US3162925A - Apparatus for producing expanded metal - Google Patents

Description

Dec. 29, 1964 R. M. Fl-:LSENTHAL APPARATUS FOR PRODUCING EXPANDED METAL 5 Sheets-Sheet l Filed April 24, 1962 -F/G. 9 M 30 DSC, 29, 1964 R. M. FELSENTHAI. 3,162,925

APPARATUS FOR PRODUCING EXPANDED METAL Filed April 24, 1962 3 Sheets-$11691. 2

37 le 26 J7 A f6 /39 F/G. /Z r/ )ai "WWW hij, 33 -|/3 (34 35 F/G /4 4g "44 4Z /44 fn Y will! L Dec- 29, 1964 R. M. FELSENTHAL 3,162,925

APPARATUS FOR PRODUCING EXPANDED METAL Filed April 24, 1962 3 Sheets-Sheet 3 United States Patent O 3,162,925 APPARATUS FR FRGDUCING IEXIANEED METAL Robert M. Felsenthal, 48 Vine Road, Larchmont, NSY. Filed Apr. 24, 1962, Ser. No. 189,839 3 Clair-ns. (Cl. 29-6.2)

This invention relates generally to metallic sheet material commonly known as expanded metal, in which successive staggered rows of pendant sheared strands are linked together by connecting bridges, and has particular reference to improved apparatus for making such material. Coordinately, the invention relates to the improved products thereby created.

It is a general object of the invention to remedy one of the shortcomings of the commonly employed manufacturing procedure in which a shear plate and a serrated punch are reciprocated in shearing relation to each other and laterally shifted between shearing operations, while the sheet to be treated is advanced stepwise to subject successive areas to the she-aring action of the punch. An almost inevitable result of this method of procedure is the creation of expanded metal in which the connecting bridges between the strands are of angled character. This is especially manifest in ca-ses involving relatively ductile metals or in which the stnands are relatively wide in comparison to the thickness of the original sheet. The angling referred to is in the lengthwise direction of the sheet and resides in the disposition of the forward half of each connecting bridge in a plane at an angle to the rearward half. This structural condition has certain disadvantages, and it is a specific object of this invention to overcome this. A further object is to attain the added advantages of an expanded met-al in which the connecting bridges are relatively straight and lie in substantially single planes.

It is a well-known characteristic of expanded metal, manufactured as described, that the connecting bridges lie at tan oblique angle to the plane of the iinished product. By avoiding the buckling or angling mentioned above, and by causing each bridge to remain in a substantially single pl-ane, improved characteristics can be imparted to the product, depending upon the use for which it is intended. For example, the product can be caused to have greater overall thickness, increased stiifness, or greater crushing resistance. Also, the free iiow of fluids through the mesh can be enhanced. These are illustrative of the benets resulting from the present invention.

' Some `of these advantages have been sought to be achieved, heretofore, by special stretching or distortion of the mesh longitudinally, 'after its initial formation, and by procedures combining slitting and stretching in closely related sequences. The present invention achieves the desired objectives without necessitating `any additional stretching operations. Moreover, it is applicable to metals and alloys of specialized character, and useful in mesh sizes and shapes for which apparatus and procedures heretofore employed have been unsuitable.

It is a further object of the invention to achieve all these desirable results by apparatus of relatively simple chanacter, thoroughly practical and inexpensive from a manufacturing standpoint, and reliable and effective in use.

Several ways of achieving these objectives, and such other objects and advantages as may hereinafter be pointed out, are shown by way of example in the accompanying drawings, in which- FIG. 1 is a fragmentary elevational View, of simpliied diagrammatic character, of a conventional shear plate and punch at the commencement of a sequence of operations resulting in the formation of expanded metal;

ICC

FIGS. 2-5 fare similar views of successive operations;

FIG. 6 is a. cross-sectional view substantially along the line 6-6 of FIG. 4;

FIG. 7 is a view similar to FIG. 6 showing a subsequent step in :the process;

FIG. 8 is a cross-sectional view substantially along the line 8-3 of FIG. 5;

FIG. 9 is a face view of a piece of the resultant expanded metal;

