Padlock with protected slide bolt and locking means

A padlock is disclosed having an outer case preferably of hardened steel and having no shackle or bow which can be sawed or broken off. The case has an opening for insertion of a staple and has a slide bolt which extends through the opening to engage the staple. The slide bolt is secured by a locking means which includes a lock sleeve located within a cylindrical bore in the case, the sleeve being movable between a locked position and an unlocked position. The slide bolt is attached to the sleeve and extends through the opening when the sleeve is in the locked position. The lock sleeve has a retractable locking member projecting from a hole in the wall of the sleeve. The locking member is capable of fitting within an indentation in the interior bore wall when in the locked position to hold the sleeve in the locked position and capable of retracting into the hole to free the sleeve when in the unlocked position. A lock cylinder is fixedly mounted within the shell. The cylinder has an interior locking mechanism operatively connected to a camming means for forcing the locking member to project outwardly through the hole when the locking mechanism is locked and allowing the locking member to retract inwardly when the mechanism is unlocked.

FIELD OF THE INVENTION 
This invention relates to locking devices, and specifically to a padlock of 
the type commonly used to lock a hasp. 
BACKGROUND OF THE INVENTION 
Padlocks are commonly used to lock a hasp having a slot through which there 
is a projecting staple. The typical design of prior art padlocks includes 
a shackle or bow which fits through the loop of the staple and prevents 
the staple from removal through the hasp. The padlock case usually has 
within it a lock cylinder with a keyway or combination tumbler device with 
a latching mechanism to latch the end of the shackle and prevent its 
removal from the case. 
The prior art padlocks have had features which allow the lock to be broken 
open, since the shackle can usually be sawed off or broken off to open the 
lock. Even if the shackle cannot be broken, it is possible to saw or break 
off the exposed staple. 
Another problem with prior art padlocks involves the latching mechanism 
which holds the end of the shackle within the case. After a period of 
time, such latching mechanisms can become susceptible to jamming, 
preventing one from opening of the lock with a key. 
SUMMARY OF THE INVENTION 
The disadvantages of prior art padlocks are overcome by the improved 
padlock of the present invention. It is an object of the present invention 
to provide a padlock without a shackle or bow which can be sawed or broken 
off. Another object is to provide a padlock with a solid, smooth, outer 
case preferably of hardened steel which has no internal latches or levers 
likely to jam and which has a smooth surface which frustrates attempts to 
pry open the case. Still another object is to provide a padlock with a 
case which is adapted to fit completely around a staple preventing access 
to the staple. 
These and other objects are accomplished by the improved padlock of the 
present invention which has a smooth solid case which fits over the staple 
and has an opening for insertion of the staple. A slide bolt, secured by 
locking means within the case, extends through the opening to engage the 
staple. The locking means includes a lock sleeve mounted within a 
cylindrical bore in the case, which sleeve is movable between a locked 
position and an unlocked position. The slide bolt is attached to the lock 
sleeve, and extends through the opening when the sleeve is in the locked 
position. A retractable locking member, which projects from a hole in the 
wall of the sleeve, is capable of fitting within an indentation in the 
interior bore wall to hold the sleeve in the locked position and is 
capable of retracting into the hole to free the sleeve when in the 
unlocked position. A lock cylinder is fixedly mounted within the sleeve 
and has an interior locking mechanism operatively connected to a camming 
means for forcing the locking member outwardly through the hole when the 
locking mechanism is locked and allowing the locking member to retract 
inwardly when the mechanism is unlocked.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring more particularly to the drawings and initially to FIGS. 1 and 2, 
there is shown a padlock 11 of the present invention. The padlock 11 is 
specifically designed for locking a hasp H by attachment to a staple S 
which projects from a bar B and fits through the slot in the hasp H. The 
padlock 11 has a keyway 12 along its bottom surface 13 (FIG. 9), adaptable 
for insertion of a key K (FIG. 1). 
The interior of the padlock 11 is shown in more detail in FIGS. 3-5. The 
body of the padlock 11 comprises a case 15, preferably of hardened steel 
with smooth outer surfaces. The rearward surface 16 of the case 15, which 
fits against the hasp H and the staple S, has formed therein a transverse 
rectangular recess 17 into which the hasp H fits (FIG. 4). An opening 19, 
capable of receiving the projecting staple S, extends into the padlock 
case 15 from the recess 17. 
To lock the staple S, a slide bolt 20 extends upwardly through the opening 
19 and through the loop of the staple S (FIG. 10). The slide bolt 20 is 
movable within a passage 21 in the case 15 (FIGS. 3 and 4). The top of the 
passage 21 extends through the opening 19, so that when the slide bolt 20 
is fully extended within the passage 21, the staple S is effectively 
secured by the padlock and the hasp H is incapable of removal from the 
staple. 
The slide bolt 20 is secured within the passage 21 by the operation of a 
locking means comprising an attached lock sleeve 23 and lock cylinder 24. 
The slide bolt 20 is mounted to the upper end of the cylindrical lock 
sleeve 23, which is hollow and which has a lock cylinder 24 securely 
mounted within it by means of a removable set screw 25. The lock cylinder 
24 is of conventional design comprising a nonrotatable outer housing which 
is secured to the lock sleeve 23 by the set screw 25, and a conventional 
internal locking mechanism which is capable of turning only when a key is 
inserted into the keyway 12, activating tumblers in the internal locking 
mechanism. A rotatable camming disk 26 is connected to the internal 
locking mechanism and is mounted at the upper end of the lock cylinder 24. 
By inserting the key K into the keyway 12 and turning the key, the 
tumblers are activated, and the locking mechanism turns resulting in 
rotation of the connected camming disk 26. 
