US3435653A

US3435653A - Forming method and apparatus

Info

Publication number: US3435653A
Application number: US522284A
Authority: US
Inventors: Joseph A Scaletta; Roland E Miller; John Valek
Original assignee: Kraft Inc
Current assignee: Kraft Inc
Priority date: 1966-01-21
Filing date: 1966-01-21
Publication date: 1969-04-01
Anticipated expiration: 1986-04-01
Also published as: DE1602515A1; BE692967A; GB1153664A; FR1508614A

Description

April 1, 1969 J. A. SCALETTA ET AL 3,435,653

FORMING METHOD AND APPARATUS Filed Jan. 21, 1966 Sheet I of 2.-

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JOSEPH A. SCALETTA ROLAND E. MILLER JOHN VALEK BY tfidmm Zum aa, ang- ATTORNEYS FORMING METHOD AND APPARATUS qa H$ JOSEPH A, emLcr'rA ROLAND MILLER JOHN VALEK BY 6m I ATTORNEYS United States Patent 3,435,653 FORMING METHOD AND APPARATUS Joseph A. Scaletta, Chicago, Roland E. Miller, Orangeville, and John Valek, Cicero, Ill., assignors to National Dairy Products Corporation, Chicago, Ill., a corporation of Delaware Filed Jan. 21, 1966, Ser. No. 522,284 Int. Cl. B21d 11/04 US. Cl. 72-336 9 Claims ABSTRACT OF THE DISCLOSURE In a method and apparatus for forming drawn containers from a metallic blank, the edge portion of the blank is clamped between a pair of opposed clamping members during the drawing operation, with the magnitude of the clamping force being limited to a predetermined maximum which will permit a gradual but not complete withdrawal of the blank from between the clamping members. All of the clamping force is relieved so as to release the edge portion of the blank before the stress in the edge portion is suflicient to fracture the blank and before any portion of the edge portion has become fully withdrawn from between the clamping members.

This invention relates generally to a forming method and apparatus, and more particularly it relates to a method and app-artus for drawing containers having a formed rim in a single stroke of the forming apparatus.

In recent years it has been increasingly desirable to form containers from lightweight thin metal stock, such as aluminum and aluminum alloy stock, reduced tin plate, double drawn steel and other lightweight materials by a drawing operation. Such containers are lightweight, easily handled, have good strength as compared to paper containers, and present attractive consumer packages. The container is preferably constructed with a formed rim which may take the shape of a curled or rolled bead or a generally flat flange. A particularly desirable container is one having a curled rim thereon for appearance and also for sealing of the lid onto the container. However, it has not been convenient to draw lightweight containers having a formed rim in a single stroke of the forming apparatus. It has been particularly difficult to draw such containers having a large depth as compared to the diameter, generally referred to as deep drawn containers.

Heretofore, it has been difiicult to form deep drawn containers having a curled rim from lightweight stock, for example, aluminum. Aluminum has a low tensile strength and the edges of the aluminum blank tear and form slivers of material during the drawing operation, leaving an uneven and unsightly rim on the container and causing the interior of the die to become obstructed by the slivers of aluminum torn from the blanks. This problem has been partially overcome in the post by forming deep drawn lightweight aluminum containers having a relatively wide flange in a drawing operation, removing the excess flange by trimming in another operation, and thereafter rolling or crimping the flange into a curled rim in a separate operation. Deep drawn containers having a curled rim formed in this manner are time consuming to produce, require a number of dies, and the plural drawing operations result in the formation of rough spots and uneveness in the sidewall of the container, and it would be advantageous to provide a method and apparatus for forming a deep drawn container having a curled rim from lightweight aluminum or aluminum alloy stock material in a single drawing operation.

Patented Apr. 1, 1969 It is the principal object of the present invention to provide a method and apparatus for forming drawn containers. A further object is to provide a method and apparatus for forming deep drawn containers having a curled rim thereon in a single drawing operation. An additional object is to provide an improved clamping mechanism which provides improved control over the container drawing operation, and eliminates tearing of the stock and the formation of slivers during the drawing operation.

