WO2000024506A2

WO2000024506A2 - Method and apparatus for making structured packing element

Info

Publication number: WO2000024506A2
Application number: PCT/US1999/024907
Authority: WO
Inventors: Franz Büchi; Ernst Vogt; Peter Dubach; Timothy Griffin; Jonathan Lloyd; Bettina Paikert
Original assignee: ABB Lummus Global Inc
Current assignee: Lummus Technology LLC
Priority date: 1998-10-28
Filing date: 1999-10-21
Publication date: 2000-05-04
Anticipated expiration: 2001-04-28
Also published as: CN1331615A; EP1124632A2; AU756567B2; CA2348263A1; US6276045B1; KR20010080350A; JP2002528247A; BR9914884A; WO2000024506A3; AU1226500A; ID29109A

Abstract

Upper and lower mirror image die plates (64, 82) are resiliently supported and have predetermined displacement values for forming vortex generators (48, 50) and foldline crease channels (75, 100) without compressive deformation in a porous sintered metal fiber sheet material (14). Cutters (44) and ridges (73, 98) coupled to the upper and lower die plates (64, 82) form the respective vortex generators and channels. The sheet of so formed material is then placed in an apparatus for bending the sheet at the foldline channels (75, 100) to corrugate the sheet without deformation of the sheet material between the corrugation bends. Fingers align with and engage the channels. The fingers are on plates (128; 130; 166; 168) that are ramped closer together simultaneously while the fingers on two mirror image coplanar sets of plates displace toward each other as the sheet material is folded. Pins on a pair of rotating levers engage each of the finger plates of the two sets for relatively horizontally displacing the plates and corresponding fingers as they are ramped together vertically.

Description

METHOD AND APPARATUS FOR MAKING STRUCTURED PACKING ELEMENT

The present invention relates to apparatus and

method for making filters or structured packing elements

employed for fluid contacting systems, for example, such as

for use with a distillate tower, mixers or catalytic

distillation, and more particularly, for fabricating sheet

material elements made of porous sintered metal fibers.

Of interest is commonly owned copending patent

application Serial No. 2539 entitled Structural Packing and Element Therefor filed January 2, 1998 in the name of

Bettina Paikert et al.

Sintered metal fiber sheets, for example, stainless

steel fibers 8-25 μm (microns) in diameter, can be employed,

for example, to make structured packing elements for

distillate towers, fluid mixers or catalytic distillation.

An example of such packing elements is disclosed in the

aforementioned copending application. The material forming

the elements has approximately 80-95% voids and may be more

or less in certain implementations. The material, which can

be, for example, initially formed in flat sheets, may have

a thickness of about 50 um to about 2 mm.

Examples of catalytic structures are disclosed in US Pat. Nos. 4,731,229 to Sperandio, 5,523,062 to Hearn,

5,189,001 to Johnson, and 5,431,890 to Crossland et al . For

example, the '229 patent discloses reactor packing elements

comprising alternating fluted and unfluted parts with

troughs that are inclined relative to the vertical.

Apertures are provided in the sheet material to provide

reagent communication flowing through the packing.

As a further example, a structured packing including vortex generators and fluid communication apertures is

disclosed in the aforementioned copending application. As shown therein and in the patents mentioned above, structured packing is also provided with undulations, corrugations or

pleats to enhance the fluid processing.

A highly porous sintered fibrous sheet material or any

other easily compressible deformable material may have the stiffness of and an apparent consistency of conventional

cardboard material although comprising metal fibers and is

stronger than paper of cellulose fibers. Such material has

a high surface to void volume.

The problem with such material is that it is not

compressible without permanent deformation and is readily subject to permanent deformation similar to sheet paper

board. Unlike cellulose fibrous paperboard material which

is resilient when compressed, sintered metal fibrous

material when compressed is permanently deformed. This substantially reduces its void volume and either destroys or

negatively impacts on the material's function as a filter, a

distillation tower and so on. This deleterious effect may

be especially so where the fibers are coated with a catalyst

for use. For example, in a catalytic distillation process. Like paperboard, the metal fibrous material is easily

deformed, creased and folded, which deformations, creases

and folds form undesirable permanent defects in the sheet

material. These properties of the material and its sensitivity to compressive pressures and deformation make it

difficult to fabricate into complex shapes. For example, as

noted above, distillation packing elements typically are

formed with vortex generators and folds forming pleats or

undulations . Such deformations are required to be

introduced in the flat sheet material without compressive

loads on the remainder of the sheet surface.

Prior art paper board processing machinery is not

suitable for such metal fibrous material. Such machinery

tends to process the sheet material with compressive loads,

which for resilient paperboard, is not a problem. Such

loads are not tolerated without permanent deformation,

however, for the sintered metal fiber material. Such loads

would permanently deform the fibrous metal material undesirably.

The present inventors recognize a need to provide a process and apparatus for producing a high void to surface

area metal fibrous material with or without vortex generators and the like, folds and the like without undesirable permanent deformation of the material.

Advantageously, the present inventors recognize such

processed material may be employed as a structured packing material that may or may not be coated with a distillation

catalyst for reaction processing of the fluids in a

distillation tower.

A method according to the present invention for forming

a compressible sheet material that permanently distorts in response to a compression load thereon comprises the step of

forming a surface feature in the sheet material at a

localized region with negligible compression load distortion

of the material in the regions of the material adjacent to and externally of the region.

In one aspect, the step of forming comprises forming a foldline channel .

In a further aspect, a further step comprises piercing

the material at a piercing site adjacent to the localized

regio .

In a further aspect, the step of forming includes

forming a plurality of spaced foldline channels each at a

localized region and then bending the material about each of the channels.

In a further aspect, the step of forming includes

forming a plurality of channels in the material with each

channel forming a different localized region. In a still further aspect, the material has opposing

broad surfaces, the method further including forming the

channels linear and parallel to each other and in the

opposing surfaces of the material .

