CA1142423A

CA1142423A - Method and apparatus for cutting plastic sheet products, and products produced thereby

Info

Publication number: CA1142423A
Application number: CA000294682A
Authority: CA
Inventors: George E. Craft; Delbert B. Graves
Original assignee: Newell Companies Inc
Current assignee: Newell Companies Inc
Priority date: 1977-01-11
Filing date: 1978-01-10
Publication date: 1983-03-08
Also published as: FR2376734A1; IT1103564B; AU517994B2; DE2800295C2; FR2376734B3; GB1599912A; AU3222978A; JPS53108568A; IE46289L; IE46289B1; JPS6124007B2; IT7847581A0; SE7800272L; MX145844A; DE2800295A1

Abstract

ABSTRACT OF THE DISCLOSURE

A window shade sheet member formed from a material having the characteristics, with respect to strength, formability and shape retention, of plastic, and having a non-planar surface comprising raised portions and recessed portions is provided with one or more continuous cut lines, the penetration of which is so controlled that the contour of the cut which forms the cut-line substantially reflects the contour of the surface in which the cut is made, whereby the sheet member can be quickly and accurately sized to width at the time of installation by the final user, by separating the sheet material along a cut line. In a method of manufacturing said sheet member, the material is temporarily and locally flattened during the cutting operation by simultaneous application of pressing and stretching forces.

Description

~242~

WI~`JDOr.`7 ~ADE, Al`~ rT~OD ~ D
Al'PAF~TUS FOi?. ?'I.A~IUFP.C~U~I~TG S~

This 7nvention related to the window shade art, and specifically to a new and improved ~indow shade, a method of manufacturing a new and improved window shade, and apparatus for the manufacture of window shades.

Window shade~ are convéntionally available for purchase in a single width of continuous, uninterrupted sheet material from the upper or top ed~e, which ls con~entionally attached to a xoller assem~ly, to ~he bottom or lower edge which is conventionally formed into a pocket having a slat therein. It is necessa~y or~the purchaser to know the exact dimer.sion between the sides of the window f~ame to which the window shade is ~o be attached at the time of purchase. ~fter making allowance for clearance, so that the window shade, after installa~ion, wil~ run free, the exac~ required width of the window shade to be purchased can be ~educed.

5irce the required shade width is seldom the same as .he width of the window shade asse~bly carried in stoc~ ~y the retail outlets, the shade assembly normally ~ust be cut to width by the vendor's personnel at the time of purchase by use of special, rather bulky, and space consuming equipment located near the point of sale.

As a conseauence, personnel must be available to interpret the purchaser's requirements, which require- -ments, with respect to width, are frequently so~ewhat vague and indeflnite, and have th~ mechanical ability ana time to operate the a~oresaid special sha~e cuttin equipment.

. ~ - 2 - 114~Z3 To the a~ove requirement is added the possibility tha,, despite the care taken by the vendor's personnel in the width cutting of the window shade, the product which is sized to width at the time of purchase is, all too frequently, too long or too short, and the purchasing process becomes a source of customer dissatisfaction through no ault of the vendor.

Frequently a window shade vendor will stock a number of different widths o~ shade so that a five foot sh~e need not be altered to produce a ~1 inch window shade, thereby reducing the cost to the cons~..er somewhat by roughly initially matching the unaltered shade wid~h to the~ customer's:re~uired width. Eowever, although '~his results in a cost saving from the standpoint of conserva~ion of material, the other dis~vantages of high labor costs, investmen~ in shaa~ cutting equipment, use o~ valuable m,erchandising space for the cutting equipment, availability of trained personnel, somewhat limited selection of window shades, and a potential for customer dissatis-faction are all present e~en when a plurality of basic widths ar- stocked.

SUM~ Y OF TU~ I~7F~;iTTo7-~J

The primary objects o the invention are to provide a sheet member especially adapted for use in window shade assemblies which are easy to purchase and install properlv by the consumex, thereby eliminatinq all of ~he afore~entione~

disadvantages of corventional windo~J shade assem~lies, a method of manufacturina such a wln~o~i shade, and apparatus for manufacturing a window shade.

114~9L23 - 3 ~

These objects are accomplished by providins a sheet member formed ~rom a material having the characteristics, with respect to strength, formability and shape retention, of plastic, which sheet member, by reason of the formation of one or more continuous cut lines, the penetration of which are controlled to rather carefully defined parameters, can be quic~ly and accurately sized to width at the time of installation by the final user.

