Abstract: An improved, highly pick-resistant tumbler lock construction incorporates at least one of the rear face of the driver sleeve or the front face of the tumbler sleeve with a plurality of notches. Each notch surrounds a driver or tumbler axial bore so as to provide at the trough of the notch a false shear plane while the crest of the notch portion of the tumbler and driver sleeve forms a plane to fixedly support two relatively thin discs which form the true shear plane. The discs include annularly spaced bores corresponding to the tumbler and driver sleeve bores. Thus when attempting to pick the lock, and the driver and tumbler pins are at the notched false shear plane, the driver sleeve will not be able to turn because the pins will be caught in the lower part of the notch.

Abstract: This specification describes a lock where a key is inserted into a key cylinder and where the key sets a series of transfer tumblers. The tumblers project from the key cylinder, and the tumblers, in turn, set a series of lock opening elements into their prescribed positions. As the key-cylinder is rotated the transfer tumblers are moved out of contact with the elements. Only at this time can the lock be opened, provided that the elements had been correctly set.

Abstract: This invention relates to a lock where a key or a dial sets a set of elements into a unique configuration. The elements do not contain any information relating to the key. They are preferably all alike and, preferably, each of them terminates in a pointed end. Co-operating with these elements, the lock contains a perforated or indented reference plate where the perforation, or indentations, are so located that when the proper key or combination is fed into the lock the ends of the elements can all enter the plate and the lock can be opened. The lock has the additional feature that when it is desired to change the key, or the combination, only the plate needs to be changed. The key-set or the dial-set elements remain the same.

Abstract: A lock has an outer casing and a lock cylinder rotatably mounted therein and having a coaxial keyway of round cross section plus several rows of radial bores to accommodate the tumblers and their springs, and also has a key which has notches on its outside profile for the engagement with the tumbler. The key has an equilateral polygonal bit cross section which matches the cross section of the keyhole in the front wall of the lock casing as well as a coaxial opening in the lock cylinder bottom, these cross sections of the keyhole and bottom opening being angularly offset from one another. The tip of the key bit has ramp surfaces corresponding to the rows of the tumblers, ascending toward the handle of the key and terminating each at one polygon face for the purpose of raising the tumblers, and the rows of notches are disposed between the polygon faces.

Abstract: The invention concerns a locking device consisting of a key and of a lock. Inside the lock is a shaft (1) that has at least two diametrically opposed cams (4 & 5 ) mounted on it. The key can be positioned against one end (2) of the shaft in such a way that it cannot rotate in relation thereto. Inside the body (6) of the lock are blocking or barricading elements (9 & 10) that can slide or pivot radially in the unbarricaded state and that are subject to springs (40) that force them radially inward. The blocking elements are barricaded by means of several blocking pins (11) that block the sliding blocking elements or operate in conjunction with them by means of special blocking extensions on them to provide a blocking action. The blocking pins are subject to spring (12 or 60) that force them into the blocking position.

Abstract: A rotary cylinder lock and a corresponding key blade are disclosed. The cylinder lock comprises a cylinder shell (19), a key plug (20) rotationally mounted in the shell (19) to provide a shear line (21) between the shell and the key plug, a key slot (11) extending into the key plug (20) parallel to the rotational axis thereof for receiving a key blade (1), at least one locking tumbler (23b) including an elongated body portion guided in a complementary cavity (33b) in the key plug (20), the elongated body portion being capable of rotational movement about its longitudinal axis, and a fence member blockingly associated with the locking tumbler and shaped so that rotational positioning of said locking tumbler with a properly shaped key blade allows said fence member to clear the shear line.

Abstract: Pivotable tumblers mounted to a cylindrical plug prevent rotation of the plug unless a correct key in a keyway moves the tumblers to an unlocked position. If the tumblers extend too far into the keyway, pawls mounted in the body and acting on steps of the plug prevent rotation of the plug to an unlocked position. If the tumblers do not extend for enough into the keyway, the tumblers jam up against a reentrant shoulder of the body preventing the plug from reaching the unlocked position. A security keyway closure or door cams off a race in the body and closes the keyway with rotation of the plug. A slot in the key passes the door during operation.

