Impact resistant lock apparatus with anti-theft lock core

Abstract: A lock apparatus includes a lock core device (10,10',10a,10b,10c, 10d,10e) received in a lock core chamber (401,801) of a lock body (40,40a,600,40b, 800,40') and having a key operable lock core (12), a shackle member (50,620,501,810) inserted into a shackle insert hole (404,405a,614,820) in the lock body (40,40a,600,40b, 800,40'), and a catch member (60,630,601,60b,60c) received in a catch chamber (403, 613, 403b, 802) that extends from the lock core chamber (401,801) to the shackle insert hole (404,405a,614,820). The lock core device (10,10',10a, 10b,10c,10d,10e) has a latch member (30,30',30a, 30b,30c) formed with a pin hole (35,35a, 35b,31c) that is eccentric to an axis of the lock core (12). The catch member (60,630,601,60b,60c) is formed with a pin (64,631,64a,64b,62c,64c) which extends rotatably into the pin hole (35,35a,35b,31c) for engaging the latch member (30,30',30a,30b,30c).

Description: The present invention relates to a lock apparatus, more particularly to a lock apparatus which has an enhanced resistance to external impact and which has a lock core device that provides an enhanced anti-theft effect. U.S. Patent No. 5, 934, 121 discloses a lock apparatus having a lock core unit and a coded key for operating the lock core unit. The lock core unit includes a stack of locking plates, each of which confines a central hole in a shape of three quarters of a circle to permit extension of the coded key therethrough. The locking plates have an outer periphery formed with engaging notches. The coded key has a cross-section in the form of a circular sector, and is formed with a plurality of key bit projections and key bit grooves which have inclined actuating surfaces at different angles to set the code of the key. The engaging notches are misaligned with one another in accordance with the code of the key when the lock core unit is in a locking position, and are aligned with one another when the lock core unit is in an unlocking position. When the key is inserted into a key hole of the lock core unit that is defined by the central holes of the locking plates, and is rotated to unlock the lock core unit, the locking plates rotate by different angles to align the engaging notches with one another to enable a locking rod of the lock core unit to extend into the aligned engaging notches and to disengage from a lock shell that houses the lock core unit so as to prevent the locking rod from hindering rotation of the lock core unit relative to a lock shell that houses the lock core unit. Misalignment of the engaging notches forces the locking rod to extend into a locking groove in the lock shell to hinder rotation of the lock core unit relative to the lock shell. Since the angles of the actuating surfaces of the key bit projections and the key bit grooves on the key can be varied in a range from 0 to 180 degrees, a relatively large number of codes can be set on the key. The lock apparatus thus has a good anti-theft effect. It is desirable to provide a lock apparatus that has a lock core unit of this type and capable of providing an enhanced anti-theft effect. U.S. Patent No. 5,931,030 discloses a padlock having a lock base, a lock core unit received in the lock base, and a U-shaped shackle with longer and shorter leg portions inserted removably into shackle insert holes in the lock base. A pair of catch members are disposed in a catch chamber within the lock base adjacent to the lock core unit. Each of the catch members has one end disposed adjacent to a plunger that is formed on a latch member of the lock core unit so as to be actuatable by the plunger, and an opposite end disposed adjacent to a respective one of the shackle insert holes for engaging a respective one of the longer and shorter legs of the shackle member. It is desirable to modify the connection between the catch members and the latch member to enhance the impact resistance of the catch members. US Patent No. 5,823,021 discloses a padlock including a lock body formed with a lock core chamber, a lock core opening for access to the lock core chamber and a shackle insert hole, the lock core chamber having a section formed as a catch chamber which is adjacent to and communicated with the shackle insert hole, a lock core device received in the lock core chamber via the lock core opening, the device including a cylindrical and axially rotatable lock core provided with a latch member that is disposed in the catch chamber, a key insertable into the lock core device via the lock core opening and operable for rotating the lock core and the latch member between locking and unlocking positions, a shackle member having a leg portion formed with a shackle groove and inserted into the shackle insert hole in the lock body, and a catch member disposed in the catch chamber, the catch member having a shackle engaging end portion for engaging the shackle groove in the leg portion, and a latch engaging end portion opposite to the shackle engaging end portion and engaging the latch member such that the catch member is movable between locking and unlocking positions when the latch member moves between the locking and unlocking positions, the shackle engaging end portion extending into the shackle insert hole for engaging the shackle groove in the leg portion when the catch member is disposed in the locking position, the shackle engaging end portion being retracted into the catch chamber for disengaging from the leg portion of the shackle member to permit removal of said member from the insert hole when the catch member is disposed in the unlocking position, the latch member having an end face transverse to an axis of the lock core and formed with a pin hole eccentric to said axis, the latch engaging end portion being formed with a pin which extends rotatably into the pin hole in the latch member for engaging the latch member. The main object of the present invention is to provide a lock apparatus with an enhanced resistance to external impact and an enhanced anti-theft effect. Accordingly, the lock apparatus of the present invention includes a lock body formed with a lock core chamber, a lock core opening for access to the lock core chamber, and a shackle insert hole, the lock core chamber having a section formed as a catch chamber which is adjacent to and which is communicated with the shackle insert hole; a lock core device received in the lock core chamber via the lock core opening, the lock core device including a cylindrical and axially rotatable lock core which is provided with a latch member that is disposed in the catch chamber; a key which is insertible into the lock core device via the lock core opening and which is operable for rotating the lock core and the latch member between locking and unlocking positions; a shackle member having a leg portion which is formed with a shackle groove and which is inserted into the shackle insert hole in the lock body a catch member disposed in the catch chamber of the lock body, the catch member having a shackle engaging end portion for engaging the shackle groove in the leg portion of the shackle member, and a latch engaging end portion opposite to the shackle engaging end portion and engaging the latch member such that the catch member is movable between locking and unlocking positions when the latch member moves between the locking and unlocking positions, the shackle engaging end portion of the catch member extending into the shackle insert hole for engaging the shackle groove in the leg portion of the shackle member when the catch member is disposed in the locking position, the shackle engaging end portion being retracted into the catch chamber for disengaging from the leg portion of the shackle member to permit removal of the shackle member from the shackle insert hole when the catch member is disposed in the unlocking position, wherein the latch member has an end face which is transverse to an axis of the lock core and which is formed with a pin hole that is eccentric to the axis of the lock core, the latch engaging end portion of the catch member being formed with a pin which extends rotatably into the pin hole in the latch member for engaging the latch member, characterized in that the key has a shank portion with a cross-section formed as a circular sector, and a handle portion connected to the shank portion, the shank portion having first and second radial surfaces that extend along length of the shank portion, and a curved surface that interconnects the first and second radial surfaces , the first radial surface being planar, the second radial surface being formed with a plurality of key bit portions that are arranged along length of the shank portion, the key bit portions having radial key bit surfaces that form different angles with the first radial surface to set code of the key, the shank portion of the key further having a distal end formed as an actuating tip portion, the lock core device includes a lock casing mounted in the lock core chamber of the lock body, the lock casing having an inner surface which confines a cylindrical chamber and which is formed with an axially extending locking groove, the lock core including: a cylindrical inner shell received rotatably in the cylindrical chamber of the lock casing, the inner shell having a rear end mounted with the latch member, and a front end, the inner shell being formed with an axially extending locking slot which is registered with the locking groove when the lock core is in the locking position; a stack of annular locking plates received in the inner shell, each of the locking plates having an inner periphery that confines a central hole, the central holes of the locking plates cooperatively defining