APPARATUS FOR THREADING AN ELONGATED TENSILE ELEMENT THROUGH

AND ALONG A CONDUIT

THIS INVENTION relates to an apparatus for threading an elongated

tensile element such as a fish tape or a fish wire through and along a conduit.

According to the invention there is provided an apparatus for threading

an elongated tensile element through and along a conduit, which apparatus includes:

a rotatable drive wheel which is operatively connected to a rotatable drive

shaft, the drive wheel having a circumferential surface providing a gripping surface

for gripping a tensile element; and

a rotatable tensioning wheel which has a circumferential surface which

provides a contact surface for contacting the tensile element,

the tensioning wheel being proximate the drive wheel, with the gripping surface of the

drive wheel and the contact surface of the tensioning wheel facing each other, the

drive wheel and the tensioning wheel defining a gap between the gripping surface

and the contact surface in which the tensile element is receivable, and the drive

wheel and the tensioning wheel being mounted in a common housing.

The tensile element may be a fish tape comprising a tape having an

end provided with a hook or loop, a further elongated element such as an electrical

lead or cable being, in use, attached to the hook or loop.

Preferably, the tensioning wheel is movable towards or away from the

drive wheel, or vice versa, so that the gap between the tensioning wheel and the

drive wheel is adjustable.

The apparatus may include an urging arrangement for urging the tensioning wheel towards the drive wheel, such that, in use, the tensioning wheel exerts a force on the tensile element to urge it into engagement with the drive wheel.

The wheels may be rotatable about parallel axes.

The gripping surface of the drive wheel and/or the contact surface of the tensioning wheel may have gripping formations, for example teeth, for gripping

the tensile element, the teeth being circumferentially spaced and projecting radially outwardly, and extending, in the nature of the teeth of a gear wheel, parallel to the axes of the respective wheels.

The drive shaft may, in use, be attached to an electrically powered drill or an electrically powered screwdriver. The drill or screwdriver may plug into an AC

plug or may be powered by one or more batteries.

The apparatus may include a plurality of tensioning wheels, each of the tensioning wheels having a circumferential surface which provides a contact surface for contacting the tensile element and each of the tensioning wheels being proximate the drive wheel, the gripping surface of the drive wheel facing the contact surfaces of the tensioning wheels, the drive wheel and each of the tensioning wheels defining a gap between the gripping surface of the drive wheel and the contact surface of the

tensioning wheel in which the tensile element is receivable, the tensioning wheels being mounted in the housing.

The housing may include two portions which are hingedly connected to each other, the drive wheel being mounted in one of the portions and the tensioning wheels being mounted in the other portion.

The invention will now be described by way of non-limiting, illustrative examples with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a side elevation of a first embodiment of an apparatus for threading a tensile element through and along a conduit in accordance with the invention, a portion of the housing of the apparatus having been removed for illustrative purposes;

Figure 2 is a second embodiment of an apparatus for threading a tensile element through and along a conduit in accordance with the invention, the apparatus being in its open condition; and

Figure 3 is a side elevation of the apparatus of Figure 2 in its closed condition, a portion of the housing of the apparatus having been removed for illustrative purposes.

Referring to Figure 1 , an apparatus for threading a tensile element through and along a conduit in accordance with the invention is generally designated by reference numeral 10. The apparatus 10 includes a rotatably mounted drive wheel 12 and a rotatably mounted tensioning wheel 14. A shaft 16 is attached to the

wheel 12, the shaft 16 being attachable to a drill brace or to a screwdriver (not shown). The wheel 14 is rotatably mounted on a shaft 17. The wheels 12 and 14 and the shafts 16 and 17 are of a hardened steel. The wheel 12 is proximate the wheel 14 and its axis is parallel to and laterally spaced from that of the wheel 14, the shafts 16 and 17 being parallel to each other. The wheel 12 and the wheel 14 are mounted within a common housing 18, the housing 18 being of a rust-resistant material and comprising an outer casing 20 and an inner casing 22. The shaft 16 extends through the housing 18 via a circular aperture (not shown) in the outer

casing 20 and an elongated slot (not shown) in the inner casing 22. The shaft 17 extends through the housing 18 via elongated slots 23 in the outer casing 20 and circular apertures 25 in the inner casing 22, said circular apertures 25 each having a diameter that is approximately the same as the diameter of the shaft 17. The wheel 12 includes a gripping surface for gripping the tensile element, the gripping surface being provided by the circumferential surface 24 of the wheel 12. The wheel 14 includes a contact surface for contacting the tensile element, the contact surface being provided by the circumferential surface 26 of the wheel 14. The circumferential surface 24 of the wheel 12 and the circumferential surface 26 of the wheel 14 are provided with radially outwardly projecting, axially extending, circumferentially spaced teeth (not shown), the wheels 12 and 14 defining between them a gap 27. The apparatus 10 is portable by a single person.

