Abstract:
The handle extension  30  comprises a base  40,  a handle  60,  a handle connector  80  and at least one base connector  100.  The handle extension  30  attaches to a wheelbarrow or other device to improve the user&#39;s leverage, and permit easier use by shorter and taller users, and users with less strength and flexibility. The base  40  is removably and adjustably attached to a wheelbarrow or other device by at least one base connector  100.  The handle  60  of the handle extension  30  is removably and adjustably attached to the base  40.  The user may adjust the handle extension  30  throughout a wide range of positions by adjusting the placement of the base  40  on the device, and by adjusting the handle  60  relative to the base  40.

Description:
FIELD OF INVENTION 
       [0001]    This invention concerns devices to extend handles. 
       BACKGROUND 
       [0002]    Wheelbarrows, carts and other wheeled containers usually have handles to assist the user in lifting, pushing, moving or otherwise operating the container. Similarly, numerous other containers and devices include a handle constituting a lever to provide the user with mechanical leverage in operating the container or device. 
         [0003]    Known wheelbarrow handles, and many other lever-handles, are fixed relative to the wheelbarrow, cart or other container or device, and do not permit adjustment based on the user&#39;s size, strength or physical condition, or on the size or weight of the load. For example, wheelbarrows do not permit adjustment of handles to allow for shorter or taller users or for users with less strength or flexibility. Wheelbarrows also do not permit adjustment of handles to allow for carrying loads longer than the wheelbarrow body, such as rakes, similar garden tools or shovels, without either extending the tool&#39;s handle over the edge of the wheelbarrow body or having the tool&#39;s handle contact the user as the wheelbarrow is moved. 
         [0004]    What is needed is a relatively inexpensive handle extension that is easy to attach to and remove from known wheelbarrow or other handles, which handle extension is adjustable for different heights, strengths and flexibility of users, and for different loads. 
       SUMMARY OF INVENTION 
       [0005]    The improved handle extension  30  comprises a base  40 , a handle  60 , a handle connector  80  and at least one base connector  100 . The handle  60  may include a grip pad  63 . The base preferably is removably and adjustably attached to a wheelbarrow or other device. Neither the wheelbarrow nor other devices, or their respective handles, are part of the invention, but a device handle  120 , such as a wheelbarrow handle, is depicted in  FIGS. 2 ,  3  &amp;  5 , to show the handle extension  30  as it may be attached to known devices. The handle  60  of the handle extension  30  preferably is removably and adjustably attached to the base  40 . The user may adjust the handle extension throughout a wide range of positions by adjusting the location of the base  40  on the device, and by adjusting the handle  60  relative to the base  40 . The handle  60  preferably is held in an adjustably fixed position relative to the base  40  by at least one handle connector  80 . The user may adjust the handle  60  relative to the base  40  by operating the handle connector  80 . 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    These and other features, aspects and advantages of the present invention will become better understood with regard to the following description, appended claims and accompanying drawings, in which: 
           [0007]      FIG. 1  is a side view of the handle extension; 
           [0008]      FIG. 2  is a side view of the handle extension attached to a wheelbarrow handle; 
           [0009]      FIG. 3  is a top view of the handle extension attached to a wheelbarrow handle; 
           [0010]      FIG. 4  is a back view of the handle extension; 
           [0011]      FIG. 5  is an exploded perspective view of the handle extension attached to a wheelbarrow handle; 
           [0012]      FIG. 6  is a top view of a base; 
           [0013]      FIG. 7  is a back view of the base; 
           [0014]      FIG. 8  is a bottom view of the base; 
           [0015]      FIG. 9  is a perspective view of the base; 
           [0016]      FIG. 10  is a top view of a base; 
           [0017]      FIG. 10A  is a top view of the base of  FIG. 10 , marked to show the sectional view of  FIG. 12A ; 
           [0018]      FIG. 11  is a left side view of the base; 
           [0019]      FIG. 12  is a back view of the base; 
           [0020]      FIG. 12A  is a sectional view of the base along the  12 - 12 ′ line in  FIG. 10A ; 
           [0021]      FIG. 13  is a right side view of the base; 
           [0022]      FIG. 14  is a bottom view of the base; 
           [0023]      FIG. 15  is a side view of the handle; 
           [0024]      FIG. 16  is a back view of the handle; 
           [0025]      FIG. 17  is a front view of the base connector compression pad; 
           [0026]      FIG. 18  is a side view of the base connector compression pad; 
           [0027]      FIG. 19  is a back view of the base connector compression pad; 
           [0028]      FIG. 20  is a top view of the base connector compression wedge; 
           [0029]      FIG. 21  is a side view of the base connector compression wedge; 
           [0030]      FIG. 22  is a perspective view of the base connector compression wedge; 
           [0031]      FIG. 23  is a perspective view of an alternative base; 
           [0032]      FIG. 24  is a top view of an alternative base; 
           [0033]      FIG. 25  is a back view of an alternative base; and 
           [0034]      FIG. 26  is a right side view of an alternative base. 
