US3046855A - Concrete finishing machine - Google Patents

Description

July 31, 1962 .1.J. MORO-LIN ETAL 3,046,855

CONCRETE FINISHING MACHINE 2 Sheets-Sheet 1 Filed Dec. 19, 1957 July 31, 1962 J. J. MoRo-L1N ETAL 3,046,855

CONCRETE FINISHING MACHINE Filed Dec. 19, 1957 2 Sheets-Sheet 2 INVENTORSl 141 JbJe/a/ Mara -Lf effraie/M iam);

y @im United States Patent O 3,046,855 CONCRETE lilNiSfHNG MAC Joseph J. Moro-Lin, Glen Rock, and Leverette Hoeningtransen, East Paterson, NJ., assignors to Kalman Floor Company, incorporated, New York, NX., a corporation of Delaware Filed Dec. 19, 1957, Ser. No. 763,94@ 8 Claims. (Cl. 94-45) This invention relates to apparatus for the surfacing of plastic bodies and particularly to apparatus intended to be used for finishing surfaces of concrete slabs such as oor slabs. This invention is a modification on the apparatus disclosed and described in detail in our application Serial No. 682,716 led September 9, 1957.

Priorly, various types of mechanically operated mechanisms have been developed which were designed and intended to reduce to the minimum the lamount of manual labor which must be expended and the time required to reduce to a true plane and impart the desired surface finish to plastic bodies such as concrete oors, walks and roadways. A number of these mechanisms lhave come into widespread use, some particularly designed for use on roadways and others primarily intended for employment in the surfacing of floors. A known type of mechanically operated surface mecha- Vm'sm comprises a work engaging member, a motor coupled to the work engaging member for rotating the work engaging member `and a handle which prevents rotation of the motor casing and constitutes a means for moving the implement over the surface of a concrete body in the desired manner.

One particular form of mechanism known in the fart includes a mechanism for imparting 'to the rotating workengaging member high frequency vibrations so that the plastic body below the apparatus is not only subjected to the action of the rotating disc but is subjected to high frequency vibrations. Such -apparatus is highly effective and enables the user to properly surface a plastic body, such as a concrete floor, in a vastly improved manner. Thus, by the aid of the rotating and vibrating disc, an extremely dry concrete mixture may be surfaced, a mixture having a low water-cement ratio that it cannot be surfaced by ordinary means or methods since it is impossible to laterally displace or horizontally push material from the higher areas of the concrete onto the lower areas. The leveling of the floor surface is brought about by vertically depressing the higher areas instead of laterally displacing these areas and the concrete slab or the like which is produced is of superior construction, being more dense and free of voids. The surface is superior inasmuch as this method of leveling the Same results in bringing to the surface a relatively stiff paste of cement and fine sand barely sufficient in thickness for the fine trowelling by hand. The improved method not only gives a `superior product but insures substantial surfacing in time and labor costs. However, we have discovered that in employing vibratory and rotary motion to finish the concrete, it is not always necessary to employ both vibratory and rotary motion. For example, after the higher areas are vertically depressed and the plastic body approaches a level surface then the vibratory motion may be discontinued while maintaining the rotary motion to thus achieve an extremely smooth surface. One example of rotary and vibratory surface iinishing machine is disclosed and described in detail in R. E. Davis Patent No. 2,386,843, issued October 16, 1945.

Briefly, in accordance with the invention disclosed in our above mentionedV application, `a concerte nishing machine is enclosed in a stationary housing and provided with a cam plate associated with a wear or oor finishing plate. A group of spring biased plungers are mounted on the housing and are operatively linked to the cam surfaces by means of rollers mounted on the plungers. The prime mover or source of power for the machine is coupled to the wear plate by means `of a splined shaft and a splined plate to impart rotary motion while permitting axial vibratory motion of the wear plate. The shaft is spring biased by a helical shock absorber spring secured between the cam or master plate and the end of the shaft. The plungers are moved upwardly by the movement vof the rollers upon the cam surfaces and the motion of the plungers may be selectively discontinued by means of hydraulic cylinders and pistons located in the cylinders and each coupled to a plunger. As the cam plate is rotated by means of the Splined shaft, the rollers ride the cam surfaces and the connected plungers move out of engagement with the cam plate and return to the cam plate under the influence of the impact springs. Thus, the energy imparted to the impact springs by the cam plate is imparted to the plungers to return the pluri-gers to the cam plate, thereby giving a vibratory lmotion to the connected wear plate.