FIG. 10 is an enlarged fragmentary cross-section along the line Iii-1t) of FIG. 9;

FIG. l1 is a view similar to FIG. 10, showing by comparison the nature of the improved result achieved by the present invention;

FIG. 12 is a view similar to FIG. 1, showing one form of the improved apparatus;

FIG. 13 is a cross-sectional view substantially along the line 13-13 of FIG. 12;

FIG. 14 is a view similar to FIG. 12, showing one embodiment of the correlating mechanism;

FIG. l5 is a View similar to FIG. 12, showing a second embodiment of the correlating mechanism;

FIG. 16 is a view similar to FIG. 12, showing an alternative tapplaratusand procedure;

FIG. 17 is a view similar to FIG. l2, showing a further modication;

FIGS. 18-20 are views similar to FIG. 17, showing successive stages of operation;

FIG. 21 is an exaggerated longitudinal cross-section of an expanded metal pnoduct resulting from this invention; and

FIG. 22 is an illustrative mechanism for intermittently advancing a sheet to be treated.

FIGS. 1-10 depict known apparatus of the guillotine type, and show in an exaggerated manner the shortcomings which the present invention has overcome.

A shear blade or plate 2@ and a punch 21 are arranged in shearing relationship. A sheet of met-al to be treated (22) is advanced intermittently (in the direction of the observer in FIGS. 1-5) to bring successive regions into an overhanging relation to the shear plate 2@ and thus subject them to the shearing action of the punch 21. (The intermittent .advance of the sheet 22 may be brought about by 'any conventional means, e.g., by a mechanism (FIG. 22) in which one oi two feed rollers 80' carries a ratchet 81 actuated by a pawl S2, reverse movement being prevented by a spring-pressed pivoted keeper 83. Pawl 82 is pivoted at 84 to an `arm 85 that rocks on axis 86 and is pivoted at S7 to an actuating link 88 connected at 89 to a drive wheel 9@ driven by the main shaft of the machine.) These Kadvznrcements of the metal 22 occur duning the periods that the punch 21 is withdrawn from the shear plate (FIGS. l, 3, 5). During these periods that is also a relative lateral shift of punch 21 and sheet 22.

The punch ZI is ser-rated, i.e., it has tooth-like pants 23 with intervening recesses or depressions 24. These can be shaped or contoured in various ways to produce correspondingly different eiects. 'Ihe ends of the teeth 23 are preferably blunted, as shown.

Assuming in FIG. 1 that the sheet 22 is in a position in which its advancing margin overhangs the edge of the shear plate 2t) by the desired amount, the punch 21 is now caused to descend to the position of maximum ad- Vance shown in FIG. 2. This shears the pendant strands 25, which nevertheless remain connected to the parent sheet in the regions 26 between the serrations 23 of the punch 21. The punch then withdraws and shifts laterally relative to sheet 22, as indicated by arrows in FIG. 3. During this period, the sheet 22 advances again to bring the next successive region into shearing position. On the next descent of the punch 21 (FIG. 4) the serrations enarcanes i linked together by connecting bridges. VIn FlG. 9, the

two rows at the bottom are numbered to'correspond to the procedural steps described in connection with FIGS. l-8. l 'Y One of the connecting bridges is shown on an enlarged scale in FIG. 10. vIt will be noted that its forward half 29 has been angled out of the plane of the rearward halt" 30. This is due to the pulling action of the punch 2i during each shearing operation. As indicated inKFIGS. 6 and 7, the rearward part of each 'connecting bridge remains ina plane parallel to the original plane of lthe sheet 22, but during the shearing operation the forward halves of the next set of connecting bridges, which are then in Vpositions overhanging the shear plate '20, are pulled downwar'dly. The successive angulations are shown in a somewhat exaggerated manner in FIGS. 6,77, 8 and 10,'t`orV the sake of clarity.

The degree to which the bridges will distort as described depends upon numerous factors. For example, it varies with the mesh length (i.e., the pitch of the teeth on the serrated punch). It also'varies with the depth to which the punch descends during the shearing procedure, with the nature and thickness of the sheet being treated, and with the ratio of strand width (W) to sheet thickness (T) as indicated in FIG. 10. Usually, if the ratio W/ T is greater than 2 (and often it may be as high as 5) the distortion of the vconnecting bridges attains appreciable magnitude.

