Cable or chain combination locks of the type having means for setting or changing the combination have been known (U.S. Patent Nos. 4,445,348 and 4,615,191).
Other combination locks have included mechanisms described in U.S. Patent Nos. 1,706,994; 1,898,947; 4,354,365; 4,441,346; and 4,831,860.
The invention relates to a changable combination U-shaped shackle lock in which the shackle has two legs and the lock further has a main body, clutches for selectively effecting locking of the shackle and combination wheels selectively arrangable in variable combination to said clutches, a first end of a lock shaft body being fixed to the main body, the main body receiving and holding a first shackle leg in the main body for limited movement therein, the lock shaft body upon which said clutches with their combination wheels are supported having at its second end opposite the first end a head including a shackle leg hole to receive the second shackle leg, said lock shaft body having a hollow shaft recess extending axially therethrough, a reciprocal shaft being positioned and guided in the hollow shaft recess so as to be resiliently urged towards the shackle leg hole in the head such that when said second shackle leg is located in the shackle leg hole it is normally maintained through action of the reciprocal shaft in the locked position, the clutches whenever in any locking combination preventing withdrawal of the reciprocal shaft from the position in which it acts to lock the shackle.
From the United States Patent US-A-1,486,934 such a lock is known. This lock is unlocked by turning the combination wheels into the right position. After unlocking, one leg can be pulled out of the main body.
A disadvantage of this known lock is, that the lock can be opened with force while in a locked position.
Broadly, the present invention includes a shackle combination lock that is readily partially disassembled when the shackle is pulled to the open position to permit change of the combination. To this end the lock according to the invention is characterized in that the lock further comprises a lock ball retained between the reciprocal shaft and the shackle leg hole such as to engagingly lock the second leg upon its insertion into the shackle leg hole, the second leg having thereby been first inserted through an opening in a spring-retained cap removably located on the head, so that said cap is removable from the head upon overcoming the spring-retention only when the shackle is in its unlocked position, the combination wheels being normally maintained in position by the cap as long as the latter is retained on the head and the combination wheels being removable axially once the cap has been removed.
A cap end is removable by causing the depression of a spring-loaded clasp permitting the combination wheels to be removed from the clutches and replaced in a selected position to attain the desired new combination.
It is a result of the invention that the removable cap is securely held by the lock shackle in the lock position and readily removable when the shackle is in the unlock position.
In Figs. 1 and 1A, lock 10 includes fixed body portion 8, removable cap end 9, lock shaft body 11, lock shaft 12, clutches 13 a-d and, combination wheels 16a-d, and U-shaped shackle 15 with shackle legs 15a, 15b. Shaft body 11 includes shaft portion 11a having both holes 25a-d and head 11b. Lock shaft body 11 is permanently fixed to body portion 8 using a pin or other suitable means.
Fixed body portion 8 in turn includes shackle sleeve opening 17, shackle leg retaining pin 18 and shaft body recess 19 (Fig. 2). Removable end cap 9 has shackle cap recess 9a and lock shaft body head 11b includes shaft recess sleeve 22 aligned to receive leg 15b Caps also has recess 23 to house head 11b.
Removable end cap 9 is held in lock position by shackle leg 15b; however, when leg 15b is moved out of head 11b and cap 9, cap 9 is readily removable by the exertion of force to cause cap 9 to be urged away from shaft body head 11b causing spring 26 to move out of lock cap cavity 27 into head dwell recess 29.
Lock 10 further includes locking mechanism 30 in which shaft 12, housed in shaft body recess 19 of shaft body portion 11a, is urged to the right (Fig. 2) by coil spring 34 causing large shackle lock ball 36 to engage shackle notch 37 of shackle leg 15b. Shaft 12 includes four (4) annular shackle depressions 12a-d for accommodating small shaft lock balls 38a-d. Lock balls 38a-d are captured in depression 12a-d and restrained by clutches 13a-d. Each clutch 13a-d includes a ball clutch pocket 44a-d which permits shaft lock balls 38a-d to be moved out of shaft grooves 12a-d to permit spring 34 to be compressed as shackle leg 15b is pulled upwardly camming ball 36 to the left (see arrow in Fig. 2) to unlock the lock. Fig. 2 shows the clutches 13a-d positioned with clutches 13a-c in positions in which balls 38a-c can not move upwardly out of grooves 12a-c while clutch 13d is turned so that clutch pocket 44d permits ball 38d to move upwardly upon laterally movement of shaft 12. Clutches 13a-d are moved to selected positions by combination wheels 16a-b which are engageable as clutch projections 47a-d enter wheel recesses 48. Clutches 16a-d also carry thumb pieces 51a-d.
Once the combination wheels 16a-d are aligned to permit balls 38a-d to be moved upwardly, a pull on shackle 15 causes shackle leg 15a to move upwardly camming ball 36 to the left (Fig. 2) to release leg 15b. As leg 15b is moved upwardly out of cap recess 9a and head recess 22, cap end 9 is free to be disassembled by applying sufficient force to cause spring 27 to move into dwell recess 29 and release cap 9.
Once cap end 9 is removed, combination wheels 16a-d can be removed laterally and replaced with each of the sets of projections 47a-d moved into a number of wheel recesses 48 on clutches 13a-d to create a new combination.