Swinging body pivot mechanism and working machine including such mechanism

Abstract

A swinging body pivot mechanism includes a rotation stopper attached to a pivot shaft and including an insertion portion into which a rotation stopper pin portion of a first member coupled to a second member via the pivot shaft is inserted. The insertion portion includes a first width in a direction along a first straight line extending in a radial direction of the pivot shaft and a second width in a direction along a second straight line perpendicular to an axis of the pivot shaft and the first straight line. The first width is defined to allow the rotation stopper pin portion inserted in the insertion portion to change a position thereof in the direction along the first straight line. The second width is defined to restrict the rotation stopper and the rotation stopper pin portion from moving relative to each other in the direction along the second straight line.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to Japanese Patent Application No. 2024-221938 filed on Dec. 18, 2024. The entire contents of this application are hereby incorporated herein by reference.BACKGROUND OF THE INVENTION1. Field of the Invention

[0002] The present invention relates to swinging body pivot mechanisms and working machines each including one or more of the swinging body pivot mechanisms.2. Description of the Related Art

[0003] Working machines such as backhoes each use one or more rotation stoppers each configured to stop a swinging body from rotating relative to a pivot shaft pivotally connecting the swinging body to another swinging body. For example, the Japanese Unexamined Patent Application Publication No. 2000-351581 discloses a rotation stopper plate that is fixed to one of axial ends of a support pin pivotally connecting a boom bracket (swing bracket) to a boom, and that is fixed at an end portion thereof to the boom bracket (swing bracket) by a bolt.SUMMARY OF THE INVENTION

[0004] Regarding the technical art as disclosed in the Japanese Unexamined Patent Application Publication No. 2000-351581, there is a problem that the bolt may be easily loosened when the bolt receives a force in a direction perpendicular to an axial direction of the support pin that is generated because of swing of the boom, vibration of a machine body and / or the like. Thus, it may be conceivable that a boss is fixedly mounted on the boom bracket (swing bracket) and is passed through a hole provided in the corresponding end portion of the rotation stopper plate so as to cause the rotation stopper plate to achieve the function as the rotation stopper to stop the boom bracket (swing bracket) from rotating relative to the support pin. However, in such a case, it may be difficult to properly mount the support pin to the boom bracket (swing bracket) if there is a situation where the boss cannot be sufficiently accurately mounted on the boom bracket (swing bracket) at an appropriate position.

[0005] For example, in a case where the boom bracket (swing bracket) as a representative target swinging body for a rotation stopper includes a main body molded integrally with the boss by casting, the boss molded with the main body may have a position error with respect to the main body as a casting defect. In a case where the boss is joined to the main body of the boom bracket (swing bracket) by welding to be mounted on the main body, the boss mounted on the main body may have a position error with respect to the main body because of inaccurate positioning of the boss to be joined to the main body by welding. In a case where the boss is fastened to the main body of the boom bracket (swing bracket) via a fastener such as a bolt to be mounted on the main body, the boss may have a position error with respect to the main body because of inaccurate forming of a threaded hole in the boss or the main body. When the boss mounted on the main body of the boom bracket (swing bracket) as a representative target swinging body has an error such as mentioned above, a position of the support pin to be attached to the rotation stopper plate may fail to correspond to the position of the boss with respect to the rotation stopper plate so that it may be difficult to connect the pivot shaft and the boom bracket (swing bracket) via the rotation stopper plate.

[0006] The present invention provides swinging body pivot mechanisms and working machines each including one or more of such mechanisms to solve issues as described above.

[0007] A swinging body pivot mechanism according to an example embodiment of the present invention includes a pivot shaft, a first member and a second member coupled to each other via the pivot shaft swingably relative to each other, and a rotation stopper attached to the pivot shaft. The first member includes a main body portion, a shaft hole provided in the main body portion to have the pivot shaft inserted therethrough, and a rotation stopper pin portion provided in a vicinity of the shaft hole and protruding from the main body portion in a direction substantially parallel to an axis of the pivot shaft. The rotation stopper includes a first end portion fixed to the pivot shaft, and a second end portion with an insertion portion into which the rotation stopper pin portion is inserted. The insertion portion includes a first width between opposite ends thereof in a direction along a first straight line that is an imaginary line which extends in a direction matching a radial direction of the pivot shaft so as to pass through the first end portion and the second end portion, and a second width between opposite ends thereof in a direction along a second straight line that is an imaginary line which is perpendicular to the axis of the pivot shaft and the first straight line. The first width is defined such as to allow the rotation stopper pin portion inserted in the insertion portion to change a position thereof in the direction along the first straight line. The second width is equal to or more than a width of the rotation stopper pin portion in the direction along the second straight line and is defined such that the rotation stopper and the rotation stopper pin portion are restricted from moving relative to each other in the direction along the second straight line, the rotation stopper pin portion being inserted into the insertion portion and abutting the rotation stopper at at least one of the opposite ends of the insertion portion in the direction along the second straight line.

[0008] The insertion portion may includes a notch which is open at one end of the opposite ends thereof in the direction along the first straight line that corresponds to an utmost end of the second end portion.

[0009] The insertion portion may include a slot closed at the opposite ends thereof in the direction along the first straight line and extending lengthwise in the direction along the first straight line.

[0010] The rotation stopper pin portion may be molded integrally with the main body portion by casting.

[0011] The rotation stopper pin portion may be integrated with the main body portion by welding.

[0012] The swinging body pivot mechanism may further include a pin defining the rotation stopper pin portion that is a cylindrical member separated from the main body portion, the pin including a threaded hole defined by an inner peripheral portion thereof that extends in a protruding direction in which the rotation stopper pin portion protrudes substantially parallel to the axis of the pivot shaft; and a fastener to fasten the pin to the main body portion. The fastener may be screwed with the pin inside of the threaded hole to restrict the pin from moving in the protruding direction.

[0013] The swinging body pivot mechanism may further include a fastener to be screwed into a threaded hole that is provided in the rotation stopper pin portion, and a retainer sandwiched between a head of the fastener screwed into the threaded hole and an end of the rotation stopper pin portion to restrict the rotation stopper from moving in a direction of the axis of the pivot shaft.

[0014] A working machine according to an example embodiment of the present invention includes a machine body, a boom swingably supported by the machine body, an arm swingably supported by the boom and the swinging body pivot mechanism provided as a pivotal junction of the boom and the arm.

[0015] A working machine according to an example embodiment of the present invention includes a machine body, a working device swingably supported by the machine body and the swinging body pivot mechanism provided as a pivotal junction of the machine body and the working device.

[0016] A working machine according to an example embodiment of the present invention includes a machine body, a working device supported by the machine body, a working tool swingably supported by the working device, and the swinging body pivot mechanism provided as a pivotal junction of the working device and the working tool.

[0017] The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0018] A more complete appreciation of example embodiments of the present invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings described below.

[0019] FIG. 1 illustrates a side view of a swiveling excavator (hereafter simply referred to as “working machine”)

[0020] FIG. 2 illustrates a side view of a swinging body pivot mechanism including a rotation stopper according to an example embodiment.

[0021] FIG. 3 illustrates a perspective view of the swinging body pivot mechanism.

[0022] FIG. 4A illustrates a side view of the swinging body pivot mechanism omitting a retainer therefrom.

[0023] FIG. 4B illustrates an enlarged side view of the swinging body pivot mechanism omitting a retainer therefrom.

[0024] FIG. 5 illustrates a perspective view of the swinging body pivot mechanism omitting a retainer therefrom.

[0025] FIG. 6A illustrates a side view of a swinging body pivot mechanism including a rotation stopper according to another example embodiment omitting a retainer therefrom.

[0026] FIG. 6B illustrates an enlarged side view of a swinging body pivot mechanism including a rotation stopper according to another example embodiment omitting a retainer therefrom.

[0027] FIG. 7 illustrates a perspective view of a swinging body pivot mechanism including a rotation stopper pin that is an alternative rotation stopper pin portion, including an exploded view of a portion of the swinging body pivot mechanism.DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

[0028] Example embodiments will now be described with reference to the accompanying drawings, wherein like reference numerals designate corresponding or identical elements throughout the various drawings. The drawings are to be viewed in an orientation in which the reference numerals are viewed correctly.

[0029] FIG. 1 illustrates a side view of a swiveling excavator (hereafter simply referred to as “working machine 1”). A schematic configuration of the working machine 1 will now be described using FIG. 1. In the present example embodiment, a direction indicated by an arrow A1 in FIG. 1 is called “front direction”, a direction indicated by an arrow A2 is called “rear direction”, one direction perpendicular to the arrows A1 and A2 and toward a viewer in front of a sheet of FIG. 1 is called “left” and another direction perpendicular to the arrows A1 and A2 and toward a side behind the sheet of FIG. 1 is called “right”.

[0030] The working machine 1 includes a traveling body 10, a machine body 20 and a working device 30. The machine body 20 is mounted on an upper portion of the traveling body 10 (specifically, on a later-discussed traveling frame 11) via a swiveling pivot (swiveling joint) including an axis Xv in an up-down direction indicated in FIG. 1, so that the machine body 20 can rotate (swivel) about the axis Xv in a horizontal direction relative to the traveling body 10 by a hydraulic swiveling motor (omitted from the illustrations).

[0031] The traveling body 10 includes a traveling frame 11 and a pair of left and right traveling devices 12, with hydraulic traveling devices (omitted from the illustrations) for driving the respective traveling devices 12. A dozer 13 is provided at a front portion of the traveling body 10. The dozer 13 includes a blade 13a provided forward of the pair of left and right traveling devices 12 and an actuator (hydraulic cylinder) and / or the like to swing the blade up and down.

[0032] A swing bracket 14 is supported by the machine body 20 via a swing pin (pivot) 14a including an axis in the up-down direction, and a swing cylinder (hydraulic actuator) omitted from FIG. 1 causes the entire working device 30 to rotate (swing) together with the swing bracket 14 in a horizontal direction relative to the machine body 20.

[0033] The working device 30 is swingably supported by the machine body 20 and a working tool (working attachment) is attached to the working device 30 and swingably supported thereby. In the present example embodiment, the working device 30 is a backhoe working device 30 that includes a boom 31 and an arm 32, and a bucket 33 is attached, as a working tool, to the working device 30.

[0034] In the working device 30, a proximal end of the arm 32 is pivotally supported by a distal end of the boom 31, and a proximal end of the boom 31 is pivotally supported by the swing bracket 14, so that the entire working device 30 is supported by the machine body 20 via the swing bracket 14. On the other hand, the bucket 33 defining a working tool is pivotally supported by a distal end of the arm 32 so as to be swingably supported by the working device 30.

[0035] The working device 30 includes a boom cylinder (hydraulic cylinder) 34, an arm cylinder (hydraulic cylinder) 35 and a bucket cylinder (hydraulic cylinder) 36 to drive the boom 31, arm 32 and bucket 33 included in the working device 30, respectively.

[0036] The following will briefly describe a basic configuration of the boom 31 illustrated in FIG. 1. The boom 31 illustrated in FIG. 1 includes a distal end section 31c, a proximal end section 31d, and a main section 31e provided between the distal end section 31c and the proximal end section 31d. The distal end section 31c, the proximal end section 31d and the main section 31e are originally separate members separated from each other, and the boom 31 is configured by joining the distal end section 31c and the proximal end section 31d to each other via the main section 31e. At least one of the distal end section 31c or the proximal end section 31d defines a component element of a swinging body pivot mechanism P as described later.

[0037] At least one of the distal end section 31c or the proximal end section 31d may be, for example, a single solid or hollow member entirely or partly molded integrally by casting or the like. Alternatively, at least one of the distal end section 31c or the proximal end section 31d may be configured by assembling a plurality of plates (steel plates or the like) together by welding or the like, or may be configured by bending a single plate (steel plate or the like) into a sectionally rectangular shape.

[0038] The main portion 31e may be configured by assembling a plurality of plates (steel plates or the like) together by welding or the like, may be configured by bending a single plate (steel plate or the like) into a sectionally rectangular shape, or may include a single member molded integrally by casting or the like. The boom 31 may be configured by joining one end of the main section 31e to the distal end section 31c, and another end of the main portion 31e to the proximal end section 31d by welding or the like.

[0039] At least one of the distal end section 31c or the proximal end section 31d may be further extended to replace the main section 31e so that the distal end section 31c and the proximal end section 31d may be directly connected to each other by welding or the like without the main section 31e therebetween. Moreover, the boom 31 may be configured from a single member including both the distal end thereof and the proximal end thereof.

[0040] The working device 30 includes at least one pivotal junction at which a first member and a second member are pivotally connected to each other, at least one of the first member or the second member being a swinging body. The backhoe type working device 30 according to the present example embodiment includes a first pivotal junction at which the distal end of the boom 31 and the proximal end of the arm 32 are pivotally connected to each other, a second pivotal junction at which the proximal end of the boom 31 of the working device 30 and the swing bracket 14 of the machine body 20 are pivotally connected to each other, and a third pivotal junction at which the distal end of the arm 32 and a bucket bracket 33a of the bucket 33 that is a working tool are pivotally connected to each other.

[0041] At least one of the first to third pivotal junctions includes the swinging body pivot mechanism P including a pivot shaft 2, the first member and the second member coupled to each other via the pivot shaft 2 swingably relative to each other, and a rotation stopper attached to the pivot shaft 2. That is, in the working machine 1, at least one of the first pivotal junction of the boom 31 and the arm 32, the second pivotal junction of the machine body 20 (swing bracket 14) and the working device 30 (boom 31), or the third pivotal junction of the working tool (bucket 33) and the working device 30 (arm 32) is configured as the swinging body pivot mechanism P.

[0042] As explained above, the swinging body pivot mechanism P includes the pivot shaft 2, the first member, the second member and the rotation stopper, and the swinging body pivot mechanism P is defined to include at least the following configuration. The first member includes a main body portion, a shaft hole provided in the main body portion to have the pivot shaft 2 inserted therethrough, and a rotation stopper pin portion provided in a vicinity of the shaft hole and protruding from the main body portion in a direction substantially parallel to an axis 2a of the pivot shaft 2. The rotation stopper includes a first end portion fixed to the pivot shaft and a second end portion with an insertion portion into which the rotation stopper pin portion is inserted. The insertion portion includes a first width between opposite ends thereof in a direction along a first straight line Dr (see FIG. 4B or FIG. 6B) that is an imaginary line which extends in a direction matching a radial direction of the pivot shaft 2 so as to pass through the first end portion and the second end portion and a second width between opposite ends thereof in a direction along a second straight line Dt (see FIG. 4B or FIG. 6B) that is an imaginary line which is perpendicular to the axis 2a of the pivot shaft 2 and the first straight line Dr. The first width is defined such as to allow the rotation stopper pin portion inserted in the insertion portion to change a position thereof in the direction along the first straight line Dr. The second width is equal to or more than a width of the rotation stopper pin portion in the direction along the second straight line Dt and is defined such that the rotation stopper and the rotation stopper pin portion are restricted from moving relative to each other in the direction along the second straight line Dt, the rotation stopper pin portion being inserted in the insertion portion and abutting the rotation stopper at at least one of the opposite ends of the insertion portion in the direction along the second straight line Dt.

[0043] In a case where the swinging body pivot mechanism P is provided as the first pivotal junction of the boom 31 and the arm 32, the swinging body pivot mechanism P is referred to as a “first swinging body pivot mechanism P1”. In a case where the swinging body pivot mechanism P is provided as the second pivotal junction of the boom 31 and the machine body (swing bracket 14), the swinging body pivot mechanism P is referred to as a “second swinging body pivot mechanism P2”. In a case where the swinging body pivot mechanism P is provided as the third pivotal junction to couple the working tool (bucket 33) and the arm 32 as the first member and the second member, the swinging body pivot mechanism P is referred to as a “first swinging body pivot mechanism P3”.

