The present invention relates to braking devices, and is concerned particularly, although not exclusively, with braking devices for use with hand-pushed vehicles, such as shopping trolleys or carts.

Various, systems have been proposed for impeding or deterring the removal of supermarket shopping trolleys or carts from the vicinity of a supermarket. One previous- approach to the problem has been to employ obstacles, such as grids and/or narrow stalls, at the exit points of the supermarket or the supermarket parking lot. The obstacle ^' s are intended, to interact with the trolley's castor wheels or with the trolley itself to impede physically its removal. Many of these known systems are easily overcome by a determined person, In addition they may be unsuitable for use in certain locations, such as motor vehicle entrances for supermarket parking lots.

All trolley retention systems are designed to allow the trolley to be legitimately used within the permitted area but to cause the trolley to stop when, a pre-detersiined perimeter line is crossed. In order to achieve, this many previously considered systems have sought to cause a wheel or castor, or some part of the vehicle, to detect a change, in environment and to respond appropriately by inhibiting further motion of the trolley. Some prior systems have attempted to do this by employing permanent, magnets which are set into the ground and are arranged to trigger a braking system. Others have used electronic systems wherein coded instructions are relayed by radio or infra-red as a trigger signal to a receptor on the trolley. All of these prior systems are expensive. In the case of the magnet- baseci system the magnets are costly to install, and in the case of the electronic system the electronic devices required are costly to manufacture, and they require batteries and other valuable components. Furthermore, the electronics-based systems have been known to be unreliable, due to difficulties in regulating the trigger signal in the vicinity of large metallic objects such as railings,

Another type of previously considered system utilises a small jockey wheel which is arranged to run alongside one of the trolley wheels and to drop into a groove at a boundary location to trigger a braking mechanism. This prior system has the disadvantage that minor undulations in the ground can cause the brake to trigger needlessly, resulting in inconvenience to a user using the trolley legitimately.

US patent number 3, 892,295 describes a bo-undary-responsive wheel lock for a shopping cart or the like, in which a brake is. made to lock a wheel of the cart when a small actuating wheel falls below the _. level of the wheel of the, cart,, tor example by dropping into a groove in the ground.

European, patent number EP 0 740 624 B1 describes a security device for preventing removal of a shopping cart from premises. A brake trigger engages with a stop member located oh the ground surface at an exit region of the premises, to activate a brake and halt the progress of the cart. Our own published PCX application WO 2009/063237 describes a braking arrangement for a shopping cart in which a braking arm moves to brake a wheel of the cart when a smaller wheel loses contact with the ground, such as happens when the cart is being lifted.

In general, where prior systems have sought the benefits of a simple mechanical actuation of a brake for a trolley, thereby obviating the need .for expensive arid unreliable components, they have often failed to deliver a completely satisfactory solution as the triggering of the mechanism has either been false, due to imperfections in the rolling surface, or has been avoided altogether, for example by lifting the trolley wheels over the _. trigger zone.

Accordingly, embodiments of the present, invention, aim to provide a brake or lock mechanism for a wheel, castor, truckle or similar in which the abovementioned problems are at least partly overcome.

According to on® aspect of the present invention there is provided retention apparatus for preventing the unauthorised removal of. a trolley, cart, barrow or similar, from a designated area, the apparatus comprising a braking device arranged to. act upon a wheel of the trolley when triggered, and at least one ground fixture fixed to a ground surface at a designated region of the said area, wherein, the ground fixture comprises a surface profile which is so configured as to trigger the braking device when an attempt is made to pass the trolley over the ground fixture. The ground fixture may comprise a trigger tile having a specific trigger profile. Preferably the specific trigger profile, comprises a plurality of studs. The height of the studs may be selected tp trigger the braking device.

According to a second aspect of the invention there is provided a braking device for a vehicle wheel, such as a trolley wheel, arranged in use to travel on a ground surface., the device comprising a braking member arranged to act upon the vehicle wheel when triggered, and a surface follower arranged to bear against the ground surface, wherein the braking member Is arranged to be triggered by displacement of the surface follower when the surface follower encounters a portion of the ground surface having a specific triggering profile .

