MECHANICALLY CHANGEABLE CYLINDER LOCK AND KEY WITH ROTATING PINS

Abstract: A cylinder lock (10) having a changeable key combination, the cylinder lock including a cylinder housing (14) defining a bore (17), a plug (16) arranged in the bore (17) and defining a keyway (22) and at least one plug pin (25) disposed in the plug along at least one plug pin axis and communicating with the keyway, the at least one plug pin (25) having a key engagement end face (37) communicating with the keyway, the key engagement end face (37) being configured such that rotation of the plug pin (25) about the plug pin axis effects a change in the key combination of the cylinder lock and wherein the cylindrical housing (14) defines at least one access opening (20) which permits access to the at least one plug pin (25) for selectable rotational positioning thereof for changing the key combination of the cylinder lock by means of rotation of the at least one plug pin (25) about the at least one plug pin axis. Various keys suitable for use with the lock are also described and claimed.

Description: MECHANICALLY CHANGEABLE CYLINDER LOCK AND KEY WITH ROTATING PINS FIELD OF THE INVENTION The present invention relates to cylinder locks and more particularly to cylinder locks having changeable key combinations. BACKGROUND OF THE INVENTION It is occasionally desirable to change the key combination of a lock. This is typically motivated by security considerations. For example, it is sometime desired to deny future access to a person who had previ¬ ously been, but is no longer, authorized to gain access. Similarly, the key combination of the lock may be changed in order to foreclose access by a thief or the finder of a lost key. Using conventional technology, the changing of a lock requires disassembling of the existing cylinder lock and the replacement of its pins. It has been proposed to construct a cylinder lock in such a way that its key combination is mechani¬ cally alterable. Illustrative of the considerable body of prior art teaching mechanically alterable locks are U.S. Patent Nos. 4,912,953; 4,376,382; 3,910,083 3,589, 153 3,210,973; 3,149,486; 3,143,875; 3,059,462 2,895,323 2,453,066; 2,266,163; 2,113,007; 1,917,302 1, 859, 451 1,778,680; 1,259,353 and 666,697. The following additional U.S. Patents believed to be relevant to the sub j ect matter of the present invention are listed hereinbelow: U.S. Patent Nos. 5, 349, 830 5,289,709; 5,176,015 5, 161,397 5, 103, 661 5, 067, 335 4,932,229; 4,866,964 4, 836, 002 4,829, 798 4, 741, 188 4,723,427; 4,635,455 4, 461, 161 4,393,673 4,359,885 4,328,690; 4,098,103 3,987, 654 3,985,010 3,955,388 3,777,520; 3,722,240 3,514,982 3,499,303 3, 413, 831 2,221,664; 2,194,469 2,023,847 1,549,581 570,391; Re30,198 and Re31,910 and Canadian Patent 1, 142, 768 While the combinations of such locks can be readily altered without having to replace the cylinder lock, all these locks suffer from the disadvantage that the key or keys must be replaced every time the cylinder lock combination is changed. SUMMARY OF THE INVENTION The present invention seeks to provide an improved lock having a changeable key combination, a key for use therewith, and a method for changing the combina¬ tion of the lock and the key simultaneously. There is thus provided in accordance with a preferred embodi¬ ment of the present invention a cylinder lock having a changeable key combination, the cylinder lock including: a cylinder housing defining a bore; a plug arranged in the bore and defining a keyway; and at least one plug pin disposed in the plug along at least one plug pin axis and communicating with the keyway, the at least one plug pin having a key en¬ gagement end face communicating with the keyway, the key engagement end face being configured such that rotation of the plug pm about the plug pin axis effects a change in the key combination of the cylinder lock; wherein the cylindrical housing defines at least one access opening which permits access to the at least one plug pin for selectable rotational positioning thereof for changing the key combination of the cylinder lock by means of rotation of the at least one plug pin about the at least one plug pin axis. Further in accordance with a preferred embodi¬ ment of the present invention there is provided a key for use with the lock, the key including: a key head; a shank attached to the key head; and at least one key engagement end face engagement element arranged for engagement with the key engagement end face of the at least one plug pin, the at least one key engagement end face engagement element being rotata- bly mounted in the shank for selectable rotational posi¬ tioning. Additionally in accordance with a preferred embodiment of the present invention there is provided a key for use with a cylinder lock having a changeable key combination including: a cylinder housing defining a bore extending along a first axis; a plug arranged in the bore and defining a keyway; and at least one plug pin disposed in the plug along at least one plug pin axis and communicating with the keyway, the at least one plug pin having a key en¬ gagement end face communicating with the keyway, the key engagement end face having a non-axially symmetric con¬ figuration; the key including: a key head; a shank attached to the key head; and at least one key engagement end face engagement element arranged for engagement with the key engagement end face of the at least one plug pin, the at least one key engagement end face engagement element being rotata- bly mounted in the shank for selectable rotational posi¬ tioning. Further in accordance with a preferred embodi¬ ment of the present invention there is provided a method for simultaneously changing the key combination of a cylinder lock and of a key inserted therein, wherein the cylinder lock includes: a cylinder housing defining a bore extending along a first axis; a plug arranged in the bore and defining a keyway; and at least one plug pm disposed in the plug along at least one plug pin axis and communicating with the keyway, the at least one plug pin having a key en¬ gagement end face communicating with the keyway, the key engagement end face having a non-axially symmetric con¬ figuration, wherein the cylindrical housing defines at least one access opening which permits access to the at least one plug pin for selectable rotational positioning thereof, and the key includes: a key head; a shank attached to the key head; and at least one key engagement end face engagement elements arranged for engagement with the key engagement end face of the plug pins, the at least one key engage¬ ment end face engagement element being rotatably mounted in the shank for selectable rotational positioning, the method including: inserting the key into the keyway such that the at least one key engagement end face engagement element is in engagement with a corresponding key engagement end face of the at least one plug pin; positioning the key and the plug such that the pin rotation end face of the at least one plug pin oppo¬ site the key engagement end face is accessible through the at least one access opening; inserting a tool through the at least one