US3531812A - Surface treating machine - Google Patents

Description

M. K. BAILEY ETAL SURFACE TREATING MACHINE Filed Oct. 31. 1968 INVENTORSZ MALCOLM \4. BAJLEY and ALBERTAJ. GQGUEN ATTORNEYS Uted States 3,531,812 Patented Oct. 6, 1970 3,531,812 SURFACE TREATING MACHINE Malcolm K. Bailey, 23 Tallman St., Jacksonville, N.C. 28540, and Albert A. J. Goguen, Rte. 1, Box 354, Carteret City, NC.

Filed Oct. 31, 1968, Ser. No. 772,114 Int. Cl. A47l 11/12 U.S. Cl. l97 6 Claims ABSTRACT OF THE DISCLOSURE A surface treating machine wherein a surface engaging tool is driven in orbital motion and wherein the surface engaging tool is mounted in skewed relation to the rotational axis of the drive shaft from which motion is derived so as to obtain wiping contact with the surface being treated and to avoid excessive heating during surface treatment.

Surface treating machines such as polishers, buffers, sanders and the like are employed in a wide range of manufacturing processes and consumer services. While different problems arise in the use of these various surface treating machines, certain common problems may best be described with reference to the polishing of a surface being treated, such as the application and bufiing of a wax coat. For example, it is conventional practice to protect the exterior finish of an automobile by the application of coats of wax and to impart a lustrous appearance to such surface by buffing the wax coat. The surface treating machines available for use in applying and bufling such wax coats have employed a surface engaging tool or head which is driven in rotation at relatively high speed by direct connection with the shaft of an appropriate motor, such as an electric motor.

As is well known to operators of service establishments such as service stations and car Washes, such a conventional buffer can do serious damage to the finish of an automobile if placed in the hands of an inexperienced worker. In particular, the speed of relative movement between the surface engaging tool and the painted surface of the automobile is sufficiently high as to frictionally generate heat at relatively high rates. Unless care is taken by the operator of the buffer, heat generated in this manner is sufficient to mar the painted finish of an automobile, in a manner known to the trade as burning. The necessity of placing a conventional buffer only in the hands of an experienced worker has significantly increased the cost of labor encountered by service establishments in proving Waxing and polishing service.

It has been noted that the high-speed rotary movement of the surface engaging tool of a conventional buffer differs markedly from the motion used in applying and polishing a wax coat by hand. More particularly, the usual hand motion is a rocking orbital motion, in which the hand is moved in a general orbital path over the surface to be treated and is simultaneously rocked somewhat from side to side to vary the contact between a polishing cloth or other tool held in the hand and the surface engaged thereby. The difiiculty noted in connection with conventional rotating buffers and the like has never been encountered with hand polishing, but the high labor cost of a hand-applied and polished surface treatment has made reliance upon hand motion economically disadvantageous.

While the discussion to this point has been particularly directed to problems encountered in the polishing of the surface being treated, as in the application and bufiing of a wax coat, it is recognized that orbital motion has heretofore been used in certain surface treating operations and notably in the sanding and finishing of wooden articles such as furniture. While orbital motion surface treating machines have been adopted for these processes in an effort to approximate the usual hand motion, the surface treating machines so used position the entirety of the rubbing surfaces of the surface engaging tools thereof in contact with the surface being treated. Thus the problems of heating or overloading of the rubbing surface materials are encountered in the use of such surface treating machines as well in the use of purely rotary polishers.

Having in mind the difficulties heretofore encountered with surface treating machines of the high-speed rotary type, it is an object of the present invention to provide a surface treating machine of the orbital motion type wherein the relative motion betwen the rubbing surface of a surface engaging tool driven by the treating machine and the surface being treated thereby approximates the wiping motion of hand polishing and excessive heating during surface treatment is avoided. In realizing this object of the present invention, a surface engaging tool having a rubbing surface for treating a surface engaged thereby is constructed and arranged in a particular manner, so that it is free to rotate while being driven in orbital motion and also moves with a rocking and wiping motion. In the surface treating machine in accordance with the present invention, the desired motion for the surface engaging tool is attained by providing that the tool is operatively connected to an eccentric mounting means for free rotation relative thereto about an axis spaced from and directed at a predetermined skew angle to an axis about which the eccentric mounting means is driven by the drive shaft.

