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JP-2026514299-A - Handheld power tools, as well as axial support devices and working elements for such power tools.

JP2026514299AJP 2026514299 AJP2026514299 AJP 2026514299AJP-2026514299-A

Abstract

The present invention relates to a handheld power tool (10) comprising a tool housing (12), a motor (24), a tool shaft (36) having a rotating shaft (40) and driven by the motor (24), and further comprising a working element (38) that can be detachably attached in the axial direction to the tool shaft (36) from the outside of the tool housing (12), and which, after being attached to the tool shaft (36), is held against the tool shaft (36) by an axial holding device (80). The axial holding device (80) comprises a first element (36;38) composed of one of a working element (38) and a tool shaft (36), a second element (38;36) composed of the other of the working element (38) and the tool shaft (36), at least two locking elements (70) assigned to the first element (36;38) so as to be radially movable between a retracted position and a locked position, and at least one recess (66) assigned to the second element (38;36) to accommodate the locking elements (70) when they are in the locked position. The locking elements (70), or the second element (38;36) in and/or around the at least one radial recess (66), include a magnetic material, and at least the other of the locking elements (70) and the second element (38;36) in and/or around the at least one radial recess (66) includes a magnetic material or a ferromagnetic material. After the working element (38) is attached to the tool shaft (36), the locking element (70) is automatically moved and held in place by magnetic force in its locked position and within at least one radial recess (66).

Inventors

  • アンドレア ヴァレンティーニ

Assignees

  • アンドレア ヴァレンティーニ

Dates

Publication Date
20260508
Application Date
20240405
Priority Date
20230419

Claims (17)

