Abstract: A pin tumbler cylinder lock having a plug eccentrically positioned within a cylindrical bore of a housing. Surrounding the plug are longitudinally aligned sleeve segments that together therewith form a composite plug unit that can be rotated in the housing bore by a proper key. Formed on the outer surface of each sleeve segment coincident with pinways therein are recesses that are spaced from the recesses in adjacent sleeve segments. Additional internal recesses are formed in the inner surface of at least one of the sleeve segments closely adjacent a pinway extending therethrough. The internal recesses receive the tumbler pin when it is forced upwardly simultaneously with the application of torque on the plug. In one embodiment, the internal recess is a single recess coincident with the pinway and extending circumferentially therefrom. In another embodiment, the internal recess comprises a pair of recesses located on opposite sides of the pinway and spaced circumferentially therefrom.

Abstract: A pin tumbler cylinder lock having a plug eccentrically positioned within a cylindrical bore of a housing. Surrounding the plug are longitudinally aligned sleeve segments that together therewith form a composite plug unit that can be rotated in the housing bore by a proper key. Formed on the outer surface of each sleeve segment coincident with pinways therein are recesses that are spaced from the recesses in adjacent sleeve segments. The bottoms of the recesses form false shear levels that hinder picking operations while the side walls thereof form pin obstructions that prevent forcible axial removal of the plug and sleeve unit from the cylindrical housing. Additional security is provided between the plug and at least one sleeve segment by a mechanical coupling that prevents relative axial motion therebetween. The coupling prevents axial removal of the plug.

Abstract: A cylinder lock comprising a plug, with an eccentric face, a cylinder and an eccentric sleeve between the plug and cylinder. When a proper key is inserted and raises the pins to operating shear level the plug and sleeve can be turned as a unit on an axis to unlock or lock, but in the event there is a single pin restraining the rotary motion of the sleeve, only a limited plug motion is permitted as it is now in an eccentric relation with respect to the cylinder. Picking of the lock is prevented by dividing the sleeve into segments rotatable with respect to each other and providing each with circumferentially extending recesses in which tumbler pins can become ledged.

Abstract: In a cylinder lock mechanism of the type in which longitudinally movable pin tumblers are housed in a normally freely rotatable lock plug which is coupled to a locking member by means of a rocking lever responding to correct alignment of the tumblers, the resistance of the lock to picking, and to fouling and corrosion may be improved, and the structure made more compact, by making the lever part of a three part linkage, the lever being pivotless and actuated by the tumblers by a laterally movable diaphragm in the lock plug and acting upon a laterally movable clutch dog to couple the locking member to the plug. A decombinating cam is provided to ensure disengagement of the diaphragm from the tumblers on removal of a key from the mechanism, and provision may be made positively to lock the locking member against rotation except when the mechanism is freed for rotation by insertion of a correct key.

Abstract: A key operated rotary plug cylinder lock having rotary disk tumblers arranged in a pack within a rotary plug sleeve normally held against rotation within the lock casing by a locking bar which spans the shear line between the disk tumbler peripheries and the confronting wall of the rotary plug sleeve. True gates are provided in the tumblers to be aligned by an appropriate key with the locking bar to accommodate inward movement of the locking bar to a position releasing the plug for rotation within the casing, and shallower depth false gates are provided in each of the tumblers having associated false bottom recess portions in the front and rear walls of the tumblers providing forward and rearward false gate profiles or outlines simulating the profile of the true gate. Frangible tabs are also provided on each tumbler extending into a sector recess which will readily break upon excess torquing forces to prevent penetration of the lock by torquing tools.

Abstract: A linearly arranged tumbler type lock construction having secondary locking means brought into operation upon an attempt to pick the lock without a key. The tumblers include portions having annular grooves extending into the surfaces thereof at spaced intervals, selectively engageable with edges of apertures in a plate disposed between a movable cylinder element and a fixed cylinder element, whereby upon applying a torque to the movable cylinder element, the grooved portions of at least some of the tumbers engage the plate which is fixed against rotation thereby preventing further axial movement of the tumblers.

Abstract: An apparatus is disclosed for preventing tampering with a locking mechanism, such as the conventional cylinder lock, which has a keyway therein and is normally rotatable when a key is in the keyway. A locking arm normally holds the locking mechanism to prevent rotation thereof even when the key or a foreign device is in the keyway. In order to release the locking arm and rotate the locking mechanism, access to the keyway is first blocked thereby prohibiting someone from attempting to pick the lock with a foreign device.

