WO1989003454A1

WO1989003454A1 - Bridge

Info

Publication number: WO1989003454A1
Application number: PCT/SE1988/000529
Authority: WO
Inventors: Frans G. Lundholm
Original assignee: Lundholm Frans G
Priority date: 1987-10-12
Filing date: 1988-10-12
Publication date: 1989-04-20
Also published as: SE9001257D0; SE465520B; SE8703939D0; SE9001257L

Abstract

This invention relates to a bridge comprising a ramp intended to be fastened at the shore of a water-coarse and a plurality of units attached to this one, each of the units comprising longitudinal supporting beams and a bridge deck resting on these ones, the unit being intended to be carried by carrying poles. According to the invention each unit (2, 3, 4) has a device (7), which functions as a float for the unit when it is empty, and which functions as ballast for the carrying poles (5, 6) when it is filled with a medium or a material, and each unit (2, 3, 4) is further provided with means (22-25), which are pivotable and lockable in relation to the unit and which are intended to cooperate with the carrying poles (5, 6).

Description

Bridge

This invention relates to a bridge comprising a ramp, intended to be fastened at the shore of a watercourse, and a plurality of units attached to the ramp, each unit comprising longitudinal supporting beams and a bridge deck resting on these ones, the unit being intended to be carried by carrying poles. Bridges are common at shores of lakes, harbours for small boats and similar. It has appeared that it is very bad for bridges to be out the whole year.

Therefore there have been wishes to lay out a bridge easily in spring and to take up the bridge equally easily in autumn and accordingly store the bridge in a safe way on land during winter. By US patent 4,037,420 is previously known a bridge comprising a plurality of units fastened to each other. This known bridge is connected with a plurality of drawbacks: firstly, there is only one floating means at hand. This means that when a first unit is laid out and a second unit shall be laid out the floating means has to be detached from the first unit and be applicated on to the second one. This is a very time-consuming and troublesome procedure. Secondly, the rear part of the fore unit has to be fastened by screws in a bracket which is also fastened by screws on to the fore part of the rear unit, which is also a time-consuming procedure. Thirdly, problems seem to arise in connection with the fastening of the bridge unit on to the supporting poles P, which procedure starts when the rear part of the fore bridge unit has been fastened to the bracket at the fore part of the rear unit. In connection with this fastening of the carrying poles there is as a rule a raising of the fore part of the bridge unit. In this connection this part describes a curved movement along a circle line with a radius, the centre of which is at the fastening point in the rear part of the unit. This curved movement should be hard to carry out in the device according to the known patent, since the carrying pole as a rule is rigid and the bracket unresiliently fastened to the rear unit. This invention intends to remove the problems with known technique and to bring about a bridge having such a construction that partly it can be easily laid out in spring and equally easily taken up in autumn, partly becomes very stable and safe to walk on. This has been made possible by a bridge of the kind mentioned by way of introduction, which is characterized in that each unit has a device functioning as a float for the unit when it is empty, and functioning as ballast for the carrying poles when it is filled with a medium or a material, and that each unit has means which are pivotable and lockable in relation to the unit and which are intended to cooperate with the carrying poles. Due to that fact each bridge unit can be easily pushed out on to the water from the bridge unit behind and be fastened to this one, whereafter the fore part of the bridge unit is raised in a suitable way to a level above the water surface under a smooth cooperation between the pivotable and lockable means on one hand and the carrying poles on the other. The remaining features of the invention will appear more closely from the description of the same with reference to the accompanying drawings, in which Fig 1 shows a bridge comprising three units, each having a floating tank and two carrying poles, during the period the units are laid out; Fig 2 shows a view of the device according to Fig 1 seen in the direction P, a winch being fastened to the supporting poles of the third unit; Fig 3 shows one of the units seen from the side and Fig 4 shows the same unit seen from above. Referring to Figs 1 and 2 there is schematically shown there a bridge when it is laid out. The bridge comprises a ramp 1 and a number of bridge units 2,3,4 connected to this ramp. Each unit has an a-end and a b- end, the a-end cooperating with two carrying poles 5,6, one in each corner. Moreover, each unit comprises a floating tank 7, which can keep the unit in question floating on the water when it is empty, and which functions as ballast for the carrying poles when it is filled with for instance water.

In Fig 2 there is shown a winch 8 which can be applied on to the carrying poles 5, 5 and be used for raising the units to a level above the water surface. Thus, this winch is easily movable between the different pairs of carrying poles.

In Figs 3 and 4 there is shown one of the units more closely. Each unit 2,3,4 has a frame comprising a number of longitudinal supporting beams 9, which can be stiffened by cross bars. On this frame there is arranged a bridge deck 10. The bridge deck 10 on each unit according to the shown embodiment comprises three sections 11,12,13, which can be locked mutually and in the frame of the unit. Each section 11,12,13 comprises two longitudinal beams 14,15 and cross bars 16 applied between these ones, which cross bars constitute the bridge deck and are intended as a bed for walking people on the bridge. As is shown in Fig 1 the different units are connected to each other. This connection to each other is smoothly made by means of hooks and loops; According to this embodiment each unit is provided with two hooks 17,18, which are fastened in a suitable way to each corner of the a-end of the unit and two loops 19,20, which are fastened in a suitable way to each corner of the b-end of the unit. Of course it is possible to apply the hooks in the b-end and the loops in the a-end and instead of loops and hooks to have other types of connecting means.

Moreover, each unit comprises a handle 21, which is retractable and suitable to use when laying out the unit.

