GB2449268A

GB2449268A - Knee protectors

Info

Publication number: GB2449268A
Application number: GB0709354A
Authority: GB
Inventors: Robert Jackson; Mark Lane
Original assignee: GREAT STAR SAW Ltd
Current assignee: GREAT STAR SAW Ltd
Priority date: 2007-05-16
Filing date: 2007-05-16
Publication date: 2008-11-19
Also published as: WO2008139217A1; GB0709354D0

Abstract

A knee protector (10) has a cushioned pad (12), straps (16,18) or the like for attaching the pad to the user's knee so that the pad covers the user's knee, and a shell (14) attached to and covering the pad so that an outer surface of the shell engages the ground when the user is kneeling. The outer surface of the shell has a channel (30) formed in it. The user can therefore use the channel as a former for bending a pipe across their knee, with the knee protector protecting their knee from injury, and the channel reducing the risk that the pipe will slip when bending. When not being used for bending a pipe, the knee protector functions in the conventional manner to protect the user's knee when kneeling.

Description

TITLE

Knee protectors

DESCRIPTION

This invention relates to a protector for protecting a user's knee when kneeling.

The invention is concerned in particular with a knee protector which comprises a cushioned pad, means (such as straps and Velcroe) for attaching the pad to the user's knee so that the pad covers the user's knee, and a shell attached to and covering the pad so that an outer surface of the shell engages the ground when the user is kneeling. Such knee protectors are well-known and are usually used in pairs, one on each knee. They are used to protect the user's knees (and clothing) when doing all sorts of jobs that entail kneeling. The pad, which typically has a foam core covered in fabric, cushions the user's knees. The shell, which is typically of moulded, semi-rigid plastics material, protects the pad from wear and the damp and protects the user's knee from sharp objects.

It is well known that, when doing plumbing work, a copper pipe of an outer diameter of mm or 22 mm can be bent by inserting a pipe-bending spring into the pipe in the region where it is to be bent, and then bending the pipe across the knee or across the upper leg just above the knee. The preferred method, for health and safety reasons, is across the leg.

However, many people, either through ignorance or because they can apply a greater bending force, lodge the pipe in the dip between the patella (knee cap) and tibia of their bent knee when bending a pipe in this way. Especially when bending a large diameter pipe, or a pipe that has age-hardened, this can cause damage to their knee joint. If a knee protector of the type described above is worn when performing this exercise, it can substantially reduce the risk of damaging the knee joint. However, the outer surface of the shell is typically convex and hard, and it is difficult to keep the pipe in place on the shell of the knee protector while the bending force is applied. The pipe tends to slip off and may bruise the user's leg or cause the user to lose their balance. The present invention, or at least specific embodiments of it, addresses this problem.

In accordance with the present invention, a knee protector of the type described above is characterised in that the outer surface of the shell has a channel formed in it, the channel when viewed in cross- section having a curved bottom and when viewed from its side being smoothly curved and extending between opposite sides of the shell. The user can therefore use the channel as a former for bending a pipe across their knee, with the knee protector protecting their knee from injury, and the channel reducing the risk that the pipe will slip when bending.

When not being used for bending a pipe, the knee protector functions in the conventional manner to protect the user's knee when kneeling.

Although the knee protector of the invention was originally conceived to assist in bending copper plumbing pipe, it may also be used when bending pipes of other materials, such as plastics conduit used in electrical wiring, and when bending solid bar. The term "pipe" used in this specification is therefore not intended to exclude these uses.

It should be noted that a pipe bending former or jig that can be attached to the knee is known from patent document JP4-93184A. However, the jig described in that document is devoid of a ground-engaging shell and is unsuitable for use as a protector for protecting a user's knee when kneeling. By contrast, with the knee protector of the present invention, the pad and/or the shell are preferably arranged, in use, to extend beyond the top, bottom and sides of the user's patella, and/or the outer surface of the shell has ground-engaging portions extending from either side of the channel preferably to an extent greater than the width of the channel.

