AU784686B2 - A key cylinder - Google Patents

Description

17-04-02 19:49 P0 P. 04 A1191TRAI.A PATENTS ACT 199(0 COM PL.EFE SiI-' C 1.1 [ICATION Applicant: StiR ITE PIY L'I'D AC'N 0-53229 252 1IiVeCT1OI1 Title: A Key Cylinder Address for servicce Suritc Pty Ltd PO Box 207 North Shore VIC 3214 Thie following 5tutemnii is at full description of this invention, including the best micthod of porfornmig it known. to the applicant(s): 17-04-02 19:49 A Key Cylinder The present invention relates to a key cylinder comprising of a case, padlock body, lock housing or the like within which a movable barrel or plug that is an assembly is mounted.

s Many key cylinders employ a barrel rotatably mounted in a casing or housing and tumblers that interlock the barrel with the casing until a suitable key passed into a keyway repositions the tumblers and voids their interlocking effect upon the barrel relative to the casing. A barrel is commonly manufactured by broaching a keyway into a single piece of material and forming holes or cavities in the material to accommodate tumblers accessible to a key passed into the keyway. Some barrels have been manufactured in two halves a first side of the keyway was milled into one half and a second side of the keyway was milled into the other half but this practice was discontinued as improved technology enabled improvements in the making of broaches and broaching machines to form keyways.

An objective of the present invention is to enable different materials to be employed in the manufacture of a key barrel to improve the resistance of the resulting product to drilling and forcing attacks. A common problem with bifurcated barrels such as those referred to above is a tendency for a key to wedge the halves apart as it was turned to drive a locking device, a difficulty users of the present invention can resolve. In addition, by employing different relative offsets of members of a barrel for a key cylinder according to the present invention the keyway profile defined by the members may be altered. One or more of the members can be rearranged or disposed differently to form a keyway having a different cross section whereby, a small number of components can be readily adapted to form a relatively large number of different keyways. By such means, significant economies during manufacture and in the holding of inventory can be achieved and/or the variety of products available from an inventory can be increased. A further objective is to enable the key combination and/or the keyway profile of a barrel to be altered when a key cylinder is in service by enabling removal and replacement of one or more of the members comprising the barrel.

And the present invention enables the forming of keyways that are closed to the perimeter of the barrel whereby, a part or the whole of the base of a key blade Page 1 A Key Cylinder r.qn h. P mplny.d .q q r .i.tr fnr the mqkinn of c.nmhinqtinn hittin.c. in thA ky to suit the tumblers mounted in the barrel.

In its broadest form the present invention provides a key cylinder comprising of a s case, body, housing or the like having an aperture, cavity or opening formed in it to receive a barrel, plug or other support means for the mounting of at least a part of at least one key operated tumbler mechanism, including at least one tumbler that can enable a releasable interlocking between the barrel and the case; wherein, the longitudinal axis of the barrel extends in substantially the same io direction as the longitudinal axis of the aperture and the barrel is reversibly rotatable about a pivot axis that extends in the general direction of its longitudinal axis and/or it is reversibly slidable in that general direction; wherein, the barrel is an assembly of at least two members that in combination define a major part of a keyway that extends within the barrel in said general direction; wherein, at least one tumbler is mounted in a hole, aperture, recess, groove, cavity or other S chamber wholly formed in a first member of the barrel and is accessible from the keyway whereby, a suitable key presented in the keyway can affect the disposition of the tumbler sufficiently to facilitate a release of the interlocking between the barrel and the case; and wherein, at least two junctions between •ill respective adjacent or abutting surfaces of the first member and at least one 0 other member of the barrel assembly extend in said general direction and a portion of the periphery of each of the at least two members form respective portions of the circumference or perimeter of the barrel.

A key cylinder according to the present invention can include tumblers of the same or different generic types, for example, sliding tumblers may engage a portion of a key blade and rotatable tumblers may engage the same or a different portion of the key blade. As a matter of convenience the following description will primarily refer to conventional pin tumbler stacks comprising a primary or bottom pin mounted in a chamber formed in a cylindrical barrel and at least one secondary pin mounted in a gallery formed in a case within which the barrel is rotatable, the secondary pin(s) being driven toward the barrel by helical compression spring(s). This type of tumbler assembly is widely known and its principles of operation are well understood reference to it is intended to simplify Page 2 17-04-02 19:50 P.07 A Key Cylinder and enhance the clarity of the following description and it is to be understood that reference to it does not narrow the scope of the present invention. It is also convenient to relate description of a key cylinder according to the present invention with reference to a three axis coordinate system for which it is s appropriate to designate the axes as being vertical, lateral and longitudinal wherein, the longitudinal axis extends in said general direction and the chamber(s) and at least one of the pin tumblers is orientated so that their respective longitudinal axes extend in a vertical direction. Even so, some key operated pin tumbler mechanisms are disposed axially in a key cylinder and extend and travel longitudinally in its barrel; other mechanisms have tumblers disposed to one or both lateral sides of a keyway and/or the barrel is able to slide longitudinally the present invention can be applied to any of these.

In some preferred forms of the present invention, a barrel comprises two members, each of which has a semicircular cross section. An upper vertical portion of a keyway is machined or otherwise formed in a first member and the remainder of the keyway cross section or profile is formed in the second member.

