The present invention relates to keys, associated lock assemblies and methods for actuating a lock using the disclosed key and lock assemblies. The disclosed apparatus and methods are particularly suitable for use with storage means for containing documents of value, such as banknote cassettes, but it will be appreciated that the invention is not so limited.

It is well known to use storage means such as cassettes for the storage and transportation of banknotes. Commonly, such cassettes may be inserted into sheet handling machines such as cash dispensers for dispensing quantities of banknotes either to bank tellers or directly to customers, or used in cash acceptors which allow users to deposit sums of money in the form of banknotes. Depending on the circumstances, banknotes may be loaded into the cassette at a remote location and transported to the dispensing machine in the cassette, which is then inserted into the machine. This is typically the case where the dispensing machine forms part of a large network of such machines and the banknotes are distributed by some central management station. In other situations, it is desirable to refill the cassettes with banknotes on site at the location of the cash dispensing machine and, likewise, empty any deposited notes. This is likely to be the case where the cash dispensing machine is owned or operated by a local convenience shop, for example.

These scenarios lead to different requirements of the banknote cassettes. In the case of remote loading, it is generally preferred that on-site personnel have little or no access to the contents of the cassettes. The cassette is preferably locked after loading and, once it has been delivered, it is unlocked or primed for unlocking by personnel from the remote management station. The cassette is preferably designed to include a "one-shot" locking mechanism which, once it has been inserted into the cash dispenser, upon removal, relocks (or "dephmes") to prevent the cassette either being opened or being reinserted into the cash dispenser. A cassette of this sort is disclosed in EP-A-0263680 and typically makes use of a key-operated lock for controlling the unlocking (or priming) mechanism. By providing only the refilling personnel with the appropriate key, the cassette's integrity is ensured.

It will be appreciated, however, that such an arrangement is not appropriate for cassettes which are to be emptied or refilled on site. Here, the provision of a key-operated lock does not significantly enhance security, since the local machine owner must be provided with the key and so would have ready access to the contents of the cassette. Indeed, the requirement for a key in order to operate the cassette every time it requires refilling becomes onerous and problematic for the user. Conventionally, this has been resolved by providing such machines with an alternative cassette which can be opened simply by actuating a handle or similar, and does not require a key.

This disparity leads to the need for more than one variant of each cassette model to be produced; a first having a lock for secure environments, and one without, known as a "convenience" cassette. As a result, the increased design time, parts number and tooling requirements raise the cost of manufacturing cassettes.

In accordance with a first aspect of the present invention, a key is provided for operation of a lock, the key comprising a bow for gripping of the key, and a shank adapted to be inserted into the lock and configured for actuation of the lock upon turning of the key, the key being provided with a frangible point between the bow and the shank, permitting parting of the bow from the shank and thereby removal of the bow, at any rotational position of the key relative to the lock, to leave the whole shank in the lock.

By providing a key with a frangible (fracturable) point in this way, it becomes possible to use a single variant of cassette in both of the scenarios described above. A "secure" cassette, with a key-operable lock, can be converted into a so-called convenience cassette by using the key to unlock or prime the cassette and then breaking off the key bow in order to leave the lock in its unlocked or primed condition. The cassette can then be inserted into a cash machine and subsequently removed, refilled and reinserted without need to operate the lock. In this way, the user has all the convenience of no key operation, whilst the manufacturer need produce only a single variant of cassette. The frangible point can take any suitable form, such as an area of weakened material, including for example a fracturable adhesive, or perforations through the key, but preferably, the frangible point comprises a region of reduced cross-section between the bow and the shank. This has been found to provide the key with sufficient rigidity to perform the operations required of it, whilst permitting relatively straightforward separation when the bow is to be parted from the shank. This feature is also relatively straightforward to produce during manufacture of the key, for example by moulding. Preferably, the region of reduced cross-section is provided in the form of a neck, although any other suitable feature, such as a groove in one side of the key, could be appropriate.

Depending on the nature of the frangible point, the bow and shank could be formed separately and later joined to one another to form the key. However, preferably the bow and shank are integrally formed with one another. Advantageously, the key is formed by moulding or casting, preferably of plastics material.

