GB2221797A - "a retractable barrier device" - Google Patents

Abstract

A retractable barrier device comprises a reel assembly including a spindle rotatable within a cylindrical housing and a flexible elongate barrier element (16), secured at one end to the spindle so as to be wound on the spindle by rotation of the spindle by a spring, which is tensioned as the element is withdrawn from the spindle. There is attached to the free end of the flexible element a magnetic assembly (17) comprising a permanent magnet (28) within a housing (21), for engagement with a suitable metal keeper spaced from the reel assembly. The magnetic assembly (17) includes a part-cylindrical concavely curved surface (25) so disposed that the magnet (28) will hold the assembly in magnetic engagement with a part-cylindrical convexly curved metal surface (26) when the concave surface (25) on the assembly (17) is brought into registering engagement with the convex surface (26). The magnet (28) lies within a mouth portion of the assembly (17), and in an alternative arrangement the mouth of the assembly may fit over a flat, correspondingly shaped, keeper plate.

Description

"A 1Retractable Barrier Device" The invention relates to retractable

ba.-rir devices of the kind comprising a reel assembly including a spindle rotatable on a support and a flexible elongate barrier element, secured at one end to the spindle so as to be capable of being wound on the spindle by rotation thereof, the tree end of the flexible element having secured thereto an assembly which magnetically engages a fixed device located in a position spaced from the reel assembly.

In one known form of such device the fixed device is in the form of a comparalCively large circular permanent magnet, and the assembly on the end of the flexIble element conprses a co.rrespondingly shaped circular metal keeper disc which can be engaged with the fixed magnet. the flexible elongate element being in the form of a strip of fabric webbing.

Such devices nay be used in situations where a temporary barrier is required to indicate that access past the barrier is prohibited or restricted. For exanple. such devices may be associated with supermarket check-outs to indicate, when required, that a particular check-out is not ir. operation. The reel assembly Is fixed at about waist he-4gh4L'1' te one side of the gangway past the check-out, and the fixed magnet is mounted at Ithe opposite side Of the gangway at the same heIght. Y.Ihen it is required to bar access throu-h the gangway, the flexible element is fro:r. the and +; he assenbly on it-t- tree and C) ill t) 11 - "' 1 / AxL.

is engaged with the f ixed magnet- so that the alement ext-ends across the gangway. When access through the gangway is to be permItted again, the keeper plte is disengaged from the magnet and the flexible element rewound on the spindle, which is normally spring loaded so that this rewinding occurs automatically.

Such devices may also be used temporarily Zc bar access through certain doorways and stairways in buildings to which the public is otherwise admitted, such as stately hoines, museums, galleries and other public buildings.

While such known devices are useful, 'thc--e is frequently a dernand for a temporary barrier in circumstances where the existing forms of device are not suit-able. Thus therc may not be available a suitable surface on which the magnet may be conveniently mounted. For example, in supermarkets one side of the gangway throuQh each check-ou'b,- is often defined by a tubular instal rai.l-l. Also, a barrier nay be requilred tc n.atk ott temporarily a large area rather than simply access through a gangway or doorway. in this case It is common to provide free-standing vertical post-s which are spaced. apart across the required area, adjacent posts being connected by flexible elements. Usually each flexible ele-ment is In the forn of a rope having---at each end a hook which colineCtS with a corresponding ring or hook on'the upper par4 of Pulst. while sucii arrangements are adequate In use; they can be inconvenient to erect, and store due to the PrOVISiOn C1, se-parat,- J-'. er,,c-hs of ropez For exa-,nplei if a -1angth of 1 - - i rope ir. stoler or otherSq4se becones losti the associated support post becomes useless.

The present -Invention sets out to provide an improved forn of retractable barrier device which can not only be used in the circumstances described above, but can also be used in conjunction with tree-standing posts or similar supports.

