Patent Publication Number: US-6904776-B1

Title: Combination lock capable of being opened by a key

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to combination locks and more particularly to a combination lock which can be opened by an authorized person by means of a key in addition to the typical opening by arranging dials into a numeral sequence desired by the user. Further, the authorization can be inhibited. 
   2. Description of Related Art 
   Combination locks are well known. One particular type of combination lock is disclosed in U.S. Pat. No. 5,715,709. While the patent may be suitable for the particular purpose to which it addresses, it still has the drawbacks of being weak of certain components, possible loosening of sealing cap, and difficult of manufacturing due to excessive internal components. Moreover, it is known that a padlock can only be opened by a key. Unfortunately, an integral combination lock and padlock has not been disclosed as far as the present inventor is aware. Further, it is understood that a user may forget the combination of a combination lock if its correct numeral sequence has been changed for several times. For solving the problem, it is desirable to provide a novel combination lock which, in addition to the typical opening by arranging dials into a numeral sequence desired by a user, it can be opened by an authorized person by means of a key. Inhibition of the authorization is also desirable. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a combination lock, comprising a substantially parallelepiped body including an elongated shackle receiving bore, a shallow shackle receiving hole on a top of the body opposite the bore, a plurality of parallel dial receiving slots crossed the bore, a plurality of ridged in an inner wall of the bore, each ridge being adjacent the dial receiving slot, a longitudinal groove adjacent and parallel with the bore, a channel perpendicular to the groove, a key hole perpendicular to the channel, a cavity recessed from the shackle receiving hole and aligned with the key hole, the cavity including a lengthwise ledge, a seat at both sides of the cavity, and a seat cover rested on the seat; a housing including mated upper and lower panels each including a dial receiving recess, a first half-circular indentation aligned with the bore, a second half-circular indentation aligned with the shackle receiving hole, and a third half-circular indentation aligned with the key hole; a plurality of separate and independent rotatable dials mounted at the dial receiving slots, each dial including a plurality of slits on an inner surface and a plurality of numeral panels on an outer surface; a plurality of tumbler sleeves each rotatably provided in the inner surface of the dial, each tumbler sleeve including a plurality of radial fins and a substantially flat member around an outer surface wherein the number of the fins is less than that of the slits by one; a resilient element including a plurality of pegs mounted in the dial receiving slots wherein each peg is forced to engage with the outer surface of the dial; a washer tightly fitted on a mouth of the bore for preventing any external contaminants from reaching inside; an elongated key lock assembly mounted in the key hole, the key lock assembly including an inward projection having a cam section; a sliding seat fitted onto the groove and the channel, the sliding seat including an opening aligned with the key hole so as to receive the projection and cause the sliding seat to be slidable by turning the key lock assembly, an aperture in communication with the opening and having a diameter smaller than that of the opening, and a plurality of legs each aligned with a portion of the body between two adjacent dial receiving slots, each leg having a substantially arcuate member; a U-shaped shackle including a short leg having its end insertable into the shackle receiving hole, and a long leg having its end inserted into a bottom of the bore and being allowed to advanced axially a distance along the bore in a locking or unlocking operation; a push button disposed in the cavity being proximate the shackle receiving hole, the push button including a toothed section around an inner surface and two opposite indentations on an outer surface; and a spring biased locking pin including a toothed member around an end, a plurality of equally spaced raised portions adjacent the toothed member with a passage formed between any two adjacent raised portions and the ledge being fitted in one of the passages, a plurality of slopes each at the raised portion, a shaft aligned with the aperture, and a spring put on the shaft, wherein the ridge is inserted into a valley between two adjacent fins of each tumbler sleeve for locking with the arcuate members being urged against the flat member; the dials are arranged into a predetermined numeral sequence by disengaging the arcuate members from the fins for unlocking; insert a key into the key hole to rotate the projection for sliding the sliding seat and disengaging the arcuate members from the fins; in response to unlocking the lock, use a tool to press the push button to advance the push button and the locking pin inside until the passage is clear from the ledge, insert a pointed portion of the tool into at least one of the indentations, rotate the push button to engage the projection with the slope, further press the push button to advance the locking pin inside and matingly engage the toothed member with the toothed section, and rotate the push button and the locking pin until the ledge inserts into the passage with the shaft being entered into the aperture for locking the sliding seat during an operation of inhibiting the lock from being opened by the key; and responsive to unlocking the lock, pull the long leg by a plurality of steps wherein in each step the fins of the tumbler sleeve are completely withdrawn from the slits and are locked by one adjacent ridge, thereby enabling a change of one numeral of a predetermined combination. 
