Powered screed and method of operating

Abstract

A lightweight, powered screed machine for screeding the surface of a quantity of concrete having a pair of rails extending to either side, includes a frame having a handle arrangement, for manual engagement by an operator, and an elongated screed blade extending between the support rails. The machine further includes a powered vibration mechanism mounted on the frame. A pair of posts or masts are provided with one of the pair of posts attached to the frame adjacent each end of the blade and extending upward. Each of a pair of supports is positioned adjacent an associated end of the blade. Each support has rollers for engaging and riding on one of the pair of support rails, and each of the supports is attached to the frame so as to support the frame over the concrete. Each of the supports includes a linear actuator for raising and lowering the frame adjacent the rail. A pair of laser receivers is provided with each of the pair of laser receivers mounted on an associated one of the pair of posts. A control controls the linear actuators such that the screed blade is maintained at a desired height as the screed blade is moved over the concrete.

1 . A lightweight, powered screed machine for screeding the surface of a quantity of concrete having a pair of rails extending to either side, comprising:
 a frame including a handle arrangement, for manual engagement by an operator, and an elongated screed blade extending between said support rails,   a powered vibration mechanism mounted on said frame,   a pair of posts, one of said pair of posts attached to said frame adjacent each end of said blade and extending upward,   a pair of supports, each of said pair of supports positioned adjacent an associated end of said blade, each support having rollers for engaging and riding on one of said pair of support rails, each of said supports attached to said frame so as to support said frame over said concrete, each of said supports including a linear actuator for raising and lowering said frame adjacent said rail,   a pair of laser receivers, each of said pair of laser receivers mounted on an associated one of said pair of posts, and   a control for controlling said linear actuators such that said screed blade is maintained at a desired height as said screed blade is moved over said concrete.   
     
     
         2 . A lightweight, powered screed machine for screeding the surface of a quantity of concrete according to  claim 1 , in which said powered vibration mechanism comprises a gasoline motor driving a rotating, off-center weight. 
     
     
         3 . A lightweight, powered screed machine for screeding the surface of a quantity of concrete according to  claim 1 , in which said powered vibration mechanism comprises an electric motor driving a rotating, off-center weight. 
     
     
         4 . A lightweight, powered screed machine for screeding the surface of a quantity of concrete according to  claim 1 , in which said control for controlling said linear actuators such that said screed blade is maintained at a desired height as said screed blade is moved over said concrete comprises a pair of control circuits, each control circuit controlling the linear actuator included in an associated one of said pair of supports. 
     
     
         5 . A lightweight, powered screed machine for screeding the surface of a quantity of concrete according to  claim 4 , in which each of said pair of control circuits is mounted on an associated one of said pair of posts. 
     
     
         6 . A lightweight, powered screed machine for screeding the surface of a quantity of concrete according to  claim 1 , further comprising a pair of displays, each of said pair of displays mounted on an associated one of said pair of supports, said displays being responsive to said control and to said laser receivers for providing a display of the operation of the screed machine. 
     
     
         7 . A lightweight, powered screed machine for screeding the surface of a quantity of concrete according to  claim 1 , in which said linear actuator in each of said pair of supports comprises an electric motor for raising and lowering said frame. 
     
     
         8 . A lightweight, powered screed machine for screeding the surface of a quantity of concrete according to  claim 1 , in which each of said pair of laser receivers includes an adjustable mount for attachment to an associated one of said pair of posts at a desired height for reception of a beam of laser light. 
     
     
         9 . A lightweight, powered screed machine for screeding the surface of a quantity of concrete according to  claim 1 , further comprising a laser transmitter for projecting a reference beam of laser light to said pair of laser receivers. 
     
     
         10 . A lightweight, powered screed machine for screeding the surface of a quantity of concrete having a pair of rails extending to either side, comprising:
 a frame including a handle arrangement, for manual engagement by an operator, and an elongated screed blade extending between said support rails,   a powered vibration mechanism mounted on said frame,   a pair of masts, one of said pair of masts attached to said frame adjacent each end of said blade and extending upward,   a pair of supports, each of said pair of supports positioned adjacent an associated end of said blade, each support configured to engage and ride on one of said pair of support rails, each of said supports attached to said frame so as to support said frame over said concrete, each of said supports including an electric motor for raising and lowering said frame adjacent said rail,   a pair of laser receivers, each of said pair of laser receivers mounted on an associated one of said pair of masts,   a pair of control circuits, one of said pair of control circuits mounted on each of said pair of masts, for controlling said electric motor of the support attached to the frame at the associated end of said blade, such that said screed blade is maintained at a desired height as said screed blade is moved over said concrete, and   a laser transmitter for projecting a reference beam of laser light for reception by said pair of laser receivers.   
     
     
         11 . The lightweight, powered screed machine of  claim 10 , in which said laser transmitter projects a substantially horizontal beam of laser light that rotates about a substantially vertical axis to define a generally horizontal reference plane of laser light. 
     
     
         12 . The lightweight, powered screed machine of  claim 10 , in which said powered vibration mechanism comprises a gasoline motor driving a rotating, off-center weight. 
     
     
         13 . The lightweight, powered screed machine of  claim 10 , in which said powered vibration mechanism comprises an electric motor driving a rotating, off-center weight. 
     
     
         14 . The lightweight, powered screed machine of  claim 10 , in which each of said pair of control circuits operates independently of the other of said pair of control circuits. 
     