The channels in the opposing surfaces may each lie in a

plane normal to the material, the channels on the opposing

surfaces lying in alternating planes.

In a further aspect, the step of bending the material

about the channels bends the material with negligible

compression distortion of the material externally the

creases.

The bending in a further aspect includes bending the

material in alternating opposite directions to form an undulating material.

In a still further aspect, the material lies in a

plane, the method including piercing the material in a given

shape and simultaneously bending the shaped pierced material

to form tabs extending from the plane. The material preferably comprises fibrous elements

forming a porous member of a given volume.

The elements are preferably metal fibers and the

material comprises voids of at least about 80% of the

volume.

The step of forming may comprise compressively

distorting the material at a distortion region.

An apparatus according to the present invention for

forming a compressible material that permanently distorts in

response to a compression load of a given magnitude

comprises means for holding the material in a fixed position with negligible compression load distortion of the material;

and means coupled to the means for holding for forming the

held material with a surface feature at a localized region

while providing negligible compression load distortion in

regions of the material adjacent to and externally the

formed region.

In one aspect, the means for forming comprises means for forming the material with a foldline channel.

In a further aspect, means are included for piercing

the material at a piercing site adjacent to the localized region. In a still further aspect, the means for forming

includes means for forming a plurality of spaced foldline channels at a corresponding localized region and means for bending the material at each of the channels with negligible

distortion of the material external the channels.

In a still further aspect, the means for forming the

surface feature includes means for compressively distorting

the material in the localized region.

Apparatus for non-compressively holding a sheet

material of a given thickness value according to a further

aspect of the present invention comprises a base; first and

second overlying plates each with facing broad surfaces secured to the base in spaced relation for receiving the

material therebetween; and means for relatively displacing

the plates from a first position to a second position toward

and spaced from each other a distance no less than the value

so that the plates do not compress said received material.

IN THE DRAWING:

FIGURE 1 is a perspective view of a structured packing

fabricated according to one embodiment of the present

invention;

FIGURE 2 is an isometric view of a sheet of sintered fibrous metal material prior to processing for use in the

embodiment of Fig. 1;

FIGURE 3 a top plan view of the sheet of Fig. 2 at an

intermediate stage of processing; FIGURE 4 is a perspective view of a portion of the

sheet of Fig. 3 ;

FIGURE 5 is an end elevation view of a representative

portion of the sheet of Fig. 3;

FIGURE 6 is a perspective view of the sheet of Fig. 3

after final formation of the sheet for use in a structured

packing arrangement;

FIGURE 7 is an end elevation view of a portion of the

sheet of Fig. 6;

FIGURE 8 is an isometric view of a representative

vortex generator in the sheet of Fig. 6;

FIGURE 9 is a top plan view of a portion of the sheet

of Fig. 6 showing several representative vortex generators;

FIGURE 10 is a perspective view of an apparatus for forming the sheet of Fig. 3;

FIGURE 11 is a fragmented sectional side elevation view

of a portion of the apparatus of Fig. 10 showing the sheet

crease forming plates; FIGURE 12 is a side elevation view of the sheet of Fig.

5 without the vortex generators shown;

FIGURE 13 is a sectional elevation view of the

apparatus of Fig. 10; FIGURE 14 is a sectional plan view of the apparatus of

Fig. 10;

FIGURE 15 is a further sectional elevation view of the

apparatus of Fig. 10;

FIGURE 16 is an end elevation view of the apparatus of

Fig. 10;

FIGURE 17 is an isometric view of a vortex generator

cutter employed in the apparatus of Fig. 10;

FIGURE 18 is a side elevation view of the cutter of

Fig. 17; FIGURE 19 is a sectional elevation view of a portion of

the apparatus of Fig. 10 and a porous metal fibrous sheet

material being processed in an intermediate stage;

FIGURE 20 is a perspective view of an apparatus

employed for forming the folds or pleats in the sheet

material of Fig. 3;

FIGURE 21 is a more detailed bottom perspective view of

an upper movable portion of the apparatus of Fig. 20 prior to assembly of the apparatus;

FIGURE 22 is a perspective view of a lower plate

assembly with a fragmented portion similar to that of Fig.

21 assembled; FIGURE 23 is a more detailed perspective view of a

fragmented portion of an upper plate assembly;

FIGURES 24 and 26 are diagrammatic top plan views of

the assembled upper and lower plates of the assembly of Fig.

20 with the plates in respective open and closed states

prior to and after bending the sheet material of Fig. 3;

FIGURE 25 is side diagrammatic sectional elevation view

of the apparatus of Fig. 24 taken along lines 25-25;

FIGURE 26a is an elevation view of a representative

finger tip of the fingers employed for bending the sheet

material of Fig. 3 into the folded pleats of Fig. 7;

FIGURE 27 is side diagrammatic sectional elevation view

of the apparatus of Fig. 26 taken along lines 27-27;

FIGURE 28 is a top plan view, partially diagrammatic,

of the lower plate assembly of the apparatus of Figs. 26 and

27;

FIGURE 29 is a bottom plan view of the upper pleat

forming plate assembly of the apparatus of Fig. 27 taken along lines 29-29 ;

FIGURE 30 is a side elevation sectional view of the

assembly of Fig. 29 taken along lines 30-30;

FIGURE 31 is a side elevation sectional view of the

assembly of Fig. 28 taken along lines 31-31;

FIGURE 32 is an end sectional view of the embodiment of

Fig. 29 taken along lines 32-32; and

FIGURE 33 is an end sectional view of the embodiment of

Fig. 28 taken along lines 33-33. In Fig. 1, structured packing assembly 2 comprises a

cylindrical housing 4 and an assembly 6 of structured packing elements 8, 10 and so on. Each of the elements 8,

10 are fabricated of the identical sheet material

composition but differ in peripheral dimensions to form the

cylindrical shape of the housing 4 core. The elements 8, 10

have the same length from the top to the bottom of the

drawing but have differing widths to accommodate the

circular cavity of the housing 4. The elements 8, 10 are

identically formed and comprise identically shaped

corrugations or pleats 12. The pleats may also be of

undulations of other shapes as desired for a given implementation. In this implementation, the assembly 2 is for use in a distillation tower, for example.

