A fluid expelling lock cylinder

Abstract

An anti-tamper cylinder lock to reduce the prospect of a freeze attack, the cylinder comprising a cylinder body, a key aperture 5, a plug 7 comprising one or more locking pins 9, a continuous channel

Description

Field of invention The present invention is in the field of vandalism-resistant lock cylinders. In particular, the present invention is in the field of fluid expelling lock cylinders. Background Steel is subject to embrittlement when it is cooled below its transition temperature. The resulting brittle state is undesirable for many applications as the material is prone to fast occurring and propagating fractures. This can be referred to as cold snapping. As such, a steel lock cylinder that is frozen to a brittle state is structurally compromised and therefore a target for vandals. Additionally, an increasingly common form of lock vandalism involves the injection of a fluid into an external lock cylinder (likely through a key aperture), utilising their substantially closed internal geometry to hold the fluid, and then flash-freezing the retained fluid through a state-changing reaction or other means of temperature reduction. As the fluid transitions to ice (in the case of water), it expands and applies considerable stress onto the structure of the cylinder as well as its internal mechanism. The ice expansion may in itself substantially weaken the cylinder or it may compound with the weakening effects of the cooled (and therefore brittle) steel. Alternatively, a mechanism of attack may be implemented with other fluids that are not water based (such as glue or other adhesive based fluids) and their internal expansion achieved through other means than freezing. It is understood other physical phenomena may also be associated with such freezing and expansion processes, and this application is not intended to be limited to any one particular phenomenon. The lock after this act is substantially compromised and can be snapped with relative ease to reveal the internal mechanism (or cam) therefore allowing a fenestration to be unlocked. The lock may also lose all function due to the disturbance to its internal mechanism. There is yet to be disclosed a means to effectively prevent such attack such that the ice formed / cooling effect can be minimised. This must be done in a manner so as to not weaken the structure of the lock or cylinder or depart too far from the current design of cylinders. The present invention addresses at least some of these aspects. Statements of Invention Aspects of the invention are set out in the independent claims. Optional features are set out in the dependent claims. In accordance with a first aspect of invention there is disclosed a cylinder for a lock, wherein the cylinder is configured to reduce the prospect of a freeze attack being successful, the cylinder comprising: a cylinder body; a key aperture; an inner plug comprising one or more locking pins, wherein when the one or more locking pins are aligned with an edge of the inner plug, the inner plug is configured to be rotated freely within the cylinder; wherein the key aperture comprises a channel that extends to the one or more locking pins within the inner plug; and a blow hole, such that there is a continuous channel from within the key aperture to external of the cylinder via the blow hole. Advantageously, such an arrangement provides a continuous channel from the likely injection point of a freeze attack fluid to the exterior of a cylinder. This arrangement may effectively expel the fluid from the cylinder (optionally utilising the force it is injected with into the cylinder) and doing so before the fluid has changed state. By expelling the fluid, or retaining as little of the fluid as possible, the likelihood of a successful freeze attack may be substantially reduced for at least two reasons. A first of which may be by limiting the amount of fluid in the cylinder, the amount of ice that can be formed within the cylinder is also reduced and hence the expansion (and therefore stress) effect of the ice onto the cylinder is decreased. A second reason may be that a smaller volume of the retained fluid has a lesser effect on the core temperature of the cylinder. Therefore, there is a smaller temperature drop and weakening of the lock or cylinder by the embrittlement of the steel it is made from. Should the above fluid be expanded by other means within the cylinder to that of freezing, it will be equally as advantageous to ensure as little of it is retained in the cylinder prior to its expansion. Furthermore, this arrangement complements the existing architectures of cylinders and does not mechanically weaken their structures. There may be other reasons that the above arrangement reduces the risk of damage to the cylinder and we are not tied to the above reasoning alone. Optionally, wherein the blow hole is positioned at the top of the cylinder. This may form a particularly effective position at which to expel fluid. Optionally, wherein top refers to the part of the cylinder configured to be furthest from the ground during use. The above two statements may define a location that is proximal to a natural obstacle within the lock that is hit by the injected fluid and guides the fluid upwards out of the channel of the blow hole. Optionally, further comprising a second blow hole. Advantageously, such additional blow hole may increase the fluid expelling capabilities of the cylinder by providing additional channels for the fluid to exit. Optionally, wherein the second blow hole is positioned so as to be angularly offset from the first blow hole. Advantageously, this separation may lead to the most effective arrangement for increasing the rate of fluid expulsion as it creates a second expelling point entirely separate from the passage created by the first blow hole. This results in the injected fluid being expelled from the cylinder through two channels at the same time rather than a backlog of fluid trying to expel through one blow hole. Additionally, the angle of the second blow hole may better align with the angle of injection and hence better utilise the injection force to expel the fluid. Therefore, the additional blow hole at a