Patent Publication Number: US-4545223-A

Title: Padlock

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a padlock with a removable cylinder lock mechanism. There are previously known padlocks in which the elements of the lock mechanism can be replaced, thus making it possible to change the opening combination of the lock. Examples of this are shown in U.S. patent application No. 535,549, filed Sept. 26, 1983 which is a continuation of U.S. Pat. application No. 240,193, filed 1981-03-03, now abandoned and in U.S. patent specification No. 3,835,675. In these known padlocks, there is a slideable lid element, which has to be removed before the replacement of the lock mechanism is possible. 
     SUMMARY OF THE INVENTION 
     A padlock, which can be assembled as late as at the moment of purchase is economically advantageous, because different kinds of padlocks can be assembled from the same components. This gives the lock retailers an opportunity to decrease stocking levels. The possibility to change the opening combination of the lock is of great interest even for the consumer. A lost key, for instance, does not result in a need of a complete new padlock, a rearranging of the cylinder lock mechanism is enough to guarantee safety against misuse. 
     The main object of the invention is to produce a new uncomplicated and inexpensive construction, applicable on padlocks with a cylinder lock mechanism. This construction makes it possible to replace the lock members, including the lock mechanism members, without destroying the lock. 
     The object of the invention is obtained by means of the lock hereinafter described. The lock comprises a lock casing and a U-formed shackle slideable therein. The shackle has two legs of different length, of which at least one is provided with a locking notch. The lock also comprises a cylinder lock mechanism, operable by a key, locking members, a retaining member to keep the cylinder lock mechanism enclosed in the lock casing and a blocking member to keep the retaining member unremovable from the same casing. 
     In a padlock according to the invention, the shackle is slideable in the lock casing between an open and a closed position. In its closed position, the shackle is firmly locked to the lock casing by means of the locking members, which are partly received by notches in the shackle, when the cylinder lock mechanism is in its locking position. In a guiding portion of the cylinder lock mechanism there are recesses enabling the locking members to move radially inwards in relation to the cylinder lock mechanism, when the last mentioned is turned from its locking position to a releasing position, by means of the key of the lock. When the cylinder lock mechanism is in its releasing position, the shackle is slideable to its open position. 
     The cylinder lock mechanism is enclosed in the lock casing by a retaining member. For removing this retaining member it has to be turned in relation to the lock casing. This turning movement is prevented by a blocking member, which can be removed when the shackle is in its open position, but not when the shackle is in its closed position. 
     After removal of the blocking member and the retaining member, the cylinder lock mechanism can be removed from the lock casing, and after that, the locking members and the shackle can be removed. In this way the padlock can be disassembled. The assembly of the padlock proceeds in reversed order. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a shackle--plane section of a locked padlock according to the invention. 
     FIG. 2 is a side view of a retaining member provided with bayonet coupling pins. 
     FIG. 3 shows from below a view of a lock casing with a retaining member opening provided with bayonet coupling grooves. 
     FIG. 4 shows, in section, a way of arranging the blocking of the retaining member. 
     FIG. 5 shows, in section, another way of arranging the blocking of the retaining member. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the drawing, reference numeral 1 indicates a lock casing and numeral 2 a shackle with two legs 2a and 2b of different length. In the lock casing there are borings 3a and 3b for said legs. The shackle legs are provided with notches 4a and 4b receiving spherical locking members 5a and 5b. The head 2c of the longer shackle leg 2b is somewhat thicker than the portion extending from this head up to notch 4b. The padlock is operated by means of a cylinder lock mechanism 6. This mechanism is kept in the casing by means of a retaining member 12, arranged in an opening 12a in the lock casing. The lock casing is also provided with drain openings 7. 
