US2322459A - Finishing and polishing equipment - Google Patents

Description

June 22, 1943. C LIPPQLD 2,322,459-

FINISHING AND POLISHING EQUIPMENT Filed Aug. 12, 1940 4 Sheets-Sheet l INVENTOR Caz. J 46/ 0 0 42 4, mam

ATTORNEYS June 1943- c. ,1. LnPFoLD FINISHING AND POLISHING EQUIPMENT 4 Sheets-Sheet 2 Filed Aug. 12, 1940 zi m l l. Fl. III

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INVENTOR C1924. J.

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' 1 M, ATTORNEY June 22, 1943. c. J. Ll PPOL D FINISHING AND POLISHING EQUIPMENT Filed Aug. 12, 1940 4 Sheets-Sheet 4 INVENTOR C924. J. in 040 BY WWW ATTORNEYJ,

Patented June 22, 1943 FINISHING AND POLISHING EQUIPMENT Carl J. Lippold, Wauwatosa, Wis., assignor to J. M. Nash Company, Milwaukee, Wis., a corporation of Wisconsin Application August 12, 1940, Serial No. 352,181

3 Claims.

My invention relates to improvements in finishing and polishing machines, with particular reference to equipment for finishing and polishing curved and irregular surfaces, as well as flat surfaces of pieces of work of various sizes and shapes, such, for example, as chair backs, legs, and frame members of various kinds.

Objects of my invention are to provide simple, inexpensive and effective means for feeding pieces of work at controlled speed and under regulated pressure across a polishing belt or equivalent abrasive surface traveling at relatively high speed; to provide means whereby said equipment can be employed for abrading and polishing pieces of work of varying thicknesses, shapes and degrees of curvature; to provide means whereby the pressure of the speed controlling and pressure regulating member or members and the driving connections may be adjusted to vary the pressure of the Work upon the abrasive, or to control the rate of work advancement; and to provide means whereby curved pieces of work may be fed through the machine along paths curving in opposite directions, whereby successive polishing operations may be performed on the concave and convex sides.

In general, it is my object to provide a finishing and polishing machine capable of mechanically feeding and guiding pieces of work of various sizes and shapes across an abrading surface traveling at a relatively high speed, the rate of Work advancement being automatically controlled by a feed roller, preferably driven through variable speed mechanism independently of the speed of the abrasive surface, whereby the abrading effect may be kept under constant regulation as to all parts of the surface to be finished in any single traverse of the work through the machine.

A further object is to provide an attachment embodying my invention, in a form capable of being connected with an ordinary sanding ma chine for finishing and polishing curved surfaces of Work of special shape, for the finishing of which the ordinary sanding machines are unsuitable.

In the drawings:

Figure 1 is a side elevation of one embodiment of my invention, portions thereof being shown in vertical section.

Figure 2 is a detail view of a variable speed driving belt assembly associated with a speed controlling feed roller.

Figure 3 is a plan view of theembodiment shown in Figure 1.

Figure 4 is an end elevation, with portions of the cabinet and table illustrated in vertical section.

Figures 5, 6, and 7 illustrate pieces of work which differ radically in contour, but which can be readily finished and polished by my improved machine.

Figure 8 is a plan view of an attachment adapted to be applied to an ordinary sanding machine to convert the same into a machine embodying my invention.

Figure 9 is a front elevation of the attachment as it appears when mounted upon the casing of an ordinary sanding machine, having an abrasive belt traveling in a horizontal plane.

Figure 10 is a plan view of a machine embodying my invention, in a modified form, in which the feed roller or rollers are mounted upon a horizontal shaft above a sanding belt traveling in a vertical plane.

Figure 11 is an end elevation of the machine shown in Figure 10, illustrating the casing in vertical section.

Figure 12 is a front elevation of the same, partly in vertica1 section.

Figure 13 is a plan view of a further modification.

Like parts are identified by the same reference characters throughout the several views.

