AU2006100989A4

AU2006100989A4 - Shock Absorbing Anchorage Link for Safety Helmet Suspension System

Info

Publication number: AU2006100989A4
Application number: AU2006100989A
Authority: AU
Inventors: Lee Ngai Mun
Original assignee: Paramount Safety Products Pty Ltd
Current assignee: Paramount Safety Products Pty Ltd
Priority date: 2006-11-24
Filing date: 2006-11-24
Publication date: 2006-12-21
Anticipated expiration: 2014-11-24

Description

0O

O

0 Our Ref: 3741Inno P/00/009 Regulation 3.2

AUSTRALIA

Patents Act 1990 INNOVATION SPECIFICATION FOR AN INVENTION ENTITLED Invention title: Name of Applicants: Address for Service Shock Absorbing Anchorage Link For Safety Helmet Suspension System Lee Ngai Mun and Paramount Safety Products A.P.T. Patent and Trade Mark Attorneys PO Box 222 Mitcham, S.A. 5062 The invention is described in the following statement: \O2 2 SHOCK-ABSORBING ANCHORAGE LINK FOR SAFETY HELMET SUSPENSION 0 SYSTEM z BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an anchorage link for a safety helmet suspension system, 00 and more particularly to an anchorage link for a safety helmet suspension system that has superior shock-absorbing properties. The present invention further extends to a safety \helmet that incorporates the anchorage link of the present invention in its suspension S 10 system.

Description of the Related Art Industrial protective headwear such as safety helmets and the like are commonly worn by people such as firefighters, construction workers, and athletes to shield their heads from flying or falling objects and electrocution and from bumping their heads. Naturally, safety requirements for industrial head protection directed to safety helmets have been promulgated by the relevant authorities. Generally, the requirements for safety helmets are that the helmet must have an impact-resistant dome-shaped shell of one-piece seamless construction, an adjustable headband, and a helmet suspension system assembled to form a cradle for supporting the helmet shell over the wearer's head. The suspension system, along with the helmet itself, is designed to absorb the shock of an impact to the helmet so that the amount of force reaching the wearer's head is minimized or fully dissipated. The suspension system, together with the headband, is also used to position the helmet on the worker's head.

An illustrative example of a typical present-day safety helmet suspension system is taught in presently pending Malaysian patent application no. PI 20031471 which is incorporated herein by reference. In patent application number PI 20031471, Lee Ngai Mun describes a web-like helmet suspension system as shown in Figures 1 and 2 which is generally designated by reference numeral 1. The suspension system 1 includes a crown pad 2 and webbing made of a plurality of individual flexible crown straps. The straps are normally made of a nylon weave which has the characteristic of being partially elastic but exceedingly strong in resisting tensile forces. Typically, there are three crown O 3 straps that extend radially in a hexagonal configuration from a center portion where they z crisscross one another and are held in place in the center by the crown pad 2. The horizontal flexible crown strap 3 is shorter than the two diagonal flexible crown straps 4 (-i and terminates at each end in a U-shaped attachment member 5. In industrial safety 5 helmets, the U-shaped members 5 are attached, in use, to sockets in the lateral sides of 00 0the helmet shell. The horizontal strap 3 is shorter than the diagonal straps 4 so that, in the event of excessive impact on the helmet, the horizontal strap gives way before the Idiagonal straps. In this manner, the helmet suspension collapses in stages and this Sreduces the force transferred to the wearer's head as it increases the time over which the force acts. The ends of the two diagonal flexible straps 5 are attached to anchorage links 6. The anchorage links are generally wedge-shaped members as shown isolated in Figure 3. Each anchorage link 6 basically has three functional portions which are the bottom, top and intermediate portions. The bottom portion consists of an insertion member 6a, the top portion consists of a vertical slot 6b, and the intermediate portion consists of a pair of horizontal strap slots 6c disposed on the longitudinal axis of the anchorage link 6 and spaced-apart by a rigid spacer 7.

