US2182952A - Air conditioned buffing and polishing system - Google Patents

Description

Dec. 12, 1939; G, TODD H ,1 2,182,952

AIR CONDITIONED BUFFING AND POLISHING SYSTEM Filed ApriI 30, 1938 2 Sheets-Sheet 1' F2621.

HUM IDIFIER I INVENTORS BY WM 4 M Dec. 12, 1939. G, TODD A 2,182,952

AIR CONDITIONED BUFFING AND POLISHING SYSTEM Filed April 30, 1938 .2 Sheets-Sheet 2 V {7W JAHDCA/ c vrwm Izaak/l5 ATTORNEY.

Patented Dec. 12, 1939 PATENT @FFRQE AIR CONDITIONED BUFFING AND POLISH- ING SYSTEM I Guerin Todd, Shrewsbury, and Octavius Knight,

N. J., assignors to Hanson-Van Winkle-Manning Company, Matawan, N. J., a corporation of New Jersey Application April 30, 1938, Serial No. 205,158

1 Claim.

This invention relates to the buffing and pOlishing of materials or objects, and has for its objects to increase production, to economize in supplies and materials used in bufilng and pol- 5 ishing, and to improve the character of the work. Other objects and advantages will be apparent to those skilled in the art.

The terms bufling and polishing are not strictly synonymous in the art, but the principles of the present invention are applicable to both of these operations, and to simplify the description the terms buffing and buff will be employed to include either of these fields of work, except where a distinction between bufling and polishing, or buffs and polishing wheels, is clearly intended.

The heat developed by friction in bufilng operations causes a temperature rise in the work piece, the buffing composition and the buff itself.

In many bufiing operations the temperature rise imposes a limit on the speed of production, the economical use of supplies or equipment, or the quality of the work done. Some materials which might otherwise be buffed to advantage, are of such low melting point or softening point that they cannot be satisfactorily'bufied with ordinary equipment in common use. These and, other disadvantages or limitations in the buffing art are largely eliminated by the present invention,

in accordance with which the buff is supplied with refrigerated air or other gas to prevent or limit the temperature rise incident to the bufiing operation. The principles of the invention may readily be applied in such a way as to bring as about a temperature reduction in the article considerably below room temperature, so that objects normally too soft at room temperature to withstand bufing may be hardened sufiiciently to enable them to be buffed. This may be done, for

40 example, by precooling the work before buflln'g, or by cooling the work during buffing, or by both of these expedients. Precooling the work piece may also be employed to advantage in the case of materials other than those of low melting point,

45 and especially where high thermal conductivity and specific heat of the material tend to reduce the local temperature rise at the surface being buffed. Likewise, fats, greases, oils, waxes and similar supplies, which are normally liquid or too 550 soft to be advantageously employed in bumng compositions or wheel dressings under ordinary conditions, may be congealed upon the buff to adapt them for use in bufing.

Another preconditioning feature of the inven- 55 tion is the preconditioning of the air or other gas supplied to the buff, in respect to its moisture content, or its chemical constituents or composition. Examples of such uses of the invention are the increase or decrease in the moisture content or humidity of the air or gas, the modifi- 5 cation of its ability to support combustion, as by the use of carbon dioxide in partial or complete substitution for the normal atmospheric air, or the introduction of a chemically acting gas where special effects are desired. 10

Several embodiments of the invention are illustrated by way of example in the accompanying drawings.

Figure 1 represents diagrammatically a buffing system comprising the bumng wheel asseml5 bly in conjunction with means for drying or humidifying, and refrigerating air and supplying it to the bufi.

Figure 2 represents diagrammatically in front elevation a type of refrigerating cabinet some- 20 what different from that shown in Figure l, and including a shelf compartment for precooling pieces of work to be bufied.

Figure 3 is a side elevation with parts in central vertical section, illustrating a type of ven- 25 tilated buff assembly which may be employed in carrying out some forms of the invention.

