US2693136A - Screed for cement surfaces - Google Patents

Description

NOV'. 2, 1954 R, G, BARNES y 2,693,136

SCREED FOR CEMENT SURFACES Filed May 7, 1949 IIl l 37 4511:: I9 45",

United States Patent Oiiice SCREED FOR CEMENT SURFACES@ Ralph-G.-I Bames, Brtland'0reg. assignerr ofrone-half -to Jessev J.Gard, Portland;l Oleg and. one-halt to Master" Vibrator Company@ Dayton Ohiog, a.- corporartion,of.0hio'- Application.May'1,.1949,.seriarNa9zgo11' sacianns: (c1. lski-4er This; invention: relates to'..concrete-vibratorsioffthe kind characterized;Sby/-aevibratony'screed on'beami.

Initheuse'of devicesiofirtlristypeg-'thecbeamiszsupported at or adjacentto its ends and is dragged over the surface the aworlc', tor example;l a: roadway in: which: fresh. con- 'cretehasfbeenrpoured Tfhea tendency] ofr'thebearni tosa'g or'bow'when. sot supported and v'used haspreclude'di the use"V 'of' elongated beams', which' would be. more-efficient and* 4desirable in: some.l applications.' lyiorelzwer',.inA equipnient ofi this' type'. no means' have been heretofore 'provided whereby a' predeterminedlbow or-'arch may be.; ad-

.justajbly imparted' to'- the' beam', adapting` th'eifscre'ed. for

work uponiconcave andoonvex surfaces. v

The instan-t invention: contemplates an'y improvement uponv concrete screeds. ofr the class described to' the' end tliati bothl limitations above. mentionedi maye bel obviate'd. A"trussing.l of the scree'df or'bearni is'proposed throughl 'a 'rigid"br-idge 'resisting sagging ofl 'therscreedpai feature' of the'- truss residing inadjustmenti means: whereby the-.truss 'may bev lengthened andfshort'ened relativelyfto the screed.

tionas wellf'asfthe nreansandimodeof operation of v-ibratory'scre'ed'b'eams 'whereby such. deyiceslm'ay'not only be economically manufactured-but w-ill 'b'e'tnoreweii'cientand satisfactory in' use, adaptable toi-'a1 Widefvariety of work, having relatively' few partsrandf be' )unlikely 'to igetjoutfof repair.

Ai further' object 'of the' invention'. istoprovidel in'fga yibratory screed rn'eans'- for -adjustab'ly/iiexing.' the* screed 'for'the 'finishing of 4"con'teuredisurfaces.

Al further4 objeet of' the inventioni isntoiproyid'e' a screed beam of1 'extraordinary length; which may beraceurately controlled aste-contour.'

- AA further' lobject 'off the' linventiorn istov provider in' an elongated' vibratery' screed means forfcontrollingftheiiiexing thereofintermediate' 'itswidely spacedlpoints lof supportsfurther' object' vof thernvention isfto'Y simplifyI 'the 'meansvandi mode fof-."adju'stab'hy securing supportinganemitiers to thetends-ofarvibratonyfscreed.

A further object of'th'eiinvention lis toprovidefavibra- 'tory screedpossessing. thezadvant'ageous' structural features, tlie i-nlierent meritorious 4chara'oteristics and the modeofloperatiorthereinmentionedi.

With the above'prirnary'an'd.s.otller` iincidentalobjectsin Viewy 'as' will; more'r :fully appean ini thespecicationgnthe :invention intended? tov be 'protected #byl Letters :Patent 'consists' of vfthe features ofoonstructionnfthe pants and -rcombinationsthereof; .andthe .mede .of operatiomrasshereinafter described.l or illustrated ini the accompanying drawings; or theirequivalent.

