US2139279A - Roll roofing fastener - Google Patents

Description

Dec.'6, 1938. H. M. MAzE ROLL RooFING FASTENER Fil'ed Feb. '15, 1937 Patented 6, 1938 ROIL BOOFING FA'STENER Hamilton M. Maze, Peru, lll., aslignortow. HL l Maze Company, Pern, Ill., a corporation of Illinois Application February 13, 1937, Serial No. 125,524

, n 6A This invention relates to roll roofing, and more .particularly to a fastener of the nail type which will securely hold so-called roll roofing on a roof for an extended period of time and fully meet all of the desirable requirements of the roofing manufacturers, dealers and users. Recent years have seen a general advance and improvement in the quality of all types of roofing, and it is well recognized, for example, that asphalt 1o roll roolngs are at a high state of perfection. By means of accelerated atmospheric conditions, in which air, water, heat, cold, and even intense artificial sunlight are all faithfully reproduced, roll roofing can now, for the purpose of testing, be artificially weathered in a few days time. These few days are equivalent to years of normal out-of-door conditions. As a result, asphalt rooflngs, in their respective grades, have passed and are passing through tests and checking methods so rigorous that the factors making for their long life are well known and the finished productis high in quality, long life and uniformity.

l However, the best roll roofing must still be de- 26 pendent on its fastening, and while the roll roofing itself is very satisfactory for the purpose and may.. be secured in place by means of ordinary roofing nails, the finished roof may be unsatisfactory after a comparatively short period. of time 30 on account of the limited holding power of the fasteners, and the ineiilciency of the sealing means. t

The completed roof secured in the ordinary manner, is apparently very satisfactory for a short time. However, the nails or other fasteners soon become loose or even entirely remoyed, a condition known to the trade as drawing, easing ou or popping. `This causes` a great deal of dissatisfaction with this type of roof; and it is necessary for roof manufacturers,. dealers and contractors to make many costly adjustments on roofs of this type. 'Ihe fastenersfordinarily used are unsatisfactory for several reasons. For-4nstance, the shank does not .have sufllcient holding power. Also the opening formed bythe shank l when driven .through the roofing cannot be properly sealed by the ordinary nail head.` Therefore, moisture may enter under the head and around the shank, ultimately'destroying the 60 setting -and also causing the nails to rust, and

the roof will no longer be held securely in place.

To provide a satisfactory and permanent roof under all: normal conditionsl has' been a very serious problemand it is essentialy that the fas- 56 tenets` or nails shlouldrnot become even slightly (Cl. 10B-33) loosened as this causes the roof `to leak around the shank of thel fastener, and even when a leak is not immediately apparent any access of moisture under the head of the nail or to the fibres ofA the wood surrounding the nail shank will cause .5 the nail to be forced outwardly. I

It is desirable that the holding power of the shank should be greatly increased over that of fasteners in common use at the present time, and that the shank should be of such size, structure 10 and length that the sheathing will not be split and large slivers will not be knocked out from the under side thereby reducing the holding power by a large percentage. Also the nail head must be such as tol snugly fit the inequalities of the roof 15 and prevent access of moisture thereunder.

It is therefore an object of the present invention to provide a fastener of the nail type in which the holding power is greatly increased and will be effective to retain the roofing material snugly in 20 place over a period of time considerably longer than has'heretofore been possible, and in which the vhead of the fastener is of such a type that it will prevent moisture from entering thereunder and will effectively seal the opening made by thef 2tv In lthe application of roll roofing," fasteners having rigid heads integral with the shank have not been satisfactory because roofing nails are often driven at an angle, and also have a tendency to 30 -tilt under the hammer thus causing an uneven clamping action of the rigid head against the roofing thereby allowing .moisture to enter under the head. Also this tilting, or even irregularities it the thickness of therroll roofing or in the surface 35 o the sheathing, may cause the rigid'head to clamp unevenly and -angular1y, often cutting or otherwise'injuring the roll roofing. It is therefore an object to provide afastener in which the holding power and sealing characteristics are un- 40 usually efi'ctive even when lthe .nail is driven at an angle. In order to secure the maximum holding power in a roofing nail of this" type the shank of the Y nail must be of such size and construction thatit 45 will not unduly injure or displacethe fibres of thesheathing to which it is applied. .Alsoit must be easily driven with a hammer inthe ordinary manner without splitting the wood even for a short distance, as any splitting of the wood or crushing of fibres reduces the holdingefficiency thereof. It is also desirable that the nail should not tilt veasily under the hammer. l

