US3203393A

US3203393A - Apparatus for applying stripes of low viscosity coating material

Info

Publication number: US3203393A
Application number: US259042A
Authority: US
Inventors: Richard H Colwill
Original assignee: Burroughs Corp
Current assignee: Unisys Corp
Priority date: 1963-02-18
Filing date: 1963-02-18
Publication date: 1965-08-31
Anticipated expiration: 1982-08-31

Description

1965 R. H COLWILL 3,203,393

NG' STRI APPARATUS FOR A1 PLYI OF Low VISCOSITY COATING MAT AL Filed Feb. 18, 1963 2 Sheets-Sheet 1 Fly. i.

z/qa/D Fig. 3.

.Fig. 2.

W INVEINTOR.

M 70 RIC/MED /'/.C'0LW/LL HTTOENEY Aug. 31, 1965 R. H. COLWILL 3,203,393

APPARATUS FOR APPLYING STRIPES OF LOW VISCOSITY COATING MATERIAL Filed Feb. 18, 1965 2 Sheets-Sheet 2 Figo 4-.

fizF/sa INVENTOR.

iP/CHARD H. 00mm 1 BY M0 470 7' 7'0 RNEY United States Patent 3,203,.93 AiPARATUS FQR APPLYING STRIPES 0F LSW VESCOEITY CUATING MATERKATL Richard H. Coiwiii, Victor, N.Y., assignor to Burroughs Corporation, Detroit, Mich a corporation of Michigan Fiied lFeb. 3.8, 1963, Ser. No. 259,042 '13 Uairns. (Cl. 118-412) The present invention relates to apparatus for applying stripes of a liquid onto a web member. It is herein described for illustrative purposes with respect to apparatus for applying three spaced stripes of magnetic material on a paper web, the paper web serving as a record medium wherein the magnetic stripes are used for magnetically storing data read into and out of the paper web by a machine.

Paper webs or sheets carrying magnetic stripes have heretofore been used for purposes of storing data. Such magnetic stripes have been applied by several types of applicators. The previously used applicators, however, have generally suffered from a number of drawbacks, among which are: they are subject to wear for which it is diflicult to compensate; they are difficult to adjust for different stripe thickness; they have a tendency to form ragged or unsharp edges and streaked surfaces particularly after experiencing some wear; and they are expensive to produce and maintain.

An object of the present invention is to provide an applicator which is particularly suitable, but not solely useful, for applying magnetic ink stripes and which produces improved results in one or more of the above respects.

A further object of the invention is to improved striping applicators for achieving stripes of uniform width, thickness, and texture in the application of liquids or fluids to moving webs.

In accordance with one aspect of the invention, there is provided an applicator for applying a stripe of a liquid material, supplied from a liquid source, onto a web member having relative movement in a predetermined direction with respect to a web-engaging surface of the applicator, the applicator comprising a body member formed with a passageway connected at one end to the source of liquid, the body member being further formed on the web-engaging surface with a striping orifice connected to the other end of the passageway; characterized in that the striping orifice is defined by at least first and second connecting cutsouts and is wider at the trailing edge than at the leading edge thereof with respect to the direction of relative movement of the web applicator.

In accordance with another aspect of the invention, an applicator as defined above is provided with a metering pin extending into one of said cut-outs and having a doctoring edge disposed in the striping orifice and defining the trailing edge of the orifice.

In accordance with a further aspect of the invention, an applicator is provided for applying a stripe of a liquid material, supplied from a liquid source, onto a web member having relative movement in a predetermined direction with respect to a web-engaging surface of the applicator, the applicator comprising a body member formed with a passageway therethroughconnected at one end to the source of liquid; the body member being also formed on the web-engaging surface with a flat surface projecting from the body member and engage able with the Web; the fiat surface being wider at the trailing edge than at the leading edge thereof with respect to the direction of relative movement of the web and applicator; the body member further being formed in the middle of the trailing edge of the flat projecting surface with a striping orifice which also has a trailing edge wider than its leading edge.

These and other aspects of the invention will become apparent from the following description of several preferred embodiments thereof.

