AU717223B2 - Improved energy absorbing attachment means for a motor vehicle safety screen - Google Patents

Description

Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

u.

9

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Name of Applicant: REES OPERATIONS PTY LTD Actual Inventors: James Dean Coogan and Paul Statham Address for Service: MADDERNS, 1st Floor, 64 Hindmarsh Square, Adelaide, South Australia, Australia Invention title: IMPROVED ENERGY ABSORBING ATTACHMENT MEANS FOR A MOTOR VEHICLE SAFETY SCREEN Details of Associated Provisional Application No: PO 4310 dated 20th December 1996 The following statement is a full description of this invention, including the best method of performing it known to us.

This invention relates to improved fixing means for securing an interior motor vehicle safety screen which serves as a barrier in the vehicle to inhibit the forward movement of a load carried within the vehicle behind a driver or passenger, and in particular to an improved energy absorbing fixing strap assembly which extends between an attachment point on the screen and an anchorage point within the vehicle.

In the applicant's earlier filed Australian Patent No 583738 entitled "Vehicle Safety Screen Fixing Means", there is disclosed a safety screen assembly comprising a tubular metal peripheral frame and a heavy wire mesh infill panel secured thereto, with the screen being held in position by means of a plurality of rearwardly extending rigid metal securing straps positioned one at or adjacent each corner of the screen, with each strap having its forward end pivotally attached to a bracket rigidly connected to the safety screen frame and its trailing or rear end securable to an 0:.

anchorage point fixed with respect to the vehicle body. Also disclosed is the feature of each of the securing straps being formed with a series of transverse corrugations "0 0 intermediate the ends thereof, such corrugations being effective to absorb some of the initial impact forces when the load impacts against the safety screen during sudden deceleration of the vehicle, whereby the initial loading is absorbed by the straps themselves rather than the attachment points between the straps and the screen and between the straps and the vehicle body anchorage points. There is S always the danger of the straps being torn from their anchorage points within the vehicle which of course would result in the load being allowed to move largely unrestrained forwardly into the driver and/or passenger compartment of the vehicle.

A further example of energy absorbing mounting devices is described and illustrated in another co-pending application 33762/95 filed by the present applicant, in particular Figures 7-9 of the drawings accompanying that patent specification.

Again, use is made of transverse folds in order to allow the strap to elongate under load. In one instance, a tightly fitting metal loop is positioned around the fold portion of the securing strap and secured thereto for the purpose of constraining the elongation of the strap, and thereby further assist the absorption of impact energy.

According to the Australian safety standards applicable to motor vehicle cargo barriers, a certain amount of deflection of the barrier is permissible under a specified minimum impact load. It is desirable therefore that the fixing straps used to rigidly secure the barrier to the vehicle body are designed in such a way that they allow limited bodily forward movement of the barrier under impact load while simultaneously absorbing impact energy.

It is the main object of the present invention therefore to provide an improved fixing strap arrangement for a motor vehicle safety barrier to be placed between the load receiving space and the driver and/or passenger compartment of the vehicle, which has an improved energy absorption capacity in the event of a load impacting against the barrier and which is designed so that the barrier will deflect forwardly in a controlled manner, and which will significantly reduce the likelihood of the barrier S: •.breaking away from its anchorage points under impact conditions.

It is a further object of the present invention to provide an improved energy absorbing fixing device for securing a motor vehicle safety screen within a vehicle •"which is of simple construction and relatively inexpensive to manufacture.

Broadly, according to this invention therefore, a fixing strap assembly for securing a corner portion of an interior vehicle screen or barrier to the floor or ceiling of the vehicle, comprises: an elongate metal fixing strap arranged to extend rearwardly away from the screen or barrier and having a leading end and a trailing end, an attachment plate in mating surface contact with said strap, means for anchoring one of the said fixing strap and said attachment plate to an anchorage plate fixed to the vehicle body, screen attachment means for attaching the other of said fixing strap and said attachment plate to the comer region of the screen or barrier, guide means between the fixing strap and the attachment plate for allowing relative sliding movement therebetween, and friction creating means between said fixing strap and said attachment plate for producing a braking force when the attachment plate and the fixing strap slide relative to one another, arranged and constructed so that when a load impacts against the screen and deflects the screen forwardly, the braking force produced by said friction creating means is effective to restrain forward movement of the screen and absorb impact energy imparted to the screen by the load.