The present invention overcomes all of the above noted objections to prior devices and it is 56.

therefore an object to provide a nail for fastening fabric base roll roofing to roof sheathing, in which all of the component parts are so correlated and coordinated with special reference to form. and dimension that when applied in the normal manner unusual holding power and sealing qualities are obtained.

It is a further object to provide a fastener of the character described having the above noted desirable characteristics in whichthe hole through the roll roofing made by the shank of the fastener will not be distorted and will conform snugly to the cross-sectional contour of the fastener and particularly that part of the fastener adjacent the head, and the head will conform to the sur-- face of the roll roofing and clamp snugly over its entire lower surface.

It is also an object to provide a fastener of the character described in which the shank is small relative to the diameter of the head and which will not rotate while being driven in the sheathing under a normal blow of the hammer, and will not materially tear or distort the fibres of the wood to thereby reduce their holding engagement with th-e shank over long periods of time.

As previously pointed out, the permanence of the roof depends upon eiiicient sealing combinedk with great holding power. The present invention provides such a combination of desirable characteristics and the holding power of fasteners made in accordance with this invention has been found by actual tests to be many times greater than that of any other fasteners in common use.

Many expedients have been resorted to in attempting to provide the shank with more holding power. High pitched threads which cause the nail to turn as it is being driven in have been used. It has been common practice to merely form barbs on the shanks to provide projections or a roughened surface-which it was thought tended to increase the holding power. However, the increased holding power has been very slight and the barbs make an irregular hole through the roofing material.

It is therefore an object of the present invention to provide a fastener in which the shank is provided with means for greatly increasing the holding power of the nail without causing rotation of the nail when it is being driven in place and without material destruction of the wood flbers, whereby the nails may be used to secure roll roofing to very thin sheathing of various types, with sufficient holding power to retain the covering snugly in place and prevent leakage under extreme weather conditions and over long periods of time.

In order to meet the requirements of established standards in the trade, it is desirable to provide nails in which each standard gauge and corresponding length will meet standard tests as to cross sectional strength and which will provide a predetermined count per pound. If the material of the shank is cut away or it is reduced in cross section at certain points, to increase holding power, then the size `or gauge of theshank must be increased to provide standard'cross sectional strength. If this is done the count per pound is reduced and the stock or total amount of material used for a predetermined count is increased, which adds materially to the manufacturing and transportation costs.

It is therefore a. very important object of the present invention to provide a nail of the character described having materially-increased holding power and which will satisfactorily meet standard requirements with respect to gauge of stock, cross sectional strength, and count per pound.

As previously stated, nails with high pitch threads tend to ease out. That is, the strains caused by expansion of the roofing and other conditions cause the nails to rotate backward slightly and they gradually work out sufficiently to loosen the roof covering and also to permit moisture to enter through the opening around the nail shank. It is therefore an object of this invention to provide a nail which will not ease out but which will remain fixed in holding position until a pull equivalent to its maximum holding power is applied.

