The present invention relates to a multi component key that enables access to a lock only when a full complement of key components are assembled together.

BACKGROUND

A high level of security for property and possessions in the workplace is often desirable. There are security risks however involved in distributing keys to moneyboxes, doors, windows, filing cabinets and the like to casual employees and contractors. In these situations it is often desirable for an employer to provide some level of supervised access to these locked items. For example, consider a filing cabinet that is kept under lock and. key because it contains information that is sensitive to an organisation. Further, there exists an employee within the organisation who has a key to the filling cabinet through operational necessity, as the employee needs access to the filing cabinet to undertake his daily duties within the organisation. There is the potential for the employee to use the sensitive material in a way that could adversely affect the organisation. In this situation the organisation would wish to supervise any access the employee has to the cabinet and provide access facilities to ensure that such supervision takes place. Providing standard keys to employees is sometimes problematic as keys can be easily duplicated. Prior to termination, an employee may decide to create a copy of a key to a source of sensitive information. The employee can then use the copy after he has left the organisation to acquire access to and to use the information in an inappropriate way. Organisations may also have materials that are locked in safes, or similar such secure areas, where access should be allowed in abnormal or emergency circumstances and at no other times. To ensure that this occurs these organisations may require the consent of two or more high-ranking persons to access the material. It is necessary to provide access devices to facilitate such consent by limiting access to the material to when all high- ranking persons agree that access is required. Hence, it is necessary to provide a higher level of security to valuable and/or sensitive information so that it is not possible for one person alone to access the information without appropriate supervision or make copies of keys to be used at a later date. US patent 3338078, in the name of Schlage Lock Company, discloses a two part key which replaces a conventional key in a conventional lock cylinder for purposes of temporary use wherein one of the parts is a plastic or similar material insert which replaces a portion of the conventional key, and another part is a short complementary key which permits operation of the lock in conjunction with the insert. The insert is secured in the cylinder by means of the lock cylindering pins and being removable only by means of a special installation and extraction tool. This separable key is known to persons skilled in the art as a construction key as it is predominantly used for allowing construction workers into a project site during the construction phase by providing these workers with the short complementary key only. Hence, these workers are not able to gain access to the project site, post construction, when the insert is removed from the lock, nor are they able to make copies of a key that could be used to access the site post construction. The complementary and insert sections of the key are separated along a cut made on the shank of the key with the complementary section consisting of the entire head and part of the blade and the insert piece consisting of the blade only. It is not possible to have more than two components of this key as when there are three or more components the key does not offer the structural integrity required to overcome the axial forces applied to the components when locking and unlocking is taking place. Hence, this device does not adequately address the situation of when the agreement of more than two persons is required for access. Furthermore, an additional tool is required to remove the insert component. Therefore an improved key is required that is capable of facilitating supervised access to valuable and or sensitive material that is accessed via a key in a lock.

SUMMARY OF THE INVENTION

Accordingly, in one form the present invention is a multi component key that includes a primary component having a shank portion, a contoured edge portion including a step, and a head portion. One or more secondary components are also included, each having a shank portion, a contoured edge portion and a head portion. The primary component and the one or more secondary components form, when assembled together, a complete key for opening a lock. Removal of the primary component from a lock is facilitated by the assembly of the one or more secondary components with the primary component; however removal of the primary component from a lock is prevented in the absence of the one or more secondary components because the step abuts a pin of the lock. The multi component key is thus useful for granting conditional access to a facility, where access first requires assembly of all the components of the key. The step in the contoured edge of the primary component may be orthogonal to the shank portion of the primary component. The one or more secondary components of the key may include having two secondary components. Where there are two secondary components, one of the secondary components may include a step in its contoured edge portion. The key may further include a component integrator that receives the heads of the primary component and the one or more secondary components for assembly of the complete key. The heads of the primary component and the one or more secondary components may include integrator attachment holes, and the component integrator may include fastening nodes adapted to secure the components to the integrator when each fastening node is received in a corresponding attachment hole. The component integrator thus holds the multi component key of the present invention in the shape of a one-piece prior art key, enabling the multi component key to also function as a one-piece prior art key. The primary component and the one or more secondary components may be rigidly attached to each other along one or more frangible cut lines, whereby the components may be separated from each other by breaking the key along the cut lines. Such a frangible key thus may be used either as a standard key or as a multi component key according to the present invention. The one or more frangible cut lines may be interrupted laser cut lines.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG 1 shows a multi component key with components integrated;

FIG 2 shows a multi component key when the components are apart;

FIG 3 shows a multi component key with one primary component and two

secondary components;

FIG 4 shows the top view, side view and front view of a component

integrator;

FIG 5 shows a multi component key with component integrator attached;

and

FIG 6 shows a multi component key in a lock cylinder wherein the primary

component is fixed in the lock and the complimentary secondary component

is not present.

