US2355093A - Machine for press forming sheetlike articles - Google Patents

Description

4 s. H. MILLER ETAL- 2,355,093

MACHINE FOR PRESS FORMING SHEET-LIKE ARTICLES Filed Nov. 18, 1942 3 Sheets-Sheet l INVENTORS SAMUEL h. Mn. 1. ER GORDON 1.. JEN/(1N6 ATTORN KS.

FREDERICK 7. McGU/RE, JR.

Aug. 9 s. H. MILLER E j 2,355,093

MACHINE FOR PRESS FORMING SHEET-LIKE ARTICLES Filed Nov. 18, 1542 3 Sheets-Sheet 2 47 $5 l as H F fH/m I 1 1 $3 H I 84 30/ I 32 05 //0 97 I0! 23 22 1a 24 2o lo/ 25 I6 I Maw-- 2g ll! 18 T" 7 INVENTORS SAMUEL H MILLER GORDON L. J'ENK/MS l6 FREDERICK 7'. Mcu/eL- J/a ATTO 5K3.

Patented Aug. 8, 1944 MACHINE FOR PRESS FORMING SHEETLIKE I ARTICLES Samuel H. Miller, Cleveland, Gordon L. Jenkins, Lakewood, and Frederick T. McGuire, Jr., Shaker Heights, Ohio, assignors to Industrial Fabricators Inc., Cleveland, Ohio, a corporation of Ohio Application November 18, 1942, Serial No. 466,078

2 Claims.

The invention relates to apparatus for deforming sheet,- and more specifically to apparatus for simultaneously producing a plurality of bending operations on fiat sheet of wood-like, synthetic nature.

While'the invention may be used with little or no modification to produce permanent deformations in sheets from a wide variety of materials of this general type, the description hereinafter given involves the production of a trough shaped, elongated reflector made from a board formed by synthesis of exploded wood fiber. It should be understood that the specific example illustrated and described is descriptive merely, and not limiting.

One object of the invention, therefore, is the provision of a simple yet efilcient apparatus for producing, simultaneously, a plurality of deforming operations on sheet material.

' A further object is the provision of an apparatus of this nature, wherein improved means are provided for the application of heat and pressure to a plurality of spaced locations on the sheet.

A further object of the invention is the provision of an apparatus such as just described, and wherein improved means are provided for guiding, controlling, and evenly distributing the application of the deforming pressure.

' Other objects and advantages will be apparent to those skilled in the art on consideration of the following description, in conjunction with the attached drawings illustrating one specific embodiment of the invention.

, Fig. 1 is a perspective view of an apparatus embodying the invention;

, Fig.2 is a perspective view of a trough shapedreflector, after its formation on the apparatus shown in Fig. 1;

Figs. 3, 4 and are transverse vertical sections taken on the line 55 of Fig. 1, Figs. 3 and 4 however showing certain parts in positions other than as shown in Figs. 1 and 5; and

Figs. 6. and 7 are detail views, in section of slightly modified portions of the apparatus shown in Figs. 1, 3,4 and 5.

Before the present invention is described in detail, it is, to be understood that the invention here involved is not limited to the details of construction or the specific arrangement of parts herein illustrated or described, as the invention obviously may take other forms. It also is to be understood that the phraseology or terminology hereinempIQYed is for the purpose of description and not of1imitation,the scope of the present invention being indicated by the appended claims.

The apparatus here illustrated consists, in essentials, of a lower die or bed having suitable supporting means therefor, heating means for said bed, means for positioning a sheet-like article on said bed, and means for applying to said article,'when thus positioned, a deforming force at a plurality of spaced locations on said sheet, and particularly outwardly beyond the bed edges, the pressure being maintained for a period necessary to plastically deform the sheet. Further means are providedfor controlling the pressure within proper bounds, and for evenly distributing the pressure. One of the significant features of the invention is the presence of means which permits regulation of the pressure to a value insufiicient to exceed the cold elastic limit of the material, but sufiicient to produce permanent deformation of the material above a critical temperature. In the specific embodiment here shown such pressure regulation is accomplished by varying both the absolute pressure and its zone of application to the sheet, due consideration being given to the .thickness and specific grade of 'the material.

In view of the aforesaid it is apparent that the deforming pressure might be supplied from various sources, hydraulic, electrical, mechanical, or various arrangements involving two or more of. such sources. The relatively simple arrangement shown inthe attached drawings utilizes gravity, augmented in part by a leverage arrangement, to furnish the deformation pressure, and when the operation is completed the pressure load is removed by a conventional hydraulic power hoist, using compressed air to produce the power stroke of the-piston. When the next work piece is ready to be deformed, the cylinder is valved to exhaust, and the next op-' eration again takes place under gravity.