In the embodiment of my invention illustrated in Figures 1 to 4, inclusive, an ordinary sanding belt 20 is mounted upon a driving roller 2! and an idle roller 22 about which the outer end of the belt extends. The work is fed between the portion of the belt passing around the driving roller 2| and a work feeding and speed controlling roller 24, which is preferably surfaced with a covering 25 of frictional material such as rubber. The belt driving roller 2! is mounted directly upon the shaft 26 of an electric motor 21. The other end of the shaft 26 carries a pulley which drives the work controlling feed roller 25 at reduced speed through the belt 28 (Figures 1 and 2), shaft 29, belt 30, and the shaft 3!, to which roller 24 is fixedly secured by means of its hub.

A pair of belt tightener pulleys 32 and 33 are mounted upon one arm of a bell crank 34 and kept under tension by a compression spring 35 interposed between the other arm of the bell crank and the casing wall. The tension of the spring isregulated by a hand wheel 36 on an adjusting screw 36. By employing two belt tightener pulleys for the respective sides of the belt 23, the area of belt contact with its driving and driven pulleys is maintained under increased speed or feed when the driving pulley shortens its radius, as will now be explained.

The driving pulley on the motor shaft 216 is of a well-known speed reducing type having two members 31 and 38, which form a V-shaped groove to receive the belt 30, the member 38 being resiliently held to the member 3?, subject to slight separation under tension of the belt 39,

whereby the radial distance of the beltfrom the motor shaft may be manually changed by adjustment of the hand wheel 36 to increase or decrease the belt tension and vary the rate of feed. As the tension of the belt 28 increases the pulley members 31 and 38 tend to separate, with a corresponding reduction in the radius of contact. The roller 24 is then rotated at reduced speed. In Figure 2 the belt 23, as shown in solid lines, transmits maximum speed to shaft 215, and in it dotted line position it transmits minimum speed. Any desired number of intermediate speeds may be obtained by intermediate adjustments of the hand Wheel. Such pulleys are commercially known as of the Reeves type, and require no detailed illustration or any further description.

I may also employ speed reducing gearing in the casing indicated at 49, whereby the roller supporting shaft 31 may be driven at a much slower speed than that of the motor shaft regardless of speed variations, due to the adjustments of the hand Wheel 36. 7

The distance of the feed controlling roller 24 from the sanding belt 26 and its driving roller 2| may be varied to suit the requirements for work pieces of different thickness. 'Ioaccomplish this I mount the roller supporting shaft 3| in bearings 4!, carried by arms 42, which are pivoted to a pivot shaft 35 mounted in suitable bearings connected with the inner face of the front wall of the casing, as best shown in Figure 4. Arms 42 are preferably connected by a web 35.

Inward movement of shaft 3i and feed controlling roller 24 is limited by a set screw 8'! which bears against a stop bracket 48 on the motor casing, as shown in Figures 2 and 3.

Outward movement of this shaft 31 and the roller 24 is opposed by a weight 48 carried by one arm of a bell crank t9, connected by link 59 with the pivoted web 46 and its side arms or flanges 42.

Normally, the spacing of the feed controlling roller 24 from that portion of the abrasive belt which travels around its driving roller 2! is slightly less than the thickness of the work, so that when the work is fed between these rollers the roller 24 will yield slightly, and its pressure against the work will be controlled by the weight 48'. This weight 48 'may be adjusted upon the bell crank so as to vary the pressure of roller 24 upon the work, but under normal conditions of operation the pressure will, of course, be uniform.

Similar means are employed to maintain the tension of the sanding belt at. The shaft 52 which supports the idle roller "22 (Figure 1) is mounted in a bearing'53 carried by the arm to (Figure 3'), pivoted at 55 'to aprojecting frame arm 56. The bearing '53 is connected by a link '5'! with a bell crank 58, one arm of which'carries a weight 59, preferably adjustable on the arm.

The frameor'c'asing of the maohine'is provided with an adjustable table G0 supported by adjusting screws fil, (-Fig. 4) connected for uniform movement by a sprocket chain 62 (Figure 3). A driving sprocket wheel 63 may be manually actuated from a hand wheel 63 through its shaft; and the bevel gear wheels 65 and 66, the latter being mounted upon a Vertical shaft which carries the driving sprocket 63.

It will be observed in Figure 4 that the shaft 3i and feed controlling roller 24 extend through an aperture in the table 60, and by varying the height of the table the degree of roller exposure above the table may be varied.

