초록

A multi-mode load carrier is convertible to assume a storage mode, a cart mode, and a hand-truck mode. The load carrier includes a rolling base and a base pusher having a handgrip.

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1. A collapsible load carrier comprising a rolling base including a load-support frame and left and right front wheel units coupled to the load-support frame and arranged to roll on ground underlying the rolling base,a base pusher mounted for pivotable movement relative to the load-support frame of

1. A collapsible load carrier comprising a rolling base including a load-support frame and left and right front wheel units coupled to the load-support frame and arranged to roll on ground underlying the rolling base,a base pusher mounted for pivotable movement relative to the load-support frame of the rolling base about a base-pusher pivot axis from a stored position arranged to lie alongside and on top of the load-support frame of the rolling base and associated with a flat storage mode of the load carrier in a first direction through a first pivot angle to an upright cart position associated with a front-and-rear-wheel cart mode of the load carrier wherein a rear wheel included in the base pusher is arranged to engage and roll on ground underlying the rolling base and further in the first direction through a second pivot angle to a two-wheel laidback hand-truck position to lie in generally coplanar relation to the load-support frame of the rolling base to define an included angle of 180° therebetween to establish a 2-wheel hand-truck mode of the load carrier in which any rear wheel in the base pusher is disengaged from ground underlying the rolling base and the rolling base is supported for rolling movement only on front wheels included in the left and right front wheel units, anda load-carrier mode changer including a rotator-support platform mounted on the load-support frame and a rear linkage coupled to the base pusher and to the rotator-support platform, wherein the rear linkage includes a pivotable base-pusher rotator mounted on the rotator-support platform for pivotable movement about a pusher-rotator pivot axis from a first position associated with the front-and-rear-wheel cart mode of the load carrier to a second position associated with the 2-wheel hand-truck mode of the load carrier, a push rod mounted for movement relative to the pivotable base-pusher rotator and to the base pusher and configured to move the base pusher relative to the load carrier from the two-wheel laidback hand-truck position to the upright cart position in response to pivoting movement of the pivotable base-pusher rotator about the pusher-rotator pivot axis from the first position to the second position, a forward hand-truck lock coupled to the rotator-support platform and configured to engage the pivotable base-pusher rotator when the pivotable base-pusher rotator is moved to assume the first position to retain the pivotable base-pusher rotator in the first position so as to retain the base pusher in the upright cart position, and an aft cart lock coupled to the rotator-support platform to lie in spaced-apart relation to the forward hand truck lock and configured to engage the pivotable base-pusher rotator when the pivotable base-pusher rotator is moved to assume the second position to retain the pivotable base-pusher rotator in the second position so as to retain the base pusher in the two-wheel laidback hand-truck position. 2. The load carrier of claim 1, wherein the base pusher includes a top portion having a handgrip and extending upwardly above the base-pusher pivot axis and a bottom portion extending downwardly below the base-pusher pivot axis, the load-support frame is pivotably coupled to the top portion of the base pusher, and the push rod is pivotably coupled to the bottom portion of the base pusher. 3. The load carrier of claim 1, wherein the forward hand-truck lock is mounted on a forward portion of the rotator-support platform to lie between the left and right front wheel units and the pusher-rotator pivot axis and to pivot about a forward lock pivot axis relative to the rotator-support platform to engage and retain the pivotable base-pusher rotator in the second position on the rotator-support platform and wherein the aft cart lock is mounted on a rearward portion of the rotator-support platform to lie between the pusher-rotator pivot axis and the base-pusher pivot axis and to pivot about an aft lock pivot axis relative to the rotator-support platform to engage and retain the pivotable base-pusher rotator in the first position on the rotator-support platform. 4. The load carrier of claim 3, wherein base-pusher rotator includes a horizontally extending anchor rod that is arranged to lie in spaced-apart relation to the pusher-rotator pivot axis and the pivotable base-pusher rotator is arranged to be engaged by the forward hand-truck lock to retain the pivotable base-pusher rotator in the second position and is also arranged to be engaged by the aft cart lock to retain the pivotable base-pusher rotator in the first position. 