US2826971A - Power floats - Google Patents

Description

March 18, l1958 R. sTEvl-:Ns

POWER /FLoATs 2 Sheets-Sheet 1 Filed oct. 15, 1953 .hn l

lN/Elvrola. Rosen' L. Srsvews R. L. STEVENS POWER FLOATS March 18, 1958 2 Sheets-Sheet 2 INVEN TOR. Foefer ..Srfvf/vs BY i Filed oct. 1s, 495s fi Tra/#Wins Unite States Patent M' POWER FLoArs' Robert L. Stevens, Boston, N. Y., assignor to Wiesner-l Rapp Company, Inc., Buffalo, N. Y.

Application October 13, 1953, Serial No. 385,731

7 Claims. (Cl. 94-45) My invention relates in general to a machine for treating the surfaces of cementitious bodies and specifically to a troweling compacter for floating and finishing cement floors and the like.

As is well known to those skilled in the art, in the surface treatment of cementitious bodies, it is the practice to begin the troweling action upon the surface at a relatively slow speed with the trowel at a small angle or pitch, but as the cement mixture gets harder, the speed of movement of the trowel and the angle or pitch is increased.

The principal object of my invention is to provide a device in which the speed of rotation and the angular relation of the blade in respect to the surface being treated may be increased during the treatment of the surface.

. Another object is to provide hydraulic means for changing the angle of attack of the blade.

A further object is to provide hydraulic blade-lifting means automatically controlled by the speed of the driving motor or power means.

A further object is to provide a rotary trowelng device having a plurality of blades adjustable in unison.

Moreover, my device is of such a nature that the hydraulically-actuated means of each trowel under normal working conditions is distended an amount equal to the hydraulically-actuated means of the other trowels, each of the members being sufficiently resilient to permit additional momentary expansion to allow the associated blade to move independently when striking a stone or other foreign object without changing the angle of the other blade.

Furthermore, each of the blades of my device is individually actuated by means of an inflatable member receiving fluid under pressure produced by inexpensive means connected to the motive power and controlled by the speed thereof.

The above objects and advantages have been accomplished by the device shown in the accompanying drawings, of which:

Fig. 1 is a side elevation, partly in section of my complete device;

Fig. 2 is a reduced side elevation of the same;

Fig. 3 is a plan view of the device;

Fig. 4 is an enlarged fragmentary isometrica] perspective view of one of the trowels and associated means;

Fig. 5 is an enlarged sectional View of the trowel and is taken on line V--V of Fig. 4; and,

Fig. 6 is an enlarged fragmentary view of the flexible means.

The device comprises a casing 10 having a top Wall 11 and a bottom wall 12 provided with a removable cover plate 13. A main shaft 14 is mounted for rotation in suitable bearings carried by the upper wall of the casing and the cover plate. Also carried by the upper wall 11 is a gear support 15 in the form of a vertically arranged tube 16 secured to the casing wall and having a gear shaft 17 rotatably mounted therein. The lower end of the gear shaft 17 projects into the casing and is provided with a driving sprocket 18 which is connected to a driven Patented Mar. 18, 1958 ICS sprocket 20, carried by the main shaft 14, by means of a sprocket chain 21.

The upper end of the gear support isformed with a gear casing 22 in which is mounted a driven bevel gear 23 carried by the upper end of the gear shaft 17. A driving gear pinion 24 meshes with the gear 23 and is mounted upon a pinion shaft 25 rotatably supported by the gear housing 22 and extending out beyond the housing where it is provided with a driven sheave 26.

Any suitable form of motive power may be provided for the device, but I prefer to use `an internal combustion engine 30 of any conventional type. The driven sheave 26 is connected to the usual drive pulley 31 of the engine by means of a belt 32. In order to connect and disconneet the motive power with the driven sheave 26, I employ a bell crank lever 38 which is pivotally carried by the engine upon a pivot pin 33. The lever 38 has a control arm 34 which is connected by means of a rod 35 to a control lever 36 mounted upon the upper end of the handle 40 of the device. The bell crank lever is also formed with an idler arm 41 which carries an idler wheel 42 at itsv outer end. The idler wheel is designed to bear against the outer surface of the belt 32, so as to take up the slackness in the belt when it is desired to'connect the motive power with the device. The lower end of the handle 40 is suitably attached to the housing, whereby the device may be moved about over the surface being treated.

