US2269710A - Method of and apparatus for making weatherproof nails - Google Patents

Description

Jan. 13, 1942. e. E. DICKSON 2,269,710

METHOD OF AND APPARATUS FOR MAKING WEATHEEHPROOF NAILS I wmgvs Filed Oct. 27, 1939 Patented Jan. 13, 1942 METHOD OF AND APPARATUS FOR MAKING WEATHERPROOF NAILS George E. Dickson, Evan ston, 111., assignor to Dickson Weatherproof Nail Company, Evanston, 111., a corporation of Delaware Application October 27, 1939, Serial No. 301,534

22 Claims.

This invention relates to improvements in methods of and apparatus for making weatherproof nails and its consists of the matters hereinafter described and more particularly pointed out in the appended claims.

The weatherproof nail with which the invention is more especially concerned is one wherein the'head is enclosed in a cap of softer metal, with a part of the cap surrounding an adjacent portion of the shank. Heretofore nails of this kind have been made by means of the so-called hot process and wherein the cap was formed by molten cap metal poured into a mold cavity about the head of a nail disposed therein and by means of the so-called cold process in which relatively movable dies form the cold lead around the head. Both such processes as heretofore practiced are open to one or more objections. The hot process is relatively slow and requires the use of more metal in each cap so that the cost of the capped nails is increased. In the cold process it happens at times that the nail head is not always completely covered.

One of the objects of the present invention is to provide a method whereby weatherproof nails of this particular kind may be made by the socalled cold process employing relatively movable pressure dies whereby finished capped nails of more uniform character than have heretofore been made by the cold process may be produced.

Again it is an object of the present invention to provide a method whereby the uniformity of the cast process may be obtained in the cold process, but in which the capped nails may be produced rapidly at low cost.

Another object of the invention is to provide simple apparatus by which the improved method may be more readily carried out.

.The above mentioned objects of the invention, as well as others, together with the advantages thereof, will more fully appear as the specification proceeds.

In the drawing:

Fig. 1 is a view in side elevation of a weatherproof nail made in accordance with the improved method, with the cap thereof shown in cross section.

Fig. 2 is a vertical sectional view through associated die members, of one form of apparatus for carrying out the improved method, showing the nail in its centered and inverted position and engaged upon a mass of cap material resting upon the closed end of the cavity in one of the die members.

Fig. 3 is a horizontal sectional view through one of the die members appearing in Fig. 2 as taken on the line 3-3 of said Fig. 2.

Figs. 4, 5, 6 and '7 are fragmentary views of parts appearing in Fig. 2 showing the relative movements between certain of said parts corresponding to certain of the steps of the improved method.

Referring now. in detail to the weatherproof nail shown in Fig. l which has been produced by the improved method, the same comprises a conventional or stock wire nail H3 and a weatherproof cap ll of a metal softer than that of the nail. Lead is a metal which is much softer and which is well adapted for the purpose. The nail includes a shank l2 having a driving point l3 at one end and around substantially flat head Id at the other end. The underside l5 of the head flares upwardly and outwardly from the shank to the peripheral edge of the head.

The cap I l, as here shown, includes a crowned top wall or portion It enclosing the top of the nail head, a peripheral portion I! surrounding the periphery of the nail head and a. bottom portion l8 enclosing the'flared bottom of the nail head and surrounding that portion or neck of the shank adjacent the head. In this particular instance the bottom surface IQ of the cap is shown as extending at the same angle as that of the bottom surface [5 of the nail head but this angle is not absolutely essential.

The apparatus shown in Figs. 2 to 7 inclusive of the drawing includes a die member 20, having an axial 'bore or cavity 2! of a diameter that approximates that of the cap ll before mentioned which, of course, is somewhat greater than that of the nail head. The cavity Zl' is open at the top end and is closed or bottomed at the other end by the head 22.0f an ejector 23 which normally engages in supporting relation upon an annular shoulder 24 at the bottom end of the die member 20. The ejector head 22 has a snug piston-like fit in the bore. or cavity 2| so as to be movable longitudinally for ejecting the finished or even partially finished capped nail from the die member 20. The top surface of the elector head is convexed as shown to produce the crowned top surface for the cap II.