~ DESCRIPTIO~ OF T~E I~VEMTION
': . . -~he invention is illustrated more or less diagrammatically in the accompanying drawing wherein:

Figure 1 illustrates the step of sizi~g the window shade asse~bly of this invention during the installation process by the.final user, which, in this instance is shown to be a home~dweller;

Figure 2 illustrates the subsequent step of stripping the~window shade assembly to its proper width fo1lowing the sizi~g step;

Figure 3 illustrates the subse~uent step of preparing means for se-uring the upper end portion of .

the sheet member of the window shade assembly to 2 roller assem~ly;

Figure 4 illustrates the sub3equent step of securing the upper end portion of the sheet memke~ to the roller assembly;

~42~

Figure 5 i;lust ates the step of inser~ing slat means into the lower end portion of the window shade assembl~;

Figure 6 is a top view o a portion of the sheet material from which a window shade is formed;

Figure 7 is a view taken substantially along the line 7-7 of Figure 6 with depth dimension shown to an enlaxged scale, ~

Figur 8 is a~view taken substantially along the ~line 8-8 o~ Figurè 6 with the depth dimension shown to an enlar~ed scale;
..
Figure g is a view taken substantially along the line 9-9 ~f Figure 6 with-the depth dlmension shown to an enlarged scale;

Figure 10 is a schematic view of an essential step in the unique method of manu~acture of the window shade of the invention; ~ -Figure 11 is a detailed view to an enlarged scale of the cutting operation in the shade manufacturing method illustrated in Figure 10;

Figure 12 is an exploded, perspective view of the cutting apparatus illustrated in Figure 10 and 11; and Figure 13 is an end vie~J of the cutting apparatus illustrated in Figures 10 through 12 inclusive.

Like reference ~.umerals will be used to re~er to like parts from Figure to Figuxe of the drawing.

Z~23 In Figure 1 through.5 inclusive, the new and improved window shade of this invention, and its method of installation by the final user, are ill~strated.

In Figure 1 a window frame to which the improved window shade of this invention is to be secured is indicated generally at 10, the frame consisting of left side frame member 11, right side frame member 12 and top rame member 13. Conventional window shade brackets are indicated at 14 and 15, riyht bracket 15 being adapted to receive a conventional flatted end pin of a window shade roller assembly, and left bracket 14 being adapted to receive a conventional round end pin.

The window shade assembly is indicated generally at : ) 17. It i~cludes a sheet member, indicated generally at 18, a telescopic roller assembly, indicated generally at 19 and a slat assembly, indicated generally at 20.

. The sheet member 18 is formed from a material having the characteristics, with respect to compressibility, strength ~nd forma~ility, of plastic~ One suitable material ;20 i5 polyvinyl chloride, although other materials such as polyethylene,~polypropylene and other polyole~ins may be used. Also the ~ roduct k.nown as-~ r*j a polyester ~ prc~uoed b~.E I~ Pu~ont de Nemours Inc., : may, L~cer~in circ~*2X~s be employed. Fo.r.the:pL~se o~ f~er descr~ption it will ~e assumed ~hat a polyvinyl chloride flexible sheet material whose thickness lies in the range of from about 3.5 mils to about 8 mils will be used. It should be understood however that the thickness, or depth, of the material rom which the sheet member is formed ma~ be somewhat thinner, or somewnat t~icker than the above mentioned range, ,0 *Trade mark ......... .

~2~Z3 dependent upon other factors, such as cost, handling ability, side strength, and cutting ability, all as will appear hereinafter.

Irrespective of what plastic type material is employed however the material will have a plastic memory whereby the material, when deformed, as by cutting to a depth less than the thickness of the material, tends to return to its original configuration.

The telescopic roller assembly illustrated in Figure lconsists of an outer, larger diameter section 22 and an inner, smaller diameter section 23. The inner section 23 is received within the outer section 22, and the inner section 23 is slideable with respect to the outer section 22 so that the overall length dimension of the telescopic roller assembly (which represents the width of the window shade) may be adjusted as needed. As indicated in Figure 1, the left portion 24 of the upper end portion 25 o-f the sheet member 18 is affixed to the outer, larger diameter roller section 22 by any suitable means, and, in this instance, is wrapped once there around.