More specifically, the invention provides a fixing strap assembly for securing an interior safety screen or barrier to the floor or ceiling of a vehicle, comprising: "an elongate metal fixing strap arranged to extend rearwardly away from the screen or barrier and having a leading end and a trailing end, 15 an attachment plate in mating surface contact with said strap and slidable .relative to the strap, means for anchoring one of said fixing strap and said attachment plate to an Sanchorage plate fixed to the vehicle body, screen attachment means for attaching the other of said fixing strap and said attachment plate to the corner region of the screen or barrier, guide means for slidably fastening together said strap and said attachment Splate, said guide means including an elongate guide slot formed in said fixing strap or said attachment plate and extending longitudinally thereof, a guide pin, rivet, stud or the like passing through said slot at or near its leading end, said guide pin, rivet or stud being arranged to guide one end of the fixing strap when it slides relative to said attachment plate, and friction creating means between said fixing strap and said attachment plate for producing a braking force when the attachment plate and the fixing strap slide relative to one another, arranged and constructed so that when a load impacts against the screen and deflects the screen forwardly, the braking force produced by said friction creating means is effective to restrain forward movement of the screen.

The attachment plate can be integrally formed with the screen attachment means which can comprise an attachment flange securable to an edge portion of the screen and a rearwardly projecting portion which contains the guide slot.

The guide pin can also serve as a fastener for releasably securing the attachment plate to the anchorage plate in the vehicle body.

a. a In one embodiment of the invention, an energy absorbing securing means for securing a motor vehicle safety screen or barrier within the vehicle so as to extend transversely from side to side and from top to bottom of the vehicle so as to separate 0a..

the load carrying area from occupants within the vehicle, includes a plurality of I fixing strap assemblies each of which comprises: an elongate rearwardly extending metal strap, having a leading end and a trailing end, a.

an attachment plate having a first portion arranged to be fixedly secured, eg by means of rivets or bolts, to an edge portion of the screen or barrier, and a second portion projecting rearwardly of the screen or barrier, said attachment plate being formed with an elongate slot which extends longitudinally thereof, a headed stud or rivet slidably securing the leading end of the metal strap to said attachment plate in face-to-face contact therewith, said stud or rivet passing through said slot at or near the leading end thereof, said stud or rivet, upon relative sliding movement between the attachment plate and the metal bar, being guided for movement along said slot, friction creating means between the metal strap and said second portion of the attachment plate for producing a braking force when the attachment plate and the metal strap slide relative to one another, eg when a load impacts against the screen and deflects the screen and the attachment plate forwardly, said braking force being effective to restrain forward movement of the screen and absorb impact energy imparted to the screen by the load, and securing means for securing the trailing end of the securing strap to an anchorage plate fixed to the vehicle body.

Preferably, the metal strap passes snugly through a correspondingly shaped slot-like guide aperture formed adjacent an end of the attachment plate, with the opposite longitudinal edges of the fixing strap frictionally contacting inner surfaces of the walls defining said guide aperture, said opposite longitudinal edges of the strap forming a taper such that the transverse width of the strap increases from an intermediate region thereof to one of •its ends, whereby, when a load impacts against the screen or barrier, and the screen °together with said attachment plate, is deflected forwardly, the relative sliding S movement between the attachment plate and the fixing strap produces a frictional braking force effective to resist forward movement of the screen, with the taper on the strap providing a resistance force which increases as the strap is pulled further through the guide aperture in the attachment plate.

Desirably, the slot-like guide aperture in the attachment plate is formed by means of a cutting and pressing operation with the aperture lying in a plane offset from the Splane of the attachment plate to thereby allow the strap to maintain mating surface :o oI contact with the inner facing surface of the attachment plate.

Preferably the screen attachment portion of the attachment plate is rigidly secured to a peripheral portion of the safety screen or barrier by means of rivets or bolts.