The friction between the key shank and the lock may be sufficient to retain the key shank in place when the bow is removed. However, in certain preferred embodiments, the shank is further provided with at least one barb for retention of the shank within the lock. In many cases, the "conversion" of the cassette into a convenience cassette need not be reversed. However, there are some situations in which it may be desirable to return the lock to its former, operational state, for example if the cash dispensing machine is hired to the local operator and is later returned and put into use in conjunction with a remote loading facility. Therefore, in a particularly preferred embodiment, the shank further comprises a keying feature adapted to couple to a drive tool for turning thereof after removal of the bow. This makes it possible to turn the key shank back to its original position and hence extract it from the lock, which can then be used in a secure environment with a standard key. Preferably, the drive tool is provided on the bow of the key. This is a particularly convenient way of supplying the drive tool since it permits the keying feature and design of the drive tool to be unique to each key, if desired. Even if not, this ensures that the user has ready access to the drive tool when required, and reduces the part count.

Preferably, the keying feature comprises at least one hole, and the drive tool comprises at least one corresponding pin arranged to couple thereto for turning of the shank. The hole and pin could have any desired cross-section and it is typically preferable to provide at least two holes and corresponding pins in order to ensure sufficient leverage is achievable to turn the key.

Depending on the type of key in use, the shank (or blade) of the key may itself be accessible from the exterior of the lock. However, in preferred embodiments, the shank further comprises a shoulder arranged to abut the service of the lock in use. This provides a convenient surface upon which the keying features can be disposed and assists in levering the shank out of the lock should removal be required.

The key could be of any desired type, including a flat key and a barrel key. However, preferably, the key is a tubular key, the shank including a hollow barrel and a nib arranged to retain the shank within the lock when the key is angularly displaced from its insertion position.

A second aspect of the invention provides a lock assembly comprising a lock mechanism and a key as described above. In one particularly preferred embodiment, the lock mechanism comprises a lock mechanism for a sheet store adapted for the dispensing or accepting of sheets, the sheet store comprising a container having a lid openable for access to the interior of the container and a shutter openable for the passage of sheets therethrough, the lock mechanism comprising: a locking plate movable relative to the container, the locking plate being operable to control a lid lock element and a shutter lock element; and an actuator arranged to, in use, mechanically couple with the key so as to control movement of the locking plate; wherein the locking plate is movable between three positions, including: a closed position, in which the shutter lock element prevents opening of the shutter; a primed position, in which the shutter can be opened; and an open. position which controls the lid lock element to permit opening of the lid. In another preferred embodiment, the lock mechanism comprises a lock mechanism for a sheet store adapted for the dispensing or accepting of sheets, the sheet store comprising a container having a shutter openable for the passage of sheets therethrough, the lock mechanism comprising: a locking plate movable relative to the container, the locking plate being operable to control a shutter lock element, and wherein the locking plate is movable between two positions, including: a closed position, in which the shutter lock element prevents opening of the shutter; and a primed position, in which the shutter can be opened; an actuator arranged to, in use, mechanically couple with the key so as to control movement of the locking plate; and a de-priming device adapted to urge the locking plate towards its closed position upon opening of the shutter; wherein the actuator is selectively configurable to be fixed at one of at least two positions, including a priming position, in which the actuator prevents the locking plate from returning to its closed position, and a default position, in which the locking plate is not prevented from returning to its closed position upon activation of the de-priming device.

Preferably, the actuator comprises a lever operable to move the locking plate between the closed, primed and open positions.

Advantageously, the actuator further comprises a key operated lock cam coupled to a key operated lock barrel for operation of the lever.

The invention further provides a cassette for storing banknotes which is provided with the lock assembly as set out above. In accordance with a third aspect of the present invention, a method of actuating a lock is provided, using a key comprising a bow for gripping of the key, and a shank adapted to be inserted into the lock and configured for actuation of the lock upon turning of the key, the key being provided with a frangible point between the bow and the shank, the method comprising: inserting the shank of the key into the lock; turning the key from a first position to a second position to thereby actuate the lock; parting the bow from the shank at the frangible point and removing the bow, leaving the whole shank in the lock at the second position, thereby maintaining the lock in its actuated state.

Preferably, the first position of the key corresponds to its insertion position, and at the second position of the key, the shank cannot be removed from the lock.

In a preferred embodiment, the first position of the key corresponds to the lock being in a locked state, and the second position of the key corresponds to the lock being in an unlocked state. In an alternative preferred embodiment, the first position of the key corresponds to the lock being in a locked state and the second position of the key corresponds to the lock being in a primed state.

