Non-contact direction selection mechanism

Abstract

The present invention relates to a direction selection mechanism adapted to selectively rotate a motor in a first rotational direction or a second rotational direction. The direction selection mechanism includes: a selector switch slidably or rotatably coupled to a tool and adapted to be selectively positioned in a first position or a second position; a contactless actuator disposed in the selector switch; and a contactless sensor adapted to detect proximity of the contactless actuator.

Description

Technical Field

[0001] The present invention relates generally to manual switches and, more particularly, to a direction selection mechanism for a power tool. Background Art

[0002] Power tools (such as, for example, impact wrenches, electric drills, electric screwdrivers, electric ratchets, etc.) are typically used to output torque to a workpiece (such as a threaded fastener) or via a drill bit or socket. Sometimes, for example, when the workpiece is left-hand threaded, or when the user wishes to loosen a right-hand threaded workpiece with the power tool rather than tighten it, it is necessary to rotate the tool's motor in the opposite direction.

[0003] Existing power tools generally include a direction selection mechanism that selectively controls the rotation direction of the tool motor. The direction selection mechanism is generally located near the starting trigger of the tool.

[0004] In other conventional tools, the direction selection mechanism typically includes a printed circuit board (PCB) having a first exposed conductive trace that is maintained at a reference voltage. Adjacent to the first exposed conductive trace are a plurality of additional exposed conductive traces. A spring-shaped element creates mechanical contact between the first exposed conductive trace and one of the additional exposed conductive traces, and due to the properties of the conductive material from which it is constructed, the spring-shaped element also creates electrical contact between them. The spring-shaped element is used to conduct a reference voltage from the first conductive trace to one of the additional conductive traces, where the reference voltage can be measured. The measured voltage is then converted into a user-desired motor rotation direction. The desired direction of rotation is then transmitted to the power tool's motor by selectively switching a motor control element. The additional conductive trace that receives the reference voltage is selected by sliding the spring-shaped element via a user-operated selector lever or switch.

[0005] However, conventional direction select mechanisms are expensive and complex to manufacture due to the complexity and number of parts that need to be manufactured and assembled. In addition, electrical contact corrosion, mechanical wear (i.e., abrasion), mechanical fatigue, ingress of foreign debris, and vibration-related contact loss often occur in conventional direction select mechanisms. Summary of the Invention

[0006] The present invention generally relates to a direction selection mechanism for a power tool (such as, for example, an impact wrench, a power drill, a power screwdriver, a power ratchet, etc.) for selecting between a first motor rotation direction and a second motor rotation direction (e.g., clockwise and counterclockwise). The direction selection mechanism utilizes a non-contact sensor and an actuator to sense the position of a selector lever or switch operated by a user relative to a known point to determine the motor rotation direction of the power tool desired by the user. The non-contact sensor and the non-contact actuator can be separated by arranging the non-contact actuator outside the housing of the trigger switch assembly. Compared with current designs, the present invention results in a smaller number of parts, simpler manufacturing, and longer component life.

[0007] In one embodiment, the present invention generally comprises a tool. The tool includes a motor adapted to selectively rotate in a first rotational direction or a second rotational direction; a trigger adapted to operate the motor; and a direction selection mechanism adapted to select the direction of motor rotation. The direction selection mechanism includes a selector switch coupled to the tool and adapted to be selectively positioned in a first position or a second position; a contactless actuator disposed in the selector switch; and a contactless sensor adapted to detect proximity of the contactless actuator.

[0008] In another embodiment, the present invention broadly includes a direction selection mechanism adapted to selectively rotate a tool motor in a first rotational direction or a second rotational direction. The direction selection mechanism includes a selector switch coupled to the tool and adapted to be selectively set in a first position or a second position; a contactless actuator disposed in the selector switch; and a contactless sensor adapted to detect proximity of the contactless actuator. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to facilitate understanding of the claimed subject matter, embodiments thereof are shown in the accompanying drawings. By examining these embodiments, when considered in conjunction with the following description, the claimed subject matter, its construction and operation, and its many advantages should be readily understood and appreciated.

[0010] Figure 1 is a perspective view of an example tool incorporating an embodiment of the present invention.

[0011] Figure 2 yes Figure 1 A side cross-sectional view of an example tool.