Abstract: A wafer type tumbler lock construction in which the individual wafer tumblers have a serrated edge for engagement with side bar tumbler inhibiting means actuated when an attempt is made to pick the lock. The side bar means includes a plurality of T-shaped elements, the cross bar portion of which has a serrated edge of length equal to a major portion of the length of the serrated edge on the respective tumbler. The angle of the serrations is such that under normal lock operation, the side bar will be cammed out of engagement with the introduction into the lock cylinder of a correct key.

Abstract: A tumbler lock comprises a rotatable cylinder member formed with a plurality of bottomed holes arranged in parallel along an axis of the rotatable member on a circle coaxial with the axis, a corresponding number of biasing springs disposed in the bottoms of the respective holes, a corresponding number of tumbler pins each formed with annular groove at a different axial position and inserted into different one of the holes against a biasing spring and a cylindrical stationary member for rotatably holding the rotatable member, wherein the rotatable cylinder member is formed with the corresponding number of radial holes each communicated with corresponding one of the bottomed holes and, wherein a corresponding number of recesses are formed on the inner surface of the stationary member at positions corresponding to the radial holes and wherein a corresponding number of balls are provided for each of the tumbler pins in the rotatable member in such a manner that, in a normal state, the rotation of the rotatable me

Abstract: A key operated rotary plug cylinder lock having rotary disc tumblers with a concentric cylindrical boss on one face of each disc tumbler projecting axially into internesting relation into a complemental cylindrical well or recess in the confronting face of the next adjacent disc tumbler. A lock-out pin mechanism to lock the plug against rotation when excessive rearward stress is exerted thereon, and a frangible lost motion coupling between the tumblers and the shell portion of the plug breakable upon excess torquing forces are also provided.

Abstract: A warning light housing includes a casing having an aperture which aligns with a chamber in the base to present a receptacle for receiving a plug-type lock. With the lock residing within the receptacle, separation of the base and casing is prohibited thus preventing access to the housing interior. The lock includes a latch element which is selectively movable between locking and non-locking positions by turning a key within the lock. In its locking position, the latch element extends radially outwardly from the lock periphery into a slot in the housing base to restrain the lock within the receptacle; and, in its non-locking position, the latch element lies within the lock periphery allowing removal of the lock from the receptacle.

Abstract: An improved lock assembly of the wafer tumbler type is provided which includes a plurality of wafer-type tumblers mounted in a cylindrical plug or carrier at spaced positions along the axis of the carrier. The tumblers are slidable radially in the carrier to project beyond the carrier into restricted annular pockets in the inner surface of the housing, so as to hold the lock in a locked condition. Only when the proper key is inserted into the plug are all the tumblers drawn within the confines of the plug by the key, allowing the key to turn the plug and to operate the latch or bolt controlled by the lock.

Abstract: A pin tumbler lock in which a master cylinder is rotatably mounted within a housing and is drivable by a non-concentrically located drive cylinder also rotatably mounted within the housing. Bolt means are actuable by rotation of the master cylinder. A plurality of pin tumblers are positioned within respective pin bores and normally prevent rotation of both cylinders but are shiftable by key means into alternate positions whereby rotation of the master cylinder by the drive cylinder is permitted to thereby unlock the lock through actuation of the bolt means by the master cylinder.

Abstract: Conventional tumbler type locks are capable of being breached by lock picking tools, punches, drills and the like. This particular lock includes a plurality of flat strip tumblers mounted transversely in a cylinder and which are positioned relative to one another when a flat key is inserted. The key edges are symmetrically shaped and the edges of different keys are shaped differently so that any number of variations of keys is possible. When the correct key is inserted into the lock, slots cut in the upper sides of the flat tumblers align at which time a knife edge strip clears the aligned slots. When the key and lock are turned, the member engages serrations formed on the upper sides of the tumblers thus locking same into position. The upper side of the member engages an interior cam formed on the casing thus moving the member into engagement of the aforesaid.

Abstract: Methods and apparatus for decoding twisting tumbler locks and improvements in such locks to resist such methods and apparatus. To determine depth of cut of bit for a given tumbler, a blade is inserted into key way to position a wirelike probe at tumbler to be decoded. Wirelike probe is advanced upwardly until it engages tit at top of tumbler. Depth of cut of key bit is function of length of tumbler and device can be calibrated to give direct readout of depth of bit cut. Angle of key bit can be measured by hooking a wirelike probe in side gate groove in tumbler and then twisting tumbler until tit engages key plug or shell. Amount of twist permitted is function of angular position required to register tumbler groove with side gate and device can be calibrated to give direct reading of such angle. To defeat depth of cut decoder, twisting tumbler lock wherein tits on tumblers are located at different distances from tops of tumblers is disclosed.

