US3319856A - Method and apparatus for supporting members - Google Patents

Description

Maly i6, W67 c. J. STANLEY METHOD AND APPARATUS FOR SUPPORTING MEMBERS 6 Sheets-Sheet l Original Filed Aug. 11, 1961 INVENTOR O J @,QM

ATTORNE CHARLES J. STANLEY May 16, 1967 c J. STANLEY 3,319,856

METHOD AND APPARATUS FOR SUPPORTING MEMBERS Original Filed Aug. ll, 1961 6 Sheetsheet j INVENTOR CHARLES J. STANLEY ATTORNE ay 16, 1967 c. J. STANLEY 3,319,856

METHOD AND APPARATUS FOR SUPPORTING MEMBERS Original Filed Aug. ll 1961 6 Sheets-Sheet 3 CHARLES J. STANLEY ATTORNEY May 16, 1967 c. J. STANLEY 3,319,855

METHOD AND APPARATUS FOR SUPPORTING MEMBERS 6 Sheets-Sheet 4 Original Filed Aug. 11 1951 l NVENTOR CHARLES J. STANLEY BY g Z ggf ATTOREY May i6, i967 c. J. STANLEY 3,319,856

METHOD AND APPARATUS FOR SUPPORTING MEMBERS Orlglnal Flled Aug. 1l. 1961 6 Sheets sheet 5 INVENTOR CHARLES J. STANLEY Q? z g 5 BY f ATTORNEY!L May T6, T957 C, J, STANLEY 3,3l955 METHOD ANI) APPARATUS FOR SUPPORTING MEMBERS Original Filed Aug. ll, 1961 6 Sheets-Sheet 6 INVENTOR CHARLES J. STANLEY ATTORNEY United States Patent O 3,319,356 li/liE'lHD AND APPARATUS FR SUPPR'IING MEMBERS Charles d. Staniey, Walnut Creek, Calif., assigner to Kaiser Aluminum de Chemical Corporation, akland, lCalit., a corporation of Delaware @riginal appiication Aug. 11, 1961, Ser. No. 130,889, now Patent No. 3,198,499, dated Aug. 3, 1965. Divided and this application Dec. 30, 1964, Ser. No. 432,9@ 4 Claims. (Cl. 226-7) This is a division of application Ser. No. 130,889, led Aug. l1, 1961, now U.S. Patent No. 3,198,499.

The present invention relates broadly to supporting members by utilizing a gaseous medium. The members may be supported in any direction by practicing the present invention. The invention :is adaptable to lifting or conveying members in continuous or noncontinuous manner.

The invention has particular utility in supporting elongated members. More specically, gaseous supporting, according to the invention, may be advantageously used to support thin members having little self-supporting ability and/or internal rigidity. In conjunction with this latter application, the invention is advantageously usable in the continuous heat treatment of thin metallic members wherein a metallic member is subjected to any given thermal treatment to produce various properties.

The lifting of members from the top side thereof is accomplished in one embodiment of the invention. Lifting may also be a continuous or noncontinuous operation.

Supporting and/or conveying by a gaseous medium such as air, has been known in the art along with methods and devices of diierent kinds for that purpose. Typical of conventional methods for conveying or supporting members :involves the continuous discharge of a gaseous medium directly against the under surface of the member to be supported. lmpingement of the gaseous medium against their under surface will support members in a vertical position if the force of the gaseous medium is sutiicient to overcome the weight of the member. Such supporting devices typically comprise beds of various shapes containing numerous apertures for ejection of the gaseous medium.

Similarly, various top side lifting devices and methods have been proposed. Conventional lifting mechanisms typically involve merely the creation of a vacuum force of suilicient strength to pick up desired member and operate much in the same manner as the household vacuum cleaner.

The lifting and supporting devices above mentioned are capable of limited utility and, in general, are not satisfactory for the safe lifting or supporting of substantially lat members, in particular at members having little or no self-supporting ability and/or internal rigidity.

The present invention provides new and improved methods and apparatus for safely supporting members, particularly those having substantially at surfaces, with or without physical contact with solid supporting elements. That is to say, supporting such members with little or no risk of damage thereto.

The invention involves ejecting or omitting a gas and directing atleast a part of the ejected gas toward opposing peripheral portions of the article to be supported and subsequently contacting the article with at least a portion of the directed gas, progressively confining the ow of the gas so as to provide restrictive openings for the discharge of gas along said peripheral portions of the article being supported. The ejecting and directing of the gas may be performed sequentially or simultaneously.