Figure 4 is a transverse section thereof on the line fl-t of Figure 3.

Figure 5 is a diagrammatic end elevation of 30 a buff enclosed in a hood provided with an air or gas inlet.

Figure 6 is a side elevation thereof with the hood in vertical section on the line 6-5 of Figure 5.

Figure '7 is an end elevation, with parts broken away, showing a hooded buff having an enclosed chamber through which the work passes while being buffed. I

Figure 8 is a top plan view, showing diagram- 40 matlcally the application of some of the features of the invention to automatic machinery.

Referring more specifically to the drawings, in Figure l the bufi assembly is indicated at It. This bull may be of the ventilated type, such as shown in the U. SQ patent to Zucker, No.

1,573,961. We have illustrated, for example, in Figures 3 and a, a ventilated buff in which the bufiing spindle H has distributed around its periphery a number of longitudinally extending surface grooves or channels E2 to which access of air is provided by a corresponding series of ports it formed in the hub portion of the inner flange M. A hood I5 is supported by any suitable means so as to surround the ports it, with- H], which latter is secured by theusual nut 20 on the threaded outer end of the spindle I I. Thespacers 18 which intervene between each pair of buiI sections I! may be of any suitable type admitting of the flow of air outward between the sections l'l. They are diagrammatically shown in Figure 3 as corrugated discs in which each corrugation is radially disposed about the center, and flat rings 2i are welded or otherwise secured near the outer periphery to prevent closure of the radial air passages by displacement of the buff sections into the corrugations. Other types of ventilated bufis may be employed.

Referring again to Figure 1, the air conduit I6 is provided with ahand valve 22, to control or adjust the admission of air coming from therefrigerator unit 23. The refrigerator unit herein illustrated may be of any suitable type, thecoil 24 representing by way of example a brine coil or the cooling coil of an electric refrigerator. Therefrigerator unit 23 communicates by way of a passage or conduit 25 with adryer unit 26 into which air enters under pressure or suction by wa'y of theintake 21. The dryer may be of any type, supplied for example with calcium chloride or other drying medium. Theunit 26 may be supplied with moistening equipment instead of drying medium, when humidifying is desired. Therefrigerator unit 23 may be replaced by a somewhat different type of unit as that illustrated, for example, in Figure 2, which comprises thedry ice tank 28 over which is provided acabinet 29 furnished with shelves 38 on which work pieces 3! may be placed for precooling, prior to being subjected to bufiing. The hingeddoors 32 normally keep the cabinet closed. Awall 33 may be provided in thedry ice tank 28 to maintain anopen passageway 34 by which the dry air entering through theconnection 25 has access to thecabinet space 29,

It will be understood that the circulation of air or other gas through the apparatus described may be entirely induced by the rotation of the buff or by pressure, and that the air or gas is preconditioned to be difierent from the ambient atmosphere of the bufling room.

Instead of the type of air connection leading to the buffing unit, as shownin Figure 3, a modification, such as illustrated in Figures 5 and 6, may be employed. In this form of the invention, the air pipe l6 enters ahood 35 which encloses thebuff unit 10 and is provided with a hingedcover 36 normally closed bylatches 31. The bufi unit It] may be of the ordinary type or of the ventilated type such as the constructionalready described in connection with Figures 3 and 4 so that air is drawn through the spindle into the spaces between the bufi sections, as well as being distributed outside of the buff unit within the en closing hood. Figure 5 illustrates a conveyor 38 carrying the work pieces 39 through the buffing operation.