a keyhole that permits insertion of the shank portion of the key there into, each of the locking plates further having an outer periphery that is formed with an engaging notch, the engaging notches of the locking plates being misaligned with one another in accordance with the code of the key when the lock core is in the locking position, the engaging notches being aligned with one another when the lock core is in the unlocking position, the inner periphery of each of the locking plates being formed with a radial inward key engaging protrusion which abuts against the key bit surface of a corresponding one of the key bit portions on the key when the key is inserted into the keyhole and is rotated, the locking plates being rotated by different angles according to the code of the key to align the engaging notches when the key is inserted into the keyhole and is rotated for moving the lock core to the unlocking position; a locking rod received in the locking slot of the inner shell, misalignment of the engaging notches on the locking plates enabling the outer peripheries of the locking plates to force the locking rod to extend into the locking groove in the lock casing in order to hinder rotation of the inner shell relative to the lock casing when the lock core is in the locking position, alignment of the engaging notches on the locking plates enabling the locking rod to disengage the locking groove and to extend into the engaging notches in order to permit rotation of the inner shell relative to the lock casing during unlocking movement of the lock core; and an annular drive plate disposed in the inner shell at the rear end of the inner shell and disposed between the locking plates and the latch member, the drive plate having an inner periphery which confines a key engaging hole and which is formed with a key actuatable projection that projects radially and inwardly, the actuating tip portion of the key being extendible into the key engaging hole for engaging the key actuatable projection so as to enable co-rotation of the drive plate with the key, the drive plate being formed with a drive projection, the latch member having an actuatable section which is driven by the drive projection such that rotation of the drive plate can result in corresponding rotation of the latch member between the locking and unlocking positions, and in that the lock core device further includes a spring-loaded tumbler unit, the lock casing being formed with a first tumbler hole, the inner shell being formed with a second tumbler hole, one of the locking plates being formed with a third tumbler hole, the first, second and third tumbler holes being aligned with one another prior to insertion of the key into the key hole, the tumbler unit including a first tumbler member received in the first tumbler hole, a second tumbler member received in the second tumbler hole, a third tumbler member received in the third tumbler hole, and a first biasing spring for biasing the first, second and third tumbler members to move inwardly to enable the first tumbler member to project into the second tumbler hole in the inner shell so as to hinder rotation of the inner shell relative to the lock casing, to enable the second tumbler member to project into the third tumbler hole in said one of the locking plates so as to hinder rotation of said one of the locking plates within the inner shell, and to enable the third tumbler member to project from the inner periphery of said one of the locking plates, the curved surface on the shank portion of the key being formed with a tumbler recess that is defined by a recessed tumbler push wall, the third tumbler member projecting into the tumbler recess when the key is inserted into the key hole, the third tumbler member being pushed by the tumbler push wall in a direction against biasing action of the first biasing spring so as to retract the second tumbler member into the second tumbler hole in the inner shell, thereby preventing the second tumbler member from hindering rotation of said one of the locking plates relative to the inner shell, and so as to retract the first tumbler member into the first tumbler hole such that the first tumbler member ceases to hinder rotation of the inner shell relative to the lock casing. Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which: Figure 1 is an exploded perspective view showing a lock core device and a key of a lock apparatus of a first preferred embodiment of the present invention; Figure 2 is an exploded perspective view illustrating how the key engages a protective plate, a locking plate and a drive plate of the lock core device of the first preferred embodiment; Figure 3 is a cross-sectional view illustrating the engagement between the key and the locking plate; Figure 4 is a cross-sectional view illustrating the engagement between a distal end of the key and the drive plate; Figure 5 is a perspective view illustrating a lock core of a second preferred embodiment of the lock apparatus of the present invention; Figure 6 is a perspective view illustrating a lock core of a third preferred embodiment of the lock apparatus of the present invention; Figure 7 is a partly-exploded perspective view illustrating a lock core of a fourth preferred embodiment of the lock apparatus of the present invention; Figure 8 is a fragmentary exploded perspective view illustrating a key and a lock core device of a fifth preferred embodiment of the lock apparatus of the present invention; Figures 9 and 10 are cross-sectional views of the fifth preferred embodiment, illustrating how the key is retained in the lock core device by a retaining plate; Figure 11 is a perspective view illustrating the engagement between the key and the retaining plate in the fifth preferred embodiment; Figure 12 is an exploded perspective view illustrating a key and a lock core device of a sixth preferred embodiment of the lock apparatus of the present invention; Figure 13 is a cross-sectional view illustrating the lock core device of the sixth preferred embodiment prior to insertion of the key into the lock core device; Figure 14 is a cross-sectional view of the lock core device of the sixth preferred embodiment, where the key is inserted into the lock core device and engages a third tumbler member; Figure 15 is a cross-sectional view of the lock core device of the sixth preferred embodiment when the key is rotated in the lock core device, where the key is rotated and the third tumbler member is disengaged from the key; Figure 16 is a cross-sectional view of the lock core device of the sixth preferred embodiment, where the key continues to rotate independently of a corresponding locking plate; Figure 17 is a cross-sectional view of the lock core device of the sixth preferred embodiment, where the key is rotated to unlock the lock core device; Figure 18 is a schematic plan view of a lock core device of a seventh preferred embodiment of the lock apparatus of the present invention; Figure 19 is a cross-sectional view of the lock core device of the seventh preferred embodiment; Figure 20 is an exploded perspective view of a key and a lock core device of an eighth preferred embodiment of the lock apparatus of the present invention; Figure 21 is a cross-sectional view of a lock core device of a ninth preferred embodiment of the lock apparatus of the present invention; Figure 22 is an exploded perspective view showing a latch member and a catch member of a tenth preferred embodiment of the lock apparatus of the present invention; Figure 23 is an exploded perspective view of the tenth preferred embodiment; Figure 24A is a sectional view of the lock apparatus of Figure 23 in a locking state; Figure 24B is a cross-sectional view of the lock apparatus of Figure 23 in the locking state; Figure 25A is a sectional view of the lock apparatus of Figure 23 in an unlocking state; Figure 25B is a cross-sectional view of the lock apparatus of Figure 23 in the unlocking state; Figure 26A is a sectional view of a eleventh preferred embodiment of a lock apparatus of the present invention in a locking state; Figure 26B is a cross-sectional view of the eleventh preferred embodiment in the locking state; Figure 27A is a sectional view of a twelfth preferred embodiment of the lock apparatus of the present invention in a locking state; Figure 27B is a cross-sectional view of the twelfth preferred embodiment in the locking state; Figure 28A is a sectional view of a padlock incorporating a lock core device of the twelfth preferred embodiment; Figure 28B is a cross-sectional view of the padlock of Figure 28A; Figure 29 is a fragmentary, partly sectioned, exploded perspective view showing a thirteen preferred embodiment of the lock apparatus of the present invention; Figure 30 is an exploded perspective view illustrating a catch member and a latch member of a fourteenth preferred embodiment of the lock apparatus of the present invention; Figure 31A is a sectional view of the lock apparatus of the fourteenth preferred embodiment in an unlocking state; Figure 31B is a cross-sectional view of the lock apparatus of the fourteenth preferred embodiment in the unlocking state; Figure 32A is a sectional view of the lock apparatus of the fourteenth preferred embodiment in a locking state; Figure 32B is a cross-sectional view of the lock apparatus of the fourteenth preferred embodiment in the locking state; Figure 33 is an exploded perspective view illustrating a catch member and a latch member of a fifteenth preferred embodiment of the lock apparatus of the present invention; Figure 34 is a top view of the latch member of Figure 33; Figure 35 is a fragmentary sectional view of the latch member and the catch member of Figure 33, illustrating engagement between a pin