US2333930A

US2333930A - Rivet construction

Info

Publication number: US2333930A
Application number: US415506A
Authority: US
Inventors: Hedstrom Lars
Original assignee: Individual
Current assignee: Individual
Priority date: 1941-10-18
Filing date: 1941-10-18
Publication date: 1943-11-09
Anticipated expiration: 1960-11-09

Description

Nov. 9, 1943. L. HEDSTROM I 2,333,930

- RIVET CONSTRUCTION I Filed Oct. 18, 1941 axioms-sheet '1 Lara Hecisrom ZZA/LMY/ W2 [ATTORNEYS Nov. 9, 1943. L. H EDSTROM RIVET' CONSTRUCTION Filed Oct. 18, 1941 4'Sheets-Sheet 2 mm MW 0 TN T I R mH w 6 A l m Y Nov. 9, 1943.

L. HEDSTRO'M RIVET CONSTRUCTION Filed oct. 18. 1941 4 Sheets-Sheet 4 TTORNEYS Lars Heals from Patented Nov. 9, 1943 UNITED STATES PATIENT 1 OFFICE This invention relates to rivet construction. One of the objects of this invention is to, provide a rivet construction which is simple, thor oughly practical, and durable in use. Another f object is to provide a construction of the above character which can be securely set in a hole. only one end of which is accessible to the workman setting the rivet. Another object of this invention is to provide a construction of the above character, the manufacture of which will be economical both from the standpoint of labor and materials used. A further object is to P i vide a construction of the above character which may be quickly and easily secured in place by a single workman. A-still further object is to provide a construction of the above character in which th structural elements are so disposed j as to attain a high degree of strength without hea construction. St an ther c w m obje t is to 20 parts throughout the several views :of the drawprovide a construction of the above character which will be sturdy and well able to withstand heavy strains. obvious and in part pointed out hereinafter.

The invention accordingly consists in the features of construction; combinations of elements,

'in Figure 2 after being set;

Figure 4 is a top plan view, on a reduced scale. of a sheet metal blank used in th construction or the rivet shown in Figures 1 through 3;

Figures 5, 6, 7, and 8' are side elevations, on a reduced scale, showing steps followed in the form- 4 ing of the rivet shown in Figures 1 through 3;-. Figure 9 is a side elevation, on a reduced scale, of a completed rivet:

Flgure i0 is a section taken on the u e n-ls of Figure 9;

Figurell is a perspective view of another em-' bodiment of the rivet shown in'Figure 1 Figure 12 is a side. elevation'of the rivet shown intFigure 11 in position within a hole before being a I Other objects will bein part.

' rivet.

Figure 13 is aside elevation of the rivet shown in Figure 12 after beingset;

Figure 14-is a perspective view of another em bodiment of the rivet shown in Figure 1;

Figure 15 is a vertical section of the rivet shown v in Figure 14, the rivetbeing in position within a, hole before being set:

' Figure 16 is a vertical section ofthe rivet shown in Figure 15 afterthe'rivet is set;

Figure 17 is a top plan view of the head of the rivet shown in Figure 16;

Figure 18 is a perspective view of portions of the construction shown in Figure 15 showing means for locking the rivetin a set position} Figure 19 is a horizontal section taken on the line IS-IO of Figure 11-; and,

Figure 20 is a horizontal section taken on the 1 line 28-20 of Figure 12.

. Similar reference charactersrefer to similar ings. a

As conducive to a clearer understanding of certain features of this invention, it might here be pointed out that in the constructionof airplanes, radios, and other devices in which rivets are used, it has proved extremely difficult in many instances and impossible in others to use the standard type of rivet. The main cause for .the dimculties encountered lies in the inaccessi-.

30 bility, in many instances, of the inner end of the rivet which either prevents or makes it extremely dimcul-t to form a head on that end of the In many instances, screws, expanding bolts, and other threaded securing members have been used in place of rivets. These have -not provedsatisfactory, however, because'under the strains and vibrations existing'in many places,

' such as in airplanes, there is always the possibility that a threaded securing member may 40 loosen, which, in theicase of airplanes and in many other instances, may have very-serious consequences. Another dimculty with this type of securing element lies in the time consumed in setting it which because of the extremely large number of securing elements used in'certain instances such as in planeaj is-a major factor." rivets are the mm satisfactory form of securing element in planes and in many other places because of their strength. permanence, and

' ease'of'setting. It'is aecordintly another ohdiiiiculttoreachorisinsccusible."

