US2187131A - Finishing and polishing method and equipment - Google Patents

Description

Jan. 16, 1940. c. .1. LIPPOLD.

FINISHING AND POLISHING METHOD AND EQUIPMENT 5 Sheets-Sheet 1 Filed March 13. 1937 attorneys Jan. 16, 1940. c. J. LIPPOLD 2,187,131

FINISHING AND POLISHING METHOD AND EQUIPMENT Filed latch is. 195'! 5 Sheets-Sheet 2 Z 3nvfavxtor WMMQ MM Gttornegs c. J. LIPPOLD 2,187,131

5 Sheets-511961. 3

Enventor Jan. '16, 1940.

FINISHING AND rousnme umnon AND EQUIPMENT 1 Filed March 13. 193'! 1g I J I": a: 1

1- l n a 1 i N N K r L a J FINISHING AND POLISHING METHOD AND EQUIPMENT Filed latch 13, 1937 5 Sheets-Sheet 4 IIII/I (Ittornegw Jam 1940- C. J. LIPPOLD FINISHING AND romnme METHOD AND EQUIPMENT- 5 Sheets-Sheet 5 Filed larch 13. 1937 Snoentor GttomeyS;

Patented Jan. 16, 1940 PATENT OFFICE j 'FINISHING AND POLISHING METHOD AND EQUIPMENT CarlJ. Lippold, Wauwatosa, Wis., assignor to J. M. Nash Company, Milwaukee, Wis., a corporation of Wisconsin Application'March 13, 1937, Serial No. 130,673

8 I Claims.

. My invention relates to improvements in methods of and equipment for abrasively finishing or polishing spokes, handles, poles, rollers,

tubes, and other articles.

Objects of my invention are to providemea-ns for obtaining greater precision, expedition, and uniformityofabrasive. action,-to provide for in creasing the efiiciency of an abrasive belt or strip in proportion toits width,-to provide a. method of polishing in which the abrasive follows the grain of the wooden pieces of work of circular cross section to such an extent as to" obtain substantially absolute uniformity of abrasive action, and conforms closelyto the contours ofturned pieces of ;work which are being'rotated about their axes while advancing across 'the abrasive .surface,.,- -to provide means-whereby the same equipment can be employed to' polish pieces of work of different cross sectional diameters,- and in general, to provide a method whereby pieces of work may be completely and uniformly finished throughout their'length in a. single traverse of-anabrasive surface, or of a plurality of abrasive surfaces, where finishing with a coarse. abrasive is to be followed by finishing withma finer abrasive. v 1

A further object is toprovide means for'opcrating rough finishing and smooth finishing belts either in the same or in opposite directions.

More specifically, my objectisto provide a method for axially advancing pieces of work of circular cross. section while rotating suchpieces about their own axes, and simultaneously subjecting each such piece of work to the actionof polishing strips of. material moving along lines oblique to the axis of thework, whereby to, increase the effective surface of the abrasive strip in proportion to its width and enable the strip to follow the grain of a wooden piece of work along helical lines of contact with the work in a manner to reach every portion of the work with substantially equal polishing effects.

A further object'is to provide a compact and eilicient polishing machine having the working parts completely housed and organized in such a manner: as to permit maximum accessibility by opening hinged doors or wall members at one side of the machine, which maybe regarded as the front side, Whereas the'motor and its driving connections are accessible through a rear door, and may be largely separatedfrom the working parts by an intermediate partition. l

Further objects are to provide improved work advancing, work guiding, and thrust resisting devices in association with adjusting means peculiarly adapted-to the requirements imposed by the novel mode of operation.

In the drawings:

Figure 2 is a front elevation, with the doors largely broken away.

Figure 3 is a fragmentary view, in elevation, as

Figure 7 is a sectional view taken on line l''l of Figure 5.

Figure 1 is a plan View with the cap removed.'-

Figure 8 is an end elevationof the parts shown I in Figure 3.

j Figure 9 is a fragmentary plan view showing pins and rail.