access opening to engage a pin rotation end face of at least one plug pin, while at the same time the key en¬ gagement end face of the plug pm is in engagement with a corresponding key engagement end face engagement ele¬ ment; and rotating the tool m engagement with the pm rotation end face of a plug pm, while at the same time the key engagement end face of the plug pin is in engage¬ ment with the corresponding key engagement end face engagement element, thereby rotating the key engagement end face engagement element by an amount corresponding to the rotation of the plug pm. Preferably, the key engagement end face has a non-axially symmetric configuration. In accordance with a preferred embodiment of the present invention, the plug pin includes a plurality of plug pins. Preferably, the key engagement end face has a configuration which is not symmetric under 180 degree rotation. In accordance with a preferred embodiment of the present invention, the plug pin is arranged to be selectably rotatable without azimuthal restriction about the plug pin axis when the pin rotation end face is rotatably engaged by a tool but not to be freely rotata¬ ble without azimuthal restriction otherwise. Preferably, the plug pin includes a collar portion which is arranged for selectable rotation rela¬ tive to the end faces when the pin rotation end face is rotatably engaged by a tool and the collar portion is restrained against rotation, but not otherwise. In accordance with a preferred embodiment of the present invention, the cylinder lock includes a side locking element for selectably locking engagement between the cylinder housing and the plug, the side locking element being arranged for mating engagement with the collar portion. There is also provided m accordance with a preferred embodiment of the present invention a key for use with a cylinder lock having a changeable key combina¬ tion including: a cylinder housing defining a bore extending along a first axis; a plug arranged in the bore and defining a keyway; and at least one plug pin disposed in the plug along at least one plug pm axis and communicating with the keyway, the at least one plug pin having a key en- gagement end face communicating with the keyway, the key engagement end face being configured such that rotation of the plug pin about the plug pin axis effects a change in the key combination of the cylinder lock; the key including: a key head; a shank attached to the key head; and at least one key engagement end face engagement element arranged for engagement with the key engagement end face of the at least one plug pin, the at least one key engagement end face engagement element being rotata¬ bly mounted in the shank for selectable rotational posi¬ tioning and subsequently fixable so as to resist further rotational positioning. Additionally in accordance with a preferred embodiment of the present invention there is provided a key for use with a lock having at least one plug pin arranged along a plug pin axis and communicating with a keyway, the key including: a key head; a shank attached to the key head and defining at least one flat shank surface; and at least one plug pin engagement location on the at least one flat shank surface and bearing a three dimensional plug pin engagement configuration which is not axially symmetric with respect to the plug pm axis and which is not symmetric under 180 degree rotation about the plug pm axis. Further in accordance with a preferred embodi¬ ment of the present invention there is provided a tool for changing the key combination of a cylinder lock, wherein the cylinder lock includes: a cylinder housing defining a bore extending along a first axis; a plug arranged in the bore and defining a keyway; and at least one plug pin disposed in the plug along at least one plug pin axis and communicating with the keyway, the at least one plug pm having a key en¬ gagement end face communicating with the keyway, the key engagement end face having a non-axially symmetric con¬ figuration, wherein the cylindrical housing defines at least one access opening which permits access to the at least one plug pin for selectable rotational positioning thereof, the tool including: a holder for holding a cylinder; and an elongate element defining a hand held por¬ tion at one end thereof and a plug pin engagement portion at an opposite end thereof and being configured so as to pass through the at least one access opening in the cylindrical housing. BRIEF DESCRIPTION OF THE DRAWINGS The invention is herein described, by way of example only, with reference to the accompanying draw¬ ings, wherein: Fig. 1 is an end view of a cylinder lock ac¬ cording to the present invention; Fig. 2 is a cross-sectional view of the cylin¬ der lock of Fig. 1 taken in a plane parallel to that of Fig. 1; Fig. 3 is a side cross-sectional view of one embodiment of a cylinder lock according to the present invention taken along the section lines III-III of Fig. 1; Fig. 4 is a top cross-sectional view of the cylinder lock of Fig. 1 along section lines IV-IV of Fig. l; Fig. 5 is a perspective view of one possible pin used in the present invention; Fig. 6 is a top view of one embodiment of the cylindrical lock of Figs. 1 - 4; Fig. 7 is an end cross-sectional view of anoth¬ er embodiment of a cylindrical lock according to the present invention; Fig. 8 is a side cross-sectional view of the cylinder lock of Fig.7; Fig. 9 is an enlarged illustration of a por¬ tion of the cylinder lock of Fig. 8 Fig. 10 is a perspective view of another embod¬ iment of a pm according to the present invention; Fig. 11 is a top cross-sectional view of yet another embodiment of a cylindrical lock according to the present invention employing a pm of the type illustrated Fig. 12 depicts a method for simultaneously changing lock and key combination; Fig. 13 is an enlarged view of a portion of Fig. 12; Fig. 14 shows one embodiment of a key according to the present invention; Fig. 15 is a perspective view of a rotatable key engagement end face engagement element, featuring protrusions, for use in a key according to the present invention; Fig. 16 is a perspective view of a rotatable key engagement end face engagement element, featuring a recess, for use in a key according to the present inven¬ tion; Fig. 17 is a sectional illustration of a key having rotatable key engagement end face engagement elements of the type shown in Fig. 16, which have been rendered non-rotatable by pressing; Fig. 18 depicts the process of changing the key combination of the key of Fig. 14 independently of the lock. Fig. 19 is a side cross-sectional view of another embodiment of a cylinder lock according to the present invention: Fig. 20 is an end cross-sectional view of the cylinder lock of Fig. 19, taken along the section lines XX - XX in Fig. 19; Fig. 21 is an enlarged view of a portion of Fig. 19; Fig. 22 is a partial illustration of still another embodiment of a key according to the present invention; Fig. 23 is a partial illustration of the oppo¬ site side of the key shown in Fig. 22; Fig. 24 shows a plug pm for use in a lock having a non-changeable key combination according to another embodiment of the present