In contrast to this, the expanded metal produced by the present invention (using the same sheet material, sheet thickness, and W/ T ratio) has a cross-sectional 'configuration of the nature indicated in FIG. 11. The `forward halt of each bridge lies in substantially the same plane as the rearward half. This result is achieved by providing a special means for supporting the overhanging areas of the sheet, during each shearing operation, in the regions between the serrations of the punch. Y Y

In the embodimentsfof the invention shown in FlGS. 1'2-17, the support'means is a comb-like element directly adjacent to the shear plate and directly beneath the overhanging sheet area, the comb being provided with serrations or -teeth-like parts facing toward and in complementary alignment with those of the punch. In FIGS. 12

and 13, for example, a comb 32 of this character is secured v flat against the outer face of the shear plate 33, directly adjacent to the shearing edge. The element 32 has teeth 34 and intervening 'depressions 3S, corresponding in size and spacing to the teeth 36 and depressions 37 of the In FIG. 14, the supporting comb el is mounted in laterally rshiftable manner with respect to the Vshearing plate 42. This shiftability is indicated by the arrows 43. At its ends lthe comb il carriesV guide posts 44. The punch 45. is` provided with ears or projections 46 Vhaving guide holes through which the posts 44 extend. Inrthis way the punch 45 is able to reciprocate up and down (arrows 47) relative to the shear plate 42 and support comb 41, Whereas both the vpunch 45 and the comb 4]; are laterally shiftable in unison. Y n v Y The means for moving the punch toward and away from the shear plate,` and 'also laterally lback and forth, andthe means "for intermittently advancing the sheet being treated, have not beenY shownin detail in any of the gures. Any known motive power or mechanisms, properly actuated in timed relation, can be employed for these purposes. Guiding meansV such as, guide rails or the like, and other structural elements and expedients of commonly known character, have also been omitted from the drawings forthe sake of simplicity. l f g It will be understand that the treatment of a sheet of metal by the apparatus shown in FIG. 14 will be'ucarried out in the manner` hereinbefore described. The sheet has not been illustrated, butit is advanced intermittently along the top face of the lshear plate t2 to bring successive areas intoV an overhanging relationship and intoY the range of action of the shearing punch 45. During each period-of withdrawal of the punch 45 the sheet to be treated is advanced, while the punch 45 (and with it the comb Y 41) is shifted laterally, eg., by push rodsm145 or the like. vIn this way there is always a prop or support under each overhanging area lying between the serrations of the In FIG. 15, an arrangement is shown inwhich the punch 4S has ears 49 provided Vwith vertical slots vSi). Riding in each slot is a .pivot 4.pin 51 carried at the upper end of a connecting 'link 52. VT he link 52 is .pivoted to a xed centr-al aXis'VSS mounted -on a stationary part of the apparatus. At its lower end, the link 52 is pivoted as at 5d to the supporting comb 55, guided in any suitable way for lateral reciprocation as indicated by arrows'Se. The slots 59 allow the punch 4S to move up and down in shearing relation to the shear plate 57, and the links 52serve to interengage the punch 48 v,and the comb 55 ,so that the required complementary alignment is automatically est-ablished during each .cycle ofV operation. Unlike the arrangement Yof FlG. 14, the punch .t-S and the comb 55 punch 38. The blunted ends of teeth 34 lie substantially Y at the level of the shearing edge of plate 33. As a result,

Y when the punch 38 descends to the position shown in dotand-dash lines, the sheet 39 is correspondingly sheared as hereinbefore described, but the overhanging Aregions 40 between the serrations 36 of the punch are supported from beneath by thev serrations 34 of the comb 32. This effectively counteracts the tendency of the punch 38 to pull these regions 40 out of the plane of the sheet 39, and thusV the connecting bridges of the resultant product are straight and unbent as shown in FIG. 11.