' Figure 10 is a viewsimilar to Figure 1, showing a modification, and with end portions broken away.

Figure 11 is a diagram showing independent means for driving successive sanding belts.

Figure 12 is a detail view showing a modi- Like parts are identified by the same reference characters throughout the several views.

By my improved method I hold the piece of work to be polished in contact with a traveling abrasive surface, with the axis of the work, or,

its grain, oblique tothe line of travel of the abrasive, and preferably at approximately a degree angle thereto. I positively rotate the work about its own axis and axially advance it preparatory to bringing it in contact with said abrasive surfacaand'also during such contact and while it is moving-out of such contact, while holding it to said oblique line and. regulating its rotative and axial movement independently of the tractive effect of the belt.

1 preferably employ mechanical means to automatically predetermine the rate of work rotation and the rate of axial advancement of the work and its oblique pitch with reference to the line of travel of the abrasive and maintain both factors of movement at a rate of speed much slower thanthe abrasive material, but with a higher rate tating Work conforms to a helical line.

Due to the relatively slow movement of the work in planes of advancement and of rotation oblique to the line of travel of the abrasive, the abrading operation is in helical paths, approaching parallelism with the grain. And if the speed of Work advancement is predetermined by the work supporting rollers, all surfaces of the work may be polished more perfectly and with substantial uniformity than by moving the polishing material across the grain at substantially right angles thereto, and the polishing operation may be completed in a single traverse of the work across an abrading belt or set of belts.

In this manner the field of abrasive operation is greatly increased in proportion to the width of the belt or belts, since the work travels across the abrasive surface in an oblique line of much greater length than that of a transverse line at right angles to the belt. The increase in length is proportional to the pitch or degree of divergence from the line of travel of the abrasive material. Tearing effects upon the fibers of Wooden articles are considerably reduced.

In the accompanying drawings I have shown my invention applied to a machine designed for polishing spokes, handles, and other articles composed of wood, although my invention may be utilized for polishing articles composed of any material, molded, cast, or otherwise shaped or rough finished preparatory to a final finishing or polishing operation in the machine herein disclosed.

In Figure 1, trough-shaped work holders I4 and 15 are employed to guide the work through a housing l2 within which one or more sanding belts l3 and 14 are mounted. The sanding belts may be of ordinary type, and it may be assumed that the sanding belt I 3 carries a relatively coarse abrasive material, whereas the sanding belt l4 carries a finer abrasive.

As shown in Figure 2, these sanding belts pass over driving pulleys I 6 and idle pulleys ll, l1 and I1", respectively, the working portion of each belt being the portion between its associated pulleys l1 and I1. Belt tensioning pulleys l8 may also be employed. Each of these tensioning pulleys i8 is supported by a bell crank I9, fulcrumed at 20, and having its short arm connected by a spring 2| with a frame bracket 22. The short arm of the bell crank is pivotally connected with stop arm 23, which is provided with stop shoulders 24 and 25, either one of which may be engaged with a fixed shoulder 26 on the bracket 22. If the associated sanding belt should break, the spring 2| will recoil and tend to drive the tension roller I8 outwardly. but this movement is limited by the shoulder 24 on the stop arm when it engages the fixed shoulder 25.

Also, when replacing a worn belt, the operator may retract tension roller H! by pushing outwardly on the arm 23 until shoulder 25 engages the shoulder 26. When the substitute belt is in place, the operator manually releases the stop arm from the shoulder 26 and allows it to rest loosely on the upper surface of the bracketQas shown in Figure 2.

It will be understood that belt I4 is similarly mounted and driven. The driving pulleys l6 are mounted upon a shaft 27, driven by a belt 28 from a motor 29.

The working portions of the belts l3 and I4 are supported in the area of work contact by the upper surfaces of suitable supporting pads 30, preferably formed of canvas, mounted upon yielding blocks 3! of sponge rubber, socketed in spring supported shoes 32 carried by the frame brackets 33. The strips of canvas 30 are hooked to the shoes 32 as indicated at 34, and their upper surfaces are coated with graphite or other antifriction material, whereby wear upon the sanding belts may be reduced to a minimum.