[0044] As shown in FIG. 1, the first swinging body pivot mechanism P1 includes the boom 31, which defines the first member as one swinging body, and the arm 32, which defines the second member as another swinging body, coupled together via the pivot shaft 2. That is, the distal end section 31c of the boom 31 corresponds to the main body portion of the first member, a shaft hole 31a to have the pivot shaft 2 inserted therethrough is provided in the distal end section 31c, and a rotation stopper pin portion 31b to be inserted into the insertion portion of a rotation stopper plate 3 (rotation stopper) is provided on the distal end section 31c.

[0045] Alternatively, the boom 31 may define the second member and the arm 32 may define the first member. In such a case, a proximal end portion of the arm 32 corresponds to the main body portion of the first member, the shaft hole to have the pivot shaft 2 inserted therethrough is provided in the proximal end portion of the arm 32, and the rotation stopper pin portion to be inserted into the insertion portion of the rotation stopper is provided on the proximal end portion of the arm 32.

[0046] As shown in FIG. 1, the second swinging body pivot mechanism P2 includes the boom 31 of the working device 30 defining the first member of the swinging body and the swing bracket 14 of the machine body 20 defining the second member of the swinging body coupled together via the pivot shaft 2. That is, the proximal end section 31d of the boom 31 corresponds to the main body portion of the first member, the shaft hole to have the pivot shaft 2 inserted therethrough is provided in the proximal end section 31d, and the rotation stopper pin portion to be inserted into the insertion portion of the rotation stopper plate 3 is provided on the proximal end section 31d.

[0047] Alternatively, the boom 31 of the working device 30 may define the second member, and the swing bracket 14 of the machine body 20 may define the first member. In such a case, an upper portion or the like of the swing bracket 14 corresponds to the main body portion of the first member, the shaft hole to have the pivot shaft 2 inserted therethrough is provided in the upper portion or the like of the swing bracket 14, and the rotation stopper pin portion to be inserted into the insertion portion of the rotation stopper is provided on the upper portion or the like of the swing bracket 14.

[0048] As shown in FIG. 1, the third swinging body pivot mechanism P3 includes the bucket 33 that is a working tool defining the first member and the arm 32 of the working device 30 defining the second member coupled together via the pivot shaft 2. That is, the bucket bracket 33a of the bucket 33 corresponds to the main body portion of the first member, the shaft hole to have the pivot shaft 2 inserted therethrough is provided in the bucket bracket 33a, and the rotation stopper pin portion to be inserted into the insertion portion of the rotation stopper plate 3 is provided on the bucket bracket 33a.

[0049] Alternatively, the arm 32 of the working device 30 may define the first member and the bucket 33 that is a working tool may define the second member. In such a case, a distal end portion of the arm 32 corresponds to the main body portion of the first member, the shaft hole to have the pivot shaft 2 inserted therethrough is provided in the distal end portion of the arm 32, and the rotation stopper pin portion to be inserted into the insertion portion of the rotation stopper is provided on the distal end portion of the arm 32.

[0050] In the present example embodiment, the working machine 1 includes all the first to third swinging body pivot mechanisms P1 to P3. Alternatively, the working machine 1 may include only one or two of the first to third swinging body pivot mechanisms P1 to P3 (that is, one or two of the first to third pivotal junctions each may be provided with the swinging body pivot mechanism P).

[0051] Working machines each of which can use one or more swinging body pivot mechanisms P include not only excavators (backhoes) as shown in FIG. 1 but also various kinds of working machines each of which includes one or more swinging bodies. For example, one or more swinging body pivot mechanisms P are applicable to at least one of skid steer loaders, truck loaders or the like each of which includes a working device that includes at least one swinging body, such as a boom, to which a working tool can be swingably attached.

[0052] Working tools each of which can use the swinging body pivot mechanism P (that is, the third swinging body pivot mechanism P3) are not limited to buckets including the bucket 33 as shown in FIG. 1. The swinging body pivot mechanism P (third swing body pivot mechanism P3) is broadly applicable to working tools, each of which can be swingably attached to a working device of a working machine. For example, such working tools each of which is to be swingably attached to a working device of a working machine include breakers, earth drills and the like each of which includes a hydraulic actuator that is to be fluidly connected to a hydraulic pressure take-off (AUX) port of a working machine such as an excavator (backhoe) when the working tool is attached to a working device of the working machine.

[0053] A specific configuration of the swinging body pivot mechanism P1 as a representative example of the swinging body pivot mechanism P will now be described with reference to FIGS. 2 to 5. FIG. 2 illustrates a side view of the swinging body pivot mechanism P1 (P) including a rotation stopper (rotation stopper plate 3) according to an example embodiment. FIG. 3 illustrates a perspective view of the swinging body pivot mechanism P1 (P). FIG. 4A illustrates a side view of the swinging body pivot mechanism P1 (P) omitting a retainer (retainer plate 5) therefrom. FIG. 4B illustrates an enlarged side view of the swinging body pivot mechanism P1 (P) omitting a retainer (retainer plate 5) therefrom. FIG. 5 illustrates a perspective view of the swinging body pivot mechanism P1 (P) omitting a retainer (retainer plate 5) therefrom.

[0054] In the swinging body pivot mechanism P1 (P), the boom 31 corresponding to the first member includes the main body portion 31c, the shaft hole 31a provided in the main body portion 31c to have the pivot shaft 2 inserted therethrough, and the rotation stopper pin portion 31b provided in the vicinity of the shaft hole 31a and protruding from the main body portion 31c in a direction substantially parallel to the axis 2a of the pivot shaft 2.

[0055] The rotation stopper plate 3 as an exemplary rotation stopper includes a first end portion 3b fixed to the pivot shaft 2 and a second end portion 3d provided thereon with a notch 3e as an exemplary insertion portion into which the rotation stopper pin portion 31b is inserted. Referring to FIG. 4B, the notch 3e defining the exemplary insertion portion includes a first width Wr between opposite ends 3e1 and 3e2 thereof in the direction along the first straight line Dr that is an imaginary line which extends in a direction matching a radial direction of the pivot shaft 2 so as to pass through the first end portion 3b and the second end portion 3d, and a second width Wt between opposite ends 3e3 and 3e 4 thereof in the direction along the second straight line Dt that is an imaginary line which is perpendicular to the axis 2a of the pivot shaft 2 and the first straight line Dr.

[0056] In the notch 3e, the first width Wr is defined such as to allow the rotation stopper pin portion 31b inserted in the notch 3e to change a position thereof in the direction along the first straight line Dr. The second width Wt is equal to or more than a width of the rotation stopper pin portion 31b in the direction along the second straight line Dt and is defined such that the rotation stopper plate 3 is restricted from moving relative to the rotation stopper pin portion 31b in the direction along the second straight line Dt, the rotation stopper pin portion 31b being inserted in the insertion portion 3e and abutting the rotation stopper plate 3 at at least one of the opposite ends 3e3 and 3e4 of the notch 3e in the direction along the second straight line Dt.

[0057] The above-mentioned swinging body pivot mechanism P1 will now be described in greater detail. In the swinging body pivot mechanism P1 for the first pivotal junction of the boom 31 and the arm 32, the distal end section 31c of the boom 31 corresponds to the main body portion of the first member of the swinging body pivot mechanism P1. That is, the distal end section 31c of the boom 31 corresponding to the main body portion includes the shaft hole 31a and the rotation stopper pin portion 31b.

[0058] Thus, the distal end section 31c includes one or more members whose sizes (lengths and widths) and strengths are defined such as to allow the distal end section 31c to include the shaft hole 31a and the rotation stopper pin portion 31b. For example, as previously described, the distal end section 31c may be molded integrally by casting or may include one or more plates (steel plates or the like) assembled together by welding, formed by bending or the like.

[0059] The shaft hole 31a may be integrally included in the distal end section 31c molded by casting, or may perforate a solid member by drilling or the like. The rotation stopper pin portion 31b may be integrally included in the distal end section 31c molded by casting, or may be included in a member that is originally separate from the distal end section 31c and is fixed (joined) to the distal end section 31c by welding or the like.

[0060] With the rotation stopper pin portion 31b integrated with the distal end section 31c of the boom 31 (the main body portion of the first member) by casting, welding or the like, even when a force is applied on the rotation stopper pin portion 31b from the pivot shaft 2 via the rotation stopper plate 3, the rotation stopper pin portion 31b has a rigidity that prevents the rotation stopper pin portion 31b from detaching or deviating from the boom 31.

[0061] Alternatively, the rotation stopper pin portion may be a member separate from the main body portion of the first member such as the distal end section 31c of the boom 31 and may be fastened to the main body portion of the first member via a fastener such as a bolt. FIG. 7 illustrates an alternative swinging body pivot mechanism P1 (P) including a rotation stopper pin 6 that is an exemplary rotation stopper pin portion separate from the main body portion, as described later.

[0062] The shaft hole 31a extends axially horizontally, and one axial end of the shaft hole 31a is open at a side surface of the distal end section 31c of the boom 31 (the main body portion of the first member of the swinging body pivot mechanism P). The pivot shaft 2 including the horizontal axis 2a is inserted into the shaft hole 31a. The rotation stopper plate 3 is an example of the rotation stopper 3. A portion of the rotation stopper plate 3 close to a proximal end (first end) 3a thereof is fixed in a flange-like manner to one axial end of the pivot shaft 2 protruding outward from the open axial end of the shaft hole 31a. A portion of the rotation stopper plate 3 that includes the proximal end (first end) 3a and encircles the pivot shaft 2 in the flange-like manner is referred to as a first end portion 3b.

[0063] The pivot shaft 2 and the rotation stopper plate 3 (first end portion 3b) may be joined to each other by welding or may be molded integrally with each other by casting. That is, the pivot shaft 2 and the rotation stopper plate 3 may be fixed together in any way only if the condition in which they are fixed together without rotating relative to each other can be maintained even when a force is applied in a rotational direction about the axis of the pivot shaft 2.

[0064] The rotation stopper pin portion 31b in a boss-like shape protrudes in a horizontal direction from an outer side surface of the distal end section 31c of the boom 31 in the proximity of the shaft hole 31a. The rotation stopper plate 3 extends in a radial direction of the pivot shaft 2 from the proximal end (first end) 3a to a distal end (second end) 3c placed close to the rotation stopper pin portion 31b and spreads in parallel to the outer side surface of the distal end section 31c of the boom 31.

[0065] A portion of the rotation stopper plate 3 close to the distal end 3c includes an insertion portion into which the rotation stopper pin portion 31b is inserted. In the present example embodiment, the notch 3e which is open at the distal end 3c is provided as the insertion portion. A portion of the rotation stopper plate 3 that includes the distal end (second end) 3c and defines the notch 3e is referred to as the second end portion 3d. That is, in the rotation stopper plate 3 according to the present example embodiment, the second end portion 3d includes the distal end (second end) 3c as an utmost end thereof and bifurcates along the notch 3e.

[0066] This type of rotation stopper plate 3 includes the notch 3e and the second end portion 3d (including the distal end 3c) surrounding the notch 3e such that, when a distance on the boom 31 between the shaft hole 31a and the rotation stopper pin portion 31b (hereinafter, this distance may be referred to as “specific distance”) is equal to a reference value (average or the like), the rotation stopper pin portion 31b is positioned at a proximity of an open end (that is a later-discussed “second end 3e2”) of the notch 3e. This configuration reduces a length of the rotation stopper plate 3 between the proximal end 3a and the distal end 3c so as to contribute to reducing costs and weights of corresponding component parts.

[0067] A configuration of the notch 3e as the insertion portion according to the present example embodiment will now be described with reference to FIG. 4B. In the side view of the boom 31 in FIG. 4B, the first straight line Dr is drawn as an imaginary line which passes through the axis 2a of the pivot shaft 2 (that is, matching the radial direction of the pivot shaft 2) and extends so as to pass through the first end portion 3b (including the portion joined to the axial end of the pivot shaft 2) and the second end portion 3d (including the notch 3e as the insertion portion), and the second straight line Dt is drawn as an imaginary line which extends perpendicularly to the first straight line Dr and the axis 2a of the pivot shaft 2.

[0068] That is, the first straight line Dr is a straight line extending in the radial direction of the pivot shaft 2 and the second straight line Dt is a straight line extending in a tangential direction at an intersection of an outer periphery of the pivot shaft 2 and a diameter of the pivot shaft 2 extending in the direction along the first straight line Dr. Accordingly, the direction along the second straight line Dt substantially matches a rotation direction centered on the axis 2a of the pivot shaft 2.

[0069] The notch 3e provided as the insertion portion into which the rotation stopper pin portion 31b is inserted needs to have, in the direction along the first straight line Dr, sufficient room such as to absorb a dimension error in the specific distance on the distal end section 31c of the boom 31 between the shaft hole 31a (through which the pivot shaft 2 is passed) and the rotation stopper pin portion 31b on the distal end section 31c, and needs to have, in the direction along the second straight line Dt, a restrictive dimension such as to restrict the rotation stopper plate 3 (that is integral with the pivot shaft 2) and the rotation stopper pin portion 31b (that is integral with the boom 31) from rotating relative to each other about the axis 2a of the pivot shaft 2.

[0070] Regarding the rotation stopper plate 3 according to the present example embodiment, the notch 3e defining the insertion portion into which the rotation stopper pin portion 31b is inserted includes a first end 3e1 on the first end 3a side and a second end 3e2 on the second end 3c side as opposite ends in the direction along the first straight line Dr, and includes the first width Wr between the opposite ends 3e1 and 3e2 in the direction along the first straight line Dr.

[0071] The second end 3e2 of the notch 3e corresponding to the second end 3c (utmost end of the second end portion 3d) of the rotation stopper plate 3 is an open end. That is, the rotation stopper pin portion 31b to be inserted in the notch 3e defining the insertion portion may abut the rotation stopper plate 3 at the first end 3e1 of the notch 3e, whereas the rotation stopper pin portion 31b cannot abut the rotation stopper plate 3 at the second end 3e2 of the notch 3e but is allowed to enter and leave, via the second end 3e2, the notch 3e defining the insertion portion.

[0072] On the other hand, the notch 3e includes a third end 3e3 and a fourth end 3e4 as opposite ends in the direction along the second straight line Dt, and includes a second width Wt in the direction along the second straight line Dt between the opposite ends 3e3 and 3e4. The second width Wt is equal to or more than a width Wp of the rotation stopper pin portion 31b in the direction along the second straight line Dt as a minimum required to allow the rotation stopper portion 31b to enter the notch 3e, and is defined such that the rotation stopper plate 3 (that is integral with the pivot shaft 2) and the rotation stopper pin portion 31b (that is integral with the boom 31) are restricted from moving relative to each other in the direction along the second straight line Dt (rotation direction centered on the axis 2a of the pivot shaft 2) while the rotation stopper pin portion 31b inserted in the notch 3e abuts the rotation stopper plate 3 at at least one of the opposite ends 3e3 and 3e4 of the notch 3e in the direction along the second straight line Dt.

[0073] Thus, the boom 31 that is integral with the rotation stopper pin portion 31b inserted in the notch 3e is stopped (restricted) by the rotation stopper plate 3 from rotating relative to the pivot shaft 2.

