CHAINSAW

Abstract

A chainsaw may include: a saw chain; a guide bar extending in a front-to-back direction to which the saw chain is attached; a sprocket configured to run the saw chain along a circumference of the guide bar; a motor configured to rotate the sprocket around an axis extending in a left-to-right direction; a battery pack configured to supply electrical power to the motor; a body housing that contains the motor and holds the guide bar; and a top handle positioned above the body housing and configured to be gripped by a user. When viewed from the right side, the lower end of the battery pack may be positioned above a centerline of the guide bar.

Description

TECHNICAL AREA The present disclosure relates to a chainsaw. BACKGROUND European patent no. 2747949 describes a chainsaw. The chainsaw comprises: a saw chain; a guide bar extending in a front-to-back direction to which the saw chain is attached; a sprocket configured to run the saw chain along a circumference of the guide bar; a motor configured to rotate the sprocket about an axis of rotation extending in a left-to-right direction; a battery pack configured to supply electrical power to the motor; a body housing that accommodates the motor; and a top handle located above the body housing and configured to be gripped by a user. When viewed from the right side, the lower end of the battery pack is positioned below a centerline of the guide bar. SUMMARY Generally, battery packs have a certain weight, which is why a chainsaw like the one described above has a large moment of inertia around the upper handle. This can reduce ease of use when a user grips the upper handle to turn the chainsaw so that it is laterally aligned. This patent discloses a technique configured to reduce the moment of inertia around an upper handle. A chainsaw disclosed herein may comprise: a saw chain; a guide bar extending in a front-to-back direction to which the saw chain is attached; a sprocket configured to drive the saw chain along a circumference of the guide bar; a motor configured to rotate the sprocket around an axis of rotation extending in a left-to-right direction; a battery pack configured to supply electrical power to the motor; a body housing that contains the motor and supports the guide bar; and a top handle positioned above the body housing and configured to be gripped by a user. When viewed from a right-side perspective, the lower end of the battery pack may be positioned above a centerline of the guide bar. Another chainsaw disclosed herein may comprise: a saw chain; a guide bar extending in a front-to-back direction to which the saw chain is attached; a sprocket configured to drive the saw chain along one circumference of the guide bar; a motor configured to rotate the sprocket about an axis of rotation extending in a left-to-right direction; a battery pack configured to supply electrical power to the motor; a body housing that accommodates the motor and holds the guide bar; and a top handle located above the body housing and configured to be gripped by a user. In a state in which the chainsaw is resting on a support surface or-surface, the height of a center of gravity of the battery pack in a vertical direction from the support surface can be equal to or greater than half the height of an upper end of the upper handle in a vertical direction from the support surface. A further chainsaw disclosed herein may comprise: a saw chain; a guide bar extending in a front-to-back direction to which the saw chain is attached; a sprocket configured to drive the saw chain along a circumference of the guide bar; a motor configured to rotate the sprocket about an axis of rotation extending in a left-to-right direction; a battery pack configured to supply electrical power to the motor; a body housing that accommodates the motor and holds the guide bar; and a top handle located above the body housing and configured to be gripped by a user. A trigger switch configured to be operated by the user may be located on a lower surface or face of a front end of the top handle.When viewing the chainsaw from the right side, the distance from a reference line, which is an extension of a center line at the front end of the upper handle, to a lower end of the battery pack may be equal to or less than 2.6 times the width of the front end of the upper handle in a direction perpendicular to the center line. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 illustrates a perspective view of a chainsaw 2 according to one embodiment. Fig. 2 illustrates a right side view of the chainsaw 2 according to the embodiment. Fig. 3 illustrates a perspective view of the chainsaw 2 according to the embodiment, with a battery pack BT removed from a battery pack mounting part 22c. Fig. 4 illustrates a left side view of the chainsaw 2 according to the embodiment, with a side handle 14, a hand guard 16, and a left housing 10 removed. Fig. 5 illustrates a lateral cross-sectional view of a motor 36 and its surroundings in the chainsaw 2 according to the embodiment. Fig. 6 illustrates a vertical cross-sectional view of a control device 42 and its surroundings in the chainsaw 2 according to the embodiment. Fig. 7 illustrates a right side view of the chainsaw 2 according to the embodiment, with a sprocket cover 20 removed.Figure 8 illustrates a right-side view of the chainsaw 2 according to the embodiment, with the sprocket cover 20 and an outer cover plate 72 removed. Figure 9 illustrates a right-side view of the chainsaw 2 according to the embodiment, with the sprocket cover 20, the outer cover plate 72, a guide bar 6, an inner cover plate 70, a brake cover 18, and a brake drum cover 98 removed. Figure 10 illustrates a lateral cross-sectional view of the guide bar 6 and its surroundings in the chainsaw 2 according to the embodiment in an upper cross-section that includes an upper rear end portion 6c of the guide bar 6. Figure 11 illustrates a lateral cross-sectional view of the guide bar 6 and its surroundings in the chainsaw 2 according to the embodiment in a lower cross-section that includes a lower rear end portion 6d of the guide bar 6.Figure 12 illustrates a perspective view of the chainsaw 2 according to the embodiment, with the sprocket cover 20, the outer cover plate 72, the guide bar 6, the inner cover plate 70, and the brake cover 18 removed. Figure 13 illustrates a perspective view of an inner sprocket cover 21a in the chainsaw 2 according to the embodiment. Figure 14 illustrates a right-side view of the chainsaw 2 according to the embodiment in a state placed on a support surface P. DETAILED DESCRIPTION Representative, non-limiting