According to the Invention there is provided a retractable barrier device comprising a reel assembly including a spindle rotatable on a support and a flexible elongate barrier element, secured at one end to the spindle so as to be capable of being wound on the spindle Iby rotation thereof, the free end of the flexible element having secured thereto an assenbly which magnetically engages a fixed device located in a position spaced from the reell assembly, characterised in that the assembly on the flexible elemen4S a magnetic asr.(!inbly cc,-rprisinci a oUS 4 permanent magnet within a h Lng, and said fixed device comprises a metal keeper surface which. in use, is located in a position spaced from the reel assembly, the magnetic assembly including a part-cylindrical concavely curved surface so disposed in relation to the magnet that, in use, the magnet will hold the assembly in magnetic engagement with a part -cyl indri ca convexly curved metalkeepo-surface when the two curved surfaces on the assenbly and keeper respectively are brought into registering engagement.

u r, -4 n er a device according to the pl",essnt invention, the inagnet-,c assembly on the end af, the flexible barrier element may be readily engaged direct-ly with the surface of a tubular rail or post, provided the retil or post is formed of ferrous metal, without the necessity of 5 fitting a magnet or keeper plate to it. Alternatively the assombly nay be engaged with a keeper plate curved around the surface of the rail or post in the case where It is inade of some non-magnetic material.

There may be provided a number of posts on each of which is mounted a reel assembly so that, In use, the posts may be spaced apart in the required positions and then each flexible element may be withdrawn from its spindle and the magnetic assembly on the free end thereof engaged with an adjacent post or a keeper plate thercon.

The device according to the invention may also be used in the conventional manner across a fixed gangway or doorway in which case a keeper plate may be nounted at one side of Ithe gangway or doorway in the Conventional manner. In this case the keeper plate may have a part- cylindrical curved convex surface for engagement with the -,aacjne"L-.ic assembly, but preferably the magnetic assembly is such that it will also inagnetically engage with a filat keeper plate.

The pa-lt-cylindrical concavely cUrVed SurfaLCe Ot thG magnetic assembly m'a,- 35e provided oA- the housing..of the magnetic assembly, and 'in this case the magnet. is preferably so disposed in relation. to said curved surface that- at least part of the magnet W12.11 contact a curved :3url.'--cft which is broug,,,.-;- into engage,,T.ent with the curved surface of the housing.

The magnet nay comprise a main magnetic body sandwiched between two platelike pole pieces, tile Inagnstic body being set back from said curved surface of the 1housing but the pole pieces projecting from the magnetic body to engage a cunred surface brought into registering engagement with the curved surface on the housing. (Altho-jg., for convenience, reference is made to pole pieces, as explained later this term is intended to cover elements which engage any opposite faces of the magnetic body, and is not limited to elements which engage the north and south pole faces of the magnetic body.) The aforesaid support for the spindle may include i part-cylindrical convexly curved surface of fer-rous netal.

the radius of curvature of said surface being substantially the sane as the radius of curvature of the concavely curved surface on the magnetic assembly, -so that the magnetic assembly may be brought into registering engagement With the convexly curved surface on the reel assembly of another similar device. For example,, the support may comprise a generally cylindrical housing of ferrous metal within which the spindle is coaxially rctatable.

In any of the above arrangements wherein thre is provided a separatekeeper- plate assembly for magnetic engagement by said magnetic assembly, said housini; may include an open mouth portion, and the keepe--plate assembly,ray be so shaped and dimensioned as to be at least Partly receivable in the nouth cf tne hous4;.n-.J,.

This featurs nay be advanzageQus whether or not the magnetic asserably incorporates a concavely curved surface, since Jit locates Che magnetic asse,,n.bly accurately with the %eepe-r plate, and makes it less likely that the assembly 5 will become accidentally detached from the keeper plate by sideways force. Accordingly, the Invention also provides retractable barrier device comprising a reel assorJly including a spindle rotatable on a suppwrt and a flexible elongate barrier element, secured at one end to the spindle so as to be capable of being wound on the spindle by rotation thereof, the free end of the flexible elp-lnent havinq secured thereto an assembly whilch magnetically engages a device located in a position spaced from the reel assembly, characterised in that the assembly on the flexible, element is a magnetic assembly comprising a pernanent magnet urithin a housing, and said fixed deVice cor.pries a metal keeper surface which, in use, is located in a position spaced -from the reel asser.bly, said housing including an open mouth portion and the keeper plate assembly being so shaped and dimensioned as to be at least partly receivable In the nouth of the housing.

In any a--rangement according to the Invention where the keener plate is received within the mouth of the housing, the peripheral shape of the keeper plate prefLerably subst-antially matches and-fits within the mouth of the housing. The keeper plate is aisc preferably dinansloned so as to contact at least- pa--z of the magnet wIthin t-he when the keeper plate is received w1Lthin the mouth of the housing.

