A hand truck is convertible to assume an expanded use mode and a flat storage mode. The hand truck includes a rolling base and a base pusher. The rolling base is arranged to support goods and to roll on ground underlying the hand truck. The base pusher is mounted on the rolling base for pivotable mo
A hand truck is convertible to assume an expanded use mode and a flat storage mode. The hand truck includes a rolling base and a base pusher. The rolling base is arranged to support goods and to roll on ground underlying the hand truck. The base pusher is mounted on the rolling base for pivotable movement about a base-pusher pivot axis from an upright hand-truck position to a storage position to rearrange the hand truck between the expanded use mode and the flat storage mode.
대표청구항▼
1. A collapsible hand truck comprising a rolling base including a load-support frame and a toe-plate shelf coupled to the load-support frame,a base pusher mounted for movement relative to the load-support frame of the rolling base about a base-pusher pivot axis from an upright hand-truck position ar
1. A collapsible hand truck comprising a rolling base including a load-support frame and a toe-plate shelf coupled to the load-support frame,a base pusher mounted for movement relative to the load-support frame of the rolling base about a base-pusher pivot axis from an upright hand-truck position arranged to lie in generally coplanar relation to a top of the load-support frame of the rolling base to establish an expanded use mode to a storage position arranged to lie along the load-support frame of the rolling base to establish a flat storage mode of the hand truck, andhand-truck mode changer means for freeing the base pusher for rotation about the base-pusher pivot axis from the upright hand-truck position to the storage position in response to a user lifting a base-pusher rotation blocker with one hand and for allowing the base pusher to return to the upright hand-truck position from the storage position without further interaction with the base-pusher rotation blocker by the user so that the base pusher is freely movable to the upright hand-truck position from the storage position,wherein hand-truck mode changer means includes a pusher latch coupled to the base pusher for rotation with the base pusher about the base-pusher pivot axis as the base pusher is moved between the storage position and the upright hand-truck position and the base-pusher rotation blocker is coupled to the rolling base to pivot relative to the rolling base from a closed position arranged to block movement of the pusher latch relative to the rolling base to an opened position arranged to allow the pusher latch to move relative to the rolling base. 2. The hand truck of claim 1, wherein the base-pusher rotation blocker includes a lever handle sized to be gripped by a user to pivot the base-pusher rotation blocker and a stopper coupled to the lever handle for movement with the lever handle, the stopper is arranged to engage the rolling base to limit movement of the base-pusher rotation blocker from moving beyond the closed position, and the stopper is arranged to engage the rolling base to limit movement of the base-pusher rotation blocker from moving beyond the opened position. 3. The hand truck of claim 2, wherein the lever handle and the stopper cooperate to provide a monolithic component. 4. The hand truck of claim 1, wherein the base-pusher rotation blocker includes a catch arranged about midway between a left leg of the base pusher and a right leg of the base pusher to engage the pusher latch and block movement of the base pusher when the base pusher is in the upright hand-truck position. 5. The hand truck of claim 1, wherein the pusher latch includes a left receiver coupled to the left leg of the base pusher, a right leg receiver coupled to the right leg of the base pusher, and an anchor body extending therebetween that is engaged by the catch of the base-pusher rotation blocker when the base pusher is in the upright hand-truck position. 6. The hand truck of claim 5, wherein the anchor body is formed to include a blocker ramp arranged to engage the base-pusher rotation blocker and pivot the base-pusher rotation blocker from the closed position to the opened position when the base pusher is rotated about the base-pusher pivot axis from the flat storage position to the expanded use position. 7. A collapsible hand truck comprising a rolling base including a load-support frame and a toe-plate shelf coupled to the load-support frame,a base pusher mounted for movement relative to the load-support frame of the rolling base about a base-pusher pivot axis from an upright hand-truck position arranged to lie in generally coplanar relation to a top of the load-support frame of the rolling base to establish an expanded use mode to a storage position arranged to lie along the load-support frame of the rolling base to establish a flat storage mode of the hand truck, andhand-truck mode changer means for freeing the base pusher for rotation about the base-pusher pivot axis from the upright hand-truck position to the storage position in response to a user lifting a base-pusher rotation blocker with one hand and for allowing the base pusher to return to the upright hand-truck position from the storage position without further interaction with the base-pusher rotation blocker by the user so that the base pusher is freely movable to the upright hand-truck position from the storage position,wherein hand-truck mode changer means includes a rotation blocker coupled to the base pusher to pivot relative to the base pusher from a closed position arranged to block movement of the base pusher relative to the rolling base to an opened position arranged to allow the base pusher to move relative to the rolling base. 8. The hand truck of claim 7, wherein the base pusher is configured to pivot about the base-pusher pivot axis relative to the rotation blocker during movement from the upright hand-truck position to the storage position. 