examples of the present disclosure will now be described in more detail with reference to the accompanying drawings. This detailed description is intended solely to provide the person skilled in the art with further details on the implementation of preferred aspects of the present teachings and is not intended to limit the scope of the present disclosure. Furthermore, each of the additional features and teachings disclosed below can be applied separately or in combination with other features and teachings to provide improved chainsaws and methods for their use and manufacture. Furthermore, combinations of features and steps disclosed in the following detailed description may not be necessary to realize the present disclosure in its broadest sense and are instead taught merely to concretely describe representative examples of the present disclosure. Moreover, various features of the representative examples described above and below, as well as of the various independent and dependent claims, can be combined in ways not specifically and expressly enumerated to provide additional convenient embodiments of the present teachings. All features disclosed in the description and / or the claims are intended to be disclosed separately and independently of one another for the purpose of an original written disclosure and for the purpose of limiting the claimed subject matter, irrespective of the combinations of features in the embodiments and / or the claims. Furthermore, all value ranges or information relating to groups of units are intended to disclose any possible intermediate value or unit for the purpose of an original written disclosure and for the purpose of limiting the claimed subject matter. A chainsaw disclosed herein may comprise: a saw chain; a guide bar extending in a front-to-back direction to which the saw chain is attached; a sprocket configured to drive the saw chain along a circumference of the guide bar; a motor configured to rotate the sprocket around an axis of rotation extending in a left-to-right direction; a battery pack configured to supply electrical power to the motor; a body housing that contains the motor and supports the guide bar; and a top handle positioned above the body housing and configured to be gripped by a user. When viewed from a right-side perspective, the lower end of the battery pack may be positioned above a centerline of the guide bar. In the aforementioned configuration, the moment of inertia around the upper handle is small because the battery pack, which is a heavy object, is positioned relatively close to the center line of the upper handle and / or its extension line. Another chainsaw disclosed herein may comprise: a saw chain; a guide bar extending in a front-to-back direction to which the saw chain is attached; a sprocket configured to drive the saw chain along one circumference of the guide bar; a motor configured to rotate the sprocket about an axis of rotation extending in a left-to-right direction; a battery pack configured to supply electrical power to the motor; a body housing that accommodates the motor and holds the guide bar; and a top handle located above the body housing and configured to be gripped by a user. In a state in which the chainsaw is resting on a support surface or-surface, the height of a center of gravity of the battery pack in a vertical direction from the support surface can be equal to or greater than half the height of an upper end of the upper handle in a vertical direction from the support surface. Even with the aforementioned configuration, the moment of inertia around the upper handle is low, since the battery pack, which is a heavy object, is positioned relatively close to the center line of the upper handle and / or its extension line. A further chainsaw disclosed herein may comprise: a saw chain; a guide bar extending in a front-to-back direction to which the saw chain is attached; a sprocket configured to drive the saw chain along a circumference of the guide bar; a motor configured to rotate the sprocket about an axis of rotation extending in a left-to-right direction; a battery pack configured to supply electrical power to the motor; a body housing that accommodates the motor and holds the guide bar; and a top handle located above the body housing and configured to be gripped by a user. A trigger switch configured to be operated by the user may be located on a lower surface or face of a front end of the top handle.When viewing the chainsaw from the right side, the distance from a reference line, which is an extension of a center line at the front end of the upper handle, to a lower end of the battery pack may be equal to or less than 2.6 times the width of the front end of the upper handle in a direction perpendicular to the center line. Even with the aforementioned configuration, the moment of inertia around the upper handle is low, since the battery pack, which is a heavy object, is positioned relatively close to the center line of the upper handle and / or its extension line. In one or more embodiments, the chainsaw may further include a control device configured to control the operation of the motor. When viewed from the rear, the motor may at least partially overlap the control device. In the aforementioned configuration, the dimensions of the chainsaw can be reduced in the top-bottom direction. In one or more embodiments, the chainsaw may further include a control device configured to control the operation of the motor. When viewed from below, the battery pack may at least partially overlap the control device. In the aforementioned configuration, the dimensions of the chainsaw can be reduced in the front-to-back direction. In one or more embodiments, the battery pack can be configured to be detachably attached to the body housing by being moved in a left-right direction. In the aforementioned configuration, the user can attach and detach the battery pack from the body housing by sliding the battery pack in the left-right direction. FORM OF EXECUTIONAs illustrated in Figs. 1 and 2, a chainsaw 2 according to the present embodiment comprises a body 4, a guide bar 6, and a saw chain 8. The guide bar 6 is an elongated, plate-shaped link attached to the body 4 such that it projects forward from the body 4. The saw chain 8 comprises a plurality of blades connected to one another and arranged along the circumference of the guide bar 6. A battery pack BT is attached to the body 4. The battery pack BT contains a plurality of secondary battery cells (not shown) and is configured to be rechargeable by an external power supply. The chainsaw 2 cuts a target, such as