US 2748408 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
June 5, 1956 Filed NOV. 8, 1951 L- ZAiGER ET AL 2,748,408
APPLYING AND POLISHING APPARATUS 2 Sheets-Sheet l Iva 6 225022? Z0052? Z0 er Hafieri Z: [a Z! W/Mmmm June 5, M56 Q L- ZAEGER ET AL 2,748,408
APPLYING AND POLISHING APPARATUS Filed Nov. 8, 1951 2 Sheets-Sheet 2 J/////%%///////////////II'IIM Q, 3 a [9' J United States Patent APPLYING AND POLISHING APPARATUS Louis Zaiger, Swampscott, and Robert I. Lappin, Marblehead, Mass.
Application November 8, 1951, Serial No. 255,374
2 Claims, (Cl. 49)
This invention relates to power operated apparatus for applying a dressing to floors and like surfaces and for polishing the dressing after it has been applied.
Apparatus of this kind is available with one or two applicator pads or brushes. Apparatus equipped with a single applicator has the advantage of low power consumption, simplicity and cheapness, but has also a strong inherent tendency to wander in the direction of rotation of the applicator so that there is a constant pull in one direction or the other which must be counteracted by a conscious effort on the part of the user. This becomes tiring, annoying and in inexperienced hands, frequently results in temporary loss of control which results in damage to the paint on base boards and/or badly scarred furniture. At the expense of simplicity, lightness and cheapness, heavier machines have been made equipped with two applicators or brushes arranged to rotate counter to each other so that the tendency of one brush to cause wandering in one direction is theoretically balanced by an equal tendency for the other brush to wander in the opposite direction. It was found, however, that while wandering was reduced to a large degree by the use of counterrotating brushes, it was not entirely. eliminated especially if one brush has more weight on it than the other, for example, if the overall weight of the applicator is not evenly distributed so that the brushes are unevenly loaded.
The principal object of this invention is to provide an applicator which will have little or no tendency to wander, and hence may be guided with a minimum of effort. Another object is to provide improved attachment of the applicators or brushes to their driving shafts to eliminate in so far as possible the transmission of wobble and vibration to the unit induced by uneven brush surfaces. A still further object is to provide improved fastening means so that the brushes or applicators can easily be removed and replaced.
As herein illustrated the apparatus has a frame and applicators and a motor for driving the same mounted on the frame, the foregoing parts being so designed and located that the center of gravity of the parts falls midway between the centers of rotation of the applicators and on a line passing through the centers of rotation. The frame is symmetrical with respect to the aforesaid center of gravity. The applicators are mounted for rotation on a pair of applicator shafts journaled on the frame so as to be equidistant from the center of gravity and to lie along the line extending transversely of the frame through the center of gravity. The shafts are substantially perpendicular to the plane of the frame and their upper ends are operably connected to the driving meanswhich is also mounted on the frame at its center and is symmetrical with respect to the center. The driving means is in the form of an electric motor arranged so that its weight is distributed evenly about the center and its armature and shaft tur-nabout an axis passing through the center of gravity, parallelto the applicator shafts and has a comparatively high operating speed so that it provides a gyroscopic effect which resists lateral displacement of the apparatus as a whole from straight line movement. The applicators have sockets which telescope over the ends of the shafts and are made fast thereto by spring locks. To permits rotation about the true centers of the shafts, the sockets have slightly larger cross sections than the shafts so that a slight clearance is left between them which permits the applicators to tilt with reference to the shafts and the spring locks are designed to permit such movement while preventing the applicators from endwise movement on the shafts.
The invention will now be described in greater detail with reference to the accompanying drawings wherein:
Fig. l is a plan view of the top of the frame;
Fig. 2 is a plan view of the top of the frame with the motor and cover removed to show the gearing;
Fig. 3 is an elevation at one end of the frame showing a part of the handle, the remainder being broken away;
Fig. 4 is a vertical section, transversely of the frame taken on the center line 4-4 of Fig. 1;
Fig. 5 is an enlarged fragmentary vertical section taken on the line 5-4? of Fig. 1, showing the applicator shaft, the applicator and the locking means for securing the applicator to the shaft; and
Fig. 6 is a plan view of the latch for securing an applicator to its shaft.