An apparatus according to the invention comprises gas emitting means having discharge opening means for directing at least a portion of the emitted or ejected gas in divergent paths, said gas directing means, during the supporting operation being adapted to direct the gas in divergent paths toward peripheral portions of the article to be supported, means to conne the flow of said directed gas, said article to be supported being positioned so that at least part of the said gas directing means is located between the article and said discharge opening means, said gas confining means forming, with at least a portion of the periphery of the supported article, orifice means for discharging said gas. The gas emitting means and the gas directing means may comprise separate components or may be combined in a single structure.

One aspect of the present invention is the discovery that by proper distribution and direction of the supporting gas flowing beneath the member to be supported, it is possible to support thin, ilat members in a substantially level plane without lateral bowing or humping. Moreover, it has been discovered that by supporting the member from the underside according to one embodiment of the invention, the weight of the supported member provides a restoring force which renders the support self-centering. Thus, it is possible to support and/ or convey continuous strip of thin members in a substantially at position without physical contact with solid supporting members and while simultaneously rendering the supported strip selfcentering thereby eliminating the need for additional centering or guiding devices. The member, which may, for example, be metallic sheet or strip, supported in the manner of the invention tends to be self-centering in that it tends to stay symmetrical about the longitudinal center line of the gas support bed. Thus, if the strip is displaced sideways the supported sheet will return to the center position and has a tendency to remain in that position.

In the accompanying drawings are illustrated several embodiments ofthe invention wherein:

FIGS. 1 and la are transverse cross-sections of supporting devices embodying the principles of the invention to support an article from the underside thereof.

FIG. 2, comprised of FIG. 2a and FIG. 2b, is a side elevational view of a continuous metal strip heat treating system utilizing the underside supporting embodiment of the invention described in FIG. 1.

FIG. 3 is a transverse cross-sectional view of an air support furnace shown in FIG. 2 which utilizes the underside supporting embodiment o the invention.

FIG. 4 is a schematic representation of an advantageous arrangement including the illustrative dimensional details of an air supporting unit according to an embodiment of the invention.

FIG. 5 is a transverse cross-sectional view of a triple pass continuous heat treating furnace utilizing the underside supporting unit embodiment of the invention.

FlG. 6 is a side elevational view of the triple pass continuous heat treating furnace utilizing the underside supporting embodiment of the invention such as shown in FIG. 5.

FIG. 7 is a transverse cross-sectional view of an embodiment of the invention for supporting an article from the topside thereof.

FIG. 8 is a side elevational view of a materials handling system utilizing the embodiment of topside supporting illustrated in FIG. 7.

FIG. 9 is a transverse cross-sectional view of a topside supporting unit as might be used in the material handling system depicted in FIG. 8.

As an illustration of one embodiment of the invention, reference is made to FIG. 1 in the accompanying drawings. As can be seen therein, gaseous supporting medium is ejected through suitable gas emitting means 1i) preferably including a plenum and having at least one discharge opening disposed at one side (the underside) in this embodiment of the substantially fiat surface member to be supported. The gaseous supporting medium may be any suitable substance. However, for purposes of simplification and illustration the invention will be described herein with respect to the use of air as a gaseous supporting medium. The air is discharged through discharge opening means 12 of the gas emitting means and at least a portion thereof is directed by gas directing means 14, which may be a plate as shown, disposed between the first orifice means and the member to be supported 20. In this manner, at least a portion of the gas is defiected prior to contacting or impingement thereof against the member 20 to be supported and is thereby directed toward lperipheral portions of the member. The fiow of the gaseous medium is restricted by gaseous fiow confining means 16. The gaseous medium flow confining means 16, which may be referred to as an inclined hearth, progressively confines the fiow of said gas outwardly in diverging paths from the discharge opening means to peripheral portions of the supported member. The progressively confined fiow results from providing a progressively decreasing cross-sectional area for the fiow passageway. As can be seen by arrows indicating direction of fiow of gaseous medium, the air upon ejection and discharge from gas emitting means through the discharge opening or orifice means 12, is directed outwardly from a center line through the plenum of gas emitting means 10 toward -portions of the edges of the member to be supported 20. The gaseous medium is ultimately discharged through second orifice means 18 resulting from the coaction of the edges or periphery of the member to be supported 20, and the fiow confining means 16. Where the flow confining means 16 are inclined, the gas fiow is correspondingly directed outwardly at angles inclined toward said member to be supported.

