Barrel Combination Lock

Barrel combination locks which allow the user to change the combination without the use of tools have been proposed (see U.S. Pat. Nos. 4,354,365 and 4,445,348). The permutation wheels of the locks of these patents carry outer rings which can be set by the user for selecting a combination of the user's choosing.

Prior proposals have not provided a simple and reliable way of holding the outer rings in place during normal lock operation and permitting the ready disassembly of the outer rings to permit changes in the combination.

Broadly, the present invention comprises a barreltype combination lock having a cable sleeve and a lock body into which the sleeve is engaged to effect locking. The combination can be readily changed by sliding the permutation wheels off the clutches and replacing them in different radial positions. The permutation wheels are held on the lock body by a removable end cap. The end cap is removable only when the sleeve is withdrawn because the presence of the sleeve in the lock body prevents operation of a release latch arrangement.

FIG. 1 is a perspective view of the barrel combination lock as locked;

FIG. 2 is an exploded perspective view of the lock as disassembled;

FIG. 3 is a sectional view taken along line 3--3 of FIG. 1; and

FIG. 4 is a partial plan view of the shaft body including its grooved collar.

In the figures, barrel lock 10 includes flexible cable 11, fixed end cap 12, lock shaft body 13, clutches 14a, 14b, 14c and 14d, combination wheels 17, removable end cap 18 and shackle 19.

Cable sleeve 21 is swaged to cable 11. Fixed end cap 12 includes cap body 22 internal and shaped cavity 23. Cable sleeve 21 prevents cable 11 from being withdrawn from shaped cavity 23. Shaft body 13 is pinned to cap 12 by passing lock pin 24 through cap hole 26 and shaft body hole 27.

Shaft body 13 includes an internal cavity 13a (not shown) for receiving shackle 19 and four (4) aligned cylindrical well holes 28a, 28b, 28c, and 28d communicating with the shaft cavity for receiving four (4) locking balls 29. Shaft body 13 also has a shaft collar 31 which in turn includes collar cavity 32, pin-receiving hole 33 and locking grooves 34, 36. Clutches 14a, 14b, 14c and 14d each carry locking ball recesses 38a, 38b (not shown), 38c and 38d (shown) into which locking balls 29 move when the clutches 14a, 14b, 14c and 14d are in their unlocked positions and the shackle is pulled toward its removal. Shackle 19 includes four (4) lock ball grooves 39a, 39b, 39c and 39d which are shaped so that when the shackle is pulled in an effort to withdraw it from shaft body 13, balls 29 will be cammed up through holes 28 into clutch recesses 38. Clutches 14 also carry projections 41 which are engageable with the plurality of combination wheel internal recesses 42 on each wheel 17. Combination wheels 17 also carry thumb pieces 45 to assist rotating and translating wheels 17.

In its assembled and unlocked condition, lock 10 clutches are positioned on shaft body 13 and wheels 17 are positioned on and around the clutches 14 whereby rotation of a wheel 17 causes its mating clutch 14 to rotate. In its assembled condition, shaft collar 31 prevents removal of clutches 14 and removable end cap 18 prevents removal of wheels 17.

With particular reference to FIGS. 3 and 4, end cap 18 has short internal tangs 18a, 18b which align with L-shaped sleeve grooves 34, 36 during assembly of cap 18 onto sleeve 31. Each groove 34, 36 includes longitudinal portion 34a, 36a and cross portion 34b, 36b. Once cap 18 is axially moved onto sleeve 31, cap 18 is then turned as tangs 18a, 18b move in cross portion grooves 34b, 36b until pin 46 as biased by spring 48 moves upwardly into recess 47 in the interior of cap 18. Cap 18 is removed by turning it in a reverse direction which initial turning cams pin 46 downwardly releasing the cap 18 for further turning and subsequent removal. When cap 18 is in its installed position and shackle 19 in its locked position, detent pin 46 cannot be moved downwardly by placing a torque on cap 18 because pin 46 abuts against the shackle 19 and cannot therefore move downwardly out of cap recess 47 (FIG. 3).

To place lock 10 in its locked position, wheels are dialed to the unlock combination (note pin 24 marks the zero reference position), shackle 19 is inserted through end cap cavity 18c, collar cavity 32 and into shaft body cavity 13a. As shackle 19 enters shaft body cavity 13a balls 29 are cammed upwardly through well holes 28 and into clutch recesses 38. Upon completion of entry of shackle 19 into cavity 13a, the balls 29 will descend into shackle grooves 39. One or more of the wheels 17 is then dialed to a lock position. In the lock position, removable end cap 18 cannot be removed because detent pin 46 is positioned in cap lock groove 47 and the end of the detent pin 46 rests against cable sleeve 19 preventing pin 46 from being depressed against its spring 48. To unlock the lock, wheels 17 are dialed to the unlock combination and the shackle 19 withdrawn.

To change the combination, lock 10 is first placed in the unlock condition and shackle 19 removed. In this condition, detent pin 46, biased upwardly by spring 48, is capable of being moved downwardly against spring 48 to move the lower end of pin 46 out of the lock groove. With end cap 18 removed, wheels 17 can be translated from their position on the clutches 14 by passing wheels 17 over collar 31, leaving clutches 14 in their lock-open positions. Wheels 17 are then translated back over clutches 14 to provide any desired combination.