9. The hand truck of claim 7, wherein the rolling base includes a left wheel unit mounted for pivotable movement on the load-support frame about a left pivot axis from an unfolded rolling position to a folded storage position and a right wheel unit mounted for pivotable movement on the load-support frame about a right pivot axis from an unfolded rolling position to a folded storage position, the unfolded rolling position of the left and the right wheel units is associated with the expanded use mode of the hand truck in which wheels in the wheel units are arranged to engage and roll on ground underlying the rolling base and rotate about a common axis of rotation, and the folded storage position of the left and the right wheel units is associated with the flat storage mode of the hand truck in which wheels in the wheel units disengage ground underlying the rolling base and the wheel in the left wheel unit is arranged to extend toward the wheel in the right wheel unit. 10. The hand truck of claim 9, wherein hand-truck mode changer means includes a wheel-spreader system configured to cause the wheels in the left and right wheel units to pivot from the unfolded rolling position to the folded storage position in response to movement of the base pusher from the upright hand-truck position to the storage position, the wheel-spreader system includes a slidable spreader driver coupled to the rolling base to slide along the rolling base, a lower linkage interconnecting the rolling base and the slidable spreader driver, and an upper linkage interconnecting the base pusher and the slidable spreader driver, and the upper linkage is configured to rotate and move the slidable spreader driver upward away from the wheel units relative to the load-support frame to cause the lower linkage to pivot the wheels from the unfolded rolling positions to the folded storage positions when the base pusher is rotated about the base-pusher pivot axis from the upright hand-truck position to the storage position. 11. The hand truck of claim 10, wherein the rotation blocker is configured to engage the slidable spreader driver when in the closed position to block movement of the base pusher relative to the rolling base and to disengage the slidable spreader driver when in the opened position to allow the base pusher to move relative to the rolling base. 12. A collapsible hand truck comprising a rolling base including a load-support frame, a left wheel unit mounted on the load-support frame, and a right wheel unit mounted on the load-support frame,a base pusher mounted for movement relative to the load-support frame of the rolling base about a base-pusher pivot axis from an upright hand-truck position arranged to lie in generally coplanar relation to a top of the load-support frame of the rolling base to establish the expanded use mode to a storage position arranged to lie along the load-support frame of the rolling base to establish the flat storage mode of the hand truck, anda base-pusher lock movable from a locked configuration in which the base pusher is held in the upright hand-truck position relative to the load-support frame to maintain the hand truck in the expanded use mode and an unlocked configuration in which the base pusher is free to move from the upright hand-truck position to the storage position, the base-pusher lock including a base-pusher rotation blocker mounted to pivot from a closed position arranged to block movement of the base pusher relative to the rolling base to an opened position arranged to allow the base pusher to move relative to the rolling base and a spring configured to bias the base-pusher rotation blocker toward the closed position, wherein the base-pusher rotation blocker is arranged to engage a ramp surface formed by another component of the collapsible hand truck to cause the base-pusher rotation blocker to pivot from the closed position to the opened position in response to movement of the base pusher from the storage position to the upright hand-truck position and is arranged to disengage the ramp surface upon arrival of the base pusher to the upright hand-truck position so that the base-pusher rotation blocker is free to be moved to the closed position by the spring such that the base pusher is held in place automatically upon arrival of the base pusher to the upright hand-truck position. 13. The hand truck of claim 12, wherein the base-pusher lock includes a pusher latch coupled to the base pusher for rotation with the base pusher about the base-pusher pivot axis as the base pusher is moved between the storage position and the upright hand-truck position and the base-pusher rotation blocker is coupled to the rolling base to pivot relative to the rolling base from the closed position to the opened position. 14. The hand truck of claim 13, wherein the base-pusher rotation blocker includes a lever handle sized to be gripped by one hand of a user and a catch arranged to engage the pusher latch when the base pusher is in the upright hand-truck position and the base-pusher rotation blocker is in a closed position. 