US2198929A

US2198929A - Cement floor finisher

Info

Publication number: US2198929A
Application number: US271527A
Authority: US
Inventors: Whiteman Marvin Edwin
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-05-03
Filing date: 1939-05-03
Publication date: 1940-04-30
Anticipated expiration: 1957-04-30

Description

@man 'n.603 vrnrsnmg Filed lay 3. `19:59

...U-.- n n v af j; i-V AMT?! Patented Apr. 30', 1940 e l y .i

artsen:

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'rms invention 'relates tdaf machine. for fari.-

`and the like.

ishing or surfacingcement floors.;pavements,

Vventin: An object of the invention `is to provide a ma'- chine whichv will surface cement byV machine trowelling. The surfacing vof cement doors, pave-j ments, and the like heretcfcre has been gen-'- erally done vily-hand whereinthe vvfinisher` surfaces the -cement by` manipulating va' finishing trowel thereover. During suchvmanipulation the vnishing trowel is slightly tilted inthe direction of its movement and asv itl passes `over the cement, applies or 'forms thesrnooth finished surface. It has heretofore-been proposed to supplant this hand labor with a machine capable of applying orv frming this finished surface. However, machines heretofore devised have generally proven unsuccessful because of the inability to form the desired smooth surface. This is mainly due tothe fact that the machinedriven trowels in such machines are incapable of lbeing tilted with respect to thel surface of the cement or if given a tiltwith respect to such cement the degree of tilt of the trowels vcannot 25. be varied while the machine is in operation.

During the finishing operation with the trowel there is a tendency for the water content of the cement te work toward the surface. Thus, tcward the end of the flnishing'operation there is 30 usually more water content on the surface than at the` start of the finishing operation. This increase of water content in the cement as the finishing operationprogresses requires that the tilt of the trowel relative to the surface be slightly varied.

- It is an object of the present invention to provide a cement .floor flnisher'wherein there are a plurality of motor-driven trowels that are caused to pass over the surface of the cement licor to produce the finished surface, and wherein the trowels are tiltably mounted 'so that they may impart the dsired smooth surface to the cement.

'More specifically, an object of the invention is to provide a cement floor finisher having tiltable trowels so designed and arranged that the tilting may be adjusted or varied easily and while the machine is in operation. Thus, as the finishing operation proceeds' and the water content 50 in the cement works its way toward the surface, the trowels may be easily and quickly adjusted to accommodate themselves to the changing condition orconsistency of the cement being-nnished.

.-With the foregoing and other objects in view, which will be made manifest in the following detailed descriptionv and specifically vpointed out .in the appended claims, referencel is had vte the accompanying drawing for an' illustrativel embodiment of the'invention, wherein:

Figure i-l is a' top planfview of the-'preferred form er sement :door funnierenflamme the in- Fig. 211s a -view insideele'vation of the same `aud-may be considered as having been taken in s,

.thedirection of the arrows 2 upon Fig. 1; 3 is a sectional view taken substantially upon the line 3-3. uponFlg. 1;

Fig. 4 is aview in front elevation of the cement v floor finisher; and Y Fig. 5 is al partial view in vertical section of the upper end of the handle. Referring to the accompanying drawing wherein similar reference characters deslgnate'similar partsV throughout, the improved cement floor finisher comprises a suitable gear case I0 on `which is mounted a suitable source of power such as anelectric motor I'I'supplied with electric current through conductors I2. An electric switch I3 is mounted on the handle IA which is Lattached to the gear case and this switch is preferably'located near the upper end of the handle for convenience in turning on or shutting off motor II.

vWithin the gear case I have shown a.worm I5 which is driven by ymeans of a belt I6 off the motor. The worm meshes with a worm wheel I1 on a vertical shaft I8. The lower end of the shaft Il extends into a socket I9 which is pinned thereon as by pin 20. IOn the lower end of 'a socket there is a circular plate 2I attached to the'socket as by a pin 22. The plate 2I provides three equally spaced bearings 23.

In the above-described construction the shaft I8 and the socket I9 together may be considered .as a vertical motor driven shaft driven by motor II. While a worm wheel is preferably employed so as to secure a speed reduction it will be appreciated that any other suitable 'type of driving' connection between motor II and the vertical shaft may be substituted therefor if found desirable.

A ring 24 is arranged concentrically around' the plate 2i. This ring has three pins 25 thereon extending radially inward and which are equally spaced from each other. -Three trowels 26 are equally spaced from each other and are radially arranged between plate 2I and ring 2d. On thebacks of these trowels there are attached outer bearings 21 which receive the pins 25 andv inner bearing pins 23 which extend into bearings 23.. Arms 29 are pinned on the inner ends 'of the pins 28. These arms act as cranks capable of turning or tilting the trowels 26 about their radial axes. The upper ends of the arms are equipped with small adjusting screws A39 engageable with the under surface or face of a thrustcollar 3| fitting around socket I9.