In Figure 4 I have indicated the relation of a rod or piece of work A to the portion of the sanding belt l3, which has its under surface traveling upon the pad 30, and it will be observed, in Figures 2, 3, and 4, that the thrust of the work is received by a guide rail 31 on pins 33 depending from an overhanging plate 39. This plate forms part of an adjustable frame supported by an overarm 4a (Figure 8), carried by the housing or main frame of the machine.

The plate 39 has an extension 42 which may be clamped by bolts 43 to a flange 44 projecting horizontally from a vertically adjustable carrier plate 45. The flange 44 has depending marginal projections which support adjusting screws 41 operated by hand wheels 48 to shift the plate 39 forwardly or backwardly when the clamping screws 43 are loosened. This adjustment is made to accommodate work of differing diameters.

In Figure 3, plate 45 is illustrated as provided with a pinion 50, operable by means of a hand wheel 5|. The teeth of the pinion mesh with the teeth of a, rack member 52 carried by the overarm 40, whereby rotation of the hand wheel 51 may raise or lower the plate 45.

The plate 45 is provided with vertical slots 53, through which clamping bolts 54 extend to clamp the plate 45 to the overarm after it has been adjusted to the desired elevation by the hand wheel 5|.

By moving plate 45 upwardly and moving'the plate 39 forwardly, work of increased diameter may be accommodated. The contrary adjustment is made for work of decreased diameter.

In Figure 8 it will be observed that a vertically adjustable bracket 55 is mounted upon the rear face of the vertically adjustable carrier plate 45. These plates are normally secured by clamping bolts 56. When these screws are retracted the bracket 55 may be moved upwardly by the adjusting screws 51. Vertical slots in the plate 45. through which the bolts 55 pass, permit this adjustment.

The bracket 55 carries a series of roller supporting bell cranks 58, each of which has a stud 59 upon which a roller 60 is mounted in a position to bear upon the upper surface of the work. Each bell crank is placed under resilient tension by a spring 5| (Figure 3), connected with bell crank short arm 52. The rollers 50 are preferably formed of rubber, having suificient resistance to hold the work to the sanding belts under a pressure predetermined by the tension of the springs 5|.

Each roller 60 is individually mounted and adapted to yield independently, whereby turned pieces of work differing in diameter in difierent portions may be moved axially along this line of rollers and their associated guide pins 38.

The rollers 60 are idle rollers, the work being actuated from below, as will now be explained.

In Figures 1 and 5, work supporting and driving rollers 63, 64 and 65 are illustrated as mounted upon driving shafts 66, 61, and 68, respectively. The sanding belt l3 runs across the space between rollers 63 and 64, and the sanding belt l4 runs across the space between the driving rollers 64 and 65. Except along their marpressure contact; by one or more of the overhead determine, the rate of pressure rollerstii. Ihe sanding beltsare depressed by the work as it'advances: over their inclined margins; :11 the work were not rotated while. approaching and leaving the sanding belts,

the latter would grind flatsurfaces on the endv portions. Therefore such preliminary and final rotation is important.

-The1driving shaft 5!; for the-roller- 63 is driven from :the' motor 29 by means of the belt 10, shaft H, and sprocket chain 12, the latter runningo-ver a'sprocket wheel 13 secured to theshaft 6'6.- The shaft 6;! is driven from the. shaft 66 through sprocket chains 15 (Figure 1-) and shaft 68; is driven-from shaft 8'!- through the sprocket chain "it. Resilient mountings'l'l may be provided for the shaft'bearings.

