US3304760A

US3304760A - Shelf handling and forming apparatus

Info

Publication number: US3304760A
Application number: US390647A
Authority: US
Inventors: Milton E Handler
Original assignee: Hirsh Manufacturing Co SA Co
Current assignee: Hirsh Manufacturing Co SA Co
Priority date: 1964-04-01
Filing date: 1964-08-19
Publication date: 1967-02-21
Anticipated expiration: 1984-02-21

Description

Feb. 21, 1967 M. E. HANDLER SHELF HANDLING AND FORMING APPARATUS 3 h ets-sheet 1 Filed Aug. 19, 195

m T N E V m 1967 M. E. HANDLER SHELF HANDLING AND FORMING APPARATUS 5 Sheets-Sheet 3 Filed Aug. 19, 1964 MILTON E. HANDLER ATT'Y United States Patent 3 304,760 SHELF HANDLTNG A ND FQRMING APPARATUS Milton E. Handler, Evanston, Ill., assignor to Hlrsh Mfg. Co., Skokie, 111., a corporation of Illinois Filed Aug. 19, 1964, Ser. No. 390,647 11 Claims. (Cl. 72324) The present invention relates to shelf handling and forming apparatus and has particular reference to a fully automatic high speed apparatus for shaping the lateral end edges of sheet steel blanks whose length is cut crosswise from commercially supplied unslit or mill-edge prefinished coiled steel and which are ultimately formed into generally rectangular shelves marginally reinforced on all four sides and adapted at their corners for squared attachment against corner posts in the assembly of knockdown steel shelving units.

The shelf handling and forming apparatus of the present invention is essentially of the roll forming type wherein the side edges and then the end edges of the blanks are turned progressively out of the plane of the blank by means of a series of forming rolls, the net effect of which is to produce, on all four edges, marginal reinforcing flanges which not only reinforce the shelves but also, in part, constitute attachment means whereby the shelf flanges solidly engage two sides of each corner post when they are assembled in a shelving unit.

The specific character, i.e., shape, of the flange formed by the apparatus of the present invention may vary from simple right angle bend members to compound flanges preferably having one or more re-entrant bends, ultimately producing, if desired, a closed box-type marginal reinforcement. Irrespective however of the particular shape which is applied to the four edges of the shelf blanks undergoing formation, the essential features of the invention remain substantially the same.

The shelves which are produced by the apparatus of the present invention are essentially of elongated generally rectangular design. In their finished form, the shelves are shown marginally reinforced by compound flanges along their longitudinally extending side edges, as well as by compound flanges along their shorter transverse end edges. An example of a shelf of this general type, and one which is capable of being, in part, formed by the apparatus of the present invention has been shown and described in a copending application of Irwin W. Ferdinand and Dale R. Lopatka, Serial No. 368,634, filed May 19, 1964, now abandoned, and entitled Knockdown Steel Shelving Unit and Corner Fastening Means Therefor.

In shaping rectangular panels or blanks into shelves of the type shown and described in the above mentioned application with roll forming equipment, considerable difliculty has been encountered in rolling the short end edges of the blanks to produce exactly dimensioned compound flanges along such edges. Whereas, during formation of the long side edges of the blanks to produce the longitudinally extending compound flanges, simple edge guides are effective to hold the blanks in longitudinal alignment with the progressive forming rolls, both during entry of the blanks into the rolls and during travel therethrough, such edge guides cannot be relied upon to hold the blanks straight and in alignment with the rolls when the short side edges of the blanks are undergoing shaping. The factors which contribute toward blank misalignment are manifold and are based upon a combination of physical factors, many of which have an economic origin in connection with the manufacture of steel shelving and particularly from coiled stock.

It is understood that a relatively long rectangle of sheet metal, Whose side edges are to be rolled, can be fed endwise between opposing series of flange edgeforming rolls with fairly accurate alignment of the blank with the rolls maintained by the use of guides on opposite sides of the strips. The comparative long length of the edge guides between the first and last roll forming stations and the short cross distance between opposing side edge guides provides a geometric vectorial relationship that leaves little opportunity for misalignment, cocking or binding of the blank in the guides. On the other hand, where a relatively short but wide blank is concerned, i.e., short in its longitudinal direction of travel, and wide between opposing guides, particularly where the width of the blank is relatively great, i.e., long in a direction transverse to its directionof travel, it is essential that the blank be fed squarely to the first pair of forming rolls so that its end edges are engaged by such rolls simultaneously. Otherwise jamming or binding of the blank is apt to occur when close guide tolerances are maintained, the first pair of rolls to engage one of the end edges of the blank will advance that end edge before the opposite pair of rolls engages the other end edge of the blank and a cocking of the blank will occur that will pass the blank obliquely through the entire set of forming rolls With the result that the shelf formed is not square at its corners and will not square up with the shelf support columns along with shelves that are square at their corners. These difficulties prevail even when close tolerances in the transverse width of the blanks are maintained and are greatly augmented when the blanks are stamped crosswise from mill run strip steel. Moreover, in forming steel shelving by a roll forming operation, numerous other factors are involved in the proper handling and guiding of the-shelf blanks to and through the various forming stations without darnage to the finish of the precoat on the strip stock. Many of these factors are determined by and have an economic significance as will be described presently.

