Double locking combination lock
This is a continuation of application Ser. No. 703,360 filed Feb. 20, 1985 and now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     Double locking combination locks have been proposed in which a combination padlock is also capable of being opened by key. The use of steel balls to engage and lock shackles of combination locks has been proposed in prior patents (see U.S. Pat. Nos. 2,931,204 and 3,855,824). Arrangements for upsetting a permutation wheel during closing and locking a padlock has been proposed. 
     None of the prior proposals or uses has provided a satisfactory lock with the strength, security and reliability of the present invention. 
     SUMMARY OF THE INVENTION 
     Broadly, the invention comprises a double locking combination lock in which a plurality of steel balls in a lock body cavity are controlled by movement of a cam plate associated with the housing to lock the shackle with two of the balls or with the unlocked shackle withdrawn from the body to hold the cam plate means in the open position. 
     The cam plate means is also controllable by a key lock with a rotatable cylinder which connects to the cam plate through a key cam and slide plate. 
     It is a feature of the invention that the shackle carries an upset spring to cause the discs to be upset when the shackle is moved downwardly into a locked position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded perspective view as seen from the front of the lock; 
     FIG. 2 is an exploded perspective view as seen from the back of the lock; 
     FIG. 3 is a sectional view taken along line 3--3 of FIG. 4; 
     FIG. 4 is a sectional view taken along line 4--4 of FIG. 3; 
     FIG. 5 is a sectional view taken along line 5--5 of FIG. 4; 
     FIG. 6 is a sectional view taken along line 6--6 of FIG. 3; 
     FIG. 7 is similar to the sectional view of FIG. 3 in which the lock is shown in its unlocked condition; 
     FIG. 8 is a sectional view taken along line 8--8 of FIG. 7; 
     FIG. 9 is an elevational view partially broken away to show the key lock operation; 
     FIG. 10 is a sectional view taken along line 10--10 of FIG. 9; 
     FIG. 11 is a sectional view taken along line 11--11 of FIG. 10; 
     FIG. 12 is a partial elevational view showing the upset mechanism clearing a disc in upward shackle movement; and 
     FIG. 13 is a view similar to FIG. 12 showing the upset mechanism operation in downward shackle movement. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1 and 2, lock 10 includes a dial knob 11 carrying front combination disc 12, a main body housing 13, a shackle 14, a steel ball cam member 17, a cam member return spring 18, three (3) steel balls 21, 22, 23, a center ball spring 24, a drive lever 26, a main lock body 27, a key cylinder follower 28, a key control plate 31, a key lock body 32, an upset spring 33, an upset spring mount plate 34, middle combination disc 36, rearward combination disc 37, disc support plate 38, and housing ring 39. 
     Turning more broadly to FIGS. 1-8, main lock body 27 includes a steel ball chamber 41 in which steel balls 21, 22 and 23 together with control cam member 17, are housed and controlled. Chamber 41 is sized and shaped to permit cam member 17 to reciprocate partially therein, with spring 18 urging cam member 17 normally to the right as viewed in FIGS. 1 and 6. Cam member 17 can be moved to the left against spring 18 by counterclockwise movement of dial knob 11 provided the drive lever 26 has been engaged with discs 12, 36 and 37 as explained hereinafter. Cam member 17 includes vertical plate 42, plate ridge 42a, plate hole 43, ball cam piece 44 and spring mount extension 46. 
     Driver lever 26 includes lever body piece 48, tubular extension 49, cam member boss 51 and bar extension 52. Tubular extension 49 ridges in lock body slot 49a while bar extension 52 rides in lock body opening 52a. 
     Driver lever 26 is rotatable about tubular extension boss 51 which bears in plate hole 43 and therefore driver lever 26 translates back and form together with the side-to-side movement of cam member 17. Driver lever 26 is biased by spring 25 urging extension 52 downwardly against discs 12, 36 and 37. Shackle 14 includes long shackle leg 53 and short shackle leg 54. Shackle leg 53 is held locked by ball 23 in leg notch 56 and leg 54 is held locked by ball 21 in notch 57 (see FIG. 6). 
     Operation of the lock to free shackle 53, 54 from balls 21 and 23 requires translating cam member 17 to the left (FIGS. 1 and 6) to permit center ball 22 to be urged by its spring 24 into cam piece opening 44a. As ball 22 moves into opening 44a, outer balls 21 and 23 move out of notches 56, 57 as upward movement of the shackle legs 53 and 54 begins to permit full release of the shackle legs. 
     Cam member 17 can be moved to the left (FIGS. 1 and 6) only by movement of driver lever 26 which in turn can be moved to the left (1) upon entry of bar extension 52 in grooves 12a, 36a and 37a of discs 12, 36 and 37 and subsequent turning of dial knob 11, or (2) by operation of the key system as described below. When the combination is dialed, disc grooves 12a, 36a and 37a are aligned to receive bar extension 52, rotation of dial knob 11 counterclockwise causes driver lever 26 to move to the left carrying with it cam member 17. The shackle legs 53, 54 become freed and the lock can be opened by pulling out the legs 53, 54. 
     Turning now to FIGS. 9-11 and the operation of key lock arrangement, key lock body 32 which fits in body cavity 27a of lock body 27 (see FIG. 2) has a key-operated cylinder 64 in its interior and a slot 32a (FIG. 2) which permits key cam projection 28a to engage the cylinder 64. When the key 64a (FIG. 10) turns cylinder 64 clockwise as viewed in FIG. 9, key cylinder follower 28 is moved to the right (all as viewed in FIGS. 2, 5 and 9). Rear key follower boss 67 engages in vertical slot 68 of plate 31 to cause plate 31 together with front key follower boss 65, riding in lock body archway groove 66 to move to the right (see FIGS. 5 and 9). As plate 31 moves rightward it carries tubular extension 49 captured in slot 69 of plate 31. Movement of tubular extension 49 in turn translates cam member 17 to open the lock position. 
     Turning finally to FIGS. 12 and 13, during the upward movement of long shackle leg 53, upset spring plate 34 is moved upwardly due to its engagement with pin 70 positioned in notch 55 on leg 53 and bearing in housing groove 61. Plate 34 is guided by pin 58 riding in groove 59 of disc plate 38 (see FIG. 2). Spring 33 which is mounted on plate 34, deflects to pass detent 72 of rearward disc 37 (see FIG. 12). When shackle 53 is pushed downwardly to the lock position, ball 23 moves into shackle notch 56 releasing cam member 17 to move to its lock position. As cam member 17 moves its bar extension 52 ridges out of disc notches (including notch 37a; see FIG. 13). As shackle leg 53 nears its locking position, extension 52 leaves notch 37a and spring 33 engages detent 72 commencing its upset rotation of disc 37 (see FIG. 13). Shackle leg 53 continues its further movement downwardly with pin 70 bottom out in housing groove 61 and as spring 33 disengages from detent 72 rotation of disc 37 is completed.