Abstract: An auto-directing lever lock includes a case housing a cylinder (4) with a plug (3) mounted for movement therein. The plug includes a keyway (14) for accepting a key bit (7). A keyway opening (15) on the surface of the plug provides access for lever tumblers (6) to engage lever steps on the key bit. The key bit is detachable from a bow and shank section (8), and inserted in to the keyway through a key hole (39) in the case. The tumblers ride on a surface of the plug and are held away from the lever steps of the key bit during rotation of the plug, until the tumblers disengage the plug surface due to the keyway opening therein. The tumblers, when disengaged from the plug surface, fall onto the lever steps of the key bit to align gatings (32) of the tumblers so a bolt stump (28) may pass therethrough to retract a bolt (5) of the lock.

Abstract: A cylinder lock of the type having twisting tumblers operated by a bitted key having at least one skew-cut bit provided with a side bar which is symmetrical with regard to a radius through a center of the key plug perpendicular to the plane of the key so that the side bar intersects not only slots in the twisting tumblers, but the profile of the key. The key has slots in its side face which extend perpendicular to its longitudinal axis.

Abstract: A cylinder lock whose stator is a longitudinal groove and whose rotary cylinder has a key receiving slit, two series of seatings and two orthogonal slits; a series of sliders pushed by springs is inserted, with mobility in two directions, into the first series of seatings of the cylinder and cooperates with a key, and each slider is provided with projections and with a member for sliding engagement; a series of tumblers is slidingly inserted into the second series of seatings of the cylinder, and each tumbler is provided with recesses turned towards the sliders and with at least one recess at the opposite side; a stop bar pushed by springs is inserted into an orthogonal slit and is provided with projections turned towards the tumblers and with a continuous projection suitable for being inserted into the groove of the stator; and a translation bar pushed by springs is inserted into the other orthogonal slit of the cylinder, engages the members for sliding engagement of the sliders and is provided with a contin

Abstract: A removable core (15) for a lockset (10) has a core removal ring (35') which is provided with a gap therein which prevents the lock from being picked by turning the core removal ring with an elongate wire having a wedge-shaped end. One of the end edges of the core removal ring (35') defining the gap is positioned in substantial registration with a keyway (18) at an approximate 6 o'clock position. The other end edge of core removal ring (35') normally resides at an approximate 3 o'clock position.

Abstract: A cylinder lock with key, incorporating a picking preventing means, comprises a plug mounted rotatably within the cylindrical seat of a lock cylinder and has a first set of holes lying on a radial plane. The holes accommodate pins which cooperate with tumbler pins accommodated in a second set of holes formed in the cylinder and being aligned with the first set of holes. A longitudinal key slot extends through the plug which is in communication with the first set of holes and has a longitudinal rib arranged to project thereinto to provide support for the pins. The rib conceals the ends of the pins resting thereon, and defines an intersection of the longitudinal key slot with the cylindrical portions of said first set of holes accommodating said pins. One of the pins has the same length as the hole accommodating it, thereby if deceitfully shifted, it will unavoidably engage the hole of the respective tumbler pin and produce a locked condition of the lock.

Abstract: An axial type, tubular key operated, cylinder lock which utilizes a plurality of variable strength and variable tension spring-biased pin arrangements which are to be movable when connected with the proper key to a shear-line position achieving operation of said lock. A pin assembly is normally movable longitudinally to its shear-line position. Any attempt to move the pin assembly other than with a properly coded key will result in the pin assembly being deflected to a displaced position deterring against operation of the lock.

Abstract: Fiber optic sensors are used at one or more of the top pin and spring asslies in a pin tumbler lock to sense either authorized or unauthorized attempt to open the lock. A fiber optic switching element, in a simple capsule form, can be installed in new or existing locks. Fiber optic circuitry signals surreptitious attempts to open the lock.

