WO2015114454A1

WO2015114454A1 - Improvements in safety caps

Info

Publication number: WO2015114454A1
Application number: PCT/IB2015/000182
Authority: WO
Inventors: Peter Howard
Original assignee: Acteuro Limited
Priority date: 2014-02-03
Filing date: 2015-02-02
Publication date: 2015-08-06

Abstract

A safety cap (10) has a body portion (12) which is open at a proximal end and defines an internal aperture (14) configured to locate over the end of a length of reinforcing bar (rebar) or the like. A head portion (18), defined at an end distal from the open end, is enlarged relative to the tubular portion and defines a preferably circular flat head, and a deformable/compressible section (20), typically located adjacent the head and located between the head and the proximal end which deforms to absorb impacts on the head of the cap. A series of external reinforcing ribs (28) extend between the head (18) and the body portion (12) and. The diameter of the internal aperture (40) is stepped or includes a series of stepped internal ribs (42) which progressively reduce the internal diameter of the aperture from the open end to a closed end adjacent the head. The end cap is preferably made of nylon.

Description

"Improvements in Safety Caps"

Cross-Reference to Related Applications

[0001] The present application claims priority from Australian provisional applications Nos 2014900306 and 2014900313 the content of which is incorporated herein by reference.

Technical Field

[0002] This invention relates to improvements in safety caps. In particular it relates to an improved safety cap for a reinforcing bar.

Background

[0003] Reinforcing bar (often referred to as "rebar" or "re -bar") is used in construction of concrete structures such as buildings, bridges and the like, for reinforcing concrete.

Reinforcing bar is typically made of steel. During construction, the rebar may be embedded in concrete in stages. Thus, it is common during construction to have rebar partly embedded in concrete, with a length of the rebar projecting vertically or horizontally from the concrete. The upwardly projecting bars present a particular work hazard due to the risks of construction workers and the like falling onto the bars and being impaled on, or suffering injury due to, the bars penetrating their skin and damaging their internal organs. Other lesser risks include persons injuring themselves through glancing contact with the ends of the bars.

[0004] To mitigate against this problem, it is known to provide safety caps which fit over the end of a reinforcing bar to spread and reduce the impact and potential damage caused by rebar in the event of a person coming into contact with the end of the bar. Existing safety caps comprise a hollow tubular portion which includes internal tapered ribs which are engaged when the tubular portion is pushed onto and over a length of rebar and a head intended to spread any load applied to the safety cap and prevent penetration of the cap by the rebar. Such end caps are typically moulded in a plastics material in a bright colour such as yellow or orange so that they are readily visible. The shape of the head varies. Some are rounded, some have a generally planar square end face, some are perforated to prevent the formation of voids if concrete is poured over the rebar with the cap still fitted to the end of the rebar. [0005] Currently there is no known load rating on end caps to test if the safety cap performs the function it is intended to perform, which is to distribute the impact of a worker falling onto the rebar, and in particular prevent the steel bar penetrating the safety cap and potentially damaging construction personnel. Clearly, the effectiveness of the end caps depends on the height the worker falls onto the bar from. The greater the height, the more likely it is that the end cap will fail.

[0006] In one aspect, the present invention therefore aims to provide an improved end safety cap which may provide consistent, reliable performance. In particular, the aim is to reduce or eliminate impalement of workers and reduce bone fractures, ideally to bruising only, for persons falling from heights of up to five metres.

[0007] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.

[0008] Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

Summary

[0009] In a first broad aspect, the present invention provides a safety cap having a body portion which is open at a proximal end and defines an internal aperture configured to locate over the end of a length of reinforcing bar (rebar) or the like, a head portion, at an end distal from the open end, which is enlarged relative to the tubular portion, the head portion defining a preferably circular flat head, a deformable/compressible section, typically adjacent the head and located between the head and the proximal end which deforms to absorb impacts on the head of the cap, a series of external reinforcing ribs extending between the head and the body portion and wherein the diameter of the internal aperture is stepped or includes a series of stepped internal ribs which progressively reduce the internal diameter of the aperture from the open end to a closed end adjacent the head.