Desirably, the trailing end of each of the upper fixing straps is rigidly secured to its anchorage plate by means of a nut and bolt assembly. The rear or trailing end of each of the lower straps can be provided with a hook forming member rigidly secured thereto, with the hook being arranged to releasably interlock with a locating slot formed in a respective anchorage plate.

Desirably, the attachment portion of the attachment plate is additionally secured to the safety screen by means of a double-sided adhesive tape positioned between the plate and the screen.

Preferably the metal securing strap is provided with laterally projecting protrusions on opposite sides thereof, said protrusions being arranged to abut against the trailing end of the guide aperture prior to the stud or rivet travelling the full length of the guide slot formed in the attachment plate.

The fixing system of the present invention is designed primarily for use with a moulded plastics safety screen or barrier of the kind described and illustrated in the applicant's co-pending Australian patent application 33762/95, wherein fixing straps i" are used to fixedly secure the upper corner regions of the screen to the cantrail of the vehicle roof.

•99* In order to more fully explain the present invention, several preferred embodiments are described hereunder in some further detail with reference to the accompanying drawings in which: Figure 1 is a fragmentary perspective view of a safety screen assembly according to a first embodiment of the invention, showing two upper fixing strap oeo..i assemblies used to secure the upper corner regions of the screen to the roof of a vehicle; Figure 2 is a view similar to Figure 1 showing the safety screen and the securing strap assembly after an impact load has impacted against the screen, Figures 3(a) and 3(b) show an underside plan view of the attachment plate and fixing strap assembly (shown in Figure 1) in its initial undeformed state and a plan view of the fixing strap only, respectively; Figure 4 is a perspective view of a fixing strap assembly, according to a second embodiment of the invention; while Figure 5 is a partly sectioned plan view of the assembly shown in Figure 4.

Referring to the embodiment shown in Figures 1 to 3 of the drawings, a safety screen assembly 10 is arranged to be mounted between the load carrying area of the a vehicle and its rear passenger seat and comprises a moulded polycarbonate safety screen 11 which extends transversely from side to side and from the roof to the floor of the vehicle, a pair of upper securing straps 12 for releasably fixing the upper corners of the panel 11 to respective anchorage points in the vehicle roof, and a pair of lower mounting devices (not shown) for releasably securing lower corner regions :i of the panel 11 to respective anchorage points in the floor of the vehicle.

o 15 In this embodiment the sheet polycarbonate panel 11 is formed by a vacuum forming process, the polycarbonate material being particularly advantageous on account of its extremely high impact strength and its transparency. The panel 11 is provided with t a rearwardly directed peripheral flange 14 which extends continuously around the o periphery of the panel 11. The flange 14 is designed to suitably stiffen the outer peripheral region of the panel 11 and also provide suitable attachment points for the i upper securing straps 12 and the lower mounting devices.

As shown in Figure 1, each metal fixing strap 12 extends rearwardly from the panel 11 and has its leading end 15 fastened to an attachment plate 16 which in turn is rigidly attached to an edge portion of the panel 11 by means of rivets 17, and its trailing end 19 being releasably secured to an anchorage plate 20 fixed to the vehicle cantrail 22 by means of fixing bolts 21.

The metal strap 12 is slidably secured to the attachment plate 16 by means of a headed rivet 23 which passes through a longitudinal guide slot 24 formed in the attachment plate 16 centrally thereof, the guide slot 24 being arranged to guide the rivet 23 (and thus the strap 12) in a longitudinal direction along the attachment plate 16 when the strap 12 slides relative to the attachment plate 16.

At or near the trailing end of the attachment plate 16, there is provided a strap retention web 26 which projects from the plane of the attachment plate 16 so as to form a closed guide slot or eyelet 27 through which the strap 12 passes. The rivet connection between the leading end of the strap 12 and the attachment plate 16 together with the retention web 26 are designed so that the strap 12 is held firmly against the attachment plate 16 in face to face mating relationship and that the strap 12 and plate 16 maintain alignment during relative movement therebetween.