In opposite sides of the die member 20, at a point between'the ends of the bore or cavity 2!, are provided transverse recesses 25 in each of which a nail centering plunger 26 is positioned for sliding guided movement. Said plungers, which are counterparts, are so formed that their inner ends may be moved in overlapping engagement as appears in Fig. 2. Each plunger, which is of a width approximating the diameter of the bore or cavity, has an arcuate inner edge 2'! of the same diameter as the bore or cavity 2| and centrally in each edge is a recess 28 of a diameter approximating that of the nail shank. The recess 28 best appears in Fig. 3. The outer end of each plunger is made as a stem 29 which extends through a closure plate 30 for the outer end of each recess 25. A collar 3| is disposed on the outer end of each stem and an expansion coiled spring 32 surrounds the .stem between the collar 31 and plate 30. The springs 32 normally urge the nail centering plungers outwardly so that their arcuate inner edges 21 are flush with the associated side of the bore or cavity 2!.

33 indicates as a whole a duplex die-like plunger including inner and outer tubular parts 34 and 35 respectively. The inner plunger has a central passageway 34a therein of a diameter suificient to receive the shank I2 of the nail and this plunger snugly fits in the outer plunger for a relative movement. The outer plunger-35 snugly fits the bore or cavity 2| of the die 28 for a relative movement. The inner end of each plunger is made to form a concave end as shown.

In the making of a weatherproof nail in accordance with the improved method, with the aid of the structure above described, a mass of lead 36 of any convenient shape, is dropped into the open end of the bore or cavity 2| in the die 20. Said mass of lead comes to rest centrally upon the concaved surface of the ejector head 22 that bottoms said bore or cavity. Thereafter a nail I is dropped or inserted head down, into said bore or cavity from its open end, so that said head rests on the mass of lead. In so dropping the nail into said bore or cavity, the shank I2 usually falls to one side or the other of the axis of the bore or cavity so that the nail assumes the inclined position indicated by dotted lines in'Fig. 2. It is pointed out at this time that the diameters of the nail head, the mass of metal and the bore or cavityare so.correlated that the nail head will always engage upon some point on the top of the mass of lead and cannot enter into the space between the bore and said mass of lead therein.

Both plungers 26 are now moved inwardly toward each other preferably at the same time. As the arcuate inner end edges 21 of said plungers approach each other they coact with a-gathering action to engage the shank l2 of the nail and straighten the same up so that when opposed parts of the shank are engaged by the recesses 28 in said edges, the'nail is centered in the cavity, and with respect'to the passageway 34a in the plunger 34.

The duplex plunger 33 isnow entered into the open top end of the bore or cavity and as said die 2|! and said plunger are initially moved relatively to each other, the driving point end 13 of the nailenters the center passage 34a of the inner plunger member 34. At this time the centering plungers 2,6 are released so that their associated springs 32 withdraw them outwardly to positions where their inner end edges 21 coincide with the surface of the bore or cavity.

The part 34 of the plunger is now moved to engage the inner portion .of the surface I5 of the nail head and the part 35 of the plunger is moved into a position spaced a suitable distance away from the outer portion of the surface l5 of the nail head. This position .of the parts appears in Fig. 4. The plunger parts :34 and 35 are now locked together so as to form a unitary plunger with a stepped bottom end. The plunger 33 and the die member 20 are then moved relatively to each other under heavy pressure so that the end containing the member 22 and plunger parts ap proach one another. This causes the mass of metal 36 to change its shape so as to flow around the peripheral edge of the nail head and into the annular space between the bore or cavity and the outer surface of the plunger member and which space is topped by the bottom edge of the outer plunger member 35. This position of the parts appears in Fig. 5.

