US2318019A - Device for removing curvature from metallizing wires - Google Patents

Description

y 1943. A. P. SHEPARD 2,318,019

DEVICE FOR REMOVING CURVATURE FROM METALLIZING WIRES Filed April 10, 1941 2 Sheets-Sheet l 9 a ll/v, z

i a v n I A INVENTOR: Arfizur f? Shepard A BY a u i ATTORNEY y 1943- A. P. SHEPARD 2,318,019

DEVICE FOR REMOVING CURVATURE FROM METALLIZING WIRES Filed April 10, 1941 2 Sheets-Sheet 2 INVENTOR liiTORNE Patented May 4, 1943 2,318,019 DEVICE FOR REMOVING CURVATURE FROM METALLIZING WIRES Arthur P. Shepard, Forest Hills, N. Y., assignor to Metallizing Engineering Company, Inc., Long Island City, N.

Y., a corporation of New Jersey Application April 10, 1941, Serial No. 387,812 Claims. (01. 140-148) This invention relates to new and useful improvements in a device for removing curvature from a metallizing wire.

Metal spray guns are commonly equipped with a mechanism -for feeding metal in the form of slender rods or wire into the gun thence through a heating zone where the metal is melted, and finally into an atomizing zone where the molten metal is atomized by a blast of air or other gas and from which the atomizing metal is propelled in the form of a finely divided metal spray. Metal spray guns are often used forhand work, they are usually of a light construction and the amount of power available for feeding the metal rods or wire is considerably limited. The metal used for spraying is most commonly supplied in the form of wire wound into coils for convenience in handling. The coils are usually placed on a reel so that the wire can unwind from the coil as it is fed into the metallizing gun. This practice, however, has one serious disadvantage, for the wire unwinds from the coil retains a permanent set or curvature which causes considerable difiiculty in the successful operation of the spray gun. This difiiculty is primarily of two kinds. First, interference of the curvature of the wire with the wire feeding mechanism of the metal spray gun, and second, interference of the curvature of the wire with the proper centering of the same in the heating zone.

Interference of the curvature of the wire with the feeding mechanism of the metal spray gun is serious because in some cases it causes premature wear and damage .to the mechanism, as the result of the excess drag imposed upon the mechanism by the curvature of the wire which is particularly bad where large wires of hard materialsuch as 4;" diameter wires of nickel, carbon steel, stainless steel, etc., are used. In some cases the drag due to such curvature is so great that it slows down the mechanism and the proper feeding speed cannot be obtained. The major trouble with the mechanism is in most cases encountered, however, as the result of fluctuations in the feeding speed caused by the curvature of the wire. Furthermore, the wire tends to flop around as it feeds into the gun thereby continually varying the drag on the Wire feed mechanism. .This in turn varying atomizing condition spray at times fine and at ant upon the speed of the Wire. metal coats, however, are in most cases undesirable. Inasmuch as the spray gun tends to spray a coarse coat when the wire feeds too fast,

so that the gun will Coarse spray causes a continually times coarse dependit is generally the practice of the operator to slow the gun down to such extent that coarse spraying is avoided even though the wire surges ahead at times. Such practice, however, causes an average wire speed of far less than could be obtained with a steady feed and hence results in loss of time and money.

Even if the metallizing gun feeds the wire with a comparatively steady feed, coiled wire still causes the second type of difliculty mentioned above, as the result of improper centering of'the tip of the wire in the heating or melting zone. The melting zone is usually a small cone of intense heat such as would be produced by an oxygen/acetylene flame, the most intense heat being at the center of the cone. The wire extends into this melting zone and should be centered as accurately as possible was to take advantage of the more intense heat in the center. When the wire has a curvature, it tends to run off to the side of the zone, hence requiring reduced spraying speed with loss of time and money, due to a slower rate of melting. In addition to this trouble, the wire tends to melt off somewhat crooked when it is not in the center of the melting zone and hence it is not evenly atomized by the blast of atomizing gas, so that a coarse or spattering type of spray results.

