Abstract: A key, comprising: a key head; and a key shank (10), characterized in that the key shank (10) includes a torsion section (20) that is formed, in particular cold formed, along a longitudinal axis (L) at least in sections, wherein the key shank (10) includes a base cross-section (26) in a transition portion to the torsion section (20), wherein a cross-section (30) of the key shank (10) protrudes at least in sections beyond the base cross-section (26) in the torsion section (20) in a direction towards the key tip (70).

Abstract: A lock includes a housing, a cylindrical core body and a tumbler unit. The core body is rotatably mounted in the housing, and includes a core axle, and a core tube sleeved on the core axle. The core axle has a helical keyway. The tumbler unit includes a housing pin hole formed in the housing, a tube through hole formed through the core tube, a pin assembly movably mounted in the housing pin hole and the tube through hole, a hole-defining surface defining the tube through hole and having a shoulder surface portion, and a resilient member disposed in the housing and resiliently biasing the pin assembly to abut against the shoulder surface portion and extend into the helical keyway.

Abstract: A locking device includes a lock and a key. The lock includes a housing, a cylindrical core inserted into and rotatable relative to the housing, and a tumbler unit that is mounted between the housing and the cylindrical core to permit or prevent the relative rotation between the housing and the cylindrical core and that has a first pin extending into a helical keyway formed in the cylindrical core. The key has a helical blade capable of being inserted into the helical keyway to access the first pin, so as to switch the tumbler unit to permit the relative rotation between the cylindrical core and the housing.

Abstract: A method for profiling the broad sides of a flat key, a key blank being clamped in a clamping device so that the broad side of the key blank is exposed. Guide grooves and variation grooves which are complementary to the longitudinal sectional profile of the cutter teeth are milled into the broad side by advance in the longitudinal direction of the key, in one work operation, using a milling cutter that has cutter teeth on its peripheral surface and rotates about a cutter shaft. To produce undercut grooves, the axis of the cutter shaft is inclined at an angle of inclination relative to the longitudinal center plane of the key, ribs of the cutter teeth producing an undercut guide wall using at least one rib.

Abstract: A method for profiling broad sides of a flat reversible key. A key blank is clamped to expose the first broad side of the key blank and complementary grooves and ribs are milled using a milling cutter with cutter teeth by advance in the longitudinal direction of the key relative to the longitudinal section profile of the cutter teeth. The key blank is then clamped in a position turned by 180° about the longitudinal center axis of the key so that the second broad side of the blank is exposed, and complementary grooves and ribs are milled into the broad side with milling cutter, by advance in the longitudinal direction of the key. The cutter shaft axes is inclined at an angle of inclination (?) relative to the longitudinal center plane of the key, at least one cutter tooth rib of the cutter teeth producing an undercut guide wall.

Abstract: Some embodiments disclosed include keys, lock cylinders, and key and lock cylinder combinations. The keys include a bow and a blade extending from the bow, where the blade includes at least one undercut groove in a lateral side thereof that receives at least one projection defining a keyway passage of a lock cylinder in which the key is positioned.

Abstract: A lock and key combination that uses a key device which includes a shaft portion, and at least one movable key combination element which is retained within the shaft portion and which includes first and second portions adjacent one another, the first portion of the at least one movable key combination element being located along on the shaft portion and the second portion of the at least one movable key combination element being located offset to the first portion.

Abstract: A key blank comprises a shaft and a head connected to the shaft, the shaft including first and second surface that are oppositely facing, wherein the surfaces are configured to include combination elements to operate a lock and a pair of coaxial operating elements, wherein one element of the pair is operative from the first surface of the shaft and the other element of the pair is operative from the second surface of the shaft, and wherein at least one of the operative elements is a resilient element mounted inside a bore provided in the shaft, wherein the resilient element is operative to exert a compressive force on a pin mechanism of the lock in response to the operative engagement and thereby release the pin mechanism from a lock position, without requiring any pressure on the coaxial element on the other side.