Some of the objects and advantages of the invention having been stated, others will appear as the description proceeds, when taken in connection with the accompanying drawings, in which FIG. 1 is an elevation view, in partial section, of a surface treating machine in accordance with the present invention;

FIG. 2 is an inverted plan view, in reduced scale, of portions of the machine of FIG. 1, taken generally as indicated by the line 22 in that figure;

FIG. 3 is a plan view, in reduced scale, somewhat similar to FIG. 2 of other portions of the machine of FIG. 1, taken generally as indicated by the line 33 in FIG. 1;

FIG. 4 is an enlarged scale elevation view, in partial section, through a portion of the machine of FIG. 1, il lustrating in detail an eccentric mounting means and a portion of a surface engaging tool;

FIG. 5 is an enlarged scale perspective view of the eccentric mounting means of FIGS. 1 and 4;

FIG. 6 is a reduced scale elevation view similar to FIG. 4, particularly illustrating a skew angle between certain elements of the machine of FIG. 1; and

FIG. 7 is a view similar to FIG. 6, taken from a direction perpendicular to the direction from which FIGS. 6, 4 and l are taken.

Referring now more particularly to the drawings, a surface treating machine 10 in accordance with the present invention is there disclosed (FIG. 1) and the particular details thereof which result in approximation of the wiping motion of hand polishing will be described hereinafter. In order to permit an operator of the machine 10 to hold and traverse the machine across a surface being treated, the machine includes a housing 11 formed by any suitable means, such as injection molding of plastic material, and having a pair of laterally extending handle mounting arms 12 and 13. Extending between the arms 12 and 13, on opposite sides of the housing 11, are a pair of handgrip bars 15 and 16, secured to the arms 12 and 13 in any appropriate manner. Supported within the housing 11 is a drive means, illustrated as being an elec- 3 tric motor 18. In the embodiment shown, the electric motor 18 is secured in place within the housing 11 by a mounting flange '19 bolted to one end of theframe of the motor 18 and to a flared depending skirt portion 20 of the housing 11. The electrical motor 18 receives current through suitable conductors 21, wired through a snap switch 22 which provides an operator of the surface treating machine 10 with control over energization of the motor 18.

The surface treating machine 10 includes a surface engaging tool, generally indicated at 25, having a rubbing surface for engaging and moving relative to the surface being treated. Preferably, the rubbing surface of the surface engaging tool 25 is substantially planar, and defines a principal plane for the tool 25, indicated in FIG. 1 by a dash line 26. Where the surface treating machine 10 is to be employed in waxing and polishing painted surfaces of automobiles, it is preferred that the surface engaging tool 25 be constructed of a body of foam or sponge material 28 secured to and supported by a pan-like reinforcing member 29 of fiber glass or thin metal sheet. A suitable polishing bonnet 30 is positioned encompassing the foam member 28 and reinforcing member 29 and is made of an appropriate polishing material, such as terry fabric. In use, the bonnet 30 directly engages the surface to be treated and relative movement between the bonnet 30 and the surface imparts the desired buffing and polishing elfect.

In order to drive the tool 25 in orbital motion, an eccentric mounting means, preferably in the form of a member as generally indicated at 34, provides an operative connection between the motor 18 and the tool 25. The eccentric mounting member 34 includes an axis defining portion 35 and a counterweight portion 36, for purposes to be described more fully hereinafter. The axis defining portion 35 has a pair of openings formed therein, preferably as drilled and tapped holes 38 and 39. As pointed out more fully hereinafter, each of the holes 38 and 39 is formed about a predetermined central axis, respectively identified as the axes 40 and 41 (FIG. 5).

In order to drive the eccentric mounting member 34 in rotation, the member 34 is secured to the shaft 44 of the electric motor 18, for rotation with the shaft 44 about a first axis defined thereby. The operative connection between the eccentric mounting member 34 and the drive means shaft 44 is made by threaded engagement of a free end of the shaft 44 with the larger drilled and tapped hole 38 of the two holes formed in the axis defining portion 35 of the eccentric member 34. The direction of threading for the shaft end and the cooperating threaded opening 38 are chosen in predetermined relation to the direction of rotation in which the mounting member 34 is driven by the motor 18, in order to insure that eccentric member 34 does not become loosened from the shaft 44 during use of the treating machine 10'.