on the latch member and a stepped straight hole section of a pin hole in the latch member; Figure 36A is a sectional view of the lock apparatus of the fifteenth preferred embodiment in a locking state; Figure 36B is a cross-sectional view of the lock apparatus of the fifteenth preferred embodiment in the locking state; Figure 37 is a cross-sectional view of the fifteenth preferred embodiment, where leg portions of a shackle member are inserted into a pair of shackle insert holes in a lock body of the lock apparatus; Figure 38 is a schematic view illustrating the engagement between a latch member and a catch member of a sixteenth preferred embodiment of the lock apparatus of the present invention; Figure 39 is an exploded perspective view illustrating a latch member and a catch member of a seventeenth preferred embodiment of the lock apparatus of the present invention; Figure 40 is a schematic view illustrating relative positions of the latch member and a pair of the catch members of the lock apparatus of the seventeenth preferred embodiment in a locking state; Figure 41 is a schematic view illustrating relative positions of the latch member and the catch members of the lock apparatus of the seventeenth preferred embodiment in an unlocking state; Figure 42 is a sectional view of the lock apparatus of the seventeenth preferred embodiment in the locking state; Figure 43 is a fragmentary sectional view of an eighteenth preferred embodiment of the lock apparatus of the present invention, where a cover unit is shown to be in a closed position; and Figure 44 is a fragmentary sectional view of the lock apparatus of the eighteenth preferred embodiment, where the cover unit is shown to be in an open position. Before the present invention is described in greater detail, it should be noted that like elements are denoted by the same reference numerals throughout the disclosure. Referring to Figures 1 to 3, in a preferred embodiment of the lock apparatus according to the present invention, a lock core device 10 is shown to include a lock casing 11 with an inner surface that confines a cylindrical chamber 110 for receiving an axially rotatable lock core 12. The lock core 12 includes a cylindrical inner shell 120, a stack of annular locking plates 13, 13', 13a received in the inner shell 120, a plurality of annular spacer plates 14 disposed among the locking plates 13, 13', 13a, a locking rod 124 received in an axially extending slot 125 formed in the inner shell 120, an annular drive plate 15 received in the inner shell 120 at a rear end of the inner shell 120, and a latch member 30' connected to the rear end of the inner shell 120. Each of the locking plates 13, 13', 13a has an inner periphery formed with a radial inward key engaging protrusion 134 so as to define a central hole 131 that has an arc length equal to three quarters of a circle. Each of the locking plates 13, 13', 13a further has an outer periphery formed with at least one engaging notch 132. The central holes 131 of the locking plates 13, 13', 13a cooperatively confine a keyhole aligned with a key access hole 112 formed in a front end of the lock casing 11. The drive plate 15 has an inner periphery which confines a key engaging hole 151 and which is formed with a key actuatable projection 153 that projects radially and inwardly. The drive plate 15 has a drive projection 154 which extends axially and rearwardly toward the latch member 30'. The latch member 30' has an actuatable section 31' which is driven by the drive projection 154 such that rotation of the drive plate 15 can result in corresponding rotation of the latch member 30' between locking and unlocking positions. A coded key 20 is insertible into the key access hole 112 and into the keyhole defined by the central holes 131 of the locking plates 13, 13', 13a. The key 20 has a handle portion 22 and a shank portion 21 extending from the handle portion 22. The shank portion 21 has a cross-section formed as a circular sector, a flat first radial surface 211 extending along the length of the shank portion 21, a second radial surface 212 constituted by a plurality of key bit portions 24, 24a which are arranged along the length of the shank portion 21 and which have radial key bit surfaces that form different angles with the flat first radial surface 211 to set a code of the key 20, and a curved surface 213 that extends along the length of the shank portion 21 and that extends circumferentially between the first and second radial surfaces 211, 212. The shank portion 21 further has a distal end formed as an actuating tip portion 23 that is extendible into the key engaging hole 151 in the drive plate 15 for engaging the key actuatable projection 153 so as to enable co-rotation of the drive plate 15 with the key 20. Considering that a base portion with a cross-section in the form of a quarter of a circle is to be maintained on the key 20, the angles of the actuating surfaces on the key bit portions 24, 24a relative to the first radial surface 211 can be varied in a range from 0 to 180 degrees. As such, a relatively large number of codes can be selected for the key 20. With further reference to Figures 2 and 3, in the present embodiment, the inner periphery of one of the locking plates 13' is further formed with a radial inward engaging protrusion 133. The shank portion 21 of the key 20 is formed with an axially extending engaging groove 25 on the curved surface 213. The engaging groove 25 extends along the length of the shank portion 21 for engaging the engaging protrusion 133. In other embodiments, the engaging protrusion 133 may be formed on the shank portion 21 of the key 20, while the engaging groove 25 may be formed on one of the locking plates. The shape of the engaging protrusion 133 is not limited to that shown in Figures 2 and 3. Moreover, the angular position of the engaging groove 25 on the curved surface 213 can be varied. An improved anti-theft effect is thus achieved. Referring to Figures 2 and 4, the inner periphery of the drive plate 15 is further formed with a radial inward engaging protrusion 152. The actuating tip portion 23 of the key 20 is formed with an engaging groove 231 for engaging the engaging protrusion 152. Likewise, the position of the engaging protrusion 152 on the inner periphery of the locking plate 15 can be varied to further improve the anti-theft effect of the lock core device 10. Referring back to Figures 1 and 2, an annular protective plate 16 is received rotatably in the cylindrical chamber 110 of the lock casing 11 between the key access hole 112 and a front end of the inner shell 120. The protective plate 16 has an inner periphery that confines a key passage hole 161 with a shape of three quarters of a circle to permit extension of the shank portion 21 of the key 20 therethrough. Before the key 20 is inserted into the key access hole 112, the protective plate 16 is fully rotatable within the cylindrical chamber 110. When a drill extends into the key access hole 112 and works on the protective plate 16 for the purpose of damaging the lock core device 10, the protective plate 16 will rotate idly relative to the lock casing 11, thereby preventing the drill from reaching the interior of the lock core device 10. In order to withstand a drilling action, the protective plate 16 is preferably made from a high strength metal alloy. In the present embodiment, the inner periphery of the protective plate 16 is formed with a radial inward engaging protrusion 162 for engaging the engaging groove 25 on the curved surface 213 of the shank portion 21 of the key 20, thereby providing the lock core device 10 with an improved anti-theft effect. Preferably, one of the locking plates 13a that is disposed at a selected position within the inner shell 120 is increased in thickness relative to the remaining ones of the locking plates 13, 13'. Accordingly, a selected one of the key bit portions 24a that is corresponding to the thicker locking plate 13a is increased in width measured in a longitudinal direction of the shank portion 21. In order to diminish noise generated during rotation of the locking plates 13, 13', 13a and the spacer plates 14, an annular positioning plate 17 is secured to the front end of the inner shell 120 to reduce spaces formed among the locking plates 13, 13', 13a and the spacer plates 14. The positioning plate 17 may be welded to the inner shell 120 at three points 121 on its outer periphery, as shown in Figure 5. In another embodiment, the front end of the inner shell 120 may be formed with three angularly displaced stop members 122 which are bent to extend radially and inwardly for retaining the positioning plate 17 within the inner shell 120 at the front end of the inner shell 120, as shown in Figure 6. Alternatively, with reference to Figure 7, the inner shell 12 is formed with an annular groove 126 on its inner surface at the front end. The positioning plate 17 is first received in the inner shell 120 adjacent to the annular groove 126. Then, a C-shaped resilient ring 18 is disposed in the annular groove 126 anteriorly of and adjacent to the positioning plate 17. The resilient ring 18 normally expands to engage the inner shell 120 for retaining the positioning plate 17 in the inner shell 120 at the front end of the latter. Referring to Figure 8, in another preferred embodiment of the lock apparatus according to the present invention, a limiting groove 123 is formed on an inner surface of the inner shell 120a of the lock core device to limit rotation of the locking plates 13b within the inner shell 12a so as to facilitate operation of the key 20b. The limiting groove 123 extends longitudinally along the length of the inner shell 120a, and extends circumferentially on the inner