Crankshaft assembly for handheld power tools

Abstract

Crankshaft assemblies for handheld power tools are specified. A crankshaft assembly comprises a first engagement element defining a first opening, a second engagement element defining a second opening, a crankshaft coupled to the first and second engagement elements and configured to rotate about an axis of rotation, and at least one crank arm coupled to the crankshaft to drive the first engagement element and / or the second engagement element. The crankshaft assembly further comprises a first sliding element located in the first opening and a second sliding element located in the second opening and in contact with the first sliding element.

Description

Cross-reference to related registrations

[0001] This application claims priority over preliminary US patent application No. 63 / 698615, filed on September 25, 2024, the entire contents of which are incorporated herein by reference. Area

[0002] The present disclosure relates essentially to crankshaft mechanisms and hand-held power tools, such as hedge trimmers, with crankshaft mechanisms. background

[0003] Typically, handheld power tools like hedge trimmers and chainsaws use a crankshaft to convert the rotary motion of a small machine into a translational motion. These mechanisms allow handheld power tools to effectively cut objects or perform other desired tasks. However, this translational motion can generate unwanted vibrations and noise. Therefore, improved crankshaft mechanisms are desirable in engineering. In particular, crankshafts that reduce vibrations and noise would be advantageous. Overview

[0004] Aspects and advantages of the present disclosure are partly set forth in the following description, or may be evident from the description, or can be learned through the practical application of the technique.

[0005] According to one embodiment, a crankshaft assembly for a handheld power tool is described. The crankshaft assembly comprises a first engagement element defining a first opening, a second engagement element defining a second opening, a crankshaft coupled to the first and second engagement elements and configured to rotate about an axis of rotation, and at least one crank arm coupled to the crankshaft to drive the first engagement element and / or the second engagement element. The crankshaft assembly further comprises a first sliding element arranged in the first opening and a second sliding element arranged in the second opening and in contact with the first sliding element.

[0006] According to a further embodiment, a handheld power tool is described. The handheld power tool comprises a first reciprocating element extending between a first end and a second end opposite the first end, and a second reciprocating element extending between the first end and the second end. The first end of the first reciprocating element comprises a first engagement element defining a first opening, and the first end of the second reciprocating element comprises a second engagement element defining a second opening. The handheld tool also comprises a drive device and a crankshaft assembly that couples the drive device to the first end of the first reciprocating element and the first end of the second reciprocating element.The crankshaft assembly comprises a crankshaft arranged to rotate about an axis of rotation, at least one crank arm coupled to the crankshaft to drive the first reciprocating element and / or the second reciprocating element, a first sliding element arranged in the first opening, and a second sliding element arranged in the second opening and in contact with the first sliding element.

[0007] These and other features, aspects, and advantages of the present disclosure will be better understood with reference to the following description and the accompanying claims. The accompanying drawings, which are included in and form part of this description, illustrate embodiments of the technology and, together with the description, serve to explain the principles of the technology. Brief description of the drawings

[0008] A complete and understandable disclosure of the present application, which includes the best way of manufacturing and using the present systems and processes, and which is addressed to a person skilled in the art in this field, is set out in the description which refers to the attached figures. Fig. Figure 1 is a cross-sectional view of a hedge trimmer according to embodiments of the present disclosure; Fig. Figure 2 is a perspective view of a crankshaft assembly according to embodiments of the present disclosure; and Fig. Figure 3 is a detailed perspective view of the crankshaft assembly. Fig. 2 according to embodiments of the present disclosure. Detailed description

[0009] Reference will now be made in detail to embodiments of the present disclosure, one or more examples of which are shown in the drawings. The word "exemplary" is used here to mean "serving as an example, case, or illustration." Each embodiment described here as exemplary is not necessarily to be understood as preferred or advantageous over other embodiments. Moreover, each example is given for clarification and not to limit the technology. Indeed, it will be obvious to the person skilled in the art that modifications and variations can be made in the present technology without departing from the scope or concept of the claimed technology. For example, features shown or described as part of one embodiment can be combined with another embodiment to obtain yet another embodiment.The present disclosure therefore covers all modifications and variations that fall within the scope of the appended claims and their equivalents. In the detailed description, numerical and letter designations are used to refer to features in the drawings. Identical or similar designations in the drawings and the description have been used to refer to identical or similar parts of the disclosure.