5e nefen'ingnowtothedrawlngsandtol'lgurei in particular, the rivet construction shownin .cludes outer stationary and innermovable portions. The outer portion of the rivet is held during setting of the rivet in a substantially stationary position with respect to the object in which the rivet is being set and includes sections it and ii, while the inner portion, which moves as the rivet is being set, includes sections I2, l3, l4, and I5. Tne outer and inner portions of therivet are interconnected through-the rivets head and feet, generally indicated at l6, l1, and 18, respectively, in such a manner that when the movable portion of the rivet is moved downwardly by striking head IS, the outer and. inner portions of the rivet coact to cause the feet i1 and 18 to spread (Figures 2 and 3) and firmly grip the object being riveted, such as

plates

19 and 20, between the head and feet of the rivet, all as will be described hereinafter.

Referring now to Figures 4 through 10, the rivet shown in Figures 1 through 3 is preferably formed from a fiat metal blank generally indicated at 21 (Figure 4). This blank is first preferably cut and scored on the full and dotted lines, respectively, shown on the blank in Figure 4, dividing the-blank into the head, feet, and movable and stationary portions of the rivet. Th portions of the blank to the left of the score line 22a and between

score lines

23c and 24 form the movable sections l2, i3, i4 and i5 (Figure 1) of the rivet, the portion between score lines 220 and 23a (Figure 4) form the stationary (Figure 1) sections it and H, and the remainder of the blank forms the head and feetpf the rivet as best shown in Figures 5, 6 and '7. After cutting and scoring, the blank is placed in a press to crimp the blank at

transverse score lines

22a, 22b, 22a, 23a, 23b, 23c and 24 as shown in Figure 5. Thus,'the portions of the blank between score lines 2311 and 230 and lines 22:; and 220 are bent downwardly as viewed in Figure 5 to form por- V the blank between lines 22b and He is bent downwardly.

After the blank is pressed into the shape shown in Figure 5, the right-hand portion of the blank, as viewed in Figure 5, is bent on score line 230 on top of the center portion of the blank (Figure 6) so that sections [2 and 15 are substantially parallel to sections II and H. Next, the outer end of the blank is bent on score line I!!! over the center portion (Figure '1) of the blank so that it is superimposed on sections ll, I L1! and is. when the blank is folded into this position, longitudinal score lines 21, 28 and 2! (Figure 4) are in alignment 1 with 'each other, and the construction 22a and 220 and the

reenforcing elements

25 and 25 form the legs l1 and 18 of the rivet, while the portions of the blank between score lines 23a and 230, in conjunction with portions of sections l2, l3, H and i5, form the rivets head. Also, from these figures it may be seen that the distance between

transverse score lines

22c and 22b and between lines 231) and 23c is substantially greater than the distance between lines 22? and 22c and 231). This makes the

inner legs

30 and 3! (Figure 9) of feet I! and 18 of substantially greater length than the

outer legs

32 and 33, and

the

upper head portions

34 and 35 of greater length than the lower head portions 3t and 31. These members are preferably constructed in this manner both to aid in setting the rivet and to add to its strength after it is set, all as will be disclosed hereinafter.

In operation, a rivet of this type is placed in a hole 38 (Figure 2) extending through plates 19 and 28. when the rivet is in position in the hole, the head 16 is struck. As the

lower portions

36 and 31 of the head are in contact with the edge of hole 38, they preventvdownward movement of the stationary sections l0 and H and of the outer'legs 32 and 33 of the feet. Sections i2, it, It, and 15, however, move downwardly, and as they move, the

upper portions

33 and 35 of the head spread the lower portions 36 and 3'! downwardly and outwardly into contact with the upper surface of plate 59. Sections 12 and i5 exert a downward force on inner legs 30 and 3i which because of the connection to the outer legs makes them iold around the lower edge of hole 38 to securely grip the under surface of plate 28. As'sections I3 and 14 move downwardly simultaneously with sections l2 and i5, reinforcing

elements

25 and 25 move with the inner legs of the feet to act as reenforcing members for them and aid in carrying out the feet of the rivet.