surface along a curved line. The curved line can be designed to have an arc length of 180 degrees, greater than 180 degrees or smaller than 180 degrees. The outer periphery of at least one of the locking plates 13b is formed with a radial limiting projection 134b which projects into the limiting groove 123 to limit rotation of the locking plate 13b within an angle defined by the arc length of the limiting groove 123 during operation of the key 20b. When the arc length of the limiting groove 123 is short, the locking plates 13b are rotatable within a small angular range, and are thus actuatable by the key 20 within a short amount of time for unlocking the lock core device. On the other hand, when the arc length of the limiting groove 123 is long, the locking plates 13b are rotatable within a large angular range. A longer amount of time would be required for actuating the locking plates 13b by operating the key 20b to unlock the lock core device. In the present embodiment, an annular retaining plate 14a is received in the inner shell 120a proximate to the front end of the inner shell 120a, and is disposed between the positioning plate 17 and one of the locking plates 13b that is disposed proximate to the front end of the inner shell 120a. The retaining plate 14a has an outer periphery formed with a fan-shaped retaining projection 143a that extends fittingly into the limiting groove 123 in the inner shell 120a. The retaining plate 14a further has an inner periphery formed with a radial inward blocking protrusion 142a and defining a key passage hole 141a in the shape of three quarters of a circle. The shank portion 21b of the key 20b has a retainer section 24b which is formed between the key bit portions 24 and the handle portion 22b of the key 20b and is disposed immediately adjacent to the key bit portions 24. The retainer section 24b has a semi-circular cross-section. As shown in Figure 9, the retainer section 24b extends into the key passage hole 141a of the retaining plate 14a when the key 20b is inserted into the keyhole. The key bit portions 24 are blocked by the blocking protrusion 142a on the retaining plate 14a when the key 20b is rotated in the keyhole, as best illustrated in Figures 10 and 11. In this manner, untimely removal of the key 20b from the lock core device can be prevented during operation of the key so as to facilitate operation of the key 20b within the keyhole. Referring to Figures 12 and 13, in another preferred embodiment of the lock apparatus of the present invention, a plurality of spring-loaded tumbler units 19 are installed in the lock core device 10a. The lock casing 11a of the lock core device 10a is formed with a plurality of radial first tumbler holes 113a. The inner shell 120b is formed with a plurality of radial second tumbler holes 127b. Each of the locking plates 13c is formed with a radial third tumbler hole 133c that extends through inner and outer peripheries thereof. Each of the tumbler units 19 includes a first compression spring 194 and a first tumbler member 191 which are received in a respective one of the first tumbler holes 113a in the lock casing 11a, a second tumbler member 192 received in a respective one of the second tumbler holes 127b in the inner shell 120b, and a third tumbler member 193 and a second compression spring 196 which are received in the third tumbler hole 133c in a respective one of the locking plates 13c. Before insertion of the key 20b into the keyhole of the lock core device 10a, the first tumbler holes 113a are aligned respectively with the second tumbler holes 127b and with the third tumbler holes 133c in radial directions. In each of the tumbler units 19, the first compression spring 194 biases the first, second and third tumbler members 191, 192, 193 to move radially and inwardly so as to enable the first tumbler member 191 to project into a respective one of the second tumbler holes 127b in the inner shell 120b, to enable the second tumbler member 192 to project into the third tumbler hole 133c in a respective one of the locking plates 13c, and to enable the third tumbler member 193 to project radially from the inner periphery of the respective locking plate 13c. The third tumbler hole 133c in each of the locking plates 13c is provided with a mounting sleeve 195 within which the second compression spring 196 is installed. The second compression spring 196 biases the third tumbler member 193 in a radial outward direction toward the inner surface of the inner shell 120b. The curved surface 213' on the shank portion of the key 20' is formed with a plurality of tumbler recesses 26, each of which is defined by a recessed tumbler push wall. As shown in Figure 13, before the key 20' is inserted into the keyhole, the engaging notches 132 on the locking plates 13c are misaligned with one another, and the locking rod 124 is forced by the outer peripheries of the locking plates 13c to extend into an axially extending locking groove 115 formed on the inner surface of the lock casing 11a in order to hinder rotation of the inner shell 120b relative to the lock casing 11a. Referring to Figure 14, when the key 20' is inserted into the keyhole, the third tumbler member 193 of each of the tumbler units 19 projects into a respective one of the tumbler recesses 26 on the shank portion of the key 20'. Each of the tumbler recesses 26 has a predetermined depth such that the third tumbler member 193 of each of the tumbler units 19 is pushed by the tumbler push wall of the respective tumbler recess 26 in a radial outward direction against biasing action of the first compression spring 194 so as to retract the second tumbler member 192 into the second tumbler hole 127b in the inner shell 120b and to retract the first tumbler member 191 into the first tumbler hole 113a. At this time, engagement of the third tumbler member 193 with the respective tumbler recess 26 enables co-rotation of the respective locking plate 13c with the key 20'. Since the second tumbler member 192 ceases to hinder rotation of the respective locking plate 13c relative to the inner shell 120b, the locking plate 13c rotates with the key 20' by a certain angular range when the key 20' is rotated, such as in a clockwise direction shown in Figure 15. The third tumbler member 193 then extends into the limiting groove 123 formed on the inner surface of the inner shell 120b, and is disengaged from the corresponding tumbler recess 26 and from the key 20' due to biasing action of the second compression spring 196. The key 20' continues to rotate relative to the locking plate 13c until the actuating surface of the key bit portion 24 that corresponds to the respective locking plate 13c is in contact with the key engaging protrusion 134c on the respective locking plate 13c, as shown in Figure 16. Co-rotation of the key 12' and the respective locking plate 13c occurs once again at this moment due to the engagement between the key engaging protrusion 134c and the actuating surface of the corresponding key bit portion 24 on the key 20'. After the actuating surfaces of the key bit portions 24 on the key 20' drive the locking plates 13c to rotate by different angles to align the engaging notches 132 of the locking plates 13c with the axially extending slot 125 of the inner shell 120b, the locking rod 124 is extendible into the aligned engaging notches 132 and is disengaged from the locking groove 115, thereby permitting rotation of the inner shell 120b relative to the lock casing 11', as shown in Figure 17. Referring to Figures 18 and 19, in another embodiment, a plurality of pairs of tumbler units 19 are installed in the lock core device 10d, in which each locking plate 13d has a thickness sufficient to form two tumbler holes 133d which are angularly and axially displaced from each other for receiving a respective pair of the tumbler units 19. When one of the pairs of the tumbler units 19 on one of the locking plates 13d is damaged, there remain one other tumbler unit 19 which engages said one of the locking plates 13d with the lock casing. An enhanced anti-theft effect can thus be achieved. Under this condition, the number of the locking plates 13d required in the lock core device 10d may be reduced, and the length of the lock core device 10d may be shortened. In other embodiments, a plurality of tumbler units 19 are installed in a lock core device and are displaced angularly by predetermined angles. Examples of the lock core device of this type are shown in Figures 20 and 21. The key 20 shown in Figures 1 and 2 is formed with key bit portions 24, 24a and an axially extending groove 25, and thus works to operate the lock core device 10, which is installed with the locking plates 13, 13', 13a, the drive plate 15, and the protective plate 16 that are each formed with the radial inward protrusion 133, 152, 162. The key 20' shown in Figure 12 is formed with tumbler recesses 26 on its curved surface 213', and thus works to operate the lock core device 10a that is installed with the tumbler units 19. As such, a key of the type that is formed with the key bit portions 24, 24a, the engaging groove 25, and the tumbler recesses 26 work for operating any of the lock core devices described above. In the lock apparatus of the present invention, the latch member mounted on the rear end of the inner shell of the lock core may be one formed integrally with a plunger, such as the latch member 30' shown in Figure 1 and the latch member 30a shown in Figure 30, or one mounted resiliently with a plunger, such as the latch member 30 shown in Figure 22. Referring to Figures 22 and 23, in another preferred embodiment, the latch member 30 is provided on a lock core device 10' and includes a latch base 301 which is formed with a cavity 31. A plunger 