[0010] The terms "first," "second," and "third" may be used interchangeably to distinguish one component from another and are not intended to indicate the location or significance of any individual component. The singular forms "a," "an," and "the" encompass the multitude unless the context clearly indicates otherwise. The terms "coupled," "fixed," "attached to," and the like refer to both direct coupling, fixing, or attaching and indirect coupling, fixing, or attaching via one or more intermediate components or features, unless otherwise specified herein. The terms "includes," "comprehensive," "includes," "has," or other variations thereof, as used herein, are intended to include non-exclusive elements.For example, a process, procedure, object, or device that includes a list of characteristics is not necessarily limited to those characteristics but may also include other characteristics not expressly listed or inherent in such a process, procedure, object, or device. Unless expressly stated otherwise, "or" refers to an inclusive or and not an exclusive or. For example, a condition A or B is satisfied if any of the following conditions is met: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

[0011] Terms of approximation such as "about," "generally," "approximately," or "essentially" include values ​​that are within ten percent above or below the stated value. When used in conjunction with an angle or direction, these terms include values ​​within ten degrees greater or less than the stated angle or direction. For example, "essentially vertical" includes directions within ten degrees of the vertical in any direction, such as clockwise or counterclockwise.

[0012] As used here, the terms "integral," "uniform," or "monolithic" refer to a structure formed entirely from a single, continuous material or group of materials without seams, joints, or the like. The integral, uniform structures described here can be produced by additive manufacturing to achieve the described structure, or alternatively by a casting process or similar method.

[0013] Advantages, further benefits, and solutions to problems are described below with reference to specific embodiments. However, the advantages, benefits, solutions to problems, and all features that may lead to the emergence or clarification of advantages, benefits, or solutions are not to be understood as significant, necessary, or essential features of one or all claims.

[0014] Essentially, handheld power tools incorporate a crankshaft to convert the rotary motion of a drive unit, such as an electric motor, into translational motion. This translational motion can generate secondary vibrations and unwanted noise within the handheld power tool. It can also place increased stresses on crankshaft components. Therefore, incorporating one or more sliding elements into the crankshaft assembly of the handheld power tool can reduce these vibrations, noises, and stresses.

[0015] Referring to the drawings, shows Fig. 1. A cross-section of a hedge trimmer 100 according to embodiments of the present disclosure. The hedge trimmer 100 essentially comprises at least one reciprocating cutting tool. For example, the hedge trimmer 100 can comprise a first reciprocating element, such as a first blade 102, and a second reciprocating element, such as a second blade 104. The first blade 102 and the second blade 104 comprise "teeth" which, when the tools are moved back and forth, cause the blades to cut into material, such as branches of hedges. For example, the first blade 102 can be a first cutting blade comprising a first plurality of teeth, and the second blade 104 can be a second cutting blade comprising a second plurality of teeth. In other embodiments, only one of the first blade 102 and the second blade 104 is arranged to move back and forth.For example, one of the first blade 102 and the second blade 104 can remain stationary, while the other of the first blade 102 and the second blade 104 is moved back and forth to allow the blades to cut into the material.

[0016] The hedge trimmer 100 can also include a housing 106. The first blade 102 and the second blade 104 can extend from the housing 106. Furthermore, the first blade 102 and the second blade 104 of the hedge trimmer 100 can be coupled to a bar 120 that extends from the housing 106 to hold the first blade 102 and the second blade 104. The hedge trimmer 100 can include a handle 108.

