Improvements relating to smoothing or finishing trowels

摘要

622,244. Vibrating screeds. CLIPSON, S. Oct. 4, 1946. No. 29628. [Class 86] [Also in Group XXIII] A portable smoothing trowel or screed has a blade 1 which is subject to vibration, for example, pneumatically, hydraulically, electromagnetically or mechanically. The blade 1 is mounted on a strap 2 secured to a vibrator to which are also attached a yoke 11 and handle 8. The vibrator described is of the plunger type, in which the plunger slides inside a cylinder 7, and compressed air, admitted through a port 13, reciprocates the plunger to repeatedly strike the cylinder head and vibrate the blade 1 which is secured to it. In the case of long smoothing trowels more than one vibrator may be attached. Specifications 614,582, [Group X], and 622,243 are referred to.