wood, by driving the motor 36 (see Fig. 5) with electrical energy supplied by the battery pack BT, thereby causing the saw chain 8 to run along the circumference of the guide bar 6.In the following description, the longitudinal direction of the guide bar 6 is referred to as the front-back direction of the chainsaw 2, a direction perpendicular to the front-back direction is referred to as the up-down direction of the chainsaw 2, and a direction perpendicular to both the front-back and up-down directions is referred to as the left-right direction of the chainsaw 2. It should be noted that, for the sake of clarity, the illustration of the saw chain 8 is omitted in some of the drawings. The body 4 comprises a left housing 10, a right housing 12, a side handle 14, a hand guard 16, a brake cover 18, and a sprocket cover 20. A body housing 22 and an upper handle 24 are formed by the left housing 10 and the right housing 12. The left housing 10 forms the outer shape of the surfaces of the left half of the body housing 22 and the upper handle 24, whereas the right housing 12 forms the outer shape of the surfaces of the right half of the body housing 22 and the upper handle 24. The sprocket cover 20 comprises an inner sprocket cover 21a and an outer sprocket cover 21b, which is arranged in contact with the outer surface of the inner sprocket cover 21a. The body housing 22 comprises a lower body housing 22a, which is essentially cuboid in shape, its longitudinal direction being the front-to-back direction of the body 4, and an upper body housing 22b, which extends from a rear upper section of the lower body housing 22a to a rear top surface. As illustrated in Fig. 3, the rear surface of the upper body housing 22b includes a battery pack receptacle 22c configured to accommodate the battery pack BT, which is detachably attached to it by sliding the battery pack BT in the left-to-right direction. A user can attach the battery pack BT to the battery pack receptacle 22c by sliding the battery pack BT to the right with their left hand while gripping the upper handle 24 with their right hand.The user can also remove the battery pack BT from the battery pack mounting part 22c by sliding the battery pack BT to the left with his left hand while gripping the upper handle 24 with his right hand. As illustrated in Fig. 1, the upper handle 24 comprises a support part 24a having a substantially square column shape, extending upward from a front upper surface of the lower body housing 22a, and a handle part 24b, extending from a rear upper section of the support part 24a to a rear underside and connected to an upper front surface of the upper body housing 22b. The cross-sectional shape of the handle part 24b is substantially circular. A recess part 24c is defined on the upper surface of the support part 24a. Within the recess part 24c are arranged a power switch 26, which the user uses to turn the chainsaw 2 on / off, and an operating lamp 28, which indicates the on / off status of the chainsaw 2.The front end of the handle part 24b includes a linearly extending front end handle part 24d, and a trigger switch 30 is arranged on the lower surface of the front end handle part 24d to enable the user to rotate the saw chain 8. A trigger lock lever 32, configured to switch between a state in which the user is permitted to actuate the trigger switch 30 and a state in which the user is prohibited from acting the trigger switch 30, is arranged on the upper section of the handle part 24b. A locking pin 34 is rotatably mounted on the trigger lock lever 32, and a portion of the locking pin 34 is exposed from the upper surface of the trigger lock lever 32. The side handle 14 has an essentially U-shaped outer form, connecting an upper rear left surface of the support part 24a of the upper handle 24 and a lower rear left surface of the lower body housing 22a. The cross-sectional shape of the side handle 14 is essentially circular. When the user operates the chainsaw 2, they grip the upper handle 24 with their right hand and the side handle 14 with their left hand to hold the chainsaw 2. When the user rotates the locking pin 34 of the upper handle 24 to push it into the trigger lock lever 32, and then presses down the trigger lock lever 32 with the palm of their right hand, the user is now permitted to actuate the trigger switch 30. In this state, when the user pulls the trigger switch 30 upward with the index finger of their right hand, the saw chain 8 is set in motion. As illustrated in Fig. 4, the motor 36, an oil tank 38, an oil pump 40, and a control device 42 are housed in the lower body casing 22a. The oil tank 38 is located in front of the motor 36 and the oil pump 40. The control device 42 is located behind the motor 36 and the oil pump 40. When viewed from the rear of the chainsaw 2, the oil tank 38 partially overlaps the motor 36, the control device 42, and the battery pack BT. When viewed from the rear of the chainsaw 2, the motor 36 partially overlaps the control device 42 and the battery pack BT. When viewed from the rear of the chainsaw 2, the battery pack BT partially overlaps the trigger switch 30. When viewed from below, the oil tank 38 does not overlap the motor 36, the control device 42, or the battery pack BT. When viewed from below, the motor 36 does not overlap the control device 42 or the battery pack BT. When viewed from below, the control device 42 partially overlaps the battery pack BT. As illustrated in Fig. 5, the motor 36 is a brushless DC motor with an external rotor. The motor 36 rotates about an axis of rotation AX extending in the left-right direction. The motor 36 comprises a stator 46 around which a coil 44 is wound, a rotor 48 arranged radially outside the stator 46, a cooling fan 50 fitted into the rotor 48, and an output shaft 52 extending through the centers of the stator 46 and the rotor 48 and fitted into the cooling fan 50. The coil 44, the stator 46, the rotor 48, and the cooling fan 50 are housed in a motor casing 37. The motor casing 37 and the stator 46 are fixed relative to the body housing 22. The coil 44 of the stator 46 is connected to the control device 42. The output shaft 52 is arranged in the left-right direction of the chainsaw 2 and is rotatably mounted through the body housing 22 via bearings 54, 56. As illustrated in Fig. 6, the control device 42 is fixed to the lower body housing 22a. The control device 42 comprises a printed circuit board 58, a housing 60, and potting compound 62. The printed circuit board 58 is housed within the housing 60. The printed circuit board 58 includes a plurality of switching elements (not shown) and a