The plunger members 34 and 35 are now released from each other and the inner member 34 is moved outwardly relatively to the outer one until its bottom edge registers with the like edge of the outer plunger member as appears in Fig. 6. This leaves an annular space 36a about a portion of the shank that is bottomed by the inner portion of the tapered surface 15 of the nail head. The plunger 33 as a whole and the die 20 are again moved relatively to each other under pressure so that the metal between the head and the bottom edge of the plunger 34 is reduced in thickness to fiow or be displaced into the space 36a before mentioned to cover said inner portion of the surface I5 and substantially enclose the exposed portion of the shank I 2 to form the bottom wall I8 of the cap heretofore described. This position of the parts appears in Fig. 7.

The plunger 33 and the die 26 are then moved relatively in the other direction to separate them and thereafter the ejector 23 is caused to move upwardly in the bore or cavity 2| to eject the finished, lead capped, Weatherproof nail from the die 20.

It is apparent from the above that the metal of the mass 36 is first caused to flow or be displaced so as to enclose the top and the periphery of the nail head as a partially completed cap, thus providing an annular space about a portion of the shank adjacent the nail head. That the metal is then caused again to flow or be displaced so that it fills this space, thereby completely covering the nail head and substantially enclosing a part of the shank adjacent the nail head.

The method when carried out by a machine employing the apparatus parts described, operates to produce capped nails much faster than it is possible to produce similar nails by the socalled hot process. It is also more economical in the use of capping metal. Again, the capped nails produced are more uniform in character than nails produced by cold processes heretofore available. Importantly, the top part of the nail head is always completely covered with a smooth unbroken or unfissured lead layer. If there is any irregularity it shows up simply on the underside of the cap adjacent the nail shank at which point the defect is relatively of little functional importance.

While in describing the invention I have referred in detail to the steps of the method and the sequence of said steps as well as to the parts of the apparatus by which said steps may be performed, the same is to be considered only in the illustrative sense so'that I do not wish to be limited thereto, except as may be specifically pointed out in the appended claims.

I claim as my invention:

1. The method of making weatherproof nails which consists in providing a nail having a shank and a head, enclosing the top, the periphery and a marginal part of the bottom of the head outwardly from the associated portion of the shank in a partially completed cap of softer metal while said shank portion is surrounded by a member preventing engagement of cap metal therewith, causing said member to expose said shank portion, and then causing that part of the cap metal enclosing the marginal part of the bottom of the head to be displaced inwardly so as to cover the inner portion of said bottom of the nail head adjacent said shank portion and to substantially surround the latter.

2. The method of making weatherproof nails which consists in positioning cap metal against the top surface of the head of a nail, causing relative movement between said cap metal and nail head in a die cavity so that the nail head is forced into said cap metal so that said cap metal is displaced to cover said top surface of the nail head as well as the periphery thereof along with the outer marginal portion only of the bottom surface of the nail head in spaced relation to the adjacent shank portion of the nail, and then displacing that part of the cap metal on said marginal portion of the bottom surface of the nail head inwardly toward said shank portion to substantially cover the inner portion of said bottom surface of the nail head adjacent said shank portion and to substantially enclose the latter.

3. The method of making weatherproof nails which consists in providing a nail having a shank and a head, enclosing at least the top and the periphery of the head in a partially completed cap of softer metal while providing a protection for a portion of said shank and adjacent part of the bottom of said head against the engagement therewith by such softer metal, removing said protection so as to leave an annular space about said shank bottomed by a part of said head, and then causing a part of the cap metal to be displaced into said annular space so as to surround and substantially enclose said shank portion and cover the last mentioned part of the head to complete the cap.

4. The method of making weatherproof nails which consists in providing a nail having a shank and a head, enclosing the top, the periphery and an outer portion of the bottom of the head outwardly from the associated shank portion in a partially completed cap of softer metal while providing protection for said shank portion and adjacent inner part of the bottom of said head against the engagement therewith by such soft metal, removing said protection so as to leave an annular space around said shank portion bottomed by said inner part of the bottom of the head, and then causing a part of the cap metal to be displaced into said annular space so as to surround and substantially enclose said shank portion and cover said part of the bottom of the head to complete the cap.

