GB2155433A - Winding drum - Google Patents

Abstract

A winding drum including a barrel B and at least one separate flange F5 in which the flange has an extension FES around and along the barrel outwardly of the turns-winding region and is retained to the barrel against loading by a winding on the barrel by the extension co-operating with the barrel or an attachment BP thereto. <IMAGE>

Description

SPECIFICATION Winding drum This invention relates to the construction of winding drums for winches and the like machines.

When a winding drum is wound with several layers of cable and the cable is under tension the layer or layers of turns beneath the outer most layer can be forced along the barrel of the drum to such an extent that flange or cheek of the drum is burst away from the barrel. The results of such a failure are disasterous on an installation such as an oil rig.

It is an object of the invention to provide a drum construction to resist such damage.

According to the invention there is provided a winding drum including a barrel and at least one separate flange in which the flange has an extension around and along the barrel outwardly of the turns-winding region and is retained to the barrel against loading by a winding on the barrel by the extension co-operating with the barrel or an attachment thereto.

Preferably the extension is retained to the barrel by an abutment on the barrel engaged by the extension. The extension co-operates with the abutment by reacting against it when the flange is loaded by winding turns on the barrel. The extension may have a curved extremity which engages the abutment to provide said co-operation with a pivotal freedom. Conveniently the abutment is a brake path for the winding drum.

An embodiment of the invention will now be described with reference to the accompanying drawing which shows, partly in cross-section, a winding drum embodying the invention.

The winding drum includes a barrel B and a first flange F attached at one end. Flange F may be conventional, as shown, or according to the invention.

A second flange FS is toward the other end of the barrel. Both flange F and flange FS may have a conventional stiffening web W. Flange FS has an extension FES which encircles the barrel B but neither flange F nor extension FES are attached directly to the barrel. An abutment BP, which may be a brake path, is attached to the end of the barrel outwardly of flange FES. The abutment BP can be attached to the barrel by a weld at Y.

in operation turns CT of cable or the like are wound on the barrel B between the flanges. When tension is applied to an overlying turn the inner turns are forced outwardly along the barrel towards the flanges. When the turns build up against the flanges the outward force applied near the periphery of the flange exerts a large moment which can destroy a flange conventionally welded to the barrel at point X.

The flange in the winding drum according to the invention is not secured to the barrel at point X, and is not necessarily secured anywhere else. The flange is retained by its contact with abutment BP where any turning action of the flange is supported without undue stress. The attachment of the abutment to the barrel, e.g. a weld at Y, is more suitable to withstand the load, which is now applied along the barrel. If there is a weld at the end of the barrel this is now in shear, not bending stress as it would be at X. Preferably the extension FES is shaped to a curve, as shown at C, to provide a pivot for the deflection of the flange and extension.

The curve may be on the abutment BP, or both elements may be curved.

In one example of the winding drum emboding the invention the barrel diameter is 1.3 m with a thickness of 80 mm. The drum is to hold 900 m of rope of 77 mm diameter. The load with 14 layers of rope is 400 kN to 1600 kN (40.4 Ton f to 160.2 Ton f). By arranging the flange with an extension as shown and avoiding the weld, such as at X or elsewhere, between the flange and the barrel which can be put under bending stress and thus concentrate stress to above that elsewhere in the barrel the barrel can be economically constructed with an adequate margin of safety. Thus a barrel designed so that the material of which it is made carries a reasonable factor of safety on yield and will not be excessively stressed, as it wouid be if constructed conventionally with a weld to the flange at X.The construction using the flange F and extension FES is more compliant and should withstand high loading without the damaging and potentially dangerous stress concentration. Also the path for a band-brake is provided.

1. A winding drum including a barrel and at least one separate flange in which the flange has an extension around and along the barrel outwardly of the turns-winding region and is retained to the barrel against loading by a winding on the barrel by the extension co-operating with the barrei or an attachment thereto.

2. A winding drum according to Claim 1 in which the extension is retained to the barrel by an abutment on the barrel engaged by the extension.

3. A winding drum according to Claim 2 in which the extension is arranged for co-operation with the abutment by reacting against it when the flange is loaded by winding turns on the barrel.

4. A winding drum according to Claim 2 or Claim 3 in which the extension has a curved extremity to engage the abutment to provide said cooperation with a pivotal freedom.