, rigidly attached to uprights I0. The bed assembly may be constructed in any suitable way but one convenient method is here illustrated which is particularly adapted for the manufacture of a trough like reflector H such as is shown in perspective in Fig. 2. The bed assembly consists of two elongated hollow cylindrical members I3 and I9 carried in parallel arrangement by a spacing andsupporting member 29 which is here conveniently represented by an I beam, the cylindrical members being welded or otherwise firmly attached to the beam 20. Beam 29 is carried by, and amxed to, cross members 15. For the manufacture of the particular shape shown in Fig. 2, the upper outer quadrants of cylinders l8 and I9 represent the actual forming faces of the bed assembly, as will appear as the description proceeds.

Heating means is provided for the cylinders l8 and I9, such means in the present instance consisting of elongated, perforated gas burners 22 and 23 supported respectively within cylinders l8 and I9 by spiders 24 and 25. The burners are fed in the usual way through flexible couplings 26 and 21, and are valved in conventional manner, as shown at the left of Fig. 1. Suitable flues 28 and 29 are also provided, asshown towards the right of Fig. 1.

The pressure applying means" hereinafter termed the head will, now be described. The drawings show a longitudinally disposed structural member or I beam 32 positioned above and in the present embodiment generally parallel to the beam 20 already described. 'Attached to the base flange 33 of the I beam by suitable hinges 34 are two angle members '30 andl3l coextensive in length with beam,32, and so disposed that their vertical flange portions 36 and 3'! lie' somewhat outside cylinders l8 and I9. Attached respectively to angle members 30 and 3l'by welding or otherwise are two projecting wing brackets 38 and 39 which may be conveniently formed from channel sections. These wing members respectively carry loading weights 40 and 4|, which weights may be arranged to be replaceable, either by removal and substitution, or by removal of the wing members 38 and 39. The wing members carry respective eye bolts, and 46 which are retained by means of nuts 41 as will be apparent.

Beam 32 is maintained. in parallel alignment with beam 29, while capableofapproaching and receding motion relative thereto, byguiding and aligning means now to be described. Since each end of the machine is provid ed with such iden; tical guiding and aligning means, ,only one such means will for simplicity be'described, V v I Beam 20 carried nearits end, and projecting normally to its upperflange, a rod 59. Beam 32 is perforated by two vertically aligned openings in which isfixedly seated, by welding or otherwise, an elongated bushing .51. Bushing slides telescopingly on rod 59with sufficient clearance to allow beam 32 to befreely raised and lowered with respect to beam 20. Provision of such aligning means at both ends of the machine maintains the beams in parallel alignment. Suchalignment is subject to further adjustment by means of compression springs ,5 3 which are maintained between flanges 54 onthe bushings and adjustable collars 55 on rods 50.

As will subsequently appear, the assembly just described, comprising the beam 32, the angles 3| and 30, and the wings 38and 39, supplies the deforming force which simultaneously produces a plurality of bends in a synthetic wood sheet. Thi ass mblyris e a ed i th foll w g m n? ner. In connection with this description, see Figs. 1, 3 and 5.

.A bracket, generally indicated by reference numeral 69, is transversely disposed upon, and permanently attached to, top frame members [4, at about the mid point thereof. Bracket 60 carries two spaced, upright, bifurcated members El and 62 which respectively support levers 63 and 64, said levers being mounted in swinging relationship on pivots 6 5 and 66. Levers 63 and 64 have their outer ends connected to the upper ends of two hoisting chains 6'! and 69, which chains are in turn respectively connected, at their lower ends, to eye bolts 45 heretofore described.

Bracket 69 also carries a conventional hydraulic powerapparatus comprising a cylinder block 10 in which a piston H is reciprocably slidable, the piston being actuated in one direction by compressed air supplied to a chamber through line 12 under the control of a three way valve 13 arranged either for the admission of air, or the exhaust thereof. Piston H is affixed to a rod 14 (Fig. 5) which is movable vertically through an opening in bracket I59. A conventional extensible dust cap 15 prevents the entry of dust to 'the cylinder interior through the rod packing. The upper end of the rod is suitably linked to the inner adjoining ends of levers 63 and 54, by a chain connection 16 or otherwise.