invention; Fig. 25 is an illustration of a key having a non- changeable key combination according to the present invention; Fig. 26 is an illustration of a plug pin having a non-axially symmetric key engagement end face in accordance with a preferred embodiment of the present invention; Fig. 27 is an illustration of a rotatable engagement element useful in a key designed for use in a lock having pins of the type shown in Fig. 26; Fig. 28 is an illustration of seating engagement between the pin of Fig. 26 and the engagement element of Fig. 27; Fig. 29 is an illustration of non-seating engagement between the pin of Fig. 26 and the engagement element of Fig. 27, wherein the pin position in Fig. 29 is separated by 180 degrees in azimuth from the pin position in Fig. 28; Fig. 30 is an illustration of a cylinder lock according to still another embodiment of the present invention which employs both changeable combination pins and conventional pins; Fig. 31 is a sectional illustration taken along the lines XXXI - XXXI of Fig. 30; Fig. 32 is an illustration of a reversible key useful in the lock of Figs. 30 and 31; Figs. 33A and 33B are top view illustrations of key combination changing apparatus according to a preferred embodiment of the present invention in respective first and second operational modes; Figs. 34A and 34B are sectional illustrations taken along the lines XXXrV - XXXrV of Fig. 33A in respective first and second operational modes; and Figs. 35A and 35B are sectional illustrations taken along the lines XXXV- XXXV of Fig. 33A in respective first and second operational modes. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a cylinder lock, a cylinder lock key and a cylinder lock system which allows the user to readily change the combination of both the lock and the key using simple tools. The principles and operation of the cylinder lock, key and system constructed and operative according to the present invention may be better understood with reference to the drawings accompanying the description. Referring now to the drawings, Figs. 1 and 2 are respective end and sectional views, taken in parallel planes, of a basic embodiment of cylinder lock according to the present invention. Views represented by the two section lines indicated in Fig. 1, III-III and IV-IV, appear m Figs. 3 and 4, respectively. A changeable key combination cylinder lock 10 according to a preferred embodiment of the present inven¬ tion is designed to be operated by a key 12 whose key combination is also changeable, either simultaneously with the change in the key combination of the cylinder lock 10 or independently, as described below. Non- changeable keys can also be employed, as described below. Cylinder lock 10 includes a cylinder housing 14 and a plug 16 which is rotatably mounted within a bore 17 formed in cylinder housing 14. As seen in Fig. 2, cylin¬ der housing 14 preferably is formed with a longitudinal- ly-extendmg housing sidebar accommodating recess 18 communicating with bore 17 and plug 16 is formed with a longitudinally-extending plug sidebar accommodating recess 19 on its outside surface. As seen in Fig. 3, cylinder housing 14 prefera¬ bly includes one or more access openings, which are seen to be radially-extending access openings which communi¬ cate with bore 17 and preferably extend perpendicularly to and intersect the axis of bore 17, which axis is indicated by reference numeral 21. Five such openings 20 are shown in Figs. 3 and 6. Plug 16 is formed with an axial keyway 22 and with one or more plug pin bores 23 which preferably extend perpendicularly to and intersect keyway 22. Plug pin bores 23, five of which are shown in Figs. 3 and 4, each extend through plug 16 from keyway 22 to the outside surface of plug 16 at a location which can be aligned, by suitable rotation of the plug 16, with a corresponding access opening 20 of cylinder housing 14. Bores 23 are each preferably formed with a limited azimuth recess 24, which is seen in Fig. 4. Plug pins 25 are located within plug pin bores 23. As will be described herembelow, access open¬ ings 20 are provided in order to allow the key combina¬ tion of cylinder lock 10 to be changed by suitable rota¬ tion of plug pins 25 disposed within bores 23. The limited azimuth recess 24 is provided in order to permit the plug pin 25 disposed within the bore 23 to rotate freely about a plug pm axis, defined to coincide with the longitudinal axis of bore 23, within a certain limited range of angular orientations, in order to facilitate correct engagement of a key engagement end face of the plug pin 25 with a corresponding end face engagement portion of the key. Fig. 3 shows five rotatable plug pins 25 which are each mounted in a respective plug pin bore 23. Plug pins 25 are rotatable about their respective plug pm axes and are axially displaceable within plug pin bores 23 when engaged by a key 12, as described in more detail below. As mentioned heremabove, the amount of free angular rotation of plug pins 25 is preferably limited by a protrusion 26 on the plug pin which is able to move only within recess 24. One embodiment of a rotatable plug pin 25 is shown in perspective view in Fig. 5. It is seen that rotatable plug pin 25 is made up of three parts: a main portion 32 which defines a key engagement end face and a pm rotation end face which are preferably integrally formed and separated by a central region, a main collar portion 34 which generally surrounds the central region and a spacer collar 35 which surrounds the pm rotation end face and which is freely rotatable relative to collar portion 34 of rotatable plug pin 25. Collar portion 34 is "joined to the main portion 32 as by press fitting, so as to preclude free relative rotation therebetween but so as to permit relative rota¬ tion when a predetermined threshold of rotational force is exceeded. Collar portion 34 is preferably formed with an axial slot 36. Axial slot 36 in collar portion 34 provides necessary flexibility to collar portion 34, so as to enable relative rotation between collar portion 34 and main portion 32 when at least a threshold rotation force is applied. Axial slot 36 also is provided for the purpose of engagement with a side locking element, as will be described herembelow. This latter purpose may alternatively be realized by providing an axial protru¬ sion, rather than an axial slot, as described in greater detail below with reference to Fig. 10. The key engagement end face is indicated by reference numeral 37 and faces keyway 22, while the pm rotation end face, indicated by reference numeral 38, faces the outer periphery of the plug 16 and can be aligned by suitable rotation of the plug to face access opening 20. Key engagement end face 37 is shown to have a configuration which is symmetric under 180 degree rota¬ tion. Key engagement end face 37 is, however, preferably configured to have an non-axially symmetric configura¬ tion, so as not to display symmetry under rotation through any angle, for engagement with a corresponding rotatable engagement element of a key-combination change- able key 12, as described in more detail below in connec¬ Preferably, key engagement end face 37 of