Patent Application
20120204367
The present invention relates generally to vacuum cleaners, and, more specifically, to a shaft driven vacuum cleaner brushroll that can be mounted in the nozzle of the cleaner in direct connection to its motor drive.
Prior art vacuum cleaner brushrolls typically have bearing end assemblies that support the brushrolls for rotation in the vacuum cleaner nozzle. The brushrolls are driven by pulley belts tied to the motor drive systems of the cleaners. When a pulley driven brushroll is replaced, it is necessary to disengage the belt, replace the old brushroll with a new one, and re-engage the pulley belt in the proper place. The pulley belts themselves require periodic replacement.
In an effort to avoid the problems and disadvantages of pulley drive arrangements, a construction has been devised for directly connecting the brushroll to the motor drive shaft system of the vacuum cleaner. A known shaft driven brushroll comprises a hollow plastic spindle having internal, integral ribs, and a one-piece, injection-molded drive member that coacts with the ribs of the spindle to transmit torque from the driver shaft system to the spindle. Since the described arrangement requires a spindle having internal ribs, the spindle must be a plastic member that can be extruded or injection molded. Wood spindles, which have many advantages, cannot be used. Another disadvantage is that one-piece plastic drive member that transmits torque from the vacuum cleaner drive has a complex configuration that must be injection molded using an intricate mold.
An object of the invention is to provide an improved shaft driven vacuum cleaner brushroll that can be mounted in the nozzle of the vacuum cleaner and directly connected to a shaft of the motor driven shaft system of the vacuum cleaner. The term motor drive shaft system means one or more shafts driven by the motor. The invention features a two-piece spindle drive assembly at one end of the spindle. The drive assembly consists of a ferrule secured to the end of the spindle and a drive pin inserted through the ferrule into the spindle end. The ferrule and drive pin are assembled together as a unit to effectively transmit torque from the motor drive shaft system of the vacuum cleaner to the brushroll.
In the disclosed embodiment, the ferrule member has a skirt that is fitted around the brushroll spindle and an inner neck that seats in a recess formed in the end of the spindle. The end of the spindle is captured between the ferrule skirt and its neck portion. The drive pin has a shaft section inserted through the ferrule into the spindle and a head section having a quick connect-disconnect permitting easy attachment of the brushroll to a shaft of the motor drive shaft system of the cleaner. Cooperating locking surfaces on the ferrule neck and drive pin securely lock the two parts together so that they function as a unit.
The above-described construction has a number of features and advantages. The ferrule and drive pin can be made separately and then assembled simply by inserting the drive pin into the ferrule. The ferrule is locked on the end of the spindle by capturing the spindle end between the ferrule skirt and neck, and by extending the end bristles of the brushroll through the ferrule skirt. Another important advantage is that the ferrule and drive pin assembly can be used in conjunction with a wood spindle. As described above, the prior art shaft driven brushroll can be used only in conjunction with a plastic spindle having internally formed ribs.
Referring to the drawings, the illustrated brushroll is generally indicated by reference number 10. The brushroll consists of a wood spindle 11 having helical rows of bristle tufts 12, a drive assembly 13 that embodies the invention at one end of the brushroll, and an end assembly 14 at the other end of the brushroll. The end assembly 14, which is not part of the invention, rotatably supports the brushroll in the nozzle (not shown) of a vacuum cleaner. As disclosed in U.S. Pat. Nos. 5,272,785 and 6,591,440, the end assembly 14 may include a stub shaft extending from the end of the spindle and a bearing having its inner race press fitted on the stub shaft and its outer race fixed in an end cap that mounts in the vacuum cleaner nozzle.
As shown in
The drive pin 21, which is shown most clearly in
The effective transmission of torque to rotate the brushroll is accomplished by combination of the above-described features of construction, namely, the skirted ferrule 20 that fits around the end of the spindle to capture the spindle end between the skirt and the spindle neck, and the cam surfaces 30, 37 that effectively lock the drive pin 21 in the ferrule. The two-piece construction of the ferrule and the drive pin 21 can be fitted in the end of a wood spindle, as distinguished from the prior art assembly involving a one-piece drive element that coacts with ribs on the inside of a plastic spindle. At the same time, the ferrule and drive pin can be separately made without the complex die construction required to make the plastic one-piece drive element of the prior art.
Other features and advantages of the invention will be apparent to those skilled in the art. Therefore, it is to be understood that, within the scope of the appended claims, the invention can be practiced otherwise than as specifically shown and described.