During the setting of the rivet, as

head portions

34 and 35 and inner legs}! and Si are longer than the

lower head portions

36 and 31 and

outer legs

32 and 33, they exert forces on the lower head portions and the outer legs tending to draw them outwardly from the vertical axis of the rivet to the left and right thereof, as viewed in Figures 2 and 3. These forces in the head and feet act against each other because of the connection of the lower head portions and outer legs by stationary sections Ill and H, and thus, as the rivet is set,- plates is and 20 are drawn toward each other so that they are firmly gripped together. Furthermore, thissame action forces the stationary sections outwardly against the inside of the hole so that they firmly gr p both the inside and edges thereof. After the rivet is set, the upper portions -ofthe head and the inner legs 3| and SI form shown in Figure 7. is folded through 180' on these lines so that movable sections ll and I4 are face to face. An intermediate stage of this step tlon I3 with section ll because of their'connection along score lines 21, 28 and 2!, respectively -(Flgures 4, 9 and 1 0).

Asbestscc'nbyacom'parisonofl 'lgurcs4and- 9, the portions of blank between score lines effective braces to prevent turning or loosening of the head or the feet when the rivet is placed under a strain. This bracing also'prevents reverse movement of the movable portions of the rivet after the rivet has been set. Beenforcinz elements 25 and 28 increase the stmngth of the rivet by .both aiding in the action drawing plates II and 2| towardeachother, as describedhereinabove, andalsobyactingassupplementarybraces to recnforce inner legs II and II after the rivet is Thus, a rivet is disclosed which may be easily and economically manufactured. Furthermore, therivetmaybesetquicklyandeasilybyasingle man whohns access to only one side of the hole throughwhichtherivet Also,because of the construction-of the rivet, there is a drawing action between t e head and the feet thereof which exerts great force in drawing the objects being riveted together, and the same portions of the .rivet which efiect this action form effective braces to prevent the turning or loosening of the head or feet of the rivet when they are placed under a strain.

Referring now to Figures 511, 12 and 13, another of sheet metal and includes a head generally indicated at 40, feet generally indicated at 4| and 42,

movable sections

43 and 44, and

stationary sections

45 and 46. As best shown in Figure 12, the ends of the ribbon-like strip of metal from which the rivet is formed are positioned in the angles formed by the upper and lower portions of head 46, and the material extends upwardly to the top of the head to form

reenforcing elements

41 and 49 for the

upper portions

49 and 50 of the head. From the top of the head the two portions of the'strip extend downwardly to form

movable sections

43 and 44 of the rivet, thence outwardly wardly and inwardly. to a meeting point at the top of the rivet to form the rivets head 40.

Referring to Figures 12 and 13, it may be seen that the

upper portions

49 and 50 of the rivets head are of substantially greater length than the

lower portions

55 and 56 and that the inner legs and 52 of the feet are of substantially greater length than the

outer legs

53 and 54. These portions of the feet and head coact with the other lar portions of, the head and feet of theembodiment shown in Figures 1 through 3 to increase the strength and gripping action of the rivet.

As best shown in Figures 11, 12 and 20, the legs of thefeet are preferably channel-shaped, each leg having its longitudinal edges flanged inwardly toward the vertical axis of the rivet. This materially, strengthens the, legs and assures bending at the desired points, the flanges being broken at the points where bending is desired as shown at the lower ends of the feet. Any straight section of the rivet may be strengthened by this orotherextending-through a. pair of

plates

58 and 59 to be riveted together (Figure 12). When the head is struck,

stationary sections

45 and 46 are held in their respective positions by the abutment of the lower portions 55 and 560i the head against the edge of hole 51, while the movable sections are driven downwardly by the

upper portions

49 and 50 of the head striking against

reen forcing elements

41 and 48 and the upper ends of the movable sections. Movement of

sections

43 and 44.

downwardly causes the inner legs 5| and 52 to force the

outer legs

53 and 54 into contact with the under surface of plate 59. During the setting ofthe rivet, reenforcing

elements

41 and 48 in thehead materially increase the strength of the upper'portions 49 and 50 of the head, while at the embodiment of the rivet is shown. This construction isformed from a single ribbon-like strip Y portions of the rivet in the same manner as simisame time the flanges upon the edges of the legs of the feet materially strengthen them. Thus, a very strong drawing action is exerted by the upper portions of the head and inner legs upon the stationary sections of the rivet, as described with reference to the construction shown in Figures 1 through 3, because of the strength of the elements causing or supporting this action.

