Support leg construction for a container or the like

Abstract: The invention relates to a support leg construction for a container being supported by a chassis (4), the support leg construction including a support leg (1) comprising a rotatable part (2) and a turnable part (3) at an angle to the rotatable part, the support leg being turnable by means of a bearing structure from a first, mainly horizontal, rest position in which it is retracted to the chassis to a second, mainly vertical, pulled out parking position in relation to the chassis for supporting the chassis, whereby the support leg and the chassis comprise supporting surfaces (6a, 8a) placed against each other and arranged to be pressed against each other when the support leg is in the pulled out position, and locking devices (6, 7, 9 to 11) for keeping the support leg locked to the chassis when the support leg is in the pulled out position, the locking devices comprising two co-operating locking means (6, 8). In order that the support leg construction is able to support the chassis firmly, is safe and can rapidly be placed in different operating positions without obstructing the towing vehicle, and that the function thereof is not liable to dirt etc., the locking means comprise self-tightening wedge-shaped tightening surfaces (6a, 8a) arranged to be pressed against each other more strongly as the mass placed upon the chassis (4) increases, i.e. the greater the mass is, whereby the first tightening surface (6a) of the tightening surfaces is formed on a first rotatable part and the second tightening surface (8a) of the tightening surfaces is formed on a reception part (7) arranged to the chassis (4) so as to receive a container or a corresponding load placed thereupon when the support leg (1) is in the parking position.

Description: The invention relates to a support leg construction for a container and a corresponding covering structure being supported by a chassis, the support leg construction including a support leg comprising a rotatable part and a turnable part at an angle to the rotatable part, the support leg being turnable by means of a bearing structure from a first, mainly horizontal, rest position in which it is retracted to the chassis to a second, mainly vertical, pulled out parking position in relation to the chassis for supporting the chassis, whereby the support leg and the chassis comprise supporting surfaces placed against each other and arranged to be pressed against each other when the support leg is in the pulled out position, and locking devices for keeping the support leg locked to the chassis when the support leg is in the pulled out position, the locking devices comprising two co-operating locking means. Turnable and/or detachable support leg constructions are needed in various types of chassis, such as the chassis of trailers, to temporarily support them. Support leg constructions are needed in the cabins of towing vehicles and in trailers, when the towing vehicle is detached from the trailer. Generally there are four support legs. When the towing vehicle is detached from the trailer the support legs are turned from a horizontal rest position, where the legs are meant to be when the trailer is moving, to a vertical parking position against the ground for supporting the trailer substantially horizontally. Turning the support legs into different operating positions, i.e. from a rest position to a parking position and vice versa, requires a great deal of muscular strength, as the support leg constructions are heavy. Furthermore, to turn the support legs from a rest position to a parking position involves high risks due to the heavy weight and may cause injuries when the heavy steel parts hit a person's feet. A known support leg construction for trailers comprises a massive triangle-support-hook construction that swings freely as a pendulum when it drops from a rest position to a parking position, and may thus cause leg injuries. Fingers are also at risk in this prior art solution, as scissors-shaped cutting parts may be created between the support leg and the hook when the hook swings freely. Another problem with this prior art support leg construction is that the support leg does not support the chassis adequately, and the system has a lot of looseness and the construction swings. Another significant problem with this prior art leg construction is that the hook thereof is inappropriately placed regarding the wheel of the towing vehicle (cf. attached Figure 1). The space between the legs is limited, thus making it difficult to drive the towing vehicle beneath the chassis. In practice the problems above mean that placing the chassis on the support legs is slow and that attention has to be paid on several matters. US patent 3112836 discloses a support leg construction according to the preamble in the attached claim 1. The problem with this prior art solution is that the co-operating locking means have to be produced practically free from tolerance, so that the covering structure supported by the support leg construction cannot swing back and forth. As the locking means are practically free from tolerance, dirt and rust etc. therein prevent the locking means from functioning. Dirt may be carried into the locking means in the open position. BRIEF DESCRIPTION OF THE INVENTION It is an object of the present invention to remove or at least substantially reduce the above problems. This object is achieved with a support leg construction, characterized in that the locking means comprise self-tightening wedge-shaped tightening surfaces arranged to be tightened against each other more strongly as the mass placed upon the chassis increases, i.e. the greater the mass is, whereby the first tightening surface of the tightening surfaces is formed on the rotatable part and the second tightening surface of the tightening surfaces is formed on a reception part arranged on the chassis so as to receive a container or a corresponding load placed upon the chassis when the support leg is in the parking position. These tightening surfaces can be defined as gripping surfaces as well. The first tightening surface is preferably formed on a wedge-shaped cam part of the rotatable part, whereby the