To insure that the surface engaging tool 25 has imparted thereto orbital motion and that Wiping contact between the rubbing surface of the tool 25 and the surface being treated is obtained, the tool 25 is operatively connected to the eccentric mounting member 34 for free rotation relative thereto about an axis spaced from the axis of rotation of the drive shaft 44 and directed at a predetermined skew angle thereto. This operative connection between the surface engaging tool 25 and the eccentric mounting means 34 preferably is attained through the use of a mounting means including, in part, a boss 45 secured to the reinforcing member 29 of the tool 25, at a central location thereof (FIG. 1 and 4). The mounting boss 45 defines a relatively large diameter central opening therein, sized to receive therewithin the outer races of a pair of antifriction bearings 48 and 49. The inner races of the bearings 48 and 49 are penetrated by a mounting bolt 50, which enters into and engages the smaller diameter threaded opening 39 in the axis determining portion 35 of an eccentric member 34. By

means of the connection of the mounting bolt 50 to the eccentric mounting member 34, the inner races of the bearings 48 and 49 are held fixed in relation thereto and rotate with the eccentric member 34 about the first axis as defined by the drive shaft 44 of the motor 18. Due to the connection of the mounting boss 45 and thus the tool 25 with the outer races of the bearings 48 and 49, the tool 25 is free to rotate relative to the eccentric member 34 about a second axis, defined by the central axis 41 of the smaller diameter threaded opening 39 and the central axis of the mounting bolt 50 and the bearings 48 and 49 which are aligned therewith.

In order to provide a rocking, wiping action for the rubbing surface of the tool 25 as the same moves with orbital motion over a surface to be treated, the first and second axes extend at a skew angle relative to each other. Preferably, skewing of the first and second axes is obtained by skewing the central axes 4:0 and 41 of the threaded openings 38 and 39 in the axis determining portion 35 of eccentric member 34. Such skewing is accomplished during machining of the eccentric member 34, and results in positioning the principal plane 26 of the rubbing surface of the tool 25 at an angle other than a right angle to the first axis as defined by the drive shaft 44. This nonperpendicular relationship results in contact between the rubbing surface of the tool 25 and the surface being treated being a wiping motion approximating the wiping motion of hand polishing and in the drawing beneath the tool 25 of a flow of air which serves to cool the rubbing surface of the tool and the surface being treated, thereby avoiding the burning problem which has heretofore been encountered with high-speed rotary buffers and the like.

In an operating embodiment of the surface treating machine 10 of the present invention, the skew angle between the first and second axes is doubly skewed. That is, as measured when porjected into one or more planes, the skew angle will be found to have varying values. Thus, in order to fully state the direction and magnitude of skew, it is preferred that the skew angle be designated as projected to each of two planes for measurement. In connection with measurement of the skew angle in this matter, it is pertinent to point out other additional characteristics of the eccentric mounting member 34 and surface treating tool 25 which contribute to attainment of the desired operating characteristics for the machine 10.

In particular, in order to assure smooth orbital movement of the surface engaging tool 25, it is preferred that the center of gravity of that tool lies directly on the second axis, about which that tool rotates relative to the eccentric mounting member 34. In the illustrated embodiment and as constructed in an operating embodiment of this invention, the center of gravity is located substantially in the plane of the reinforcing member 29, and thus is spaced a predetermined distance upwardly of the rubbing surface at which the surface undergoing treatment is engaged. The center of gravity of the counterweight portion 36 of the eccentric mounting member 34 preferably is located relative to the larger threaded opening 38 in a position diametrically opposite the smaller opening 39, as being approximately at the juncture of the vertical reinforcing web 51 and the outer radial mass of the counterweight portion 36. As may be noted from FIGS. 1 and 4, the center of gravity of the eccentric mounting member 34- is spaced a predetermined distance above the principal plane 26 of the rubbing surface of the tool 25 which distance is greater than the distance of spacing of the center of gravity of the tool 25 itself. Further, due to the skewing of the axes 40 and 41 about which the rotation of the eccentric mounting member 34 and the polishing tool 25 rotate, movement of the centers of gravities is in nonparallel planes. That is, the plane defined by the path of movement of the center of gravity of the eccentric member 34 is not parallel to the plane defined by the path of movement of the surface engaging tool 25.

In defining the specific angles of skew between the first and second axes, it is necessary to define the particular planes to which the skew angle is to be projected for measurement. Inasmuch as a plane is defined by the location of a line and a point, reference to this geometrical fact is used in defining the planes to which the skew angle is projected for measurement. A first plane for projection of the skew angle may be defined by the line of the first axis of rotation, namely the central axis of the driving shaft 44, and the center of gravity point of the eccentric mounting member 34. In the drawing, the view of FIG. 6 is taken as though in a plane parallel to a projection plane as so determined. For purposes of illustration, the skew angle has there been exaggerated so as to be more readily apparent. In an operating embodiment of the machine 10, the skew angle as so measured in a first plane of projection is at least about 1. For convenience, the second plane to which the skew angle is projected for measurement is taken as a plane through the first axis and directed perpendicular to the plane employed in measurement as represented by FIG. 6. That is, the second plane for propection and measurement of the skew angle extends through the central axis of the drive shaft 44 and at right angles to a plane through that axis and the center of gravity of the eccentric mounting member 34. FIG. 7 is a representation of the pertinent elements of the surface treatment machine 10 as viewed in a plane parallel to the second projection plane, with the skew angle between the axes of rotations exaggerated for purposes of ready comprehension. In the operating embodiment of the present invention, the angle of skew between the first and second axes as measured in the second plane of projection is at least about 2.

