DE2161437A1 - Mobile lifting device - Google Patents

Description

Patent attorneys
Dr. Ing.Walter Abitz Dr. Dieter F. Morf
Dr. Han »-A. Browns

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December 10 I97I 12 170

NATIONAL RESEARCH DEVELOPMENT CORPORATION

Kingsgate House 66/74, Victoria Street, London SW I,

.England

Mobile lifting device

The invention relates to mobile lifting devices of the type with a lifting frame carried by a vehicle, In particular, such are ·. Devices intended for use on the construction site and in other cases in which has an uneven floor. There is a great need for a lifting device in the construction industry, which has many of the characteristics of a conventional forklift truck with a simple rigid chassis. Unfortunately, although the adjustability of the direction of the mast of such a truck with respect to the vehicle is known, neither the known adjusting devices. of the right kind, nor are they complete or simple enough that such forklifts can pick up construction loads on uneven ground and do it on their own after picking them up can be transported safely.

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Lifting frames that are articulated on the chassis about a transverse axis are known per se. When using in the case of a forklift truck in which the mast has a mast on which a fork can slide up and down, if the operator uses this articulated arrangement, to tilt the mast a little backwards when the fork has just picked up a new load "so that the load is inclined slightly inwards towards the vehicle and does not fall forward from the forks. About weaning To lighten a load, the operator can tilt the mast forward slightly so that the forks follow pointing down and the load tends to slide slowly forward from the forks. Far less is it known to arrange the mast also pivotable about a longitudinal axis with respect to the vehicle. On some vehicles, which, however, are not of the forklift type such inclinability achieved in that the chassis itself is pivotably mounted so that the mast can be tilted with part of the chassis, or by having the suspension on one side of the vehicle is depressed so that the mast and the chassis both tilt to the respective side. Sole marriage Systems, however, are not robust for a simple ^ Vehicle suitable on construction sites when the mast needs to be kept vertical when driving over a sloping floor. Such vehicles must remain stable when carrying a heavy load of construction material over sloping floors, which include an angle of up to 15 ° with the horizontal can. The few known vehicles in which the mast is about a longitudinal axis with respect to the chassis is pivotable, are special designs and for use with the typical loads on construction sites entirely not suitable. For example, the vehicle described in U.S. Patent 2,707,063 is for light loads,

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for which it is intended, fully suitable, but can easily run the risk of tipping over sideways, when it is driven on sloping ground and its mast is held vertically, but at some distance is heavily loaded from the ground. - '* -

The mobile lifting device according to the invention can be used for the same work can be used, but behaves independently of the height of the load on Mast, even more stable when loaded than when unloaded. The invention is characterized in the claims and is described below using an exemplary device in conjunction with the enclosed Drawings described in more detail, namely show:

Fig. 1 is a front view of the device; Fig. 2 is a side view and

3 is a perspective view from the left and from the front.

The device has a typical rigid chassis 1 for a forklift truck, which front wheels la and Rear wheels Ib carries and with a steering column 2, shift levers 3 for the vehicle and the lifting mechanism, with a power source 4 and a stub axle 5 in the middle between the front wheels la is equipped, which latter from the front end of the chassis protrudes straight forward, i.e. parallel to the normal direction of movement of the vehicle, The mast comprises a mast 6, guide rails 7, a hoist with ropes 8 and rollers 9 and load handling devices, This load handling device consists of the

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provided device not from the usual fork, but from a frame with two cross members 10, 11, a support 12 and an extension arm 13.

The must 6 and the guides 7 form a rigid construction, at 14 along an axis which runs transversely to the stub axle 5 ', hinged to a bracket "15" is. The holder carries a bearing (not shown) through which a swivel fit around the stub axle 5 is obtained.

k hoses 16 are to a connection (not shown) of the Power source 4 out. The pivoting of the mast and the guides with respect to the bracket 15 to the Axis 14 is done with the help of a double acting Hydraulic cylinder 17. The closed end of the hydraulic cylinder is articulated around a pin 18, the is carried by a bracket 19 which is arranged on the vehicle in the vicinity of the steering column 2. The remote one End of the piston 20 of the hydraulic cylinder 17 carries a Ringansats 21, which means a similar articulated connection of a pin 2 2 which is attached to a bracket 23 which is attached to a cross member 24, which bridges the two guides 7. The wasting

