The subject invention relates to a quick release lock mechanism for securing objects on a cylindrical rod, and in particular, for securing weights on dumbbells,
Many devices utilize a cylindrical rod to carry one or more elements where it is necessary to secure the elements on the rod at selected locations. One such application is dumbbells where a plurality of weights placed on the opposite ends of a bar are held in place by locks that are affixed to the ends of the bar. These locks are continually being removed and reinstalled in order to change the weights carried on the bar and, thereby, increase or decrease the overall weight of the dumbbell.
Dumbbell locks typically use a set screw of some type to attach the lock to the bar. Set screws not only make it difficult to quickly change weights, if they are not properly tightened the lock may be forced off of the rod by the weights when the dumbbell is in use.
The subject invention overcomes the foregoing shortcomings and limitations of the prior art dumbbell locks by providing a torus-like case which has a cylindrical passageway extending through it that receives the rod the lock will be affixed to. Located in the case is one or more pistons which are moveable between an unlocked position where they are located completely in the case and a locked position where they project out of the case into the passageway. The rod has holes arranged to receive the pistons when they are in the locked position. These holes are placed at a number of desired locations along the length of the rod. An actuation mechanism located in the case facilitates movement of the pistons between their locked and unlocked positions.
In a preferred embodiment of the invention, a spring urges the pistons toward their locked positions and rotation of a pair of levers, that are pivotally mounted in the case, moves the pistons to their unlocked positions. The levers are rotated by pushing a plunger that extends through the case.
In the preferred embodiment, the pistons fit in bosses that are located in the case. The pistons and bosses have aligned slots which receive one end of the associated lever. Holes in the pistons extend through the slots and receive tabs located at the ends of the spring and to hold the ends of the lever in the slots in the pistons.
Accordingly, the lock can be quickly and easily removed and replaced to facilitate changing weights carried by the dumbbell.
The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.