[0017] As in Fig. As shown in Figure 1, the hedge trimmer 100 can also include a drive device 125, such as an electric motor or a gasoline-powered engine, which drives a crankshaft assembly 130. For example, the drive device 125 can be arranged inside the housing 106. The crankshaft assembly 130 can, as explained in more detail below, engage with the first blade 102 and the second blade 104, such that the rotation of a crankshaft of the crankshaft assembly 130 causes the first blade 102 and the second blade 104 to move back and forth. Although the crankshaft assembly 130 is described in relation to the hedge trimmer 100, it is understood that the crankshaft assembly 130 can also be used with other power tools, for example with reciprocating saws, oscillating saws (or multi-tools), oscillating shears, compressors, dual-action grinders and jigsaws.

[0018] The drive device 125 can be powered, for example, by a rechargeable energy source such as a battery 116, a fuel source such as gasoline, or the like. In the illustrated embodiment, the hedge trimmer 100 includes an actuating element 118. The actuating element 118 is located near the handle 108. When pressed, the actuating element 118 can engage the drive device 125 to move the first blade 102 and the second blade 104. If the actuating element 118 is pressed further, the speed of the device can increase from zero to a maximum speed. In this respect, the actuating element 118 can variably influence the speed of the device between a standstill speed, which occurs when the actuating element 118 is not pressed, and a maximum speed, which occurs when the actuating element 118 is fully pressed.

[0019] Fig. Figure 2 shows a perspective view of the crankshaft assembly 130. Fig. 1 according to embodiments of the present disclosure.

[0020] The first blade 102 and the second blade 104 extend from a first end 201 to a second end 202, which is opposite the first end 201. For example, the first end 201 of the first blade 102 and the second blade 104 can be coupled to the crankshaft assembly 130 and be at least partially located within the housing 106 ( Fig. 1) be arranged. The crankshaft assembly 130 comprises a crankshaft 205 and a gear 210. The gear 210 can be coupled to the drive device 125 and the crankshaft 205 to transmit the rotary motion from the drive device 125 to the crankshaft 205, causing the gear 210 and the crankshaft 205 to rotate about an axis of rotation 215. For example, when the crankshaft 205 rotates about the axis of rotation 215 in a first direction A, the first blade 102 and the second blade 104 move back and forth perpendicular to the axis of rotation 215 in a second direction B. Accordingly, the rotary motion of the crankshaft 205 about the axis of rotation 215 in the first direction A is converted into a linear motion of the first blade 102 and the second blade 104 in the second direction B.

[0021] Fig. Figure 3 shows a detailed perspective view of the crankshaft assembly 130. Fig. 2 according to embodiments of the present disclosure. More precisely, it shows Fig. 3 the crankshaft assembly 130 with gear 210 removed.

[0022] As in Fig. As shown in Figure 3, the first end 201 of the first blade 102 comprises a first engagement element 305 defining a first opening 310, and the first end 201 of the second blade 104 comprises a second engagement element 315 defining a second opening 320. In at least one embodiment, the first opening 310 and the second opening 320 can have a square or rectangular shape. In other embodiments, the first opening 310 and the second opening 320 can have a round or polygonal shape. The first engagement element 305 can be formed integrally with the first blade 102, and the second engagement element 315 can be formed integrally with the second blade 104. In other embodiments, the first blade 102 can be coupled to and extend from the first engagement element 305, and the second blade 104 can be coupled to and extend from the second engagement element 315.

[0023] The first opening 310 of the first blade 102 and the second opening 320 of the second blade 104 are configured to accommodate at least one section of the crankshaft assembly 130. For example, the crankshaft 205 can be arranged within the first opening 310 and the second opening 320. Accordingly, the crankshaft 205 is configured to drive the first blade 102 and / or the second blade 104.

[0024] Furthermore, the crankshaft assembly 130 can comprise at least one crank arm 325, which is coupled to and extends from the crankshaft 205. The at least one crank arm 325 can be configured to drive the first blade 102 and / or the second blade 104 when the crankshaft 205 is rotated. As shown in Fig. As shown in Figure 3, the at least one crank arm 325 can be arranged in the first opening 310 to drive the first blade 102. Additionally or alternatively, the at least one crank arm 325 can comprise a first crank arm arranged in the first opening 310 to drive the first blade 102 and a second crank arm arranged in the second opening 320 to drive the second blade 104.