[0074] In the case where the second width Wt is defined to be substantially the same as the width Wp of the rotation stopper portion 31b in the direction along the second straight line Dt (if the rotation stopper pin portion 31b is configured to have a uniform diameter, substantially the same as the diameter (outer diameter) of the rotation stopper pin portion 31b) that is the minimum width required for the second width Wt to allow the rotation stopper pin portion 31b to be inserted into the notch 3e, it is possible to most tightly restrict the rotation stopper plate 3 and the rotation stopper pin portion 31b from rotating relative to each other in the direction along the second straight line Dt. That is, in such a case, the rotation stopper pin portion 31b abuts the rotation stopper plate 3 at both the opposite ends 3e3 and 3e4 of the notch 3e in the direction along the second straight line Dt, so that the notch 3e has no room to allow the rotation stopper pin portion 31b to move relative to the rotation stopper plate 3 in the rotation direction of the pivot shaft 2 that substantially matches the direction along the second straight line Dt. Accordingly, regardless of in which of opposite rotation directions the boom 31 and the arm 32 rotate relative to each other, the boom 31 and the pivot shaft 2 are constantly integral with each other rotatably about the axis 2a of the pivot shaft 2 without rotating relative to each other.

[0075] If the second width Wt is defined to be slightly larger than the width Wp of the rotation stopper pin portion 31b in the direction along the second straight line Dt, the notch 3e has some room (play) in which the rotation stopper pin portion 31b is allowed to move relative to the rotation stopper plate 3 (pivot shaft 2) in the direction along the second straight line Dt. As the rotation stopper pin portion 31b rotates relative to the rotation stopper plate 3 (pivot shaft 2) by this room, the rotation stopper pin portion 31b abuts the rotation stopper plate 3 at one of the opposite ends 3e3 and 3e4 of the notch 3e in the direction along the second straight line Dt so that the boom 31 and the pivot shaft 2 (integral with the rotation stopper plate 3) are restricted from rotating relative to each other.

[0076] On the other hand, the first width Wr between the opposite ends 3e1 and 3e2 of the notch 3e in the direction along the first straight line Dr is defined such as to allow the rotation stopper pin portion 31b to change a position thereof in the direction along the first straight line Dr inside the notch 3e. That is, there is enough room (play) to change a position of the rotation stopper pin portion 31b in the direction along the first straight line Dr inside the notch 3e defining the insertion portion.

[0077] With this configuration, even if there is a dimension error in the specific distance on the distal end section 31c of the boom 31 between the shaft hole 31a and the rotation stopper pin portion 31b, the rotation stopper pin portion 31b can as well be inserted into the notch 3e as be inserted thereinto by adjusting the position of the rotation stopper pin rotation 31b the direction along the first straight line Dr.

[0078] For example, in a case where the specific distance on the distal end section 31c of the boom 31 between the shaft hole 31a and the rotation stopper pin portion 31b is shorter than a reference value (average or the like), the rotation stopper pin portion 31b is allowed to be inserted into the notch 3e at a position closer to the first end 3e1 that is an innermost end of the notch 3e than a position at which the rotation stopper pin portion 31b is allowed to be inserted into the notch 3e when the specific distance is equal to the reference value.

[0079] On the other hand, in a case where the specific distance on the distal end section 31c of the boom 31 between the shaft hole 31a and the rotation stopper pin portion 31b is longer than the reference value (average or the like), a portion of the rotation stopper pin portion 31b opposite to the first end (closed end) 3e1 of the notch 3e in the direction along the first straight line Dr is located outward from the second end (open end) 3e2 of the notch 3e, and only the remaining portion of the rotation stopper pin portion 31b toward the first end 3e1 in the direction along the first straight line Dr is allowed to be inserted into the notch 3e.

[0080] As mentioned above, even if the distal end section 31c of the boom 31 has some dimension error in the specific distance in the direction along the first straight line Dr between the shaft hole 31a and the rotation stopper pin portion 31b, the rotation stopper pin portion 31b can be surely inserted into the notch 3e defining the insertion portion of the rotation stopper plate 3, so that the distal end section 31c of the boom 31 is restricted by the rotation stopper plate 3 from rotating relative to the pivot shaft 2 in the direction along the second straight line Dt.

[0081] The rotation stopper plate 3 illustrated in FIGS. 2 to 5 uses the notch 3e that defines the insertion portion into which the rotation stopper pin portion 31b is inserted and that includes the open end (second end) 3e2 corresponding to the distal end 3c of the rotation stopper plate 3 (utmost end of the second end portion 3d). Therefore, if there may be a dimension error in the specific distance on the distal end section 31c of the boom 31 between the shaft hole 31a and the rotation stopper pin portion 31b that is either the specific distance abnormally long to be larger than the reference value (average or the like) (hereinafter the dimension error of the specific distance abnormally long to be larger than the reference value may be referred to as “long distance error”) or the specific distance abnormally short to be smaller than the reference value (average or the like) (hereinafter, the dimension error of the specific distance abnormally short to be smaller than the reference value may be referred to as “short distance error”), the long distance error can be overcome by shifting the position of the rotation stopper pin portion 31b relative to the rotation stopper plate 3 further outward of the open end 3e2 of the notch 3e (in the direction away from the pivot shaft 2).

[0082] Accordingly, in the situation where there may be a dimension error in the specific distance on the boom 31 that is either the long distance error or the short distance error, only the short distance error needs to be taken into account when the first width Wr of the notch 3e in the direction along the first straight line Dr is determined. Thus, processes to form the notch (insertion portion) 3e in the rotation stopper plate (rotation stopper) 3 can be simplified.

[0083] Incidentally, regarding the above-mentioned swinging body pivot mechanism P, it is possible that, when the pivot shaft 2 unexpectedly moves inside the shaft hole 31a in the direction of the axis 2a, the rotation stopper plate 3 moves integrally with the pivot shaft 2 in the direction of the axis 2a and disengages from the rotation stopper pin portion 31b that has been inserted into the notch 3e. In order to prevent the rotation stopper plate 3 from disengaging from the rotation stopper pin portion 31b, the swinging body pivot mechanism P includes a retainer plate 5 and / or the like.

[0084] In this regard, as shown in FIGS. 4A, 4B and 5, a threaded hole 31b1 is provided in the rotation stopper pin portion 31b. As shown in FIGS. 2 and 3, a bolt 4 defining a fastener is screwed into the threaded hole 31b1. The bolt 4 is passed through a center hole of the discoid retainer plate 5 and screwed into the threaded hole 31b1 (see FIG. 7). Thus, the flange-like retainer plate 5 is held between a head of the bolt 4 screwed into the threaded hole 31b1 and one side end surface (end) of the rotation stopper pin portion 31b.

[0085] By providing the retainer plate 5 fastened to the rotation stopper pin portion 31b via a fastener such as the bolt 4 at a position where the retainer plate 5 adjoins or abuts the rotation stopper plate 3, the rotation stopper plate 3 is restricted from moving in the direction of the axis 2a of the pivot shaft 2 and is prevented from disengaging from the rotation stopper pin portion 31b. In this way, the retainer plate 5 functions as a retainer to restrict the movement of the rotation stopper plate 3 in the direction of the axis 2 of the pivot shaft 2.

[0086] The discoid retainer plate 5 shown in FIGS. 2, 3 and the like is an exemplary retainer. The retainer need only be configured to restrict a movement of a rotation stopper in the direction of the axis 2a of the pivot shaft 2, and is not limited in shape, material and / or the like as long as the retainer includes the required configuration. The fastener is not limited to the bolt 4 and may be a screw or the like.

[0087] Instead of the rotation stopper plate 3 including the notch 3e defining the insertion portion as shown in FIGS. 2 to 5, an alternative rotation stopper plate 3X including a slot 3h defining the insertion portion as shown in FIGS. 6A and 6B may be used as a rotation stopper to connect the pivot shaft 2 and the rotation stopper pin portion 31b.

[0088] FIG. 6A illustrates a side view of the swinging body pivot mechanism P1 (P) including a rotation stopper (rotation stopper plate 3X) according to an alternative example embodiment. FIG. 6B illustrates an enlarged side view of the swinging body pivot mechanism P1 (P) including the rotation stopper (rotation stopper plate 3X) according to the alternative example embodiment.

[0089] The rotation stopper plate 3X of FIGS. 6A and 6B will now be described. The rotation stopper plate 3X includes a proximal end (first end) 3a and a first end portion 3b in common with the rotation stopper plate 3. The first end portion 3b encircles the axial end of the pivot shaft 2 and is fixed to the axial end of the pivot shaft 2.

[0090] In comparison to the notch 3e defining the insertion portion of the rotation stopper plate 3, the slot 3h defining the insertion portion of the rotation stopper plate 3X is closed by a distal end (second end) 3f of the rotation stopper plate 3X opposed to the proximal end 3a. That is, a second end portion 3g of the rotation stopper plate 3X including the distal end 3f and opposed to the first end portion 3b entirely encloses (closes) the slot 3h.

[0091] With the explanation of the foregoing swinging body pivot mechanism P, a configuration of the slot 3h as the insertion portion of the rotation stopper plate 3X shown in FIGS. 6A and 6B is defined as follows. Referring to FIG. 6B, the slot 3h as the exemplary insertion portion includes a first width Wrx between opposite ends 3h1 and 3h2 thereof in the direction along the first straight line Dr that is an imaginary line which extends in a direction matching a radial direction of the pivot shaft 2 so as to pass through the first end portion 3b and the second end portion 3g, and a second width Wtx between opposite ends 3h3 and 3h4 thereof in the direction along the second straight line Dt that is an imaginary line which is perpendicular to the axis 2a of the pivot shaft 2 and the first straight line Dr.

[0092] The slot 3h is a long hole closed at the opposite ends 3h1 and 3h2 thereof in the direction along the first straight line Dr and extending lengthwise in the direction along the first straight line Dr (radial direction of the pivot shaft 2). That is, the first width Wrx is larger than the second width Wtx and is defined such as to allow the rotation stopper pin portion 31b inserted in the slot 3h to change a position thereof in the direction along the first straight line Dr.

[0093] The second width Wtx is defined such as to allow the rotation stopper pin portion 31b to be inserted in the slot 3h, and to restrict the rotation stopper pin portion 31b inserted in the slot 3h from moving in the direction along the second straight line Dt relative to the rotation stopper plate 3 while the rotation stopper pin portion 31b inserted in the slot 3h abuts the rotation stopper plate 3 at at least one of the opposite ends 3h3 and 3h4 in the direction along the second straight line Dt.

[0094] In particular, the slot 3h of the rotation stopper plate 3X is configured in position and size (first width Wrx) thereof in the direction along the first straight line Dr such that, when the specific distance on the boom 31 (distance between the shaft hole 31a and the rotation stopper pin portion 31b) is equal to the reference value (average or the like), the rotation stopper pin portion 31b is at a substantially middle point between the opposite ends 3h1 and 3h2.

[0095] That is, the first width Wrx of the slot 3h in the direction along the first straight line Dr (radial direction of the pivot shaft 2) is determined in consideration of both the long distance error and the short distance error that may occur in the specific distance. Therefore, regardless of whether there is the long distance error or the short distance error as a dimension error in the specific distance, the dimension error can be overcome by adjusting, in the slot 3h, the position of the rotation stopper pin portion 31b relative to the rotation stopper plate 3X in the direction along the first straight line Dr.

[0096] Specifically, the rotation stopper plate 3X according to the present example embodiment is configured to include the slot 3h with the second width Wtx in the direction along the second straight line Dt such as to allow the rotation stopper pin portion 31b to be inserted in the slot 3h regardless of whether there is the short distance error that is the specific distance abnormally short to be smaller than the reference value or the long distance error that is the specific distance abnormally long to be larger than the reference value. Thus, even if there is either the short distance error or the long distance error as a dimension error in the specific distance, the rotation stopper plate 3 (second end portion 3g of the rotation stopper plate 3X at the opposite sides of the slot 3h in the direction along the second straight line Dt) effectively affects the rotation stopper portion 31b at the opposite ends 3h3 and 3h4 of the slot 3h with a sufficient rotation stopper force (force to restrict the pivot shaft 2 and the boom 31 from rotating relative to each other).

[0097] Regarding the rotation stopper plate 3 according to the previous example embodiment, even if there is a dimension error in the specific distance referred to as the short distance error, the rotation stopper pin portion 31b having the short distance error is allowed to be inserted into the notch 3e including the second width Wt in the direction along the second straight line Dt so as to receive, at the opposite ends 3e3 and 3e4 of the notch 3e, a sufficient rotation stopper force from the rotation stopper plate 3 (to restrict the pivot shaft 2 and the boom 31 from rotating relative to each other). On the other hand, if there is a dimension error in the specific distance referred to as the long distance error, a portion of the rotation stopper pin portion 31b having the long distance error may protrude outward from the open end (second end) 3e2 of the notch 3e (only the remaining portion thereof may be inserted into the notch 3e). Thus, the rotation stopper plate 3 may insufficiently affect the rotation stopper pin portion 31b at the opposite ends 3e3 and 3e4 of the notch 3e in the direction along the second straight line Dt with a reduced rotation stopper force (force to restrict the pivot shaft 2 and the boom 31 from rotating relative to each other) compared to a case where the rotation stopper pin portion 31b having the short distance error is inserted into the notch 3e.

[0098] However, such a problem of the rotation stopper plate 3 can be eliminated, for example, by increasing the first width Wr of the notch 3e in the direction along the first straight line Dr such as to allow the rotation stopper pin portion 31b, even if having the dimension error in the specific distance referred to as the long distance error, to be inserted into the notch 3e including the second width Wt in the direction along the second straight line Dt.

[0099] FIGS. 6A and 6B each omit the retainer plate 5 from the rotation stopper pin portion 31b illustrated therein (FIG. 6B further omits the bolt 4). However, similar to the previous example embodiment (see FIGS. 2 and 3), the restriction of the rotation stopper plate 3X from moving in the direction of the axis 2a of the pivot shaft 2 may be achieved by screwing the bolt 4 passed through the retainer plate 5 into the threaded hole 31b1 of the rotation stopper pin portion 31b, and providing the retainer plate 5 held between the head of the bolt 4 and the end surface of the rotation stopper pin portion 31b at a position where the retainer plate 5 adjoins or abuts the rotation stopper plate 3X.

[0100] An alternative swinging body pivot mechanism P1 illustrated in FIG. 7 according to an alternative example embodiment will now be described. FIG. 7 illustrates a perspective view of a first swinging body pivot mechanism P1 (as a representative swinging body pivot mechanism P) including a rotation stopper pin 6 that is a rotation stopper pin portion according to an alternative example embodiment, and an exploded view of a portion of the first swinging body pivot mechanism P1.

[0101] As previously mentioned, an exemplary rotation stopper pin portion of the swinging body pivot mechanism P may include a separable component member separate from the main body portion of the first member (the distal end section 31c of the boom 31 in the present example embodiment) that is an exemplary swinging body, and the separable component member may be fastened to the main body portion of the first member via a fastener. The alternative swinging body pivot mechanism P1 (swinging body pivot mechanism P) illustrated in FIG. 7 includes the rotation stopper pin 6 as such an exemplary rotation stopper pin portion.

[0102] The rotation stopper pin 6 defining the rotation stopper pin portion (rotation stopper pin portion 31b of the boom 31 or the like) of the swinging body pivot mechanism P is a cylindrical pin separate from the main body portion (distal end section 31c of the boom 31 or the like).