location angularly separate from the first may lead to a greater probability of efficient fluid expulsion. Optionally, wherein the angular offset is 90 degrees. Advantageously, blow hole location at such offset may better expel fluid that has pooled within the key aperture. Additionally, blow holes that are squarely positioned from one another may allow for a more timely manufacturing process. Optionally wherein the first blow hole and second blow hole are aligned longitudinally. Advantageously, this arrangement may save time in the manufacturing process by minimising the number of manoeuvres needed to form the holes on the cylinder. Additionally, such longitudinal location may define a natural exit location for a fluid within a cylinder as it may be proximal to an obstacle that is hit by the injected fluid and one that diverts the fluid outwards. Such a component of the lock mechanism may be a drive bar. Optionally, wherein the cylinder comprises a proximal end, and the key aperture is situated at the proximal end, and a distal end, and wherein the blow hole is situated towards the distal end of the cylinder. Such an arrangement may ensure that a substantial amount of the fluid injected into the cylinder is expelled and that no (or little) fluid is propelled beyond the blow hole by the force of the injection. Should the blowhole be located towards the proximal end, the force of the injected fluid may propel some of the fluid beyond the blow hole and hence prevent its exit. Additionally, such longitudinal location may define a natural exit location for a fluid within a cylinder as it may be proximal to an obstacle that is hit by the injected fluid and one that diverts the fluid outwards. Such as a component of the lock mechanism may be a drive bar. Optionally, wherein the cylinder further comprises a cam, wherein the cam is connected to the distal end of the cylinder body such that rotation of the inner plug leads to rotation of the cam. Such arrangement ensures that the door is easily operated. Furthermore, since the blow hole defines a passage from the key aperture within the inner plug to the cylinder exterior, the location of the cam being at the distal end of the cylinder ensures substantial fluid is expelled before it reaches (or upon reaching) the cam mechanism. Optionally, wherein cam is provided with a lug which will interact with a lock in a door, such that rotation of the cam leads to the cylinder being transferred from a locked to unlocked state. Furthermore, since the blow hole defines a passage from the key aperture within the inner plug to the cylinder exterior, the location of the cam being at the distal end of the cylinder ensures substantial fluid is expelled before it reaches (or as it reaches) the cam mechanism. Optionally, wherein the blow hole is situated on the cylinder body adjacent the cam; or wherein the blow hole is situated on an outer surface of the cam. Advantageously, both these locations ensure the fluid has a passage out of the lock. Additionally, such blow hole location may be in line with a natural exit location for a fluid within a cylinder as it may be proximal to an obstacle that is hit by the injected fluid, and wherein the obstacle causes the diversion of the fluid outwards. Such as a component of the lock mechanism may be a drive bar. Optionally, wherein the diameter of the blow hole is between 0.5mm and 3mm. Advantageously, such a diameter range may be optimal in balancing the rate of fluid expulsion from the cylinder with its structural integrity. Additionally, a hole too big may open up the inner workings of the cylinder which may enable other forms of manipulation of the lock. Optionally, wherein the continuous channel is configured such that fluid received into the key aperture is directed to exit the cylinder via the blow hole. Advantageously, such arrangement may substantially reduce the fluid retained within the cylinder that can be frozen. Hence, such arrangement reduces the likelihood of a successful freeze attack by reducing the ice formation within the cylinder that would compromise the lock either by the embrittlement of the steel or by expansion within the lock. Optionally, wherein the cylinder further comprises a washer. Advantageously, such a washer may be effective in diverting the injected freeze attack fluid away from critical components of the lock mechanism should the fluid pass beyond the blow hole. It may also be used in ensuring enough pressure within the cylinder to expel the fluid when the fluid is injected with force. Optionally, wherein the washer is situated within the cylinder body. Advantageously, such a location for a washer may be the most effective to divert fluid away from critical components of the lock or cylinder. Such a location may also involve the washer being adjacent an opening or blow hole of the cylinder such that the washer can divert fluid out of the cylinder. Optionally, the cylinder further comprising a drivebar. Advantageously, a drivebar may effectively convert the rotation of the key or inner plug to the rotation of the cam. Optionally, wherein the drivebar forms an internal drivebar and an external drivebar, wherein the external drivebar is configured to be displaced by the insertion of a key within the key aperture, and wherein the internal drivebar is displaced by the external drivebar. Advantageously, such an arrangement allows for the selective engagement of the cam from either side of the fenestration. Should the lock be vandalised from an exterior side, this arrangement may allow for the exclusive control of the lock from an interior side and hence provide additional security. Optionally, wherein the displacement of the drivebar allows the cam to rotate. Advantageously, a drivebar may be the most effective way to convert the rotation of the key or inner plug to the rotation of the cam. Optionally, wherein the washer has a central aperture. Advantageously, such a central aperture may allow the washer to fit around components within the lock or cylinder to form a seal across a majority of their perimeters. This may substantially reduce the amount of fluid entering and compromising the lock mechanism. Optionally, wherein the washer is a soft washer. Advantageously, a