5. The method of making a weatherproof nail which consists in placing the headed end of a nail including a shank against a mass of softer cap metal engaged with the closed end of a cavity in a die, covering an inner part of the underside of the head of the nail and associated part of the shank by a part of a second die engaged in the cavity in the first mentioned die so as to be relatively movable with respect to said first mentioned die, moving said dies relatively to cause a part of said mass of cap metal to be displaced about the periphery of the head and around the outer portion of the underside of the nail head up to said part of said second die to partially form a cap on said head, removing said part of said second die from its covering position to a second position uncovering said inner part of the underside of the nail head and associated shank portion and there leaving an annular channel bottomed by said inner portion of the underside of the nail head, and thereafter causing a part of the metal of said partially formed cap to be displaced into said channel and substantially enclose said shank portion and cover said inner portion of the underside of said head.

6. The method of making a weatherproof nail which consists in placing the head end of an inverted nail including a shank downwardly upon a mass of softer cap metal engaged upon the closed bottom of a cavity in a die, covering an inner part of the underside of the head of the inverted nail and the associated shank portion by a part of a second die engaged in the cavity in the first mentioned die so as to be relatively movable with respect to the first mentioned die, moving said dies relatively to cause a part of said mass of cap metal to be displaced upwardly about the periphery of the head and associated outer portion of the underside of the nail head up to said part of said second die to partially form a cap upon said head, removing said part of said second die from its covering position to one uncovering said inner part of the underside of the nail head and associated shank portion and there leaving an annular channel bottomed by said inner portion of the underside of the nail head, and thereafter causing a part of the metal of said partially formed cap to be displaced into said channel and substantially enclose said shank portion and cover said inner portion of the underside of said head.

'7. The method of making a weatherproof nail which consists in providing a plurality of dies one with a cavity therein closed at one end and open at the other end and which cavity receives a second die for a relative movement therebetween, placing a mass of softer cap metal in said cavity against its closed end, placing a nail having a shank and a head in said cavity with said head engaged with said mass of cap metal, moving said dies relatively in one direction into an initial position wherein the second die receives the nail shank and covers the inner portion of the underside of the nail head, further moving said dies relatively in the same direction so that the mass of cap material is displaced about the periphery of said head and around the outer portion of the underside of the nail head up to said part of said second die to partially form a cap on said nail head, moving said dies relatively in a second direction to cause said part of the second die to uncover said inner portion of the nail head and an associated part of the nail shank and there leave an annular channel bottomed by said inner portion of the underside of the nail head, and thereafter producing a further relative movement between said dies that causes said cap material to be displaced into said channel to substantially enclose said shank portion and cover said inner portion of the underside of the nail head.

8 In an apparatus for making weatherproof nails, the combination of a die member having a cavity open at one end and closed at the other end to provide a nail cap forming surface and a second die fitting in said cavity and comprising parts relatively movable with respect to each other and with respect to said die member, said parts of said second die having ends coacting to provide a second cap forming surface and one of said parts being further formed to receive apart of'theshank of a nail.

9. In an apparatus for making weatherproof nails, the combination of a die member having a cavity open at one end and closed. at the other end to provide a nail cap forming surface and .a second die fitting in said cavity and comprising inner and outer concentric parts movable with respect to each other and with respect to said die member, said parts of said die having ends coacting to provide a second cap forming surface, said inner part of said second die being formed to receivea part of the shank of a nail.

10. In an apparatus for making weatherproof nails, the combination of a die member having a cavity open at one end and closed at the other end to provide a nail cap forming surface and a second die fitting in said cavity and comprising parts relatively movable with respect to each other and with respect to said die member, said parts of said second die having ends coacting to provide a second cap forming surface and one of said parts being further formed to receive a part of the shank of a nail, and means associated with the closed end of the cavity and movable longitudinally thereof for ejecting a capped nail from the cavity.

11. In an apparatus for making Weatherpoorf nails, the combination of a die member having a cavity open at one end. and closed at the other end to provide a nail cap forming surface, a second die fitting in and movable longitudinally of said cavity and formed at one end to provide a second nail cap forming surface, said second die including a part formed to receive a nail shank, and means carried by said die member and movable transversely thereof to engage the shank of the nail for centering the same in said cavity so as to be received. by said part of said second die.