°In this embodiment, a portion of the securing strap 12, near its leading end, is formed with a taper, in the order of 1 (refer Fig so that the transverse width of the strap progressively increases from an intermediate point 28 of the strap in the 15 direction of its leading end (ie in the direction towards its fastening rivet 23). The taper on the strap 12 is designed to provide a progressively increasing interference fit between the opposite edges of the strap 12 and the opposite end portions of the web 26, so that a progressively greater braking force is produced as the strap 12 and the attachment plate 16 move further apart. The frictional forces generated between the opposite edge surfaces of the strap 12 and the mating surfaces of the attachment plate 16 are extremely effective to provide a braking force for restraining forward deflection of the safety screen 11 when a substantial load impacts thereagainst.

To further assist in restraining the forward deflection of the screen 11, particularly in a situation where the impact forces against the screen are significantly large, the strap 12 is provided with a pair of transversely aligned outwardly projecting stop formations 30 located a short distance inwardly of the rivet connection 23, the stop formations 30 being designed to abut against an end face of the web 26 should the relative movement between the attachment plate 16 and the metal securing strap 12 exceed a predetermined distance.

Desirably, a layer of double-sided adhesive tape is positioned between the underside of the attachment plate 16 and the surface of the panel 11 to assist in the securement of the attachment plate 16 to the panel. A backing plate 32 located on the opposite side of the panel 11 to that of the attachment plate 16 can also be provided so that the edge portion of the panel 11 can be firmly clamped between the two plates 16, 32.

Referring to the embodiment shown in Figs 4 and 5, the principle of operation of the fixing strap assembly 35 remains the same, except in this case, the metal strap 36 is designed to move with the screen while the strap attachment plate 37 is held stationary with respect to the anchorage plate (not shown) fixed to the vehicle cantrail. In this embodiment an elongate guide slot 39 is formed in the strap 36 near its trailing end, with the leading end of the strap 36 being pivotally secured to a screen attachment bracket 40 which in turn is rigidly attached to an edge region of the screen by rivets (not shown).

a *ii The strap 36 slidably locates through a guide slot or eyelet 41 formed in the S• attachment plate 37 by a bridging web 42 which lies in a plane offset from the plane of the plate 37 by a distance equal to the thickness of the strap 36, whereby the strap 36 and plate 37 are firmly retained in face to face mating contract.

-i The strap 36 and plate 37 are slidably fastened together by means of a pin assembly 43 which includes a pin member 44 which passes through the slot 39 and a close fitting hole formed in the plate 37, and releasably interlocks within a keyhole opening formed in the anchorage plate fixed to the cantrail. This ensures that the attachment plate remains fast with the anchorage plate whilst permitting the strap 36 to slide forwardly (with the screen) in the event of a load impacting against the screen.

The pin assembly 43 is of the quick-release bayonet pin type and is spring loaded to facilitate its removal from the anchorage plate (ie by pushing the knob end inwards and rotating). With the pin 43 released, the strap 36 and plate 37 can be rotated about the axis of the pivot connection 46 and swung away from the anchorage plate. The pivot connection 46 also facilitates the attachment of the strap assembly 35 to the anchorage plate in the vehicle body.

The attachment of the trailing end of the fixing strap, to its anchorage plate in the vehicle body can, for example, be achieved by means of a hook member welded to the strap end and which releasably interlocks with a slot-like opening formed in the anchorage plate. This is particularly suitable for the bottom mountings where the hooks can be inserted into slots formed in anchorage plates secured to the floor of the vehicle.

Both the attachment plate 16, 37 and the metal securing strap 12, 36 can be formed of malleable mild steel and produced by a laser cutting operation. The offset strap retention web 26, 42 on the attachment plate can be formed by a simple cutting and pressing operation.

A brief consideration of the abovedescribed embodiments will indicate that the invention provides a fixing assembly for a safety screen or barrier for a motor vehicle which has vastly improved energy absorption capabilities for absorbing impact forces which are imparted to the screen when a load impacts thereagainst.