rotatable plug pin 25 features protrusions, most prefera¬ bly in the form of a chisel head, as shown in Figs. 5 and 25. Such a chisel head protrusion is dimensioned to engage a complementary slot on the rotatable engagement element of the key as described below. It is also possi¬ ble for key engagement end face 37 to be slotted for engagement with a protrusion formed on the rotatable engagement element of the key, as described below with reference to Fig. 10. As seen in Figs. 2 and 3, the pin rotation end face 38 preferably includes a slot 39 or similar feature to facilitate rotation of key engagement end face 37 as described below. As noted above, collar portion 34 is rotatable relative to key engagement end face 37 upon the applica¬ tion of sufficient force, as described in more detail below. This relative rotation about the plug pin axis is preferably unlimited in azimuth and allows the combina¬ tion of cylinder lock 10 to be readily changed by use of a tool, as described below. As noted above, spacer collar 35 is disposed adjacent collar portion 34 and surrounding pin rotation end face 38. Spacer collar 35 is not connected to the remainder of rotatable plug pm 25 and is freely rotata¬ ble relative to collar portion 34. The function of spacer collar 35 is described below. A suitable biasing mechanism, such as a pm spring 40, shown in Fig. 2, is employed to bias spacer collar 35 in the direction of keyway 22. As seen particularly in Figs. 2 and 4, cylinder lock 10 includes a side locking element, such as a side¬ bar 41, which serves to selectably immobilize plug 16 against rotation about bore axis 21 relative to cylinder housing 14. The immobilization is effected by virtue of sidebar 41 straddling plug sidebar accommodating recess 19 and housing sidebar accommodating recess 18 whenever a proper key is not inserted keyway 22, as can be seen, for example, in Fig. 7. Sidebar 41 preferably includes projections 42, which are seen clearly in Fig. 4, one for each rotatable plug pin 25 having a slotted collar portion 34. It is appreciated that projections 42 can be replaced with slots as described below with reference to Figs. 10 and 11. Sidebar projections 42 are dimensioned to penetrate axial slots 36 of the collar portion 34 of the corresponding rotatable plug pm 25. Preferably, axial slot 36 is just slightly longer than the corresponding dimension of projection 42 so that projection 42 can penetrate slot 36 only if projection 42 and slot 36 are accurately aligned both in the rotational and in the axial sense. This requirement makes it virtually impossi¬ ble to pick a cylinder lock according to the present invention and greatly adds to the security of the lock. Each of projections 42 is positioned and shaped so that the rotational and axial positions of rotatable plug pm 25 and spacer collar 35, upon engagement of rotatable plug pins 25 with a proper changeable key 12, permit sidebar 41 to withdraw from cylinder housing sidebar recess 18, thereby permitting rotation of key plug 16 within cylinder housing 14. In some cases, it may be desirable to make one or more axial slots 36 of a width which is larger than necessary to accommodate corresponding projection 42, in order to enable the use of master keys, i.e., keys which will open more than one particular lock. A master key can alternatively or additionally be created by providing more than a single axial slot 36. Preferably, sidebar 41 is biased, as with a suitable spring 43, shown in Fig. 4, in a direction away from keyway 22. This biasing is operative when sidebar 41 is aligned with cylinder housing sidebar recess 18, to cause a portion of the sidebar 41 to enter cylinder housing sidebar recess 18 and thus straddle cylinder housing 14 and plug 16 so as to immobilize plug 16 against rotation about axis 21 relative to cylinder housing 14 and prevent unlocking of cylinder lock 10. It will be appreciated that sidebar 41 need not necessarily be shaped as shown in the figures and as described above. For example, the sidebar may be in the form of a side pin or another element or elements which serve the same functions. All these elements are intended to be covered by the terms sidebar and side locking element as used herein in the specification and claims. Reference is now made to Figs. 10 and 11 which illustrate an alternative engagement of a sidebar with plug pins. As mentioned above, and as shown in Fig. 11, an alternative embodiment of a sidebar 100 may feature sidebar slots 101 rather than protrusions 42, as in the embodiment of Figs. 1 - 6. Sidebar slots 101 are dimen¬ sioned to accommodate pin protrusions 102, shown m Fig. 10, which may replace axial slots 36 in the embodiment of Figs. 1 - 6. Sidebar slots 101 and pin protrusions 102 may engage each other in the same way as axial slots 36 and sidebar protrusions 42 in the embodiment of Figs. 1 - 6. An illustrative embodiment of a changeable key 12 according to the present invention is shown in Fig. 14. Key 12 includes a key head 50 and a shank 52. Shank 52 preferably includes one or more rotatable key engage¬ ment end face engagement elements 54, five of which are seen in Fig. 14. Rotatable key engagement end face en¬ gagement elements 54 may each be slotted, as indicated by reference numeral 56 in Fig. 16, or may feature a protru¬ sion as indicated by reference numeral 57 in Fig. 15 to accommodate, respectively, a projecting or a slotted rotatable key engagement end face of a plug pin 25. Each of rotatable key engagement end face engagement elements 54 is designed to be engaged by a corresponding key engagement end face 37 of rotatable plug pin 25. For example, for the rotatable plug pin embodiment illustrated in Fig. 5, the chisel head portion of key engagement end face 37 of rotatable plug pin 25 is dimensioned to fit into key engagement end face engage¬ ment element 54 which is suitably slotted as seen in Fig. 16, so that the sloping sides of the chisel head of end face 37 directly engage the beveled edges of slot 56. Similarly, for the slotted key engagement end face con¬ figuration shown in Fig. 10, the slotted portion of plug pin 25 is dimensioned to engage the protrusions 57 of the engagement element. Preferably, rotatable key engagement end face engagement element 54 resembles a horseshoe or a special purpose circlip, similar to those available from Bossard of Switzerland and Seeger of Germany. In accordance with a preferred embodiment of the present invention, each of rotatable key engagement end face engagement elements 54 fits snugly into a recess 58, preferably circular, in shank 52 of key 12. The tight fit of rotatable key engagement end face engagement element 54 within recess 58 and the elasticity and out¬ wardly directed bias of rotatable key engagement end face engagement element 54 are selected so that rotatable key engagement end face engagement element 54 may be rotated within recess 58 but only upon the application of a rotational force beyond a given threshold, preferably with the use of a screwdriver-like tool, as described below. In accordance with one embodiment of the invention, locking protrusions 59 are provided adjacent recesses 58 as the result of operation