In the drawings:

FIG. 1 is .a side elevational view of a simplified system including an applicator constructed in accordance with the invention for applying stripes of a liquid onto a web member;

FIG. 2 is a longitudinal sectional view through the applicator illustrated in FIG. 1;

'FIG. 3 is a perspective view of a metering pin incorporated in the applicator;

FIG. 4 is a bottom plan View, with parts in section, of the applicator of FIG. 2;

FIGS. 5a-5d are enlarged views of several configurations of inking orifices that may be used in the applicator;

FIG. 6 is a longitudinal sectional view through a modified applicator constructed in accordance with the present invention.

With reference to FIG. 1, the applicator, generally designated 19, is supported by a bracket 12 adjacent to the path of movement of a paper web member 14 which is to be striped by the applicator. Paper web 14 is moved from a supply reel 16 to pass between the applicator i0 and a back mandrel 18, around

idler reels

20, 22 and 24, to a take-up reel (not shown). The applicator is supported by bracket 12 to press against the paper Web with a moderate amount of pressure, merely enough to ensure contact with the paper without significantly loading the paper or binding it between the applicator 1d and the back mandrel 18.

The liquid to be applied to the web member 14 is supplied from a liquid source 26 connected to the ap plicator by conduit 28. The applicator of the present invention is particularly useful for applying magnetic ink stripes onto Web member 14, and therefore the liquid in source 26 would be a liquid magnetic ink. A preferred form of magnetic ink composition includes magnetic particles dispersed in an aqueous medium, such :as disclosed in U.S. Patent No. 3,023,123.

As seen particularly in FIG. 2, the applicator includes a body member 30, such as of steel, comprising a main section 31 and a mounting plate 32. secured together by four tie bolts 33. Mounting plate 32 carries a pair of end pins 34- welded thereto to which is attached the bracket 12 for mounting the applicator when in use. The body member is formed with a chamber or reservoir 35 connected by a passageway 36 extending through mounting plate 32 to the conduit 28. The opposite surface of applicator 10, i.e., the surface which engages the web 14, is formed with a series of striping orifices 4t) connected to the reservoir 35. As shown in FIG. 4, three spaced, parallel inking orifices 40 are formed in the body member, so that the applicator will apply three spaced, parallel inked stripes on the paper web 14. A metering pin 42 is disposed in each of the striping orifices 4t) and controls the thickness of the ink stripe applied from its respective orifice. Each pin 42 passes through an opening 43 in mounting plate 32 (FIG. 2), and through .an aligned opening 44 in the main section 31 of the applicator, and is fixed in a set position by set screw 45, so that its bottom edge is disposed at a preset distance above the web-engaging surface of the applicator in accordance with the desired thickness of the stripe to be applied.

Variou configurations of inking orifices can be used as seen in FIGS. 5a 5d. In all these configurations, the striping orifice is wider at the trailing edge than at the leading edge, with respect to the direction of relative movement of the paper Web and applicator. The

views in FIGS. Sa-Sd are such that the paper web is in effect moving from the top toward the bottom of the figure. Therefore, the leading edge of the orifice would be toward the top of the figure, and the trailing edge would be at the bottom. The orifices of FIGS. 5a5c are each formed of connecting cut-outs with the openiing rat the leading edge substantially narrower than the opening at the trailing edge of the orifice.

The striping orifice of FIG. 5a is identified as a, and as shown, it is defined by a pair of connecting cutouts formed on the web-engaging surface of the applicator. The first cut-out includes curved sides with the widest transverse dimension of the cut-out terminating at the trailing edge (bottom of FIG. 5a) of the orifice. The second cut-out includes curved sides 51, but these sides are of a substantially smaller radius of curvature than those of the first cut-out. The second out-out is connected to the first cut-out at the apex of the first cut-out, with the apex of the second cut-out defining the leading edge of the orifice 40a.

This orifice can be simply produced by two drilling operations, using a smaller-diameter bit for producing the cut-out defined by sides 51. A part of the .lower body member surface is cut away from a line extending through the middle of the three larger cut-out to the trailing edge of the body member. This produces a step 47 in the lower surface of the body member 30 terminating at a wall 48 (FIG. 4) extending through the middle of the first cut-outs of all three orifices, forming a semicircular configuration for each of those cutouts.

The FIG. 5a orifice configuration is illustrated in the applicator of FIGS. '2 and 4. As shown particularly in FIG. 2, the first cut-out is formed by drilling the hole 44 through section 31 of the body member perpendicularly to its web-engaging surface, and the second cut-out is formed by drilling the second, smaller-diameter hole at an angle to join with chamber 35.