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Claims (14)

1. A fixing strap assembly for use in securing a motor vehicle safety screen or barrier to the interior of the vehicle, comprising: an elongate fixing strap arranged to extend rearwardly away from the screen or barrier, a strap attachment plate slidable relative to said fixing strap in mating surface contact therewith, guide means for slidably fastening together said strap and said attachment plate, screen attachment means for attaching the forward end of the strap assembly to an edge portion of the screen, and friction creating means between said strap and said attachment plate for producing a frictional braking force when the attachment plate and the metal strap slide relative to one another, eg when a load impacts against the screen and deflects the screen forwardly, said braking force being effective to restrain forward movement of the screen and absorb impact energy imparted to the screen by the load, and 4 securing means for securing one of the said fixing strap and said attachment plate with respect to an anchorage fitting fixed to the vehicle body.

2. A fixing strap assembly for securing an interior safety screen or barrier to the floor or ceiling of a vehicle, comprising: an elongate metal fixing strap arranged to extend rearwardly away from the screen or barrier and having a leading end and a trailing end, an attachment plate in mating surface contact with said strap and slidable relative to the strap, means for anchoring one of said fixing strap and said attachment plate to an anchorage plate fixed to the vehicle body, screen attachment means for attaching the other of said fixing strap and said attachment plate to the corner region of the screen or barrier, guide means for slidably fastening together said strap and said attachment plate, said guide means including an elongate guide slot formed in said fixing strap or said attachment plate and extending longitudinally thereof, a guide pin, rivet, stud or the like passing through said slot at or near its leading end, said guide pin, rivet or stud being arranged to guide one end of the fixing strap when it slides relative to said attachment plate, and friction creating means between said fixing strap and said attachment plate for producing a braking force when the attachment plate and the fixing strap slide relative to one another, arranged and constructed so that when a load impacts against the screen and °deflects the screen forwardly, the braking force produced by said friction creating means is effective to restrain forward movement of the screen. e* 15

3. A fixing strap assembly according to claim 2 wherein said attachment plate is formed with a guide slot displaced from the plane of the plate, said fixing strap slidably locating through said guide slot with the opposite longitudinal edges of the fixing strap frictionally contacting inner wall surfaces of said guide slot, said opposite longitudinal edges of the fixing strap defining a taper, whereby, the relative sliding movement between the attachment plate and the fixing strap produces said braking force by virtue of the friction forces generated between the strap edges and said inner wall surfaces, said braking force increasing as the extent of sliding relative movement between the fixing strap and the attachment plate increases.

4. A fixing strap assembly according to claim 3 wherein said elongate slot is formed in the attachment plate and extends longitudinally thereof, and wherein said guide pin, stud or rivet slidably secures the leading end of the fixing strap to said attachment plate, said anchoring means fixing the trailing end of the strap to said anchorage plate.

A fixing strap assembly according to claim 3 wherein said elongate slot is formed in said strap and extends longitudinally thereof, and wherein the attachment plate is fastened to the anchorage plate by means of said guide pin, the leading end of said fixing strap being pivotally attached to an attachment bracket which itself is rigidly secured to a corner region of the screen or barrier.

6. A fixing strap assembly according to claim 5 wherein said pin forms part of a quick release pin assembly for releasably anchoring the strap assembly to the anchorage plate in the vehicle body.

7. A fixing strap assembly according to claim 5 wherein said attachment bracket '.is secured to the screen or barrier by means of rivets or bolts. @0

8. A fixing strap assembly according to claim 4 wherein the trailing end of the 15 fixing strap is ridigly secured to said anchorage plate by means of a nut and bolt assembly. •c T'.l

9. A fixing strap assembly according to any one of claims 2 to 8 wherein said Sfixing strap is provided with laterally projecting transversely aligned protrusions on opposite sides thereof, for abutting against an end face of the guide slot, wherein the distance from the protrusions to said guide slot end face is approximately the same as or less then the length of said elongate slot formed in either the fixing strap or the attachment plate.