When the barrel is assembled, complimentary portions of respective members are brought into an adjacency or abutment with each other and in combination they form a more or less cylindrical rod or bar wherein, respective portions of the keyway define a complete keyway profile. In some embodiments, the keyway profile so formed can be varied by reversing the longitudinal disposition of one or both of the members and/or by altering the lateral disposition of the first member with respect to the second member, or vice versa. For example, a simple keyway can be formed by milling slots into two members and assembling them so that the abutting slots form a rectangular keyway into which a number of keys may pass.

A number of different keyways can be formed by varying the lateral disposition of the members so that the slot in one member is offset to a greater or a lesser extent with respect to the slot in the other member. Employing members that .io have a semicircular cross section enables economical use of material, however, some materials cannot be produced in that shape and suitable square, rectangular or other shaped materials may be used. Machining of the assembled members may be necessary to form a cylindrical barrel, for example, and members with almost any shape can be assembled, then machined together so Page 3 r 17-04-02 19:51 P.08 A Key Cylinder that the finished barrel meets exacting dimensions. In other preferred forms of the present invention, there are more than two members and users of the present invention may choose the most desirable number of members to suit their purposes. However, advantage is derivable from the present invention by minimising the number of members and configuring each member so that the greatest number of different keyways can be achieved when assembling the members together to form a barrel.

In a number of preferred forms of the present invention the extents of the cross sectional area of a second member approximates the finished size of the barrel and a first member is accommodated within an aperture, groove or other suitable opening formed in the second member. For example, a cylindrical steel second member has a groove extending from its pivot axis to its circumference in a vertical direction within which a brass or steel first member containing a number I of chambers can be received. When the first member is a cylindrical member, it can be rotated within the first member to form different keyway profiles. A set screw in the second member may enable the first member to be secured into one of a number of different positions either during manufacture, during installation of the key mechanism or at some later time. In other embodiments, the first member may be generally cylindrical or rectangular in shape and mounted to the second member such that when a suitable key or other tool is introduced into the keyway a release of an interlocking between the first and second members whereby, the first member can be removed from the key cylinder. At least one of the tumblers can be replaced by a different tumbler to cause the original service key to be made incompatible with the key cylinder and/or the original first member can be replaced with a different but interchangeable first member causing an alteration of the key profile of the key cylinder.

A number of advantages can be derived from the present invention. A barrel can :io be manufactured by assembling members made from otherwise incompatible materials. For example, brass can be readily broached with relatively small and complex shapes whereas the same process when applied to steel or stainless steel is likely to result in an unacceptably high failure rate. The present invention enables simpler shapes to be formed in individual members that are then used in Page 4 17-04-02 19:52 P.09 A Key Cylinder combination to form relatively complex keyway profiles, enabling a wider range of materials to be employed in a key cylinder. A further advantage is that a keyway profile can be wholly contained within the cross sectional area of a barrel, without necessitating that a part of the keyway is open at the periphery of the barrel to s facilitate access for a broaching tool during manufacture, for example.

Accordingly, a keyway can be manufactured without a register groove or shoulder because the bottom of a suitable key can register against the bottom of the keyway, thereby enabling more or at least a different freedom to be made available in the design of keyway profiles. A closed keyway also enables users of the present invention to employ the base of the keyway as a register for the blade of a key instead of employing a register groove or shoulder for the purpose. As the majority of key cutting machines position a key to be bitted by locating its base of the key blade against a stop, more accurate keys can be produced by employing the base of the key blade to register the key within a keyway. Still is further advantage is available from the present invention by enabling the ready provision of a control ledge within the keyway against which the ends of the primary tumblers can abut or almost abut, thereby reducing access to the tumblers and making manipulation of the tumblers by picks or other tools more difficult. Forming a suitable control ledge in a broached keyway profile can cause problems in manufacture, including relatively high failure rates and tool breakage and for these reasons most barrels with broached keyways do not include a control ledge. In a number of preferred forms of the present invention disposition of the chamber(s) formed in the first member is such that the longitudinal axis of the tumbler(s) is near or at perpendicularity with respect to the junction(s) between the members or substantially perpendicular to a tangent at a point adjacent to the intersection between a chamber and a junction. When a key interacts with the primary tumbler(s) to operate a key mechanism and the key is used to move the barrel within its case, forces act against the lateral sides of the keyway and the chamber(s) which would tend to separate respective members should the junction between them be nearly parallel to the vertical axis of the keyway and/or the longitudinal axis of the chambers. This 'wedging' effect may be sufficient to cause separation of the members whereby, the tumbler(s) would become misaligned andlor the barrel to jam within its case, rendering the key mechanism inoperable. This wedging effect can also occur in key barrels that Page 17-04-02 19:53 A Key Cylinder have a keyway open at the periphery of the barrel. For example, a key that operates a pin tumbler key mechanism has bittings on a vertical edge of its blade adjacent to the tumblers and the junctions between the first member and the other member(s) of the barrel extend laterally of the keyway into which the key s blade is passed. Should a junction intersect with the chambers then the force applied to the key to rotate the barrel would tend to dislocate the member(s) and the size of the chambers would be enlarged causing operation of the key mechanism to be adversely affected. The present invention resolves this difficulty by requiring that the part of the key blade that has bittings is received in the jo portion of the keyway that intersects with the chamber(s) formed within the first member whereby, lateral movement available to the key within the barrel is substantially reduced and the force applied to the key to drive the barrel is transferred primarily to the first member. A significant economic advantage is derivable by enabling users of the present invention to form commercially viable is keyways by making relatively small adjustments to the dispositions of the members during assembly of a barrel without necessitating the inclusion of additional components to the barrel. Users of the present invention are able to readily manufacture relatively long barrels because respective parts of a keyway can be reliably extruded, milled or broached over a greater length in respective members than could otherwise be broached into cylindrical material, for example, and it is practical to manufacture key cylinders containing a larger number of tumblers with significantly larger numbers of potential bitting combinations.