microcomputer (not shown). The switching elements are, for example, IGBTs or MOSFETs. The microcomputer controls the operation of the motor 36 by switching the on and off states of the switching elements. The housing 60 has a box shape with an opening at its top. The housing 60 includes a plurality of heat dissipation fins 60a, which are arranged along the front-to-back and left-to-right directions of the housing 60.Each of the plurality of heat dissipation fins 60a has a square column shape and projects downwards perpendicularly from the lower surface of the shell 60. The potting material 62 is, for example, made of resin. The potting material 62 is placed inside the shell 60 by being poured into the shell 60 in a molten state and then hardened. The potting material 62 encapsulates the circuit board 58 within it. Next, the airflow during rotation of the cooling fan 50 is described. In Figures 5 and 6, the airflow is indicated by arrows. As illustrated in Figure 6, when the cooling fan 50 rotates, air flows from outside the housing 22 through an air inlet 22d into the housing 22. The air flowing into the housing 22 flows to a position in front of the control device 42 after passing through gaps between the heat dissipation fins 60a. As the air flows between the heat dissipation fins 60a, the heat from the control device 42 is transferred from the heat dissipation fins 60a to the air. In the present embodiment, the housing 22 comprises a front fin 22e and a rear fin 22f, which extend inwards from the wall surface of the housing 22. The anterior rib 22e and the posterior rib 22f each have a substantially flat shape.In the direction in which the heat dissipation fins 60a extend, the tips of the front fin 22e and the rear fin 22f are positioned between the tips and the extensions (i.e., the connecting sections between the heat dissipation fins 60a and the lower surface of the casing 60) of the heat dissipation fins 60a. As a result, air flows between the areas surrounding the extensions of the heat dissipation fins 60a. Since the extensions of the heat dissipation fins 60a are positioned close to the circuit board 58, the heat from the control device 42 can be transferred from the extensions of the heat dissipation fins 60a to the air, thus effectively cooling the control device 42. As illustrated in Fig. 5, the air flowing to the position in front of the control device 42 flows through an air supply opening 37a into the motor housing 37. The air flowing into the motor housing 37 flows into a gap between the stator 46 and the rotor 48, cools the stator 46 and the rotor 48, and then reaches the cooling fan 50. The air that has reached the cooling fan 50 flows radially outwards along the blades 50a and then flows circumferentially along the inner surface of the motor housing 37 to flow through an air outlet opening 37b of the motor housing 37 and an air outlet 22g of the body casing 22, and is discharged outside the body casing 22. As illustrated in Fig. 5, a sprocket 64 and a brake base 66 are fixed around the right side end portion of the output shaft 52. The sprocket 64 and the brake base 66 are arranged on the right side of the bearing 56. A brake drum 68 fits into the brake base 66. The brake drum 68 comprises a base portion 68a and a projecting portion 68b that extends outwards from the base portion 68a (i.e., to the right of the chainsaw 2). The base portion 68a comprises a circular cylinder portion 68c and a flange portion 68d, which is arranged outside the circular cylinder portion 68c and whose diameter is reduced compared to the circular cylinder portion 68c. The projecting part 68b comprises a circular cylinder part 68e, the outer diameter of which is smaller than the outer diameter of the circular cylinder part 68c, and a flange part 68f, which is arranged outside the circular cylinder part 68e and whose diameter is reduced compared to the circular cylinder part 68e.The flange part 68f of the projecting part 68b is in contact with the sprocket 64. The sprocket 64 is exposed on the outside of the right-hand housing 12. The saw chain 8 (see Fig. 1) is tensioned by the guide bar 6 over the sprocket 64. When the motor 36 is driven, the sprocket 64 rotates with the output shaft 52 about the axis of rotation AX of the motor 36, causing the saw chain 8 (see Fig. 1) to run along the sprocket 64 and the circumference of the guide bar 6. In the present embodiment, the axis of rotation AX of the sprocket 64 coincides with the axis of rotation AX of the motor 36. As illustrated in Fig. 7, the guide rail 6 is fixed to the right housing 12, sandwiched between the inner cover plate 70 and the outer cover plate 72. The inner cover plate 70 is shaped such that its upper end and its immediate vicinity, and its lower end and its immediate vicinity, are curved inwards (i.e., to the left of the chainsaw 2). The outer cover plate 72 is shaped such that its upper end and its immediate vicinity, and its lower end and its immediate vicinity, are curved outwards (i.e., to the right of the chainsaw 2). As illustrated in Fig. 8, an elongated slot 6a is defined in the guide rail 6, extending along the longitudinal direction of the guide rail 6 (i.e., the front-to-back direction of the chainsaw 2). The guide rail 6 is held in the body housing 22 by a support pin 74 and a support bolt 76, which extend through the elongated hole 6a.The support bolt 76 extends through the outer cover plate 72 (see Fig. 7) and the sprocket cover 20 (see Fig. 2) to protrude outside the sprocket cover 20. As illustrated in Fig. 2, a nut 78 is attached to the support bolt 76 and tightened from outside the sprocket cover 20. The user can adjust the tension of the saw chain 8 by loosening the nut 78 and moving the guide bar 6 forward and backward, thereby changing the distance between the guide bar 6 and the sprocket 64. As illustrated in Fig. 8, an engagement hole 82 is defined in the guide rail 6, which engages with an engagement claw 80. As illustrated in Fig. 9, the engagement claw 80 is coupled to an adjusting screw 86 via a rotary-to-linear motion conversion mechanism 84. The rotary-to-linear motion conversion mechanism 84 converts the rotary motion of the adjusting screw 86 into linear motion of the engagement claw 80 in one direction along the elongated hole 6a (i.e., in the front-to-back direction). As illustrated in Fig. 8, the adjusting screw 86 extends through the elongated hole 6a without contacting the inner circumferential surface of the elongated hole 6a. When the user turns the adjusting screw 86, the engagement claw 80 moves in the front-back direction, causing the guide bar 6 to