[0025] In at least one embodiment, the crankshaft assembly 130 comprises one or more sliding elements for reducing vibrations and high contact loads. For example, the crankshaft assembly 130 can comprise a first sliding element 330 arranged in the first opening 310 and a second sliding element 335 arranged in the second opening 320. Additionally, the first sliding element 330 can contact at least a portion of the second sliding element 335. Furthermore, the first sliding element 330 can, as shown in Fig.Figure 3 shows the at least one crank arm 325 surrounding it. Accordingly, the at least one crank arm 325, the first sliding element 330, and the second sliding element 335 convert the rotary motion of the crankshaft into a reciprocating motion of the first blade 102 and / or the second blade 104. The first sliding element 330 and the second sliding element 335 can have a substantially square, rectangular, or other polygonal shape. A substantially square or rectangular shape ensures reduced vibrations and lower contact loads with the inner surfaces of the first opening 310 and the second opening 320. In other embodiments, the first sliding element 330 and the second sliding element 335 can have a round or oval shape.In further embodiments, a plurality of needle bearings can be arranged in one or both of the first sliding elements 330 and the second sliding elements 335 to reduce the sliding friction with the inner surfaces of the first opening 310 and the second opening 320.

[0026] The first sliding element 330 and the second sliding element 335 can be made of an elastic, damping material designed to absorb vibrations and reduce the loads exerted on the components of the crankshaft assembly 130. For example, the first sliding element 330 and the second sliding element 335 are designed to contact the inner surfaces of the first opening 310 and the second opening 320 during operation of the crankshaft assembly 130, and not the at least one crank arm 325 of the crankshaft 205. Furthermore, the first sliding element 330 and the second sliding element 335 are designed to slide relative to each other during rotation of the crankshaft 205. Thus, the first sliding element 330 and the second sliding element 335 move within the first opening 310 and the second opening 320, respectively.the second opening 320 when the crankshaft 205 rotates and the first blade 102 and the second blade 104 are moved back and forth by the at least one crank arm 325. Accordingly, the first sliding element 330 reduces the loads exerted on an inner surface of the first engagement element 305, which defines the first opening 310, and the second sliding element 335 reduces the loads exerted on an inner surface of the second engagement element 315, which defines the second opening 320.

[0027] Further aspects of the disclosure are indicated by one or more of the following embodiments: A crankshaft assembly for a handheld power tool, the crankshaft assembly comprising: a first engagement element defining a first opening; a second engagement element defining a second opening; a crankshaft coupled to the first engagement element and the second engagement element and arranged to rotate about an axis of rotation; at least one crank arm coupled to the crankshaft to drive the first engagement element and / or the second engagement element; a first sliding element arranged in the first opening; and a second sliding element arranged in the second opening and in contact with the first sliding element.

[0028] The crankshaft assembly of one or more of the embodiments, in which the at least one crank arm is arranged in the first opening and the first sliding element at least partially surrounds the at least one crank arm.

[0029] The crankshaft assembly of one or more embodiments, in which the at least one crank arm, the first sliding element and the second sliding element are arranged to convert the rotary motion of the crankshaft about the axis of rotation into a linear motion of the first engagement element and / or the second engagement element.

[0030] The crankshaft assembly of one or more of the embodiments, wherein the at least one crank arm comprises a first crank arm arranged in the first opening and a second crank arm arranged in the second opening.

[0031] The crankshaft assembly of one or more of the embodiments in which the first opening and the second opening define a rectangular shape.

[0032] The crankshaft assembly of one or more of the embodiments, wherein: the first sliding element is configured to reduce the stresses exerted on an inner surface of the first engagement element defining the first opening; and the second sliding element is configured to reduce the stresses exerted on an inner surface of the second engagement element defining the second opening.

[0033] The crankshaft assembly of one or more of the embodiments, further comprising a drive device coupled to the crankshaft for driving the rotation of the crankshaft about the axis of rotation.