The above described difficulties and drawbacks inherent in the use of coiled metal spray I wire are considered so serious by many operators in the metallizing industry that the practice developed by using straight rods instead of coiled wire. Straight rods overcome the above described disadvantages of coiled wire, and make it possible to increase spraying speeds and produce finer, more uniform, atomization of the metal. The use of straight rods, however, has been found to be impractical, except in very limited cases because of the difficulty of handling a sufficient quantity of metal in the form of rods without continued interruption of the spraying operation. The maximum practical lengths for rods which can be handled conveniently is from 12 to 20 feet long and even these cannot be handled as conveniently as coiled wire. Each time a rod has fed through the gun, another rod must be inserted in its place, but each time this is done, a small piece of rod is wasted, as the end or remnant of the'flnished rod blows out of the end of the gun without being melted. This requires that either the gun be stopped or that a shutter or damper be placed in front of the gun to prevent this remnant of rod from splattering on the work being sprayed.

hence throw the wire from the same.

There have been wire straightening devices known in the past for the solution of other wire straightening problems, but none has as yet been known which can solve this particular problem. Most wire straightening devices are adapted for removing kinks from wires with the result that they require considerable energy to draw the wire through them. The removing of kinks is not a problem in metal spraying as wire which is entirely free of kinks is easily obtainable for metallizing purposes. For the purpose of straightening wire for metallizing, attemptshave been made to pull the wire through a series of rollers which are so located as to bend the wire back and forth several times in an attempt to straighten it. Such methods have been unsuccessful because bending the wire several times requires too much energy and imposes too much drag on the wires, as it enters the metallizing gun.

The device in accordance with the invention for removing curvature in metallizing wire, due to the coiling of such wire, overcomes all of the troubles caused by coiled wire and retains all of the advantages and convenience of using coiled wire for metallizing work. This device by its special construction removes the curvature from the wire due to coiling thereof and require a minimum of pull or drag on the wire to d so. In fact, the pull required is so slight that the actual work by the driving mechanism of the metallizing gun is reduced more by the straightness of the wire as it goes through the gun, than it is increased by the energy required in the curvature removing operation of the device.

The wire curvature removing device, in accordance with this invention will be more fully understood from the following description read in conjunction with the drawings in which:

Fig. 1 is a perspective view of the device shown with the coiled wire in the operating position.

Fig. 2 is a top view of the device.

Fig. 3 is a section taken through the plane III-III in the showing of Fig. 2.

Fig. 4 is a section taken through a part of the device through the plane IVIV in the showing of Fig. 2.

Fig. 5 shows a top view of the device with a different arrangement of parts than that shown in Fig. 2.

As illustrated in the drawings a mounting base preferably on legs 2 carrie at one end wire reel 3, upon which rests the coiled metallizing wire 4. Wire reel 3 has a rotating top 4a mounted on a stationary base 5. .5 ball bearing (not shown) is preferably utilized as a Divot in the center between stationary base 5 and rotating top 4a of the wire reel 3. A friction or brake member (not shown) is preferably provided between members 40 and 5 to exert a slight amount of friction opposing the rotation of member 4a. This is sometimes desirable with springy wire as it prevents the uncoiling of the wire. The reel 3 is preferably so constructed that it rotates as freely as possible, and yet not so freely that the springiness of the wire will unwind the reel and Reel top 40. may be provided with extension cros arms 8. as for instance shown in Fig. 1 to permit using large coils of wire or it may be used without such cross arms, as shown in Figs. 2 and 5, where small coils of wire are being used.

The pins 1 are inserted into the cross s 5 to locate the coiled wire when large coils are used, or the sac e pins 1 may be inserted directly Into the wire reel top 4a when small coils of wire are used.