33 is installed in the cavity 31 in the latch base 301. A cover plate 34 is mounted on the latch base 301 for closing one end of the cavity 31. A compression spring 32 is disposed in the cavity 31 between the plunger 33 and the cover plate 34 for biasing the plunger 33 to extend out of the cavity 31 via an open end of the cavity 31 that opens in a direction transverse to the axis of the lock core device 10'. The latch member 30 has a distal end face 302 which is transverse to the axis of the lock core device 10' and which is formed with a pair of circular pin holes 35 that have axes eccentric to the axis of the lock core device 10' and that are symmetric to each other with respect to the axis of the lock core device 10'. A catch member 60 has a latch engaging end portion 63 formed with a pin 64 that extends rotatably into and that engages one of the pinholes 35 in the latch member 30, and a shackle engaging end portion 61 opposite to the latch engaging end portion 63. The catch member 60 has a pair of side walls, each of which has a sliding block 62 projecting therefrom. The sliding block 62 extends in a direction from the shackle engaging end portion 61 toward the latch engaging end portion 63. Referring to Figures 23, 24A and 24B, the lock apparatus of the present embodiment is in the form of a padlock which includes a lock body 40 formed with a lock core chamber 401 that extends from a bottom end of the lock body 40 toward a top end of the same for receiving a lock core device 10', and first and second shackle insert holes 404, 405 which extend from the top end toward the bottom end of the lock body 40. The lock core chamber 401 has an upper section formed as a catch chamber 403 which extends between and which is communicated with the first and second shackle insert holes 404, 405 for accommodating the latch member 30 and the catch member 60. A rectangular lock core opening 402 is formed in a bottom wall of the lock body 40 for access to the lock core chamber 401. A shackle member 50 with an inverted U-shaped configuration has longer and shorter leg portions 51, 52 extending respectively into the first and second shackle insert holes 404, 405. Each of the longer and shorter leg portions 51, 52 is formed with a shackle groove 53. The longer leg portion 51 is further formed with a longitudinally extending retaining groove 54 and an annular groove 55 adjacent to a distal end of the longer leg portion 51 and communicated with the retaining groove 54. The retaining groove 54 does not extend to the shackle groove 53 on the longer leg portion 51 such that the shackle member 50 has an increased strength to resist an external pulling force. The lock body 40 is installed with an L-shaped retaining member 41 which has one end extending into the retaining groove 54. A compression spring 42 is disposed deep within a bottom end of the second shackle insert hole 405 for biasing the shorter leg portion 52 upwardly. When the lock core device 10' is in a locking position shown in Figures 24A and 24B, the shackle engaging end portion 61 of the catch member 60 extends into the first shackle insert hole 404 for engaging the shackle groove 53 on the longer leg portion 51, and the plunger 33 extends into the second shackle insert hole 405 for engaging the shackle groove 53 on the shorter leg portion 52. Referring to Figures 25A and 25B, when the lock core device 10' is operated to dispose the latch member 30 in the unlocking position, the plunger 33 turns with the latch member 30 to retract into the catch chamber 403, and the latch member 30 pulls the catch member 60 so as to retract the shackle engaging end portion 61 of the catch member 60 into the catch chamber 403. The shackle member 50 is thus disengaged from the catch member 60 and the plunger 33, and springs upwardly due to biasing action of the compression spring 42, thereby permitting removal of the shorter leg portion 52 from the second shackle insert hole 405. At this time, the retaining member 41 extends into the annular groove 55 to prevent removal of the longer leg portion 51 from the lock body 40. The engagement between the pin 64 on the catch member 60 and the pin hole 35 in the latch member 30 provides the catch member 60 and the padlock with an increased impact strength such that the catch member 60 is not susceptible to undesired displacement within the lock body 40 and undesired disengagement from the latch member 30 when the padlock is subjected to strong impact. Referring back to Figure 23, the lock body 40 is mounted fixedly with a nut 43 which is disposed within the lock body 40 between the lock core chamber 401 and the first shackle insert hole 404. A threaded rod 44 extends threadedly through the nut 43 and has one end abutting tightly against an outer surface of the lock core device 10' for retaining the lock core device 10' in the lock core chamber 401. The lock body 40 has a lateral side wall adjacent to the first shackle insert hole 404 and formed with an aperture 406 that is communicated with the first shackle insert hole 404 and that is aligned with the threaded rod 44. When the padlock is in the locking state, as shown in Figure 24A, the aperture 406 is blocked by the longer leg portion 51 to prevent access to the threaded rod 44. When the padlock is in the unlocking state, as shown in Figure 25A, the threaded rod 44 is accessible by a tool (not shown) extending into the aperture 406 and is operable by the tool for disengaging from the lock core device 10' so as to permit removal of the lock core device 10' from the lock body 40 for replacement of the lock core device 10'. Referring again to Figures 24A and 24B, the catch chamber 403 is formed in the lock body 40 between confronting front and rear walls, each of which is formed with a slide groove 408 for receiving a respective one of the sliding blocks 62 on the catch member 60. The sliding blocks 62 are slidable along the slide grooves 408 when the catch member 60 is pushed by the latch member 30 to move to the locking position shown in Figures 24A and 24B, and when the catch member 60 is pulled by the latch member 30 to move to the unlocking position shown in Figures 25A and 25B. The provision of the slide grooves 408 in the lock body 40 and the sliding blocks 62 on the catch member 60 further enhances impact resistance of the padlock, and increases strength of the padlock to resist external pulling forces applied in opposite directions to the shackle member 50 and the lock body 40, respectively. Referring to Figure 26A and 26B, in another embodiment of the present invention, the plunger 33 engages resiliently an inner side wall 403a in a catch chamber of a lock body 40a to prevent removal of the lock core device 10' from the lock body 40a. An aperture 407a is formed in a lateral side wall of the lock body 40a and is communicated with the second shackle insert hole 405a. To remove the lock core device 10' for replacement purposes, the lock core device 10' is first operated to unlock the padlock so as to permit removal of the shorter leg portion 52 from the second shackle insert hole 405a. Then, a tool (not shown) is extended into the aperture 407a to depress the plunger 33 for retracting the plunger 33 into the cavity 31 (see Fig. 22) in the latch base 301 of the latch member 30. The latch member 30 is thus disengaged from the inner side wall 403a of the lock body 40a to permit removal of the lock core device 10' from the lock body 40a via the lock core opening 402. Referring to Figures 27A and 27B, yet another preferred embodiment of the lock apparatus of the present invention is shown to be in the form of a padlock with a U-shaped lock body 600 that has a lock core mounting portion and parallel first and second shackle mounting portions 610, 610' which extend upwardly from the lock core mounting portion 612 and which are spaced-apart from each other. The lock core device 10' is received in a lock core chamber formed in the lock core mounting portion 612. A catch member 630 has a pin 631 engaging one of the pin holes 35 in the latch member 30. The catch member 630 and the latch member 30 are disposed in a catch chamber 613 that extends from one end of the lock core chamber into the first shackle mounting portion 610 and that is communicated with a shackle insert hole 614 formed through the first shackle mounting portion 610. When the padlock is in a locking state, a shackle bar 620 extends transversely between shackle insert holes 614, 614' formed in the first and second shackle mounting portions 610, 610', and has a shackle groove 622 that engages the shackle engaging end portion of the catch member 630. When the lock core device 10' is operated to rotate the latch member 30 to the unlocking position, the catch member 630 is pulled by the latch member 30 to retract into the catch chamber 613 for disengaging from the shackle groove 622 in the shackle bar 620. The shackle bar 620 springs leftwardly due to biasing action of a compression spring 616 installed in the shackle insert hole 614' in the second shackle mounting portion 610', and is removed from the second shackle mounting portion 610'. The shackle bar 620 is provided with a spring-loaded stop member 621 which engages a retaining groove 615 formed in the first shackle mounting portion 610 to prevent removal of the shackle bar 620 from the lock body 600 when the padlock is unlocked. It is noted that the lock core device 10 in the lock apparatus of the present invention is also useful in a conventional lock apparatus which does not includes a catch member, such as a padlock 100 shown in Figure 28A and 28B. As shown, the plunger 33 projects resiliently from the latch member 30 in a direction transverse to the axis of the lock core device 10'. When the lock