5. The load carrier of claim 4, wherein the aft cart lock includes a pivotable rod retainer mounted for pivotable movement on the rearward portion of the rotator-support platform between a locked position wherein the anchor rod is trapped between the pivotable rod retainer and the rearward portion of the rotator-support platform to retain the pivotable base-pusher rotator in the first position and an unlocked position wherein the anchor rod is released to allow pivoting movement of the pivotable base-pusher rotator from the first position to the second position, a spring coupled to the rotator-support platform and arranged to yieldably urge the pivotable rod retainer normally to the locked position, and a cam ramp coupled to the pivotable rod retainer and arranged to intercept the anchor rod during pivoting movement of the pivotable base-pusher rotator from the second position to the first position, wherein the cam ramp is configured to provide means for pivoting the pivotable rod retainer against the spring from the locked position to the unlocked position due to camming engagement of the anchor rod on the cam ramp during pivotable movement of the pivotable base-pusher rotator from the second position to the first position so that the anchor rod can be moved to assume a trapped position between the pivotable rod retainer and the rearward portion of the rotator-support platform to retain the pivotable base-pusher rotator in the first position. 6. The load carrier of claim 5, wherein the aft cart lock further includes a rearward-portion retainer stop coupled to the rearward portion of the rotator-support platform and arranged to extend upwardly away from the load-support frame to provide means for limiting pivotable movement of the pivotable rod retainer toward the forward hand-truck lock in response to exposure of the pivotable rod retainer to movement-inducing torque generated by the spring to establish the locked position of the pivotable rod retainer. 7. The load carrier of claim 5, wherein the forward hand-truck lock further includes a forward-portion retainer stop coupled to the forward portion of the rotator-support platform and arranged to extend upwardly away from the load-support frame to provide means for limiting pivotable movement of the pivotable rod retainer toward the aft cart lock in response to exposure of the pivotable rod retainer to movement-inducing torque generated by the spring to establish the locked position of the pivotable rod retainer. 8. The load carrier of claim 7, wherein the pivotable base-pusher rotator also includes first and second pivot links arranged to lie in spaced-apart relation to one another and mounted for pivotable movement about the pusher-rotator pivot axis and a rotator handgrip coupled to free ends of the first and second pivot links, the anchor rod is arranged to interconnect the first and second pivot links and to lie between the pusher-rotator pivot axis and the rotator handgrip, and the pivotable base-pusher-rotator also includes a crossbar arranged to interconnect the first and second pivot links and lie between the pusher-rotator pivot axis and the anchor rod and to lie in and fill a space provided between the forward-portion stop and the pusher-rotator pivot axis to provide means for blocking access to a fold button that is mounted for movement in the forward portion of the rotator-support platform and operable to initiation collapse of the load carrier to regulate movement of the base pusher from the front-and-rear-wheel cart position to the stored position. 9. The load carrier of claim 4, wherein the forward hand-truck lock includes a pivotable rod retainer mounted for pivotable movement on the forward portion of the rotator-support platform between a locked position wherein the anchor rod is trapped between the pivotable rod retainer and the forward portion of the rotator-support platform to retain the pivotable base-pusher rotator in the second position and an unlocked position wherein the anchor rod is released to allow pivoting movement of the pivotable base-pusher rotator from the second position to the first position, a spring coupled to the rotator-support platform and arranged to yieldably urge the pivotable rod retainer normally to the locked position, and a cam ramp coupled to the pivotable rod retainer and arranged to intercept the anchor rod during pivoting movement of the pivotable base-pusher rotator from the first position to the second position, wherein the cam ramp is configured to provide means for pivoting the pivotable rod retainer against the spring from the locked position to the unlocked position due to camming engagement of the anchor rod on the cam ramp during pivotable movement of the pivotable base-pusher rotator from the first position to the second position so that the anchor rod can be moved to assume a trapped position between the pivotable rod retainer and the forward portion of the rotator-support platform to retain the pivotable base-pusher rotator in the second position. 