In mass production of steel shelving as an automatic continuous process, it is more economical to purchase mill run, prefinished coiled sheet steel Whose width is the length of the shelf blank and pass it through the shelf-forming mill at this width rather than incurring the added expense of marginally trimming or slitting it to an exact width dimension. The blanks are stamp cut from the coiled strip as fed and therefore have a closely held width tolerance. They are passed l'ength wise through a first forming mill section and the longitudinal side edges thereof are formed to produce the marginal side flanges therealong. The blank is then passed laterally through the second or final forming mill section for shaping the short end edges of the blank where there is apt to be a discrepancy of as much as 30 or 40 thousandths of an inch in the length of the blanks which occur due to variations in the width of the mill run strip. Thus, with wide guide tolerances provided to allow for this discrepcancy the forming rolls on one side of the forming mill are presented quite frequently With more material than the forming rolls on the other side thereof. In such an instance, even though bot-h end edges of the blank arrive at and are theoretically engaged by opposing pairs of forming rolls precisely at the same time, the peripheral speed of roll engagement of the blank at its end edge that contains the most material will be greater than the peripheral speed of roll engagement along the other edge. This is due to the frusto-conical shape of the first forming rolls where the peripheral speed increases with the increasing diameters nearer the major base of the cone frustum. Since one end edge of the blank is thus driven at a greater speed than is the other end edge, the tendency for the blank is to become cocked so that it will pass obliquely through all of the forming rolls in the second mill, or else become jammed between the edge guides. These considerations are particularly applicable and blank jamming is an especially prevalent factor when the forming rolls are grip blasted to increase the frictional characteristics thereof and when the steel material of the blank is prefinished and waxed so that it is extremely slippery and is gripped only at its edges to avoid damage to the finish.

From the above discussion it will be apparent that proper guiding of the blanks to and through the second forming mill where the short end edges of the blank are formed, and particularly to and through the opposing pairs of forming rolls at the first station of the end forming mill, is essential to the successful forming of compound flanges along the short edges of the blanks. Because of the wide tolerances required and the relatively short length of the blank ends arriving at the second forming mill, the use of edge guides alone does not prevent cocking or twisting of the blanks at or in the vicinity of the second forming mill. The greater driving force exerted by one pair of forming rolls on one side at a given station will invariably be encountered and it is a purpose of the present invention to nullify the effect of such unequal driving forces and hold the blanks to a true longitudinal course as they pass to and through the second forming mill, even in a direct relationship relation to their existence.

The invention is thus designed to overcome the abovenoted difliculties and to utilize the character of the polish finish to assist therein to provide an improved blankfeeding and blank-guiding apparatus and methods, for blanks whether made from slit or unslitted strip steel stock but particularly where shelving blanks that have been formed along their long side edges in a first forming mill are fed to a second mill for formation along their short end edges.

In carrying out the invention, special and novel guide means are provided on the entrance end of the second forming mill to assure a square entry of the blanks into the first stand of the mill. The guide means includes opposing guides which cooperate under close tolerances with the square ends of the compound flanges just formed along the longitudinal edges of the blanks. These longitudinal flanges now extending transversely of the direction of travel of the blanks to the second forming mill are made with identical lengths as determined by the stamping operation.

The guide means also include bottom guides to support the laterally projecting end edges of the blank which initially lie in the plane of the blank. Such bottom guides engage only the end portions of the blank and align them in a plane tangent to the bite of the opposing pairs of rolls at the first station of the mill. The guide means also include top guides which cooperate with the laterally projecting end edges of the blank and hold the panels down as they progres toward and enter between the rolls of the first station of the mill. These guides are designed to present the blanks to the first stand of the forming mill with extreme accuracy of alignment, i.e. so that both side edges of the blanks approach the rolls of the first stand of the mill together. Then, in order to maintain this accuracy of alignment for the passage of the blanks through the forming mill, the rolls at the first are so constructed that they do not bend the end edge of the blank but preferably have cylindrical blank-gripping surfaces which exert no forming function whatsoever upon the blanks. In effect, these first rolls preferably are simply blank-gripping and power-feeding rolls. The pressure they exert upon the blanks is considerable so that they will resist slippage of the blanks therebetween and counteract any tendency for the blanks to cock or twist after they have been engaged by the first forming rolls. These latter rolls constituting, in, effect, the first forming rolls of the series of forming rolls at the second forming mill.

It is an accomplished fact that where a given blank is of suflicient length to enable the forming rolls of at least three successive stations to be in simultaneous engagement with the side edges of the blank, longitudinal alignment of the blanks passing through the mill may readily be attained and no problem of accurate tracking presents itself. However, where a given blank is of such short longitudinal extent in its direction of travel that less than three stands may simultaneously engage the side edges thereof, then blank width must be exact and the driving forces which propel the blank through the mill must be very carefully controlled lest the tendency for the blank to twist occasions jamming of the machine. Where blank width is not controlled by reason of purchase of the sheet material at mill width instead of slitting it to exact width, edge guiding of the blank, no matter how carefully per-formed, is totally ineffective to keep a blank from twisting after the first forming rolls have engaged the blank.

The tendency for a blank to twist in one direction or another, or not to twist, is not a matter of chance. If one side edge of a blank projects laterally a greater distance than does the other side edge, invariably and without exception the longer projecting side edge will be pulled forwardly at a greater rate than will the other side edge and no amount of care in guiding the blank before it arrives at the first forming stand, can induce the blank to maintain or recover its alignment in passing through that station. The passage of a blank through the first forming station is regarded as an exception rather than as the rule.