The raising and lowering of the head proceeds as follows: Assuming the head to be in its lowest position, shown in Fig. 5, compressed air is admitted to the upper chamber 80 of the 1 cylinder by suitable operation of valve 73. This causes piston H and rod 14 to move downwardly, thereby swinging lever 64 counterclockwise and lever 63 clockwise, elevating chains 61 and 68 and raising Wings 38 and 39,,and the aflixed '1; angles 30 and 3| which assembly in a preliminary phase of the operation, merely pivots on hinges 34 without producing upward motion of beam 32. Angles 39 and 3|, however, are respectively equipped with upwardly directed, projecting studs 83 and 84 which, by said pivotal motion around hinges 34, are brought into contact with abutment brackets or pads. 85. and 85.v Further hoisting motion of chains 6'! and 6B lifts beam 32, causing bushings 5| to slide upwardly on rods 59 against the snubbing' action of springs 53, as best shown in Fig. 3,'which indicates approximately top position of the head, corresponding to extreme inward travel of the piston Him the cylinder.

This position maybe maintained as long as desired. The head assembly is lowered by venting the chamber 80 of the cylinder to exhaust by means of valve 13. The compressed springs 53 assist in starting the head downwardly and the weight of the head assembly, exerted at the outer ends oflevers 63 and 64, and transmitted, to piston rod 14, returns the piston H to top position as indicated in Fig. 5, the head descending meanwhile. To facilitate this operation the lower chamber 9 0 of the cylinder, is vented to atmosphere through stub pipe 9|, which may carry a conventional air cleaner and filter 92.

The manner of formation 'ofa 'sheet'article of wood like material to a, contour such asshown in Fig. 2 will now be described. This specific article, a trough shaped reflector having opposed, oonvexly curved portions 94 and 95, is'used as alsubstitute fora similarly shaped farticle prev i m nse-1a meie fwhi h i now P.

strategic character, and hence such material substitution is highly desirable. e

A sheet of material of suitable area and thicknessis first allowed to soak in water for a number of hours, the'moisture penetrating the fibers andconditioning the sheet for the bending operations. With the head in fully elevated position, as shown in Fig. 3, and with the cylinders preheated to desired temperature as previously described, the sheet Ila. is inserted from right to left (Fig. 3) until its leading edge abuts a stop 96 which is carried by frame post III. Two such stops may be provided, one at each end of the frame. For convenience the stop 96 may be adjustably mounted by means of slots 9? and bolts 98 on fixed brackets 99, the brackets in such instancebeing fixed on the frame posts I0. When thus placed in position the sheet is in line contact with cylinders 18 and I9 of the bed assembly, itsmiddle portion being out of contact with said cylinders, as shown in Fig. 3. Proper manipulation of valve 13, as heretofore described permits the head to descend until the lower fiange of the beam 32 makes contact with the sheet Ila. In the embodiment here shown, a pressure pad Ice is provided along the lower contacting face of beam 32, such pad being conveniently formed from several laminations of the same material as sheet Ila, and being retained in fixed relationship to the beam by machine screws or bolts Illl, the screw head seats being countersunk in the bottom surface. In such instance the pad establishes the preliminary contact between the head and sheet Ila.

Such contact having been established, the dead weight of the head assembly confines and maintains sheet Ila in fixed position on the cylindrical elements is and IQ of the bed. The hingably mounted side assemblies comprising angles 36 and 3| and wings 38 and 39 continue to move downwardly until contact is established between the sheet and the elongated, narrow abutment formed bythe lowermost edge portion I 05 of angle member 3!. Since the operation of both hinged side elements of the head is identical, the action of one only is described, reference now being had to Figs. 3 and 4. As the weight of the angle member 3i and its wing Bfi'is applied to sheet Ila through. the medium of angle edge abutment me which is outwardly positioned beyond cylinder is, the sheet first yields resiliently without per- 'manent set, at the same time being bowed upwardly at its central portion I06 so as to slightly raise the beam 32 against the resistance of springs 53. At first the sheet contacts with the heated cylinders only along two parallel lines. In a short time the heat softens it along these lines so that it begins to bend with a permanent set at those lines. 7 further the effect is to extend the area of contact between heated cylinder I9 and sheet Ila, the effect of the heat and moisture on the sheet producing an increasing plasticizing or softening action locally throughout the area of actualcontact, so as to cause the sheet progressively to acquire a local permanent set of the specific shape of the contacting portion of the bed. Downward gradual motion of the wingelements continues, under gravity, until a stop member I II] makes contact with a bracket or other abutment III carried at the cylinder ends (Figs. 1 and 5). The length of the stop H9 and the position of bracket III are so arranged that the downward motion of the head is terminated when the desired contour, as shown in Fig. 2 is imparted to As the hinged assembly descends the sheet. Since the middle portion of the sheet is never in contact'with the cylindrical formers it never becomes heated sufficiently to become as plastic as other portions of the sheet. Therefore, as the bending operation-proceeds, this middle portion, which at first arched upwardly as in Fig; 4, finally relaxes to its original fiat form, as in Figs. 3 and 5. To allow for some slight residual resiliency in the opposed .convex portions of the refiector the stop III) may be disposed to allow the side portions I'Ic of the reflector to, be carried somewhat past the required angular deilection since, when the pressure is removed, the side portions tend to spring back slightly.