The assembly of the lock sleeve 23 and the attached lock cylinder 24 is 
slidable within a cylindrical bore 27 in the case 15. To restrain the 
assembly within the bore 27, the lock sleeve 23 has a longitudinal groove 
28 along its side (FIG. 3). A retaining member, such as pin or screw 29, 
is mounted in the wall of the bore 27 and fits within the groove 28. As 
the sleeve 23 slides within the bore 27, the screw 29 moves within the 
longitudinal groove 28, preventing the sleeve from being fully removed 
from the bore 27. To permit installation and removal of the screw 29, the 
sleeve 23 has a pair of radially extending holes 30 and 31 which extend 
through the wall of the sleeve. Holes 30 and 31 are coaxial with each 
other, and the hole 31 communicates directly with groove 28. A hole 32 is 
also formed through the case 15 coaxial with the screw 29. 
To provide a means by which the sleeve 23 and attached lock cylinder 24 are 
locked within the bore 27, an annular indentation 34 extends into the case 
15 from the interior bore wall around the top of the bore 27. A plurality 
of holes 35 extend through the wall of the lock sleeve 23 around its upper 
portion. A retractable locking member, preferably a ball bearing 36, is 
placed in each of the holes 35. In the preferred embodiment of the present 
invention, three holes 25 each containing a bearing 36 are provided (FIG. 
5). The lock cylinder 34 secured within the sleeve 23 has mounted at its 
upper end a camming means, such as the rotatable camming disk 26, having 
projections 39 and recesses 40. The camming disk 26 is capable of rotating 
only when the key and the internal locking mechanism of the lock cylinder 
24 rotates. The motion of the camming disk 26 is restrained by a pin 37 
which projects from the top surface of the interior of the lock sleeve 23 
and which engages an arcuate slot 38 on the top of the camming disk 26. 
The number of projections 39 and recesses 40 on the camming disk 26 
corresponds to the number of bearings 36 within the holes 35 of the sleeve 
23. The recesses 40 are proportioned such that, when the recesses 40 are 
adjacent the holes 35, the bearings 36 fit within the recesses 40 and do 
not project from the outer surface of the sleeve 23 (FIG. 8). However, 
when the projections 39 of the camming disk 26 are opposite the holes 35, 
the bearings 36 project outwardly through the holes 36 beyond the outer 
surface of the sleeve 23 (FIG. 5). When the sleeve 23 is in the locked 
position, the projecting bearings 36 fit within the annular indentation 34 
in the bore 27 (FIG. 4). When the sleeve 23 is in the unlocked position, 
the bearings 36 retract within the sleeve 23 and the sleeve is movable 
within the bore 27 (FIG. 7). 
To operate the padlock 11 of the present invention, a key K is placed 
within the keyway 12 of the lock cylinder 24, and the key is turned. The 
key activates the tumblers within the lock cylinder 24 and allows the 
internal locking mechanism to turn, thereby rotating the camming disk 26 
mounted on the upper end of the lock cylinder. The nonrotatable outer 
portion of the lock cylinder 24 remains fixedly secured to the lock sleeve 
23 by set screw 25. As the camming disk 26 is rotated, the projections 39 
in the disk move away from the holes 35 in the sleeve 23 and the recesses 
40 move into a position adjacent the holes 35 (FIGS. 5 and 8). This allows 
the bearings 36 to retract into the holes 35 and clear of the annular 
recess 34. With the bearings 36 removed from the recess 34, the lock 
sleeve 23 is free to slide within the bore 27 (FIGS. 6 and 7), restrained 
only by the screw 29 within the groove 28 of the lock sleeve. The lock 
sleeve 23 and attached lock cylinder 24 can then be pulled downwardly 
beyond the bottom surface 13 of the case 15. (See FIG. 11). The slide bolt 
20 attached to the upper end of the lock sleeve 23 also moves downwardly 
through its passage 21 until it is completely clear of the opening 19 
(FIGS. 6 and 7). The staple S is then free to be removed from the opening 
19. The outward extension of the lock sleeve 23, (FIG. 1) provides an easy 
visual indication that the padlock is unlocked, thereby avoiding the 
possibility of inadvertently leaving the padlock unlocked. The reverse 
procedure is used to lock the padlock with the staple S reinserted into 
the opening 19. 
Another feature of the padlock of the present invention is that the 
elements can be disassembled to replace worn or defective parts, but only 
when the padlock 11 is in the unlocked position. To remove the lock 
cylinder 24 from the lock sleeve 23, the padlock is first unlocked so that 
the sleeve 23 slides downwardly through the bore 27 and projects from the 
lower surface 13 of the lock case 15. In this position (FIGS. 6 and 7), 
the head of the set screw 25 is accessible. Removal of the set screw 25 
permits removal of the lock cylinder 24 from the lock sleeve 23. With the 
lock cylinder 24 removed, the sleeve 23 can be pushed back into the bore 
partially so that the hole 32 in the case 15 is aligned with the holes 30 
and 31 in the sleeve 23. In this position, a small screwdriver or socket 
wrench can be inserted through the aligned holes 30, 31 and 32 to remove 
the screw 29. With screw 29 removed, the lock sleeve 23 is no longer 
restrained with the bore 27, and it can be easily removed from the case 
15. It can be seen that, when the lock sleeve 23 is completely removed 
from the hole 27, the bearings 36 which are placed within the holes 35 
also easily removable. 
While the invention has been shown and described with respect to a specific 
embodiment thereof, this is intended for the purpose of illustration 
rather than limitation, and other modifications and variations will be 
apparent to those skilled in the art, all within the intended spirit and 
scope of the invention.