GB2207211A

GB2207211A - Winching cable through duct

Info

Publication number: GB2207211A
Application number: GB08717003A
Authority: GB
Inventors: John Thomas Spiers
Original assignee: GALLIFORD PIPELINE SERVICES LI
Current assignee: GALLIFORD PIPELINE SERVICES LI
Priority date: 1987-07-18
Filing date: 1987-07-18
Publication date: 1989-01-25
Also published as: GB8717003D0

Abstract

A cable (23) is drawn from an underground duct (24) into a hole in the ground by means of a winch (16) disposed in the hole and carried on an arm (14) of a machine which stands on the surface of the ground at a position away from the hole. The arm is swivelled about an axis (13) to move a drum (18) of the winch axially and maintain in alignment with a length of the cable in the duct the turn of the cable which is being formed on the drum. In this way travel of the cable around a corner between the duct 24 and the drum 18 is avoided. <IMAGE>

Description

Title:"Method of drawing a cable from a duct and apparatus for use in the method" Description of Invention The present invention relates to drawing a cable from a duct and is primarily concerned with drawing a cable from an underground duct to which access can be gained through a hole in the ground. In the course of cleaning and reinstatement of water pipes, sewers and other underground ducts, it is common to draw one or more devices along the duct by means of a cable.

The cable is wound onto a winch drum which may be mounted on a vehicle parked near to the hole in the ground. With this arrangement, it is generally impossible to position the winch drum in alignment with that part of the cable which is contained in the duct. It is an object of the present invention to facilitate drawing of the cable onto the winch drum without significant deviation of the cable from a rectilinear path.

According to a first aspect of the invention, there is provided a method of drawing a cable from a duct wherein the cable is wound onto a rotating drum disposed adjacent to an opening defined by the wall of the duct and wherein the drum is moved in the direction of its axis of rotation to align with a length of the cable in the duct a turn of the cable which is being formed on the drum.

According to a second aspect of the invention, there is provided a winch having a drum disposed in a hole in the ground and supported by an arm which extends from the drum to a body above ground level, the arm being connected with the body for swivelling relative thereto about a generally upright swivel axis.

Provided the drum is offset from the swivel axis, axial movement of the drum of a winch in accordance with the second aspect of the invention can be effected by swivelling of the arm relative to the body. It will be understood that the required displacement of the drum will generally not exceed the length of the drum and that, provided the drum is separated from the swivel axis by a distance which is a plurality of times greater than the length of the drum, the angle through which the drum will be turned by swivelling of the arm will be quite small.

There is also provided in accordance with the invention a vehicle comprising a chassis supported on ground-engoging wheels or tracks, a power unit, an arm mounted on the chassis for swivelling relative thereto about a generally upright axis, a winch mounted on the arm and an hydraulic system for transmitting power hydraulically from the power unit to the winch. A vehicle in accordance with this third aspect of the invention may be produced by substituting for the bucket of a known bucket excavator a winch incorporating an hydraulic motor and connecting the hydraulic motor in the hydraulic circuit of the excavator.

According to a fourth aspect of the invention, there is provided a winch comprising a body, a drum mounted on the body for rotation relative thereto about a drum axis and an hydraulic motor for rotating the drum relative to the body, wherein the body defines a first pair of circular, co-axial apertures which are spaced apart in a direction parallel to the drum axis and collectively define a first axis parallel to the drum axis and wherein the body defines a second pair of circular, co-axial apertures which are spaced apart in said direction parallel to the drum axis and which collectively define a second axis parallel to the drum axis and spaced from the first axis.

The bucket of a bucket excavator is generally connected with the arm through the intermediary of two horizontal pins; Each pin passes through a pair of apertured lugs on the arm and a pair of apertured lugs on the bucket.

A winch according to the fourth aspect of the invention is especially adapted to be mounted on the arm of a bucket excavator in substitution for the bucket thereof.

An example of a vehicle in accordance with the third aspect of the invention which incorporates a winch according to the invention and which is used in a method according to the first aspect of the invention will now be described, with reference to the accompanying drawing, wherein FIGURE I shows a cross-section in a vertical plane through an underground duct, together with a winch drawing a cable from the duct and a vehicle supporting the winch; and FIGURE 2 shows the winch and adjacent parts as viewed in a direction along the axis of the winch drum.

The vehicle illustrated in the accompanying drawing comprises a chassis 10 having ground-engaging, driven tracks 11 and a body 12 mounted on the chassis for swivelling relative thereto about a generally upright axis 1 3. The body incorporates a cab for an operator and controls in the cab for controlling the various systems of the machine. The machine also includes an internal combustion engine or other power unit which may be mounted on the chassis or on the body. Means is provided for transmitting drive from the power unit to the tracks II. It will be understood that running wheels may be provided in ploce of the tracks II.

The machine further comprises an articulated arm 14 mounted on the body 12 for pivoting relative thereto about an horizontal axis 15. Hydraulic rams are provided for pivoting the arm relative to the body and pivoting the articulated parts of the arm in the usual manner.

