Ergonomic adjustable grip for handheld power tool

Abstract

The present disclosure relates to an ergonomic adjustable grip for a handheld power tool. An ergonomic handheld power tool is disclosed. A handheld power tool includes a housing including a tool axis and a drive axis. The housing also includes a rear handle, a switch positioned proximate the rear handle, a front grip handle, and a thumb seat disposed on an upper side of the housing proximate the front grip handle. A motor is held within the housing, the motor driving the working head via a drive shaft and a gear arrangement. The rear handle is generally parallel to the tool axis. The front grip handle is substantially parallel to the drive axis. The thumb seat is generally perpendicular to the tool axis. The handheld power tool also includes an accessory axis and a removable handle. The accessory axis is substantially perpendicular to both the tool axis and the drive axis, and the removable handle is substantially parallel to the accessory axis.

Description

Technical Field

[0001] The present disclosure generally relates to an ergonomically adjustable grip for a handheld power tool. Background Art

[0002] Many handheld power tools provide limited ways to grip, manipulate and use the tool. For example, such handheld power tools typically include a main grip, a switch for actuating the handheld power tool, and sometimes an integrated auxiliary grip for allowing two-handed operation of the tool. By way of specific example, a typical handheld orbital polishing power tool includes a rear handle, a switch, and an auxiliary extension handle positioned near the work head opposite to the rear handle. However, this design does not allow for alternative ergonomic manipulation of the handheld orbital polishing power tool based on the operator's personal preferences, working conditions, and / or the working angle of the tool. Therefore, some operators may shift the positioning of their hands to a part of the handheld power tool that is not suitable for the control operation of the power tool. In addition, conventional grips for handheld power tools may require the operator's hand to be positioned in such a way that the operator's forearm is pronated or pronated, thereby increasing the risk of fatigue and / or reducing grip strength.

[0003] It would therefore be beneficial to provide a handheld power tool including an ergonomically adjustable grip that provides a variety of ergonomic ways to safely operate and control the tool based on the operator's personal preferences, operating conditions, and or desired working angle of the power tool. Summary of the invention

[0004] As illustrated by and described in conjunction with the drawings of the present disclosure, and as set forth in the claims, an ergonomic and adjustable grip for a handheld power tool is disclosed.

[0005] Specifically, an embodiment of a handheld power tool is disclosed. In one embodiment, the handheld power tool includes a housing, the housing including: a tool axis, a drive axis, a rear handle, a switch positioned proximate to the rear handle, a front grip handle, and a thumb rest, the thumb rest being disposed on an upper side of the housing proximate to the front grip handle. The handheld power tool also includes a motor retained within the housing, and a working head driven by the motor via a drive shaft and a gear arrangement. In this embodiment, the rear handle is generally parallel to the tool axis, the front grip handle is generally parallel to the drive axis, and the thumb rest is generally perpendicular to the tool axis.

[0006] In another embodiment, the tool axis and the drive axis are substantially perpendicular. In some embodiments, the rear handle and the front grip handle are integrated with the housing. In such embodiments, the front grip handle includes a front grip recess operable to ergonomically position an upper extremity of an operator. In addition, the position of the front grip handle relative to the thumb rest can provide an ergonomic resting position for the operator's hand.

[0007] In another embodiment, the handheld power tool includes an accessory axis and a removable handle. The accessory axis is generally perpendicular to both the tool axis and the drive axis; and the removable handle is generally parallel to the accessory axis. In such an embodiment, the thumb rest is generally parallel to the accessory axis and is operable to provide a mounting position seat for the removable handle. In an additional embodiment, the position of the removable handle relative to the housing is adjustable about the accessory axis.

[0008] In yet another embodiment of a handheld power tool, the removable handle includes at least one fastener receiver, the housing includes at least one threaded hole, and the removable handle is operable to removably fasten to the housing by engaging a threaded fastener with the at least one fastener receiver and the at least one threaded hole. Such an embodiment may further include a tool operable to engage the threaded fastener, and a tool storage portion on the housing operable to stow the tool on the housing. In one example, the handheld power tool is a handheld orbital polishing power tool.

[0009] A handheld power tool is also disclosed, the handheld power tool comprising a housing, the housing comprising: a tool axis, an accessory axis, a rear handle; a switch positioned proximate the rear handle, and a removable handle. The handheld power tool also comprises a motor retained within the housing, and a working head driven by the motor via a drive shaft and a gear arrangement. In such an embodiment, the rear handle is generally parallel to the tool axis, and the removable handle is generally parallel to the accessory axis.