According to a farther aspect of the .invention, there is provided a braking device for a vehicle wheel, such as- a trolley wheel, arranged in use to travel on a ground surface, the device comprising a braking member arranged, to act upon the vehicle wheel when triggered, and a surface follower arranged to bear against the ground surface, wherein the braking member is arranged to be triggered by displacement of the surface follower when the surface follower becomes displaced beyond a predetermined extent.

In a preferred arrangement the surface follower is mounted, on the braking device for sliding movement relative thereto. Alternatively or additionally the surface follower is mounted on the braking device for pivotal movement relative thereto. The surface follower may be biased into contact with the ground surface. Preferably the surface follower comprises a jockey wheel. The. surface follower may be arranged to monitor the ground surface.

The braking member ^' may be mounted on the braking device for pivotal movement relative to the wheel, so as to come between the wheel and a ground surface when triggered. In a preferred arrangement the braking member is arranged to pivot eccentrically with respect to the. rotation of the wheal .

In a preferred arrangement the braking device comprises a reset aperture arranged in use to receive a reset member for resetting the device. The braking device preferably includes, reset gate means, arranged to be opened by the reset member prior to resetting. The reset gate member may be arranged to be actuated magnetically. Preferably resetting is prevented in the absence of a reset member.

The braking member may be arranged to be triggered when the vehicle is tilted and/or when it is lifted.

According to another aspect of the invention there is provided a method of retaining a trolley in a designated area, the method comprising installing a ground fixture at a designated place in the area, which ground fixture has a surface profile so configured as to. trigger a braking device on the trolley when an attempt is made to pass, the trolley over the ground fixture. The invention also includes a wheel comprising a braking device according to any statement herein. The invention also includes a trolley comprising a wheel according to any stacement herein .

The invention also provides a ground tile for fixing to a ground surface as part of a trolley retention system for arresting movement of a trolley, the. cile having a specific triggering, profile arranged in use to trigger a braking device of a trolley wheel or pastor when the wheel or castor is caused to travel over the tile.

The ground tile preferably comprises a plurality of protrusions or studs, at least one of which is arranged to engage with the braking device when a surface follower of the braking device falls between the studs as ^' the trolley wheel or castor is rolled over the tile.

In a preferred arrangement the ground tile comprises at least one weight-bearing portion for supporting the weight of a vehicle so as to resist wear on the protrusions.

The present invention is defined in the attached independent claims, to which reference should now be made. Further, preferred features may foe found in the sub-claims appended thereto.

The present invention may include any feature or combination of features described, herein, except a combination of features that are mutually exclusive. A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a side view of a trolley wheel together with a braking device, according to an embodiment of the present invention;

Figure 2 shows the wheel and braking device in front view;

Figure 3 shows the braking device of Figures 1 and 2 in a first inoperative configuration;

Figure 4 shows an internal face of a case lid of the brake device of Figures 1. to 3;

Figure 5 shows a trigger surface in the form of a tile, for use with the braking device of Figures 1-4;

Figure 6 is a similar view to that of Figure 3, but with the braking device encountering a triggering, stud;

Figure 7 shows the braking device in another configuration;

Figure 8 shows the braking device in an operative

configuration in which, braking has been triggered;

Figure 9 shows the device from an alternative view;

Figure 10 shows a. retaining pin of Figurs 9 being moved into a triggered position by a stud on the tile; Figure 11 shows a stud of the device being moved into a triggered position as a result of the braking device being lifted from the running surface;

Figure 12. shows internal parts of a ski member {not itself shown) of the device that, prevents the trolley being taken over the studs at an angle;

Figure 13 is another view of the brake assembly and the rear of the case;

Figure 14 shows a reset strip about to be inserted;

Figure IS shows the reset, strip of Figure 14 being

inserted;

Figure 16 shows the reset strip resetting the braking device;

Figure 17 shows a non-return ratchet, mechanism of the brake device;

Figures IS to 20 show an alternative embodiment of trigger mechanism; figures 21 to 23 show another embodiment of trigger

mechanism;

Figure 24 is an enlarged view of a retaining pin of the embodiment of Figures 21-23; and Figure 25 is a partial view of an alternative embodiment in which a different type of biasing Spring is utilised,