In the case where the knee protector is for use in bending pipes of circular cross-section, the channel when viewed in cross-section preferably has an arcuate bottom. In the case where the knee protector is for use in bending domestic plumbing pipe, the radius of curvature of the arcuate bottom is preferably generally equal to one half of the external diameter of a domestic plumbing pipe that is standard in the country, or one of the countries, for which this application is made. For example, in the United Kingdom, the radius of curvature may be 7.5 mm or 11 mm for use with 15 mm or 22 mm pipe respectively. In the case where the knee protector is for use in bending electrical wiring conduit, the radius of curvature of the arcuate bottom is preferably generally equal to one half of the external diameter of an electrical wiring conduit that is standard in the country, or one of the countries, for which this application is made. For example, in the United Kingdom, the radius of curvature may be 10 mm or 12.5 mm for use with 20 mm or 25 mm conduit respectively.

The channel when viewed from its side is preferably arcuate in order to produce an arcuate bend in the pipe.

In one embodiment, the shell has a single such channel. However, in an alternative embodiment, the shell has a further such channel formed therein alongside the first-mentioned channel. The channels, when viewed in cross-section, may have differently curved bottoms, for use in bending different diameter pipes. Alternatively, or additionally, the channels, when viewed from their sides, may be curved differently, for use in putting different radius bends in pipes.

The knee protector may be provided as one of a pair of knee protectors. In this case, at least one of the channels of one of the knee protectors may be shaped differently to the or each channel of the other knee protector.

Specific embodiments of the present invention will now be described, purely by way of example, with reference to the accompanying drawings, in which: Figure 1 is a three-quarters view from the front, top and left side of a first embodiment of knee protector; Figure 2 is a three-quarters view from the rear, bottom and left side of the knee protector; Figure 3 is a front view, on a larger scale, of a shell of the knee protector; Figure 4 is a sectioned top view of the shell, taken on the section line IV-IV shown in Figure 3; Figure 5 is a sectioned side view of the shell, taken on the section line V-V shown in Figure 3; Figure 6 is a side view of the shell; and Figure 7 is a side view of a modified shell.

Referring first to Figures 1 and 2, a knee protector 10 comprises a pad 12, a shell 14 and a pair of straps 16,18. The pad 12 has a central portion 20 stitched at its top to a top skirt portion 22 and at its left and right sides to left and right skirt portions 24,26, respectively. The portions 20,22,24,26 of the pad 12 each have a foam plastics or rubber core covered in fabric.

The straps 16,18 are of fabric and are stitched to the edges of the left and right skirt portions 24,26 of the pad 12. Complementary strips 28 of hook-and-loop fastening material (such as VeIcro) are stitched to the distal ends of the straps 16,18. The shell 14 is generally pear-shaped in front view and covers the central region of the central portion 20 of the pad 12, being stitched thereto around the periphery of the shell 14. The shell 14 is injection-moulded from plastics or synthetic rubber, such as neoprene, and is semi-rigid and relatively hard. The front (outer) face of the shell 14 is convex, while its rear face is concave. In use, the pad 12 is placed on and in front of the user's knee, and the straps 16,18 are passed behind the knee and joined by the Velcro strips 28 so as to hold the knee protector 10 in place. The top skirt portion 22 of the pad 12 is disposed above the wearer's patella, and the left and right skirt portions 24,26 of the pad 12 are disposed to the left and right sides of the knee. The central portion 20 of the pad 12 covers and extends below the user's patella. The user can walk and kneel. When kneeling on the ground, the user's weight is borne through the pad 12, which has a cushioning effect, and the shell 14, which protects the pad 12 from abrasion damage and from damp and protects the user's knee against sharp objects. Typically, the shell 14 has a height A of about 160 mm and a width B of about 135 mm. As described in this paragraph, the knee protector 10 is conventional.

Referring now also to Figures 3 to 6, in the embodiment of the invention, a pipe-bending channel 30 is moulded into, and extends transversely across, the front face of the shell 14. The channel 30, when viewed in cross-section (Figure 5), is part-circular in shape. The depth C of the channel 30 is no greater than half its width D and is preferably no less than about one-third of its width D. Its radius of curvature E is generally equal to, or slightly larger than, half of the outer diameter of the pipe with which the pipe-bending channel 30 is intended to be used. For example, the radius of curvature E is 7.5 mm for 15 mm o.d. pipe; 10 mm for 20 mm o.d. conduit; 11 mm for 22 mm o.d. pipe; or 12.5 mm for 25 mm o.d. conduit. The channel 30, when viewed from the side of the channel 30 (Figure 4) is also pan-circular in shape, with the bottom of the channel 30 having a radius of curvature of about 100 mm, and with the channel extending through an arc G in the range of about 75 to 90 degrees.