   The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded view of a preferred embodiment of combination lock according to the invention; 
       FIG. 2  is a cross-sectional view of the combination lock in an unlocked position; 
       FIG. 3  is a greatly enlarged view of a portion of lock housing shown in  FIG. 1 ; 
       FIG. 4  is an exploded, perspective view of the combination lock; 
       FIG. 5  is a cross-sectional view of the combination lock taken along line A–A′ of  FIG. 2 ; 
       FIG. 6  is a perspective view of push button and locking pin; 
       FIG. 7  is a cross-sectional view of the push button, the locking pin, and other associated components assembled in seat; 
       FIGS. 8 ,  9 ,  10 , and  11  are views similar to  FIG. 7  for illustrating operation of inhibiting an opening of the lock by a key by rotating the push button; 
       FIG. 12  is a cross-sectional view of the combination lock in a locked position; 
       FIG. 13  is a cross-sectional view of the combination lock which is unlocked by a key; 
       FIG. 14  is a cross-sectional view of the combination lock taken along line B–B′ of  FIG. 13 ; 
       FIG. 15  is a cross-sectional view showing the pivoted shackle since the lock has been opened by a key; 
       FIG. 16  is a cross-sectional view showing the insertion of locking pin into aperture for inhibiting any other person from opening the lock by a key after a short leg of shackle being pivoted about 180 degrees from its locked position in an unlocked state; 
       FIG. 17  is a cross-sectional view of the combination lock in a locked position, where opening the lock by a key is inhibited since the locking pin is inserted into the aperture; 
       FIG. 18  is a view similar to  FIG. 16 , where short leg of shackle has pivoted back to a position slightly above a shackle receiving hole and an opening of the lock by a key still inhibited; and 
       FIG. 19  is a cross-sectional view depicting the combination lock in its combination changing configuration. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIGS. 1 to 19 , a combination lock constructed in accordance with the invention is shown. The combination lock comprises a substantially parallelepiped body  10  including an elongated shackle receiving bore  101  extended from a top of the body  10  almost to a bottom thereof, a shallow shackle receiving hole  16  on the top of the body  10  opposite the bore  101 , three parallel dial receiving slots  11  crossed the bore  101 , a ridge  12  in an inner wall of the bore  101  adjacent each slot  11 , a longitudinal groove  13  adjacent and parallel with the bore  101 , a channel  14  perpendicular to the groove  13 , a key hole  15  perpendicular to the channel  14 , a cavity  19  recessed from the shackle receiving hole  16  and aligned with the key hole  15 , the cavity  19  including a lengthwise ledge  191  having a slope  192  at its inner end, a seat  17  at both sides of the cavity  19 , and a seat cover  18  rested on the seat  17 ; a housing  80  including mated upper and lower panels  81  and  82  each including a dial receiving recess  83 , a first half-circular indentation  84  aligned with the bore  101 , a second half-circular indentation  85  aligned with the shackle receiving hole  16 , and a third half-circular indentation  86  aligned with the key hole  15 ; three separate and independent rotatable dials  20  mounted at the slots  11 , each dial  20  including a plurality of slots  21  on its inner surface and a plurality of slits  22  on its outer surface on which a plurality of (e.g., ten) panels are formed with each slit  22  sandwiched between two adjacent panels wherein, for example, one numeral ranging from 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 is formed on each panel; three tumbler sleeves  40  each rotatably provided in the inner surface of the dial  20 , each tumbler sleeve  40  including a plurality of radial fins  41  and a substantially flat member  42  around an outer surface wherein the number of the fins  41  is less than that of the slots  21  by one; a resilient element  50  including three legs  51  mounted in the slots  11  wherein each leg  51  is forced to engage with the slit  22  so that an audible click can be produced when the dial  20  is rotated to a proper orientation for each numeral; a washer  52  tightly fitted on the opening of the bore  101  for preventing any external contaminants from reaching the rotating components therein; an elongated key lock assembly  70  mounted in the key hole  15 , the key lock assembly  70  including an inward projection  71  having a cam section; a T-shaped sliding seat  60  fitted onto the groove  13  and the channel  14 , the sliding seat  60  including an opening  62  aligned with the key hole  15  so as to receive the projection  71  and cause the sliding seat  60  