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Publication numberUS2514626 A
Publication typeGrant
Publication dateJul 11, 1950
Filing dateSep 22, 1947
Priority dateOct 4, 1946
Publication numberUS 2514626 A, US 2514626A, US-A-2514626, US2514626 A, US2514626A
InventorsSamuel Clipson
Original AssigneeSamuel Clipson
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Smoothing or finishing trowel
US 2514626 A
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Description  (OCR text may contain errors)

y July 11195 S--fCI-'iPSON- `-'.2`;,51'4,626


Filed sept. 22, 1947 1 Inventor By.V

Patented July 11, 1950 2,514,626 SMOOTHING OR FINISHING TROWEL Samuel Clipson, London, England Application September 22, 1947, Serial No. 775,556 In Great Britain October 4, 1946 3 Claims.

This invention relates to hand trowels or screeds, particularly for use in finishing or smoothing the surfaces of slurries applied to walls, ceilings and the like.

I h'ave found that with certain so-called wallsurfacing compositions, a better finish is obtained by subjecting the hand screed when in use to a rapid vibratory motion.

Accordingly, the invention provides, as a new article of manufacture, a hand screed incorporating pressure fluid operated means whereby it can be subjected to transverse vibration while being manipulated over the surface to be finished or smoothed.

Preferably, the said pressure uid operated means comprises a plunger-type vibrator fixed on the blade of the screed, the plunger of the vibrator working in a cylinder suitably ported for the supply of motive fluid and for the exhaust of the expanded fluid as required to set up rapid vibration by repeated impact of the plunger against the ends of the cylinder.

The screed proper may be of any desired size and cross-sectional shape (fiat, arcuate and so forth).

One form of vibrating hand screed is illustrated on the accompanying drawing, on which:

Fig. 1 is a face view of the screed;

Fig. 2 is a corresponding end view; and

Fig. 3 shows the vibrator in longitudinal section on line III-III of Fig. 2.

The screed blade I is secured to a bent metal strap 2 by a bolt 3 and nut 4, and the strap is secured by a bolt 5 and nut 6 to the cylinder 1 of a. plunger type vibrator. An elongated handle 8 for holding and manipulating the screed is secured by bolts 9 and nuts I0 to a yoke I I which is also secured to the vibrator cylinder 1 by means of the bolt 5 and nut 6.

As shown in Fig. 3 the barrel of the vibrator cylinder 1 is stepped as also is the plunger I2` therein. A connection I3 for pressure air opens into the part of the barrel of larger diameter. Further, this part of the barrel has a series of exhaust ports I4, while the part of smaller diameter has a series oi.' exhaust ports I5. The plunger I2 Ihas an axial passage I6 open to its larger end and communicating with radial ports I'I opening to the periphery oi.' its smaller part.

When pressure iluid is admitted via I3 it first moves the plunger to the left in Fig. 3, air in the larger part of the barrel then exhausting via ports I4. As the plunger reaches the end of this stroke these ports are closed and pressure air passes via ports I1 and passage I6 to the larger end of the plunger to return the plunger. During the return stroke air in advance of the plunger is exhausted via ports I5. Thus, the plunger is rapidly reciprocated so long as pressure air is supplied to the connection I3.

This rapid reciprocation of the plunger I2 vibrates the cylinder 1 and therefore the screed so that the working surface Ia of blade I is subjected to a tamping action whilst it is manipulated over the surface to be smoothed or finished. This movement produces coacting cornponents of forces that are effective in establishing both an impacting action and a smoothing action through the trowel blade on the surface being treated.

Reference 'is made to my copendng patent application Serial Number 775,555, filed September 22, 1947 for Compositions for Surfacing Walls, Ceilings and the Like, for an explanation of the compositions with which the smoothing or iinishing trowel of my invention is employed. Reference is also made to my copending application Serial Number 6,233 led February 4, 1948 and patented as Patent No. 2,504,805, for Method and Apparatus for Applying Slurries to Structural Surfaces, for information regarding the appli cator and method of employing the same.

I claim:

l. A hand screedl for use in finishing the surface of slurries applied to structural surfaces comprising in combination a cylinder, a bracket having an angularly inturned portion attached at one end to said cylinder, an elongated trowel blade secured to the inturned portion of said bracket, a working surface on said trowel blade, a handle secured to the side of said cylinder opposite said bracket, a reciprocating piston in said cylinder, and means for rapidly reciprocating said piston whereby rapid Vibratory pulses are transmitted to said trowel blade in the direction of movement of the piston and with a component normal to the working surface of the trowel blade.

2. A hand screed as set forth in claim 1 in which said handle is secured to the side of said cylinder through a yoke that extends at an angle with respect to the axis of said housing.

3. A hand screed as set forth in claim 1 in which said handle is constituted by a transversely extending bar projecting substantially parallel to the axis of said trowel blade.


REFERENCES CITED The following references are of record in the le of this patent:


Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1955101 *Apr 7, 1932Apr 17, 1934Sloan Francis PApparatus for compacting concrete or similar surfaces
US2015899 *Dec 12, 1927Oct 1, 1935Corwill JacksonTamping machine
US2239785 *Apr 29, 1940Apr 29, 1941 Tamping and like implement
AT145056B * Title not available
GB435590A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2617336 *Sep 17, 1948Nov 11, 1952Brickler Andrew RMechanical edging and grooving tool
US3376798 *Jul 14, 1965Apr 9, 1968Albert G. BodineSonic trowel
US4431336 *Feb 8, 1982Feb 14, 1984Nightengale Stanley AConcrete prefinishing tool
US4653957 *Jun 21, 1985Mar 31, 1987Smith Wallis WAir driven vibration cement float
US5234283 *Jan 23, 1992Aug 10, 1993Adkins Arthur DVibratory concrete float apparatus
US5837298 *Oct 15, 1997Nov 17, 1998Face International Corp.Piezoelectrically-actuated vibrating surface-finishing tool
U.S. Classification404/113, 15/235.4
International ClassificationE04F21/08, E04F21/02
Cooperative ClassificationE04F21/08
European ClassificationE04F21/08