As has been mentioned previously each unit 2,3,4 is intended to cooperate with two carrying poles 5,6, which are placed in each corner of the a-end of the unit. The carrying poles 5, 6 are intended to move through each guide pipe 22,23, each of which being fastened on to a shaft 24,25, which is positioned in the horizontal direction and essentially perpendicularly to the longitudinal direction of the bridge unit at its outer part. The shaft 24,25 is pivotably and lockably attached to the supporting beam of the unit in order to be able to allow the carrying poles to be inclined when raising and lowering the unit. Due to that fact a soft slide for the carrying poles in the guide pipes is made possible. The guide pipes 22,23 are suitably attached on to the outside of the unit. The carrying poles, which can be joined for different water depths, are prevented from falling freely through the guide pipe due to shoulders applied on the carrying poles, which shoulders must move in slots in the guide pipe for making possible for the carrying poles to move freely in the guide pipes.

As is shown in Fig 3 the tank 7 is applied under the supporting beams 9 at the a-end of the unit. Its purpose is to function as a floating body when laying out and taking up the bridge and as ballast on the poles when the bridge is raised to the desired height over the water surface.

When laying out the bridge the first step is to fasten the ramp steadily on land, which is facilitated by the fact that the ramp is provided with strap irons. After that a bridge unit is taken out by means of the handle at the b-end of the unit and its a-end is pushed out into the water. Since the floating tank is empty in this position, the a-end floats on the water. The b-end is connected to the ramp and the carrying handle is lowered forwardly. After that the bridge deck is laid on the bridge unit, the different sections being locked partly to the supporting beams of the unit, partly mutually. The carrying handle is now under the bridge deck and accordingly locked. It is now possible to go out on the bridge, which at its rear part is attached to the ramp and at its fore part floats on the float tank, and then put in the carrying poles in that way that they move through the guide pipes at the a-end of the unit. In this connection the carrying poles are joined so that they get such a length that the reach the bottom. A winch is now fastened to the carrying poles and is used for raising the unit laid out, whereby the unit inclusive the floating tank comes above the water surface. In this position the unit is locked on to the carrying poles, whereafter a material or a medium is filled into the tank in order to make this one serve as ballast on the poles. The locking of the unit on the poles can be made in a similar way by screwing a screw through the wall of the guide pipe so that it is applied against the carrying pole itself.

When laying out the next unit, the b-end of this one is connected to the a-end of the unit already laid out, whereafter the same procedure as previously is repeated. When the bridge shall be taken up for winter storage the method is similar but the different partial moments are made in a reverse order. As the different units are taken up they are laid on land and are stacked on each other. In this connection the carrying poles can function as pillars for a cover.

Besides the advantages already mentioned with this bridge the following advantages can be mentioned:

- it becomes uninfluenced by uneven loads;

- it is stackable and easy to transport; - it can be laid out without aiding devices like for instance a boat;

- it can be manufactured in different widths according to a module system, bridge units having the same and different sizes being able to be combined with each other;

- it can be used as a loading bridge on land.

Claims

1. A bridge comprising a ramp intended to be fastened at the shore of a water-coarse and a plurality of units attached to this one, each of the units comprising longitudinal supporting beams and a bridge deck resting on these ones, the unit being intended to be carried by carrying poles, c h a r a c t e r i z e d in that each unit (2,3,4) has a device ( 7 ) , which functions as a float for the unit when it is empty, and which functions as ballast for the carrying poles (5,6) when it is filled with a medium or a material, and that each unit (2,3,4) has means (22-25), which are pivotable and lockable in relation to the unit and which are intended to cooperate with the carrying poles (5,6).

2. A bridge according to claim 1, each unit (2,3,4) having an a-end and a b-end, c h a r a c t e r i z e d in that the device (7) comprises a floating tank, which is placed on the underside of the unit at its outer part, i e its a-end.

3. A bridge according to claim 2, c h a r a c t e r i z e d in that the a and b-ends have connecting means ( 17, 18; 19, 20) arranged in that way that the a-end of the one unit can easily be connected together with the b-end of the other unit.

4. A bridge according to claim 3, c h a r a c t e r i z e d in that the a-end has hooks (17,18) while the b-end has loops (19,20).

5. A bridge according to anyone of the preceding claims, c h a r a c t e r i z e d in that the means

(22-25) comprise guide pipes (22,23), which are positioned at the outer part of the unit (2,3,4), i e its a-end, and a shaft (24,25), which is positioned in a horizontal direction and essentially perpendicularly to the longitudinal direction of the bridge unit at the outer part of the unit and is pivotably and lockably attached to the supporting beam of the unit, and that the guide pipes (22,23) are attached on the shafts (24,25). 6. A bridge according to claim 5, c h a r a c t e r i z e d in that the carrying poles (5,

6) are intended to slide in the guide pipes (22, 23 ) , and that the carrying poles and the guide pipes can be locked in relation to each other.

7. A bridge according to anyone of the preceding claims, c h a r a c t e r i z e d in that the carrying poles (5,6) are joinable for different water depths and function as anchoring elements for a winch (8).

8. A bridge according to claim 7, c h a r a c t e r i z e d in that the carrying poles have shoulders intended to move in slots in the guide pipes for making possible for the carrying poles to move freely in the guide pipes.

9. A bridge according to anyone of the preceding claims, c h a r a c t e r i z e d in that bridge deck on each unit (2,3,4) comprises sections (11,12,13), which can be locked mutually and in the frame of the unit, each section (11,12,13) comprising two longitudinal beams (14,15) and cross bars (16) applied between these ones.

10. A bridge according to anyone of the claims 2-9, c h a r a c t e r i z e d in that the floating tank (7) is filled with water in the raised position.