to be slidable by turning the key lock assembly  70 , an aperture  64  in communication with the opening  62  and having a diameter smaller than that of the opening  62 , and four legs  61  for forming three slots aligned with the slots  11 , each leg  61  having a substantially arcuate member  63 ; a U-shaped shackle  30  including a short leg  32  having its end insertable into the shackle receiving hole  16  for being locked therein, and a long leg  31  having its end inserted into a bottom of the bore  101  and being allowed to advanced axially a small distance along the bore  101  in a locking or unlocking operation; a push button  90  including a toothed member  901  around an inner surface wherein an end of the short leg  30  is adapted to engage with the push button  90 , and two opposite indentations on an outer surface; a locking pin  92  including a toothed member  921  around an end engageable with the toothed member  901 , a plurality of equally spaced raised portions adjacent the toothed member  921  with a passage  922  formed between any two adjacent raised portions wherein the ledge  191  is fitted in one of the passages  922 , a plurality of slopes  923  each at the raised portion, and a shaft  924  with the toothed member  921 , the passages  922 , and the slopes  923  formed therearound proximate one end; and a spring  91  put on the shaft  924  wherein the push button  90 , the locking pin  92 , and the spring  91  are disposed in the cavity  19  with only a small portion of the shaft  924  being extended to a position about flush with the edge of the seat  17 . 
   The ridge  12  is inserted into a valley between two adjacent fins  41  of each tumbler sleeve  40  for locking. Also, the arcuate members  63  are urged against the flat member  42 . Hence, an outward advancing of each of the long leg  31  and the short leg  32  is prevented, i.e., the combination lock is locked ( FIG. 12 ). It is obvious that the lock can be opened once the arcuate members  63  are not urged against the fins  41  by arranging the dials  20  into a numeral sequence desired by the user. Alternatively, as shown in  FIGS. 13 ,  14 , and  15  it is possible to insert a key  700  into the key hole  15  to rotate the projection  71  for sliding the sliding seat  60  toward the side of the lock for disengaging the arcuate members  63  from the fins  41 . This permits an outward advancing of each of the long leg  31  and the short leg  32  (i.e., the lock can be opened). Note that the inner end of the shaft  924  is always aligned with the aperture  64  in a non-operating state of the lock. 
   After unlocking the lock, for inhibiting any other person from opening the lock by a key, the following operations should be done in sequence. First, use a tool  93  (e.g., pen) to press the push button  90  to cause the push button  90  and the locking pin  92  to advance inside by compressing the spring  91  until the passage  922  is clear from the ledge  191  ( FIG. 8 ). Next, insert a pointed portion of the tool  93  into either indentation on the push button  90  and rotate the push button  90  to cause the slope  192  to engage with and to be stopped by the slop  923  ( FIGS. 9 and 10 ). At this position ( FIG. 10 ), the push button  90  and the locking pin  92  are locked in the cavity  19 . Next, use the tool  93  to press the push button  90  again to cause the push button  90  and locking pin  92  to advance further inside by compressing the spring  91  and the toothed member  921  to engage the toothed member  901  ( FIG. 11 ). Then rotate the push button  90  and thus the locking pin  92  until the ledge  191  inserts into the passage  922  again. This completes the desired rotation of the push button  90  and the locking pin  92 . Note that the shaft  924  enters into the aperture  64  for locking the sliding seat  60  by advancing the locking pin  92  in the inhibition operation.  FIG. 16  shows the insertion of the shaft  924  into the aperture  64  after finishing the inhibition operation with the short leg  32  being pivoted about 180 degrees from its locked position in the unlocked state. Then pivot the shackle  30  to the position shown in  FIG. 17  and lock the same. At this position, the lock can only be opened by arranging the dials  20  into a numeral sequence desired by the user ( FIG. 18 ). 
   As shown in  FIG. 19 , for changing the combination of the lock, in the unlocked position a user should pull the long leg  31  slowly by several steps (e.g., three steps in the embodiment) wherein in each step the fins  41  of one tumbler sleeve  4  are required to completely withdraw from the slots  21  of the dial  20  and be locked by one adjacent ridge  12 , thereby enabling a change of one numeral of the combination. 
   While the invention herein disclosed has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.