[0010] The end cap is preferably made of nylon, preferably nylon 6, which provides greater resistance to damage.

[0011] Typically three or more internal ribs are provided. The size of at least some of the ribs may increase in at least three steps providing three zones in the aperture where the effective diameter of the aperture is progressively reduced.

[0012] Advantageously, the safety cap provides features which may combine to provide a velocity reduction zone (VRZ) which may eliminate impalement of workers and also reduce bone fractures to bruising only, for falls of 5 metre or less.

[0013] Advantageously, in the event of an impact the safety cap will provide a staged impact absorption as the bar is engaged in a step wise fashion by progressively reduced diameter portions. This minimises fractures and bruising creating a more cushioned impact.

[0014] The provision of different internal diameters also improves the fit of the safety cap on reinforcing bars and provides stability in both horizontal and vertical planes compared with safety caps, which are generally a very loose fit on the bars and may be easily dislodged.

Brief Description of Drawings

[0015] A specific embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:-

Figure 1 shows an isometric view of a safety cap embodying the present invention;

Figure 2 is an enlarged view of part A of Figure 1 showing an absorption zone of the safety cap;

Figure 3 is a side view of the safety cap of Figure 1; Figure 4 is an enlarged view of part B of Figure 1 showing reinforcing fins of the safety cap;

Figure 5 is a front end view of a tubular portion of the safety cap of Figure 1; Figure 6 is a section on H-H of Figure 5;

Figure 7 shows the safety cap of Figure 1 used in conjunction with a system cover; Figure 8 shows an end view of the arrangement shown in Figure 7; Figure 9 shows an isometric view of a variant of the safety cap shown in Figure 1; Figure 10 is a side view of the safety cap of Figure 10;

Figure 11 is a front end view of a tubular portion of the safety cap of Figure 1; and Figure 12 is a section on XII-XII of Figure 11; Description of Embodiments

[0016] Referring to the drawings, and in particular as shown in Figures 1 and 2, a safety or end cap 10 for a reinforcing bar (rebar) includes an elongate tubular body portion 12 defining a cylindrical exterior surface and a circular opening 14 defined at a proximal end of the tubular portion. Extending from the opening, the tubular body portion 12 is initially of fixed external diameter before its diameter gradually increases at a flared portion 16. At the end of the safety cap there is a large generally flat circular head portion 18.

[0017] Between the head portion 18 and the flared portion 16 there is a compressible velocity reduction zone (VRZ) or absorption zone 20 (best seen in Figure 2) where kinetic energy of falling objects is absorbed/dissipated. The velocity reduction zone comprises two annular portions 22, 24 of similar diameter 22 connected by a portion of lesser diameter 26, which compress together when an object impacts on the head 18 with the deformation of the plastic material of the end cap particularly the portion 26, absorbing kinetic energy. [0018] With reference to Figures 3 and 4, a series of eight reinforcing ribs 28 extend between the tubular portion 12 and the rear face of the head portion 18 to support the head. These strengthen the cap and are radiussed to reduce stress and reduce or eliminate forces coming from the top of the protection cap.

[0019] As is best seen in Figures 5 and 6, the interior/bore 40 of the cylindrical body portion 12 is hollow and has an annular cross section but defines, in this embodiment, a series of five internal radially extending ribs 42 which extend towards the central axis of the body portion 12. However, the number of ribs is not critical and could be reduced or increased.

[0020] As is best seen in Figure 6, the internal ribs 42 are stepped from the open end to the closed end of the interior so that the gap between the internal faces of the ribs decreases in five steps towards the closed end of the bore 40.

[0021] The specific embodiment shown in Figure 3 thus provides five different internal diameters in the body portion. This feature provides a number of significant advantages. It allows the end cap to be used for receiving reinforcing bars having different diameters. More importantly, it allows for controlled movement of the end cap on the rebar under load, as the bar moves into progressively narrower sections under force. The fins also support the velocity reduction zones 20.

