NZ528007A

NZ528007A - Rotating pin tumbler side bar lock with side bar control

Info

Publication number: NZ528007A
Application number: NZ528007A
Authority: NZ
Inventors: Peter H Field; Andy E Perkins
Original assignee: Medeco Security Locks
Priority date: 2001-02-06
Filing date: 2002-01-28
Publication date: 2004-06-25
Also published as: AU2002237938B2; HK1060606A1; PL363376A1; TW513510B; JP4219685B2; NO20033392L; CN1260453C; DK1366256T3; JP2004521201A; EP1366256B1; NO20033392D0; MXPA03006983A; IL157250A0; BR0207036A; EP1366256A1; IL157250A; AR032543A1; BR0207036B1; CN1491311A; CA2435335A1

Abstract

A twisting tumbler lock with a side bar is provided with additional levels of security by a axially reciprocal slider which is normally positioned to block operation of the side bar but is moved by a specially configured key to free operation of the side bar. This provides a third level of locking security, it also allows master keying. The unique key has a portion of a rib formed to cooperate with the slider to further allow key control

Description

528007 WO 02/066773 PCT/US02/02211 ROTATING PIN TUMBLER SIDE BAR LOCK WITH SIDE BAR CONTROL REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of application 5 Serial No. 09/776,929 filed February 6, 2001.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to improvements in rotating pin 10 tumbler side bar locks and keys therefor. 2. Background and Prior Art Rotating or twisting tumbler locks with side bar control of the tumblers and keys for operating such locks are well known in the prior art and have been manufactured and sold by 15 Medeco Security Locks, Inc. Of Salem, Virginia for over twenty years. Examples are in the following patents assigned to Medeco Security Locks, Inc. 3,499,302 Spain et al (1970) 3,722,240 Spain et al (1973), 4,635,455 Oliver (1987), 5,289,709 Field (1994), 5,419,168 Field (1995), 5,570,601 20 Field (1996), 5,615,565 Field (1997) and 6,023,954 Field (2000) .

:Security is a necessary feature of a lock and additional security that could be applied to twisting tumbler locks with dual mechanisms would be highly desirable.

A further and extremely desirable feature of a high security lock is the capability for master keying. Providing additional security and utilizing such provision for master keying provides capability for master keyed systems.

It is also advantageous to have a unique key and key blank for locks of the type in order to provide the additional security that key control can accomplish.

SUMMARY OF THE INVENTION This invention relates to improvements to enhance the security of the basic twisting tumbler dual locking mechanism lock known as the Medeco type lock and can be applied to any Medeco type lock with a side bar mechanism including the original Medeco cylinder lock, the Medeco cam lock, the Medeco Biaxial® lock, and the Medeco Bi-Level® lock with offset tip tumbler pins. The invention utilizes a sliding member which slides generally axially in the cylinder of the lock and has a projection for contact with an end of a rib on a key blade. The key thus positions the slider which controls the side bar to allow the side bar to move to an unblocked position. The slider control of the side bar and the unique key and key blade provide further degrees of security, allow master keying and key control. It is an object of the present invention to at least provide the public with a useful choice.

BRIEF-DESCRIPTION OF THE DRAWINGS FIG. 1 is a end elevation view of the cylinder or plug of a twisting tumbler lock having a side bar; FIG. 2 is a longitudinal section view taken along line 2-2 of FIG. 1; FIG. 3 is a horizontal section view taken along line 3-3 of FIG. 2; FIG. 4 is a plan view of a key blank of this invention; WO 02/066773 PCT/US02/02211 FIG. 5 is an end elevation view similar to FIG. 1 with the lock in unblocked position; FIG. 6 is a longitudinal sectional view taken along lines 6-6 of FIG. 5; FIG. 7 is a longitudinal sectional view taken along lines 7-7 of FIG. 6; FIGS. 8, 9, 10 and 11 are alternative embodiments showing a cut key of this invention with the slider superposed thereon to illustrate the possibilities of master keying. 10 FIG. 12 is a sectional elevation view of the prior art, Medeco cylinder lock, to show the setting of this invention.

FIG. 13 is a sectional view taken along line 13-13 of FIG.■12.

FIG. 14 is an end elevational view of the cylinder of a 15 twisting tumbler lock having a side bar and showing a further embodiment of embodiment of this invention.

FIG. 15 is a longitudinal sectional view taken along line 15-15 of FIG. 14.

FIG. 16 is a horizontal view taken along line 16-16 of 20 FIG..15.