According to the present invention, and as heretofore indicated, by feeding relatively short blanks to the first effective pair of forming rolls of the forming mill by pairs of gripper rolls which are truly cylindrical and exert no forming function on the edge regions of the blank, the trailing regions of the blanks are still engaged by the gripping rolls at the time that the first forming rolls seize the blank. With careful guiding of the blanks at the approach to the gripping rolls there are no factors associated with such gripping rolls tending to misalign the blanks, regardless of whether one side edge thereof projects a greater distance laterally than does the other side edge. In fact if one end projects further than the other it is proportionally gripped by the gripping rolls. There are no conical gripping surfaces on the gripping rolls to increase the linear speed of either end edge of the blank. Once engaged by the gripping rolls, the blanks are held to their initial alignment even until the leading edges of the blanks are engaged by the second set of forming rolls. The gripping rolls are still effective along the trailing regions of the blanks to counteract any tendency for the blank to twist. By the time that a blank has progressed sufiiciently far into the mill that the gripping rolls release the trailing edges of the blank, the leading edge of the blank has been formally engaged and advanced some distance by the second pair of forming rolls at the third station and, thereafter, the problem of blank misalignment has been resolved due to the rigidity which has been created along the edges undergoing forming by reason of the bends imposed thereon. In fact beyond the second length one end edge of the blank has been moved to a position where such imposes little if any cocking action on the blank.

Apart from the matter of attaining proper tracking of the shelf blanks to and through the first set of forming rolls in the second forming mill where the short end edges of the blanks are shaped to their flanged condition, the present invention is concerned with a novel means and method whereby an originally rectangular blank may be initially shaped as to its contour in an improved manner and then fed longitudinally endwise, i.e. in the direction of its longest extent, to and through a first forming mill wherein the longitudinal side edges of the blank are shaped or flanged by a downward rolling operation. The blank is then inverted and fed sidewise, i.e. in the direction of its short dimension, to the second forming mill wherein the transverse end edges of the blank are shaped or flanged by an upward rolling operation.

The initial blank-shaping operation includes the removal of metal by a notching operation at the four corners of the originally rectangular blank so that after the formation of flanges along the longitudinal edges of the blank in the first forming mill no metal is raised which would obstruct the formation of flanges along the transverse end edges of the blank in the second forming mill. Stated otherwise, the invention involves a novel means and method of shaping and handling an originally rectangular blank so that after marginal side flanges are formed along its longitudinal side edges, open corners are provided at the ends of the blank so that the thus formed side flanges will clear the forming rolls which are employed in the formation of similar marginal flanges along the end edges of the blank. In both instances the prefinished blank is pressure contacted only along the flange areas. In this manner, the work performed by the side edge forming rolls in the first mill will be independent of the work performed by the end edge forming rolls in the second mill, yet the flanges will be square to each other and the latter will not deform or otherwise disturb any material previously formed by the first mill.

The provision of a fully automatic apparatus for and method of shaping the short lateral end edges of sheet metal blanks in the production of shelf units as briefly outlined above being among the principal objects of the invention, numerous other objects and advantages will readily suggest themselves with the following description.

In the accompanying three sheets of drawings forming a part of this specification, one illustrative embodiment of the invention has been shown.

'In these drawings:

FIG. 1 is a perspective view, entirely schematic in its representation of a shelf forming and handling apparatus embodying the principles of the present invention;

FIG. 2 is a perspective view of one exemplary form of a marginally reinforced shelf constructed according to the method and apparatus of the invention;

FIG. 3 is a plan view of a blank from which the shelf of FIG. 1 is formed;

FIG. 4 is a fragmentary perspective view of a portion of the shelf forming apparatus illustrating the manner in which partially formed shelf blanks are conducted from the first forming mill, inverted and redirected to the second forming mill for further forming operations;

FIG. 5 is a fragmentary perspective view of a portion of the shelf forming apparatus in the vicinity of the second forming mill and illustrating specifically certain blank impelling and edge guiding means employed in connection with the present invention;

FIG. 6 is a fragmentary sectional view taken substantially along the vertical plane represented by the line 66 of FIG. 5 in the direction of the arrows;

FIG. 7 is a fragmentary sectional view taken substantially along the vertical plane indicated by the line 77 of FIG. 5 and in the direction indicated by the arrows; and

FIG. 8 is a fragmentary sectional view taken substantially along the vertical plane indicated by the line 3-45 of FIG. 5 and in the direction indicated by the arrows.

Referring now to the drawings in detail and in particular to FIG. 1, there has been disclosed in this view in an entirely schematic manner, an apparatus for forming steel shelves such as the shelf 10 shown at the extreme right hand end of the view and also in FIG. 2. While the apparatus of FIG. 1 is adapted, by modification or interchange of certain forming rolls associated therewith, for the construction of a wide variety of generally rectangular shelves, the shelf 10 has been selected for illustration herein as being exemplary of at least one particular shelf configuration capable of being effectively formed by the apparatus.