[0012] Figure 3 is a top view of an exemplary direction selection mechanism according to an embodiment of the present invention, wherein one of a first rotational direction and a second rotational direction is selected.

[0013] Figure 4According to one embodiment of the present invention Figure 3 A top view of an exemplary direction selection mechanism of FIG. 1 , wherein the other of a first rotational direction and a second rotational direction is selected. DETAILED DESCRIPTION

[0014] Although the present invention admits of many different forms of embodiment, embodiments of the invention are shown in the accompanying drawings and will be described in detail herein, including preferred embodiments. It should be understood that this disclosure should be considered an example of the principles of the invention and is not intended to limit the broad aspects of the invention to any one or more embodiments shown herein. As used herein, the term "present invention" is not intended to limit the scope of the claimed invention, but is used to discuss exemplary embodiments of the invention for illustrative purposes only.

[0015] The present invention generally relates to a rotational direction selection mechanism for a power tool having a rotational output (such as, for example, an impact wrench, a power drill, a power screwdriver, a power ratchet, etc.), for selecting between a first motor rotational direction and a second motor rotational direction (e.g., clockwise and counterclockwise). The direction selection mechanism of the present invention utilizes one or more non-contact sensors and one or more non-contact actuators to sense the position of a selector lever or switch operated by a user relative to a known point to determine the user's desired motor rotational direction of the power tool. The non-contact sensor and the non-contact actuator can be separated by arranging the non-contact actuator outside the housing of the trigger switch assembly and arranging the non-contact sensor inside the housing.

[0016] See also Figures 1 to 4 , an exemplary tool (e.g., an impact wrench) 100 incorporating one embodiment of the present invention is described. However, it should be appreciated that the present invention is not so limited and may be implemented not only in other power tools (such as, for example, impact wrenches, power drills, power screwdrivers, power ratchets, impact drivers, etc.), but also in other devices that include a motor with a selectable rotational output (e.g., kitchen appliances). In one embodiment, the tool 100 includes a housing 102 assembled from a first clamshell housing portion and a second clamshell housing portion, the first clamshell housing portion and the second clamshell housing portion being joined together to collectively form the housing 102. The motor 108 and other additional components of the tool 100 are disposed in the motor housing portion 106. The output driver 110 is adapted to engage with a suitable tool (such as a socket or tool head, etc.) for connection to an associated fastener, etc., that applies torque in a known manner.

[0017] A trigger 112 for controlling the operation of the motor 108 is provided on the handle portion 104, adjacent to the motor housing portion 106. By pressing the trigger 112, power can be supplied to the motor 108, so that the motor 108 selectively rotates in a first rotational output direction or a second rotational output direction (e.g., a clockwise rotational output direction or a counterclockwise rotational output direction), thereby selectively driving the output driver 110 in the first direction or the second direction.

[0018] In one embodiment, the tool 100 is powered by a battery (not shown) that can be removably engaged at the battery interface 114 of the handle portion 104. In one embodiment, the battery can be rechargeable. However, the present invention is not limited to battery-powered tools and can be implemented in tools that receive power from other power sources (such as, for example, external power via a cord).

[0019] In one embodiment, the handle portion 104 is a trigger handle that extends substantially perpendicular to the motor housing portion 106, and the trigger 112 is disposed near the intersection of the handle portion 104 and the motor housing portion 106. The trigger 112 can be biased so that the user can depress the trigger 112 inward relative to the tool 100 (which is detected by a trigger switch 116 using known methods) to operate the motor 108, and release the trigger 112, wherein the biased nature of the trigger 112 biases the trigger 112 outward relative to the tool 100 (which is detected by the trigger switch 116) to stop the motor 108. The trigger switch 116 is disposed in the trigger housing 118. In one embodiment, the trigger 112 can be a position-sensitive trigger that also operates the motor 108 at different speeds. For example, the further the trigger 112 is depressed, the faster the motor 108 will operate.

[0020] The direction of the motor 108's rotational output is selectively controlled by a direction selection mechanism 120, thereby selectively controlling the direction of the output rotational output of the output driver 110. The direction selection mechanism 120 includes a selection switch 122, a contactless actuator 124, and a contactless sensor 126. The selection mechanism is adapted to switch the user's desired rotational direction of the motor 108 by determining the proximity of the contactless actuator 124 to the contactless sensor 126. The motor controller can utilize the determination of the proximity of the contactless actuator 124 to selectively switch the motor control element to control the direction of current flowing through the motor 108, thereby controlling the rotational direction of the motor 108.