[0010] In another embodiment, the tool axis and the accessory axis are generally perpendicular. The housing may further include an elongated recess disposed in an upper side of the housing. In such an embodiment, the elongated recess is generally parallel to the accessory axis and is operable to provide a mounting location seat for a removable handle. In yet another embodiment, the handheld power tool includes a drive axis, and the housing includes a front grip handle. In such an embodiment, the drive axis is generally perpendicular to both the tool axis and the accessory axis, and the front grip handle is generally parallel to the drive axis.

[0011] In some embodiments, the rear handle and the front grip handle are integrated with the housing. In such embodiments, the front grip handle includes a front grip recess operable to ergonomically position an operator's upper extremity. Additionally, the elongated recess may be positioned proximate the front grip handle such that the elongated recess is operable to provide an ergonomic thumb rest when the removable handle is removed.

[0012] In another embodiment, the position of the removable handle relative to the housing is adjustable about the accessory axis. In yet another embodiment, the removable handle includes at least one fastener receiver, the housing includes at least one threaded hole, and the removable handle is operable to removably fasten to the housing by engaging a threaded fastener with the at least one fastener receiver and the at least one threaded hole. Such an embodiment may further include a tool operable to engage the threaded fastener, and the housing may include a tool storage portion operable to stow the tool on the housing. In one example, the handheld power tool is a handheld orbital polishing power tool.

[0013] A removable handle for a handheld power tool is also disclosed. The removable handle includes a gripping portion and a tool attachment portion. In such an embodiment, the handle is operable to permit ergonomic operation of the handheld power tool in at least a first configuration and a second configuration. The first configuration positions an operator's upper extremity so that the operator's forearm is in a generally neutral position. The second configuration positions the operator's upper extremity to apply leverage to a work surface through a work head along a drive axis.

[0014] In another embodiment, the tool attachment portion includes at least one fastener receiver for receiving a threaded fastener, and the removable handle is attachable to the handheld power tool by inserting the threaded fastener through the at least one fastener receiver and engaging the threaded fastener with the housing of the handheld power tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The following is a brief description of the drawings related to the present disclosure, which will be discussed in more detail in the detailed description section below:

[0016] Figure 1 A partially exploded perspective view of a handheld power tool is illustrated, showing a removable handle, threaded fasteners, and the tool.

[0017] Figure 2 The diagram shows the Figure 1 A side elevation cross-sectional view taken along the tool axis in FIG. 1 and showing the motor, gear arrangement and drive shaft.

[0018] Figure 3 is a diagram of representative body mechanics associated with operating a hand-held power tool.

[0019] Figure 4 A perspective view of a handheld power tool operating in a first configuration utilizing a front grip and a thumb rest is illustrated, and an operator's hand is shown grasping the handheld power tool.

[0020] Figure 5 A perspective view of the handheld power tool operating in a second configuration including a removable handle is illustrated, and an operator's hand is shown gripping the handheld power tool.

[0021] Figure 6 A perspective view of a handheld power tool without a removable handle is illustrated.

[0022] Figure 7 A side elevation view of a handheld power tool without a removable handle is illustrated.

[0023] Figure 8 A perspective view of a handheld power tool including a removable handle is illustrated.

[0024] Fig. 9 A side elevation view of a handheld power tool including a removable handle is illustrated.

[0025] The foregoing summary and the following detailed description of certain features of the present application are better understood when read in conjunction with the accompanying drawings. For illustrative purposes, certain features are shown in the accompanying drawings. However, it should be understood that the claims are not limited to the arrangements shown in the accompanying drawings. Although specific features of various embodiments may be shown in some drawings and not in other drawings, this is only for convenience. Any feature of any drawing may be referenced and / or claimed in conjunction with any feature of any other drawing.