core device 10' is in the locking position, the plunger 33 extends through a plunger passage 101 between a lock core chamber and a shackle insert hole 102 of a lock body of the padlock 100, and projects into the shackle insert hole 102 for engaging the shorter leg portion 130 of a shackle member. By operating the lock core device 10' to rotate the latch member 30 to the unlocking position, the plunger 33 turns with the latch member 30 and moves into the lock core chamber to disengage from the shorter leg portion 130, thereby unlocking the padlock 100. Referring to Figure 29, in another embodiment of the lock apparatus according to the present invention, the lock body 40b is provided with a protective sleeve 70 which is disposed fittingly in the catch chamber 403b. The protective sleeve 70 has an inner surface that defines a cavity 71 with opposite open ends for receiving a catch member 60a, and that is formed with a pair of confronting slide grooves 712 which extend between the opposite open ends of the cavity 71. The sliding blocks 62a on the catch member 60a extend respectively into the slide grooves 712 and are slidable along the slide grooves 712. The protective sleeve 70 is preferably formed from a high strength metal alloy to protect the catch member 60a from being damaged by a drilling action. Referring to Figure 30, in still another embodiment of the lock apparatus of the present invention, a latch member 30a is shown to be formed integrally with a plunger 33a, and has a distal end face 302a formed with a pin hole 35a which is in the form of a curved slot extending along a curved line on the end face 302a and which has opposite first and second ends 354a, 355a. The latch member 30a has a curved pushing surface 36a which is adjacent and transverse to the end face 302a of the latch member 30a. A catch member 60a has a latch engaging end portion 63a which is formed with a pin 64a that extends into the pin hole 35a in the latch member 30a, a shackle engaging end portion 61a opposite to the latch engaging end portion 63a, and two opposite side walls formed with sliding blocks 62a that extend in a direction from the shackle engaging end portion 61a toward the latch engaging end portion 63a. The catch member 60a is formed with an abutment wall 65a to contact the pushing surface 36a of the latch member 30a so as to be actuated thereby. Referring to Figures 31A and 31B, in the present embodiment, the lock apparatus of the present invention is formed as a padlock with a lock body formed with a lock core chamber that has the lock core device 10b received therein. The latch member 30a and the catch member 60a are received in a catch chamber that is communicated with first and second shackle insert holes of the lock body. When the lock core device 10b is operated to rotate the latch member 30a to the unlocking position, the plunger 33a turns with the latch member 30a and retracts into the catch chamber for disengaging from the shorter leg portion 52a of a shackle member 50a, and the latch member 30a pulls the catch member 60a so as to retract the catch member 60a into the catch chamber for disengaging from the longer leg portion 51a of the shackle member 50a. At this time, the pin 64a of the catch member 60a is disposed at the first end 354a of the pin hole 35a. Referring to Figures 32A and 32B, when the lock core device 10a is operated to rotate the latch member 30a to the unlocking position, the plunger 33a turns with the latch member 30a and extends into the second shackle insert hole for engaging the shackle groove 53a in the shorter leg portion 52a of the shackle member 50a. The curved pushing surface 36a of the latch member 30a pushes the abutment wall 65a of the catch member 60a and forces the catch member 60a to move apart from the latch member 30a, thereby enabling the shackle engaging end portion 61a of the catch member 60a to extend into the first shackle insert hole to engage the shackle groove 53a in the longer leg portion 51a of the shackle member 50a, and thereby moving the pin 64a to the second end 355a of the pin hole 35a. Referring to Figures 33 and 34, in another embodiment of the lock apparatus of the present invention, a latch member 30b is formed with a pair of pin holes 35b on its distal end face 300. Each of the pin holes 35b includes a curved hole section 351 that extends along a curved line on the end face 300 and that has opposite first and second ends 354, 355, and a straight hole section 352 that extends along a straight line on the end face 300 and that extends transversely from the second end 355 of the curved hole section 351. As shown in Figure 35, the straight hole section 352 is defined by a stepped hole defining wall and is formed to include a wider hole portion 352a proximate to the end face 300, and a narrower hole portion 352b adjacent to the wider hole portion 352a. Both the wider and narrower hole portions 352a, 352b extend along the length of the straight hole section 352 and are communicated with the second end 355 of the curved hole section 351. The latch member 30b engages a pair of catch members 60b (only one is shown in Figure 33), each of which has a latch engaging end portion 63b formed with a pin 64b, and a shackle engaging end portion 61b formed with a spring abutment stud 66b for abutting against a compression spring 67b. As shown in Figures 33 and 35, the pin 64b has adjacent wider and narrower sections 641b, 642b which are extendible respectively into the wider and narrower hole portions 352a, 352b of the straight hole section 352 of a respective one of the pin holes 35b when the pin 64b extends into the straight hole section 352. Referring to Figures 36A and 36B, the lock apparatus in the present embodiment is in the form of a padlock which includes a lock body 800, a lock core device 10e received in a lock core chamber 801 of the lock body 800, and a U-shaped shackle member 810 mounted in a pair of shackle insert holes 820 of the lock body 800. The lock core device 10e is mounted with the latch member 30b of Figure 33. The latch member 30b and the catch members 60b are disposed in a catch chamber 802 formed between the shackle insert holes 820 of the lock body 800. The compression spring 67b has one end abutting against an outer surface of the lock core device 10e, and another end abutting against the spring abutment stud 66b on a respective one of the catch members 60b for biasing the catch member 60b in a direction away from the latch member 30b. Figures 36A and 36B show the padlock in a locking state, in which the shackle engaging end portion 61b of each of the catch members 60b extends into a respective one of the shackle insert holes 820 to engage a respective leg portion of the shackle member 810, and in which the pin 64b of each of the catch members 60b is disposed in the second end 355 of the curved hole section 351 of a respective one of the pin holes 35b immediately adjacent to the straight hole section 352. The shackle engaging end portion 61b of each of the catch members 60b has a tapered guiding wall 68b confronting an opening in a respective one of the shackle insert holes 820. To unlock the padlock, the lock core device 10e is operated to rotate the latch member 30b to the unlocking position, thereby pulling the catch members 60b inwardly toward each other for disengaging the catch members 60b from the leg portions of the shackle member 810. The shackle member 810 can be entirely removed from the lock body. In this embodiment, the latch member 30b is designed to be normally disposed in the locking position. When the leg portions of the shackle member 810 are once again inserted into the shackle insert holes 820 of the lock body 800, the leg portions push the catch members 60b at the tapered guiding wall 68b and depress the catch members 60b for retracting the catch members 60b into the catch chamber 802 against biasing action of the compression spring 67b to enable the pins 64b to move into and slide along the straight slot sections 352 of the pin holes 35b, respectively, as best illustrated in Figure 37. When the shackle grooves 813 on the leg portions of the shackle member 810 are subsequently registered with the catch chamber 802, the compression spring 67b expand to enable the shackle engaging end portions 61b of the catch members 60b to extend into the shackle insert holes 820 and into the shackle grooves 813 and to enable the pins 64 to move back to the second ends 355 of the curved hole sections 351, as shown in Figure 36B. In this manner, the catch members 60b operate automatically to lock the shackle member 810 on the lock body 800 when the shackle member 810 is inserted into the shackle insert holes 820 without the use of a key. Referring to Figure 38, in a modified embodiment, the pin 64b on each of the catch members 60c may be designed to have a cross-section larger than the narrower hole portion 352b of the straight hole section 352 of the pin hole 35b such that the pin 64c is prevented from moving into the straight hole section 352, thereby preventing retraction of the catch members 60c into the catch chamber 802 (see Figure 36A) and preventing insertion of the leg portions of the shackle member 810 into the shackle insert holes 820 when the latch member 30b is in the locking position. In this case, insertion of the leg portions of the shackle member into the shackle insert holes is allowed only after the lock core unit has been operated by a correct key to dispose the latch member 30b in the unlocking position. Referring to Figure 39, in another preferred embodiment, the latch member 30c has a distal end face 35c formed with a pair of circular pin holes 31c which are eccentric to an axis of the lock core device 10c (see Figure 42) on which