Patent Application
20080106053
1. Field of the Invention
This invention relates to a handle-positioning device for a hand truck, particularly to one possible to easily adjust the height of the handle of a hand truck.
2. Description of the Prior Art
There is a U.S. Pat. No. 6,938,905 disclosing a hand truck, which has a handle that is adjusted in its height by the function of three components, plural stop bars 2210, a spring 2211 and two rings. But this structure is too complicated, not convenient to handle.
This invention has been devised to offer a handle-positioning device having a simple structure than that of the US patent.
The feature of the invention is two position bases and a pull rod. The position bases are fixed on two cross-shaped vertical tubes combined with two side tubular portions of an inverted U-shaped handle. The pull rod can be pulled to the front side a little to release the handle from the cross-shaped vertical tubes to move up and down, and then when the handle is moved up or down, it can be positioned at a needed height by function of the pull rod elastically letting its two bent ends to fit snappingly and automatically in one of the position holes of two vertical sides of the handle to keep the handle at that position or height newly adjusted.
This invention will be better understood by referring to the accompanying drawings, wherein:
A preferred embodiment of a handle-positioning device for a hand truck in the present invention, as shown in
The vertical cross-shaped tubes 10 are respectively provided with a position hole 11 in an inner lower portion, and a center hole for each side tube of the inverted U-shaped handle 14 to fit in from above.
The position bases 12 are respectively made of a plate with an upper bent horizontal portion and a vertical portion, having a position hole 120 in a lower point in the vertical portion to be aligned to the position hole 11 of the vertical cross-shaped tubes 10, a washer 121 welded on the surface of the position base 12 and having a position hole 1210 aligned to the position hole 11 of the vertical cross-shaped tube 10. The upper horizontal portion of each position base 12 is provided with a recessed outer edge 122 having a front shallow curve and a rear deep curve for two side vertical portions of the inverted U-shaped pull rod 13 to resiliently hook in either of the front shallow curve or the rear deep curve.
The inverted U-shaped pull rod 13 is made of a elastic material, having two side vertical portions, which are formed with a short bent end 130 for fitting in the position hole 1210 of the washer 121, the position hole 120 of the position base 12 and further in one of the position holes 140 of each side vertical portions of the handle 14 to keep the handle 14 at a proper height relative to the vertical cross-shaped tubes 10.
The handle 14 is inverted U-shaped, having two side vertical tubular portions and a plurality of the position holes 140 equidistantly bored in the inner side of each side vertical tubular portion for the bent ends 130 of the pull rod 13 to fit therein to keep the handle 14 stabilized at a height relative to the vertical cross-shaped side tubes 10.
In using, when the handle 14 of the hand truck 1 is adjusted at a certain height, the pull rod 13 is in a position with the two bent ends 130 fitted in the position holes 1210, 220, 11 and 140 (one of selected), keeping the handle 14 immovable in a height relative to the two cross-shaped side tubes 10, with a lower point of the two side vertical portions of the pull rod 13 elastically kept in the rear deep curve of the recess 122 of the upper horizontal portion of each position base 12. If the handle 14 in the height just mentioned is needed to be adjusted in a different height relative to the two cross-shaped tubes 10, the pull rod 13 is gripped with one hand at the intermediate section of the horizontal portion and pulled to the front side a little, letting the two side portions to slide from the rear deep curve to the front shallow curve of the recess 122 of each position base 12 and stopped there by the hand still holding the pull rod 13. Meanwhile the two bent ends 130 of the pull rod 13 may retreat out of the position hole 140 of the two vertical tubular portions of the handle 14 but still stays in the position holes 11 and 120 of the cross-shaped vertical tube the position base. At this time, the vertical tubular portions of the handle 14 are no longer stopped by the two bent ends 130, possible to be pulled up or down depending on the necessity. Then a user pulls the handle 14 up or down to let the two side vertical tubes slide up and down in the cross-shaped vertical tubes 10 to permit one of the position holes 140 to move to align to the position hole 11 of each position base 10. Then the pull rod 130, already released by the hand, may resiliently permit the two bent ends 130 to fit snappingly and automatically in the selected one of the position holes 140 of the handle 14, with the two vertical portions of the pull rod 13 automatically shifting to the rear deep curve of the recess 122 of each position base 12 and stopped there, keeping the handle 14 stabilized at that adjusted position or the height selected relative to the two cross-shaped tubes 10.
The handle-positioning device for a hand truck in the present invention has the following advantages, as can be understood from the foresaid description.
1. The handle-positioning device has a simple structure, with the pull rod in conjunction with the position bases for adjusting the height or position of the handle.
2. The pull rod can take place of the stop bars 2210, the spring 2211 and the two rings 2212 of the US patent mentioned above, lowering the cost of the material and assembly of the device.
3. The handle-positioning device has simple components, very convenient to assemble and repair.
While the preferred embodiment of the invention has been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications that may fall in the spirit and the scope of the invention.