Specifically, the shelf 10 is of the type shown and described in the above-mentioned patent application, Serial No. 368,634 and reference is hereby made to such application for a full understanding of the nature of the shelf and of its use. Briefly however the shelf is designed for used, in conjunction with other like shelves, in connection with knockdown steel shelving wherein the shelves are removably secured at their corners to vertical corner posts. The shelf 10 is generally of rectangular configuration and it includes a horizontal planar body portion 12 having downturned longitudinally extending marginal compound side flanges 14 and downturned transversely extending marginal compound end flanges 16. The side flanges 14 are provided with narrow inturned rim flanges 18 which terminate in upturned reentrant flanges 20. The end flanges 16 are provided with narrow inturned rim flanges 22. The upper edges of the flanges 14- project above the plane of the body portion 12 and are connected to the body portion by narrow rim flanges 24 and vertical offset flanges 26, the latter preventing objects from rolling or sliding from the shelf. Each of the four corner regions of the shelf 10 is notched out as at 28, thus exposing the squared ends of the

flanges

14 and 16 for reception therein of a corner post (not shown) by means of which the shelf 10 may be assembled in a shelving unit, all in a manner set forth in the above mentioned patent application. The shelf It) is adapted to be formed by the apparatus of FIG. 1 from a blank such as the blank 30 (FIG. 3), this blank being of rectangular design and having notched corners 32 which establish the previously mentioned notched out corners 28 of the completed shelf 10' and which also serve a function in connection with the formation of the end flanges 16 by the apparatus of FIG. 1 and a squaring engagement between shelf flanges and corner posts.

It is to be noted that the shelf 10, as well as the blank 30 from which it is formed is of elongated design and that its longitudinal extent is several times greater than its transverse extent. Thus, the flanges 14 are formed from late-rally projecting elongated narrow strip portions 34 which are partially outlined by dotted lines in FIG. 3, while the flanges are formed from laterally projecting relatively short strip portions 36 which likewise are partially outlined by dotted lines.

Referring again to FIG. 1, the shelves 10 are successively formed from finish-coated mill run coiled steel 40 which passes through straightened rolls 41 and from thence to a punch press 42 where the notched blanks 30 are formed. The notched blanks are then conducted endwise, i.e. in their long direction, along a conveyor section 44 to a first mill 46 where the elongated narrow strip portions 34- thereof are operated upon by a series of successive forming rolls to produce the

marginal side flanges

14 and 16, these flanges being turned downwardly out of the plane of the blank by the rolls 48. Due to the relatively great length of the strips in their direction of travel, little or no difliculty is encountered in blank alignment with the forming rolls. Additionally, since the blanks are cut by the punch press 42 to proper width, the lateral strip portions which supply the metal for the flanges 14 are substantially of equal and constant width on opposite sides of the blanks so that there is little if any tendency for one pair of forming rolls to engage more metal than the other pair of forming rolls on the opposite side of the strip and thus equal driving speed will obtain on both sides of the blanks as they pass through the first forming mill 46. Still further, the relatively great length of the blanks will permit many stations of the first forming mill 46 to operate upon the strip simultaneously so that the strip is held securely in proper longitudinal alignment.

The disclosure of FIG. 1, being entirely schematic, no attempt has been made to disclose therein all of the blank handling devices and instrumentalities associated with the machine other than those described herein. For example, the details of the various pairs of forming rolls at the successive stands of the first forming mill 46, the driving mechanism for this mill or for the illustrated conveyors, the driving mechanism for the turn-over device 50, the numerous electric controls for such instrumentalities have been omitted from the disclosure since they are not directly involved in the invention disclosed and claimed herein other than the length of the blank varying with wide tolerances in mill run strip width. The stamping and notching of the blanks by the punch press 42 as shown in FIG. 1, the manner in which the partially formed blanks are conducted, and especially the manner in which they are guided to the turn-over 50 are subject matter covered elsewhere. This invention is essentially concerned with the turn-over, the blank delivery to the second forming mill 60, and the nature of the first several stations of the second forming mill 60 which constitute the salient features of the present invention and they have been illustrated in detail in FIGS. 4 to 8 inclusive.

From the first forming mill 46, the blanks are then conducted to a blank-inverting and direction-changing station where a turn-over device in the form of a rotary rack 50 having radial arms 52 receives the blanks and inverts them by flipping them over and onto a conveyor 54 which conducts them to a second conveyor 56, the latter being driven in timed relation with a second mill 60 which receives the blanks from the conveyor 56 and, by means of a series of successive forming rolls operates upon the short strip portions 36 and shapes them into the form of the flanges 16, thereby completing the finished shelf 10.

Whereas, in connection with the first forming mill 46, guiding of the stamped formed elongated blanks through the mill endwise with close tolerance edge guides provides a proper tracking of the blanks, in the second forming mill 60 the prefinished blanks with mill run edges of short length presents many problems including tolerances, twisting, scuffing of the shelf finish and jamming of the machine. For these reasons, and according to the present invention, a novel control and edge guide means is provided for the second mill 60.

Referring now to FIG. 4, the rolls associated with the first forming mill 46 are down-forming rolls and when the blank is discharged onto the conveyor section 44 from the last opposing pairs of rolls 70 of the mill 46, fragmentarily illustrated, the side flanges 14 project downwardly and are guided between side rails 72. It is to be noted that the side flanges 14 of the blanks discharged from these rolls 70 are completely formed, but the short strip portions 36 remain unformed and remain in the plane of the blank.

These partially formed blanks 10 progress endwise, i.e. in the direction of their length, to the turn-over device 50 which is indexed intermittently and in timed relation with the arrival of blanks thereto so that the blanks enter pockets 74 which are established between adjacent groups of radial arms 52. These arms project radially outwardly from a hub 76 carried on a shaft 78 which projects into a gear box 80 mounted on the stationary framework 8-2 of the conveyor 54. The gear box 80 is connected through a long coupling shaft 84 to a second gear box 86 (FIGS. 4 and wherein the shaft is coupled to an intermittently operated drive shaft 88 for the conveyor 54. The drive shaft carries a series of sprockets 90 which are connected by chains 92 to respective sprockets 94 secured to and rotatable with the shaft 78.