soft washer may be particularly effective in forming a seal with the lock component. Optionally, wherein the washer is formed from silicone or nylon. Advantageously, a washer made of silicone or nylon may be particularly effective in forming a seal with the lock component. These materials may also be particularly unreactive with the fluids used as part of the freeze attack. Optionally, wherein the washer has a thickness of between 0.5mm and 1mm. Advantageously, such a thickness may allow for the washer to withstand the pressure of the injected fluid without giving way to it. Optionally, wherein the washer is positioned around the drivebar. The drivebar may likely be the first barrier encountered by the freeze attack fluid as it is injected into the key aperture and the washer may ensure that no fluid passes through this barrier by providing a seal around the drive bar. Optionally, wherein drivebar is situated within the central aperture of the washer. The drivebar may likely be the first barrier encountered by the freeze attack fluid as it is injected into the key aperture and the washer may ensure that no fluid passes through this barrier by providing a seal around the drive bar. Optionally, wherein the washer is situated within the cam. Advantageously, this arrangement may prevent the freeze attack fluid from progressing beyond the cam or beyond the portion of the cam at which the seal from the washer is formed. Optionally, wherein the washer is configured to prevent the ingress of fluid through the key aperture from passing into moveable elements of the cam. This prevents damage to the lock mechanism by reducing the amount of fluid that enters the movable elements of the cam. Optionally, wherein the cylinder further comprises a second cylinder body. Optionally, wherein the cam is situated between the first cylinder body and the second cylinder body. With regards to the above two statements, the second cylinder allows control of a cam from a second side, wherein the first side is the side of abovedescribed cylinder of the first aspect. This second side may be the interior side of a fenestration. In accordance with a second aspect there is disclosed a cylinder for a lock, wherein the cylinder is configured to reduce the prospect of a freeze attack being successful, the cylinder comprising: a cylinder body; a key aperture; an inner plug comprising one or more locking pins, wherein when the one or more locking pins are aligned with an edge of the inner plug, the inner plug is configured to be rotated freely within the cylinder; wherein the key aperture comprises a channel that extends to the one or more locking pins within the inner plug; and further comprising a washer situated within the cylinder. Advantageously, such an arrangement may provide protection against a freeze attack by forming a seal that prevents the ingress of the injected fluid from reaching critical components within the lock or cylinder. This seal may also be used to increase the pressure of the freeze attack fluid within the cylinder, whereby a higher pressure of the fluid may aid in expelling the fluid more efficiently. In accordance with a third aspect of invention, there is provided a lock comprising the cylinder of the first and second aspects, and further comprising a bolt, wherein the bolt is configured to be actuated by rotation of the inner plug of the cylinder. Advantageously, this may be the most effective way to actuate the bolt form a locked to an unlocked state and vice versa. In accordance with a fourth aspect there is provided a door comprising the lock of the third aspect. In accordance with a fifth aspect there is provided a method of overcoming a freeze attack, the method comprising the steps of: receiving an injection of a first fluid into a lock; ejecting at least a portion of the first fluid out of the lock via a blow hole. Said method steps may be advantageous as they reduce the amount of fluid retained within the lock. This reduces the likelihood of a successful freeze attack as it reduces the amount of fluid available for freezing, or expansion through other means. Said steps may also ensure the fluid is expelled from the cylinder whilst it is still in a fluid state. Optionally, wherein the method further comprises receiving a second fluid, wherein the second fluid is configured to cause the temperature of the first fluid to decrease and change state. Optionally, wherein the method further comprises ejecting at least a portion of the second fluid out of the lock via the blow hole. Advantageously, this may reduce the amount of the second fluid available to cause the temperature decrease of the first fluid. This may delay or prevent change of state of the first fluid. Optionally, wherein the ejection of a portion of the first fluid prevents a change of state of any remaining first fluid from fluid to solid from damaging a cylinder such that a cam can be rotated freely regardless of the position of a locking pin and / or a drivebar. Optionally, wherein the first fluid is water. Optionally, wherein the first fluid is an adhesive or glue, preferably wherein the first fluid is super glue. Optionally, wherein the second fluid is configured to be at a temperature lower than 0 degrees Celsius. Optionally, wherein the second fluid is a solvent. Optionally wherein the second fluid is a cleaning solvent. Optionally, wherein the method further comprises a washer preventing at least a portion of the first fluid from either: (i) entering the cam; or (ii) coming into contact with moveable elements within the cam. Advantageously, such an arrangement may provide protection against a freeze attack by forming a seal that prevents the ingress of the injected fluid from reaching critical components within the lock or cylinder. This seal may also be used to increase the pressure of the freeze attack fluid within the cylinder, whereby a higher pressure of the fluid may aid in expelling the fluid more efficiently. Optionally, wherein the method is configured to be performed by the cylinder of any of the first and second aspect. Brief Description of Figures Figure 1 shows a side-on, cross section view of a first embodiment of a cylinder with a blow hole and shows a path of an injected