WO1991006930A1

WO1991006930A1 - Coin-freed shopping trolley lock

Info

Publication number: WO1991006930A1
Application number: PCT/AU1990/000508
Authority: WO
Inventors: Clarence Victor Neal
Original assignee: Huntmont Pty. Ltd.
Priority date: 1989-10-24
Filing date: 1990-10-24
Publication date: 1991-05-16

Abstract

A trolley lock body (10) is of narrow profile and has a cover (13, 17) contoured so that in use, it can be secured to the side of a shopping trolley so that the protruding lock reduces the possibility of collisions. A lock mechanism (26) inside the lock body has a coin receiving aperture (24) such that insertion of a coin (27) automatically releases a key (23) and a coin retaining finger (37) automatically retains the coin in the lock body while the key is released. The coin (27) engages a coin engaging slide (30) as the coin is manually pushed into the lock body, this action causes the slide to be drawn into the lock body such that the coin follows the slide such that the coin (27) does not protrude from the lock body. The key or coin is automatically released by the single action of insertion of the key or coin into the lock, this simplifies use of the lock.

Description

COIN-FREED SHOPPING TROLLEY LOCK

TECHNICAL FIELD

THIS INVENTION relates to a coin-freed apparatus and in particular to a coin-freed lock and more particularly to a coin-freed shopping trolley lock used to encourage shoppers to return shopping trolleys to a central storage location .

In the specification the word coin should be understood to mean any coin, token, card or the like to which value can be attached for the purpose of the bearer receiving reward for being in possession of same.

BACKGROUND ART It has been proposed to provide a coin-freed keyed lock in which a key is freed on insertion of a coin into the lock. The coin is retained in the lock until the key is replaced, thereafter the coin is freed.

One particular application of this type of lock is in relation to the returning of shopping trolleys to a central location at a shopping centre. The key is chained directly or indirectly to a shopping trolley and the lock is mounted on the trolley so that when two trolleys are nested together the key of one trolley can free a coin in the lock of the other, thereby securing the two trolleys together via the chain. The keyhole is so positioned on the lock and the chain is of a length which does not allow a key to be used to free a coin from its corresponding lock.

In one known trolley lock the lock is mounted on the trolley handle adjacent a folding baby seat. The lock has a number of projections including a projecting plunger, when the key has been released and the key and chain hang from the lock. This arrangement is unsafe and a number of small children have been injured as a result of the lock's design and the position of the lock on the trolley and its design. Another problem associated with this form of lock is that when trolleys are nested in a train and the train is being moved about a shopping centre the forces created by turns and twists of the train can damage the trolleys.

As a consequence of these problems it has been proposed to locate the trolley lock on the side of the trolley. However, the locks that have been employed are generally of box-like construction, having complex internal mechanisms resulting in a bulky lock which in use is unsafe. The lock can cause injury as it projects from the side of the trolly providing a generally abrupt front face which not only can injure other shoppers but can damage shop fittings and stock.

DISCLOSURE OF THE INVENTION It is an object of the present invention to alleviate at least to some degree the aforementioned problems of the prior art.

In one aspect the invention resides broadly in a coin- freed lock mechanism suitable for a shopping trolley lock operable to release a key from a lock when a coin is inserted into the lock, the lock mechanism including a coin receiving aperture, a keyhole and a key retainer, a key retainer biasing means adapted to bias the key retainer into a key retention position, a coin retaining means adapted to retain a coin in the lock when the key retainer is in a key release position, the arrangement being that as a coin passes into the coin receiving aperture the key retainer is moved against the key biasing means to release the key and the coin retaining means operates automatically to inhibit removal of the coin from the lock until a key is inserted into the lock through the keyhole to release the coin.

In another aspect the invention resides in a shopping trolley lock body suitable for housing a lock mechanism and for attachment to the side of a shopping trolley, the body being generally rigid and being adapted to project from the side of the trolley and having an inclined wall between a broad aspect and a narrow aspect so that the lock body can be positioned on the trolley so that its narrowest aspect is forwardmost on the trolley and the wall is inclined to the side of the trolley. Preferably the body is generally wedge shaped. Advantageously the lock body includes an outer wall and a nose portion located in front of the outer wall. The nose portion including an inclined wall portion extending from adjacent the side of the trolley to the outer wall so that as the trolley travels through a shopping centre the nose portion presents a sloping surface during collisions. Advantageously, the nose portion is wedge shaped.