The right portion 26 of the upper end portion of the sheet member is not connected to the telescoping roller assembly at the commencement of the sizing operation in the installation process, for purposes which will be explained hereinafter.

The left end of the outer roller section 22 includes a conventional flatted end pin assembly 28, and the right end portion of the inner roller section includes conventional round end pin assembly 27. The telescopic roller assembly includes a ,~
, ~ ' conventional s:h~ce ~otor assem~ly, but since the con-struction and op--ation of the shade motor is conven~ional, it is not illustrated or described.

The lower end portion of the sheet member has been doubled back and fastened to itselr to form a slat pocket, indicated generally at 30, in which a slat assembly 31 i5 received. Any suitable means ~.ay be employed to secure the doubled back edge of the sheet me~ber to the body of the sheet member. In this instance a plurality of heat seals h~ve been employed, indicated at 32j which hea.t seal locations are carefully selecte2 as will be apparent hereina~ter.
-In ~he sizing ~tep illustrated in Figure 1, tkeinstaller, here a home dweller, is holding the telescopic roller 2sse~bly up to the window snade brackets l4 and 15 in order to size the shade. The inner telescopic roller section 23 is then slide inwardly, or to the left as viewed in Figure l, 7 nt~ the outer telescopic roller section 22 in order to correctly adjust the overall length o~ the .
telescopic roller assembly, and thereby the ~Jidth o~
the shade. Preferably the telescopic roller assembly is p1aced in the brackets 14 and 15 to ensure correct sizins.

Thereafter the roller is removed rrom the brac~et without charging the relative posi~ions of the inner and outer telescoping roller sections. The window shade is then placed or. a flat sur~ace such as a table or a ~loor as indicated in Fiaure 2.

Peerring now io ~i~ure 2 i. will be noted that right portion 26 o,- the upper end portion 25 of the shade ~2S a series o- _abs ~ormed therein, two of whicn are indicated at 34 and 35. ~ach taD is formed by a cut which extends completely through the material fro~ ~Jhich the sheet member is formed, com~encing from the top edge.

As will be explainecl in detail hereinafter each tab actually represents the terminus of a contLnuous cut line which is formed within the ~odY of the flexible material, each tab being de~ined by the ends o~ the cut lines. ~ach cut line extends c~n~inuously from the upper end portion of the sheet membar to the lower edge, and penetrates inwardly from one surface of the sheet member a distanre less than the thic~ness o~ the shee~ me~er.
'' ' ~ ' Typical depth O,c penetration ir a material havin~
a thickness of about 3-1/2 mils to about 8 ~ils is 1.5 mils to 1.75 mils. It should be un~erstocd however that peretrations of greater or lesser depth may be employed, the only requirement being that the depth of penet~ation of the continuous cut line be sufficient to enable the excess material to be peeled or stripped easily, and that the depth of material lying between ,~ '~
bottom o~ the continuous cut and the other side o~ the shade ha~ sufficient stren~th to resis~ deformation o~
the shéet member when exposed to normal manufacturir.g, transportation and handling stresses to which thP sheet member may be subjectea prior to and ~uring final installation.

As illustrated in Fi~ure 2 the installer ha~
determined that the cut line ~hich lies bet~le~n tahs 3~ and 35 repre~en.s the correct shade width, and, accordingly, a'~er grasping the sheet member ~o the le~t of the cut line wit'n one hand, and to the right of the cut line with the other hand, the excess material, represented at 38, is being stripped away.

. The heat seals 3~ are located between adiacent continuous cut lines. Accordingly, when the pe~ling .
action reaches the bottom of the shade, the installer, -with the exercise of reasonable care, is ahle.to tear around the slat pocket so that the entire excess portion 38 may be easily removed. It will be understood o course that the slat assembly 31 will have been removed prior to the stripping of the excess por~ion of the sheet mem~er.
.
A~ter the sheet member has been stripped to its proper width, the installer pulls a protective paper strip 40 away ~rom an adhesive substance 41 which is coated on the inner seotio~ 23 or the telescopic roller assembly as best illustrated in ~igure 3. The protecti~e paper strip is peeled away only to the point where the right edg~ of outer telescopic roller section 22 besins.

After the protecti~e paper strip is peeled zway ~, ~
the remaining unattached portion of the upper end portion of the sheet member is ~7rapped aroun2 the inner telescopic roller section 23 and secured thereto by means of the adhesive 41, as ~est illustrated in Figure 4.