10. The load carrier of claim 4, wherein the pivotable base-pusher rotator also includes first and second pivot links arranged to lie in spaced-apart relation to one another and mounted for pivotable movement about the pusher-rotator pivot axis and a rotator handgrip coupled to free ends of the first and second pivot links and wherein the anchor rod is arranged to interconnect the first and second pivot links and to lie between the pusher-rotator pivot axis and the rotator handgrip. 11. The load carrier of claim 1, wherein pivotable base-pusher rotator includes a horizontally extending anchor rod that is arranged to lie in spaced-apart relation to the pusher-rotator pivot axis, the pivotable base-pusher rotator is arranged to be engaged by the forward hand-truck lock to retain the pivotable base-pusher rotator in the second position and is also arranged to be engaged by the aft cart lock to retain the pivotable base-pusher rotator in the first position, the pivotable base-pusher rotator also includes first and second pivot links arranged to lie in spaced-apart relation to one another and mounted for pivotable movement about the pusher-rotator pivot axis and a rotator handgrip coupled to free ends of the first and second links, and the anchor rod is arranged to interconnect the first and second pivot links and to lie between the pusher-rotator pivot axis and the rotator handgrip. 12. The load carrier of claim 11, wherein the push rod includes a first pusher link having an inner end that is pivotably coupled to the first pivot link at a first pivot axis and an outer end that is pivotably coupled to the base pusher. 13. The load carrier of claim 12, wherein the anchor rod includes an inner portion arranged to lie between the first and second pivot links and an outer portion arranged to extend in a direction away from the first and second pivot links to mate with the first pusher link at the first pivot axis. 14. The load carrier of claim 12, wherein the base pusher includes a top portion having a pusher handgrip and extending upwardly above the base-pusher pivot axis and a bottom portion extending downwardly below the base-pusher pivot axis and wherein the outer end of the first pusher link is pivotably coupled to the bottom portion of the base pusher at a link pivot axis. 15. The load carrier of claim 14, wherein the load-support frame is pivotably coupled to the top portion of the base pusher to cause the base-pusher pivot axis to lie between the link pivot axis and the pusher handgrip. 16. The load carrier of claim 1, wherein the rotator-support platform is a slidable spreader driver that is mounted for sliding movement on the load-support frame to cause the pivotable base-pusher rotator to move back and forth relative to the load-support frame of the rolling base as the slidable spreader driver slides on the load-support frame, the load-carrier mode changer further includes a wheel spreader coupled to the slidable spreader driver and arranged to engage a cam provided on each of the left and right front wheel units to move the left and right front wheels relative to the load-support frame from folded storage positions to unfolded rolling positions in response to movement of the base pusher about the base-pusher pivot axis in the first direction to move, in unison, the rear linkage, the slidable spreader driver, and the wheel spreader as a unit toward the front wheels so that the front wheels in the left and right wheel units are spread apart to cause the front wheels in the left and right front wheels to rotate about a common axis and on ground underlying the rolling base. 17. The load carrier of claim 16, further comprising a spreader-driver lock including a slider-retainer pin and a companion spring configured to provide means for yieldably urging the slider-retainer pin to engage a pin receiver formed in the spreader driver to hold the slidable spreader driver in a stationary position on the load-support frame when the base pusher reaches the upright cart position. 18. The load carrier of claim 17, wherein the spreader-driver lock further includes a fold button mounted for movement on the spreader driver from a raised inactive position to a depressed activated position and a pin release coupled to the fold button and mounted for movement relative to the slidable spreader driver to provide means for pushing the slider-retainer pin into the pin receiver formed in the load-support platform and out of engagement with the slidable spreader driver when the fold button is pushed by a user to allow the base pusher to be collapsed from the upright cart position to the stored position. 