[0021] The selector switch 122 can be, for example, a lever or a knob. In one embodiment, the selector switch 122 is slidably coupled to the housing 102 and is adapted to be selectively moved by a user in a linear direction between a first position and a second position. For example, if the selector switch 122 is set in the first position (e.g., Figure 3As shown in FIG, when the trigger 112 is pressed, the motor 108 rotates the output driver 110 in a first rotational direction (eg, clockwise). Similarly, if the selector switch 122 is set to the second position (eg, Figure 4 16. As shown in FIG. 16 , when the trigger 112 is depressed, the motor 108 rotates the output driver 110 in a second direction (e.g., counterclockwise or clockwise) that is opposite to the first direction. In another embodiment (not shown), a selector switch 122 is rotatably coupled to the housing 102 and is adapted to be selectively rotated clockwise and counterclockwise by a user between a first position and a second position to select the rotational direction of the output driver 110. U.S. Patent Application No. 16 / 834,665 illustrates an exemplary selector switch rotatably coupled to the housing of a power tool.

[0022] In the embodiment shown, the selector switch 122 is an elongated lever having opposing first and second ends 128 and 130. Figure 3 and Figure 4 ), the selector switch 122 includes spaced-apart recesses 132 formed to provide structural rigidity thereto. The selector switch 122 can be made of various types of polymeric materials or other suitable materials. In one embodiment, the selector switch 122 is a single integral body formed, for example, by injection molding. In another embodiment, the selector switch 122 includes a first portion and a second portion that are releasably engaged together and can be separated from each other to allow the non-contact actuator 124 to be arranged within the selector switch 122. In one embodiment, a stop structure (such as, for example, a stop ball or a stop pin) can maintain the selector switch in the first position or the second position and provide tactile feedback to the user when the user has successfully selected the direction of rotation of the motor 108 using known methods.

[0023] The non-contact actuator 124 is provided in the selection switch 122. Figure 3 and Figure 4 , the selector switch 122 is shown transparently to better illustrate the contactless actuator 124 disposed within the selector switch 122. In one embodiment, the contactless actuator 124 is disposed within one of the recesses 132. In another embodiment, the selector switch 122 is molded around the contactless actuator 124. In one embodiment, the contactless actuator 124 is a magnet.

[0024] The contactless sensor 126 is adapted to detect the proximity of the contactless actuator 124 without physically contacting it. Thus, the selector switch 122 can be positioned to determine whether the selector switch 122 is in the first position or the second position. In one embodiment, the contactless sensor 126 is a transducer (such as, for example, a Hall effect sensor) that changes its output voltage in response to changes in a magnetic field. The output voltage can then be used by the motor controller to control the motor 108. For example, when the contactless actuator 124 and the contactless sensor 126 are close (i.e., when the contactless actuator 124 passes over the contactless sensor 126), the contactless sensor 126 outputs a first voltage that causes the motor controller to operate the motor 108 in a first rotational direction. Conversely, when the contactless actuator 124 moves away from the contactless sensor 126, the contactless sensor 126 changes its output voltage to a second voltage that causes the motor controller to operate the motor 108 in a second rotational direction. In another embodiment, the contactless sensor 126 is a capacitive sensor adapted to sense the proximity of the contactless actuator 124. In another embodiment, the contactless sensor 126 is an inductive sensor adapted to sense the proximity of the contactless actuator 124. In this embodiment, the contactless actuator 124 is constructed of a metallic material. In another embodiment, the contactless actuator 124 emits light adapted to be detected by the contactless sensor 126, which comprises a light sensor.

[0025] In one embodiment, the contactless sensor 126 is coupled to a printed circuit board (PCB) 134. The PCB 134 can be disposed within the trigger housing 118 and positioned proximate to the contactless actuator 124 relative to the selector switch 122 when the selector switch 122 is moved between the first position and the second position. The PCB 134 can also include various electronic components for operating the tool 100. Although a single contactless sensor 126 is shown, the present invention is not limited in this regard, and any number of contactless sensors can be utilized to determine the position of the contactless actuator 124. In another embodiment, the PCB 134 is not disposed within the trigger housing 118, thereby allowing the direction selection mechanism 120 to be moved away from the trigger 112 to any desired position on the housing 102.