It is obvious that articles of various contours may be produced by proper variation in the extent and contour of the head and bed portions. Other such changes-can be, effected by a change in the dimensions and lateral spacing of the vertical portions 36 and 31 of the hinged angle members which, of course, need not be identical in either size or contour with each other.

The weight of the wing members 38 and 33 may be Varied to produce desired changes in pressure resulting from the varied requirements of sheets of respectively varying thicknesses. The weights 40 and 4| may be made to be adjustable in distance from the fulcrums 34, as shown, for instance, in Fig- 6 wherea flat plate 38a is provided with a slot H2 which serves as a track for a movable counterweight H3. The counterweight is retained by a suitable threaded stud I I4 and washer H5. The eye bolt I I6, corresponding in function to bolts 45 and 46 previously described, is adjustable in length, as shown.

The utilization of a pressure head assembly of the naturedescribed has a number of advantageous features. For instance the cylinders I8 and I9 may be replaced by others of smaller or larger outside diameter, depending on the radius desired in the fabricated article. Other curved or variously contoured edge portions may be substituted for the cylinders. The use of a pressure edge or elongated narrow abutment, such as I05, for the application of the bending force along a line eliminates a substantial proportion of the large frictional losses encountered when a fullcontact die face is used to form material, As seen for instance in Fig. 3 the edge I05 is rounded to provide for low friction slippage along the upper surface of the sheet after first contact, as already described. The angle of impingement of edge I05 against the sheet may be altered, and its distance from the fulcrum 34 otherwise varied, as desired.

Fig. 7 shows a slightly modified form of the invention wherein the edge I05 of angle 3| is provided with a contacting pad I I! of softer material than metal, and preferably of the same material as that being formed. This reduces any tendency of the contacting edge to scufi or mar the material.

The invention has been described with special reference to synthetic wood sheet of disintegrated and pressed wood fibers since this material has in the past given rise to serious problems. As a matter of fact no previous successful method or apparatus is known for simultaneously producing a double bend such as here shown. Other types and configurations involving bending operations of varied character may be produced by modifications in the apparatus here shown and described, such modification being a simple matter for a mechanic after consideration of the present invention.

What we claim is:

1. Apparatus for bending worksheets of woodp ximately the same width as the space between t e side portions of the bed, and a swinging b nder hinged to each side edge of the platen and provided with an elongated narrow abutment lying outwardly beyond the adjacent forming portion of, the bed, the platen. and the benders being relatively of such weight and the arrangement being such that when the forming head is lowered upon a moistened work sheet lying upon the bed the weight of the two benders at first arches the middle portion of the sheet and holds the sheet applied to the heated bed along two lines and then progressively bends the outer edge portions of the sheet downwardly to conform them to the curved forming portions of the bed while the middle of the sheet relaxes to fiat form.

2. Apparatus for bending work sheets of woodlike ,material to channel form, comprising a frame, two cylindrical formers supported thereby in spaced parallel relation at the same level, heating means therefor, said formers being adapted to contact with and support and heat a work sheet at first along two lines only, leaving the intervening middle portion of the sheet free of contact with and support by them and with the side sheet edges extending outwardly beyond said former, and a forming head vertically movable in the frame above said formers, said head including a platen portion wide enough to bridge the space between said formers and including two narrow bending abutments movably connected thereto, said abutments extending parallel to the axes of the formers and lying outwardly beyond the same, whereby upon downward movement of the head the abutments engage the outer portions of a work sheet along two lines and progressively bend the sheet around and apply it to the formers as the sheet becomes plastic by contact therewith, and whereby also the middle portion of the sheet which is out of contact with the formers at first arches upwardly and then relaxes to fiat form.

SAMUEL H. MILLER.

GORDON L. JENKINS. FREDERICK T. MCGUIRE, JR.

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