In Figure 7, the air or gas pipe l6 leads into ahood 40 provided with a hinged cover 4|, which may be similar to that illustrated in Figures 5 and 6. Thehood 40 encloses the bufi unit 42 which may be similar to 'those described in connection with Figures 5 and 6. The lower part of thehood 40 extends a suitable distance along the direction of travel of aconveyor 48 to form point compositions.

theextensions 44 and 45 which have swing or dropdoors 48, 41. This construction provides aprecooling space 48 into which the work pieces 49 are carried by theconveyor 43 on their way to passage through the bufllng operation. Preconditioned air or other gas may be delivered locally or directly into thiscooling space 48 by way of the pipe I6 and withdrawn by way of the pipe I6 It will be obvious that thedrop doors 46, 41 open and close automatically as the work pieces pass through. Since thespace 48 may be substantially closed ofi from the outside air, by suitable design of the walls, this construction provides an approximately closed work chamber and may advantageously be employed where it is desired to subject the work piece to special gases other than normal atmospheric air. The withdrawal of gases by way of the pipe l6 may be under suction so as to maintain the pressure within the space orchamber 48 somewhat below atmospheric pressure and thereby minimize the escape of the special gas into the atmosphere, while at the same time reducing any tendency of the gas to pass into the space immediately surrounding the buff.

In Figure 8 we have illustrated one form in which the invention may be applied to automatic bufling machines. It will be understood that the details of the bufiing machine per se form no part of our present invention, and that many types are familiar to those skilled in the art. The type we have chosen for diagrammatic illustration is assumed to be that in which a revolvingautomatic indexing head 50 is provided with work holders or chucks 5i distributed around the axis and carrying thework pieces 52 under thebuff 53, where the work holders revolve. The machine is loaded and unloaded at the position where the unoccupied chuck is illustrated in the drawings. In applying our invention to such a machine, theindexing head 50 is provided in the present example with a circumferential series ofcams 54 on a plane above that of thework holders 52. Thecams 54 intermittently operate against aroller 55 to open avalve 56 in the air conduit 5'! which leads into ahood 58 enclosing a buff unit such as already illustrated and described, or of any other suitable type. The earns 54 and the valve mechanism described are so positioned that thevalve 56 automatically opens as the work piece approaches the buffing station, and closes as the work piece leaves the bufling station. In this way, the supply of refrigerated or otherwise preconditioned air or gas flows only while the work piece is being bufied.

The use of refrigerated air, and especially when it is supplied under pressure, enhances the cooling effect beyond that obtained by ordinary ventilation of the bufi. This improvement is due not only to the lower temperature of the air but also to its greater density due to its lower temperature and its higher pressure. The relative humidity of the air is naturally increased due to the reduction in temperature. This improves the wearing quality of cloth bufis and a number of other materials used in bufiing and polishing. The ability to use lower melting point compositions represents an economy, as such compositions are, as a rule, much cheaper than the higher melting Furthermore, the composition will adhere better to the wheel and the wheel may be operated at higher speed without fear of burning. Any tendency of the work to oxidize, which would prevent adherence of a subsequent plate, is considerably reduced by the reduced temperature, and may be further reduced by the partial or complete'substitution of the atmospheric air by carbon dioxide (for example, from dry ice), or other gases having less tendency to oxidize the work. Some materials, such as low melting metals and alloys and plastics, take a better finish cold than hot. Glue on faced wheels will have less tendency to soften and lose its grip on the abrasive when operated in the refrigerated environment.

In the foregoing description of certain embodiments of the invention, it is believed that those skilled in the art will derive sufficient information to enable them to apply the invention in many ways, in addition to those specifically shown and described. Cloth wheels, various types of wheel brushes, polishing wheels of wood, felt, canvas, and in fact any of the usual materials employed, either faced with glue and emery or other composition, or unfaced, may be employed within the principles of the invention.

We claim:

Apparatus of the character described, comprising in combination a bufling unit, means for carrying work pieces successively into and out of bufflng position with respect to said buffing unit, means for providing and supplying to said bufiing unit a preconditioned atmosphere, control means for turning on and shutting off the supply of preconditioned atmosphere, and means coordinated with the movement' of said carrying means for actuating said control means as each work piece enters and leaves the bufling position.

GUERIN TODD. OCTAVIUS KNIGHT.

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