5. A winding drum according to Claim 2 or Claim 3 or Claim 4 in which the abutment is a brake path for the winding drum.

6. A winding drum substantially as herein described with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Winding drum This invention relates to the construction of winding drums for winches and the like machines. When a winding drum is wound with several layers of cable and the cable is under tension the layer or layers of turns beneath the outer most layer can be forced along the barrel of the drum to such an extent that flange or cheek of the drum is burst away from the barrel. The results of such a failure are disasterous on an installation such as an oil rig. It is an object of the invention to provide a drum construction to resist such damage. According to the invention there is provided a winding drum including a barrel and at least one separate flange in which the flange has an extension around and along the barrel outwardly of the turns-winding region and is retained to the barrel against loading by a winding on the barrel by the extension co-operating with the barrel or an attachment thereto. Preferably the extension is retained to the barrel by an abutment on the barrel engaged by the extension. The extension co-operates with the abutment by reacting against it when the flange is loaded by winding turns on the barrel. The extension may have a curved extremity which engages the abutment to provide said co-operation with a pivotal freedom. Conveniently the abutment is a brake path for the winding drum. An embodiment of the invention will now be described with reference to the accompanying drawing which shows, partly in cross-section, a winding drum embodying the invention. The winding drum includes a barrel B and a first flange F attached at one end. Flange F may be conventional, as shown, or according to the invention. A second flange FS is toward the other end of the barrel. Both flange F and flange FS may have a conventional stiffening web W. Flange FS has an extension FES which encircles the barrel B but neither flange F nor extension FES are attached directly to the barrel. An abutment BP, which may be a brake path, is attached to the end of the barrel outwardly of flange FES. The abutment BP can be attached to the barrel by a weld at Y. in operation turns CT of cable or the like are wound on the barrel B between the flanges. When tension is applied to an overlying turn the inner turns are forced outwardly along the barrel towards the flanges. When the turns build up against the flanges the outward force applied near the periphery of the flange exerts a large moment which can destroy a flange conventionally welded to the barrel at point X. The flange in the winding drum according to the invention is not secured to the barrel at point X, and is not necessarily secured anywhere else. The flange is retained by its contact with abutment BP where any turning action of the flange is supported without undue stress. The attachment of the abutment to the barrel, e.g. a weld at Y, is more suitable to withstand the load, which is now applied along the barrel. If there is a weld at the end of the barrel this is now in shear, not bending stress as it would be at X. Preferably the extension FES is shaped to a curve, as shown at C, to provide a pivot for the deflection of the flange and extension. The curve may be on the abutment BP, or both elements may be curved. In one example of the winding drum emboding the invention the barrel diameter is 1.3 m with a thickness of 80 mm. The drum is to hold 900 m of rope of 77 mm diameter. The load with 14 layers of rope is 400 kN to 1600 kN (40.4 Ton f to 160.2 Ton f). By arranging the flange with an extension as shown and avoiding the weld, such as at X or elsewhere, between the flange and the barrel which can be put under bending stress and thus concentrate stress to above that elsewhere in the barrel the barrel can be economically constructed with an adequate margin of safety. Thus a barrel designed so that the material of which it is made carries a reasonable factor of safety on yield and will not be excessively stressed, as it wouid be if constructed conventionally with a weld to the flange at X.The construction using the flange F and extension FES is more compliant and should withstand high loading without the damaging and potentially dangerous stress concentration. Also the path for a band-brake is provided. CLAIMS

1. A winding drum including a barrel and at least one separate flange in which the flange has an extension around and along the barrel outwardly of the turns-winding region and is retained to the barrel against loading by a winding on the barrel by the extension co-operating with the barrei or an attachment thereto.

2. A winding drum according to Claim 1 in which the extension is retained to the barrel by an abutment on the barrel engaged by the extension.

3. A winding drum according to Claim 2 in which the extension is arranged for co-operation with the abutment by reacting against it when the flange is loaded by winding turns on the barrel.

4. A winding drum according to Claim 2 or Claim 3 in which the extension has a curved extremity to engage the abutment to provide said cooperation with a pivotal freedom.

5. A winding drum according to Claim 2 or Claim 3 or Claim 4 in which the abutment is a brake path for the winding drum.

6. A winding drum substantially as herein described with reference to the accompanying drawing.