The member is supported by static pressure which is dependent upon the volume, velocity and pressure of the gaseous medium projected from the gas emitting means 10. In operation the gas emitting means includes means for supplying air under pressure such as an air blower which blows air through a plenum pressure chamber and out at least one discharge opening. The air which discharges from a discharge opening, which may be a continuous slot or orifice 12 formed by gas directing means raised a suitable distance off the hearth plate 16 as shown in FIG. l, is ejected from this orifice to the sides of the hearth plate with sensibly the same volume at each side of the center line through the plenum of gas emitting means 10. The air is ultimately discharged at the second orifice means 18 between the surface of hearth plate 16 and the underside of the member to be supported 20 by progressively confining the fiow outwardly.

The self-centering characteristic of the invention described above is achieved because the gas support seeks to establish an equilibrium condition with the volume of gas being discharged equally at opposing peripheral portions of the supported member. Displacement of the supported member laterally disrupts the discharge by raising the member a greater distance above the flow confining means at one side thereof thereby in effect providing a larger orifice at one edge 18 in FIG. 1 and a smaller orifice at the opposite edge 18. The change in orifice size causes a change in velocity pressure at the respective orifices. The increased velocity pressure at one edge causes the member to move in that direction and the net effect is an ultimate balance of pressures and return to the equilibrium condition.

By adjusting the inclination of hearth plates 16, the height of orifice 12, the width of defiector plate 14, and/ or the pressure of plenum 10, various effects in the supporting device can be achieved. An increase in the inclination of hearth plates 16 reduces the gas velocity required to support a given fiat member without lateral bowing or humping therein and reduces the support height clearance at orifice 18. Increasing the inclination of the hearth plate also increases the tendency of the fiat member to be self-centering. As an illustration, an aluminum sheet 0.04 thick x 60 wide when supported in a fiat position with the fiow confining means inclined at a slope of l in 40 results in an orice height at 18 (at the periphery of the supported sheet) of 7/16 when the static pressure in plenum 10 is 0.93 water column. When the same sheet is supported in a fiat position on flow confining means inclined at a slope of 3% in 40" the orifice height at 18 is reduced to fyig and the static pressure in plenum 10 is reduced to 0.7 water column. In both cases the orifice 12 is maintained constant at 1A and the static pressure in the plenum adjusted to obtain a fiow under the sheet which establishes a fiat support therefor.

An increase in the orifice height at 12 with inclination of the flow confining means and plenum pressure remaining constant enables the member to be supported fiat at an increased height off the hearth at the edge 18. For example, referring to FIG. l, a 1A Orifice 12 supports the above sheet at 5%52" off the hearth at 18 with 0.7 water column pressure in plenum 10. Using 0.8" water column in plenum 10 and increasing the plenum orifice 12 to 1/2" enables a sheet to be supported substantially flat at a height of Ss" at the edge 18. In both cases the inclination of the fiow confining means is the same, i.e., inclined at a slope of 3% in 40".

By increasing the pressure in plenum 10 above that required to maintain the sheet or strip fiat, other factors being constant, one can introduce a concave or downward bow in the sheet. Further increases in the pressure in the plenum enables the fiat member to be held against the top of the defiector plate in such a manner that the fiat member is effectively clamped. For illustration, with fiow confining means inclined at a slope of 1/2 in 40" and the orifice maintained at a 1A, an aluminum sheet of 0.04" by 60 can be effectively clamped against the defiector plate at a plenum pressure of 3.75 water column. A sheet of 0.081 by 48 can be similarly clamped when the plenum pressure is 6l water column. Although the clamping action can be obtained at lower pressures than in the above examples, the degree of attachment to the defiector plate is determined by the pressure maintained in the plenum. The deflector plate can be of various sizes and if made wider, the required plenum pressures for a given clamping force can be reduced.

The supporting device as described above, may assume almost any configuration depending only upon design considerations. For example, if the members to be supported are of a suitable shape the hearth plates may be circular, rectangular, square, etc. It is necessary, however, that the gaseous medium being discharged from the plenum through the orifice, be ejected and -at least :a portion thereof directed outwardly in opposite directions from the discharge opening of the gas emitting means and toward opposing peripheral portions of the supported article.

It should also be noted that the means for directing the gas outwardly from orifice 12 in FIG. l may com-prise divergent nozzles or other similar means in place of defiector plate 14. Thus, any means which directs the gaseous medium outwardly in a similar manner, other than a defiector plate, may also be suitably employed.