A winch 16 is mounted on the arm 14 at the end thereof remote from the body 12. The winch incorporates a body 17, a drum 18 mounted on the body for rotation relative thereto about a drum axis and an hydraulic motor for rotating the drum relative to the body. The body incorporates lugs 19 which project away from the drum 18 and have a nested relation with lugs 20 provided on the arm 14. The winch body 17 is connected with the arm by means of two pins, each of which extends through respective apertures formed in the lugs on the arm and on the winch body. The pins 21 and 22 are mutually parallel, are spaced from each other and are spaced from the drum 18. The pins are parallel to the drum axis.

The hydraulic system of the vehicle incorpdrates an hydraulic pump arranged to be driven by the power unit, a reservoir of hydraulic fluid and ducts for coveying hydraulic fluid under pressure from the pump to the winch motor. Controls for controlling flow of hydraulic fluid to the winch motor are provided in the operators cab.

The machine illustrated in the accompanying drawing can be produced by demounting the bucket from the arm of a bucket excavator and mounting the winch 16 on the arm in place of the bucket. The hydraulic motor of the winch is then connected into the hydraulic circuit of the machine in a known manner. When the cable has been wound completely onto the drum 18, the winch can be demounted from the arm and the bucket mounted once more on the arm, if the machine is required to excavate a further hole.

The winch is illustrated in the drawing when used for drawing a cable 23 from an underground duct 24. Typically, the duct 24 is a water moin or sewer which is generally horizontal and spaced two or more metres below ground level. A hole has been excavated in the ground and the wall of the duct 24 defines an opening, disposed in the hole, through which the interior of the duct is accessible. The cable 23 extends from the drum 18 into the duct and the winch is supported by the arm 14 at a level such that the lowest part of a turn of cable which is being formed on the drum is aligned with that part of the cable which is disposed in the duct 24 near to the opening thereof.The winch can be tilted by articulation of the arm as successive turns of cable are formed on the drum, the drum is displaced axially relative to the duct 24 to maintain in alignment with the duct 24 the turn of the cable which is being formed on the drum. In this way, travel of the cable around a corner between the duct 24 and the drum 18 is avoided.

Axial movement of the drum 18 during winding of the cable onto the drum is effected by swivelling of the body 12 and arm 14 about the axis 13.

It will be noted that the drum 18 is spaced several metres from the axis 13.

Accordingly, movement of the drum through an arc of sufficient length to move one end portion of the drum out of alignment with the duct 24 and the opposite end portion of the drum into alignment with the duct requires swivelling about the axis 13 through an angle of only a few degrees. The axis of rotation of the drum 18 is maintained in an approximately perpendicular relation to the length of the cable emerging from the duct 24. The operator has, from the cab of the vehicle, a good view of the drum 18. In the event of the cable 23 breaking, it is unlikely that any part of the cable will leave the hole in the ground. Accordingly, persons are protected from the risk of being struck by a breaking cable, provided they do not descend into the hole in which the winch is disposed.

The features disclosed in the foregoing description, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS:

I. A method of drawing a cable from a duct wherein the cable is wound onto a rotating drum disposed adjacent to an opening defined by the wall of the duct and wherein the drum is moved in the direction of its axis of rotation to align with a length of the cable in the duct a turn of the cable which is being formed on the drum.
2. A method according to Claim I wherein the duct is underground, the opening lies in a hole in the ground, the drum is disposed in the hole adjacent to the duct, the drum is supported on an arm which extends from the drum to a position above the surface of the ground and the arm is moved to align the turn being formed on the drum with the length of the cable in the duct.
3. A method according to Claim 2 wherein the arm is swivelled about a generally upright axis which is offset from the drum.
4. A winch having a drum disposed in a hole in the ground and supported by an arm which extends from the drum to a body above ground level, the arm being connected with the body for swivelling relative thereto about a generally upright swivel axis.
5. A vehicle comprising a chassis supported on ground-engaging wheels or tracks, a power unit, an arm mounted on the chassis for swivelling relative thereto about a generally upright axis, a winch mounted on the arm and an hydraulic system for transmitting power hydraulically from the power unit to the winch.
6. A winch comprising a body, a drum mounted on the body for rotation relative thereto about a drum axis and an hydraulic motor for rotating the drum relative to the body, wherein the body defines a first pair of circular, co-axial apertures which are spaced apart in a direction parallel to the drum axis and collectively define a first axis parallel to the drum and wherein the body defines a second pair of circular, co-axial apertures which are spaced apart in said direction parallel to the drum axis and which collectively define a second axis, parallel to the drum axis and spaced from the first axis.
7. A winch substantially as herein described with reference and as illustrated in the accompanying drawing.
8. A vehicle substantially as herein described with reference to the accompanying drawing and incorporating a winch according to Claim 7.
9. Any novel feature or novel combination of features disclosed herein or in the accompanying drawing.