The opening in the table top is of a generally U-shaped form. It extends laterally to one side margin of the table underneath the sanding belt 29, whereby the degree of sanding belt exposure above the table will correspond with that of the roller 2'4. Therefore, when the sanding belt becomes worn in one zone by abrasive contact with pieces of work of less width than the belt, the table may be vertically adjusted to bring the succeeding pieces of work into contact with a different or unworn portion of the sanding belt surface.

In operation, pieces of work may be fed along the table top from the front or right-hand side, illustrated in Figure 4, until their front end are gripped between the roller 24 and the portion of the sanding belt 20 traveling about its driving roller 2 I. In Figure 4 I have illustrated th sanding belt 28 as having a slight rearward offset with reference to the roller 24, the top of th roller being partially broken away to more clearly expose the abrasive belt.

As soon as the work is gripped between the roller 24 and the sanding belt, it will be guided, and its rate of movement will be controlled by the roller 24. Therefore, curved pieces of work, such as are shown in Figures 5 and 6, may be progressively advanced at a controlled rate of speed with the same facility that straight bars would be advanced. The abrasive products or dust may be drawn downwardly through the grating 16 into the suction tube H, and it may also pass through a vertical grating indicated at 13 at the upper end of the suction tube 74. These suction tubes are made in telescoping sections,

whereby the upper sections may be raised or lowered in correspondence with the adjustment of the table 66, the lower portions of these tubes being supported from the frame or casing by the supporting rod 75 and its collars 76.

It will, of course, be understood that only the surfaces in contact with the abrasive belt will be abraded during any single passage of the work through the machine. To polish the opposite sides, the work pieces will be inverted or reversed in position and again passed through the machine, and where the work pieces are curved, they will swing in one direction along the rear side of the table when polishing a concave face, and in the opposite direction when polishing a convex face. The weight 48 maintains a constant pressure of the roller 24 upon the work, and not only controls the rate of work advancement, but also keeps uniform the abrading or polishing effect regardless of the thickness of the work, the roller 24 being pressed outwardly as the thickness increases, and being drawn by the weight it inwardly as the thickness of the work decreases.

Work .guides are unnecessary, inasmuch as work supported upon the table will be securely held, and not only its rate of movement but the direction of its movement will be controlled by the roller 24.

My improved machine may be used with substantially equal effectiveness upon pie'ces'of work like the work A indicated in Figure 5, or a serpentine piece of work indicated at B in Figure 6, or a pyramidal piece as indicated at C in Figure 7, or an arcuate or nearly hoop-shaped piece indicated at D in Figure 11, or a U-shaped piece indicated at E in Figure 13.

In Figures 8 and 9 my invention is illustrated as embodied in an attachment which can be applied to any ordinary finishing and polishing machine having a sanding belt or roller. In this construction the motor 21a is mounted upon one end or arm of the lever 80, the work controlling feed roller 24a being mounted upon the other end or arm of the lever. The lever is intermediately supported by the pivotal fulcrum pin ill from bracket 82, adapted to be attached to a side wall of the casing 83 of an ordinary sanding machine equipped with a sanding belt a which travels over an end roller 2Ia. It is not essential that the roller 2 Ia should be the driving roller for the belt, but that is desirable because the portion of the belt which passes over this roller is in engagement with the work.

As shown in Figure 9, the roller 24a is driven from the motor 27a through the motor shaft pulley members 31a, 38a, belt 23a, shaft 29a, the speed reducer in the casing 40a, belt a and the roller supporting shaft 3Ia. Similar belt tightening mechanism to that described with reference to Figure 2 is employed to control the tension of the belt 28a under varying rates of feed.

It will be observed, in Figure 8, that the lever 80 supports the feed controlling roller 24a as a pinch roller for work passing between it and the roller 2Ia with its sanding belt 20a.

The approach of the roller 24a to the sanding belt is limited by the adjusting screw 41a, and its outward movement is limited by a pivoted rod 86 having a hand wheel 81 screwed to its outer end, with a compression spring 88 interposed between the hand wheel hub and the arm of the lever which carries the roller 24a.