FIG. 17 is an end elevational view of the cylinder shown in FIG. 14 showing the components of' the cylinder in their locked position.

FIG. 18 is a longitudinal section view taken along line 25 18-18 of FIG. 17.

FIG. 19 is a horizontal sectional view taken along line 19-19 of FIG. 18.

FIG. 20 is a plan view of a key blank for key of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1-3 a cylinder or plug 10 has a keyway 12 as is conventional in Medeco locks. Tumbler holes 14 are provided for rotating, reciprocating, i.e., twisting tumblers 10 11 (FIG. 12) which have configurations 13 on their side for reception of a side bar 16 as taught and shown in the prior art Medeco constructions and patents identified above, see FIGS. 12 and 13. Because remaining portions of such Medeco locks are known, for the sake of simplicity they have not been 15 shown, except for the illustration of prior art in FIGS. 12 and 13.

The side bar 16 is positioned to reciprocate transverse to the axis of the cylinder plug 10 and biased by springs away from the plug to provide a further level of locking control 20 for the lock, as is known. The side bar has a cam 18 for cooperating with a cam groove 19 on the inside of the casing, also.as is conventional in Medeco locks, see FIG. 13. When the plug is attempted to be rotated by the key the cam groove 19 allows the side bar to be forced inwardly toward the center 25 of the cylinder. The side bar has projections 20 for engaging the configurations 13 on the tumblers 11 to allow the side bar to move toward the axis of the plug and clear the casing when the tumblers are rotated by the key to a correct position, as in known Medeco locks.

In the present invention, the side bar also has spaced 5 slots 22 positioned along its lower surface as shown in FIGS. 1 and 2. Projections 23 are defined by the spaces between the slots.

Positioned in an axial hole 30 in the cylinder plug is a slider 24 which can slide on an axis parallel to the axis of 10 the rotatable cylinder plug. The slider itself has a projection 2 6 at one end which extends into the keyway 12 for engagement with proper key as will be described. A spring 28 is provided for biasing the slider axially in hole 30 in a duration toward the front or key entry point of the lock. 15 The slider 24 also has spaced tangs 32 on its surface as shown in FIGS. 1, 2 and 3. These tangs are of sufficient size and length to either fit in the slots 22 of the side bar when the slider is properly positioned, or interfere with the projections 23 on the side bar when not properly positioned. 20 As shown in FIG. 2, the tangs 32 on the slider and projections 23 on the side bar 16 interact thus preventing the side bar from moving inwardly, thus blocking operation of the side bar and hence the lock.

As shown in FIG. 6 when the slider spring 28 has been 25 compressed and the tangs 32 on the slider are positioned within the slots 22 of the side bar, the side bar is allowed WO 02/066773 PCT/US02/02211 to operate as shown in FIGS. 5 and 6. Thus, the slider provides a third level of lock control in addition to the reciprocation and rotation of the tumblers.

A unique key blank 34 may be provided with proper bitting 5 35 for operating the lock. The key blank has a bow 36 and a blade 38. The blade has a profile which conforms to the profile of the keyway 12. On the side of the key blank (and the key) there is a rib 40 having a contact surface 42 formed for contacting the projection 26 on the slider 24. As shown 10 in FIG. 6, when the key is inserted and rib end 42 contacts projection 26 it compresses spring 28 and positions the slider so as to not to interfere with operation of the side bar.

FIGS. 8, 9, 10 and 11 show other embodiments having different configurations of the contact surface 42 on key rib 15 40 and showing the slider 24 superimposed, the slider projection 26 having a surface complimentary to the contact surface 42. FIG. 8 is the same as the FIGS. 1-7 embodiment, but in the open position of FIG. 6. In FIG. 9 the slider projection as a step 44 for receiving a similarly configured 20 key rib end 42a. FIG. 10 has a slanting surface 46 for cooperating with a slant surface 42b on the distal end of key rib 40. FIG. 11 has a tooth shaped surface 48 on projection 26 for cooperating with a complimentary shaped rib surface 42. To illustrate master keying possibilities, the key of FIG. 8 25 will correctly position the slider shown in FIG. 8 and the key of FIG. 11 will correctly operate the slider in FIG. 11. The WO 02/066773 PCT/US02/02211 key in FIG. 8 will also correctly position the slider of FIG. 11. However, the key of FIG. 11 will push the slider of FIG. 8 too far and the lock will not open. Similarly, the key of FIG. 8 will not operate with a slider configured as in FIG. 9 5 or as in FIG. 10 because it would push the slider too far and the lock will not open. By providing different keys with differently configured distal ends of the key rib, and providing different cylinders with differently configured slider projections, the cylinders can be selectively operated 10 by the different keys.