of a press in engagement with regions of the key shank adjacent the recesses 58, which causes a portion of the key material at such regions to protrude into locking engagement with engagement elements 54, thereby locking the engagement elements 54 against inadvertent rotation once the key combination of the key has been set. The locking engage¬ ment of the protrusions, after engagement by a press is illustrated in Fig. 17. It is appreciated that, if de¬ sired, the protrusions 59 may subsequently be removed as by the use of tool 60 (Fig. 12), thus allowing the key combination to be changed again. In operation, a lock and key combination ac¬ cording to the illustrated embodiment of the present invention functions as follows. Each of rotatable plug pins 25 features a certain changeable angle, Z, between the axis of an axial projection or slot formed on the key engagement end face 37 and the axial slot 36 or protru¬ sion 102 of collar portion 34, as seen in Figs. 5 and 10 respectively. A correct key 12 has its rotatable key engage¬ ment end face engagement elements 54 oriented so that, when key 12 is inserted fully into keyway 22, key en¬ gagement end face 37 and collar portion 34 of each of rotatable plug pins 25 are together made to automatically orient themselves by rotation to the extent necessary to ensure that the projections or slots of key engagement end faces 37 of each of the rotatable plug pins 25 prop¬ erly engage the corresponding rotatable key engagement end face engagement elements 54 on key 12. The correct orientation of rotatable plug pins 25 causes all the slots 36 (Fig. 5) or projections 102 (Fig. 10) of rotatable plug pins 25 to be mutually aligned as seen in Figs. 3 and 11 respectively, in the direction facing sidebar 41. If key 12 is rotated about plug axis 21, thus rotating the plug 16 about axis 21, the inclined surfaces of recess 18 and of the corresponding facing surfaces of the sidebar 41 cause the sidebar 41 to be displaced towards the interior of plug 16 and towards rotatable plug pins 25. Since the slots 36 or projections 102 are all properly aligned, the projections 42 of sidebar 41 penetrate slots 35 and/or pin projections 102 of rotata¬ ble plug pin 25 penetrate sidebar slots 101, thus per¬ mitting the sidebar 41 to be displaced towards the plug axis 21. The resulting displacement of sidebar 41 allows it to withdraw completely from cylinder housing sidebar recess 18, thereby allowing the rotation of key plug 16 within cylinder housing 14 about plug axis 16 so as to open the cylinder lock. If an incorrect key is used, one or more of slots 36 or projections 102 will not be properly aligned so that penetration engagement of the sidebar and the collar portions 34 of the plug pins 25 is precluded, thus leaving sidebar 41 partially in cylinder housing sidebar recess 18 and thus preventing the rotation of key plug 16 within cylinder housing 14. Whenever it is desired to change the combina¬ tion of cylinder lock 10, the following procedure is preferably followed: As illustrated in Figs. 12 and 13, first, cylinder lock 10 is removed from a door or other mounting structure, so as to permit access to access openings 20 of cylinder housing 14. A correct key 12 is inserted into keyway 22 so as to allow plug 16 to be rotated within cylinder housing 14. Plug 16 is then rotated, through approximately 180 degrees in the case of the configuration illustrated in Figs. 3 and 13, so that access openings 20 are aligned with the pin rotation end faces 37 of rotatable plug pins 25, as seen in Fig. 13. Once access openings 20 have been properly aligned with rotatable plug pins 25, a screw- driver-like tool 60 is inserted through access opening 20 so as to engage slot 39 in the pm rotation end face 38 of rotatable plug pin 25. Spacer collar 35 is hollow so as to allow access to slot 39 of pin rotation end face 38. Rotation of tool 60 brings about a relative rotation between key engagement end face 37 and collar portion 34 which is unable to rotate relative to plug 16, because it is immobilized against rotation by the presence of protrusion 42 of sidebar 41 in slot 36 of collar portion 34. It will be noted that the rotation of tool 60 also simultaneously serves to rotate the corresponding rotatable key engagement end face engagement element 54 of key 12 which is engaged by key engagement end face 37 of rotatable plug pin 25. In this way, the combination of key 12 is automatically altered at the same time, and in the same way and amount, as the alteration of the combi¬ nation of cylinder lock 10. In this manner, any desired relative angle between key engagement end face 37 and slot 36 or pin protrusion 102 of collar portion 34 may be achieved. To facilitate the setting of a proper angle, the outer surface of cylinder housing 14 surrounding each access opening 20 may feature suitable cylinder housing markings 70 (Fig. 6) while tool 60 features a marking 72, as seen in Fig. 13. Various reproducible angles can thus be set by aligning a specific housing marking 70 with tool marking 72. The alignment process may be facilitated by using a magnifying lens 74 or other optical system which is properly focused to provide the user an accurate view of the markings. Preferably, magnifying lens 74 is at¬ tached to tool 60 to ensure proper focus and facilitate the process. The number of possible combinations available for each cylinder lock is quite large. For example, if only 12 different angles, as indicated in Fig. 6, are used on each of five pins, the number of possible permu¬ tations is 12 5 or 248,832. To increase the number of permutations further one could use more than 12 angles per pin and/or more pins. Alternatively or additionally, pins of several different lengths and corresponding rotatable key engage¬ ment end face engagement elements which are recessed in the key to greater or lesser extents may be employed. An example of this is shown in Fig. 8, where rotatable plug pins 125 are of different lengths and wherein the various rotatable key engagement end face engagement elements 154 have different heights relative to an exterior surface of a shank 152 of a key 112. The use of pins of different lengths is also effective in the embodiment of Figs. 1 6, wherein spacer collar 35 defines a maximum extent of slot 36 which is identical to the corresponding extent of the sidebar projections 42, thereby requiring precise axial positioning of plug pm 25. A key according to the present invention may feature rotatable key engagement end face engagement elements on only one side or on both sides. As described above, the combination of one set of rotatable key en¬ gagement end face engagement elements is automatically altered when the combination of the cylinder lock is altered. If desired, the rotatable key engagement end face engagement elements on the other side of the key, as well as the rotatable key engagement end face engagement elements on one or both sides of any duplicate keys are readily changed as depicted in Fig. 18. A tool 161 which may be similar to tool 60 (Fig. 12) s used to rotate rotatable key engagement end face engagement elements 54 to the desired positions. To facilitate the