In brief summation, it is believed apparent that a surface treatin-g machine has now been disclosed which permits attaining a wiping contact with the surface being treated, which wiping contact more nearly approximates the wiping of hand polishing and permits entrainment of cooling air flow between the rubbing surface of a surface engaging tool and the surface being treated, thereby precluding excessive generation of heat by friction.

In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

What is claimed is:

1. A surface treating machine of the orbital motion type wherein wiping contact is obtained with the surface being treated and excessive heating during surface treatment is avoided, the machine comprising:

drive means including a shaft defining a first axis and driven in rotation thereabout,

eccentric mounting means secured to said shaft for rotation therewith about said first axis,

a surface engaging tool having a rubbing surface for treating a surface engaged thereby, and

means mounting said surface engaging tool on said eccentric mounting means for free rotation of said surface engaging tool about a second axis spaced from and skewed relative to said first axis, for orbital motion about said first axis upon said eccentric mounting means being driven in rotation by said drive means, and for rocking movement of said rubbing surface relative to a surface engaged thereby, in approximation to the wiping motion of hand polishing and so as to entrain cooling air between said rubbing surface and the surface being treated.

2. A surface treating machine according to claim 1 wherein said rubbing surface of said surface engaging tool is at least substantially planar and defines a principal plane of said tool and further wherein said principal plane extends in nonperpendicular relation to said first axis.

3. A surface treating machine according to claim 1 wherein said rubbing surface of said surface engaging tool defines a principal plane of said tool, said tool has a center of gravity lying substantially on said second axis and spaced a first predetermined distance from said principal plane, and said eccentric mounting means includes a counterweight portion having a center of gravity lying on the opposite side of said first axis from said second axis and spaced a second predetermined distance from said principal plane, said first and second distances being unequal.

4. A surface treating machine of the orbital motion type wherein wiping contact is obtained with the surface being treated and excessive heating during surface treatment is avoided, the machine comprising:

drive means including a shaft defining a first axis and driven in rotation thereabout,

eccentric mounting means secured to said shaft for rotation therewith about said first axis and including a counterweight portion,

a surface engaging tool having a rubbing surface for treating a surface engaged thereby and defining a principal plane of said tool, said surface engaging tool being operatively connected to said eccentric mouning means for free rotation relative thereto about a second axis on the opposite side of said first axis from said counterweight portion and spaced from and skewed relative to said first axis,

the operative connection between said surface engaging tool and said eccentric mounting means driving said surface engaging tool in orbital motion about said first axis upon said eccentric mounting means being driven in rotation by said drive means, with said principal plane in nonperpendicular relation to said first axis for rocking movement of said rubbing surface relative to a surface engaged thereby, in approximation to the wiping motion of hand polishing and so as to entrain cooling air between said rubbing surface and the surface being treated.

5. A surface treating machine according to claim 4 wherein said skew angle between said first and second axes is at least about 1 when measured as projected to a plane determined by said first axis and the center of gravity of said counterweight portion.

6. A surface treating machine according to claim 4 wherein said skew angle between said first and second axes is at least about 2 when measured as projected to a plane through said first axis and perpendicular to a plane determined by said first and the center of gravity of said counterweight portion.

References Cited UNITED STATES PATENTS 1,521,620 1/1925 Hadaway. 1,609,508 12/1926 Cavicchi. 7 1,648,663 11/ 1927 Stratford. 2,034,455 3/1936 Baird. 2,547,057 4/1951 Stieglitz. 2,917,979 12/1959 Dening et al. 2,942,384 6/ 1960 Higley. 2,967,315 1/ 1961 Helbig et a1. 3,084,364 4/1963 Hutchins. 3,251,087 5/ 1966 'Platt. 3,416,177 12/1968 Young. 3,448,476 6/ 1969 Zaccone. 3,445,877 5/1969 Stout.

WALTER A. SCHEEL, Primary Examiner L. G. MACHLIN, Assistant Examiner

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