15. The hand truck of claim 13, wherein the catch includes an upper face arranged to engage the pusher latch when the hand truck is in the expanded use mode to block rotation of the base pusher about the base-pusher pivot axis and a catch ramp arranged to be contacted by the pusher latch to cause the base-pusher rotation blocker to pivot about the blocker pivot axis from the closed position to the opened position when the base pusher is rotated about the base-pusher pivot axis to the upright hand-truck position from the storage position. 16. The hand truck of claim 13, wherein the pusher latch includes a left receiver coupled to a left leg of the base pusher, a right leg receiver coupled to a right leg of the base pusher, and an anchor body extending therebetween. 17. The hand truck of claim 12, wherein the left wheel unit is mounted for pivotable movement on the load-support frame about a left pivot axis from an unfolded rolling position to a folded storage position and the right wheel unit is mounted for pivotable movement on the load-support frame about a right pivot axis from an unfolded rolling position to a folded storage position, the unfolded rolling position of the left and the right wheel units is associated with the expanded use mode of the hand truck in which wheels in the wheel units are arranged to engage and roll on ground underlying the rolling base and rotate about a common axis of rotation, and the folded storage position of the left and the right wheel units is associated with the flat storage mode of the hand truck in which wheels in the wheel units disengage ground underlying the rolling base and the wheel in the left wheel unit is arranged to extend toward the wheel in the right wheel unit. 18. The hand truck of claim 17, further comprising a wheel-spreader system configured to cause the wheels in the left and right wheel units to pivot from the unfolded rolling position to the folded storage position in response to movement of the base pusher from the upright hand-truck position to the storage position, the wheel-spreader system includes a slidable spreader driver coupled to the rolling base to slide along the rolling base, a lower linkage interconnecting the rolling base and the slidable spreader driver, and an upper linkage interconnecting the base pusher and the slidable spreader driver, and the upper linkage is configured to rotate and move the slidable spreader driver upward away from the wheel units relative to the load-support frame to cause the lower linkage to pivot the wheels from the unfolded rolling positions to the folded storage positions when the base pusher is rotated about the base-pusher pivot axis from the upright hand-truck position to the storage position. 19. The hand truck of claim 18, wherein the rotation blocker is configured to engage the slidable spreader driver when in the closed position to block movement of the base pusher relative to the rolling base and to disengage the slidable spreader driver when in the opened position to allow the base pusher to move relative to the rolling base. 20. The hand truck of claim 18, wherein the base-pusher rotation blocker includes a lever handle sized to be gripped by one hand of a user, a stopper arranged to engage the wheel-spreader system to limit movement of the base-pusher rotation blocker past the closed position, and a catch arranged to engage the pusher latch when the base pusher is in the upright hand-truck position and the base-pusher rotation blocker is in a closed position. 21. The hand truck of claim 12, wherein the base-pusher rotation blocker is coupled to the base pusher for rotation therewith relative to the rolling base between the storage position and the upright hand-truck position and the base-pusher rotation blocker is coupled to the base pusher to pivot relative to the base pusher between the closed position and the opened position. 22. The hand truck of claim 21, wherein the rolling base includes a left wheel unit mounted for pivotable movement on the load-support frame about a left pivot axis from an unfolded rolling position to a folded storage position and a right wheel unit mounted for pivotable movement on the load-support frame about a right pivot axis from an unfolded rolling position to a folded storage position, the unfolded rolling position of the left and the right wheel units is associated with the expanded use mode of the hand truck in which wheels in the wheel units are arranged to engage and roll on ground underlying the rolling base and rotate about a common axis of rotation, and the folded storage position of the left and the right wheel units is associated with the flat storage mode of the hand truck in which wheels in the wheel units disengage ground underlying the rolling base and the wheel in the left wheel unit is arranged to extend toward the wheel in the right wheel unit. 23. The hand truck of claim 22, wherein hand-truck mode changer means includes a wheel-spreader system configured to cause the wheels in the left and right wheel units to pivot from the unfolded rolling position to the folded storage position in response to movement of the base pusher from the upright hand-truck position to the storage position, the wheel-spreader system includes a slidable spreader driver coupled to the rolling base to slide along the rolling base, a lower linkage interconnecting the rolling base and the slidable spreader driver, and an upper linkage interconnecting the base pusher and the slidable spreader driver, and the upper linkage is configured to rotate and move the slidable spreader driver upward away from the wheel units relative to the load-support frame to cause the lower linkage to pivot the wheels from the unfolded rolling positions to the folded storage positions when the base pusher is rotated about the base-pusher pivot axis from the upright hand-truck position to the storage position. 