In order to prevent rust, it is desirable to galvanize nails of this type. However, it has been found thatif ordinary annular grooves are provided in the shank to increase holding power, the nails may not be properly galvanized for the reason that the galvanizing material does not flow evenly over the surface, nor does the surplus metal drain freely, but instead accumulates in these annular grooves, and therefore the coating is very rough and uneven and tends to destroy the wood fibers and prevent their engaging in the grooves. The galvanizing material tends to more or less completely ll such grooves and forms a rough and uneven surface over the shank of the nail.

sheathing has been materially reduced in thickness as compared to old standards, and a new type of sheathing comprising laminated wood has lately been introduced in an effort to reduce the thickness to a minimum consistent with strength. The laminated sheathing is made of a plurality of thin sheets of wood which may be veneer and which are glued together with the grain of adjacent sheets in cross wise relation. sheathing of this typeis sometimes as thin as five-sixteenths of an inch and it is essential that the nails used should have maximum holding power, as only a small area of the nail is engaged by the wood flbers. The present invention contemplates anail particularly adapted for use with such thin sheathing and having materially increased holding power.' in proportion to the area engaged by the wood bers. t

The present invention, therefore, provides a highly eflicient means for increasing the holding power of the shank in combination with a flexible or resilient sealing means whereby a snug weatherproof engagement is maintained for a very ylong period of time regardless of expansion and contraction of the roofing material by extreme weather conditions, also, a construction is provided which may `easily be galvanized or otherwise coated.

Further objects will be apparent from the specification and the appended claims.

In the drawing:

Fig. 1 is an enlarged side elevation of one of the nails as applied to a roof, the roll roofing and sheathing being shown in section.

Fig. 2 is a side elevation similar to Fig. 1, but illustrates the adaptability of the head when the fastener is driven in a tilted or angular position.

Fig. 3 is a fragmentary view of the nail as used inconnection with comparatively thin laminated sheathing.

Fig. 4 is a view similar to Fig. 3, but illustrates the nail as used with very thin laminated sheathmg.

Fig. 5 is an enlarged fragmentary detail of the shank, partly in section better to illustrate the galvanized coating.

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Fig. 6 is a full size elevation of the fastener.

Referring to the drawing in detail, the embodiment illustrated comprises relatively small, short, threaded shank l having a comparatively large and very thin head 2 thereon. The entire nail is preferably of malleable material, whereby the thin head maybe more or less flexible to conform to uneven surfaces, and sumciently resilient to retain a sealing relationship under extreme weather conditions.

The shank may be sharply pointed at t and is provided with a low pitch helical groove t preferably formed by rolling the shank so that no material is 'out away and the original cross section of the shank is retained. The groove preferably forms a buttress type helical shoulder 5 so that when the nail is driven in place the wood bers engage over the shoulder as shown in Fig. 5 and the holding power of the nail is thereby greatly increased.

'I he lower surface of the groove forming the shoulder is substantially perpendicular tothe axis of the nail and the remaining surface forms a comparatively small angle with the axis of the nail. This provides a long substantially flat helical shoulder which may extend completely over that portion of the shank which is driven vinto the supprt. It has been found preferable, however, to terminate the shoulder a short distance from the point of the nail to provide a pilot portion l as shown. @This is somewhat more elfective in'driving the nails and also prevents excessive rupture of the wood bers. A

The smooth surfaces' of the angular sides 'l of the groove force the ends of the fibers outward While the nail is being driven without materially breaking or crushing them and enables their down-turned ends to spring inwardly over the shoulder as shown in Fig. 5, thereby providingl very great holding powr with no tendency for the nail to rotate whil being driven.

During the nal seating of the nail, the flexible head makes possible its adjustment to the surface of the roong in such a way as to compress the roofing material snugly around the shank and between the head and the sheathing, thereby making a snug weatherproof engagement, which is one of the rst essentials of a good fastener. The shank is engaged by cooperating wood bers in a maximum holding relation, and, due to the combination with the ilexible head, this holding Arelation is maintained, even when subjected vto strains incident to expansion and contraction of the rooting material under extreme weather conditions.

It is well known that freezing of moisture under a rigid nail head will pull the nail. The present invention provides the novel combinationof a i -peculiarly emcient shank which prevents the nail being eased out, and a peculiar type of head having the required flexibility and resilience to maintain a perfect seal.