The apparatus 10 includes a cylindrical knob 28 and a rod 30 which is attached at its inner end to the inner casing 22, the rod 30 being connected to the wheel 14, by means of the inner casing 22 and the shaft 17. The knob 28 has a

central, axially extending socket 34. The rod 30 is provided with screw threads (not

shown) which engage with complementary screw threads (not shown) defined in the

wall of the socket 34, the spacing between the wheels 12 and 14 being adjustable by

rotating the knob 28 to screw the rod 30 into, or out of, the socket 34. A spring 36,

when compressed, bears, at one of its ends, on the outer casing 20 and, at its other

end, on a head or flange 35 at the inner end 38 of the rod 30 proximate the wheel 14.

The head or flange 35 is fast with the inner casing 22 in a fashion which prevents

rotation of the rod 30 relative to the inner casing 22 and which prevents any relative

movement between the rod 30 and the outer casing 20, in the axial direction of the

socket 34.

The rod 30 protrudes out of the outer casing 20 via an opening in the

wall 37 of the casing 20, the opening having a diameter smaller than that of the knob

28. The housing 18 has an inlet provided by a pair of registering openings in the

casings 20, 22, and the housing 18 has an outlet provided by a pair of registering

openings in the casings 20, 22. The outlet opening of the casing 22 is shown at 39,

the outlet opening of the casing 20 and the inlet openings of the casings 20, 22 not

being shown in the drawing.

Referring to Figures 2 and 3, a second embodiment of an apparatus for

threading a tensile element through and along a conduit in accordance with the

invention is generally designated by reference numeral 100. Figure 2 shows the

apparatus 100 in its open condition and Figure 3 shows the apparatus 100 in its

closed condition. Unless otherwise specified, like features to those of the apparatus

10 are designated by like reference numerals. The apparatus 100 includes a rotatably mounted drive wheel 12 and three rotatably mounted tensioning wheels 114a, 1 14b and 114c. A shaft 16 is fixedly attached to the wheel 12, the shaft 16 being attachable to a drill brace or to a screwdriver (not shown). The wheels 114a, 114b, 1 14c are rotatably mounted on shafts 17a, 17b, 17c. When the apparatus 100 is in its closed condition (Figure 3), the wheel 12 is proximate the wheels 1 14a, 114b, 114c and its axis is parallel to and spaced from the axes of the wheels 1 14a, 114b, 114c, the shafts 16, 17a, 17b and 17c being parallel to one another. The wheel 12 and the wheels 114a, 114b, 1 14c are mounted within a common housing 1 18. As shown, the wheel 1 14b is between the wheels 114a and 1 14c, and the wheels 114a and 1 14c subtend an angle of about 90 " between them.

The housing 118 includes two portions 150, 152 which are hingedly connected to each other via a hinge 154 (shown in Figure 2 only). The portion 150

includes two parallel, spaced plates 156, 158, arranged face-to-face with each other, the drive wheel 12 being rotatably mounted between the opposed faces of the plates 156, 158. The portion 152 also includes two parallel, spaced plates 160, 162, arranged face-to-face with each other, the tensioning wheels 1 14a, 1 14b, 1 14c being rotatably mounted between the opposed faces of the plates 160, 162. In Figure 3 the plates 156 and 160 have been removed for illustrative purposes. The portion 152 is movable about the hinge 154, the ends 164 of the plates 160, 162 remote from the hinge 154 being adjacent the ends 166 of the plates 156, 158 when the apparatus 100 is in its closed condition. The ends 164 are spaced away from the ends 166 when the apparatus 100 is in its open condition. When the apparatus 100 is in its

closed condition, the tensioning wheels 114a, 1 14b, 1 14c are adjacent the drive wheel 12 (Figure 3), the tensioning wheels 1 14a, 1 14b, 114c being arranged in a series in which the tensioning wheels 1 14a, 1 14b, 1 14c are circumferentially spaced around a portion 168 of the periphery of the drive wheel 12, the wheel 1 14c being the closest wheel in the series to the hinge 154 and the wheel 1 14a being furtherest away from the hinge 154. When the apparatus 100 is in its open condition (Figure 2), the tensioning wheels 114a, 1 14b, 1 14c are spaced from the drive wheel 12 so that the portion 168 of the drive wheel 12 is exposed. The wheels 1 14a, 1 14b, 114c each include a contact surface for contacting the tensile element, the contact surfaces being provided by the circumferential surfaces 172 of the wheels 114a, 114b, 114c. The circumferential surfaces 172 of the wheels 1 14a, 1 14b, 1 14c are provided with circumferentially extending grooves 174. The wheel 12 includes a gripping surface for gripping the tensile element, the gripping surface being provided by the circumferential surface 176 of the wheel 12. The circumferential surface 176 of the wheel 12 is provided with a circumferentially extending groove 178. When the apparatus is in its closed condition, a gap is defined between the bottom of the groove 178 and the bottom of each of the grooves 174.

The apparatus 100 includes a T-piece 180 which comprises a leg 182 and a cross-piece 184, the cross-piece 184 being attached to an inner end of the leg 182 and extending transversely thereto. Opposite ends 186 and 188 of the cross- piece 184 are hingedly attached to the plates 156 and 158 respectively so that the cross-piece 184 extends parallel to the shafts 16, 17a, 17b, 17c, the cross-piece being located between the ends 166 and the drive wheel 1 14a when the apparatus

100 is in its closed condition. The outer end of the leg 182 is provided with screw threads.