     When the padlock is to be opened, cylinder lock mechanism 6 is first turned into its releasing position, which means that recesses 8 of a guiding portion 6a of the cylinder lock mechanism, are brought to face notches 4a and 4b and locking members 5a and 5b. The depth of recesses 8 are dimensioned to allow locking members 5a and 5b to move radially inwards against the cylinder lock mechanism far enough, to enable the shorter leg of shackle 2 to completely slide out from the lock casing, while head 2c of the longer shackle leg is still retained in boring 3b by locking member 5b. 
     In the lock casing there are two cavities 9 and 10 in line, of which the first extends from the outer surface of the lock casing to boring 3b and the second extends from boring 3b to opening 12a. The inner cavity 10 is concealed from the outside when shackle 2 is in its closed position, but it is operable from the outside when shackle 2 is in its open position. Cavity 10 has threads receiving a similarly threaded blocking member 11. In the embodiment shown in FIG. 1, blocking member 11 is a set screw and retaining member 12 is a threaded ring formed element. In the outer mantle surface of this retaining member there is a recess 13, dimensioned to partly receive blocking member 11. In this way retaining member 12 is blocked from turning by means of the blocking member. 
     When the cylinder lock mechanism is to be removed, the padlock is first opened, then blocking member 11 is removed by operating it through cavity 9. Now, retaining member 12 is turnable and thus removable. In order to get out the key (not shown) the shackle is locked in its closed position before the removal of the retaining member. The inner mantle surface of retaining member 12 is provided with recesses 14, dimensioned to coact with an expandable tool for the turning of the retaining member. 
     After the retaining member has been removed, cylinder lock mechanism 6 is free to slide out from the lock casing and the opening combination of the padlock can be changed and the shackle can be replaced by another shackle. The assembly and the locking of the padlock then proceeds in reversed order. In the outer end surface of retaining member 12 there is an indicator mark in the form of a recess 15, indicating when the turning position of the retaining member allows the blocking member to move into recess 13. 
     As shown in FIGS. 2-3, retaining member 12 can also be attached to the lock casing by means of a bayonet coupling. Bayonet coupling pins 16 are dimensioned to coact with preferably slightly helical grooves 17 in the lock casing. In the embodiment shown in FIGS. 2-3, there is an indicator mark 15a in the lock casing corresponding to mark 15 in retaining member 12. When marks 15 and 15a are next to each other, retaining member 12 is in its blocking allowing position. 
     Blocking member 11 can also be a short separate member 11a as shown in FIGS. 4-5. To prevent radial movement outwards from retaining member 12, the blocking member 11a can be supported by a supporting member 18 threaded in cavity 10 (FIG. 4), or alternatively cavity 10 can be dimensioned so, that member 11a will not completely move into boring 3b when shackle 2 is in its open position. This can be achieved by means of a protruding part 20 of the lock casing in cavity 10 as shown in FIG. 5. When shackle 2 is in its open position, the distance to protruding part 20 allows blocking member 11a to move into boring 3b far enough, to make the turning of retaining  member 12 possible. In this embodiment there is no need of threads in cavity 10, neither is cavity 9 necessary. This is because blocking member 11a can be inserted and removed from opening 12a. The key of the lock can be removed when the shackle is in its open position. For this purpose there is a notch 19 in shackle 2, to partly receive locking member 5b (not shown in FIG. 5) when the shackle is in its open position. This construction is described in detail in U.S. patent application No. 240,193, now Ser. No. 535,549. Compared to the embodiment shown in FIG. 1, the embodiments shown in FIGS. 4-5 have many advantages. Blocking member 11a can be made from extraordinarly hard material, preferably from hardened steel. In order to increase the strength of the construction, these embodiments also provide the largest possible cross-section for the blocking member. Still another advantage is, that the threads of the blocking member will not get damaged as a result of attempts to turn the retaining member by force while the blocking member is in its blocking position. This is because the threads are either in supporting member 18 or not needed at all. FIG. 4 shows the best mode of the invention. 
     The invention is not limited to the embodiments shown, but several modifications thereof are feasible within the scope of the attached claims.