With the knee protector 10 fitted to the knee in the manner described above, the knee protector 10 is used to bend a pipe by: inserting a pipe-bending spring into the pipe in the region where the bend is to be made; bending the knee at an angle of about ninety degrees; placing the region of the pipe where the bend is to be made into the channel 30; and pulling the pipe to either side of the knee protector 10 so that the pipe bends in the channel 30 through the required angle.

Various modifications and developments may be made to the embodiment of the invention described above.

For example, Figure 7 shows a modified shell 12 having two channels 30,32. The channel 30 is similar to that described above and is sized for bending 22 mm o.d. pipe. The channel 32 is disposed beneath the channel 30 and is sized for bending 15 mm o.d. pipe.

The knee protectors 10 may be supplied in pairs. In this case, one of the pair may have a channel 30 for bending 15 mm o.d. pipe, and the other of the pair may have a channel 30 for bending 22 mm o.d. pipe. Alternatively, one of the pair may have a channel 30 for bending mm o.d. electrical conduit, and the other of the pair may have a channel 30 for bending 25 mm o.d. electrical conduit. Alternatively, one of the pair may have a first channel 30 for bending 25 mm o.d. electrical conduit and a second channel 32 for bending 20 mm o.d.

electrical conduit, and the other of the pair may have a first channel 30 for bending 22 mm o.d.

pipe and a second channel 32 for bending 15 mm o.d. pipe.

The shell 12 may be lightened by forming recesses in its rear, concave face. The outer surface of the shell 12 may be formed with a tread to increase grip with the ground, and the surface of the channel 30 may be coated with a skin, which may be integrally moulded, to increase grip with a pipe.

It should be noted that the embodiments of the invention have been described above purely by way of example and that many other modifications and developments may be made thereto within the scope of the present invention.

Claims

1. A protector for protecting a user's knee when kneeling, the knee protector comprising a cushioned pad, means for attaching the pad to the user's knee so that the pad covers the user's knee, and a shell attached to and covering the pad so that an outer surface of the shell engages the ground when the user is kneeling, the outer surface of the shell having a channel formed therein, the channel when viewed in cross-section having a curved bottom and when viewed from its side being smoothly curved and extending between opposite sides of the shell, whereby the user can use the channel as a former for bending a pipe across their knee.

2. A knee protector as claimed in claim 1, wherein, when attached to the user's knee, the pad is arranged to extend beyond the top, bottom and sides of the user's patella.

3. A knee protector as claimed in claim 1 or 2, wherein, when attached to the user's knee, the shell is arranged to extend beyond the top, bottom and sides of the user's patella.

4. A knee protector as claimed in any preceding claim, wherein the outer surface of the shell has ground-engaging portions extending from either side of the channel to an extent greater than the width of the channel.

5. A knee protector as claimed in any preceding claim, wherein the channel when viewed in cross-section has an arcuate bottom.

6. A knee protector as claimed in claim 5, wherein the radius of curvature of the arcuate bottom is generally equal to one half of the external diameter of a domestic plumbing pipe that is standard in the country, or one of the countries, for which this application is made.

7. A knee protector as claimed in claim 5, wherein the radius of curvature of the arcuate bottom is generally equal to one half of the external diameter of an electrical wiring conduit that is standard in the country, or one of the countries, for which this application is made.

8. A knee protector as claimed in any preceding claim, wherein the channel when viewed from its side is arcuate.

9. A knee protector as claimed in any preceding claim, wherein the shell has a further such channel formed therein alongside the first-mentioned channel.

10. A knee protector as claimed in claim 9, wherein the channels, when viewed in cross-section, have differently curved bottoms.

11. A knee protector as claimed in claim 9 or 10, wherein the channels, when viewed from their sides, are curved differently.

12. A knee protector substantially as described with reference to the drawings.

13. A pair of knee protectors, each as claimed in any preceding claim.

14. A pair of knee protectors as claimed in claim 13, wherein at least one of the channels of one of the knee protectors is shaped differently to the or each channel of the other knee protector.