'Fhese and other objects of the invention may be readily understood from the following detailed description and from the drawings of which:

FIGURE 1 is a partial schematic view of a form- 7 ing press and its associated hydraulic actuating system, portions of the forming press being illustrated in vertical cross-section;

FIGURE 2 is a graph showing the hydraulic pressure on the draw ring of a forming press as a function of the rotation of the press crankshaft;

FIGURE 3 is a partial cross-sectional rview of the forming press of FIGURE 1, the press being shown in the position where the blank has been cut from the stock material;

FIGURE 4 is similar to FIGURE 3 and shows the press in a partially closed position;

FIGURE 5 is similar to FIGURES 3 and 4 and shows the press in a fully closed position; and

FIGURE 6 is similar to FIGURE 5 and shows the press after formation of a curled rim on the container.

Very generally, the present invention is directed to a method and apparatus for forming drawn containers having a formed rim in a single stroke of a forming press without attendant problems of slivering and tearing of the edges of the stock material during the forming operation. More specifically, the present invention is directed to a forming press which includes means for forming a blank of stock mateiral to be drawn, means for clamping the edges of the blank during the drawing operation, means for controlling the clamping pressure on the edges of the blank, and means to release the clamping pressure at a particular point during the drawing operation, and to a method of forming deep drawn containers utilizing such a forming press. The invention also contemplates a hydraulic actuated clamping mechanism for clamping and releasing the edges of the blank during the drawing operation.

It has been found that in accordance with the present invention it is possible to provide a deep drawn container of suitable lightweight stock such as aluminum or aluminum alloy stock in a single drawing operation without slivering of the stock material. The method and apparatus of the invention are particularly useful in forming a deep drawn containing having a curled rim thereon, such as is desired where the container is to be sealed with a cover. Of course, the invention is also useful in drawing shallow containers.

Referring now to FIGURE 1 there is shown a partial schematic elevational cross-sectional view of a die set 11 of a forming press for forming deep drawn cylindrical containers, and a hydraulic actuating mechanism 12 for controlling the clamping pressure on the edges of the blank during the drawing operation. It is understood that the parts of the forming press not illustrated, such as the ram, crankshaft, and auxiliary support members, may be of any desired configuration, and do not form a portion of the present invention.

The press die set 11 includes an upper punch holder 13 and a lower die holder 15. An annular blanking punch 17 is carried by the punch holder, and a cylindrical forming punch 19 is slideably carried within the annular blanking punch 17. One or more hydraulic cylinders 21 having a liner 23 are provided in the punch holder 13. A piston 25 is disposed within the cylinder 21, the piston having a shaft 27 extending from. the cylinder 21 and abutting the upper surface of the forming punch 19 for controlling the movement of the forming punch 19 relative to the blanking punch 17 as explained hereinafter. The hydraulic cylinders 21 is connected to a source of fluid pressure which may be a sump 55 and pressure booster 57 of the hydraulic actuating system 12, or may be a separate hydraulic system, by means of a bore 29 and conduit 30. A solenoid or other suitably operated valve 32 is provided in the conduit 30 for controlling the pressure in the conduit 30. A stripper plate 31, which may be spring mounted, surrounds the blanking punch and acts to free the stock from the punch 17 at the end of each stroke of the press.

The die holder 15 supports a backing plate 33 upon which is supported an annular yoke 35. An annular draw ring 37 is concentrically mounted within the cavity in the yoke 35 and is adapted for sliding movement relative to the yoke. An annular groove 38 is provided in the draw ring 37 for forming a curled rim on the container as described hereinafter. A cylindrical forming die 39 is mounted on the backing plate 33 centrally of the annular draw ring 37 in a mating position with the forming punch 19 carried by the punch holder 13. The draw ring 37 and the blanking punch 17 cooperate in a manner as hereinafter described to form a gripping means for aligning and gripping the edge of the blank during the drawing operation.

One or more hydraulic cylinders 41 are provided in the die holder 15 beneath the draw ring 37 and each is provided with a cylindrical liner 43. A piston 45 is mounted for reciprocating movement within each of the hydraulic cylinders 41, and a shaft 47 is connected to the upper end thereof extending through the backing plate 33. The upper end of the shaft 47 abuts the lower surface of the draw ring 37 and the shaft is of a length so that when the piston 45 is in its uppermost position, as shown in FIGURE 1, the upper surface of the draw ring 37 is even with the upper surface of the yoke 35.