ψ ken of the holder 15 about the stub shaft 5 is done by a second double-acting hydraulic cylinder 25, which is arranged in a similar manner and the closed end with the vehicle chassis by a ball joint 2 6 is hinged, while the remote end of the piston rod articulation with the left guide 7 of the mast by a ball joint 27 has. The mast can turn around the axis 5 pivoted by about 15 ° to each side from its central position, the articulated connection 27 of the hydraulic cylinder with the mast near the center line 29 of the latter and the hydraulic cylinder 25 at an angle of about 90 °

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the center line 2 includes 9 in all positions of the mast, so that the greatest possible pivoting force of the hydraulic cylinder can be exerted on the mast. The chosen arrangement of the hydraulic cylinder, namely horizontal and approximately at the level of the top of the wheels la avoids that the hydraulic cylinder interferes with any other necessary equipment, and allows sufficient leverage on the lifting frame, if in the example described would be tried _s the hydraulic cylinder vertical In practice, it would have to be located between the wheels, ie at the same height as the axles. In this case it would be undesirably close to another device, Z ₀ B _{0 of} the suspension, and the lever arm of its effect on the mast be limited to half the distance between the wheels la.

The focus of the whole apparatus ¹ in the unloaded condition should of course be as low as possible ,, but with the required distance from the ground and other obvious factors are taken into account. It is represented in FIGS. 1 and 2 by the cross 28. However, it is also necessary that the axle stump 5 is not higher than this center of gravity. In the device shown it can be seen that the stub axle 5 is substantially below the center of gravity. If the device is moving on a slope and picks up a load from this, the hydraulic cylinder 25 can be used to tilt the bracket 15 about the axis 5 so that the mast is tilted with respect to the vehicle, as shown in FIG. 1 shown. However, since the vehicle is on an inclined floor, the axles of the vehicle are gnawed and the inclination of the mast can be adjusted so that the mast is vertical

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and optionally inclined slightly inwardly towards the sloping floor so that the lifted load tends to make the effort has to shift the center of gravity of the entire loaded device on the incline a little further upwards, which increases the stability, - If the center of gravity 2 8 is below the stub axle 5, Any load on the mast would result in the center of gravity shifting downwards on the GE trap, thereby increasing the risk of tipping over if the vehicle swings sideways, especially if the Load on the mast is in a high position. If the stub axle 5 does not intersect the center line 29, but is to the side of the same, the vehicle would less predictably stable because of the balancing effect a demanded load on the mast would be different, depending on whether the stub axle is on the Slope side or on the S-slope side of the moving vehicle.

The hydraulic cylinders 17 and 25 receive their pressure medium supply from the power source 4 and can be operated by hand. If necessary, they can after a load once has been picked up, are automatically cleaned, to keep the center of gravity of the loaded vehicle as stationary as possible with respect to the chassis while the vehicle is moving on uneven ground. For those skilled in the art it is obvious that the mast an additional freedom for pivoting movement can be given, for example by means of a further axis, which is perpendicular to both 5 and 14.

Instead of being articulated directly to the chassis, as shown, the mast can also be indirect, for example be articulated by a} Ausf ahrmechani smu ε, which enables the mast to transport loads that are far in front of the chassis.

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Claims (3)

216H37 170 Claims before '' hearing lifting device, characterized by a ν— ^ vehicle with a rigid chassis (1), of at least three wheels are carried, and with a mast, which is in relation to the chassis is articulated on this about an axis (5) pivotable to the normal direction of movement of the Vehicle is parallel and not higher than the center of gravity (28) of the unladen vehicle. 2. Device according to claim 1, characterized in that that the pivot axis (5) and the center line (29) of the mast intersect. 3. Apparatus according to claim 1, characterized by a hydraulic cylinder (25) for pivoting the mast around the chassis (1), one end of the hydraulic cylinder (25) is articulated to the chassis (1) and the other end to the Mast near its center line (29), and with the hydraulic cylinder approximately in the right Angle to the center line of the mast during the entire population area of the latter. Device according to claim 1 »characterized in that - 8 - 209828/0717 170 O that two of the wheels of the same are coaxial and are located at one end of the chassis (1), the articulation of the mast on the chassis (1) in one between the mentioned wheels lies essentially in the central plane. 209826/0717