[0103] The cylindrical rotation stopper pin 6 includes a through-hole defined by an inner peripheral portion thereof that surrounds an axis thereof, and an inner peripheral surface thereof facing the through-hole is not a smooth surface but a female screw formed with a screw thread. That is, the through-hole is configured as a threaded hole 6a. Thus, the rotation stopper pin 6 includes the inner peripheral portion defining, the threaded hole 6a extending in a protruding direction in which the rotation stopper pin portion protrudes substantially parallel to the axis 2a of the pivot shaft 2.

[0104] The distal end section 31c of the boom 31 defining the main body portion of the first member includes a threaded hole 31f open at a side surface thereof to correspond to the threaded hole 6a. The rotation stopper pin 6 is axially extended substantially parallel to the axis 2a of the pivot shaft 2, is inserted through the insertion portion (notch 3e in the present example embodiment) of the rotation stopper plate 3, and is caused to abut the side surface of the distal end section 31c of the boom 31 so that the threaded hole 6a and the threaded hole 31f in (the distal end section 31c of) the boom 31 are joined coaxially to each other, and the position of the rotation stopper pin 6 relative to the distal end section 31c of the boom 31 is secured.

[0105] The bolt 4 defining a fastener is screwed into the threaded hole 6a of the rotation stopper pin 6 positioned in the above-mentioned way, and into the threaded hole 31f coaxial to the threaded hole 6a. With the bolt 4 screwed into the threaded hole 31f in the distal end section 31c, the rotation stopper pin 6 held between the head of the bolt 4 and the side surface of the distal end section 31c is fastened to the distal end section 31c of the boom 31.

[0106] Inside the threaded hole 6a of the rotation pin 6, a screw thread of the bolt 4 and a screw thread on the inner peripheral surface of the threaded hole 6a are screwed together. Accordingly, the rotation stopper pin 6 and the boom 31 are integrated together via the bolt 4. That is, the rotation stopper pin 6 whose inner peripheral portion defines the threaded hole 6a is screwed together with the bolt 4 passed through the threaded hole 6 so that the rotation stopper pin 6 can hardly move (in the axial direction thereof and the peripheral direction thereof) relative to the bolt 4 compared to a case where the rotation stopper pin 6 is configured as a simple boss whose inner peripheral surface is a smooth surface.

[0107] In this way, the bolt 4 defining the fastener restricts the rotation stopper pin 6 defining a pin separate from the main body portion of the first member from moving (from being separated and removed from the distal end section 31c) in the protruding direction in which the rotation stopper pin 6 projects as the rotation stopper pin portion (in the direction substantially parallel to the axis 2a of the pivot shaft 2).

[0108] Further, as shown in FIG. 7, and similar to the previous example embodiment shown in FIGS. 2 and 3, the restriction of movement of the rotation stopper plate 3 (3X) in the direction of the axis 2a of the pivot shaft 2 may be achieved by screwing the bolt 4 passed through the retainer plate 5 into the rotation stopper pin 6, and providing the retainer plate 5 held between the head of the bolt 4 and the end surface of the rotation stopper pin 6 at a position where the retainer plate 5 adjoins or abuts the rotation stopper plate 3 (or 3X).

[0109] The following describes some configurations (items) of the swinging body pivot mechanism P and the working machine 1 including the swinging body pivot mechanism P and effects and / or the like thereof.

[0110] (Item 1) A swinging body pivot mechanism P including: a pivot shaft 2; a first member 31 and a second member 32 coupled to each other via the pivot shaft 2 swingably relative to each other; and a rotation stopper 3 (3X) attached to the pivot shaft 2; wherein the first member 31 includes a main body portion 31c, a shaft hole 31a provided in the main body portion 31c to have the pivot shaft 2 inserted therethrough, and a rotation stopper pin portion 31b (6) provided in a vicinity of the shaft hole 31a and protruding from the main body portion 31c in a direction substantially parallel to an axis 2a of the pivot shaft 2; the rotation stopper 3 (3X) includes a first end portion 3b fixed to the pivot shaft 2, and a second end portion 3d (3g) with an insertion portion 3e (3h) into which the rotation stopper pin portion 31b (6) is inserted; the insertion portion 3e (3h) includes a first width Wr (Wrx) between opposite ends thereof in a direction along a first straight line Dr that is an imaginary line which extends in a direction matching a radial direction of the pivot shaft 2 so as to pass through the first end portion 3b and the second end portion 3d (3g), and a second width Wt (Wtx) between opposite ends 3e3 and 3e4 (3h3 and 3h4) thereof in a direction along a second straight line Dt that is an imaginary line which is perpendicular to the axis 2a of the pivot shaft 2 and the first straight line Dr; the first width Wr (Wrx) is defined such as to allow the rotation stopper pin portion 31b inserted in the insertion portion 3e (3h) to change a position thereof in the direction along the first straight line Dr; and the second width Wt (Wtx) is equal to or more than a width of the rotation stopper pin portion 31b (6) in the direction along the second straight line Dt and is defined such that the rotation stopper 3 (3X) and the rotation stopper pin portion 31b (6) are restricted from moving relative to each other in the direction along the second straight line Dt, the rotation stopper pin portion 31b (6) being inserted in the insertion portion 3e (3h) and abutting the rotation stopper 3 (3X) at at least one of the opposite ends 3e3 and 3e4 (3h3 and 3h4) of the insertion portion 3e(3h ) in the direction along the second straight line Dt.

[0111] With the swinging body pivot mechanism P of item 1, for example even if a positioning accuracy of the rotation stopper pin portion 31b (6) on the main body portion 31c of the first member 31 is not sufficient and there is a dimension error in a distance on the first member 31 between the shaft hole 31a and the rotation stopper pin portion 31b (6), the insertion portion 3e (3h) is configured to include the first width Wr (Wrx) between the opposite ends 3e1 and 3e2 (3h1 and 3h2) in the direction along the first straight line Dr substantially matching a radial direction of the pivot shaft 2 that is sufficient to allow the rotation stopper pin portion 31b (6) having the dimension error to be inserted into the insertion portion 3e (3h), so that the rotation stopper 3 (3X) can surely affect the rotation stopper portion 31b (6) inserted in the insertion portion 3e (3h) with a sufficient rotation stopper force at the at least one of the opposite ends 3e3 and 3e4 (3h3 and 3h4) of the insertion portion 3e (3h) in the direction along the second straight line Dt substantially matching the rotation direction of the pivot shaft 2 so as to restrict the first member 31 and the pivot shaft 2 from rotating relative to each other (or to stop the first member 31 from rotating relative to the pivot shaft 2).

[0112] (Item 2) The swinging body pivot mechanism P according to item 1, wherein the insertion portion 3e includes a notch 3e which is open at one end 3e2 of the opposite ends 3e1 and 3e2 thereof in the direction along the first straight line Dr that corresponds to an utmost end 3c of the second end portion 3d.

[0113] With the swinging body pivot mechanism P of item 2, the rotation stopper pin portion 31b can be surely inserted into the insertion portion 3e, and the rotation stopper 3 can surely affect the rotation stopper pin portion 31b with a sufficient rotation stopper force at the at least one of the opposite ends in the direction of the second width of the insertion portion 3e.

[0114] (Item 3) The swinging body pivot mechanism P according to item 1, wherein the insertion portion 3h includes a slot 3h closed at the opposite ends 3h1 and 3h2 thereof in the direction along the first straight line Dr and extending lengthwise in the direction along the first straight line Dr.

[0115] With the swinging body pivot mechanism P of item 3, the rotation stopper pin portion 31b can be surely inserted into the insertion portion 3h, and the rotation stopper 3 can surely affect the rotation stopper pin portion 31b with a sufficient rotation stopper force at the at least one of the opposite ends in the direction of the second width of the insertion portion 3h.

[0116] (Item 4) The swinging body pivot mechanism P according to any one of items 1 to 3, wherein the rotation stopper pin portion 31b is molded integrally with the main body portion 31c by casting.

[0117] With the swinging body pivot mechanism P of item 4, the insertion portion 3e (3h) of the rotation stopper 3 (3X) is configured to allow the rotation stopper pin portion 31b, even if having a dimension error in a distance on the first member 31 between the shaft hole 31a and the rotation stopper pin portion 31b that may be generated during casting, to be inserted therein, so that the rotation stopper 3 (3X) can connect the pivot shaft 2 and the rotation stopper pin portion 31b to each other and stop the first member 31 from rotating relative to the pivot shaft 2 (restrict the pivot shaft 2 and the first member 31 from rotating relative to each other) even if a positioning accuracy of the rotation stopper pin portion 31b on the main body portion 31c of the first member 31 is not sufficient.

[0118] (Item 5) The swinging body pivot mechanism P according to any one of items 1 to 3, wherein the rotation stopper pin portion 31b is integrated with the main body portion 31c by welding.

[0119] With the swinging body pivot mechanism P of item 5, the insertion portion 3e (3h) of the rotation stopper 3 (3X) is configured to allow the rotation stopper portion 31b, even with a dimension error in a distance on the first member 31 between the shaft hole 31a and the rotation stopper pin portion 31b that may be generated because of imprecision in positioning thereof for welding, to be inserted therein, so that the rotation stopper 3 (3X) can connect the pivot shaft 2 and the rotation stopper pin portion 31b to each other and stop the first member 31 from rotating relative to the pivot shaft 2 (restrict the pivot shaft 2 and the first member 31 from rotating relative to each other) even if a positioning accuracy of the rotation stopper pin portion 31b on the main body portion 31c of the first member 31 is not sufficient.

[0120] (Item 6) The swinging body pivot mechanism P according to any one of items 1 to 3,further including a pin 6 defining the rotation stopper pin portion 31b that is a cylindrical member separated from the main body portion 31c, the pin 6 including a threaded hole 6a defined by an inner peripheral portion thereof that extends in a protruding direction in which the rotation stopper pin portion 31b protrudes substantially parallel to the axis 2a of the pivot shaft 2; and a fastener 4 to fasten the pin 6 to the main body portion 31c; wherein the fastener 4 is screwed with the pin 6 inside of the threaded hole 6a to restrict the pin 6 from moving in the protruding direction.

[0121] With the swinging body pivot mechanism P of item 6, the pin 6 separate from the main body portion 31c of the first member 31 defines the rotation stopper pin portion, and the main body portion 31c needs only include the threaded hole 31f corresponding to the threaded hole 6a of the pin 6, so that it is possible to contribute to simplification of manufacturing processes, weight reduction and cost reduction for the main body portion 31c of the first member 31. In addition, the fastener 4 can surely restrict the pin 6 from moving in a direction of the axis 2a of the pivot shaft 2 and maintain, for a long time, the rotation stopper 3, with the pin 6 prevented from removing therefrom, having a rotation stopper effect to stop the first member 31 from rotating relative to the pivot shaft 2.

[0122] (Item 7) The swinging body pivot mechanism P according to any one of items 1 to 6, further including a fastener 4 to be screwed into a threaded hole 31b1 (6a) that is provided in the rotation stopper pin portion 31b (6), and a retainer 5 sandwiched between a head of the fastener 4 to be screwed into the threaded hole 31b1 (6a) and an end of the rotation stopper pin portion 31b (6) to restrict the rotation stopper 3 (3X) from moving in the direction of the axis 2a of the pivot shaft 2.

[0123] With the swinging body pivot mechanism P of item 7, even if problems may exist that the pivot shaft 2 may move inside of the shaft hole 31a in the direction of the axis 2a because of rattling and the rotation stopper 3 (3X) may move because of the rattling and remove from the rotation stopper pin portion 31b (6), the retainer 5 fastened to the rotation stopper pin portion 31b (6) via the fastener 4 adjoins or abuts the rotation stopper 3 so as to restrict the rotation stopper 3 from moving in the direction of the axis 2a of the pivot shaft 2, and prevent the rotation stopper 3 from removing from the rotation stopper pin portion 31b (6).

[0124] (Item 8) A working machine 1 including: a machine body 20; a boom 31 swingably supported by the machine body 20; an arm 32 swingably supported by the boom 31; and a swinging body pivot mechanism P1 according to any one of items 1 to 7 provided as a pivotal junction of the boom 31 and the arm 32.

[0125] With the working machine 1 of item 8, it is possible to apply an appropriate effect of the swinging body pivot mechanism P1 including the configuration according to any one of items 1 to 7 to the pivotal junction of the boom 31 and the arm 32.

[0126] (Item 9) A working machine 1 including: a machine body 20; a working device 30 swingably supported by the machine body 20; and a swinging body pivot mechanism P2 according to any one of items 1 to 7 provided as a pivotal junction of the machine body 20 and the working device 30.

[0127] With the working machine 1 of item 9, it is possible to apply an appropriate effect of the swinging body pivot mechanism P2 including the configuration according to any one of items 1 to 7 to the pivotal junction of the machine body 20 (swing bracket 14) and the working device 30 (boom 31).

[0128] (Item 10) A working machine 1 including: a machine body 20; a working device 30 supported by the machine body 20; a working tool 33 swingably supported by the working device 30; and a swinging body pivot mechanism P3 according to any one of items 1 to 7 provided as a pivotal junction of the working device 30 and the working tool 33.

[0129] With the working machine 1 of item 10, it is possible to apply an appropriate effect of the swinging body pivot mechanism P2 including the configurations according to any one of items 1 to 7 to the pivotal junction of the working device 30 (arm 32) and the working tool (bucket 33).

[0130] While example embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.

Examples

Embodiment Construction

[0028]Example embodiments will now be described with reference to the accompanying drawings, wherein like reference numerals designate corresponding or identical elements throughout the various drawings. The drawings are to be viewed in an orientation in which the reference numerals are viewed correctly.

[0029]FIG. 1 illustrates a side view of a swiveling excavator (hereafter simply referred to as “working machine 1”). A schematic configuration of the working machine 1 will now be described using FIG. 1. In the present example embodiment, a direction indicated by an arrow A1 in FIG. 1 is called “front direction”, a direction indicated by an arrow A2 is called “rear direction”, one direction perpendicular to the arrows A1 and A2 and toward a viewer in front of a sheet of FIG. 1 is called “left” and another direction perpendicular to the arrows A1 and A2 and toward a side behind the sheet of FIG. 1 is called “right”.

[0030]The working machine 1 includes a traveling body 10, a machine bo...

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to Japanese Patent Application No. 2024-221938 filed on Dec. 18, 2024. The entire contents of this application are hereby incorporated herein by reference.BACKGROUND OF THE INVENTION1. Field of the Invention

[0002] The present invention relates to swinging body pivot mechanisms and working machines each including one or more of the swinging body pivot mechanisms.2. Description of the Related Art

[0003] Working machines such as backhoes each use one or more rotation stoppers each configured to stop a swinging body from rotating relative to a pivot shaft pivotally connecting the swinging body to another swinging body. For example, the Japanese Unexamined Patent Application Publication No. 2000-351581 discloses a rotation stopper plate that is fixed to one of axial ends of a support pin pivotally connecting a boom bracket (swing bracket) to a boom, and that is fixed at an end portion thereof to the boom bracket (swing bracket) by a bolt.SUMMARY OF THE INVENTION

[0004] Regarding the technical art as disclosed in the Japanese Unexamined Patent Application Publication No. 2000-351581, there is a problem that the bolt may be easily loosened when the bolt receives a force in a direction perpendicular to an axial direction of the support pin that is generated because of swing of the boom, vibration of a machine body and / or the like. Thus, it may be conceivable that a boss is fixedly mounted on the boom bracket (swing bracket) and is passed through a hole provided in the corresponding end portion of the rotation stopper plate so as to cause the rotation stopper plate to achieve the function as the rotation stopper to stop the boom bracket (swing bracket) from rotating relative to the support pin. However, in such a case, it may be difficult to properly mount the support pin to the boom bracket (swing bracket) if there is a situation where the boss cannot be sufficiently accurately mounted on the boom bracket (swing bracket) at an appropriate position.