Referring to the drawings the apparatus has a frame 10 of substantially rectangular shape with parallel front and back sides, and rounded ends. The frame is preferably a casting consisting of a rigid panel 12 with which there are formed upwardly and downwardly extending integral flanges 14 and 16 which extend peripherally thereof. The upper flange 14 forms with the upper side of the panel a shallow upwardly facing chamber 13 for receiving parts of the operating mechanism as will appear hereinafter. The downwardly projecting flange 16 has a laterally projecting substantially horizontal flange 18, from the perimeter of which extends downwardly a skirt 19. The flanges 16 and 18 and the skirt 19 form with the underside of the panel 12 a downwardly facing housing for the heads of the applicators as will appear hereinafter. The frame as thus constructed is preferably made of some light metal such as cast aluminum and is symmetrical with reference to both its geometric center and center of gravity as represented by the intersection of the lines aa and bb (Fig. 2) so that its weight is distributed evenly about the center 0. The underside of the panel 12 also has formed integral with it bearing bosses 20 and 22.
A cover 24 also made of cast aluminum is provided for closing the open top of the chamber 13 and has a downwardly projecting rim 23 for engagement with the upper edge of the flange l4. Screws 15 (Fig. 1) provide means for fastening the cover down. The cover has formed integral with its underside bearing bosses 30 and $2. The upper side of the cover 24 has cast integral therewith an annular housing 34 which has a circular opening 36 (Fig. 1) in its top and an opening 38 projecting rearwardly therefrom. The housing 34 is adapted to receive a motor M which is mounted therein with its axisof rotation perpendicular to the frame and with its drive shaft not shown extending through the bearing boss 30 in the cover into the chamber 13. The housing 34 and its opening 36 are symmetrical with respect to the center of gravity c and hence when the motor is mounted therein its weight is distributed equally about the center of gravity.
The motor used to power the apparatus in contrast .to.
prior apparatus is of comparatively high speed operating at about 16,000 R. P. M. Running at this high speed the motor behaves somewhat like a gyroscope and this tends to keep the entire mass of the apparatus in place and to reduce its tendency to displace itself from its initial position.
A pinion 44 is made fast to the motor shaft and meshes with a gear 48 mounted on a shaft 46 which is journaled in bosses formed between the cover 24 and panel 12. The shaft 46 is parallel to the motor shaft and is centered on the line bb behind the motor shaft as illustrated in Fig. 2. The gear 48 has integral with it on its undesired (Fig. 2) a smaller gear for engagement with a pair of gears 52.52 mounted on spaced parallel shafts 5656 centered on the line aa at opposite sides of the motor shaft. The gears 52-52 in turn mesh with a pair of gears 5454 mounted on spaced parallel shafts 5858, centered on the line a-a and parallel to the motor shaft. The shafts 56-66 are journaled in the bosses 22 and 32 while the shafts 5853 are journaled in the bosses and extend through the panel 12 to the underside thereof for receiving the applicators shown at 60.
As illustrated, the applicators 60 are brushes although it is to be understood that they may be felt or lambs wool pads depending upon the use to be made of the apparatus. In Figs. 3, 4 and 5, each applicator 60 is shown as being comprised of a rigid circular wooden head-block 62, the underside of which has fastened to it a plurality of tufts of bristles or yarn 64 forming an applicator or brush 66 having a working surface 68. The center of each block 62 has an opening 70 therethrough in which is placed a sleeve 72. The sleeve has a peripheral flange 74 for engagement with the block about the opening 70 through which may be inserted attaching means such as screws or nails 75. The sleeve opening 76 is hexagonal and the lower end of the shaft 58 is made hexagonal in shape as indicated at 78 and of somewhat smaller cross section than the cross section of the sleeve so that there is some play between the shaft and the sleeve permitting lateral tilting or wobbling of the brush head on the shaft. The clearance between the sleeve and shaft will permit the brush to find its own center of rotation in the event that the brush surface 68 is not perfectly flat. Such uneveness may be the result of storage on an uneven surface or for long periods with uneven weight so that they take a permanent set.
The lower end of the sleeve 72 has an inwardly projecting annular lip 70a and the hexagonal portion 78 of the shaft 58 is turned down to provide a cylindrical portion 74a and shoulder 72a which rests on the lip 70a. The brushes or applicators are held in place on the shafts by latch members 78a, one of which is shown more fully in Fig. 6. Each latch is a substantially wedgeshaped sheet metal plate. The latch plate has a hole 82 in its apex end through which a screw 80 may be inserted for pivotally fastening it to the underside of the block 62. A wide slot 84 extends from one edge of the plate at its wide end to about its mid point and has an inner rounded end 86 for engagement within a groove 76a cut in the surface of the cylindrical end 74a of the shaft 58. The plate is made of springy metal and a narrow slot 87 extends from the inner rounded end 86 of the wide slot toward and nearly to the opposite edge of the plate so that the portions of the plate at opposite sides of the slots 84 and 87 will yield appreciably in the plane of the plate. Thus, even though the applicator is locked to the shaft it has flexibility as to its center of rotation, that is the locking plate will yield to permit the applicator to find its own center of rotation with respect to the shaft. A finger hold 88 in the form" of a lip formed integral with the plate and bent at right angles thereto so as to extend vertically downward from the plate at a point opposite the end of the narrow slot 87, provides means for disengaging the plate from the shaft when it is desirable to remove the brush and also strengthens and gives flexibility to the plate.