fluid through the cylinder. Figure 2 is a side-on, cross section line drawing of a cylinder substantially similar to the cylinder of Figure 1 but without the path of the injected fluid, and showing some additional internal details. Figure 3a shows an internal view of the cylinder of Figure 1 with a washer placed around a drivebar. Figure 3b shows the drivebar of Figure 3a in isolation. Figure 3c shows the washer of Figure 3a in isolation. Figure 4 shows a flowchart outlining a method of overcoming a freeze attack on a cylinder. Detailed Description of Figures Figure 1 shows a cylinder 1 for a lock, wherein the cylinder 1 is configured to reduce the prospect of a freeze attack being successful, the cylinder 1 comprising: a cylinder body 3; a key aperture 5; an inner plug 7 comprising one or more locking pins 9, wherein when the one or more locking pins 9 are aligned with an edge of the inner plug 7, the inner plug is configured to be rotated freely within the cylinder 1; wherein the key aperture 5 comprises a channel 11 that extends to the one or more locking pins 9 within the inner plug 7; and a blow hole 13, such that there is a continuous channel from within the key aperture 5 to external of the cylinder 1 via the blow hole 13. Figure 1 also shows a cylinder 1 for a lock, wherein the cylinder 1 is configured to reduce the prospect of a freeze attack being successful, the cylinder 1 comprising: a cylinder body 3; a key aperture 5; an inner plug 7 comprising one or more locking pins 9, wherein when the one or more locking pins 9 are aligned with an edge of the inner plug 7, the inner plug 7 is configured to be rotated freely within the cylinder 1; wherein the key aperture comprises a channel 11 that extends to the one or more locking pins 9 within the inner plug 7; and further comprising a washer 15 situated within the cylinder (optionally within the cam of the cylinder). Figure 1 shows a cylinder 1 for a lock within a door (not shown). The cylinder of Figure 1 comprises a first cylinder body 3 that is located on an exterior side of a fenestration (and seen on the right hand side of Figure 1), a second cylinder body 17 located on the interior side of the same and a cam 19 situated between the two cylinder bodies 3,17. The second cylinder body 17 may have a substantially similar arrangement to that of the first cylinder body 3. Due to the likelihood of a freeze attack occurring from an exterior side of a cylinder 1, the content of this specification may be more likely to be applied to a first cylinder body 3, and for convenience sake, this first cylinder body 3 will herein be referred to as simply the cylinder body 3. However, in some embodiments, the discussed features may apply to the interior cylinder body 17 too (should there be a need to utilise a blow hole on both the first and second cylinder bodies). The cam 19 of Figure 1 is configured such that it can be rotated by the rotation of the inner plugs 7 held within either of the two cylinder bodies 3, 17. Also seen in Figure 1 is the lug 21 of the cam which will engage with a recess in a door, such that the rotation of the cam 19 leads to the lug 21 being transferred from a locked to unlocked state. The key aperture 5 seen in Figure 1 defines a channel 11 that extends from a proximal to a distal end of the cylinder body 3 and through the length of the cylinder body 3. Figure 1 also shows a blow hole 15 that is located at the top of a distal end of the cylinder body 3, adjacent the cam 19. Here, the top of the cylinder body 3 is referred to as the portion furthest from the ground during use. The channel 11 is configured to form a continuous channel with the blow hole 13. Whereby the continuous channel allows access for any fluid that is within the channel 11 to the external side of the cylinder body 3. Furthermore, in the embodiment seen in Figure 1, the described location of the blow hole 13 aids in the expulsion of such fluid by complementing the internal structure of the cylinder 1. It does so by placing an exit point adjacent to a first natural obstruction in the channel 11 whereby this exit point utilises the dispersion of the fluid upon hitting the obstruction. Here, 'natural' refers to the existing architecture of common locks or cylinders. Additionally, in alternative embodiments to Figure 1, it is also entirely possible for the blow hole 13 to be located in a longitudinal position that is not adjacent to this first natural obstruction. The blow hole 13 in said embodiments will still be able to guide the injected fluid to the exterior of the cylinder body 3 and do so effectively. The functionality of the blow hole 13 is not limited to being proximal to this first obstruction, it is merely particularly advantantageous for expelling the fluid effectively. The blow hole 13 may be situated at any longitudinal position along cylinder 1. The benefits of this continuous channel formed by the channel 11 and the blow hole 13 are described in more detail later in the specification. In other embodiments, the blow hole may be located on an outer surface of the cam 19 instead of the cylinder body 3. The blow hole 13 may have a diameter in the range of 0.5mm to 3mm in both embodiments. To visualise the fluid expulsion in the embodiment of the cylinder 1 of Figure 1, there is also seen a path of a fluid injected into the cylinder 1 through the key aperture 5 during a freeze attack. This fluid may be water (or an alternative primary fluid) and / or a secondary fluid injected after the injection of the water and used to change the state of the water. Both fluids may follow the same path through the cylinder 1. The fluid may alternatively be another form of solvent, such as a glue or curing agent. The fluid is seen to travel along the channel 11 of the key aperture 5 and towards the distal end of the cylinder body 3 prior to forcefully impacting a first obstacle and separating into different directions, or portions as will be referred to herein. In Figure 1, this first obstacle is a proximal end of an external drivebar 23 that is used to engage the cam 19 upon the insertion of a key (not shown) from an exterior side. In other embodiments, this obstacle may be another piece of lock infrastructure, such as another