In this connection reference is made to FIG. la wherein is depicted ow confining means 16a, which in this illustration are shown with outer sections of decreased slope, and gas emitting means 10a which includes all the equipment used to supply the supporting gas. As is seen, divergent nozzles 14a are substituted for deflector plate 14 in FIG. l. Discharge openings 12a of the nozzles function the same as the orifices 12 in FIG. 1 to provide air for the support of member 20a. Moreover, the flow of the gas is similarly progressively confined so as to result in the discharge thereof along opposing peripheral portions of the member 20a at restrictive openings 18a. Where divergent nozzles are employed in place of gas defiecting means, the nozzles themselves serve as the gas directing means to direct the gas toward opposing peripheral portions of the article to be supported. Thus, the gas directing means and the gas emitting means may comprise separate structural components as in FIG. l or alternatively, may be formed from the same structural unit -as in FIG. la. In the latter arrangement the upper surface 13a of the nozzles may be considered the portion of the gas emitting means which functions `as the means for directing the gas outwardly or, toward peripheral portions of the supported article, and the corresponding portions of the oppositely directed nozzles thereby coact to direct at least a portion of the gas toward opposing peripheral portions of the article to be supported. It is seen, therefore, that in all embodiments of the invention at least a part of the gas directing means is positioned or located so as to be between the discharge opening (or openings) of the gas emitting means and the article to be supported and at least a portion of the gas is so directed prior to contacting the article.

The nozzles Ma of the gas emitting means a may be attached to independent sources of gas and thus be independently controlled, or they may merge into a single header. Moreover, the nozzles may elbow and extend downwardly as shown or be extended axially at an inclined anule to be attached to a suitable pressure source.

It should also be noted that where a defiecting means, as in FIG. l, is used for directing the gas outwardly toward peripheral portions of the article, the defiecting means need not be a single planar member as depicted in FIG. l or a unitary structure. The deflecting means may comprise a plurality of components arranged to accomplish the intended function. Moreover, the deflecting means need not defiect all the gas emerging from the orifice, the deflecting means may comprise a perforated plate or two plates disposed adjacently leaving -a slot therebetween, thereby allowing some of the gas to contact the article directly. However, in order to achieve the advantages of the invention it is necessary that at least a portion of the gas from the orifice be directed outwardly as described above because the outwardly directed gas provides the advantageous support realized by practicing the invention. The amount of gas which should be directed outwardly varies with the type, size and weight of the member to be supported, as well as the gas pressure, velocity, size of the orifice and inclination of the flow confining means, if any. However, the optimum values of the above variables are readily determined for a given system depending only upon the result desired, i.e., extent of support (off bottom hearth), clamping force (topside supporting), degree of iiatness of support, etc.

Since the total pressure in the plenum of the gas emitting means equals the total pressure at the periphery of the supported member, plus losses, 'any `arrangement is satisfactory for support which meets the above requirements and which enables the total plenum pressure to be converted to velocity pressure plus suitably distributed and controlled static pressure under the load of the member. Where flat support is desired, the static pressure under the load that is required is an amount sufficient to support the load fiat without lateral bowing or humping.

The gas flow confining means, e.g., hearth plates, may be constructed as elongated members and together with an elongated plenum and corresponding elongated orifice means, can provide an elongated gaseous supporting device. Such a device is useful both as a support for substantially fiat members and as a gaseous or air conveyor. The gas flow confining means progressively connes the iiow by providing la flow passageway of gradually decreasing cross-sectional area. The supported member may be moved along the air support base by external means such as pull rolls, pulleys, etc. or the gaseous medium itself may impart a motion to a supported member. In the latter arrangement the elongated orifice or plenum may be periodically interrupted and inclined nozzles may be interposed which cause the gaseous medium to contact the member to be supported at an angle, thereby imparting a forward thrust or movement to the member. Similarly, the direction of some or all of the air emerging from orifice l2 may be inclined to the direction of movement of strip 2f) so as to impart motion therein. Alternatively, the member to be supported may in effect be dragged or pulled across the Iair support. Air supporting according to the invention has the advantage of being able to provide, if desired minimum frictional contact with solid supporting means thereby enabling only a very small force to move a member across an air supporting bed of the invention.

A continuous metallic strip heat treating system utilizing air support furnaces employing the underside supporting embodiment of the invention is depicted in FIGS. 2a 'and 2b. According to the preferred `heat treating operation the-re is provided in tandem suitable metallic strip feeding assembly 29, heat treating furnace 48, quenching assembly 54, and rewind assembly 66. The feeding assembly 29 comprises two payoff rolls 32, which, with movable joining means 40, enable metallic strip to be continuously fed into the heat treating system. When one of the payoff rolls has completed uri-winding a feed coil, the other payoff roll may begin to feed metallic strip from its feed coil. From one of the feed rolls 32, the metallic strip then pases through feed rolls 34 onto movable joining means 40.