The curvature removing head assembly 8 is preferably mounted on base I opposite the wire reel. Bracket 9 mounted on base I is of such height as to locate the top of the head assembly at the approximate level at which the wire unwinds from reel 3. Through the upper end of bracket 9 extends a flat head cap screw I0, which is fastened on the underside by a nut II. This cap screw and nut serve to secure the bracket to the two plates I2 and I3, the plate l3 being under the plate l2. The flat head of the' cap screw I8 is secured to the plate I2 by means of two small pins I4 which prevent the head from rotating and make it easy to loosen or tighten the cap screw by simply turning the nut II, which is underneath. The plate I3 is turned at an angle with respect to plate I2 and in the specific embodiment of the invention shown in this illustration, the angle between their axes is approximately degrees. To locate the angle of plate I3 with respect to plate I2, and to locate plate I2 properly with respect to the bracket 9, a hole may be provided in each of these members I2, I3 and 9 so that these three holes line up when the three members are in the proper location in respect to each other. These holes in plates I2 and I3 are clearance holes for screw l5 and the hole in plate 9 is a tapped hole to fit the threads on screw l5. Therefore, when screw I5 is inserted through the holes in plates I2 and I3, and screwed into the hole in bracket 9, the relative location of the three members is fixed. At the other end of plate I2 a plate I6 is pivotally fastened by means of flat head cap screw I1 and nut I8 which is underneath. Plate I6 is underneath plate I2. The head of cap screw I1 is fastened to plate I2 by means of two pins I8, which prevent the rotation of the head of the cap screw and make it convenient to loosen -or tighten the screw by simply turning the nut |8 underneath. Washers 20 are provided for both nut |8 andnut II.

Extending from and fastened to plate I3 are two strips 2|. On the ends of these two strips 2| are mounted the small right angle bracket pieces 22, 23, 24 and 25. These pieces are clamped together and to the strips 2| by the two screws 28, and between the brackets as shown in Fig. 4 are clamped the ball bearings 21 and 28. Ball bearings 29 and 38 are clamped between the bracket pieces by screws 3|. Washers 32 are provided on each side of each bearing to provide the properspacing and to permit all of the bearings to rotate freely even though they are clamped on the inner races. This arrangement of the four ball bearings 21, 28, 29 and 30 provides a ball bearing wire guide orifice through which passes the wire 4. The ball bearings are spaced so that they do not quite touch each other and yet are set close enough to each other to retain the wire within the orifice.

On the front end of plate I6 two ball bearing wheels 33 and 38 with channeled rims are mounted and held in place by the two screws 35 and nuts 36. Cupped shaped washers 31 are mounted one each on top of the ball bearing wheels under the screw heads to act as dust shields for the bearings. Block 38 is placed on top of plate I5 and under the bearings 33 and 34 so as to locate the bearings at the proper height. This arrangement of the ball bearing wheels 33 and 34 provides a wire guide between the wheel rims, so

that the wire 4 can pass through the guide space defined by the wheel rims as shown in Fig. 3.

Ball bearing channeled wheels 39, 40, 4| and 42 are mounted on plate I2 in pairs as shown. The mounting of these bearing wheels is similar to that described for bearing wheels 33 and 34, they being fastened to the plate by screws and shielded by cupwashers 31. However, in the case of the ball bearing wheels 39, 40, 4| and 42, no block such as block 38 is provided as the wheels are of the proper height when mounted directly on to plate I2.

The relative location of the various ball bearings and ball bearing wheels is important. The location of the wire reel 3 with respect to these ball bearing wheels and ball bearings is also important. First it is essential that the centers of the wire guiding spaces between the ball bearing wheels 33, 34, and 39, and 4|, 42 and 21, 28 be all in approximately the same plane and in approximately the same plane as that in which the wire unreels from the coil of wire 4 resting on wire reel 3. Second, it is essential that the path of travel of the wire defined by the pairs of ball bearing wheels 21, 28 and 4|, 42 and 39, 40 be fixed in substantially the same plane on a curve which approximates the curvature of the wire as it leaves the wire reel. The wire reel is preferably so located with respect to the wire guiding spaces of these last mentioned three sets of ball bearing wheels, that the wire leaving the wire reel is fed to the pair of guide wheels 21, 28 in substantially its natural curvature and thereafter continues in its path of travel at approxi mately the same curvature through the two guiding spaces between the two pairs of wire guiding wheels aforementioned 21, 28 and 4|, 42 respectively. Third, it is essential that the path of travel of the wire defined by the wire guiding spaces between the pairs of ball bearing wheels 33, 34; 39, 40; 4|, 42 is fixed in a substantially eountercurvature direction in substantially the same plane at an angle or curve sufllcient to straighten the wire.