Abstract: The present invention is directed to key assemblies and their mating locks, and more particularly, to keys with mutually compressible, actuating elements capable of being continuously positioned axially within apertures in a key blade.

Abstract: A cylinder lock with a rotatable key plug (112) having a profiled keyway (113,116), the keyway being configured to accommodate an elongated, substantially flat key blade (120) with a longitudinal groove (122). The keyway in the key plug has two opposite lateral sides and a profile rib (150) located at a substantially flat lateral side. The profile rib has a downwardly projecting tongue portion (161) configured to extend inside the profile groove (122) upon inserting the key (120) into the key plug (112) of the lock, and the tongue portion of the profile rib is extended downwardly into a lowermost, massive end portion (162) which has two opposite side surfaces (163,164) and a lowermost transverse end surface (165) which is substantially flat or slightly curved.

Abstract: A key device for use with more than one lock, the key device including a shaft portion, and at least one movable key combination element retained within the shaft portion and including first and second portions adjacent one another, the first portion of the at least one movable key combination element being located along on the shaft portion and the second portion of the at least one movable key combination element being located offset to the first portion.

Abstract: The present invention is directed to key assemblies and their mating locks, and more particularly, to keys with mutually compressible, actuating elements capable of being continuously positioned axially within apertures in a key blade.

Abstract: A key for use in a cylinder lock with a rotatable key plug having a profiled keyway. The key comprises an elongated, substantially flay key blade (120; 120?) having a longitudinal profile groove (122; 122?) extending along at least a portion of the length of the key blade. The groove has an undercut portion (129) adjacent to a ridge portion (128, 128?), the outside of which forms part of a side surface (123; 123?) of the key blade. The undercut portion (129; 129?) of the groove is expanded, at its innermost part adjacent to and inside said ridge portion, into a longitudinally extending pocket (135; 135?).

Abstract: A key for use in a cylinder lock with a rotatable key plug having an elongated key blade with a relatively wide lower portion and a relatively narrow upper portion. A step-like transition region between the wider lower portion and the narrow upper portion. The key blade includes a longitudinal profile groove located adjacent to the step-like transition region that extends along at least a portion of the length of the blade. An inner wall of groove is substantially parallel to a side surface of the lower portion of the key blade. The longitudinal profile groove includes an undercut portion adjacent to and inside a ridge portion of the key blade. The outside of ridge portion forms a part of the side surface of the blade in the relatively wide lower portion up to the step-like transition region and the inside of ridge portion facing inner wall of the groove.

Abstract: A lock system includes keys, key blanks, keyways, and lock cylinders, and the keys or key blanks have opposite sides formed with grooves for cooperating with a conforming keyway. More particularly, the sides of the key or key blank have a portion grooved for registration, another portion grooved for top-level hierarchical master keying, and two other portions, one on each side of the blade, for further master key variations and different combinations. One of the two further sections being curvilinear and the other rectangular or angular cuts. The conforming keyway of the lock includes ridges and grooves corresponding to the grooves and ridges, respectively, of the key or key blank. Instruments other than keys or key blanks may be used to enter the grooves and ridges of the keyway to operate the lock without the use of a precisely configured key.

Abstract: A lock system includes keys, key blanks, keyways, and lock cylinders, and the keys or key blanks have opposite sides formed with grooves for cooperating with a conforming keyway. More particularly, the sides of the key or key blank have a portion grooved for registration, another portion grooved for top-level hierarchical master keying, and two other portions, one on each side of the blade, for further master key variations and different combinations. One of the two further sections being curvilinear and the other rectangular or angular cuts. The conforming keyway of the lock includes ridges and grooves corresponding to the grooves and ridges, respectively, of the key or key blank. Instruments other than keys or key blanks may be used to enter the grooves and ridges of the keyway to operate the lock without the use of a precisely configured key.