Bef-ore unwinding the coils into the furnace the end of the coiled strip may be trimmed by a strip end cutter to provide a uniform edging surface for joining to the end of the preceding metallic strip. After trimming, the coils are mounted on one of the two dual payoff rolls 32 from which the strip is passed through feedv rolls 34 ,onto joining means 40 which may be a stitching device. Preferably, stitching device 40 is the type which clamps ends of succeeding lengths of strip firmly within a traversing cl-amp and end stitcher 3S and traverses a support table 42, during which time it stitches the succeeding lengths of strip in order to provide a feed of continuous metal strip for the heat treating furnace. The strip passes along rolls 44 and i5 into Ithe air support furnace 1.18. A pit 46 is provided to permit suitable looping of the metallic strip 30.

Air support furnace 48 preferably comprises a plurality of individual air support sections or units, two of which are illustrated as Sti and 5l and part of one support unit fas 52. The heat treating furnace is advantageously divided into several heating and holding zones. Strip which has been heat treated in the furnace 48 then passes through a quenching assembly 54 from which it is drawn lby pull-out pinch rolls 56. In the embodiment illustrated, pull-out pinch rolls 56 provide the driving force for advancing 4the metallic strip through the furnace. Thus, the speed of the strip through the furnace 48 may 'be regulated by adjustment of pull-out pinch rolls 56.

The quenched strip is then passed along inspection table 58, over guide rolls tft) into a suitable flattening device 62. After flattening, the strip is sheared in a shearing unit 64'-, passed through tension bridle rolls 67 and then coiled on rewind assembly 66. As illustrated, two rewind rolls 68 are provided to be consistent with the dual payoff rolls 32 illustrated at the beginning of the system. In practice, however, as many as desired may be provided.

The rate of heat treating strip through the heat treating system depends upon a number of factors including the length of the heating furnace, heat up rate and soak time. In one system a ZOO-foot furnace is capable of heating 0.06 inch thick aluminum strip at about 20 feet per minute.

As indicated above, the heat treating furnace, as shown in FIGS. 2a and 2b, generally comprises a plurality of individual air support sections. As an example, l0

twenty-foot individual air support sections may be advantageously arranged in tandem to form an air support furnace. The furnace may be constructed in multiples of two or three support sections with each section substantially identical. Each twenty-foot unit preferably comprises an air heating unit and a gas blower and is a complete and self contained unit with individual circulation, heating and control. The heated air is blown through suitable ducting or piping means into an elongated plenum chamber. In addition, each twenty-foot supporting unit contains a corresponding elongated defiector plate (or equivalent means) which directs the heated air outwardly from the center line of the plenum chamber toward the edges of the metallic strip being supported.

FIG. 3 is a transverse, cross-sectional View of a heat treatin-g furnace across one of the air support sections 50 comprising heat treating furnace 48 in FIG. 2a. The heat treating furnace comprises an outer shell 72 and suitable equipment for providing the air support which, in combination, comprise the gas emitting means. A motor 74 is provided to energize belt drive 76 which in turn operates fan 78. Fan 78 blows air through the air feeding assembly 80 which comprises ducting for air flow past a burner and radiant tube 82 which heats the air up to the desired heat treating temperature. The heated air may comprise the sole source of heat for the heat treating operati-on. A damper assembly 84 is provided to assist adjustment of the volume of air and pressure. Damper assembly 84 may advantageously comprise a plurality of substantially parallel leaves, each of which is attached to a central lever system 85 for adjusting the air flow within the wind feeding assembly 80. This damper may be automatically regulated to maintain a desired constant predetermined pressure in the plenum 86. The heated air passes through plenum pressure chamber 86, running longitudinally underneath the hearth 90, against defiector plate 88 from which it is deflected outwardly in opposite directions away from the center line of the plenum pressure chamber 86. The air is thereby substantially uniformly -distributed and, depending upon velocity, pressure, etc., can provide substantial uniform support for member 92. Air support hearth 90 functions as air ow confining means directing the deflected air outwardly toward the edges of metallic strip 92 being supported. Thus, at least part, and in general, most of the heated air is outwardly directed prior to contacting the metallic strip. As is seen in FIG. 3, the air support hearth 90 is substantially divergent, V-shaped members with t-he upwardly directed angle of inclination advantageously compounded in increments and illustrated as 90a and 90b. Thus, the fiow confining means has outer sections of decreased slope. The overall configuration of the flow confining means is such as to provide a iiow passageway of gradually decreasing cross-sectional area thereby progressively confining the fiow outwardly. support hearth 90 is preferably made of stable and nondeforming plane sections such as refractory brick or castings inasmuch as the temperature of the air may be of the order of 1000 F. to heat treat the metallic strip.