In many forms of the present invention the at least two members when assembled together comprise substantially the whole of the barrel, however, this need not be the case. For example, a first member may have a relatively narrow rectangular cross section into which chambers for tumblers are drilled and into which a part of a keyway profile is formed and a second member has a semicircular cross section into which the remainder of the keyway profile is formed. Three basic altematives are available when manufacturing a cylindrical barrel using these members firstly, to introduce a third and fourth members that have quadrant like cross sections to be located at the lateral sides of the first member secondly, to increase the size of the rectangular member so that it can be machined back to a desirable size or thirdly, to introduce a bonding agent or Page 6 r. cl 17-04-02 19:53 P.11 A Key Cylinder bondable material suitable to form a part of the structure of the barrel. It will be readily understood that the present invention enables the casting and moulding of one or more of the members comprising a barrel because relatively simple portions of a keyway profile can be combined to form a more or less complex whole. While a bonding agent or a bondable material may form a minor part of keyway profile, it may be desired that the majority of the keyway portions and the tumbler chambers are contained in the at least two members which are of sufficient robustness to give the resulting barrel a structural strength and integrity that bonding may be unable to offer. While the at least two members may contain grooves, shoulders and like respective interlocking configurations along their joining faces or edges to assist in maintaining their dispositions in the assembled barrel, it may be more economical to use a suitable industrial adhesive to bond the members including recesses and apertures to improve the bonding if necessary. Some materials can be sweated together, brazed or soldered and in a number of preferred forms of the present invention, the members are assembled using sleeves and/or end caps to maintain their positions and alignments within the barrel. In some particularly preferred embodiments, common ends of the members are machined to become a friction fit within a sleeve or an end cap that also serves as a forend for the barrel. When a cap is manufactured from steel and hardened it can also offer drill resistance to the barrel and/or it can be configured to accommodate a profile plate between the adjacent ends of the members and the underside of the cap. Where a profile plate is included within a cap its cross section can be the same as or more restrictive than the profile of the keyway within the barrel. A keyway may be able to receive a number of suitable keys and the introduction of a profile plate may restrict the suitability of the barrel to receive only one key from that number when a different profile plate is installed with the cap the barrel may allow only one or two different keys to pass into the barrel, for example. Whether or not a forend cap is installed, the opposite end of a barrel can have a cap installed that contains a suitable helical thread engageable with a thread formed in that end of the barrel. This cap serves to maintain the members in a proper alignment and can also serve to prevent the barrel from being forced from its case along its longitudinal axis. It can also enable different cams, connecting bars and the like to be mounted to the barrel so that motion of a suitable key is transferred to a locking device, for example. Alternatively, Page 7 17-04-02 19:54 P.12 A Key Cylinder commercially available circlips, sleeves, pins, rivets and other fasteners can be employed to maintain the members in a proper assembled alignment and users of the present invention may choose to employ any combination of the foregoing methods or devise methods and/or components, compounds or adhesives of their own for the purpose. It is not a requirement of the present invention that there is an absence of movement between the members, however, in practice it is usually desirable that any movement that is available between the members is confined to predetermined limits.

io When there is more than one tumbler mounted in a barrel, any tumbler may be a part of the same or a different set or series of tumblers. For example, a key cylinder may accommodate six conventional pin tumbler stacks disposed in a longitudinally extending series within the barrel and its case; each stack extending in a vertical direction. The key cylinder may also include a different tumbler stack or series of stacks that extend in a different direction and are accessible from the same or a different part of the keyway. Interaction between the lateral side(s) and/or bottom of the key and the different tumbler(s) may be necessary to move the barrel relative to its case or the function of one or more of the tumbler(s) may be to increase the complexity of a suitable key rather than to cause further interlocking between the barrel and its case. A key may contain a number of different series of bittings and while there are some practical limitations it is not uncommon for keys to have two, three or four bitting series that interact with respective different series of tumblers mounted in a barrel. Some tumblers may interact with a side bar or the like instead of secondary tumblers.

It is common industry practice to disassemble a barrel from its case and replace it with a barrel compatible with the cylinder case but having a different keyway broached into it. In some preferred forms of the present invention a barrel can be manufactured so that at least one of its members can be disassembled from the barrel by an operator and replaced by a different suitable member. In this way the keyway of a key barrel can be altered sufficiently to necessitate the use of a different key to access the primary tumblers without removing the whole of the barrel from its case or disassembling the key cylinder. For example, a member containing a part or the whole of a lower portion of keyway may be assembled to PaRgc 17-04-02 19:55 P.13 A Key Cylinder the other member(s) in the barrel by radially or vertically extending metal thread screws, whereby when the barrel is moved to a predetermined position in its case removal of one or more of the screws can enable the member to be removed from the remainder of the barrel and replaced by a different but interchangeable s member. The different member may necessitate the use of a different key to pass the changed keyway profile and depending upon the configuration of the different member the original key may or may not be allowed to pass the changed keyway profile. This form of the present invention readily Tends itself to profile master keying and it is relatively economical both in terms of the material cost in introducing a different keyway to a barrel and a reduction in the time taken by service personnel to complete the task.