The work supporting rollers 63, 64 and 65 are rotated in planes parallel with the lines of sanding belttravel, and their upper surfaces travel in the same direction as the belts, but at con siderably slower speed,.t he speed being predetermined by their driving connections. The result of" thedriving: force applied to the work by the sanding beltsaids the rollers 53, 64 and 65 in advancing the, work axially along the supporting guides l4 and-i5, and also in rotating the work about its own axis. The thrust is absorbed by the guide pins 38' which cooperate with the guides l4 and it in holding the work uniformly to its proper'line of travel, but the supporting rollers and the cooperative idle pressure rollers work rotation and of work advancement, r

In Figure I have illustrated an overarm 48a which has a nose piece 8d provided with a circular face-or, under surface to serve as a bear- I ing surface for a similar bearing face on a prov 83 through which a, clamping bolt 86 extends tolock the turntable memberv 8! to the nose piece jection 8! extending rearwardly from a vertical plate i5a. The members 88 and 81 provide a turntable, being centrally connected by a' king bolt 82. The nose piece 88 has an arcuate slot 80 in various positionsof angular adjustment of the plate are. By this means'the line of t'ravel of the work through the machine may be varied in pitch. Work guide members l ia'and i564 may be correspondingly shifted in position by means of slotted supporting links 85 and 86' pivoted to the frame and adapted to be adjustably'secured to the guidesby set screws or clamping bolts at The housing I2 is horizontally slotted at 89 and St to permit the desired swinging adjustments of the guides and the. feedway defined by the thrust receiving pins 38 and the idle pressure within a range permitted by the slot 83. The

shaft bearings, for the driving rollers 63 and 65, maybe adjustedalcng slots 93 in their supports to correspondingly vary the spacing of said driving rollers.

By relieving the pressure of the work upon the feed rollers 63, 64 and 65, it would be possible to manually reciprocate pieces of work, but for work which is round or conical, reciprocation is unnecessary for the reason that by varying the adjustments above described, and by varying the speed of the feed rollers, the time of exposure of any given portion of' the work to abrasive action may be predetermined with reference to the nature of the work to be performed, and the finishing and polishing operations may. be completed during a single traverse of any given piece of work' through the machine.

- To polish pieces of work having fiat surfaces, reciprocation, manual or otherwise, and under light idle roller pressure to aid in holding the work in place, may be desirable.

In ;.Figure 2 I have illustrated the working parts of my improved equipment as occupying a cavity of shallow depth from front to rear between partition wall 98) (Figure 5) and a front Wall which preferably comprises-a set' of doors 92. The end walls of the housing l2 converge and gcurve inwardly to an upwardly extending I portion'M-of different curvature, this upward ex- The motor connections I ure 5 as being housed in a rearward extension it having a door lit! to provide access to said.

driving connections. The entire cabinet is thereby made very compact, and free access to are illustrated in Fig-- all parts is easily obtained, although the housing affords full protection of the workmen from dust and particles of abrasive when the equipment is in operation. The, partition 96 protects the m0- tor and the bearings.

In the illustrated embodiment of my invention, two sanding belts, each five inches in width, providetwenty inches of work contacting or abrading surface. Therefore, a given degree of pressure upon the work belts is distributed and amounts to only one half the pressure per lineal inch that would be exerted by the work upon the belts if held at right angles thereto. For this reason, and also because of ,the oblique position of the work and consequent relative helical traverseiof the abrading surface thereon, scratching effects are minimized and surfaces much more finely and uniformly polished than heretofore.

For any given setting of the machine, pieces of work which differ in diameter or which taper to some extent, either throughout their length or in different portions thereof, may be polished without readjustment of the guide pins or of the pressure applying rollers, but theadjusting means herein described will be found useful when the requirements imposed by the diametrical dimensionsof the work require re-setting in order that the work' maybe maintained under the proper pressure and sufficiently centered upon the supporting rollersto adequately control its movements of rotation and advancement.

For ordinary purposes the setting illustrated in Figures 1, 2, 3, and 9 will be preferred, and in that event the axes of the presser roller (it will preferably beat an angle of sixty degrees from the axes of the driving feed rollers 63, M and 65,

whereby the resultantthrust pressures of the advancing'and rotating work are so balanced as, to automatically-tend to hold the work in a centered position across, the tops of the driving rollers with only a light pressure against the guide rail 31.