Abstract: A key blank or key has a rectangular parallel metal shaped blade which has side edges formed with grooves for cooperating with a complementary shaped keyway; the sides of the blank having a portion grooved for registration, another portion grooved for top-level hierarchical master keying, and two other portions, one on each side of the blade, for further master key variations and different combinations. One of the two further sections being curvilinear and the other rectangular or angular cuts.

Abstract: A lock barrel and a driving part for the same comprises a plurality of key channels for the insertion o the driving part (key) and a plurality of transverse gateways for housing movable parts, which will bulge into the key channels for making the channels effectively small and therefore shielding them from illegally intruded tools.

Abstract: An exemplary method of making a key is provided. A bitted surface is formed in a key blade of a key blank. A groove is formed in a first side of the key blade. At least one receptacle is formed in the groove. A notch is formed in the groove adjacent to the at least one receptacle for mating with a rib in a lock cylinder.

Abstract: The present invention provides a burglarproof lock core structure which forms a curved passage between a key slot of a plug and a lower pin chamber, such that at least a bending concave surface offsetting the center of the key slot is formed at one side, and cone apexes of a plurality of lower pins are extended out of the lower pin chamber and aligned in the wall edge of the key slot. Moreover, a control valve with a cone apex is located at the other end corresponding to the bending surface inside the key slot, such that a key with curvature corresponding to the passage and notches corresponding to the cone apexes is required to open the lock, thereby having the effect of high security of burglarproof.

Abstract: The present application advantageously provides at least one keyway in a lock core that poses tremendous difficulty for a lock breaker by not allowing the lock breaker to see all of the pin tumblers in the keyway. The keyway according to a preferred embodiment of the present application comprises two helical keyways oppositely extending along a longitudinal axis of the lock core and formed of rectangular cross section. The present application further comprises an accompanying helical key having at least one helical key blade for fitting into the keyway having a corresponding helical shape to turn the core and open the lock.

Abstract: A picklock-proof key slot for a lock device and a key thereof, which comprises a rotary cylinder and a lock casing, between which plural upper tumblers and lower tumblers are furnished; the center of the rotary cylinder is provided with a key slot; under lock up condition, the lower tumblers are pushed into the key slot; the center of the tumbler groove is furnished with a salient plate, of which both sides are furnished with symmetrical guide slots; a guide slot is furnished between the two symmetrical guide plates on the key plate; a plurality of unlock-tumbler holes is furnished on the guide slot between the two guide plates; the hole has a curved surface to fit with the curve surfaces on both sides of the lower tumbler so as to reduce the pushing-up space of the lower tumbler, and also to reduce the possibility of unlocking the lock device with a master key to push the lower tumbler.

Abstract: A cylinder lock with a key, the lock having a plug with at least one hole intersecting the keyway. The hole is provided with two shoulders, one whereof lies further outward, the other one lying further inward with respect to the surface of the plug. An auxiliary tumbler is accommodated in the hole and comprises an auxiliary pin, an auxiliary complementary pin and a spring acting by expansion between the auxiliary pin and complementary pin. The tumbler can assume an elongated configuration, wherein the pin and the complementary pin are mutually spaced and axially offset angularly with respect to each other, or a shortened configuration, wherein they are aligned in mutual abutment without axially offset. The key has an elastic element adapted to cooperate with the auxiliary tumbler to allow, with the key inserted, compression thereof to the shortened configuration and disengagement from the notch and rotation of the plug.

Abstract: Locking arrangement having a lock cylinder with an associated key (1), in particular a flat turning key, wherein a core (2) of the lock cylinder has a keyway (3) which is open in the direction of an end side of the cylinder, is provided with profile ribs/grooves and in the center thereof the vertex of a conical opening (4), which opens in the direction of the end side of the cylinder, is located. At an insertion end, the key (1) forms a tip (5) with flanks (6) in the form of arcuate lines. The tip (5) is formed by two arcuate lines (6), of which a point of intersection is located in a broad-side center (7) of the key, and a tangent angle (delta) at the point of intersection (5) is greater than the vertex angle (&mgr;) of the cone opening (4), wherein the arcuate lines (6) have bevels (9), in the direction of the mutually opposite broad sides (8), having a bevel angle (omega) which is smaller than the vertex angle (&mgr;) of the cone opening (4).