Carried by the lower projecting end 43 of the main shaft 14 is a driving head 44 which carries a number of arms 45, preferably five in number. Each of these arms carries a trowel holder 46 secured to its under surface. Each trowel holder is formed with an integral bearing block 50 near its extreme ends for supporting a pivot rod 51. A trowel 52 is disposed beneath each of the trowel holders, and each carries a bearing 53 at each end, one of which is pivotally mounted upon each of the projecting ends of the pivot rod 51. As clearly shown in Figs. 4 and 5, each of the trowels is provided with a stilfening member 54-preferably of angle iron cross section which extends preferably the length of the trowel. It is desirable that the trowels be normally held in the position shown in Figs. 4 and 5 and to accomplish this I employ a hold-up spring 55 which may be mounted about the pivot rod, having one end fixed to the block or bearing against the holder, and the other end bearing against the trowel on the opposite side of its pivot point.

As shown in Figs. 4 and 5, the holder is spaced from the trowel 52 and is maintained in this spaced relation by means of a ange 56 formed on the edge thereof opposite the pivot rod. Within this space is mounted the inflatable member 60 of my device. Each of these inatable members is preferably formed from circular tubing of resilient material or the like, having the opposite sides fastened together at the ends 61 in fluid-tight manner by means of an end clip 62. As shown in Fig. 5 each inflatable member is formed with a metallic stem 63 which is suitably secured in the wall of the member and which extends up through openings 64 formed in the 'holder and in the arm. The stem is formed with a central passageway through which iiuid under pressure may be supplied to the exible member.

Since the angle relation of the trowels is governed by liuid pressure, a suitable fluid pump 65 is provided. This pump is preferably arranged on top of the gear casing 22, and is driven by means of a shaft 66 which is connected to the gear shaft 17 in any suitable manner. The outlet 67 of the pump is connected to a supply pipe 70. This supply pipe s connected to a supply head 71 disposed within the casing 10 and rotatably connected to the main shaft 14. rIlle supply head is formed with a central aperture 72 3' which 'communicates with a central aperture -73 `formed in the main shaft. A fluid distributing head 74 is mounted about the lower end of the main shaft below the cover which `is, in communication withthe central'fpassageway 73 of the shaft through `a lateral-passageway-frmed therein: Th"e"distributing headisfprovided"witha number of uid `outlets equal `in Anumber, `to ftheltnumbe'r VJof trowels, and a `distributing pipefl" connectsfeachof'the outlets with 'oneof the stems63 vof the intltable members. A iluid reservoir 80 is mounted preferably-upon the casing 10, and a suctionpipe v81 connects "this `reservoir with thetluid pump 65. A'pressure regulatingfvalve'z of -any suitable type is `mounted in the` supply line -70 extending to the supply` head and `it is` provided withiareturn pipe 83` connecting the `relief `outlet -valve' withithe reservoir. This "pressure regulating device is adjustedl to supply-fluid at the desired pressure to `the flexible membersjof the device. The usual throttlecontrol `86 is'carri'ed-by the handle, whereby the speedof rotation of ithemairi-lshaft may` beregulated,` thereby regulating ther amount of distension of the inflatable members -and'theangular relation of thetrowels.` A guard ring 84 `is provided iforthe device,` which'has an outer'diameter slightly Alarger than the outer sweep ofthetr'owels. This' ring 'isicarried' by radiating arms85 whichare secured tothe casing `10.

When the device 4is to be"used,thecontrolllndle 36 is actuated to connectY the 'motive power with the'cmain' shaft 14 through`1thebelt and gears above described." As' is well known the first action of a trowel upon"freshly mixed cement or concelrete is that `of draggingor floating with' the trowels in `substantially flat position.` However,

as the cementstarts to harden, the`angle `of 'the trowels` with the cementitiousj surface is' increased; and the troweling is completed by the 'trailing edges ofthe trowels. In order to change the tangle of the trowels',"pthenr`otor 'is speeded up, the pressurerof` the tluid' is increzased,andthe` trowels are automatically tilted by th'e distendingactionv of the inflatable members. `The position of fthe trowels with respect to the surface being treated is therefore under the control of the operator at all' times and the utrowels may be` accurately adjusted in unison to'treatthefcernentV t at `the various stages during the hardeningperiod without' will momentarilyyield individuallyjtothe' impacfwithout' disturbing theangle of the other trowels;