Preferably, the shank of the key is further provided with a keying feature adapted to couple with a drive tool for turning of the shank, and the method further comprises: coupling a drive tool to the shank; and turning the shank from the second position to the first position using the drive tool.

Advantageously, the drive tool is integral with the bow of the key.

Preferably, the method further comprises removing the shank from the lock once it has been returned to the first position.

An example of a key in accordance with the invention, as well as exemplary lock assemblies and banknote cassettes will now be described with reference to the accompanying drawings, in which:

Figure 1 shows a first embodiment of a banknote cassette; Figure 2 shows a lock suitable for use in the banknote cassette of Figure

1 ;

Figure 3 i-iv show four orthographic projections of an embodiment of a key;

Figure 4 i-iii show perspective views of the key of Figure 3 and an enlarged detail thereof;

Figure 5 shows a second embodiment of a banknote cassette;

Figure 6 depicts a lock mechanism suitable for use in the banknote cassette of Figure 5; and Figure 7 shows a slide element forming part of the lock mechanism of Figure 6.

The cassette 10 shown in Figure 10 comprises a base 11 and a lid 12. The two halves are hinged together so as to permit opening of the cassette by a user in order to access the contents and/or to refill the cassette. The cassette 10 is particularly well adapted for the storage of banknotes, although it could be used to store and dispense any sheet document, and in particular documents of value such as certificates, cheques, tokens etc.

In use, the cassette is inserted into a sheet handling machine such as a cash dispenser (not shown), which retrieves documents from the cassette 10 (or inserts them into the cassette 10) through a shutter 14. The shutter 14 is opened on insertion of the cassette 10 into a sheet handling machine by cooperation between the machine and a shutter opening device 15 provided on the cassette. In certain embodiments, the machine may also couple to a electrical connection 16 on the cassette, which provides the sheet handling machine with information as to the cassette content. This may be stored in a memory within the cassette (not shown) which is programmed on either manufacture or on loading of the cassette.

The cassette 10 is opened by depressing a latch 13 which releases the lid 12 from the base 11 to allow access to the cassette's interior. The latch 13 is secured by a key lock 20 which is operable between locked and unlocked positions. In the locked position, the lock 20 prevents the latch 13 from being depressed and so restricts opening of the lid 12. In certain embodiments, the lock 20 may also cooperate with the shutter 14 to prevent opening of the shutter when the lock 20 is in its locked position. When the lock 20 is moved to its unlocked position, the latch 13 is operable and the lid 12 can be opened. Similarly, the shutter 14 can be opened on insertion of the cassette into a suitable sheet handling machine. In certain embodiments, the coupling between the key lock 20 and the shutter 14 may include a priming mechanism such that when the lock 20 is moved into its "unlocked" position, the lock mechanism is primed, permitting opening of the shutter. Removal of the cassette from the sheet handling apparatus serves to "deprime" the lock mechanism (providing the key lock 20 has been returned to its original position) which prevents the shutter being reopened without the key. Such a mechanism is disclosed for example in EP-A-0263680.

It will therefore be appreciated that the cassette 10 shown in Figure 1 is suitable for use in "secure" environments such as cash dispensing machines which are replenished from a central location, in which case only cash transportation personnel will be supplied with the appropriate key for operation of the lock 20. However, as will now be described, the present invention makes it possible to "convert" such a cassette into a "convenience cassette".

Figure 2 shows in more detail the lock 20, which is a conventional tubular lock having a tubular keyway 21 and a recess 22 for receiving the nib of a tubular key in use. It will be appreciated that any other lock type may be substituted for the tubular lock 20 as desired by the cassette designer.

Figures 3 and 4 show a corresponding key 30 according to an embodiment of the invention. The key 30 comprises a bow 31 (or "handle"), which is the portion which a user would hold whilst inserting the key 30 into a lock, and a shank 32 which is the portion inserted into the lock in use. It will be appreciated that here the term "shank" is used simply because the embodiment relates to a tubular key type, however, in other key types this corresponds to the "blade" (of a cylinder or flat key) or the "post" (of a bit key). In the present embodiment, the shank 32 comprises a hollow tubular blade with a nib 32a in the form of a small protrusion at the tip of the key, and cuts 32b are provided to cooperate with the lock mechanism inside keyway 21 of lock 20.