The coin receiving aperture is preferably a slot in which is located a coin engaging slide which can be an interchangeable coin box to account for variations in coin size, the coin engaging slide is coupled directly, or indirectly or is formed integral with the key retainer so that movement of the coin engaging slide will cause movement of the key retainer. Preferably movement of the coin engaging slide is initiated by a user pushing a coin into the slot. In one advantageous form the coin engaging slide has a peaked coin abutment to inhibit tampering. Preferably the slot is upwardly facing so that as a coin passes into the slot and it initiates movement of the coin engaging slide, after the coin edge is flush with the slot the coin engaging slide continues to move but is under the influence of a slide drive means so that coin "free-falls" into the slot to a point where the coin is completely within the slot. The slide drive means is preferably a biased finger having a cam which slides over a camming surface on the slide to draw the slide away from the coin. When the mechanism is applied to a trolley lock the slide is preferably located in an upper side wall of the trolley lock body.

The keyhole can have any desired transverse cross- section but preferably includes a cylindrical passage aligned with the key retainer. In the case of a trolley lock the keyhole is preferably located in the inclined wall or in the nose portion of the trolley lock body.

The key retainer is preferably a slotted plate having a tapered slot through a broad portion of which the key can travel, the narrow portion being adapted to co-operate with a waisted portion of the key to retain the key captive.

The coin retaining means is preferably a projection or finger which is biased into the coin receiving aperture when the key is released. The coin retaining means and the slide drive means are preferably form integrally or are actuated by a main actuating means which is biased toward the keyhole and is retained in an unactuated state when the key is captive, but moves under the influence of its biasing means to actuate the slide drive means and the coin retaining means as a coin acts on the coin engaging slide.

The lock mechanism can be located at any position with the cover but it is preferable to use a spacer to locate the internal locking mechanism nearer the backing plate than the cover. As the locking mechanism is preferably generally planar in configuration, the coin slot is effectively moved nearer to the trolley and is less likely to be damages by collisions of other trolleys impacting the cover. The spacer is preferably a solid filler which is contoured to the internal shape of the cover and locates the delicate parts of the locking mechanism at a safe distance from the cover. In this way, impacts on the cover are distributed through the filler material directly to the trolley. The filler preferably includes machined or moulded cavities which carry the components of the locking mechanism. This facilitates assembly of the lock as the filler and locking mechanism can be assembled prior to the cover and backing plate being fixed thereto. Advantageously, the filler provides solid bulk bridging between the cover and the backing plate. A chain is preferably employed to secure the key to the lock body and advantageously, the chain connection to the lock body is made automatically on assembly of the lock by having a chain link positioned between registered parts of the lock. In the illustrated embodiment, the filler and backing plate include registering flanges which automatically secure the chain to the lock body during assembly of the lock.

In a preferred form, the key is conveniently made of multi-part construction so that on assembly, the chain is automatically secured to the key. Preferably, the key includes a shaft and a locking member connectable to the shaft to automatically lock the chain to the shaft so that the chain and locking member cannot be easily removed from the shaft. Advantageously, a hinge pin arrangement is used to couple the chain to the shaft and the locking member includes a hinge pin retaining fork which conceals the hinge pin against removal.

In order that the invention can be more readily understood and be put into practical effect reference will now be made to the accompanying drawings and wherein:- BRIEF DESCRIPTION OF THE DRAWINGS Figures 1 and 2 illustrate a preferred trolley lock body constructed in accordance with the present invention; Figures 3, 4 and 5 illustrate a coin-freed mechanism constructed in accordance with a preferred embodiment of the invention;

Figures 6A, 6B and 6C are respective plan side views illustrating a preferred trolley lock cover; Figures 7A, 7B and 7C are respective plan and side views illustrating a preferred backing plate;

Figures 8A, 8B, 8C, 8D and 8E are respective plan, elevation and sectional views of a preferred filler applicable to the cover and backing plate illustrated in Figures 6A through 7C respectively;

Figures 9A and 9B are respective side views illustrating part of a preferred locking mechanism; and

Figures 10A and 10B are schematic views illustrating a preferred key.