exact rota¬ tion of elements 54, a portion of shank 52 of key 12 surrounding rotatable key engagement end face engagement elements 54 may feature markings similar to markings 70 (Fig. 6) on cylinder housing 14. To further facilitate the precise rotational positioning of rotatable key engagement end face engage¬ ment elements 54, each of rotatable key engagement end face engagement elements 54 preferably features notches 58, as shown in Figs. 14-16, which are used in the align¬ ment process. Preferably a magnifying lens 174 is at¬ tached to tool 61 as described above with reference to tool 60. Preferably rotatable key engagement end face engagement elements 54 each include a series of small spaced protrusions (not shown) at their periphery. These protrusions are designed to engage complementary spaced depressions (not shown) in the inner wall of recess 58. The presence of these protrusions and depressions makes it possible to more accurately reproduce a combination on a key by providing more secure engagement of rotatable key engagement end face engagement element 54 and recess 57, preferably, with the production of an audible click. A similar mechanism may be used to the same advantage with rotatable plug pins 25, at least a portion of which may feature small protrusions (not shown) which can click into corresponding depressions in the corre¬ sponding pm holes. The basic embodiment described above relies entirely on the sidebar to rotationally immobilize the key plug relative to the cylinder housing. In an alterna¬ tive embodiment according to the present invention, use is made of driver pins which penetrate the cylinder housing when a proper key is not inserted in the keyway so as to provide additional, or alternative, rotational immobilization of the key plug relative to the cylinder housing. In this alternative embodiment, illustrated m Figs. 7 and 8, use is made of driver pms 180. A cylinder housing 181 includes a cylinder housing pm bore 182 which corresponds in position to a plug pin bore 183. Cylinder housing pin bore 182 is located and dimensioned to accommodate driver pin 180. Driver pin 180 serves to immobilize a plug 116 against rotation about a plug axis 121 relative to cylin¬ der housing 181 by straddling plug pin bore 183 and cylinder housing pin bore 182 whenever a correct key 186 is not in a keyway 188, as seen in Fig. 7. Driver pm 180 is biased, preferably by means of a spring 189, towards keyway 188 and against a spacer collar 190 at a shearlme boundary and thereby biases spacer collar 190 and the remainder of a rotatable plug pin 125 in the direction of keyway 188. Rotatable plug pin 125 and spacer collar 190 are of a combined length such that the axial position of rotatable plug pm 125, upon the engagement of rotatable plug pin 125 with a correct changeable key 186, is such that rotatable plug pms 125 and spacer collars 190 are located entirely within plug pin bore 183 and driver pins 180 are located entirely within cylinder housing pin bore 182, as seen in Fig. 8, thereby permitting rotation of the key plug within the cylinder housing. A key suitable for use in a changeable cylinder lock of the present invention has been described hereto¬ fore as a key whose combination is also changeable and is illustrated in Figs. 14 - 16. However, under certain circumstances, it may be desirable to use flat keys whose combination is not changeable and is instead permanently fixed upon manufacture or cutting. Such a flat key would still enjoy a significant advantage over a conventional Medeco-type key in that a great many different angles can be used, rather than just a few angles (typically three) currently available with conventional Medeco-type keys. An example of a flat key having an unchangeable combination is shown in Fig. 25. Key 212 includes one or more permanently oriented slots 213 which are dimensioned to engage the chisel-headed portions of the respective rotatable pins of a cylinder lock, such as the pins illustrated in Fig. 24. Preferably the chisel-headed portions are non-axially symmetric, so as to present a different configuration with every rotational orientation through 360 degrees. The procedure for simultaneously changing the key combination of a cylinder lock and key, where the key does not have a changeable key combination is identical to that described above with reference to Figs. 12 and 13, provided that at least one of the keys which operates the changeable cylinder lock is of the changeable combi¬ nation type, as shown n Fig. 14. However, once a new cylinder key combination has been established, additional keys with the correct unchangeable combination of the type illustrated in Fig. 25, may be made using any suit¬ able technique, instead that described in Fig. 18 which shows a method for changing the combinations of addition¬ al changeable keys. To further enhance the security of a cylinder lock system according to the present invention, it is desirable to ensure that keys which are operative in such a system are not readily reproducible using conventional technology and readily available key blanks. To this end, it is proposed in accordance with a preferred embodiment of the present invention that each key include at least one floating member, whose function and structure are described herembelow with reference to Figs. 19 - 23. For purposes of illustration, Figs. 19 and 20 show in end and side views, respectively, a cylinder lock similar to that of Figs. 7 and 8 m that it includes driver pms. It will be readily understood that a cylin¬ der lock such as that of Fig. 3 without driver pms could alternatively be employed. A key 312 which is operative to operate the cylinder lock of Figs. 19 and 20 differs from that shown in Fig. 14 in that at least one of the elements for engaging rotatable plug pins 325 is able to move up or down relative to key 312 within a predefined range of displacement. In the illustrations of Figs. 19 and 20, and Fig. 21 which shows a close-up view of the relevant portion of Fig. 20, key 312 is seen to include a single floating key engagement face engagement element 330. It is appreciated that any one or more key engagement end face engagement elements may be constructed to be float¬ ing. The other engagement elements, indicated by refer¬ ence numeral 340, which are preferably rotatable about their respective axes as described above, are fixed at a predetermined position along their axes. In contrast to engagement elements 340, float¬ ing engagement element 330, which may be, but is not necessarily rotatable about its axis, is not fixed in the axial direction but is rather able to "float". Thus, for example, floating engagement element 330 may include an enlarged flange 350 which is slidable within a small window between a first position shown in Fig. 21, and a second position wherein flange 250 moves upward until it abuts a retaining member 360. Retaining member 360 is preferably a circlip or other outwardly-biased spring or spring-like mechanism which fixes floating engagement element 330 in the rota¬ tional sense in the absence of a rotational force which exceeds a predetermined threshold, for instance, when changing the combination