When operating upon work of unusually small diameter the guide rail 31 may be removed from the supporting pins 38, as indicated in Figure 13, in which event the pins will be adjusted in close proximity to the sanding belts and the work will be allowed to contact directly with the pins, whereas for work of larger diameter the guide rail is preferred, inasmuch as the friction of the rotating work thereon affects all portions of the surface of the work in substantially the same manner and avoids rubbing marks, such as the guide pins tend to produce.

For some classes of work it is desirable to run the rough polishing and smooth polishing belts in different directions, and in Figure 11 I have shown a modification in which an auxiliary motor 29a is employed to drive the polishing belt M. The motor 29 is mounted on shaft 21, whereby the belt 53 may be independently driven. In Figure 12 I have illustrated modified means for supporting the pressure rollers 80, whereby in place of the bell cranks 58 above described, I may employ fiat springs 58a, the lower ends of which carry trunnions for the rollers 66, and the upper ends of which are secured directly to the frame member 55.

In Figures 5 and 7 I have illustrated means for varying the speed of the driving rollers 63, 64 and 65 for the purpose of varying the rate of work rotation and the rate of work advancement across the polishing belts with reference to the diameter of the work and its character. To accomplish this the shaft H is supported on the long arms of hell cranks 95 pivoted to the frame at 93, whereby the distance of the pulley 91 from the motor shaft 29 maybe varied. The pulley 98 (Figure 5) comprises two side members having opposed cone-shaped faces urged toward each other by a spring 88, and the pull upon the belt tends to spread the pulley members and shorten the driving radius progressively as shaft H moves away from the motor shaft.

A screw 99 threaded in the frame at 00 is employed to adjust the bell crank 95 and thus vary the distance between said shafts or between the pulleys 97 and 58, thereby varying the speed of the driven pulley 9'1, and correspondingly varying the speed of the work actuating rollers with corresponding variation in work rotation and advancement.

Insofar as I am aware, attempts heretofore made to polish cylindrical pieces of work along helical lines and uniformly throughout their length and with minimum surface scratching, have not been successful for reasons which are abstruse and difficult to perceive. This is particularly true as to power driven polishing machines, in which an abrading belt is being driven at high speed.

It has not heretofore been appreciated that the relative movement of the abrasive particles along the surface of the work should be in a steeply pitched helical line, generated in the direction of the leading end of the work, and that the rate of movement of the work, both rotatively and axially, should be accurately controlled and maintained at all times in the same proportion to the speed of the abrasive belt.

Also, it has not heretofore been perceived that, in order to obtain uniform polishing of wooden or other fibrous materials under such conditions and with minimum destruction of fiber, the abrasive material and the contacting work surface should travel in the same general direction and largely in the direction of the grain, i. e., lengthwise of the fibers.

In my improved construction the work contacting surfaces of the rollers 63 travel in the same direction as the working portion of the abrasive belt l3, and along parallel lines. Therefore these rollers not only cooperate with the belt in advancing the work, but, also, they cooperate with the idle or pinch rollers 60 to maintain continuously a speed of work advancement and rotation, having at all times the same proportionate rate of travel with reference to the speed of the belt. The rollers 63 and the belt are driven from the same source of power, but at different speeds, and the idle rollers 60 hold the work to the rollers 63 under suflicient pressure to prevent the belt from causing the work to slip along the surfaces of rollers 63. The axis of the work is at approximately a thirty degree angle to the line of travel of the belt, and as the work rotates and advances in the direction in which it is urged by the belt, the abrasive particles tend to follow the grain.

Also, it has not heretofore been appreciated that when the work is being passed obliquely along the surface of an abrading belt, all Working portions of the abrasive surface must be maintained in a truly horizontal position. If the abrasive belt is permitted to sag between supporting rollers it assumes an arcuate position and operates upon the work with varying pressure from one side of the belt to the other.

I claim:

1. The method of abrasively finishing and polishing elongated pieces of work of circular cross section, consisting in moving an abrasive surface in one direction across a working zone while supporting it in a single plane, simultaneously holding the work in contact with the abrasive surface with its axis extending along a line oblique to the direction of movement of said surface, guiding and advancing the work axially and rotating it about its axis in directions in which it is urged by resultant force derived from the abrasive material, maintaining a uniformly retarded and constant rate of work advancement and rotation while maintaining constant and uniform pressure of the work upon the abrasive surface at all points along its line of contact therewith.