[0005] For example, in a case where the boom bracket (swing bracket) as a representative target swinging body for a rotation stopper includes a main body molded integrally with the boss by casting, the boss molded with the main body may have a position error with respect to the main body as a casting defect. In a case where the boss is joined to the main body of the boom bracket (swing bracket) by welding to be mounted on the main body, the boss mounted on the main body may have a position error with respect to the main body because of inaccurate positioning of the boss to be joined to the main body by welding. In a case where the boss is fastened to the main body of the boom bracket (swing bracket) via a fastener such as a bolt to be mounted on the main body, the boss may have a position error with respect to the main body because of inaccurate forming of a threaded hole in the boss or the main body. When the boss mounted on the main body of the boom bracket (swing bracket) as a representative target swinging body has an error such as mentioned above, a position of the support pin to be attached to the rotation stopper plate may fail to correspond to the position of the boss with respect to the rotation stopper plate so that it may be difficult to connect the pivot shaft and the boom bracket (swing bracket) via the rotation stopper plate.

[0006] The present invention provides swinging body pivot mechanisms and working machines each including one or more of such mechanisms to solve issues as described above.

[0007] A swinging body pivot mechanism according to an example embodiment of the present invention includes a pivot shaft, a first member and a second member coupled to each other via the pivot shaft swingably relative to each other, and a rotation stopper attached to the pivot shaft. The first member includes a main body portion, a shaft hole provided in the main body portion to have the pivot shaft inserted therethrough, and a rotation stopper pin portion provided in a vicinity of the shaft hole and protruding from the main body portion in a direction substantially parallel to an axis of the pivot shaft. The rotation stopper includes a first end portion fixed to the pivot shaft, and a second end portion with an insertion portion into which the rotation stopper pin portion is inserted. The insertion portion includes a first width between opposite ends thereof in a direction along a first straight line that is an imaginary line which extends in a direction matching a radial direction of the pivot shaft so as to pass through the first end portion and the second end portion, and a second width between opposite ends thereof in a direction along a second straight line that is an imaginary line which is perpendicular to the axis of the pivot shaft and the first straight line. The first width is defined such as to allow the rotation stopper pin portion inserted in the insertion portion to change a position thereof in the direction along the first straight line. The second width is equal to or more than a width of the rotation stopper pin portion in the direction along the second straight line and is defined such that the rotation stopper and the rotation stopper pin portion are restricted from moving relative to each other in the direction along the second straight line, the rotation stopper pin portion being inserted into the insertion portion and abutting the rotation stopper at at least one of the opposite ends of the insertion portion in the direction along the second straight line.

[0008] The insertion portion may includes a notch which is open at one end of the opposite ends thereof in the direction along the first straight line that corresponds to an utmost end of the second end portion.

[0009] The insertion portion may include a slot closed at the opposite ends thereof in the direction along the first straight line and extending lengthwise in the direction along the first straight line.

[0010] The rotation stopper pin portion may be molded integrally with the main body portion by casting.

[0011] The rotation stopper pin portion may be integrated with the main body portion by welding.

[0012] The swinging body pivot mechanism may further include a pin defining the rotation stopper pin portion that is a cylindrical member separated from the main body portion, the pin including a threaded hole defined by an inner peripheral portion thereof that extends in a protruding direction in which the rotation stopper pin portion protrudes substantially parallel to the axis of the pivot shaft; and a fastener to fasten the pin to the main body portion. The fastener may be screwed with the pin inside of the threaded hole to restrict the pin from moving in the protruding direction.

[0013] The swinging body pivot mechanism may further include a fastener to be screwed into a threaded hole that is provided in the rotation stopper pin portion, and a retainer sandwiched between a head of the fastener screwed into the threaded hole and an end of the rotation stopper pin portion to restrict the rotation stopper from moving in a direction of the axis of the pivot shaft.

[0014] A working machine according to an example embodiment of the present invention includes a machine body, a boom swingably supported by the machine body, an arm swingably supported by the boom and the swinging body pivot mechanism provided as a pivotal junction of the boom and the arm.

[0015] A working machine according to an example embodiment of the present invention includes a machine body, a working device swingably supported by the machine body and the swinging body pivot mechanism provided as a pivotal junction of the machine body and the working device.

[0016] A working machine according to an example embodiment of the present invention includes a machine body, a working device supported by the machine body, a working tool swingably supported by the working device, and the swinging body pivot mechanism provided as a pivotal junction of the working device and the working tool.

[0017] The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0018] A more complete appreciation of example embodiments of the present invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings described below.

[0019] FIG. 1 illustrates a side view of a swiveling excavator (hereafter simply referred to as “working machine”)

[0020] FIG. 2 illustrates a side view of a swinging body pivot mechanism including a rotation stopper according to an example embodiment.

[0021] FIG. 3 illustrates a perspective view of the swinging body pivot mechanism.

[0022] FIG. 4A illustrates a side view of the swinging body pivot mechanism omitting a retainer therefrom.

[0023] FIG. 4B illustrates an enlarged side view of the swinging body pivot mechanism omitting a retainer therefrom.

[0024] FIG. 5 illustrates a perspective view of the swinging body pivot mechanism omitting a retainer therefrom.

[0025] FIG. 6A illustrates a side view of a swinging body pivot mechanism including a rotation stopper according to another example embodiment omitting a retainer therefrom.

[0026] FIG. 6B illustrates an enlarged side view of a swinging body pivot mechanism including a rotation stopper according to another example embodiment omitting a retainer therefrom.

[0027] FIG. 7 illustrates a perspective view of a swinging body pivot mechanism including a rotation stopper pin that is an alternative rotation stopper pin portion, including an exploded view of a portion of the swinging body pivot mechanism.DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

[0028] Example embodiments will now be described with reference to the accompanying drawings, wherein like reference numerals designate corresponding or identical elements throughout the various drawings. The drawings are to be viewed in an orientation in which the reference numerals are viewed correctly.

[0029] FIG. 1 illustrates a side view of a swiveling excavator (hereafter simply referred to as “working machine 1”). A schematic configuration of the working machine 1 will now be described using FIG. 1. In the present example embodiment, a direction indicated by an arrow A1 in FIG. 1 is called “front direction”, a direction indicated by an arrow A2 is called “rear direction”, one direction perpendicular to the arrows A1 and A2 and toward a viewer in front of a sheet of FIG. 1 is called “left” and another direction perpendicular to the arrows A1 and A2 and toward a side behind the sheet of FIG. 1 is called “right”.

[0030] The working machine 1 includes a traveling body 10, a machine body 20 and a working device 30. The machine body 20 is mounted on an upper portion of the traveling body 10 (specifically, on a later-discussed traveling frame 11) via a swiveling pivot (swiveling joint) including an axis Xv in an up-down direction indicated in FIG. 1, so that the machine body 20 can rotate (swivel) about the axis Xv in a horizontal direction relative to the traveling body 10 by a hydraulic swiveling motor (omitted from the illustrations).

[0031] The traveling body 10 includes a traveling frame 11 and a pair of left and right traveling devices 12, with hydraulic traveling devices (omitted from the illustrations) for driving the respective traveling devices 12. A dozer 13 is provided at a front portion of the traveling body 10. The dozer 13 includes a blade 13a provided forward of the pair of left and right traveling devices 12 and an actuator (hydraulic cylinder) and / or the like to swing the blade up and down.

[0032] A swing bracket 14 is supported by the machine body 20 via a swing pin (pivot) 14a including an axis in the up-down direction, and a swing cylinder (hydraulic actuator) omitted from FIG. 1 causes the entire working device 30 to rotate (swing) together with the swing bracket 14 in a horizontal direction relative to the machine body 20.

[0033] The working device 30 is swingably supported by the machine body 20 and a working tool (working attachment) is attached to the working device 30 and swingably supported thereby. In the present example embodiment, the working device 30 is a backhoe working device 30 that includes a boom 31 and an arm 32, and a bucket 33 is attached, as a working tool, to the working device 30.

[0034] In the working device 30, a proximal end of the arm 32 is pivotally supported by a distal end of the boom 31, and a proximal end of the boom 31 is pivotally supported by the swing bracket 14, so that the entire working device 30 is supported by the machine body 20 via the swing bracket 14. On the other hand, the bucket 33 defining a working tool is pivotally supported by a distal end of the arm 32 so as to be swingably supported by the working device 30.

[0035] The working device 30 includes a boom cylinder (hydraulic cylinder) 34, an arm cylinder (hydraulic cylinder) 35 and a bucket cylinder (hydraulic cylinder) 36 to drive the boom 31, arm 32 and bucket 33 included in the working device 30, respectively.

[0036] The following will briefly describe a basic configuration of the boom 31 illustrated in FIG. 1. The boom 31 illustrated in FIG. 1 includes a distal end section 31c, a proximal end section 31d, and a main section 31e provided between the distal end section 31c and the proximal end section 31d. The distal end section 31c, the proximal end section 31d and the main section 31e are originally separate members separated from each other, and the boom 31 is configured by joining the distal end section 31c and the proximal end section 31d to each other via the main section 31e. At least one of the distal end section 31c or the proximal end section 31d defines a component element of a swinging body pivot mechanism P as described later.

[0037] At least one of the distal end section 31c or the proximal end section 31d may be, for example, a single solid or hollow member entirely or partly molded integrally by casting or the like. Alternatively, at least one of the distal end section 31c or the proximal end section 31d may be configured by assembling a plurality of plates (steel plates or the like) together by welding or the like, or may be configured by bending a single plate (steel plate or the like) into a sectionally rectangular shape.

[0038] The main portion 31e may be configured by assembling a plurality of plates (steel plates or the like) together by welding or the like, may be configured by bending a single plate (steel plate or the like) into a sectionally rectangular shape, or may include a single member molded integrally by casting or the like. The boom 31 may be configured by joining one end of the main section 31e to the distal end section 31c, and another end of the main portion 31e to the proximal end section 31d by welding or the like.

[0039] At least one of the distal end section 31c or the proximal end section 31d may be further extended to replace the main section 31e so that the distal end section 31c and the proximal end section 31d may be directly connected to each other by welding or the like without the main section 31e therebetween. Moreover, the boom 31 may be configured from a single member including both the distal end thereof and the proximal end thereof.

[0040] The working device 30 includes at least one pivotal junction at which a first member and a second member are pivotally connected to each other, at least one of the first member or the second member being a swinging body. The backhoe type working device 30 according to the present example embodiment includes a first pivotal junction at which the distal end of the boom 31 and the proximal end of the arm 32 are pivotally connected to each other, a second pivotal junction at which the proximal end of the boom 31 of the working device 30 and the swing bracket 14 of the machine body 20 are pivotally connected to each other, and a third pivotal junction at which the distal end of the arm 32 and a bucket bracket 33a of the bucket 33 that is a working tool are pivotally connected to each other.

[0041] At least one of the first to third pivotal junctions includes the swinging body pivot mechanism P including a pivot shaft 2, the first member and the second member coupled to each other via the pivot shaft 2 swingably relative to each other, and a rotation stopper attached to the pivot shaft 2. That is, in the working machine 1, at least one of the first pivotal junction of the boom 31 and the arm 32, the second pivotal junction of the machine body 20 (swing bracket 14) and the working device 30 (boom 31), or the third pivotal junction of the working tool (bucket 33) and the working device 30 (arm 32) is configured as the swinging body pivot mechanism P.

[0042] As explained above, the swinging body pivot mechanism P includes the pivot shaft 2, the first member, the second member and the rotation stopper, and the swinging body pivot mechanism P is defined to include at least the following configuration. The first member includes a main body portion, a shaft hole provided in the main body portion to have the pivot shaft 2 inserted therethrough, and a rotation stopper pin portion provided in a vicinity of the shaft hole and protruding from the main body portion in a direction substantially parallel to an axis 2a of the pivot shaft 2. The rotation stopper includes a first end portion fixed to the pivot shaft and a second end portion with an insertion portion into which the rotation stopper pin portion is inserted. The insertion portion includes a first width between opposite ends thereof in a direction along a first straight line Dr (see FIG. 4B or FIG. 6B) that is an imaginary line which extends in a direction matching a radial direction of the pivot shaft 2 so as to pass through the first end portion and the second end portion and a second width between opposite ends thereof in a direction along a second straight line Dt (see FIG. 4B or FIG. 6B) that is an imaginary line which is perpendicular to the axis 2a of the pivot shaft 2 and the first straight line Dr. The first width is defined such as to allow the rotation stopper pin portion inserted in the insertion portion to change a position thereof in the direction along the first straight line Dr. The second width is equal to or more than a width of the rotation stopper pin portion in the direction along the second straight line Dt and is defined such that the rotation stopper and the rotation stopper pin portion are restricted from moving relative to each other in the direction along the second straight line Dt, the rotation stopper pin portion being inserted in the insertion portion and abutting the rotation stopper at at least one of the opposite ends of the insertion portion in the direction along the second straight line Dt.

[0043] In a case where the swinging body pivot mechanism P is provided as the first pivotal junction of the boom 31 and the arm 32, the swinging body pivot mechanism P is referred to as a “first swinging body pivot mechanism P1”. In a case where the swinging body pivot mechanism P is provided as the second pivotal junction of the boom 31 and the machine body (swing bracket 14), the swinging body pivot mechanism P is referred to as a “second swinging body pivot mechanism P2”. In a case where the swinging body pivot mechanism P is provided as the third pivotal junction to couple the working tool (bucket 33) and the arm 32 as the first member and the second member, the swinging body pivot mechanism P is referred to as a “first swinging body pivot mechanism P3”.

[0044] As shown in FIG. 1, the first swinging body pivot mechanism P1 includes the boom 31, which defines the first member as one swinging body, and the arm 32, which defines the second member as another swinging body, coupled together via the pivot shaft 2. That is, the distal end section 31c of the boom 31 corresponds to the main body portion of the first member, a shaft hole 31a to have the pivot shaft 2 inserted therethrough is provided in the distal end section 31c, and a rotation stopper pin portion 31b to be inserted into the insertion portion of a rotation stopper plate 3 (rotation stopper) is provided on the distal end section 31c.

[0045] Alternatively, the boom 31 may define the second member and the arm 32 may define the first member. In such a case, a proximal end portion of the arm 32 corresponds to the main body portion of the first member, the shaft hole to have the pivot shaft 2 inserted therethrough is provided in the proximal end portion of the arm 32, and the rotation stopper pin portion to be inserted into the insertion portion of the rotation stopper is provided on the proximal end portion of the arm 32.

[0046] As shown in FIG. 1, the second swinging body pivot mechanism P2 includes the boom 31 of the working device 30 defining the first member of the swinging body and the swing bracket 14 of the machine body 20 defining the second member of the swinging body coupled together via the pivot shaft 2. That is, the proximal end section 31d of the boom 31 corresponds to the main body portion of the first member, the shaft hole to have the pivot shaft 2 inserted therethrough is provided in the proximal end section 31d, and the rotation stopper pin portion to be inserted into the insertion portion of the rotation stopper plate 3 is provided on the proximal end section 31d.

[0047] Alternatively, the boom 31 of the working device 30 may define the second member, and the swing bracket 14 of the machine body 20 may define the first member. In such a case, an upper portion or the like of the swing bracket 14 corresponds to the main body portion of the first member, the shaft hole to have the pivot shaft 2 inserted therethrough is provided in the upper portion or the like of the swing bracket 14, and the rotation stopper pin portion to be inserted into the insertion portion of the rotation stopper is provided on the upper portion or the like of the swing bracket 14.

