprising in the housing (2) a motor (4) with a motor shaft (5) adapted for performing a rotational movement about an axis of rotation (6), and means (7, 8) for transforming the rotational movement of the motor shaft (5) into the orbital or random orbital movement of the backing pad (3), the backing pad (3) being supported in respect to the housing (2) of the hand-held power tool (1) in a manner freely rotatable about a longitudinal rotational axis (9) extending perpendicular to the extension plane (25) of the backing pad (3), wherein the housing (2) or the backing pad (3) comprises at least two sets of first magnetic elements (16), the first magnetic elements of each set spaced apart from and facing each other in a circumferential direction extending in a second plane extending parallel to, and at an axial distance from, the extension plane (25) of the backing pad (3), a space (41) between the first magnetic elements of each set (16) extending in the circumferential direction by less than 45% and the backing pad (3) or the housing (2) comprises at least one second magnetic element (17) located in the second plane and in the space (41) between the first magnetic elements (16) of each set in such a manner that the at least one second magnetic element (17) is held at a distance to the first magnetic elements (16) by means of a magnetic force acting in the circumferential direction around the longitudinal rotational axis (9) at least when the motor (4) of the hand-held power tool (1) is running and the hand-held power tool (1) is in an idle state, thereby limiting the movement of the backing pad (3) to an orbital movement. ### Claim 2 (depends on 1) The hand-held power tool (1) according to claim 1, wherein at least one of the number, magnetic characteristics, dimensions and position of the first magnetic elements (16) and the at least one second magnetic element (17) are configured such that, at least when the motor (4) of the hand-held power tool (1) is running and the hand-held power tool (1) is in an idle state, the backing pad (3) is configured to perform the orbital movement in the extension plane (25) of the backing pad (3) and to prevent contact between the first magnetic elements (16) and the at least one second magnetic element (17). ### Claim 3 (depends on 1) The hand-held power tool (1) according to claim 1, wherein at least one of the number, magnetic characteristics, dimensions and position of the first magnetic elements (16) and the at least one second magnetic element (17) are configured such that, during use of the hand-held power tool (1), the backing pad (3) is configured to perform the orbital movement in the extension plane (25) of the backing pad (3) and to prevent contact between the first magnetic elements (16) and the at least one second magnetic element (17). ### Claim 4 (depends on 1) The hand-held power tool (1) according to claim 1, wherein the hand-held power tool (1) comprises damping elements (42) located between corresponding surfaces of the first magnetic elements (16) and a respective surface of the at least one second magnetic element (17) directly facing each other. ### Claim 5 (depends on 4) The hand-held power tool (1) according to claim 4, wherein the damping elements are located on at least one of the corresponding surfaces of the at least two first magnetic elements (16) and the respective surface of the at least one second magnetic element (17). ### Claim 6 (depends on 4) The hand-held power tool (1) according to claim 4, wherein the damping elements are made from sheets of rubber or soft plastic. ### Claim 7 (depends on 1) The hand-held power tool (1) according to claim 1, wherein at least some of the first magnetic elements (16) and the at least one second magnetic element (17) are permanent magnets or solenoids. ### Claim 8 (depends on 1) The hand-held power tool (1) according to claim 1, wherein a first part of the hand-held power tool (1) consisting of the housing (2) or the backing pad (3) comprises a first set (37) of the first magnetic elements (16) spaced apart from each other in a direction extending parallel to the extension plane (25) of the backing pad (3), and a corresponding other part of the hand-held power tool (1) consisting of the backing pad (3) or the housing (2) comprises the at least one second magnetic element (17) located in the space (41) between the first magnetic elements (16) of the first set (37) in such a manner that the at least one second magnetic element (17) is held at a distance to the first set (37) of the first magnetic elements (16) at least when the motor (4) of the hand-held power tool (1) is running and the hand-held power tool (1) is in an idle state. ### Claim 9 (depends on 8) The hand-held power tool (1) according to claim 8, wherein the first part of the hand-held power tool (1) consisting of the housing (2) or the backing pad (3) comprises a second set (38) of the first magnetic elements (16) spaced apart from each other in a direction extending parallel to the extension plane (25) of the backing pad (3), and the corresponding other part of the hand-held power tool (1) consisting of the backing pad (3) or the housing (2) comprises at least another second magnetic element (17) located in the space (41) between the first magnetic elements (16) of the second set (38) in such a manner that the at least another second magnetic element (17) is held at a distance to the second set (38) of the first magnetic elements (16) at least when the motor (4) of the hand-held power tool (1) is running and the power tool (1) is in an idle state. ### Claim 10 (depends on 8) The hand-held power tool (1) according to claim 8, wherein the first part of the hand-held power tool (1) consisting of the housing (2) or the backing pad (3) comprises two second sets (38a, 38b) of at least two first magnetic elements (16) spaced apart from each other in a direction extending parallel to the extension plane (25) of the backing pad (3), and the corresponding other part of the hand-held