Referring now to Figures 4 and 5, the pair of horizontal spaced-apart strap slots 6c in the intermediate portion of each of the anchorage links 6 is used for attaching the anchorage links to the ends of the flexible crown straps 4. This is achieved beforehand by looping the end 8 of the flexible crown strap 4 around the rigid spacer 7 by slotting it firstly into the lower strap slot from the rear of the anchorage link, then into the upper strap slot, and finally attaching it onto itself, by way of sutures 9, for example, to form a closed loop configuration. The insertion member 6a at the bottom portion of each anchorage link 6 is adapted for removable insertion into receiving sockets 10 on the helmet shell. This is illustrated in Figure 6, which shows a suspension system as fitted to an industrial bump cap 11 which consists of two diagonal flexible straps 5 attached, via two pairs of anchorage links 6, to receiving sockets 10. The vertical slot 6b at the top portion of each anchorage link is likewise adapted to be removably attached to the headband 12 of the bump cap 11. To securely position the bump cap on a wearer's head, a nape-strap 13 is provided at the rearward end of the headband 12 to allow the circumference of the headband to be adjustable to fit the appropriate head size. Therefore, by way of the O 4

O

anchorage links 6, the flexible straps and the headband are connected to the bump cap O shell or helmet shell.

When a safety helmet or bump cap is placed on a wearer's head, part of the weight of the helmet is supported by the webbing consisting of the crown pad 2 and the flexible crown 0straps 4 resting on the wearer's head. In this configuration, the webbing is spaced apart from the top inner portion of the helmet. A part of the weight is also supported by the Ifriction between the wearer's head and the circumscribing headband. The generally

O

0 upward resultant force of the wearer's head against the webbing causes the anchorage links 6 to be pulled in the upward direction due to the looping of the flexible crown straps 4 around the rigid spacer 7. This static configuration of forces ensures that the insertion member 6a of each anchorage link 6 remains firmly embedded in its receiving sockets The principal function of a safety helmet suspension system is to protect a wearer's head by attenuating the force of an impact against the helmet shell. When a safety helmet is struck by a downwardly directed blow to the rigid shell, the forces developed causes the safety helmet to be pushed downward. This in turn causes the receiving sockets 10 of the helmet shell to push the insertion member 6a of each of the anchorage links 6 downward, forcing the anchorage links themselves downward. Since the flexible crown straps 4 are looped around the rigid spacer 7 of the anchorage links, the downward motion of the anchorage links causes the crown straps to be likewise displaced downwards. This causes the crown straps 4 and the crown pad 2 attached thereto to be urged against the wearer's head. However, the amount of force reaching the wearer's head in reduced considerably due to certain reasons. Firstly, the initial force of the impact is spread out over the entire surface of the helmet shell, causing the force to be partially attenuated. Secondly, the remaining force is then further absorbed by the crown straps 4 and the crown pad by virtue of their elastic nature.

With all other factors being equal, the shock absorbing capability of a safety helmet, or other industrial protective headgear such as bump caps, depends on the shock absorbing characteristics of the crown straps 4. It has been found that there is a need in the industry O for an improved safety helmet suspension system that does not depend exclusively on the z elasticity of the crown straps for attenuating the force of an impact. It is also important from an economic standpoint that such an improved safety helmet suspension system is inexpensive and can be produced by conventional safety helmet producing apparatus.

S 00 For the purposes of this specification the word "comprising" means "including but not limited to", and the word "comprises" has a corresponding meaning. Also a reference within this specification to a document is not to be taken as an admission that the disclosure therein constitutes common general knowledge in Australia.

SUMMARY OF THE INVENTION The present invention provides an improved anchorage link for a safety helmet suspension system. It should be understood that the term "safety helmet" is used herein in a broad sense and is meant to include all forms of protective headgear that utilize a suspension system such as industrial-grade impact-resistant helmets and industrial-grade bump caps.