In operation the wire 4 is drawn from between the ball bearing wheels 33 and 34, by the feed mechanism in the metallizing gun, and the wire emerges from between these two ball bearing wheels with the curvature removed. The wire coiled on reel 3 unwinds from the reel assuming the curvature due to the coiling thereof. It feeds to and through the orifice defined by the ball bearing wheels 21, 2B, 29 and 30. From these wheels it continues to maintain approximately its curvature until it passes between the two ball bearing wheels 4| and 42. This arrangement of Wheels and their location with respect to the wire reel locates the wire 4 positively in the plane of its curvature so that it cannot rotate from this plane. This makes it possible for the two sets of ball bearing wheels 33, 34; 39, 40, to act on the wire in a single plane and to bend it in the opposite direction from its curvature and in the same plane as its curvature. The curvature in the wire is thereby removed by a single bending action produced by the last two sets of rollers so that the wire emerges from the device as straight wire. No unnecessary bending or gripping of the wire is required and the curvature is thus removed with the least possible expenditure of energy.

It is obvious from the foregoing that the head assembly 8 must be in proper location with respect to the wirereel 3, and that the device will vided in plate not operate'properly unless this relationship as described above is maintained.

The device as illustrated in Fig. 2 is arranged to operate with wire coiled so as to unwind from the coil when the wire reel turns counterclockwise as 'viewed from the top. Sometimes the wire coils are wound in the reverse direction, so that it is desirable to unwind the wire from the coil as the reel turns clockwise as viewed from the top. Therefore, provision has been made for reversing the arrangement of the plates I6, I2 and I3 as shown in Fig. 5. To facilitate ready and accurate locationof the relative position of plates I2 and I3, an additional hole 43 may be provided in plate I2 and an additional hole 44 may be pro- I3. When the plates I2 and I3 the reverse position as shown In 43 and 44 line up with the tapped have assumed Fig. 5 holes hole in bracket 9 at I5, so that screw I5 may be used to lock them in position. Therefore, to reverse the position of the head assembly 8 for the use of oppositely coiled wire it is only necessary to loosen nut II, remove screw I5, swing the plates around to the new position about the center of cap screw III, replace screw I5 through holes 43 and 44 and into the tapped hole in bracket 9, re-tighten nut II, loosen nut I8, and finally reverse the angle of plate IB'with respect to plate I2 and tighten nut I8.

It has been found that it is usually possiblefor commercial sizes of wire and commercial sizes of coils, to predetermine the angle between plate I3 and plate I2, so as to approximate an entering curvature between the ball bearing wheels and the curvature of the various wires used. In such a case, the screw I5 is used to locate the plate I3 at approximately the correct angle with plate I2. If a more accurate adjustment is required, screw I5 can be omitted, and the angle between plate I3 and plate I2 can be adjusted to any desired angle and then held in position by tightening nut II. This may be necessary in cases where the temper of the wire, size of the coil, or' size of the wire, are considerably difierent from the usual wire used. The angle of the axis of plate I6 with respect to the axis of plate I2 must be adjusted in each case so as to be just enough to remove the curvature from the wire completely and yet not give the wire a permanent curvature in the opposite direction. This is easily done as the wire through the various ball as indicated in Fig. 2', then pull on the end of the wire 4 until about one or two feet of wire extends from the rollers 33 and 34. If this extending wire is curved in the direction of the curvature of the wire on the coil, the plate I6 should be further set over until the correct angle with respect to plate I2 is obtained; alternatively, if thewire extending from beyond the ball bearing wheels 33 and 34 has a curvature in the opposite direction from the original curvature of the wire, sitely adjusted with respect to plate I 2. It is thus possible to determine in this simple manner the correct angle necessary to produce a wire having its curvature completely removed therefrom.