The details of the control means for intermittently actuating the turn-over device 50 and the conveyor 54 in timed relationship forms no part of the present invention but various means are usable. If desired, either a photocell or a proximity switch may be employed to detect the deposition of a shelf blank in position within a pocket 74 which registers with the conveyor 44, at which time the turn-over device 50 is indexed one position at a time to bring another pocket into register with the conveyor 44 and elevate the previously deposited shelf blank from register with the conveyor. This provides a convenient station for inspection with or without removal.

Upon successive indexing operations, the shelf blanks are ultimately turned over so that the downturned side flanges 14 become upturned when the shelf blanks are deposited laterally on the conveyor 54. The speed of the conveyor 54 is preferably relatively great but in any event, it is such that a shelf blank 10 deposited on the conveyor 54 will clear the radial arms 52 which carry a succeeding shelf blank at the time they deposit such blank on the conveyor at mass production speeds.

It is to be noted at this point that because the conveyor 54 extends at a right angle to the conveyor 44, and because the turn over device 50 does not change the longitudinal direction of the shelf blanks 10 during the transfer operation, the blanks are deposited square to and on the conveyor 54 with their short dimension extending in the direction of travel and, as previously stated, with the longitudinal side flanges 14 projecting upwardly and the rim flanges 24 downwardly.

Referring now to FIG. 5, edge guiding of the shelf blanks 10 along the conveyor 54 is not critical and simple guide rails 96 along the sides of the conveyor with wide tolerances suffice to maintain the shelf blanks substantially centered during their travel along the conveyor. The exit end of the conveyor 54 registers with the entrance end of the conveyor 56 and this latter conveyor is comprised of a pair of conveyor chains 98 and a series of guide rail devices the nature of which will be described presently.

The framework 82 is common to the two

conveyors

54 and 56 and it extends from the turn-over device 50 to the second forming mill and includes side frame members 109. The speed of the conveyor chains 98 is appreciably less than the speed of the conveyor chains 92 and the chains 98 are supported upon driving sprockets 102, driven end sprockets 104, and a series of idler sprockets 106 which support the reach sections of the conveyor chains. The sprockets 102 are driven in unison with the rolls associated with the first stand of the second forming mill 69 in a manner that will be described after the nature of this forming mill has been made clear.

The end sprockets 104 are rotatable on studs 103 mounted on supporting rails and they are sufficiently close to the sprockets 92 that the chains 93 will receive the leading edges of the shelf blanks 10 thereover after an appreciable degree of overhang from the chains 92 takes place. Adjustable stops 112 are secured to the rails 110 to block any tendency for a shelf blank to fall between the exit end of the conveyor 54 and the entrance end of the conveyor 56 in the event of a machine slowdown or stall. The idler sprockets 106 are similarly supported on studs 114 carried by the supporting rails 110. Hold down rails 115 are afiixed to the guide rails 96 and overlie the supporting rails 110 in close superimposed relationship. These hold down rails are provided with bevelled forward end regions 116 for initial blank-centering purposes as will be described presently.

Except for special considerations associated with the first station of the second forming mill 60, the mill rolls may be of conventional design. Only the first three stations of this forming mill have been illustrated in FIG. 5, these three stations being designated at 120, 122 and 124. Each station includes opposing pairs of blank-engaging rolls, mounted on upper spindles 126 and lower spindles 128. The rolls are provided with hub portions 129 and are power driven in unison by internal gearing disposed within the

side structures

130 and 132 of the mill 60. The previously mentioned driving sprockets 102 of the conveyor 56 are mounted on the hub portions 129 and are driven by the lower spindles 128 of the first stand 120. Thus the conveyor chains 98 are driven in timed relation with the various pairs of rolls at the successive mill stands.

As shown in FIGS. 6, 7 and 8, the upper and lower blank-engaging rolls at the first station 120 are designated at 1410 and 142; the rolls at the second station 122 being designated at 144 and 146; and those at the third station 124 being designated at 148 and 151 The rolls 140 and 142 are blank-gripping and feeding rolls, while all of the rolls at the remaining station of the mill 60 are progressive blank-forming rolls. All of the rolls engage only the short strip portions 36 of the blanks, and opposing pairs are adjustable en banc towards and away from each other for different shelf widths.

It is essential to a full understanding of the present invention that the manner in which the successive blanks are fed to and through the second forming mill 6% be understood. Since these blanks are relatively short in their direction of travel along the conveyor 56 and are relatively long in a direction transversely of the direction of travel, great care must be exercised in guiding them from the conveyor 54 along the conveyor 56 to the first stand 120 of the second forming mill 6d so that they will enter such stand squarely. Thereafter, care must be taken to maintain accurate alignment of the blanks as they travel through the mill.

As previously described, the blanks 1t approaching the mill 60 on the conveyor 56 are inverted, which is to say that the previously formed long marginal side flanges 14 (FIG. 2) now project vertically upwardly and extend transversely of the direction of travel of the blanks as shown in dotted lines in FIG. 5. The laterally projecting and yet unformed short strip portions 36 (FIG. 3) are caused to rest and slide upon the upper edges of the supporting rails 110. The level of support for the strip portions is slightly above the level of the upper reach portions of the conveyor chains 18 so that the rim flanges 24 contact the conveyor chains 98 for impelling the shelf blanks 10 forwardly toward the mill 6!). In moving for wardly under the influence of the chains 98, the laterally projecting strip portions 36 of the blanks 10 enter the narrow slot or space existing between the hold down rails 115 and the supporting rails 110 while the squared terminal end edges of the compound flanges 14 of the blanks 10 are closely confined between and are guided by the inside opposed edges of the rails 115. The free exposed side edges of the strip portions 36 are not confined and the strip portions 36 therefore pass freely along the slot existing between the

rails

110 and 115 subject only to close guiding tolerances at the squared end edges of flanges 14. The bevelled portions 116 of rails 115 initially engage the terminal end edges of the formed side flanges 14 of the blanks 16' and effect initial centering of the blank between the rails 115. These latter rails thus constitute the sole guiding means for the blanks in travelling along the conveyor 56 to the mill 60.

