GB2028243A

GB2028243A - Means for removing rope tackle and the like from a rotating shaft

Info

Publication number: GB2028243A
Application number: GB7929069A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-08-22
Filing date: 1979-08-21
Publication date: 1980-03-05
Also published as: GB2028243B; NO141983B; DK349179A; SE7906984L; IS2507A7; SE443758B; DK149427C; DK149427B; NO141983C; IS1219B6; NO782857L

Abstract

The invention relates to a means for removing rope tackle and the like which has been wound around a rotating shaft, such as a propeller. In order to remove the rope tackle or the like, knives are mounted on a stationary shaft casing (6) on the propeller shaft, with the knife edges directed axially outwards. <IMAGE>

Description

SPECIFICATION A means for removing rope tackle and the like from a rotating shaft The invention relates to a means for removing rope tackle and the like which has become wound around a rotating shaft, especialiy a propeller shaft.

Awell known problem in connection with smaller boats, such as fishing vessels and the like, is that rope tackle and similar gear, drifting in the sea, can become wound around the propeller shaft and impede propulsion. Such problems have become steadily worse after nylon and other artificial fibers began to be used for fishing gear. Ropes of nylon and other artificial fibers are very strong, and most types also have a certain buoyancy, such that they float on or near the surface of the water and can become wound around the propeller shaft and the rudder post, which can cause great damage. In addition, it frequently happens that a fishing net or the like, when being dragged and set, comes into the propeller.

In the worst case, this can mean that the boat has to go into dock, or that the help of a diver is required to remove the rope. In all instances, the lashing of the rope around the propeller shaft results in a stoppage of operations.

Material which becomes wound around a rotating shaft can also cause problems on other types of equipment, for example, on lawn mowers.

The purpose of the present invention, therefore, is to provide a means by which this type of coiling around shafts can be avoided. In particular, the invention seeks to provide a means which will cut through any rope tackle and gear which interferes with the propeller on a boat, such that an operating stop will be avoided. The means prevents rope tackle and the like from interfering with or lashing onto the propeller casing, which would eventually stop the engine.

This is obtained by means of an arrangement whose characteristic features are disclosed in the appurtenant patent claims.

The means of the invention is adapted to be mounted on a propeller shaft, and comprises knives mounted upstream of the propeller, said knives having a cutting edge which cuts the rope with the aid of the pulling power of the propeller, the rope becoming tightened around the knives and thus being cut through.

The invention will be explained in greater detail in the following with reference to an embodiment example, which is illustrated on the accompanying drawings, where Figure 1 is a perspective drawing of a knife for cutting rope tackle on the means provided in accordance with the invention, and Figure 2 is a schematic side view of the means of the invention installed on a propeller shaft.

The means of the invention consists preferably of four knives which are mounted on a stationary casing which is provided on a propeller shaft, the knives being arranged such that their cutting edges are directed axially outwards. Such a knife is shown in Figure 1. The knife 1 is formed with a pointed tip 2 which points towards the propeller. At the pointed end, the knife is formed with an upwardly sloping or rising edge 3, with a slightly downwardly sloping section 4 in back of the edge 3, and a short rising section 5 in back of the section 4. To the rear of said rising portion 5 is the knife body itself, which has no cutting edge. These knives are mounted as shown on Figure 2.Four such knives are welded an equal distance apart, i.e., at an angular distance of 90" relative to one another, onto a metal casing 6 which is mounted so as to be stationary on the propeller shaft. The knives cover the space between the shaft mounting and the head of the propeller, as shown on the drawing. Each knife is mounted such that the tip 2 of the cutting edge projects beyond the casing toward the propeller 7, ending in the vicinity of the propeller blades 8. With a variabie pitch propeller, this will correspond to the innermost position of the propeller blades. The knives are mounted at an angle of 12 - 15" in relation to the longitudinal direction of the vessel, with the knife tips toward the normal direction of rotation of the propeller.

If rope tackle comes into the space between the hull of the ship and the propeller head, it will wind around the knives, and as the rope is pulled tighter owing to the rotation of the propeller, it will be pressed against the edges of the knives, tightening around them until the rope is cut through. The rope tackle might first, for example, encounter the sloping portion 3, and as it tightens, slide along the edge toward the flatter section 4, finally coming into the corner against the steeper section 5, where it becomes very tightly drawn and will be cut through.

The mounting of such knives on the propeller shaft thus ensures, in a simple manner, that undesired rope tackle around the propeller will be cut through, such that the problem of rope in the propeller is solved without entailing any interruption of normal operations or, in the worst case, having to dock the boat.

1. A means for removing rope tackle and the like which has become wound around a rotating shaft, especially a propeller shaft, characterised by knives (1 ) which are mounted on a stationary shaft casing (6) on the propeller shaft, with the knife edge directed axially outwards.

2. A means according to claim 1, characterised in that the knives (1) are mounted at angular distance of 90" relative to one another around the casing.