[0026] Unless otherwise indicated, the drawings provided herein are intended to illustrate features of the embodiments of the present disclosure. These features are believed to be applicable to a wide variety of applications, including one or more embodiments of the present disclosure. Therefore, the drawings are not intended to include all conventional features known to those of ordinary skill in the art required for practicing the embodiments disclosed herein. DETAILED DESCRIPTION

[0027] Figure 1A partially exploded view of a handheld power tool 1 is shown. The illustrated embodiment shows a handheld orbital polisher power tool, but it should be understood that the present disclosure is equally applicable to any and all other applicable handheld power tools. The handheld power tool 1 includes a housing 10 that defines a tool axis 2, a drive axis 3, and an accessory axis 4. As shown, the tool axis 2 is generally horizontal and extends coaxially with the housing 10 of the handheld power tool 1. It should be understood that the terms "coaxial" and "generally parallel" as used in the present disclosure mean that two components appear to be and are substantially parallel (i.e., a 0 degree angle), but a certain angle of less than plus or minus 20 degrees is allowed between the two components. As illustrated, the drive axis 3 is generally vertical and generally perpendicular to the tool axis 2. It should be understood that the term "generally perpendicular" as used in the present disclosure means that two components appear to be and are substantially perpendicular (i.e., a 90 degree angle), but a certain angle of less than plus or minus 20 degrees from 90 degrees is allowed between the two components. It should be further understood that the present disclosure does not limit the drive axis 3 to being generally perpendicular to the tool axis 2, and other arrangements are contemplated. The accessory axis 4 is generally perpendicular to both the tool axis 2 and the drive axis 3. The present disclosure utilizes the reference system of the tool axis 2, the drive axis 3, and the accessory axis 4 to explain the physical relationship, orientation, and / or arrangement of various components of the grip of the handheld power tool 1 that achieve ergonomic operation of the handheld power tool 1.

[0028] like Figure 1 and Figure 2As shown, the handheld power tool 1 includes a housing 10 that encloses a motor 6, a gear arrangement 7, and one or more drive shafts 8. The housing 10 can be made of any suitable material, including, for example, plastic, metal, or a combination thereof. The motor 6 is positioned substantially parallel or coaxially with the tool axis 2. The motor 6 generates a rotational force when connected to a power source (not shown), which rotates one of the one or more drive shafts 8. The optional gear arrangement 7 is operable to change the direction, speed, or torque of the rotational force. In the illustrated embodiment, the handheld power tool 1 includes a motor drive shaft 8 that is coaxial with the tool axis 2, coupled to the motor 6 at one end and coupled to the gear arrangement 7 at the opposite end. The gear arrangement 7 may include, for example, a bevel gear arrangement. As illustrated, the gear ratio of the bevel gear arrangement is 1, but it should be understood that the present disclosure contemplates other gear ratios. The auxiliary drive shaft 8 coaxial with the drive axis 3 is also coupled to the gear arrangement 7 at one end and coupled to the work head 9 at the opposite end (so that the work head 9 is driven by the motor 6). The work head 9 may include, but is not limited to, an orbital polishing pad, a sanding pad, or a drill chuck. The gear arrangement 7, and in particular the bevel gear arrangement, is operable to change the rotational force generated by the motor 6 that first rotates about the tool axis 2 to rotate about the drive axis 3 (in the illustrated embodiment, it is an approximately 90 degree change, but other direction changes are also contemplated). Finally, as shown in the illustrated embodiment, because the motor 6, gear arrangement 7, and drive shaft 8 are coaxial with the tool axis 2, the center of mass of these components is also substantially located along the tool axis 2.

[0029] In the illustrated embodiment, the housing 10 of the handheld power tool 1 further includes a rear handle 20, a front grip handle 30, and a removable handle 40. The rear handle 20 is generally integrated with the housing 10 (but may also be a non-integrated component) and is positioned at the rear end of the housing 10. In addition, the rear handle 20 is generally parallel and coaxial with the tool axis 2. As shown, the rear handle 20 includes a recess 21 and a textured surface 22. The rear handle textured surface 22 may include a pattern of grooves and is made of a rubberized material. Therefore, regardless of environmental conditions (e.g., moisture, dirt, etc.), the rear handle textured surface 22 helps the operator to more firmly grasp the rear handle 20 of the handheld power tool 1.

[0030] Adjacent to the rear handle 20 is a switch 24. In an exemplary embodiment, the switch 24 is a spring-loaded trigger switch. In alternative embodiments, the switch 24 may be a slider switch, a capacitive touch switch, or any other type of switch operable to activate the motor 6 of the handheld power tool 1. Optionally, the handheld power tool 1 may also include a lock 25 and a speed selector 26. The lock 25 is operable to lock the switch 24 in an engaged position so that the operator does not need to apply pressure to the switch 24 during the entire time of activating and using the handheld power tool 1. Therefore, the lock 25 can help reduce operator fatigue during the operation period of the handheld power tool 1. The speed selector 26 is operable to change the speed of the motor 6. In a preferred embodiment, the switch 24, the lock 25, and the speed selector 26 are all adjacent and positioned close to the rear handle 20 so that the operator can engage and disengage each of the switch 24, the lock 25, and the speed selector 26 without having to substantially reposition their hands on the rear handle 20.

