The present disclosure relates to power tools, and more particularly to rotary impact tools, such as impact wrenches.
Power tools may produce vibration during operation that can negatively impact the performance and service life of a connected battery. In particular, rotary impact tools, such as impact drivers and impact wrenches, may produce vibration due to reciprocation of a hammer within the tool and periodic impacts between the hammer and an anvil. Such vibration can cause wear and intermittent connection between the battery and battery terminals on the tool. Vibration can also cause wear on a latching mechanism of the battery, which can result in the battery decoupling from its receptacle. Accordingly, a need exists for a vibration mitigation system able to mitigate the effects of vibration on a battery connected to a power tool. A further need exists for a vibration mitigation system able to reduce vibration experienced and transferred to a user of such a power tool.
The present disclosure provides, in one aspect, a power tool including a housing with a motor housing portion and a handle portion extending from the motor housing portion, a motor supported within the motor housing portion, a drive assembly operatively coupled to the motor, the drive assembly producing vibrations during operation of the power tool, a battery receptacle located within the handle portion, a battery at least partially insertable into the battery receptacle along a battery axis, the battery configured to provide power to the motor, and a vibration mitigation system configured to reduce transmission of the vibrations produced by the drive assembly to the battery.
The present disclosure provides, in another aspect, a power tool including a housing with a motor housing portion, an upper handle portion extending from the motor housing portion, and a lower handle portion coupled to the upper handle portion, a motor supported within the motor housing portion, a drive assembly operatively coupled to the motor, the drive assembly producing vibrations during operation of the power tool, a battery receptacle located within the lower handle portion, a battery at least partially insertable into the battery receptacle along a battery axis, the battery configured to provide power to the motor, and a vibration mitigation system configured to reduce transmission of the vibrations produced by the drive assembly from the upper handle portion to the lower handle portion. The vibration mitigation system includes a damping element configured to dampen vibration in a direction along the battery axis and in all directions perpendicular to the battery axis.
The present disclosure provides, in another aspect, a power tool including a housing with a motor housing portion and a handle portion extending from the motor housing portion, a motor supported within the motor housing portion, a drive assembly operatively coupled to the motor, the drive assembly producing vibrations during operation of the power tool, a battery receptacle located within the handle portion, a battery at least partially insertable into the battery receptacle along a battery axis, the battery configured to provide power to the motor, and a vibration mitigation system configured to reduce transmission of the vibrations produced by the drive assembly from the handle portion to the battery. The vibration mitigation system includes a damping element configured to dampen vibration along the battery axis and in a direction perpendicular to the battery axis.
Other features and aspects of the disclosure will become apparent by consideration of the following detailed description and accompanying drawings.
Before any embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
The illustrated housing 14 also includes an end cap 30 coupled to the motor housing portion 18 opposite the front housing portion 22. The first and second housing portions 28a, 28b can be coupled (e.g., fastened) together at an interface or seam 31 along a parting plane between the clamshell halves 28a, 28b. In the illustrated embodiment, the end cap 30 is continuous and may be pressed or fitted over a rear end of the clamshell halves 28a, 28b. In other words, the end cap 30 may not include two halves such that the end cap 30 may extend over the seam 31. The end cap 30 is coupled to the motor housing portion 18 by a plurality of fasteners 120 (
Referring to
Referring to
The illustrated motor 42 is a brushless direct current (“BLDC”) motor with a stator 46 and a rotor with an output shaft 50 that is rotatable about an axis 54 relative to the stator 46. The brushless motor 42 may have a nominal diameter of 50 millimeters. In yet other embodiments, other types or sizes of motors may be used. A fan 58 is coupled to the output shaft 50 behind the motor 42 to generate airflow. The impact wrench 10 also includes a trigger 62 (which may include an actuator and a switch) supported by the housing 14 and operable to selectively connect the motor 42 (e.g., via suitable control circuitry provided on one or more printed circuit board assemblies (“PCBAs”) and the battery 34 electrically, to provide DC power to the motor 42.