The apparatus is provided with a handle 128 which has a central socket (not shown) which extends axially into the handle from an inner end 192 of the handle 128. The screw threads of the leg 182 engage with complementary screw threads (not shown) defined in the wall of the socket. When the apparatus 100 is in its closed condition (Figure 3), the inner end 190 of the handle 128 is adjacent the housing 1 18, with the surface 192 of the handle being adjacent the surfaces 194 and 196 of the plates 160 and 162 respectively. A tension spring 136 (Figure 2) bears, at one of its ends, on the surface 192 and, at its other end, on a washer 197 which is slidably mounted on the leg 182. When the apparatus 100 is in its closed condition, the spacings between the wheels 1 12 and 1 14 are adjustable by rotating the handle 128 to screw the leg 182 into, or out of, the socket. The housing 1 18 is provided with an outlet opening 198 which is defined by the plates 156, 158 and a pair of guides 199 (Figure 3), one of the guides 199 being attached to the plate 156 and the other guide 199 being attached to the plate 158.

Referring to Figure 1 , in use, when an electrical lead or cable (not shown) is required to be threaded through and along a conduit 40, a fish tape 42, comprising an elongated tape 44 with a hook 46 at an end of the tape 44, is inserted, hook-end first, into the apparatus 10 via the inlet, is then threaded between the wheels 12 and 14, and is finally pulled out the other side of the apparatus 10 via the outlet, and the hook-end of the fish tape 42 is fed into an end 48 of the conduit 40, as

shown in the drawing. The gap 27 is narrowed by turning the knob 28 in a direction so that the rod 30 is screwed out of the socket 34, thus allowing the spring 36 to push the end 38 of the rod 30 into the apparatus 10, thereby causing or allowing the wheel 14 to move towards the wheel 12, until the tape 44 is gripped by the teeth (not shown) of the wheels 12 and 14. The spring 36 causes the tensioning wheel 14 to exert a force to urge it into engagement with the drive wheel 12. Abutment of the inner end of the knob 28 on the wall 37 of the casing 20 limits the movement of the wheel 14 towards the wheel 12. To enlarge the space 27, if desired, so as to cause the wheels 12, 14 to release the tape 44, the knob 28 is turned in the opposite direction to screw the rod 30 into the socket 34, while compressing the spring 36 between the head or flange 35 and the wall 37. This causes the inner casing 22 to move downwardly which, in turn, causes the shaft 17 to move downwardly along the length of the elongated slot 23. The opposite occurs when the knob 28 is turned in the opposite direction.

An electrically-powered, reversible drill or screwdriver (not shown) is attached to the shaft 16 and is energised, to cause the wheel 12 to rotate in a direction which causes the fish tape 42 to be drawn through the apparatus 10 and to be fed through and along the conduit 40 until the hook 46 reaches the opposite end (not shown) of the conduit 40. An end of the cable or lead which is to be threaded through and along the conduit is then attached to the hook 46 and the drill or screwdriver is operated in the opposite direction so that the wheel 12 is rotated in the opposite direction. This causes the fish tape 42 to move in the opposite direction, the hook 46 being drawn back towards the end 48 of the conduit 40, thus drawing the

lead or cable through and along the conduit 40 until the wire or cable reaches the end 48.

Referring to Figures 2 and 3, in use, when the apparatus is in its open condition (Figure 2), a tape 44 of a fish tape 42 comprising the tape 44 with a hook

(not shown) at the end of it is inserted, hook end first, between the plates 156, 158, threaded around the portion 168 of the drive wheel 12 and is fed through the outlet

198.

The apparatus 100 is closed by moving the portion 152 about the hinge

154 so that the ends 166 are adjacent the ends 164 (Figure 3). The handle 128 is screwed down the leg 182, thereby compressing the spring 136 between the surface 192 and the washer 197, with the washer 197 being seated against the surfaces 194, 196, until the tape 44 is gripped between the circumferential surface 172 of the wheel 114a and the circumferential surface 176 of the wheel 12, the tape 44 also being captured between the circumferential surface 176 and the circumferential surfaces 172 of the wheels 1 14b, 1 14c. Again, the spring 136 causes the tensioning wheels 114 (primarily wheels 1 14b and 1 14c) to exert a force on the tape 44 to engage it with the drive wheel 12.

The apparatus 100 is then used in the same fashion as the apparatus 10 by attaching an electrically-powered reversible drill or screwdriver (not shown) to the shaft 16 and energising the drill or screwdriver, to cause the wheel 12 to rotate in a direction which causes the fish tape 42 to be drawing through the apparatus 100

and out of the outlet 198. Thus, as with the apparatus 10, the fish tape 42 can be threaded through and along a conduit (not shown) until it reaches the opposite end of the conduit. An end of a cable or lead is attached to the hook and the drill or scredriver is operated in the opposite direction, which causes the fish tape 42 to move in the opposite direction, drawing the lead or cable with it.