A bore 49 is provided in the die holder 15 in fluid communication with the hydraulic cylinders 41, the bore being connected in fluid communication to a conduit 51 of the hydraulic actuating system 12. The hydraulic actuating system 12 includes a sump or reservoir 55 for hydraulic fluid connected to the bore '49 by means of the conduit 51. A pressure booster 57 is positioned in the conduit 51 between the sump 55 and the bore 49. The pressure booster 57 may be connected to a suitable source of air under pressure, not shown, and operates to insure that the hydraulic system 12 and the cylinders 41 are constantly filled with hydraulic fluid. The pressure booster 57 may be controlled by means of a suitable switch 59, which in the embodiment of the invention illustrated in FIGURE 1 is actuated by a cam 61 in response to the stroke of the press as described hereinafter.

A check valve 63 is positioned in the conduit 51 between the booster 57 and the cylinders 41 to prevent backflow of hydraulic fluid from the cylinders into the booster during the drawing operation. A pressure relief valve 65 is connected in fluid communication with the conduit 51 between the check valve 63 and the cylinders 41. The pressure relief valve 65 is normally closed and is set to open and relieve the pressure in the cylinders 41 and conduit 51 at a fixed pressure determined by the operating conditions of the press, and it is desirable that the pressure at which the pressure relief valve 65 opens be adjustable for different forming operations and for different materials. As shown in FIGURE 1, the pressure relief valve is connected by a conduit 67 to the sump 55 so that the hydraulic fluid exhausted from the cylinders 41 is returned to the sump 55.

Means are also provided in the hydraulic actuating system to rapidly relieve the pressure in the cylinder 41, and to consequently relieve the gripping pressure between the blanking punch 17 and the draw ring 37 during a particular portion of the drawing operation. As shown in FIGURE 1, such means includes a dump valve 69 positioned in a conduit 71 connected to the conduit 51. The dump valve is utilized to rapidly relieve or exhaust substantially all of the pressure within the hydraulic cylinders during a particular portion of the forming operation as described hereinafter. Preferably, the hydraulic fluid exhausted from the cylinders 41 by the dump valve 69 is returned to the sump 55 by the conduit 71. The dump valve 69 is preferably a fast acting valve, such as a solenoid valve, and may be controlled by a switch 73 responsive to the stroke of the press. The switch 73 may be actuated by a suitable cam 75 which is carried by a crank shaft on the press. The cam 75 is adjusted to actuate the switch during a desired portion of the stroke of the press, thereby instantly relieving the pressure within the hydraulic cylinders 41 and the gripping pressure between the blanking punch 17 and the draw ring 37.

In accordance with the present invention, the dump valve 69 is opened for only a short period of time during each stroke of the press and the cam 75 is contoured accordingly.

The operation of the forming press and the hydraulic actuating system 53 may be readily understood by reference to FIGURES 1 through 6.

The operation of the press is explained in connection with the formation of a deep drawn container having a curled rim from 0.009 gauge aluminum stock. The container is 1.37 inches deep and has an outside diameter of 4.066 inches and an inside diameter of 3.878 inches. The container is drawn from a circular blank having a diameter of 6.188 inches, and the curled rim formed on the finished container has a diameter of 0.09 inch. FIG- URE 1 shows the position of the press at the beginning of a stroke or cycle of the press at the point where the punch holder 13 and die holder 15 are separated and a sheet of stock material 77 from which the container is to be formed is fed therebetween.

FIGURE 2 is a graph of the pressure in the hydraulic cylinders 41 versus the degrees of rotation of the press crankshaft, in the manufacture of the described container. At the beginning of the stroke of the press, the position of FIGURE 1, the crankshaft is at zero degrees rotation.

FIGURES 3 to 6 are partial sectional elevational yiews, similar to FIGURE 1, of the forming press, and illustrate the movement of the press during one stroke thereof for forming the described deep drawn container having a curled rim.