The keeper plate is prefeerably substantially flat, and mav be mounted on a separate carrier which, in use, may be mounted on a fixed surface.

with any of the devices according to the invention there nay be provided an electrically Operated audible and/or, visual alarm unit, said alarm unit being controlled by operation of an alarr, switch which Is adapted to be actuated by disturbance of the device from its nornal operative condition. The alarn. unit may be integrally formed with an electrical plug adapted to be received In an electrical power gocket.

The aforesaid alarm switch may comprise a magnetically operated switch so lccated in the carrier for the keeper plate as to be operated by the nagnet When the magnetic assembly is engaged with, or disengaged from, the keeper plate.

Alternatively, the alarr, switch may be a iniCroswitch adapted to be operated by rotation of the spindle of the reel assenbly. With such an arrangement the alarm unit may be integral with the r--el assembly, or a post Or Other structure on which the reel assembly is mounted.

in another arrangement the alarm switch may Include means for sensing retraction of' the flexible element onto the spindle of the reel assembly, the switch being adapted to be operated upon such retraction being sensed.

The.Following is a more detailed description 0.f embod-4mentn of the Invention, reference beIng made tc the

X 1 9 -a- a;company.4n- drawings in which:

Figure 1 is a diagrammatic representation of a bar--ier installation in which an assembly according to the.invention may be used, Figure 2 is a similar view of an alternative torn, of installation, Figure 3 is an exploded view of a real asset.-bly 6k a device according to the invention, Figure 4 is a vertical section through a magnetic 3.0 assembly of a device according to the invention, Figure 5 is a horizontal section through the magnetic assembly, Figure 6 Is a sln,4Iar view of a modified form of magnetic assembly, rigure 7 is a perspective view of a combined power plug and alarr. for use with the invention, Figure B is a diagrammatic horizontal section through a barrier- device according to the invention, showing neans for mounting the device in a concealed manner, and Figure 9 is a front view of the housing for the magnetic assembly in the arrangement of Figure B. Figure 1 shows a typical barrier inst&llation incorporating rerractable barrIer devices according- to the 2r5 Present Invention.- The installation comprises a plurality of free- standing support posts 10 each having a b&se 11. Mou-.ite--' at the upper end oil.' each post 10 is a --eel asecUblY 1_ of' a dev-ce according to the inventlon. As shcwn in F.4.gur,.-- 3, each reel asser-biy co-.ipr4ises a fixed cylindrical iretal housing 13 'forned with an axially extending slot 14.

A spindle 40 is rotatable coaxially within the housing 13.

The spindle is rotatable 1,n bushes 41 mounted in OPPOS6d circular end caps (15 and 42, or 15 and 43,) of the housing 13 and Is connected to the lower end cap 42 or 43 by a clock spring 44 wh.ich becones wound up as the spindle 40 is rotated in one direction, thereby to provide automatic retraction of the flexible elongate barrier element 16 which is wound on the spindle. When the reel aBsembly is to be mounted on a vertical post 10, a lower end cap of the kind indicated at 43 in Figure 3 is used. This has a downwardly projecting, reduced diameter portion 45 which can be secured withIn the hollow upper end of the post. In the case where the asseribly is to be mounted on a vertical surface (as will be described with reference to Figure 2) a plain lower end cap is used, of the kind-Indicated at- 42 in Figure 3.

ReterrIng again to Figure 1, the flexible elongate 2C barrier element 16 extends Ithrough the slot 14 in the housing 13 and is secured at one end to the spindle 40.

The elemenz 10 may zonprioo, to= emamplc, fabl-le %4&bblng.or a flat plastics at,-!-ip, although Che invention includes wilthin its scope other forms of flexible elements such as chains or cerds. Connected to the free end of the element 16 is a -jnagne-.-ic assembly 17, which wiMI be described in greater detail below.

14 t-e n.i.,- 1.ele-ment!6 Ls wouncl or- the sp4.ndle 40 2= within the reel asser.l',111 12 w--',t.'.I the magnetic assembly 17 adjacent the slot 14. As the element 16 is withdrawn fror. the reel assenbly, rotating the spindle 40, the clock spring 44 is wound up. The element Is extended until the magnetic assembly 17 can be engaged with the housing 13 of the reel assembly on an adjacent post 10. The loading of the clock spring 4-1. tensions the element 16 and also rotates the spindle, once the magnetic assembly 174 has been detached from the adjacent post, so as automatically to retract the element back into the reel assembly.

