Luggage truck

A luggage truck, including a base equipped with wheels in the corners at the bottom thereof and having a track and a slide moved along the track, a pull arm extended upward from the front end of the base, a handle coupled to the pull arm, an extension member connected between the handle and the slide, and two wheel holders pivotally mounted on the base at the bottom and bilaterally engaged with the slide to hold a respective wheel, wherein when the extension member is pulled out of the pull arm after the handle has been released from the pull arm, the slide is pulled forward causing the movable wheel holders to turn outwards and to extend out of two opposite sides of the base; when the extension member is pushed back inside the pull arm, the slide is moved back causing the movable wheel holders to turn inward and to be received inside the base at the bottom.

BACKGROUND OF THE INVENTION 
The present invention relates a luggage truck which comprises a base 
equipped with wheels at the bottom, a slide made to slide in a track on 
the base, a pull arm at one end of the base thereof, a handle coupled to 
the Pull arm and having a flexible extension member at the bottom 
connected to the slide, and two movable wheel holders meshed with the 
slide, wherein when the extension member is pulled out of the pull arm by 
the handle, the handle can be turned in either direction to drag the 
truck, and the slide is moved forwards to turn the movable wheel holders 
bilaterally outwards causing the movable wheel holders to extend out of 
the opposite sides of the base. 
Various hand trucks are known and intensively used for carrying luggage. 
These hand trucks are commonly made of metal and not collapsible. There is 
also know such a hand truck having a retractable handle. The retractable 
handle can be collapsed to reduce the storage space when the hand truck is 
not in use. However, because the retractable handle is not flexible, it 
cannot be bent when the person who pulls the hand truck turns it to 
another direction. Therefore, the person who pulls the hand truck must be 
very careful when makes a turn. Furthermore, because the wheels of a hand 
truck are commonly mounted in the four corners of the base, the hand truck 
becomes unstable when making a turn. 
SUMMARY OF THE INVENTION 
The present invention has been accomplished to provide a luggage truck 
which eliminates the aforesaid drawbacks. 
According to one aspect of the present invention, the luggage truck 
comprises a base equipped with wheels in the four corners thereof at the 
bottom and having a track longitudinally disposed in the middle, a slide 
moved back and forth along the track, a pull arm extend upward from the 
front end of the base at the top and is covered with a decorative cover 
board, the pull arm having an opening at the top and a locating hole at 
one side near the top, a handle extending out of the top opening of the 
pull arm and having a bolt inserted into the locating hole on the pull 
arm, an extension member received inside the pull arm and connected 
between the handle and the slide, two movable wheel holders pivotally 
mounted on the base at the bottom and bilaterally meshed with the slide to 
hold a respective wheel at an outer side, a lock connected between the 
extension member and the slide for locking the extension member in an 
extended-out position outside the top opening of the pull arm, and wherein 
when the extension member is moved to the extended-out position by the 
handle after the bolt of the handle has been pushed inwards from the 
locating hole on the pull arm, the slide is pulled forward causing the 
movable wheel holders to turn bilaterally outward and to extend out of the 
opposite sides of the base. When the movable wheel holders extend out from 
the two opposite sides of the base, the luggage truck is stably supported 
on the ground for carrying luggage. 
According to another aspect of the present invention, the lock is connected 
between the extension member and the slide such that it is moved into the 
locking position to lock the extension member in the extended-out position 
when the extension member is pulled out of the top opening of the pull arm 
by the handle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to the annexed drawings in detail, a luggage truck in accordance 
with the present invention is generally comprised of a base 1, a pull arm 
2, a handle 3, an extension member 4, a lock 5, and a pair of movable 
wheel holders 6. 
Referring to FIG. 1, the base 1 comprises four wheel assemblies 11 in the 
four corners at the bottom thereof. The pull arm 2 is shaped with a bend 
extending from the top of the base 1 and covered with a decorative cover 
board 21. The handle 3 is inserted into a hole (not show) on the top of 
the pull arm 2, having a bolt 31 extended out of a side hole 37 thereof 
and inserted into a side hole 22 on the pull arm 2. Therefore, the handle 
3 is pivotally connected to the pull arm 2. The extension member 4 has one 
end fixedly fastened to the handle 3, and an opposite end connected to the 
lock 5. The lock 5 comprises a connecting frame 51 fixedly connected to a 
plate 12 on the base 1. The plate 12 is fixedly mounted on a slide 13. The 
slide 13 has two racks 131 longitudinally disposed at two opposite sides 
respectively engaged with the movable wheel holders 6. A cover plate 19 is 
fastened to the base 1 at the top and covers over the movable wheel 
holders 6, having downward mounting rods 191 respectively fitting into 
respective mounting holes 192 on the base 1. 