Turning to Figures 1 and 2, these show, respectively side and front views of a braking device according to an. embodiment of the present invention. A trolley wheel assembly is shdwn generally at 10 and includes a fork 10a, a fixing bolt and nut 10b, and a bearing housing 10c. The wheel itself is shown at 12 and is of the castor type. commonly used in shopping trolleys. In this example the wheel is of a particular design for use with a travelator, or moving roadway, but it could be of any other troiiey wheal design. A braking device, shown generally at 14, comprises a pivoting brake arm 14a, end a wedge-shaped brake pad 14b, located at a distal end of the brake arm 14a, and arranged in use to come between the Wheel and a running surface 16 on which the trolley runs in use when actuated. The braking device is housed in a case 15. A forward direction of travel is indicated by Arrow A, In the example shown, the braking device 14 is located, between the forks of the wheel 12, but in an alternative arrangement it could be located on the outside of the forks. In another, alternative embodiment, the braking device 14 could be positioned between a pair of wheels.

As part of the braking device a jockey wheel 18 is mounted so es to run on the running ground surface 16 alongside the trolley wheel 12, The jockey wheel follows the surface 16 and effectively monitors it. In front of the jockey wheel 18 is a ski member 20, the purpose of which is to assist the jockey wheel's progress over small obstacles, such as stones, without inadvertently triggering the braking device, as will be described further below. The jockey wheel 18 is resiliently mounted in a sliding carriage (not shown in. Figures 1 and 2} and is biased to bear against the running surface 16 in normal use. Behind the jockey wheel 18 is a trigger arm 22 which is used to trigger the braking device as will foe described in. more detail below, A. rubber pad 24 is mounted on the case alongside the jockey wheel and provides additional support tq the caster when the wheel engages with a travelator.

Figure 3 shows the braking device 15 revealing the internal parts. For ease of manufacture the braking device is made with a main case body 15a and. a lid 1.5b. In Figure 3 the lid 15b of the case 15 has been removed. The trolley wheel 12 has itself been Omitted from this drawing in the interests of clarity. A. sliding carriage 26 retains the jockey wheel 18 and the trigger arm 22, and a biasing spring 28 presses the jockey wheel onto the running surface 16, so that the jockey wheel monitors the surface over which the trolley wheel runs at all times. If the profile of the running surface .1.6 allows, the jockey wheel and sliding carriage will move downwards under the influence of the biasing, spring 28. A braking device retaining pin 30 controls the actuation of the braking device, as will be described below. A damper 32. slows the final stages of the sliding motion of the carriage 26 towards maximum extension.

A slot 15c placed at the top of the case 15 permits access for an operative seeking to reset the braking device, as will be described below. In order to trigger the braking device, the trigger arm 22 must foe forced to rotate around location point 22a so that trigger face 22b is moved agaiftst the braking device retaining pin 30 in order to move it from a first position, in which actuation of the braking device is prevented, to a second position, in which actuation of the braking device is permitted. In order to prevent false! triggering a contact tip 22c of the trigger arm 22 is protected from contact with other running surface protrusions by the ski member 20 which is both closer to the running surface than tip 22c and is also wider, so that, it will push out of the way anything small or lose, such as a small stone or ride over any other protrusions, Trigger arm 22 is biased towards a non-triggered position by leaf spring 22d. The. jockey wheel is free to rotate on a spindle on the ski member 20 and it is in permanent contact with the running surface {not shown in this figure} . Studs, described below, which are designed to trigger the braking device, are all at the same height, for example 9mm, and are spaced in such a way as to allow the jockey wheel to travel between adjacent studs but not the trolley wheel. A trigger arm locating pin 22e prevents rotation of the trigger arm 22. and thereby prevents release of the pin 30 unless the sliding member 26 has extended to a predetermined degree out of the case 15, In this way two conditions need to be met before the device can be triggered - firstly the jockey wheel 13 needs to be a predetermined distance below the running surface, and secondly a triggering stud or

projection must be of a certain size in order to come between the ski member 20 and the trigger tip 22c of the trigger arm 22. Thus the device has two _. distinct ways of rejecting other bumps and ridges that might be found on the running surface and only triggers on specially provided studs which are set for example at exit points determined by the owners of the vehicle.