19. The load carrier of claim 18, wherein the pivotable base-pusher rotator includes first and second pivot links arranged to lie in spaced-apart relation to one another and mounted for pivotable movement about the pusher-rotator pivot axis, a rotator handgrip coupled to free ends of the first and second links, an anchor rod arranged to interconnect the first and second pivot links and to lie between the pusher-rotator pivot axis and the rotator handgrip, and a crossbar arranged to interconnect the first and second pivot links and lie between the pusher-rotator pivot axis and the anchor rod, and wherein the crossbar is configured to provide means for covering the fold button when the pivotable base-pusher rotator is moved to assume the second position to block application of an external movement-inducing force to the fold button to cause the fold button to remain in the raised inactive position when the pivotable base-pusher rotator occupies the second position and for uncovering the fold button when the pivotable base-pusher rotator is moved to assume the first position to allow application of an external movement-inducing force to the fold button to free the fold button to be moved to the depressed activated position when the pivotable base-pusher rotator occupies the first position. 20. The load carrier of claim 16, wherein the base pusher includes a top portion having a pusher handgrip and extending upwardly above the base-pusher pivot axis and a bottom portion extending downwardly below the base-pusher pivot axis, the load-support frame is pivotably coupled to the top portion of the base pusher, and the push rod is pivotably coupled to the bottom portion of the base pusher. 21. The load carrier of claim 16, wherein the pivotable base-pusher rotator and the push rod cooperate while the pivotable base-pusher rotator remains in the first position owing to engagement of the aft cart lock and the pivotable base-pusher rotator to convert pivoting motion of the base pusher about the base-pusher pivot axis from the stored position to the upright cart position into sliding motion of the slidable spreader driver on the load-support frame in a direction toward the front wheels to urge the wheel spreader into camming engagement with the left and right front wheel units to move those wheel units from their folded storage positions to their unfolded rolling positions. 22. The load carrier of claim 21, wherein the pivotable base-pusher rotator is coupled for pivotable movement to an inner end of the push rod and an opposite outer end of the push rod is coupled for pivotable movement to the base pusher and the push rod is configured to provide means for pivoting the base pusher automatically about the base-pusher pivot axis relative to the load-support frame of the rolling base in response to manual pivoting of the pivotable base-pusher rotator about the pusher-rotator pivot axis. 23. The load carrier of claim 1, wherein the pivotable base-pusher rotator is coupled for pivotable movement to an inner end of the push rod and an opposite outer end of the push rod is coupled for pivotable movement to the base pusher and the push rod is configured to provide means for pivoting the base pusher automatically about the base-pusher pivot axis relative to the load-support frame of the rolling base in response to manual pivoting of the pivotable base-pusher rotator about the pusher-rotator pivot axis. 24. The load carrier of claim 23, wherein the base pusher includes a top portion having a handgrip and extending upwardly above the base-pusher pivot axis and a bottom portion extending downwardly below the base-pusher pivot axis, the load-support frame is pivotably coupled to the top portion of the base pusher, and the push rod is pivotably coupled to the bottom portion of the base pusher. 25. The load carrier of claim 1, wherein the base pusher includes a top portion having a pusher handgrip and extending upwardly above the base-pusher pivot axis and a bottom portion extending downwardly below the base-pusher pivot axis and wherein an outer end of the push rod is pivotably coupled to the bottom portion of the base pusher. 26. The load carrier of claim 1, wherein the pivotable base-pusher rotator includes first and second pivot links arranged to lie in spaced-apart relation to one another and mounted for pivotable movement about the pusher-rotator pivot axis and a rotator handgrip coupled to free ends of the first and second pivot links and an inner end of the push rod is pivotably coupled to at least one of the first and second links. 27. The load carrier of claim 26, wherein the push rod includes a first pusher link having an inner end that is pivotably coupled to the first pivot link at a first pivot axis and an outer end that is pivotably coupled to the base pusher.