It has been found that a multi-slope configuration in the hearth plates of the type described enables a more uniform temperature distribution across the cross-sectional area of the metallic sheet being supported and heat treated. Moreover, by compounding the slope of the inclined hearth plates, it is possible to increase the height of the strip over the discharge opening at the plenum while maintaining a relatively low inclination of the hearth. This is important where contact between the metallic strip `and deflector plate is t-o be avoided and, particularly, where the metallic strip being supported is lof a narrow width.

An illustration of this advantageous feature of slope compounding is described in FIG. 4. The schematic representation shows illustrative dimensional details of an embodiment designed for the air support of any strip but Air showing wide aluminum strip being supported. A plenum pressure of 1.1 inch water column can support 0.40 X 60" wide aluminum sheet 17/8 ofithe hearth at the edge of the sheet. A 3" plenum orifice and a 3 deflector plate which is 15/3 above the inner edge of the inclined hearth plate are shown. The slope of the inclined hearth is compounded in increments with the inner increment or section providing a 1%" elevation in lOl/2, and the second increment or outer section with an elevation of 1 in 20". It is apparent, however, that particular dimensions for various systems can be readily determined.

In the event it is desirable to minimize the over-all length of the heat treating furnace, it is possible to arrange several individual units stacked vertically above one another. Referring to FIGS. 5 and 6 there is depicted a multi-pass continuous heat treating furnace utilizing the underside supporting embodiment of the invention.

As can be seen in FIG. 5 there is provided an outer furnace shell 112 and a plurality of sections. Three sections, 118, 122 and 126 are depicted for illustrative purposes. Each air support assembly has associated with it independent gas emitting means having feeding units 119, 123 and 127 respectively, and blowers 120, 124 and 128 for independent control of each section. Heated air is blown from blowers 120, 124 and 128 through pressure chambers 117, 125 and 129 and out plenum orifices 116, 121 and .130 (as shown by the arrows), wherein the heated air is directed outwardly toward lateral peripheral portions of the strip 140 by defiector plates 132, 134 and 136 and is progressively confined. The heated air is recirculated as shown (by arrows) and dampers 133, and 137 are provided for regulation thereof.

As can be seen in FIG. 6, metallic strip 140 enters the triple pass furnace at the top over guide roll 142 and traverses the length of the furnace. Each section may comprise a plurality of individual air support zones (as many as desired) arranged in tandem, similar to the furnace 48, shown in FIG. 2, extending substantially the length of the furnace as shown. Direction changing means are preferably disposed at alternate ends of the sections of the furnace for changing the direction of travel of the metallic strip and to direct the strip to an adjacent section. The turning means are advantageously located between adjacent sections. Thus, at the ends of each section the metallic strip is turned on suitable turning rolls 144 and 145 which may be, for example, air rolls or graphite-covered metal rolls. Metallic strip 140 preferably (but not necessarily) leaves the furnace from the side opposite that which it enters over guide roll 143.

Heated air for the heat treating is introduced at 149, circulates as indicated -by the arrows in FIGS. 5 and 6 and is withdrawn at 150. Doors 151 and 152 are provided for access to the furnace and to facilitate threading of the metallic strip 142 when necessary. Guides or shoes 153 and 154 serve to direct the strip onto the air support hearths. The furnace may contain as many horizontal passes as required, furthermore, the strip may enter at the top or bottom and leave at the same or opposite side from which it enters.

Another embodiment of the present invention is the use thereof for lifting members having a substantially flat surface from the top side of the member. In stacking and unstacking certain articles such as substantially fiat thin members it is often difficult, if not impossible, to perform the operation without significant risk of damage to the members themselves. Typical of this category of articles are thin sheets of metal such as aluminum or thin .sheets of glass, paper, etc.

In one present day operation thin sheets of aluminum are stacked and unstacked by devices employing suction cups or the like which are designed to contact the metallic sheet and apply a sufficient lifting force to transport the members. The suction cups generally leave marks on the metallic sheet and are rather unsatisfactory. The

vacuum cups used to unstack sheets are additionally unsatisfactory in that the clamping action of the lip which may be of rubber or other material contacting the sheet results in a sliding or squeegee action of the cup lip on the sheet when the vacuum force is created. This contact further results in some cases of marking of the sheets and in addition the ring-like mark persists throughout subsequent sheet processing. The supporting device, according to the present invention, may advantageously be used to support from a topside position or, in other words, to lift substantially thin, fiat mem-bers from above without the aforementioned difiiculties.