In Fig. 2, sheet 14, forming the elements 8, 10 is

planar and cut to size from a relatively larger sheet of 3 by ₄ foot sheets, for example (not shown) . Sheet 14

comprises porous sintered stainless steel or other metal

fibers. The sheet 14 has a high surface area to void volume

for example, a void volume in the 85% to 95% range discussed in the introductory portion. The fibers are also as

discussed previously herein. Sheet 14 is rectangular or diamond polygon shape in

accordance with a given implementation. The peripheral dimensions are determined according to the desired size, for

example, to fit within the cylindrical housing 4. All of the elements 8, 10 in the housing are arranged parallel.

Thus the elements are dimensioned accordingly.

The sheet 14 is formed with two notches 16, 18, at

opposite edges. These notches are for aligning the sheet

for further processing as will be described below. The

location and angle of the notches is important as will also

be explained.

In Figs. 10-16, apparatus 20 for initially forming the

sheet 14 includes a base assembly 22 including a base 23, a pair of cylindrical guide and support posts 24 fixed to base

23 and an upper assembly 26. The assembly 26 is supported on the posts 24 by bearing assemblies 28. The upper assembly 26 is selectively displaceable in the vertical

directions 66 by an operating device (not shown) which may be a manually operated lever, a pneumatic or motor operated

device or other power source (not shown) . A pneumatic device

can provide an air cushion for providing a damping action.

The base assembly 22 includes a plate 30 fixed to the base 23 by locating guide pins 32 and bolts 34, Fig. 13. An

array of four cylindrical guide pins 36 are secured fixed to

the base 23 and pass through the plate 30. The pins 36 each

are slidably mounted in a mating sleeve 37. The sleeves 37

are press fit in mating bores in movable die plate 64. The

sleeves 37 each have a shoulder 39 abutting the plate 64.

The sleeves 37 guide and locate the plate 64 relative to the plate 30 as the plate 64 displaces.

An array of four bolt pins 38 are secured to plate 30

and pass through a chamber 40. Pins 38 also are in mating

bores in plate 64. A compression spring 42 is in each

chamber 40. The springs 42 normally urge the plate 64

upwardly direction 66". An array of cutters 44 is fixed to plate 30 in a corresponding array of bores 46. The cutters 44 form vortex

generators 48, 48' (Figs. 4-9) in the sheet 14 (Fig. 2) in

the process of forming an intermediate stage sheet 14 ' . The vortex generators 48, 48' are mirror image triangular

tabs projecting from the plane of the sheet material of

sheet 14' in alternating fashion, for example. The

generators 48, 48' are arranged in parallel linear arrays in accordance with a given design configuration of the packing

elements. The orientation, shape, number and configuration of the generators is in accordance with a given

implementation, and are shown by way of example in the Figs.

In Figs. 17 and 18, a representative cutter 44

comprises a cylindrical shank 52 which fits in a bore 46 and

may be press fitted fixedly attached in the bore to plate 30

(Figs. 13 and 15) . Extending from the shank 52 is a second

shank 54, which is triangular in plan view. The cutter edge

56 tapers at one side of the shank 54 and edge 58 tapers at

a different taper at a second side of the shank 54 forming a

tapering cutting surface 60 having a further tapering edge

62. The cutting edges 56, 58 and 62 project above the plate

30. The cutters 44 are secured in the bores 46 in the desired array for the vortex generators 48, 48'. The shanks

5₄ and cutting edges extend above the plate 30.

Movable die plate 64 is slidably attached to pins 36

and 38 for vertical displacement in directions 66. Plate 64

is resiliently supported on springs 42. Plate 64 is normally in an upper quiescent position as shown in Figs. 13

and 15. Plate 64, Fig. 15, also has a plurality of bores 68

in an array, each bore 68 accommodating a separate cutter 44

shank 54 (Fig. 17) . The cutting edges of the cutters 44 are

just below the top surface 70 of the plate 64 in the normal

upper quiescent position of the plate 64. The lowermost

sheet material processing position of plate 64 permits the cutters 44 cutting edges to protrude above the plate 64 top

surface 70. The amount that the plate 64 is displaced is

determined by the gap between the plates 30 and 64.

Plate 64 has four raised peripheral triangular mesa

regions 71 relative to surface 70. The raised regions 71

form surface 70 into a diamond shaped recess.

In Fig. 11, the plate 64 surface 70 preferably has an

array of upstanding linear ridges 73 extending therefrom in

the present embodiment. The ridges 73 are parallel and are

equally spaced, with an array of cutters 44 aligned between adjacent ridges 73 and with cutters also linearly aligned in a direction normal to the ridges 73. The ridges 73 have a

height h preferably about 0.4 mm or about 50% of the

thickness of sheet 14. The ridges have a width w also of

preferably about 0.4 mm in this embodiment. The ridges 73

have a preferably curved edge with parallel sides. However, the ridges 73 may have other shapes such as

rectangular or triangular in end view or transverse section. The ridges 73 are used to form surface features in

the sheet material 14. In particular, the ridges form

foldline creases or channels 75 in the sheet 14, as shown in

Figs. 3-5 and 12. The ridges 73 penetrate into the sheet

14 an amount that just equals the height h of the ridges in

a manner to be explained. The broad surface 70 (Figs. 13

and 15) of the sheet 14 just touches and lays against the

plate 64 surface without any compression and deformation of

the sheet 14 material in the region between the ridges 73

and the crease foldline channels 75 in a manner to be

explained. The guide pins 38 guide the plate 64 during its

displacement.