Abstract: A flat key for a tumbler-containing locking cylinder of a locking apparatus, with a key grip and, attached thereto, a key shank for locking grooves cut into the shank towards the end surface, the shank having a basic profile exhibiting an essentially T-shaped cross-sectional configuration, of which the T-bar forms a guide bar with guiding surfaces, and of which the T-stem extending in the longitudinal mid-plane provides the end surface and has wide side surfaces for the provision of profile ribs that have curvilinear cross-sectional contours.

Abstract: A dual cam, reversible key includes first and second patterns of notches in first and second edges of the shank of the key on a common side of the key shank of the key, providing a dual cam key. The patterns of notches are formed to have complementary symmetry and to make the width of the shank constant along at least the portion of the shank that includes the notches. The first pattern of notches is identical with the second pattern of notches insomuch as they are "parallel" to each other. The key operates tumblers each of which has an opening defining a pair of staggered generally rectangular windows, each of the windows defining cam surfaces for accommodating the dual cam, reversible key. Also disclosed is a method for making the dual cam, reversible key.

Abstract: A cylinder lock/key combination includes a lock cylinder (2), a plug (3) rotatably mounted in the cylinder (2) and having a key slot (4), and a number of tumbler pins (6) that are activatable by the code (5a) on the key (5). The key slot carries or houses an element (7) which extends axially along a substantial part of the slot. The key (5) has a blade part (5c) which includes an axially extending portion (5d) in which there is provided a hole (8) for receiving the slot-carried element (7) as the key is inserted into the lock. The slot-carried element (7) and the hole (8) provided in the key (5) are located eccentrically in relation to the center of the plug (3) and accompany rotation of the plug while aided by the key (5). The profile shape of the slot-carried element (7) and the hole (8) in the key may vary within wide limits. The invention also relates to a key belonging to a combination of the aforementioned kind, and to a key blank from which such a key can be produced.

Abstract: A lock and key combination including a lock cylinder made by connecting a plurality of locking pieces in a stack, each locking piece including a base, which has a top recess at the top side, a front recess, keyway in the middle of the front recess, and a plurality of receiving chambers disposed in the front recess at two opposite sides by the keyway, a plurality of retainer elements mounted in the receiving chambers and forced by a respective spring toward the keyway and having a respective lug at one side, an actuating plate mounted within the front recess of the base, having a projecting locating plate at the top inserted into the top recess of the base and forced upwards by a spring, and a plurality of T-shaped control slots which receive the lugs of the retainer elements, and a cover fastened to the base by hooks and cover over the actuating plate, wherein when the lugs of the retainer elements are moved to the unlocking position by the key, the projecting locating plate is forced into the top recess of t

Abstract: A lock assembly includes a lock and a flexible key. The lock includes a lock and an elongated plug unit having a longitudinal curved keyway that is accessible by the key. The keyway has several turns and several branch slots, each of which extends from one of the turns of the curved keyway in a direction different from that of a portion of the curved keyway succeeding the turn so as to mislead an undesirable flexible stick into the slot.

Abstract: The assembly is used in leftward- and rightward-retractable door units, and provides wide variations of key to prevent the assembly from being illegally unlocked. In the assembly: a left 25 and a right 28 latch plate are supported on pivots 22 and 54, respectively; a lock casing 17 connected with a thumb turn 15 has locking blades 18, 48; locking projections 30 and 31 abutting against the blade 18 are in the plates 25 and 28, respectively; an interlocking shaft 35 receiving torque transmitted from a front 6 and a rear 9 handle has a driving plate 40; a driving projection 39 abutting against the arms 37, 38 is in the plate 40; a locking hole 50 of a core 20 received in a lock casing 17 assumes a regular hexagonal shape in cross-section, provided that one of its six corners forms a curved surface 50a; a locking pin 51 extends from an inner surface of the hole 50; and, a locking projection 53 is in a center of the bottom of the core 20.

