Patent Application
20160258291
The present invention relates broadly to reversing mechanisms for pneumatic or hydraulic power tools. More particularly, the present invention relates generally to a reversing mechanism that selectively changes the rotational direction of a pneumatic or hydraulic power tool by redirecting air or fluid in a desired direction.
Many tools are powered by pneumatic air or hydraulic fluid that provides the necessary pneumatic or hydraulic power to the tool. Impact wrenches, for example, can use pressurized air to impart torque to a work piece to loosen or tighten the work piece. At times, the rotational direction of the tool must be reversed, for example, when the work piece is left-hand threaded or when the user wishes to tighten the work piece instead of loosen it with the power tool.
Existing pneumatic and hydraulic tools include reversing mechanisms that selectively control the rotational direction of the tool. In some conventional pneumatic or hydraulic tools, the reversing mechanism is located on the rear of the tool, and can be a rotational knob that the user can use to select the desired rotational direction of the tool when rotated accordingly. In other tools, the reversing mechanism is an axially depressible button that changes the rotational direction of the tool by directing air or fluid in either of the clockwise or counterclockwise directions. These reversing mechanisms, however, are also typically located on the rear of the tool or in an otherwise hard to reach place, and not ergonomically located near the user's fingers during use of the tool, for example, near a trigger that causes the release of pressurized air or fluid. Such a location typically requires the user to disengage the tool from a work piece to change the rotational direction of the tool.
An embodiment of the present invention includes a reversing mechanism for pneumatically or hydraulically powered tools that converts axial motion of a mechanical button into rotational motion of a valve disposed in the tool to selectively change a rotational direction of the tool. A user can selectively depress the button to select, for example, either of clockwise or counterclockwise rotational directions of the tool. By depressing the button, the button linearly moves an internally disposed base, and thus rotates a valve coupled to the base. Rotation of the valve aligns a barrier disposed on the valve in to a position to direct pressurized air or fluid into a rotor housing in a direction substantially tangential to the selected rotational direction of the tool.
Another embodiment of the present invention broadly comprises a tool having a motor with a rotor adapted to be operated pneumatically or hydraulically to rotate in either of first and second rotational directions, such as clockwise and counterclockwise, and a reversing mechanism adapted to allow a user to select either of the first and second rotational directions.
The reversing mechanism includes a base having first and second openings, first and second buttons respectively coupled to the base in the first and second openings and opposingly disposed on the tool (e.g., the first button disposed on the left side of the tool and the second button disposed on the right side of the tool), and a valve rotatably or movably coupled to the base, such that axial movement of the first or second buttons causes the valve to rotate and direct air or fluid in a desired direction to cause the tool to rotate in either of the first and second directions.
Another embodiment comprises a reversing mechanism including a base having first and second openings, first and second buttons respectively coupled to the base in the first and second openings to allow a user to select either of first and second rotational directions for the tool, based on which of the first and second buttons are depressed, and a valve rotatably coupled to the base such that axial movement of the first or second button causes the valve to rotate and direct air or fluid in a desired direction to cause the tool to rotate in either of the first or second rotational direction.
Yet another embodiment comprises a method of operating a tool including providing a valve rotatable between first and second positions, wherein the valve is adapted to direct air or fluid in a first direction when disposed in the first position to cause the tool to rotate in a first direction, and a second direction when disposed in the second position to cause the tool to rotate in a second direction, actuating the first button in an axial direction, thereby causing a valve operably coupled to the first button to rotate to the first position, and actuating the trigger to cause air or fluid to dispense, thereby causing the tool to rotate in the first rotational direction.
For the purpose of facilitating an understanding of the invention, there are illustrated in the accompanying drawings embodiments thereof, from an inspection of which, when considered in connection with the following description, the invention, its construction and operation, and many of its advantages should be readily understood and appreciated.
While the present invention is susceptible of embodiments in many different forms, there is shown in the drawings, and will herein be described, embodiments of the invention, including a preferred embodiment, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to any one or more embodiments illustrated or disclosed.
An embodiment of the present invention comprises a reversing mechanism for a pneumatic or hydraulically operated tool. The reversing mechanism allows a user to selectively change the rotational direction of a motor having a rotor disposed in the tool by depressing one of first and second buttons respectively disposed on opposing first and second sides of the tool. The buttons can be coupled to a base internally disposed in the tool that, when actuated, causes rotation of a valve rotatably or movably coupled to the base and shift a barrier disposed on the valve to cause pressurized fluid or air to travel in a direction tangential to the selected rotational direction of the tool. The barrier selectively directs pressurized air or fluid from an external source and more efficiently causes the air or fluid to rotate a rotor disposed in a motor housing in a desired rotational direction by being angled substantially tangential to the desired rotational direction of the rotor. It will be appreciated that while the present invention is discussed generally as applicable to pneumatically powered tools, the present invention is applicable and adaptable to any type of tool that uses pressurized air or fluid, such as hydraulically powered or other tools.