[0022] In use, the safety cap can be placed over the ends of a reinforcing bar with the reinforcing bar being a relatively snug fit in the safety cap regardless of its diameter due to the different diameter apertures provided. Advantageously, it will be appreciated that for the large diameter reinforcing bars there is a greater amount of material between the head of the safety cap and the reinforcing bar providing greater resistance to the penetration of the safety cap by the reinforcing bar in the event of, for example, a person falling onto the safety cap.

[0023] In the event of an impact on the cap, it will also be appreciated that as the cap is driven further onto the reinforcing bar due to the impact, the resistance to penetration of the cap by the bar increases as the aperture diameter decreases as the rebar penetrates further into the cap. The compressible VRZ absorption zone 20, and external fins also assist in reducing the impact of a fall and reducing or eliminating the risk of impalement or bone fracture for falls of up to 5 metres, with the ribs and VRZ flexing and dissipating the force of the impact, directing the force of the impact over the sides of the head.

[0024] The safety cap will typically be moulded in a single piece from a suitable plastics or thermoplastic material. The preferred material is nylon, most preferably nylon 6.

[0025] Although the described embodiment provides three internal diameters, clearly, the safety cap could be designed to accommodate only two different diameters or four or more different diameters. The cap may also be produced in different sizes to suit different rebar diameters.

[0026] Figures 7 and 8 show the use of the end cap 10 with a clip on cover 100. The cover comprises an elongated plate 102 with depending side walls 104 which define internally projecting flanges 106. The bottom of the side walls is angled at 108. The cover is made of a plastics material and the cover can be pushed over a safety cap 10 with the side walls 104 deflecting outwards as the cover is located over the head 18 of an end cap 10 and then deflecting inwards after the head 18 has passed to allow the flanges 106 to engage behind the head 18. The cover can be attached to multiple end caps. The cover helps dissipate the forces when a worker falls onto the end caps and spreads the forces over a greater area reducing the likelihood of serious injury.

[0027] Figures 9 to 12 show a variant 10a of the safety cap shown in Figures 1 to 6 which functions in the same way as the cap 10. . The principal of operation is the same and the differences are minor. Equivalent parts have the same reference numerals as are used in Figures 1 to 6. In the variant 10a, the fins 28 are generally trapezoidal in cross-section and increase in size and flare outwards where they join the rear of the head portion 18. The sides of the ribs are generally convex. The compressible velocity reduction zone 20 is generally the same as that of the safety cap 10 shown in Figure 1.

[0028] As is best seen in Figures 11 and 12, the interior/bore 40 of the cylindrical body portion 12 is hollow and has an annular cross section but defines in this embodiment a series of six internal radially extending ribs 142 which extend towards the central axis of the body portion 12. However, the number of ribs is not critical and could be reduced or increased. [0029] Three of the internal ribs 142a are stepped from the open end to the closed end of the interior so that the gap between the internal faces of the ribs decreases in three steps towards the closed end of the bore 40. Three of the ribs 142b are not stepped but, linearly increase in size from the open end of the bore to the closed end.

[0030] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

CLAIMS:

1. A safety cap having a body portion which is open at a proximal end and defines an internal aperture configured to locate over the end of a length of reinforcing bar (rebar) or the like, a head portion, at an end distal from the open end, which is enlarged relative to the tubular portion, the head portion defining a generally flat head, a generally

deformable/compressible section, located between the head and the proximal end, which may deform to absorb impacts on the head of the cap, a series of external reinforcing ribs extending between the head and the body portion towards the perimeter of the cap, wherein the diameter of the internal aperture is stepped or includes a series of stepped internal ribs which progressively reduce the internal diameter of the aperture from the open end to a closed end adjacent the head.

2. A safety cap as claimed in claim 1 wherein the flat head is circular in plan.

3. A safety cap as claimed in claim 1 or claim 2 wherein the material from which the end cap is made comprises nylon.

4. A safety cap as claimed in any one of claims 1 to 3 wherein at least three internal ribs are provided.

5. A safety cap as claimed in claim 4 wherein the size of the ribs increases in three or more steps providing at least three zones in the aperture where the effective diameter of the aperture is progressively reduced.

6 A combination of one or more safety caps as claimed in any preceding claim and a cover, the cover comprising an elongated plate with depending side walls which define internally projecting flanges which engage over the head of the safety cap.