the latch member 30c is mounted, and which are symmetric to each other with respect to the axis of the lock core device 10c. The latch member 30c has a pair of opposite side walls 34c transverse to the distal end face 35c. Each of the side walls 34c is formed with a slide slot 32c that extends along a plane parallel to the end face 35c, and a communicating hole 33c that extends parallel to the axis of the lock core device 10c from the end face 35c to the slide slot 32c to communicate with the slide slot 32. A curved stop flange 341c is formed on a respective side wall 34c between the slide slot 32c and the end face 35c. The latch member 30c engages a pair of catch members 60c, each of which has a latch engaging end portion 61c formed with a cylindrical pin 62c, and a shackle engaging end portion 64c opposite to the latch engaging end portion 61c. Each of the catch members 60c is further formed with a stop projection 63c which extends in a direction transverse to the pin 62c from the shackle engaging end portion 64c toward the latch engaging end portion 61c. The pin 62c on each of the catch members 60c extends rotatably into a respective one of the pin holes 31c in the latch member 30c. The stop projection 63c passes through an adjacent one of the communicating holes 33c during assembly of the respective catch member 60c to the latch member 30c, and is disposed in a corresponding one of the slide slots 32c of the latch member 30c. Referring to Figures 40 and 42, the present embodiment is in the form of a padlock which has a lock body formed with a lock core chamber that is installed with the lock core device 10c. The latch member 30c and the catch members 60c are received in a catch chamber that extends between a pair of shackle insert holes of the lock body. When the lock core device 10c is in a locking position, the catch members 60c are pushed apart from each other toward the shackle insert holes for engaging longer and shorter leg portions of the shackle member. At this time, as shown in Figure 40, a distal end 631c of the stop projection 63c on each of the catch members 60c is registered with the curved stop flange 341c on a respective one of the side walls 34c of the latch member 30c. Since the stop projections 63c of the catch members 60c are blocked respectively by the stop flanges 341c of the latch member 30c, removal of the catch members 60c from the latch member 30c in the direction along the axis of the lock core device 10c can be prevented. This increases the strength of the engagement between the catch members 60c and the latch member 30c. The catch members 60c do not easily disengage from the latch member 30c even when the padlock is subjected to strong impact. Referring to Figures 41 and 42, when the lock core device 10c is in the unlocking position, the latch member 30c turns by an angle of 90 degrees, and the catch members 60c are pulled inwardly toward each other for disengaging the shackle engaging end portions 64c from the leg portions of the shackle member. At this time, the stop projections 63c of the catch members 60c are aligned respectively with the communicating holes 33c in the latch member 30c. In this state, after the threaded rod 44 is operated by a tool extending into the lock body via the aperture 406c, and is unthreaded for disengaging from the lock core device 10c, the lock core device 10c can be removed from the lock body and the catch members 60c in a direction along axis thereof. Referring to Figures 43 and 44, preferably, a cover unit 900 is provided for covering the lock core opening 402 of the lock body 40' and the key access hole 112 of the lock core device 10. The cover unit 900 includes a mounting seat 910 mounted on a bottom wall of the lock body 40' adjacent to the lock core opening 402. The mounting seat 910 is provided with a spring-loaded ball member 912. A cover flap 920 has a hinge end portion 924 disposed adjacent to the ball member 912 and hinged to the lock body 40' by means of a pivot shaft 921 such that the cover flap 920 is pivotable toward the lock core opening 402 to a closed position shown in Figure 43 for covering the lock core opening 402, and away from the lock core opening 402 to an open position shown in Figure 44 to permit access to the lock core opening 402. The ball member 912 is biased toward the hinge end portion 924 of the cover flap 920. The hinge end portion 924 has an annular outer periphery formed with three angularly displaced ball retaining grooves 923 for engaging resiliently the ball member 912 so as to retain the cover flap 920 releasably at a selected one of the open and closed positions. As shown, the cover flap 920 is formed with a plug 922 which extends fittingly into the key access hole 112 to prevent entry of dust and moisture into the interior of the lock core device 10.

Claims: A lock apparatus including: a lock body (40, 40a, 600, 40b, 800, 40') formed with a lock core chamber (401, 801), a lock core opening (402) for access to the lock core chamber (401, 801), and a shackle insert hole (404, 405a, 614, 820), the lock core chamber (401, 801) having a section formed as a catch chamber (403, 613, 403b, 802) which is adjacent to and which is communicated with the shackle insert hole (404, 405a, 614, 820); a lock core device (10, 10', 10a, 10b, 10c, 10d, 10e) received in the lock core chamber (401, 801) via the lock core opening (402), the lock core device (10, 10',10a, 10b,10c,10d,10e) including a cylindrical and axially rotatable lock core (12) which is provided with a latch member (30, 30', 30a, 30b, 30c) that is disposed in the catch chamber (403, 613, 403b, 802); a key (20, 20b, 20') which is insertible into the lock core device (10, 10', 10a, 10b, 10c, 10d, 10e) via the lock core opening (402) and which is operable for rotating the lock core (12) and the latch member (30, 30', 30b, 30c) between locking and unlocking positions; a shackle member (50, 620, 50a, 810) having a leg portion (51, 52, 51a) which is formed with a shackle groove (53, 622, 53a, 813) and which is inserted into the shackle insert hole (404, 405a, 614, 820) in the lock body (40, 40a, 600, 40b, 800, 40'); a catch member (60, 630, 60a, 60b, 60c) disposed in the catch chamber (403, 613, 403b, 802) of the lock body (40, 40a, 600, 40b, 800, 40'), the catch member (60, 630, 60a, 60b, 60c) having a shackle engaging end portion (61, 61a, 61b, 64c) for engaging the shackle groove (53, 622, 53a, 813) in the leg portion (51, 52, 51a) of the shackle member (50, 620, 50a, 810), and a latch engaging end portion (63, 63a, 63b, 61c) opposite to the shackle engaging end portion (61, 61a, 61b, 64c) and engaging the latch member (30, 30', 30a, 30b, 30c) such that the catch member (60, 630, 60a, 60b,60c) is movable between locking and unlocking positions when the latch member (30, 30', 30a, 30b, 30c) moves between the locking and unlocking positions, the shackle engaging end portion (61, 61a, 61b, 64c) of the catch member (60, 630, 60a, 60b, 60c) extending into the shackle insert hole (404, 405a, 614, 820) for engaging the shackle groove (53, 622, 53a, 813) in the leg portion (51, 52, 51a) of the shackle member (50, 620, 50a, 810) when the catch member (60, 630, 60a, 60b, 60c) is disposed in the locking position, the shackle engaging end portion (61, 61a, 61b, 64c) being retracted into the catch chamber (403, 613, 403b, 802) for disengaging from the leg portion (51, 52, 51a) of the shackle member (50, 620, 50a, 810) to permit removal of the shackle member (50, 620, 50a, 810) from the shackle insert hole (404, 405a, 614, 820) when the catch member (60, 630, 60a, 60b, 60c) is disposed in the unlocking position, wherein the latch member (30, 30', 30a, 30b, 30c) has an end face (302, 302a, 35c) which is transverse to the longitudinal axis of the lock core (12) and which is formed with a pin hole (35, 35a, 35b, 31c) that is eccentric to the longitudinal axis of the lock core (12), the latch engaging end portion (63, 63a, 63b, 61c) of the catch member (60, 630, 60a, 60b, 60c) being formed with a pin (64, 631, 64a, 64b, 62c, 64c) which extends rotatably into the pin hole (35, 35a, 35b, 31c) in the latch member (30, 30', 30a, 30b, 30c) for engaging the latch member (30, 30', 30a, 30b, 30c), characterized in that the key (20, 20b, 20') has a shank portion (21, 21b) with a cross-section formed as a circular sector, and a handle portion (22, 22b) connected to the shank portion (21, 21b), the shank portion (21, 21b) having first and second radial surfaces (211, 212) that extend along length of the shank portion (21, 21b), and a curved surface (213) that interconnects the first and second radial surfaces (211, 212), the first radial surface (211) being planar, the second radial surface (212) being formed with a plurality of key bit portions (24, 24a) that are arranged along length of the shank portion (21, 21b), the key bit portions (24, 24a) having radial key bit surfaces that form different angles with the first radial surface (211) to set code of the key (20, 20b, 20'), the shank portion (21, 21b) of the key (20, 20b, 20') further having a distal end formed as an actuating tip portion (23), the lock core device (10, 10', 10a, 10b, 10c, 10d, 10e) includes a lock casing (11, 11a) mounted in the lock core chamber (401, 801) of the lock body (40, 401, 600, 40b, 800, 40'), the lock casing (11, 11a) having an inner surface which confines a cylindrical chamber (110) and which is formed with an axially extending locking groove (115), the lock core (12) including: a cylindrical inner shell (120, 120a,120b) received rotatably in the cylindrical chamber (110) of the lock casing (11, 11a), the inner shell (120, 120a, 120b) having a rear end mounted with the latch member (30, 30', 30a, 30b, 30c), and a front