type of a clutch component, the face of the cam, the end of a pin, or any other element within the cylinder. Upon impact with the external drivebar 23, a first portion 25 of the fluid in Figure 1 is diverted / ricocheted upwards and through the blow hole 13. This results in the fluid being expelled out of the cylinder body 3 before it can enter the cam 19 mechanism. A second portion 27 of the fluid seen in Figure 1 relates to the fluid path being diverted below the external drivebar 23 and out of an aperture on an underside of the cylinder body 3 and cam 19. This aperture may be an existing opening in the cylinder or may be an additional blow hole 13. It is noted that in alternative embodiments there may be a single fluid path, and this single fluid path may exit the cylinder 1 at an earlier point, for example closer to a proximal end of the cylinder body 3. This may be for embodiments with blow holes 13 located more towards a proximal end of the cylinder body 3 and away from the first obstruction seen. In the cylinder 1 of Figure 1, an aspect of the lock mechanism is to have a distal end of a key (not shown) abut and longitudinally displace the external drivebar 23 so as to selectively engage the cam 19. However, this is optional and may not be implemented in other embodiments (some of which would not even comprise a drive bar). In this embodiment the channel 11 defined by the key aperture 5 comprises open geometry through to the external drivebar 23 so as to allow access for this abutment. Therefore in this embodiment, means to close this geometry in a bid to divert fluid directly out of the cylinder 3 may compromise this aspect of the lock's mechanism. Hence, the present blow hole 13 arrangement offers the most optimum means for expelling the fluid without compromise to the lock mechanism. It does so by virtue of its specific location utilising the fluid's dispersion upon impact with the first obstacle (external drivebar 23). This blow hole placement and its resultant effect is particularly beneficial as it complements the internal, existing geometry of common locks and does not implement means of artificially diverting the fluid which may close the channel 11. It is noted that in alternative embodiments alternative placement of the blow hole may be used, depending on the composition of the cylinder and / or lock. In other embodiments that do not require such access, or wherein the access is not critical to the lock's normal function, it is understood a blow hole 13 may extend from any longitudinal location along the channel 11 of the key aperture and form a passage / exit point to the exterior of the cylinder body 3. It is to be understood that the blow hole 13, in any embodiment, is not dependant on the dispersion of the fluid upon impact with a first obstacle. However, the blow hole 13 situated proximal to the cam 19, i.e. at the distal end of the cylinder body 3, may provide certain additional benefits. These may include ensuring that any tool used to inject the fluid into the cylinder 3 does not extend beyond the blow hole 13 nor does it deliver the fluid beyond the longitudinal point from where it can't be expelled effectively. Said location may also prevent a vandal from manually blocking the blow hole 13 prior to injecting the fluid. The injection tool may be a syringe (not shown). A third portion 29 of the fluid is also seen to continue through the centre opening of the external drivebar 23 with the injected fluid path / stream being undisturbed until it impacts a second, internal drivebar 31 located within the cam 19. Upon impact with the internal drivebar 31, the third portion 29 of the fluid, is directed downwards and out of a further aperture (not shown) inside the cam 19. This aperture may be an opening for the lug 21 or an additional blow hole (not shown). To prevent fluid ingress into the cam from this third portion 29 of the fluid, also seen in Figure 1 is a washer 15 placed within the cam 19 and around the perimeter of the internal drive bar 31. The internal drivebar 31 resides within the washer's 15 central aperture and the arrangement forms a seal against the injected fluid. This arrangement may be particularly beneficial for vandalism-resistant locks that require the protection of complicated cam-held mechanisms. For example, the internal drivebar 31 of Figure 1 may in normal use grant control of a cam 19 from an interior side of a fenestration and, like the external drivebar 23, may selectively engage with a cam 19. And in the case of a vandalising act on the (exterior) cylinder body 3 may be configured so as to translate forward and lock with the cam to gain exclusive control of the cam 19. The mechanism (not shown in detail) used to implement this functionality is held within the cam 19, comprises moving parts and therefore needs protecting from the injected fluid. Additionally, and although not shown, the washer 15 may be implemented within the cylinder body 3 or any other longitudinal position within the cylinder 1. The washer 15 may also be placed around the external drive bar 23 (or other components not identified by name but part of a cylinder's common architecture), in order to guide the fluid out of the cylinder 1 or prevent its ingress beyond the longitudinal point of the washer 15. It is also entirely possible in embodiments that do not utilise a blow hole 13 that all of the fluid injected into the cylinder 1 follows the path outlined by this third portion 29. In such instances, the washer 15 may still be used and its implementation into the cylinder 1 is not dependant on the presence of the blow hole 13. The cylinder 1 in such embodiments may simple seek to prevent water ingress beyond a critical point. The above described washer 15 arrangement in combination with the blow hole 13 can in one interpretation be seen to simply provide a secondary line of defence to the injected fluid in the event of a blow hole 13 not functioning as intended or as quickly as intended to expel the fluid. Although not seen in Figure 1, the cylinder body 3, or cam 19, can in other embodiments comprise second and third blow holes positioned at any angular offset from the first blow hole, and may specifically be positioned at 90 degrees