Figure 4 shows the interior of the lid 15b of the case 15, A compression spring 30a (not shown, in this drawing) presses against the interior of the lid 15b biasing the retaining pin 30 in a non-actuating position. There is also a pivoting blocking member 32a which is? arranged to pivot about an axis which is substantially perpendicular to the direction of travel of the sliding carriage 26, and is also substantially perpendicular to the axis about which the jockey wheel 18 rotates (i.e. in the plane of the page, as Figure 4 is viewed) . In normal operation, when the sliding carriage is not extended, the blocking member is biased by spring 32b against the side of the ski member 20, as shown in Figure 3, with the spring 32b in extension, However, when the sliding carriage 26 extends beyond a threshold point, after which the ski member is no longer positioned beneath the pivoting blocking member 32a, the blocking member, under the influence of spring 32b, moves into the path of the damper 32 and acts to provide a stop for the damper 32 so that, when, the trolley wheel is lifted away from the running surface, the sliding carriage 26, biased by spring 28 _. to extend out of the case IS* is prevented from escaping by the blocking member 32a, which acts upon the damper 32. In the final 10mm or so of movement the tip of the damper 32 abuts against the blocking member 32a which slows, the last movement of the sliding carriage.

Figure 4 also shows a recess 15d and a raised surface ,15e. This is created so that when the sliding carriage 26 has extended out of the housing by the pre-deterroined height, i.e. when the jockey wheel IS ^' is running between the studs and the. main wheel 12 is running over the top of the studs, the recess will accept the trigger arm locating pin 22e. If the sliding member, is not at the right height to use the recess then, no ether bumps can trigger the mechanism as trigger member 22 is prevented from rotation by arm 22e abutting against raised surface 15e.

Figure 5 shows generally at 36 a trigger tile for. use with a trolley having a braking device as described above, and together with the braking device forming a trolley

retention apparatus according to the present invention. The tile is substantially rectangular and is made of moulded nylon or similar material. The tile 36 has an upper surface on. which are a number of moulded protrusions or studs 38 which are arranged in a pattern of rows at generally 45 degrees to a direction of travel of the trolley, as

Indicated by Arrow B. The studs are aligned in this way, and are spaced apart, in such a way,, as to allow the trolley wheels to pass over the studs. However the ski member 20 and jockey wheel 18 drop between the studs to a lower surface 40 and when the ski member encounters a stud it becomes urged upwards before falling back down over the stud which then becomes located in a gap between the ski member 20 and the jockey wheel 18. Further forward movement of the trolley at this point causes the stud to push against the trigger arm 22, triggering actuation of the braking device. The tile also includes weight-bearing portions or platforms 42, for supporting the weight of a vehicle and avoiding needless wear on the studs, ramps 44 to allow smooth access over the tile and. avoid a trip hazard, and securing holes 46, for receiving fixings, such as bolts, for securing the tile to the ground, The edges adjacent the ramps have complementary shapes so as to fit together closely with other tiles. A. heavy duty version of the tile (not shown) includes metal reinforcements in the platforms 42,

Figure 6 shows the braking ^' device encountering a stud while parsing over the tile of Figure 5. The trolley wheel is omitted from this diagram, but would be resting on top of the studs, while the jockey wheel 19 and ski member 2.0 have dropped between the studs under the bias of the spring 28. The. ski member 20 has slid over a stud 38 and the Stud has become located between the ski member and the trigger arm 22, Further forward motion of the trolley causes the trigger arm 22 to push against the trapped stud 38, causing the trigger arm 22. to pi.vpt, which in turn causes trigger face 22b to push against the retaining pin 30. The

retaining pin 30 is resiliently biased in a non-actuating position by the biasing spring 30a, and the force of the trigger face 22b against the pin 30 ^' overcomes the bias of spring 30a to displace the pin 30 which allows the brake to activate. At this height the trigger arm locating pin 22e is permitted movement as it can drop into recess 15d within lid 15b. As part of the sliding carriage 26 there is also provided a leg 26b that extends from the sliding carriage 26 so that it also lifts the retaining pin 30 when the sliding carriage is fully extended. Figure 7 shows the sliding carriage 26 at a height which would be required, if the trolley wheel (not shown) was on a travelater or the jockey wheel 18 (but not the trolley

*whsel) was pushed over some protrusion on the running surface 16» The sliding carriage 26 is its fully retracted position. At: this point the spring. 28 is extended as it is fixed to the sliding carriage at point 2.6a and fixed to the case lid 15b at point 28b.

