Patent Application
20120241654
The present invention relates generally to hand knobs. More specifically, the present invention relates to hand knobs having asymmetrical flutes.
Hand knobs are used in a variety of applications to provide a gripping object or gripping surface. Some hand knobs are provided on items that need to be pulled, e.g., dresser drawers. These hand knobs are generally fixed with respect to the item. Typical hand knobs of this type include a larger body portion and a narrowed neck portion that is attached to the item. A user may grasp the larger body portion, placing a palm of the hand proximate the larger body portion, while the fingers wrap around a back of the larger body portion, the narrowed neck portion fitting between two fingers. The larger body portion in this case is generally circular or conical in shape with a smooth or textured exterior.
In other situations, a hand knob is rotated to operate a mechanism, such as a door latch, or a fluid valve. In the case of a door latch, the hand knob (or door knob) is shaped similar to the fixed hand knobs discussed above, but the door knob is rotatably connected to a door. When the door knob is rotated, a door latch operates to latch and unlatch a door. The rotation forces required to operate the door latch are substantially similar in each direction, whether. latching or unlatching the door. Often, the door knob may be biased to the latched position with a biasing member, such as a spring. Because the rotational forces are substantially similar in each direction and because the rotational forces are generally light, such door knobs are generally smooth and symmetrically shaped on an outer surface.
In the case of fluid control valves, operation of the valve may require greater rotational forces on the hand knob. As a result, valve hand knobs may include one or more symmetrical protrusions or recesses in an external surface to increase leverage and/or gripping effectiveness for the hand knob.
Known hand knobs for fluid control valves are based on the assumption that rotational forces in either direction will be substantially the same. As a result, known hand knobs for fluid control valves are generally symmetrical about a rotational axis. Moreover, any protrusions or recesses in the hand knob are also known to he symmetrical both with respect to a radius extending from the rotational axis to the outer perimeter of the hand knob, and with respect to other protrusions or recesses. While such hand knobs provide a more effective gripping surface than smooth surfaced hand knobs, known hand knobs are not generally as effective in a valve closing direction as a valve opening direction because closing the valve often requires mo rotational force to overcome fluid flowing through the valve, than opening the valve.
An ergonomic hand knob for a control valve includes a valve body and a plurality of flutes disposed on the valve body, each flute including a flute surface. The flute surface is asymmetric with respect to an innermost point of the flute surface. A first flute surface has a greater slope than a second flute surface. The first flute surface lays in a direction of tightening from the innermost point and the second flute surface lays in a direction of loosening from the innermost point.
Although the following text sots forth a detailed description or an exemplary embodiment of the invention, it should be understood that the legal scope of the invention is defined by the words of the claims set forth at the end of this patent. The detailed description is to be construed as exemplary only and does not describe every possible embodiment of the invention since describing every possible embodiment would be impractical, if not impossible. Based upon reading this disclosure, those of skill in the act may be able to implement one or more alternative embodiments, using either current technology or technology developed after the filing date of this patent. Such additional indictments would still fall within the scope of the claims defining the invention.
Referring now to the drawings,
The knob body 12 includes one or more flutes 14 that provide an improved gripping surface. The flutes 14 are defined by hollowed out or concave portions of the knob body 12. The flutes 14 are separated by one or more protrusions or teeth 16. Outer surfaces of he teeth 16 may define a generally circular perimeter 18 of the valve body 12. The flutes 14 include an innermost point 20 that is defined as an intersection between a flute surface 22 and a radius 23 drawn from an axis rotation 24 of the hand knob 10, wherein the distance between the flute surface 22 and the axis of rotation 24 is minimized about a circumference of the valve body 12. The innermost point 20 defines a line or trough 26 along the flute 14, as illustrated in
The flute surfaces 22 as illustrated in
y=7E−05x4+0.002x3+0.0295x2+0.0389x−0.0289
wherein the origin lies at the innermost point 20 of the flute 14. Because the knob body 12 tapers inwardly from top to bottom (as viewed in
Each flute 14 is asymmetric about the line or trough 26. Each flute 14 includes a first surface 40 and a second surface 42 separated by the line or trough 26. The first surface 40 lies in the tightening direction A from the radius 23 and the second surface 42 lies in the loosening direction from the radius 23. Each surface 40, 42 has a slope defined by a line drawn from the innermost point 20 or trough 26 to an intersection of the surface 40, 42 and the circular perimeter 18. A first slope 46 of the first surface 40 is steeper than a second slope 48 of the second surface 42. In other words, the first slope 46 is inclined more relative to the circular perimeter 18 than the second slope. An angle D between the first slope 46 and the radius 23 is in the range of approximately 48 degrees to approximately 68 degrees, preferably in the range of approximately 52 degrees to approximately 64 degrees, and more preferably in the range of approximately 56 degrees to approximately 60 degrees, and angle G between the second slope 48 and the radius 23 is in the range of approximately 70 degrees to approximately 90 degrees, preferably in the range of approximately 74 degrees to approximately 86 degrees, and more preferably in the range of approximately 78 degrees to approximately 82 degrees. The relationship between the first and second surfaces 40, 42 results in greater leverage and thus, the application of greater turning force, in the tightening direction A when the hand knob 10 is rotated.
In other embodiments, the hand knob 10 may be operatively engaged with a planetary gear system to provide increased or reduced torque, as required, when operating the hand knob 10. The hand knob 10 could be engaged with the planetary gear system to provide more torque when tightening the hand knob 10, and disengaged from the planetary gear system into direct drive contact when loosening the hand knob 10.
Turning now to
Numerous modifications and alternative embodiments of the invention will be apparent to those skilled in the art in view of the forgoing description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the present disclosure may be varied without departing from the spirit of the invention, and the exclusive use of all modifications which are within the scope of the claims is reserved.