As indicated above, the manufacture of the at least two members can include standard commercial methods and processes of producing components for key cylinders and also enables users of the present invention to access a greater range of options when selecting materials and manufacturing procedures. Even so, brass, steel and stainless steel are common materials employed in the manufacture of key cylinders and locks for a variety reasons including corrosion resistance and commercial economies. These materials are particularly suitable for manufacturing the members, the casing or housing and other components, however, users of the present invention also have additional options for the use of 'soft' materials such as plastics and aluminium without necessarily compromising the security or durability of the resulting key cylinder.

Brief Description of Drawings In order that the present invention may be understood in more detail, description is now directed to the accompanying drawings. The particularity of those drawings and the associated description does not supersede the generality of the preceding broad description of the present invention.

Page 9 17-04-02 19:5fi P.14 A Key Cylinder In the drawings: Figure 1 is an exploded isometric view of a barrel for a key cylinder according to the present invention comprising two members of semicircular cross section; Figure 2 is an isometric view of a barrel for a key cylinder according to the present invention comprising two cylindrical members; Figure 3 is an isometric view of a barrel for a key cylinder according to the present invention comprising of two separable cylindrical members; Figure 4 is a cross sectional view of a key cylinder according to the present invention including a barrel comprising of three members.

ii In Figure 1 a barrel 100 for a key cylinder according to the present invention is shown to comprise a first member 101 and a second member 102 having respective 'flat' mating surfaces 116 (hidden from view) and 117. A portion 1 10 of a keyway is formed in member 10 1 and another portion 111 of the keyway is formed in member 102. When mating faces 116 and 117 abut one another, portions 110 and I111 in combination define a substantially complete keyway profile. There may be one or more small gaps between parts of mating surfaces 1 16 and 117, however, the resulting keyway can serve its intended purpose for guiding and supporting a key that it able to pass into it. If an industrial adhesive were used to bond members 101 and 102 together, two relatively small portions of the perimeter of the keyway profile would be defined by the presence of the adhesive. While it is usually desirable that a keyway is defined by durable material, the selection of materials for the composition of members 101 and 102 is a matter left to the discretion of the users of the present invention, as is the choice of a desirable bonding material and the extent to which it may define part(s) of a keyway. Member 102 is shown to have through or blind holes I 078 and 1 07b formed in it to receive fasteners, locating pins or stumps or the like that can be aligned with blind holes (not shown) in member 101 whereby, members 101 and 102 can be maintained in a more or less constant alignment and/or for fastening members 101 and 102 together. Although not shown, mating surfaces Page 17-04-02 19:56 A Key Cylinder 116 and 117 may have grooves, shoulders, recesses, protrusions formed in them or be configured otherwise to aid their alignment and to limit available movement (if any) between members 101 and 102.

Chambers 103a to 103g formed in member 101 intersect with portion 110, enabling a part of the blade of a suitable key that occupies portion 110 to interact with any tumblers that may be mounted to chambers 103a to 103g. Portion 111 comprises a relatively narrow groove 114 and broader shallower groove 115 that are shown to extend longitudinally within member 102 for the whole of its length, o1 however, grooves 114 and 115 may be somewhat shorter than the full length of member.102. And the oblique 'halves' 112 and 113 of portion 110 may extend less than the full length of member 101. Respective ends 104a and 104b of members 101 and 102 may be considered to define the mouth of the keyway in barrel 100. Alternatively, respective ends 105a and 105b may define the mouth of the keyway, in which case the profile of the keyway would be the reverse of the keyway presented at ends 104a and 104b. If either groove 114 or 115 stopped short of end 105b then a part of a key presented into portion 111 may need to have a different profile if it is to pass that part of the keyway. Similarly, if either of halves 112 or 113 stopped short of end 105a then a part of the key profile may need to be differently shaped to be fully received into portion 110. It is a feature of the present invention that the cross section of the keyway contained within barrel 100 may be different at some points along its length than it is at others. Further alterations in the keyway profile are available by reversing the longitudinal orientation of member 101 with respect to member 102 and/or by altering the lateral disposition of member 101 with respect to member 102. Variations in the relative lateral disposition of members 101 and 102 can also affect the manner in which said primary tumblers interact with a key presented in thekeyway and can also alter the performance characteristics of a key mechanism. If member 101 is moved laterally to the right (as drawn) then the ends of the tumblers will be further protected by the control ledge in the form of the base of groove 115. Whereas, moving member 101 to the left would align the ends of the tumblers toward groove 114, making them more accessible to manipulation tools, for example, but by moving member 101 further leftwards the intersecting edges of groove 114 and face 116 would begin to'act as a control ledge. Further variations may be Page 11 17-04-02 19:57 P.16 A Key Cylinder introduced by varying the manufacture of members 101 and 102 and additional members used in combination with either of them to form a different barrel 100.