FIGS. 14-20 show an alternative embodiment in which the blocking member or slider instead of being a rod insertable into the end of the cylinder is in the form of a block which is insertable from the bottom of the keyway. This is shown in 15 more detail with reference to FIGS. 14, 15 and 16 showing the slider in position to not block the side bar. As shown the plug 10 has its keyway 12 open at the bottom. The side bar 16' has spaced slots 22' which will allow the sidebar to either clear or be blocked by the slider as will be described 20 below. As with the prior described embodiment, the invention is in the environment of the Medeco twisting tumbler locks as shown in FIGS. 12 and 13 in which the side bar 16 reciprocates transverse to the axis of the cylinder plug to provide a higher level of locking and the side bar is biased inwardly by 25 springs to either be held by or passed over and out of cam groove 19 on the inside of the casing which cooperates with WO 02/066773 PCT/US02/02211 cam 18 on the side bar as shown in FIGS. 16 and 19 and as is conventional in Medeco locks. When the plug is attempted to be rotated by a key, the cam 18 causes the side bar 16' to be forced inwardly toward the center of the cylinder. The side 5 bar has projections 20' for cooperating with the twisting cylinders as is known in the art. The side bar also has spaced slots 22' positioned along its side surface.

The slider in this embodiment is a block shaped member 24' shaped to fit within the cylinder shell and to be inserted 10 from the open bottom of the keyway 12. A spring 28' is provided by biasing the slider toward the bow of the key as shown in FIGS. 15 and 18.' The slider moves axially of the key in space 30'. The plug shaped slider has spaced tangs 32' on its upper surface as shown in FIGS. 15 and 18. These tangs 15 can move into slots 22 in the side bar when the slider is positioned by the key as shown in FIGS. 15 and 16. However, as shown in FIG. 18, when the key is not moving the slider, the tangs 32' intersect with the portions of the side bar outside the slots 22' as indicated by interference points 33 20 and this prevents the side bar from moving axially inwardly and prevents the lock from being operated to accomplish unlocking. This would happen at all times except when a proper key such as key 34' shown in FIG. 20 is inserted into keyway 12 to move the slider member 24' from the normal 25 position of FIG. 18 to the unlocking position of FIG. 15.

This is accomplished by a further projection 35 on the slider WO 02/066773 PCT/US02/02211 24' which extends into the keyway so as to intersect with the profile of the key blade 38'. The key blade has a stop 42' which contacts projection 35 and compresses the spring 28' when the key is inserted to allow the side bar to operate when the tangs 32' are in the grooves 22' as shown in FIG. 15.

In operation the key 34' is inserted into the keyway 12 to move the slider 24' against the bias of spring 28' and when the projections 32' are in the position to cooperate with grooves 22', the side bar 16' can operate to allow the key to turn the plug and operate the lock. Unless the portion 42' of the key 34' contacts the projection of 35, the slider or block 24' will block operation of the lock.

The keys of FIGS. 8-11 could also be used with this embodiment.

The advantage of this construction is that it allows master keying and provides further security because it does not require the conventional pin and tumbler master keying techniques to be used to configure the locks with the selective master keying capability. When used to supplement conventional master keying techniques, it provides additional capability thus offering the customer the most secure system.

Although the present invention has been described with reference to the particular embodiments disclosed, it is understood that these embodiments are merely illustrated of the application and principles of the invention. Numerous other configurations can be made and other arrangements can WO 02/066773 PCT/US02/02211 be devised without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

