US 2351278 A
Description (OCR text may contain errors)
June 13, 1944. .y MATHEWS 2,351,27s-
FLOOR FINISHING MACHINE Filed April 27. 1942 A TTORNEY Patented June 13, 1944 UNITED STATES. PATENT "OFFICE ,2,351,278 FLOOR FINISHING MACHINE Lee Vci. Mathews, Los Angeles, Calif; Applieation april 27, 1942, serial No. 440,665
7 claims. tol. :a4- 45) This invention relates to a machine. for smoothing surfaces which have been coated with plastic substances.
Although the machine which forms the subject matter of this invention may be used to smoothen a. variety of surfaces, yet it is more particularly intended for use as a cement floor finishing machine.
Among the objects of the invention are to provider in a machine for operating a set of surface smoothing trowels, means means whereby said trowels are supported `in an improved manner for adjustably tilting them at various angles in rela-- tion. to the surface being troweled by the machine; to provide a simplified means for adjusting at one time a plurality of the trowels; to provide an improved arrangement, in relation to a set of smoothing trowels, of means for rotating all of said trowels in unison about a common center; and. to provide a more sturdy and durable structure for a machine of the class to which the invention pertains.
A more specic, very important object of the invention is to provide, for a set of tiltable, mechanically operable trowels, bearing means coinciding with the axes of tilt for said trowels, said bearing means supporting the weight of the machine upon the rotating trowels along radiating vertical planes which are parallel to and vonly slightly in advance of the trailing edges of the trowels. 'I'his arrangement of said bearing means reduces vertical vibration of the structure above the rotating trowels, thereby insuring a more satisfactory .troweling operation; and it also makes it much easier .to tiltably adjust the trowels, be-
cause substantially no vertical movement of themachine takes place during such adjustment,
Other objects, advantages and features kof'invention will hereinafter appear. Y j
Referring to the. accompanying drawing, which illustrates what is at present deemed to be a preferred embodiment of the invention,
Fig. 1 is a transverse section ofthe machine, on v line I-I of Fig. 3.
Fig. 2 `is a vertical section taken on line 2 2 of Fig. 3, dotted lines showing the trowels in the troweling position.
Fig. 3 is a section on line 3 3 of Fig. 1, a portion of the operating handle being broken away.
gine) and downwardly from whichframe extends` the motor Vdriven shaftY I2 which rotates the tubular head I3, being connected with said head `in the means whereby the trowels I5 are connected with the head I3 and are tiltably'ad'justed in relation to the floor or surface being troweled. Said head I3 hasy welded to it a triangular basal portion 2| to the upper side of which is bolted or otherwise secured a plurality of bearing blocks 22., there being three of.these blocks in the illustrated embodiment of the invention. Three trowel carryingarms I4 are shown, each having an angularly offset inner end portion 2,3 reduced in its cross section to forma stub shaft 24 which has its bearing Within the block 22 provided for it. A finger 25 is bolted or otherwise attached to that side of each trowel carryingarm I4 which is opposite to its offset part 23, the inner end portion of this finger entering a suitably shaped seat 26V of the aforesaid sleeve 9. Said finger 25 is shownrhaving a slightly'offset part 2'I which alines with said seat 26 and which isv provided with an enlarged bearingextremity 21a to cooperate with 'said seat without binding during the swingingv movement of Vsaid offset part incident to tiltably adjusting the trowels.I y Said sleeve 9 is vertically adjusted in relation to the head I3 by means of a yokeA 28 carried by a vertically vswingable lever 229 which is fulcrumed on a pin 30 carried.. by a bifurcated downward extension 3l ofthe frame Ill, said yoke having a pair of inwardly directed roller-carrying plns'32 which enter a groove 33 around said sleeve 9.
To the aforementioned shaft I2 is Xed a large driven worm gear 35 with which meshes a driving worm gear 36 carried by a transmission shaft 3l'. Power from the motor' shaft 33l is transmitted to said shaft 31 .by means of pulleys 39 and 43 over which passes a b'elt 4I.
A circular rim 42 surrounds the trowels I5, the outer part of each trowel having bolted to its upper side a member 43 which carries a pivot pin 44 that projects through said rim and alines axially with the finger 25l at the opposite end of the same trowel.
The already mentioned adjusting lever 29, which carries the yoke 28, is locked in the ad'- justedposition by reason of its dog 46 cooperating 'with a toothedsegment 41 which, together with the handle I Ii, is bolted to a projecting plate 48 which forms a part of the frame I0, a single set of bolts 49 serving to secure both the base |6a of the handle I6 and the segment 41 to said frame.
In operation of the device the workman, by grasping the handle I6, will move it around over the fioor as he desires and will at the same time hold against rotation the frame I together with the parts in a xed relation thereto. But the head I3 and its sleeve 9 will rotate and together with these parts will rotate the trowels l5 and rim 42. Adjustment of the yoke 28 and lever 29 may be effected to vary the tilt of the trowels, while the device is in operation. The rim 42 spaces the trowels properly from each other and also constitutes a safety feature.
At all times during the operation of the machine the trailing edges of the trowels are in contact with the work, the set of trowels being ro-` tated in the clockwise direction, as indicated by the arrow in Fig. 1. By the lifting and lowering action ofthe sleeve 9 upon the inner end portions 21a of the fingers 25 the trowels are tilted as indicated by the arcuate broken lines in Fig. 3. This tilting of the trowels so as to raise and lower their front edges is accomplished without appreciable raising or lowering of the machine, because the axis of tiltk for each trowel is almost directly vertically above the trailing edge portion of the trowel. The base plate 2l is at all times maintained in an upwardly spaced relation to the cement being troweled.