Bosses 90 having threaded studs 92 are screwed into the opposite ends of the frame (Fig. 4) on the line aa. Each boss has projecting from it a stud 95 for pivotally receiving a handle. The handle is an elongate shaft 94 of tubular stock to the lower end of which is fastened a yoke 96 having legs. The lower extremities of the legs are substantially vertical. and have openings 98 therein for receiving the ends of the studs 95. The shanks of the studs 95 close to the bosses are smooth so as to provide smooth bearing surfaces for the legs and their outer ends are threaded to receive nuts 102. As thus mounted, the handle may be rocked about the axis a-a and its weight, is evenly distributed about the center of gravity of the apparatus.
To prevent damage to base boards and furniture in use, a resilient guard 104 preferably of rubber or some rubber-like composition is mounted on the flange 19. To this end the flange 19 is provided with a horizontal shoulder 19a and the guard is made substantially C-shaped so as lockably to engage the shoulder and the lower extremity of the skirt.
The frame may also have on it forwardly and rearwardly extending bosses 106 (Fig. 2) in which are threaded openings 108 for receiving screws in the event that it is desirable to place a dust-proof cover over the entire top of the frame so as to conceal the motor and impart an overall streamlined appearance to the apparatus.
The important aspects of this improved apparatus are principally in so designing the frame and component parts of the drive carried by the frame that the weight of the frame and its parts are distributed evenly about a common center both as to geometry and weight, thereby distributing the weight of the entire apparatus equally on the two brushes or applicators, and of using a high speed motor located in such a position that its rapidly turning armature and drive shaft produces a gyroscopic effect on the apparatus as a whole which tends to prevent its displacement for straight line motion. By taking care to distribute not only the brushes and motor symmetrically with. respect to the center of gravity but also the gearing drivably connecting them and the handle for pushing the apparatus about, the tendency to wander is reduced to the vanishing point. In addition to the uniform weight distribution, uniform and even movement of the apparatus is further insured by mounting the applicators so that they are free to wobble slightly and hence find their own centers of rotation.
It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.
1. In an applicator a substantially symmetrical frame, a motor mounted on the frame at the geometrical center thereof with its drive shaft perpendicular to the frame and coinciding with the geometrical center thereof, a pair of spaced parallel, rigid applicator shafts journaled on the frame at equally spaced points at opposite sides of the motor shaft in a plane extending transversely of the frame through the axis of the motor shaft for rotation about their vertical axes, means operably connecting the motor shaft to the applicator shafts, said means being symmetrically disposed about the motor shaft, each shaft having a tapered lower portion of polygonal right crosssection for drivably receiving the head block of an applicator, and a cylindrical end portion of smaller diameter than the smaller end of the tapered portion, each shaft having an annular shoulder at the junction of the tapered portion and the cylindrical portion and an annular groove in the cylindrical portion, an applicator mounted on the tapered portion of each shaft having a central opening in which is fixed a hollow sleeve having an inner polygonal surface. correspondingin cross-section to the crosssection of the larger end of the tapered portion of the shaft and being of uniform cross-section throughout, so
that there is lateral play between the sleeve and the shaft which permits rocking the applicator on the shaft, an
annular, inwardly extending shoulder at the lower end of the sleeve constituting a thrust bearing against which the shoulder on the shaft bears, and a latch pivotally fastened to the underside of the head block adjacent the sleeve opening for arcuate swinging movement relative thereto, to lock the head block to the shaft or release it, said latch having a slotted recess therein engageable with the annular groove in the shaft to retain the applicator on the shaft, the portions of the latch at opposite sides of the slotted recess being yieldable in the plane of the latch to permit play of the applicator on the shaft with respect thereto as afforded by the tapered portion of the shaft, and said latch being comprised of a thin spring sheet metal elastically yieldable perpendicular to its plane to permit the applicator to move axially on the shaft.
2. In an applicator according to claim 1, a one piece frame having a transverse division wall through which are bearing openings for the applicator shafts and upwardly and downwardly projecting peripheral walls forming with the transverse wall an upper shallow recess for housing the driving mechanism and a lower recess for housing the upper portions of the applicators.
References Cited in the file of this patent UNITED STATES PATENTS