&s explained above, the action of the spring .2.8 to bias the sliding carriage 26 to fully extend out of the case 15 is delayed by the damper 32, so that a momentary absence of the running surface does not cause the braking device to trigger. This enables, for example, the shopping trolley to be pushed off a kerb without triggering as this, would only leave the wheel off the ground for a fraction of one second, However if the wheel were to be lifted for a longer period then the braking systera would need to come into operation, otherwise the trolley could be lifted over the tile and stolen, The damper 32 is a email oil-filled unit of the. type often used to soften the closure of drawers in domestic storage units.

Figure 8 shows the braking device when the trolley wheel 12 has been lifted away from the running surface 16. The sliding carriage 26 has been urged by spring 28 to fully extend out of the case 15. The damper 32 has been fully compressed, by blocking member 32a and the trigger face 22b has pushed the retaining pin 30 into a release position. Thus, released, the braking arm 14a has pivoted into a braked position as shown in the figure under the influence of a biasing spiring, as will be described below. In the braked position the brake pad 14fo has become located between the trolley wheel (not shown) and the. running surface, thereby preventing further movement of the wheel and therefore the trolley itself.

Figure 9 shows' a. view of pin .30, brake 14 and sliding carriage 2.6 without the case, In this view, pin 30 being biased by spring 3.0a, prevents the brake 14 from rotational movement by positively locating in a slot 14f. Also shown is a lifting face 30c on pin 30.

Figure 10 shows the retaining pin 30 being moved away from its brake retaining position by trigger face 22b after the trigger arm 22 has been rotated by a triggering stud (not shown) . Trigger face 22b is also set at 45 degrees to the required movement of pin 30 so that as trigger arm 22 is moved by the stud it can lift the pin 30 as the two faces coding together cause the pin to move laterally and release the brake 14.

Figure 11 shows the retaining pin 30 being moved away from its brake retaining position by a leg 26b on the sliding carriage 26 as. the trolley wheel {not shown} has been lifted, away froro the running surface. It should, be noted that leg 26b also has a face which is. set at 45 degrees to the direction of the movement of pin 30. As it slides past, the leg 26b bears against an angled portion 30b of the pin 30 and compresses the spring 30a .

An additional feature set into the ski member 20 ensures that the braking device triggers if a user lifts the rear of the trolley so that the trigger tip 22c no longer faces the stud. In order to prevent the user from avoiding a trigger in this way there is provided ski trigger member 20a within the ski member 20.

Figure 12 shows a cutaway section of the ski member 20 to reveal the ski trigger member 20a which has a front face portion. 2Ob that is flush with the front edge of the ski member 20, and a rear rod portion 20c. 'When a user lifts the back of the trolley, the new angle ensures that the stud contacts the front face portion 20b and moves the ski trigger member 20a backwards causing the rear rod. portion 20c to push the trigger arm 2.2 in the same way as a stud would do. In this way, when s user pushes the trolley over a trigger tils, triggering of the braking device cannot be avoided by tilting the trolley.

Figure 13 shows the braking device and the exterior side of the case body 15a. The braking arm 14a is located on spindle: 14c by means of. an aperture which is off-centre to the rotation point for wheel 12 . This advantageously allows the braking pad 14b to be sset away from the wheel 12 when in its free running position but when the brake is released and rotates in a clockwise direction it moves closer to the wheel and increases the effectiveness of the braking action. The braking device 14 is held in its free running position by retaining pin 30 which is located in slot 14f . It is important that the braking device does not move away from case 15 and that pin 30 does not lose contact with slot 14f as this would permit the device to trigger falsely. In order to prevent this there is provided a finger 14e on the brake which slides between, a finger 15c and the case 15. This holds braking arm 14a close to the case 15. As the retaining pin 30 is intended to be triggered by a stud as the trolley is pushed over a trigger tile, the tetaining pin 30 might only be Withdrawn very briefly. To ensure that the braking arm 14a begins its rotation in that time period, there is provided leaf spring 50 arranged to bias the brake plate to start its clockwise rotation, When the braking arm moves into Its braking position it is prevented from over-rotation- as face 14d comes into contacts with stop member XSe.

