초록 ▼

A convertible hand truck includes first and second truck frames coupled with each other through a pair of fixed members and a pair of pivoting members such that the second truck frame is turnable relative to the first truck frame among a folded position, a platform-cart position and a reclined-truck

A convertible hand truck includes first and second truck frames coupled with each other through a pair of fixed members and a pair of pivoting members such that the second truck frame is turnable relative to the first truck frame among a folded position, a platform-cart position and a reclined-truck position. A stabilizing lever is pivotably connected with the second truck frame or the pivoting members to be engaged with or disengaged from the fixed members in response to the turning of the second truck frame. The second truck frame extends outwardly from the first truck frame in the reclined-truck position so as to expand and enlarge the carrying area of the hand truck for more loads.

대표청구항 ▼

1. A convertible hand truck comprising: a first truck frame having a pair of first pivot end portions opposite to each other in a left-and-right direction, and a pair of first end portions disposed opposite to said first pivot end portions, respectively, in a first direction transverse to the left-a

1. A convertible hand truck comprising: a first truck frame having a pair of first pivot end portions opposite to each other in a left-and-right direction, and a pair of first end portions disposed opposite to said first pivot end portions, respectively, in a first direction transverse to the left-and-right direction;a second truck frame having a pair of second pivot end portions opposite to each other in the left-and-right direction, and a pair of second end portions disposed opposite to said second pivot end portions, respectively, in a second direction transverse to the left-and-right direction;a pair of fixed members disposed outboard of said first pivot end portions, respectively;a pair of pivoting members disposed outboard of said second pivot end portions, respectively, and each pivotably connected with a respective one of said fixed members about a first pivot axis in the left-and-right direction such that said second truck frame is turnable relative to said first truck frame among a folded position, where said second end portions are close to said first end portions to coincide the second direction with the first direction, a platform-cart position, where the second direction is transverse to the first direction, and a reclined-truck position, where said second end portions are remote from said first end portions to coincide the second direction with the first direction;each of said fixed members having a platform-cart positioning groove and a reclined-truck positioning groove angularly displaced from each other about a second pivot axis that is parallel to and offset from the first pivot axis;a stabilizing lever pivotably connected with either said second truck frame or said pivoting members about the second pivot axis, and having a weight end and a power end which are disposed at two opposite sides of the second pivot axis such that said weight end is disposed to be engaged with respective ones of said platform-cart positioning grooves and said reclined-truck positioning grooves when said second truck frame is in a respective one of the platform-cart position and the reclined-truck position, and such that, in response to a turning movement of said second truck frame about the first pivot axis, said power end is turned about the second pivot axis to move said weight end toward respective ones of said platform-cart positioning grooves and said reclined-truck positioning grooves, and, in response to a turning movement of said power end, said weight end is disengaged from the respective ones of said platform-cart and reclined-truck positioning grooves to permit the turning movement of said second truck frame toward the folded position;a wheel unit coupled with said first end portions; anda roller unit coupled with ones of said first pivot end portions, said second pivot end portions and said pivoting members. 2. The convertible hand truck as claimed in claim 1, wherein said second truck frame having a pair of first side rods spaced apart from each other and extending in the second direction to have said second pivot end portions and said second end portions, and a first grip rod interconnecting said second end portions, said stabilizing lever having a pair of second side rods which are pivotably connected with either said first side rods or said pivoting members, an engaging crossbar which interconnects ends of said second side rods to serve as said weight end, and a gripping crossbar which interconnects opposite ends of said second side rods to serve as said power end. 3. The convertible hand truck as claimed in claim 2, further comprising a pair of biasing springs disposed to bias said engaging crossbar toward said fixed members so as to engage said engaging crossbar in respective ones of said platform-cart and reclined-truck positioning grooves. 4. The convertible hand truck as claimed in claim 1, wherein said roller unit includes a roller mounting crossbar interconnecting said second pivot end portions, and two rollers rotatably mounted on said roller mounting crossbar. 5. The convertible hand truck as claimed in claim 1, wherein said wheel unit includes a pair of wheel mounts respectively sleeved on said first end portions, and two wheels respectively and pivotably mounted on said wheel mounts such that said wheel mounts are turnable relative to said first truck frame to bring said wheels close to or remote from each other. 6. The convertible hand truck as claimed in claim 5, wherein said wheel unit further includes a pair of rotary members each pivotably mounted on said first truck frame about a rotary axis in the left-and-right direction and meshed with a respective one of said wheel mounts, a driving member having a connecting portion which is connected to said rotary members and an operating portion which is disposed close to said first pivot end portions such that movement of said operating portion toward said first end portions results in turning of said rotary members about the rotary axis and turning of said wheel mounts about said first end portions so as to move said wheels remote from each other. 7. The convertible hand truck as claimed in claim 6, wherein said wheel unit further includes a rotary crossbar disposed to rotate about its axis in the left-and-right direction along with the turning of said second truck frame, and a force translating mechanism disposed between said rotary crossbar and said operating portion to translate rotary movement of said rotary crossbar into the movement of said operating portion toward said first end portions. 8. The convertible hand truck as claimed in claim 7, wherein said force translating mechanism includes a revolving member which is sleeved on said rotary crossbar to be rotated therewith and which has a plurality of driving teeth that are angularly displaced from each other about the axis of said rotary crossbar, and a plurality of driven grooves formed in said operating portion and displaced from each other in the first direction such that, when said revolving member is rotated along with the turning of said second truck frame, one of said driving teeth is engaged with a respective one of said driven grooves so as to make the movement of said operating portion. 9. The convertible hand truck as claimed in claim 8, wherein said operating portion has a retaining groove adjacent to said driven grooves, said stabilizing lever having a pair of second side rods which are respectively and pivotably connected with said pivoting members, an engaging crossbar which interconnects ends of said second side rods to serve as said weight end, and a gripping crossbar which interconnects opposite ends of said second side rods to serve as said power end, said engaging crossbar being configured to have two engaging segments extending from said second side rods in the left-and-right direction to be engaged with respective ones of said platform-cart positioning grooves or said reclined-truck positioning grooves, and a middle curved segment disposed to be retained in said retaining groove when said second truck frame is in the reclined-truck position. 10. The convertible hand truck as claimed in claim 1, wherein said second truck frame and said pivoting members are disposed such that, when said second truck frame is moved from the folded position to the reclined-truck position, the second pivot axis is moved from a proximate position, where the second pivot axis is closer to said first end portions than the first pivot axis, to a distal position, where the second pivot axis is remoter from said first end portions than the first pivot axis, such that said second truck frame extends parallel to and outwardly from said first truck frame in the reclined-truck position.