Therea~ter the slat assem~ly 20 is reinserted in the slat pocket 30.

The window shade i~ now inser.ed in brackets 14 an~ 15 and is ready fo- ~se.

Referring no~t to Figures fi, 7, 8 and 9, the construction of the body of the sheet member of ~he ~indo~ shade is illustrated in greater detail.

From an examination of those Figures it will be noted that the shade is maae from a typical embossed material, with the result that high points and low points appear; in this instance,- high points and low points appear in both the upper surface and-the lower surfaSe or the shade.

Specifical1y, and éreerrlng to Figures 6 and 8, --it will be noted that a series of ele~ated areas a~pear as a result of ridges 43, and a series of low poin~s are formed as a result of the valleys 44 which are formed between ad~acent ridgges 43. The under surfa~e tor ex~erior side wh~n installed in the braokets 14 and 15) re1ect,s high poin.s and low point.s which are the opposite of those describea in connection with the top (or, when ins~alled,) interior surface of the sheet member.

As will be noted ~rom Figure 9, the shade may be em~ossed in the direction of the drop of the shade as w~ll as the direction of th~ width as illustrated in ~igures 6 and 8.

In Figure 9, a rather substan~ial depression i5 formed in the sheet member as a result of the embossing of a major rib 45, the ex~erior surface of the sheet memb2r including a rather deep impression, indicated a~ 46.

The cut lines referred to above are illustrated best in Figurés 7, 8 and 9.

Reerring 'irst ro Figure 7, the sheet member is indicated in its condition prior to ~he stripping to width operation illustrated in ~igure ~.

A series of cut lines 4~, 49, 50, 51, 52, 53, 54 and 55 are formed in the body of the sheet member adjacent one side, here right side edge 56. It will be noted that cut lines 48-55 are straigkt and parallel to one another, and right sidQ edge S6 is parallel to the closes cut line 5S.

Referring now to Figure 7, it will be noted that each of cuts 48-55 penetrate downwaraly from top surface 57 of the sheet member 18 a su~stantially equal distance.
Thus, an ~cut thickness 58 exis~s between the bottom 59 of each cut and tne lower surface 60 of shee~ member 18.

As can be appreciated from ~iguxes 1-4, the cuts extend c~mpletely through the flexible sheet material for a short ~istance a~ the upper end of the sheetn If desired, cu~s may be made at the lower end thereof~
As best seen in Figures l, 2, an~ 3, the result o~ ~hrough cutting is the series of tabs, two or which are indicated at 34 an~ 35.

The pu~pose of forming tabs in at leas one end of the flexi~le sheet me~ber are, firstly, to provide an indication to the consumer as ~o where the material should be grasped to facilitate a subseauent sizing to width by stripping, and, secondly, to facilitate the commencement of the stripping action.

Referring specifically now .o F~ure 8, t~e condition of the shee~ mem~er is illustrated after the sheet member . - ~

;nas been forme~ to its final size by tearin~ along a cutline, such as cut line 50, which is located ~etween tabs 34 and 35. As can be appreciated, the portion of the sheet member to the right of cut line 50 has been determined 'to be excess material, and the user, after grasping the sheet ~.ember on either side of cut line 50, and preferably at tabs 34 and 35, has stripped the sheet along cut line 50, thereby severing th~ portion of the sheet member to the right o~ cut line 50.
The sevexed area which corresponds to the uncut thickness 58, is illustrated, in a greatly exag~erated form for pur~oses of illus~ration at 61. Since the thickness of the sheet member is only a f,ew mils, i~ will be appreciated that ~he severed area 61 is,'for all practLcal purposes, not detectable by the hu~n eye.

Figures 10 ~hrough 13 illus~rate a unique me~hod of .
manufacturing the window illustrated in Figures 1-9, and apparatus or manufacturing the shade.

In Figure 10 a source of supply of the flexible sheet material rom which the sheet members 18 are formed is indicated generally at 63. ~he rlexible sheet ma~erial is shown in roll form of a suitable width which may~ for example, be up to 72 inches, or e~en widerO It passes from the source of supply to a pair of idler roliers ~4, 65, the purpose of which is-to ensuxe that the ~lex~ble' sheet material approaches the support structure, here roller 66, at the proper angle and under some tnesion., From the support structure 66, and following the cu.ting action which occurs there, the ma~erial passes to another idler 67, a dri~e -oller 68 an~ a final idler 69 from where it moves toward a subsequent processing station. ~aid ~Z423 ' - 13 -sta.ion may, '~or ex~m?le, be a cutting sta~ion which cuts the rlexible s'..eet material into sheet members of the desired drop distance, and simultantously forms the tabs 34, 35 in one end of the sheet by any suitable means, suc~
as a separation under vertically applied pressure forces.