The FIG. 5b variation of the striping orifice is generally designated as 4012. Like orifice 40a of .FIG. 5a, orifice 40b is also defined by a pair of connecting cutouts, with the first cut-out including curve-d sides 52 and with the widest transverse dimension of the cut-out terminating at the trailing edge of the orifice. The second cut-out in orifice 40b has straight parallel sides 53 and is of substantially smaller width than the widest dimension of the first cut-out. The second cut-out is connected at one end to the apex of the first cut-out with the opposite end of the second cut-out defining the leading edge of the orifice. produced in a simple manner, by drilling a hole a in FIG. 5a to form the sides 52, then saw-cutting the hole to form the sides 53, and then forming the step 47 as described above.

The FIG. 5c variation of the striping orifice is generally designated as 400. It too is defined by a pair of connecting cut-outs formed on the web-engaging surface of the applicator. The first cut-out, however, has straight sides 54 which converge toward each other, the widest transverse dimension of the cut-out terminating at the trailing edge of the orifice. The second cut-out is similar to that in orifice 4017 (FIG. 5b) in that it includes straight parallel sides 55 of substantially smaller width than the widest dimension of the first cut-out. The second cut-out is connected at one end of the smallerwidth end of the first cut-out with the opposite end of the second cut-out defining the leading edge of the ori- A further variation of the striping orifice is illustrated in FIG. 5d. This orifice, generally identified by the reference numeral 40d, is defined by but a single cutout. This cut-out, however, is of a continuously curved configuration having its widest dimension terminating at the trailing edge of the orifice and its apex defining the This orifice can also be 4 leading edge of the orifice. FIG. 5d is half an ellipse.

During coating, the paper moves from the right side toward the left side, in the FIGS. 2 and 4 views, and accordingly the right side of the applicator would be the leading section, and the left side of the applicator would be the trailing section. Metering pins 42 are disposed in the striping orifices at the trailing (left) edges thereof. As seen in FIG. 4, pin 42 is of substantially the same diameter as hole 44, so that it snugly fits in the largerdiameter first cut-out (defined by sides 50 in FIG. 5a) of the striping orifice.

All of the orifices shown in FIGS. Sa-Sc are operated with a shaped metering pin disposed within the cut-out formed opening at the orifice trailing edge, thus leaving unobstructed the smaller opening at the leading edge of the orifices through wihch the coating material first contacts the moving web. The leading edge opening is made narrower than both the metering pin and trailing edge opening to provide a controlled lateral or transverse spreading of the coating material for over-riding the effect of uncontrolled spreading or flaring in the striping of many liquid materials.

FIG. 3 illustrates the structure of one metering pin. The bottom end is notched at one side to form a fiat wall 62 and a straight edge 64. The other side of the bottom end is formed with a rounded surac 66. Each pin is placed in

openings

43 and 44 of the applicator body member 30 and is secured in position by set screw 45. Each pin is disposed so that its rounded surface 66 faces the leading side of the applicator, and its straight edge 64 faces the trailing side with straight wall 62 being substantially coplanar with the wall 48 of step 47. Actually, straight edge 64 defines the trailing edge of the inking orifices 40. Straight edge 64 of each of the pins is positioned at a level slightly above the paper-engaging surface of the applicator, so that it constitutes the doctoring edge and controls the thickness of the ink stripe applied to the paper from its respective orifice. Set screw 45 for each pin permits this doctoring edge to be individually adjusted for varying the thickness of the ink stripe.

The bottom or web-engaging urface of the applicator 10 is formed with a fiat projecting surface 70 which is the surface actually engageable with the web. There is such a fiat projection 70 for each of the inking ori fices. Since, in the embodiment illustrated, there are three inking orifices, there would be three such flat surface projections 70, as clearly illustrated in FIG. 4.

Each of these fiat surfaces has a rounded leading edge and is wider at the trailing edge than at the leading edge with respect to the direction of movement of the paper web past the applicator. Its respective inking orifice 40 is formed in the middle of the trailing edge. The metering pin 42 is disposed so that its fiat wall 62 and doctoring edge 64 are substantially in alignment with the trail ing edge of flat surface 70.