In the alternative, the channels may be formed by

cutting devices (not shown) . In this case the ridges are optional and not necessary. A second apparatus (not shown)

would hold the sheet material. Slots (not shown) in the second apparatus permits cutting devices to cut the channels in the material without compression distortion of the

material.

The amount of travel of the plate 64 is such that the

cutting edges of the cutters 44 protrude above the surface 70 of the plate 64 a distance to penetrate through the sheet

14 and form the vortex generators 48, 48'. This travel

amount is set by the gap between the plates 30 and 64.

The upper assembly 26, Figs. 10, 13 and 15, comprises a

support base plate 75 having a recess 76 for receiving a mechanism (not shown) for selectively displacing the plate

75 vertically in directions 66. In this embodiment, a lever

(not shown) is manually operated to displace the assembly 26

in directions 66. The base plate 75 slidably displaces via

bearing assemblies 28 along posts 24. The assembly 26

normal quiescent position is in its uppermost position as

shown in the figures.

Fixedly secured to base plate 75 is a fixed upper plate

78. An array of bores 80 are in plate 78. The bores 80 are

aligned vertically with the bores 68 in the lower die plate 64. A portion of the bores 80 are dimensioned and located

to receive the cutters 44 in the lower base assembly 22

plate 64. A second portion of bores similar to bores 46 are in plate 64 to receive cutters 44 ' . A second portion of

cutters 44 ' identical to cutters 44 are in others of the

bores 80 and fixed to plate 78. The cutters 44 in the lower

plate 64 generate vortex generators 48, Fig. 5, and the

cutters 44 ' in the fixed upper plate 78 generate vortex

generators 50. The cutters preferably penetrate into the bores of the opposing die plates.

An upper die plate 82 is resiliently secured to plate

78 by four bolt guide pins 84 and mating compression springs

86. An array of four pins 88 and sleeves 90 (one each being shown) identical to respective pins 36 and sleeves 37 locate

and guide the movable upper plate 82. Locating pins 92 and bolts 94 (one each being shown) are fixed to plate 75 for

locating and securing the plate 78 to plate 75.

In Fig. 11, the movable die plate 82 surface 96

has an array of upstanding ridges 98 depending therefrom

toward the lower die plate 64. The ridges are linear and

parallel and are equally spaced, the same spacing as ridges

73 but alternating therewith vertically. These ridges also form surface features, e.g., channels, in the sheet

material and would be optional, in the alternative, should cutting devices (not shown) be used to cut the channels. An

array of cutters 44' (Fig. 13) are aligned between adjacent ridges 73. The cutters 44 ' are also linearly aligned in a direction normal to the ridges 98. The ridges 98 have a

height h preferably about 0.4 mm or about 50% of the

thickness of sheet 14. The ridges 98 have a width w also of

preferably about 0.4 mm in this embodiment. The ridges 98

have a preferably curved edge with parallel sides. However, the ridges 98 may have other shapes such as

rectangular or triangular in end view or transverse section.

The ridges 73 and 98 preferably are identical.

The ridges 73 and 98 may have other dimensions and

shapes in accordance with a given implementation, the

heights and widths being given by way of example only for a

given sheet material. The height may be set to minimize the

degree of compression and the width set at a value to

minimize the surface area magnitude that is compressed. Plate 82 has four raised triangular peripheral mesa

regions 83 relative to surface 96. The raised regions 83

form surface 96 into a diamond shaped recess . The regions 83 overly and are aligned with the regions 71 on lower plate 64. The recesses formed by the regions 71 and 83 form a single chamber when the plates 64 and 82 abut a these

regions 71 and 83. The chamber is sufficiently thick such that the sheet 14 placed in the so formed combined chamber

is not compressed by surfaces 70 and 96 when closed to form the vortex generators 48, 50 and crease channels 75, 100,

Fig. 5. The surfaces 70 and 96 barely touch the sheet 14

during the formation of the creases and vortex generators.

The abutting regions 71 and 83 limit the depth of penetration compression of the ridges 73 and 98, Fig. 11,

into the sheet 14. This depth can be adjusted, if desired

by providing adjustment screws (not shown) in the regions 71 or 83. In the alternative, shims (not shown may be placed

in these regions to also adjust the amount of penetration of the ridges 73 and 98 into the sheet to form the desired

crease foldlines.

The ridges 98 form crease foldline channels 100 in the

sheet 14, as shown in Figs. 3-5 and 12. The mesa regions 71

and 83 are provided a height value above the plane of

respective surfaces 70 and 96 to limit the amount of travel of the upper die plate 82 during its displacement in direction 66" toward lower die plate 64 during formation of

the sheet 14', Fig. 3. This is so that the ridges 98 penetrate into the sheet 14 an amount that just equals the

height h of the ridges. That is, when the mesa regions 71

and 83 abut, the depth of penetration of the ridges into the

sheet 14 is limited and simultaneously precludes compressive

deformation of the sheet 14 between the localized distortion regions at the crease foldlines.

In this way, the broad surface 96 (Figs. 13 and 15) of

the sheet 14 just touches and lays against the plate 82

surface 96 during formation of the foldline channels 100 and

vortex generators 50. This contact is without any

compression and deformation of the sheet 14 material in the

region between the ridges 98 and the foldline channels 100.

The guide pins 84 and 88 guide the plate 82 during the plate

displacement during formation of the foldline channels and vortex generators, Figs. 3 and 13.

The vortex generators 50 are in alternating rows with

the vortex generators 48, alternating on opposite sides of

the sheet 14', Figs. 3-5. While one row of generators is

disposed between adjacent foldline channels 75 and 100 which

also alternate in vertical orientation as seen in Fig. 5, more rows or fewer generators may be provided according to a

given implementation.