[0034] The crankshaft assembly of one or more of the embodiments, further comprising a first reciprocating element extending from the first engagement element and a second reciprocating element extending from the second engagement element.

[0035] The crankshaft assembly of one or more of the embodiments, in which the first engagement element is formed integrally with the first reciprocating element and the second engagement element is formed integrally with the second reciprocating element.

[0036] The crankshaft assembly of one or more of the embodiments, wherein: the first reciprocating element comprises a first cutting blade with a first plurality of teeth; and the second reciprocating element comprises a second cutting blade with a second plurality of teeth.

[0037] A handheld power tool comprising: a first reciprocating element extending between a first end and a second end opposite the first end, the first end comprising a first engagement element defining a first opening; a second reciprocating element extending between the first end and the second end, the first end comprising a second engagement element defining a second opening; a drive device; and a crankshaft assembly coupling the drive device to the first end of the first reciprocating element and the first end of the second reciprocating element, the crankshaft assembly comprising: a crankshaft configured to rotate about an axis of rotation;at least one crank arm coupled to the crankshaft to drive the first reciprocating element and / or the second reciprocating element, a first sliding element arranged in the first opening, and a second sliding element arranged in the second opening and in contact with the first sliding element.

[0038] The hand-held power tool of one or more embodiments, in which the at least one crank arm is arranged in the first opening and the first sliding element at least partially surrounds the at least one crank arm.

[0039] The hand-held power tool of one or more embodiments, wherein: the drive device drives the rotation of the crankshaft about the axis of rotation; and the at least one crank arm, the first sliding element and the second sliding element are arranged to convert the rotary motion of the crankshaft about the axis of rotation into a linear motion of one or both of the first reciprocating elements and the second reciprocating elements.

[0040] The hand-held power tool of one or more embodiments, wherein the at least one crank arm comprises a first crank arm arranged in the first opening and a second crank arm arranged in the second opening.

[0041] The hand-held power tool of one or more embodiments, in which the first opening and the second opening define a rectangular shape.

[0042] The hand-held power tool of one or more embodiments, wherein: the first sliding element is configured to reduce the stresses exerted on an inner surface of the first engagement element defining the first opening; and the second sliding element is configured to reduce the stresses exerted on an inner surface of the second engagement element defining the second opening.

[0043] The hand-held power tool of one or more embodiments, wherein: the first reciprocating element comprises a first cutting blade with a first plurality of teeth; and the second reciprocating element comprises a second cutting blade with a second plurality of teeth.

[0044] The hand-held power tool of one or more of the embodiments, wherein the hand-held power tool comprises a hedge trimmer.

[0045] The hand-held power tool of one or more of the embodiments, wherein the hand-held power tool comprises a reciprocating saw, an oscillating saw, an oscillating shear, a compressor, a dual-action grinder or a jigsaw.

[0046] The hand-held power tool of one or more embodiments, in which the first engagement element is integrally formed with the first reciprocating element and the second engagement element is integrally formed with the second reciprocating element.

[0047] This written description uses examples to disclose the present application, which comprises the best embodiment, and to enable a person skilled in the art to put the disclosure, which includes the manufacture and use of devices or systems and the performance of methods contained therein, into practice. The patentable scope of the disclosure is defined by the claims and may include other examples that might occur to people skilled in the art. Such other examples shall fall within the scope of the claims if they comprise design elements that do not differ from the wording of the claims or if they comprise equivalent design elements that differ only insignificantly from the wording of the claims. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 698.615

[0001]