24. The hand truck of claim 23, wherein the rotation blocker is configured to engage the slidable spreader driver when in the closed position to block movement of the base pusher relative to the rolling base and to disengage the slidable spreader driver when in the opened position to allow the base pusher to move relative to the rolling base. 25. A collapsible hand truck comprising a rolling base including a load-support frame and a toe-plate shelf coupled to the load-support frame,a base pusher mounted for movement relative to the load-support frame of the rolling base about a base-pusher pivot axis from an upright hand-truck position arranged to lie in generally coplanar relation to a top of the load-support frame of the rolling base to establish an expanded use mode to a storage position arranged to lie along the load-support frame of the rolling base to establish a flat storage mode of the hand truck, anda base-pusher lock movable from a locked configuration in which the base pusher is held in the upright hand-truck position relative to the load-support frame to maintain the hand truck in the expanded use mode and an unlocked configuration in which the base pusher is free to move from the upright hand-truck position to the storage position, the base-pusher lock including a latch coupled to the base pusher for rotation therewith about the base-pusher pivot axis, a base-pusher rotation configured to selectively engage the latch to block movement of the base pusher only when the base pusher is in the upright hand-truck position, and a bias member,wherein the latch is located to be engaged by the base-pusher rotation blocker when the base pusher is in the upright hand-truck position and is spaced apart from the base-pusher rotation blocker and the rolling base when the base pusher is in the storage position such that engagement by the base-pusher rotation blocker is avoided, the base-pusher rotation blocker is mounted to the rolling base to pivot relative to the rolling base from a closed position arranged to block movement of the base pusher relative to the rolling base while the base pusher is in the upright hand-truck position to an opened position arranged to allow the base pusher to move relative to the rolling base while the base pusher is in the upright hand-truck position, and the bias member is configured to bias the base-pusher rotation blocker toward the closed position. 26. The hand truck of claim 25, wherein the rotation blocker is arranged to engage a ramp surface formed by another component of the collapsible hand truck to cause the rotation blocker to pivot from the closed position to the opened position in response to movement of the base pusher from the storage position to the upright hand-truck position and is arranged to disengage the ramp surface upon arrival of the base pusher to the upright hand-truck position so that the base-pusher rotation blocker is free to be moved to the closed position by the bias member such that the base pusher is held in place automatically upon arrival of the base pusher to the upright hand-truck position. 27. The hand truck of claim 25, wherein the rolling base includes a left wheel unit mounted for pivotable movement on the load-support frame about a left pivot axis from an unfolded rolling position to a folded storage position and a right wheel unit mounted for pivotable movement on the load-support frame about a right pivot axis from an unfolded rolling position to a folded storage position, the unfolded rolling position of the left and the right wheel units is associated with the expanded use mode of the hand truck in which wheels in the wheel units are arranged to engage and roll on ground underlying the rolling base and rotate about a common axis of rotation, and the folded storage position of the left and the right wheel units is associated with the flat storage mode of the hand truck in which wheels in the wheel units disengage ground underlying the rolling base and the wheel in the left wheel unit is arranged to extend toward the wheel in the right wheel unit. 28. The hand truck of claim 27, wherein hand-truck mode changer means includes a wheel-spreader system configured to cause the wheels in the left and right wheel units to pivot from the unfolded rolling position to the folded storage position in response to movement of the base pusher from the upright hand-truck position to the storage position, the wheel-spreader system includes a slidable spreader driver coupled to the rolling base to slide along the rolling base, a lower linkage interconnecting the rolling base and the slidable spreader driver, and an upper linkage interconnecting the base pusher and the slidable spreader driver, and the upper linkage is configured to rotate and move the slidable spreader driver upward away from the wheel units relative to the load-support frame to cause the lower linkage to pivot the wheels from the unfolded rolling positions to the folded storage positions when the base pusher is rotated about the base-pusher pivot axis from the upright hand-truck position to the storage position, and wherein the rotation blocker is configured to engage the slidable spreader driver when in the closed position to block movement of the base pusher relative to the rolling base and to disengage the slidable spreader driver when in the opened position to allow the base pusher to move relative to the rolling base.
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이 특허에 인용된 특허 (30)
Meier James W., Brake and retractable rear stabilizer apparatus for a hand dolly.
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