By removing at least a part of face 116, for example, a third member may be introduced between the remaining part of face 116 and a respective part of face 117. This third member may be relatively thin length of material that extends beyond adjoining edges of face 116 and groove 114, for example, and necessitates a groove be formed in the blade of a suitable key if it is to pass into the keyway thus formed in barrel 100. The presence of the third member may prevent a flat key or other material being passed into barrel 100 and the presence 1o of a third member at the left hand side (as drawn) of portion 111 could also serve to make access to tumblers mounted in chambers 103a to 103g significantly more difficult, other by using a proper key. A third and/or other additional members may form a greater or lesser portion of the keyway and can be individually configured so that interchangeable members can introduce selectable alterations to the keyway profile.

Ends 105a and 105b have respective reduced portions 106a and 106b that are of similar dimension to the aperture 109 formed in sleeve 108. Reduced portions 106a and 106b may be plain surfaces as shown enabling them to become a friction fit within sleeve 108 or in combination a helical thread may be formed in them for engagement with a suitable thread formed within sleeve 108.

Alternatively, sleeve 108 may be a more or less loose fit in relation to combined reduced portions 106a and 106b and sleeve 108 may be held in place by an industrial adhesive, a transverse pin, a portion of the wall of sleeve 108 press formed into a suitable recess in reduced portion 106a or by any other suitable means. By reducing the combined diameter of ends 104a and 104b, sleeve 108 may be mounted to the opposite end of barrel 100 and it may have a blind end, thereby capping a respective end of barrel 100. As drawn, sleeve 108 is shown to be of a constant diameter and of a size approximating the combined dimensions of members 101 and 102, but sleeve 108 can be of any size thought desirable by users of the present invention. A cap installed adjacent to ends 104a and 104b may have a rectangular opening in its blind end to allow a key to pass into barrel 100. An annular shoulder (not shown) may prevent barrel 100 passing through an aperture in a case suitable for mounting barrel 100 because it would be end Page 12 17-04-02 19:58 P.17 A Key Cylinder stopped by the larger diameter of the shoulder on the cap abutting a part of the case. A profile plate may also be installed between the cap and ends 104a and 104b further restricting the keys that can pass into barrel 100 by installing different profile plates the same cap and members 101 and 102 may be used to s assemble a wide variety of different keyways for barrel 100. To improve security the cap or sleeve may be extended to include the positions of chambers 103a and 103b whereby, the respective secondary tumblers at these two positions in a pin tumbler mechanism, for example, could help to prevent sleeve 108 or a cap being withdrawn from the front of barrel 100 or to deter the forcing of members 0o 101 and/or 102 from the sleeve 108 or a cap. A helical thread within sleeve 108 or a cap that is of larger diameter than the combined size of members 101 and 102 could act to prevent barrel 100 assembly from being pulled from its cylinder case. Employing a larger diameter sleeve or cap at both ends of barrel 100 may prevent it being withdrawn from its case in either direction, limiting interference is with the barrel by authorised or unauthorised operators and enabling users of the present invention to enhance the security of a key cylinder by having an option to make a factory seal a part of a key mechanism. In these embodiments, facility can be made for service personal to combinate and/or master key a sufficient number of the tumblers in a key mechanism without removing barrel 100 from its case.

In addition to a first series of primary tumblers that may occupy holes 103a to 103g formed in member 101, chambers for a different series of tumblers may be formed in member 102 so that chambers intersect with groove 114 to enable an additional interlocking between barrel 100 and its cylinder case, independently of the interlocking of the tumblers mounted in chambers 103a to 103g. This different series may comprise one or more primary tumblers and respective secondary tumblers that would occupy a different series of galleries formed in the cylinder case. A suitable key may contain a respective different series of bittings and one or all of the different series of tumblers may interact with respective parts of the key profile. The presence of at least one different series in barrel 100 may increase the security and the utility of the key cylinder by providing additional key bitting combinations.

Page 13 7C~-T 7 17-04-02 19:59 P.18 A Key Cylinder In Figure 2 a barrel 200 for a key cylinder according to the present invention is shown to comprise a first member 201 having a longitudinally extending cylindrical groove 210 formed in it that accommodates a cylindrical second member 202 that has a series of chambers 203a to 203f formed in it. Member 201 has a longitudinally extending polygonal groove 205 formed in it that intersects with groove 210. Member 202 has a polygonal groove 207 extending longitudinally within it that intersects with chambers 203a to 203f whereby, primary tumblers mounted in chambers 203a to 203f may interact with the portion of the blade of suitable key presented within groove 207. In polygonal groove 207 and polygonal groove 205 define and form a keyway 211 that extends in said general direction when barrel 200 is mounted into a casing or housing. As drawn, the left side of groove 207 and the left side of groove 205 are shown to be substantially in alignment and portion 209 of groove 205 is shown to act as a control ledge with respect to the primary tumblers that may be mounted within Is member 202. The relieved portion 208 of groove 207 enables a key blade to be shaped to facilitate its engagement with the primary tumblers. Member 202 is rotatable within groove 210 whereby, an operator is able to modify the cross section of the keyway formed by altering the relative disposition of grooves 205 and 207 by rotating member 202 clockwise or anticlockwise. If member 202 is rotated clockwise then the left side of groove 205 would no longer be aligned with the left side of groove 207 but the intersection between the left side of groove 205 and groove 210 may act as a control ledge for the primary tumblers mounted in member 202 and portion 209 would cease to act as a control ledge because it would be substantially aligned with relieved portion 208. The keyway profile and its functionality may be altered by rotating member 202 within member 201 to a greater or to a lesser degree whereby, the profile of key suitable to pass the keyway resulting from the changed disposition of groove 205 with respect to groove 207 is necessarily altered. The position of member 202 within member 201 is able to be maintained by employing a pin, set screw or other suitable means to enable a permanent or releasable engagement between member 201 and member 202. Within groove 205 a chamber 206 is shown to intersect with the left side of groove 205 to enable a primary tumbler of a different series to be mounted within member 201 and there may be more than one chamber similar to Page 14 17-04-02 19:59 P.19 A Key Cylinder chamber 206 and/or chambers suitable for mounting tumblers other than pin tumblers.