[0031] In addition, as shown in the illustrated embodiment, the front grip handle 30 is generally integrated with the housing 10 (but can also be a non-integrated component) and is positioned adjacent to the working head 9 of the handheld power tool 1 at the front end of the housing 10. The front grip handle 30 is generally parallel to the drive axis 3. As shown, the front grip handle 30 is generally perpendicular to the tool axis 2 and the rear handle 20, however, other non-perpendicular arrangements are contemplated. The front grip handle 30 includes a recess 31 and a textured surface 32. The front grip textured surface 32 can include a pattern of grooves and is made of a rubberized material. Therefore, regardless of environmental conditions (e.g., moisture, dirt, etc.), the front grip textured surface 32 helps the operator to more firmly grip the front grip handle 30 of the handheld power tool 1.

[0032] The removable handle 40 is attached (i.e., removably fastened) to the housing 10 near and adjacent to the front grip handle 30. The removable handle 40 is generally parallel to the accessory axis 4. In some embodiments, the removable handle 40 is adjustable and operable to rotate around the accessory axis 4. In an exemplary embodiment, the removable handle 40 is a duckbill handle. In an alternative embodiment, the removable handle 40 can be another configuration in which the operator can grasp the removable handle 40 with one hand and grasp the rear handle 20 with another hand. The removable handle 40 can be made of any suitable material, including, for example, plastic, metal, or a combination thereof. As shown, the removable handle 40 includes a recessed portion 41, a textured surface 42, and a lip 44. The removable handle textured surface 42 can include a pattern of grooves and is made of a rubberized material. Therefore, regardless of environmental conditions (e.g., moisture, dirt, etc.), when attached to the handheld power tool 1, the removable handle 40 textured surface 42 helps the operator to more firmly grasp the removable handle 40.

[0033] The removable handle 40 is attached to the housing 10 via one or more threaded fasteners 5. As illustrated, the removable handle 40 includes two fastener receivers 43 (i.e., tool attachment portions) operable to receive one or more threaded fasteners 5. In addition, the housing 10 includes corresponding two threaded holes 13 that are generally concentric and coaxially positioned with the accessory axis 4. The removable handle 40 is positioned within an elongated recess 11 provided in the housing 10 such that the two fastener receivers 43 are concentrically aligned with the corresponding two threaded holes 13 in the housing 10. The elongated recess 11 is configured to receive the removable handle 40, thereby ensuring that the removable handle 40 is properly aligned with the threaded holes 13 when positioned in the elongated recess 11. At least one of the threaded fasteners 5 is inserted through each of the fastener receivers 43 of the removable handle 40 and rotatably engaged with the threaded holes 13. For example, the threaded fastener 5 is a hexagon socket bolt, and a tool 50 (e.g., a hexagonal wrench) is used to turn (i.e., rotatably engage) the hexagon socket bolt to secure the removable handle 40 to the housing 10 of the handheld power tool 1. In alternative embodiments, other fasteners 5 may be used to secure the removable handle 40 to the housing 10 of the handheld power tool 1, such as a pin and ring, a rod and a collar, etc.

[0034] In an exemplary embodiment, the housing 10 includes a tool storage portion 51 that is operable to stow or hold a tool 50 on the housing 10. The tool storage portion 51 is useful for the operator to avoid losing the tool 50 between uses of the handheld power tool 1. When the tool 50 is properly held in the tool storage portion 51, the tool 50 is available when it is necessary to attach, adjust or remove the removable handle 40. In the illustrated embodiment, in the case where the tool 50 is a hexagonal wrench, the tool storage portion 51 includes a tool holder 52 and a clamp 53. A typical hexagonal wrench has an elongated handle end 50a and a shortened tool end 50b that form an L shape. The tool holder 52 is operable to receive the elongated handle end 50a, and the clamp 53 is operable to receive and hold the shortened tool end 50b. The tool holder 52 and the clamp 53 are jointly operable to hold the tool 50 to the housing 10. In an alternative embodiment, the handheld power tool 1 may not include a tool storage portion 51 extending from the housing 10.