The amount of travel of the plate 82 is such that the cutting edges of the cutters 44 ' also protrude above the

surface 96 of the plate 82. This protrusion is that

distance to penetrate through the sheet 14 and form

generators 50 and 50'. The difference between the

generators 50, 50' and 48, 48' is their relative orientation, which is not important for purposes of the

present invention. What is important is that the lower and

upper die plates 64 and 82, respectively are set to abut at

regions 71 and 83 so that the respective surfaces 70 and 96 just contact the sheet 14 when the foldline channels and

vortex generators are fully formed. This eliminates

possible deformation of the sheet 14 ' during such formation

that might otherwise occur.

The sheet 14, Fig. 2, is located in the fixtures of the apparatus 20 by notches 16, 18 in the sheet 14 (Fig. 2) and

a pair of mating guide pins 103 in the plate 64, Figs. 10

and 14. The notches 16, 18 and holes 102, Fig. 2, in the

sheet 14 are formed by other apparatus (not shown) during

the cutting of the sheet 14 from larger sheets. No deformation of the sheet 14 occurs during such formation and

cutting. Different size sheets 14 are formed for use in the packing assembly 2, Fig. 1. Holes 102 serve to permit an operator to properly orient the final formed sheets 14 ' ,

5 Fig. 6.

The sheets 14', Fig.3, are now ready for formation of

the pleats 12, Figs. 1, 6 and 7. The pleats 12 are in

linear rows of preferably identical transverse widths, W,

Fig. 7. Preferably the pleats 12 are at an angle α of about

10 90°, but may be at other angles as desired. Each pleat 12

is formed by a strip containing vortex generators 48, 48' in

a row or vortex generators 50, 50' in another row. The generators 48 face in one direction and the generators 50

face in the opposite direction from the surface of the 15 formed sheet 14", Figs. 6 and 7.

Apparatus 104 forms the pleats 12, Fig. 20. Identical

reference numerals or primed numerals in the different

figures refer to identical structures or identical mirror

image structures of the unprimed numerals. The apparatus

20 104 forms the pleats 12 without any permanent deformation of

the sheet 14". Such deformation includes compression, creases, wrinkles or other deformation of the material

between any of the foldline channels 75 and 110, Fig. 12.

In Fig. 20, the apparatus 104 includes a pneumatic

controller 106, which is commercially available, and a pleat forming assembly 108. The assembly 108 includes a base 110, a pair of upright support posts 112 and an upper angle iron

support 114 bolted fixed to posts 112.

An upper pleat forming assembly 116 includes a plate

126 and is movably secured to support 114 for displacement

in the vertical directions 118 along bearing rods 161. A

lower pleat forming assembly 117 is fixed to base 110 by

supports 111. The upper and lower assemblies 116 and 117

mate and cooperate to form the pleats 12 in the sheet 14",

Fig. 6.

A pneumatic operator 120 moves assembly 116 vertically

upwardly via piston 122. Operator 120 is secured to the support 114. Piston 122 is secured to assembly 116 by

connector 124. Connector 124 is secured to plate 126. The

operator 120 may be a solenoid and the like operated by

controller 106. The controller 106 pneumatically lifts the

assembly 116 vertically from lower assembly 117, direction

118', and releases the assembly 116 which falls by its weight via the force of gravity toward lower assembly 117.

This falling action is dampened by the pneumatic action of the operator 20, which provides an air cushion.

In Fig. 30, in the upper assembly 116, two sets 128,

130 of mirror image identical pleat forming plate members

131, 132, 133, 134 and 135 are slidably secured to and beneath the plate 126 at opposite ends of the plate 26 and

coplanar with each other. There are five pleat forming

plate members 131, 132, 133, 134 and 135 in each set, set

128 being representative. Each member 131-135 comprises a

planar metal sheet with linear right angle fingers 131', 132' and so on at an inner edge. Member 131 has finger

131', member 132 has a finger 132 ' and so on. A central

finger 136 is fixed to plate 126 between the two sets of

fingers. All of the fingers are equally spaced from each

other the same spacing as the foldline channels 100, Fig. 5.

Each finger depends from its plate member and is dimensioned

to be received in a corresponding foldline channel of the

sheet 14 ' , Fig. 3.

Each finger extends transversely the same extent, e.g.,

completely across the corresponding pleat forming member

131-135 (normal to the sheet of drawing Fig. 30) . The fixed finger 136 also has the same transverse extent as the other fingers. Representative finger 136, Fig. 26a, has a planar sheet metal shank 137 that tapers to its depending edge

138. The edge 138 has a transverse width the same as that

5 desired for the foldline channels 100, the edges 138 engaging the foldline channels 100. The fingers all depend

that distance in which their depending edges 138 are all coplanar for engaging the foldline channels 100 uniformly in

the same plane.

10 In Figs. 21, 29 and 30, slots 140 are formed in each

pleat forming member 131-135. A fastener 142 is secured to

plate 126 and passes through a corresponding slot 140 so

that the members 131-135 may slide horizontally relative to each other in directions 14 . The fasteners 142 ' in slots

15 140', Fig. 29, permit the set 130 to slide in an opposite direction as the set 128 in directions 144.

Thus, in Fig. 29, set 128 can slide to the left in the

drawing and the set 130 can slide to the right, directions

144. Both sets in Fig. 29 are in their most central

20 position in directions 144 with their respective fingers

closest to the central finger 136. This is referred to

hereinafter as the closed position. When the fingers are opened so that the spacing therebetween is the greatest,

this is referred to hereinafter as the open position. Figures 26, 27 and 30 show the closed position of the

fingers and Figures 24 and 25 show the open position. The pleat forming members of the sets 128 and 130,

Figs. 21 and 29, each have an overlying opening 150

juxtaposed with a corresponding opening in the plate 126. The members 131-135 of set 128 and the corresponding members

of the other set 130, Fig. 28, each have respective extensions 145-149 in the opening 150. Each extension has

an elongated hole 152 in the opening 150 (Fig. 21) . Plate

126, Fig. 21, has a bore 162 for receiving bearing rod 161.