Referring to the drawings and initially to Figures 1 and 2 there is illustrated respective outer and inner views of a trolley lock body 10 according to a preferred embodiment of the present invention. The inner wall 11 shows screw holes 12 which enable the trolley lock body 10 to be mounted to the side of a trolley using suitable brackets (not shown) . An outer wall 13 is illustrated spaced from the inner wall 11 by an upper side wall 14 and a lower side wall 15 such that the trolley lock body projects from between 2 to 3 centimeters from the side of a trolley when the trolley lock body is secured to the trolley. The trolley lock body includes an inclined wall 17 which in this case is part of a nose portion shown generally at 16 such that the inclined wall 17 extends in use from a location generally adjacent the side of the trolley (i.e. the narrow aspect of the body) up to the outer wall 13 (i.e. the broadest aspect of the body) and as the nose portion is in front of the outer wall 13 the nose portion presents a sloping surface during collisions. In the illustrated embodiment the trolley lock body 10 is of two part construction with the wall 13, upper side wall 14 and rear wall 18 being pressed from stainless steel and the rear wall 11 and lower wall 15 being formed from mild steel. As can be seen the stainless steel pressing includes rounded edges 19, 20 and 21 which also enhance the safety of the trolley lock. Another safety feature is displayed at the front edge where the stainless steel includes a return flange 22 which is wrapped rearwardly so that a bluntened or safe edge is afforded at the very front of the trolley lock.

Other features illustrated in Figure 1 include the keyhole 23 and the coin receiving slot 24. The coin receiving slot 24 is located in the upper side wall 14 and the keyhole 23 is located in the wall 17 of the nose portion 16 and is generally elliptical in shape and extends into a cylindrical passage 25.

Referring to Figures 3, 4 and 5 a preferred coin- freed lock mechanism as applied to the trolley lock described in relation to Figures 1 and 2 will now be described. As can be seen the coin-freed lock mechanism 26 is illustrated in cutaway view in Figure 3 and Figure 4 and a section through A-A is illustrated in Figure 5. Figure 3 illustrates the mechanism just prior to a coin being pushed into the slot 24 and Figure 4 illustrates the mechanism with the coin 27 fully retained within the lock. Figure 3 shows a key 28 and a portion of a key chain 29 with the key captive in the lock. While a coin 27 has been illustrated in Figures 4 to 5 as the operating part, the coin engaging slide is illustrated at 30 but it can be an exchangeable coin carrier which is slidable and is sized to locate the coin. This is useful where it may be desirable to alter the lock so that it accepts a different sized coin. The coin carrier is typically a coin box having a slot to suit the coin size so that in order to change the required coin, one need only replace the coin box.

The mechanism is operable to release the key from the lock when a coin is inserted into the lock. The lock includes a coin receiving aperture which in this embodiment is a slot 24 and a keyhole 23 extending into a cylindrical passage 25, (see Figure 1) and a key retainer which in this case is a slotted plate 30 having a tapered slot 31. In this embodiment the key retainer 30 also functions as the coin engaging slide. The broadest portion 32 of the slot 31 is adapted to allow passage of the free end 33 of the key 23 through the slot while the narrow portion 34 co¬ operates with a wais ed portion 35 of the key 23 to retain the key captive (as illustrated in Figure 3). Figure 3 illustrates the key retainer in a key retention position and Figure 4 illustrates the key retainer in a key release position. A key retainer biasing means in the form of a spring 36 biases the key retainer into the key retention position.

As can be seen, as the coin passes into the slot the key retainer is moved against the biasing spring 36 until the enlarged portion 32 of the slot 31 is aligned with the free end 33 of the key 23 so that the key can be withdrawn through the slot. When the key is fully within the slot 24 and the key is released a coin retaining means in the form of a finger 37 moves into slot 24 to retain the coin in the lock. The finger 37 is formed as part of a main actuating block 38 which is biased toward the key retaining means by a main biasing spring 39, and therefore the coin retaining finger remains in position as illustrated in Figure 4 until the key is replaced, thereby forcing the main actuating block to the left and hence retracting the finger 37 to release the coin.

It will be appreciated that the finger 37 also serves to hold the key retainer in its key release position but in the illustrated embodiment a catch 49 is employed and is formed integrally with the main actuating block 38. As can be seen as the key is released the main actuating block will move to the right and the catch 39 will engage the lower edge 40 of the slot 31. The lower edge 40 of the slot 31 will travel along the ramp portion 42 of the catch 49 thus pulling the key retainer away from the coin 27, therefore as the edge 43 of the coin becomes flush with the outer edges of the slot 24 key retainer will continue to retract and the coin will free-fall a small distance so that the coin is fully within the lock.