It is important that the helical'groove 4 should be of suiiciently low pitch so that there will be no tendency for the nail to turn during the process 4of driving through the roofing and into the wooden sheathing. A still more important characteristic of the low pitch is that the nail has no tendency toV ease out as itfcan not be moved until the maximum pulling power is applied. Furthermore, although it has been found that annular non-helical grooves of a contour similar to the helical groove illustrated will provide increased holding power, such grooves present dimculties in the process of lgalvanizing the nails, as the suraisaavo plus coating does not drain freely. The single continuous elongated groove overcomes these difculties by providing a continuous path for the flow or drainage of the galvanizing material G and causes the material to form a thin, smooth, and substantially uniform coating over the entire 4,surface of-the groove, as shown in Fig. 5. at, the

same time this type of groove does not present any increased resistance to the driving of the nail and materially increases the holding power after it is in place.

Careful tests have shown that nails made in accordance with the present invention have more than three times the holding power oi ordinary high pitch threaded nails and that the thin heads cooperate therewith to provide an em'cient seal. The nails do not ease out but become loosened only when maximum pulling power is applied whereby they break loose entirely from the wood fibers. The'factor of safety is so great, however, that they do not become loosened under ordinary `onditions of use. In comparative tests, nails with high pitch threads, which cause the nails to rotate, ease out under a continuous two hundred and fty pound pull, while the same size nails made in accordance with this invention resist up to ve hundred pounds pull without movement and then suddenly pop completely out.

The helical groove is preferably comparatively shallow and the cross sectional strength of thel nail is not materially weakened, as the material from the groove is merely pressed outwardly to form the shoulder, and the nail retains substanltially the same cross sectional area at all points.

The nails 'are preferably formed by irst 11p-5 f setting thereon a very thin head to the required dimensionskand then rollingthe shank to form the helical high pitch groove. 'I'he shank of the nail is very small in cross section, and this method all@ of forming the groove and shoulder leaves the process of upsetting the head.

Figs. 3 and 4 illustrate the use'oi' the nails in connection with very thin veneered material for which they are particularly adapted, as the long helical shoulder hooks under a maximum number of bers over its entire length. The flbeware not materially injured by the'entering nail, but are merely pressed outwardly by the' inclined surface of the groove and theirl resilience causes them to engage snugly in the groove and over the top of the shoulder. Fig. 3 is an enlarged view drawn to scale of five ply veneer five-eighths of an inch thick, While Fig. 4 is an enlarged scale drawing of three-eighths of an inch threeply veneer:

The nails are preferably completely covered with a galvanized metal coating G (Fig. 5) which also assists in providing asurface suitable for emcient engagement of the wood fibres therewith and prevents oxidation of the entire nail under all weather conditions. When the nail is driven vertically into the sheathing the extreme thinness of the head, which is preferably malleable will cause it to adjust itself to slight variations in the thickness of the roll roong or to irregularities in the surface of the sheathing.

These nails are usually driven very rapidly by f7! the roofer and are very often somewhat angularly disposed relative to the sheathing. Any angular displacement of a rigid-head nail while being driven causes the head to cut or distort the roll roofing and also to exert its greatest clamping pressure upon the lowest portion leaving the opposite side tilted upwardly whereby moisture enters under the head of the nail and may even enter the sheathing around the shank. This destroys the eiliciency of the nail in a short time and is particularly undesirable in cold weather as the moisture freezes under the head of the nail and causes the nail to raise or pop and ultimately become entirely removed.

In applicants device, as mentioned previously, the head isrelatively large in diameter and very thin, and as it is made of malleable material it is easily bent or deformed to fit the irregularities in the roofing or sheathing and will assume an angular position relative to the shank and parallel with the surface of the roofing even when the nail is driven into the sheathing at a considerable angle thereto. 'I'he head, however, while malleable and capable of conforming to the irregularities is suiliciently rigid and resilient to maintain the roll roofing securely clamped against the sheathing and overthe entire lower area of the head. The material of the nail, the

lfinish, and the dimensions of its component parts are so correlated' as to cooperatively function in a manner to maintain the nail snugly in position and to prevent the access of moisture thereto for a considerably longer period than heretofore possible.

