US2942536A - Troweling machine - Google Patents

Description

June 28, 1960 w. w. IRWIN 2,942,535

momma momma Filed Nov. 23, 1956 2 Sheets-Sheet 1 BY ikmmw June 28, 1960 w. w. IRWIN 2,942,536

momma MACHINE Filed Nov. 23, 1956 2 Sheets-Shut 2 INVENTOR. w/z Ara vv. Lew/4' Ila- DMILWM United States Patefi O TROWELING MACHINE Wilfred W. Irwin, Dayton, Ohio, assignor to Master Vibrator Company, Dayton, Ohio, a corporat on of Ohio Filed Nov. 23, 1956, Ser. No. 624,162

2 Claims. (CI. 94-45) This invention relates to surfacing tools, and more particularly to a rotary power driven tool provided-with sweep blades having a progressive circular wiping engagement over the surface upon which it operates, as for example an unset concrete surface.

In the embodiment of the invention in which it assumes the form of a concrete finishing tool, such tool comprises a generally upwardly extending handle by which an operator, while standing erect may move the tool about on the work surface. Also, in the 'concrete finishing embodiment of the apparatus the sweep blades are adjustable in order better to perform floating, fimshing and intermediate operations.

The object of the invention is to simplify the construction as well as the means and mode of operation troweling machines,'whereby such machines may notonly be economically manufactured, but will bemore eflicient and satisfactory in use, "adaptable to a ;wide variety of applications, andbe unlikely to get out of repair.

It is a further Object of theinvention to enable the blades to be adjusted by the operator from a convenient positioncjnthehandle: I 1

Another object of the invention is to. provide for handle mounted adjustment of the sweep blades in conjunction with a telescoping type of handle as found in.a troweling machine of the so-called midget or readily portable type. J t. A further object of the invention is to provide a generally new blade adjustment mechanism especially char.- acterized by an ease of operation which precludes the necessity for relatively rigid and heavy controls. In this latter regard, a troweling machine comprises an engine, gear box and other mechanisms, the whole comprising a relatively heavy package which rests upon the sweep blades which in turn are directly in contact with the work surface. In adjusting the sweep blades in one direction, it is necessary according to conventional construction and arrangements of parts, bodily to lift the relatively heavy machine. The instant has in view a new structureproviding for increased leverage of the adjustment forces acting upon the sweep blades and for increased flexibility in the sweep blades whereby the blades may more easily be tilted and whereby at least a part of the desired tilt is accomplished through a flexing of the sweep blades.

Still another object of the invention is to present a generally new mounting for the sweep blades" providing as j i As indicated; the present handle is for a different distribution of weight upon the sweep. 1

blades as well as for a diti'erent action thereof in opera? tion and in response to tilting adjustments thereof.

A further object of the invention is to' provide a troweling machine possessing the advantageous structural features, the inherent meritorious characteristics and the mode of operation herein mentioned.

With the above primary and other incidental objects in view as will more fully appear in the specification, the invention intended to be protected by Letters Patent consists of'the features of construction, the parts and shown one but obviously not necessarily the only form of embodiment of the invention,

Fig, l is a view in perspective of a concrete troweling machine in accordance with the illustrated embodiment of the invention;

Fig. 2 is a detail view, partly broken away, showing the lower part of the troweling machine and the train of mechanism comprised in the means for adjusting the sweep blades, including manipulative control means on the handle;

Fig. 3 is a view taken in the direction of the arrows in Fig. 2 and turned V p a Fig. 4 is a detail view, in plan, of a lever arm comprised in the sweep blade adjustment mechanism;

Fig. 5 is a view in side elevation of the armof Fig. 4;

Fig. 6 is a detail view, in plan, of a connector device or spider having a common connection with the several 'sweep blades for unison adjustment thereof.

1. 13, r The machinev is supported in the generally upright position illustrated in. FigJ'l, with the shaft 13 in a plane substantially normal. to theisurface of the work by' a handle. 14 pivotally connected to the gearbox 12.