WO 02/066773 PCT/US02/02211 We claim: 1. A cylinder lock of the type having a rotatable cylinder with an axis and a keyway, the lock being controlled by rotatable reciprocating tumblers which are selectively 5 contacted by a side bar under control of a key, with the improvements comprising; a moveable member operable by contact with the key and cooperating with the side bar to control movement of the side bar and control operation of the lock. 10 2. A cylinder as defined in claim 1, wherein the moveable member is a slider which slides in the cylinder parallel to the axis of the cylinder. 15 3. A cylinder lock as defined in claim 2, wherein the slider is biased in a direction parallel to the axis of the cylinder. 4. A cylinder lock as defined in claim 3, wherein the 20 bias is provided by a spring in the cylinder to force the slider in a direction toward an entrance of the keyway. 5. A cylinder lock as defined in claim 3, wherein the slider has an extension which extends into the keyway for 25 contacting the key. - 11 - WO 02/066773 PCT/US02/02211 6. A cylinder lock as defined in claim 5 wherein the extension is a projection shaped to cooperate with a portion of a key when inserted into the keyway. 7. A cylinder lock as defined in claim 3 wherein the slider is insertable into the lock through a keyway opening therein. 8. A cylinder lock as defined in claim 3 wherein the slider is insertable longitudinally through an opening in the end of the plug. 9. A key for a cylinder lock of the type defined in claim 1, the key fitting into the keyway, a rib on the key, a portion of the rib positioned to contact and control the ■ locking movement of the movable member when the key is inserted into the keyway. 10. A key blank for a cylinder lock of the type defined in claim 1, the key blank fitting into the keyway, a rib on the key blank, a portion of the rib positioned to contact a contact portion of the slider and control the locking movement of the slider when the key blank is inserted into the keyway. - 12 - WO 02/066773 PCT/US02/02211 11. A master keying system comprising a cylinder lock as defined in claim 1 and keys as defined in claim 7, the keys having different configurations on the contact portions of the rib and slider so that one key will operate to control and 5 another key will not control operation the slider. 12. A cylinder lock combination, including a rotatable cylinder with an axis and a keyway therein, the lock being controlled by rotatable reciprocating tumblers which contact 10 and further control a side bar with the improvements comprising, a slider carried by the cylinder, a spring for biasing the slider to a position toward entrance of the keyway, 15 the slider having spaced tangs, the side bar having spaced projections, the tangs on the slider and the projections on the side bar interfering with each other to prevent operation of the side bar unless the slider is moved against the bias of it spring until the tangs 20 of the slider are within spaces between the side bar projections, ; the slider having a projection with a contact surface which extends into the keyway, and a key configured for insertion into the keyway, the key 25 having a contact surface for contacting the contact surface projection on the slider and moving the slider against the - 13 - WO 02/066773 PCT/US02/02211 bias of the spring to a position where the tangs on the slides clear the projection on the side bar. 13. A cylinder lock combination as in claim 10 wherein 5 the slider is insertable into the lock through a bottom of the keyway. 14. A cylinder lock combination as in claim 10 wherein the slider is insertable longitudinally into the lock through 10 a hole in the end of the plug. 15. A key blank for forming a key for a cylinder lock having a rotatable cylinder with an axis and a keyway, rotatable reciprocating tumblers, a movable side bar for 15 contacting the tumblers and a slider for controlling operation of the side bar, a projection on the slider extending into the keyway, the key blank comprising a key bow, a key blade with grooves providing a profile complimentary to the configuration of the profile of the keyway, with at least one rib on the key 20 blank, and a contact surface on the rib for cooperating with the projection and moving the slider to unblock the side bar. 16. A key for a cylinder lock having a rotatable cylinder with an axis and a keyway, rotatable reciprocating 25 tumblers, a movable side bar for contacting the tumblers and a slider for controlling operation of the side bar, a projection - 14 - WO 02/066773 PCT/US02/02211 on the slider extending into the keyway, the key comprising a key bow, a key with grooves with a profile complimentary to the configuration of the profile of the keyway, at least one rib on the key, and a contact surface on the rib for 5 cooperating with the projection and moving the slider to unblock the side bar. 17. A cylinder lock having a rotatable cylinder with an axis and a keyway therein, the lock being controlled by 10 rotatable reciprocating tumblers which contact and control a side bar, with the improvement comprising, a slider carried by the cylinder, a spring for biasing the slider toward the entrance to the keyway, 15 the slider having spaced tangs, the side bar having spaced projections, the tangs on the slider and the projections on the side bar interfering with each other to prevent operation of the side bar unless the slider is moved against the bias of it' 20 spring until the tangs of the slider are within spaces between the side bar projections, and the slider having a projection with a contact surface which extends into the keyway for cooperation and activation by a proper key insertable into the keyway. 