Concrete vibrator with offset rotor

A lightweight, portable concrete vibrator comprising:

• a vibrator head including a hollow casing and eccentric rotor mounted at its ends therein for rotation;
• a drive shaft for imparting rotary motion to the rotor along a center axis of rotation;
• a motor for driving said shaft to cause vibration of the head upon rotation of the rotor;
• and
• said rotor having an integral curved segment between said ends disposed only along one side of the center axis of rotation, said curved segment extending in an arc of less than 180.degree., the rotor centroid being offset except for said ends from the center axis of rotation and positioned between the center axis of rotation and the outer face of said curved segment, an integral stiffening segment extends along the other side of said rotor to further resist lateral flexing of said rotor in said casing, said stiffening segment having an outer surface that is substantially V-shaped and inverted along said other side, the apex of the V being positioned adjacent the center axis of rotation and the distal ends of the V-shaped segment being integrally connected adjacent the ends of the curved segment,
• whereby the offset of said rotor and said centroid of said rotor except for said ends provides maximum vibration to distribute the aggregate and fill voids in wet concrete, while maintaining sufficient rotor strength to resist lateral flexing of the rotor in the casing.

A lightweight, portable concrete vibrator comprising:

• a vibrator head including a hollow casing and eccentric rotor mounted at its ends therein for rotation;
• a drive shaft for imparting rotary motion to the rotor along a center axis of rotation;
• a motor for driving said shaft to cause vibration of the head upon rotation of the rotor;
• and
• said rotor having an integral curved segment between said ends disposed only along one side of the center axis of rotation, said curved segment extending in an arc of less than 180.degree., the rotor centroid being offset except for said ends from the center axis of rotation and positioned between the center axis of rotation and the outer face of said curved segment, said casing and rotor being elongated and a first bearing is provided adjacent the first end of the rotor connected to said drive shaft and a second bearing adjacent the second end of the rotor spaced from said first end for support of said rotor in the casing;
• a bearing sleeve in said casing adjacent said second end for engagement by said curved segment upon any incidental lateral deflection of said rotor,
• whereby the offset of said centroid of said rotor except for said ends provides maximum vibration to distribute the aggregate and fill voids in wet concrete, while maintaining sufficient rotor strength to resist lateral flexing of the rotor in the casing.

A vibrator head comprising an eccentric rotor mounted for rotation;

• a casing and a shaft in said casing for mounting said rotor at at least one end;
• said rotor having an integral curved segment between said at least one end and an opposite end disposed only along one side of the center axis of rotation, said curved segment extending in an arc of less than 180.degree., the rotor centroid being offset except for said at least one end from the center axis of rotation and positioned between the center axis of rotation and the outer face of said curved segment,
• an integral stiffening segment extends along the other side of said rotor to further resist lateral flexing of said rotor;
• and
• said stiffening segment having an outer surface that is substantially V-shaped and inverted along said other side, the apex of the V being positioned adjacent the center axis of rotation and the distal ends of the V-shaped segment being integrally connected adjacent the ends of the curved segment,
• whereby the offset of said rotor and said centroid of said rotor except for said at least one end provides maximum vibration to distribute the aggregate and fill voids in wet concrete, while maintaining sufficient rotor strength to resist lateral flexing of the rotor in the case.