GB2535973A

GB2535973A - Handle

Info

Publication number: GB2535973A
Application number: GB1501203.2A
Authority: GB
Inventors: Blick Vivian
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-01-26
Filing date: 2015-01-26
Publication date: 2016-09-07
Also published as: GB201501203D0

Abstract

A handle 10 for a duct rod 100 comprising; a handle body 12 having an outer grip surface, a slot 20 for receiving and locating a portion of the duct rod, and a cam cleat 24 for gripping the duct rod and preventing sliding when force is applied in a first direction (A, Figure 2), and for releasing the duct rod and allowing sliding of the duct rod within the slot when force is applied in a second direction (B). The cam cleats of the fish tape puller may comprise a pair of pivoting sprung cams 26 and be coated in rubber. The handle may be used to push a portion of the duct rod through a pipe or duct

Description

HANDLE

The present invention relates to a handle, and in particular to a handle for use with duct rods.

BACKGROUND TO THE INVENTION

Duct rods, also known as cobra rods, are commonly used when installing cables (for example, power or communications cables) in ducts. The flexible duct rod can be pushed through a pipe or duct, from one end to the other, and then used to pull a cable through. Typically, duct rods are made from fibreglass, which is preferred due to its low density, flexibility and strength. The rods are generally about 14mm in diameter, sometimes smaller. The small diameter is important because there may be limited space in a crowded duct for new cabling. The rods have a smooth surface to prevent damage to existing cabling which is already present in the duct.

In some applications, where there is plenty of space in the duct and the duct is relatively straight, duct rod can be fed by machine. This is fast and efficient. However, for more complex jobs where the duct is crowded, obstructed, or turns reasonably sharp corners, the duct rod may have to be fed manually for at least part of its length. Manual guiding means that the operator can feel for obstructions and corners, and manipulate the rod around them. However, manually gripping and pushing a small diameter smooth rod can lead to injury, specifically hand muscle fatigue, arthritis and RSI. This is a serious problem, as small diameter rod often has to be fed through several hundred metres of ducting manually.

It is an object of the invention to reduce or substantially obviate the problem of injury caused by gripping and pushing a small diameter duct rod.

STATEMENT OF INVENTION

According to the present invention, there is provided a handle for a duct rod, the handle 25 comprising: a substantially elongate handle body having an outer grip surface; a slot in the handle body for receiving and locating a portion of the duct rod along an elongate central axis of the handle body; and a cam cleat secured to and disposed within the handle body, for gripping the duct rod and preventing sliding when force is applied in a first direction substantially in line with the central axis of the handle body, and for releasing the duct rod and allowing sliding of the duct rod within the slot when force is applied in a second direction substantially opposite to the first direction.

The handle can be fitted to the duct rod, to provide an increased diameter grip section. With the handle engaged with the duct rod, it can be pushed in one direction to feed the duct rod into a duct. Whilst the handle is being pushed, the cam cleat engages with the duct rod so that force is transmitted to the duct rod. After the rod has been pushed a short distance, say around 30 to 60cm, the handle can be moved in the other direction, back along the rod in the opposite direction to the direction that the rod is being pushed into the duct. As force is applied in this 'outward' direction, the cam cleats disengage the rod, so that the handle slides along the rod to a new position on the rod. The handle can then be used to push the rod another 30 to 60cm into the duct.

The handle, when used as described, reduces the risk of fatigue and injury by providing a larger diameter area which does not need to be gripped tightly, allowing the muscles in the hand to relax. Also, the rod can be pushed using the arm and shoulder muscles, rather than the much smaller muscles in the fingers and wrist. The distance of travel with each push can also be increased, leading to fewer repetitions and faster, more efficient work.

The handle can be used for pulling rod out of a duct as well as for pushing it in -the handle is simply placed over the rod in whatever direction the rod needs to be pushed or pulled. When the job is finished, the handle can simply be removed from the rod by pulling it slightly away from the direction in which the cleats grip, and also substantially in a direction perpendicular to its elongate extent.

Preferably the handle body includes a grip section, the surface of which is the outer grip surface, and an end section. The end section is preferably of larger diameter to the grip section, and so provides a support for the operator's hand to maximise push / pull forces and to minimise the need to grip.