power tool (1) consisting of the backing pad (3) or the housing (2) comprises at least two other second magnetic elements (17) each located in the space (41) between at least two of the first magnetic elements (16) of the second sets (38a, 38b) in such a manner that the at least two other second magnetic elements (17) are each held at a distance to the two second sets (38a; 38b) of the first magnetic elements (16) at least when the motor (4) of the hand-held power tool (1) is running and the hand-held power tool (1) is in an idle state. ### Claim 11 (depends on 8) The hand-held power tool (1) according to claim 8, wherein the first part of the hand-held power tool (1) consisting of the housing (2) or the backing pad (3) comprises a second set (38) of one first magnetic element (16), the corresponding other part of the hand-held power tool (1) consisting of the backing pad (3) or the housing (2) comprises one other second magnetic element (17) spaced apart from the one first magnetic element (16) of the second set (38) in a direction extending parallel to the extension plane (25) of the backing pad (3), and the one other second magnetic element (17) is held at a distance to the one first magnetic element (16) of the second set (38) at least when the motor (4) of the hand-held power tool (1) is running and the hand-held power tool (1) is in an idle state. ### Claim 12 (depends on 9) The hand-held power tool (1) according to claim 9, wherein the second set (38) of the at least one first magnetic element (16) and the at least one other second magnetic element (17) are located at a rearward region of the housing of the power tool (1). ### Claim 13 (depends on 2) The hand-held power tool (1) according to claim 2, wherein at least part of the first magnetic elements (16) and the at least one second magnetic element (17) are permanent magnets or solenoids. ### Claim 14 (depends on 2) The hand-held power tool (1) according to claim 2, wherein a first part of the hand-held power tool (1) consisting of the housing (2) or the backing pad (3) comprises a first set (37) of the first magnetic elements (16) spaced apart from each other in a direction extending parallel to the extension plane (25) of the backing pad (3), and a corresponding other part of the hand-held power tool (1) consisting of the backing pad (3) or the housing (2) comprises the at least one second magnetic element (17) located in the space (41) between the first magnetic elements (16) of the first set (37) in such a manner that the at least one second magnetic element (17) is held at a distance to the first set (37) of the first magnetic elements (16) at least when the motor (4) of the hand-held power tool (1) is running and the hand-held power tool (1) is in an idle state. ### Claim 15 (depends on 14) The hand-held power tool (1) according to claim 14, wherein the first part of the hand-held power tool (1) consisting of the housing (2) or the backing pad (3) comprises a second set (38) of the first magnetic elements (16) spaced apart from each other in a direction extending parallel to the extension plane (25) of the backing pad (3), and the corresponding other part of the hand-held power tool (1) consisting of the backing pad (3) or the housing (2) comprises at least another second magnetic element (17) located in the space (41) between the first magnetic elements (16) of the second set (38) in such a manner that the at least another second magnetic element (17) is held at a distance to the second set (38) of the first magnetic elements (16) at least when the motor (4) of the hand-held power tool (1) is running and the power tool (1) is in an idle state. ### Claim 16 (depends on 14) The hand-held power tool (1) according to claim 14, wherein the first part of the hand-held power tool (1) consisting of the housing (2) or the backing pad (3) comprises two second sets (38a, 38b) of at least two first magnetic elements (16) spaced apart from each other in a direction extending parallel to the extension plane (25) of the backing pad (3), and the corresponding other part of the hand-held power tool (1) consisting of the backing pad (3) or the housing (2) comprises at least two other second magnetic elements (17) each located in the space (41) between at least two of the first magnetic elements (16) of the second sets (38a, 38b) in such a manner that the at least two other second magnetic elements (17) are each held at a distance to the two second sets (38a; 38b) of the first magnetic elements (16) at least when the motor (4) of the hand-held power tool (1) is running and the hand-held power tool (1) is in an idle state. ### Claim 17 (depends on 14) The hand-held power tool (1) according to claim 14, wherein the first part of the hand-held power tool (1) consisting of the housing (2) or the backing pad (3) comprises a second set (38) of one first magnetic element (16), the corresponding other part of the hand-held power tool (1) consisting of the backing pad (3) or the housing (2) comprises one other second magnetic element (17) spaced apart from the one first magnetic element (16) of the second set (38) in a direction extending parallel to the extension plane (25) of the backing pad (3), and the one other second magnetic element (17) is held at a distance to the one first magnetic element (16) of the second set (38) at least when the motor (4) of the hand-held power tool (1) is running and the hand-held power tool (1) is in an idle state. ### Claim 18 (depends on 8) The hand-held power tool (1) according to claim 8, wherein the first set (37) of the first magnetic elements (16) and the at least one second magnetic element (17) are located at a front region of the housing (2) of the hand-held power tool (1). ### Claim 19 (depends on 14) The hand-held power tool (1) according to claim 14, wherein the first set (37) of the first magnetic elements (16) and the at least one second magnetic element (17) are located at a front region of the housing (2) of the hand-held power tool (1).