  1. A handheld power tool (10) comprising: a tool housing (12); a motor (24) disposed therein; and a tool shaft (36) having a rotating shaft (40), wherein the tool shaft (36) is driven by the motor (24) during operation to perform rotational motion about its rotating shaft (40), and the distal end of the tool shaft (36) is accessible from the outside of the tool housing (12); and further comprising a working element (38) that is detachably attached to the distal end of the tool shaft (36) from the outside of the tool housing (12) in an axial direction parallel to the rotating shaft (40) of the tool shaft (36), and after being attached to the tool shaft (36), is held against the tool shaft (36) by an axial holding device (80), The axial holding device (80) A first element (36; 38) composed of the following elements, namely the working element (38) and the tool shaft (36), and a second element (38; 36) composed of the other of the elements, namely the working element (38) and the tool shaft (36), At least one locking element (70) is assigned to the first element (36;38) so as to be radially movable between a retracted position in which the locking element (70) is retracted into the first element (36;38) and a locked position in which the locking element (70) radially protrudes from the first element (36;38) toward the second element (38;36), The second element (38; 36) comprises at least one recess (66) having a radial extension, wherein the at least one radial recess (66) is configured to accommodate a portion of the at least one locking element (70) when the working element (38) is in the locked position after being attached to the tool shaft (36), A handheld power tool (10) characterized in that, after the working element (38) is attached to the tool shaft (36), the at least one of the following elements, namely the at least one locking element (70) and the second elements (38; 36) in and/or around the at least one radial recess (66), includes a magnetic material, and the other of the elements, namely the at least one locking element (70) and the second elements (38; 36) in and/or around the at least one radial recess (66), includes a magnetic material or a ferromagnetic material, and as a result, after the working element (38) is attached to the tool shaft (36), the at least one locking element (70) is automatically moved by magnetic force to its locked position and to be held in the at least one radial recess (66), thereby engaging with the at least one radial recess (66) and holding the working element (38) in the axial direction relative to the tool shaft (36).
  2. The power tool (10) according to claim 1, wherein the first element is the tool shaft (36) and the second element is the working element (38).
  3. The power tool (10) according to claim 1, wherein the first element is the working element (38) and the second element is the tool shaft (36).
  4. The power tool (10) according to any one of claims 1 to 3, wherein the first elements (36; 38) have an axial bore (68), and the at least one locking element (70) is held within a hollow cylindrical jacket (78) that radially defines the bore (68).
  5. The power tool (10) according to claim 4, wherein the second element (38; 36) has cylindrical pins (58; 64), and the at least one radial recess (66) is provided on the outer circumferential surface of the cylindrical pins (58; 64).
  6. The power tool (10) according to any one of claims 1 to 3, wherein the first elements (36; 38) have cylindrical pins (58; 64), and the at least one locking element (70) is held on the outer circumferential surface of the cylindrical pins (58; 64).
  7. The power tool (10) according to claim 6, wherein the second element (38; 36) has an axial bore (68), and the at least one radial recess (66) is provided on the inner surface of a hollow cylindrical jacket (78) that radially defines the bore (68).
  8. The power tool (10) according to any one of claims 4 to 7, wherein the distal end (82) of the cylindrical pin (58; 64) and/or the outer edge (96) defining the inlet hole into the axial bore (68) have a tapered or rounded shape to facilitate insertion of the cylindrical pin (58; 64) into the axial bore (68) and/or to automatically push the at least one locking element (70) radially into its retracted position during insertion of the cylindrical pin (58; 64) into the axial bore (68).
  9. The power tool (10) according to any one of claims 4 to 8, wherein the axial bore (68) and the cylindrical pins (58; 64) each have an axially extending portion (84) having a corresponding, non-rotationally symmetrical cross-section, and the portions are configured to mechanically engage with each other after the working element (38) has been attached to the tool shaft (36), thereby enabling the transmission of torque from the tool shaft (36) to the working element (38) during the operation of the motor (24) of the power tool (10).
  10. After the working element (38) is attached to the tool shaft (36), the distal end face (74) of the at least one locking element (70) facing the second element (38; 36), and/or, after the working element (38) is attached to the tool shaft (36), the outer edge (94) defining the entrance hole to the at least one recess (66) facing the first element (36; 38), has a tapered or rounded shape (76) to facilitate the automatic radial pushing of the at least one locking element (70) to its retracted position while the working element (38) is removed from the tool shaft (36). (The power tool (10) according to any one of claims 1 to 9.)
  11. The power tool (10) according to any one of claims 1 to 10, wherein the at least one locking element (70) and the at least one radial recess (66) have corresponding shapes in at least the portions thereof that engage with each other in the locked position of the at least one locking element (70).
  12. The power tool (10) according to any one of claims 1 to 11, wherein the working element (38) comprises an eccentric element (54) detachably attached to the tool shaft (36) in the axial direction, and a backing pad (48) attached to the side of the eccentric element (54) opposite to the tool shaft (36) so as to be freely rotatable about a second rotation axis (60) of the backing pad (48), wherein the second rotation axis (60) extends parallel to and at a distance from the rotation axis (40) of the tool shaft (36), or the working element (38) comprises the backing pad (48) detachably attached to the tool shaft (36) in the axial direction.
