EP0064521B1

EP0064521B1 - Container lift truck

Info

Publication number: EP0064521B1
Application number: EP81903056A
Authority: EP
Inventors: Anders Bjurling
Original assignee: DYNATRANS AB
Current assignee: DYNATRANS AB
Priority date: 1980-11-18
Filing date: 1981-11-17
Publication date: 1985-04-24
Also published as: JPS57501726A; SE8008079L; EP0064521A1; SE431078B; WO1982001690A1; BR8108873A

Abstract

A container lift truck has a U-shaped frame (1, 2), which is provided with wheels and which has four vertical columns (5). In order to achieve a simple and practical construction, lifting beams (12) are mounted for sliding on the columns (5) under the action of hydraulic cylinders, while a lifting yoke (15) provided with container locks lies on the lifting beams. The lifting yoke can be displaced sideways and turned by means of hydraulic cylinders (20) so as to come in a locking position over a container which is to be lifted.

Description

Technical field

The present invention relates to a container lift truck comprising a U-shaped frame, which is provided with wheels and which has at least four substantially vertical columns, whereby extending transversely between the columns is a pair of lifting beams, which can slide at each end on one of the columns under the action of hydraulic cylinders disposed on the columns, and wherein a lifting yoke is provided with container locks.

Background art

In a previously known container lift truck of this kind, shown in SE-B-355 556 (taken as the closest prior art), the rectangular lifting yoke is hanging in the lifting beams. This construction with a hanging lifting yoke is admittedly practical and reliable in operation but comparatively heavy and expensive, which is accentuated by the fact that the lifting yoke is movable to a certain extent in its plane under the lifting beams so as to be able to be directed in over the container which is to be lifted.

Disclosure of the invention

A simpler and cheaper but nevertheless completely suitable construction for a container lift truck of the kind indicated at the beginning is achieved by the invention, which is characterized in that the lifting yoke is slidably supported upon the lifting beams for lateral displacement relative to the lifting beams.
In this case, yoke control cylinders can be disposed between the respective lifting beam and the lifting yoke for the lateral displacement or moderate turning of the lifting yoke on the beams into a locking position over a container which is to be lifted.
In the known lift truck briefly described above, two special wheels at each side are bogie mounted. For less demanding use and where a wheel projecting sideways is not a decisive disadvantage, it is possible to consider a simple bracket-mounted twin-wheel arrangement.
A better alternative to this latter arrangement with better distribution of the wheel loading is achieved if the wheel arrangement at each side of the frame comprises a swing axle, which can be turned in the longitudinal direction of the truck and on which twin wheels are rotatably mounted.

Brief description of the drawings

The invention will be described in more detail below with reference to the accompanying drawings, in which Figs. 1-4 show a lift truck in a side view, a front view (from the right in Figs. 1 and 2) and a back view, respectively, Figs. 1 and 3 showing a container in dash-dotted lines in a raised position and Fig. 4 the container in a lowered position and Figs. 1 and 2 showing a different wheel arrangement from Figs. 3 and 4.

Description of a preferred embodiment

A container lift truck according to the invention has a frame consisting of two longitudinal beams 1 and a connecting transverse beam 2, to which there is secured a draw bar 3 for coupling to a motor-driven draught vehicle, not shown (truck, tractor). Disposed on the frame is a control unit 4 with an operation described below. Four columns 5 are fixed to the frame and are braced by means of struts 6.
A wheel arrangement shown in Figs. 1 and 2 comprises two brackets 7, which are fixed to each longitudinal beam 1 and between which a rotatable swing axle 8 is mounted. Twin wheels 9 are rotatably mounted on the swing axle 8. For the sake of clarity, the arrangement is shown in a partially cut-away state at the bottom of Fig. 2.
A somewhat different and simpler wheel arrangement is shown in Figs. 3 and 4. In this case, twin wheels 10 are rotatably mounted direct on a bracket 11 fixed to each longitudinal beam 1.
Extending transversely over the lift truck between opposite columns 5 are two lifting beams 12, which are adapted to slide along the columns. Fixed to each end of each lifting beam 12 is a piston rod 13 of a hydraulic cylinder 14 fixed low down to longitudinal beam 1. As a result, as can be seen by a comparison between Figs. 3 and 4, the lifting beams 12 can be raised and lowered along the columns 5. Slots at the ends render inclination of the beams 12 possible.
Lying on the lifting beams 12 is a substantially rectangular lifting yoke 15 which is provided, at its four corners, with container locks 16 for a container 17 indicated in dash-dotted lines in Figs. 1, 3 and 4. These locks 16 are of conventional rotary type and are controlled in pairs for locking and releasing the container 17 by means of a locking cylinder 18 and a link arm 19 in a manner easily understood by one skilled in the art.
Disposed in the transverse direction of the lift truck, between the respective lifting beam 12 and the lifting yoke 15, as can be seen in Fig. 2, is a hydraulic cylinder 20, while a strut 21 is articulately secured between the lifting yoke 15 and a lifting beam 12. By the appropriate supply of oil under pressure to one or both hydraulic cylinders 20, it is possible with this arrangement to displace the lifting yoke 15 sideways or to turn it to bring it into position over a container which is to be lifted.
For the transmission of oil between the frame 1, 2 of the lift truck and the lifting yoke 15, an articulated connection 22 is disposed between these.
The main art of the hydraulic and possibly electrical control members of the lift truck for the lifting hydraulic cylinders 15, the locking cylinders 18 and the yoke control cylinders 20 is disposed in the control unit 4, which is normally connected, by means of members not shown, to the hydrauiic and possibly electrical system of the draught vehicle.
It is easily understood that the lift truck described works in the following manner: With the lifting beams 12 and the lifting yoke 15 raised to a suitable level, the lift truck is backed in over a container 17, which is to be lifted, with the longitudinal beams 1 at each side thereof. The lifting yoke 15 is displaced or turned into position by means of the yoke control cylinders 20 and the lifting means 12 and the yoke 15 are lowered towards the container by means of the lifting cylinders 14, so that the locks 16 can engage corresponding recesses in the corner housings of the container and are firmly locked by means of the locking cylinders 18, so that the position shown in Fig. 4 is achieved. After this the container 17 is lifted to the desired height by means of the lifting cylinders 14, as shown in Figs. 1 and 3, and can be transported away. Modifications are possible within the scope of the appended claims.

Claims

1. A container lift truck comprising a U-shaped frame (1, 2), which is provided with wheels (9; 10) and which has a least four substantially vertical columns (5), whereby extending transversely between the columns is a pair of lifting beams (12), which can slide at each end on one of the columns under the action of hydraulic cylinders (14) disposed on the columns, and wherein a lifting yoke (15) is provided with container lock (16), characterized in that the lifting yoke (15) is slidably supported upon the lifting beams (12) for lateral displacement relative to the lifting beams.

2. A truck as claimed in claim 1, characterized in that yoke control cylinders (20) are disposed between the respective lifting beam (12) and the lifting yoke (15) for the lateral displacement or moderate turning of the lifting yoke on the beams into a locking position over a container (17) which is to be lifted.

3. A truck as claimed in claim 1 or 2, characterized in that the wheel arrangement at each side of the frame (1, 2) comprises a swing axle (8) which can be turned in the longitudinal direction of the truck and on which twin wheels (9) are rotatably mounted.