[0048] As shown in FIG. 1, the third swinging body pivot mechanism P3 includes the bucket 33 that is a working tool defining the first member and the arm 32 of the working device 30 defining the second member coupled together via the pivot shaft 2. That is, the bucket bracket 33a of the bucket 33 corresponds to the main body portion of the first member, the shaft hole to have the pivot shaft 2 inserted therethrough is provided in the bucket bracket 33a, and the rotation stopper pin portion to be inserted into the insertion portion of the rotation stopper plate 3 is provided on the bucket bracket 33a.

[0049] Alternatively, the arm 32 of the working device 30 may define the first member and the bucket 33 that is a working tool may define the second member. In such a case, a distal end portion of the arm 32 corresponds to the main body portion of the first member, the shaft hole to have the pivot shaft 2 inserted therethrough is provided in the distal end portion of the arm 32, and the rotation stopper pin portion to be inserted into the insertion portion of the rotation stopper is provided on the distal end portion of the arm 32.

[0050] In the present example embodiment, the working machine 1 includes all the first to third swinging body pivot mechanisms P1 to P3. Alternatively, the working machine 1 may include only one or two of the first to third swinging body pivot mechanisms P1 to P3 (that is, one or two of the first to third pivotal junctions each may be provided with the swinging body pivot mechanism P).

[0051] Working machines each of which can use one or more swinging body pivot mechanisms P include not only excavators (backhoes) as shown in FIG. 1 but also various kinds of working machines each of which includes one or more swinging bodies. For example, one or more swinging body pivot mechanisms P are applicable to at least one of skid steer loaders, truck loaders or the like each of which includes a working device that includes at least one swinging body, such as a boom, to which a working tool can be swingably attached.

[0052] Working tools each of which can use the swinging body pivot mechanism P (that is, the third swinging body pivot mechanism P3) are not limited to buckets including the bucket 33 as shown in FIG. 1. The swinging body pivot mechanism P (third swing body pivot mechanism P3) is broadly applicable to working tools, each of which can be swingably attached to a working device of a working machine. For example, such working tools each of which is to be swingably attached to a working device of a working machine include breakers, earth drills and the like each of which includes a hydraulic actuator that is to be fluidly connected to a hydraulic pressure take-off (AUX) port of a working machine such as an excavator (backhoe) when the working tool is attached to a working device of the working machine.

[0053] A specific configuration of the swinging body pivot mechanism P1 as a representative example of the swinging body pivot mechanism P will now be described with reference to FIGS. 2 to 5. FIG. 2 illustrates a side view of the swinging body pivot mechanism P1 (P) including a rotation stopper (rotation stopper plate 3) according to an example embodiment. FIG. 3 illustrates a perspective view of the swinging body pivot mechanism P1 (P). FIG. 4A illustrates a side view of the swinging body pivot mechanism P1 (P) omitting a retainer (retainer plate 5) therefrom. FIG. 4B illustrates an enlarged side view of the swinging body pivot mechanism P1 (P) omitting a retainer (retainer plate 5) therefrom. FIG. 5 illustrates a perspective view of the swinging body pivot mechanism P1 (P) omitting a retainer (retainer plate 5) therefrom.

[0054] In the swinging body pivot mechanism P1 (P), the boom 31 corresponding to the first member includes the main body portion 31c, the shaft hole 31a provided in the main body portion 31c to have the pivot shaft 2 inserted therethrough, and the rotation stopper pin portion 31b provided in the vicinity of the shaft hole 31a and protruding from the main body portion 31c in a direction substantially parallel to the axis 2a of the pivot shaft 2.

[0055] The rotation stopper plate 3 as an exemplary rotation stopper includes a first end portion 3b fixed to the pivot shaft 2 and a second end portion 3d provided thereon with a notch 3e as an exemplary insertion portion into which the rotation stopper pin portion 31b is inserted. Referring to FIG. 4B, the notch 3e defining the exemplary insertion portion includes a first width Wr between opposite ends 3e1 and 3e2 thereof in the direction along the first straight line Dr that is an imaginary line which extends in a direction matching a radial direction of the pivot shaft 2 so as to pass through the first end portion 3b and the second end portion 3d, and a second width Wt between opposite ends 3e3 and 3e 4 thereof in the direction along the second straight line Dt that is an imaginary line which is perpendicular to the axis 2a of the pivot shaft 2 and the first straight line Dr.

[0056] In the notch 3e, the first width Wr is defined such as to allow the rotation stopper pin portion 31b inserted in the notch 3e to change a position thereof in the direction along the first straight line Dr. The second width Wt is equal to or more than a width of the rotation stopper pin portion 31b in the direction along the second straight line Dt and is defined such that the rotation stopper plate 3 is restricted from moving relative to the rotation stopper pin portion 31b in the direction along the second straight line Dt, the rotation stopper pin portion 31b being inserted in the insertion portion 3e and abutting the rotation stopper plate 3 at at least one of the opposite ends 3e3 and 3e4 of the notch 3e in the direction along the second straight line Dt.

[0057] The above-mentioned swinging body pivot mechanism P1 will now be described in greater detail. In the swinging body pivot mechanism P1 for the first pivotal junction of the boom 31 and the arm 32, the distal end section 31c of the boom 31 corresponds to the main body portion of the first member of the swinging body pivot mechanism P1. That is, the distal end section 31c of the boom 31 corresponding to the main body portion includes the shaft hole 31a and the rotation stopper pin portion 31b.

[0058] Thus, the distal end section 31c includes one or more members whose sizes (lengths and widths) and strengths are defined such as to allow the distal end section 31c to include the shaft hole 31a and the rotation stopper pin portion 31b. For example, as previously described, the distal end section 31c may be molded integrally by casting or may include one or more plates (steel plates or the like) assembled together by welding, formed by bending or the like.

[0059] The shaft hole 31a may be integrally included in the distal end section 31c molded by casting, or may perforate a solid member by drilling or the like. The rotation stopper pin portion 31b may be integrally included in the distal end section 31c molded by casting, or may be included in a member that is originally separate from the distal end section 31c and is fixed (joined) to the distal end section 31c by welding or the like.

[0060] With the rotation stopper pin portion 31b integrated with the distal end section 31c of the boom 31 (the main body portion of the first member) by casting, welding or the like, even when a force is applied on the rotation stopper pin portion 31b from the pivot shaft 2 via the rotation stopper plate 3, the rotation stopper pin portion 31b has a rigidity that prevents the rotation stopper pin portion 31b from detaching or deviating from the boom 31.

[0061] Alternatively, the rotation stopper pin portion may be a member separate from the main body portion of the first member such as the distal end section 31c of the boom 31 and may be fastened to the main body portion of the first member via a fastener such as a bolt. FIG. 7 illustrates an alternative swinging body pivot mechanism P1 (P) including a rotation stopper pin 6 that is an exemplary rotation stopper pin portion separate from the main body portion, as described later.

[0062] The shaft hole 31a extends axially horizontally, and one axial end of the shaft hole 31a is open at a side surface of the distal end section 31c of the boom 31 (the main body portion of the first member of the swinging body pivot mechanism P). The pivot shaft 2 including the horizontal axis 2a is inserted into the shaft hole 31a. The rotation stopper plate 3 is an example of the rotation stopper 3. A portion of the rotation stopper plate 3 close to a proximal end (first end) 3a thereof is fixed in a flange-like manner to one axial end of the pivot shaft 2 protruding outward from the open axial end of the shaft hole 31a. A portion of the rotation stopper plate 3 that includes the proximal end (first end) 3a and encircles the pivot shaft 2 in the flange-like manner is referred to as a first end portion 3b.

[0063] The pivot shaft 2 and the rotation stopper plate 3 (first end portion 3b) may be joined to each other by welding or may be molded integrally with each other by casting. That is, the pivot shaft 2 and the rotation stopper plate 3 may be fixed together in any way only if the condition in which they are fixed together without rotating relative to each other can be maintained even when a force is applied in a rotational direction about the axis of the pivot shaft 2.

[0064] The rotation stopper pin portion 31b in a boss-like shape protrudes in a horizontal direction from an outer side surface of the distal end section 31c of the boom 31 in the proximity of the shaft hole 31a. The rotation stopper plate 3 extends in a radial direction of the pivot shaft 2 from the proximal end (first end) 3a to a distal end (second end) 3c placed close to the rotation stopper pin portion 31b and spreads in parallel to the outer side surface of the distal end section 31c of the boom 31.

[0065] A portion of the rotation stopper plate 3 close to the distal end 3c includes an insertion portion into which the rotation stopper pin portion 31b is inserted. In the present example embodiment, the notch 3e which is open at the distal end 3c is provided as the insertion portion. A portion of the rotation stopper plate 3 that includes the distal end (second end) 3c and defines the notch 3e is referred to as the second end portion 3d. That is, in the rotation stopper plate 3 according to the present example embodiment, the second end portion 3d includes the distal end (second end) 3c as an utmost end thereof and bifurcates along the notch 3e.

[0066] This type of rotation stopper plate 3 includes the notch 3e and the second end portion 3d (including the distal end 3c) surrounding the notch 3e such that, when a distance on the boom 31 between the shaft hole 31a and the rotation stopper pin portion 31b (hereinafter, this distance may be referred to as “specific distance”) is equal to a reference value (average or the like), the rotation stopper pin portion 31b is positioned at a proximity of an open end (that is a later-discussed “second end 3e2”) of the notch 3e. This configuration reduces a length of the rotation stopper plate 3 between the proximal end 3a and the distal end 3c so as to contribute to reducing costs and weights of corresponding component parts.

[0067] A configuration of the notch 3e as the insertion portion according to the present example embodiment will now be described with reference to FIG. 4B. In the side view of the boom 31 in FIG. 4B, the first straight line Dr is drawn as an imaginary line which passes through the axis 2a of the pivot shaft 2 (that is, matching the radial direction of the pivot shaft 2) and extends so as to pass through the first end portion 3b (including the portion joined to the axial end of the pivot shaft 2) and the second end portion 3d (including the notch 3e as the insertion portion), and the second straight line Dt is drawn as an imaginary line which extends perpendicularly to the first straight line Dr and the axis 2a of the pivot shaft 2.

[0068] That is, the first straight line Dr is a straight line extending in the radial direction of the pivot shaft 2 and the second straight line Dt is a straight line extending in a tangential direction at an intersection of an outer periphery of the pivot shaft 2 and a diameter of the pivot shaft 2 extending in the direction along the first straight line Dr. Accordingly, the direction along the second straight line Dt substantially matches a rotation direction centered on the axis 2a of the pivot shaft 2.

[0069] The notch 3e provided as the insertion portion into which the rotation stopper pin portion 31b is inserted needs to have, in the direction along the first straight line Dr, sufficient room such as to absorb a dimension error in the specific distance on the distal end section 31c of the boom 31 between the shaft hole 31a (through which the pivot shaft 2 is passed) and the rotation stopper pin portion 31b on the distal end section 31c, and needs to have, in the direction along the second straight line Dt, a restrictive dimension such as to restrict the rotation stopper plate 3 (that is integral with the pivot shaft 2) and the rotation stopper pin portion 31b (that is integral with the boom 31) from rotating relative to each other about the axis 2a of the pivot shaft 2.

[0070] Regarding the rotation stopper plate 3 according to the present example embodiment, the notch 3e defining the insertion portion into which the rotation stopper pin portion 31b is inserted includes a first end 3e1 on the first end 3a side and a second end 3e2 on the second end 3c side as opposite ends in the direction along the first straight line Dr, and includes the first width Wr between the opposite ends 3e1 and 3e2 in the direction along the first straight line Dr.

[0071] The second end 3e2 of the notch 3e corresponding to the second end 3c (utmost end of the second end portion 3d) of the rotation stopper plate 3 is an open end. That is, the rotation stopper pin portion 31b to be inserted in the notch 3e defining the insertion portion may abut the rotation stopper plate 3 at the first end 3e1 of the notch 3e, whereas the rotation stopper pin portion 31b cannot abut the rotation stopper plate 3 at the second end 3e2 of the notch 3e but is allowed to enter and leave, via the second end 3e2, the notch 3e defining the insertion portion.

[0072] On the other hand, the notch 3e includes a third end 3e3 and a fourth end 3e4 as opposite ends in the direction along the second straight line Dt, and includes a second width Wt in the direction along the second straight line Dt between the opposite ends 3e3 and 3e4. The second width Wt is equal to or more than a width Wp of the rotation stopper pin portion 31b in the direction along the second straight line Dt as a minimum required to allow the rotation stopper portion 31b to enter the notch 3e, and is defined such that the rotation stopper plate 3 (that is integral with the pivot shaft 2) and the rotation stopper pin portion 31b (that is integral with the boom 31) are restricted from moving relative to each other in the direction along the second straight line Dt (rotation direction centered on the axis 2a of the pivot shaft 2) while the rotation stopper pin portion 31b inserted in the notch 3e abuts the rotation stopper plate 3 at at least one of the opposite ends 3e3 and 3e4 of the notch 3e in the direction along the second straight line Dt.

[0073] Thus, the boom 31 that is integral with the rotation stopper pin portion 31b inserted in the notch 3e is stopped (restricted) by the rotation stopper plate 3 from rotating relative to the pivot shaft 2.

[0074] In the case where the second width Wt is defined to be substantially the same as the width Wp of the rotation stopper portion 31b in the direction along the second straight line Dt (if the rotation stopper pin portion 31b is configured to have a uniform diameter, substantially the same as the diameter (outer diameter) of the rotation stopper pin portion 31b) that is the minimum width required for the second width Wt to allow the rotation stopper pin portion 31b to be inserted into the notch 3e, it is possible to most tightly restrict the rotation stopper plate 3 and the rotation stopper pin portion 31b from rotating relative to each other in the direction along the second straight line Dt. That is, in such a case, the rotation stopper pin portion 31b abuts the rotation stopper plate 3 at both the opposite ends 3e3 and 3e4 of the notch 3e in the direction along the second straight line Dt, so that the notch 3e has no room to allow the rotation stopper pin portion 31b to move relative to the rotation stopper plate 3 in the rotation direction of the pivot shaft 2 that substantially matches the direction along the second straight line Dt. Accordingly, regardless of in which of opposite rotation directions the boom 31 and the arm 32 rotate relative to each other, the boom 31 and the pivot shaft 2 are constantly integral with each other rotatably about the axis 2a of the pivot shaft 2 without rotating relative to each other.

[0075] If the second width Wt is defined to be slightly larger than the width Wp of the rotation stopper pin portion 31b in the direction along the second straight line Dt, the notch 3e has some room (play) in which the rotation stopper pin portion 31b is allowed to move relative to the rotation stopper plate 3 (pivot shaft 2) in the direction along the second straight line Dt. As the rotation stopper pin portion 31b rotates relative to the rotation stopper plate 3 (pivot shaft 2) by this room, the rotation stopper pin portion 31b abuts the rotation stopper plate 3 at one of the opposite ends 3e3 and 3e4 of the notch 3e in the direction along the second straight line Dt so that the boom 31 and the pivot shaft 2 (integral with the rotation stopper plate 3) are restricted from rotating relative to each other.

