US 2671915 A
Description (OCR text may contain errors)
March 1954 R. FRASER ETAL FLOOR-CONDITIONINGASSEMBLY FOR FLOOR MAINTENANCE MACHINES 3 Sheets-Sheet 1 Filed Sept. 24, 1948 A/l E/VTdAS 4 SER.
I hiwa iiliiu March 1954 R. FRASER ET AL FLOOR-CONDITIONING ASSEMBLY FOR FLOOR MAINTENANCE MACHINES 5 Sheets-Sheet 2 Filed Sept. 24, 1948 42 fig Ma'rch R FRASER ETAL FLOOR-CONDITIONING ASSEMBLY FOR FLOOR MAINTENANCE MACHINES 5 Sheets-Sheet 3 Filed Sept. 24, 1948 pw e/v m/a s 1905597- FRASER Vex/v0 6 54 77/ Two/y VIIIII'IA Patented Mar. 16, 1954 OFFICE FLOOR-CONDITIONING ASSEMBLY FOR FLOOR MAINTENANCE MACHINES Robert Fraser and Vernon Heath Tuson, Beckenham, England Application September 24, 1948, Serial No. 51,046
This invention relates to floor conditioning assemblies for machines of the kind adapted for use in maintaining floors cleaned or polished.
An object of this invention is to ensure, in a machine adapted to be moved along a floor and having power-driven gyrating floor-conditioning units, that the said units are protected against the effect of their engaging a projection on the floor while in operation.
Further objects and advantages of the invention will be apparent from the following description of an embodiment thereof, as applied to a floor scrubber, which is given by way of example and with reference to the accompanying diagrammatic drawings, in which:
Fig. 1 is a side elevation of the complete scrubber part of one wall of a tank 95 for dirty cleansing solution being broken away to show its interior and one part (41) being broken away for better illustration,
Fig. 2 is a front elevation with a tank for soap solution and carrying handles omitted,
Fig. 3 is a section of a detail on the line 3-3 in Fig. 1,
Fig. 4 is a half plan view of the complete scrubber, an operators handle being omitted,
Fig. 5 is a section of part of driving and control means for the brushes,
Fig. 6 is a section of a detail of these control means. I
Fig. '7 is a section of an adjustable control valve for the cleansing solution.
Fig. 8 is a rear elevation of a fishtail nozzle, partly in section on the line 88 in Fig.1, the rear end wall of the scrubber being removed to show details,
Fig. 9 is a section on the line 9-9 in Fig. 8,
Fig. 10 is a plan of part of the brush driving gear, sectioned on the line I0-l0 in Fig. 5,
Fig. 11 is a side elevation of this gear, with only one of three brush-carriers in position.
A carriage, which is about 30 inches long, consists of a fiat platform 20 roughly pear-shaped in plan, raised about 4 inches above the ground and having a skirt-like flange 2| depending almost to ground level, the stem end of the pear shape being at the rear end of the carriage. The flange 2! follows a 180 circular are at the front end of the platform and continues rearwards firstly as two parallel walls for a short distance and finally as two straight walls 2lA converging towards the rear end of the carriage. The side portions of the flange 2| have rubber lips 22 extending down to floor level and serving as splash guards. The converging walls 2IA are provided 2 with rubber lips which act on the floor as squeegees and each of which consists of two strips of rubber 23 and 24 (Fig. 3) held by screws 25 and a clamping strip 26 against the inner face of the wall ZIA.
The carriage runs on two co-axial rubber-tired wheels 21 outside the flange 2| near the front end and two rubber-tired castors such as 28 between the walls 2 IA.
A sleeve-shaped housing 29 (Fig. 5) projects vertically through the platform 20 co-axially with the arcuate portion of the flange 2|, and a hollow shaft 30 is slidable vertically and rotatable in a bushing 29 in the housing sleeve 29. The lower end of the shaft 30 projects below the platform 20 and. is rigidly connected to a gear wheel 3!. A lowering pin 32 passes co-axially through the hollow shaft 30 and is provided near its upper end with an annular abutment flange 33 cooperating with the upper end of the hollow shaft 30. A sun wheel 34, 6 inches in diameter and having a tire of friction material 35, is fast on the lower end of the pin 32. The hub of this wheel forms an annular abutment co-operating with the lower end of the hollow shaft 30. This shaft is therefore constrained to slide up and down with the pin 32 but can rotate around the pin. A helical spring 36 compressed between the I upper end of the housing sleeve 29 and the flange 33 tends to keep the hollow shaft 30 and the pin in a raised position.