Abstract: The lock cylinder comprises a cylinder body wherein a cylinder plug (1) comprising a slot (2) for the key (18) of the lock is rotatable arranged. The profile of the key slot and therefore also of the key is determined by profile forming elements in the form of rotation bodies (6,7) which are inserted in bores (4,5) extending through the cylinder plug (1) parallel to and adjacent to the middle plane (10) of the key slot (2). The profile elements (6,7) may be made of hardenable steel, for instance by turning, and may comprise a number of portions of different diameters so that the total number of key profiles obtainable becomes high while permitting the key profile to be made very thin and correspondingly difficult to copy.

Abstract: A key for a rotationally adjustable cylinder core (4) with a lock cylinder (3) containing a cryptochannel (11) freely leading into the peripheral area of the cylinder core (4) and, more particularly, to a key for a cylinder core of locking systems, which is provided with a profiled region (15), which is provided with lateral recesses (such as 17, 18), facing the back of the key that is flush with the peripheral area of the cylinder core when the key is inserted, and with a notched region (13), which faces the opposite key breast, can be inserted into the central cylinder core region of the cryptochannel (11), has a round, cylindrical and, particularly, a circular, cylindrical shape, as well as milled slots, depressions or similar notches (16) disposed peripherally and axially offset in the key for arranging tumbler elements (8), which are mounted in the lock cylinder (3) and can be adjusted radially to the core center of the lock cylinder (3).

Abstract: A key-operated lock has a shell mounted securely in a closure, and a removable lock-actuator cartridge insertable into and withdrawal from the shell to facilitate changing the tumbler disk combination in the lock. The cartridge includes an annular hollow housing seatable in the shell, and a tumbler disk carrier telescopically insertable into the housing. The carrier and associated tumbler disks are rotatable within the housing to operate the lock. An anti-damage feature comprises the cartridge being insertable into the open front end of the shell. A thickened rear wall of the shell reinforces the cartridge against destructive attack by rod and hammer action exerted on the front face of the lock. Principal features are quick changing of the tumbler disk pattern, and a rigid damage-resistant lock structure.

Abstract: A cylinder lock assembly includes a core, a key plug mounted for rotation in the core, and a key. The key plug is formed to include a keyway and a plurality of tumbler pin bores opening into the keyway. The key has a bow and a blade appended to the bow. The blade includes a bitted portion and includes a stop shoulder at the tip of the blade for positioning the bitted portion in alignment with the tumbler pin bores. A separate drive member is provided on the key for rotating the key plug relative to the core to actuate the cylinder lock assembly. The drive member is located between the bitted portion and the bow and is configured to cooperate with a bottom portion of the key blade to provide the primary torque or force for rotating the key plug in response to turning of the key in the cylinder lock assembly so that the bitted portion and an offset portion of the blade not carry substantial torque transmission load between the key and the key plug to rotate the key plug in the core.

Abstract: A flat plastic key suitable for replacing a corresponding metal key having a key alignment groove disposed in a side of the key is configured to actuate a rotary cylinder lock having a rectangular lock entrance slot. The plastic key includes a head, a shank and a bit. The shortened key alignment groove extends along the side of the key creating a decreased key thickness adjacent to the groove. The shortened groove terminates in the key shank at a groove termination point to define a groove length less than the corresponding groove length of the metal key to thereby increase the volume and strength of the plastic key shank relative to the volume and strength of an exact plastic duplicate of the metal key shank to increase the strength of the plastic key and its capacity to transfer the input torque to the sidewalls of the lock entrance slot.