[0026] Thus, during use of the tool 100 (i.e., when the operator actuates the trigger 112), the motor 108 selectively drives the output driver 110 in a clockwise or counterclockwise direction based on the position of the selector switch 122 determined using non-contact sensing. By utilizing non-contact sensing, the present invention can avoid problems associated with existing selectors, such as electrical contact corrosion, mechanical wear (abrasion), mechanical fatigue, ingress of foreign debris, and vibration-related contact loss.

[0027] As used herein, the term "bonded" may refer to any direct or indirect physical, electrical, magnetic or other connection between two entities. The term "bonded" is not limited to a fixed direct connection between two entities.

[0028] The content set forth in the above description and accompanying drawings is provided by way of example only and not limitation. Although specific embodiments have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the broader aspects of the inventor's contribution. The actual scope of protection claimed is intended to be defined by the following claims when viewed in their proper perspective based on the prior art.

Claims

1. A tool adapted to apply torque to a workpiece, the tool comprising a motor adapted to selectively rotate in a first rotational direction or a second rotational direction, a motor controller, and a trigger adapted to operate the motor, the tool comprising: a direction selection mechanism adapted to selectively rotate the motor in the first rotational direction or the second rotational direction, the direction selection mechanism comprising: a selector switch coupled to the tool and adapted to be selectively disposed in a first position or a second position, wherein the selector switch includes a recess; a non-contact actuator disposed within one of the recesses of the selector switch; and A contactless sensor is adapted to detect proximity of the contactless actuator.

2. The tool according to claim 1, characterized in that The first rotational direction is selected when the selector switch is set to the first position, and the second rotational direction is selected when the selector switch is set to the second position.

3. The tool according to claim 1, characterized in that Also included is a trigger housing, wherein the non-contact sensor is disposed within the trigger housing.

4. The tool according to claim 3, characterized in that The contactless sensor is coupled to a printed circuit board that is disposed within the trigger housing and is proximate to the contactless actuator.

5. The tool according to claim 1, characterized in that The contactless actuator includes a magnet.

6. The tool according to claim 1, characterized in that The non-contact sensor includes a Hall sensor.

7. The tool according to claim 1, characterized in that The non-contact sensor includes an inductive sensor.

8. The tool according to claim 1, wherein The non-contact sensor includes a capacitive sensor.

9. The tool according to claim 1, wherein The contactless actuator emits light, and the contactless sensor includes a light sensor adapted to sense the light emitted by the contactless actuator.

10. The tool according to claim 1, wherein The contactless sensor is bonded to a printed circuit board.

11. The tool according to claim 1, wherein Also included is a detent structure adapted to retain the selector switch in either the first position and the second position.

12. A direction selection mechanism, adapted to selectively rotate a motor in a first rotational direction or a second rotational direction, the direction selection mechanism comprising: a selector switch slidably engaged to the tool and adapted to be selectively disposed in a first position or a second position, wherein the selector switch includes opposing first and second end portions, recesses formed in the selector switch between the first and second end portions, and ribs separating the recesses; a non-contact actuator disposed within one of the recesses of the selector switch; as well as A contactless sensor is adapted to detect proximity of the contactless actuator.

13. The direction selection mechanism according to claim 12, characterized in that: The first rotational direction is selected when the selector switch is set to the first position, and the second rotational direction is selected when the selector switch is set to the second position.

14. The direction selection mechanism according to claim 12, characterized in that: The non-contact sensor is disposed in a trigger housing of the tool.

15. The direction selection mechanism according to claim 12, characterized in that: The contactless actuator includes a magnet.

16. The direction selection mechanism according to claim 12, characterized in that: The non-contact sensor includes a Hall sensor.

17. The direction selection mechanism according to claim 12, characterized in that: The contactless sensor is bonded to a printed circuit board.

18. The direction selection mechanism according to claim 12, characterized in that: The selector switch is molded over the contactless actuator.

19. The direction selection mechanism according to claim 12, characterized in that: The non-contact sensor includes an inductive sensor.

20. The direction selection mechanism according to claim 12, characterized in that: The non-contact sensor includes a capacitive sensor.

21. The direction selection mechanism according to claim 12, characterized in that: The contactless actuator emits light, and the contactless sensor includes a light sensor adapted to sense the light emitted by the contactless actuator.

Images