Itis necessary, of course, to correlate the relative movements of the shearing parts and the sheet itself so that a supporting comb or its equivalent is always in position to exert the desired supporting function upon the connecting bridges that are being formed. There are several ways of doing this, and they are illustrated in FIGS. 14-17 inclusive.

move laterally lin opposite directions, and the extent of movement of each ishalt` the pitch` of the serratOnS. Thus, whereasthe tooth 58 of the comb l5S is shown in FIG. 15 in'alignment with the recess or depression 59 of the punch 43, the recess 59 will become aligned with theY tooth 66 of the comb .after the parts have shifted laterally as indicated by the dot-and-dashposition V'of ,the link 52.

As a result, upon each descent of the .punch 48 into shear- Y ing relationship to the shear plate 57, there is a prop or support under theV overhanging areas of the sheet lying between the serrations of the punch. vAs in the case of FIG. 14, thesheet to be treated hasnot been shown in FIG. 15, but the mode of procedure will be readily understood from the description` hereinbefore given.

FIG. 16 shows the possibility of leaving the punch 6.1` and therslrlpportingv comb 62 laterally xed at alltirnes (although the punch is movable up and down as indicated at 63), and achieving the desired objective by shifting the sheet 64 laterally back and forth as indicated by the arrows 65 and the pushers 66. Ot course the entire shearV plate 67 might be caused to participate in this lateralreciprotion, if desired, provided .that relative 4movement of the shear plate 67 with respect to the fixed comb 62 is provided for. Y K y FIG. 17 illustrates a mechanism of Slightly modified character. .Slidably mounted in front of thersheeltplt@ 68 is a combV 69 engaged by coanpression'springs or equiva- Y extend in opposite directions and are anchored at their outer ends to a stationary part of the apparatus, thereby maintaining the comb 69 in a normal centered disposition shown in FIGS. 17 and 19. The punch 72 is movable up and down and laterally back and forth as hereinbefore described, vand the comb is cammed by the descending strands, as they are formed, into propping or supporting positions beneath the overhanging regions of the sheet between the serrations of the punch. The metal sheet to be formed iby this embodiment is prevented from lateral movement, so that the comb moves laterally relative to` the sheet. Thus, in FIG. 18, the comb 69 has been pushed to the left of its normal position by the descending strands 73 being sheared from the sheet by the teeth of the punch. When the punch rises again, .as indicated in FIG. 19, the comb 69 automatically resumes its normally centered position. Then, when the punch 72 descends for the next shearing operation, as shown in FIG. 20, the descending strands 74 cam the comb 69 to the right, thus again insuring the presence of a supporting prop beneath each of the overhanging sheet areas in the regions between the serrations of the punch.

Instead of a single supporting comb 69, as illustrated in FIGS. 17-20, separate supporting elements might be mounted on the face of the shear plate 68, each supported by springs so as to be resiliently shiftable from a normal central disposition.

In FIG. 21 some of the advantages of the improved expanded metal are illustrated diagrammatically. The overall thickness of the improved product is indicated at '77. In contrast to this, because of the angling of each of the connecting bridges, as indicated in dot-and-dash lines, the overall thickness of the conventional expanded metal product, vformed of the same original sheet, would be as indicated at 76. Coupled with this increased overall thickness is added rigidity, greater strength, and wider passages through the mesh. Wider passages allow flow or accommodation of more fluid, paste, or fine powder than would lbe aorded by narrower passages.

While several embodiments of the invention have been illustrated and described, it will be understood that the broader phases of the invention are not restricted to any particular mechanism, and in general it will be understood that many of the details herein described and illustrated may be modified by those skilled in the art without necessarily departing from the spirit and scope of the invention as expressed in the appended claims.`

What is claimed is:

1. In apparatus for producing an expanded metal sheet in which successive staggered rows of pendant shearedout strands are linked together by connecting bridges:

(a) a shear plate and a serrated punch reciprocable in shearing relation to each other,

(b) means for causing stepwise advancement of the sheet to be treated, to bring successive areas into overhanging relation to the shear -plate and thus subject them to the shearing action of said punch,

(c) means for moving the punch laterally to eect a relative back-and-forth lateral shift of punch and sheet between shearing operations,

(d) means for supporting the overhanging area during each shearing operation in the regions between the serrations of the punch so as to counteract the tendency of the punch to pull the connecting bridges out of the plane of the sheet,

said means comprising a comb directly adjacent and in contact with the shear plate and directly beneath the overhanging sheet area, said comb having serrations facing toward and in complementary alignment with those of the punch, the peak of each comb serration lying substantially at the level of the shearing edge of said plate, and

(e) means for effecting relative lateral shifts of comb and sheet with respect to each other to establish said complementary alignment during each shearing cycle,

said means comprising a mechanism interengaging said punch and combso that lateral movements of the punch are automatically transmitted to the comb.