end, the inner shell (120, 120a, 120b) being formed with an axially extending locking slot (125) which is registered with the locking groove (115) when the lock core (12) is in the locking position; a stack of annular locking plates (13, 13', 13a, 13b) received in the inner shell (120, 120a), each of the locking plates (13, 13', 13a,13b) having an inner periphery that confines a central hole (131), the central holes (131) of the locking plates (13, 13', 13a, 13b) cooperatively defining a keyhole that permits insertion of the shank portion (21, 21b) of the key (20, 20b, 20') there into, each of the locking plates (13, 13', 13a, 13b) further having an outer periphery that is formed with an engaging notch (132), the engaging notches (132) of the locking plates (13, 13', 13a, 13b) being misaligned with one another in accordance with the code of the key (20, 20', 20b) when the lock core (12) is in the locking position, the engaging notches (132) being aligned with one another when the lock core (12) is in the unlocking position, the inner periphery of each of the locking plates (13, 13', 13a, 13b) being formed with a radial inward key engaging protrusion (133) which abuts against the key bit surface of a corresponding one of the key bit portions (24, 24a) on the key (20, 20', 20b) when the key (20, 20', 20b) is inserted into the keyhole and is rotated, the locking plates (13, 13', 13a) being rotated by different angles according to the code of the key (20, 20' ,20b) to align the engaging notches (132) when the key (20, 20', 20b) is inserted into the keyhole and is rotated for moving the lock core (12) to the unlocking position; a locking rod (124) received in the locking slot (125) of the inner shell (120, 120a, 120b), misalignment of the engaging notches (132) on the locking plates (13, 13', 13a, 13b) enabling the outer peripheries of the locking plates (13, 13', 13a, 13b) to force the locking rod (124) to extend into the locking groove (115) in the lock casing (11, 11a) in order to hinder rotation of the inner shell (120, 120a, 120b) relative to the lock casing (11, 11a) when the lock core (12) is in the locking position, alignment of the engaging notches (132) on the locking plates (13, 13', 13a, 13b) enabling the locking rod (124) to disengage the locking groove (115) and to extend into the engaging notches (132) in order to permit rotation of the inner shell (120, 120a, 120b) relative to the lock casing (11, 11a) during unlocking movement of the lock core (12); and an annular drive plate (15) disposed in the inner shell (120, 120a, 120b) at the rear end of the inner shell (120, 120a, 120b) and disposed between the locking plates (13, 13', 13a, 13b) and the latch member (30, 30', 30a, 30b,30c), the drive plate (15) having an inner periphery which confines a key engaging hole (151) and which is formed with a key actuatable projection (153) that projects radially and inwardly, the actuating tip portion (23) of the key (20, 20b, 20') being extendible into the key engaging hole (151) for engaging the key actuatable projection (153) so as to enable co-rotation of the drive plate (15) with the key (20, 20b, 20'), the drive plate being formed with a drive projection (154), the latch member (30, 30', 301, 30b, 30c) having an actuatable section (31') which is driven by the drive projection (154) such that rotation of the drive plate (15) can result in corresponding rotation of the latch member (30, 30', 301, 30b, 30c) between the locking and unlocking positions, and in that the lock core device (10a) further includes a spring-loaded tumbler unit (19), the lock casing (11a) being formed with a first tumbler hole (113a), the inner shell (120b) being formed with a second tumbler hole (127b), one of the locking plates (13c) being formed with a third tumbler hole (133c), the first, second and third tumbler holes (113a, 127b, 133c) being aligned with one another prior to insertion of the key (20') into the key hole, the tumbler unit (19) including a first tumbler member (191) received in the first tumbler hole (113a), a second tumbler member (192) received in the second tumbler hole (127b), a third tumbler member (193) received in the third tumbler hole (133c), and a first biasing spring (194) for biasing the first, second and third tumbler members (191, 192, 193) to move inwardly to enable the first tumbler member (191) to project into the second tumbler hole (127b) in the inner shell (120b) so as to hinder rotation of the inner shell (120b) relative to the lock casing (11a), to enable the second tumbler member (192) to project into the third tumbler hole (133c) in said one of the locking plates (13c) so as to hinder rotation of said one of the locking plates (13c) within the inner shell (120b), and to enable the third tumbler member (193) to project from the inner periphery of said one of the locking plates (13c), the curved surface (213') on the shank portion of the key (20') being formed with a tumbler recess (26) that is defined by a recessed tumbler push wall, the third tumbler member (193) projecting into the tumbler recess (26) when the key (20') is inserted into the key hole, the third tumbler member (193) being pushed by the tumbler push wall in a direction against biasing action of the first biasing spring (194) so as to retract the second tumbler member (192) into the second tumbler hole (127b) in the inner shell (120b), thereby preventing the second tumbler member (192) from hindering rotation of said one of the locking plates (13c) relative to the inner shell (120b), and so as to retract the first tumbler member (191) into the first tumbler hole (113b) such that the first tumbler member (191) ceases to hinder rotation of the inner shell (120b) relative to the lock casing (11a). The lock apparatus as claimed in Claim 1, further characterized in that the inner shell (120b) of the lock core has an inner surface which is formed with a circumferential groove (123) that extends circumferentially along a curved line on the inner surface of the inner shell (120b), the third tumbler hole (133c) in said one of the locking plates (13c) being provided with a mounting sleeve (195) through which the third tumbler member (193) extends, the tumbler unit (19) further including a second biasing spring (196) received in the mounting sleeve (195) and disposed around the third tumbler member (193) for biasing the third tumbler member (193) to move outwardly, the third tumbler member (193) moving outwardly and extending into the circumferential groove (123), due to biasing action of the second biasing spring (196), for disengaging from the key (20') when the key (20') is inserted into the keyhole to align the tumbler recess (26) with the tumbler unit (19) and when the key (20') is rotated for moving the lock core to the unlocking position. The lock apparatus as claimed in Claim 1, further characterized in that the lock core device (10a) includes a plurality of the tumbler units (19) which are displaced from one another along the axis of the lock core. The lock apparatus as claimed in Claim 1, further characterized in that the lock core device (10d) includes a pair of the tumbler units (19), said one of the locking plates (13d) being formed with a pair of the third tumbler holes (133d). The lock apparatus as claimed in Claim 1, further characterized in that the lock core device includes a plurality of the tumbler units (19) which are angularly displaced from one another with respect to the axis of the lock core. The lock apparatus as claimed in Claim 1, further characterized in that the lock core device (10) further includes an annular protective plate (16) disposed rotatably in the cylindrical chamber (110) of the lock casing (11) adjacent to the front end of the inner shell (120), the protective plate (16) having an inner periphery that confines a key passage hole (161) with a shape of three quarters of a circle to permit extension of the shank portion (21) of the key (20) therethrough, the inner periphery of the protective plate (16) being formed with a radial inward engaging protrusion (162), the curved surface (213) of the shank portion (21) of the key (20) being formed with an axially extending engaging groove (25) that extends along length of the shank portion (21) for engaging the engaging protrusion (162) The lock apparatus as claimed in Claim 1, further characterized in that the lock core (12) further includes an annular positioning plate (17) fixed to the front end of the inner shell (120) for positioning the locking plates (13,13',13a) in the inner shell (120). The lock apparatus as claimed in Claim 7, further characterized in that the positioning plate (17) is welded to the inner shell (120) at the front end of the inner shell (120) The lock apparatus as claimed in Claim 7, further characterized in that the front end of the inner shell (120) is formed with angularly displaced stop members (122) which are bent to extend radially and inwardly for retaining the positioning plate (17) in the inner shell (120). The lock apparatus as claimed in Claim 7, further characterized in that the positioning plate (17) is received in the inner shell (120), the inner surface of the inner shell (120) being formed with an annular groove (126) at the front end, the lock core (12) further including a resilient ring (18) which is received in the annular groove (126) and which is disposed anteriorly of the positioning plate (17), the resilient ring (18) normally expanding to engage the inner shell (120) for retaining the positioning plate (17) in the inner shell (120) at the front end.

Inventors: CHEN WATERSON, CHEN, WATERSON
Applicants: CHEN WATERSON, CHEN, WATERSON
Application year: 2001
Main classification: E05B67
IPC codes: E05B29, E05B21, E05B67, E05B31