Apparatus for raising and lowering a platform on an upright column comprising a pair of vertically spaced ring assemblies, each comprising an outer support ring and an inner ring which can be wedged between the support ring and the column to anchor the support ring against displacement on the column. The surfaces of engagement between the support ring and the clamping ring are tapered upwardly and hydraulic actuators are provided for displacing the rings independently of one another along the column. These actuators are connected at one end to an element in one ring assembly and are effectively connected at the other end to an element in the other ring assembly so that each element in the ring assembly is free to be displaced longitudinally of the column independently of the other element.

Current U.S. Class:	254/106
Current International Class:	E02B 17/08 (20060101); E02B 17/00 (20060101); B66f 001/00 ()
Field of Search:	254/894,93,105,106,107

Howson and Howson

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Claims

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We claim:

1. Apparatus for displacing a platform relative to an elongated support, comprising: a first support ring surrounding said support; a second support ring surrounding said support a spaced distance from said first ring; means providing a rigid coupling between said platform and one of said support rings; main extensible means connected to and intermediate said first and second support rings operable by pressure-fluid to displace said support rings selectively toward and away from one another and thereby to displace the other of said support rings relative to said platform; first and second clamping rings associated with said first and second support rings respectively, each of said clamping rings being mounted for displacement relative to its associated support ring for being selectively engaged and disengaged between said support and said support ring; said clamping ring being contractible upon engagement between said support and said support ring to firmly engage, support and anchor said clamping ring and its associated support ring on said support; at least two secondary extensible means respectively operable by pressure-fluid to selectively displace said clamping rings relative to their associated support rings, one of said secondary means being connected intermediate said second support ring and said first clamping ring and the other of said secondary means being connected to said second clamping ring and being operable to displace said second clamping ring selectively toward and away from said first clamping ring; and the engaging surfaces of said clamping and support rings including at least one tapered surface disposed so that the platform may be displaced along the support by causing the extensible means to displace the support ring along the support and separate the support ring from its associated clamping ring in one of the ring assemblies, thereafter displacing the associated clamping ring to reengage the separated clamping ring with its associated ring, and thereafter repeating the same procedure with the other ring assembly, whereby the platform is displaced along the support.

2. Apparatus according to claim 1 wherein said second support ring is disposed intermediate said platform and said first support ring and said platform terminates adjacent said support, and said other one of said secondary extension means is connected intermediate said second clamping ring and said platform.

3. Apparatus according to claim 1 wherein said main extensible means includes an auxiliary extensible means connected between said second support ring and said platform.

4. Apparatus according to claim 1 wherein said second support ring is located intermediate said first support ring and said platform and said rigid coupling means extends from said first support ring to said platform in substantially parallel relation to said support, and said main and secondary extensible means being located inwardly of said coupling means, so that the apparatus possesses a compact profile transverse to the support.

5. Apparatus according to claim 1 wherein each of said clamping rings is segmented so as to be radially expandable and including resilient means biasing said clamping rings into their radially expanded positions.

6. Apparatus according to claim 1 wherein each of said clamping rings has an internal support engaging surface and an external tapered surface, each support ring having a mating tapered internal surface, said mating tapered surfaces on the two support rings being similarly inclined with relation to the axis of said support.

7. Apparatus according to claim 6 wherein said support is upright and tapered surfaces are all tapered upwardly whereby the weights of said platform on said support ring assists in contracting said clamping rings on said support.

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Description

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This invention relates to apparatus for raising and lowering a heavy weight such as a ship or a derrick used for investigating the nature of the soil of the sea bottom or drilling for exploitation of the oil field of the sea bottom, and the like.

A principal object of this invention is to provide an apparatus which can easily raise or lower a heavy weight and secure it at desired position.

Other objects and advantages will appear in the description and in the drawings, in which:

FIG. 1 is an elevational view in which a right half portion thereof is shown in vertical section;

FIG. 2 is a sectional view taken on line A--A of FIG. 1;

FIGS. 3a to 3d are diagrammatical view showing the operating order for raising a heavy weight; and

FIGS. 4a to 4f are diagrammatical view showing the operating order for lowering.

Referring to the drawings, and especially FIGS. 1 and 2 thereof, character P is a cylindrical support for a heavy weight such as a ship or a derrick and being secured on the sea bottom. An upper ring 1 and a lower ring 2 are provided surrounding the periphery of the cylindrical support P. The both rings 1 and 2 have taper rings 3 and 4 comprise three arcuated members, and extension springs 11 are provided between each ring. On the inner surfaces of the taper rings 3 and 4, rubber rings 5 are pasted. A platform B of the heavy weight is hanged from the upper ring 1 by a rod 6, and the support P penetrates through the platform B.

