HAND TRUCK LATCH MECHANISM
Material handling devices are disclosed. Specifically disclosed is a hand truck latch for a convertible hand truck that provides a simpler mechanism which is less prone to malfunctioning; visually conveys to a user of the material handling devices whether the handle mechanism is locked or unlocked; and is less prone to accidental unlocking.
1 . A convertible hand truck comprising:
a frame comprising a pair of uprights, each upright comprising an axle bracket;
a loop handle comprising a pair of legs, each leg comprising a caster wheel;
a toe plate connected to the frame;
a pair of wheels connected by an axle, the axle supported by the axle brackets; and
a latch mechanism for selectively locking and unlocking the loop handle to the frame, the latch mechanism comprising:
a latch bar;
a pair of latch housings, each housing mounted to a respective frame upright, each latch housing comprising a latch flipper arm, a latch flipper arm biasing member, and a latch housing notch; and
a latch release comprising a latch release bar and a pair of latch release plates, each latch release plate being pivotal to a respective latch housing at a respective latch release plate pivot located in front of the latch release bar and having a latch release plate indent.
2 . The convertible hand truck of claim 1 wherein the biasing member is a torsion spring.
3 . The convertible hand truck of claim 2 wherein each latch flipper arm biasing member biases its respective latch flipper arm against the latch bar.
4 . The convertible hand truck of claim 2 wherein each latch flipper arm biasing member biases the latch bar against its respective latch release plate indent.
5 . The convertible hand truck of claim 4 wherein the loop handle is unlocked from the frame by lifting the latch release bar.
6 . The convertible hand truck of claim 1 wherein at least a portion of the latch bar extends beyond each latch housing notch when the latch mechanism is unlocked.
7 . The convertible hand truck of claim 1 wherein the latch release plates rest on the latch bar when the latch mechanism is locked.
8 . The convertible hand truck of claim 1 wherein the latch release bar is moveable to a position completely exterior of the pair of latch housings.
9 . The convertible hand truck of claim 1 wherein each latch flipper arm biasing member is fixed to its respective latch housing.
10 . The convertible hand truck of claim 1 wherein the latch flipper arms do not contact the latch release.
11 . A convertible hand truck comprising:
a frame comprising a pair of uprights,
a handle pivotal to the frame and comprising a pair of caster wheels;
a toe plate connected to the frame;
a pair of wheels operably connected by an axle mounted to the frame; and
a latch mechanism for selectively locking and unlocking the handle to the frame, the latch mechanism comprising:
a latch bar;
a pair of latch housings, each housing mounted to a respective frame upright, each latch housing comprising a latch flipper arm, a latch flipper arm biasing member, and a latch housing notch; and
a latch release comprising a latch release bar and a pair of latch release plates;
wherein the latch flipper arms do not contact the latch release.
12 . The convertible hand truck of claim 11 wherein the latch flipper arm biasing member comprises a torsion spring.
13 . The convertible hand truck of claim 12 wherein the loop handle is unlocked from the frame by lifting the latch release bar.
14 . The convertible hand truck of claim 13 wherein each latch release bar comprises a grip.
15 . The convertible hand truck of claim 14 wherein the latch release bar is moveable to a position completely exterior of the pair of latch housings.
16 . The convertible hand truck of claim 15 wherein each latch flipper arm biasing member is fixed to its respective latch housing.
17 . The convertible hand truck of claim 16 wherein the latch release plates rest on the latch bar when the latch mechanism is locked.
18 . A convertible hand truck comprising:
a frame comprising a pair of uprights,
a handle pivotal to the frame and comprising a pair of caster wheels;
a toe plate connected to the frame;
a pair of wheels operably connected by an axle mounted to the frame; and
a latch mechanism for selectively locking and unlocking the handle to the frame, the latch mechanism having a locked position and unlocked position comprising:
a latch bar;
a pair of latch housings, each housing mounted to a respective frame upright, each latch housing comprising a latch flipper arm, a latch flipper arm biasing member, and a latch housing notch; and
a latch release comprising a latch release bar and a pair of latch release plates;
wherein the latch release plates rest on the latch bar when the latch mechanism is in the locked position.
19 . The convertible hand truck of claim 18 wherein the handle is unlocked from the frame by lifting the latch release bar.
20 . A convertible hand truck comprising:
a frame comprising a pair of uprights, each upright comprising an axle bracket;
a loop handle comprising a pair of legs, each leg comprising a caster wheel;
a toe plate connected to the frame;
a pair of wheels connected by an axle, the axle supported by the axle brackets; and
a latch mechanism for selectively locking and unlocking the loop handle to the frame, the latch mechanism comprising:
a latch bar;
a pair of latch housings, each housing mounted to a respective frame upright, each latch housing comprising a latch housing notch; and
a latch release comprising a latch release bar fixed to a pair of latch release plates, each latch release plate being pivotal to a respective latch housing at a respective latch release plate pivot located in front of the latch release bar and having a latch release plate indent.