       
    
    
     DETAILED DESCRIPTION 
       [0035]    As shown in  FIGS. 1 ,  3 ,  4  &amp;  15 , the handle extension  30  comprises a base  40 , a handle  60 , a handle connector  80  and at least one base connector  100 . The handle  60  may include a grip pad  63 . The base preferably is removably and adjustably attached to a wheelbarrow or other device handle  120 , shown in  FIGS. 2 ,  3  &amp;  5 . The device handle  120  is not part of the invention, but is depicted to show how the handle extension  30  may be used on a device. The handle  60  of the handle extension  30  preferably is removably and adjustably attached to the base  40 , permitting the user to adjust the extension handle throughout a wide range. 
         [0036]    As used in the specification and claims, “device” refers to wheelbarrows, carts or other containers, structures, products, machines or manufactures which are operated or used with a handle or lever. The containers may be wheeled, as are wheelbarrows, hand carts and wagons. Other devices frequently employ handles or handle-levers having a relatively straight portion, or may be annular, as with many valve handles. Some devices, such as trash containers, may be without wheels, and may have handles of limited size, fixed handles, or no handles. 
         [0037]    The base, shown in  FIGS. 2 ,  5  &amp;  6 - 14 , is used to connect or mount the handle extension  30  to the wheelbarrow or other device. In the embodiment shown in  FIGS. 6-14 , the base  40  comprises a base handle aperture  41 , a base handle aperture port  42 , a base device aperture  43 , a base device aperture port  44 , and a base handle aperture ledge  45 . The base  40  is placed on a device handle  120  or other device attachment point, and removably attached to the device by at least one base connector  100 , shown in  FIGS. 4 &amp; 5 . 
         [0038]    As seen in FIGS.  5  &amp;  17 - 19 , the base connector  100  comprises a base lever  101 , and a compression pad  103  connected by a base post  102 . The base post  102  is movably placed in the base device aperture port  44 , shown in  FIGS. 8 &amp; 11 , so that the base lever  101  is outside the base  40  and the base compression pad  103  is inside the base device aperture  43 . The base device aperture port  44  and base post  102  are threaded with matching threads so that as the base lever  101  is turned, the base compression pad  103  moves in the base device aperture  43 . If a device handle  120  is placed in the base device aperture  43 , the base lever  101  may be turned to rotate the threaded base post  102  within the complimentary threaded base device aperture port  44  to press the compression pad  103  against the device handle  120 . By firmly turning the base lever  101 , the base may be removably fixed to the device. 
         [0039]    The compression pad  103 , shown in  FIG. 5  and in detail in  FIGS. 17-19 , preferably is larger than the base post  102  to compress the device handle  120  more effectively. In the preferred embodiment, the compression pad  103  is approximately circular, having a compression pad diameter  107  of approximately 1.25 inches. The compression pad  103  alternatively may include compression pad projections  104 , shown in  FIG. 18 , to assist in compressing the device handle  120  more effectively. The compression pad  103  may be of a variety of materials, including metal, and if strong enough to withstand the stresses it experiences, plastics. The compression pad front surface  110  may be coated with abrasive materials to increase the coefficient of friction between the compression pad  103  and the device handle  120 . 
         [0040]    Alternatively, the compression pad  103  could be rectangular or other shapes, and could be a variety of sizes as needed to balance economy of construction and the need for adequate compression to resist forces during use. 
         [0041]    As shown in  FIG. 5 , the device handle  120  may be rectangular. In the preferred embodiment for rectangular device handles, there are two base connectors  100 , positioned with the longitudinal axes of their respective base posts at right angles so that the respective compression pads  103  can compress different sides of the rectangular device handle  120 , as shown in  FIGS. 4 &amp; 5 . For rounded or arced device handles, a single base connector  100  having a shape sized to fit the shape of the device handle  120  may be sufficient to hold the base  40  securely on the device. Compression pad projections  104  or abrasive coatings on the compression pad  103  may increase the strength of the connection between the base  40  and device handle  120 . Substantial forces may be exerted on the base  40  due to the leverage created by the handle  60 . 