In the arrangement described and shown each post assembly is purpose built and the ree! assembly 12 Is nount-ed coaxially w-1th the post and at the upper end thereof in any suitable manner. Yor example the fElange 45 of the lower end cap 43 of the housing may be screwed or welded within the upper end of the main part, of the post 10. Alternatively, however, the reel assembly may be provided as a separate unit having means for securing it to a pre-existing post. For example, the reel assembly may have welded to its housing 13 a bracket, clamp or strap by means of which the assenbly may be secured to a post. In v such a case, the reel assembly may be used alternatively with a!ixed installation for example as shown -in Figure 2.

Referring to Figure 2, the reel. assembly 12 has a bracket IS welded to its housing by -means of w'lm;-1i%-h the assenbly Pay be screwed to the side of a supe--rarke,N-. checkout counter 19. The ragrcj41--ic assemblly 17 -ray then bs re c 1 -- 1, engaged with e. post or rail 21.) spaced the i counter 19 te def4,.ne the gangway pa5t the countr.

The reel assenbly 12 may be of the kind shown in Figure 3. However, in a further improved arrangement thors Pay be associated with the spindle, within the assemblyf a latch mechanism which operates in a similar fashion to the latch nechanisir, in a roller blind so that once the flexible element has spindle tne elertent and spring 44. element 16 required by twitching the element- so as to release ths latch mechanism, allowing the spring to rotate the spindl and wind in the flexible eleinent.

is Figures 4 and 5 show in greater detail the magnotia assen.bly 1"7 mounted on the end of the flexible clemnt 16. The ividgnetic assembly comprises a two part housing 2:1 which is preferably moulded from plastics material although it nay also be formed froin other materialso suc,-i as Matal.

The two parts of the housing are held together by selftapping screws whidh pass through bosses 22 intogrally moulded in each half of the housina 21.

As bes't- seen in Figures a and 5, the two parts of the housing define. a cavity 23 which is generally reczangular in cross -secti on having at one and a rectangular open mouth 24. The verticall, side edge 46 of the routla'.', 24 are flat, buIL- the parts of housihg above anCIA the are r d C&Y Ccn-avel..,.- an- cylin ri 11 been withdrawn to a required extent from ths latch mechanissi operates to ena&ge and hold the prevent its retraction into the housing by the As in a roller blind arrangementp the flaxiblo may be retracted into the reel assemblY when curvad as indica4b-.p-d at 25 so as to be engageat',Ic with th convexly curved outer surface 26 of a tubular neta2 post 27 (cr the outer casing of another reel assembly) as shown in Tigure 5.

At the upper end of the concavely curved surface 25 the housing 21 is formed with a straight transverse lip 62.

When the magnetic assembly is attached to a reel housing 13, as shown in Figure 1, or is attached to the topmost end of a post, the lip 62 sits on the upper surface of the housing or post to prevent 1Che assembly sliding downwards.

In cases where the assembly is required to engage the curved surf ace of a post away from the end, as ehown in Figure 2, the lip 642 is removed so that the curved surf ace can fLit closely on to the curved surface of the post.

1V Mounted within the cavity 23 is a permanent magnet 28 comprising a central magnetic body 29 on oppositt sidan of which are pole plates 1.0. As best seen in rigure 5, the pole plates 30 are wider than the magnetic body 29 and the magnet 28 is so located within the cavity 23 that the pole plates touch the surface 26 of the post when the curved surfaces 25 of the housing engage said surface. (A sinilar ef feCk. could be obtained by having the plates 30 of the same width as the body 29, but displacing thent towards the moutl. of the cavity.) it is not. essential that- the po-le plates touch the surface of the post, and tha mazrna';, could be so located that its main body and pole plater. are slightly spaced from 4C. h e surface of the poot. Alternatively, 1Che surface of the magnet 2S could h cylindr.-.Lcally and conCavely. curved so as te engage with the surface of the post over a large area.

As best seen in Figure 4, the magnet 28 -4s retained within the cavity 23 in the housing by means of projeo4%..ions 31 moulded on the inner surface of the housing which ongag in corresponding recesses in the upper and lower end facca of the magnet 28. However, other means may be pro,%.,ided for retaining the magnet withir. the housing. Por example it may be arranged for the screws which hold 1Che two halves of the housing together to pass through or otherwise engage with the magnet.

