Patent Application
20110221147
The present invention relates to handles for garden tools and, more specifically, to a handle shaped as a triangular loop and structured for use with a wheelbarrow.
As is well known, a wheelbarrow has a hopper or tray and a frame assembly. The frame assembly includes at least one wheel, typically disposed at the front of the tray, and a pair of handles extending behind the tray. While some wheelbarrows are structured for transport only, most wheelbarrows include a wheel guard that extends around the front side of the wheel. When the handles are lifted, the wheel guard engages the ground, thereby allowing the user to more easily tip the tray.
Traditionally, the handles of a wheel barrow were simple shafts which may have included a shaped grip. When the wheelbarrow was at rest, the handles extended generally horizontally, or more typically with a slight upward angle. In this configuration, the handles, and more specifically the grips, could be supported by a user's fingers. That is, the user's fingers would engage the lower side of the grips. When the user lifted their hands, the wheelbarrow would rotate slightly about the axis of the wheel, thereby lifting a pair of supports off the ground and allowing the user to easily move the wheelbarrow. Generally, this is an ergonomic configuration. That is, the user's wrists were generally straight.
This type of handle, however, was not as ergonomic as the user lifted the handles when dumping the cargo out of the tray. That is, as the user lifted the handles, the user's wrist's bent until the user could no longer grip the handles from above. At that point, if the tray needed to be tilted further, the user would have to switch from an overhand grip on the handle to an underhanded grip. This motion was, typically, performed quickly and may be described as “clean-and-jerk,” as in weightlifting. Thus, the handles and grips of a traditional wheelbarrow handle is not especially ergonomic when used to tip the tray. Moreover, this type of handle required the user to, essentially, release the handle during the clean-and-jerk transition between grips.
Several attempts have been made to overcome this uncomfortable type of wheelbarrow grip. Generally, and as seen in U.S. Pat. Nos. 5,601,298; 5,810,375; and 6,336,254 the solution was to provide a downwardly extending arcuate grip extending from the distal end of the handle. This type of handle allowed the user to “walk” their grip about the handle. That is, as the handle traveled over the arc defined by the lifting motion, the user could make small adjustments in the position of their hands on the arcuate portion of the handle. The size/shape of the arcuate portion was structured to provide the user with a handle that allowed their wrist to be generally straight as the wheelbarrow handle traveled through the lifting arc. While such handles are an improvement over the traditional straight handles, such handles are still uncomfortable as a human hand is not structured to comfortably grip a member with a small and/or continuous radius of curvature. This is a disadvantage given the stress placed on a user's fingers when tilting the wheelbarrow.
The disclosed and claimed concept relates to a handle that has three grips. Such a handle is adapted for use with a wheelbarrow, but may be used on other tools or devices as well. The handle body forms a triangular loop having generally arcuate transition portions between the grips. The grips are angled relative to the wheelbarrow frame assembly handle shafts so as to provide the user with a comfortable grip during both transport of the wheelbarrow as well as during a lifting motion of the handles. That is, the handle includes a first grip that, essentially, corresponds to a traditional grip in that the grip is substantially parallel, and more preferably aligned, with the longitudinal axis of the handle shafts. The first grip is used during normal transport of the wheelbarrow with the user's fingers engaging the lower side of the grip. The second grip, which is disposed below the first grip, is angled about 60 degrees relative to the first grip. In this configuration, the second grip is positioned so that the user may comfortably grasp the handle while the wheelbarrow is being tilted forward. The third handle is angled about 25 degrees relative to the first grip. In this configuration, the third grip is positioned so that the user may comfortably grasp the handle while the wheelbarrow is in a substantially vertical orientation.
A full understanding of the invention can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which:
As used herein, directional terms, such as, but not limited to, “forward,” “back,” “right,” “left,” “upper,” “lower,” and “lateral” correspond to the orientation of the wheelbarrow from the perspective of a user standing at the handle portion looking toward the tray—that is, the normal position a user would occupy to move the wheelbarrow. Such directional terms are not limiting upon the claims.
As used herein, “coupled” means a link between two or more elements, whether direct or indirect, so long as a link occurs.
As used herein, “directly coupled” means that two elements are directly in contact with each other.
As used herein, “fixedly coupled” or “fixed” means that two components are coupled so as to move as one while maintaining a constant orientation relative to each other.
As used herein a “handle” is an element that is generally structured to be grasped by a user and not an element that is merely capable of being grasped. For example, a wheelbarrow frame assembly may have a plurality of elongated members that may be grasped, but only the handles are structured, i.e. positioned and sized, to be grasped by the user.
As used herein, a “grip” is the portion of a handle structured to be gripped by a user. A “grip” includes a portion of a handle having a sufficient, substantially straight length of handle to accommodate the width of four fingers, and may also include a textured surface on the handle and/or a padded portion of the handle. A “grip” must, however, be distinguishable from other portions of the handle. For example, a smooth, straight broomstick is a handle without an identifiable grip because no portion of the handle is different than any other portion. Similarly, a smooth, arcuate wheelbarrow handle, such as the one disclosed in U.S. Pat. No. 6,336,254, is only a handle that does not include a “grip” as no portion of the arcuate handle is different than any other portion.
