초록 ▼

The power trowel of this invention has a chassis comprising a gear box and a prime mover and has a plurality of blades which engage a surface to be finished and which are driven by the prime mover, through the gear box, for substantially edgewise rotation about a vertical axis. An elongated handle f

The power trowel of this invention has a chassis comprising a gear box and a prime mover and has a plurality of blades which engage a surface to be finished and which are driven by the prime mover, through the gear box, for substantially edgewise rotation about a vertical axis. An elongated handle for controlling movements of the machine across the surface has a pivotal connection to the chassis to be swingable up and down, but has an upper limit of such motion from which it is swingable downwardly. An elastically compressible shock absorber, confined between the handle and the chassis under compressive preload, tends to maintain the handle at that limit and is further compressed by downward force on the rear end of the handle. The center of gravity of the chassis is spaced forward of the vertical axis. Control of machine movements is minimally influenced by machine vibration, and is therefore more precise and less fatiguing.

대표청구항 ▼

A power trowel for concrete finishing, comprising a chassis having a gear box and a prime mover, a plurality of blades which support the entire weight of the chassis by their engagement with a surface to be finished and which are driven by the prime mover through the gear box for substantially edgew

A power trowel for concrete finishing, comprising a chassis having a gear box and a prime mover, a plurality of blades which support the entire weight of the chassis by their engagement with a surface to be finished and which are driven by the prime mover through the gear box for substantially edgewise rotation about a vertical axis which is in fixed relation to the chassis, and an elongated handle that normally projects obliquely upward and rearward from the chassis and provides for control of the blades, said power trowel being characterized by: A. said gear box and said prime mover being arranged to dispose the center of gravity of the chassis in forwardly spaced relation to said vertical axis; B. cooperating connection means on the chassis and on the handle defining a horizontal pivot axis about which the handle is swingable up and down relative to the chassis and which is spaced behind said vertical axis; C. rigid means fixed on the chassis and on the handle, respectively, defining opposing force transmitting surfaces, (1) said force transmitting surface on the handle facing substantially upward and being in forwardly spaced relation to said pivot axis, and (2) said force transmitting surface on the chassis facing substantially downward; D. a resiliently compressible shock absorber fixed on one of said force transmitting surfaces to be compressively engaged by the other one; and E. cooperating abutment means on the chassis and on the handle, spaced from said pivot axis, arranged to define a limit of upward movement of the rear end of the handle relative to the chassis at which said shock absorber is under compressive preload but to permit downward movement of the rear end of the handle from said limit whereby compressive force on the shock absorber is increased.