offsets from the first blow hole 13 on either lateral side of the cylinder 1. All three holes may be longitudinally aligned so that they are proximal to the first obstacle in the channel 11. These additional blow holes located at 90 degrees offsets from the top blow hole may be particularly effective in expelling water that has pooled within the channel 11 or they may simply increase the rate of liquid expulsion by allowing further exit points out of the cylinder 3. Figure 1 also shows a spring clip 33 and a PVC cover 35. These may be optional features. Figure 2 is a simplified line drawing of a cylinder substantially similar to the cylinder of Figure 1 but without the fluid path being highlighted in the same manner. The same features discussed above are also seen in this Figure. Also shown are internal feature relating to the operation of the pins, and the cam, as well as features relating to the construction of the cylinder. It is noted that the blow hole and / or washer may be implemented in any suitable cylinder and / or lock. The implementation fo these features is not dependent on the specific construction of the cylinder. Any lock that has an open aperture (such as an aperture for a key) may be susceptible to this form of vandalism, and so the use of a blow hole to expel fluid, and / or a washer to prevent fluid from accessing certain internal portions of the cylinder may be advantageous in many other embodiments with different cylinders. Figure 3a shows a perspective view of a washer 15 encircling the internal driverbar 31 at a distance away from its proximal end so as to not affect the mechanism by which it engages with a distal end of the external driver bar 23. The washer may alternatively encircle any other feature within the cylinder such that fluid is prevented from reaching a portion beyond the washer. Figure 3b shows the internal drivebar 31 isolated from the rest of the cylinder 1 assembly. The internal driverbar 31 comprises first and second lugs so as to engage with recesses in the cam 19 and whereby the rotation of the internal driverbar 31 when the lugs are within the recesses allows for the rotation of the cam 19. Figure 3c shows a closer view of a washer 15. The washer seen is a soft washer 15, and may be formed of silicone or nylon. Although not seen in this Figure, the thickness of the washer may be between 0.5mm to 1mm. This thickness may allow the washer 15 to withstand the pressure / force of the injected fluid without displacing the washer off of the internal drivebar 31. The soft material of the washer 15 may also absorb some of this force and aid in diverting the fluid as well as providing a greater purchase on the surface of the internal drivebar 31. Once more, the arrangement seen in Figure 3a provides a seal against the injected fluid and prevents from progressing further into the cam 19. This seal may also be advantageous in maintaining the pressure of the fluid within the cam 19, whereby this pressure may be utilised in expelling the fluid more efficiently. Figure 4 shows a flowchart 40 of a method of overcoming a freeze attack. The first step 41 of which is receiving an injection of a first fluid into a lock or cylinder. A second step 42 is then ejecting at least a portion of the received fluid out of the lock via the blow hole. This method may optionally then comprise receiving a second fluid 43, wherein the second fluid is configured to cause the temperature of the first fluid to decrease and change state. In the event that the first fluid is water, the second fluid may be a fluid that freezes the water, such as a cleaning solvent. The second fluid may also be a temperature lower than 0 degrees Celsius to achieve the cooling / freezing capabilities (alternatively this temperature change may be achieved through other means such as a chemical reaction). Alternatively, the second fluid may be a curing solvent and the first fluid may be a type of glue such as a super glue. Whereby the addition of the curing agent is used to cure or harden the super glue, resulting in its expansion and / or solidification. This second fluid, or a portion of the second fluid, may be ejected in the same way the first fluid is 44 i.e. via the blow hole or blow holes. The ejection of the first fluid, or at least a portion of it, in the above described manner prevents a change of state of any remaining first fluid from fluid to solid. This prevents damage to the cylinder that may otherwise occur due to the expansion associated with such fluid to solid transition, i.e. the expansion of ice as it forms. This means that a cam 19 can be rotated freely regardless of the position of a locking pin 9 and / or drivebar 23. The method may further comprise a washer 15 preventing the fluid from entering the cam 19 and / or coming into contact within the moveable elements of the cam 19. The method may further comprise ejecting the first or the second fluid from multiple blow holes. Optionally these may be angularly offset from one another, and optionally these may be at the same longitudinal position as one another. One of the holes may be positioned at the top of the cylinder. Further the method may comprise ejecting the fluid out of the cam, or out of the cylinder body. This is dependent on where the blow hole(s) is positioned. An alternative or additional method may comprise receiving an injection of a first fluid into a lock or cylinder. A second step is then a washer preventing the fluid from accessing a pre-determined protected internal portion of the cylinder. This may for example comprise the portion of the cylinder that houses the cam. In this manner any damage to the cylinder may limited to portions of the cylinder that do not allow the vandal to access the cam, and so the vandal may be thwarted from changing the lock state of the lock, and accessing the inside of the building. These two methods may be used in combination with each other such that fluid (or a portion thereof) is ejected out of the blow hole, and the remainder is prevented from accessing protected internal portions of the cylinder. The above embodiments are to be understood as illustrative examples. Further embodiments are also envisaged. It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims. Clauses 