reception part comprises a recess substantially corresponding to the form of the cam part for receiving the cam part. The support leg construction preferably includes a pin-hole type of locking device that enables the support leg to be easily locked into two operating positions. The preferred embodiments of the invention are disclosed in the appended claims 2 to 7. The invention is based on the idea to lock the support leg without a massive support hook, and to utilize instead light support means that comprise self-tightening surfaces. By arranging these surfaces close to the rotation axis of the rotatable part the support leg can easily be turned as no torque impeding turning exists. The most significant advantages provided by the support leg construction of the invention are that the support leg supports the chassis firmly in such a manner that it does not move back and forth, and the support leg construction is safer to use than prior art constructions, it may be rapidly mounted into different operating positions and it allows to easily drive a towing vehicle or a trailer beneath the chassis. The greater the vertical load placed upon the support leg construction the firmer the support provided by the support leg construction becomes. Dirt or rust in the locking means do not prevent the support leg construction from functioning. Even if the support leg is mounted on an uneven surface, the wedge-shaped tightening surfaces function as guiding surfaces so as to lock the locking means tightly to one another. BRIEF DESCRIPTION OF THE DRAWINGS In the following the invention will be described in greater detail by means of a preferred embodiment with reference to the attached drawing, in which Figure 1 shows a prior art support leg construction, Figure 2 shows a support leg construction of the invention attached to a chassis and set into a parking position, Figure 3 illustrates the support leg construction in Figure 2 in a rest position, and Figure 4 illustrates the support leg construction in Figure 2 in a parking position. DETAILED DESCRIPTION OF THE INVENTION Figure 1 shows a prior art support leg construction including a support leg 1' comprising a rotatable part 2' and a turnable part 3' attached thereto at a straight angle. The rotatable part 2' is pivotally mounted into a chassis 4'. Bushings 20' surrounding the rotatable part 2' form the bearing. In order to keep the support leg 1' in a vertical position, the support leg construction includes a turnable support hook 5', which is attached to the chassis 4' from one end while the other end is pivotally mounted to the turnable part 3' of the support leg. In this prior art support leg construction the support hook 5' narrows, as is understood from Figure 1, the distance between the support legs 1' close to the rotatable part 2', thus significantly impeding a towing vehicle to be driven between the support legs. The massive support hook 5' is very hard to turn which creates a further problem. In addition, the support hook 5' does not support the support leg to the chassis 4' firmly and without tolerance. Figure 2 shows a support leg construction of the invention. In general, support legs indicated with reference numeral 1 comprise a rotatable part 2 and a turnable part 3. The rotatable part 2 is mounted to the chassis 4 with bush-like bearings 20. This solution does not include a support hook (5') in contrast to the solution shown in Figure 1. The structure is therefore lighter than the structure shown in Figure 1, and there is no need to turn a massive support hook (using muscle strength). Furthermore, the "effective distance" between the support legs 1 at the edges of the chassis 4 equals the distance between the support legs close to the ground. Figures 3 and 4 describe how the support leg 1 is locked to the chassis 4. Figure 3, where the support leg 1 is in the retracted rest position supported by a holder 13 indicated by dashed lines, shows that the rotatable part 2 of the support leg comprises an upwards tapering wedge-shaped cam part 6 which is pushed into a recess 8, corresponding in shape with the cam part, in a reception or form locking part 7. As the reception part 7 is built into the chassis 4 in such a manner that it receives a load placed upon the chassis, for example the load provided by a container 17, a surface 6a of the cam part which can be referred to as a tightening surface is wedged against the recess 8 of the reception part 7 forming a tightening surface 8a corresponding to the tightening surface 6a of the cam part. The greater the vertical load placed upon the chassis, i.e. the greater the mass the chassis supports, the tighter and firmer the wedging force is. At the same time the support leg 1 is more firmly wedged to the chassis 4. The form locking part 7 is formed as a fixed part of the chassis. As the form of the tightening surface 8a corresponds with the form of the tightening surface 6a of the cam part, the reception part can be referred to as the form locking part. Deviating from Figure 4 the reception part 7 may comprise a recess which is differently shaped than the cam 6. Accordingly the reception part 7 may comprise, for example, a recess shaped as a gap or a jaw for receiving the cam. The main point is that the reception part 7 receives in a tightening manner, when loaded, the cam or another wedge-shaped part of the rotatable part 2. The tightening surfaces 6a, 8a may also be referred to as guiding surfaces, as they guide the cam part into the recess 8, even if the support leg 1 is obliquely positioned, i.e. if the turnable part 3 is not in a vertical position. Figure 4 shows that a space 21 is left between the cam of the cam part 6 and the recess 8 of the reception part 7. The space 21 may receive dirt, for example, which is why the cam of the cam part 6 is always capable of being directed sufficiently deep into the recess 8 so that the tightening surfaces 6a, 8a provide said tightening function (wedging and self-tightening). The cam 6 and reception part 7 are to be designed so as to be able to receive also such - sometimes even heavy - loads that tend to turn the support leg 1 when it is in the parking position. Said loads are typically created when a forklift supported on