  13. The power tool (10) according to any one of claims 1 to 12, wherein at least two locking elements (70) are arranged at equidistant circumferentially around the rotation axis (40) of the tool shaft (36) after the working element (38) has been attached to the tool shaft (36), and/or the axial holding device (80) comprises preferably at least three, particularly preferably at least four locking elements (70).
  14. The power tool (10) according to any one of claims 1 to 13, wherein the axial holding device (80) comprises one or more radial recesses (66) in the same number as the locking elements (70) provided on the axial holding device (80), or the axial holding device (80) comprises a single annular radial recess (66) configured to accommodate one or all of the locking elements (70) in their locked positions.
  15. After the working element (38) is detachably attached in the axial direction to the distal end of the tool shaft (36), an axial holding device (80) for holding the working element (38) of the handheld power tool (10) in the axial direction extending parallel to the rotation axis (40) of the tool shaft (36) of the power tool (10), The axial holding device (80) A first element (36; 38) composed of the following elements, namely the working element (38) and the tool shaft (36), and a second element (38; 36) composed of the other of the elements, namely the working element (38) and the tool shaft (36), At least one locking element (70) is assigned to the first element (36;38) so as to be radially movable between a retracted position in which the at least one locking element (70) is retracted into the first element (36;38) and a locked position in which the at least one locking element (70) radially protrudes from the first element (36;38) toward the second element (38;36), The second element (38; 36) comprises at least one radial recess (66) assigned to it, wherein the at least one radial recess (66) is configured to accommodate a portion of the at least one locking element (70) when the at least one radial recess (66) is in its locked position and after the working element (38) has been attached to the tool shaft (36), An axial holding device (80) is characterized in that, after the working element (38) is attached to the tool shaft (36), the at least one of the following elements, namely the at least one locking element (70) and the second elements (38; 36) in and/or around the at least one radial recess (66), comprises a magnetic material, and the other of the elements, namely the at least one locking element (70) and the second elements (38; 36) in and/or around the at least one radial recess (66), comprises a magnetic material or a ferromagnetic material, and as a result, after the working element (38) is attached to the tool shaft (36), the at least one locking element (70) is automatically moved by magnetic force to its locked position and within the at least one radial recess (66) and held therein, thereby engaging with the at least one radial recess (66) and holding the working element (38) in the axial direction relative to the tool shaft (36).
  16. The working element (38) of the power tool (10) is configured to be detachably attached to the distal end of the tool shaft (36) of the power tool (10) in an axial direction parallel to the rotation axis (40) of the tool shaft (36), and is further configured to be held in the axial direction relative to the tool shaft (36) by an axial holding device (80) after the working element (38) has been attached to the tool shaft (36) in the axial direction, The work element (38) comprises a first element and the second element forms part of the tool shaft (36), or the work element (38) comprises a second element and the first element forms part of the tool shaft (36), If the working element (38) is the first element, then at least one locking element (70) is assigned to the working element (38) so as to be radially movable between a retracted position in which the at least one locking element (70) is retracted into the working element (38) and a locked position in which the at least one locking element (70) protrudes radially from the working element (38) toward the tool shaft (36), and at least one radial recess (66) is assigned to the tool shaft (36) and is configured to accommodate a portion of the at least one locking element (70) when it is in the locked position and after the working element (38) has been attached to the tool shaft (36), or If the working element (38) is the second element, then at least one radially extending recess (66) is assigned to the working element (38), and the at least one radial recess (66) is configured to accommodate a portion of the at least one locking element (70), and the at least one locking element (70) is movably assigned to the tool shaft (36) between a retracted position in which the at least one locking element (70) is retracted into the tool shaft (36) and a locked position in which the at least one locking element (70) protrudes radially from the tool shaft (36) toward the working element (38) when the at least one locking element (70) is in its locked position and after the working element (38) has been attached to the tool shaft (36), A work element (38) characterized in that, after the work element (38) is attached to the tool shaft (36), the at least one locking element (70) and the second elements (38; 36) in and/or around the at least one radial recess (66) comprises a magnetic material, and the other of the elements, namely the at least one locking element (70) and the second elements (38; 36) in and/or around the at least one radial recess (66) comprises a magnetic material or a ferromagnetic material, and as a result, after the work element (38) is attached to the tool shaft (36), the at least one locking element (70) is automatically moved by magnetic force to its locked position and to be held in the at least one radial recess (66), thereby engaging with the at least one radial recess (66) and holding the work element (38) in the axial direction relative to the tool shaft (36).
  17. The work element (38) according to claim 16, comprising: an eccentric element (54) detachably attached to the tool shaft (36) in the axial direction; and a backing pad (48) attached to the side of the eccentric element (54) opposite to the tool shaft (36) so as to be freely rotatable about a second rotation axis (60) of the backing pad (48), wherein the second rotation axis (60) extends parallel to and at a distance from the rotation axis (40) of the tool shaft (36), or the work element (38) comprises a backing pad (48) detachably attached to the tool shaft (36) in the axial direction.