[0035] Figure 3The diagram illustrates the relative positioning and movement of the human upper limb (i.e., arm) and specifically the forearm, wrist, and hand. As shown, the forearm can move into pronation or supination. Starting from the neutral position as shown, the forearm can rotate around the x-axis to a supinated position or a pronated position. Similarly, the forearm can rotate around the x-axis from a pronated position to a supinated position, or from a supinated position to a pronated position. The forearm muscles that produce supination include the supinator, biceps brachii, and brachioradialis (from a supinated position). The forearm muscles that produce pronation include the pronator teres, pronator quadratus, flexor carpi radialis, and brachioradialis (from a pronated position). Due to the size and orientation of the muscles that produce supination in the forearm compared to the muscles that produce pronation, the muscles that produce supination are stronger and more fatigue-resistant. For pronation, smaller muscles must work harder to maintain the forearm in a pronated position compared to the muscles that maintain the forearm in a supinated position. These pronators will also fatigue faster than the muscles that produce supination due to their size and orientation in the forearm. In Figure 3 In the neutral position shown, the muscles that produce supination and pronation can work together to hold the forearm in a neutral position, thereby providing increased fatigue resistance and increasing the grip strength of the hand. Therefore, the grip strength and fatigue resistance of the hand are greater when the forearm is in a neutral position than when the forearm is in a pronated position.

[0036] In addition, if Figure 3 As shown in the figure, the wrist can be moved into ulnar deviation and radial deviation. Starting from the neutral position, the wrist can be pivoted to the position of ulnar deviation or the position of radial deviation around the x-axis. Similarly, the wrist can be pivoted to the position of radial deviation from the position of ulnar deviation around the x-axis, or pivoted to the position of ulnar deviation from the position of radial deviation. The muscle that produces ulnar deviation comprises flexor carpi ulnaris and extensor carpi ulnaris. The muscle that produces radial deviation comprises flexor carpi radialis, extensor carpi radialis longus, extensor carpi radialis brevis and abductor pollicis longus. Due to the size and orientation in forearm and wrist compared with the muscle that produces radial deviation, the muscle that produces ulnar deviation is stronger and more fatigue-resistant. In addition, as shown in the figure, compared with the range of motion realized when moving with radial deviation away from the x-axis, the wrist can have a greater range of motion when moving with ulnar deviation away from the x-axis. Thus, grasping and holding an object in a position of ulnar deviation is easier than grasping and holding an object in a position of radial deviation due to the increased range of motion available. Thus, designing handheld power tools taking into account the biomechanics of the forearm, wrist, and hand results in a more ergonomic tool that allows for maximum grip force and is more resistant to fatigue.

[0037] Figure 4A handheld power tool 1 is shown in a first configuration manipulated by an operator using a rear handle 20 and a front grip handle 30, wherein the removable handle 40 is removed. As illustrated, a representative operator hand (output with gray shading) grasping the rear handle 20 and the front grip handle 30 is shown. As illustrated, the operator's hands are positioned so that the operator's two forearms are in a generally neutral position. This alignment substantially eliminates supination and pronation of the operator's forearms, and therefore, helps to reduce fatigue, maintain grip strength, and provide ergonomic operation of the handheld power tool 1. In addition, as illustrated, the design and configuration of the rear handle 20 positions the operator's forearm in a neutral position and positions the operator's wrist in a slightly ulnar deviation position. Studies have shown that grip strength is greatest when the arm is in neutral and the wrist is slightly ulnarly deflected by a few degrees. Therefore, the ergonomic handle shape disclosed herein helps to ensure that the operator can apply and maintain maximum grip strength on the rear handle 20.

[0038] In addition, because the rear handle 20 is generally coaxial and parallel to the tool axis 2, when the operator grasps the rear handle 20, the operator's hand grasps the handheld power tool 1 about the tool axis 2. Similarly, because the front grip handle 30 is generally parallel to the drive axis 3, when the operator grasps the front grip handle 30, the operator's hand grasps the handheld power tool 1 about the drive axis 3. This arrangement can improve the operator's ability to control and / or maintain balance of the handheld power tool 1 (e.g., apply a counter-torque force) where the motor 6 is generating a large amount of torque and / or the work head 9 is rotating at a high rate of speed. For example, when the work head 9 is rotating clockwise and applied to a static work surface, the friction and / or resistance between the work surface and the work head 9 may cause some opposing rotational force to be applied to the handheld power tool 1, thereby forcing the handheld power tool 1 to rotate counterclockwise about the drive axis 3. In order to maintain control of the handheld power tool 1, the operator must generate a counterclockwise rotational torque force.