Abstract: A pin and tumbler type lock in which a slide element is disposed at that end of the cylinder opposite the end from which the key is inserted, the slide element cooperating with a pin in the barrel and having a projecting portion diametrically opposite to the pin with which it cooperates which, in the locked condition, engages in an opening of the barrel. The slide element has a configuration for cooperation with the leading end of a key so that insertion of the correct key causes disengagement of that portion of the slide extending into the opening in the barrel and additionally brings abutting portions of the slide element and the cooperating pin to a shear line between the cylinder and the barrel to free the lock. Additionally, at least one pin in the lock has an electrically conductive extension adapted, when the pin with which it is associated is raised beyond the shear line to complete a circuit to an alarm device.

Abstract: Method and apparatus for decoding twisting tumbler lock of the type wherein side bar is sole locking element and normally bridges shear plane unless radial apertures in twisting tumblers are all in vertical and horizontal register with complementary side bar protrusions. Decoding apparatus comprises three devices each with a blade insertable in keyway and having upwardly and rearwardly sloping front surface angulated at one of three angles to which tumblers must be twisted for horizontal registration of apertures. Each blade has indicia for indicating that front surface is at particular tumbler and further has indicia for determining amount of elevation of tumbler resulting from camming action between chisel shaped tumbler bottom and blade front surface when blade is advanced from initial engagement with tumbler to elevate tumbler.

Abstract: A turnover key with indentations on both sides for operation of bolt keepers of a cylinder lock, and with a sloped keyway at the tip of the key. The sloped keyway, which is situated before each row of indentation, runs almost to the opposite broad side of the key and into it.

Abstract: A detector cylinder is used in a door lock and includes a cylinder body having a plug bore therein and having one or more pin bores in the body opening into the plug bore. A plug is rotatable in the plug bore and has a keyway and one or more pin openings communicating with the keyway and in one rotated position of the plug also communicating with the pin bore or bores. There are one or more first pins slidable in the pin bores and one or more second pins slidable in the pin openings. A spring or springs are disposed to urge the pins towards the keyway. An electrically conducting contact is disposed on the cylinder body in position to be abutted by a first pin in one of the longitudinal locations of the first pin. There is an electrical circuit that is completed when the first pin abuts the contact. The circuit may include an alarm and a switch for preventing an alarm.

Abstract: An automotive trunk lid latch assembly including a housing, a pair of latching members and a cam member, each rotatably mounted in the housing, a shaft extending into the housing from a lock cylinder assembly and adapted to rotate the cam member in response to manual rotation of a key in the lock cylinder assembly, and a spring-loaded lever rotatably mounted intermediate the cam member and one of the latching members and retained therebetween by the end of the shaft, and adapted to be rotated by the cam member to, in turn, unlatch the latching members. In the event of removal of the shaft, the spring-loaded lever will snap away from the cam member into an inoperable position, thus preventing any unlatching operation thereafter by the insertion of a probe or a screwdriver to rotate the cam member.

Abstract: A pick-proof lock system and method for locking a door, window, or other closure which includes a first movable barrier such as a door mounted to be closed into a second related barrier such as a frame. This pick-proof lock system comprises coded locking means remotely located from the public region outside of the closure barriers with a transportable key movable along a route from the public region into the remote locking means and carrier means for moving the key along said route which may include multiple intersecting path segments with blocking means preventing access from the public region to the remotely located coded locking means, the carrier means acting cooperatively with said barrier means for moving the key long said route.

Abstract: A pin tumbler lock comprising a plug with top and bottom pins operable by a key, said plug being surrounded by an enclosure which may be alternatively a rotary sleeve for grand mastering or the cylinder of a lock. The sleeve or cylinder as the case may be is provided with a longitudinal recess in which is mounted alternatively one or more rotationally movable baffle inserts or slide pieces for each tumbler. These inserts are apertured for receiving the pins. Where the sleeve is present there is a recess at the internal surface thereof receiving the inserts and there is also a similar recess in the cylinder receiving inserts on the interior surface of the cylinder. These inserts may be circumferentially slidable or rotational.

Abstract: A highly safe, relatively pick-proof lock to be used as a replacement for standard lock cylinders in conventional doors. A plurality of independently operating locking means serving to enhance the difficulty of picking a lock including split keyways, locking cams, shear line blocking means and a hardened steel face plate.