2. In a finishing and polishing machine of the described class, the combination with a set of finishing and polishing belts and cooperative work supporting rollers adapted to support the work in a line oblique to that of belt travel, an overhead support, a carrier connected therewith and rotatively adjustable in a plane parallel with the working portions of the belts, a set of work guiding pins mounted on said carrier, an associated set of idle rollers resiliently connected with the carrier and adapted to regulate the pressure of the work upon the supporting rollers, means for yieldingly pressing the working portions of the belts against the work so supported, and a motor for driving the belts and work supporting rollers at predetermined differing speeds, said motor having connections for actuating said belts and rollers in a direction tending to rotate and advance the work in the same direction.

3. In a finishing and polishing machine of the described class, the combination with a set of finishing and polishing belts and cooperative work supporting rollers adapted to support the work in a line oblique to that of belt travel, an

overhead support, a carrier connected therewith and rotatively adjustable in a plane parallel with the working portions of the belts, a set of work guiding pins mounted on said carrier, an associated set of idle rollers resiliently connected with the carrier and adapted to regulate the pressure of the work upon the supporting rollers, means for yieldingly pressing the working portions of the belts against the work so supported, and a motor for driving the belts and work suporting rollersat differing speeds, said guide pins being horizontally adjustable with reference to the carrier, said carrier being vertically adjustable with reference to its support, and said idle rollers being vertically adjustable with reference to the carrier.

4. In a finishing and polishing machine of the described class, the combination with a set of abrading belts, of means for supporting, rotating and advancing pieces of work along an oblique line of contact with the belts at a relatively slow speed compared with that of belt travel, a housing for the belts and work actuating devices, an overarm connected with said housing and provided with a work guiding carrier having one member adapted for vertical adjustment, another member adapted for horizontal adjustment and provided with work guiding projections, and a third member vertically adjustable on the first mentioned member and provided with resiliently yielding idle rollers adapted to apply pressure to the work while being abraded by said belts.

5. A finishing and polishing machine provided with plural polishing belts of substantial width,

- in combination with means for holding both belts with working portions in a common plane along an obliquely extending line, feed rollers for advancing rods and tubes axially along said zone, and thrust guides and pressure devices for holding the work to the belts along said line with substantially equal pressure at all points of-con tact, one of said belts having a relatively coarse abrasive surface, means for driving said belt in a direction tending to accelerate work rotation, and means for driving the other belt in an opposite direction.

6. In a finishing and polishing machine of the described class, the combination with a supporting frame and a work abrading belt and belt driving means mounted in the frame, of a pivoted member provided with a belt tensioning roller, a spring connecting said member with the frame and adapted to normally hold the roller in tensioning relation to the belt, and a latch arm pivoted to said member and engageable with the frame to automatically limit outward n1ovement of the roller when the belt breaks, said latch arm being also manually engageable with the frame to hold the roller in a position of retraction from its normal belt tensioning position against the urge of the spring.

7. The combination with a revoluble abrasive belt having a working portion provided with means for supporting it in a single plane along a line oblique to that of belt travel, a thrust receiving guide spaced from the belt and adapted to hold pieces of work to said oblique line and against deflection under thrust pressure derived from the belt, a series of resiliently yielding idle rollers for holding the work to the belt under predetermined pressure, a vertically adjustable support for the guide and rollers, means for sepaspaced from the plane of belt travel, said guide comprising a series of pins having their axes perpendicular to the working portion of the belt,

a rail detachably secured to the ends of therpins in a position to receive the thrust of the work, means for adjusting the guide in accordance with the diameter of the pieces of work and with the pins in close proximity to the belt when the rail is removed, and means for rotating and advancing the work at predetermined rates of speed difierentfrom the speed of the belt.

CARL J. LIPPOLD.

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