As also seen in FIG. 4, the web-engaging surface of the applicator may be formed with a second group of fiat projecting surfaces, these being generally identified with the reference numeral 72. Each fiat projection 72 1s 1n alignment with a flat projection 70, is also wider at the trailing edge than at the leading edge, and also includes a rounded surface at its leading edge.

In operation, the paper web 14 is continuously driven between applicator 10 and the back mandrel 18. It may be operated at speeds in the order of 400 feet per minute, and higher. Ink is supplied, as by a pump, from source 26 through conduit 28 to chamber 35 of the applicator It This chamber serves as an ink reservoir supplying all the inking orifices 40, which communicate with the chamber. The ink is first deposited from the leading edges of the orifices, i.e., the narrower and completely unobstructed part of the orifices. This would be the second cut-out, defined by curve-side 51, in the FIG. 5a configuration.

Actually, the cut-out in As the paper continues to move past the inking orifices, each metering pin 42 spreads the ink smoothly and evenly by virtue of its rounded surface 66, until the ink stripe extends completely across the widest part of the cut-out at the trailing edge of the orifice. The outward spreading of material around the leading narrower part of the orifice, which occurs when applying stripes of low viscosity liquids, is thus overlapped and covered by a wider opening at the trailing edge in which is disposed a metering pin having a doctoring edge. Straight edge 64 of the metering pin doctors the ink stripe at the trailing edge of the orifice and thereby controls its thickness in accordance with the setting of the pin. The foregoing striping action, of course, is produced at each one of the three inking orifices, so that three spaced, parallel ink stripes are formed on the paper web.

The thickness of the ink stripe applied from each orifice depends primarily upon the setting of the doctoring blade, the speed of the paper, and the rate of liquid discharge. An illustrative doctor blade setting is one that would provide a gap of between 0.0030.005 inch. As mentioned earlier, the paper can be driven at a speed of approximately 400 feet per minute. It has been found that by maintaining the doctoring blade at the preset gap and the paper at a preset speed, the stripe thickness can be conveniently varied, within limits, by adjusting the speed of the pump (preferably, a constant displacement type) to vary the rate of flow of ink to the striping orifices.

Applicators which apply magnetic ink stripes are subject to rapid wear because of the eroding effect the magnetic particles have on the parts of the applicator. The effects of this eroding action, however, are substantially reduced in the applicator of the present invention. In this applicator, the eroding effects appear to be concentrated at the metering pins 42. However, because of the curved surface 66 forming the leading edge of the metering pin, the erosive action of the magnetic particles appears to dissipate over this gradually curved surface; also, it is spread over a relatively large surface. Moreover, the pins may be easily adjusted, through set screws 45, to compensate for wear and erosion, and once this has reached a point where a new part must be used, the metering pins may be easily removed and new pins attached. The curved configuration of the operating surface of the metering pin also greatly reduces streaking in the applied stripe since ink agglomerates and other lumps which would tend to build up in front of sharp edges are passed under the curved surface without delay.

All in all, the head is of very simple construction, is inexpensive to produce and to maintain, has been found to produce magnetic stripes having clean and sharp edges and surfaces which are practically free of streaks, can be conveniently adjusted to vary the stripe thickness, and has been found to have a long useful life.

A further variation of an applicator constructed in accordance with the invention is illustrated in FIG. 6. This variation is particularly useful for systems operating at higher speeds. For this purpose, it has been designed so as to have a smaller mass to thereby minimize the loading effect it produces on the web when traveling at high speed. It has also been found that the reduced mass of the applicator shortens the duration of its oscillations when the applicator engages a bump in the paper, such as a paper splice. By reducing the duration of the oscillations of the applicator, the amount of paper spoilage is also thereby reduced when the applicator intercepts a paper splice, for example.

In the FIG. 6 embodiment, the body member is identified with the reference numeral 130. It is of smaller dimension and may be made of a lighter metal, such as titanium. It includes the central chamber 135 which serves as the ink reservoir, and a passageway 136 connected to the conduit 12$ for the ink supply, as in the earlier-described embodiment. However, in FIG. 6- the body member does not include a mounting plate comparable to mounting plate 32 of the FIG. 2 embodiment. For purposes of minimizing its mass, the end pins, there identified as 1.34, are attached directly to the main section 1361; also, the body member is formed with only one paper-engaging section, at the trailing end in which are disposed the inking orifices 140.