At the oppos-ite end of the housing to the Tnouth 24, the housing is forned with a narrow elongate slot 33 through which the webbing element 16 passes. The and of the element 16 W4 thin the cavity 23 is engaged by generally U-sectioned metal clip 34 which is clamped into engagement with the end of the webbing and prevents its withdrawal through the slot 33.

It will be seer. that due to the concavuly curved Z 0 shape of the end surfaces 25 of the magnetic assembly it may be broug'4-1t firmly into engagement with the curved surface Of the post 27. If the post is formed of ferrous metal the magnet 26 will hold the assembly directly in P-ngagem.p-nt with the pcst. If --he post is not made of ferrous metal then a suitable keepe-- plate can be &f'1xd to its surface. Suc.h keeper plate may be curved around the surface of the post so as tc be engaged by the whc.,lc ef the cur,je% C surface ot tne nagnetfe llt naY be c flat. Plate.. In this case the keeiper plate is preferably adapted to enter w.,;±^hin the mouth 24 of. the housing in the manner shown in Figure 6.

Referring to Figure 6, there in shown an arrangement whereby a modified version of the magnetic assembly of Figures 4 and 5 may also be used If required for engagement with a flat surface rather than a tubular rail or post. In such arrangerer.,1b,, the pole plates 30 ara of the same width as the magnetic body 29 and are thus act back froin the mouth 24 of the housing. There Is mounted on the f-lat surf-ace 35 a moulded plasi,-ics carrier 47 for a rectangular metal keeper plate 36 of such thickness that it nay project into the 24 of the housing, preferably to contact t-he magnet 28, although it. may be slightly spaoad therefron. it will be seen that in this case the keeper plate 36 also- serves "-c prevent lateral displacement of the magnetic assembly 17.

The arrangement of Figure 6 may also be used for at,i--achm.ent of the assembly to a curved surface of a support pos"k^.i as rentioned above, sinply by mounting the flat plate '6 d-rect"y or. the support post, the thickness of the plate beinq such as to allow the curved surface 25 of the asseicibly to come intc engagenent with the surf etce of the post.

In an alternative a--.-aiiger,.ent f or allowing co&".nec.'.-4Lon the magnetic assenbly 111 to a flat surfaco, th may be p--rv,;tded a special keeper plate having a cor,cavc---,,r su-face,,iith which the -Is- aasenbly may engage.

1.n any of the arrangemen'q..-.s described abOve, MY be darirab"e for an audlible or visual warning occur should t-he magnetic assembly 17 become disengaged from its keeper, posSibly indicating that sonebody har. passed the barrier. In this; case, there may be associated with the keeper plate, for example as indicated diaarantftatically in rigure 6, a magnetically operated reed switch 37 which is arranged to be operated upon removal of the magnet 2a fron its vicinity. Operation of the switch 37 is arranged, In known manne--, to actuate an alarn, bell, buzzer, E;ynthatic spoken warning, light, or any other forn of audible or visual indicator, either in the immediate vicinity of the barrier device or at a renote monit'oring location.

is In tChis arrangement, ilt the pole pieces 30 war to engage- the north and south pole faces respectively of the magnetle body 29 they would, with the keeper plate 36f comiplete a magnetic circuit and there may thran he insufficient stra magnet4C Olux to operate the reed switchy 3". For this reason, therefore, the plateg 30 actually engage the faces which are at right angles to the north and south faces of the magnetic body 29. In other words, the face of the magnetic body 29 which engages flat against thm.

J keeper plate is either the north or south pole faca of the net4- CirCUit magnetic body. The nag 1 ls not then coyftplete anwl there is sufficient stray magnet-ic flux to ensure that the reed switch 317 is actuated.

Figure 7 shows d.-'Legrar.mat-4ca-l-lv, by way of example, a co-.1-veriien't form of alarn, buzzer. The buzzer inechanism, tIne necessary transformer if required, in housed w-1thin a rectangular casing 48 which also incorporates a conventional 13 amp three pin plug assembly, the rectangular section pins being Indicated at 49. The unit may thus be sinply plugged into a conventlonal 13 amp socket and this provides the necessary power for the ala= buzzer. Alternatively the plug assembly may be of any ot-her forn appropriate to the count-ry in which the unit is to be used. The casing is formed with slots 50 to allow the sound of the alarm to en.erge. A snall indicating lamp 51 is provided to in-licate that the unit is ',on" and an on/off swit-ch 52 is also provided on the caning.