10. Securing means for securing a motor vehicle safety screen or barrier within the vehicle so as to extend transversely from side to side and from top to bottom of the vehicle so as to separate the load carrying area from occupant(s) within the vehicle, said securing means including a plurality of fixing strap assemblies each of which comprises: an elongate rearwardly extending metal strap, having a leading end and a trailing end, securing means for securing the trailing end of the strap to an anchorage plate fixed to the vehicle body, an attachment plate having a first portion arranged to be fixedly secured to an edge portion of the screen or barrier, and a second portion projecting rearwardly of the screen or barrier, said second portion being formed with an elongate slot which extends longitudinally thereof, said second portion having a strap guide slot or eyelet spaced rearwardly from said elongate slot for slidably attaching the strap to the attachment plate in mating surface contact, a headed stud or rivet securing the leading end of the metal strap to said attachment plate in face to face contact therewith, said stud or rivet passing through said slot at or near the leading end of, said stud or rivet and said elongate guide slot being arranged to slidably guide the attachment plate with respect to the fixing strap, and 4 a. friction creating means between said fixing strap and said strap guide slot for 15 producing a braking force when the attachment plate and the fixing strap slide relative to one another, eg when a load impacts against the screen and deflects the screen forwardly, said braking force being effective to restrain forward movement of the screen and absorb impact energy imparted to the screen by the load. 4

11. Securing means according to claim 10 wherein said fixing strap has its opposite longitudinal edges frictionally contacting respective inner wall surfaces of 4.a..a Ssaid guide slot or eyelet, said opposite longitudinal edges of the strap defining a taper such that the transverse width of the strap increases from an intermediate region thereof in the direction of its leading end, said taper being effective to provide a braking force which increases as the attachment plate is pulled further along the fixing strap in the direction of its leading end.

12. Securing means according to claim 10 or claim 11 wherein said guide slot or eyelet is formed by a bridging web displaced from the plane of the attachment plate by a distance approximately equal to the thickness of the fixing strap.

13. Securing means for securing a motor vehicles safety screen or barrier within a vehicle so as to extend transversely from side to side and top to bottom of the vehicle so as to separate the load carrying area from occupant(s) within the vehicle, said securing means including a plurality of fixing strap assemblies each of which comprises: an elongate metal fixing strap arranged to extend rearwardly away from the screen, an attachment bracket having a first portion arranged to be fixedly secured to an edge portion of the screen and a second portion projecting rearwardly of the screen, pivot means pivotally securing the leading end of said strap to said second So. portion whereby the strap is able to pivot about a substantially transverse horizontal axis, S. an elongate guide slot formed in the fixing strap and extending longitudinally thereof, a strap attachment plate mounted for relative sliding movement with respect to said fixing strap and being in mating surface contact therewith, a slot-like opening or eyelet formed in said attachment plate near the leading end thereof, said fixing strap passing through said slot-like opening, the strap and the opening being shaped and sized so that the opposite longitudinal edges of the fixing strap frictionally •i .•engage opposite inner wall surfaces of said opening, a releasable locking pin passing through said elongate slot formed in the fixing strap and through a hole, aligned with the slot, formed in said attachment plate and releasably attaching to an anchorage plate fixed to the vehicle body, said locking pin and said elongate slot co-operating together to slidably guide the fixing strap, when the screen is deflected forwardly by an impact load, with respect to the attachment plate, wherein said opposite longitudinal edges of the fixing strap form a taper such that the transverse width of the fixing strap increases from an intermediate region thereof in the direction of its trailing end, whereby when a load impacts against the screen and the screen is deflected forwardly, the relative sliding movement between the attachment plate and the fixing strap produces a frictional braking force effective to resist forward movement of the screen by virtue of the frictional forces generated between the edges of the strap and said inner wall surfaces of the slot-like opening.

14. A motor vehicle screen or barrier fixing means substantially as hereinbefore described and with reference to and illustrated in Figures 1 to 3 or Figures 4 and 5 of the accompanying drawings. A motor vehicle safety screen or barrier having fixing means for securing the screen or barrier within the vehicle so as to extend transversely from side to side and from top to bottom of the vehicle, substantially as hereinbefore described, with reference to and illustrated in Figures 1 to 3 or Figures 4 or 5 of the accompanying drawings. DATED this 17th day of December 1997. REES OPERATIONS PTY LTD By its Patent Attorneys MADDERNS 0 0@* *o **o*go *oooo