Abstract: A lock according to the present invention includes an interchangeable core including a core body, a core sleeve, and a key plug having a key slot. A sloping shoulder is provided on at least one of the tumbler pin passageways in the key plug to define an enlarged opening on the exterior surface of the key plug that is non-concentric with said passageway. A sloping shoulder can also be provided on at least one of the tumbler pin passageways in the core sleeve to define an enlarged opening on the exterior surface of the core sleeve that is non-concentric with said passageway.

Abstract: A cylindrical tumbler lock including a barrier member between and interfacing a first and second connected latch operating members, the members having corresponding holes receiving spring biased split pin tumblers, a key positioning the tumblers for interfacial clearance between the members for rotation and operation of a latch member, the holes in one of the members being larger, the split tumblers in the holes of the first latch operating member including false segments of the tumblers and the tumblers extending to the face of the lock or some extending near thereto whereby the lock is caused to be very resistant to picking or manipulation.

Abstract: The usual pin tumbler lock core is provided with an additional set of security disc tumblers adapted to engage contours on the bottom rail of a key and in so doing the security tumblers are rotated as the key is inserted in the lock so that when the key is fully inserted, gates on the security tumblers all align to permit the inward movement of a side bar. The invention also envisions the key which is an otherwise conventional key having a bevelled tip and a security contour on a lateral surface for activation of the security tumblers of the lock of the invention.

Abstract: A twisting tumbler lock with dual locking function has tumbler points at tumbler positions selectively offset forwardly or rearwardly and selectively rotatable to different angular positions to create an enormous number of keying combinations. A key according to the invention includes one or more bits which are offset forwardly or rearwardly of a corresponding tumbler axis.

Abstract: In a locking system, a combination of mechanical tumblers which are moved into a release position by the shape of the key and at least one magnetic tumbler which is drawn into the release position by a visually nondiscernible magnet placed on the key. The lock style being standard in that it includes inner and outer cylinders wherein the inner cylinder rotates between an open and locked position. In an alternate embodiment of the subject invention, an additional tumbler made from a magnetically attractible material is placed in the cylinders and biased to the open position. Should the key being used to open the lock contain a magnet substantially adjacent to this additional magnetic tumbler, the tumbler will be drawn to the locked position thereby preventing the rotation and opening of the inner cylinder.

Abstract: This disclosure relates a cylinder lock with anti-picking device. A shaft is provided to extend into the keyway of the lock to prevent the entry of any foreign object. Only when a special tool is used to retract the shaft can a key be inserted into the keyhole, thereby eliminating the risk of picking by unauthorized persons.

Abstract: A lock and key system is provided wherein the flat sides of the keys are equipped with locking ribs projecting beyond the normal profile and provided with indentations (depressions) over their course, i.e., are equipped with height-modulated locking ribs. In order to achieve an additional scope of variation which adds to the variations presently available in locked key systems, based on locks having identical bore patterns, the auxiliary locking ribs of the keys of the individual locks are provided with a differing distribution of elevations and depressions and, interacting with these locking rib designs are a number of species of sensing pins. A first species of pins serve to sense elevations, a second species of pins serve to sense depressions and a third species of pins is provided at those locations of the locks at which the individual key comprises an elevation, but the superordinated or master key for the actuation of locks combined into a system comprises a rib depression at the same location.

Abstract: This specification describes a lock where a key sets a multiplicity of elements such as disks, levers or others. After setting the elements, the key and the key slot (through which the key enters the lock) is moved out of contact with the elements and is subsequently completely isolated from them. The fence or any other component that co-acts with the previously set elements to open the lock cannot be brought into contact with them until the above isolating action has been completed.