The applicator of FIG. 6 also includes metering pins 142 corresponding to those of the earlier embodiment, but these pins are mounted in a separate element 137 attached to the main section of the body member 136 by tie bolts 138. Element 137 also carries set screws 145 for fixing the positions of the metering pins 142. Element 137 is formed with an enlarged bore at the lower end, in which is disposed an insert 139 of hardened material, which can be replaced, with metering pins 142, when these parts wear out.

The body member of the applicator in FIG. 6 is formed with fiat projection at the trailing edge of the webengaging surface, in a manner similar to the structure in the earlier-described embodiments. However, since the body member engages the paper web only at the trailing end, it does not include the forward section or the flat projections corresponding to projection 72 of the FIG. 2 version.

The position of the applicator in the striping system is not critical. It is shown in FIG. 1 mounted in a vertical position, but it could just as well be operated horizontally. If it is desired to apply stripes to both sides of the paper web 16, a second inking applicator, comparable to that described. could be substituted for the back mandrel 18, so that both sides of the paper will be striped in one pass through the system.

While there has been illustrated and described several embodiments of the invention, it is to be understood that these are illustrative only, and that various features of the invention, alone or in combination, may be used in other embodiments and applications.

I claim:

1. An applicator for applying a stripe of a liquid material, supplied from a liquid source, onto a web memher having relative movement in a predetermined direction with respect to a web-engaging surface of the applicator, comprising a body member formed with a passageway connected at one end to the source of liquid, said body member being further formed on said web-engaging surface with a striping orifice connected to the other end of said passageway; characterized in that said striping orifice is wider at the trailing edge than at the leading edge thereof with respect to the direction of relative movement between said Web and applicator and is defined by at least first and second connect-ing cut-outs, said second cut-out being substantially narrower than said first cutout and being positioned for defining the leading edge of said orifice.

2. An applicator as set forth in claim 1, further including doctoring means located in said first cut-out, said doctoring means including a straight edge forming the trailing edge of said orifice and a rounded surface forward of said straight edge toward the leading edge of said orifice.

3. An applicator as set forth in claim 1 wherein the first cut-out has curved sides with its widest transverse dimension terminating at the trailing edge of said orifice, and the second cut-out has curved sides of a smaller radius of curvature than said first cut-out, said second cut-out being connected to said first cut-out at the apex of said first cut-out with the apex of said second cut-out defining the leading edge of said orifice.

4. An applicator as set forth in claim 1 wherein the first cut-out has curved sides with its widest transverse dimension terminating at the trailing edge of said orifice, and the second cut-out has straight parallel sides, said second cut-out being connected at one end to the apex of said first cut-out with the opposite end of said second cut-out defining the leading edge of said orifice.

5. An applicator as set forth in claim 1 wherein the first cut-out has straight converging sides with its widest transverse dimension terminating at the trailing edge of said orifice, and the second cut-out has straight parallel sides, said second cut-out being connected at one end to the smaller width end of the first cut-out with the opposite end of said second cut-out defining the leading edge of said orifice.

6. An applicator for applying a stripe of a liquid material, supplied from a liquid source, onto a Web mem ber having relative movement in a predetermined direc tion with respect to a web-engaging surface of the applicator, comprising: a body member formed with a passageway connected at one end to the source of liquid; said body member being further formed on said web-engaging surface with a striping orifice connected to the other end of said passageway; said striping orifice being defined by connecting cut-out defined openings, the opening at the trailing edge being substantially Wider than the opening at the leading edge thereof with respect to the direction of relative movement of said web and applicator; and a metering pin disposed in the trailing edge opening and having a doctoring edge defining the trailing edge of said orifice.

7. An applicator as set forth in claim 6, wherein said metering pin is settably mounted so as to permit its doctoring edge to be variably positioned with respect to the web-engaging surface of the striping orifice, and means for fixing the metering pin in its set position.

8. An applicator as set forth in claim 6, wherein said metering pin is disposed in said trailing edge opening and includes a rounded surface facing the leading edge of said orifice and a straight edge defining the trailing edge of said orifice, said straight edge constituting the doctoring edge which controls the thickness of the applied stripe.