kind, comprising a part 15 connected to the gear box and a part*16fislidable within the first part and held 40 in a selected position of extension-by 'a-locking mechanism-17. I 1 ,The rotary. drive shaft 13. carries on its outer or lower end'a mounting plate or base- 18, the base being secured to the shaft'13 for unison rotation by means including a bolt19 and a conventional key 21 as is shown'in Fig. 2 of the drawings. The base plate 18 carries sweep blade assemblies 22 upon which the machine rests on the surface of the work and which are driven, as will be described, in a rotary direction about the shaft 13 for progressive wiping engagement with the surface of the work. The power source l0'is effective to rotate a shaft 23 which is connected'by pu1leys24 and 25 and a belt 26 with another. shaft -It will be understood that, in the conventional manner of devices of the present class, the power source'10 is effective to rotate the shaft 23, and that the motion of such shaft is transmitted through the elements 24-26. and the elements-of the gear 13, causing this shaft tor'o tate shaft23.,, .2 The base -plate18 is in correspondence with the formed 'with a circumferential V series of radial,- portions or spokes 28, each terminating in a bossin'which is a'bore or bearing mount29' extending in a direction transverse to or substantially at right angles to the longitudinal axisofwits respective :v spoke 28." The several bearing mounts 29 the present I saidrto lie in, planes tangential to a common circle concentric with the shaft 13.; Each bearing mount .29 receives abolt, 31 which-may begsuitr instance may thus be ably secured, as by a set screw 32, against rotary and longitudinallmotion relatively to the base plate 18 within its respective mounting.

Patented .June

The tool is moved about over the surface of the work of the telescoping 27 extending into'the gear box 12. 1

box 12 to the, rotary shaft On a projecting part of the bolt 31 isrotatably"mounted an attachment means or plate '33 including abearing portion 34 on the bolt 31. From the bearing portion 34 the attachment member 33 extends in theform of a web 35 in a direction substantially parallel to the longitudinal axis of-the-companion spoke 28 and toward a line at right anglesthereto'passing through the axis of the shaft 13. In=relative1yspaced relation to the bearing portion 34, the web portion 35 terminates in a flange 36 secured toabar 37 which-is in turn made fast to a sweepblade 38. Thesweep blade is generally rectangular in shape and'has a leading edge 39 and a trailing-edge 41, and may have, as indicated, a swept back formation placing one end of the trailing edge 41 closer to a line'drawn'throughthe axis of the shaft 13 than-the corresponding end of'the leading-edge 39. The latter is bent upward slightly :out of the plane of the body proper of the sweep blade. Immediately back up of such upturned portion is fastened the bar 37 which extendsover "a substantial part-ofthe width of the blade in parallel, comparatively adjacent relation to the leading edge '39. The construction and arrangement of parts provides for a substantially rearward extension of the blade 38 beneath the attachment member 33 in such Wise as to placethe mounting bolt 31 and bearingportion 34 .in relatively elevated relation to'the sweep blade and in a location substantially parallel to the trailing edge of the blade and-closer to such trailing edge than to the leading edge.

Also extending from the bearing portion 34 of the attachment member 33,.in parallel relation to the web portion 35,.is a lever arm 42. Theouter free end of the lever arm 42 terminates substantially in line with the flange 36 and bar 37 and .is received-in a depending bifurcated portion 43 ofaispider '43, to which bifurcated portion thelever is pivotally connected.

,. Thespider 43 is mounted upon the shaft 13 for freedom of .rotary'and vertical slidingmotion and is formed with a-plurality of the bifurcated portions 43', one for each sweep blade assembly. The :spider thus establishes acommon connection between the several sweep blade assemblies'and it will beunderstood that'a'vertical raising'and loweringfofthe spider upon the shaft 13 will result in rocking movements of'the lever arms 42 and thereby a tilting of the sweep blades 38 about their respective bolts 31. Also slidably mounted upon the shaft .13 is a sleeve 44 having a threadedlower end received in and secured to the spider 43. A setiscrew 45 maybe used as indicated further to hold thespider'and sleeve 44 from relative rotary'motion. At the opposite or upper end of the sleeve 44 is a flange 46 and in immediately underlying relation to the .flange 46 there is mounted on sleeve'44 -a thrust bearing 47. A substantially U-shaped lift arm '48 is in embracing relation to the sleeve 44 and bearing 47 thereon, and carries studs 49 and 51 which underlie the bearing 47. On one side of then-shaft 13 and sleeve-spider assembly thereon the lifting arm 48 is pivotally connected to a :bracket 52 dependent from the gear box 12. Onthe other-side of the shaft 13 the lift arm terminates in -a finger 53 pivotally connected to an attachment clevis .54 on one end of the core 55 of a Bowden wire or like-flexible cablei56. The cable 56 is attached by a bracket 57 tozthe gearbox 12 and by another bracket 58 to the stationary part 15 of thehandle 14.- Projecting beyond the bracket 58,

the core 55 of the cable has attached thereto a hand grip a or finger grip portion 59 accessible to the-hand of the operator in order that it may be drawn .upward or lifted to effect a corresponding lifting motion of thearrn 48 about-the bracket 52. v Sucha lifting motion of-the arm 48 is effective through the studs 49 and '51 to raise-the =slecve'44 and thereby the spider 43. As a result, the

several 'attachment'means 33 are rocked in a clockwise "direction (-Fig. '2) about their mounting bolts 31 in a directionto tiltthe severalb1ades38, or more'particularly to raise-'theleading edges 39 thereof. Differing extents 4 of pulling motion upon the handle grip 59 will, of course, effect different degrees of elevation of'the-leading edges of the sweep blades. The lift mechanism may be locked in such position by rotating'the handle 59 approximately 90 and releasing it whereupon it will be held in the selected position of adjustment until it is desired again to change the blade adjustment;