In accordance with other aspects of the invention disclosed in our above mentioned application, the plungers may vbe moved away from the cam or undulation plate by the operator during the finishing operation such that the rollers are disengaged from the cam surfaces. The reciprocating motion of the plungers formerly caused by the cam plate is thus terminated. The operator may thus terminate the vibratory motion imparted to the Wear plate and hence to the concrete floor without modifying the rotary operation.

In accordance with other yaspects of the invention dis- V closed in our above mentioned application, the plungers are spaced approximately apart on the housing of the machine while opposite pairs of the plungers are olfset a few degrees so that a beat frequency is generated by the cooperation of the plungers and the cam plate. By means of this beat frequency, the number of vibrations imparted to the wear plate and hence to the floor is greatly increased without the requirement that the wear plate be rotated at exceedingly high speeds.

During subsequent tests we have determined that still further improved results may be achieved by increasing the vibrating frequency and impact yof the reciprocating plungers while actually decreasing the power required to be imparted to the plungers. We have also discovered a novel pump mechanism for selectively controlling the actuation ofthe reciprocating plungers. n

Accordingly, it is van object of this invention to provide an improved concrete finishing machine.

It is another object of this invention to provide an improved conorete finishing machine which is adapted selectively .to apply vibratory motion -to the concrete mass.

It is another object of lthis invention to provide an improved vibratory-rotary concrete finishing machine which is simple in `construction and operation.

It is another `object of this invention to provide an improved concrete finishing machine in which vibratory motion of a higher frequency is imparted to the concrete mass from a single primemover yand the vibratory impact is increased without increasing the speed of the prime mover and while decreasing the power required to be impanted to the reciprocating plungers.

It is another object `of this invention to provide` an improved vibratory and rotary `concrete nishing machine which is simple in construction yand operation and thus economical yto build.

It is another object of this invention -to provide `an improved fiuid system for selectively controlling the actuation of the reciprocating plungers.

It is another object of this invention to provide an imline 3 3, of FIGURE 1.

aca-.6,855

proved uid pump for the fluid system which controls the actuation of the reciprocating plungers.

It is another object of this invention to provide the uid systempumpwith a piston which, in addition to pumping duid, also may ibe employed' to operate selectively a valve lassoci-atedr'with the pump.

. It visja further object of this-invention to provide the fluid control system of 4the machine with a piston which provides an `additional fluid passageway for Lthe fluid when the piston moves to open the valve associatedl with the pump. Y

[t isv a further object of this invention to provide the fluid controlsystem of the machine with a pump having Vcylinder and reduced the eiective impact of our prior Ymachine,V do not lmove with the reciprocating plunger butare nevertheless actuable to raise the plungers so that the rollers will lbe disengaged from the cam surfaces on the Wear plate.Y Such movement is possibile since the piston has ahollow tubular extension having an annular diange on the inner periphery which engages an annular protrusion or shoulder onthe reciprocating plunger. A plurality of curved members, such as metallic buttons, areV mounted in the Wear plate between the cam surfaces and are engaged :bythe tip of the reciprocating plunger. Advantageously, these .buttons are located concentrically with respect to the-cam surfaces andare positioned to engage the -tip of.I the plunger immediately after the associated roller 'has passed over thecrest of the foam surfaces. The' buttons thus cause the reciprocating plunger to have va vibratory motion at a frequency ygreater than that produced-by the rollers `and cam surfaces alone. Further, since'the plunger is reciprocally mounted with respect to the fluid piston, the piston does not act was a damping device to reduce the 'impact of the plungers;

It is another feature of this invention to provide undulatory surfaces on the Wear plate intermediate the cam surfaces to engage the reciprocating plungers and thus impart a greater frequency of vibration than could be achieved by the cam surfaces alone. Y

llt i-snanother feature of this invention -to provide undulatory surfaces on the Wear plate concentrically arranged with respect to the cam surfaces, which undulatory surfaces engage the tip of the reciprocating plungers and thus increase the frequency of the reciprocation of the plungers Without increasing the speed of motion of fthe Wear plate. j i

A complete understanding of this invention and of Vthese and various other features thereof may =be gained of FIGURE 1 to a larger scale.