On each %ide of IZhe casing 48 Is a 3.5 mn mono jack socket 53, the two sockets being wired in series and connected to the buzzer Circuit. The reed switch 37 In the fixed part of the nagnetic assembly is connected by a flexible cable to a small jack plug which, in use, is p-lugged into one of the sockets 53 on the alarm unit. The read switch 37 is normally omen but Is closed when the ina;net'xc asse-mbly 17 engages the keeper plate 36, thus completing the circuit to the alarr. unit. in this condi.cion the operatCing circuit for 4the alarn is latchad. Should the m-.gne-ic assentbly 17 be detached fror the,keaz-er 21,5 P-1ate --,pg5, the-removal. of the P.agnet 28 fron the vicinity of tne reed switch 37 causes the.reed switch to open, breaking the c.-;ircu- J-L to the alarm unit. The elec-tric 1atch holding the a-Larr, iz tinus released and the alarry soundlo.The alarm Duzzer can be turnea off by switching off or unplugging the ala---r, unit, and reset by switching it on again or re-plugglan5 it in.

If required, a series of magnetic assemblies may he wired together in a loop and connected to a common alarn unit, by means of the two sockets 53, so that the alarm unit will sound should any of the assemblies be detached.

The alarn unit shown in rigure 7 may also incorporate a rechargeable back-up battery pack. This enables the unit to be used in a situation where no maind supply is available, but in the case where a mains supply is available the presence of the battery back-up ensures that the alarm can still operate even it there ic a power failure or the unit is unplugged from the mains supply.

The alarm unit may incorporate additional switCh contacts which become closed when the alarr, is activatedr Iiich contacts may be connected, if desired, to an w. h. h.

auxiliary warning circuit, such as a circuit supplying a renote indicating deviCe.

Instead of the alarm being activated by a magnetically operated reed switch associated with the keeper plate, it may be activated by a micro-swi"h associated with the real assembly. in this case, reterri ng to the form of real assembly shown in riqure, 3, the lower -5 end o-F the sp4nlle 40 o-lc thr. asseirbl., may, be extended downwardly and ar-ranged to project completelyt-hrough a cent.ral aperture in lower end cap 4.2 or 43 of the as-se,,,ib-ly housing,;,_ (as indicated at;g in 2 0 Figure 3) is car-ried on a mounting plate 60 which is apaced below the lower end cap 12 or 43 and is secured theralk.o by nount-ing posts 61. The movable operating eleinent of the rnicro-switch carries a small roller 63 which bears against 5 the periphery of the projecting lower and of the spindle 40, so as to maintain the switch in a norinally closed condition.

As may be seen from Figure 3, the spindle 40 is formed with a longitudinal slot 40A. If the barrier, once extended, is tampered with by removing the inagnetic assembly from its keeper, or if the flexible barrier element 16 is cut or even merely pulled, the spindle 40 W4L11 rotate, either due to the barrier element being retracted into the device by the spring, or due to a further length of '-.-.he element being withdrawn from the devic-e. As the spindle 40 rotates, the roller 63 on the operating element of the micro-switch 59 will fall into the slot 40a in the spindle, opening the a witch and thus activating the alarm.

Instead of being mounted to engage the lower end of the spindle 40 as shown, the nicro-swit-ch 59 night be nounted at the top of the reel assem. bly, to engage the upper end o..ir the spindle 40, or night be located within the cylbindrical housing 15 -ltself so as to engage an intermadiate portion of the spindle.

The micro-switch arrangement ray be providetd as a back-up, in addition to the above -ment icned reac5 switch $, 41 U assGzia'%-ed with the keeper plate. However, llt is alaz J particularly suitable f or use in an arrangement where an alarm unit controlled by the micro-switch is mounted on or in the post itself. In this case the alarm unit may be battery powered and the post and alarm will then be entirely self-contained, providing great convenience in use.

The electrical circuitry required to achieve the above methods of operation will be apparent to those skilled in the design of such circuitry, and will not therefore be described in detail.

Figures 8 and 9 show a neat and unobtrusive method of mounting the barrier device within a structure, such as a vertical surface of a check- out counter in a supermarket.