Abstract: A restricted key system providing keys/key slots with an angled or chevron shaped cross sectional profile. Each key blade of the restricted key system includes an upper planar portion which is bitted or cut to position the standard pin tumblers, an intermediate portion which forms a horizontal ledge, and a lower planar portion which extends from the intermediate portion at an angle in the range of 5.degree.-85.degree. relative to the upper planar portion. The horizontal ledge of the key blade may be provided with at least two additional bitting surfaces for wards, tumblers and/or other key differing elements.

Abstract: A cylinder lock assembly includes a core, a key plug mounted for rotation in the core, and a key. The key plug is formed to include a keyway and a plurality of tumbler pin bores opening into the keyway. The key has a bow and a blade appended to the bow. The blade includes a bitted portion and includes a stop shoulder at the tip of the blade for positioning the bitted portion in alignment with the tumbler pin bores. A separate drive member is provided on the key for rotating the key plug relative to the core to actuate the cylinder lock assembly. The drive member is located between the bitted portion and the bow and is configured to cooperate with a bottom portion of the key blade to provide the primary torque or force for rotating the key plug in response to turning of the key in the cylinder lock assembly so that the bitted portion and an offset portion of the blade not carry substantial torque transmission load between the key and the key plug to rotate the key plug in the core.

Abstract: A key for a cylinder lock has a relatively slender profile region and a bitting region of greater thickness and a generally cylindrical configuration with or without longitudinally-extending flats. The bitting recesses can be provided round this bitting region and axially therealong and the profile region can be formed with grooves milled in its parallel flanks to increase key variability.

Abstract: A cylinder lock and key includes one or more lateral ribs extending from a flat key and formed of a shape memory material. Auxiliary lock pins arranged in a cylinder core read the shape of the lateral ribs of the key and enable the lock to be opened only when the memory material of the ribs responds to the application of energy.

Abstract: A key blade having a longitudinal axis (A) of insertion and comprising an elongated, wave-like generally longitudinally extending code pattern (38) for cooperation with a row (23) of elevationally and rotationally movable locking tumblers (23a-23e) of a rotary cylinder type lock (18). Each of the locking tumblers is provided with a transversely projecting finger which engages with the code pattern (38) when the key blade is inserted into the lock. The code pattern (38) includes a number of concavity locations (40-44) which are displaced longitudinally and transversely so as to correspond to specific rotational and elevational positions of the locking tumblers which will permit releasing of the lock.

Abstract: For increased security the key (2; 40; 44) has one or more blade portions (43; 45; 46; 5, 6). The longitudinal central plane (A, B) of the or each blade portion is offset from the guide region (42; 7) running along the back edge of the key shaft (3). Furthermore, the or each blade portion is connected to the guide region by means of a bridging portion (14, 14') which forms an obtuse angle (alpha) with the guide region, as well as forming an obtuse angle with the blade portion. In one preferred embodiment two blade portions (45, 46; 5, 6) are provided; they may be of the same cross-sectional shape (FIG. 2) or symmetrical (FIG. 11). The blade portions and guide region may be divided into two portions to provide partner keys (FIG. 12).

Abstract: A peripheral key for a tumbler lock, the key being transversely curved concentrically with the axis of the lock, and having an L-shaped groove to pass a sentry lug on a lock. The L-shaped groove has a longitudinal leg opening longitudinally at the free end of the lock, and a lateral leg communicating with the inboard end of the longitudinal leg and opening laterally to enable the sentry lug to pass along and out of the L-shaped groove to free the key for further operative movement. A tumbler lock having code discs and actuating discs, and a pusher plate having a lost-motion connection with a mounting plug to pick up the plug after predetermined movement of a curved peripheral key. A key as first described above, together with a lock having a sentry lug for accommodating insertion of the key into the lock.