Thus, a rivet construction is disclosed which may be readily formed from a ribbon-like trip of etal and which may be easily and quickly set by a single person having access to only one end of a hole in which a rivet is to be set. Furthermore, the rivet is so constructed and reenforced that it has a very effective gripping action in drawing the

plates

58 and 59 together as the'rivet is set, and elements are provided which form strong braces to prevent the heads from being turned when the rivet is placed under a strain.

Referring now to Figures 14 through 18, another embodiment of the rivet is shown. This rivet is of tubular construction and is preferably formed from a fiat metal sheet by the method described hereinabove with respect to the construction shown in Figures 1 through 3 and then rolled into its cylindrical shape. This rivet construction includes a head generally indicated at 60, a plurality of feet generally indicated at 61, a' stationary cylindrical section 63, and movable

cylindrical sections

64 and 65. Head 60 includes a plurality of separate elements, each comprising upper and

lower portions

66 and 61, respectively,

which are angularly disposed with respect to each other, extend radially from the rivet, and connect stationary section 63 to the top of movable section 65. The stationary section 63 extends downwardly to the tops of the outer legs 68 of feet. 6!. The lower ends of legs 68 join the lower ends of the inner legs 69 which extend upwardly to join the lower end of movable section 64. The legs of the feet are preferably of the-same width, and thus, when they spread to form the lower end of the rivet, they extend radially from the rivet, all as will be described fully hereinafter. I

The upper end of movable section 64 has a head, generally indicated at 10, formed thereon of substantially the same construction and contour as head 60. The uppermost portion of head 10 is spaced below the upper portions of head 60 (Figure 15) and a cylindrically shaped member 1| joining the lower ends of the elements forming head 10 extends upwardly a substantial distance toward the upper'end of the rivet for pur-,

poses to be disclosed more fully hereinafter. At-

, therein. 7

-In operation, this rivet, which is constructed 1 for use in a countersunk hole so that th head of the rivet will be flush with the outer surface when it is set, is placed in a countersunk hole 13 (Figme! 15) extending through '

plates

14 and 15. When the head is struck, the stationary section of the rivet is prevented from moving by the .lower portions 61 of the head contacting the edges of the countersunk hole. During the first part of the setting of the rivet, the inner'movable section 65 is the only section of the rivet which moves, and. during thismovement, the wingshaped elements 12 move downwardly freeing the of the hole and its edges.

ends of the rivets feet. When the movable sec tion 65 is moved sufiiciently to free the feet 6|, the head 60 of the rivet strikes the head 10 formed on movable section 65. This drives section 64 downwardly which, acting through the inner legs 69, drives the outer legs 68 intocontact with the under surface of plate 15. The downward movement of the heads continues until the upper edge of cylindrically shaped member H (Figure 16) strikes upon the upper portions of head 10f As the lower end of member H rests against the lower portion 61 of head 60, further movement of head 60 in a downward direction is prevented. Thus, by forming cylindrically shaped member H of the proper length, further downward movement of the head is prevented when the head fills the countersunk hole and the upper portions of the rivet are flush with the top surface of plate 14.

Referring to Figure 15, it may be seen that the stationary sections of the rivet are substantially shorter than the length of the hole in plates 14 and (5. Thus, both the outer legs and the inner legs, which are substantially longer than the outer legs, extend upwardlyinto the hole in plate 15. When the rivet is set, the upper portions of the outer legsare forced into contact with the lower edge of the hole extending through

plates

14 and 15. By this type of construction, the drawing action described hereinabove with regard to the construction shown in Figures 1 through 3 is materially aided, and a tight'grip between the sides of the rivet and the hole is assured.

Referring to Figures 15, 16 and 18, a flap 80 is 1 ing the remainder of the setting of the rivet (Figures and 18). When the movable sections reach their final position as shown in Figure '16. the flap resiliently moves out into a hole 82 in stationary section 63. Thus, as the rivet is driven, the flap automatically locks the sections together, and when the rivet is set, it eflectively prevents the movement of the movable and sta-'- tionary sections with respect to each other.