At the beginning of the stroke of the press (FIGURE 1) the punch holder 13 and the die holder 15 are separated and the stock material is fed therebetween by the press feed mechanism. The press crankshaft then commences rotation, causing the punch holder 13 and the die holder 15 to move toward each other to begin the drawmg operation. For purposes of illustration, FIGURES 3 to 6 show the die holder as being stationary and the punch holder as reciprocating down and up during each stroke of the press. At the beginning of the stroke of the press, the draw ring 37 is in its uppermost position, FIGURE 1, and the hydraulic cylinders 41 are filled with hydraulic fluid due to the action of the booster 57 during the previous stroke of the press. The pressure in the cylinders 41 is relatively low, about 50 p.s.i.g. as seen in FIGURE 2. The pressure relief valve 65, which may be set to open at a pressure of about 1200 p.s.i.g., is closed and the cam actuated dump valve 69 is also closed. The check valve 63 prevents back flow of hydraulic fluid from the cylinders 41 and it can be seen that a closed and filled hydraulic system is established which acts to retain the draw ring 37 in its extended position.

Continued rotation of the crankshaft causes the punch holder 13 to begin its downward travel, and the blanking punch 17 engages the stock material 77. As the punch holder 13 continues its downward travel, the blanking punch punches the blank 79 from the stock, the relative position of the components at that point bing illustrated in FIGURE 3. As seen in FIGURE 3, as the blank 79 is being punched from th stock 77 by the blanking punch 17, the downward movment of the blanking punch 17 causes the draw ring 37 to be slightly depressed from its fully extended position in which it is even with the upper surface of the forming die and the die yoke. Since the hydraulic system 12 is full of hydraulic fluid, and since the pressure relief valve 65 and dump valve 69 are closed and the check valve 63 prevents back flow of hydraulic fluid into the booster, the dawnward movement of the blanking punch 17, and the concurrent downward movement of the draw ring 37, causes the pressure in the hydraulic cylinders 41 to begin to increase. As seen in FIGURE 2, this occurs after about 120 rotation of the press crankshaft.

The downward pressure of the blanking punch 17 and the upward pressure of the draw ring 37 on the edge portion 81 of the blank 79 held therebetween grips the edge 81 of the blank 79 securely during the drawing operation. As the press crankshaft continues to rotate, the punch holder 13, blanking punch 17 and draw ring 37 continue to travel downwardly against the hydraulic pressure in the cylinders 41. As seen in FIGURE 2, the pressure in the cylinders 41 rises sharply, thus increasing the gripping pressure on the edge 81 of the blank 79, and the blank 79 begins to be stretched and formed over the forming die 39 (FIGURE 4). The increase in the pressure in the hydraulic cylinders 41 causes a concurrent increase in the gripping pressure applied to the edge 81 of the blank 79. An increasing gripping pressure is desired as the drawing operation continues due to increased tensile forces exerted during drawing and stretching of the blank into the desired shape. The desired gripping pressure may be adjusted for a particular drawing operation by proper selection of the size of the pistons 45 and the pressure established in the cylinders 41 at the beginning of the drawing operation.

In order to provide a deep drawn container in a single stroke of the forming press, the gripping pressure applied to the edge 81 of the blank 79 by the blanking punch 17 and the draw ring 37 is selected so that as the drawing operation proceeds the tensile forces applied to the edge 81 of the blank 79 by the stretching of the blank during the drawing are suflicient to cause the edge 81 to be slowly pulled from between the blanking punch 17 and the draw ring 37. As seen in FIGURE 4, the edge 81 of the blank 79 has partially withdrawn from between the blanking punch 17 and the draw ring 37.

As the punch holder 13, blanking punch 17 and draw ring 37 continue their downward movement, the drawing operation proceeds and the pressure in the hydraulic cylinders 41 continues to build up until the preselected maximum pressure is reached, at which time the pressure relief valve 65 opens and the hydraulic fluid is exhausted to the sump 55. As seen in FIGURE 2, if the pressure relief valve is set to open at a pressure of about 1200 p.s.i.g., the maximum pressure established in the cylinders 41 is 1200 p.s.i.g. At a pressure of 1200 p.s.i.g. the tensile forces created in the blank during the forming operation continue to withdraw the edge 81 of the blank from between the blanking punch 17 and the draw ring 37 As the punch holder 13 continues its downward travel, the forming punch 19 engages the blank and the container is shaped between the forming punch 19 and the forming die 39. At the same time the annular edge 81 of the blank 79 continues to be further withdrawn from between the blanking punch 17 and the draw ring 37.