As used herein, the “radius of curvature” of a specific component means a general radius of curvature for the component. That is, the component may not be exactly arcuate, i.e. having a single center, but rather formed from one or more curves, lines and/or splines that approximate an arc. It is noted that a straight handle does not have a “radius of curvature” under this definition. Similarly, the phrase “extending over an arc” includes lines and/or splines that approximate an arc without being exactly arcuate.
A wheelbarrow 10 is shown in
The wheelbarrow 10 further includes a handle 30, shown in
The body handle portion 34 defines an asymmetrical loop 50. The loop 50 has three elongated grip portions, a first grip 52, a second grip 54 and a third grip 56. The loop 50 further has a first transition portion 58 disposed between the first grip 52 and the second grip 54, as well as a second transition portion 60 disposed between the second grip 54 and the third grip 56. The elongated grips 52, 54, 56 provide a surface having sufficient length so as to allow a user to comfortably grasp the grip 52, 54, 56. That is, the grips 52, 54, 56 do not have a radius of curvature smaller than 120 mm. Preferably, the first grip 52 has a length between 120 mm and 210 mm, and more preferably 150 mm. The second grip 54 has a length between 100 mm and 200 mm and more preferably 150 mm. The third grip 56 has a length between 100 mm and 200 mm, and more preferably 140 mm. Further, the first grip 52 has a radius of curvature between about 300 mm and 400 mm, and more preferably about 350 mm. The second grip 54 has a radius of curvature between about 120 mm and 250 mm, and more preferably about 217. The third grip 56 has a radius of curvature between about 300 mm and 400 mm, and more preferably about 280. These measurements are for one embodiment of the body handle portion 34, e.g. for a wheelbarrow handle 30.
The curvature of the grips 52, 54, 56 is, preferably, convex relative to the perimeter of the loop 50. That is, the curvature of the grips 52, 54, 56 compliments the curvature of the loop 50. In an alternate embodiment, as shown in
Another feature of the grips 52, 54, 56 is their angle relative to the handle shaft 26. That is, as described below, the grips 52, 54, 56 are configured to reduce the stress on a user as the user tilts the wheelbarrow 10. As such, the grips 52, 54, 56 are angled so as to allow a comfortable hand/wrist position by the user as the handle shafts 26 move through an arc. The “angles” of the grips 52, 54, 56 are described in reference to the longitudinal axis 29 of the handle shaft 26. The first grip 52 is structured to be used in a manner similar to a traditional wheelbarrow handle. As such, the first grip 52 is structured to extend substantially parallel to, and more preferably aligned with, the handle shaft longitudinal axis 29. The handle body 32 then curves downwardly to the second grip 54. Thus, the second grip 54 is structured to extend at an angle of between about 45 degrees and 75 degrees, and more preferably about 61 degrees, relative to the handle shaft longitudinal axis 29. The handle body 32 then curves forwardly to the third grip 56. Thus, the third grip is structured to extend at an angle of between about 45 degrees and 15 degrees, and more preferably about 25 degrees, relative to the handle shaft longitudinal axis 29.
The first and second transition portions 58, 60 (as well as an unnumbered third transition portion between the third grip 56 and the first grip 52) complete the loop 50. The first transition portion 58 has a radius of curvature between about 40 mm and 200 mm, and is more preferably about 45 mm. The first transition portion 58 extends over an arc of between about 80 degrees and 100 degrees, and more preferably about 90 degrees. The second transition portion 60 has a radius of curvature between about 50 mm and 300 mm, and is more preferably about 57 mm. The second transition portion 60 extends over an arc of between about 45 degrees and 90 degrees, and more preferably about 54 degrees.
As shown in
While the point of changeover varies from person to person, most users will change from the first grip 52 to the second grip 54 when the handle shafts 26 are at an angle of about 25 degrees relative to a horizontal surface, e.g. the ground. At this point in time, the second grip is at an angle of about 95 degrees to a horizontal surface. In this orientation, the user flips from a “finger” grip to a palm grip. That is, the weight of the wheelbarrow 10 is on the user's palms with the fingers encircling the second grip 54 for control. The user may then continue to tilt the wheelbarrow forwardly. As the handle shafts 26 approach a vertical orientation, at about 90 degrees to a horizontal surface, the user will slide their hands to the third grip 56. At the point of the second changeover, the third grip 56 is typically at an angle of about 85 degrees to a horizontal surface. It is noted that just before the first changeover in the user's grasp, the first grip 52 is at an angle of about 25 degrees to a horizontal surface. Just before the second changeover in the user's grasp, the second grip 54 is at an angle of about 29 degrees to a horizontal surface.
While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of invention which is to be given the full breadth of the claims appended and any and all equivalents thereof.