move in the front-back direction of the chainsaw 2.In this way, the front-back directional position of the guide rail 6 relative to the sprocket 64 can be adjusted. As illustrated in Fig. 2, the sprocket 64, the inner cover plate 70, the outer cover plate 72, and the support pin 74 are covered by the sprocket cover 20. A recess 20a is defined in the sprocket cover 20. A tightening opening 20b, in which the support pin 76 extends, and an adjustment opening 20c for external access to the adjusting screw 86 are defined in the recess 20a. The nut 78 is tightened onto the support pin 76 from outside the recess 20a. The user can tighten and loosen the nut 78 with the sprocket cover 20 in place. Furthermore, the user can adjust the tension of the saw chain 8 by turning the adjusting screw 86 through the adjustment opening 20c with the sprocket cover 20 in place. As illustrated in Fig. 9, the hand guard 16 is coupled to a brake band 90 via a joint mechanism 88. The joint mechanism 88 and a section of the brake band 90 are covered by the brake cover 18 (see Fig. 2). The hand guard 16 is configured to pivot along a pivot axis along the left-right direction of the chainsaw 2. The brake band 90 is arranged to surround the circular cylinder part 68c (see Fig. 5) of the brake drum 68. When the hand guard 16 is tilted forward, the joint mechanism 88 reduces the diameter of the brake band 90, whereas when the hand guard 16 is tilted backward, the joint mechanism 88 increases the diameter of the brake band 90.When the diameter of the brake band 90 decreases, the inner circumferential surface of the brake band 90 and the outer circumferential surface of the circular cylinder part 68c of the brake drum 68 contact each other, causing friction between the two to limit the rotation of the output shaft 52. The oil tank 38 shown in Fig. 1 is configured to store lubricating oil for the saw chain 8. The oil tank 38 includes a cap 92, which is configured to be removable and attached to a filling port for filling the oil tank 38 with lubricating oil. The cap 92 of the oil tank 38 is exposed on the outside of the left housing 10 and is located on the left surface of the front section of the body housing 22. As illustrated in Fig. 4, the oil pump 40 draws the lubricating oil from inside the oil tank 38 through an inlet pipe 94 and supplies the guide bar 6 and the saw chain 8 (see Fig. 1) to the lubricating oil through an outlet pipe 96 in conjunction with the rotation of the motor 36. The delivery quantity of lubricating oil supplied to the guide bar 6 and the saw chain 8 (see Fig. 1) from the oil tank 38 by the oil pump 40 can be adjusted via an adjusting pin 97. As illustrated in Figs. 10 and 11, a space SP1 is defined by the body housing 22, the brake drum 68, the sprocket 64, and the guide rail 6. A wall 22h, extending in the left-right direction of the body housing 22, is located in front of the space SP1, and a wall 22i, extending in the front-back direction of the body housing 22, and the flange portion 68d of the brake drum 68 are located to the left of the space SP1. The circular cylinder portion 68e of the brake drum 68 and an outer circumferential surface 64a of the sprocket 64 are located behind the space SP1, and the guide rail 6 is located to the right of the space SP1. If the SP1 chamber is formed in this way, during the cutting process using the chainsaw 2, cutting waste can penetrate into the SP1 chamber along with the rotation of the saw chain 8, and the penetrating cutting waste can remain in the SP1 chamber. With regard to the aforementioned problem, in the present embodiment the inner cover plate 70 prevents the ingress of cutting waste into the SP1 chamber. As illustrated in Figs. 10 and 11, the inner cover plate 70 is arranged between the body housing 22 and the guide rail 6. As illustrated in Fig. 8, a rear end 6b of the guide rail 6 comprises an upper rear end section 6c, which projects rearward above the center in the top-bottom direction of the guide rail 6, a lower rear end section 6d, which projects rearward below the center in the top-bottom direction of the guide rail 6, and a middle rear end section 6e, which is set back forward between the upper rear end section 6c and the lower rear end section 6d. In the guide rail 6 of the present embodiment, the front-back position of the upper rear end section 6c is essentially the same as the front-back position of the lower rear end section 6d. As illustrated in Figs. 10 and 11, in the present embodiment, when considering the inner cover plate 70 in a specific cross-section extending in the front-to-back and left-to-right directions and including the rear end 6b of the guide rail 6 (i.e., the upper rear end part 6c, the lower rear end part 6d, or the middle rear end part 6e), the inner cover plate 70 is in contact with a surface of the guide rail 6 facing the body housing 22 (i.e., the left surface of the guide rail 6), and a rear end 70a of the inner cover plate 70 is positioned behind the rear end 6b of the guide rail 6. As shown in Fig.Figure 10 illustrates, for example, that when considering the inner cover plate 70 in an upper cross-section extending in the front-back and left-right directions and including the upper rear end part 6c of the guide rail 6, the inner cover plate 70 is in contact with the left surface of the guide rail 6, and the rear end 70a of the inner cover plate 70 is positioned behind the rear end 6b of the guide rail 6 (here the upper rear end part 6c). As shown in Fig.Figure 11 further illustrates that, when considering the inner cover plate 70 in the lower cross-section extending in the front-back and left-right directions and including the lower rear end part 6d of the guide rail 6, the inner cover plate 70 is in contact with the left surface of the guide rail 6, and the rear end 70a of the inner cover plate 70 is positioned behind the rear end 6b of the guide rail 6 (here the lower rear end part 6d). These configurations can prevent the ingress of cutting debris into space SP1. As illustrated in Fig. 8, the rear end 70a of the inner cover plate 70 is positioned behind the rear end 6b of the guide rail 6 and near the sprocket 64. "Near the sprocket 64" can, for example, mean that the distance from the sprocket 64 in the radial direction of the axis of rotation AX of the sprocket 64 is 1 mm or less, and can also, for example, mean that the distance from the sprocket 64 in the radial direction of the axis of rotation AX of the sprocket 64 is 0.5 mm or less. As illustrated in Fig. 12, the brake drum cover 98 is fixed to the right-hand surface of the body housing 22. The brake drum