Description

The present invention relates to a handheld power tool comprising a tool housing, a motor disposed therein, and a tool shaft having a rotating axis, the tool shaft being driven by the motor during operation to perform rotational motion about its rotating axis, and the distal end of the tool shaft being accessible from outside the tool housing. The power tool further comprises a working element that is detachably attached to the distal end of the tool shaft from outside the tool housing in an axial direction parallel to the rotating axis of the tool shaft, and which, after being attached to the tool shaft, is held axially relative to the tool shaft by an axial holding device. Furthermore, the present invention relates to an axial holding device for holding the working element of a handheld power tool relative to the tool shaft of a power tool in an axial direction parallel to the rotation axis of the tool shaft, after the working element has been axially mounted to the distal end of the tool shaft from the outside of the tool housing. Finally, the present invention also relates to a working element of a handheld power tool, configured to be detachably mounted to the tool shaft of a power tool in an axial direction parallel to the rotation axis of the tool shaft, and further configured to be held axially by the axial holding device after the working element has been mounted to the tool shaft. The above-described type of handheld power tool, taking the form of an electric power tool for angle sanding or polishing, is known, for example, from U.S. Patent Application Publication No. 2011/036604 (Chervon Corporation). The power tool comprises a tool housing and an electric motor located therein. The tool shaft of the power tool rotates about its axis of rotation by the electric motor. The distal end of the tool shaft is accessible from outside the tool housing. The power tool further comprises a working element that can be detachably mounted axially to the distal end of the tool shaft from outside the tool housing, extending parallel to the axis of rotation of the tool shaft. After the working element is mounted on the tool shaft, the working element is held axially relative to the tool shaft by an axial retaining device. The first type of working element comprises an eccentric element and a backing pad. The backing pad is mounted on the eccentric element so as to be freely rotatable about a second axis of rotation of the backing pad, which extends parallel to and at a distance from the axis of rotation of the tool shaft. The eccentric element is detachably mounted axially to the tool shaft and held against the tool shaft by an axial retaining device. The second type of working element comprises only a backing pad that is detachably mounted axially to the tool shaft and held against the tool shaft by an axial retaining device. The distal end of the tool shaft is provided with an axial bore configured to accommodate a cylindrical pin, which is assigned to the eccentric element of a first type of working element, or alternatively, to the backing pad of a second type of working element. The proximal end of the cylindrical pin has an annular recess extending on the outer surface of the pin. The hollow cylindrical jacket radially defining the axial bore of the tool shaft has two opposing locking elements, each radially movable between a retracted position and a locked position. In the retracted position, the locking elements do not engage with the annular recess on the proximal end of the cylindrical pin, leaving a free axial passage along the axial bore, allowing the working element to be attached to the tool shaft and/or axially removed from the tool shaft. In the locked position, the locking elements engage with the annular recess, axially holding the working element relative to the tool shaft. Each locking element is designed as a lever element capable of pivoting tangentially to the rotation axis of the tool shaft, around a pivot axis extending within the hollow cylindrical jacket of the tool shaft. The locking elements are held in the locked position by a spring element. The locking elements can be moved to their retracted position against the force of the spring element by a manually operated drive mechanism in the form of a push button. Each lever element has a front end on the first side of the pivot axis that engages with an annular recess assigned to the working element when the lever element is in its locked position, and a rear end on the second side opposite the pivot axis, configured to be actuated by the drive mechanism and spring element. Known drawbacks of power tools include the large number of moving parts, the fairly complex and intricate design, and the considerable complexity of operating the axial retaining mechanism by the user, which is especially difficult when the user is wearing work gloves. This is a side view of a power tool according to the present invention in a preferred embodiment.Fi