Referring to the accompanying drawing, wherein is` found the preferred but obviously not necessarily the only form of'embodinent off'the invent-ion;

Fig. 1 is a. perspective view of a vibratory screed in accordance with't'lie instant'- invention, showing a manner of use thereof;

Fig; '.2 is aA view of the vibratory screed 1n .-frontfelevaftionpartly diagrammatic, indicating yliow the` beamamay assume'aiiexed contour; y

Fig.' '3 issa' detail View in frontelevatron oftjon eendA of the soreedgshowing the mounting meansffor theqbeam;A

vflat base. portion 1'4 .(jsee .Ei

sof. the. web portion in conjunction with the beannis productive of '.a general respective ends. thereof. and .iis

2,693,136 `Patented Nov. 2,. 1954 Fig. 4 an .end view of the' screed partly in section', beingftaken. alongthe line4-4ofFigz 3';

Fig. 5 is a' fragmentary view similartoFig.' 4'but. look.- ing at"tlie.-opposite endg' being taken"along^ the line 5 5 ofFig. 3;

Fig. 'fisa detail Viewl partly'broken' away of" the-acfjustment means embodied! in lthe tr-nss;, and

Fig. 7 is a' detail view ,partly in section showingg'tlie linkage. interconnecting the truss y,and thescreed.

Like. `parts.-are' indicated by similar cliaracters'ofi'reference throughout the several views:

Thepresent disclosure' represents a further' development andlimprovement' inthe screed shown and claimed inmy Patent No'. 2,5.42;979,.issued'February'27;A 1951'.

Referring to fthe drawings .a' vibratoryV screed lin .accord- .ancewitlithe .instant invention is shown being used .the construction. offa roadway or. .the like, spaced ledgesfor side forms 1102 providingsupportfor the deviceat .itsoppositeend's.. The screedisguided itsadvanceoverthe fresh' concrete byr-menwalkingfon'the. ledges 10 andproduces. a smoothcompactedsurface 11 asv-compared with therough uninislied .surface 12Lwhieh. may' be seenin advance .of .the device..

The. screed' comprises anl elongated beam ,13 of inv erted. T-shape,. the beam being. formed with a broad g.. 4) and-an upstanding web port-ion. 15.. Secured. as. by welding, to the upper edge IS-ofthe beam is-a tube 16 which,

and4 uniform amplitude of. vibra-tion. Centrally of the beam: 13. U -bolts,.17 project :outwardly and i upwardly from the; oppositesides of' web. vportion 1'5' and support. a .table .18 upon whichfis mounted a y source. of. powen 19' (a .gasoline enginefor electric motor). The power source .19tv is connected; to a. rotary, unbalanced weight (not shown), arranged'. beneathy .the table,. rotation. of. which serves to. vibrate the .beam 13. to compact' the surface on. which. it. rests.

The. structure so. far. describedf is substantially. the same .as that showmand. describedin my above-identifiedlcopending application for. United' .Statesv Letters .Batent For. better vihratory;` action the.y beam 15 is resiliently mounted .uponfits supports. Asshown .in Figs. 3 and4, therer isfprovided adjacent eachv end of the .beam a twopart clamp L21. arra-ngedto be compressed'into gripping engagement.' with, thertub'e .I6 by. adjustment of. nut assernblies .22.. Gverlying. .the upper. end. ofl each. clamp .Zl iswone endof a leaf .spring ..23 .securedr between. the clamp. .and;.a -plate 2`.4. by a. nut'. and' bolt .assembly 2'5. Each..spring..23' .extendsY axially .of the beam, I3` toward fastened; at. its opposite endtnfa bracket '26' .of inverted. U.-shape. The vopposing 'legs .of-each)` .bracket '26 extend downwardin embracing relationto ,the .tube i161* and beam 13 and are bent 0ut ward .at their. ends to...de'ne. flanges 27' lyingin aplane paralleLto vthe base 114i of-l the .bearn.1`3`. Securedto the angesl are. Througlithe use.of`sliirns..2'9 placed -between. the. feet. S285 and fflangeslT accurate ,positioningo ttieeeLrnay beaccornplished'. order. that they may'l'ie in a plane slightly lower than the base ofthe bearn13 which thus isheld in an elevated position yieldin'gly' supported. by 'the 'leaf springs' 2'3l The 'feet 28' are' adapted "to rid'e` upon a. track' or'slid'eway, 'for example, the ledges i shown' in Fig. l'.