of the cylinder lock. In certain embodiments it is not possible to rotate floating engage¬ ment element 330. In such a case, its rotational orienta¬ tion remains fixed following initial manufacture. The amount of "float" in floating engagement element 330 is preferably such that when floating engage¬ ment element 330 is positioned away from key 312 to the greatest possible extent, a portion of floating engage- ment element 330 projects beyond the surface of key 312. In the embodiment of Figs. 19 - 23, plug 364 is modified as compared to corresponding plugs described above in that plug 364 includes a biasing pin 366 which is anchored in plug 354 and which is biased radially inward by a suitable mechanism, such as biasing pin spring 368. To prevent the inadvertent rotation of floating engagement element 330, floating engagement element 330 may be shaped as shown in Fig. 21 so that floating en¬ gagement element 330 is not rotatable without the simul¬ taneous rotation of rotatable retaining member 360, the rotation of which can be effected only upon the applica¬ tion of a rotational force exceeding a predetermined threshold. In operation, the insertion of key 312 is effected as described above, but with floating engagement element 330 being pushed toward key 312 to allow for key 312 to be properly inserted into the keyway. When float¬ ing engagement element 330 reaches its destined location, biasing pm 366 serves to push radially inward on float¬ ing engagement element 330 so as to effect firm engage¬ ment between floating engagement element 330 and the key engagement end face of rotatable plug pm 325, which engagement takes place outside of a plane defined by the surface of key 312, as seen in Figs. 19 and 21. A non-changeable key 212, such as that shown in Fig. 24, may also be employed with a cylinder lock whose combination is not changeable. As seen in Fig. 24, such a non-changeable cylinder lock has a pm 380 which is made of a single part wherein the angle X, between an axial slot 386 and the chisel head 390 for the particular p is fixed upon manufacture. This one-piece construction is in contrast with the plug pin 25 (Fig. 5) made up of three mutually rotatable parts which is employed m the cylinder lock embodiments having a changeable key config- uration. While a non-changeable cylinder lock system suffers from the disadvantage that the combination of the cylinder lock cannot be changed, the system still enjoys the benefit of using a flat key with slots which can be arranged in a large variety of angles over 360 degrees. The large number of angles greatly increases the number of possible combinations and thereby enhances the securi¬ ty of the lock. Reference is now made to Fig. 26, which is an illustration of a plug pin 425, having a non-axially symmetric key engagement end face in accordance with a preferred embodiment of the present invention. Other than the non-axially symmetric configuration of the key en¬ gagement end face, the plug pin 425 may be identical to that shown in Fig. 5 and described heremabove. The provision of a non-axially symmetric configuration of the key engagement end face has the advantage that the number of available key combinations provided thereby is greatly increased, since no symmetry exists in the end face under rotation about its longitudinal axis, the plug pin axis. Fig. 27 is an illustration of a rotatable engagement element 454 useful in a key designed for use in a lock having pins of the type shown in Fig. 26. Comparing the configuration of the engagement element of Fig. 27 with the corresponding element shown in Fig. 16, it is seen that m the element of Fig. 27, the central portion 460 is higher than the corresponding portion in the embodiment of Fig. 26, so as to prevent seating engagement of the chisel head 462, when the chisel head is rotated by 180 degrees from its correct position. This can be seen clearly from a comparison of Figs. 28 and 29. Fig. 28 illustrates correct seating wherein the chisel head 460 is seated alongside portion 460. Fig. 29 illustrates non-seating engagement, wherein the chisel head 460 is prevented from seating by portion 460 and thus the entire plug pm 425 is axially dis¬ placed, preventing unlocking of the lock. Reference is now made to Fig. 30, which is an illustration of a cylinder lock according to still anoth¬ er embodiment of the present invention which employs both changeable combination pins and non-changeable combina¬ tion pins and to Fig. 31, which is a sectional illustra¬ tion taken along the lines XXXI - XXXI of Fig. 30. The lock of Figs. 30 and 31 is seen to have two rows of plug pms 525 of the type described heremabove in connection with the embodiment of Figs. 1 - 6, preferably configured as shown in Fig. 26, and a single, centrally disposed row of conventional plug pins 530. Referring now to Fig. 32, which is an illustra¬ tion of a reversible key 535 useful in the lock of Figs. 30 and 31, it is seen that non-axial symmetric plug pin face engagement locations 540 are provided for engagement with plug pins 525; and plug pin engagement locations 550, which are typically axially symmetric, are provided for engagement with conventional plug pins 530. It is appreciated that the key of Fig. 31 may be reversible. Reference is now made to Figs. 33 - 35B, which illustrate the structure and operation of apparatus for changing combinations on locks and/or keys in accordance with a preferred embodiment of the present invention. Fig. 33 is a top view illustration of the key combination changing apparatus. The key combination changing apparatus com¬ prises a housing 600 defining a bore 602 for receiving a cylinder, which may or may not contain a key in its keyway, and a second keyway bore 604 for separately receiving a key. A plurality of rotation tool passage bores 606 communicate with bores 602 and 604 and are aligned so that when a cylinder or key are fully inserted into respective bores 602 and 604, the tool passage bores communicate with the access openings 20 (Fig. 6) of the cylinder in bore 602 and with the rotational engagement elements 54 (Fig. 14) of the key. It is noted that since the keys may be right handed or left handed, appropriate key positioning stops 608 and 610 are preferably provided for suitable posi¬ tioning of the key in bore 604. The locks may also be right handed or left handed. Both types of locks are accomodated by means of a suitable mounting adapter 611, which is seated in a socket 612. It is appreciated that adapters 611 may be provided for any suitable external configuration of cylinder. A dial 613 is provided with a suitable scale for relatively easy viewing of various possible rotation¬ al position orientations of the plug pins. Figs. 34A and 35A illustrate changing of the combination of a cylinder lock of the type described heremabove simultaneously with the changing of the combination of a key inserted in its keyway. Alternative¬ ly, the key may not be present in the keyway. Figs. 34B and 35B illustrate changing of the combination of a key located in bore 604 independently of a change in combination of a cylinder. While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made.