The apparatus for forming the continuous cut lines 48'-55 in the flexible sheet material is indicated generally at 71 in Figure 10, and illustrated in greater detail in Figures 11-13 inclusive.

The cutting apparatus 67 includes a cutting asserhlyJ
indicatPd generally at 72, which is, in this instance, pivotally suspended, as at 73, ~rom the balance of the cutting ap~a~~atus at the cutting station.

.
The c~tting assembly includes a cutter, in this instance an elongated blade, 74, which is s2cured, as by retainer screws 75 and blade retainer plate 76, to a press me~ber 77, and a blade holder 78. The press member 77 may be secured direc~ly to the blade hqlder 78 by re~ainer screws 79. It will be understood that by -~sing slots in cutter 74 and press member 77 which are disposed with their major axis perpen- '~
dicular to the edge of the cutter, the relative positions of the cutter and the press member can be varied relati~Je to one another, ar.d relative to the blade assembl~ holder 78, all as illustrated best in the exploded perspective vie~7 of ~lgure 12.-The cutter includes a shank section ~0 which terminates at its -~70rking end in a blac'e or cutter ~1.
mhe hlade is fo~med by the intersection of two ~lanes as can be bes~ visllalized in Figure 12 and 13. The ~.~42~23 , ængle of the bl~e ~av be varied corsiderably and still produc- an acceptable cut, but a blade angle on the order of about 20 degrees is preferred.

As can best be noted from Figures 11 and 13, the press member 77 abuts the cutter 74 and is displaced inwardly, as viewed in Figure 3, or outwardly, as viewed in Figure 11, a short distance.

The cutting action can ~est be appreciated fro~
Figure 11.

The ~lexlble sheet material 63 passes around the support structure 66 under substantial tension : .
derived from suitable adjus~ment of idler rollers 64, 65, 67, and ~he force imposed by drive roller 68.
Further, ~he cutting assembly 72 i5 pxessed against $he outer sur~ace of flexible sheet ma.erial 63, as viewed with respect to the center of support structure 66 in Figure 11, by a force derived from the action of gra~ity acting upon the cutting assembly 72 and, to a lesser extent, by a yieldable, externally applied force ~erived rom spring means 82. The spring means 82 is supported rrom a ixed support 83 and bears against the rear or outer face of blade assembly holder;78, as best lllustrat~d in Figure 10.

Spring means 83 also serves the function of dampenirg undesirable osciilation of the cutting asse~bly 7~ due to machine vi~ration, irregularities in the surface o~
the flexible sheet ma~erial 63, or other causes.

42~
.. . . - 15 -As best note~. in Fi~ure 11, the .orce imposed agains~
,he fle~ible s~ ma.e.rial ~3 rom press member 77 is sufficient to de?ress the sheet material into continuous abutting contact with both the extermal surfaces of the support structure 66, and the internal pressing sur~ace 84 of press member 77. As a result, the cutter 74 will al~a~s cut to a uniform depth.

Since the flexible sheet material as a plastlc memory, the material will return to its precutting shape which is ~~
typified ~y Figures 6 through 9. Sinc~ the cut area 6~
of~Figures 8 and 9 was cut when the condition or the ~-flexible sheet material was ~eforme~ so that the upper ....:, .. ..
. and lower surfaces 57 and 60 of the sheet material were ,, . , ..,... , ~ , ... , :
flat an~ parallel to one another,lthe bottom of the cut , . . , .,, . , . . . . ,~
wi~1 assume the substantially sinuous con~iguration illustrated in Figures 8 and 9~