In this example, the shank 32 also includes a shoulder 35 which abuts the surface of lock 20 in use. In other lock types, the shoulder 35 may be omitted since the tip of the key may itself act as a stop on meeting the end of keyway 21.

Between the bow 31 and shank 32 is provided a frangible or fracturable point 33 which, in this example, takes the form of a neck joining the bow 31 onto the surface of shoulder 35. Due to the reduced cross-section at point 33, this provides a weak point at which the bow 31 may be separated from the shank 32. The weak point is such that the bow of the key may be snapped off manually without the need for additional tools, leaving the shank 32 (including shoulder 35) retained in the lock. In some cases, the friction between shank 32 and the lock keyway 21 may be sufficient may itself to retain the shank in position. However, in preferred embodiments, one or more retention barbs 34 are provided on the circumference of the shank 32 in the form of protrusions to assist in retention of the shank within the lock.

In use, the key 30 is inserted into a lock 20 such as that shown in Figures 1 and 2. For this to be achieved successfully, the nib 32a of the key must be aligned with recess 22 of the lock. This ensures that the cuts 32b in the shank 32 are properly aligned with the lock mechanism within keyway 21. This position of the lock, at which the key may be inserted, typically corresponds to its locked condition where the lid 12 and shutter 14 are prevented from being opened. The user then turns key 30 from its insertion position to a second position which, depending on the lock mechanism's configuration, may correspond to an "unlocked" or a "primed" condition of the lock. At the second position (which is angularly displaced from the insertion position), the shank 32 cannot be removed from keyway 21 since nib 32a is not aligned with recess 22. In this position, the user applies force to the bow 31 of the key, separating it from the shank 32 at the frangible point 33. The bow 31 can then be removed, leaving the whole of shank 32 (including the shoulder 35) retained by the lock 20. The lock mechanism is thus maintained in its unlocked (or primed) condition and the cassette can be inserted into the cash dispenser machine or opened for refilling as necessary. Even in the case of a lock mechanisms having a priming mechanism, since the lock 20 stays at its priming position throughout, the mechanism is not "deprimed" by removal from the cash dispenser machine and the cassette can be reinserted as many times as necessary. Since the shoulder 35 of the shank 32 sits substantially flush with the lock 20, it does not obstruct movement of the cassette into or out of the cash dispenser machine.

In some cases, it may be necessary to subsequently remove the shank 32 from the lock 20 in order to return the cassette 10 to use in a secure environment requiring the use of a standard key. For this reason, in a particularly preferred embodiment, the shank 32 is provided with a keying feature 41 which enables rotation of the shank 32. In this example, the keying features take the form of holes 41 disposed in the surface of shoulder 35. The keying feature 41 is designed to cooperate with a drive tool 42 which is preferably provided on the bow of the key 31. Here, the keying feature 41 comprises five circular holes spaced in a circular arrangement around the axis of rotation of the lock 20, and the drive tool 42 comprises five corresponding pins arranged on a side surface of the key bow 31. To remove the shank 32 from the lock 20, the pins 42 are inserted into corresponding holes 41 and the key bow 31 is used to apply torque to the shank 32, returning it to the insertion position at which nib 32a aligns with recess 22. The shank can then be removed and the lock mechanism returned to standard use.

Figures 5, 6 and 7 show a second embodiment of a banknote cassette 100 which can be used in conjunction with the key 30 shown in Figures 3 and 4 and described above. This cassette is described in our International patent application number PCT/GB2008/000570, which is hereby incorporated by reference.

The cassette 100 comprises a base 114 to which is attached a lid 112 via a hinge 160. In use, the cassette 100 is loaded with banknotes (not visible) and inserted into a store housing 200 which forms part of a sheet handling apparatus (not visible). Upon command from a user, the sheet handling apparatus removes notes from the cassette 100 and dispenses them to the customer. Notes exit the cassette 100 through an opening 20 in one end face of the base 14 which, when not in use, is closed by shutter 22. In this particular example, the cassette is further adapted to accept reject notes from the sheet handling apparatus which may occur, for example, if double banknotes are fed or if there is a jam. For this purpose, an opening 24 is provided in lid 12, closed when not in use by cover 26. Further, the lid 12 is arranged to be opened a small amount inside the store housing 100 which is achieved by the engagement of boss 15 provided on each side of the lid 12 with a slot 110 provided in the side of store housing 100. The slot 110 is angled such that, as the cassette 10 is slid into the store housing 100, the boss 15 follows the slot 110 upward and so lifts the lid.