The lower pleat forming assembly 117, Figs. 25, 27, 28

comprises a lower plate 164. Plate 164 is supported on

supports 111 secured to base 110 represented by symbols

110', Figs. 25 and 27. Circular cylindrical bearing rods

161 extend upwardly from the supports 111 through the plate

164. The bearings 160 of the upper assembly slide vertically on the rods 161.

In Figs. 28 and 31, two sets 166, 168 of mirror image

identical respective pleat forming plate members 169, 170,

171, 172 and 173 of set 166 and members 169', 170', 171', 172' and 173' of set 168 are horizontally slidably secured to each other and over the plate 164 at opposite ends of the

plate 26 and coplanar with each other. There are five pleat forming plate members in each set, set 168 being

representative. These plate members are substantially similar to and correspond to the plate members 131-135 of

the upper assembly 116 in that each member comprises a

planar metal sheet with respective linear right angle

fingers 175, 175, 176, 177 and 178 (Fig. 28) at an inner

member edge.

However, there is no central finger such as finger 136

fixed to plate 126. All of the fingers are equally spaced

from each other the same spacing as the foldline channels 75, Figs. 5 and 12 in the open position of Figs. 24 and 25.

Each finger extends upwardly from its plate member and is

dimensioned to be received in a corresponding foldline

channel 75 of the sheet 14', Fig. 3.

Each finger, e.g., fingers 175-178, extends

transversely the same extent, e.g., completely across the

corresponding pleat forming members 169-173 (normal to the

sheet of drawing Fig. 30) . The fingers all extend upwardly

that distance in which their extended edges are all coplanar for engaging the sheet 14' foldline channels 75, Fig. 3,

uniformly in the same plane in the open position of Figs. 24

and 25.

A projection 191 is attached to end finger 175 at the finger upper edge and a like projection 191' is attached in mirror image fashion to the mirror image finger 175'. The

projections 191 and 191' receive the respective end notches

16 and 18, Fig. 3, of the sheet 14'. These projections

align the foldline channels in the sheet 14 ' exactly over

the edges of the respective corresponding fingers of the

lower assembly 117. In this way the fingers each engage a

corresponding foldline channel 75 of the sheet 14 ' . This

also aligns the foldline channels 100 with the overlying

fingers of the upper assembly 116.

The pleat forming members of the sets 166 and 168 each

have an opening 190 corresponding to the opening 150 in the

members of the upper assembly 116, Fig. 21. Members 169-173

and 169 '-173', Fig. 28, each have respective extensions 184-

188 overlying the opening 190 . Each extension has an

elongated hole aligned with the respective extension

openings 152 (Fig. 21) in the upper assembly 116 pleat

forming members. The fingers of the upper assembly 116, Fig. 27, are aligned vertically medially between the fingers of the lower

assembly 117 as shown. This is to align the fingers with

the corresponding foldline channels 75 and 100 in the sheet

14 ' , Figs . 5 and 19. The fingers of the upper and lower pleat forming assemblies have sufficient height so as to

receive the vortex generators 48 and 50, Fig. 5.

therebetween during folding of the sheet 14 ' .

In Fig. 28, slots 180 are formed in each pleat forming

member 169-173 and corresponding slots 180' in the mirror image pleat forming members 169' -173'. A fastener 182 is

secured to plate 164 and passes through a corresponding slot 180, 180'. The members 169-173 and 169'-173' of each set 166

and 168 is selectively slid horizontally in opposite

directions 144 relative to each other. The fasteners 182 in

slots 180, Fig. 29, permit the set 166 and 168 to so slide.

In Fig. 28, pleat forming member set 166 can slide to

the left in the drawing and the set 168 can slide to the

right, directions 144. Both sets in Fig. 28 are in the

closed position with their most central position in

directions 144. When the fingers are located so that the spacing therebetween is the greatest in the opposite directions 144, they are in the open position. Figures 26, 27 and 28 show the closed position of the fingers and

Figures 24 and 25 show the open position.

In Figs. 22 and 28, a pair of levers 192 and 194 are

pivoted to plate 164 at respective pivots 196, 198. The

levers 192 and 194 are connected by a crank mechanism 200. The mechanism 200 comprises two links 202 and a central

crank 204. The links 202 are threaded and include an

adjustment screw sleeve 212 with a nut at one end of the

sleeve for adjustably receiving the threaded link and a ball

socket 213 at the sleeve other end attached to each lever, Fig. 28, and to the crank 204. Rotation of the links about

their longitudinal axes provides adjustment of the link length between the crank 204 and levers 192 and 194. This

adjusts the travel of the pleat forming members as will be

explained below. A pneumatic motor 206 rotates the crank 204. Controller 106 selectively drives motor 206, Fig. 20.

In Fig. 23, a stop device 214 is attached to the base

110 adjacent each lever to limit the associated lever

rotation. Representative device 214 comprises two spaced

limit blocks 216 and an adjustment screw 218 associated with each block for adjustably setting the amount the lever 192 may rotate .

A linear array of five pins 208 are attached vertically to each lever 192 and 194 adjacent to the corresponding pivot 196 and 198, Figs. 22-28 and 33. The pins 208 extend

vertically through each lever and project above and beneath

each lever. Each pin passes through and engages a

corresponding elongated hole 152, Fig. 21, of each

extension, e.g., 145-149, of the respective pleat members of the upper assembly 116 and lower assembly 117. In

addition, a cam pin 210, Figs. 22, 28, and 33, rides against

the ramp surface of ramp 154, Figs. 25, 27 and 32.

The crank mechanism 200 as it rotates in response to

the motor 206 simultaneously opens and closes the levers 192

and 195 in the direction of the arrows, Fig. 28. Normally

the levers are in the quiescent open position of Fig. 24 so

that the planes of the edges of the fingers of the upper and

lower pleat forming assemblies 116 and 117 are spaced apart

and just engaged with the foldline channels of the sheet 14" .