12. In an apparatus for making weatherproof nails, the combination of a die member having a cavity open at one end and closed at the other end to provide a nail cap forming surface, a seccavity but movable across the same to engage the shank of the nail for centering the same in said cavity so as to be received by said part of said second die.

13. In an apparatus for making weatherproof nails, the combination of a die member having a cavity open at one end and closed at the other end to provide a nail cap forming surface, a second die fitting in and movable longitudinally of said cavity and formed at one end to provide a second nail cap forming surface, said second die including a part formed to receive a nail shank,

means carried by said die member and movable transversely thereof to engage the shank of the {65 nail for centering the same in said cavity so as to be received by said part of said second die, and means associated with the closed end of the cavity and movable longitudinally thereof for ejecting a capped nail from said cavity.

14. In an apparatus for making weatherproof nails, the combination of a die having a cavity open at one end and closed at its other end to provide a nail cap forming surface, a die member fitting in said die, a second die member mov- 15 able relatively to and in the first die member and formed to receive a part of the shank of a nail, both of said die members having ends which in one relative position thereof coact to provide a second cap forming surface, and means associated with the closed end of said cavity and movable longitudinally thereof for ejecting a capped nail from the cavity.

15. The method of making a weatherproof nail which consists in supporting a nail in operative position in the cavity of a die by means which surround a part of the shank of the nail near its head and also engages the underside of said head in a manner exposing at least a portion of said underside of said head inwardly of its periphery, enclosing the top, the periphery and the exposed portion of the underside of the nail head in softer metal to form a partially completed cap thereon, separating said head with the partially completed cap thereon and said supporting means relatively in the direction of the length of the nail so as to expose another portion of the underside of the head and leave the nail supported in said cavity by said partially completed cap and then causing a portion of said partially completed cap to flow inwardly toward the shank so as to cover the last mentioned portion of the underside of the head and to engage upon said part of the shank near said head.

16. The method of making a Weatherproof nail which consists in supporting a nail in operative position in the cavity of a die by means which surround a part of the shank of the nail near its head and also engages the inner marginal part of the underside of said head so as to cover said parts of said shank and said head respectively, enclosing the top, the periphery and the outer marginal portion of the underside of said head in a partially completed cap of softer metal, separating said head with the partially completed cap thereon and said supporting means relatively in the direction of the length of the nail so as to uncover said parts of said shank and said head respectively and leave the nail supported in said cavity by said partially completed cap and then causing portions of the partially completed cap to flow inwardly toward the shank so as to cover the uncovered inner marginal part of the underside of the head and to surround the uncovered part of said shank.

17. The method of making a weatherproof nail which consists in supporting a nail in operative position in the cavity of a die by means which surround a part of the shank of the nail near its head and also engages the inner marginal part of the underside of said head so as to cover said parts of said shank and said head respectively, enclosing the top, the periphery and the outer marginal portion of the underside of said head in a partially completed cap of softer metal, moving said supporting means in the direction of the length of the nail away from the head of the nail so as to uncover said parts of said shank and said head respectively and leave the nail supported in said cavity by said partially completed cap, and then causing portions of the partially completed cap to flow inwardly toward the shank so as to cover the uncovered inner marginal part of the underside of the head and to surround the uncovered part of said shank.

18. The method of forming lead head nails comprising feeding a lead slug into a die, forcing the head of a nail into said slug and compressing said slug into a cup-shaped head.

19. The method of forming lead head nails comprising feeding a lead slug into a die, forcing the head of a nail into said slug and compressing said slug into a cup shaped head and forcing the metal about the underside of the nail head and shank.

20. The method of forming lead head nails comprising feeding a lead slug into a female die, feeding a nail shank into an axial bore in a plunger member for forcing said nail head into said female die member and compressing said 10 slug into a cup shaped head.

21. The method of forming lead head nails comprising feeding a lead slug into a female die, feeding a nail shank into an axial bore in a GEORGE E. DICKSON.

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