Claims: WHAT IS CLAIMED IS: 1. A cylinder lock having a changeable key combi¬ nation, the cylinder lock comprising: a cylinder housing defining a bore; a plug arranged in said bore and defining a keyway; and at least one plug pin disposed in said plug along at least one plug pin axis and communicating with said keyway, said at least one plug pin having a key engagement end face communicating with said keyway, said key engagement end face being configured such that rota¬ tion of the plug pin about the plug pin axis effects a change in the key combination of the cylinder lock; wherein said cylindrical housing defines at least one access opening which permits access to said at least one plug pin for selectable rotational positioning thereof for changing the key combination of the cylinder lock by means of rotation of the at least one plug pin about the at least one plug pin axis. 2. Apparatus according to claim 1 and also com¬ prising a key including: a key head; a shank attached to the key head; and at least one key engagement end face engagement element arranged for engagement with said key engagement end face of said at least one plug pin, said at least one key engagement end face engagement element being rotata¬ bly mounted in said shank for selectable rotational positioning. 3. A key for use with a cylinder lock having a changeable key combination comprising: a cylinder housing defining a bore extending along a first axis; a plug arranged in said bore and defining a keyway; and at least one plug pin disposed in said plug along at least one plug pin axis and communicating with said keyway, said at least one plug pin having a key engagement end face communicating with said keyway, said key engagement end face having a non-axially symmetric configuration; the key comprising: a key head; a shank attached to the key head; and at least one key engagement end face engagement element arranged for engagement with said key engagement end face of said at least one plug pm, said at least one key engagement end face engagement element being rotata¬ bly mounted in said shank for selectable rotational positioning. 4. A method for simultaneously changing the key combination of a cylinder lock and of a key inserted therein, wherein the cylinder lock comprises: a cylinder housing defining a bore extending along a first axis; a plug arranged in said bore and defining a keyway; and at least one plug pin disposed in said plug along at least one plug pin axis and communicating with said keyway, said at least one plug pm having a key engagement end face communicating with said keyway, said key engagement end face having a non-axially symmetric configuration, wherein said cylindrical housing defines at least one access opening which permits access to said at least one plug pm for selectable rotational positioning thereof, and the key comprises: a key head; a shank attached to the key head; and at least one key engagement end face engagement element arranged for engagement with said key engagement end face of said plug pins, said at least one key engage¬ ment end face engagement element being rotatably mounted in said shank for selectable rotational positioning, the method comprising: inserting the key into the keyway such that said at least one key engagement end face engagement element is in engagement with a corresponding key engage¬ ment end face of said at least one plug pin; positioning said key and said plug such that said pm rotation end face of said at least one plug pin opposite said key engagement end face is accessible through said at least one access opening; inserting a tool through said at least one access opening to engage a pin rotation end face of at least one plug pin, while at the same time the key en¬ gagement end face of said plug pin is in engagement with a corresponding said key engagement end face engagement element; and rotating said tool in engagement with said pm rotation end face of a plug pin, while at the same time the key engagement end face of said plug pin is in en¬ gagement with a corresponding said key engagement end face engagement element, thereby rotating said key en¬ gagement end face engagement element by an amount corre¬ sponding to the rotation of the plug pm. 5. Apparatus according to either of claims 1 and 2 and wherein said key engagement end face has a non-axial¬ ly symmetric configuration. 6. Apparatus according to either of claims 1 and 2 and wherein said at least one plug pin comprises a plu- rality of plug pins. 7. Apparatus according to any of claims 1, 2, 5 and 6 and wherein said key engagement end face has a configuration which is not symmetric under 180 degree rotation. 8. Apparatus according to any of claims 1, 2 and 5 - 7 andwherein said at least one plug pin is arranged to be selectably rotatable without azimuthal restriction about said at least one plug pin axis when said pin rotation end face is rotatably engaged by a tool but not to be freely rotatable without azimuthal restriction otherwise. 9. Apparatus according to any of claims 1, 2 and 5 8 and wherein said at least one plug pin includes a collar portion which is arranged for selectable rotation relative to said end faces when said pin rotation end face is rotatably engaged by a tool and said collar portion is restrained against rotation, but not other¬ wise. 10. Apparatus according to claim 8 and wherein said cylinder lock comprises a side locking element for se¬ lectably locking engagement between said cylinder housing and said plug, said side locking element being arranged for mating engagement with said collar portion. 11. A key for use with a cylinder lock having a changeable key combination comprising: a cylinder housing defining a bore extending along a first axis; a plug arranged m said bore and defining a keyway; and at least one plug pm disposed in said plug along at least one plug pin axis and communicating with said keyway, said at least one plug pin having a key engagement end face communicating with said keyway, said key engagement end face being configured such that rota¬ tion of the plug pin about the plug pin axis effects a change in the key combination of the cylinder lock; the key comprising: a key head; a shank attached to the key head; and at least one key engagement end face engagement element arranged for engagement with said key engagement end face of said at least one plug pin, said at least one key engagement end face engagement element being rotata¬ bly mounted in said shank for selectable rotational positioning and subsequently fixable so as to resist further rotational positioning. 12. A key for use with a lock having at least one plug pin arranged along a plug pin axis and communicating with a keyway, the key comprising: a key head; a shank attached to the key head and defining at least one flat shank surface; and at least one plug pin engagement location on said at least one flat shank surface and bearing a three dimensional plug pm engagement configuration which is not axially symmetric with respect to the plug pin axis and which is not symmetric under 180 degree rotation about said plug pin axis. 13. A tool for changing the key combination of a cylinder lock, wherein tne cylinder lock comprises: a cylinder housing defining a bore extending along a first axis; a plug arranged in said bore and defining a keyway; and at least one plug pin disposed in said plug along at least one plug pin axis and communicating with said keyway, said at least one plug pin having a key engagement end face communicating with said keyway, said key engagement end face having a non-axially symmetric configuration, wherein said cylindrical housing defines at least one access opening which permits access to said at least one plug pin for selectable rotational positioning thereof, the tool comprising: a holder for holding a cylinder; and an elongate element defining a hand held por¬ tion at one end thereof and a plug pin engagement portion at an opposite end thereof and being configured so as to pass through said at least one access opening in said cylindrical housing. 14. A tool according to claim 13 and also compris¬ ing a second holder for holding a key having at least one plug pin engagement portion for engagement of said at least one plug pm engagement portion by said elongate element.

Inventors: DOLEV MOSHE, DOLEV, MOSHE
Applicants: DOLEV MOSHE, MUL T LOCK TECHNOLOGIES LTD, MUL T LOCK U S A INC, DOLEV, MOSHE, MUL-T-LOCK TECHNOLOGIES LTD., MUL-T-LOCK U.S.A., INC.
Application year: 1996
Main classification: E05B27
IPC codes: E05B19, E05B27