In the closed position, these planes are situated as

depicted in Fig. 27 forming an interdigitated relation among

the fingers . This latter position is after the sheet 14 ' is folded as in Fig. 7. These two different open and closed

positions are determined by the cammed position of the camming pin 210, Fig. 33, abutting the ramps 154, Fig., 32.

In operation, Fig. 20, the upper assembly 116 is lifted

by operator 120 in response to the operation of the

controller 106. The levers 192 are in the open position

(Fig. 24) . The fingers of the pleat forming member of the

upper and lower sets 128, 130 and 166, 168, Fig. 25, are

spread apart the maximum amount corresponding to the spacing of the foldline channels 75 and 100 in the sheet 14' (Fig.

5). The sheet 14' is then place over the fingers of the

lower sets 166, 168, with the fingers of the lower sets

engaged with the foldline channels 75 (Fig. 5) . This alignment is assisted by placing the notches 16 and 18 of

the sheet 14' into the projections 191 and 191' (Fig. 28) at

the end fingers 175 and 175 ' . At the same time the

controller 106 is not operating the motor 206 (Fig. 28) so

that the levers 192 remain open.

The controller 106 is then operated to open the valving

to the operator 120, Fig. 20, to release the piston 122.

The piston 122 permits the upper assembly 116 to drop by its

own weight via gravity. When the assembly 116 reaches the lowermost position, the camming pin 212, Fig. 33, comes to

rest at the base of the ramp 154, Fig. 32. At this time the

fingers are all fully engaged in the corresponding foldline

channels of the sheet 14 ' . No compressive load is on the sheet 14 ' in the regions between the fingers or at the fingers because the spacing

between the fingers, Fig. 25, is set to correspond exactly

to the thickness of the sheet 14 ' . Thus no compressive

deformation of the sheet 14 ' occurs at any location between

the folds during the folding process.

At this time the controller 106 starts the operation of

the crank motor 206, Fig. 28. The crank links 202 are

displaced so that the levers 192, 194 rotate toward one another to the position of Fig. 28 from the position of Fig.

24. As the levers rotate, the pins 208 Figs. 22-28 also rotate. Because the pins 208 are different radial distances

from the levers 192, 194 pivots 198, each pin will rotate a

different angular extent about the pivot 198.

Each pleat member extension being engaged with a

different pin is translated in directions 144 by that

corresponding pin toward the center of the assemblies 116

and 117. The members at the opposing sets move in opposing relation simultaneously toward one another. At the same time, the camming pins 210 ramps along the corresponding

ramps 154 due to the weight of the upper assembly 116. This ramping action displaces the upper assembly vertically

toward the lower assembly 117 until the fingers reach their interdigitated position of Fig. 27.

This interdigitated movement folds the sheet 14 ' at the

foldline channels 75 and 100 to produce the corrugations of

Fig. 7. This folding action occurs with no compressive

loading on the sheet outside the foldline channels 75 and

100. The spacing is such between the upper and lower assemblies during the folding action such that no contact is

made on the sheet 14 ' in the regions between the foldline

channels. This precludes damaging the previously formed

vortex generators and the sheet 14' in this region.

Since the compressive loading only occurs at the

previously deformed foldline channels 75 and 100, the

porosity of the remaining portions of the sheet 14 ' remains

without deleterious deformation.

The apparatus may be provided with different finger pleat forming members in the upper and lower assemblies 116

and 117 to accommodate different size sheets 14 ' . It will occur to one of ordinary skill that various modifications may be made to the disclosed embodiments

without departing from the scope of the invention as defined in the appended claims. For example, while one set of pins

and one set of levers are provided, with a set of pins on each lever, two levers may be provided for each of the lower

and upper pleat forming sets. Each lever may be provided

with pins for engaging only the pleat forming members of

that set . A camming pin may be provided the upper assembly

lever for engaging a ramp in the lower assembly.

Also, completely automatic operation may be provided if desired with automatic feed of the sheet material to the different apparatuses of Figs. 10 and 20. The number of

creases or foldline channels in the sheet material, the

thickness and other parameters including foldline channel

depths and spacings as well as the shapes and angles of the

pleat folds are according to a given implementation. The

number of fingers is given by way of example. More or fewer

fingers may be provided as desired. Also, it does not

matter whether the upper or lower assemblies have a fixed central finger.

There thus has been described an apparatus for forming foldline channels and vortex generators in a porous sintered

high void to surface volume sheet material and an apparatus for forming undulations or pleats in the material with no deleterious deformation of the material during the

processes. While sheet material is disclosed, it is

intended that material other than sheet material may be

processed as disclosed as long as that material is bendable. Also, while triangular folds are disclosed, other

shaped corrugations may be provided, such as continuous

undulating curves, or rectangular troughs and ridges. In

the latter case, two alternating sets of pairs of fingers

may cooperate in the lower and in the upper sets of fingers

to simultaneously form rectangular channels. The fingers

engage adjacent foldlines for displacing the adjacent

foldlines the same depth. Such pairs may be adjacent each

other in alternating fashion in the upper and lower dies.

Further, while the channels 73 and 100, Figs. 5 and 12

are illustrated as being formed by compression, for example, by ridges 75 and 96, respectively, Figs. 11 and 12, these

channels may be formed in the alternative by cutting slits

in the sheet material. Such slits may be cut by any

conventional cutting tool such as a circular cutting disc suitable for cutting metals, e.g., a carbide tipped disc or

by any other known metal cutting device. The sheet material may be held in place by a first apparatus similar to the apparatus 20, Fig. 10, without compression by a clamp

apparatus during the cutting. The clamp apparatus may have

a cavity for non-compressibly holding the sheet material and

having slots therein (not shown) in place of the ridges 73

and 98, Fig. 11, for receiving the cutting tool. The depth

of the cuts are provided by devices known in the machine

tool art. No piercing of the sheet material would be

performed by this apparatus.

A second apparatus may be provided similar to the

apparatus 20, Fig. 10 wherein no ridges 73 and 98, Fig. 10,

are provided. The second apparatus is otherwise the same

as apparatus 20 for piercing the sheet material.

