Loading carriage

A loading carriage for transport of an object in a partially raised position, and particularly for use in a mechanical parking garage. The loading carriage includes a lifting frame movably linked to a traveling frame by lifting elements. The traveling frame has running wheels and the lifting frame is provided with mechanical grippers which are switched between an open and a closed position. The loading carriage grips the object and raises the lifting frame by a single actuating mechanism. A limit stop is installed on the lifting frame to ensure that the lifting frame is raised only after the grippers are completely closed.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention concerns a loading carriage for the transport of an 
object in an at least partially raised position, comprising a traveling 
frame and a lifting frame, which is removably linked to the said traveling 
frame and connected thereto by means of lifting elements, whereby the 
traveling frame consists of several running wheels and the lifting frame 
is provided with at least one mechanical gripper which may be switched 
between an open and a closed position, whose actuating mechanism includes 
at least one actuating element, movable basically along the length of the 
loading carriage. 
2. Description of the Related Art 
A similar loading carriage is known from German Patent Publication 3607910. 
It is especially appropriate for use in a mechanical parking garage. In 
that connection, it is used to transport a passenger car from a drive-in 
box to a transport platform, whereby the front wheels of the car are 
gripped and raised by the gripper and the passenger car is pulled or 
pushed rolling on its back wheels. 
In the loading carriage described in the aforementioned German Patent 
3607910, the traveling frame is telescopic in construction, it consists of 
a front section and a rear section which moves in the longitudinal 
direction of the front section. The lifting frame is pivotally linked, on 
a horizontal axis, to the front section of the traveling frame. Between 
the rear section of the traveling frame and the lifting frame are 
connecting rods, so constructed as to raise the back portion of the 
lifting frame when the traveling frame is telescopically shortened. The 
front and rear sections of the traveling frame and the lifting frame 
gripper are mechanically coupled with a drive device including a chain. 
The loading carriage known from the prior art exhibits a number of 
disadvantages. The most prominent of these is its heavy weight. Additional 
disadvantages are its complicated and vulnerable mechanism, this is 
because the working planes of the various coupling rod assemblies for the 
gripper and the two sections of the traveling frame penetrate each other, 
and the ability of the traveling frame to telescopically vary its length 
constitutes an additional complication of construction. Finally, in the 
loading carriage known from the prior art, the generally time-staggered 
course of gripping and raising the car cannot always be reliably assured. 
SUMMARY OF THE INVENTION 
The object of the present invention is to design a generic loading carriage 
with a simple construction, as light-weight as possible and the greatest 
possible degree of reliability. With regard to the latter, it is 
especially vital to ensure that the lifting frame begins to rise only 
after the gripper is completely closed. 
According to the present invention, this object is achieved by making the 
lifting frame movable along the length--i.e. in the travel direction--of 
the traveling frame, by the fact that the lifting elements raise or lower 
the lifting frame according to the direction of its longitudinal movement 
relative to the traveling frame, and that a limit stop is associated with 
the lifting frame, against which the gripper actuating element lies when 
the gripper is closed. Since the frame is movable relative to the 
traveling frame in the direction of its length, it can be made 
significantly shorter and thus also lighter than the present state of the 
art. In addition, the movability of the lifting frame relative to the 
traveling frame enables also the latter to be lighter in construction than 
in the present state of the art, due to the requirement for the traveling 
frame to telescopically vary its length. In the loading carriage according 
to the invention, the raising and lowering of the lifting frame are 
achieved through its displacement in the longitudinal direction of the 
traveling frame, and not by the telescopic shortening or lengthening of 
the traveling frame--as is the case in the state of the art. Thus, given 
that the gripper actuating element (whose guide is preferably installed on 
the lifting frame), which moves along the length of the traveling frame, 
lies against a limit stop installed on the lifting frame, the actuation 
mechanism for the gripping of the object and the raising of the lifting 
frame is made considerably simpler and especially more reliable than the 
state of the art. If it is intended to grip and raise the object to be 
transported, once the loading carriage has been brought into position, the 
actuating element--which is preferably directly, but may be indirectly, 
driven by the lifting frame--is moved in the appropriate manner, until it 
comes up against the limit stop installed on the lifting frame when the 
gripper is closed; then, on a construction of the same motion, the lifting 
frame is moved relatively to the traveling frame, thus raising the lifting 
frame. The two individual steps--namely, the gripping of the object and 
the raising of the lifting frame--may be performed in a preset course 
through the actuation of a single actuating element. The loading carriage 
according to the invention is thus provided with an extraordinary simple 
actuation mechanism. Since it is ensured that the lifting frame is only 
raised when the gripper is completely closed, the loading carriage 
according to the invention is also superior to the state of the art with 
regard to safety and reliability. 
In a preferred embodiment of the loading carriage according to the 
invention, the lifting frame is connected to the traveling frame by a pair 
connecting rods on opposite side of the loading carriage, each pair, in 
conjunction with the lifting frame and traveling frame, forming a 
parallelogram. In another effective embodiment of the loading carriage 
according to the invention, slanted guides are used as lifting elements 
between the lifting frame and the traveling frame. 