When the above described attachment is applied to a standard sanding machine, as shown in Figures 8 and 9, that sanding machine is converted into a machine which corresponds generally with the one shown in Figures 1 to 4, inclusive. It will be understood, however, that in the modification separate motors will be employed to drive the sanding belt and the feed controlling roller, inasmuch as ordinary sanding machines will be equipped with their own motors.

In Figures 10, 11 and 12, I have illustrated another modification of my invention. One or more sanding belts 20b travel vertically within a towerlike housing 89. The driving roller 90 is located in the lower part of this housing, and is mounted directly on the shaft 26b of a motor 21b. The upper end of the belt travels over an idle roller 22b, mounted on the shaft 9| at the top of the housing, with the belt passing through an opening in the top wall. The work is fed across the portion of the belt which travels over this idle roller 22b. The work is held to the roller and belt, and its motion controlled, by a feed controlling or pinch roller 2%. In this form of construction one or more vertically traveling belts may be employed, two belts 202) being illustrated in Figures 10 and 12, and a corresponding number of feed controlling rollers 24b being employed.

These feed controlling rollers 2421 are supported by arms or levers 80b from a pivot shaft 8Ib, journaled in suitable bearings carried byv supporting members 93 mounted on the top of the housing 89. The adjusting screws 41b bear upon stops 94 (Figure 11) also mounted on the housing, and limit the approach of the rollers 24b toward the sanding belt.

In this construction the upward or outward movement of the rollers 24b is resiliently opposed by springs 96, the lower ends of which are connected with the housing, and the upper ends are secured to ears 9! at the front ends of the arms or levers 8012-.

No work table being provided on the front or infeeding side of this machine, I employ a guard, preferably comprising a roller I00, mounted in a frame IOI, supported by vertical arms I02 from parallel links I03. These links are pivoted to the housing at I04, and springs I05 coiled about the pivot pins tend to hold the guard roller I00 at or above the gap between the feed controlling roller and the sanding belt. The infeeding work depresses the guard.

Roller 241) is driven from the motor shaft 26b by means of a belt I06, a speed reducer in casing 40b, belt I01, and belts I08 (Figure 10).

On the rear side, the housing is recessed at each end to receive an adjustable work table I09, supported by rods I09, movably mounted in the brackets I I0 and secured by set screws II I. Below the recesses which "receive the work table, ordinary belt tightener rollers I I2 may be employed to regulate the tension of the sanding belts.

In Figure 13 I have illustrated a modification in which a sanding roller 2Ic is mounted upon a vertical driving shaft H4 and provided with an abrasive coating II5. This roller projects upwardly through an aperture H6 in the table 600, and a feed controlling pinch roller 240 is supported by a vertical shaft 3Ic mounted for adjustable swinging movement in the table aperture II8.

As to this modification, the construction is otherwise similar to that illustrated in Figures 1 to 4, inclusive, and detailed description of the driving mechanism is unnecessary. The construction shown in Figure 13 is particularly adapted for finishing U-shaped or circular pieces of work, such as the chair back indicated at E-in this figure or the cylinder indicated by dotted lines. The work may be fed between the sanding surface and the feed controlling roller, either transversely of the line of roller contact, or it may be pushed in endwise along said line of contact. If the work is cylindrical it .will be fed into the machine along a line parallel to its axis and that of the rollers.

It will be observed that in each embodiment of my invention as illustrated in the drawings, the work is fed between a pair of rollers, one of which may be covered by a sanding belt as shown in Figure 1, while the other may be provided with -a surface having a high frictional characteristic adapted to regulate the rate of feed. It i a matter of choice, dependent in part upon th character of the work, whether to revolve the roller in the same direction or in opposite directions. In either case the more slowly revolving roller tends to control the rate of feed. Since the more slowly revolving roller has a relatively high frictional or work engaging characteristic, it tends to require the rate of work advancement to conform to its own rate of travel, and under ordinary circumstances it will do so.

In each embodiment, except that illustrated in Figure 13, the abrasive working surface of the high speed roller is furnished by a belt, whereas in Figure 13 the abrasive surface is concentric with the high speed roller and constitutes the roller surface per se, although the abrading effect rollers are commercially known as sand drums.