The wheel assembly 11 comprises a socket 111 mounted within a hole 15 in 
either corner of the base 1, a bearing block 113 mounted within the socket 
111 at the top to hold a plurality of steel balls 114 around a circle, and 
a spherical wheel 112 turned within the steel balls 114 and partially 
extended out of a bottom opening (not shown) on the socket 
The base 1 further comprises two parallel rails 16 longitudinally disposed 
in the middle, each having two raised portions 17 at two opposite ends. 
The slide 13 is made to slide on the parallel rails 16 between the raised 
portions 17. The slide 13 is fixedly mounted with a spring 14. The spring 
14 has an opposite end fastened to a stub rod 18 on the base 1. 
The aforesaid plate 12 is attached to the slide 13 at the top, having slots 
121 fastened to a peg 132 on the slide 13 by screws. 
The handle 3 comprises two symmetrical handle shells 33 joined together, 
defining a hand hole 32 through both handle shells 33. The aforesaid side 
hole 37 is made on one handle shell. The other handle shell has a recessed 
hole 34 corresponding to the side hole 37, and a stub rod 35 disposed in 
the recessed hole 34. A spring 36 is mounted on the stub rod 35 to support 
the aforesaid bolt 31 causing it to partially extend out of the side hole 
37. 
The extension member 4 comprises a barrel 41 molded from flexible plastics, 
a first mounting ring 42 fastened to a stub rod 38 inside the handle 3, a 
second mounting ring 44 fastened to the lock 5, and a steel cable 43 
connected between the first and second mounting rings 42 and 44. 
The lock 5 further comprises a bolt 52, to which the steel cable 43 is 
connected, a spring 53 stopped between the bolt 52 and the decorative 
cover board 21, a socket 54 fixedly fastened to the connecting frame 51 to 
hold the front end of the bolt 52. 
The movable wheel holder 6 comprises a casing 61 having a hole 62 at one 
end, a cap 64 mounted on the hole 62, a spherical wheel 63 revolvably 
retained in the cap 64 by steel balls 65 and partially extended out of the 
hole 62 on the casing 61, a cover shell 67 covered on the casing 61 over 
the cap 64, a sector gear 66 fixedly fastened to the casing 61 and meshed 
with either rack 131 and having mounting rod 68 at the angle fastened to 
the base 1 through a screw joint. 
Referring to FIGS. 1 and 2 again, when the bolt 31 is pushed backwards from 
the side hole 22 on the pull arm 2, the extension member 4 can then be 
pulled out of the pull arm 2 by the handle 3. Because the barrel 41 of the 
extension member 4 is molded from flexible plastics, it can easily be bent 
for allowing the handle 3 to fold dragged in any direction. When the 
extension member 4 is pulled out of the pull arm 2, the connecting frame 
51 of the lock 5 is simultaneously pulled upward by the extension member 4 
causing the plate 12 and the slide 13 move forward along the parallel 
rails 16. When the extension member 4 is pulled out of the pull arm 2, the 
socket 54 of the lock 5 is stopped at the bottom of the top wall of the 
pull arm 2, and the bolt 52 is forced back into the side hole 22 by the 
spring 53 to stop the connecting frame 51 from moving backwards. 
Referring to FIG. 3 and FIG. 1 again, when the plate 12 is moved forward by 
the connecting frame 51, the slide 13 is moved forward along the parallel 
rails 16. Because the sector gears 66 of the movable wheel holders 6 are 
respectively meshed with the racks 131 of the slide 13, moving the slide 
13 forward along the parallel rails 16 causes the movable wheel holders 6 
to turn bilaterally outwards and to extend out of the two opposite sides 
of the base 1. Therefore, the base 1 is stably supported on the ground by 
the spherical wheels 63 of the movable wheel holders 6 and the spherical 
wheels 112 of the wheel assemblies 11 when it is pulled by the handle 3. 
When the movable wheel holders 6 are bilaterally turned outwards and 
extended out of the two opposite sides of the base 1, the bolt 52 is 
simultaneously forced into the side hole 22 on the pull arm 2 (see FIG. 2) 
preventing the connecting frame 51 from moving backwards, and therefore 
the movable wheel holders 6 are locked in the respectively extended out 
positions. 
Referring to FIG. 4, when the movable wheel holders 6 are bilaterally 
extended out of the base 1, the base 1 becomes stably supported on the 
ground by the spherical wheels 63 of the movable wheel holders 6 and the 
spherical wheels 112 of the wheel assemblies 11. On the contrary, when the 
bolt 52 is pushed back from the side hole 22 and the extension member 4 is 
moved back inside the pull arm 2 by the handle 3, the movable wheel 
holders 6 are turned back into and received inside the base 1 at the 
bottom. When the handle 3 is moved back inside the pull arm 2, the bolt 31 
of the handle 3 is forced into the side hole 22 again to lock the movable 
wheel holders 6 in the respective received positions.