A coupling rod assembly acting on the actuating element is provided for 
effective actuation of the gripper and the lifting mechanism. In an 
especially preferred embodiment of the loading carriage according to the 
invention, this assembly is linked to a coupler mechanism, which 
coordinates the movement of the loading carriage and the actuation of the 
gripper. In such a coupler mechanism, a lever is flexibly connected to the 
coupling rod assembly, the lever, in turn, is connected to a pusher, whose 
other end is flexibly fastened to the traveling frame. A shaft is 
furthermore flexibly connected to the traveling frame, it is linked to the 
pusher via a coupling rod. The distance between the connection point of 
the coupling rod to the shaft and the connection point of the shaft to the 
traveling frame is thus greater than the distance between the connection 
point of the coupling rod to the pusher and the connection point of the 
pusher to the traveling frame. In a coupler mechanism of this type, a 
pivot motion of the shaft in the direction of the traveling frame will 
result in a rapid movement of the coupling rod assembly, with the result 
that this rapidly closes the gripper and moves the lifting frame for 
raising it in respect of to the traveling frame. The shaft has a suitable 
linkage via a carrier to a pull chain running around two wheels, said 
chain belonging to a drive device for the loading carriage. As long as the 
carrier moves horizontally along the course of the pull chain, the entire 
loading carriage moves in its longitudinal direction, while, on the other 
hand, when the carrier runs around the deflection wheel, as described 
above, the gripper closes and the lifting mechanism rises, without the 
traveling frame being notably moved. 
The above-described embodiments of the coupler mechanism is by no means the 
only one possible. Within the framework of the invention, many other types 
of drives--both coupler mechanisms and drives independent of the loading 
carriage movement--may be used to move the actuating element in order to 
actuate the gripper and to move and raise the lifting frame. 
The invention is more clearly explained below, by means of the following 
drawings, showing in:

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The loading carriage consists of a traveling frame 1 and a lifting frame 2, 
movable (arrow A) in the direction of the traveling frame 1. The traveling 
frame 1 includes four longitudinal braces 3, which are connected to each 
other in front by means of two cross braces 4, 5. 
Mounted on the underside of longitudinal braces 3 are--shown in FIGS. 2 to 
4--running wheels 6; these enable the loading carriage to move in the 
direction of its length on the ground. 
The lifting frame 2 also includes four longitudinal braces 7, each one of 
which is assigned to a longitudinal brace 3 of traveling frame 1. The four 
longitudinal braces 7 of lifting frame 2 are connected to each other in 
front by means of the cross brace 8. The two inner longitudinal braces 7 
are also connected to each other in the rear portion of lifting frame 2 by 
an additional cross brace 9, each of the outer longitudinal braces 7 is 
connected to its adjacent inner longitudinal brace 7 by a limit stop brace 
10. Each longitudinal brace 7 of the lifting frame 2 is connected to its 
respective longitudinal brace 3 of the traveling frame 1--as shown in 
FIGS. 2 to 4--by means of two connecting rods 11 in such a way that this 
lifting frame 2 is raised when it is moved backward (arrow B) with respect 
to the traveling frame 1 and in the longitudinal direction thereof. 
The gripper provided on the lifting frame 2 includes two claws 12, each of 
which is pivotally linked, on a vertical axis, to a limit stop brace 10. 
Each claw 12 includes three legs, of which the limit stop leg 14 is so 
dimensioned that, when the gripper is closed (FIG. 1, top), each claw 12 
rests on the two respective longitudinal braces 7 of the lifting frame 2. 
In its open position (FIG. 1, bottom), both claws 12 are so far tilted 
inward and forward that the space between the two neighboring longitudinal 
braces 7 of the lifting frame 2 is entirely open in its rear portion. When 
the gripper is open, the loading carriage can be pushed from the front so 
far under a vehicle, that its front wheels 15 are within the area of the 
gripper and can be gripped by it. 
An actuation mechanism 16 is provided to actuate the gripper. This consists 
of a block 17 serving as an actuation element, this block 17 is movably 
guided in the longitudinal direction of the loading carriage (arrow C) by 
two longitudinal guides 18, firmly connected to the front cross brace 8 of 
lifting frame 2 and fly interconnected to each other by means of cross 
spar 19. Two connecting rods 20 are flexibly connected to the block. The 
free end of each of these connecting rods 20 is connected to the 
respective claw 12. This embodiment of the actuation mechanism has the 
result that, when block 17 is moved along longitudinal guides 18 in the 
longitudinal direction of the loading carriage, the claws 12 close (FIG. 
1, top). 
Firmly connected to the block 17 is a coupling rod assembly comprising two 
coupling rods 21, and a cross traverse 22 connecting them. Both coupling 
rods 21 are and movably guided in the longitudinal direction (arrow C). 