In the illustrated embodiment the coin engages a peaked edge of the key retainer and in this case the key retainer and the coin engaging slide 44 are formed as an integral unit but it will be appreciated that these two elements may be constructed as separate co-operating elements. In order to inhibit tampering the slide includes a peaked coin abutment 45. The key includes a tapered end wall 46 adjacent the end of the key and a cone shaped end 47 which is adapted to register with the countersunk aperture 48 of the main actuating block 38. The taper on the key, the cone portion and the countersunk aperture 48 are exaggerated substantially in Figure 4 to illustrate the operation of the lock. It is proposed that the key, the aperture 48 and the slot portion 32 be machined to close tolerance so that the key can just clear the slot portion 32 and engage the aperture 48 as an interference fit. Thus, the diameter of the passage 25, the key cone 47 and the clearance through slot portion 32 are almost the same. In fact, there only need be a few thousandths of an inch clearance between the slot 32 and the key 23 and the aperture need only be a few thousandths of an inch smaller again to provide an interference fit so the key acts on the actuating block only. Thus, in order to successfully release a coin, the rod or other object used must be machined to the same tolerance. That is, if it is a few thousandths of an inch too small to pass completely through the aperture 48 and not engage the actuating block 38. As can be seen in Figure 5 when the key retainer is in the key release position the countersunk aperture 48 is slightly out of alignment with the broad portion 32 of the slot 31 so that tampering with a rod or the like inserted along the passage 25 is likely to engage the key retainer 32 before engaging the main actuating block 38. Thus unless the rod is formed similar to the key it is unlikely that the rod will be able to operate the lock to release the coin.

Many variations to the present invention can be made, for example the finger 27 can include lines of weakness so that an end portion of the finger can be easily removed in order to cater for larger coins. Similarly, the length of the slide can be easily altered. The mechanism can be supported in any suitable fashion but a moulded plastics support is preferred. Preferably the support in-fills the trolley lock body as a filler to reinforce the body against damage.

As can be seen, an alternative embodiment is illustrated in Figures 6A, 6B and 6C, there is illustrated a trolley lock cover 100 from which a trolley lock body can be assembled. As the embodiment of Figures 6A, 6B and 6C has features in common with the embodiment of Figures 1A to 1C, where appropriate, like numerals have been used to illustrate like features. The cover 100 includes an outer wall 13, an upper side wall 14, a lower side wall 15, and an inclined wall 17 which in this case, is part of a nose portion shown generally at 16 such that the inclined wall 17 extends in use from, a location generally adjacent the side of a shopping trolley up to the outer wall 13. As the nose portion 16 is in front of the outer wall 13, the nose portion presents a sloping surface during collisions.

In the illustrated embodiment, the trolley lock body is made by securing the cover 100 to a rear wall which in this case comprises a backing plate 11 shown in phantom in Figure 6B and more fully described in relation to Figures 7A, 7B and 7C below. It will be appreciated that the backing plate 11 is fixed to a shopping trolley and as a consequence, it is preferred that the cover 100 be pressed from stainless steel and be formed such that all external edges between the walls are rounded for added safety. The nose portion 16 of the cover includes a return flange 22 which facilitates connection of the backing plate 11 to the cover 100. In the illustrated embodiment, the backing plate 11 protrudes beyond the wall 18 of the cover 100. The wall 14 includes a coin slot 24 through which a coin can pass into the interior of the cover 100. The inclined wall 17 includes a keyhole 23 through which a key can be passed into the interior of the cover 100. In the illustrated embodiment, a filler carrying a locking mechanism is adapted to be retained between the cover 100 and backing plate 11 so as to be aligned with the keyhole 17 and coin slot 24. The filler is described more clearly below in relation to Figures 8A through 8E. In this regard, the cover 100 includes a hole 101 whereby the cover 100 can be secured to the filler. The plate 11 includes additional holes whereby the plate 11 can be secured to the filler (see Figures 7A, 7B and 7C).

Referring to Figures 7A, 7B and 7C the backing plate 11 is illustrated in more detail. The backing plate includes holes 102 as mentioned above which enable the backing plate to be secured to the filler and therefore to complete assembly. Additional holes 103 are employed in order to attach the backing plate 11 to a trolley via a suitable clamp (not shown) . As can be seen, a chain 104, part of which is shown in Figures 7A and 7B is connected to the backing plate 11. To facilitate automatic connection of the chain to the backing plate 11, a hole 105 has been punched in the backing plate 11. The hole 105 includes a flange 106 over which a link 107 of the chain 104 can be positioned prior to assembly. The filler includes a flange 108 (see also Figures 8A and 8B) which registers with the flange 106 so as to automatically lock the link 107 in position. Thus, on assembly of the backing plate to the cover with the filler in position, the chain 104 is automatically secured to the lock without the need for additional fasteners.