ALthough a preferred emhodiment o~ the i~vention has been illustrated and described, i~ will be under-stood that the foregoing descrip.ion is intended to be exemplary and not definitive. Accordingly it is intended that ~he scope o~ the invention be deined, not by the scopé o~ ihe foregoing aescription, but rather by the .
claims when interpreted in light of the pertinen~ prior art.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. For use in a window shade assembly, a sheet member, having a non-planar surface comprising raised portions and recessed portions, said sheet member having a first end, a second end, and two sides, said sheet member being formed of a material having the characteristics, with respect to compressibility, strength and formability of plastic, said material being further characterized by having a plastic memory whereby said material, when deformed, as by cutting to a depth less than the thickness of the material, tends to return to its original configuration, said sheet member having at least one linear cut therein which is located generally adjacent and parallel to a first side of the sheet, said cut, by virtue of the plastic memory of the sheet material, being substantially invisible to the naked eye, said cut extending below the surface of the sheet member to a depth less than the thickness of the sheet member, the contour of the cut substantially reflecting the contour of the surface in which the cut is made, including raised portions and recessed portions, the uncut portion of the sheet member beneath the bottom of the cut being sufficiently thick to resist tearing of the sheet member when exposed to normal manufacturing, transportation and handling stresses to which it may be subjected prior to and during final installation, and sufficiently thin that the portions of the sheet member on opposite sides of the cut are readily separable by the application of human hand applied separation forces on two sides of the cut adjacent one end portion of the sheet member, that portion of the sheet member in which the cut is formed having a non planar surface, and therefore raised portions and recessed portions with respect to a linear reference line which is parallel and co-planar with the plane of the cut, said cut being continuous from the first end portion to the second end portion of the sheet member, said cut penetrating into the sheet member to a substantially constant depth at all points along its drop from the first end portion to the second end portion of said sheet member, including the raised portions and recessed portions along the cut.

2. The sheet member of claim 1 further characterized in that the cut extends completely through the entire thickness of the sheet member for a short distance at one end portion of the sheet member.

3. The sheet member of claim 1 further characterized in that a plurality of cuts are formed in the sheet member adjacent to said one side.

4. The sheet member of claim 3 further characterized in that said cuts are spaced substantially constant distances from one another in a direction generally perpendicular to the major orientation of the cuts from point to point along each cut.

5. The sheet member of claim 4 further characterized in that said cuts are uni-directional.

6. In a method of manufacturing the flexible sheet member of claim 1, the steps of providing a source of supply of flexible sheet material, said sheet material being formed of a material having the characteristics, with respect to compressibility, strength and formability of plastic, said material being further characterized by having a plastic memory whereby said material, when deformed, as by cutting to a depth less than the thickness of the material, tends to return to its original configuration, one surface of said flexible sheet material having, in a normal, non-tensioned condition, a non-planar configura-tion, and therefore raised portions and recessed portions along a linear reference line which is parallel to the direction of movement of said flexible sheet material as it moves away from the source of supply during the manufacturing process, moving the flexible sheet material away from the source of supply, passing said moving flexible sheet material over a support surface, imposing a tension on said flexible sheet material in the direction of movement of said flexible sheet material, imposing a pressing force on the flexible sheet material in a direction to act upon the flexible sheet material and press it against the support surface, said pressing force acting generally perpendicularly against the flexible sheet material and the support surface at the area in which said flexible sheet material contacts said support surface, said tension being of a magnitude sufficient, when acting in conjunction with said pressing force, to cause said flexible sheet material to have a constant, uniform depth without high spots or low spots during contact with said support surface, and forming a cut in said tensioned, pressed flexible sheet material by contacting said tensioned, pressed flexible sheet material with a cutting member while said tensioned, pressed flexible sheet material is in a condition of uniform depth, and in contact with said support surface, the extremity of said cutting member being located in a position remote from the support surface a distance sufficient to form a cut in said flexible sheet material of a depth such that the uncut portion of the sheet material beneath the bottom of the cut is sufficiently thick to resist tearing of the sheet member when exposed to normal manufacturing, transportation and handling stresses to which it may be subjected prior to and during final installation, and sufficiently thin that the portions of the sheet member on opposite sides of the cut are readily separable by the application of human hand applied separation forces on two sides of the cut adjacent one end portion of the sheet member. 19

7. The method of claim 6 further characterized in that said support surface is stationary.

8. The method of claim 6 further characterized by and including the step of regulating the depth of cut by application of a force to the cutting member in a flexible sheet material penetrating direction composed of, firstly, a component derived from the force of gravity acting upon the cutting member in a sheet penetrating direction, and, secondly, an external force which is yieldably applied to the cutting element in a direction to act with increasing resistance on the cutting element when it tends to move away from the flexible sheet material.