The speed of the intermittently operated conveyor 54 is appreciably greater than that of the continuously operable conveyor 56. The blanks 10 are thus projected by the conveyor 54 onto the conveyor 56 successively and with appreciable momentum -to assure clearance of the radial arms 52 and the chains 98 move the blank into roller gripping position. Thereafter the movement of the blanks along the conveyor 56 is somewhat slower and uniform.

Heretofore, in connection with conventional mills such would otherwise be used at mill 60 for the shaping of the lateral short end edges of blanks, it has been impossible to effect proper tracking of the shelf blanks through the mill rollers unless the projecting planar end edge regions, i.e., the short strip portions 36 (FIG. 3) are of uniform width. The slightest discrepancy between the widths of these mill edge strip portions on opposite sides of the mill will cause cocking or twisting of the blanks and a consequent jamming of the machine. This has been because ordinarily the first set of rolls encountered are forming rolls and have bevelled forming surfaces which engage the strip portions 36 unequally. A strip portion 3s wider on one end edge of the blank than the one on the other end edge will preempt this strip portion to ride outwardly on the frusto-conical portions of the forming rolls and thus be propelled on a greater driving radius than obtains on the other side of the mill. Cocking of the blank will result regardless of how accurately aligned the blank may be when it enters the mill.

According to the present invention, to obviate such twisting of the blanks, even when wide tolerances in the widths of the strip portions 36 are to be expected by reason of the use of mill width steel, the rolls 140 and 142 at the first stand (FIG. 6) are truly cylindrical and they exert a relatively powerful gripping action on the strip portions 36 as they initially enter the mill. The

rolls

144 and 146 at the second stand 122 are forming rolls and they are shown in FIG. 7 as being provided with complementary frusto-conical forming surfaces 160. The short strip portions 36 of the blanks 10 which are initially fed to these forming

rolls

144 and 146 remain firmly engaged by the gripping r-olls 14d and 142 during passage of the strip portions 36 through the

rolls

144 and 146 and thus, although the tendency for the blank to twist remains prevalent, the gripping rolls and 142 which engage the trailing region of the blanks, hold the blanks against such twisting until such time as engagement by the forming rolls 148 and at the third station 124 (FIG. 8) take over. At the time that the blanks thus reach the third stand of the mill 60, the danger of twisting or cocking of the blanks has largely passed. An appreciable bend has been applied to the short strip portions 36 and the trailing regions of these partially formed strip portions are firmly seized by the forming

rolls

144 and 146 at the second stand 122 at the time that the leading edge of the blank arrives at and is engaged by the forming

rolls

148 and 150 at the third station 124. As shown in FIG, 8, these latter forming

rolls

148 and 150 are provided with radial mating forming surfaces 161. At successive stands of the mill 60 additional forming operations take place but, since an appreciable degree of rigidity has been applied to the originally flat strip portions 36, accurate tracking of the blanks throughout the remainder of their travel through the mill 60 will be maintained.

A pair of guide rails 162 extend between the various upper and

lower spindles

126 and 128 and support the blanks near the working areas thereof during their passage through the mill 60. These latter guide rails have lateral extensions 164 which project laterally between the rolls of adjacent stands and prevent the strip portions 36 from attempting to curl around the forming rolls.

The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings or described in this specification as various changes in the details of construction may be restorted to without departing from the spirit of the invention. Therefore, only insofar as the invention has particularly been pointed out in the accompanying claims is the same to be limited.

What is claimed is:

1. In a successively operable, shelf-forming apparatus for simultaneously bending, by progressive rolling operations, oppositely directed narrow coplanar strip portions which project outwardly at the opposite ends of partially formed longitudinally elongated generally rectangular sheet metal shelf blanks to produce compound transversely extending marginal lateral flanges at the ends of the blanks, the blanks having previously been formed with longitudinally extending marginal lateral side flanges which terminate short of the strip portions, in combination, a forming mill establishing a linearly straight working area through which the blanks are adapted to pass sidewise, a series of successively arranged opposed identical pairs of cooperating blank-engaging rolls at the opposite sides of said working area, said opposed pairs of rolls being successively engageable with said coplanar strip portions and operable to impel the blanks forwardly through the working area while progressively bending said strip portions to form said transversely extending marginal lateral flanges, the first identical pair of opposed rolls in the series presenting cooperating cylindrical blankgripping surfaces, the second identical pair of rolls in the series having cooperating mating frusto-conical blank-engaging surfaces engageable with the leading edges of said coplanar strip portions prior to release of the trailing edges thereof by the first identical pair of opposed rolls, and means for driving said opposed pairs of rolls in unison.

2. In a successively operable shelf-forming apparatus, the combination set forth in claim 1 and including, additionally, a pair of horizontal blank-supporting rails on opposite sides of said Working area and coextensive with the latter, said supporting rails presenting upper supporting surfaces which lie substantially at the horizontal level of the blank-engaging surfaces afforded by said pairs of rolls.