Abstract: A cylinder lock has a plug (2) provided with coaxial pin passages (6, 8) arranged to accommodate lock pins (7, 9). At least one pin (9) has a necked portion (9a) and a head (9b), and at least one of the pin passages (6) exhibits a widened portion (6a). The pin head (9b) has a smaller diameter than the major part of the pin, and the widened portion (6a) of the recess has a smaller radius in a direction transversely of the axis of plug (2) than half the pin diameter. One or more disc-like pin members (11) may be provided between upper and lower pins (9, 7), these disc-like pin members being prevented from entering the widened portion of the recess when activating the lock with the correct key. The arrangement is such, however, that the head (9b) is readily hooked-up when an attempt to pick the lock is made.

Abstract: A cylinder lock which prevents picking is disclosed. The lock comprises an outer shell having a cavity therein, a plug having a hole and a plurality of circumferential apertures extending partially through the plug, with grooves around the openings of the apertures. The plug is snugly disposed in the cavity. Spring biased pins are slidably received in the plug apertures. The cylinder lock also has a shaft member disposed in the cavity with a flange portion extending outwardly from said shaft member. The flange portion has a plurality of apertures with grooves around the openings of the apertures which face the plug. The apertures extend through the flange portion, and are alignable with the apertures of the plug. The shaft member passes through the hole of the plug, and is adapted to be rotated. The flange portion fits snugly in the cavity. Pins are slidably received in the flange portion apertures.

Abstract: An improved quincunx-shaped lock device comprises a lower pin seat, a lower lock pin and a check ring. The whole lengths of the lower lock pins are different. The lengths of the pin head and pin tail having different outer diameters are also different. The bottom of the lower pin holes of the lower pin seat has pin-tail-through holes. The check ring is furnished with several irregular notches. Whenever the lower lock pins are pressed by a key other than that for the lock to the bottom of the lower pin holes, the pin tails will penetrate through the pin-tail-through hole, and some of them will touch the check ring, while others penetrate out of the notches of the check ring. Since numerous variations are designed in the lock, it is impossible to unlock it without the correct key.

Abstract: A tamper-resistant lock assembly includes a pair of cooperating keyway guard plates, each of which has a keyway formed therethrough. The guard plates are laterally displaceable relative to one another for movement between an open position, in which the keyways thereof are substantially aligned to allow for passage of at least a portion of a key shank therethrough, and a closed position, in which the keyway of one of the guard plates is at least partially blocked by the other of the guard plates. A uniquely-configured key is also disclosed for use in combination with such guard plates.

Abstract: This invention describes a pickproof key lock where the key sets up a series of tumblers each of which has a notch or other configuration that cooperates with a sidebar. This sidebar, when out of engagement with the tumblers, keeps the lock in the inoperative position. The sidebar does not contact the tumblers and is kept in this position normally by the action of two opposing preloaded springs. When a key is inserted into the lock, the internal mechanism is made to operate on the sidebar to move it further away from the tumblers. The mechanism then releases the sidebar and the sidebar is propelled towards the tumblers by the action of a spring. If the tumblers have been properly set, as by a correct key, the sidebar enters the notches in the tumblers and is latched in that position. The lock can then be opened. If any of the tumblers were not set correctly, the sidebar simply impacts against such tumblers and is returned to its normal rest position out of contact with the tumblers.

Abstract: A cylinder lock mechanism includes a tubular barrel, a lock cylinder rotatable in the barrel, tumblers longitudinally and reciprocally movable within the cylinder, a cap on a front end of the barrel and having a key opening therethrough, a facing member interposed between the cap and the cylinder and having an opening registering with the cap opening, a spacer interposed between the facing member and the cylinder and having an opening registering with the cap opening, such openings when in registry receiving a key for insertion thereof into engagement with the tumblers, an engagement member extending transversely of the cylinder for engagement with the tumblers and laterally movable to and from the tumblers, a locking member extending longitudinally of the cylinder for engagement with the engagement member and laterally movable to and from the tumblers, structure on the cylinder and the barrel respectively for engaging the locking member therealong for locking purposes, structure on the tumblers for engaging

Abstract: A compact cylinder lock operated by a key having smooth edges and detents in opposed side faces. The locking mechanism includes series connected pin tumblers and side bars which are resiliently biased. A resiliently biased fence cooperates with the side bars and lock housing; the fence moving out of engagement with the housing and into gates in the side bars when the side bars are moved a sufficient distance by the pin tumblers.