[0039] Therefore, the positioning of the operator's hand is important for maintaining control of the handheld power tool 1. In the exemplary embodiment, one hand of the operator is positioned adjacent to the work head 9 about the drive axis 3, and the other hand is positioned about the tool axis 2. Therefore, the operator may find it easier to control the torque forces generated by the motor 6 and the work head 9 because the handheld power tool 1 will rotate about the drive axis 3. Therefore, regardless of any torque forces generated by the handheld power tool 1, the operator's hand positioned about the drive axis 3 will be in a more stable position. Therefore, even if the drive axis 3 has a different orientation than the illustrated embodiment (i.e., an angle other than 90 degrees to the tool axis 2), one of the operator's hands will be in a stable position about the drive axis 3. With one hand effectively "anchored" about the drive axis 3, any counter-torque forces required to maintain control of the handheld power tool 1 can be applied only via the rear handle 20. In addition, because the operator's hand is gripping the rear handle 20 about the tool axis 2, the weight of the handheld power tool 1 is evenly distributed, thereby reducing the amount of unwanted additional rotation or imbalance when applying counter-torque forces.

[0040] In addition, if Figure 4 As shown, the rear handle 20 and the front grip handle 30 are both designed to ergonomically position the upper limbs of the operator. For example, the shape of the rear handle 20 is determined to adapt to the shape of the operator's hand, thereby ensuring that the operator can ergonomically and comfortably grip the rear handle 20. Specifically, the rear handle 20 may include a slight bend 23 (as shown), which fits the palm and / or thumb of the operator. In addition, the illustrated embodiment depicts a rear handle recess 21 that is operable to receive at least some or all of the fingers of the operator. In addition, as described above, the positioning of the switch 24, the locking member 25, and the speed selector 26 relative to the rear handle 20 allows the operator to access each of the switch 24, the locking member 25, and / or the speed selector 26 without substantially shifting their grip on the rear handle 20. Similarly, the rear handle 20 includes a textured surface 22, which helps the operator maintain control of the handheld power tool 1.

[0041] Likewise, the front grip handle 30 is shaped to accommodate the shape of the operator's hand, thereby ensuring that the operator can ergonomically and comfortably grip the front grip handle 30. Specifically, the front grip handle 30 includes a front grip recess 31 operable to receive the operator's palm and / or some or all of the operator's fingers. In addition, the handheld power tool 1 includes an elongated recess 11 positioned on the upper side of the handheld power tool 1, which is operable to receive the operator's thumb (i.e., a thumb rest). The positioning of the elongated recess 11 relative to the front grip handle 30 provides an ergonomic and comfortable resting position for the operator's hand. In other words, the positioning of the elongated recess 11 relative to the front grip handle 30 allows the operator's thumb to be naturally positioned in the elongated recess 11 and the operator's palm and / or other fingers to be naturally positioned in the front grip recess 31 when the operator grips the front grip handle 30. Additionally, the front grip handle 30 and / or the elongated recess 11 include a textured surface 32 that helps the operator maintain control of the handheld power tool 1. In combination, the shape, texture, and position of the rear handle 20 and the front grip handle 30 help the operator to ergonomically, comfortably, and securely grip and maintain control of the handheld power tool 1.

[0042] Figure 5 The handheld power tool 1 is shown in a second configuration being manipulated by an operator using the rear handle 20 and the removable handle 40. The positioning of the operator's hand on the rear handle 20 is substantially consistent with the above disclosure, thereby maintaining the operator's forearm in a neutral position and the wrist in a slightly ulnar deviation position. The operator's hand holding the removable handle 40 is positioned so that the operator's forearm is in a pronated position (the palm of the hand faces in a downward direction). Although pronation may cause the forearm muscles to fatigue more quickly, the positioning of the removable handle 40 relative to the work head 9 has certain other benefits. For example, as illustrated, the operator holding the removable handle 40 is able to apply more leverage and downward force to the work surface along the drive axis 3. Specifically, due to the positioning of the removable handle 40 parallel to the attachment axis 4, which is perpendicular to both the tool axis 2 and the drive axis 3, the operator is able to use the center of mass of the handheld power tool 1 to push the handheld power tool 1 downward in a balanced manner. Furthermore, in this arrangement, the operator is able to take advantage of both the weight of the handheld power tool 1 (most of which is at the front of the tool due to the positioning of the gear arrangement 7, one or more drive shafts 8, the motor 9 and the working head 9) and the operator's own mass. In alternative embodiments, the removable handle 40 can be positioned at different angles relative to the tool axis 2 to accommodate the operator's comfort preferences. In contrast, in the operator's hand such as Figure 4 Positioned as depicted, the operator must pull the handheld power tool 1 downward to apply a downward force.