3. In a successively operable shelf-forming apparatus for simultaneously bending, by a progressive rolling operation, oppositely directed narrow coplanar strip portions which project outwardly at the opposite ends of partially formed longitudinally elongated generally rectangular sheet metal shelf blanks to produce compound transversely extending marginal lateral flanges at the ends of the blanks, the blanks having previously been formed with longitudinally extending marginal lateral side flanges which terminate short of the strip portions, in combination, a forming mill establishing a linearly straight working area through which the blanks are adapted to pass sidewise, a series of successively arranged opposed identical pairs of cooperating blank-engaging rolls at the opposite sides of said working area, said opposed pairs of rolls being successively engageable with said coplanar strip portions and operable to impel the blanks forwardly through the Working area while progressively bending said strip portions to form said transversely extending marginal lateral flanges, the first identical pair of opposed rolls in the series presenting cooperating cylindrical blankgripping surfaces, the second identical pair of rolls in the series having cooperating mating frusto-conical blankengaging surfaces thereon engageable with the leading edges of said coplanar strip portions prior to release of the trailing edges thereof by the first identical pair of opposed rolls, an endless conveyor for conducting blanks to said working area, said conveyor having an upper reach section in horizontal alignment with said working area at the entrance end thereof, at the horizontal level of the blank-engaging surfaces afforded by said pairs of rolls, and of an effective width slightly less than the width of the working area, and means for driving said opposed pairs of rolls and conveyor in unison.

4. In a successively operable shelf-forming apparatus, the combination set forth in claim 3 and including, additionally, a pair of horizontally disposed opposed cooperating centering guides on opposite sides of said conveyor and substantially coextensive with the latter, said centering guides being engageable with the opposite end edges of the longitudinally extending side flanges of the blanks and constituting the sole centering means for guiding the blanks in their sidewise relationship into said working area.

5. In a successively operable shelf-forming apparatus, the combination set forth in claim 3 and including, additionally, a pair of horizontally disposed opposed cooperating centering guides on opposite sides of said conveyor and substantially coextensive with the latter, said centering guides being positioned so as to overhang the coplanar strip portions of the blanks passing along said conveyor and to engage the opposite end edges of the longitudinally extending side flanges of the blanks, said centering guides constituting the sole centering means for guiding the blanks in their sidewise relationship into said working area, and an additional pair of guides on opposite sides of the conveyor coextensive with and spaced vertically from said centering guides a distance substantially equal to the thickness of the sheet metal of the blanks and defining, in combination with said centering guides, a narrow elongated slot into which said coplanar strip portions loosely project and along which they are adapted to slide during travel of the blanks towards said working area.

6. In a successively operable apparatus for simultaneously bending, by progressive rolling operations, oppositely directed narrow coplanar strip portions which project outwardly at the opposite ends of a partially formed longitudinally elongated generally rectangular sheet metal shelf blanks to produce compound transversely extending marginal lateral flanges at the ends of the blanks, the blanks having previously been formed with longitudinally extending marginal lateral side flanges which terminate short of the strip portions, in combination, a forming mill establishing a linearly straight working area through which the blanks are adapted to pass sidewise with said lateral side flanges projecting upwardly, a series of successively arranged opposed identical pairs of cooperating blank-engaging rolls at the opposite sides of said working area, said opposed pairs of rolls being successively engageable with said coplanar strip portions and operable to impel the blanks forwardly through the working area While progressively bending said strip portions upwardly to form said transversely extending marginal lateral flanges, the first identical pair of opposed rolls in the series presenting cooperating cylindrical gripping surfaces, the second identical pair of rolls in the series having cooperating mating frusto-conical blank-engaging surfaces engageable with the leading edges of said coplanar strip portions prior to release of the trailing edges thereof by the first identical pair of opposed rolls, an endless conveyor for conducting blanks to said working area, said conveyor having an upper reach section in horizontal alignment with said working area at the entrance end thereof, at the horizontal level of the blank-engaging surfaces afforded by said pairs of rolls, and of an effective width slightly less than the width of said working area, a pair of horizontally disposed blank-supporting rails on opposite sides -of said conveyor and having upper surfaces at substantially the horizontal level of the reach section of the conveyor and on which the blanks are adapted to be slidingly supported, said conveyor impelling the blanks forwardly along said upper surfaces of the blank-supporting rails, a pair of horizontally disposed cooperating centering guides on opposite sides of the conveyor a slight distance above said rails and positioned to overlie and overhang the coplanar strip portions of the blanks passing along the conveyor and to engage the opposite end edges :of the longitudinally extending side flanges of the blanks, said centering guides constituting the sole centering means for guiding the blanks in their sidewise relationship into said working area, and means for driving said opposed pairs of rolls and conveyor in unison.

7. In a successively operable shelf-forming apparatus, the combination set forth in claim 6 and including, additionally, a pair of horizontally disposed blank-supporting rails on opposite sides of said working area and coextensive with the latter, said latter supporting rails presenting upper supporting surfaces which lie substantially at the horizontal level of the blank-engaging surfaces afforded by said pairs of rolls.