In this arrangement there is welded to the cylindrical housing 13 of the device a metal mounting lug 54 by means of which the device may be secured to a vertical wall panel 55 of a f ixed structure, so as to lie behind the wall. Adjacent the barrier device, the wall panel 55 is formed with arectangular slot 5.6 within which is fitted a sleeve 57 which extends from the front surface of the wall panel 55 to the housing 13. The sleeve 57 has an integral front flange 58 which overlies and is secured to the f ront surface of the wall panel. The slot 14 in the housing 13 is in register with the sleeve 57, which is so dimensioned and shaped as to receive the magnetic assembly 17 when the flexible element 16 is fully retracted into the reel assembly.

In order to withdraw the magnetic assembly from the r_ sleeve 15-7 when is required to set up the barrier, there may be- provided a key which is so shaped that 141-1 may be 4 Inserted Into the sleeve 56. At least the end of the key is formed from ferrous metal so that, when inserted in the sleeve 57, It at-tracts and holds the magnetic, aasembly, and th.us enables the assenbly to be withdrawn froin the In the arrangement of Figures 8 and 9, associated alarm device ray be controlled by an intra-red or similar device (not shown) which is mounted behind the wall panel 55 and projects a beam through an eyelet or sirillar hole (also not shown) in the flexible 16, which hole is positioned so as to come into registet with the beam when the elerment is fully extended. if the barri-e-r is tampered with the element will move, bringing the eyelet hole out of register with the beamt and this may be arranged, in known nanner, to activate the alarr.i devica.

Any ot-her known forr. of proxi,.n.ity detection device nay be used, instead of an;Infra-red beam to detedt the presen-ce of a hole in the element 16 or a device attached to it, when the element is tullv extended or fully retracted, so as to operate an alarm switch 4n the appropriat e manner should the barrier be tampered with.

In arrangep.enta desc,--.ibed above the - hblding Power cE the magnet- 2;S will normally be sufficientto en4- Prev detachme-nd--" of the inagnet'assenbly fron the k'C6piaplate; rail or post upon &c--idental pressure on the P-'LeT-P-n-t-, a---..ce tnis will nornally resUlt in. a i i 1 fair!,' direct pull in -2ne direction of the len-_"_.'&'-. of the elongate eler,,enIb, 16. The assembly nay, however, be ranjoyed fron the keeper plats, rail or post when required by levering the assembly sideways, pivoting it about one side edge of the housing, so as to break the magnatic connection.

Howe,.rer, in the event of an emergency, someone running at the barrier or pushing firmly against- lt will readlly apply sufficient pressure to disengage the magnetic assembly from its keeper and thus open the burrIer. The arrangement has the advantage that an soon as the nagnetic contact- is broken the flexilble element- will immediately be automatically retracted Into IZhe real assembly, so as not in any way to Impede passage past the barrier.

!QLhIDIS A retractable barrier device co pr4sing a real assembly includingr a spindle rotatable on a support and a flexible elongate barrier element, secured at one and to the spindle so as to be capable of being wound on the spindle by rotation thereole, the '."'roe end of the flexible element having secured thereto an assembly which magnetically engages a -fixed device located in a posi"%.ion spaced from the reel assembly, characterised in that the assembly on the flexible element is a magnet.'- assembly comprising a permanent magnet within a housing, and said fixed device comprises a metal keeper surface which, In use, is located in a position spaced from the roal assembly, the magnetic assembly including a part- cylindrical concavely curved surface so disposed in relation to the magnet that, in use, the magnet wIll hold the assembly in magnetic engagement with a part-cylindrical convexly curved netal keeper surface when the two curved surfaces on the assembly and keeper respectively are brought into registering engagement.

Claims (1)

1. 2. A device according to Clairn 1, wherein said partcylindrical concavely

   curved surface -is provided on the housing of the magnetic assembly, and wherein the magne-t. is so disposed in relation to said curved surface that at least part of the. magnet will contact a curved surface which is brought into registering engagement with the curved surface of the housing.

   3. A device according to CILair. 1, wherein the r,,ag,-kiet 1 comprises a main magnetic body sandwiched between two plate-.'&.ike pole pieces and wherein the magnetic body is sat back from said curved surface on the housing but the pole pieces project from the magnetic body to engage a curved surface brought Into registering engagement with the curved surface on the housing.

