Rekeyable Shrouded Lock

Shrouded shackle locks with curved shackles are old. Locks rekeyable by replacement of the lock cylinders or parts therein when the locks are in their open position have earlier been proposed (U.S. Pat. Nos. 4,290,279; and 4,138,868). Locks in which tools can be inserted only when the lock is unlocked are also known (U.S. Pat. No. 3,977,221).

Broadly, the present invention is a shrouded shackle lock having a readily removable retainer cover attached to the housing through contained fasteners. Insertion of a tool for removal of such fasteners is prevented by a rotatable blocking cam plate unless the lock is in its open position.

It is a feature that the fasteners are retained in the lock ready for reattachment during retainer cover removal and replacement.

FIG. 1 is an exploded perspective view of selected lock parts;

FIG. 2 is a sectional elevational view of the inventive shrouded shackle lock in its lock position;

FIG. 3 is a sectional elevational view in the open position;

FIG. 4 is a cross-sectional view of the lock in the unlock position with a tool wrench inserted;

FIG. 5 is an exploded sectional view with the lock cover removed and lock cylinder shown both installed and removed;

FIG. 6 is a cross-sectional view of an alternative embodiment of the invention in unlocked position;

FIG. 6a is an enlarged partial view of FIG. 6 showing undercut bolt captured in a stationary plate;

FIG. 7 is an exploded sectional view of the second embodiment;

FIG. 8 is a side elevational view of a lock retainer ring; and

FIG. 9 is a side elevational view showing the retainer ring being installed and bent.

In FIGS. 1-5, lock 9 includes round casing 10 having front casing half 11 and back casing half 12 (FIG. 3). Casing half 11 includes cowling 11a for receiving retainer cover 15 within cowling 11a (FIG. 4). Casing halves 11, 12 are adjoined along line 13 (FIG. 4). Back casing half 12 includes a blister 12c with two spaced apart holes 12a, 12b. Within case 12 is curved shackle 16 having drive notch 16a and lock notch 16b, shackle drive cam 17 and lock latch 18 pivotal about pin 18a (FIG. 2). Also shown is stationary rear plate 20. Drive cam 17 has projection 17p which rotates in plate opening 20c and engages block cam recess 19r.

Drive cam 17 including its projection 17p is connected to key cylinder prong 21p for rotation by cylinder plug 40 from open to closed positions (FIG. 5). Drive cam 17, rotatable about hole 20c in plate 20, includes shackle drive prong 22 and two spaced-apart holes 23a, 23b located to align with holes 12a, 12b when drive cam 17 is in the open position (FIGS. 1-3). Blocking cam 19 which is preferably made of hardened sheet to resist drilling carries notches 19a, 19b. Finally, internal frame piece 25 has two spaced-apart holes 25a, 25b (FIG. 4). Thus, when the following holes or notches are aligned:

1) hole 12a of casing half 12; notch 19a of blocking cam 19; 20a of stationary rear plate 20; 23a of drive cam 17 and hole 25a of frame 25, then and only then can wrench tool 28 be insertable to reach and turn bolt 29; and

2) hole 12b of casing half 12; 19b of blocking cam 19; 20b of rear plate 20, 23b of drive cam 17 and hole 25b of frame 25, then and only then can wrench tool 28 be insertable to reach and turn bolt 30.

Bolts 29, 30 are threadable into holes 32a, 32b of retainer cover 15. Bolt 29 has stem 29a, head 29b and is restrained in cavity 29c as it is fully unscrewed out of cover hole 32b. Cavity 29c is shaped and sized so that bolt 29 remains oriented therein to receive wrench 28 for turning when cover 15 is reattached. Head 29b has a depression in it (not shown) to receive wrench 28. As captured and restrained in cavity 29c, bolt 29 can be screwed back into hole 32b by manipulating wrench 28. Similarly, bolt 30 has stem 30a, head 30b and cavity 30c.

Turning to FIG. 5, retainer cover 15 includes external end portion 15a, side skirt portion 15b sized for positioning within cowling 11a. Lock-receiving recess 34 including tail recess portion 34a and key accommodating opening 36. Lock cylinder 21 includes housing 39 with tail 39a. Rekeyable plug 40 is rotatable within housing 39. Lock cylinder 21 is removable for rekeying or replacement as described.

Turning now to FIGS. 6, 6a and 7, an alternative embodiment is shown in which retainer cover 15' has face piece 15a' and side skirt 15b'. Retainer cover 15' is shaped to be positioned with its skirt 15b' on the outside of the cowling 11a'. Cover 15' includes two spaced-apart beveled holes 41, 42 for receiving fasteners 43, 44 respectively. Fastener 43 includes beveled head 43a, stem 43b and threaded recess 43c in stem 43b for receiving a bolt 46. Similarly, fastener 44 has beveled head 44a, stem 44b and recess 44c (not shown) for receiving bolt 47. Bolts 46 and 47 with heads 46b, 47b include undercuts 46a, 47a (not shown) which retain bolts 46, 47 in holes 51a, 51b of front plate 52 (see FIG. 6a). Bolts 46, 47 as mounted on plate 52 are free to spin but are otherwise captured by plate 52. When cover 15' is removed bolts 46 and 47 remain captured by plate 52. Other elements corresponding to the first embodiment are front casing 11', back casing 12'; shackle 16', drive cam 17', blocking cam 19', lock cylinder 21' and so forth.

In FIGS. 8 and 9, there is the preferred arrangement for securing casing halves 11 and 12 together includes use of a lock retainer ring 56 having circular base piece 57 and bendable generally circular curved side piece 58. To accomplish assembly, back casing half 12 is placed in ring 56 and spot welded to ring 56. Front casing 11 is then placed on top of casing half 12 and side piece 58 is bent from its vertical position shown in dashed lines (FIG. 9) to its curled position (shown in solid lines in FIG. 9) to secure the halves 11 and 12 together. This construction improves good security of the lock.