[0043] In addition, if Figure 5 As shown, the removable handle 40 is designed to ergonomically position the upper extremity of the operator. For example, the removable handle 40 may include a curved portion 45 that fits the palm of the operator. In addition, the removable handle 40 includes a recessed portion 41 operable to receive at least some or all of the operator's fingers. Likewise, the removable handle includes a textured surface 42 that helps the operator maintain control of the handheld power tool 1. In combination, the shape, texture, and position of the removable handle 40 help the operator to ergonomically, comfortably, and securely grip the handheld power tool and maintain control thereof.

[0044] Thus, the flexibility provided by the present disclosure enables ergonomic operation of the handheld power tool 1 by reducing fatigue and maintaining grip strength while enabling the operator to change the geometry of the handle shape for operations that require more force to be applied to the handheld power tool 1 and the work surface. Thus, the operator has maximum control over the handheld power tool 1 depending on the operator's personal preferences, operating conditions, and / or the desired working angle of the handheld power tool 1. Finally, in Figure 4 and Figure 5 The operating configuration depicted in is ambidextrous, meaning that the above-described benefits apply equally to right-handed and left-handed operators.

[0045] Figure 6 and Figure 7 Shown above about Figure 4 The handheld power tool 1 of the described configuration (using the rear handle 20 and the front grip handle 30) is not shown for the sake of clarity of the illustration. It is worth noting that the positioning of the operator's hands is not limited to the above description of Figure 4 Discussion of Description. For example, an operator may place a hand on top of the handheld power tool 1 and apply a downward force along the drive axis. Figure 6 and Figure 7 Additional detailed views of the curvature and shape of: the rear handle 20 and rear handle recess 21 ; the front grab handle 30 and front grab handle recess 31 ; and the elongated recess 11 are provided.

[0046] In addition, if Figure 6 and Figure 7As shown, the threaded fastener 5 can be engaged with (screwed into) the threaded hole 13 in the housing 10, even when the removable handle 40 is not attached to the handheld power tool 1. This has the benefit of reducing the likelihood of the threaded fastener 5 being lost and making it available for use when the removable handle 40 needs to be installed. In addition, when the threaded fastener 5 is fully engaged with the threaded hole 13, the head of the threaded fastener 5 is substantially coplanar with the nearby housing 10, so that the threaded fastener 5 does not interfere with the operator's hand gripping the handheld power tool 1. Likewise, the tool 50 is retained in the tool storage portion 51 so as not to interfere with the operator's hand when the handheld power tool 1 is in use.

[0047] Figure 8 and Fig. 9 Shown above about Figure 5 The handheld power tool 1 of the described configuration (using the rear handle 20 and the removable handle 40) is not shown for the sake of clarity of the illustration. It is also worth noting that the positioning of the operator's hands is not limited to the above description of Figure 5 For example, due to the shape and positioning of the removable handle 40 (and specifically the recess 41), the operator can grip the front grip handle 30 even with the removable handle 40 installed. In addition, the lip 44 on the removable handle 40 can provide a thumb rest when the removable handle 40 is installed and the operator is gripping the front grip handle 30. Finally, Figure 8 and Fig. 9 A detailed view of the curvature and shape of the removable handle 40 is provided. Specifically, as shown, the removable handle 40 is shaped to fit the operator's hand and / or fingers when the fingers curl down and grasp the removable handle 40.

[0048] The present disclosure described at present is described in such complete, clear, concise, and accurate terms so that any technician in the field involved in the present disclosure can practice the present disclosure. It should be understood that the preferred aspects of the present disclosure are described above, and modifications can be made in the present disclosure without departing from the spirit of the scope of the present disclosure set forth in the appended claims. The scope of the appended claims will be given the broadest interpretation to cover all such modifications and equivalent structures and functions. Therefore, the application is not intended to be limited to the specific aspects disclosed, but the application will include all aspects falling within the scope of the appended claims.

Claims

1. A handheld power tool, comprising: A housing, the housing comprising: Tool axis; Drive axis; rear handle; a switch, the switch being positioned proximate to the rear handle; Front grab handle; and a thumb rest disposed on an upper side of the housing proximate the front grip handle; a motor held within the housing; and A working head driven by the motor via a drive shaft and a gear arrangement, wherein: The rear handle is generally parallel to the tool axis; The front grip handle is generally parallel to the drive axis; and The thumb rest is generally perpendicular to the tool axis.