2. Apparatus as defined in claim l, wherein said interengaging mechanism comprises a part carried by one of the interengaged elements and extending into the path of lateral movement of the other.

3. Apparatus as delined in claim 1, wherein said interengaging mechanism comprises guide posts carried by one of the interengaged elements and extending parallel to the direction of shearing movement, and ears carried by the other of the interengaged elements and provided with guide holes through which said posts extend, whereby punch and comb move Ilaterally in unison but shearing movements at right angles thereto remain unimpeded.

References Cited in the le of this patent UNITED STATES PATENTS 928,610 Klocke July 20, 1909 928,917 Klocke July 20, 1909 1,048,617 Whetstone Dec. 31, 1912 1,504,629 Lentz Aug. 12, 1924 1,514,229 Redding Nov. 4, 1924 2,095,465 Cross Oct. 12, 1937 2,244,305 McNeil June 3, 1941 2,245,642 Bell June 17, 1941 2,261,530 Strickler Nov. 4, 1941 2,322,204 Ballard June 22, 1943 2,781,097 Nold Feb. 12, 1957 FOREIGN PATENTS 623,253 Great Britain May 13, 1949

Claims (1)

1. IN APPARATUS FOR PRODUCING AN EXPANDED METAL SHEET IN WHICH SUCCESSIVE STAGGERED ROWS OF PENDANT SHEAREDOUT STRANDS ARE LINKED TOGETHER BY CONNECTING BRIDGES: (A) A SHEAR PLATE AND A SERRATED PUNCH RECIPROCABLE IN SHEARING RELATION TO EACH OTHER, (B) MEANS FOR CAUSING STEPWISE ADVANCEMENT OF THE SHEET TO BE TREATED, TO BRING SUCCESSIVE AREAS INTO OVERHANGING RELATION TO THE SHEAR PLATE AND THUS SUBJECT THEM TO THE SHEARING ACTION OF SAID PUNCH, (C) MEANS FOR MOVING THE PUNCH LATERALLY TO EFFECT A RELATIVE BACK-AND-FORTH LATERAL SHIFT OF PUNCH AND SHEET BETWEEN SHEARING OPERATIONS, (D) MEANS FOR SUPPORTING THE OVERHANGING AREA DURING EACH SHEARING OPERATION IN THE REGIONS BETWEEN THE SERRATIONS OF THE PUNCH SO AS TO COUNTERACT THE TENDENCY OF THE PUNCH TO PULL THE CONNECTING BRIDGES OUT OF THE PLANE OF THE SHEET, SAID MEANS COMPRISING A COMB DIRECTLY ADJACENT AND IN CONTACT WITH THE SHEAR PLATE AND DIRECTLY BENEATH THE OVERHANGING SHEET AREA, SAID COMB HAVING SERRATIONS FACING TOWARD AND IN COMPLEMENTARY ALIGNMENT WITH THOSE OF THE PUNCH, THE PEAK OF EACH COMB SERRATION LYING SUBSTANTIALLY AT THE LEVEL OF THE SHEARING EDGE OF SAID PLATE, AND (E) MEANS FOR EFFECTING RELATIVE LATERAL SHIFTS OF COMB AND SHEET WITH RESPECT TO EACH OTHER TO ESTABLISH SAID COMPLEMENTARY ALIGNMENT DURING EACH SHEARING CYCLE, SAID MEANS COMPRISING A MECHANISM INTERENGAGING SAID PUNCH AND COMB SO THAT LATERAL MOVEMENTS OF THE PUNCH ARE AUTOMATICALLY TRANSMITTED TO THE COMB.

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