cover 98 is located below the brake cover 18. The brake drum cover 98 comprises a circular portion 98a that surrounds the projecting portion 68b (see Fig. 5) of the brake drum 68, and a projecting portion 98b that is located at the front end of the circular portion 98a and projects further outwards than the circular portion 98a. As illustrated in Figs. 10 and 11, the brake drum cover 98 is located inwards of the inner cover plate 70 (i.e., to the left of the inner cover plate 70). The projecting portion 98b is in contact with the left-hand surface of the inner cover plate 70. The position in the front-back direction of a rear end 98c of the protruding part 98b is essentially the same as the position in the front-back direction of the rear end 70a of the inner cover plate 70. As illustrated in Fig. 12, a central lower end portion 18a of the brake cover 18 is arranged between the body housing 22 and the projecting part 98b of the brake drum cover 98. As illustrated in Fig. 10, the brake cover 18 is positioned inwards of the inner cover plate 70 (i.e., to the left of the inner cover plate 70). The central lower end portion 18a is in contact with the left surface of the inner cover plate 70. As illustrated in Figs. 10 and 11, a rear end part 70b of the inner cover plate 70, part of the circular part 98a and the projecting part 98b of the brake drum cover 98, as well as the middle lower end part 18a of the brake cover 18, are arranged in the space SP1. Since the space SP1 is occupied by the rear end part 70b of the inner cover plate 70, part of the circular part 98a and the projecting part 98b of the brake drum cover 98, as well as the middle lower end part 18a of the brake cover 18, the ingress of cutting debris into the space SP1 and / or the accumulation of cutting debris in the space SP1 can be prevented.In the present embodiment, the distance in the front-to-back direction between the rear end 70b of the inner cover plate 70 and the rear end 98c of the projecting part 98b of the brake drum cover 98 and the outer circumferential surface 64a of the sprocket 64 is 6 mm or less, and the distance in the left-to-right direction between the inner cover plate 70 and the projecting part 98b of the brake drum cover 98 and the left surface of the guide rail 6 is 3 mm or less. As a result, the ingress of cutting debris into space SP1 and / or the accumulation of cutting debris in space SP1 can be effectively prevented. In one modification, the distance in the front-to-back direction between the rear end part 70b of the inner cover plate 70 or the rear end 98c of the projecting part 98b of the brake drum cover 98 and the outer circumferential surface 64a of the sprocket 64 can be 6 mm or less.Additionally or alternatively, the distance in the left-right direction between the inner cover plate 70 or the projecting part 98b of the brake drum cover 98 and the left surface of the guide rail 6 can be 3 mm or less. In this configuration as well, the ingress of cutting debris into space SP1 and / or the accumulation of cutting debris in space SP1 can be effectively prevented. The circular part 98a of the brake drum cover 98 covers the base part 68a of the brake drum 68 (i.e., the circular cylinder part 68c and the flange part 68d) and a section of the circular cylinder part 68e. This prevents cutting debris from accumulating and remaining near the outer circumferential surface of the brake drum 68. Furthermore, the brake drum cover 98 is fixed to the body housing 22 in such a way that it is removable. Therefore, if cutting debris has entered the SP1 space, it can be easily removed by detaching the brake drum cover 98 from the body housing 22. As illustrated in Fig. 13, a stepped section 20d of the sprocket cover 20 projects inwards from a wall 20e forming the outer shape of the sprocket cover 20. As illustrated in Figs. 10 and 11, the stepped section 20d is arranged parallel to the guide rail 6. As illustrated in Figs. 10 and 11, a chamber SP2 is formed by the support pin 74 (see Fig. 5), the sprocket cover 20, the sprocket 64, and the guide rail 6. The support pin 74 is located in front of chamber SP2, and the guide rail 6 is located to the left of chamber SP2. The outer circumferential surface 64a of the sprocket 64 is located behind chamber SP2, and the stepped portion 20d of the sprocket cover 20 is located to the right of chamber SP2. When chamber SP2 is configured in this way, during a cutting operation using the chainsaw 2, cutting debris can enter chamber SP2 along with the rotation of the saw chain 8, and this cutting debris can remain within chamber SP2. With regard to the aforementioned problem, in the present embodiment the outer cover plate 72 prevents the ingress of cutting debris into the SP2 chamber. As illustrated in Figs. 10 and 11, the outer cover plate 72 is arranged between the sprocket cover 20 and the guide rail 6. The outer cover plate 72 is fixed to the sprocket cover 20. In the present embodiment, when considering the outer cover plate 72 in a specific cross-section extending in the front-to-back and left-to-right directions and including the rear end 6b of the guide rail 6, the outer cover plate 72 is in contact with a surface of the guide rail 6 facing the sprocket cover 20 (i.e., the right surface of the guide rail 6), and a rear end 72a of the outer cover plate 72 is positioned behind the rear end 6b of the guide rail 6. As shown in Fig.Figure 10 illustrates, for example, when considering the outer cover plate 72 in the upper cross-section, which extends in the front-back direction and the left-right direction and includes the upper rear end part 6c of the guide rail 6, the outer cover plate 72 is in contact with the right surface of the guide rail 6 and the rear end 72a of the outer cover plate 72 is positioned behind the rear end 6b of the guide rail 6 (here the upper rear end part 6c). As illustrated in Fig. 11, when considering the outer cover plate 72 in the lower cross-section, which extends in the front-back direction and the left-right direction and includes the lower rear end part 6d of the guide rail 6, the outer cover plate 72 is in contact with the right surface of the guide rail 6 and the rear end 72a of the outer cover plate 72 is positioned behind the rear end 6b of the guide rail 6 (here the lower rear end part 6d).These configurations can prevent cutting debris from entering the SP2 space. As illustrated in Fig. 7, the rear end 72a of the outer cover plate 72 is positioned behind the rear end 6b of the guide rail 6 and near the sprocket 64. As illustrated in Fig. 13, the sprocket cover 20 comprises a contact rib 20f which