the chassis is in motion and breaks abruptly. When the support leg is in the position indicated in Figure 4, a handle 9 provided with a spring 12 comprising a pin 10, cf. Figure 3, in the support leg construction is pushed into a hole 11 or recess in the rotatable part 2 and prevents the rotatable part from moving away from the pulled out parking position shown in Figure 4. The spring 12 urges the pin 10 of the handle 9 into the hole 11; if the pin 10 is to be removed from the hole 11, the handle 9 is pulled against the load of the spring 12. When the pin is removed from the hole 11, the support leg 1 can be revolved 90 degrees counter-clockwise - assuming that the chassis is supported by a towing vehicle (not shown) - and simultaneously push it inwards towards the chassis 4 to the rest position shown in Figure 3. In the position shown in Figure 3 the handle 9 and the pin 10 thereof are pushed into a second hole 14 or recess (cf. Figure 4) in the rotatable part; the hole 14 or recess being at a distance and at a straight angle, or at an almost straight angle, in relation to the hole 11. The pulled out position of the handle 9 (in which case the tip of the pin 10 is spring-loaded against the curved surface of the rotatable part 2) shows whether the support leg 1 is in a non-locking position, or in a position that does not correspond to either of the positions shown in Figures 3 or 4. The support leg is locked when the handle 9 is pushed in (and the tip of the pin is in either of the holes 11 or 14). Figures 2 to 4 illustrate that the distance between the support legs 1 can be relatively long, as no support hook (5') exists and the effective distance between the support legs is, for example, 2840 mm, providing approximately 200 mm more space than the prior art solution in Figure 1 and plenty of space is left for the wheels of a towing vehicle provided with mudguards 18. The rotatable part 2 of the support leg construction, the form locking part 7 and the spring 12 are formed within a cover 15. Thus, said parts remain covered from dirt and from possible impact. The cover 15 comprises a through-hole 16 for the axis of the handle 9. The invention has above been described by means of an example. However, the details of the invention can be implemented in various ways within the scope of the appended claims. Therefore, it may, for instance, be considered that the reception part 7 (and not the rotatable part 2) comprises a wedge-shaped cam, in which case a recess or a groove is formed into the rotatable part 2 for receiving the wedge-shaped cam. The support leg does not have to be, in accordance with Figure 3, in an entirely horizontal position when it is in the rest position, but the position thereof may deviate from the horizontal position, as the expression "mainly horizontal" indicates in claim 1.

Claims: A support leg construction for a container and a corresponding covering structure being supported by a chassis (4), the support leg construction including a support leg (1) comprising a rotatable part (2) and a turnable part (3) at an angle to the rotatable part, the support leg being turnable by means of a bearing structure (20) from a first, mainly horizontal, rest position in which it is retracted to the chassis to a second, mainly vertical, pulled out parking position in relation to the chassis for supporting the chassis, whereby the support leg and the chassis comprise supporting surfaces (6a, 8a) placed against each other and arranged to be pressed against each other when the support leg is in the pulled out position, and locking devices (6, 7, 9 to 12) for keeping the support leg locked to the chassis when the support leg is in the pulled out position, the locking devices comprising two co-operating locking means (6, 8), characterized in that the locking means comprise self-tightening wedge-shaped tightening surfaces (6a, 8a) arranged to be tightened against each other more strongly as the mass placed upon the chassis (4) increases, i.e. the greater the mass is, whereby the first tightening surface (6a) of the tightening surfaces is formed on the rotatable part (2) and the second tightening surface (8a) of the tightening surfaces is formed on a reception part (7) arranged on the chassis (4) so as to receive a container or a corresponding load placed upon the chassis when the support leg (1) is in the parking position. A support leg construction as claimed in claim 1, characterized in that the first tightening surface (6a) is formed on a wedge-shaped cam part (6) of the rotatable part (2), whereby the reception part (7) comprises a recess (8) substantially corresponding with the shape of the cam part for receiving the cam part. A support leg construction as claimed in claim 2, characterized by leaving a space (21) between the recess (8) and the cam part (6) when the support leg (1) is in the parking position and the cam part is placed in the recess. A support leg construction as claimed in claim 1, characterized in that the locking device (9 to 12) further comprises pin-hole locking means (9, 11) loaded with a spring (12) for locking the rotatable part (2) to the chassis (4) so as to prevent the support leg (1) from moving from the pulled out position to the retracted position. A support leg construction as claimed in claim 4, characterized in that the hole (11) in the locking means is formed on the rotatable part (2) of the support leg, whereby the pin is formed on a manually operated handle (9). A support leg construction as claimed in claim 5, characterized in that the rotatable part (2) of the support leg comprises an additional hole (14) formed at a distance from the hole (11) seen from the longitudinal direction of the rotatable part and approximately at a straight angle in relation to the hole. A support leg construction as claimed in claim 6, characterized in that the rotatable part (2) of the support leg is arranged in a cover (15) formed on the chassis (4) comprising an opening (16) for an axis of the handle.

Inventors: AYSTOE JUSSI, EKLUND GOERAN, NICKULL TOMMY, AYSTOE, JUSSI, EKLUND, GOERAN, NICKULL, TOMMY, Aystö, Jussi, Eklund, Göran
Applicants: NAERKO AB OY, OY NAERKO AB
Application year: 2000
Main classification: B65D90
IPC codes: B65D90