The gear wheel 31 has three spokes on each of which is mounted a lever 31 carrying a respective floor-conditioning unit and angularly movable about a vertical pin 38 fast in the spoke. Fixed to the free end of each lever 31 is a depending journal pin 39 carrying the floor-conditioning unit; in this embodiment the unit comprises a wheel-shaped. brush backing member 40 which is 6 inches in diameter and the periphery of which is held in frictional engagement with the tire 35 of the wheel 34 fixed on the lower end of the lowering pin 32 so that the backing 40 acts as a planet pinion and the wheel 34 acts as a fixed reaction member. The brush backing has a central oil-less bushing 4| and is retained on the pin by a snap ring (not shown) engaged in a groove 42. The lower face of the backing 40 is provided with vertically depending bristles, only one tuft of which is shown at 43. The engagement of the rim of each backing 40 with the tire 35 is maintained by a tension spring 44 (Fig. 10) having one end anchored to a pin 45 on the 44 on the lever 31 tends to rotate the latter on its bearing pin 38 in such a direction that the brush backing 40 is urged radially inwards into frictional engagement with the fixed tire 35.
An operators handle 46 (Figs. 1 and 2) is forked at its lower end, the two prongs of the fork being pivotally mounted in bearing brackets 41, fixed onthe platform 20, for rocking about a transverse axis. Tension springs 48 acting between the ends of the handle prongs and anchorages 49 on the brackets 41 bias the handle towards a vertical position.
Means are provided for preventing the lower ing pin 32 from rotating and for causing it to be lowered under control of the operator" to en'- gage the brushes with the floor. These means include a bell-crank lever 50" (Fig.5): capable-rot. rocking in a transverse vertical plane about a pivot pin carried by a dome 52 fixedby screws 53 to a flange 54 on the housing sleeve 29 and enclosing the upper part of the hollow shaft 30. The screws 53 pass through the platform 20, which is nipped between the dome 52 and the flange 54. One arm of the bell-crank lever 50 extends through diametrically opposed vertical guide slots 55 in the dome 52 and engages'in a transverse slot 56 in the upper end portion of the lowering pin 32, whereby this pin is prevented from rotating. The other arm of the bellcrank lever terminates in an anchorage for a flexible cable 5! passing through a flexible casing 58 to a stirrup 59 (Figs. 1 and 2) pivoted to a hand lever 60 which is pivoted to a lug 6'I- on' the handle 46. When the hand lever 80 is raised through 180 it draws the cable 51, and tension in the cable locks the lever in the raised position. The upper end of the casing 58- reacts against an abutment G2 fixed to the handle" 48. The lower end of the casing 58 reacts against a plunger 63 slidable in a hollow adjusting screw 64 (Fig. 6) engaged in a tapped hole in one of the brackets 41. The plunger 63 is loaded by a compression spring 65 and thus forms a resilient abutment for the casing 58.
Movement of the flexible cable 5'! to the left as seen in Fig. 5 causes downward" movement of the arm of the bell-crank lever 50 engaging the lowering pin 32, so that-the pin-and the sun wheel 34 are. moved downward. against the action of the spring 36. 3| is moved downward. by the engagement of abutment flange 33 with the upper end of the hollow shaft 30, so that the three brush backing members 40 remain in engagement with the wheel 34. Thus, raising and lowering of the hand lever 60 causes downward and upward movement respectively of the brushes to engage them with and to disengage them from the floor, also respectively. The resilient abutment for the casing 58, provided by the plunger 63 and the spring 65, ensure that a sudden upward movement of the brushescaused for example. by a projection on the floor, does not cause undue strain of the cable 51.
An electric motor 66 having a continuous rating of A; H. P. at 1400 R. P. M. is fixed to the platform 20. The motor spindle 61 (Fig. 11) projects below the platform and carries a pinion E8 engaging the gear wheel3I, the pinion being long enough to accommodate the. rise and. fall of the gear wheel. The reduction ratio is 98/11.
A tank 69 on the front of. the platform carries cleansing solution. On the top of. the tank is a filling funnel i0 adapted to receive a. stream. tipped from a bucket. The funnel is externally Simultaneously, the gear wheel of box-like form. A floor II slopes rearwards and downwards over the front half which is open, and a cover I2 encloses the rear half. Liquid passes from the funnel to the tank 69 through a transverse slot 13 at the rear of the base of the funnel. Two air vent pipes I4 open above the cover I2 and pass downwards into the tank in which". they open horizontally.