   4. A device accord-Ang to any of Claims 1 to 3, wherein the support for the spindle includes a par4,,-cylLndrical convexly curved surface of ferrous metal, and the radius of curvature of said surface is substantially the same as the radius of curvature of the concavely curved surface on the magnetic assembly, whereby the magnetic assembly may be brought into registering engagement with the convexly curved surface on the reel assembly of another similar device.

   5. A device according to Claim 4, wherein the support comprises a generally cylindrical housing of ferrous metal within which the spindle is coaxially rotatable.

   6. The combination, with a retractable barrier device 20 accordilig to any of the preceding claims, of an elongate post, said device being mounted at or adjacent the end of the post which, in use, is uppermost.

   7. The combination according to Claim 6, wherein the post is provided with a base to render Ithe post free- standing.

   8. A device according to any of Claims 1 to S# wherein there is pro,, rided a separate keeper plate assembly for m-agnetiz engagement by salLd nagnetil-O assemtly.

   9. A device according to Claim 5. wherein said housing includes an open mouth portion and wherein the keeper plate assembly is so shaped and dimensioned as to be at least partly receivable In the mouth of the housing.

   10. A retractable barrier device comprising a real assembly including a spindle rotatable on a support and a flexible elongate barrier element, secured at one end to the spindle so as to be capable of being wound on the spindle by rotation thereof, the free and of the flexible element having secured thereto an assembly which magnetically engages a fixed device located in a position spaced from the reel assembly, characterised in that the assembly on the flexible element is a magnetic: assembly comprising a permanent magnet within a hous,4,.ng,, and said fixed device comprises a metal keeper surface which, in use, is located In a position spaced from the real assembly, said housing including an open mouth portion and the keeper plate assembly being so shaped and dimensioned as to be at least partly receivable in the mouth of the housing.

   11. A device according to Clain 9 or Claim 10, wherein the peripheral shape of the keeper plate substantially inatches and fits within the mouth of the housing.

   12. A device according to Clair. II, wherein the keeper plate is dimensioned so as to contact at least pa-ht of the magnet within the housing when the keeper piate is received within the mouth of the housing.

   13. A device accordina to Clain 12, wherein tne lr.Geprt-" plate is substantially flat.

   14. A device according to any of Clairis 8 to 13r wherein the keeper plate is mounted on a separate carrior which, in use, may be mounted on a fixed surface.

   15. The combination, with one or more devices according to any of the preceding claims, of an eleCtrically operated audible and/or visual alarm unit, said alarm unit being controlled by operation of an alarm switch which is adapted to be actuated by disturbance of the device from its normal operative condition in which the magnetic assembly engages said keeper surface.

   16. A device according to Claim 14 and Claim 15p wherein said alarm switch comprises a magnetically operated switch so located in the carrier for the keeper plate as to be operated by the magnet when the magnetic assembly is engaged with, or disengaged from, the keeper plate.

   17. A device according to Claim 15, wherein said alarm switch is a nicroswitch adapted to be operated by rotation of the spindle of the reel assembly.

   18. A device according to Claim 17, wherein the alarm unit is integral with the reel assembly, or a post or other structure on which the reel assembly is mounted.

   19. A device according to Claim 15, wherein Said alarm switch Includes means for sensing retraction of the flexible element onto the spindle of the reel assembly, ths switch being adapted te be operated upon such retraction being sensed.

   20. A device 15, wl-lerain alarr.

   unit- is integrally formed with an electrical plug adapted to be received in an elect.rical power socket.

   21. A device according to any of the preceding Clainar wherein there is provided a sleeve having mean for -iftounting it adjacent the reel assembly, which sleeve Is shaped and dimensioned to accomnodate the magnetic anaembly when the flexible barrier element Is retracted into the rael assembly.

   22. Barrier equipment comprises a plurality of barrier 10 devices combined with elongate posts according to Claim 6 or Claim 7.

   23. A retractable barrier devIce according to any of the Figures of the accompanying drawings.

   i,Ued 1990 athe Patent=ce. State House. 66.71 High Holborn. Lond-WIR 4TP. Further copies maybe obtainedfroM The patent Office- Illplex techniques ltd. St Mary Crey. Kent. Con. 1'87 Sales Branch- St Mary Cray. Orpingtop.,Kel.t BR5 3P.D. Prr-ted by Vii