The cassettes also include a pusher plate 118 which, in use, is sprung against the loaded banknotes to urge them towards the shutter 122 for dispensing. A handle 111 may also be provided for assisting the user in carrying the cassette and withdrawing it from the store housing 200.

As shown in Figure 5, a lock mechanism 130 is arranged in a side wall of the cassette 100. A duplicate locking mechanism 130a may be provided in the opposite wall of the cassette as shown in Figure 5. However, in most cases it is sufficient to have a single locking mechanism 130 in one side of the cassette and only selected components in the other, as will be described below.

Figure 6 shows the components making up the locking mechanism 130 in more detail. The components are mounted to an internal wall 113 of the cassette 100 which is machined or moulded to support the various components in the manners described below. A locking plate 131 is slideably mounted on the wall 113 in a manner which permits movement along the length of the cassette, towards and away from shutter 122. The locking plate 131 , which may for example be machined from metal, is abutted by lever 132 at its inboard end which, when rotated in a clockwise direction by lock 150, acts on an end of the locking plate to slide it towards the shutter 122 (to the position shown in Figure 6). The locking plate 131 is urged against the lever 132 by a resilient member such as a compression spring (not visible).

The locking plate 131 has a recess (which in this example extends through the thickness of the locking plate), which includes a cam surface 131a. The cam surface includes a ramp section of increasing height away from the shutter 122 and a notch at increased height at the end of the of cam surface furthest from shutter 122.

A stop element in the form of plunger 133 is slideably mounted to the wall 113 perpendicularly to the slide direction of locking plate 131. The plunger 133 couples with locking plate 131 via a cam follower in the form of a pin 133a, which rests on cam surface 131a. The plunger 133 is urged downwards such that the pin 133a abuts cam surface 131a by a resilient means in the form of a compression spring 133b. A latch element 134 is pivotably mounted to the wall 113 between the shutter 122 and the locking plate 131. The latch member 134 is pivotable about an axis 135. At its uppermost end, the latch member includes a hook 134a which, when in its uppermost position, couples with a feature provided in lid 112 (not shown) to secure the lid 112 in a closed position. The latch member 134 is urged into this position by a resilient element in the form of a tension spring 134b.

Also pivotably mounted on axis 135 is a toothed gear wheel 137. The gear wheel 137 couples to shutter rack 138 which is provided on shutter 122 and to slide rack 136a provided on a slide element 136. The slide element 136 is shown in more detail in Figure 7 and is positioned adjacent to the wall 113 which constrains it to slide along its length (towards and away from the shutter). The gear wheel meshes with rack gear 136a provided on slide element 136 and with the shutter rack 138 in such a way that movement of one results in movement of the other.

When the locking plate 131 is in its closed position, the stop element 133 rests in its lowermost position, urged downward by spring 133b and supported by pin 133a at the lowermost point of cam surface 131a. In this position, the lowermost extremity of the stop member 133 prevents any sliding motion of slide element 136 by extending downwardly into its path. It is therefore not possible to open the shutter 122 in this configuration.

Clockwise movement of the lever 132 using the lock 150 moves the locking plate 131 to the left, as viewed in Figure 6, against the force of the resilient element (not visible) which urges the locking plate 131 towards lever 132. This movement causes the pin 133a on stop element 133 to be carried up the cam surface 131a, which lifts the stop member 133 against spring 133b. This movement is continued until the pin 133a drops into the notch provided in cam surface 131a at which point the locking mechanism is in a "primed" condition.

With the stop member in this raised position, its lower extremity is aligned with a first cam surface 136b on slide element 136 in the form of a ramp. Should an attempt now be made to slide the slide element 136 to the right, the cam surface 136a will contact the lower extremity of locking member 33 and cause it to rise up, allowing the slide element 136 to move past, and so opening the shutter 122 via gear wheel 137. This movement is actuated by insertion of the cassette 100 into store housing 200. Assuming for the time being that the cassette is not presently to be inserted into a store housing, from the primed position, turning the handle further in the clockwise direction moves locking plate 131 further to the left as shown in Figure 6. During this motion, a protrusion provided on locking plate 131 contacts the latch member 134 and causes it to rotate in an anticlockwise direction by a small amount. In doing so, the hook 134a moves out of engagement with the lid 112 (not shown), against the resilient force of spring 134b. The user is now free to open lid 112 and so load or unload the cassette as necessary. It should be noted that in doing so, there is no need to open shutter 122, which remains closed throughout.