9. An applicator for applying a stripe of a liquid material, supplied from a liquid source, onto a web member having relative movement in a predetermined direction with respect to a web-engaging surface of the applicator, comprising: a body member formed with a passageway therethrough connected at one end to the source of liquid; said body member being also formed on said web-engaging surface with a flat surface projecting from said body member and engageable with said web; said flat surface being wider at the trailing edge than at the leading edge thereof with respect to the direction of relative movement of said web and applicator; said body member further being formed in the middle of the trailing edge of said fiat projecting surface with a striping orifice also wider at its trailing edge than at its leading edge.

10. An applicator for applying a stripe of a liquid material, supplied from a liquid source, onto a web member having relative movement in a predetermined direction with respect to a web-engaging surface of the applicator, comprising: a body member formed with a passageway therethrough connected at one end to the source of liquid; said body member being also formed on said web-engaging surface with a fiat surface projecting from said body member and engageable with said web; said fiat surface being wider at the trailing edge than at the leading edge thereof with respect to the direction of relative movement of said web and applicator; said body member being further formed with a striping orifice in the middle of the trailing edge of said fiat projecting surface; said striping orifice being defined by connecting cut-outs in said web-engaging surface and being wider at the trailing edge than at the leading edge thereof with respect to the direction of relative movement of said web and applicator.

11. An applicator as defined in claim 10, said applicator further comprising a metering pin disposed in said striping orifice at its widest portion, said metering pin being formed with a straight doctoring edge substantially in alignment with the trailing edge of said fiat projecting surface and defining the trailing edge of said orifice.

12. An applicator as defined in claim 10 wherein said body member is formed on said web-engaging surface with a second fiat projection engageable with said web, said second flat projection being in alignment with the first flat projection and also being wider at the trailing edge than at the leading edge thereof with respect to the direction of relative movement of said web and applicator.

13. An applicator for applying stripes of a liquid material, supplied from a liquid source, onto a web member having relative movement in a predetermined direction with respect to a web-engaging surface of the applicator, comprising: a body member formed with a liquid reservoir and with a passageway connected thereto to the source of liquid; said body member being further formed on said web-engaging surface with a plurality of spaced striping orifices defined by connecting cut-outs and disposed in a line perpendicular to the direction of travel; said body member being further formed with passageways connecting said striping orifices to said liquid reservoir; all said striping orifices being wider at the trailing edges thereof than at the leading edges thereof with respect to the direction of relative movement of said web and applicator; and an adjustable metering pin having a doctoring edge disposed in each of said orifices and defining the trailing edges thereof.

References Cited by the Examiner UNITED STATES PATENTS Re. 10,462 4/84 Buchanan 118-412 44,952 11/64 Henze 118-413 1,972,457 9/34 OBrein et al. 118-413 2,526,991 10/50 Biddle 118-413 X 2,763,235 9/56 Speed et al. 118-415 2,774,327 12/56 Saint-Hilaire 118-33 2,891,506 6/59 Saint-Hilaire 118-415 3,087,850 4/63 Cole 118-413 X RICHARD D. NEVIUS, Primary Examiner.

JOSEPH B. SPENCER, Examiner.

Claims

1. AN APPLICATOR FOR APPLYING A STRIP OF A LIQUID MATERIAL, SUPPLIED FROM A LIQUID SOURCE, ONTO A WEB MEMBER HAVING A RELATIVE MOVEMENT IN A PREDETERMINED DIRECTION WITH RESPECT TO A WEB-ENGAGING SURFACE OF THE APPLICATOR, COMPRISING A BODY MEMBER FORMED WITH A PASSAGEWAY CONNECTED AT ONE END TO THE SOURCE OF LIQUID, SAID BODY MEMBER BEING FURTHER FORMED ON SAID WEB-ENGAGING SURFACE WITH A STRIPING ORIFICE CONNECTED TO THE OTHER END OF SAID PASSAGEWAY; CHARACTERIZED IN THAT SAID STRIPING ORIFICE IS WIDER AT THE TRAILING EDGE THAN AT THE LEADING EDGE THEREOF WITH RESPECT TO THE DIRECTION OF RELATIVE MOVEMENT BETWEEN SAID WEB AND APPLICATOR AND IS DEFINED BY AT LEAST FIRST AND SECOND CONNECTING CUT-OUTS, SAID SECOND CUT-OUT BEING SUBSTANTIALLY NARROWER THAN SAID FIRST CUTOUT AND BEING POSITIONED FOR DEFINING THE LEADING EDGE OF SAID ORIFICE.