As discussed previously, by increasing the pressure in the plenum above that required to maintain the sheet or strip flat it is possible to pull the center of the sheet tight againts the defiector plate in such a manner that the sheet is effectively clamped. A deflector plate can be made as wide as required for adequate supporting contact with the surface of the supported member. Moreover, wider defiector plates allow reduction of plenum pressures required for an equivalent clamping force. Thus, by turning the support unit described with reference to FIG. 1 upside down, the invention can be adapted to lift substantially thin flat members such as aluminum sheet or thin sheets of glass from the topside of the member.

As can be seen in FIG. 7, gas emitting means comprising a plenum 155 attached to a suitable pressure source and defiector plate 156 are disposed above a flat member 157 to be lifted with the gas directing means (deector plate) positioned between the member 157 and the discharge opening 159. The gaseous flow confining means 158 may still be inclined uniformly to a plane substantially parallel to the fiat member to be lifted, however, the V-shaped cross-section is inverted as shown. Thus, the gas flow is progressively confined outwardly to peripheral portions of member 157. Discharge openings 159, formed by the coaction of the deflector plate 156 with the inner edges of gaseous fiow confining means 158, are generally of smaller magnitude than required in supporting from the underside, and the ow confining means 158 are of a single uniform angle without slope compounding. At least part of the gas flow contacts the article subsequent to being -outwardly directed. The member 157 will be clamped directly against defiector plate 156 by maintaining a suitable plenum pressure and wind velocity. Defiector plate 156 can be covered with a suitable material such as buff cloth or the like to provide a safe surface of large contact area without risk of injury to the surface of the member being lifted and clamped.

FIGS. 8 and 9 illustrate one application of the topside lifting embodiment of the invention wherein a plurality of individual supporting sections are used together. In this ararngement two independent lifting assemblies 160' and 170 as schematically depicted in FIG. 8 include gas emitting means having plenum pressure chambers, inclined V-shaped flow confining means and deflector plates. Air is introduced into the supporting sections at 161 and 171 respectively, under regulated pressure and from a suitable source, not shown, through appropriate piping means. Regulating means provided at 162 and 172 enable adjustment and regulation of the velocity pressure of the introduced air. The regulating means are preferably quick opening valves designed to introduce or shut off air to support units 160 and 17d as required. Shutting off the air will release the support provided by the lifting units. A continuous belt 180 on an independently controlled drive is arranged to travel along and beneath the lowermost deflector plate of independent air lifting units 160 and 170. As is shown, drive sheaves 181 and 182 support the continuous belt 180 at the ends of the contiguously arranged air supporting sections.

The air support structure is shown in more detail in FIG. 9. As can be seen lifting units 160 and 170 advantageously comprise a plurality of deflector plates 191, 192 and 193. Divergent V-shaped flow confining means 19t) and deflector plates 191, 192 and 193 are arranged so as to be symmetrical about a center line through plenum pressure chamber 189 of the gas emitting means. Beneath the lowermost deflector plate 193 is the continuous conveyor belt 180. Endless conveyor belt 180 which is shown in FIG. 8 and FIG. 9 is motor-driven and individually controlled. The deflector plates are arranged at a predetermined distance apart so as to provide suitable discharge openings therebetween for the discharge of the wind introduced under pressure into plenum 189 from piping 194.

Three deliector plates are illustrated by the way of eX- ample. As a practical matter a plurality of deflector plates are advantageously utilized in topside supporting or lifting to obtain uniform support of wide sheets and the number of defiector plates used would depend on size of sheet to be supported, weight, length of support, etc. The drawing in FIG. 9 is not to scale but serves to depict the relationship of the components. For one example, the slope of the gaseous fiow confining means 19t)A might be 1/2 in 40 and the distance from the orifice defined `by the top defiector plate, middle and bottom, to the center line of the plenum, may be 12, 7 and 2 respectively, with ls orifices. The deflector plates can be 1/16 thick and made of steel.

As shown in FIG. 8, continuous conveyor belt 18) operates across both lifting units and 170 as shown which are arranged in tandem to be adjacent one another (they may also be contiguous if desired), and rotate about drive sheaves 181 and 182. If desirable, the surface of the conveyor belt may be of soft cloth or similar material to prevent injury to the surface of the substantially thin fiat members 211i) to be lifted and transported.