8. In a successively operable shelf-forming apparatus for simultaneously bending, by progressive rolling operations, oppositely directed narrow coplanar strip portions which project outwardly at the opposite ends of partially formed longitudinally elongated generally rectangular sheet metal shelf blanks to produce compound transversely extending marginal lateral flanges at the ends of the blanks, the blanks having previously been formed with longitudinally extending lateral rim and marginal side flanges which terminate short of the strip portions, in combination, a forming mill establishing a linearly straight Working area through which the blanks are adapted to pass sidewise with said lateral side flanges projecting upwardly, a series of successively arranged opposed identical pairs of cooperating blank-engaging rolls at the opposite sides of said working area, each pair including upper and lower rollers presenting inwardly directed hub portions, said opposed pairs of rolls being successively engageable with said coplanar strip portions and operable to impel the blanks forwardly through the working area while progressively bending said strip portions upwardly to form said transversely extending marginal lateral flanges, the first identical pair of opposed rolls in the series presenting cooperating cylindrical gripping surfaces, the second identical pair of rolls in the series having cooperating mating frusto-conical blank-engaging surfaces engageable with the leading edges of said coplanar strip .portions prior to release of the trailing edges thereof by the first identical pair of opposed rolls, an endless conveyor for conducting blanks to said working area, said conveyor including a pair of blank-impelling chains and having upper reach sections in alignment with the rolls on opposite sides respectively of said working area to engage said rim flanges, driving sprockets for said chains on the hub portions of the lower rollers of the first opposed pair of blank-engaging rolls, and means for driving said opposed pairs of rolls in unison.

9. In a successively operable shelf-forming apparatus, the combination set forth in claim 8 and including, additionally, a pair of horizontally disposed blank-supporting rails on opposite sides of said conveyor and having upper surfaces at substantially the horizontal level of the reach sections of the conveyor chains and on which the blanks are adapted to be slidingly supported, and a pair of horizontally disposed cooperating centering guides on opposite sides of the conveyor a slight distance above said rails and positioned to overlie and overhang the coplanar strip portions of the blanks passing along the conveyor and to engage the opposite end edges of the upwardly projecting longitudinally extending side flanges of the blanks, said centering guide-s constituting the sole centering means for guiding the blanks in their sidewise relationship into said working area.

10. A method of formng a generally rectangular sheet metal shelf having a rectangular planar body :portion provided with marginal depending longitudinal side flanges and transverse end flanges, said method comprising: removing the four corner regions of a flat rectangular sheet metal blank by cutting rectangular notches therein by a metal removing operation so as to provide said rectangular planar body portion and establish elongated narrow rectangular strip portions along the longitudinal side edges of said body portion and in the plane thereof, and short narrow strip portions along the transverse end edges of said body portion and in the plane thereof, passing the thus notched blank endwise and in the plane of said body portion through successive opposed pairs of forming rolls and causing said elongated narrow rectangular strip portions along the longitudinal edges of said body portion to be rolled downwardly out of the plane of the body portion to produce said marginal depending longitudinal side flanges, moving the blank laterally so that said side flanges are disposed normal to the line of blank movement, and passing the blank sidewise and in the plane of said body portion through successive opposed pairs of forming rolls and guiding said short narrow strip portions solely from contact with the ends of said side flanges along the transverse end edges of said body portion to be rolled out of the plane of the body portion to produce said marginal transverse end flanges.

11. The method called for in claim 10 including engaging said short narrow strip portions with a rolling feed clamped relationship while said blank is being guided by said contact with the ends of the side flanges.

No references cited.

WILLIAM W. DYER, IR., Primary Examiner. L. VLACHOS, Examiner.

Claims

10. A METHOD FOR FORMING A GENERALLY RECTANGULAR SHEET METAL SHELF HAVING A RECTANGULAR PLANAR BODY PORTION PROVIDED WITH MARGINAL DEPENDING LONGITUDINAL SIDE FLANGES AND TRANSVERSE END FLANGES, SAID METHOD COMPRISING: REMOVING THE FOUR CORNER REGIONS OF A FLAT RECTANGULAR SHEET METAL BLANK BY CUTTING RECTANGULAR NOTCHES THEREIN BY A METAL REMOVING OPERATION SO AS TO PROVIDE SAID RECTANGULAR PLANAR BODY PORTION AND ESTABLISH ELONGATED NARROW RECTANGULAR STRIP PORTIONS ALONG THE LONGITUDINAL SIDE EDGES OF SAID BODY PORTION AND IN THE PLANE THEREOF, AND SHORT NARROW STRIP PORTIONS ALONG THE TRANSVERSE END EDGES OF SAID BODY PORTION AND IN THE PLANE THEREOF, PASSING THE THUS NOTCHED BLANK ENDWISE AND IN THE PLANE OF SAID BODY PORTION THROUGH SUCCESSIVE OPPOSED PAIRS OF FORMING ROLLS AND CAUSING SAID ELONGATED NARROW RECTANGULAR STRIP PORTIONS ALONG THE LONGITUDINAL EDGES OF SAID BODY PORTION TO BE ROLLED DOWNWARDLY OUT OF THE PLANE OF THE BODY PORTION TO PRODUCE SAID MARGINAL DEPENDING LONGITUDINAL SIDE FLANGES, MOVING THE BLANK LATERALLY SO THAT SAID SIDE FLANGES ARE DISPOSED NORMAL TO THE LINE OF BLANK MOVEMENT, AND PASSING THE BLANK SIDEWISE AND IN THE PLANE OF SAID BODY PORTION THROUGH SUCCESSIVE OPPOSED PAIRS OF FORMING ROLLS AND GUIDING SAID SHORT NARROW STRIP PORTIONS SOLELY FROM CONTACT WITH THE ENDS OF SAID SIDE FLANGES ALONG THE TRANSVERSE END EDGES OF SAID BODY PORTION TO BE ROLLED OUT OF THE PLANE OF THE BODY PORTION TO PRODUCE SAID MARGINAL TRANSVERSE END FLANGES.