' A lever .32is pivotaly mounted as at 33 on the form a shifting yoke or fork. 'I'he ends of lever 32 may be equipped with rollers 34 bearing on the upper surface or face of the thrust collar. The outer end of the lever 32 has a Vcable 35 attached thereto which is trained up through the hollow handle Il where the cable is connected to a nut 36. A screw 3'I extends into the nutA through a slot 38 in the handle so that the nut is slidably keyed in the handle. A knob 33 carrying a threaded stem 46 is mounted on the end of the handle Il with the threaded stem Il threaded into nut 36.

The operation and advantages of the iinproved cement finisher are as follows. On closing switch I3 themotor Il is energized to drive the vertical rotary shaft. The 4vertical rotary shaft causes the carrier plate 2| to rotate and the trowels 26 are thus-rotated about the vertical shaft as a center.

36 and causes lever 32 to have its outer end lifted. This forces the thrust collar 3l downwardly and causes the arms 29 on the inner ends of the trowels to be simultaneously swung` downwardly. The trowels are thus simultaneously tilted. The troweisare held -in tilted or adjusted positions as long as knob 39 remains in adjusted position. The tilting action vmay -take place at any time while the` machine is in iioor that is to be finished the machine can of course be pushed or pulled by means of the handle. I find, however, it can also bereadily moved' in a sidewise manner byeither lifting slightly or pushing'downwardly on the handle. Thus, if the trowels shown in rFig.1 are driven by the motorin a clockwise direction lifting on the lhandle I4 will be effective to cause the machine to work itself toward the left. Conversely, if the handle I 4 is pressed downwardly slightly, the tendency is for the machine to work itself toward the right. In this manner by either pushing or pulling on the handle r slightly elevating it or depressing it the machine will cause itself to progress inthe direction desired across the cement floor that is being finished.

` From the above-described construction it will be appreciated that the improved cement'nisher will successfully supplant hand finishing of cement floors. The trowels of the machine can be tilted and adjusted at any time during the operation to produce the desired fioating and finished surface. While 'the vvnumber of trowels shown is three and this number is preferred, it will be understood that the number oftrowels employed may vary and where desiredv the number of trowels may be .either decreased or increased. As each arm 29 is equipped with its own adjusting screw for engagement with the thrust collar 3| thetrowels may be accurately scope of the invention as defined by the appended claims.

v'Iilting of the trowels isl accomplished by turning knob 39 which. retracts nut I claim: 1. A cementfloor finisher comprising a plurality of trowels, means for rotating the' trowels over the trowels about their longitudinal axes" during rotation and `holding-them in their tilted positions. l

2. A cement fioor finisher comprising a pluralu ity of trowelarmeans for rotating the trowels, said trowels being tiltably mounted, and means for adjusting the tilt ofthe trowels during rotation and holdingthetrowels in tilted positions.

3.'A cement fioor finisher comprising means providing a carrier, means for rotating the carrier about a verticall axis, trowels tiltably mounted upon the carrier, and. means for simultaneously varying the tilt of the trowels during rotation thereof by the carrier and holding the trowels in tilted positions. 4. A cement fioor providing a carrier, means for rotating the carrier about a vertical ,axistrowels,tiltably mounted` upon .the carrier and radially arranged with respect to the axis of rotation of the carrier, and

means for simultaneously varying the tilt of the trowels `during rotation thereof by thecarrier,

6. A cement fioor finisher comprising a vertical y shaft, means for rotating said shaft, a plurality of trowels radially arranged with respect to the shaft and adapted to be rotated thereby, each trowei being tiltably mounted, a thrust collar on the shaft, armson'the trowels actuated by the thrust collar, means for adjusting each arm with respect to the thrust collar, and means for varying the position of the thrustcollar on the shaft whereby the tilt of the trowels may be varied.

7. A cement floor finisher comprising a motordriven, vertical shaft, a thrust collar thereon, va

finisher comprising means thesurface of thefloor, and means for tilting plurality of trowels radially arranged with respect to the shaft adapted to be rotated thereby, each trowel being tiltable about its radial axis, means operable by the thrust collar for simultaneously varying the tilt of all the trowels, and means for shifting the position of the thrust collar relative to the shaft. l

8. A cement floor finisher comprising a `motordrlven, vertical shaft, a ring arranged around the bottom of the shaft, a plurality of trowels radially arranged between the shaft and the ring, and means mounting the inner ends of the trowels on the shaft and their outer ends on the rings whereby the trowels may be rotated by the shaft.

9. A cement floor finisher comprising a motordriven, vertical shaft, a ring arranged around the bottom of the shaft, a plurality of trowels radially arranged betweenl the shaft and the ring, means tiltably mounting the inner` ends of the trowels upon the shaft and the outer ends of the trowels on the ring, a thrust collar-on the shaft. means for shifting the thrust collar relative to the shaft, and means operable by the shifting of the thrust cenar for simuuaneously tilting the trowels about their radial axes. f

MARVIN EDWIN u