FIGURE Y3 is a `plan view, partly in section, taken on FIGURE 4 is a view taken along the lines 4-4 of FIGURESZandS.

FIGURE 5 is a view in elevation, vpartly in section, of the fluid pump land a portion of the handle.

Referring now to the drawing, there is depicted one illustrative embodiment of this invention. As shownrn FIGURE l, a concrete finishing machine housing has a suitable prime mover 12 mounted thereon. This prime mover may be of `any convenient type such as an internal 4 combustion engine Ior an electric motor. connected to prime mover l2 and has a pulley le secured thereto to provide a means for operatively connecting the prime mover with the concrete contacting plate` as will be subsequently explained. A shaft 20 is rotatably mounted in housing 22 and has a pulley iii secured theret0. Pulleys 16 and 18 are oonnectedby means of a suitable V belt (not shown). on and secured to shaft 2u Within housing 22. A wheel gear 23 is secured to vertical'shaft 24-and positioned adjacent worm gear 2l so that Worm gear 21 drives wheel gear 23 when shaft 20 is rotatated by the prime mover 12. Shaft 24 is rotatably mounted in housing 1Q: Drive plate 26 is secured to the lower end of shaft 24 by means of nut 66.

Spaced around the periphery of drive plate 26 are aV Y plurality of bolts 2S used to interconnect drive plate 26 and master plate 32. Resilient bushings surround each of bolts 28 and are held in place by plates 29 which are secured to plate 26 by bolts 3l. Bushings Si) provideVV means for coupling the plate 26 -to masterplate 32 whilej preventing the vibration of master plate 32, from beingA transmitted to the gears 21-and 23,.p1ime mover 1Z-and to the operator of the machine. Vibration of gears and the prime mover would cause excessive Wear. Addi'-,

tionally, this vibration, if allowed toY reach the handle,

would make the machine diiiic'ult forthe operator vto, K

. control.

:Wear plate 34, which contacts ythe rsurface to lbe` tin-V ished, isz-connectedto master plate 32 by means of suit-V Y able bolts 36. A plurality of plunger assemblies 33 are mounted around the periphery of housing il?. Any convenient number of plunger assemblies may be employed,

depending on the lfrequency of vibration desired. For

example, six may be employed and they maybe spacedl Y approximately 60 apart. If itis vdesired to developa As best seeen in FIGURE 2, rollers 42 are rotatably" mounted on the lower portion of plungers 40 and these rollers operatively engage cam surfaces 43 and 45. A plurality of undulatory impact buttons 44 are concentrically arranged with respect to cam surfaces 43 and V45 in plate member 32. These impact buttons engage the tips 47 of plungers 40 .to produce supplemental vibrations` as will be subsequently explained.

Pistons 4S are slidably mounted in the upper housing of each vofjplunger assemblie'ss.Y These pistons include a tubular extension 52 havingan axial passageway therethrough to permit the plungersV 40 reciprocated relative to the pistons and :to act as arguide member 'forthe yreciprocating plungersyt. A suit-able fluid seal '.Stl'is secured to the lowerfportion off the outer-peripheryof piston 4S. 'Iubular-extension-SZ also acts as a guide member for the reciprocating plungers 40.' These Itubular extensions 52 have an annular shoulder 53 on Vtheirinn'er Y surface. Shoulder 52 engages Iannular ring 55 -on the plungers 40 when the pistons 4# are moved )upwardly by the introduction of fluid between pistons `iS/and the housings of plunger lassemblies 38. This duid is pumped through uidrpassage 56 from a vpump conveniently located on the machine handle, which will be subsequently described. The upward movement of pistons 48 disengages' the reciprocating plungers from the impact buttons 44 and disengages the rollers 42' irom the cam surfaces 43 and 45. Shoulders 53'areflocated lat .'a'point suiciently removed from they yupper, surfaces lof pistons A staan is A worm gear 21 is mounted f 48 to permit the plungers to reciprocate freely when the piston is in its lower position, as shown in FIG. 2. Fluid sealing washers 57 and 58 are positioned in the housings of the plunger -assemblies 38 'to provide a fluid seal'between the housings and the tubular extensions 52.