Between the upper ring 1 and the lower ring 2, three main hydraulic means 7 comprising a cylinder and a ram with fixing the ram thereof to the under surface of the upper ring 1 and fixing the cylinder to the upper surface of the lower ring 2 are provided, and also three hydraulic means 8 are provided between the lower ring 2 and the platform B in the same manner. Three hydraulic means 9 for raising and lowering the upper taper ring 3 are provided between the upper taper ring 3 and the lower ring 2, and three hydraulic means 10 are provided between the lower taper ring 4 and the platform B.

Weight of the platform B forces the upper ring 1 and downwardly and the lower ring 2 is also forced in the same direction through the hydraulic means 7. The horizontal component of the gravity produced by the taper surface contact between the upper ring 1 and the upper taper ring 3 exerts to cause the ring 3 to press onto the support P through the rubber ring 5. The lower taper ring 4 is also pressed to the support P through the rubber rings by the same reason. Thus, the upper ring 1 and the lower ring 2 shown in FIG. 1 are secured to the support P.

In raising operation, pressure oil is supplied into the cylinder of the main hydraulic means 7 and the oil in the cylinder of the hydraulic means 8 is withdrawn, which causes the upper ring 1 and the platform B to raise, as a result the platform B is supported by the lower ring 2 which is secured to the support P by the grasping force of the lower taper ring 4 (FIG. 3a). Since upwardly movement of the upper ring 1 bring to form the gap between the both rings 1 and 3, the taper ring 3 is expanded by the extension of the springs 11 and the rubber ring 5 is separated from the periphery of the support P. Then, the taper ring 3 is raised by the operation of the hydraulic means 9, and, when the upper ring 1 is stopped the taper ring 3 is forced into fitting with the inner surface of the upper ring 1 by increasing the pressure of the oil (FIG. 3b). And then, the pressure oil is supplied into the cylinder of the hydraulic means 8 and the oil in the cylinders of the hydraulic means 7 and 9, which will cause the lower ring 2 to lift as shown in FIG. 3c, and the platform B is supported by the upper ring 1. When the lower ring 2 is lifted and separated from the lower taper ring 4, the lower taper ring 4 is expanded and separated from the support P by the operation of the extension springs 11. The taper ring 4 is raised by the operation of the hydraulic means 10 and brought to close contact with the lower ring 2 and the support P (FIG. 3d). The main hydraulic means 7 is operated again, and the above mentioned operation is repeated. Thus, the platform B can be raised to a great height within the limits of the support and secured at desired position.

In lowering operation, the lower ring 2, firstly, is slightly raised by operation of the hydraulic means 8 under the free operative condition of the hydraulic means 7 (FIG. 4a). In this state the platform B is supported by the upper ring 1 only. Since the gap is formed between the upper ring 2 and the taper ring 4, the taper ring 4 is expanded by the springs 11 and the rubber ring 5 is separated from the support P. Then, the taper ring 4 is lowered by supplying the pressure oil into the cylinder of the hydraulic means 10 in the reverse direction to the raising operation as shown in FIG. 4b). And then, oil in the cylinders of the hydraulic means 7 and 8 is withdrawn and pressure oil is supplied into the cylinder of the hydraulic means 9 in the reverse direction to the direction of the said raising operation of the platform which will mean that the lower ring 2 will be lowered (FIG. 4c). When the lower ring 2 stopped, the pressure oil is supplied into the cylinder of the hydraulic means 7, the ring 2 is fitted with the taper ring by force, and the upper ring 1 is slightly lifted by the further supply of the pressure oil as shown in FIG. 4d. Thus, the upper ring 1 is separated from the taper ring 3 and the taper ring is expanded by the spring 11. Then, the taper ring 3 is lowered by the operation of the hydraulic means 9 (FIG. 4e). And then, the oil in the cylinder of the hydraulic means 7 is withdrawn little by little, which results in lowering of the upper ring 1 and the platform B. The upper ring 1 is firmly fitted to the taper ring 3 and stopped as shown in FIG. 4f. If the above-mentioned operation is repeated, the platform B can be lowered to desired position on the support P.

It will be obvious that pressure water or pressure air may be substituted for pressure oil in the above description. In the above described embodiment, the support P is fixed and the platform B is movable. However, it will be understood that the support P can be raised and lowered, if the platform B is fixed or floated and the above-mentioned operation is performed. In this case, the raising operation in the aforesaid embodiment will cause the support to lower, and the lowering operation cause it to raise.

From the foregoing, it will be understood that the present invention provides a novel apparatus which can raise and lower the heavy weight B to desired position on the support P.

Since the heavy weight is always supported by both the upper rings 1 and 3 and the lower rings 2 and 4 necessity for other safety means. Thus, the present invention can provide an apparatus which is of simplified construction, may be manufactured easily and cheaply, and is of safety and effective in operation.

While particular embodiments of the present invention have been illustrated and described herein, it is not intended to limit the invention to such a disclosure.

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