The foregoing description is given by way of illustration and not of limitation and it is therefore my intention that the invention be limited only by the appended claims or their equivalents wherein I have endeavored to claim broadly all inherent novelty.

I claim:

1. Device for removing curvature from a metallizing wire, feeding into a metal spray gun, said curvature being due to coiling of such wire, wflch comprises means for rotatably supporting a coil of wire, a first set of wire guide means comprising a multiple number of rotatable guide wheels adapted and positioned to define a wire guide orifice, and at least one pair of rotatable guide wheels adapted and positioned to guide said wire therebetween and, together with said orifice in a substantially fixed path of travel in approximation of said curvature, and a second set of wire guide means comprising at least two pairs of rotatable guide wheels adapted, and positionedto further' guide said wire between the wheel rims of each pair in a substantially fixed path of travel in a counter curvature direction substantially sufficient to straighten said wire, each of said pairs of guide wheels defining a wire guide space, the centers of all of said wire guide spaces being substantially in the same plane, with the center of said orifice, said means for rotatably supporting a coil of wire being adapted and positioned to permit feeding of said wire to and through said orifice substantially in said plane and in continuation of said curvature.

2. Device for removing curvature from a metallizing wire, feeding into a metal spray gun, said curvature being due to coiling of such wire, which comprises means for rotatably supporting a coil of wire, a center portion, a first end portion adiustably connected to one end of said center portion, a second end portion adjustably conwheels defining a wire guide space, the centers of all of said wire guide spaces being substantially in the same plane with the center of said orifice, said means for rotatably supporting a coil of wire being adapted and positioned to permit feeding of said wire to and through said orifice substantially in said plane and in continuation of said curvature.

3. Device in accordance with claim 2 in which said first end portion and said center portion carry means to bring the same into substantially fixed predetermined location with respect to each other.

4. Device for removing curvature from a metallizing wire, feeding into a metal spray gun, said curvature being due to the coiling of such wire beyond the limit of its elasticity, which comprises means for rotatably supporting a coil of wire, a first wire guide means defining a fixed path of travel for such wire, substantially the same as said curvature and substantially in the plane of said curvature and of said coil, and positioned with respect to said first mentioned means to receive said wire from said coil substantially in continuation of said curvature, and a second wire guide and bending means defining a substantialnected to the other end of said center portion, a

multiple number of rotatable guide wheels carried by said first end portion adjacent the free end thereof and positioned thereon to define a wire guide orifice, at least one'pair of rotatable rim channeled guide wheels carried by said second end portion adjacent the free end thereof, at least two pair of rim channeled guide wheels carried by said center portion, at least one near each end thereof, the pair of rim channeled guide wheels on said center portion nearest said first end portion and said orifice being positioned to guide said wire in a substantially fixed path of travel in approximate simulation of said curvature, the pair of rim channeled guide wheels on said center portion nearest said second end portion and said pair of rim channeled guide wheels adjacent the end of said second end portion being positioned to guide said wire in a substantially fixed path of travel in a counter curvature direction substantially sumcient to straighten said wire, each of said pairs of rim channeled guide ly fixed continuation of said path of travel of such wire in substantially the same plane in a counter-curvature direction and bending such wire sufilciently beyond its elastic limit to fixedly remove said curvature from said wire.

5. Device for removing curvature from 9. metallizing wire, feeding into a metal spray gun, said curvature being due to the coiling of such wire beyond the limit of elasticity thereof which comprises means for rotatably supporting a coil of wire, a first multiple number of wire guide means, positioned to define a first multiple number of wire guide spaces having their centers substantially along a curved line substantially the same as said curvature, and substantially in the plane thereof, and positioned with respect to said first mentioned means to receive said wire from said coil substantially in continuation of said curvature, and a second multiple number of wire guide means positioned to define a second multiple number of wire guide spaces having their centers in substantially the same plane substantially along a curved line extending in a counter-curvature direction for reversely bending said wire suf- Q ficiently beyond the elastic limit to fixedly remove the said curvature from said wire.

ARTHUR P. SHEPARD.

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