Referring to
In some embodiments, the first and second buttons 110, 115 are operatively coupled together so that only one of the first and second buttons 110, 115 can be depressed at a time. In such an embodiment, depressing the first button 110 inwardly relative to the tool 10 causes the second button 115 to move outwardly relative to the tool 10. Likewise, depressing the second button 115 inwardly relative to the tool 10 causes the first button 110 to move outwardly relative to the tool 10. For example, the first and second buttons 110, 115 can be rotatably or movably coupled to a base 120 disposed within the tool 10. The base 120 serves as the structural backbone of the reversing mechanism 100. The base 120 is coupled to a valve 125 that extends from the base 120 toward a rear of the tool 10. The valve 125 is rotatably coupled to the base 120 such that translational movement of the base 120 causes the valve 125 to rotate about an axis of the valve 125 and selectively distribute air or fluid to cause a clockwise or counterclockwise direction of a rotor disposed within the tool 10.
Referring to
The first and second retention members 155, 160 can have an outer diameter larger than the diameter of the first and second base openings 165, 170 such that the retention members 155, 160 retain the ends of the first and second button arms 135, 140 within the base 120 and operatively couple the button arms 135, 140 to the base 120, and further prevent the button arms 135, 140 from being disengaged from the base 120. Further, the button arms 135, 140 can have button arm ends 171, 172 that respectively push against first and second base walls 173, 174 when the relevant button 110, 115 is pushed inwardly towards the base 120. Alternately, the buttons 110, 115 can have a second retention member disposed on the button arms 135, 140 outside of the base 120 to further operatively couple the button arms 135, 140 to the base 120 and allow the button arms 135, 140 to push the base 120 when the relevant button 110, 115 is pushed inwardly. Accordingly, movement of the buttons 110, 115 causes movement of the base 120 and, by extension, rotational movement of the valve 125.
The first and second retention members 155, 160 can be any structure or device that prevents the button arms 135, 140 from being disengaged from the base 120. For example, the retention members 155, 160 can be washers, spring washers, retaining rings, spring clips, cotter pins, or any other device or structure that can operatively couple the button arms 135, 140 with the base 120.
The valve 125 can include a first end 125a distal to the base 120, and a second end 125b proximate to the base 120. The valve 125 can be rotatably coupled to the base 120 at or near the second end 125b. For example, the valve 125 can include a slot 175 where the valve 125 couples with the base 120 in any manner, for example, by rotatably coupling to a pin. The valve 125 can be operatively coupled to the tool 10 on the first end 125a in a rotatable manner, or can be freely rotating without any coupling at the first end 125a.
The base 120 can include a pin 185 that couples with the slot 175 and allows the valve 125 to rotate relative to base 120. Alternately, the valve 125 can include a pin and can be coupled to the base 120, either in a slot of the base 120 or otherwise. For example, the valve can have a radial dimension and an axial dimension, as shown. The base 120 can be coupled to the valve 125 at a substantially outermost radial portion of the radial dimension such that linear movement of the valve 125 perpendicular to the axial direction causes rotational movement of the valve about an axis of the valve 125. For example, the pin 185 can be coupled to the slot 175 at an outermost radial portion of the valve 125. In this manner, linear movement of the base 120 will be in a direction tangential or nearly tangential to the circumference of the valve 125, and will move the valve 125 rotationally.
The valve 125 can include a barrier 190 that selectively directs the flow of pressurized air or fluid from an external source 400 to within the tool 10, as shown in
The process for selecting a rotational direction tool 100 will now be discussed with reference to
Rotating the valve 125 causes rotation of the barrier 190 within the tool 10 and selects the rotational direction of the tool. For example, the barrier 190 can be aligned to the rotational direction of air flow to distribute the air through the rotor 405 along a circumferential channel 410. The barrier 190 can be a flat or ramped surface extending in a radial direction of the valve 125 to better direct the air in the direction substantially tangential to the desired rotational direction of the tool 100 to more efficiently distribute the air. As shown in
The reversing mechanism 100 can also include a tactile response mechanism that notifies the user when the user has successfully reversed the rotational direction of the tool. For example, as shown in
As is known in the art, an air motor needs early and late exhaust ports. These are sometimes referred to as primary (early) and secondary (late) exhaust ports. The primary ports are typically apertures approximately diametrically opposed of the inlet. Secondary ports are later in the expansion process of the motor.
In a reversible motor, the inlet ports in the counterclockwise direction become the secondary exhaust ports in the clockwise direction, and vice versa, creating challenges for the tool designer. The valve 125 of the present application solves this problem by having a forward section of the valve 125 control the inlet gas flow (for example, by virtue of the barrier 190) and a rear section control the exhaust air flow (for example, by virtue of the passage 192). This allows a single air-flow pocket 205 in the cylinder assembly act as either the inlet or the secondary exhaust and improve air flow in the tool 10.
The above structure allows for a single air flow pocket in the assembly shown in
As discussed herein, the tool 10 can be a pneumatic tool such as an impact wrench. However, the tool 10 can be any pneumatically or hydraulically powered or hand-held tool, such as a ratchet wrench, torque wrench, impact wrench, drill, saw, hammer, or any other tool.
As used herein, the term “coupled” and its functional equivalents are not intended to necessarily be limited to a direct, mechanical coupling of two or more components. Instead, the term “coupled” and its functional equivalents are intended to mean any direct or indirect mechanical, electrical, or chemical connection between two or more objects, features, work pieces, and/or environmental matter. “Coupled” is also intended to mean, in some examples, one object being integral with another object.
The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While particular embodiments have been shown and/or 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 invention. The actual scope of the protection sought is intended to be defined in the following claims when viewed in their proper perspective.
