A locking device including a labyrinthic passageway through which a ball may be moved until arriving at a position adjacent an associated locking mechanism that is operable solely in response to the presence of the ball. In an exemplary embodiment, the labyrinthic passageway is concealed in the bottom of an open-topped walled container and the locking mechanism is in communication with a sliding plate member employed to close the container. With the plate member in its closed position and the ball placed at a starting location within the passageway, yet away from the locking mechanism, the container cannot be opened until the ball has been encouraged, by spatial manipulation of the container, to negotiate the labyrinth, arrive at a position adjacent the locking mechanism, and operate same solely by the impression of its weight thereupon.

BACKGROUND OF THE INVENTION 
The present invention relates to a means for preventing the operation of a 
locking mechanism until a ball has been successfully moved through a 
labyrinthic passageway. Several devices have been developed that employ a 
ball to lock or unlock two or more interconnected members. Examples of 
such devices include those disclosed by La Montagne U.S. Pat. No. 
3,650,379, Hein U.S. Pat. No. 2,709,357, Maclaren U.S. Pat. No. 2,499,765, 
and Frederiksen U.S. Pat. No. 698,486. The most pertinent of these known 
prior art devices is that disclosed by Frederiksen as comprising a 
rotatable labyrinthic enclosure through which a ball may be encouraged, by 
rotation of the enclosure, to move until arriving at a position where it 
may be employed, by a separate and distinct operator-exerted force, to 
unlatch an associated locking mechanism. The remaining three prior art 
devices each employ one or more balls as obstructing elements to prevent 
the separation of interconnected members until the balls have been moved 
to predetermined positions within the device. 
SUMMARY OF THE INVENTION 
The locking device of the present invention is directed to a ball-operated 
lock of the type wherein a ball is moved through labyrinthic passageway to 
a position where it can operate, without further operator intervention, an 
associated locking mechanism. More particularly, the device of the present 
invention comprises a labyrinthic passageway, a ball residing in and 
movable therethrough by spatial manipulation of the passageway, and an 
associated locking mechanism that is operable solely in response to the 
proximate presence of the ball. In the disclosed exemplary embodiment, the 
labyrinthic passageway is concealed in the bottom of an open-topped 
container, and a movable locking member extends from the passageway to a 
position of selective latchable engagement with a slidably removable top 
plate employed to close the container. The locking member is biased in its 
locked position such that, when the top member is in place and latchably 
engaged by the locking member, the top member cannot be displaced, and 
thus the container cannot be opened, until the locking member has been 
moved to its unlocked position. Such movement of the locking member is 
accomplished by predetermined spatial orientation of the container so as 
to encourage the ball residing in the concealed passageway to negotiate 
the labyrinth from an initial starting position away from the locking 
member to an ending position adjacent the locking member. Once the ball 
reaches its ending position adjacent the locking member, the weight of the 
ball acts upon a portion of the locking member extending into the 
passageway and causes the locking member to move to its unlocked position. 
In contrast to the prior art labyrinth locking devices referred to above, 
no manipulation of the container nor of any additional element associated 
therewith, other than the spatial manipulation necessary to move the ball 
through the passageway, is required to operate the locking member and 
release the top plate. With the locking member in its unlocked position, 
the top plate may be removed and the container opened. 
The container incorporating the locking device of the present invention may 
be employed as a means for protecting valuables, as a child's educational 
and amusing toy, or as a novelty item. When used to protect valuables, its 
security against unauthorized operation is assured by the difficulty 
attendant with moving the ball through the complex labyrinthic passageway 
without having a prior knowledge of the path described thereby. This 
security is further enhanced by the concealment of the passageway and ball 
within the container, thereby preventing a person watching the device 
being operated from ascertaining readily the method of its operation. When 
use as a child's toy or novelty item, the passageway could describe a 
simplified path in order to make the device interesting and challenging 
yet relatively simple to operate. The locking device of the present 
invention may also be adapted for use with other types of lockable 
containers such as suitcases, briefcases and the like. 
Although the locking device of the present invention has been discussed 
above in the context of a weight-operated locking member, it is understood 
that other means, such as electrical, magnetic or optical sensors, could 
be employed as well to activate the locking mechanism solely in response 
to a detected presence of the ball at a predetermined location within the 
passageway. 
It is, therefore, a principal objective of the present invention to provide 
a novel locking device that is operable solely in response to the presence 
at a predetermined location of a ball that has been encouraged to 
successfully negotiate a labyrinthic passageway. 
It is an additional objective of the present invention to provide a 
lockable container utilizing a locking device of the type described. 
It is a further objective of the present invention to provide a child's toy 
or novelty item utilizing a locking device of the type described. 
It is an advantage of the locking device of the present invention that it 
may be operated in the presence of another person without necessarily 
disclosing the method of its operation.

DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT 
As shown in the figures, an exemplary embodiment of the locking device of 
the present invention comprises a labyrinthic passageway 20 formed in a 
floor member 21 and concealed under the false bottom 22 of a surrounding 
open-topped container 24, a ball 26 residing in and movable through the 
passageway upon spatial orientation of the container, and a locking 
mechanism 32 located proximate one end 30 of the passageway and operable 
solely in response to the adjacent presence of the ball. The locking 
mechanism 32 includes a rod member 40 mounted in a surrounding tubular 
housing 41 affixed to the container 24. A first portion 42 of the rod 40 
extends laterally into the passageway 20 and a second portion 44 extends 
upwardly from the passageway through the housing 41, to a position of 
selective latching engagement, when the rod is in the locked position 
shown in the figure, with a cover plate 46 employed to close the top of 
the container 24. A hole 60 is formed proximate one corner of the cover 
plate 46 to receive the upper end 62 of the rod 40, and a flange 63, shown 
partially cut away in FIG. 1, serves to limit the upward movement of the 
rod and also to protect the rod from unauthorized manipulation. 
The rod 40 is biased in its upward locked position by a spring 50 connected 
in tension between the rod and the surrounding tubular housing 41. A 
washer 54 or other suitable platform element is attached to the portion 42 
of the rod 40 extending into the passageway 20 to facilitate the 
positioning thereon of the ball 26 when the ball has been moved to the end 
30 of the passageway. The upper surface of this washer 54 is maintained at 
or slightly below the lower surface 56 of the passageway 20, as shown in 
FIG. 3, to permit ready transfer of the ball 26 from the passageway to the 
washer. The spring constant of the bias spring 50 is matched to the weight 
of the ball 26 such that the pressure of the ball on the washer 54 will 
move the rod 40 to its lower or unlocked position, indicated by the dashed 
outline of the washer 54 in FIG. 3, thereby withdrawing the rod tip 62 
from the cover plate hole 60. When the ball 26 is at any other location 
within the passageway 20, the rod 40 will remain biased upwardly and, 
assuming the top plate is in its fully closed position, the container 24 
will remain locked. 
A groove 64 formed partway around the upper edge of the container 24 serves 
to retain the cover plate 46 in its closed position, while still 
permitting its ready removal when the container is unlocked. If desired, a 
stop member or other suitable means may be provided on the top plate 46 to 
prevent the complete removal of the top plate from the groove 64. 
Moreover, a side plate or end plate may be adapted for removal instead of 
the top plate. In either case, the removable plate may be hingedly rather 
than slidably mounted, and spring biased for automatic movement to an open 
position upon operation of the locking mechanism 32. 
To lock the container 24, the ball 26 is moved, by selective spatial 
orientation of the container 24, to a position atop the washer 54, thereby 
moving the rod 40 of the locking mechanism 32 to its unlocked position, 
and the top plate 46 is slid to its fully closed position. The ball 26 is 
then moved, by further spatial orientation of the container 24 from the 
washer 54 to an initial starting position 72 away from the locking 
mechanism 32. A step 74 formed in the passageway 20 by depressing a 
portion of the passageway floor 56 serves as a blocking means to prevent 
the ball 26 from returning to a position adjacent the locking mechanism 32 
without first negotiating the labyrinth in a forward direction as 
described more fully below. Other unilateral ball-retaining means, such as 
a movable flap or gate member, could be employed at the starting position 
72 as well. Once the ball 26 is moved from the washer 54, the rod 40 moves 
upwardly by the force of the bias spring 50 to a locked position with its 
tip 62 inserted into the top plate hole 60, thereby preventing the top 
plate from being moved toward its open position. 
To unlock the container, the ball 26 is moved, by renewed selective spatial 
orientation of the container, from its starting position 72 through the 
passageway 20 in a forward direction up ramp 73, as indicated by the 
arrows of FIG. 2, until returning to a position atop the washer 54. When 
the ball is again so positioned, its weight will overcome the force of the 
bias spring 50 and cause the rod 40 to move downwardly until the upper end 
62 of the rod has been withdrawn from the hole 60 in the cover plate 46, 
thereby unlocking the container. 
It is understood that ball sensing devices other than the extending portion 
42 of the rod 40 could be employed to operate the locking mechanism 32 
solely in response to the adjacent presence of the ball 26 without 
departing from the invention as disclosed. Moreover, as indicated earlier, 
other portions of the container 24, for example a side or end member, 
could serve as the opening member in place of the top plate. 
The terms and expressions which have been employed in the foregoing 
abstract and specification are used therein as terms of description and 
not of limitation, and there is no intention, in the use of such terms and 
expressions, of excluding equivalents of the features shown and described 
or portions thereof, it being recognized that the scope of the invention 
is defined and limited only by the claims which follow.