Figure 14 and Figure 15 show a resetting system for the braking device. A reset strip 52 is provided for insertion into slot 15c of. the case 15. The strip 52 is preferably connected to a longer rod 54 so that an operative n«ed not bend to reset the device. Since the wheel 12 bearing the braking device 14 is always fined to the cart there is provided, advantageously, an angle or bend 52a in the strip 52 at the point of connection to the rod 54. The presence of the bend also prevents the user from inserting the strip 52 the wrong way round, as in such an event the rod S3 would clash with the body of the trolley, In order to provide security against any strip of the same approximate proportions from being able to reset the device, a first magnet 56 is fitted into the strip 52. The first magnet 56 operates a latch 5$ by repelling a second magnet 60 in the latch 58. If the first magnet. 56 in the reset strip 52 offers a north-pole field to face the latching mechanism 58, the. second magnet 60 therein must be oriented with a north-pole field facing the reset strip 52. When the strip 52 is inserted, the repelling force of the two magnets biases the latching mechanism to rotate from a first, closed position to a second, open position of the latch as it rotates around a post 62, Within the case 15 there is also provided a biasing means 64 which keeps the latching mechanism 58 closed when there is no resetting magnet 56 present. This could take the form of a email spring., but in the embodiment illustrated there is another small magnet 64 which is there to repel the magnet 60 in the latching mechanism to cause it to stay in. its closed position.

The latching mechanism 58 has ridge 58a which ordinarily prevents an entry gate 66 from movement, but when it is moved by the influence of the first magnet 56 it moves out of engagement and permits the entry gate 66 to move from a first, closed position to a second, open position. Gate 66 has two legs; a first 66a covers the aperture slot 15c for the reset strip 52 and a second leg 66b is biased by a spring 68 to remain in its closed position. The gate 66 is allowed to move from its first to second position rotating around its post 66c.

Figure 16 shows the reset strip 52 further inserted so that it is acting upon a. ratchet lever 70 which has a contact face 70a and blocking tip 70b. The lever 70 rotates from a first, blocking position to a second, release position around post 70c. It is biased towards the blocking position by spring 70d. Upon insertion, strip 52 comes into contact with face 70a and rotates the ratchet lever 70 so that the tip 70b no longer blocks the return of the braking assembly to its free running position. At the same time the reset strip 52 comes into contact at point 14g with the brake assembly 14. causing it to return to its free running position, When it is in. its free running position it is retained there by pin 30. Figure 17 shows in more detail part of the resetting mechanism, with some parts removed for clarity.. The

blocking tip 70b may be seen: restricting braking device. 14 from moving (anticlockwise) in. a resetting. Only when reset strip 52 overcomes the bias of spring member 70d is the brake member 14 permitted to rotate fully to its free running position. A limited degree of rotation in the resetting direction is permitted so that, the braking pad 14b is just resting on the ground and is not fully under the wheel 12. If this were not the case it would be very difficult for the reset strip 52 to bring the brake from under the weight of the trolley to a free running position.

Figures 18 - 20 show a variation on the brake blocking and release system _*

In the previous, embodiment the pin 30 is moved, by trigger face 22b or slider leg 26b, both of which require the interaction of sliding faces, which are arranged at a 45 degree angle, to move the pin 30 from its .blocking position to its released position. In environments where friction between the faces might foe increased, for example because of excess dirt, the action of the release mechanism might be impaired.

To address this, in the alternative embodiment of Figures 13 to 20, the movement of pin 30 has been converted from a. lateral one to a rotational one. This is easier to protect from dirt, and the action Of trigger leg 222b and slider leg 226b is more positive as they employ the engagement of gear teeth with the pin 230. With reference to Figures 18 to 20 these show in detail a part of the trigger mechanism in which there, is provided a pin 230 with spring 230a, which is a torsion spring, and biases the pin in its blocking position. For ease of manufacture the pin may be made in two parts. Pitv 230 has a leg 230k which is closer to the case, and is placed to rotate the pin 230 when contact face 222b from trigger 22 is moved into contact with 230k. In a similar manner, when the slider 26 is fully extended, it has leg 226b which comes into contact with leg 230c which rotates pin 230 in the same way.

The. pin _. 230 has a further leg 250 which in its first ana blocking position holds the brake from rotating, When the pin 230 is rotated by either 222b or 226b the leg 2S0 is released to rotate into its braking position. There is provided on- brake assembly 14 a recess 14k. which receives an extended portion of 250. In the blocking position this arrangement prevents lateral movement of the brake from losing connection with the blocking surface Of 250, This has the additional benefit of making, sure that, the brake cannot escape the rotational blocking surface by ^' sideways movement «

Figures 21 to 23 show an alternative embodiment which is similar to that of Figures 18-20 in that a rotating retaining pin is utilised, in this case labelled as 330.