Helical springs 62 surround a portion of each plunger 4t) 'and engage annular shoulders 63 of each plunger 4G' and the lower surface of cylindrical member 64 which denes the upper portion of housing 1i) in the regions of the plungers 40. The plunger assemblies 3S :are secured to housing 1@ by means of suitable bolts 65. The tops of plunger -assemblies 38 are defined by members 67 which are secured by suitable bolts 68.

In order to prevent the entry of foreign particles into the machine housing, -a shield 70 is secured to the master plate 32 by means of suitable bolts '72. This shield is cylindrical in shape yand extends from the master plate 32 to a region adjacent the lower surface of housing 10, thus preventing the entry of foreign matter between housing 1i) land wear plate 32.

The operation of the reciprocating plungers. might be explained with regard to FlG. 4 which shows the relationship of cam surfaces 43 and 45 and impact buttons 44. As shown in FGURE 4, rollersj42 co-operate with cam surface 45 to produce reciprocating motion of the piston 4G. Cam surface 45 includes a substantially flat trough 160 and a peak or crest 102 at the termination of an incline plane 194, which plane is connected to a trough 1G13. The entire length of a given cam surface is measured from lone crest or peak to the next crest or peak and this length is termed the cam pitch. The extreme lower portion 166 of plunger 4i? is disengaged from the undulatory buttons 44 when the rollers 42 ride up on the incline planes 164 'as master plate 32 is rotated by the 102, the energy stored in spring 62 is imparted to the plunger or piston 49, causing plunger -tip 106 to strike the undulatory Kbutton 44 as shown -in the middle dotted line of FlGURE 4 and thus impart vibratory motion to the master plate 32 each time the rollers 42 pass a pair of crests 162.

Since the plungers 40' are not rigidly connected to pistons 48, -these pistons do not move with the plungers. Thus, the plungers do not incur frictional losses which might be introduced by the pistons sliding up and down the cylindrical chambers, as they would if the pistons were secured to the plungers. Thus by virtue of the reduced drag, less power is required to ydrive the reciprocating plungers than would be required if the pistons were secured to the plungers. Further, even though less power is required an increase impact force is obtained since the pistons do not slow the downward motion of the plungers. Advantageously, a higher rate or frequency of impact is achieved by the use of the impact buttons 44 which engage the tips 47 of plungers 4G' `and this increased frequency of impactV is achieved with less driving power than the devices of the type disclosed in our application Serial No. 682,716 tiled September 9, 1957.

Referring now to FIG. 5 there is depicted a portion of handle 80 having a fluid pump 82 mounted thereon. 'I'his iiuid pump S2 is `connected through a suitable flexible conduit or hose 84 to pipe S6 located within housing 1li. Pump `rassembly 82 includes a iiuid reservoir 85, a piston housing 87, Ia pair of piston members 89 and 91, a ball check valve 93, biased into apclosed position by spring 95, and a pump handle assembly 97. Fluid reservoir 85 is provided with va ball type vacuum relief valve 99 and a cover 101 which threadably engages the reservoir 85 to permit uid to fbe inserted in the reservoir. Piston member 89 is provided with -a fluid seal 103 located in an annular recess 195 to prevent the passage of fluid beto its seat.

ture 113 in reservoir 85 when piston member 89 is at.

the forward end of its stroke.