DETAILED DESCRIPTION OF THE INVENTION

The present invention resides in a multi component key device to provide a higher level of security to sensitive and or dangerous materials, goods and or devices. The multi component key, when fully assembled, is used to unlock a lock cylinder mated to the key's contours. Throughout this description like numerals are used to refer to the same elements of the invention shown in multiple figures. Referring to FIG 1 multi component key 1 is shown consisting of multi component key head 2 and multi component key shank 3 wherein shank 3 is integrally formed with head 2. Contoured edge 4 of multi component key shank 3 is appropriately formed to engage the tumbler pins of the corresponding locking device (not shown) with which separable key 1 is mated. Referring now to FIG 2, laser cut line 5 separates primary key component 7 from secondary key component 8 as illustrated. Laser cut line 5 is formed during the manufacture of multi component key 1 , the process of which is discussed below. In this embodiment of the current invention there are only two separable sections and one laser cut line. The current invention is not limited to this configuration and it should be apparent to a person skilled in the art that there may be three or more separable key components separated by two or more laser cut lines wherein all components are required to open the mated locking mechanism. Referring to FIG 3, multi component key 16 is shown wherein key 16 is broken into three separate components, primary component 17 and secondary components 18A and 18B, along laser cut lines 19A and 19B. It is clear from this diagram that all components in multi component key 16 consist of a head portion, a shank portion and a contoured edge portion. Hence, all components of multi component key 16 are required to open the lock cylinder to which this key is mated. Furthermore, primary component 17 cannot be removed without secondary components 18A and 18B being inserted in the lock and integrated with primary component 17. Also, primary component 17 and secondary component 18A cannot be removed without secondary component 18B being inserted in the lock and integrated with these components. This will be discussed in more detail below. Referring to FIG 2, it is clear that each of the multi key components 7 and 8 have components of the key head 2, key shank 3 and contoured edge 4. Therefore, all components are required to unlock the locking mechanism as only when all components are combined along laser cut line 5 is the entire length of contoured edge 4 fully formed and hence only then is it possible to unlock the lock cylinder with multi component key 1. Similar reasoning applies when there are three or more key components that, when combined, form one key. Integrator attachment holes 6 also can be seen on multi component key 1 in FiG 1 and FIG 2. In this embodiment of the present invention there are four integrator attachment holes, two for each key component. These holes are used to fasten component integrator 9 to multi component key 1 and facilitate integration of key components 7 and 8. The mechanics of this integration process is described below. Referring to FIG 4, a top view, side view and front view of component integrator 9 is shown. Component integrator 9 is used to connect key components 7 and 8 along laser cut line 5. It is preferable for component integrator 9 to be made from moulded synthetic material but component integrator 9 can optionally be made from metal, wood, etc. Integrator 9 consists of body 14 which has cavity 11 integrally formed within. Cavity 11 has approximately the same dimensions as multi component key head 2 but cavity 11 is sufficiently larger than multi component key head 2 to enable multi component key head 2 to be inserted into cavity entrance 15 as depicted in FIG 5. Component integrator body 14 narrows and thins to tapered section 13 at a location distal to cavity entrance 15. Tapered section 13 is integrally formed with integrator fastening hole 12 traversing all the way through tapered section 13. Integrator fastening hole 12 may be used to attach component integrator 9 to a key chain or to the cabinet or device kept under lock by means of string or similar such flexible elongate material that can be fed through integrator fastening hole 12. Cavity 11 has flexible component fastening nodes 10 protruding within. These nodes substantially extend across cavity 11 as seen in FIG 4. Component fastening nodes 10 are positioned so that when multi component key head 2 is fully inserted into cavity 11 component fastening nodes 10 are aligned with integrator attachment holes 6. When this occurs each component fastening node 10 extends into its corresponding integrator attachment holes 6. Component fastening nodes 10 are flexible and hence while multi component key head 2 is being inserted into component integrator 9 component fastening nodes 10 bend to allow passage of multi component key head 2 into cavity 11. Some nodes may protrude into the incorrect attachment holes on the separable key head when the key head is being inserted into the cavity. In this case, some resistance is applied to the movement of the key head but the nodes are flexible enough so as not to provide sufficient levels of resistance to fully stop the movement of multi component key head 2 into cavity 11 and hence reaching a position where the correct component fastening nodes 10 are aligned with their correct integrator attachment holes 6 as seen in FIG 5. The insertion of component fastening nodes 10 into integrator attachment holes 6 provides sufficient fastening force such that separable key- components 7 and 8 remain integrated while forces axial to the longitudinal axis of multi component key shank 3 are being applied to these components as a result of turning the key in the lock. Hence, structurally the key is the same as if it was one integrally formed component. However, the component fastening nodes 10 do not provide so much fastening force such that multi component key head 2 cannot be easily inserted and removed from cavity 11. FIG 5 shows multi component key 1 fully inserted