Claims

What is claimed is:

1. A method of forming a compressible material that

permanently distorts in response to a compression load thereon comprising the step of forming a surface feature in the material at a localized region with negligible compression load distortion of the material in the regions

of the material adjacent to and externally of the localized

region.

2. The method of claim 1 wherein the step of forming the

surface feature comprises forming a foldline channel.

3. The method of claim 1 further including the step of

piercing the material at a piercing site adjacent to said localized region.

4. The method of claim 1 wherein the step of forming the

surface feature includes forming a plurality of spaced

recessed foldline channels each at a localized region and then bending the material at the channels.

5. The method of claim 1 wherein the step of forming the surface feature includes forming a plurality of recessed creased foldline channels in the material with each channel

forming a different localized region.

6. The method of claim 5 wherein the material has opposing broad surfaces, further including forming the crease

foldline channels linear and parallel to each other and in

said opposing surfaces of the material .

7. The method of claim 6 wherein the crease channels in

said opposing surfaces each lie in a plane normal to a broad

surface of the material, the channels on said opposing

surfaces lying in alternating planes.

8. The method of claim 5 including the step of bending said material about said channels with negligible compression

distortion of the material externally said channels.

9. The method of claim 8 wherein said bending is in

alternating opposite directions to form an undulating

material .

10. The method of claim 5 wherein the material lies in a

plane, said method including piercing said material in a given shape and simultaneously bending the shaped pierced material to form tabs extending from said plane.

11. The method of claim 1 wherein the material comprises

fibrous elements forming a porous member of a given volume.

12. The method of claim 10 wherein the elements are metal

fibers and the material comprises voids of at least about

80% of said volume.

13. The method of claim 12 including coating a catalyst on said material.

14. The method of claim l wherein the step of forming the

surface feature includes compressively distorting the material at said localized region.

15. An apparatus for forming a compressible sheet material

that permanently distorts in response to a compression load of a given magnitude comprising: means for holding the material in a fixed position

with negligible compression load distortion of the material;

and means coupled to the means for holding for forming a

5 surface feature in the held sheet material at a localized

region while providing negligible compression load

distortion in regions of the material adjacent to and

externally the localized region.

10 16. The apparatus of claim 15 wherein the means for forming

a surface feature comprises means for forming recessed

crease foldline channels.

17. The apparatus of claim 15 further including means for

15 piercing the material at a piercing site adjacent to said

localized region.

18. The apparatus of claim 15 wherein the means for forming

the surface feature includes means for forming a plurality

20 of spaced foldline channels at a corresponding localized

region and means for bending the material at each of the

foldline channels with negligible distortion of the material external the channels.

19. The apparatus of claim 18 wherein the means for forming

includes means for forming a plurality of channels in the . material with each channel at a different localized region.

20. The apparatus of claim 19 including means for bending said material at said channels with negligible compression

distortion of the material in regions externally said

channels.

21. The apparatus of claim 15 wherein the material lies in

a plane, said apparatus including means for piercing said

material in a given shape and simultaneously bending the

shaped pierced material to form tabs extending from said plane.

22. The apparatus of claim 21 including means coupled to the means for piercing for bending the pierced material at

said channels in alternating opposite directions to form said material into an undulating sheet.

23. The apparatus of claim 22 wherein the means for forming

a surface feature include a plurality of ridges, a first

portion of the ridges extending from the first plate broad surface and a second portion of the ridges extending from

the second plate broad surface toward the first plate, said

ridges each for forming a channel in said received material.

24. The apparatus of claim 23 wherein the ridges of the

first plate lie in planes that are located intermediate the planes of the ridges of the second plate.

25. The apparatus of claim 22 including at least one

cutting element coupled to said base for piercing through

the received material.

26. The apparatus of claim 25 wherein the element has a

plurality of cutting edges for forming a tab in said

received material.

27. An apparatus for folding a received foldable material

having a plurality of parallel channels in opposing material

surfaces into a plurality of parallel undulations, comprising: a first and second plurality of movable spaced fingers

defining a material receiving region lying in a plane therebetween, each plurality corresponding to a different received surface, each finger corresponding to and for

engaging a different channel of the received material;

means for relatively initially displacing the first and

second plurality of fingers toward one another normal to

said plane for engagement with the received corresponding

channel ; and means for simultaneously further displacing the fingers

of each plurality in a first direction parallel to the plane and in a second direction normal to the plane to bend the

received material at said creases.

28. The apparatus of claim 27 wherein each said fingers are

each connected to a corresponding member, the means for

simultaneously displacing including cam means for

simultaneously displacing the members in the first and second directions.

29. The apparatus of claim 28 the cam means comprises first and second plates, a plurality of first projections secured

to at least the first plate for engaging a corresponding one

of said members and for displacing the corresponding members in the first direction and a second projection and mating

cam surface coupled to said plates for causing said plates to gradually ramp toward one another in the second direction

as the members displace in the first direction.

30. The apparatus of claim 29 wherein the cam means

includes lever means for rotation about at least one pivot,

said first projections being secured to the lever means in

radially spaced relation from said at least one pivot to

linearly displace the corresponding members in said first direction in response to rotation of said lever means.

31. The apparatus of claim 30 wherein the lever means

includes first and second pivotally secured levers, the

first lever including a first portion of said first

projections coupled to a corresponding first portion of said

fingers and the second lever including a second portion of

said first projections coupled to a corresponding second

portion of said fingers for simultaneously displacing said first and second portions of said fingers toward each other in a direction parallel to said plane.

32. The apparatus of claim 31 including crank means for .

simultaneously rotating said first and second levers.

33. The apparatus of claim 27 further including means for

forming apertures through said received material .

34. The apparatus of claim 27 including means for forming channels in said received material.

35. The apparatus of claim 34 wherein the means for forming

channels includes means for compressively distorting the

material at said channels .