     
         15 . The lightweight, powered screed machine of  claim 14 , in which each of said pair of control circuits is mounted on an associated one of said pair of masts. 
     
     
         16 . The lightweight, powered screed machine of  claim 10 , further comprising a pair of displays, each of said pair of displays mounted on an associated one of said pair of supports, said displays being responsive to the control circuit mounted on the associated mast and to the laser receiver mounted on the associated mast for providing a display of the operation of the screed machine. 
     
     
         17 . The lightweight, powered screed machine of  claim 10 , in which each of said pair of laser receivers includes an adjustable mount for attachment to an associated one of said pair of masts at a desired height for reception of a beam of laser light. 
     
     
         18 . A method of operating a powered screed of the type having a frame including a handle arrangement for manual engagement by an operator, and an elongated screed blade extending between said support rails, and a powered vibration mechanism mounted on said frame, and in which a pair of rails extends to either side a quantity of concrete, comprising the steps of:
 providing a pair of masts attached to the frame adjacent each end of the blade and extending upward,   providing a pair of supports at each end of the blade for riding on the support rails, each support attached to the frame and including a linear actuator for raising and lowering the frame and blade over the concrete,   providing a pair of laser receivers, each such receiver mounted on one of the pair of masts,   projecting a beam of laser light for reception by said pair of laser receivers,   maintaining said screed blade at a desired height as said blade is moved manually over the surface of the concrete by operating said linear actuator in each of said pair of supports.   
     
     
         19 . The method of  claim 18  in which said step of maintaining said screed blade at a desired height includes the step of operating said linear actuator to move said screed blade in dependence upon the relative height of the laser light which is received by said laser receivers. 
     
     
         20 . The method of  claim 18  in which said step of providing a pair of supports at each end of the blade for riding on the support rails, each support attached to the frame and including a linear actuator for raising and lowering the frame and blade over the concrete includes the step of providing a pair of supports at each end of the blade for riding on the support rails, each support attached to the frame and including an electric motor for raising and lowering the frame and blade over the concrete. 
     
     
         21 . A lightweight, powered screed machine for screeding the surface of a quantity of concrete having at least one rail adjacent the quantity of concrete, comprising:
 a frame including a handle arrangement, for manual engagement by an operator, and an elongated screed blade extending between said support rails,   a powered vibration mechanism mounted on said frame,   at least one post attached to said frame adjacent an end of said blade and extending upward,   at least one support positioned adjacent an associated end of said blade, said support having rollers for engaging and riding on said at least one rail, said support attached to said frame so as to support said frame over said concrete, said support including a linear actuator for raising and lowering said frame adjacent said rail,   at least one laser receiver, said laser receiver mounted on said at least one post, and   a control for controlling said linear actuator such that said screed blade is maintained at a desired height as said screed blade is moved over said concrete.   
     
     
         22 . A lightweight, powered screed machine for screeding the surface of a quantity of concrete according to  claim 21 , in which said control for controlling said linear actuator such that said screed blade is maintained at a desired height as said screed blade is moved over said concrete comprises a control circuit, said control circuit controlling said linear actuator included said support. 
     
     
         23 . A lightweight, powered screed machine for screeding the surface of a quantity of concrete according to  claim 22 , in which said control circuit is mounted on said post. 
     
     
         24 . A lightweight, powered screed machine for screeding the surface of a quantity of concrete according to  claim 21 , in which said linear actuator comprises an electric motor for raising and lowering said frame. 
     
     
         25 . A lightweight, powered screed machine for screeding the surface of a quantity of concrete according to  claim 21 , further comprising a laser transmitter for projecting a reference beam of laser light to said laser receiver. 
     
     
         26 . A lightweight, powered screed machine for screeding the surface of a quantity of concrete having a pair of rails extending to either side, comprising:
 a frame including a handle arrangement, for manual engagement by an operator, and an elongated screed blade extending between said support rails,   a powered vibration mechanism mounted on said frame,   a pair of masts, one of said pair of masts attached to said frame adjacent each end of said blade and extending upward,   a pair of supports, each of said pair of supports positioned adjacent an associated end of said blade, each support configured to engage and ride on one of said pair of support rails, each of said supports attached to said frame so as to support said frame over said concrete, each of said supports including an electric motor for raising and lowering said frame adjacent said rail,   a pair of laser receivers, each of said pair of laser receivers mounted on an associated one of said pair of masts,   a pair of control circuits, one of said pair of control circuits mounted on each of said pair of masts, for controlling said electric motor of the support attached to the frame at the associated end of said blade, such that said screed blade is maintained at a desired height as said screed blade is moved over said concrete,   a laser transmitter for projecting a reference beam of laser light for reception by said pair of laser receivers,   a third mast, said third mast being adjacent to one of said pair of masts attached to said frame,   a third support, positioned adjacent an associated end of said blade and one of said pair of supports, said third support configured to engage and ride on one of said pair of support rails, said third support attached to said one of said pair of supports, said third support including an electric motor for changing the pitch angle of the screed as said third support is raised and lowered on said rail,   a third laser receiver mounted on said third mast, and   a third control circuit mounted on said third mast for controlling said electric motor of the third support such that said screed blade is maintained at a desired pitch as the blade is moved over said concrete.   
     
     
         27 . The lightweight, powered screed machine of  claim 26 , in which said laser transmitter projects a substantially horizontal beam of laser light that rotates about a substantially vertical axis to define a generally horizontal reference plane of laser light.