into cavity 11 of component integrator 9 wherein component fastening nodes 10 are inserted into their corresponding integrator attachment holes 6. Referring to FIG 6, primary key component 7 of separable key 1 is inserted into the lock cylinder (not shown) to which it is mated. Combination pins 22A, 22B, 22C and 22D of the tumbler lock are shown with pins 22A and 22B being fully engaged with contoured edge 4 of key component 7. Laser cut line 5 terminates at step 21. Step 21 is formed in the contoured edge 4 of the primary key component 7 orthogonal to the longitudinal axis of the key shank 3. Step 21 prevents removal of primary key component 7 when the secondary key component 8 is not inserted in the lock cylinder. Typically, combination pins 22 are fixed on springs and these springs are compressed when the contoured edge of a key rides over them during insertion of the key into a lock cylinder. According to the present invention, the springs of combination pins 22 are forced down initially by the leading edge 23 of the key shank 3 and stay compressed at positions as dictated by the contour edge. When the multi component key 1 is being withdrawn from a lock cylinder, providing that components 7 and 8 are appropriately combined, contoured edge 4 rides over the top of combination pins 22 as there are no acute steps in the shank 3. In the case of FIG 6, primary component 7 is inserted in the lock cylinder without the complementary secondary component 8. In this case step 21 , in conjunction with combination pin 22C, prevents the secondary component 8 from being withdrawn as the step 21 abuts combination pin 22C. Only when secondary component 8 is inserted in the lock cylinder and abuts step 21 , producing a fully formed contoured edge 4 and compressing combination pins 22C and 22D, is it possible to withdraw the primary key component 7 along with the secondary key component 8 as the contoured edge 4 will ensure that the combination pins 22C and 22D are appropriately compressed and will not impede the progress of the key 1 from the lock. Hence, if an attempt was made to open the lock with the primary key only, the lock would not open due to the absence of a fully formed contoured edge and, furthermore, the primary key component will become jammed in the lock cylinder leaving evidence that an attempt was made to open the lock without all component holders agreement. Additionally, the multi component key of the present invention is a self-retrieving component key, in which it is not necessary to have any additional tools to retrieve the components of the key from the lock.. All that is needed is all components of the key assembled in an appropriate fashion. The same mechanics of operation applies to multi component key 16 as seen in FIG 3 and to multi component keys in which four or more components are present. The first embodiment described above is of a multi component key 1 in which there are two components separated by one laser cut line. It should be apparent that there may be three or more components separated by two or more laser cut lines, as shown in FIG 3, and"that embodiments such as this do not depart from the plith and marrow of the current invention. Furthermore, it should be apparent to a person skilled in the art that each key component includes two or more integrator attachment holes 6 and that the corresponding component integrator 9 includes component fastening nodes 10 positioned in the same locations as the integrator attachment holes 6. Those skilled in the art will recognize that other means may be used to effectively align the key components with each other using a component integrator 9, or by other means. For example, a longitudinal slot in the key head 2 and a mating rib in the integrator 9 could replace the illustrated attachment holes 6 and fastening nodes 10, respectively. A person skilled in the art will be aware of the process of key manufacture. Briefly, this involves: 1. Stamping out a blank key from a sheet of metal with an appropriate metal stamping apparatus. 2. The blank key is then cut so that a contoured edge is formed that corresponds to the corresponding lock combination of the lock with which the key will be mated and sold. Befo re or after step 1 above, according to the present invention one or more frangible cut lines may made within the metal to enable a key that will be formed from the metal to be separated along the cut lines into the primary and secondary components of the present invention. For example, the frangible cut lines may be interrupted laser cut lines. The process of manufacture then continues the same as in the prior art key man ufacture process. The advantage of this process is that it is up to a purchase r of the key 1 and lock whether he or she desires to have a multi component key 1 according to the present invention or a standard integrally formed key according to the prior art. If the purchaser wishes a multi component key 1 then the key 1 can be separated along the laser cut line using a significant level of force applied by hand or, for example, with pliers. Upon sale of the key 1 with a corresponding lock, the component integrator 9 will generally be sold as well. The multi component key 1 of the present invention solves one or more of the problems described in the background. It is required to have all key components together to open a lock and any attempts made to open a lock with less than the entire compliment of components assembled correctly will be Ineffective and will result in the components becoming jammed in the lock as described. The above detailed description provides a preferred exemplary embodiment only, and is not intended to limit the scope, applicability, or configuration of the present invention. Rather, the detailed description of the preferred exemplary embodiment provides those skilled in the art with an enabling description for implementing the preferred exemplary embodiment of the invention. It should be understood that various changes can be made in the function and arrangement of elements and steps without departing from the spirit and scope of the invention as set forth in the appended claims.