The release pin 330 is made of two parts: an upper part 330u, which is arranged to come into contact with the trigger member 22, and a lower part 3301 which is arranged to block and release brake, member 14. The pin is biased towards a blocking position by spring 330a, which in this case is a tension spring. When the pin 330 is in a blocking configuration it protrudes into a curved envelope with brake member 14, shown as 314£. In this blocking position under the bias of the spring 330a it will not lose

relationship with the brake 14 as it will move in and out if there is any lateral movement of the brake 14. When the trigger member 22 is operated a protruding part 22b comes into contact with arm 330x causing the assembly 330 to rotate against the bias of spring 330a so that a. blocking finger 3301f on 3301 rotates clockwise and the brake is free to rotate anti-clockwise as shown in Figure 22. There is also shown a further protruding finger 330y on upper part 330u which is arranged to come into contact with and be triggered by slider finger 26b (not shown in these figures). In order to bias the lower part of the trigger pin 3301 towards, the brake assembly 14 and ensure that it is in the right place to drop into the. slot 314f a

compression, spring 330s is provided.

Figure 23 shows groove 14v which holds bottom part 3301 in the correct place after it has triggered and released the brake. Once the reset stick has rotated the brake arm clockwise the finger on 3301 can, under the bias Of spring 330a rotate back into a blocking position.

Fig 24 shows the trigger pin 330 in its two parts 330u and 3301. These parts are positively located by means of a shaped male part 330g shown hers as a triangular rod and in part 330u there is a receiving female part 330h. Also shown is retaining pin 330z which holds the spring 330a. Turning to Figure 25, this shows an alternative embodiment .in Which the biasing spring for the .sliding carriage 26 is a constant force spring 328. A characteristic of a tension spring, as used in the earlier embodiments, is that the force exerted increases the greater it is extended. This aspect may prove to toe unhelpful in the case of tension spring 28 which biases sliding member 26, as it will provide more force than is required when the de-vice is in a normal free running condition. To. minimise this issue a constant force spring 328 may be used instead. Figure 25 a constant force Spring 328 comprising a wound strip, of spring steel located in holding space. ISf within main case body 15a. The other end of spring 328 is- hooked around carriage 26 at point 32.88 and acts to bias the carriage in a downward or outward direction at all times.

Accordingly the present invention provides an improved, vehicle braking assembly for a wheel of a vehicle such as a supermarket trolley, the assembly including a case, a brake which is arranged to come between a wheel of the trolley and the running surface, a second, jockey wheel arranged to remain in permanent contact with the ground, a trigger system arranged, to operate the braking system When the trolley passes over a surface which has certain shapes protruding from the surface, a further trigger system which operates the brake if the wheel is lifted away from the running surface, a damper system to delay the action, of the second triggering system, and a resetting means.

The present invention .builds on some, of the principles of our previous patent application, published as WO

2009/063237 which describes the use of a second wheel being biased to stay in contact with the running surface and in which a brake releases if contact with the ^' running, surface is broken.

Embodiments of the present invention include developments in which the brake will also be released if the wheel is pushed over a running surface with, a particular profile. The triggering surface element can. be easily installed and as it will be obvious that it is intended to halt the progress of the vehicle beyond an authorised area, a second triggering system will operate the sane brake if the user attempts to lift: the wheel over the triggering surface. In this way the braking system will operate if the trolley is rolled. over the triggering surface or else if it is lifted over this or any other obstacle which may mark the

perimeter of use for that trolley. The braking device will be triggered mechanically when pushed over a plate which can be mounted on the any pedestrian or roadway or it will trigger if lifted over this or any other fence or similar deterrent .