Advantageously, piston member 91 `has a reduced portion 115 which provides a passageway between member 91 and the inner wall of piston member 89. This passageway is connected with passageway -111 and also connects with hose or conduit 84 when member 89 is advanced by rotation of knob 199 to unseat ball check valve 93. The normal position of member 91 is that shown in FIG. 5 in which enlarged member .117 acts as a valve to seal the passageway between piston members S9 and 91 so that the two piston members may act as a single unit to pump fluid from reservoir 82 into hose 84.

The operation of the uid pump is `as follows: When the handle assembly 97 is manually moved to the opposite end of its stroke, as shown in the dotted outline, piston members 89 and 91 are withdrawn beyond aperture 113 and iluid passes from reservoir S5 into the chamber thus provided between the ends of piston members S9 and 91 and ball check valve 93. When the handle assembly 97 is returned to the end of its stroke, as shown in solid lines, the iiuid in the chamber is subjected to pressure and fthe fluid causes the valve 93 to be unseated. When valve 93 is unseated, the uid passes around the Valve into conduit 34. When the piston reaches the end of its stroke, the ball check valve is again forced into its seated position. by spring 95 and the cycle may be repeated `until sufhcient iluid pressure is built up within chambers 41 to cause the pistons 48 to move into their uppermost position. Pistons 48 thus lift plunger tips 47 out of engagement with impact buttons 44 and rollers 42 out of engagement with cam surfaces '43 'and 45. Thus the reciprocation and resulting impact of the plungers may be selectively discontinued. When the operation of the reciprocating plungers is discontinued, the wear plate may be rotated and used as a vibrationless means for achieving a tine iinish on the concrete surface. Thisstep is usually employed after the concrete has reached a relatively smooth surface -and it is merely necessary to achieve a polishing action on the upper surface `of the concrete without laterally displacing portions of ythe concrete. With such 1an arrangement, it is possible for the operator to employ both rotary 'and reciprocating motion to displace the concrete from the peaks into the valleys during the initial stages of finishing the concrete surface and employing only rotary motion to achieve a high degree of finish after Ia relatively smooth surface has been achieved. If the operator then desires to move into a new or unfinished portion of the concrete surface and again employ vibratory rotation, he merely rotates handle 109 until member 91 moves to `unseat ball check valve 93. Simultaneously with the displacement of ball check valve 93 from its seat, a passageway is provided between piston members 89 and 91, through apertures 111 and y113 to the duid reservoir 85. Helical springs 62 now act to restore plungers 49 to their lower position land thus aid ythe iluid under lpressure to cause the fluid in chamber 41 to be driven through conduits 46 land 84 back to reservoir 85. When the fluid pressure is equalized by the return of a substantial volume of iluid `to the reservoir, then handle 169 maybe rotated Ito reseat member 113 in piston member S9 and `to permit ball check valve 93 to return Under these conditions, 'the plunger rollers 42 and plungers 40 impart vibratory motion to the surface of the concrete by wear plate 34 'and the cycle of operations may be repeated.

Thus, it is apparent that this simple concrete finishing machine achieves a high rate of vibratory motion to finish the surface oi the concrete and this high -rate of vibration is achieved with less power than in machines of the type known in the art.

' I-t is also apparent that the fluid system of this machine includes a simple pump to control selectively the actuation of `the reciprocating plungers by meansof anunusual piston assembly, la' portion of which piston assembly acts simultaneously to open a ball check valve and to open a passageway through the piston which communicates with the uid reservoir.

VWhile the principles of this invention have been explained with referenceV to one illustrative example, it is understood that they may be applied to various other equivalent embodiments without departing from the spirit and scope `of this invention.

We claim:

Y1. In a concrete linishing machine or the like, a stationary housing, a wear plate rotatably mounted relative to said housing, means -for rotating said wear plate, cam surface means `on said Wear plate, impact surfaces intermediate said Xcam surface means, reciprocating plunger means mounted in said housing at intervals around said housing above saidjcam surface means for selectively engaging said cam surfaces and said impact surfaces, tluid actuating means for selectively delivering a uid, and uid actuated means coupled to said lfluid actuating means `and slidably coupled to said reciprocating plunger means and having `cooperating shoulders thereon, yeach tluid actuated means having an internal shoulder cooperating with fan external shoulder on one of said plunger means for selectively lifting said plunger means out of engagement with said camvsurfaces and said impact surfaces in response to the delivery `of lluid from said fluid actuating means to said fluid actuated means.