Abstract: A self-shut type lock device comprising a self-shut protector provided in the keyhole capable of hiding the lower tumbler segments from being picked through the keyhole.

Abstract: A cylinder lock wherein both cylinder and plug are radially bored to receive pin-pairs of specific design. A pin freeze element is positioned for movement within the plug in a direction substantially orthogonal to the axis of the plug bores. The interface between the pin freeze element and the pins includes incremental notches of matching configuration such that when the plug is turned, the pin freeze element engages the pins locking them from reciprocal movement. The mating surfaces of the pin freeze element and pins must be in registration for the plug to turn at all and they must be in perfect registration and properly aligned for the lock to open.

Abstract: A protective housing and latch mechanism for securing the protective housing in a position protecting the customary housing for a coin mechanism and coin box. The protective housing permits normal operation of the coin mechanism and is of sufficient strength to resist deformation by sledge hammer blows. The protective housing carries a latch mechanism which locks the protective housing to the original housing for the coin mechanism so as to prevent separation of the two housings. The latch mechanism includes a pivotally mounted latch member which is urged to a latching position and held in that position by a barrel type lock which is disposed in an inaccessible position within a hardened block.

Abstract: The combination of a cylinder lock and key, wherein the key comprises a blade with a longitudinally extending edge portion at one side of the blade provided with a coded surface for engaging the ends of a row of locking pins in the cylinder core of the lock. The coded surface has code portions which engage a segment of the end of each pin spaced from the center thereof, and transition portions for guiding the pins between adjacent code portions and which are of concavely curved cross-sectional shape to provide for arcuate engagement with the pins, the code portions and transition portions of the coded surface being open to the side of the key blade and spaced from the other side thereof. The coded surface is produced by moving a rotary cutting tool relative to the key blank with substantially the same movement as the pins undergo relative to the key as the latter is inserted into and removed from the cylinder of the lock.

Abstract: A cylinder lock which includes plate tumblers in a lock cylinder and a locking channel arranged in a lock casing wherein, when the key is pulled out (locked position of the lock), spring-loaded plate tumblers engage with their locking ends into the locking channel up to an extension length determined by locking stops. The lock casing is provided with an escape channel diametrically opposed to the locking channel for enabling a free resetting motion of the plate tumblers with their counter ends during an insertion of the key. The plate tumblers have, in their key cutouts, tumbler edges arranged at levels corresponding with an associated key cutout depth and, with a key being inserted (free position of the lock), can be reset into the lock cylinder. Stops are provided for limiting the resetting motion of the individual plate tumblers in the escape channel at insertion depths and a varying arrangement of the blocking stops is made in dependence upon a height of the respective tumbler edge.

Abstract: In a removable core-type lock, the internal tumbler pin mechanism is modified to incorporate an antipick jamming action that is actuated whenever an attempt is made to pick the tumbler pins. The jamming action comprises a pair of security tumbler pin assemblies that cooperate with the lock's cylindrical plug which incorporates the lock's keyway and serves as the primary locking element, and with a modified control sleeve structure which forms part of the jamming action and serves as a control means for releasably retaining the core in the lock's casing. In reaction to tampering of the lock by an attempt to pick the tumbler pins, one of the security pins is forced to a position that locks the control sleeve structure and plug together in a manner that prevents the opening of the lock or the removal of the core from the lock casing by means other than the use of a properly notched primary or control key.

Abstract: A device for detecting entry or drilling attempts into cylinder locks. One or more housing bores not corresponding to core bores when the lock is in a neutral position having spring biased tripping pins connected to an alarm or indicator system and operable when an entry attempt is made not using a proper key or after having drilled-out the tumbler or tumbler and cylinder pins. The tripping pins detect the rotated cylinder having a space in the cylinder bore due an improperly made key or due to the cylinder bore having previously been emptied by the drilling operation.