With the above in mind, it is the a major objective of the present invention to provide an anchorage link for a safety helmet suspension system of the type where the suspension system includes a plurality of flexible crown straps that extend radially from a center portion. Each anchorage link primarily includes: a) a bottom portion that is adapted for removably securing the anchorage link to a helmet suspension receiving socket that is integrally formed within the safety helmet shell, b) a top portion that is adapted for removably securing the anchorage link to a corresponding receiving member located on the helmet headband, and c) an intermediate section that has spaced-apart slots for attachment of an end portion of a flexible crown strap of the suspension system, whereby the crown strap is slotted through one slot and out through the other and is attached onto itself in the configuration of a closed loop,

IND

O 6 0 the anchorage link is characterized in that z at least one shock-absorbing leaf spring bridges the space between the spaced- Sapart slots in order to absorb the energy of an impact against the helmet shell that is transmitted to the at least one shock-absorbing leaf spring.

0 0It is another objective of the present invention to provide an anchorage link for a safety helmet suspension system as described above wherein the at least one shock-absorbing Ileaf spring has three bends.

O

It is another objective of the present invention to provide an anchorage link for a safety helmet suspension system wherein there are three shock-absorbing leaf springs that are disposed side-by-side and which together bridge the spaced-apart slots through which a flexible crown strap is slotted. It is a related objective of the present invention that the shock-absorbing leaf springs disposed on the extreme left and extreme right sides are positioned in opposed directions.

It is another objective of the present invention to provide an anchorage link for a safety helmet suspension system wherein the shock-absorbing leaf springs are made of plastic.

It is a further objective of the present invention to provide a safety helmet that has a suspension system that utilizes the anchorage link of the present invention as described hereinabove.

It is a further objective of the present invention that the safety helmet mentioned hereinbefore is an industrial-grade impact-resistant helmet. It is a related objective that this industrial-grade impact-resistant helmet has at least four helmet suspension receiving sockets. It is a further related objective that this industrial-grade impact-resistant helmet has six helmet suspension receiving sockets.

It is a further objective of the present invention that the safety helmet mentioned hereinbefore is an industrial-grade bump cap. It is a related objective that this industrialgrade bump cap has at least four helmet suspension receiving sockets. It is a further 7

O

related objective that this industrial-grade bump cap has exactly four helmet suspension z receiving sockets.

It is another major objective of the present invention to provide an anchorage link for a 5 safety helmet suspension system that has a webbing of flexible straps whereby the 00 0anchorage link is characterized in that it contains at least one shock-absorbing element located between a pair of spaced-apart slots through which the ends of the flexible straps IN of the webbing are attached to the corresponding anchorage link.

O

It is another objective of the present invention to provide an anchorage link for a safety helmet suspension system as described above wherein the shock absorbing element is a set of three leaf springs disposed in a row. It is yet another objective of the present invention to provide such an anchorage link wherein the shock absorbing element comprises a plurality of leaf springs disposed in a plurality of decks. It is a related objective that the three leaf springs mentioned earlier have three bends each. It is a further related objective of the present invention that the shock-absorbing leaf springs disposed on the extreme left and extreme right sides are positioned in opposed directions.

It is a further objective of the present invention to provide a safety helmet that has a suspension system that utilizes the anchorage link of the present invention as described in the preceding two paragraphs.

Before explaining preferred embodiments of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways.

There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof of the preferred embodiments that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be

O

8 described hereinafter and which will form the subject matter of the claims appended 0 z hereto.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the invention, its operating advantages and the specific 0 objectives attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the O invention. The drawings are merely illustrative in nature and should not be construed as limiting the invention in any way.

Figure 1 shows a top view of a safety helmet suspension webbing that forms a part of the Prior Art.

Figure 2 shows a bottom view of a safety helmet suspension webbing that forms a part of the Prior Art.

Figure 3 shows an existing anchorage link for a safety helmet suspension system.

Figure 4 shows an existing anchorage link for a safety helmet with an attached flexible crown strap, positioned as when the helmet is worn.