In accordance with the present invention, and in order to provide a deep drawn container in a single stroke drawing operation without slivering or tearing of the blank,

the gripping pressure applied to the edge 81 of the blank 79 is released just prior to the time at which the edge of the blank would be pulled from between the gripping means by the tensile forces created in the blank during the drawing operation. In the manufacture of the described container, the gripping pressure is released by actuation of the dump valve 69 at the point when about to it, of an inch of the edge 81 of the blank 79 is held between the draw ring 37 and the blanking punch 17. The dump valve 69 is actuated by the cam 75 which is carried by the press crankshaft to rapidly relieve the pressure within the hydraulic cylinders 41 which releases the edge 81 of the blank 79 from between the blanki g punch 17 and the draw ring 37. This release of the pressure within the cylinder is timed so as to coincide with the bottoming or mating of the forming punch 19 and the forming die 39.

The actuation of the dump valve 69 is carried out at a point between about and of rotation of the cam 75, as shown in FIGURE 2. Between the portion of the stroke of the press wherein the crankshaft rotates from about 161 to about 178, there is substantially no pressure within the hydraulic cylinders 41 except for a static pressure of 40 to 50 p.s.i.g., and the blanking punch 17 and the draw ring 37 bottom out as shown in FIGURE 5. During the last portion of the downward travel of the punch holder, and after being released from the gripping means, the edge 81 of the blank 79 is wiped between the side of the forming die 39 andthe side of the blanking punch 17 to form a straight annular rim (FIGURE 5 When the press crankshaft has rotated to about 178, the cam 75 opens the switch 73 and the dump valve 69 is closed. At about the same time the cam 61, which may also be carried by the press crankshaft, actuates the air booster 57 to force hydraulic fluid through the check valve 63 and the

conduits

30 and 51 into the hydraulic cylinders 21 and 41. The pressure within the hydraulic cylinders 41 is increased rapidly and causes the draw ring 37 and blanking punch 17 to move upwardly. During the initial upward travel of the draw ring 37, the annular rim of the container is engaged by the groove 38 in the draw ring 37 and is formed into a curl, as shown in FIGURE 6. At the same time, the hydraulic fluid under pressure introduced into the cylinders 21 causes the forming punch 19 to remain in engagement with the forming die 39 in order to hold the container stationary during formation of the curled rim. The relative movement of the blanking punch 17, draw ring 37, and forming punch 39 during formation of the curled rim can be seen from FIGURES 5 and 6.

After the curl has been formed on the annular rim, the punch holder 13 and the die holder 15 separate and the container is ejected by means of a knockout pin 83. During this time, the pressure in the hydraulic cylinders 41 causes the draw ring 37 to move upwardly until it returns to the position of FIGURE 1. The valve 32 is also opened to relieve the pressure in the cylinders 21.

Although the invention has been described and is illustrated as including a separate dump valve and a separate pressure relief valve, it is contemplated that both functions might be performed by a single valve if desired. Such a valve should include a pressure relief mechanism for relieving the pressure within the hydraulic cylinders when the pressure exceeds the desired amount, and also includes a solenoid or other means of actuation for overriding the pressure relief and dumping the hydraulic fluid from the hydraulic cylinders to relieve the gripping pressure during that portion of the stroke of the press where it is desired to release the edge of the blank from between the blanking punch and the draw ring.

It is also contemplated to utilize a solenoid operated dump valve 69, as illustrated in FIGURE 1, and to also include an overriding mechanism in the pressure responsive valve 65 so that both the dump valve and the pressure responsive valve may be utilized to rapidly relieve the pressure from the hydraulic cylinders at the point that it is desired to release the edge of the blank from between the blanking punch and the draw ring. It has been found to be particularly desirable to relieve the pressure within the hydraulic cylinders as rapidly as possible and it has been found that the use of two lines and two valves to dump the fluid pressure has provided generally better results than a single line, particularly where the fluid lines and the valves have a small capacity.

It is also contemplated to utilize a heat exchanger in one or more of the lines of the hydraulic actuating system in order to maintain the hydraulic fluid at a constant temperature and to avoid expansion and contraction.

Although various features of the present invention have been disclosed in particularity in order to describe the invention, various alternative embodiments within the skill of the art are contemplated.

Various of the features of the invention are set forth in the following claims.