What is claimed isi 1. In a power tloat, yarevolving-lhead1havingradiating arms and formed with la central Vpassageway.ajtiowel assembly carried by eachi arm, comprising `a'trove/elifholder rigidly attached to .thej arm,.a trowel,disposedfon, the under side of the holder andfhaving ,pivotaliconnection therewith, an ntlatablef` member disposed' Ibetween and' in contact with' each` h'older and:thecooperatingtroweh conduit 'means connectingleach `offtliemernbers'with the passageway, and meansconnectedito `thecentra`l passage# way and controlled by the speedof rotationLof the'head for supplying yfluid. 'under variable" pressure 'to the [members to alter the angulaipositon ofitheftrowelsf. 'A

2; In a power float,'a'revolvingh'ea'dihavingradiatingA arms and formed witha",centralp'assageway; al trowel assembly carried by" eachfarmg'compris'ing "a Itrowelholder rigidly attached `to `eaclilfarrn-ancli'frmed:"with `spaced bearing blocks `arranged laln'gonefside thereof`,': a spacing` aange formed mangia@ opposite sidebruiefnolderfa 'pivot rod carried by the "blocks, laftrowelf disposed 4orrth'e under side of the holder.` and-having ibearingspivo'tally mounted upon the pivot\rod, anf inflatable cmember -for 'each'fassem- 4 bly mounted between and in contact with the holder and the trowel, conduit means connecting each of the members with the passageway, and variable iluid pressure means connected to the passageway of the head, whereby to alter the angular position of the trowels.

3. In a power float, a revolving head having a central passageway, a plurality of trowel assemblies carried by the head and radiating therefrom, each assembly comprising a trowel holder rigidly attached to the head, a trowel pivotally mounted upon and underneath the holder, an inilatable'member disposed between and in contact with each cooperating holder and trowel, conduit means connecting the head passageway with each of the members, and uid pressure supply means connected to the passageway of said head.

4. in a power float, a revolving head having a central passageway, a' plurality of trowel assemblies carried by the Vheadand radiating therefrom, each assembly comprising atrowel holder rigidly attached tothe head, a

trowel pivotally mounted upon and underneath the holder, an inflatable member disposed between and lin contact with each"co`operating'holder'and trowel, conduit means conuecting'each'of the members with the passageway, and

means connected to the central passageway and controlled bythe speed'of rotation of the head for'supplying fluid undervariabl-pressure to the members to alter the angular position'of thetrowels 5. In a=power lloat, the combination with a housing, and power 'means carried by the housing, of a rotatable head carried jbythe housing and connected to the power means, the'head beingformed"with'accntral passageway, a plurality `of radiating trowcl assemblies carried `by the head, each assembly comprising a trowel holder fixed to the headja trowel pivotally mounted beneath thc holder, expansibletmeans 'disposed between and `inr Contact with the holder` andthe trowel, conduit means connecting `each of the expansible means'tothe central passageway, and fluid pressure supply means supported by-thc housing and connected to the central passageway of the head for controlling the angular'position of the trowels.

6. In a power float, thecombination with a housing, and power means carried by the housing, of a rotatable head carried by the housing and connected to the power means, auid passageway carried by the head, a plurality of radiating trowel assemblies carried bythe head, each assembly comprising a trowel holder fixed tothe head, a trowel pivotally mounted beneath the holder, expansible means disposed between and incontact with the holder and the trowel, conduit means connecting each of the expansible means to thecentral passagewayand means connected to the uid passageway and controlled by the speed of rotation of the head for supplying fluid under variable pressure to the 'expansible means to alter the angular position of` the trowels.

7. In a power float, the combination with a housing, and'power means carried by the housing, of `a rotatable head carried by the housing and `connected to the power means, said head' being formed with a central passageway, a plurality of trowels carried by and radiating from the head for rotation therewith, a holder for each trowel carried by'sad head, eachtrowel being in the form of a blade independently pivoted beneath the holder for individual angular movement therewith,y inflatable means disposed between and in contact with each holder and cooperating `trowel, conduit means connecting cach of the inflatable means with the passageway of the head, and variable lluid pressure supply means connected to `the central passageway to alter the angular position of the trowels.

References Cited in the `tile of this patent UNITED STATES PATENTS 2,468,981 Huffman May 3, 1949

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