2. The handheld power tool according to claim 1, wherein: The tool axis and the drive axis are generally perpendicular.

3. The handheld power tool according to claim 1, wherein: The rear handle and the front grab handle are integral with the housing.

4. The handheld power tool according to claim 3, wherein: The front grip handle includes a front grip recess operable to ergonomically position an operator's upper extremity.

5. The handheld power tool according to claim 4, wherein: The position of the front grip relative to the thumb rest provides an ergonomic resting position for the operator's hand.

6. The handheld power tool of claim 1 further comprising an accessory axis and a removable handle, wherein: The accessory axis is generally perpendicular to both the tool axis and the drive axis; and The removable handle is generally parallel to the accessory axis.

7. The handheld power tool according to claim 6, wherein: The thumb rest is generally parallel to the accessory axis and is operable to provide a mounting location seat for the removable handle.

8. The handheld power tool according to claim 6, wherein: The position of the removable handle relative to the housing is adjustable about the accessory axis.

9. The handheld power tool according to claim 6, wherein: The removable handle includes at least one fastener receiver; The housing includes at least one threaded hole, and The removable handle is operable to be removably fastened to the housing by engaging a threaded fastener with the at least one fastener receiver and the at least one threaded aperture.

10. The handheld power tool of claim 9, further comprising a tool operable to engage the threaded fastener.

11. The handheld power tool according to claim 10, wherein: The housing also includes a tool storage portion operable to stow the tool on the housing.

12. The handheld power tool according to claim 1, wherein: The handheld power tool is a handheld orbital polishing power tool.

13. A handheld power tool, comprising: A housing, the housing comprising: Tool axis; attachment axis; rear handle; a switch positioned proximate to the rear handle; and Removable handles; a motor held within the housing; and A working head driven by the motor via a drive shaft and a gear arrangement, wherein: The rear handle is generally parallel to the tool axis; and The removable handle is generally parallel to the accessory axis.

14. The handheld power tool according to claim 13, wherein: The tool axis and the accessory axis are generally perpendicular.

15. The handheld power tool according to claim 13, wherein: The housing further includes an elongated recess disposed in an upper side of the housing, wherein the elongated recess is generally parallel to the accessory axis and is operable to provide a mounting location seat for the removable handle.

16. The handheld power tool of claim 13, further comprising a drive axis, and wherein: The housing also includes a front grip handle, wherein: The drive axis is generally perpendicular to both the tool axis and the accessory axis; and The front grab handle is generally parallel to the drive axis.

17. The handheld power tool according to claim 16, wherein: The rear handle and the front grab handle are integral with the housing.

18. The handheld power tool according to claim 17, wherein: The front grip handle includes a front grip recess operable to ergonomically position an operator's upper extremity.

19. The handheld power tool according to claim 16, wherein: The elongated recess is positioned proximate the front grip handle such that the elongated recess is operable to provide an ergonomic thumb rest with the removable handle removed.

20. The handheld power tool according to claim 13, wherein: The position of the removable handle relative to the housing is adjustable about the accessory axis.

21. The handheld power tool according to claim 13, wherein: The removable handle includes at least one fastener receiver; The housing includes at least one threaded hole, and The removable handle is operable to be removably fastened to the housing by engaging a threaded fastener with the at least one fastener receiver and the at least one threaded aperture.

22. The handheld power tool of claim 21 further comprising a tool operable to engage the threaded fastener.

23. The handheld power tool according to claim 22, wherein: The housing also includes a tool storage portion operable to stow the tool on the housing.

24. The handheld power tool according to claim 13, wherein: The handheld power tool is a handheld orbital polishing power tool.

25. A removable handle for a handheld power tool, the removable handle comprising: Grip section and tool attachment section, wherein the handle is operable to permit ergonomic operation of the handheld power in at least a first configuration and a second configuration; The first configuration positions an upper extremity of an operator such that a forearm of the operator is in a generally neutral position; and The second configuration positions the operator's upper extremity along the drive axis through the work head and applies leverage to the work surface.

26. The removable handle of claim 25, wherein: The tool attachment portion includes at least one fastener receiver for receiving a threaded fastener, and wherein the removable handle is attachable to the handheld power tool by inserting the threaded fastener through the at least one fastener receiver and engaging the threaded fastener with a housing of the handheld power tool.

Images