Barbell Having Decreased Destabilizing Forces And Method For Making Same

Abstract

A adjustable barbell producing decreased destabilizing forces during the lifting movement, and a method for making same, includes a bar having a pair of longitudinally-separated inner collars weighing no less than approximately 30 lbs, a pair of sleeves mounted for rotation about the longitudinal axis of the bar and sized to accommodate the through-holes of removable weight plates mounted on said sleeves, each sleeve being positioned longitudinally outward of a respective one of said collars, the collars thereby decreasing the stress on the bar and the moment of inertia of the weight being lifted.

Description

BACKGROUND OF THE INVENTION[0001]1. Field Of The Invention[0002]This invention relates to barbells.[0003]2. Background Art[0004]A barbell is a piece of exercise equipment used in weight training, weightlifting and power lifting. Barbells typically have a generally longitudinally-extending bar that is between 4 feet (1.2 m) and 7 feet (2.1 m) long, with a diameter of approximately one inch (2.54 cm). The bar is often engraved in its central region with a knurled pattern where it is to be gripped by the user.[0005]There are two fundamental types of barbells: the “fixed weight” type, wherein the weight plates are permanently secured on the ends of a bar, and the “adjustable” type, wherein weight plates at each end region are secured on the bar between a inner affixed collar and an outer removable collar to permit the user to add or remove individual weight plates to the bar. This invention pertains to adjustable barbells.[0006]Adjustable barbells comprise a generally longitudinally-ext...

AI Technical Summary

Benefits of technology

[0009]To reduce the destabilizing forces generated on the bar by the weight plates, the inner collar associated with the barbell is increased in weight. Because the inner collar is relatively close to the user's hand during the movement, the moment arm associated with the weight is substantially less than the moment arm that would be associated with an equal weight at a relatively longitudinally-outer position. The decreased moment arm reduces the destabilizing force attributable to that weight, resulting in a more controllable barbell at a given poundage.

[0011]The MOI associated with a given mass increases with the square of its distance from the axis of rotation. Thus, a weight plate at the end of the bar has significantly more MOI than the same weight plate near the mass' center of rotation during the lifting movement. The stress imposed on the bar by a weight plate increases linearly with its distance from the fulcrum. Accordingly, destabilizing forces and bar stresses are reduced when the inner collars associated with the barbell are increased in weight in lieu of the same weight being positioned at the longitudinally-outmost positions.

[0012]Preferably, the weight of the innermost collar is increased beyond conventional collars sufficiently so that the bar and inner collars weigh a total of approximately 80 lbs or more.

Problems solved by technology

As the barbell reaches the end of the movement, the barbell approaches zero velocity, but the inertia of the weight plates causes them to resist deceleration, resulting in a bending of the bar upward.

In addition, the lifter likely has a dominant side—be it left or right—that results in uneven forces being applied to the left and right sides of the barbell.

All of this creates a complex combination of destabilizing forces that can make the bar difficult to control.

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