1. A device of the kind described comprising a plurality of trowels, a frame, a rotatable mounting means carriedby said frame whereon each of said and means to tiltably adjust said .trowels and` maintain them in adjusted position during their rotation, the weight of said frame being sup-- ported by said trowels at points located adjacent to the vertical planes occupied'by the trailing edge portions of the latter.
V2. A device of the kind described comprising a rotary head,. a set of arms whichradiate from said head each' in a generally horizontal direction, an elongated trowel extending along and secured to each of said arms, the inner end portion of each Vof said arms being angularly crank shaped, the inner extremity of each of said arms being turnably contained within a bearing provided for it on a part carried by said head, a sleeve member carried bysaid head in a vertically adjustable relation thereto, said head slidably supporting said sleeve member, a finger carried by each of the aforesaid arms, the extremity of said crank shaped arm portion being in a horizontally offset relation to said finger; said fingers each extending turnably into a seat provided for it in said sleeve, a tongue secured to saidYV head to propel the device,rand means to manually adjust said sleeve vertically and maintain it in .the adjusted position while it rotates Ywith said head.
3. A trowelingfmachine comprising a frame or supportl having ahandle portion-whereby it is propelled and prevented from rotating, a plurality of trowels radiating from a commoncenter, each .of said trowels having a trailing edge portion, a
them, an armfrigidly connected witheach 0i sai@ 7 5 trowels, said means for rotating the trowels having a bearing portion which is engaged by an end portion of said arm at a point adjacent to the vertical plane occupied by the trailing edge portion of said trowel, whereby the weight of the aforesaid frame or support is sustained at points substantially in vertical alinement with the trailing edge portions of said trowels, and means including a nger carried by each trowel in a horizontally offset relation to said end portion of the aforesaid arm to adjust the tilt of'V each trowel and maintain it in adjusted position during the operation of the machine.
Y 1.4. A device of the kind described comprising a non-rotating support, a plurality of trowels radiatingV therefrom, means whereby said trowels are rotatably connected with said support and are tiltably adjustable in relation to their widths along axes vertically above and parallel with their trailing edge portions, the weight of said support being thus supported along horizontal lines which extend along vertical planes which pass through the trailing edge portions of said trowels,
5. The subject matter of claim 8 and, the means for tiltably adjustingsaid trowels comprising an arm and a finger both rigidly fixed to each trowel, said arm having a terminal bearing portion which alines with the axis of tilt of the trowel and hasv a bearing in a partof said support, and said finger having ay circular extremity which engages( a circular bearing seat for it formed in a vertically adjustable part of said support.
6.; In a machine of the character described,.a frame, a rotary shaft depending from the frame, a base member secured to the lower end of the shaft, a plurality of circumferentially spaced bearings fixed on the base member, a sleeve mounted to slide axially o n the shaft and having'a plu-' rality of circumferentially spaced seat openings, a' plurality of flat elongated trowels extending ra' diallyfoutward of the shaft and'base member, an' arm fixed on and extending approximately along the longitudinal center line of each trowel, a right angularly extending arm at the inner end ofthe. arm, a crank pin extending inwardly from the outer end of said arm and turnably engaging one of said bearings, said crank pin being vparallel with and offset from the center line of the trowel a'di'stance approximating one half the width of the trowel, a finger member secured to one side of the arm on the trowel and parallel therewith, an inwardly projecting journal element at the inner end of the finger turnably engagingone of said seat openings in the shaft, and manually op- I erable means connecting'with the sleeve for vertically adjusting the head and frame with reference to the supporting trowels and effecting tilting of thetrowels with relation t0 the offset crank pins.
7. In a machine of the character described, a frame, a motor carried on the frame, an actuating handle attached to the frame, a rotary shaft, journaled on and depending from the frame, gear mechanism in the frame having driving connection with the motor for rotating the shaft, a tu-v bular head xed to and projecting below the shaft, a base member secured to the lower end of, the head, a plurality of bearings fixed on the base member Aoutwardly of the vhead and in circumferentially spaced relation, a sleeve .mounted to slide axially on said head, said sleeve having an annular groove in its upper portion and a plurality of circumferentially spaced seat openings therebelow, a plurality of fiat elongated trowels extending radially outward of the head and base, member, an arm xed'on and extending substanf,
tially along the longitudinal center line of each trowel, a right angularly extending crank arm at the inner end of the longitudinal arm, a crank pin extending inwardly of the outer end of the crank arm and turnably engaging one of said bearings on the base member, said crank pin being parallel with `and oiiset from the center line of the trowel a distance approximating one half the width of the trowel, an elongated nger bar secured to one side of the longitudinal arm and parallel therewith, an inwardly projecting journal element at the inner end of the finger bar turnably engaging one of said seat openings in the head, a lever pivotally connected to the frame having a handle portion extending outwardly of the pivot, and a yoke portion extending inwardly of the lever pivot having elements projecting into the groove in the head whereby vertical movement of the lever adjusts the head and frame with relation to the supporting trowels and effects tilting of the trowels with relation to the offset 10 crank pins.
LEE G. MATHEWS.