projects inwards from the step section 20d or the wall 20e and has essentially the same outer shape as the outer shape of the outer cover plate 72. The contact rib 20f is in contact with the entire outer surface of the outer cover plate 72. As illustrated in Figures 10 and 11, a rear end portion 72b of the outer cover plate 72 and the contact rib 20f of the sprocket cover 20 are arranged in the space SP2. Since the space SP2 is occupied by the rear end portion 72b of the outer cover plate 72 and the contact rib 20f of the sprocket cover 20, the ingress of cutting debris into the space SP2 and / or the accumulation of cutting debris in the space SP2 can be prevented. In the present embodiment, the distance in the left-right direction between the outer cover plate 72 and the right surface of the guide rail 6 is 3 mm or less. Therefore, the ingress of cutting debris into the space SP2 and / or the accumulation of cutting debris in the space SP2 can be effectively prevented.In one modification, in addition to or as an alternative to the distance between the outer cover plate 72 and the right surface of the guide rail 6, the distance in the left-right direction between the stepped part 20d of the sprocket cover 20 and the right surface of the guide rail 6 can be 3 mm or less. In this case, the stepped part 20d of the sprocket cover 20 can be in contact with, or almost in contact with, the right surface of the guide rail 6. Even with this configuration, the ingress of cutting debris into space SP2 and / or the accumulation of cutting debris in space SP2 can be effectively prevented. As illustrated in Fig. 8, when viewing the chainsaw 2 from the right side, a lower end BU of the battery pack BT is positioned above a centerline CL1 of the guide bar 6. The centerline CL1 referred to here is a line extending in the front-to-back direction and in the center of the top-to-bottom direction of the guide bar 6. As illustrated in Fig. 9, when viewing the chainsaw 2 from the right side, the distance L from a reference line RL, which is an extension of a centerline CL2 at the front end grip portion 24d of the upper handle 24, to the lower end BU of the battery pack BT is equal to or less than 2.6 times the width W of the front end grip portion 24d of the upper handle 24 in a direction perpendicular to the centerline CL2.The center line CL2 referred to here is a line that passes through the midpoint between the upper and lower surfaces (excluding the projection 31) of the front end grip part 24d of the upper handle 24 at a position where a projection 31 is located on the lower surface of the front end grip part 24d of the upper handle 24. The projection 31 is positioned behind the trigger switch 30. Thus, for a chainsaw 2 without such a projection 31, the aforementioned center line CL2 can be a line that passes through the midpoint between the upper and lower surfaces of the front end grip part 24d of the upper handle 24 at a position directly behind the trigger switch 30 (e.g., 1 mm behind the trigger switch 30), which is located on the lower surface of the front end grip part 24d of the upper handle 24. As illustrated in Fig. 14, when the chainsaw 2 is placed on a support surface P, the height H1 of the center of gravity GR of the battery pack BT from the support surface P in a vertical direction is equal to or greater than half the height H2 of the upper end of the upper handle 24 from the support surface P in a vertical direction. The upper end of the upper handle 24 referred to here is the highest position in the vertical direction from the support surface P below the support part 24a and the handle part 24b, which are formed by the left housing 10 and the right housing 12. That is, the trigger locking lever 32 and the locking pin 34 are not taken into account when determining the upper end of the upper handle 24. (Modifications) When viewing the chainsaw 2 from the rear, the motor 36 does not have to overlap the control device 42. When viewing the chainsaw 2 from below, the battery pack BT does not need to overlap the control device 42. The BT battery pack can be configured to be attached to the body casing using a method other than sliding, such as inserting it into a battery pack casing. Motor 36 can be a brushless DC motor with an internal rotor. Alternatively, motor 36 can be a brushed motor or another type of drive motor. The inner sprocket cover 21a and the outer sprocket cover 21b can be configured integrally with each other. In light of the above, in one or more embodiments, the chainsaw 2 comprises: the saw chain 8; the guide bar 6, which extends in the front-to-back direction and to which the saw chain 8 is attached; the sprocket 64, which is configured to run the saw chain 8 along the circumference of the guide bar 6; the motor 36, which is configured to rotate the sprocket 64 about a pivot axis AX extending in the left-to-right direction; the battery pack BT, which is configured to supply electrical power to the motor 36; the body housing 22, which houses the motor 36 and holds the guide bar 6; and the upper handle 24, which is located above the body housing 22 and is configured to be gripped by a user. When viewing the chainsaw 2 from the right side, the lower end BU of the battery pack BT is positioned above the centerline CL1 of the guide bar 6. In the aforementioned configuration, the moment of inertia around the upper handle 24 is small because the battery pack BT, which is a heavy object, is positioned relatively close to the reference line RL, which is an extension of the center line CL2 of the upper handle 24. In one or more embodiments, the chainsaw 2 comprises: the saw chain 8; the guide bar 6, which extends in the front-to-back direction and to which the saw chain 8 is attached; the sprocket 64, which is configured to run the saw chain 8 along the circumference of the guide bar 6; the motor 36, which is configured to rotate the sprocket 64 about the axis of rotation AX, which extends in the left-to-right direction; the battery pack BT, which is configured to supply electrical power to the motor 36; the body housing 22, which houses the motor 36 and holds the guide bar 6; and the upper handle 24, which is located above the body housing 22 and is configured to be gripped by a user. In the state in which the chainsaw 2 is on the support surface, or- surface P rests, the height H1 of the center of gravity GR of the battery pack BT in the vertical direction from the support surface P is equal to or greater than half the height H2 of the upper end of the upper handle 24 in the vertical direction from the support surface P. Even with the aforementioned