In the illustrated embodiment, a first PCBA 63 is provided adjacent a front end of the motor 42 (
Referring to
The illustrated gear assembly 66 includes a pinion gear 82 coupled to the output shaft 50 of the motor 42, a plurality of planet gears 86 meshed with the pinion gear 82, and the ring gear 90, which is meshed with the planet gears 86 and rotationally fixed within the housing 14 (specifically, within the gear housing portion 74). A rearward facing side of the ring gear 90 is seated against a dividing wall 113 formed by the clamshell halves 28a, 28b (
The planet gears 86 are coupled, via pins 88, to a camshaft 94 of the drive assembly 70 such that the camshaft 94 acts as a planet carrier. Accordingly, rotation of the output shaft 50 rotates the planet gears 86, which then advance along the inner circumference of the ring gear 90 and thereby rotates the camshaft 94. In the illustrated embodiment, the camshaft 94 includes a bore 96 extending partially through the camshaft 94 along the axis 54. The bore 96 is shaped to accommodate and/or receive at least a portion of the pinion gear 82. In the illustrated embodiment, the bore 96 extends only partially through the length of the camshaft 94; however, the bore 96 may extend through the entire length of the camshaft 94, to reduce the weight of the camshaft 94, in other embodiments.
The drive assembly 70 of the impact wrench 10 will now be described with reference to
The drive assembly 70 further includes a spring 134 that biases the hammer 130 toward the front of the impact wrench 10. In other words, the spring 134 biases the hammer 130 in an axial direction toward the anvil 126, along the axis 54. The camshaft 94 includes cam grooves in which corresponding cam balls 154 are received. The cam balls 154 are in driving engagement with corresponding cam grooves in the hammer 130, and movement of the cam balls 154 within the cam grooves allows for relative axial movement of the hammer 130 along the camshaft 94 when the hammer lugs 146 are engaged with lugs (not shown) on the anvil 126 and the camshaft 94 continues to rotate relative to the hammer 130. The axial movement of the hammer 130 compresses the spring 134, which then releases its stored energy to propel the hammer 130 forward and rotate the hammer 130 once the hammer lugs 146 clear the anvil lugs.
In operation of the impact wrench 10, an operator depresses the switch 62 to activate the motor 42, which continuously drives the gear assembly 66 and the camshaft 94 via the output shaft 50. As the camshaft 94 rotates, the cam balls 154 drive the hammer 130 to co-rotate with the camshaft 94, and the drive surfaces of hammer lugs 146 to engage, respectively, the driven surfaces of anvil lugs to provide an impact and to rotatably drive the anvil 126 and the tool element. After each impact, the hammer 130 moves or slides rearward along the camshaft 94, away from the anvil 126, so that the hammer lugs 146 disengage the anvil lugs.
As the hammer 130 moves rearward, the cam balls 154 situated in the respective cam grooves 150 in the camshaft 94 move rearward in the cam grooves. The spring 134 stores some of the rearward energy of the hammer 130 to provide a return mechanism for the hammer 130. After the hammer lugs 146 disengage the respective anvil lugs, the hammer 130 is propelled forwardly, toward the anvil 126, as the spring 134 releases its stored energy. The hammer 130 rotates as it is propelled forward due to its engagement via the cam balls 154 with the generally helical cam grooves, until the drive surfaces of the hammer lugs 146 re-engage the driven surfaces of the anvil lugs to cause another impact, which in turn transmits torque to the tool element and workpiece.
Operation of the impact wrench 10 may cause vibrations, due to the reciprocating movement of the hammer 130 and the impacts between the hammer 130 and anvil 126. Accordingly, the illustrated impact wrench includes a vibration mitigation system 200 to provide vibration isolation and protection for the battery 34. In some embodiments, the vibration mitigation system 200 may provide isolation and damping between the battery receptacle 38 and at least a portion of the housing 14, including the motor housing portion 18 and front housing portion 22. In some embodiments, the vibration mitigation system 200 may additionally or alternatively provide isolation and damping between the battery 34 and the battery receptacle 38. In some embodiments, including the illustrated embodiment, the vibration mitigation system 200 may provide isolation and damping between at least a portion of the housing 14, including the motor housing portion 18 and front housing portion 22, and at least part of the handle portion 26 configured to be gripped by a user during operation of the impact wrench 10. In this way, the vibration mitigation system 200 may also reduce vibration transmitted to the user, improving comfort and reducing fatigue.
For example, referring to
The damping element 27 at least partially isolates the lower portion 26b of the handle portion 26 from the upper portion 26a and thereby inhibits transmission of vibration from the upper portion 26a to the lower portion 26b. The battery receptacle 38 is located in the lower portion 26b, such that the battery 34 is coupled to and supported by the lower portion 26b. As such, the vibration mitigation system 200, including the damping element 27, is configured to isolate the battery 34 and battery receptacle 38 from vibrations produced during operation of the impact wrench 10.