Figure 5 shows the existing anchorage link of Figure 4 as seen from the opposite side, also positioned as when the helmet is worn.

Figure 6 shows an existing suspension system as used in an industrial bump cap.

Figure 7 shows a front view of the anchorage link according to the most preferred embodiment of the present invention.

Figure 8 shows a rear view of the anchorage link according to the most preferred embodiment of the present invention.

NO

9 Figure 9a shows the leaf springs of the anchorage link of the present invention in a

O

z relaxed configuration when no stress is applied thereto.

Figure 9b shows, in exaggeration for clarity, the leaf springs of the anchorage link of the present invention in a compressed configuration when sufficient stress is applied thereto.

00 Figure 10 shows the anchorage link of the present invention according to another IO preferred embodiment.

Figure 11 shows the anchorage link of the present invention according to yet another preferred embodiment.

Figure 12 shows a top view of one variation of the anchorage link of the present invention wherein the rows of leaf springs are disposed in two decks.

Figure 13 shows a top view of one variation of the anchorage link of the present invention.

Figure 14 shows a perspective view of another variation of the anchorage link of the present invention.

In describing the preferred embodiments of the invention, which are illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific terms so selected and it is to be understood that each specific term includes all technical equivalents that operate in a similar manner to accomplish a similar purpose.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS For convenience, listed below are the reference numerals and their corresponding references that are employed in the description and drawings.

helmet suspension system IN crown pad z flexible crown strap diagonal flexible crown strap U-shaped attachment member conventional anchorage link 00 0 (6a) insertion member (6b) vertical slot S(6c) horizontal strap slot rigid spacer end of the flexible crown straps sutures receiving sockets (11) industrial bump cap (12) headband (13) nape-strap (100) anchorage link according to the present invention (110) bottom section of anchorage link (120) rectangular-shaped male member (130) top section of anchorage link (140) vertical elongate slot (150) intermediate section of anchorage link (160) spaced-apart slots (170) leaf spring (180) upper ceiling portion of lower spaced-apart slot (190) bends in leaf springs (200) two decks of leaf springs (210) horizontal slots Various aspects of the present invention will evolve from the following detailed description of the preferred embodiments thereof, which should be taken in conjunction with the heretofore described drawings.

11 Referring now to the Figures 7 and 8, there is illustrated respectively front and rear views z of an anchorage link 100 for a safety helmet suspension system according to the most preferred embodiment of the present invention. The anchorage link 100 is a one piece plastic extrusion that may be divided into three functional sections. The first section is the bottom section 110 which is adapted to be removably attachable to a corresponding 0 portion of the safety helmet. The adaptation consists of a generally rectangular-shaped male member 120 that fits snugly into a complementary female member on the IN associated safety helmet. The second functional section of the anchorage link is the top

O

Ssection 130 which is adapted to be removably attachable to a corresponding part of the safety helmet headband. The adaptation for this consists of a generally vertical elongate slot 140 that engages a complementary anchor flange on the helmet headband. The third functional section of the anchorage link 100 is the intermediate section 150.

The intermediate section 150 contains a pair of co-planar spaced-apart slots 160 which are substantially parallel to one another. Each spaced-apart slot 160 has a width and length that allows for smooth insertion of the end of a flexible crown strap of the helmet webbing which is then folded onto itself and sutured in place in a closed loop configuration. The space between the bottommost portion of the upper spaced-apart slot and the topmost portion of the lower spaced-apart slot is occupied by three discrete identically-shaped leaf springs 170. The characterizing feature of the present invention is the presence of these leaf springs 170 in the space between the spaced-apart slots 160, which in the conventional anchorage link 6 is occupied by a rigid spacer 7 (Figure 3).

When the anchorage link 100 is in use in the suspension system of a safety helmet, a flexible crown strap is looped around the leaf springs 170 hereof. When the safety helmet is fastened to a person's head, the tensile force developed in the crown strap causes the inner portion of the looped section thereof to abut the upper ceiling portion 180 of the lower spaced-apart slot.