Figure 3 shows a barrel 300 for a key cylinder according to the present invention comprising a first member 302 and a second member 308. An upper portion 305 of keyway 303 (as drawn) is formed in first member 302 and a lower portion 304 of keyway 303 is formed in second member 308. Chambers 306a to 306f are formed in first member 302 and intersect with upper portion 305 whereby, the bittings of a key blade that can pass into upper portion 305 is able to interact with lo at least one of the tumblers (not shown) that may be accommodated in chambers 306a to 306f. Second member 308 has a transverse hole 307 formed in it that intersects with cavity 309 within which first member 302 is mounted. Hole 307 (as drawn) may be aligned with a transverse hole or cavity (not shown) formed in first member 302 whereby, tumblers mounted in hole 307 and said aligned hole can is establish a releasable interlocking between first member 302 and second member 308. To release such interlocking a special key and/or tool may be passed into keyway 303 to suitably displace the tumblers so as to allow first member 302 to be moved independently of second member 308. Alternatively, hole 307 may be positioned so that it can be aligned with a transverse groove formed in member 302 near the base of upper portion 305. A leaf spring or spring wire mounted within hole 307 may be partially accommodated within said shallow groove, retaining first member 302 within cavity 309. In a further alternative, a more permanent securing of first member 302 within cavity 309 may be established by crimping the uppermost edges of cavity 309 (as drawn) so that first member becomes a friction fit within cavity 309 a bonding agent may be employed instead of or in addition to the crimping of the edges of cavity 309. A number of options are available to users of the present invention when restricting movement available to first member 302 within cavity 309 and selection of the most appropriate option will depend to some degree upon the desired permanency of the mounting of first member 302 within second member 308. As drawn, the vertical axes of portions 304 and 305 are in the same alignment, however, first member 302 may be rotated relative to second member 308 to form a different keyway profile. In this way, a number of different keyways 303 may be formed by altering the disposition of member 302 relative to second member 308.

Page '~si.

17-04-02 20:00 I A Key Cylinder In a number of preferred embodiments, first member 302 is removable from second member 308 when the key cylinder with which they are employed is in service, without necessitating the dismounting a majority of the key cylinder from the locking mechanism it drives. During operation with a change key, first member 302 and second member 308 may move substantially in unison with little, if any, loss of (rotary) motion between them. This change key would only interact with one or more of the tumblers mounted in chambers 306a to 306f and would not affect a releasable interlocking between first member 302 and second to member 308. To remove first member 302 from barrel 300, a service key having similar bitting to a change key would be of a greater length or it could be employed with a tool to enable simultaneous release of the interlocking established between barrel 300 and its casing or housing by the tumblers in chambers 306a to 306f and the tumblers, spring or other mechanism mounted in is hole 307. When barrel 300 is rotated say, 90 degrees, within its casing or housing, first member may be removed from cavity 309 by drawing the service key and/or tool outwardly of barrel 300, contact between at least one of the tumblers mounted in chambers 306a to 306f and respective bitting(s) in key blade may facilitate the driving of first member 302 by the key. When first member 302 is removed from barrel 300, one or more of the tumblers accommodated in chambers 306a to 306f can be removed and replaced by a different tumbler thereby, necessitating the use of a key having a new combination of bittings to operate the key cylinder when first member is reassembled to barrel 300. In addition or alternatively, the same tumblers may be transferred to a different first member that may be received into cavity 309 to form a barrel 300 that has a different upper portion 305 thereby, precluding passage of the original key(s) into keyway 303. This arrangement has an advantage in avoiding a necessity to dismantle parts of a lock to enable recombination of a key cylinder and/or to change the profile of keys that may operate the key cylinder. It might be thought that 'removable core' cylinders achieve the same result, however, the present invention is more economical and may be employed with a wider range of existing key cylinders and locks.

Page 16 a i -77777 7- 7 17-04-02 20:01 P.21 A Key Cylinder For the sake of clarity, neither first member 302 nor second member 308 is shown to have a flange to prevent 'shimming' of a key cylinder, to limit longitudinal movement of first member 302 through cavity 309 and to limit movement of barrel 300 within its casing or housing. When in use, it is preferred s that at least first member 302 has a flange to prevent its passing right through cavity 309 and to prevent barrel 300 from passing right through its casing or housing. The provision of a flange may be achieved by machining first member 302 (and second member 308) from material of a larger dimension. Or, by fastening a cap and/or a plate like component or assembly to cover a longitudinal to face of barrel 300 a flange like function can be performed by the plate or cap. In addition, second member 308 would have a cam plate or other arrangement to enable drive to be transferred from cylinder assembly 300 to a locking mechanism and to retain cylinder assembly 300 within its casing or housing. To assist in securing first member 302 within cavity 309, a friction fit or threaded is fastener can be introduced into the junction between them. The fastener may be installed at the face of barrel 300 or inserted into a side of keyway 303 and it may project some way into keyway 303 to form a part of the keyway profile.