1. A cylinder for a lock, wherein the cylinder is configured to reduce the prospect of a freeze attack being successful, the cylinder comprising: a cylinder body; a key aperture; an inner plug comprising one or more locking pins, wherein when the one or more locking pins are aligned with an edge of the inner plug, the inner plug is configured to be rotated freely within the cylinder; wherein the key aperture comprises a channel that extends to the one or more locking pins within the inner plug; and a blow hole, such that there is a continuous channel from within the key aperture to external of the cylinder via the blow hole. 2. The cylinder of clause 1, wherein the blow hole is positioned at the top of the cylinder, optionally wherein top refers to the part of the cylinder configured to be furthest from the ground during use. 3. The cylinder of clauses 1 or 2, further comprising a second blow hole. 4. The cylinder of clause 3, wherein the second blow hole is positioned so as to be angularly offset from the first blow hole, optionally wherein the angular offset is 90 degrees, and optionally wherein the first blow hole and second blow hole are aligned longitudinally. 5. The cylinder of any of the preceding clauses, wherein the cylinder comprises a proximal end, and the key aperture is situated at the proximal end, and a distal end, and wherein the blow hole is situated towards the distal end of the cylinder. 6. The cylinder of any of the preceding clauses, the cylinder further comprising a cam, wherein the cam is connected to the distal end of the cylinder body such that rotation of the inner plug leads to rotation of the cam, optionally wherein cam is provided with a lug which will interact with a lock in a door, such that rotation of the cam leads to the cylinder being transferred from a locked to unlocked state. 7. The cylinder of clause 6, wherein the blow hole is situated on the cylinder body adjacent the cam; or wherein the blow hole is situated on an outer surface of the cam. 8. The cylinder of any preceding clause, wherein the diameter of the blow hole is between 0.5mm and 3mm. 9. The cylinder of any preceding clause, wherein the continuous channel is configured such that fluid received into the key aperture is directed to exit the cylinder via the blow hole. 10. The cylinder of any preceding clause, further comprising a washer, optionally wherein the washer is situated within the cylinder body. 11. The cylinder of any preceding clause, the cylinder further comprising a drivebar, optionally wherein the drivebar forms an internal drivebar and an external drivebar, wherein the external drivebar is configured to be displaced by the insertion of a key within the key aperture, and wherein the internal drivebar is displaced by the external drivebar, and optionally wherein the displacement of the drivebar allows the cam to rotate. 12. The cylinder of any of clauses 9 or 10, wherein the washer has a central aperture. 13. The cylinder of clauses 9, 10 or 11, wherein the washer is a soft washer, optionally wherein the washer is formed from silicone or nylon. 14. The cylinder of any of clauses 9 to 13, wherein the washer has a thickness of between 0.5mm and 1mm. 15. The cylinder of any of clauses 9 to 14, when dependent on clause 10, wherein the washer is positioned around the drivebar, and optionally wherein drivebar is situated within the central aperture of the washer. 16. The cylinder of any of clauses 9 to 15, when dependent on claim 6, wherein the washer is situated within the cam. 17. The cylinder of any of clauses 9 to 16, wherein the washer is configured to prevent the ingress of fluid through the key aperture from passing into moveable elements of the cam; and / or wherein the cylinder further comprises a second cylinder body, optionally such that the cam is situated between the first cylinder body and the second cylinder body. 18. A cylinder for a lock, wherein the cylinder is configured to reduce the prospect of a freeze attack being successful, the cylinder comprising: a cylinder body; a key aperture; an inner plug comprising one or more locking pins, wherein when the one or more locking pins are aligned with an edge of the inner plug, the inner plug is configured to be rotated freely within the cylinder; wherein the key aperture comprises a channel that extends to the one or more locking pins within the inner plug; and further comprising a washer situated within the cylinder. 19. A lock comprising the cylinder of clauses 1-18, and further comprising a bolt, wherein the bolt is configured to be actuated by rotation of the inner plug of the cylinder. 20. A door comprising the lock of clause 19. 21. A method of overcoming a freeze attack, the method comprising the steps of: receiving an injection of a first fluid into a lock; ejecting at least a portion of the first fluid out of the lock via a blow hole. 22. The method of clause 21, further comprising receiving a second fluid, wherein the second fluid is configured to cause the temperature of the first fluid to decrease and change state; optionally wherein the method further comprises ejecting at least a portion of the second fluid out of the lock via the blow hole, optionally wherein the ejection of a portion of the first fluid prevents a change of state of any remaining first fluid from fluid to solid from damaging a cylinder such that a cam can be rotated freely regardless of the position of a locking pin and / or a drivebar. 23. The method of any of clauses 21 or 22, wherein the first fluid is water; and / or wherein the first fluid is an adhesive or glue, preferably wherein the first fluid is super glue; and / or wherein the second fluid is configured to be at a temperature lower than 0 degrees Celsius; and / or wherein the second fluid is a solvent, and optionally wherein the second fluid is a cleaning solvent. 24. The method of any of clauses 21 to 23, further comprising a washer preventing at least a portion of the first fluid from either: (i) entering the cam; or (ii) coming into contact with moveable elements within the cam. 25. The method of any of clauses 21 to 24, wherein the method is configured to be 5 performed by the cylinder of any of clauses 1-18. 21 10 25