In existing safety helmet suspension systems, the shock of an impact against the helmet is absorbed primarily by the flexible crown straps. Therefore, the cushioning effect against the force of impact is limited. In the safety helmet that incorporates the anchorage link 100 of the present invention, the shock absorbing capability of the suspension N 12 system is enhanced by the presence of the leaf springs 170. Referring now to Figure 9a z followed by 9b, there is shown (in exaggeration for clarity) the leaf springs in action during a forceful impact against the helmet. The tensile force developed by the impacting force in a flexible crown strap causes the end of the strap to tug upwards against upper 5 portion 180 of the lower spaced-apart slot by virtue of its looped configuration. This 00 0causes the leaf springs 170 to become compressed, as illustrated in Figure 9b, thus Scushioning against and further reducing the force of the impact. After the impacting force IDis attenuated, the leaf springs return to their original uncompressed state. The existing anchorage link does not have this shock-absorbing capability as the space between the spaced-apart slots 160 is occupied only by a rigid spacer 7 that has no shock-absorbing qualities whatsoever.

In the most preferred embodiment of the anchorage link 100 of the present invention, three leaf springs 170 are employed with each leaf spring having three bends 190. The inventor has researched and found that the best shock-absorbing configuration of the leaf springs is when the leaf springs that are located on the extreme left and extreme right sides are placed in opposed directions, as illustrated.

Referring to Figure 10, there is shown an anchorage link 100 for a safety helmet suspension system according to another preferred embodiment of the present invention.

The difference with the hereinbefore described anchorage link is that the number of leaf springs 170 is two. Referring to Figure 11, yet another preferred embodiment of an anchorage link 100 of the present invention is shown wherein there is only one leaf spring straddling the spaced-apart slots 160. The working principal of the embodiments of the invention shown in Figures 10 and 11 is the same as that of the most preferred embodiment with the triplet leaf spring configuration.

Referring to Figure 12, there is shown an anchorage link 100 for a safety helmet suspension system according to yet another preferred embodiment of the present invention. In this embodiment, two sets of triplet leaf springs 170 are arranged in two decks 200.

,O

N 13 Figures 13 and 14 show variations of the most preferred embodiment of the anchorage 0 z link 100 of the present invention. In both these variations, the rectangular-shaped male member 120 is located towards the center, co-axial with the leaf springs 170. In the variation of the invention illustrated by Figure 14, the top section of the anchorage link has a plurality of horizontal slots 210 which represent another type of attachment 0 member for connecting the anchorage link with the helmet headband.

IDThose skilled in the art will appreciate that various modifications may be made to the present invention without departing from the inventive concept thereof. The embodiments of the invention described herein are only meant to facilitate understanding of the invention and should not be construed as limiting the invention to those embodiments only. Those skilled in the art will appreciate that the embodiments of the invention described herein are susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications that fall within the scope of the inventive concept thereof.

Claims

2. An anchorage link (100) for a safety helmet suspension system (1) according to claim I, wherein said at least one shock-absorbing leaf spring (170) has three bends (190).
3. An anchorage link (100) for a safety helmet suspension system (1) according to claim 1 or 2, wherein there are three shock-absorbing leaf springs (170) disposed side-by-side bridging said spaced-apart slots (160).
4. An anchorage link (100) for a safety helmet suspension system having a webbing of flexible straps said anchorage link being characterized in that the space between the pair of spaced-apart slots (160) through which the ends of said flexible straps are attached to said anchorage link is occupied by a shock-absorbing element for absorbing the energy of an impact against the safety helmet. A safety helmet having a suspension system with an anchorage link (100) according to any one of the preceding claims. Dated this 24th day of November 2006 LEE NGAI MUN AND PARAMOUNT SAFETY PRODUCTS By their Patent Attorneys A.P.T. Patent and Trade Mark Attorneys