         [0042]    The base  40  alternatively may be relatively permanently attached to a device or device handle  120 , such as with screws, nails, glue, brackets, welding or numerous other known methods of connecting materials, provided the method of attachment is sufficiently strong to withstand forces exerted when the handle extension  30  is in use. Permanently attaching the base, however, may limit adjustment of the base relative to the device, and restricts use of the handle extension on multiple devices, which flexible and multiple device uses are a benefit of the preferred embodiment using a base  40  removably fixed to a device. 
         [0043]    The handle  60  is movably connected to the base  40  with a handle connector  80 . As shown in  FIG. 15 , the handle  60  comprises a handle-base segment  61  having a length  65  and a handle grip segment  62  having a length  66 . In the preferred embodiment the handle  60  is made of two lengths of 6061 aluminum tubing at an interior segments angle  67  of approximately 80°, welded at the junction of the handle-base segment  61  and the handle-grip segment  62 , where the handle-base segment length  65  is approximately 11.74 inches long, and the handle-grip segment length  66  is approximately 24.74 inches long. The preferred embodiment handle  60  includes a triangular handle reinforcement web  64  of aluminum plate, shown in  FIG. 15 , to strengthen the handle. The handle reinforcement web  64  is approximately 3 inches on each web side  68  connecting to the handle segments, and approximately one-eighth (⅛) to one-quarter (¼) inch thick, as shown by number  70  in  FIG. 16 . A variety of materials could be used for the handle, provided that the handle can withstand the forces exerted when the device is being used. The length of the handle could vary depending on the device on which the handle extension  30  will be used. 
         [0044]    The handle  60  is adjustably mounted in the base handle aperture  41 , as shown in  FIGS. 2 &amp; 3 . As shown in  FIGS. 2 &amp; 9 , the handle  60  is adjustable in the direction of the longitudinal axis  46  of the base handle aperture  41 , shown alternatively as the vertical adjustment axis  47  in  FIG. 2 . The handle is adjustable substantially throughout the range provided by the handle base segment length  65 , limited by the point where the handle reinforcement web  64  prevents insertion of the handle base segment  61  into the base, or where the handle base segment  61  is no longer held by the handle connector  80  in the base handle aperture  41 . 
         [0045]    The handle in the preferred embodiment also can be adjusted a full 360° about the longitudinal axis  46  of the handle-base segment  61 , as indicated by the horizontal adjustment direction  48 , shown in  FIG. 3 . This range of adjustment is facilitated by the round cross-sectional shape of the handle base segment  61  and the complimentary round base handle aperture  41 . 
         [0046]    Numerous alternative shapes could be used, including shapes having right angles in the cross-section of the handle base segment and base segment aperture. Complimentary angles on the base handle aperture  41  and handle base segment  61  generally restrict the range of adjustment of the handle relative to the base  40  and device, but allow the handle to experience greater forces without unwanted movement of the handle relative to the base  40  when the handle extension  30  is in use. Different users&#39; needs dictate the optimal trade-off between the range of motion of the handle base segment  61  in the base  40  and the ability of the handle to resist forces when the handle extension  30  is in use. In the preferred embodiment, the handle base segment  61  includes knurling  69  to increase resistance of the handle to rotational forces when the handle extension  30  is in use. 
         [0047]    As shown in  FIGS. 3 ,  5  &amp;  6 , the handle  60  is removably and movably attached to the base  40  by a handle connector  80  that compresses the handle base segment  61  against the wall  90  of the base handle aperture  41 . As shown in  FIGS. 12 &amp; 12A , the base handle aperture  41  has an elongated portion  49  and a round portion  50 . The elongated portion  49  is larger than the round portion  50 , in that the elongated portion  49  has a cross-section comprising a portion the same size as the cross-section of the round portion  50 , as well as a handle aperture ledge  45  portion. The cross-section of the elongated portion  49  is shown in  FIG. 6 , and the cross-section of the round section  50  is shown in  FIG. 8 . The round portion  50  is sized to movably and removably hold the handle base segment  61 , so that the handle base segment  61  can rotate in the base handle aperture  41 . The elongated portion  49  is sized to hold the handle base segment  61  and the compression wedge  83 . 