Thus, a type of rivet is disclosed which may be driven by a single man having access to only one side of the hole in which the rivet is being set. Furthermore, this type of rivet construction may be" driven into a countersunk hole, and its head is automatically stopped when its upper surface is flush with the plate in which the countersunk hole is positioned. Furthermore, the rivet is so constructed that it exerts an eiIective drawing action between its head and feet to draw the plates 14 and 15'togethe'r,',and at thesame time the stationary portion of the rivet is forced outwardly into contact with the sides The rivet includes means to guide the end of the rivet into the hole and for preventing the fouling of the feet thereof withthe sides of the hole during its in-.

sertion therein. The rivet alsohas means to lock the movable and stationary sections of the rivet [together in their set positions',; which acts as an additional safeguard to prevent loosening of the rivet when it is placed under a strain. f

Thus, an efficient and practical rivet construction has been disclosed in which the objects hereinabove set forth, as well as many others,-

are accomplished.

As many possible embodiments may be made of the mechanical features of the above invenlower ends of said movable and stationary portions, the inner legs of said feet being of considerably greater length than the outer legs thereof from their points of flexure whereby said inner legs, acting through said outer legs, exert a drawing action downwardly on the lower end of said'stationary portion as the'rivet is set and move the outer legs to the under surface of the material in which the rivet is being set, and

a collapsible head connected to the upper end of said stationary portion, said head including upper and lower sections angularly disposed with respect to each other, the lower ends of said upper sections moving outwardly as said head collapses and thus, acting through the lower sections of said head, exerting a drawing action upwardly on said stationary portion as said rivet is set.

2. A rivet including a movable portion and a stationary portion, head means connected to said stationary portion, a plurality of U-shaped feet, each foot having its upper ends connected to said movable and said stationary portion, said feet being adapted to move outwardly when said movable portion'moves downwardly with respectto said stationary portion, and reenforcing members moving with said movable portion and'extending downwardly within and to the ends of said U-shaped feet.

3. A rivet including amovable portion and a lel relationship to each other, a pair of U-shaped feet, each foot having its ends connected to one of the members of the inner movable section' and to one of said stationary members, and angularly shaped elements connecting the upper ends of the members forming said outer movable section to said stationary portion, said elements extending upwardly, first outwardly-and then inwardly, inplanes radial to the vertical axis of said rivet to form triangularly shaped portions 1 of the rivet with the upper end of the members forming the outer movable section.

4. In an article of the nature described; a Pair of inner movable'members, a. pair of 'outer sta- Y tlonary members, head means extending over the top of said members to'interconnect said outer stationary members; the upper ends of said movable members contacting the under surface of said head means, and a plurality of U-shaped feet, each foot having its upper ends connected to said movable and said stationary members.

5. A rivet including a stationary portion and a movable portion, head means including a plurality of substantially straight members connected to said stationary portion, a plurality of U-shaped feet including substantially straight members connected to the lower ends of said movable and stationary portions, said feet being adapted to move outwardly when said movable portion moves downwardly with respect to said stationary portion, and means extending longitudinally of said substantially straight members to maintain said members substantially straight as said rivet is driven.

6. A rivet including an inner movable portion and an outer stationary portion, each of said portions including a pair of flat sections, all of said sections being substantially parallel to each other, a pair of U-shaped feet, each interconnecting the lower ends of a movable and a stationary section, head means including a pair of substantially straight members which extend outwardly and upwardly from the upper ends of said stationary sections in planes radial to the vertical axis of said rivet, and a pair of substantially straight members which extend inwardly and upwardly from the upper ends of said outwardly extending members to meet above the movable portion of said rivet, .the upper end of said movable portion contacting the under surface of said head means.

'7. A rivet including a stationary portion and a movable portion, said movable portion including inner and outer sections, a plurality of U- shaped feet, each foot having its ends connected to said stationary member and one of said mov-' able sections, head means connected to'said stationary member, and means formed on the other of said movable sections to prevent said feet from moving outwardly before the driving of the rivet is begun.

8'. In an article of the nature described, an inner movable cylinder, an outer stationary cylinder, head means formed on said stationary cylinder, and a plurality of- U-shaped feet having inner legs of substantially greater length than the outer legs thereof, the inner legs of said feet being connected to said movable cylinder and the outer legs of said feet being connected to said stationary cylinder, said feet being adapted to spread as said movable cylinder moves downwardly with respect to said stationary cylinder.

9. A rivet including a pair of movable portions and a stationary portion, said portions compris-' ing three cylinders of increasing diameters positioned in telescopic relationship with respect to each other, a plurality; of U-shaped feet, each foot having its ends connected to the lower end of said stationary portion and the outer of said movable portions, and head means connecting said stationary portion to the inner movable portion, said head means comprising a pluralityof angularly shaped members including upper and lower sections whichextend-outwardly from the rivet in planes radial. to the axis of the rivet and which form triangles with the upper ends of said inner movable portions.