According t'o the `width 'of the' :surta'ce-being' worked, the distance' between' suchtracksA or'slideways'will vary. Adiust'rnent' of' the. mounting' mea n'srel'ative' to 'the' 'beam to allow for sucl'variation is easily accomplishedlrnerely .by loosening, ,the attachment means 22, coi-npriserl` in clampsl, whereupon theseparate assemblies comprising clamps 21',..springs 23, brackets. 261 and'feet .'2`8 may be .sld' .along -tliemtlibe. 15 to. annew position. of adjustment.

vXhenso positioned;l the nutassemblies .'22 are. again ,.stant invention, there are mounted upjonc'the opposite ends thereof a pair of upstanding elements 32, one element of each pair being secured on opposite sides of the web portion at each end of the beam. The upstanding arms of each pair of elements 32 project above the associated spring mounting means and may be formed with registering openings 33 to receive a lifting bar or handle 34 (see. Fig. 1). Supported between such arms, beneath the openings 33, is a pivot pin 35, the pins defining anchors for the opposite ends of the truss.

The truss itself is indicated generally at 36 and is made up of a pair of rigid tubular members 37 and 38, each having a yoke 39 at its outer end pivotally mounted upon a respective pin 35. The members 37 and 38 extend toward one another from their anchor points in overlying spaced relation to the beam 13 and engage one j another in a telescoping connection. As shown in Fig. 6, the left hand truss member 37 has a screw threaded stud 41 projecting therefrom upon which is mounted a shouldered stop nut 42 and a lock nut 43. The outer end of the stud 41 is received in the inner end of truss member 38 which limits against the nut 42, a predetermined fixed relationship of the parts being maintained against the effects of vibration by turning the lock nut 43 up into frictional engagement with the nut 42.

Centrally of the beam 13, suspension means are provided interconnecting the beam and the truss 36. These means comprise two pairs of posts 44 fixed to the beam 13 on opposite sides of the engine 19. In overlying relation to each pair of posts 44 is a saddle 45 secured to the truss 36. The opposite ends of each saddle 45 are connected to its associated posts 44 by links made up of a chain 46 and a coil spring 47, the links being crossed diagonally relatively to each other.

The suspension devices and the truss 36 jointly cooperate in inhibiting undesired sagging or bowing of the beam 13 and in obtaining a predertermined exure of the beam between arched and bowed extremes. In this connection, when an elongated beam such as the beam 13 is supported at or adjacent to its ends it tends to flex downward or to assume a bowed shape. Such tendency may be resisted or controlled by an initial adjustment of the stop nut 42 in the truss which will limit the inward telescoping motion of the truss members 37 and 38 to a predetermined extent. Further, by adjustment of the nut 42 outwardly along the stud 41 the effectivevlength of the truss 36 may be extended to enforce an arching of the beam 13. Such an adjustment is illustrated in Fig. 2 wherein the beam is shown in full lines in a normal flat horizontal plane and is shown in dotted lines as set to an arched form by adjustment of the truss.

Thus, by expansion or contraction of the truss member 36 the exure of the beam 13 is readily controlled and regulated although the beam is of extraordinary length and only supported adjacent its extremities. Of particular importance is the fact that the present means of strengthening the elongated beam in no way affects its vibratory motion or decreases its eiciency. Although the truss member is restrained by its connection to the central portion of the beam, which is necessary in order to increase the stability of the assembly and prevent tipping or side-sway of the truss member, such tie or connection is of a resilient character so as not to interfere with or decrease the desired vibratory motion of the screed.