The cross traverse 22 is provided with two link eyes 24, to each of which 
one of the coupling mechanisms described in FIGS. 2 to 4 below is 
connected. 
The coupling mechanisms presented in FIGS. 2 to 4 includes the lever 24, 
the shaft 25, the pusher 26 and a coupling connection rod 27. The shaft 25 
is pivotally connected, on a horizontal axis, to the front cross brace 4 
of the traveling frame 1, and the pusher 26 is slewably flexibly 
connected, on a horizontal axis, to rear cross brace 5 of the traveling 
frame 1. One end of the lever 24 is pivotally connected, on a horizontal 
axis running perpendicular to the longitudinal direction of the loading 
carriage, to pusher 26, the other end of lever 24 is connected to the link 
eye 23 of the cross traverse 22 of the coupling rod assembly. The pusher 
26 is connected to shaft 25 by the coupling connection rod 27. 
The coupling mechanism presented in FIGS. 2 to 4 is designed to work in 
cooperation with a loading carriage drive device with a chain 29 running 
around two deflection wheels 28. The shaft 25 is coupled to chain 29 by 
means of a carrier 30. When the deflection wheel 28 is moved 
counterclockwise (arrow D), as long as the carrier 30 is moved in a linear 
manner to the right along the lower chain strand, the loading carriage 
moves to the right with an open gripper. However, within the area of the 
deflection wheel 28, during one-half turn of the deflection wheel, the 
horizontal movement of the carrier is reduced to zero and accelerated in 
the other direction (to the left); at the same time, the carrier 30 is 
raised by the amount of the diameter of the deflection wheel 28. During 
the half-course of carrier 30 around the deflection wheel, lever 24 of the 
coupler mechanism according to FIGS. 2 to 4 is pivoted out of its slanted 
(FIG. 2) position into a nearly horizontal one (FIG. 4), in the course of 
which the coupling rod assembly connected to it moves to the right. The 
lever 24 thus moves the coupling rod assembly to the right, whereby the 
block 17 is moved along longitudinal guides 18 (arrow C in FIG. 1). This 
immediately closes the gripper by pivoting the claws 12 around the shaft 
13. When the gripper is totally closed and the block 17 rests on the cross 
brace 8 which serves as a limit stop, the lifting frame 2 is moved 
relative to the traveling frame 1, and lifted by means of the connecting 
rods 11. 
When the carrier 30, in the continued counterclockwise (arrow D) turning of 
the deflection wheel 28, is moved to the left along the upper strand of 
the chain, the loading carriage, with closed gripper and raised lifting 
frame, moves on the wheels 6 to the left. 
The coupler mechanism shown in FIG. 5 may be used in loading carriages in 
which the kinematics of the lifting frame is opposite to that shown in 
FIGS. 1 to 4. In other words, the coupler mechanism in Fig, 5 is suitable 
for loading carriages in which the gripper is closed and the lifting frame 
raised when the actuation element is pulled forward--and not pushed 
backward, as in the case of the coupler mechanism explained above. 
In this case, the coupler mechanism includes the lever 31, the shaft 32 and 
pusher 33. The shaft 32 is pivotally connected, on a horizontal axis, to 
the front cross brace 4, of the traveling frame 1, and the pusher 33 is 
pivotally connected, on a horizontal axis, to the rear cross brace 5 of 
the traveling frame 1. The lever 31 is pivotally connected, on a 
horizontal axis 34 running perpendicular to the longitudinal direction of 
the loading carriage, to the shaft 32. The lower end of the lever 31 is 
pivotally connected to the free end of the pusher 33. The coupling rod 
assembly is connected to the upper end of the lever 31. 
The coupling mechanism presented in FIG. 5 is designed to work in 
cooperation with a loading carriage drive device consisting of a chain 36 
running around two deflection wheels 35. The shaft 32 is coupled to the 
chain 36 by means of a carrier 37. When the deflection wheel 35 is moved 
clockwise (arrow E), as long as carrier 37 is moved in a linear manner to 
the left along the lower chain strand, the loading carriage moves to the 
left with open gripper. However, in the area of the deflection wheel 35, 
during one-half turn of the deflection wheel, the horizontal movement of 
the carrier is reduced to zero and accelerated in the other direction (to 
the right), at the same time, the carrier 37 is raised by the amount of 
the diameter of the deflection wheel 35. During the half-turn of the 
carrier 37 around the deflection wheel, the lever 31 of the coupler 
mechanism according to FIG. 5 is pivoted out of its almost vertical 
position into a nearly horizontal one, in which the connection point 38 of 
the coupling rod assembly moves to the right in an essentially horizontal 
manner. The lever 31 thus moves the coupling rod assembly to the right, 
whereby, according to what was stated above, the gripper closes and the 
lifting frame is raised. When the carrier 37, in the continued clockwise 
turning of the deflection wheel, is moved to the right along the upper 
strand of the chain 36, the loading carriage, with closed gripper and 
raised lifting frame, moves to the right.