1. Field of the Invention
The subject invention relates to a brake and wheel assembly for a manually operated cart, wagon, or the like, used to move heavy articles across a floor or other surface.
2. Description of the Related Art
Various devices exist in the art for applying a brake against a wheel to impede or arrest rotational movement of the wheel relative to the axle upon which the wheel is mounted. Such devices typically include a brake band having one end mounted on a wheel support adjacent the wheel. The other end of the brake band is moved by the actuator between a single brake-applying position in which the brake band engages the wheel to frictionally resist movement of the wheel, and an unlocked position in which the actuator releases the brake band so that it moves away from the wheel, which in turn allows the wheel to rotate freely about the axle.
Although prior wheel and brake assemblies have been successfully used on manually-operated carts, no brake and wheel assembly exists that is easy to operate and is specifically intended for use on low-profile carts upon which heavy machinery is permanently carried. Such carts are used to move heavy, cumbersome power tools or machines that would otherwise remain in a stationary position on a floor in a shop during use. In those shops in which floor space is limited, each machine is placed on one of the carts and remains there regardless of whether the machine is in storage or in use. The low profile of the cart permits the machine to be easily accessed for use; however, because the machine remains on the cart during use, sudden movement of the cart may compromise efficient operation of the machine.
Low profile carts need effective braking systems to keep the carts from inadvertently moving. While certain prior brake assemblies successfully prevent a wheel from rotating, such assemblies are ill-suited for use on low-profile or other carts because the assembly must be manipulated by hand or foot to force a lever or turn a threaded shaft to ensure that a brake-applying surface engages one of the cart""s wheels to prevent the cart from moving. An example of one such brake assembly is disclosed in U.S. Pat. No. 4,035,864 (xe2x80x9cSchrxc3x6derxe2x80x9d). The Schrxc3x6eder brake assembly features a foot-operated control lever with an expanding toggle pivotally mounted in a socket of a spring-loaded locking rocker. Although the Schrxc3x6eder brake assembly can be effectively used to decelerate a moving wheel, the locking rocker used in the device has only one surface capable of engaging the tire of a running wheel, and that surface is placed in only one brake-applying position to decelerate movement of the wheel. Furthermore, because the locking rocker is completely enclosed within the cavity of a caster fork, no reliable visual indicia are in place to effectively indicate whether the control lever has successfully moved the locking rocker between the single brake-applying position and a released position away from the wheel.
Prior brake and wheel assemblies are incapable of being placed in more than one brake-applying position, and lack adequate means for determining with any degree of specificity whether the brake utilized in the assembly is actually in that brake-applying position. Thus, there remains an opportunity for a brake and wheel assembly featuring multiple brake surfaces capable of being placed in a plurality of brake-applying positions.
The invention provides a brake and a wheel assembly, wherein a wheel is rotatably supported on an axle and a brake band is supported tangentially across the wheel. An actuator is movably supported for movement between first and second brake-applying positions to engage the brake band with the wheel in either of the first or second brake-applying positions.
Accordingly, the subject invention overcomes the limitations of the related art by providing a brake and wheel assembly featuring a brake band that is capable of being moved between first and second braking positions. This is achieved by suspending the brake band tangentially across the surface of a wheel and using a pivotally mounted actuator to apply a tangential force on the brake band so that first and second braking surfaces on the brake band frictionally engage the actuator in the respective first and second braking positions.
USPTO Backgrounds
USPTO Backgrounds