25 - 15 - WO 02/066773 PCT/US02/02211 18. A cylinder lock as defined in claim 13 wherein the contact surface on the slider projection is shaped to cooperate with various shaped contact surfaces on keys for the lock to provide master keying. 5 19. ' A key blank for a cylinder lock of the type defined in claim 1, the key blank shaped to fit into a keyway, a rib on the key blank, a portion of the rib positioned to contact and configured to control the locking movement of the slider 10 when the key blank is inserted into the cylinder. - 16 - WO 02/066773 PCT/US02/02211 [Received by the International Bureau on 10 July 2002 (10.07.02): original claims 1,3, 8, 9,11-14 and 16-18 replaced by amended claims claims 1,3, 8, 9, 11-14 and 16-18; claims 2,10,15 and 19 are cancelled] 1. A cylinder lock of the type having a rotatable cylinder with an axis and a keyway, the lock being controlled 5 by rotatable reciprocating tumblers which are selectively contacted by a side bar under control of a' key, with the improvements comprising; a moveable member separate from the tumblers and operable by contact with the key and cooperating with the side bar to 10 control locking movement of the side bar and control operation of the lock, ^ wherein the moveable member is a slider which slides in the cylinder parallel to the axis of the cylinder. 15 3. A cylinder lock as defined in claim 1, wherein the slider is biased in a direction parallel to the axis of the cylinder. ; 4. A cylinder lock as defined in claim 3, wherein the 20 bias is provided by a spring in the cylinder to force the slider in a direction toward an entrance of the keyway. 5. A cylinder lock as defined in claim 3, wherein the slider has an extension which extends into the keyway for ^5 contacting the key. 6. A cylinder lock as defined in claim 5 wherein the extension is a projection shaped to cooperate with a portion of a key when inserted into the keyway. 30 7. A cylinder lock as defined in claim 3 wherein the slider is insertable into the lock through a keyway opening therein. 35 8. A cylinder lock as defined in claim 3 wherein the -11- AMENDED SHEET (ARTICLE 19) WO 02/066773 PCT/US02/02211 slider is insertable longitudinally into the end of the cylinder. 9. A key for use in combination with a cylinder lock as 5 defined in claim 1, the key fitting into a keyway of the cylinder, a rib on the key, a portion of the rib positioned to contact and control locking movement of the movable member when the key is inserted into the keyway. 10 11. A master keying system comprising a cylinder lock as defined in claim 1 and keys as defined in claim 9, the keys having different configurations on the key and slider so that one key will operate to control and another key will not control operation of the slider. 15 12. A cylinder lock combination, including a rotatable cylinder with an axis and a keyway therein, the cylinder being controlled by rotatable reciprocating tumblers which contact and further control a side bar with the improvements 20 comprising, a slider carried by the cylinder, a spring for biasing the slider to a position toward entrance of the keyway, the slider having spaced tangs, 25 the side bar having spaced projections, the tangs on the slider and the projections on the side bar interfering with each other to prevent operation of the side bar unless the slider is moved against the bias of the spring until the tangs of the slider are within spaces between the side bar 30 projections, the slider having a projection with a contact surface which extends into the keyway, and a key configured for insertion into the keyway, the key having a contact surface for contacting the contact surface of 35 the projection on the slider and moving the slider against the -12- AMENDED SHEET (ARTICLE 19) WO 02/066773 PCT/US02/02211 bias of the spring to a position where the tangs on the slider clear the projections on the side bar. 13. A cylinder lock combination as in claim 12 wherein 5 the slider is insertable into the lock through a bottom of the keyway. 14. A cylinder lock combination as in claim 12 wherein the slider is insertable longitudinally into the lock through 10 an opening in the end of the cylinder. 16. A key for a cylinder lock having a rotatable' cylinder with an axis and a keyway, rotatable reciprocating tumblers, a movable side bar for contacting the tumblers and a 15 slider for controlling operation of the side bar, a projection on the slider extending into the keyway, the key comprising a key bow, a key blade with a profile complimentary to the configuration of the profile of the keyway, at least one rib on the key, and a contact surface on the rib for cooperating 20 with the projection and moving the slider in the cylinder parallel to the axis o'f the cylinder to unblock the side bar. 17. A cylinder lock having a rotatable cylinder with an axis and a keyway therein, the lock being controlled by 25 rotatable reciprocating tumblers which contact and control a side bar, with the improvement comprising, a slider carried by the cylinder, a spring for biasing the slider toward the entrance to the keyway, 30 the slider having spaced tangs, the side bar having spaced projections, the tangs on the slider and the projections on the side bar interfering with each other to prevent operation of the side bar unless the slider is moved against the bias of the 35 spring until the tangs of the slider are within spaces between -13- AMENDED SHEET (ARTICLE 19) WO 02/066773 PCT/US02/02211 the side bar projections, and the slider having a projection with a contact surface which extends into the keyway for cooperation and activation by a proper key insertable into the keyway. 18. A cylinder lock as defined in claim 17 wherein the contact surface on the slider projection is shaped to cooperate with various shaped contact surfaces on keys for the lock to provide master keying. -14- AMENDED SHEET (ARTICLE 19) We claim:

1. A cylinder lock of the type having a rotatable cylinder with an axis and a keyway, the lock being controlled by rotatable reciprocating tumblers which are selectively contacted by a side bar under control of a key, with the improvements comprising; a moveable member separate from the tumblers and operable by contact with the key and cooperating with the side- bar to control locking movement of the side bar and control operation of the lock, wherein the moveable member is a slider which slides in the cylinder parallel to the axis of the cylinder.

2. A cylinder lock as defined in claim 1, wherein the slider is biased in a direction parallel to the axis of the cylinder.

3. A cylinder lock as defined in claim 2, wherein the bias is provided by a spring in the cylinder to force the slider in a direction toward an entrance of the keyway.

4. A cylinder lock as defined in any one of the preceding claims, wherein the slider has an extension which extends into the keyway for contacting the key.

5. A cylinder lock as defined in claim 4 wherein the extension is a projection shaped to cooperate with a portion of a key when inserted into the keyway.

6. A cylinder lock as defined in any one of the preceding claims wherein the slider is insertable into the lock through a keyway opening therein.

7. A cylinder lock as defined in any one of the 11 MAR 2004 RECEIVED preceding claims wherein the slider is insertable longitudinally into the end of the cylinder.

8. A key in combination with a cylinder lock as defined in any one of the preceding claims, the key fitting into a keyway of the cylinder, a rib on the key, a portion of the rib positioned to contact and control locking movement of the movable member when the key is inserted into the keyway.

9. A master keying system comprising a cylinder lock as defined in any one of claims 1 to 7 and keys as defined in claim 8, the keys having different configurations on the key and slider so that- one key will operate to control and another key will not control operation of the slider.

10. A cylinder lock combination, including a rotatable cylinder with an axis and a keyway therein, the cylinder being controlled by rotatable reciprocating tumblers which contact and further control a side bar with the improvements comprising, a slider carried by the cylinder, a spring for biasing the slider to a position toward entrance of the keyway, the slider having spaced tangs, the side bar having spaced projections, the tangs on the slider and the projections on the side bar interfering with each other to prevent operation of the side bar unless the slider is moved against the bias of the spring until the tangs of the slider are within spaces between the side bar projections, the slider having a projection with a contact surface which extends into the keyway, and -12- a key configured for insertion into the keyway, the key having a contact surface for contacting the contact surface of the projection on the slider and moving the slider against the bias of the spring to a position where the tangs on the slider clear the projections on the side bar.

11. A cylinder lock combination as in claim 10 wherein the slider is insertable into the lock through a bottom of the keyway.

12. A cylinder lock combination as in claim 11 wherein the slider is insertable longitudinally into the lock through an opening in the end of the cylinder.

13. A key and a cylinder lock having a rotatable cylinder with an axis and a keyway, rotatable reciprocating tumblers, a movable side bar for contacting the tumblers and a slider for controlling operation of the side bar, a projection on the slider extending into the keyway, the key comprising a key bow, a key blade with a profile complementary to the configuration of the profile of the keyway, at least one rib on the key, and a contact surface on the rib for cooperating with the projection and moving the slider in the cylinder parallel to the axis of the cylinder to unblock the side bar.

14. A cylinder lock having a rotatable cylinder with an axis and a keyway therein, the lock being controlled by rotatable reciprocating tumblers which contact and control a side bar, with the improvement comprising, a slider carried by the cylinder, a spring for biasing the slider toward the entrance to the keyway, the slider having spaced tangs, the side bar having spaced projections, the tangs on the slider and the projections on the side bar interfering with -13- INTELLECTUAL PROPERTY OFRCfr OP N..7 1 I m 20M RECEIVED^ slider and the projections on the side bar interfering with each other to prevent operation of the side bar unless the slider is moved against the bias of the spring until the tangs of the slider are within spaces between the side bar projections, and the slider having a projection with a contact surface which extends into the keyway for cooperation and activation by a proper key insertable into the keyway.

15. A cylinder lock as defined in claim 14 wherein the contact surface on the slider projection is shaped to cooperate with various shaped contact surfaces on. keys for the lock to provide master keying.

16. A cylinder lock substantially as herein described with reference to the drawings.

17. A key in- combination with a cylinder lock substantially as herein described with reference to the drawings.

18. A master keying system substantially as herein described With reference to the drawings.

19. A cylinder lock combination substantially as herein described with reference to the drawings. -14-