Most preferably, a larger diameter end section is provided at each end of the grip section, to provide support both when pushing / pulling the rod, and when moving the handle along the rod between pushes. In that respect, the handle may be substantially in the shape of a dumbbell, with a narrow central grip section and two wider end sections.

Preferably, the cam cleat is disposed within one of the end sections. More preferably, two cam cleats are provided. Where two cam cleats are provided, one may be disposed in each of the two end sections. Providing cam cleats in the end sections provides maximum support and stability, allowing precise control of the rod. The end sections, being of larger diameter, can also accommodate larger and stronger cam cleats.

Preferably, each cam cleat comprises a pair of pivoting sprung cams. However it is envisaged that other one-way cam cleat arrangements may be used in the invention. For example, a single pivoting sprung cam on one side and a fixed grip member on the other side may provide acceptable performance.

The cams may have rubber grip sections, and most preferably are coated in rubber.

Preferably, the handle, including any end sections, is made integrally. Suitable materials include plastics and aluminium. Because rodding work is often required in wet and muddy areas, a corrosion resistant material is preferred.

Known marine-grade cam cleats may be used in construction of the handle. These are highly resistant to damage in harsh environments, and can be cleaned safely with water.

Preferably, the outer grip surface may be made from a high friction material. This may be in the form of a coating on a plastic or aluminium handle. Alternatively, ribs may be provided integrally with the handle body, to assist with grip on the handle.

DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, and to show how it may be carried into effect, a preferred embodiment will now be described, as an example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a handle for a duct rod according to the invention, shown engaged with a duct rod; Figure 2 is a plan view of the handle and duct rod of Figure 1; and Figure 3 is an exploded perspective view of the handle and duct rod of Figure 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring firstly to Figure 1, a handle 10 is indicated generally at 10. The handle is for use with a duct rod, a section of which is indicated at 100.

The handle is in the form of a single, integrally-formed elongate handle body, including a central grip section 12 and end sections 14, 16 at either end of the central grip section 12.

The central grip section 12 is substantially in the form of a cylinder, and has a diameter of approximately 65mm and a length of around 250mm. Each end section 14, 16 is substantially in the form of a cylinder with larger diameter (for example, around 110mm) and shorter length (for example, around SOmm).

The end sections 14, 16 and central grip section 12 are all arranged with the axes of the cylinders along the same line. The overall shape is substantially that of a dumbbell.

The central grip section has an outer grip surface, and a series of ribs 18 are provided on the outer grip surface, formed as rings extending around the curved surface of the cylindrical central grip section 12. The ribs 18 assist with manually holding the central grip section, without having to grip tightly.

A slot 20 is provided, running all the way along a side of the handle 10 and extending to a point just beyond the central axis of the handle 10. The slot is preferably sized to fit a duct rod of a certain diameter, for example 14mm. The slot will therefore be just wider than the diameter of the duct rod, for example 15mm, and will extend beyond the central axis by around half of the duct rod diameter (about 7mm in this example). This allows the duct rod to sit within the handle 10, with the duct rod 100 running approximately along the central elongate axis of the handle 10.

A cut-out 22 is provided in each of the end sections 14, 16. Each cut-out 22 is in the form of a substantially rectangular bore into the curved side of the cylindrical end section 14, 16.

The width of the rectangular bore is just less than the length of the cylindrical end section, and the length of the rectangular bore is just less than the diameter of the cylindrical end section. The depth of the bore is around half the diameter of the bore rod beyond the centre of the end section, so that the duct rod 100 can be placed adjacent the floor of the rectangular bore, when the bore rod 100 is held substantially along the central axis of the handle 10.

As best seen in Figure 2, a cam cleat 24 is provided, attached to the floor of the rectangular bore cut-out 22 of each end section 14, 16. The cam cleats are mounted to the handle 10 facing in the same direction as each other. As is clear from Figure 2, when a force is applied to the handle in one direction (indicated by arrow A), the cam cleats 24 will grip onto the duct rod 100, for pushing or pulling the duct rod into or out of a duct. When a force is applied in the other direction (indicated by arrow B), the cam cleats 24 will open out, allowing the handle to run over the duct rod 100 to a new position on the duct rod.