Claims

1. A cylinder for a lock, wherein the cylinder is configured to reduce the prospect of a freeze attack being successful, the cylinder comprising:a cylinder body;5 a key aperture;an inner plug comprising one or more locking pins, wherein when the one or more locking pins are aligned with an edge of the inner plug, the inner plug is configured to be rotated freely within the cylinder;wherein the key aperture comprises a channel that extends to the one or10 more locking pins within the inner plug; anda blow hole, such that there is a continuous channel from within the key aperture to external of the cylinder via the blow hole;further comprising a cam, wherein the cam is connected to the cylinder body such that rotation of the inner plug leads to rotation of the cam;15 wherein the blow hole is situated on the cylinder body adjacent the cam; orwherein the blow hole is situated on an outer surface of the cam .

2. The cylinder of claim 1, wherein cam is provided with a lug which will interact with a lock in a door, such that rotation of the cam leads to the cylinder being transferred from a locked to unlocked state.0 3. The cylinder of claim any preceding claim, wherein the blow hole is positioned atthe top of the cylinder, optionally wherein top refers to the part of the cylinder configured to be furthest from the ground during use.

4. The cylinder of any preceding claim, further comprising a second blow hole.

5. The cylinder of claim 4, wherein the second blow hole is positioned so as to be 25 angularly offset from the first blow hole, optionally wherein the angular offset is 90 degrees, and optionally wherein the first blow hole and second blow hole are aligned longitudinally.

6. The cylinder of any preceding claim, wherein the diameter of the blow hole is between 0.5mm and 3mm.30 7. The cylinder of any preceding claim, further comprising a washer, optionallywherein the washer is situated within the cylinder body.

8. The cylinder of any preceding claim, the cylinder further comprising a drivebar, optionally wherein the drivebar forms an internal drivebar and an external drivebar, wherein the external drivebar is configured to be displaced by the insertion of a key21 10 25within the key aperture, and wherein the internal drivebar is displaced by the external drivebar, and optionally wherein the displacement of the drivebar allows the cam to rotate.

9. The cylinder of any of claims 7 or 8, wherein the washer has a central aperture.5 10. The cylinder of claims 7, 8 or 9, wherein the washer is a soft washer, optionallywherein the washer is formed from silicone or nylon.

11. The cylinder of any of claims 7 to 10, wherein the washer has a thickness of between 0.5mm and 1mm.

12. The cylinder of any of claims 7 to 11, when dependent on claim 8, wherein the 10 washer is positioned around the drivebar, and optionally wherein drivebar is situated within the central aperture of the washer.

13. The cylinder of any of claims 7 to 12, when dependent on claim 4, wherein the washer is situated within the cam.

14. The cylinder of any of claims 7 to 13, wherein the washer is configured to15 prevent the ingress of fluid through the key aperture from passing into moveable elements of the cam; and / orwherein the cylinder further comprises a second cylinder body, optionally such that the cam is situated between the first cylinder body and the second cylinder body.20 15. A lock comprising the cylinder of claims 1-14, and further comprising a bolt,wherein the bolt is configured to be actuated by rotation of the inner plug of the cylinder.

16. A door comprising the lock of claim 15.

Images