The braking device, may be fitted alongside a conventional castor or wheel and fixed so that it cannot rotate or move in relation, to the castor. It may be made to locate between two wheels located within e.g. the yoke of a castor, or it may sit alongside the wheel. It could be made to fit on the outside of the fork of the castor or on the inside, The most effective braking method is to release a braking member which, is held in front of the wheel during free running but which is permitted to rotate to a position, between the wheel and the ground during braking. The dsvi.ce is intended to respond to a certain pattern of studs or an undulating surface of specific proportions so that it triggers on this surface bat on no others,

Accordingly the apparatus will not- trigger falsely and frustrate those using the trolley within the permitted area. The trigger means is located alongside a monitor Wheel, referred tq herein as a jockey wheel, which is not used to support the weight of the vehicle. This smaller wheel is biased to remain in .contact with the running surface by a biasing means such as a spring. To achieve this both the small wheel and the associated trigger means are located on an arm that either rotates/pivots, or, as in the embodiment described above, slides laterally. Being smaller in diameter the jockey wheel may drop .into a groove or gulley in the running surface. It may also drop into a channel between the studs on the special triggering

surface, which in the above-described embodiment takes the form of a tile, while the main trolley wheel remains supported by the top of the studs, being too large to fall between them. This allows the smaller jockey wheel and trigger means to drop a specific distance below the main wheel and below the case of the apparatus which is fixed to the wheel. Blocking means are provided to prevent the braking device from being triggered until the jockey wheel has dropped this specific distance from the case.

In the preferred embodiment the triggering member is protected from being inadvertently contacted and moved for example by a small stone or uneven ground, as it is located behind a ski portion which forms part of the arm that supports the jockey wheel. Accordingly the trigger arm will only be moved when it is extended a specific distance put of the case and when it is pushed bver one of the studs, which are spaced and shaped to locate between the ski portion and one end of the trigger member. When a stud is located in this position, any further forward movement, of the wheel ensures that the trigger member is moved by the stud. This in turn moves a retaining pin which releases the brake member to rotate from a position where it is

generally in front of the wheel, to come down between the. wheel and the ground.

The braking member moves generally around the same centre of rotation as the wheel, However in order to ensure that there is no contact with the wheel during, free running yet the brake does slide easily between the wheel and the ground, the brake member has a slightly different centre of rotation so that there is a cam effect and the brake moves closer to the wheel as it rotates from its free running position to its braking position.

It is important that the brake cannot be. simply reset by hand once it has triggered so there is provided on the brake assembly at least one tooth which operates in

conjunction with a ratchet placed within the case of the apparatus to ensure that, once the brake is close to its braking position it cannot be freely rotated back to its free running position without the use of a specific

resetting device .

A further advantage of the present invention. Is the easy resetting system. Tor resetting, to enable free movement of the trolley, other devices require a key and for the operator to bend to reset the brake into a free running position, or else they require expensive electronic

controls. Most organisations who own trolleys, of this kind employ members of staff who are responsible, for making sure that the trolleys are in. the correct place for the

customers. However when a retention system is introduced they often consider this as an additional task, and they are reluctant to take on any extra work. It is, therefore, important to make the matter of resetting the braking device as simple and easy as possible. Embodiments of. the present invention provide a slot into which a resetting strip of material can be inserted, the strip can be

supplied as part of a rod which will enable the device to be reset without the person having to bend down. The tip of the strip comes into contact with the ratchet which is holding the brake in a position very close to the ground and also on the brake assembly. As the strip is inserted it acts against these parts in order to bring them to a reset position. To ensure that the brake cannot simply be reset by any appropriately dimensioned strip there is provided a magnetically operated gate which only opens if the strip has a magnet set into it. As magnets of the correct strength and shape are not easily available to the public this form of -anti-tamper should provide adequate security.

A still further advantage of this embodiment is that it- contains a biasing means for the member that retains the jockey wheel and triggering system. In the preferred embodiment of the present invention the member which retains the jockey wheel and the triggering means is able to slide laterally in a generally up and down direction so that the jockey wheel can remain in contact with the ground. The amount of movement, given to the sliding member allows the jockey wheel to be fully retained within the case or to protrude beyond the case to allow for the jockey wheel to go over some moderately rough ground and still remain, in contact with the running, surface. If the wheel Of the vehicle, shopping trolley or the like, is lifted then the sliding member will under the force of biasing means fully extend and operate a triggering pin which will release the brake into its broking position, The biasing means i«ay advantageously take the form of a spring, though other equivalent devices may be used,

The trigger tiles: need neither special equipment nor specialist knowledge for their installation, and they can be offered in standard sizes in an off-the-shelf package. The ground surface to which they are fixed needs no special preparation beforehand.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance, it should be understood that the applicant claims protection in respect of any patentable feature or combination of features referred to herein, and/or shown in the; drawings, whether or not particular emphasis has been placed thereon.