When the locking plate is moved to this open position, the stop member 133 remains at its raised position by virtue of pin 133a and cam 131a.

Once the cassette 10 has been loaded with banknotes, the lid 112 is closed and the lock mechanism returned to its primed position by turning lock 150 anticlockwise. The locking plate 131 returns to the primed position by virtue of the resilient element (not shown). Since the pin 133a of stop member 133 is retained in the primed position by the notch of can surface 131a, the lever 132 may be returned to its default position, in which it will no longer contact the locking plate 131 (since this is held in the primed position by pin 133a). Alternatively, in some cases it may be preferred to leave the lever 132 in the priming position which has certain advantages which will become clear below.

The cassette is now ready to be inserted into a store housing provided in a sheet handling apparatus such as that shown in Figure 5. The store housing 200 includes two probes, 202a and 202b, which, as the cassette 100 is inserted into the housing 200, extend through apertures 117a and 117b provided in the base 114 of the cassette 100. The two probes 202a and 202b are provided with recesses 204a and 204b for engagement with the slide member 136 (and its counterpart in lock mechanism 130a, if provided). The slide element 136 is provided with means for coupling to the probes 202a and 202b in a manner which causes sliding of the slide element both as the cassette is inserted into the housing and as it is withdrawn. Suitable connection means are disclosed for example in EP-A-0263679. With the locking mechanism in the primed position, when the slide element 136 is pushed to the right by the probes 202a and 202b, the first cam surface on the slide element 136 causes the lower end of the stop member 133 to rise up, disengaging the pin 133a from the notch in cam surface 131a. This disengagement will allow the locking member 131 to return to its original position. Movement of the slide element 136 continues until it reaches a stop provided by wall 113, during which motion, gear wheel 137 is rotated so as to withdraw shutter 122, revealing aperture 120 and allowing dispensing of banknotes.

The slide element 131 is further provided with a second cam surface 136c which is spaced from the first cam surface 133b along the slide direction. As the slide element moves, the second cam surface 136c comes into contact with a protrusion 134c provided on latch member 134 at the opposite end to hook 134a. The cam surface 136c causes anticlockwise rotation of the latch member 134, disengaging the hook 134a from the lid 112. This allows the lid 112 to be opened inside the store housing by appropriate means such as boss 115 and slots 210.

While the cassette 100 remains in the cassette housing 200, the stop member 133 stays in its present position, resting on top of slide 136. When the cassette is withdrawn, the probes 202a and 202b will draw the slide 136 back to its initial position so that the lower end of the stop member 133 will ride back across the cam surface 136b and then drop down to its original position. In this position it will no longer be possible for a probe to push the slides 136 since the end of stop member 133 now extends lower than cam surface 136b. This prevents the cassette 100 from being reinserted into the store housing. This is "single-shot" use and, as described above, it increases security by preventing a cassette being reopened once it has been removed from a sheet handling device. The cassette can only be reopened once the locking mechanism has been re-primed by turning the lock 150.

To enable "multi-shot" use, the cassette 100 can be converted into a "convenience cassette" using a key 30 as described above. In such cases, the lever 132 will be left in its priming position when the key bow 31 is removed. With the locking mechanism in the primed position, the shutter mechanism is free to open as described above but, since the locking plate 131 is constrained laterally by the lever 132, it does not return to the closed position despite the movement of pin 133a caused by the first cam surface 136b on slide element 136. Thus, when the cassette is removed from the store housing and the slide 136 returns to its original position, the stop element 133 comes to rest with the pin 133a again in the notch provided by cam surface 131a, such that the mechanism remains primed for reinsertion.

It should be noted that the use of key 30 to 'fix' the actuator in either the "default" or "priming" positions in this way can advantageously be implemented with or without the above-described lid-locking mechanism. For example, the actuator could be used in combination with a locking plate moveable between just two positions corresponding to the closed and primed positions described above.