         [0048]    As shown in  FIG. 5 , the handle connector  80  has a handle lever  81  and a handle post  82 . Analogous to the compression connector structure used to connect the base to the device, described above, the threaded handle post  82  is placed in the threaded base handle aperture port  42 , and as the handle lever  81  is turned, the handle post  82  compresses the compression wedge  83  to hold the handle base segment  61  firmly between the compression wedge  83 , compression face  85  and wall  90  of the base handle aperture  41 . When the handle connector  80  is loosened, the handle  60  can rotate freely about the longitudinal axis  46 , of the handle base segment  61 , also shown as  48  in  FIG. 3 , to the user&#39;s optimal setting. The handle  60  also may be adjusted to the desired height relative to the device handle  120 , along the vertical adjustment axis  47  shown in  FIG. 2 , to the user&#39;s optimal setting. After adjustment, the handle connector  80  is tightened, and the handle  60  is held in a fixed position until the user again desires to adjust the handle. While the device is in use, such as when a wheelbarrow is being pushed, the base  40  is fixed relative to the device handle  120 , and the handle  60  is fixed relative to the base  40 . 
         [0049]    As shown in  FIG. 5 , the compression face  85  and wall  90  preferably are shaped complimentarily to the handle base segment  61  to better hold the handle base segment. The handle base segment  61  and compression face  85  may have knurling  69  and wedge knurling  84 , respectively, as shown in  FIGS. 5 &amp; 22 , to further improve the holding characteristics, as described above. 
         [0050]    As shown in  FIGS. 20-22 , the compression wedge  83  has a handle post slot  86  to receive the handle post  82 . The compression face  85  in the preferred embodiment, shown in  FIG. 20 , is approximately semi-circular, with a radius of approximately five-eighths (⅝) of an inch. A variety of shapes and sizes of the compression wedge may be more appropriate, depending on the user&#39;s needs. 
         [0051]    The drawings show a single handle extension, but wheelbarrows, carts and other devices having two handles, or which are ordinarily operated with two hands, preferably use two handle extensions, one for each device handle, or one for each user&#39;s hand. 
         [0052]    The preferred embodiment of the base  40  is depicted in  FIGS. 23-26 , which show a configuration having less mass than the alternative shown in  FIGS. 5-14 . Increased mass generally means that the handle extension will be more expensive to manufacture and use. As shown in  FIG. 23 , the preferred embodiment of the base  40  has a reduced base height  55  at the base handle aperture end. This difference can be seen by comparing the embodiment depicted in  FIG. 7 , in which the base height  55  is substantially uniform through out the base length  51 , to the preferred embodiment shown in  FIG. 25 , in which the base height  55  at the base device aperture  43  end is greater than the base height at the base handle aperture end  131 . Additional material is removed from the base top, at the handle aperture end  132 , shown in  FIG. 23 . 
         [0053]    As discussed before, a wide variety of materials, including aluminum, aluminum composites such as aluminum with fly ash, steel, stainless steel, and other alloys can be used to make the base  40 . The materials and method of forming the base  40  can vary depending on the strength of the base needed for a particular application, and cost. 
         [0054]    Additionally, the handle connector  80  and base connector  100  shown are the preferred embodiments primarily due to cost considerations. A wide variety of known clamping and holding structures could be adapted to the base  40  to hold the device handle  120  and the handle  60 . 
         [0055]    As discussed, a variety of sizes of components of the handle extension are appropriate, depending largely on the materials used, the size and nature of the device to which the handle extension is attached, and the optimal range of motion for the particular application. Applicant supplies the following dimensions to facilitate a better understanding of the invention, and not to suggest that the handle extension described by these dimensions is the only size that will function. 
         [0056]    As shown in  FIG. 6 , the alternative base  40  is approximately 6.8 inches in base length  51 , and approximately 4.0 inches in base width at the device aperture end  52 . For the base shown in  FIG. 7 , the device aperture  43  is approximately 2.0 inches in aperture width  53 , and approximately 2.38 inches in aperture height  54 . The base  40  is approximately 4.88 inches in base height  55 . 
         [0057]    The base  40  shown in  FIG. 10 , has a device aperture end arc  56  of approximately 4 inches in diameter; a base handle aperture diameter  58  of approximately 1.255 inches; a base width at base handle aperture  59  of approximately 3.00 inches; and the distance to center of base handle aperture  57  of approximately 1.88 inches. 
         [0058]    The base alternative shown in  FIG. 14  has a distance between the center of the handle aperture and base device aperture port  130  of approximately 2.5 inches. 
         [0059]    Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.