The backing plate 11 also includes a bracket 109 which can be located over a wire portion of a shopping trolley frame in order to facilitate connection of the backing plate to the side of a trolley.

Referring to Figures 8A through 8E, a filler 110 which can be positioned between the cover 100 and the backing plate 11 is dwHcribed. As can be seen, the filler 110 is formed to the σeneral internal configuration of the cavity between the cover 100 and backing plate 11 so that it provides a bridging mass between the cover 100 and the backing plate 11. Thus, any direct impact on the cover 100 will be transmitted through the filler 110 to the backing plate and then to the trolley to which the backing plate is secured. There will therefore be little possibility of the lock mechanism housed within the filler 110 being damaged.

The filler 110 includes a cylindrical passage 111 which automatically aligns with the keyhole 23 of the cover

100 and a coin slot 112 which automatically aligns with the coin slot 24 of the cover 100 when the filler 110 is in place. A coin 113 is shown in phantom in Figure 8A and the filler 110 includes recesses in which the parts of a suitable locking mechanism can be located so that the lock operates. A slot 114 is made to house a coin engaging slide of the type illustrated in Figures 4 to 5 and a recess 115 houses a main actuating block 38 as illustrated in Figures 9A and 9B. The locking mechanism operates in the same fashion as the locking mechanism illustrated in Figures 4 to 5. The only difference in the configuration of the main actuating block 38 is that in Figures 4 to 5, the finger 37 is formed integrally as part of the main actuating block, in the embodiment illustrated in Figures 9A and 9B the finger 37 is formed as a spring steel insert 116 for improved operation and strength. With respect to Figure 9A and 9B, similar numerals as used previously having regard to the main actuating block described earlier.

Referring to Figures 10A and 10B, the connection of the chain 104 to the key 117 will now be described. The key is in the form of a shaft 118 having a chamferred end 119 which is adapted to pass through an aperture in the key retaining slide and to engage with the main actuating block to move the main actuating block against biasing spring 39 (see Figure 9A) . The wasted portion 120 is adapted to co¬ operate with the coin engaging slide so that the key 117 will be retained in position within the lock when a coin is not in the lock. The chain 104 is connected to the other end 121 of the key 117 via a hinge coupling employing a hinge pin 122 which is positioned within the periphery of a chain link 123 and opposed holes in the fork member 124. A pin retaining collar 125 which is slid over the key, conceals the pin 122 against removal and thereby automatically couples the chain 104 to the key 117. The collar 125 is made from nylon or other plastics material and in the illustrated embodiment, includes a central bore so that it can be slid over the end 119 of the shaft 118, slid along the shaft toward the end 121 whereby the collar, due to its resilience, clips behind the shoulder 126 on the shaft 118. The collar 125 is shown in two positions at 125 when fully drawn back against pin 122 and at 125' where it has been partially slid along the shaft 118 prior to passing over the shoulder 125. The assembled state is shown in Figure 10B.

Whilst the above has been given by way of illustrative example of the present invention, it will be apparent to those skilled in the art that there are many variations and modifications to the present invention which may be made without departing from the broad ambit and scope of the invention as set forth in the appended claims.

Claims

1. A shopping trolley lock body suitable for housing a lock mechanism and for attachment to the side of a shopping trolley, the body being generally rigid and being adapted to project from the side of the trolley and having an inclined wall between a broad aspect and a narrow aspect so that the lock body can be positioned on the trolley so that its narrowest aspect is forwardmost on the trolley and the wall is inclined to the side of the trolley.

2. The trolley lock body according to claim 1 being generally wedge shaped and having a cover including an outer wall and a nose portion located in front of the outer wall, the nose portion including an inclined wall portion extending in use, from adjacent the side of the trolley to the outer wall so that as the trolley travels through a shopping centre, the nose portion presents a sloping surface during collisions.

3. The trolley lock body according to claim 1 housing a coin-freed lock mechanism, the coin freed lock mechanism including a coin receiving aperture, a keyhole and a key retainer, a key retainer biasing means adapted to bias the key retainer into a key retention position, a coin retaining means adapted to retain a coin in the lock when the key retainer is in a key release position, the arrangement being that as a coin passes into the coin receiving aperture the key retainer is moved against the key biasing means to release the key and the coin retaining means operates automatically to inhibit removal of the coin from the lock until a key is inserted into the lock through the keyhole to release the coin.