A combined metering and stop valve I5 con trols the fiow of cleansing solution from the tank 69 to a pipe I6 which feeds the solution to a point in: advance. of. the scrubbing circle. The valve 15' (Fig. 7); has-a tubular body having at its inner end a screwedspigot 11 held in a hole in the tank. 68 bya nut 18. An aperture 19 in a diaphragm wall is normally closed by a tapered needle; BIMfnrming the tip of a plunger 8! slidablaina hollow adjusting screw 82 engaged in a screw-threaded part. 83 of the valve body. A flange 84 on the plunger is a sliding fit in a cylindrical bore 85 in the body communicating with thedelivery pipe16. An enlarged portion 86 of the plunger is a sliding fit in a counterbore formed inthe inner end of the screw 82 and accommodating a helical compression spring 81 which biases the plunger towards the closed position. A resilient-packing washer 88 is fitted betweenthe flange 84 and the screw 82. The valve is opened by' pulling the plunger BI until it is arrested by the abutting of the flange 8,4v against the washer 88. This washer thereupon operates to prevent leakage of solution between the valve body and the adjusting screw and between this screw and the plunger. The position of the adjusting screw determines the degree of. opening of the valve. A hand lever 89 (Fig. 2) 0n the handle 46 is pulled upwards by the operators gripping the handle and pulls a flexible cable 90 led through a flexible casing 9| contained between an abutment 92 fixed to the handle- 46 and an adjustable abutment 93 (Fig. 7). mounted on oneof the brackets 41. The cable 90 is connected tothe plunger by a closecoiled tension spring 94. When the hand lever 89-is operated; the initial movement of the cable 90 opens the valve 15 to the full extent permittedby the setting of the screw 82, the rest of the movement of the cable bieng accommodated by expansion of the spring 94.
On the rear part of the platform 20 is a closed tank- 95 for" dirty cleansing solution and surmounted by a single-stage centrifugal fan 96 directly driven by an electric motor 91 having a continuous rating of H. P. at 10,000 R. P. M. I'hefan inlet communicates with the tank 95 and the fan discharges to atmosphere. A sight glass 98 is marked to indicate the maximum working level-ofliquid'in the t'ank95, which is fitted with a drain valve 99;
A suction flshtail' nozzle I00 (Figs. 1, 2, 4, 8 and 9) 21 inches wide is-fitted transversely close behind the trailing ends of the squeegees 23, 24 and'provided with a narrow slot-like mouth I 0|. 'I'worubber squeegee strips I02 and I03 are fixed to the back of the nozzle mouth by a clamping strip- I04 and screws I05. The nozzle I60 is integral with a tubular stem IOB'passing vertically upwards with a slight clearance through a standpipe'l 01 projecting upwards from the floor of the tank95. The bore of the standpipe may taper slightly to a minimum at its top end. The upper end of the stem I06 projects above the top of the standpipe I01, the mouth of the latter being sealed by' a rubber garter I08 stretched around the mouth of the standpipe and the part of the stem projecting above this mouth. The stem consequently is free, within limits, to tilt laterally and to move longitudinally with respect to the standpipe. The nozzle is kept at right angles to the longitudinal axis of the machine by engagement of its end portions in guide slots I in the Walls ZIA. Two helical springs H0 compressed between the platform 20 and the nozzle I00 urge the latter towards the floor. The slight clearance of the stem in the standpipe I0'I allows the nozzle to assume a position slightly out of level if an uneven floor requires this. The stiffness of the rubber strips I02 and I03 in relation to the force exerted by the springs I is such that the rubber strips are bent as shown in Fig. 9 while the machine is operating and yet do not allow the lip of the nozzle to touch the floor. The rear strip I03 is slightly deeper than the front strip I02.
On the under side of the top of the tank 95 is an annularly dished deflector HI (Fig. 1) aligned with the standpipe I01, and behind the deflector are two baffles H2 and H3 extending from side to side of the tank and from the top to a level below the mouth of the standpipe. A third bafiie H4 extends from side to side of the tank and from its bottom nearly to its top between the baflies H2 and H3. The inlet to the fan 96 opens out of the tank behind the baffle I I 3.
Means for lifting the nozzle clear of the ground, in order to facilitate sluing of the machine or wheeling it idly, include a cam shaft H5 (Fig. l) fitted with a hand lever H6 and journalled in the walls 2IA. Two cams Ill fast on the shaft I I 5 co-operate with two levers I I8 pivoted at one end to lugs H9 on the under side of the platform 20. The other ends of the levers H8 are engaged under pins I fixed in lugs on the nozzle I00. When the cams are in the position shown in Fig. 9, the nozzle is kept in its operative position by the springs I I0. If the hand lever I I6 is moved forwards the cams ll! raise the levers I I8 and lock them in the raised position, so that the nozzle is held clear of the fioor.
The machine is fitted with two lifting handles such as I2I, which are omitted from Fig. 2.