First member 302 is shown as a generally cylindrical component, but it may have a square, rectangular or other polygonal cross section. Cavity 309 may be altered to compliment the cross section of first member 302 and a rectangular first member 302 may be accommodated within a longitudinal slot cavity 309 formed simultaneously with the forming of portion 304 into second member 308. Portions 304 and 305 may be wholly formed by milling, drilling or broaching respective 2. members 302 and 308, or portions 304 and 305 may be formed by a combination of machining and broaching processes. An advantage to users of the present invention is enabling the partial formation of keyway 303 to which further complexity may be added by additional machining or broaching and which can be further altered by selective positioning of first member 302 relative to second member 308. Greater utility is obtainable from tooling in these ways and increased numbers of different products can be assembled from a limited inventory. To achieve improved security, first member 302 may be manufactured from steel or other material, which could then be hardened to offer drilling resistance to a vital area of a key cylinder. A hardened first member 302 may also Pago 17 17-04-02 20:02 P.22 A Key Cylinder offer increased protection to the tumblers in chambers 306a to 306f and limit the effectiveness of an attack on the casing or housing into which barrel 300 is mounted.

In Figure 4 a cross sectional view of a key cylinder 400 according to the present s invention is shown to comprise a casing or housing 404 within which a gallery 402 is formed to accommodate a secondary tumbler (not shown) of a pin tumbler stack and an opening 401 within which a barrel 410 is mounted. Barrel 410 comprises a first member 412, a second member 411 and a third member 413. A chamber 414 formed in first member 412 can accommodate a primary tumbler of a pin tumbler stack that is accessible from portion 415 of keyway 417 formed in first member 412. Portion 416 of keyway 417 is defined by the adjacent parts of the respective peripheries of second member 411 and third member 413. A profile tumbler 420 is accommodated in a gallery 403 and a chamber 421 that is accessible from portion 416 of keyway 417. A suitable key can pass within 1 s keyway 417 and affect the relative disposition of said primary tumbler and profile tumbler 420. When barrel 410 is rotated by the key the edge(s) of gallery 403 would have a camming effect upon profile tumbler 420 driving it further into chamber 421 and encroaching upon a part of portion 416, necessitating that the blade of the key has a bitting to receive profile tumbler 420 to allow barrel 410 to be rotated further. The diameter of chamber 414 is reduced near the edge of first member 412 that is adjacent to member 411 whereby, a tumbler is prevented from passing through first member 412. However, this need not be the case, a tumbler may be able to pass through first member 4t2. but its travel into keyway 417 limited by an abutting edge of third member 413. Or, travel of the tumbler may be limited by contact with an abutting edge of second member 411. When a key is employed to drive barrel 410, there would be a tendency for the key blade to force second member 402 and third member 403 apart. While this may not adversely affect the interaction of the key blade with said primary tumbler such 'wedging' effect might cause undesirable friction between barrel 410 and casing 404. This difficulty is shown to have been resolved by installing dowel pin 430 to fix the juxtaposition of first member 412 in relation to second member 411 and installing dowel pin 431 to fix the juxtaposition of first member 412 in relation to third member 413. Alternatively, dowel pins 430 and 431 might be replaced by Page 18 t- 17-04-02 20:02 P.23 A Key Cylinder sheet metal ribs inserted into linear grooves formed in the member. Another alternative may be to obviate the need for third member 413 by a sufficient extension of second member 411, however, the manufacture of portion 416 would then present an increased difficulty. In a further alternative or an industrial s adhesive or other bonding agent may be employed to fix members 412, 411 and 413 in a desired dispositional relationship. In addition or in a further altemative, the size of first member 412 may be increased so that the size of portion 415 is increased whereby, restriction of movement of a key depends significantly less upon the presence of either second member 411 or third member 413.

to In common with a number of other embodiments of the present invention, keyway 417 is not open at the periphery of barrel 410. Keyway 417 does have a register groove, but in the absence of a register groove the base (as drawn) of keyway 417 may serve as a register against which the bottom of a suitable key blade may bear. An advantage of this arrangement is that bitting of a key can be more accurate when employing common key cutting machinery where positioning of a key blank is by location of its base against a stop, rather than the blank being located by its register groove. A disparity between the register groove of a key blank and the base of a key relative to its combination bittings is not an uncommon problem which cannot be addressed unless a keyway is at least partially dosed as its base. The present invention enables the registration of a key within a keyway and its positioning in key cutting equipment to rely upon the base of the key blade thereby, enabling combination bittings to be produced with greater accuracy and improve the mechanical efficiency and security of key operated tumbler mechanisms. The base of portion 416 is shown to linearly extend to the full width of keyway 417, however, this need not be the case. The base of portion 416 may be generally arcuate and/or contain one or more steps, shoulders, grooves andlor include oblique aspects. In addition, the profile of keyway 417 may not be constant for the whole of its length. For example, a step in the base of keyway 417 would create a shoulder that may function as an end stop for a suitable key blade whereby, a common key profile may be modified or customised to be suitable only for use with one or more individual keying suites or systems.