4. The trolley lock body according to claim 3 wherein the coin receiving aperture is a slot in which is located a coin engaging slide, the coin engaging slide is coupled directly, or indirectly or is formed integral with the key retainer so that movement of the coin engaging slide will cause movement of the key retainer, movement of the coin engaging slide being initiated by a user pushing a coin into the slot.

5. The trolley lock body according to claim 4 wherein the slot is upwardly facing so that as a coin passes into the slot and it initiates movement of the coin engaging slide, after the coin edge is flush with the slot the coin engaging slide continues to move but is under the influence of a slide drive means so that the coin "free-falls" into the slot to a point where the coin is completely within the slot.

6. The trolley lock body according to claim 5 wherein the slide drive means is a biased finger having a cam which slides over a camming surface on the slide to draw the slide away from the coin.

7. The trolley lock body according to claim 6 wherein the key retainer is a slotted plate having a tapered slot including a broad portion and a narrow portion, through the broad portion of which the key can travel before the key is locked in place, the narrow portion being adapted to co¬ operate with a waisted portion of the key to retain the key captive.

8. The trolley lock body according to claim 7 wherein the coin retaining means is a projection or finger which is biased into the coin receiving aperture when the key is released.

9. The trolley lock body according to any one of claims 3 to 8 wherein the coin retaining means and the slide drive means are formed integrally or are actuated by a main actuating means which is biased toward the keyhole and is retained in an unactuated state when the key is captive, but moves under the influence of its biasing means to actuate the slide drive means and the coin retaining means as a coin acts on the coin engaging slide.

10. The trolley lock body according to any one of claims 3 to 8 including a backing plate coupled to the cover such that, in use, the backing plate is located nearest the shopping trolley, a spacer to locate the lock mechanism nearer the backing plate than the outer wall of the cover such that the coin slot is located nearer to the trolley than it is to the outer wall of the cover.

11. The trolley lock body according to claim 10 wherein the spacer is a solid filler which is contoured to the internal shape of the cover and locates the delicate parts of the lock mechanism at a safe distance from the cover such that impacts on the cover are distributed through the filler material directly to the trolley.

12. A coin-freed lock mechanism suitable for a shopping trolley lock, the coin freed lock mechanism including a coin receiving aperture, a keyhole and a key retainer, a key retainer biasing means adapted to bias the key retainer into a key retention position, a coin retaining means adapted to retain a coin in the lock when the key retainer is in a key release position, the arrangement being that as a coin passes into the coin receiving aperture the key retainer is moved against the key biasing means to release the key and the coin retaining means operates automatically to inhibit removal of the coin from the lock until a key is inserted into the lock through the keyhole to release the coin.

13. The coin-freed lock mechanism according to claim 12 wherein the coin receiving aperture is a slot in which is located a coin engaging slide, the coin engaging slide is coupled directly, or indirectly or is formed integral with the key retainer so that movement of the coin engaging slide will cause movement of the key retainer, movement of the coin engaging slide being initiated by a user pushing a coin into the slot.

14. The coin-freed lock mechanism according to claim 13 wherein the slot is upwardly facing so that as a coin passes into the slot it initiates movement of the coin engaging slide, after the coin edge is flush with the slot the coin engaging slide continues to move but is under the influence of a slide drive means so that the coin "free- falls" into the slot to a point where the coin is completely within the slot.

15. The coin-freed lock mechanism according to claim 14 wherein the slide drive means is a biased finger having a cam which slides over a camming surface on the slide to draw the slide away from the coin.

16. The coin-freed lock mechanism according to claim 15 wherein the key retainer is a slotted plate having a tapered slot including a broad portion and a narrow portion, through the broad portion of which the key can travel before the key is locked in place, the narrow portion being adapted to co-operate with a waisted portion of the key to retain the key captive.

17. The coin-freed lock mechanism according to claim 16 wherein the coin retaining means is a projection or finger which is biased into the coin receiving aperture when the key is released.

18. The coin-freed lock mechanism according to any one of claims 12 to 17 wherein the coin retaining means and the slide drive means are formed integrally or are actuated by a main actuating means which is biased toward the keyhole and is retained in an unactuated state when the key is captive, but moves under the influence of its biasing means to actuate the slide drive means and the coin retaining means as a coin acts on the coin engaging slide.

19. A coin-freed lock mechanism according to any one of claims 12 to 17 further including a solid filler which is contoured to the internal shape of a cover of a trolley lock in order to locate the delicate parts of the lock mechanism at a safe distance from the cover such that impacts on the cover are distributed through the filler material directly to the trolley on which the lock is mounted.