Claims

[1] Crankshaft assembly for a hand-held power tool, the crankshaft assembly comprising: a first intervention element that defines a first opening; a second engagement element that defines a second opening; a crankshaft coupled to the first engagement element and the second engagement element and arranged to rotate about an axis of rotation; at least one crank arm coupled to the crankshaft to drive the first engagement element and / or the second engagement element; a first sliding element arranged in the first opening; and a second sliding element that is arranged in the second opening and is in contact with the first sliding element. [2] Crankshaft assembly according to claim 1, wherein the at least one crank arm is arranged in the first opening and the first sliding element at least partially surrounds the at least one crank arm. [3] Crankshaft assembly according to claim 1, wherein the at least one crank arm, the first sliding element and the second sliding element are configured to convert the rotary motion of the crankshaft about the axis of rotation into a linear motion of the first engagement element and / or the second engagement element. [4] Crankshaft assembly according to claim 1, wherein the at least one crank arm comprises a first crank arm arranged in the first opening and a second crank arm arranged in the second opening. [5] Crankshaft assembly according to claim 1, wherein the first opening and the second opening define a rectangular shape. [6] Crankshaft assembly according to claim 1, wherein: the first sliding element is designed to reduce the stresses exerted on an inner surface of the first engagement element that defines the first opening; and the second sliding element is designed to reduce the stresses exerted on an inner surface of the second engagement element, which defines the second opening. [7] Crankshaft assembly according to claim 1, further comprising a drive device coupled to the crankshaft for driving the rotation of the crankshaft about the axis of rotation. [8] Crankshaft assembly according to claim 1, further comprising a first reciprocating element extending from the first engagement element and a second reciprocating element extending from the second engagement element. [9] Crankshaft assembly according to claim 8, wherein the first engagement element is formed integrally with the first reciprocating element and the second engagement element is formed integrally with the second reciprocating element. [10] Crankshaft assembly according to claim 8, wherein: the first reciprocating element comprises a first cutting blade with a first plurality of teeth; and The second reciprocating element comprises a second cutting blade with a second set of teeth. [11] Hand-held power tool, comprising: a first reciprocating element extending between a first end and a second end opposite the first end, the first end comprising a first engagement element defining a first opening; a second reciprocating element extending between the first end and the second end, the first end comprising a second engagement element defining a second opening; a drive device; and a crankshaft assembly that couples the drive device to the first end of the first reciprocating element and the first end of the second reciprocating element, the crankshaft assembly comprising: a crankshaft which is designed to rotate around an axis of rotation; at least one crank arm coupled to the crankshaft to drive the first reciprocating element and / or the second reciprocating element, a first sliding element that is arranged in the first opening, and a second sliding element that is arranged in the second opening and is in contact with the first sliding element. [12] Hand-held power tool according to claim 11, wherein the at least one crank arm is arranged in the first opening and the first sliding element at least partially surrounds the at least one crank arm. [13] Hand-held power tool according to claim 11, wherein: the drive device drives the rotation of the crankshaft around the axis of rotation; and which at least one crank arm, the first sliding element and the second sliding element are designed to convert the rotary motion of the crankshaft about the axis of rotation into a linear motion of one or both of the first reciprocating elements and the second reciprocating elements. [14] Hand-held power tool according to claim 11, wherein the at least one crank arm comprises a first crank arm arranged in the first opening and a second crank arm arranged in the second opening. [15] Hand-held power tool according to claim 11, wherein the first opening and the second opening define a rectangular shape. [16] Hand-held power tool according to claim 11, wherein: the first sliding element is designed to reduce the stresses exerted on an inner surface of the first engagement element that defines the first opening; and the second sliding element is designed to reduce the stresses exerted on an inner surface of the second engagement element, which defines the second opening. [17] Hand-held power tool according to claim 11, wherein: the first reciprocating element comprises a first cutting blade with a first plurality of teeth; and The second reciprocating element comprises a second cutting blade with a second set of teeth. [18] Hand-held power tool according to claim 11, wherein the hand-held power tool comprises a hedge trimmer. [19] Hand-held power tool according to claim 11, wherein the hand-held power tool comprises a reciprocating saw, an oscillating saw, an oscillating shear, a compressor, a dual-action grinder or a jigsaw. [20] Hand-held power tool according to claim 11, wherein the first engagement element is integrally formed with the first reciprocating element and the second engagement element is integrally formed with the second reciprocating element.

Images