From the above description it will be apparent that there is thus provided a device of the character described possessing the particular feature of advantage before enumerated as desirable, but which obviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any of its advantages. l

While in order to comply with the statute the invention has been described in language more or less specific` as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise bt one of several modes of putting the invention into e ect.

Having thus described my invention, I claim:

1. A concrete vibrator, including an elongated beam, vibratory means on said beam, means supporting said beam at its ends for motion over a concrete surface, said beam tending by reason of such support to flex downward, a truss interconnecting the ends of said beam and extending in overlying spaced relation thereto, and resilient yielding means interconnecting said truss and said beam centrally thereof.

2. A concrete vibrator according to claim 1, characterized by means shortening and extending the length of said truss to effect a corresponding change in the exure of said beam.

3. A concrete vibrator including an elongated beam, vibratory means on said beam, means supporting said beam at its ends for motion over a concrete surface, said beam tending by reason of such support to flex downward, a truss for said beam comprising rigid truss members anchored at their one ends to respective ends of said beam and extending toward one another in overlying spaced relation to the beam and joined in an adjustable connection at their opposite or adjacent ends, said connection including means to vary the effective length of said truss, and resilient 'suspension means in- 'ltjerconnecting said truss and said beam centrally of the earn.

4. A concrete vibrator including an elongated beam, vibratory means on said beam, means supporting said beam adjacent its ends for motion over a concrete surface, said beam tending by reason of such support to ex downward, a truss rigidly interconnecting the ends of said beam and lying in spaced overlying relation to the length thereof, and resilient suspension means interconnecting said truss and said beam centrally of the beam.

5. A concrete vibrator including an elongated beam, vibratory means on said beam, means supporting said beam adjacent its ends for motion over a concrete surface, said beam tending to flex downward between said supports, a truss for said beam comprising rigid arcuate truss members anchored at their one ends to respective ends of said beam and extending toward one another in overlying spaced relation to the beam into a telescoping connection at their opposite or adjacent ends, a nut on one of said truss members engageable by the other of said members to limit inward telescoping motion of said members and thereby limit the downward flexure of said beam, and a screw threaded mounting for said nut permitting adjustment thereof to vary the eifective length of said truss and thereby to vary the exure of said beam between bowed and arched extremes.

6. A concrete vibrator according to claim 5, characterized by resilient suspension means interconnecting said truss and said beam centrally of the beam.

7. An elongated screed beam for finishing cementuous surfaces resiliently suspended upon a pair of adjustably fspaced feet characterized by a truss member interconnected with the opposite ends of the beam and extending in overlying parallel spaced relation with said beam, means for varying the length of said tmss to control the flexure of said underlying beam, resilient links interposed between the beam and overlying truss centrally thereof and means for adjustably securing the spaced feet to the beam independently of the connection of the truss thereto comprising an expansible and contractible clamp carried by each of said feet and means for contracting said clamp upon the beam in any desired position of adjustment relative thereto, the construction and arrangement being such that the feet may be adjusted relative to the beam irrespective of the interconnection of the truss member with the ends of the said beam.

8. In a semi-flexible elongated vibratory screed beam, rigid tie means interconnected with opposite ends of the beam and extending into overlying parallel spaced relation with said beam, means for varying the effective length of said rigid tie means to thereby control the degree and direction of exure of said beam, and resilient stabilizing links interposed between said beam and overlying tie member and connected thereto, the links extending in upstanding diagonal intersecting planes to thereby increase the stability of said vibratory screed beam.

References Cited in the tile of this patent UNITED STATES PATENTS Number Name Date 1,388,690 Baker Aug. 23, 1921 1,813,338 Botel et al. July 7, 1931 2,038,416 Clifford Apr. 21, 1936 2,306,123 Jackson Dec. 22, 1942 2,542,979 Barnes Feb. 27, 1951

Images