Figure 3 shows how the handle 10 may be assembled, and in particular how the cam cleats 24 are attached to the floor of the rectangular bore cut-out 22. At the bottom of each rectangular cut-out, a floor provides an attachment surface for attaching the cam cleats 24 with screws 26. Each cam cleat 24 comprises two rubber-coated cams 26, and a washer 28 beneath each cam. Although not seen in the Figure, springs are provided within the cam cleat mechanism so that the cams 26 are urged towards each other, pivoting about the screws 26 which attach the cams 26 to the handle body. The cams 26 may be moved apart, against the spring.

Note that the words 'bore' and 'cut-out' are used only to describe the finished product. The grip section 12 and end sections 14, 16 of the handle are preferably moulded in one piece, without any further machining being required.

In use, an operator can hold the central grip section 12. The grip does not have to be tight, because the diameter is large and the ribbed grip surface increases the friction. The operator then fits the handle over a portion of duct rod 100 by pushing the duct rod 100 into the slot 20, and at the same time forcing the handle very slightly in the direction of arrow B, against the rod. This opens the cam cleats 24 and allows the rod to engage within the cam cleats. The operator then stands in a comfortable position, holding the grip section 12 in a single preferred hand, preferably with the slot 20 facing substantially upwards. The operator can use his arm and shoulder muscles to push the handle in the direction of arrow A, and push the rod perhaps 30-60cm with a single push. Whilst pushing, hand and wrist muscles do not need to be tense, as the hand will be supported by the end section 16, in particular on the face of the end section 16 which is adjacent the grip section 12. Supporting the hand against the end section 16 in this way allows for transfer of force from the arm and shoulder muscles, through the hand, to the handle 10 and then the duct rod 100. No tight gripping on the handle 10 is required. After moving the handle in the direction of arrow A for a comfortable distance, the operator reverses the direction and moves the handle in the direction of arrow B. As he does so, his hand is supported against the section 14 in the same way as described above. The cam cleats 24 will be forced open, and the handle 10 will slide up the rod, ready for another section to be pushed into (or pulled out of) a duct.

Use of the handle substantially reduces the risk of fatigue and/or injury, as compared to handling small-diameter duct rods with fingers directly.

The embodiments described above are provided by way of example only, and various changes and modifications will be apparent to persons skilled in the art without departing from the scope of the present invention as defined by the appended claims.

Claims

CLAIMS1. A handle for a duct rod, the handle comprising: a substantially elongate handle body having an outer grip surface; a slot in the handle body for receiving and locating a portion of the duct rod along an elongate central axis of the handle body; and a cam cleat secured to and disposed within the handle body, for gripping the duct rod and preventing sliding when force is applied in a first direction substantially in line with the central axis of the handle body, and for releasing the duct rod and allowing sliding of the duct rod within the slot when force is applied in a second direction substantially opposite to the first direction. 2. 3. 4. S. 6. 7. 8.

A handle as claimed in claim 1, in which the handle body includes a grip section and an end section, the end section being of larger diameter than the grip section.

A handle as claimed in claim 2, in which the handle body includes an end section at either end of the grip section, each end section being of larger diameter than the grip section.

A handle as claimed in claim 2 or claim 3, in which the cam cleat is disposed within an end section.

A handle as claimed in claim 4 when dependent on claim 3, in which two cam cleats are provided, one in each end section.

A handle as claimed in any of the preceding claims, in which the or each cam cleat comprises a pair of pivoting sprung cams.

A handle as claimed in any of the preceding claims, in which the cam cleats include rubber grip sections.

A handle as claimed in claim 7, in which the cam cleats are coated in rubber.

9. A handle as claimed in any of the preceding claims, in which the handle body is formed integrally as one piece.

10. A handle as claimed in any of the preceding claims, in which the handle body is made from plastics.

11. A handle as claimed in any of the preceding claims, in which the handle body is made from aluminium.

12. A handle as claimed in any of the preceding claims, in which ribs are provided on the outer grip surface of the handle body.

13. A method of pushing a duct rod into a duct, including the steps of: a) providing a handle as claimed in any of claims 1 to 12, and locating the duct rod within the slot of the handle so that the first direction is towards the duct and the second direction is away from the duct; b) applying force to the duct handle in the first direction, to push a portion of the duct rod into the duct; c) applying force to the duct handle in the second direction, to move the handle along the duct rod; d) repeating from step (b) until the duct rod has been pushed the required distance.

14. A handle substantially as described herein, with reference to and as illustrated in Figures 1 to 3 of the accompanying drawings.