To efliect a lowering of the leadingedges of the sweep blades, the handle grip 59-is releasedfrom its latched position and permitted -to bedrawn downward within the cable 56 .by the force .of gravity acting upon the troweling machine. When the desired lowered position has been achieved, the handleg ip is again locked and the parts so held in adjustedposition.

The construction .and arrangementof parts is such as substantially to reduce the force required for an upward tilting movement of the troweling blades. The relatively long lever arms 42 multiply the lifting force applied to the spider 43 with the result that a multiplied torque is applied to the attachment means 33in a direction to lift the sweep blades 38. The relatively off set mounting of the pivot for the blade, as represented by the bearing portion 34, with respect to the place of attachment of the blade, as represented by the flange '36, also is such as to provide for a greater angle of movement of the leading edge of the blade than that which takes place at the trailing edge thereof. The sweep blade thus in effect merely pivots about the trailing-edge in response to the lifting action as applied .to the handle grip '59. Further, the arrangementandspacedlocation of parts as described imparts a greater flexibility to the blade useful'in achieving alive springing "action of the blade upon the work surface and useful also to absorb some of the pulling forces applied through the handle grip 59 whereby'to avoid having to apply these forces in a manner to lift the entire machine.

In the matter of leverage, in one working embodiment of the inventiomthe leverage provided by the lever arms 42 is approximately 2.7 to l'while the advantage gained through the operator applied leverage as attained through the lifting arm 48 is approximately 4.2 to l. T he total advantage in leverage is approximately 11.4 to 1. Calculated against the weight of the machine in connection with which the adjusting mechanism is used, a machine weighing approximately pounds, the leverage enables lifting of the'sweep blades with the relatively light pull of 6.2 pounds, friction losses being neglected.

'From the .above description it will be apparent that thereis thus'provided a device of the character described possessing the particular features 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.

While in or'derto comply with the statute the invention has been described .in language more or less specific as to structural features, itis'to be understood that the invention is .not limited'to the specific features shown, but that-the means and'construction herein disclosed comprise but one of several modes of putting the invention into eifect.

Having thus describedmy invention, I claim:

1. A troweling or likemachine including a rotary'driveshaft, a circumferentially spaced series of beatingsconnected to said shaft '-for rotation therewith each projecting at right angles to a line radial to said shaft, a plate device pivotally supported on each of said hearings to one end to project at generally right angles thereto and inwardly toward said shaft, blade means attached to each of said plate devices at a line spacedfrom and generally parallel to its associated bearing, a lever arm .connected with each of said plate devices for movement therewith about its bearing and extending generally perpendicularto itsrespective bearing and extending toward its vertically adjustable on said shaft connected to said leverarms in pivotal relation adjacent said lines of attachment of said devices to their connected blade means and means for vertically adjusting said sleeve means on said shaft for tilting said blades about their bearings.

2. Apparatus for troweling or the like including drive means having a vertically depending drive shaft, a support element fixed to said drive shaft, bearing means fixed to the periphery of said support element each projecting at generally right angles to a line radial to said shaft, a spider mounted on said shaft in adjacent rela tion to said support element to have a freedom of vertical and rotary movement with respect to said shaft, a

web member with one end rotatably mounted on each of 15 said bearing means and having its other end project inwardly toward said shaft, a sweep blade secured to said other end of each web member adjacent and parallel to its leading edge, said leading edge being parallel to said bearing, a lever means connected for rotation with each Web member having a projected extremity pivotally con-, nected to said spider, means for vertically moving said 5 spider to produce a mutual tilting of said sweep blades.

References Cited in the file of this patent UNITED STATESv PATENTS 10 2,198,929 Whiteman Apr. 30, 1940 2,277,389 Conway Mar. 24, 1942 2,351,278 Mathews June 13, 1944 2,394,274 Troxell Feb. 5, 1 946 2,434,408 Huffman Jan. 13, 1948 2,662,454 Whiteman Dec. 15, 1953 V FOREIGN PATENTS 1,092,463 France Nov. 10, 1954

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