We claim:

1. A method for forming drawn containers, said method comprising disposing essentially the entire edge portion of a blank from which the container is to be formed between a pair of opposed clamping members and applying a clamping force thereto by means of said clamping members, effecting contact between the blank and a drawing die to commence a drawing operation while maintaining the clamping force on the blank, limiting the magnitude of the clamping force on the blank to a predetermined maximum so as to permit a gradual but not complete withdrawal of the blank from between the clamping members as the drawing operation progresses, relieving essentially all of the clamping force so as to release the edge portion of the blank before the stress in the edge portion of the blank is sufficient to fracture the blank in such edge portion and before any portion of said edge portion has become fully withdrawn from between the clamping members, drawing the edge portion so released around the die, and forming the released edge portion of the blank into a bead while maintaining the blank stationary relative to the drawing die.

2. A method in accordance with claim 1, wherein the blank is separated from a larger piece of sheet metal after the blank has been clamped and before the blank has been drawn to any appreciable extent.

3. A press for forming drawn containers, said press comprising a pair of opposed clamping members adapted to engage therebetween essentially the entire edge portion of a blank to be formed, means for applying a clamping force to said edge portion of said blank by means of said clamping members, a drawing die, means for effecting contact between the blank and said drawing die to commence a drawing operation while maintaining the clamping force on the blank, means for limiting the magnitude of the clamping force on the blank to a predetermined maximum so as to permit a gradual withdrawal of the blank from between the clamping members as the drawing operation progresses, means for relieving essentially all of the clamping force so as to release the edge portion of the blank before the stress in the edge portion of the blank is suflicient to fracture the blank in such edge portion and before any portion of said edge portion has become fully withdrawn from between the clamping members, means for drawing the edge portion so released around the die, and means for forming the released edge portion of the blank into a head while maintaining the blank stationary relative to the drawing die.

4. A press in accordance with claim 3, wherein an hydraulic system is provided for applying a clamping force to the edge portion of the blank by means of said clamping members, said hydraulic system including pressure responsive means for limiting the magnitude of the clamping force.

5. A press for forming drawn containers in accordance with claim 4, wherein said hydraulic system further includes a sump for hydraulic fluid, a conduit providing pressure-responsive communication between the hydraulic fluid in said sump and a blank-engaging portion of said clamping means, a dump valve in communication with the fluid in said conduit for rapidly relieving the fluid pressure exerted against said blank-engaging portion of said clamping means, and means for actuating said dump valve.

6. A press in accordance with claim 5, wherein means are provided responsive to the stroke of the press to open and close said dump valve during the forming operation, and wherein further means are provided for increasing the fluid pressure applied to said blank-engaging portion of said clamping means subsequent to the opening and closing of said dump valve.

7. A press in accordance with claim 6, wherein said pressure-increasing means is a pressure booster in said conduit, wherein means are provided responsive to the stroke of the press for actuating said pressure booster to rapidly increase the pressure applied to said blankengaging portion of said clamping means subsequent to the opening and closing of said dump valve.

8. A press in accordance with claim 3, wherein said clamping means comprises a blanking punch for forming a blank from a sheet and a draw ring positioned opposite said blanking punch, and wherein said draw ring is provided with a groove adapted to engage the edge of the blank and form said edge into a curled rim.

9. A press in accordance with claim 3, wherein means including a blanking punch are provided for forming the blank from a sheet, wherein a forming punch is slidably carried within said blanking punch, and wherein means are provided responsive to the stroke of the press for exerting pressure against said forming punch.

References Cited UNITED STATES PATENTS 1,482,732 2/ 1924 Calleson 72-351 2,192,778 3/ 1940 Stacy 72-351 3,085,530 4/1963 Williamson 72-351 3,147,722 9/ 1964 Williamson 72-351 3,292,415 12/ 1966 Hoflman 72-351 3,296,850 1/ 1967 Fiore 72-351 RICHARD J. HERBST, Primary Examiner.

US. Cl. X.R. 72-35 1 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,435 ,653 April 1, 19'

Joseph A. Scaletta et al.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shovm below:

Column 1 line 59, "post" should read past Column 2, line 38 "mateiral" should read material line 54, "containing" should read container Column 3, line 7, "cylinders" should read cylinder Column 4, line 30, "1.37 inches" should read 1.73 inches Column 5, line 5, bing should read being line 7, "th" should read the line 15, "dawnward should read downward Signed and sealed this 14th day of April 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, I

Commissioner of Paten Edward M. Fletcher, Jr.

Attesting Officer