[0076] On the other hand, the first width Wr between the opposite ends 3e1 and 3e2 of the notch 3e in the direction along the first straight line Dr is defined such as to allow the rotation stopper pin portion 31b to change a position thereof in the direction along the first straight line Dr inside the notch 3e. That is, there is enough room (play) to change a position of the rotation stopper pin portion 31b in the direction along the first straight line Dr inside the notch 3e defining the insertion portion.

[0077] With this configuration, even if there is a dimension error in the specific distance on the distal end section 31c of the boom 31 between the shaft hole 31a and the rotation stopper pin portion 31b, the rotation stopper pin portion 31b can as well be inserted into the notch 3e as be inserted thereinto by adjusting the position of the rotation stopper pin rotation 31b the direction along the first straight line Dr.

[0078] For example, in a case where the specific distance on the distal end section 31c of the boom 31 between the shaft hole 31a and the rotation stopper pin portion 31b is shorter than a reference value (average or the like), the rotation stopper pin portion 31b is allowed to be inserted into the notch 3e at a position closer to the first end 3e1 that is an innermost end of the notch 3e than a position at which the rotation stopper pin portion 31b is allowed to be inserted into the notch 3e when the specific distance is equal to the reference value.

[0079] On the other hand, in a case where the specific distance on the distal end section 31c of the boom 31 between the shaft hole 31a and the rotation stopper pin portion 31b is longer than the reference value (average or the like), a portion of the rotation stopper pin portion 31b opposite to the first end (closed end) 3e1 of the notch 3e in the direction along the first straight line Dr is located outward from the second end (open end) 3e2 of the notch 3e, and only the remaining portion of the rotation stopper pin portion 31b toward the first end 3e1 in the direction along the first straight line Dr is allowed to be inserted into the notch 3e.

[0080] As mentioned above, even if the distal end section 31c of the boom 31 has some dimension error in the specific distance in the direction along the first straight line Dr between the shaft hole 31a and the rotation stopper pin portion 31b, the rotation stopper pin portion 31b can be surely inserted into the notch 3e defining the insertion portion of the rotation stopper plate 3, so that the distal end section 31c of the boom 31 is restricted by the rotation stopper plate 3 from rotating relative to the pivot shaft 2 in the direction along the second straight line Dt.

[0081] The rotation stopper plate 3 illustrated in FIGS. 2 to 5 uses the notch 3e that defines the insertion portion into which the rotation stopper pin portion 31b is inserted and that includes the open end (second end) 3e2 corresponding to the distal end 3c of the rotation stopper plate 3 (utmost end of the second end portion 3d). Therefore, if there may be a dimension error in the specific distance on the distal end section 31c of the boom 31 between the shaft hole 31a and the rotation stopper pin portion 31b that is either the specific distance abnormally long to be larger than the reference value (average or the like) (hereinafter the dimension error of the specific distance abnormally long to be larger than the reference value may be referred to as “long distance error”) or the specific distance abnormally short to be smaller than the reference value (average or the like) (hereinafter, the dimension error of the specific distance abnormally short to be smaller than the reference value may be referred to as “short distance error”), the long distance error can be overcome by shifting the position of the rotation stopper pin portion 31b relative to the rotation stopper plate 3 further outward of the open end 3e2 of the notch 3e (in the direction away from the pivot shaft 2).

[0082] Accordingly, in the situation where there may be a dimension error in the specific distance on the boom 31 that is either the long distance error or the short distance error, only the short distance error needs to be taken into account when the first width Wr of the notch 3e in the direction along the first straight line Dr is determined. Thus, processes to form the notch (insertion portion) 3e in the rotation stopper plate (rotation stopper) 3 can be simplified.

[0083] Incidentally, regarding the above-mentioned swinging body pivot mechanism P, it is possible that, when the pivot shaft 2 unexpectedly moves inside the shaft hole 31a in the direction of the axis 2a, the rotation stopper plate 3 moves integrally with the pivot shaft 2 in the direction of the axis 2a and disengages from the rotation stopper pin portion 31b that has been inserted into the notch 3e. In order to prevent the rotation stopper plate 3 from disengaging from the rotation stopper pin portion 31b, the swinging body pivot mechanism P includes a retainer plate 5 and / or the like.

[0084] In this regard, as shown in FIGS. 4A, 4B and 5, a threaded hole 31b1 is provided in the rotation stopper pin portion 31b. As shown in FIGS. 2 and 3, a bolt 4 defining a fastener is screwed into the threaded hole 31b1. The bolt 4 is passed through a center hole of the discoid retainer plate 5 and screwed into the threaded hole 31b1 (see FIG. 7). Thus, the flange-like retainer plate 5 is held between a head of the bolt 4 screwed into the threaded hole 31b1 and one side end surface (end) of the rotation stopper pin portion 31b.

[0085] By providing the retainer plate 5 fastened to the rotation stopper pin portion 31b via a fastener such as the bolt 4 at a position where the retainer plate 5 adjoins or abuts the rotation stopper plate 3, the rotation stopper plate 3 is restricted from moving in the direction of the axis 2a of the pivot shaft 2 and is prevented from disengaging from the rotation stopper pin portion 31b. In this way, the retainer plate 5 functions as a retainer to restrict the movement of the rotation stopper plate 3 in the direction of the axis 2 of the pivot shaft 2.

[0086] The discoid retainer plate 5 shown in FIGS. 2, 3 and the like is an exemplary retainer. The retainer need only be configured to restrict a movement of a rotation stopper in the direction of the axis 2a of the pivot shaft 2, and is not limited in shape, material and / or the like as long as the retainer includes the required configuration. The fastener is not limited to the bolt 4 and may be a screw or the like.

[0087] Instead of the rotation stopper plate 3 including the notch 3e defining the insertion portion as shown in FIGS. 2 to 5, an alternative rotation stopper plate 3X including a slot 3h defining the insertion portion as shown in FIGS. 6A and 6B may be used as a rotation stopper to connect the pivot shaft 2 and the rotation stopper pin portion 31b.

[0088] FIG. 6A illustrates a side view of the swinging body pivot mechanism P1 (P) including a rotation stopper (rotation stopper plate 3X) according to an alternative example embodiment. FIG. 6B illustrates an enlarged side view of the swinging body pivot mechanism P1 (P) including the rotation stopper (rotation stopper plate 3X) according to the alternative example embodiment.

[0089] The rotation stopper plate 3X of FIGS. 6A and 6B will now be described. The rotation stopper plate 3X includes a proximal end (first end) 3a and a first end portion 3b in common with the rotation stopper plate 3. The first end portion 3b encircles the axial end of the pivot shaft 2 and is fixed to the axial end of the pivot shaft 2.

[0090] In comparison to the notch 3e defining the insertion portion of the rotation stopper plate 3, the slot 3h defining the insertion portion of the rotation stopper plate 3X is closed by a distal end (second end) 3f of the rotation stopper plate 3X opposed to the proximal end 3a. That is, a second end portion 3g of the rotation stopper plate 3X including the distal end 3f and opposed to the first end portion 3b entirely encloses (closes) the slot 3h.

[0091] With the explanation of the foregoing swinging body pivot mechanism P, a configuration of the slot 3h as the insertion portion of the rotation stopper plate 3X shown in FIGS. 6A and 6B is defined as follows. Referring to FIG. 6B, the slot 3h as the exemplary insertion portion includes a first width Wrx between opposite ends 3h1 and 3h2 thereof in the direction along the first straight line Dr that is an imaginary line which extends in a direction matching a radial direction of the pivot shaft 2 so as to pass through the first end portion 3b and the second end portion 3g, and a second width Wtx between opposite ends 3h3 and 3h4 thereof in the direction along the second straight line Dt that is an imaginary line which is perpendicular to the axis 2a of the pivot shaft 2 and the first straight line Dr.

[0092] The slot 3h is a long hole closed at the opposite ends 3h1 and 3h2 thereof in the direction along the first straight line Dr and extending lengthwise in the direction along the first straight line Dr (radial direction of the pivot shaft 2). That is, the first width Wrx is larger than the second width Wtx and is defined such as to allow the rotation stopper pin portion 31b inserted in the slot 3h to change a position thereof in the direction along the first straight line Dr.

[0093] The second width Wtx is defined such as to allow the rotation stopper pin portion 31b to be inserted in the slot 3h, and to restrict the rotation stopper pin portion 31b inserted in the slot 3h from moving in the direction along the second straight line Dt relative to the rotation stopper plate 3 while the rotation stopper pin portion 31b inserted in the slot 3h abuts the rotation stopper plate 3 at at least one of the opposite ends 3h3 and 3h4 in the direction along the second straight line Dt.

[0094] In particular, the slot 3h of the rotation stopper plate 3X is configured in position and size (first width Wrx) thereof in the direction along the first straight line Dr such that, when the specific distance on the boom 31 (distance between the shaft hole 31a and the rotation stopper pin portion 31b) is equal to the reference value (average or the like), the rotation stopper pin portion 31b is at a substantially middle point between the opposite ends 3h1 and 3h2.

[0095] That is, the first width Wrx of the slot 3h in the direction along the first straight line Dr (radial direction of the pivot shaft 2) is determined in consideration of both the long distance error and the short distance error that may occur in the specific distance. Therefore, regardless of whether there is the long distance error or the short distance error as a dimension error in the specific distance, the dimension error can be overcome by adjusting, in the slot 3h, the position of the rotation stopper pin portion 31b relative to the rotation stopper plate 3X in the direction along the first straight line Dr.

[0096] Specifically, the rotation stopper plate 3X according to the present example embodiment is configured to include the slot 3h with the second width Wtx in the direction along the second straight line Dt such as to allow the rotation stopper pin portion 31b to be inserted in the slot 3h regardless of whether there is the short distance error that is the specific distance abnormally short to be smaller than the reference value or the long distance error that is the specific distance abnormally long to be larger than the reference value. Thus, even if there is either the short distance error or the long distance error as a dimension error in the specific distance, the rotation stopper plate 3 (second end portion 3g of the rotation stopper plate 3X at the opposite sides of the slot 3h in the direction along the second straight line Dt) effectively affects the rotation stopper portion 31b at the opposite ends 3h3 and 3h4 of the slot 3h with a sufficient rotation stopper force (force to restrict the pivot shaft 2 and the boom 31 from rotating relative to each other).

[0097] Regarding the rotation stopper plate 3 according to the previous example embodiment, even if there is a dimension error in the specific distance referred to as the short distance error, the rotation stopper pin portion 31b having the short distance error is allowed to be inserted into the notch 3e including the second width Wt in the direction along the second straight line Dt so as to receive, at the opposite ends 3e3 and 3e4 of the notch 3e, a sufficient rotation stopper force from the rotation stopper plate 3 (to restrict the pivot shaft 2 and the boom 31 from rotating relative to each other). On the other hand, if there is a dimension error in the specific distance referred to as the long distance error, a portion of the rotation stopper pin portion 31b having the long distance error may protrude outward from the open end (second end) 3e2 of the notch 3e (only the remaining portion thereof may be inserted into the notch 3e). Thus, the rotation stopper plate 3 may insufficiently affect the rotation stopper pin portion 31b at the opposite ends 3e3 and 3e4 of the notch 3e in the direction along the second straight line Dt with a reduced rotation stopper force (force to restrict the pivot shaft 2 and the boom 31 from rotating relative to each other) compared to a case where the rotation stopper pin portion 31b having the short distance error is inserted into the notch 3e.

[0098] However, such a problem of the rotation stopper plate 3 can be eliminated, for example, by increasing the first width Wr of the notch 3e in the direction along the first straight line Dr such as to allow the rotation stopper pin portion 31b, even if having the dimension error in the specific distance referred to as the long distance error, to be inserted into the notch 3e including the second width Wt in the direction along the second straight line Dt.

[0099] FIGS. 6A and 6B each omit the retainer plate 5 from the rotation stopper pin portion 31b illustrated therein (FIG. 6B further omits the bolt 4). However, similar to the previous example embodiment (see FIGS. 2 and 3), the restriction of the rotation stopper plate 3X from moving in the direction of the axis 2a of the pivot shaft 2 may be achieved by screwing the bolt 4 passed through the retainer plate 5 into the threaded hole 31b1 of the rotation stopper pin portion 31b, and providing the retainer plate 5 held between the head of the bolt 4 and the end surface of the rotation stopper pin portion 31b at a position where the retainer plate 5 adjoins or abuts the rotation stopper plate 3X.

[0100] An alternative swinging body pivot mechanism P1 illustrated in FIG. 7 according to an alternative example embodiment will now be described. FIG. 7 illustrates a perspective view of a first swinging body pivot mechanism P1 (as a representative swinging body pivot mechanism P) including a rotation stopper pin 6 that is a rotation stopper pin portion according to an alternative example embodiment, and an exploded view of a portion of the first swinging body pivot mechanism P1.

[0101] As previously mentioned, an exemplary rotation stopper pin portion of the swinging body pivot mechanism P may include a separable component member separate from the main body portion of the first member (the distal end section 31c of the boom 31 in the present example embodiment) that is an exemplary swinging body, and the separable component member may be fastened to the main body portion of the first member via a fastener. The alternative swinging body pivot mechanism P1 (swinging body pivot mechanism P) illustrated in FIG. 7 includes the rotation stopper pin 6 as such an exemplary rotation stopper pin portion.

[0102] The rotation stopper pin 6 defining the rotation stopper pin portion (rotation stopper pin portion 31b of the boom 31 or the like) of the swinging body pivot mechanism P is a cylindrical pin separate from the main body portion (distal end section 31c of the boom 31 or the like).

[0103] The cylindrical rotation stopper pin 6 includes a through-hole defined by an inner peripheral portion thereof that surrounds an axis thereof, and an inner peripheral surface thereof facing the through-hole is not a smooth surface but a female screw formed with a screw thread. That is, the through-hole is configured as a threaded hole 6a. Thus, the rotation stopper pin 6 includes the inner peripheral portion defining, the threaded hole 6a extending in a protruding direction in which the rotation stopper pin portion protrudes substantially parallel to the axis 2a of the pivot shaft 2.

[0104] The distal end section 31c of the boom 31 defining the main body portion of the first member includes a threaded hole 31f open at a side surface thereof to correspond to the threaded hole 6a. The rotation stopper pin 6 is axially extended substantially parallel to the axis 2a of the pivot shaft 2, is inserted through the insertion portion (notch 3e in the present example embodiment) of the rotation stopper plate 3, and is caused to abut the side surface of the distal end section 31c of the boom 31 so that the threaded hole 6a and the threaded hole 31f in (the distal end section 31c of) the boom 31 are joined coaxially to each other, and the position of the rotation stopper pin 6 relative to the distal end section 31c of the boom 31 is secured.

[0105] The bolt 4 defining a fastener is screwed into the threaded hole 6a of the rotation stopper pin 6 positioned in the above-mentioned way, and into the threaded hole 31f coaxial to the threaded hole 6a. With the bolt 4 screwed into the threaded hole 31f in the distal end section 31c, the rotation stopper pin 6 held between the head of the bolt 4 and the side surface of the distal end section 31c is fastened to the distal end section 31c of the boom 31.

[0106] Inside the threaded hole 6a of the rotation pin 6, a screw thread of the bolt 4 and a screw thread on the inner peripheral surface of the threaded hole 6a are screwed together. Accordingly, the rotation stopper pin 6 and the boom 31 are integrated together via the bolt 4. That is, the rotation stopper pin 6 whose inner peripheral portion defines the threaded hole 6a is screwed together with the bolt 4 passed through the threaded hole 6 so that the rotation stopper pin 6 can hardly move (in the axial direction thereof and the peripheral direction thereof) relative to the bolt 4 compared to a case where the rotation stopper pin 6 is configured as a simple boss whose inner peripheral surface is a smooth surface.