It will be understood that while the tractive effect of the abrading surface would be relatively high if the machine were started with the work already in place between the rollers, it is much less when the abrading surface is traveling at high speed at the time the work is brought into contact with it. Therefore, it is found that a feed controlling roller surfaced with rubber, or other material having a high frictional characteristic, and particularlly if surfaced with comparatively soft rubber, will effectively control the rate of work advancement while regulating the pressure of the work upon the abrading surface.

As indicated in the drawings, my invention may be embodied in machines having feed rollers revolving on either vertical axes as shown in Fi ures 1, 2, 3, 4 and 14, or on horizontal axes as shown in Figures 10, 11 and 12.' The attachment illustrated in Figures 8 and 9 may be applied to either type. When the nature of the work permits, it may be fed to the machine shown in Figure 11 over a work table I20, in which event table We will have an appropriate elevation.

Iclaim:

1. In a finishing and polishing machine, the combination with a set of supporting and driving elements, of a roller provided with an abrasive surface, a pinch roller for holding pieces of work to the abrasive surface, means for supporting said rollers in an open field of work advancement along different paths in planes transverse to the rollers, and means for actuating said rollers at different speeds, said pinch roller havinga work engaging surface adapted to control the rate of work advancement independently of the speed of rotation of the roller having the abrasive surface.

2. In a finishing and polishing machine, the combination with a set of supporting and driving elements, of a roller provided with an abrasive surface, a pinch roller for holding pieces of work to the abrasive surface, means for supporting said rollers in an open field of work advancement along different paths in planes transverse to the rollers, means for causing said rollers to embrace the work under sufficient yielding pressure to wholly direct the work along a path suitable for presenting curving contours to the abrasive surface, and means for actuating said rollers at different speeds, said pinch roller havinga work engaging surface adapted to control the rate of work advancement independently of the speed of rotation of the roller having the abrasive surface.

3. In a finishing andv polishing machine, the

iii) is identical with that obtained by the belt. Such vancement independently of the speed of rotation of the roller having the abrasive surface.

4. An attachment for a finishing and polishing machine having a roller provided with an abrasive surface and projecting outwardly from the supporting and driving portions of the machine into an open field of work advancement, said attachment comprising the combination of a member adapted to be connected with the supporting portions of said machine, a lever fulcrumed to said member, a work engaging pinch roller carried by the lever in a position to engage pieces of work between it and the roller having said abrasive surface, and a motor on the lever operatively connected to actuate the pinch roller independently of the working parts of the macl he with which the attachment is connected, said pinch roller having a driving shaft operatively connected with said motor and supporting the pinch Miller at one end thereof in said open field of work advancement.

5. An attachment for a finishing and polishing machine having an abrasive roller exposed in an open field of work advancement along lines curving about said roller, said attachment comprising the combination of a motor supporting lever, a shaft journaled on said lever and provided with a roller in an ofiset position with reference to the lever, a motor on said lever operatively connected with said shaft, and a mounting to which said lever is fulcrumecl, said mounting being adapted for attachment to said machine with the roller in work positioning and feed controlling relationship to the abrasively surfaced roller carried by said machine.

6. A finishing and polishing machine, having in combination a set of supporting and driving elements capped by work supporting table elements, a roller extending upwardly between said table elements and provided with an abrading surface, a parallel pinch roller adjacent thereto and provided with a work controlling and retarding surface, shafts supporting the lower ends of the rollers, yielding means for providing pressure engagement of pieces of work between the rollers, and driving connections for actuating the shafts and rollers at different speeds, said rollers being adapted to control the direction of work advancement in planes parallel with the table elements.

7. A finishing and polishing machine, having in combination a work table, a set of abrading and feed controlling elements mounted at one side of said table and adapted to engage pieces of work between them under predetermined pressure, said table being interposed between said elements and all other portions of the machine, whereby said elements may completely control the direction of work advancement in planes parallel to the table. I

8. In a finishing and polishing machine, the combination with supporting and driving mom-i bers, of a work table capping said members, a

pair of rollers projecting into open space above the work table, said driving connections including means for actuating said rollers at different speeds, means for adjusting the work table axially of the rollers, and extensible dust collection suc tion means dependin from the work table. a

CARL J. LIPPOLD.

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