In some embodiments, the through-hole may also permit the passage of a cooling airflow generated by rotation of the fan 58. In such embodiments, the cooling airflow may be drawn into the housing 14 through the battery receptacle 38 and the through-hole 210; or, the cooling airflow may be exhausted from the housing 14 via the through-hole 210 and the battery receptacle 38. The cooling airflow may pass over the first PCBA 63, the second PCBA 65, and the motor 42 before being exiting the housing 14.
With continued reference to
In some embodiments, the damping element 27A may be integrally formed as a single piece with the overmolded grip portion 45 (i.e., during the grip overmolding process). In some embodiments, the damping element 27A may be separately formed and sleeved over the flange 206 and extension 204. As shown in
The damping element 27A at least partially isolates the lower portion 26b of the handle portion 26 from the upper portion 26a and thereby inhibits transmission of vibration from the upper portion 26a to the lower portion 26b. The battery receptacle 38 is located in the lower portion 26b, such that the battery 34 is coupled to and supported by the lower portion 26b. As such, the vibration mitigation system 200A, including the damping element 27A, is configured to isolate the battery 34 and battery receptacle 38, as well as the user, who may grip the lower portion 26b of the handle 26, from vibrations produced during operation of the impact wrench 10 along multiple axes. In particular, the illustrating vibration mitigation system 200A provides vibration damping along the battery axis 39 and, due to the generally circular construction of the damping element 27A, along all directions (360 degrees) perpendicular to the battery axis 39.
The vibration mitigation system 200B includes two damping elements 27B positioned within the handle portion 26 on opposite sides of the battery axis 39 (
The recesses 224 are configured to receive ends of the latches 41 (
The illustrated vibration mitigation system 200C includes two damping elements 27C positioned within the handle portion 26 along a rear side of the battery receptacle 38. The illustrated damping elements 27C are shaped as cylindrical lugs and extend perpendicular to and offset from the battery axis 39, and the damping elements 27C are spaced from one another in a direction parallel to the battery axis 39. The damping elements 27C are made of a vibration damping material, such as an elastomeric material, a foam material, or the like. In some embodiments, the damping elements 27C may be integrally formed as a single piece with the overmolded grip portion 45 (i.e., during the grip overmolding process). Alternatively, the damping elements 27C may be separately formed and inserted into corresponding recesses or otherwise adhered or affixed within the battery receptacle 38.
The illustrated vibration mitigation system 200C is disposed between a rear side of a housing of the battery 34 and the interior of the battery receptacle 38 when the battery 34 is inserted into the receptacle 38. The damping elements 27C may provide a pre-load on the battery 34, reducing rattling of the battery 34.
The illustrated vibration mitigation system 200D includes two damping elements 27D positioned within the handle portion 26 along a front side of the battery receptacle 38. The illustrated damping elements 27D are shaped as cylindrical lugs and extend parallel to and offset from the battery axis 39, and the damping elements 27D are spaced from one another on opposite sides of the battery axis 39. The damping elements 27D are made of a vibration damping material, such as an elastomeric material, a foam material, or the like. In some embodiments, the damping elements 27D may be integrally formed as a single piece with the overmolded grip portion 45 (i.e., during the grip overmolding process). Alternatively, the damping elements 27D may be separately formed and inserted into corresponding recesses or otherwise adhered or affixed within the battery receptacle 38.
The vibration mitigation system 200D may also include an additional damping element 27E in the form of a spring, such as a leaf spring in the illustrated embodiment. The additional damping element 27E is centered relative to the battery axis 39 in the illustrated embodiment.
The illustrated vibration mitigation system 200D is disposed between the housing of the battery 34 and the interior of the battery receptacle 38 when the battery 34 is inserted into the receptacle 38. The damping elements 27D, 27E may provide a pre-load on the battery 34, reducing rattling of the battery 34.
Although the disclosure has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the disclosure as described. For example, although the vibration mitigation systems embodying aspects of the present disclosure are described and illustrated herein in the context of the impact wrench 10, such vibration mitigation systems may also be advantageously incorporated into other types of power tools, and particularly power tools producing vibration, including, but not limited to, hammer drills, impact drivers, powered ratchets, rotary hammers, grinders, reciprocating saws, and the like. Various features of the disclosure are set forth in the following claims.
This application claims priority to co-pending U.S. Provisional Patent Application No. 63/352,671, filed Jun. 16, 2022, the entire contents of which are incorporated by reference herein.
Number | Date | Country | |
---|---|---|---|
63352671 | Jun 2022 | US |