Abstract: A lock of the cylinder type having a plurality of discs forming part of the barrel assembly and being rotatable relative to one another and to the body of the barrel assembly. The rotational axis of each disc is substantially coincident with the rotational axis of the complete barrel assembly and each disc has a keyway forming opening which contains that axis. Locking means such as a side locking bar is operative to hold the barrel assembly against rotation relative to the lock cylinder, but that locking means is responsive to the rotational positioning of the discs to release the barrel assembly for rotation when the discs have a particular rotational position relative to one another. The barrel assembly can be rotated in either direction away from the normally locked condition. A key for use with such a lock has an elongate blade which is of non-circular cross section and is twisted to create a plurality of relatively angularly disposed locating portions which are spaced apart longitudinally of the blade.

Abstract: This invention relates to a screw lock, characterized in that the screw key screws into a keyway, and the slots on the top ring screw of the screw key provide a convex-concave match with switch points in the cylinder. The screw key is then pushed in and turns the cylinder to effect locking and unlocking. The keyway of this invention is adapted to accept the spiral screw shape, and accordingly, the form and the mechanism of the switch points are not seen. Thus, the form and mechanism of the switch points in the cylinder is unknown. Also, conventional keys or wires cannot be inserted into the spiral screw hole. In case other keys are inserted into the keyway, the set points in the cylinder prevent the key form being further pushed in and prevent turning of the cylinder to effect unlocking.

Abstract: Lock and key device with the lock comprising a barrel for driving at least one bolt, rotatably mounted in a fixed hollow shaft and containing fittings the cooperation of which with wing couples formed on the key in its operational portion unblocks the barrel relative to the shaft as to a rotary movement when the key is completely driven-in, means being provided in the lock and on the key for limiting the driving-in of the key inside the lock to the unblocking position of the fittings, a longitudinal undeceiver of the key cooperating with a barrel slot, distinguishing a wing couple from another wing couple for the introduction in a correct position of the key inside the lock.

Abstract: A cylinder lock has a housing with a rotatably insertable cylinder having a key passage for an insertable flat key whose front part has locking notches associated with cylinder pins arranged in openings of the cylinder for retaining the cylinder pins. The flat key is provided at both its lateral sides with longitudinal grooves for receiving longitudinal ribs provided on the lateral sides of the key passage for the lateral profile variation. The longitudinal grooves on both lateral faces of the flat key lie with their bottom faces on lines which extend parallel to and at a distance from one another. The parallel lines extending at a distance from one another are arcuate at least in one partial region, and the convexly protruding central part of one arcuate line extend at least close to a straight line connecting the end points of the second arcuate line.

Abstract: A two-stage tumbler lock wherein there are two sets of discs, one set being actuatable by a key to free the second set for unlocking movement under the influence of the key. The invention also contemplates a lock designed to receive a peripheral key to cause the above operations.The invention further contemplates a dog leg key particularly a peripheral dog leg key for effecting the above operations.The invention still further contemplates a lock having a peripherally located reset member which makes picking most difficult. A further feature of the lock and its key is that the two coact to perform their intended functions in a manner such that the key cannot be withdrawn from the lock until it is returned to the position it first assumed when inserted into the lock.Another feature of the invention is a disc lock in which the discs have spaced lugs defining the extent of disc movement in regard to a locking member.

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 key for use in a hierarchal lock system with an elongated body and selectively spaced notches cut on an elongated edge of the body. Two rows of discontinuous rib members are attached to each side of the elongated body of the key.

Abstract: A restricted key system providing keys/key slots with an angled or chevron shaped cross sectional profile. Each key blade of the restricted key system includes an upper planar portion which is bitted or cut to position the standard pin tumblers, an intermediate portion which forms a horizontal ledge, and a lower planar portion which extends from the intermediate portion at an angle in the range of 5.degree.-85.degree. relative to the upper planar portion. The horizontal ledge of the key blade may be provided with at least two additional bitting surfaces for wards, tumblers and/or other key differing elements.