2. In a concrete nishing machine or the like, according to claim 1 wherein said impact surfaces include a plurality of impact lbuttons deiining curved surfaces which are'struck by the tips of the saidplunger means to produce vibratory motion of said wear plate.

3. In a concrete iinishing machine r the like, in accord-ance `with claim yl wherein said tluid actuating means includes a piston housing, a piston reciprocably mounted in said housing, a valve Vdefining a closure of `one end of said housing and a fluid reservoir having an aperture therein defining a fluid passage ito said piston housing, said nid actuating means Vincluding means for moving a portion of said piston relative to another portion of said piston to provide a iiuid passage between said valve and said aperture, and means for reciprocating said piston within said housing.

4. In a concrete finishing machine a combination comprising a housing, ya concrete contacting wear plate rotatably mounted relative rto said housing and having cam surface means connected thereto, `a plurality of vibratory plungers reciprocably mounted in said housing at intervals around said housing above said cam surface means to f engage said cam surface means at one end of their stroke to produce vibratory motion, said plungers having rollers thereon, said cam surface means beingV positioned to engage said-rollers, spring means on said plungers for moving said plungers toward said wear plate, piston means slidably connected to each'of said plungers, each of said piston means having an internal shoulder thereon cooperating vwith an external shoulder on one of said y i plungers for lifting said plunger when said piston means is moved away `from said wear plate and fluid means for moving said piston means in a direction to disengage said rollers from said cam surfaces while said wear plate continues to rotate, selectively to terminate the vibratory motion produced by said plurality 'of plungers.

5. In a concrete nishing machine the combination ac- A cording to claim 4 wherein said lluid means comprises a uid reservoir, a piston housing secured to said reservoir and having a passage communicating therewith, a Vpump piston reciprocably mounted therein, a valve positioned in a valve seat in said housing, springY means ,urging said valve against said valve seat, said pump piston vbeing mov'- able to a position to unseat said Valve from said valve seat.

6. In a concrete nishing machine according to claim 5 wherein said pump piston comprises an outer cylindrical member having a radial passage therethrough which cornmunicates with said reservoir only when said pump piston is at the end of its forwad stroke and an inner rod portion, oneend of which has an outer diameter substantially equal to the inner diameter of said outer cylindrical member, the other end of which inner rod portion has a diameterk of said outer cylindrical member to provide a passage therebetween, which rod portion terminates in an enlarged portion which seats against a recess in the end of `said outer cylindrical member to'act as a valve to close the iuid passage through said piston.

`7. In a concrete iinishing machine according to claim 6 the combination further comprising iirst handle means for advancing said inner rod member with respect to said',

outer cylindrical memiber t0 unseat said enlarged terminal portion of said rod member thereby opening the iluid passage through said piston and contacting said spring urged valve to open said valve and permit the passage of uid around said valve, through said piston to said reservoir.

8. The combination according to claim 4 wherein said Y shoulder is on the inner surface of said piston means and wherein one of said vibratory plungers is reciprocahly mounted within each of said piston means and has a shoulder thereon positioned to engage the shoulder on said piston means, said fluid means including means for moving said piston means whereby said shoulders engage surface.

References Cited inthe file of this patent UNITED STATES PATENTS 1,811,556 2,128,779 Knight Aug. 30, 1938 2,140,970 Reedy Dec. 20, 1938 2,557,880 Lynn June 19, 1951 2,646,729 Godenir July 28, 1953 l2,680,347 Kanuch June 8, 1954 2,723,608 Jackson Nov. 15, 1955 ,2,882,806 fThiemeu; Apr. 21, 1959 FOREIGN PATENTS 311,346 Switzerland Jan. 31, 1956 Nilson June 23, 1931

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