As can #be seen in FIG. S, individual aluminum sheets or other material may be -conveyed on handling means 176 and stacked onto the elevator platform 16e` which is adjustable. The sheet handling means 176 is arranged a predetermined distance below lifting unit 16d, or vice versa, so as to allow the sheet 260 to be brought within the air lifting force created by unit 160. As the flat plate or sheet is picked up by the forces generated by the lifting unit 160 it is effectively clamped against the coutinuous conveyor belt 181i and is thereafter transported by the belt to lifting unit 170. When the sheet is over platform assembly 166 and is no longer within the lifting force of unit 161i, lifting unit 170 may be turned off by valve means 172 allowing the sheet to fall onto the stack of sheets 201 lying on elevator platform 166. To prevent relative displacement (and subsequent sheet marking) between sheets Zitti and conveyor 176 when picking sheets off conveyor 176, conveyor 186i' should be traveling at the same speed as conveyor 176.

If desired, the lifting units may be suspended and provided with elevating means or alternatively conveyor 176 may be provided with elevating means. In such an arrangement when picking up the sheet from conveyor 176, conveyor belt 180 may be driven at a speed in excess of that of conveyor 176 thereby allowing sheet 24N) to be positioned entirely underneath lifting unit 161i before pickup and then reducing the distance between belts 18) and 176 until the sheet is lifted by the action of lifting unit 160.

It is, of course, apparent that the system depicted in FIGS. 8 and 9 may be operated in reverse. Thus, stacked sheets may be loaded on elevator platform 166 and picked up by a lifting force generated in lifting unit 170, moved along by continuous conveyor belt 180 to lifting unit 161i wherein it is released and dropped onto suitable sheet handling means 176. Sheets of metallic strip or other material may be stacked or unstacked in this fashion as desired.

The foregong examples of the various embodiments of the present invention are intended for illustrative purposes only. It is apparent that various changes and modil 1 ications of the instant invention may be made without departing from the principles and spirit of the invention. For these reasons the scope of the present invention should not be limited by the foregoing disclosure but rather only by the appended claims wherein, what is claimed is:

1. A method of supporting members comprising ejecting a gas through an orice toward the topside of a member to be supported, directing said gas outwardly in opposite paths away from the orice, progressively confining the paths of flow of said gas in a progressively decreasing flow passageway along the topside of said member so as to provide a restrictive opening for the discharge of gas along at least a portion of the periphery of the member being supported.

2. A method of supporting members comprising ejecting a gas through an orifice toward the topside of a member to be supported, directing at least a portion of said gas outwardly in divergent paths away from the orice prior to impingement upon said member, progressively confining the paths of ow of said gas in a progressively decreasing ow passageway along the topside of said member so as to provide a restrictive opening for the discharge of gas along at least a portion of the periphery of the member being supported.

3. An apparatus for supporting an article comprising gas emitting means, gas directing means for directing at least a portion of the gas emitted from said gas emitting means outwardly in diverging paths, means adapted to coi?. operate with said article to contine the ow of said outwardly directed gas in a progressively decreasing ow passageway and along the topside of said article, said article to be supported adapted to be positioned so that said gas directing means is located between the article and said gas emitting means and both said gas emitting means and said gas directing means are above Isaid article, said gas conning means adapted to form, with at least a portion of the periphery of the supported article, oricc means for discharging said gas.

4. An apparatus as in claim 3 wherein said gas directing means comprise a plurality of planar members.

References Cited by the Examiner UNITED STATES PATENTS 2,837,330 6/1958 Lawrance et al. 226-95 2,908,495 10/1959 Andrews et al. 226-95 2,953,371 9/1960 Smith 294-64 3,087,664 4/1963 Streeter 226-97 FOREIGN PATENTS 945,309 12/1963 Great Britain.

OTHER REFERENCES Hotham, G. A., v01. 1, No. 5, page 25, February 1959, IBM Technical Disclosure Bulletin.

M. HENSON WOOD, I R., Primary Examiner.

ALLEN N. KNOWLES, Examiner.

Claims (1)

1. A METHOD OF SUPPORTING MEMBERS COMPRISING EJECTING A GAS THROUGH AN ORIFICE TOWARD THE TOPSIDE OF A MEMBER TO BE SUPPORTED, DIRECTING SAID GAS OUTWARDLY IN OPPOSITE PATHS AWAY FROM THE ORIFICE, PROGRESSIVELY CONFINING THE PATHS OF FLOW OF SAID GAS IN A PROGRESSIVELY DECREASING FLOW PASSAGEWAY ALONG THE TOPSIDE OF SAID MEMBER SO AS TO PROVIDE A RESTRICTIVE OPENING FOR THE DISCHARGE OF GAS ALONG AT LEAST A PORTION OF THE PERIPHERY OF THE MEMBER BEING SUPPORTED.

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