3. A means according to claim 1, characterised in that the knives are mounted at an angle of about 12" 15 in relation to the axis of the shaft.

4. A means according to claim 1, for use on a propeller shaft for a propeller with variable-pitch blades, characterised in that the knife edge is formed with a tip (2) which, at least when the propeller blades are in a rotating position, lies near the propeller blades.

5. A means according to claim 1, characterised in that the knife edge has a rising section (3) extending rearwardly of the tip (2) followed by a flatter section

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION A means for removing rope tackle and the like from a rotating shaft The invention relates to a means for removing rope tackle and the like which has become wound around a rotating shaft, especialiy a propeller shaft. Awell known problem in connection with smaller boats, such as fishing vessels and the like, is that rope tackle and similar gear, drifting in the sea, can become wound around the propeller shaft and impede propulsion. Such problems have become steadily worse after nylon and other artificial fibers began to be used for fishing gear. Ropes of nylon and other artificial fibers are very strong, and most types also have a certain buoyancy, such that they float on or near the surface of the water and can become wound around the propeller shaft and the rudder post, which can cause great damage. In addition, it frequently happens that a fishing net or the like, when being dragged and set, comes into the propeller. In the worst case, this can mean that the boat has to go into dock, or that the help of a diver is required to remove the rope. In all instances, the lashing of the rope around the propeller shaft results in a stoppage of operations. Material which becomes wound around a rotating shaft can also cause problems on other types of equipment, for example, on lawn mowers. The purpose of the present invention, therefore, is to provide a means by which this type of coiling around shafts can be avoided. In particular, the invention seeks to provide a means which will cut through any rope tackle and gear which interferes with the propeller on a boat, such that an operating stop will be avoided. The means prevents rope tackle and the like from interfering with or lashing onto the propeller casing, which would eventually stop the engine. This is obtained by means of an arrangement whose characteristic features are disclosed in the appurtenant patent claims. The means of the invention is adapted to be mounted on a propeller shaft, and comprises knives mounted upstream of the propeller, said knives having a cutting edge which cuts the rope with the aid of the pulling power of the propeller, the rope becoming tightened around the knives and thus being cut through. The invention will be explained in greater detail in the following with reference to an embodiment example, which is illustrated on the accompanying drawings, where Figure 1 is a perspective drawing of a knife for cutting rope tackle on the means provided in accordance with the invention, and Figure 2 is a schematic side view of the means of the invention installed on a propeller shaft. The means of the invention consists preferably of four knives which are mounted on a stationary casing which is provided on a propeller shaft, the knives being arranged such that their cutting edges are directed axially outwards. Such a knife is shown in Figure 1. The knife 1 is formed with a pointed tip 2 which points towards the propeller. At the pointed end, the knife is formed with an upwardly sloping or rising edge 3, with a slightly downwardly sloping section 4 in back of the edge 3, and a short rising section 5 in back of the section 4. To the rear of said rising portion 5 is the knife body itself, which has no cutting edge. These knives are mounted as shown on Figure 2.Four such knives are welded an equal distance apart, i.e., at an angular distance of 90" relative to one another, onto a metal casing 6 which is mounted so as to be stationary on the propeller shaft. The knives cover the space between the shaft mounting and the head of the propeller, as shown on the drawing. Each knife is mounted such that the tip 2 of the cutting edge projects beyond the casing toward the propeller 7, ending in the vicinity of the propeller blades 8. With a variabie pitch propeller, this will correspond to the innermost position of the propeller blades. The knives are mounted at an angle of 12 - 15" in relation to the longitudinal direction of the vessel, with the knife tips toward the normal direction of rotation of the propeller. If rope tackle comes into the space between the hull of the ship and the propeller head, it will wind around the knives, and as the rope is pulled tighter owing to the rotation of the propeller, it will be pressed against the edges of the knives, tightening around them until the rope is cut through. The rope tackle might first, for example, encounter the sloping portion 3, and as it tightens, slide along the edge toward the flatter section 4, finally coming into the corner against the steeper section 5, where it becomes very tightly drawn and will be cut through. The mounting of such knives on the propeller shaft thus ensures, in a simple manner, that undesired rope tackle around the propeller will be cut through, such that the problem of rope in the propeller is solved without entailing any interruption of normal operations or, in the worst case, having to dock the boat. CLAIMS

5. A means according to claim 1, characterised in that the knife edge has a rising section (3) extending rearwardly of the tip (2) followed by a flatter section (4), which terminates in a short rising section (5).

6. A means for removing a rope from around a rotating shaft comprising a knife mounted on a casing, which casing is adapted to be mounted non-rotatably on the shaft with the knife edge directed radially outwardly with respect to the longitudinal axis of the shaft.

7. A means for removing a rope from around a rotating shaft substantially as hereinbefore described with reference to the accompanying drawings.