[0107] In this way, the bolt 4 defining the fastener restricts the rotation stopper pin 6 defining a pin separate from the main body portion of the first member from moving (from being separated and removed from the distal end section 31c) in the protruding direction in which the rotation stopper pin 6 projects as the rotation stopper pin portion (in the direction substantially parallel to the axis 2a of the pivot shaft 2).

[0108] Further, as shown in FIG. 7, and similar to the previous example embodiment shown in FIGS. 2 and 3, the restriction of movement of the rotation stopper plate 3 (3X) in the direction of the axis 2a of the pivot shaft 2 may be achieved by screwing the bolt 4 passed through the retainer plate 5 into the rotation stopper pin 6, and providing the retainer plate 5 held between the head of the bolt 4 and the end surface of the rotation stopper pin 6 at a position where the retainer plate 5 adjoins or abuts the rotation stopper plate 3 (or 3X).

[0109] The following describes some configurations (items) of the swinging body pivot mechanism P and the working machine 1 including the swinging body pivot mechanism P and effects and / or the like thereof.

[0110] (Item 1) A swinging body pivot mechanism P including: a pivot shaft 2; a first member 31 and a second member 32 coupled to each other via the pivot shaft 2 swingably relative to each other; and a rotation stopper 3 (3X) attached to the pivot shaft 2; wherein the first member 31 includes a main body portion 31c, a shaft hole 31a provided in the main body portion 31c to have the pivot shaft 2 inserted therethrough, and a rotation stopper pin portion 31b (6) provided in a vicinity of the shaft hole 31a and protruding from the main body portion 31c in a direction substantially parallel to an axis 2a of the pivot shaft 2; the rotation stopper 3 (3X) includes a first end portion 3b fixed to the pivot shaft 2, and a second end portion 3d (3g) with an insertion portion 3e (3h) into which the rotation stopper pin portion 31b (6) is inserted; the insertion portion 3e (3h) includes a first width Wr (Wrx) between opposite ends thereof in a direction along a first straight line Dr that is an imaginary line which extends in a direction matching a radial direction of the pivot shaft 2 so as to pass through the first end portion 3b and the second end portion 3d (3g), and a second width Wt (Wtx) between opposite ends 3e3 and 3e4 (3h3 and 3h4) thereof in a direction along a second straight line Dt that is an imaginary line which is perpendicular to the axis 2a of the pivot shaft 2 and the first straight line Dr; the first width Wr (Wrx) is defined such as to allow the rotation stopper pin portion 31b inserted in the insertion portion 3e (3h) to change a position thereof in the direction along the first straight line Dr; and the second width Wt (Wtx) is equal to or more than a width of the rotation stopper pin portion 31b (6) in the direction along the second straight line Dt and is defined such that the rotation stopper 3 (3X) and the rotation stopper pin portion 31b (6) are restricted from moving relative to each other in the direction along the second straight line Dt, the rotation stopper pin portion 31b (6) being inserted in the insertion portion 3e (3h) and abutting the rotation stopper 3 (3X) at at least one of the opposite ends 3e3 and 3e4 (3h3 and 3h4) of the insertion portion 3e(3h ) in the direction along the second straight line Dt.

[0111] With the swinging body pivot mechanism P of item 1, for example even if a positioning accuracy of the rotation stopper pin portion 31b (6) on the main body portion 31c of the first member 31 is not sufficient and there is a dimension error in a distance on the first member 31 between the shaft hole 31a and the rotation stopper pin portion 31b (6), the insertion portion 3e (3h) is configured to include the first width Wr (Wrx) between the opposite ends 3e1 and 3e2 (3h1 and 3h2) in the direction along the first straight line Dr substantially matching a radial direction of the pivot shaft 2 that is sufficient to allow the rotation stopper pin portion 31b (6) having the dimension error to be inserted into the insertion portion 3e (3h), so that the rotation stopper 3 (3X) can surely affect the rotation stopper portion 31b (6) inserted in the insertion portion 3e (3h) with a sufficient rotation stopper force at the at least one of the opposite ends 3e3 and 3e4 (3h3 and 3h4) of the insertion portion 3e (3h) in the direction along the second straight line Dt substantially matching the rotation direction of the pivot shaft 2 so as to restrict the first member 31 and the pivot shaft 2 from rotating relative to each other (or to stop the first member 31 from rotating relative to the pivot shaft 2).

[0112] (Item 2) The swinging body pivot mechanism P according to item 1, wherein the insertion portion 3e includes a notch 3e which is open at one end 3e2 of the opposite ends 3e1 and 3e2 thereof in the direction along the first straight line Dr that corresponds to an utmost end 3c of the second end portion 3d.

[0113] With the swinging body pivot mechanism P of item 2, the rotation stopper pin portion 31b can be surely inserted into the insertion portion 3e, and the rotation stopper 3 can surely affect the rotation stopper pin portion 31b with a sufficient rotation stopper force at the at least one of the opposite ends in the direction of the second width of the insertion portion 3e.

[0114] (Item 3) The swinging body pivot mechanism P according to item 1, wherein the insertion portion 3h includes a slot 3h closed at the opposite ends 3h1 and 3h2 thereof in the direction along the first straight line Dr and extending lengthwise in the direction along the first straight line Dr.

[0115] With the swinging body pivot mechanism P of item 3, the rotation stopper pin portion 31b can be surely inserted into the insertion portion 3h, and the rotation stopper 3 can surely affect the rotation stopper pin portion 31b with a sufficient rotation stopper force at the at least one of the opposite ends in the direction of the second width of the insertion portion 3h.

[0116] (Item 4) The swinging body pivot mechanism P according to any one of items 1 to 3, wherein the rotation stopper pin portion 31b is molded integrally with the main body portion 31c by casting.

[0117] With the swinging body pivot mechanism P of item 4, the insertion portion 3e (3h) of the rotation stopper 3 (3X) is configured to allow the rotation stopper pin portion 31b, even if having a dimension error in a distance on the first member 31 between the shaft hole 31a and the rotation stopper pin portion 31b that may be generated during casting, to be inserted therein, so that the rotation stopper 3 (3X) can connect the pivot shaft 2 and the rotation stopper pin portion 31b to each other and stop the first member 31 from rotating relative to the pivot shaft 2 (restrict the pivot shaft 2 and the first member 31 from rotating relative to each other) even if a positioning accuracy of the rotation stopper pin portion 31b on the main body portion 31c of the first member 31 is not sufficient.

[0118] (Item 5) The swinging body pivot mechanism P according to any one of items 1 to 3, wherein the rotation stopper pin portion 31b is integrated with the main body portion 31c by welding.

[0119] With the swinging body pivot mechanism P of item 5, the insertion portion 3e (3h) of the rotation stopper 3 (3X) is configured to allow the rotation stopper portion 31b, even with a dimension error in a distance on the first member 31 between the shaft hole 31a and the rotation stopper pin portion 31b that may be generated because of imprecision in positioning thereof for welding, to be inserted therein, so that the rotation stopper 3 (3X) can connect the pivot shaft 2 and the rotation stopper pin portion 31b to each other and stop the first member 31 from rotating relative to the pivot shaft 2 (restrict the pivot shaft 2 and the first member 31 from rotating relative to each other) even if a positioning accuracy of the rotation stopper pin portion 31b on the main body portion 31c of the first member 31 is not sufficient.

[0120] (Item 6) The swinging body pivot mechanism P according to any one of items 1 to 3,further including a pin 6 defining the rotation stopper pin portion 31b that is a cylindrical member separated from the main body portion 31c, the pin 6 including a threaded hole 6a defined by an inner peripheral portion thereof that extends in a protruding direction in which the rotation stopper pin portion 31b protrudes substantially parallel to the axis 2a of the pivot shaft 2; and a fastener 4 to fasten the pin 6 to the main body portion 31c; wherein the fastener 4 is screwed with the pin 6 inside of the threaded hole 6a to restrict the pin 6 from moving in the protruding direction.

[0121] With the swinging body pivot mechanism P of item 6, the pin 6 separate from the main body portion 31c of the first member 31 defines the rotation stopper pin portion, and the main body portion 31c needs only include the threaded hole 31f corresponding to the threaded hole 6a of the pin 6, so that it is possible to contribute to simplification of manufacturing processes, weight reduction and cost reduction for the main body portion 31c of the first member 31. In addition, the fastener 4 can surely restrict the pin 6 from moving in a direction of the axis 2a of the pivot shaft 2 and maintain, for a long time, the rotation stopper 3, with the pin 6 prevented from removing therefrom, having a rotation stopper effect to stop the first member 31 from rotating relative to the pivot shaft 2.

[0122] (Item 7) The swinging body pivot mechanism P according to any one of items 1 to 6, further including a fastener 4 to be screwed into a threaded hole 31b1 (6a) that is provided in the rotation stopper pin portion 31b (6), and a retainer 5 sandwiched between a head of the fastener 4 to be screwed into the threaded hole 31b1 (6a) and an end of the rotation stopper pin portion 31b (6) to restrict the rotation stopper 3 (3X) from moving in the direction of the axis 2a of the pivot shaft 2.

[0123] With the swinging body pivot mechanism P of item 7, even if problems may exist that the pivot shaft 2 may move inside of the shaft hole 31a in the direction of the axis 2a because of rattling and the rotation stopper 3 (3X) may move because of the rattling and remove from the rotation stopper pin portion 31b (6), the retainer 5 fastened to the rotation stopper pin portion 31b (6) via the fastener 4 adjoins or abuts the rotation stopper 3 so as to restrict the rotation stopper 3 from moving in the direction of the axis 2a of the pivot shaft 2, and prevent the rotation stopper 3 from removing from the rotation stopper pin portion 31b (6).

[0124] (Item 8) A working machine 1 including: a machine body 20; a boom 31 swingably supported by the machine body 20; an arm 32 swingably supported by the boom 31; and a swinging body pivot mechanism P1 according to any one of items 1 to 7 provided as a pivotal junction of the boom 31 and the arm 32.

[0125] With the working machine 1 of item 8, it is possible to apply an appropriate effect of the swinging body pivot mechanism P1 including the configuration according to any one of items 1 to 7 to the pivotal junction of the boom 31 and the arm 32.

[0126] (Item 9) A working machine 1 including: a machine body 20; a working device 30 swingably supported by the machine body 20; and a swinging body pivot mechanism P2 according to any one of items 1 to 7 provided as a pivotal junction of the machine body 20 and the working device 30.

[0127] With the working machine 1 of item 9, it is possible to apply an appropriate effect of the swinging body pivot mechanism P2 including the configuration according to any one of items 1 to 7 to the pivotal junction of the machine body 20 (swing bracket 14) and the working device 30 (boom 31).

[0128] (Item 10) A working machine 1 including: a machine body 20; a working device 30 supported by the machine body 20; a working tool 33 swingably supported by the working device 30; and a swinging body pivot mechanism P3 according to any one of items 1 to 7 provided as a pivotal junction of the working device 30 and the working tool 33.

[0129] With the working machine 1 of item 10, it is possible to apply an appropriate effect of the swinging body pivot mechanism P2 including the configurations according to any one of items 1 to 7 to the pivotal junction of the working device 30 (arm 32) and the working tool (bucket 33).

[0130] While example embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.

Examples

Embodiment Construction

[0028]Example embodiments will now be described with reference to the accompanying drawings, wherein like reference numerals designate corresponding or identical elements throughout the various drawings. The drawings are to be viewed in an orientation in which the reference numerals are viewed correctly.

[0029]FIG. 1 illustrates a side view of a swiveling excavator (hereafter simply referred to as “working machine 1”). A schematic configuration of the working machine 1 will now be described using FIG. 1. In the present example embodiment, a direction indicated by an arrow A1 in FIG. 1 is called “front direction”, a direction indicated by an arrow A2 is called “rear direction”, one direction perpendicular to the arrows A1 and A2 and toward a viewer in front of a sheet of FIG. 1 is called “left” and another direction perpendicular to the arrows A1 and A2 and toward a side behind the sheet of FIG. 1 is called “right”.

[0030]The working machine 1 includes a traveling body 10, a machine bo...

Claims

1. A swinging body pivot mechanism comprising:a pivot shaft;a first member and a second member coupled to each other via the pivot shaft swingably relative to each other; anda rotation stopper attached to the pivot shaft; wherein the first member includesa main body portion,a shaft hole provided in the main body portion to have the pivot shaft inserted therethrough, anda rotation stopper pin portion provided in a vicinity of the shaft hole and protruding from the main body portion in a direction substantially parallel to an axis of the pivot shaft;the rotation stopper includesa first end portion fixed to the pivot shaft, anda second end portion with an insertion portion into which the rotation stopper pin portion is inserted;the insertion portion includesa first width between opposite ends thereof in a direction along a first straight line that is an imaginary line which extends in a direction matching a radial direction of the pivot shaft so as to pass through the first end portion and the second end portion, anda second width between opposite ends thereof in a direction along a second straight line that is an imaginary line which is perpendicular to the axis of the pivot shaft and the first straight line;the first width is defined such as to allow the rotation stopper pin portion inserted in the insertion portion to change a position thereof in the direction along the first straight line; andthe second width is equal to or more than a width of the rotation stopper pin portion in the direction along the second straight line and is defined such that the rotation stopper and the rotation stopper pin portion are restricted from moving relative to each other in the direction along the second straight line, the rotation stopper pin portion being inserted in the insertion portion and abutting the rotation stopper at at least one of the opposite ends of the insertion portion in the direction along the second straight line.

2. The swinging body pivot mechanism according to claim 1, whereinthe insertion portion includes a notch which is open at one end of the opposite ends thereof in the direction along the first straight line that corresponds to an utmost end of the second end portion.

3. The swinging body pivot mechanism according to claim 1, whereinthe insertion portion includes a slot closed at the opposite ends thereof in the direction along the first straight line and extending lengthwise in the direction along the first straight line.

4. The swinging body pivot mechanism according to claim 1, whereinthe rotation stopper pin portion is molded integrally with the main body portion by casting.

5. The swinging body pivot mechanism according to claim 1, whereinthe rotation stopper pin portion is integrated with the main body portion by welding.

6. The swinging body pivot mechanism according to claim 1, further comprising:a pin defining the rotation stopper pin portion that is a cylindrical member separated from the main body portion, the pin including a threaded hole defined by an inner peripheral portion thereof that extends in a protruding direction in which the rotation stopper pin portion protrudes substantially parallel to the axis of the pivot shaft; anda fastener to fasten the pin to the main body portion; whereinthe fastener is screwed with the pin inside of the threaded hole to restrict the pin from moving in the protruding direction.

7. The swinging body pivot mechanism according to claim 1, further comprising:a fastener to be screwed into a threaded hole that is provided in the rotation stopper pin portion, anda retainer sandwiched between a head of the fastener screwed into the threaded hole and an end of the rotation stopper pin portion to restrict the rotation stopper from moving in a direction of the axis of the pivot shaft.

8. A working machine comprising:a machine body;a boom swingably supported by the machine body;an arm swingably supported by the boom; anda swinging body pivot mechanism according to claim 1 provided as a pivotal junction of the boom and the arm.

9. A working machine comprising:a machine body;a working device swingably supported by the machine body; anda swinging body pivot mechanism according to claim 1 provided as a pivotal junction of the machine body and the working device.

10. A working machine comprising:a machine body;a working device supported by the machine body;a working tool swingably supported by the working device; anda swinging body pivot mechanism according to claim 1 provided as a pivotal junction of the working device and the working tool.

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