Abstract: An axial split-pin tumbler-type lock mechanism having improved pick-resistance is provided with tumblers having substantially the same overall length, at least two of the tumblers having driver elements differing in length, and with spring means in at least two different spring rates respectively to act upon the tumblers having elements differing in length, one of the spring means which has a relatively high spring rate acting upon a tumbler having a relatively short driver element, and another of the spring means which has a relatively low spring rate acting upon a tumbler having a relatively long driver element.

Abstract: An improved cylinder lock which is very difficult to pick has at least one cylinder pin into which a set of shallow grooves has been cut as well as a deeper notch at one end of the pin. A boring is made in the cylinder at an angle to the boring of the cylinder pin and into which is placed an appropriately sized obstructing pin. The obstructing pin is free to drop into a recess made in the lock housing when the cylinder is locked. The process of attempting to pick the lock by rotating the cylinder slightly results in the obstructing pin sliding along the side of the V-shaped recess in the housing and thereby moving toward and engaging the notches in the body of the cylinder pin preventing unauthorized movement of the cylinder pin which would render the associated locking pin inoperative. When a legitimate key has been inserted into the cylinder, the cylinder pin moves to its fully unlocked position before the cylinder rotation is initiated.

Abstract: A pick-proof lock cylinder is disclosed wherein a set of lock pins accommodates the cut notches of a key and biasing means are angularly disposed to the lock pins to abut and hold the ends of the pins in locking positions. Attempts to pick the set of pins are frustrated by the interference of the biasing means. The biasing means are offset to the axis of the locking pins so that upon withdrawal of the key, the biasing means keeps the locking pins in raised condition. At least one of the locking pins is in abutment with a driver pin, so that the driver pin is disposed outside the shear line of the lock cylinder in its housing, and whereupon key insertion, the lock pin driver pin abutment line is coincident with the lock cylinder shear line so as to permit rotation of the cylinder in its housing.

Abstract: A tamper preventing tumbler lock which provides an alarm signal or prevents lock activation when any electrically conductive object, such as a pick or the like, is inserted in the keyway. The lock includes a pair of electrically conductive tumblers which complete an electrical path to activate the alarm or to activate a solenoid operated latch to prevent rotation of the lock cylinder or actuate an associated lock bolt when the conductive tumblers are bridged by the conducting object in the keyway. The lock may be operated as a conventional tumbler lock by means of an electrically non-conductive key.

Abstract: The specification describes a cylinder lock including a plurality of driver and associated follower pins movably residing in axially alignable bores in the lock core and cylinder, the lock also including spheres normally located in notches in the outer extremity of core cylinder wall, one or more of the spheres moving to a position between associated driver and follower pins preventing the alignment of these associated pins at the peripheral surface of the core when the follower or tumbler pins are manipulated without the use of a properly designed key.

Abstract: A locking device is disclosed which comprises a multi-leaved key which is adapted to be inserted within a correspondingly configured keyhole provided within an inner cylinder member. The inner cylinder member is slidably disposed within an outer cylinder member so as to permit or prevent rotation of the inner cylinder member with respect to the outer cylinder member through the interaction between a projection member and a slot or groove respectively provided upon the inner and outer cylinder members, as well as to permit or prevent the inner cylinder member from being engaged with a cam member which is operatively associated wih a lock bolt.

Abstract: A cylinder for a safety lock with a cylinder housing and a cylinder plug has tumblers made in the form of plug pins and housing pins. The tumblers are aligned by a key inserted into the lock. Each row of the housing pins is mounted with an associated pin spring in a respective separate chamber, the chambers being installed in respective recesses in the cylinder housing. The separate chambers are made in the form of sliders insertable in the axial direction in longitudinal channels in the cylinder housing, housing pins with their spring being guided in bores. The sliders are mounted so that they have axial play in the longitudinal channels.