In operation, the machine is manoeuvred, with the nozzle raised, to the point where it is required to start work, the lever H6 is operated to lower the nozzle, the motors 06 and 01 are switched on, and thereafter the hand lever 60 is raised to lower the brushes into contact with the floor and the hand-lever 89 is raised to start the delivery of cleansing solution through the pipe 76. The machine is now pulled or pushed slowly forward by means of the handle 06. The gear wheel 3I is rotated by the motor pinion 63 and the brushes are thereby rolled around the tire which, being fixed to the shaft 32, is held stationary by means of the lever so that the brushes perform a gyratory movement, imitating more or less the efiect of hand scrubbing. It will be evident that the direction of rotation of the brushes relative to the gear wheel 3|, is the same as the direction of rotation of this gear wheel relative to the floor. The brushes therefore tend to sweep the solution towards the axis of the gear wheel, and the solution is thus kept largely within the range of action of the brushes. The pressure with which the brushes bear on the fioor is determined by the extent to which the spring E (Fig. 6) becomes compressed when the hand lever 00 is in its raised position, and the extent of compression of the spring can be easily adjusted by varying the setting of the adjusting screw 04. The scrubbing pressure should be such that the tips of the bristles do the work, which is the correct action of a scrubbing brush and not such that the bristles tend to lie fiat. The minimum length of bristle depends on the irregularity of the floors to be worked on, the more irregular the floor level, the longer the bristle necessary. For general purposes a bristle projection of 1 inches is satisfactory.
As the brushes scrub the floor, the forward motion of the machine causes dirty cleansing solution to be left behind the brushes, and this solution is wiped from the borders of the scrubbed part by the squeegee strips 23 and 24 and moved towards the middle of the nozzle I00. The squeegee strips I02 and I03 on the nozzle prevent any substantial quantity of solution from being left on the floor behind the machine, the solution wiped up by these strips being carried up the stem I 06 by the air current developed through the nozzle I00 by the fan 96. The deflector III directs the solution towards the bottom of the tank 95, and the air is substantially freed from traces of moisture by its sinuous passage around the edges of the baffies H2, H4 and H3.
When the machine is required to be turned at the end of a straight run, the hand levers 60 and 89 are dropped to raise the brushes and interrupt the feed of cleansing solution, and the hand lever H6 is moved forwards to raise the nozzle so that the machine can be easily turned or slued.
1. A floor-conditioning assembly for a floor maintenance machine, comprising a housing, a
rotatable member, a bearing in said housing mounting said member for rotation about the axis of the bearing, a motor for rotating said rotatable member, a plurality of rotatable floorconditioning units carried by said rotatable memher and each including a planet pinion, a reaction member fixed relatively to the housing and engageable with the planet pinions, so that said units gyratein response to rotation of the rotatable member, means mounting said units on the rotatable member and permitting translational movement of the units with respect to the rotatable member in a direction for disengaging the planet pinions from said fixed reaction member, and resilient members biasing said units for translational movement with respect to the rotatable member in the direction to engage the planet pinions with said fixed reaction member.
2. An assembly as claimed in claim 1, wherein the said fixed reaction member comprises a stationary sun wheel and each planet pinion is frictionally engageable with said stationary sun wheel.
3. A floor-conditioning assembly for a floormaintenance machine, comprising a housing, a rotatable wheel, a bearing in said housing mounting said wheel for rotation about the axis of the bearing, a motor for rotating the wheel, a plurality of arms pivoted to said wheel about axes parallel to said bearing axis, a plurality of rotatable floor-conditioning units, each carried by the free end of one of said arms and each including a planet pinion, a reaction member fixed relatively to the housing and frictionally engageable with each planet pinion, so that the said units gyrate in response to rotation of said wheel, and springs biasing said arms for movement about their pivotal axes with respect to the rotatable wheel, so as frictionally to engage said planet pinions with said fixed reaction member.
7 4. Anassembly as-c1aimed-= in claim .3 ,wherein said. fixed reactionv member comprises a. stationary sun 7 wheel, and said, planet wheels: have their rims frictionally engageable with therim of said stationary sunwheeL I 5. An assemblyas. claimed in-claim 3, wherein said floor-conditioningunits include a plurality of backingmembers. which are circular in plan forming th said planet pinions.
ROBERT FRASER.v VERNON HEATH TUSON.
References Cited in the file of this patent UNITED STATES PATENTS Number- Number 8 I Name Date. Faustini Apr. 23, 1918 Wagoner. July 8, 1924 Carrie. Oct. '7, 1924 Newcomer June 24, 1930 Gillis Aug. 26,. 1930 Einnell' Mar. 15, 1932 Bickford Jan. 3, 1939 De Spirt Aug. 29, 1939 Finnell July 8, 1941 Steele Oct. 27, 1942 FOREIGN PATENTS Country" Date Switzerland Dec. 1, 1947 Germany June 24, 1929 Great Britain July 19, 1950