configuration, the moment of inertia around the upper handle 24 is small, since the battery pack BT, which is a heavy object, is positioned relatively close to the reference line RL, which is an extension of the center line CL2 of the upper handle 24. In one or more embodiments, the chainsaw 2 comprises: the saw chain 8; the guide bar 6, which extends in the front-to-back direction and to which the saw chain 8 is attached; the sprocket 64, which is configured to run the saw chain 8 along the circumference of the guide bar 6; the motor 36, which is configured to rotate the sprocket 64 about the axis of rotation AX, which extends in the left-to-right direction; the battery pack BT, which is configured to supply electrical power to the motor 36; the body housing 22, which houses the motor 36 and holds the guide bar 6; and the upper handle 24, which is located above the body housing 22 and is configured to be gripped by a user. The trigger switch 30, which is configured to be actuated by the user, is located on the lower surface of the front end handle portion 24d (example of a front end) of the upper handle 24.When viewing the chainsaw 2 from the right side, the distance L from the reference line RL, which is an extension of the center line CL2 at the front end handle part 24d of the upper handle 24, to the lower end BU of the battery pack BT is equal to or less than 2.6 times the width W of the front end handle part 24d of the upper handle 24 in the direction perpendicular to the center line CL2. Even with the aforementioned configuration, the moment of inertia around the upper handle 24 is small, since the battery pack BT, which is a heavy object, is positioned relatively close to the reference line RL, which is an extension of the center line CL2 of the upper handle 24. In one or more embodiments, the chainsaw 2 further comprises the control device 42, which is configured to control the operation of the motor 36. When viewed from the rear, the motor 36 at least partially overlaps the control device 42. In the aforementioned configuration, the dimensions of the chainsaw 2 can be reduced in the top-bottom direction. In one or more embodiments, the chainsaw 2 further comprises the control device 42, which is configured to control the operation of the motor 36. When viewed from below, the battery pack BT at least partially overlaps the control device 42. In the aforementioned configuration, the dimensions of the chainsaw 2 can be reduced in the front-to-back direction. In one or more embodiments, the battery pack BT is configured to be detachably attached to the body housing 22 by being moved in the left-right direction. In the aforementioned configuration, the user can attach and detach the BT battery pack from the body housing 22 by sliding the BT battery pack in the left-right direction. QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature EP 2747949

[0002]

Claims

Chainsaw (2), comprising: a saw chain (8); a guide bar (6) extending in a front-to-back direction to which the saw chain (8) is attached; a sprocket (64) configured to run the saw chain (8) along a circumference of the guide bar (6); a motor (36) configured to rotate the sprocket (64) about a pivot axis (AX) extending in a left-to-right direction; a battery pack (BT) configured to supply electrical power to the motor (36); a body housing (22) housing the motor (36) and supporting the guide bar (6); and an upper handle (24) positioned above the body housing (22) and configured to be gripped by a user, wherein, when viewing the chainsaw (2) from the right side, a lower end (BU) of the battery pack (BT) is positioned above a center line (CL1) of the guide bar (6). Chainsaw (2), comprising: a saw chain (8); a guide bar (6) extending in a front-to-back direction to which the saw chain (8) is attached; a sprocket (64) configured to run the saw chain (8) along a circumference of the guide bar (6); a motor (36) configured to rotate the sprocket (64) about a pivot axis (AX) extending in a left-to-right direction; a battery pack (BT) configured to supply electrical power to the motor (36); a body housing (22) housing the motor (36) and supporting the guide bar (6); and an upper handle (24) positioned above the body housing (22) and configured to be gripped by a user, wherein, in a state in which the chainsaw (2) is resting on a support surface or-surface (P) rests, a height (H1) of a center of gravity (GR) of the battery pack (BT) in a vertical direction from the support surface (P) is equal to or greater than half a height (H2) of an upper end of the upper handle (24) in a vertical direction from the support surface (P). Chainsaw (2), comprising: a saw chain (8); a guide bar (6) extending in a front-to-back direction to which the saw chain (8) is attached; a sprocket (64) configured to run the saw chain (8) along a circumference of the guide bar (6); a motor (36) configured to rotate the sprocket (64) about a pivot axis (AX) extending in a left-to-right direction; a battery pack (BT) configured to supply electrical power to the motor (36); a body housing (22) housing the motor (36) and supporting the guide bar (6); and an upper handle (24) positioned above the body housing (22) and configured to be gripped by a user, with a trigger switch (30) configured to be actuated by the user located on a lower surface.surface of a front end (24d) of the upper handle (24), and when viewed from the right side of the chainsaw (2), a distance (L) from a reference line (RL) which is an extension of a center line (CL2) at the front end (24d) of the upper handle (24) to a lower end (BU) of the battery pack (BT) is equal to or less than 2.6 times a width (W) of the front end (24d) of the upper handle (24) in a direction perpendicular to the center line (CL2). Chainsaw (2) according to one of claims 1 to 3, further comprising a control or regulating device (42) configured to control or regulate the operation of the motor (36), wherein, when viewing the chainsaw (2) from a rear side, the motor (36) at least partially overlaps the control or regulating device (42). Chainsaw (2) according to one of claims 1 to 4, further comprising a control or regulating device (42) configured to control or regulate the operation of the motor (36), wherein, when viewing the chainsaw (2) from below, the battery pack (BT) at least partially overlaps the control or regulating device (42). Chainsaw (2) according to one of claims 1 to 5, wherein the battery pack (BT) is configured to be detachably attached to the body housing (22) by being moved in a left-right direction.

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