10. A'rivet including, astationary portion and an inner movable portion,- head means connected to said stationary portion, and a plurality of U- shaped feet movable laterally with respect to said movable portion having inner legs of considerably greater lengththan their outer legs from their respective points of flexure, the upper ends of said inner legs being connected to said inner movable portion, and the upper ends of said outer legs being connected to said stationary portion, the upper ends of said inner legs, when said head means is in contact with the upper end of the hole in which the rivet is being set, being positioned within the hole a substantial distance from the bottom thereof, whereby, when said rivet is set, said inner legs exert a drawing action downwardly and outwardly on said outer legs, which drawing action acts through said stationary portion to firmly seat the rivet in the hole.

11. A rivet including, a stationary portion and an inner movable portion, collapsible head means connected to said stationary portion, and a plurality of U-shaped feet having inner legs of considerably greater length than their outer legs from their respective points of flexure, the upper ends of said inner legs being connected to said inner movable portion, and the upper ends of said outer legs being connected to said stationary portion, the upper ends of said inner legs, when said collapsible head means is in initial contact with the upper end of the hole in which the rivet is being set, being positioned within the hole a substantial distance from the bottom thereof, whereby, when said rivet is set, said inner legs exert a drawing action downwardly and outwardly on said outer legs, which drawing action acts through said stationary portion to firmly seat the rivet in the hole with the outer legs in snugsurface contact with the material in which the rivet is being set, said collapsible head means including upper and lower connected sections angularly disposed with respect to each other and connected to said inner movable portion and said stationary portion respectively, said upper sections being of substantially greater length than said lower sections, the lower ends of said upper sections moving outwardly as said head means collapses and thus acting through the lower sections of said head means to exert a drawing action upwardly on said stationary portion as said rivet is set, whereby the lower sections of the head means are brought into snug contact with the other side of the material in which the rivet is being set.

12. In an article of the nature described, in combination, an inner movable cylinder, an outer stationary cylinder, head means formed on said stationary cylinder, a plurality of U-shaped feet having inner legs of substantially greater length than the outer legs thereof, the inner legs of said feet being connected to said movable cylinder and the outer legs of said feet being connected to said stationary cylinder, said feet being adapted to spread as said movable cylinder moves downwardly with respect tosaid stationary cylinder, and means to lock said cylinders with respect to each other when said rivet is in a set position.

13. In 'an article of the nature described, in

combination, an inner movable cylinder, an outer stationary cylinder, collapsible head means connected to said stationary cylinder, said collapsible head means including upper and lower'connected sections angularly disposed with respect to each other and connected to said inner movable cylinder and said stationary cylinder respectively, said upper sections. being of substantially greater length than said lower sections, the lower ends of said upper sections moving outwardly as said head means collapses and thus acting through the lower sections of said head means to exert a, drawing action upwardly on said stationary cylinder as said rivet is set, and a plurality of U-shaped feet having inner legs of substantially greater length than the outer legs thereof, the inner legs of said feet being 'connected'to said movable cylinder and the outer legs of said feet being connected to said stationary cylinder, said feet being adapted to spread as said movable cylinder moves downwardly with respect to said stationary cylinder, whereby when said rivet is set, said inner legs exert a drawing action downwardly and outwardly on said outer legs which drawing action acts through said stationary cylinder to firmly seat the rivet.

LARS rmnsmour Patent No. 2,535,950.

CERTIFICATE or coRREcTi'oN. Y November 9, 1914.5 LABS I-EEDSTR'M.

It is hereby certified that. error a'pparsin the printed specification of the'aboire numbered patent requiring correction as follows: Page 2, first column, line 5h, for' "outer" read f-other--; and. second column, line l0, for "22c and 25b" read -22c and 25a and 25b--; page 5, first column, line 20, for "and k9 for-"road "3116148 for- 3 second ooiiz'xfi'ri, line 59, for "it to be" read --it' 15 to be---; and that thefsaid Letters Patent houlfl be read with this correction thereinthat tho same-may conform. to thereolord 6f the ca se in-the Patent orifice.

Signed and sealed this lnh da of April- A; D. 191m.

, Leslie Frazer (seal) Acting Commissioner-of Patents.