Abstract: An axial split-pin tumbler-type lock mechanism includes a rotatable operating part and a stationary part, which adjoin at an interfacial plane. Tumblers each including a driver element and a follower element are mounted in bores in the parts, which bores meet in alignment at the interfacial plane, and the tumblers are movable back and forth in the bores. When the joints between the tumbler elements coincide with the interfacial plane upon insertion of a key, the operating part may be rotated by means of the key, to accomplish a desired function.

Abstract: This invention describes a pickproof lock consisting of a rotating cylinder provided with two sets of opposing tumblers. The tumblers permit a very thin key to be inserted between them. The key is made of a ribbon material of the order of one-hundredth of an inch thick and the tumblers are displaced in both directions from the center so that manipulation of a lockpicking tool becomes very difficult, since the tool must be as thin as the key and each set of tumblers must be in the correct position for the cylinder in turn.

Abstract: The safety device comprises a rotatable lock-operating rotor having a first key slot extending transversely thereof, a non-rotatable inner cylindrical body adapted for fixed securement to a door or the like, and a hollow cylinder embracing the rotor and the cylindrical body and having its inner end fixedly secured to the cylindrical body or member. Key-operable pins, plungers or pistons interconnect the rotor and the fixed cylindrical body to prevent rotation of the rotor. The rotor is formed with a first key slot extending transversely thereof and the hollow cylinder has a closed outer end formed with a second key slot extending transversely thereof. A rotatable diaphragm member is interposed between the fixed outer end of the hollow cylinder and the rotor, and has a third key slot extending transversely thereof. The rotor may be disconnected from the fixed cylindrical member by a key inserted into the first slot to engage the pins, plungers or pistons.

Abstract: A pin tumbler lock cylinder having axially elongated split pin tumbler assemblies each including a pin tumbler and a driver releasably coupled in locked position to prevent rotation of a key plug relative to a supporting cylinder shell. Insertion of a proper angularly bitted key into the key plug causes the tumbler assemblies to axially translate and rotate within bores, defined by the shell and the plug in its locked position, to predetermined releasing positions wherein a split line of each tumbler assembly is aligned with a shear line between the plug and the shell and each pin tumbler is free to separate from its associated driver to permit rotation of the key plug to an unlocked position. Means are provided to prevent rotation of the drivers and tumblers relatively to the shell and plug respectively, when the plug is rotated to an unlocked position. In a master keyed lock cylinder drivers are coupled to pin tumblers by master pins.

Abstract: An axial split-pin tumbler-type lock mechanism includes a rotatable operating part and a stationary part, which adjoin at an interfacial plane. Tumblers each including a driver element and a follower element are mounted in bores in the parts. The bores meet in alignment at the interfacial plane, and the tumblers are movable back and forth in the aligned bores. When the joints between the tumbler elements coincide with the interfacial plane upon insertion of a key, the operating part may be rotated by means of the key, to accomplish a desired function.

Abstract: A cylinder lock having a barrel with annular grooves, drivers aligned with the barrel grooves, key pins having slotted upper ends, at least some key pins having diametrically disposed chisel edges to cooperate with bitting cuts in the key for rotation of the key pins, and the drivers and key pins including provision for a magnetic interlock to prevent the drivers from hanging up on the shear line and the key pins from dropping away from the drivers, as in attempts at picking the cylinder. Projections adapted to enter into the pin slots and prevent rotation of the barrel except when the key pins are lifted to the shear line and rotationally oriented as needed are formed either on a gate or on the drivers.

Abstract: A cylinder lock with a key plug rotatably mounted in the cylinder shell is described. The key plug has a plurality of tumblers that are set by the V bits of a key inserted in the key plug. The key is cut at three different levels and cut at three different angles. Each tumbler in the key plug may be positioned by the properly bitted key reciprocally to clear the shear line and also positioned rotationally to allow the fence to be cammed out of engagement with the cylinder shell. The key plug may then be rotated.A side bar cylinder lock is also described with the same key cut at three different levels and cut at three different angles. The tumblers are positioned reciprocally and rotationally by the properly bitted key to allow the fence to be cammed out of engagement with the cylinder shell. The key plug may then be rotated.