Page 19 17-04-02 20:03 P.24 A Key Cylinder Finally, it is to be understood that various alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the spirit or ambit of the present invention.

Page

Claims (9)

1. The present invention provides a key cylinder including a case, body, housing or the like having an aperture, cavity or opening formed in it to receive a barrel, plug or other support means for the mounting of at least a part of at least one key operated tumbler mechanism, including at least one tumbler that can enable a releasable interlocking between the barrel and the case; wherein, the longitudinal axis of the barrel extends in substantially the same direction as the longitudinal axis of the aperture and 1o the barrel is reversibly rotatable about a pivot axis that extends in the general direction of its longitudinal axis and/or it is reversibly slidable in that general direction; wherein, the barrel is an assembly of at least two 9 9.. members that in combination define a major part of a keyway that extends within the barrel in said general direction; wherein, at least one tumbler is mounted in a hole, aperture, recess, groove, cavity or other chamber oleo o .o wholly formed in a first member of the barrel and is accessible from the keyway whereby, a suitable key presented in the keyway can affect the disposition of the tumbler sufficiently to facilitate a release of the interlocking between the barrel and the case; and wherein, at least two junctions between respective adjacent or abutting surfaces of the first S: member and at least one other member of the barrel assembly extend in .o said general direction and a portion of the periphery of each of the at least two members form respective portions of the circumference or perimeter of the barrel.

2. A key cylinder according to claim 1 wherein, the barrel comprises at least two members, at least one of which has a generally semicircular cross section.

3. A key cylinder according to claim 1 or claim 2 wherein, the barrel comprises of at least two members, at least one of which is a generally cylindrical component or assembly. Page 21

17-04-02 20:04 P.26 A Key Cylinder 4. A key cylinder according to any of the claims 1 to 3 wherein, the barrel comprises at least two members, at least one of which is a square, rectangular or other polygonal component or assembly. 5. A key cylinder according to any of the claims I to 4 wherein, at least one member is rotatable about a pivot axis extending in said general and is offset from the pivot axis of the barrel assembly. 6. A key cylinder according to any of the claims 1 to 5 wherein, the disposition of at least one member in relation to the other member(s) is adjustable by an operator when the key cylinder is in use. 7. A key cylinder according to any of the claims I to 6 wherein, at least one member is removable from the barrel by an operator when the key cylinder is in use. 8. A key cylinder according to any of the claims 1 to 7 wherein, the profile of the keyway is changeable by an alteration to the disposition of one or more of the members within the barrel. 9. A key cylinder according to any of the claims 1 to 8 wherein, the keyway is alterable by removal of one or more of the members and replacement with at least one different member. 10. A key cylinder according to any of the claims 1 to 9 wherein, an operator can recombinate the key cylinder by removing at least one member from the key cylinder, replacing at least one of the tumblers mounted in the member with a different tumbler, then reinstalling the member. 0o 11. A key cylinder according to any of the claims 1 to 10 wherein, the perimeter of any cross sectional area of the keyway is wholly contained within the barrel without intersecting with the perimeter or circumference of the barrel. Page 22 17-04-02 20:05 P.27 A Key Cylinder 12. A key cylinder according to any of the claims 1 to 11 wherein, one or more of the members are made from material(s) different from the composition of at least one of the other members. 13. A key cylinder according to any of the claims 1 to 12 wherein, the at least one key operated tumbler mechanism is a pin tumbler mechanism. 14. A key cylinder according to any of the claims 1 to 13 wherein, at least one profile tumbler is mounted in the key cylinder. A key cylinder according to any of the claims 1 to 14 wherein, at least a portion of the base of the keyway functions as a register against which the blade of key bears when interacting with the at least one tumbler. is 16. A key cylinder according to any of the claims 1 to 15 wherein, at least one longitudinal end of the barrel has a sleeve or cap mounted to it. 17. A key cylinder according to any of the claims 1 to 16 wherein, one or more of the members has at least one hole, aperture, groove, slot, cavity or other opening that can be juxtaposed when the members are assembled whereby, their relational disposition within the barrel can be secured.

18. A key cylinder according to any of the claims 1 to 17 wherein, one or more of the members has at least one rib, fin, shoulder, stump, pin, protrusion or other projection formed in it and/or mounted to it that is cooperable with the configuration of a different member whereby, their relational disposition within the barrel can be secured.

19. A key cylinder according to any of the claims 1 to 18 wherein, the relational disposition between the members can be secured with fasteners. A key cylinder according to claim 19 wherein, the disposition of at least one member can be altered by an operator while the key cylinder Is in use. Page 23 r "i "i i l'j *P 17-04-02 20:05 P.28 A Key Cylinder

21. A key cylinder according to any of the claims 1 to 20 wherein, the barrel has at least one profile plate that is mounted to it or forms a part of a cap or sleeve or is contained within a cap or the like mounted to the barrel and the profile plate limits the number of different keys that can pass into the barrel.

22. A key cylinder according to any of the claims 1 to 21 wherein, a register groove or shoulder is absent from the keyway.

23. A device substantially as herein described with reference to the accompanying drawings. Applicant: Surite Pty. Ltd. Author: Brian Arthur Cook Date: 18 April 2002 Page 24