Satisfactory nails may be made in which the ratio of the diameter of the shank to the head may be on the order of 1 to 5 and the head may be of uniform thickness and substantially twentyfive thousandths inch thick. The ratio of the thickness of the head to the diameter thereof is preferably substantially 1 to 30.

Modifications will be apparent to those skilled in the art, and it is desired, therefore, that the invention be limited only by the prior art and the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In a non-rotating nail for securing roll roofing to thin sheathing, the combination with a short shank having a thread extending over substantially the entire sheathing engaging portion thereof, said thread being of sufliciently low pitch to prevent rotation during driving or pulling, of a relatively large integral thin flexible head on said shank, said head being suiliciently thin to permit it to flex under strains materially less than the holding power ofy said thread in standard thin sheathing.

2. A nail for securing roll roofing to thin sheathing comprising a short shank having a thin large diameter flexible head of malleable material constructed and arranged to seal the opening around the nail shank when the nail is driven snugly in place, said shank being provided/ over substantially all of that portion engaged by standard thin sheathing with a continuous helical shoulder of a diameter not less than the original diameter of said shank and arranged to be engaged by wood fibers when driven therein to materiallyresist pulling of the nail beyond the ilexing resistance of the head, the surface of said nail below and adjacent said shoulder being inwardly tapered to enable easy driving of the nail, said helical shoulder being constructed and arranged to enable driving or pulling without rotation, and terminating short of the point of said shank to provide a cylindrical pilot portion.

3. In a non-rotating nail for securing roll roofing to thin sheathing, the combination with a short pointed shank having an anfractuous shoulder thereon extending over substantially the entire sheathing engaging portion of said shank and terminating short of said head, the upper surface of said -shoulder being substantially perpendicular to the axis of said shank, of an integral malleable head on said shank, said head being suiliciently thin over its entirearea to conform to the surface of a substantially flat roof when the nail is driven angularly therein by the normal blow of a hammer and to permit flexible adjustment in accordance with irregularities of said roofing, said shank between said head and said shoulder being tapered toward said shoulder and having an external dimension adjacent said head substantially equal to the maximum external dimension of said shoulder.

4 4. A non-rotating nail for securing roll rooflng to thin sheathing, comprising a short pointed shank having a relatively large flat head integral therewith, said head being suiiiciently thin and flexible to conform to the surface of a substantially flat roof when the nail is driven therein by the normal blows of a hammer, and to permit exible adjustment in accordance with irregularities of said roofing, sand shank having a thread extending over substantially the entire sheathing engaging portion of its length and terminating short of said head, said thread being of sumciently low pitch to prevent rotation during driving or pulling, said shank between said head and said thread being tapered toward said thread and hav- .ing an external dimension closely adjacent said head substantially the same as the outside diameter of said thread.

5. In a fastener for securing roll roofing to thin sheathing the combination with a short small diameter pointed shank, of a relatively very large diameter flexible head integral therewith, said shank having a helical V-shaped groove in said shank and covering substantially the entire sheathing engaging portion thereof adjacent the point of said nail, the convolutions of said groove being closely adjacent and of such pitch that the nail will not rotate when driven, and a relatively uniform coating of .galvanizing material covering said nail, said convolutions terminating short ofl the point of said shank to provide a cylindrical pilot therebetween. l

6. A non-rotating nail for securing roll roofing to thin sheathing comprising a short pointed shank having a relatively very large flat head integral therewith, said head being sufficiently thin and flexible to conform to the surface of a substantialy flat roof when the nail is driven therein by the normal blows of a hammer, and to permit flexible adjustment in accordance with irregularities of said roofing, said shank having a thread extending over the major portion of its length and terminating short of said head and said point, said thread being of suiliciently low pitch to prevent rotation during driving or pulling of said nail, said shank between said head and said thread being tapered toward said thread and having a transverse thickness closely adjacent said head at least equal to the outside diameter of said thread, and a cylindrical pilot portion between said vthread and the point ofy said shank.

y HAMILTON M. MAZE.

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