Slitter Apparatus

In prior art slitting apparatus (insofar as applicant is aware) no means are provided to hold the tail end of scrap strip in position for easy attachment to the leading end of scrap strip from a subsequent coil of steel or other metal. Such tail end of the scrap strip thus dropped of its own accord and frequently became lodged in a very inaccessible location. Because the scrap strip is rather inflexible and sometimes has razor-like edges, handling thereof is difficult and hazardous and thoroughly disliked by the slitter operator.

Through use of my invention, the tail end of the scrap strip is held in a predetermined position so that the leading end of scrap strip from a subsequent steel coil may be easily attached to it, and welded thereto, with a minimum of handling.

In the drawings acompanying this specification and forming a part of this application there is shown, for purpose of illustration, an embodiment which my invention may assume, and in these drawings:

FIG. 1 is a schematic side elevational representation of the prior art as known by applicant,

FIG. 2 is a schematic side elevational representation of a slitter line embodying my invention,

FIG. 3 is a schematic top plan view of the construction shown in FIG. 2, the scrap strips being shown diverging from the slit sheet for purpose of clarity of illustration,

FIG. 4 is an enlarged, fragmentary side elevational view of apparatus designed to carry out my invention, and

FIG. 5 is a fragmentary sectional view corresponding to the line 5--5 of FIG. 4, with the view turned to illustrate horizontal disposition of the structure.

Warehousing of steel is big business because a steel fabricator need not carry an inventory of strip in various widths, but may order from a warehouse a supply of strip of the exact width and the exact amount for a known order.

The warehouser, on the other hand, carries an inventory of wide coils which are slit to the size required by the fabricator. In a known form of slitting (and therefore not particularly illustrated herein) wide coils of strip are loaded into a ramp from which they are permitted to roll, as required, onto a charging buggy which moves the coils to the payoff reel of the slitting machine. The buggy is provided with an elevator by which it is possible to center the coil on the reel before the retaining bands on the coil are removed. Instead of the buggy, a traveling crane may be used to position the coil on the reel. The reel, which is motor driven, is rotated to slowly unwind the strip which is threaded into a set of breaker rolls that flatten it sufficiently to facilitate threading through pinch rolls and into the slitter knives. These knives, which may take the form of tool-steel discs, are mounted on arbors above and below the strip and are spaced with rings to slit to the desired width. From the slitter, the trimmed strip passes to the recoiler and is wound thereon. The narrow strips of scrap trimmed from the edges of the wide strip are wound on scrap winders. After the leading end of the strip has been threaded completely through the line, the recoiler and slitter motors are adjusted to pull the strip through the slitter knives with any desired tension.

FIG. 1 discloses, in diagrammatic fashion, the slitter knives, K, Kl operating on the strip from a wide coil (not shown). The trimmed strip St is shown as being wound on the mandrel of a recoiler R of any known construction. The scrap strips Sr which have been slit from the opposite ends of the wide coil are shown being wound on respective scrap winders Sw. If the slit strip is not too wide, the scrap removed from both ends of the wide coil may be wound on a single scrap winder; otherwise, winders may be provided for each strip of scrap. In the prior art, when the tail end of the wide coil passes through the slitter, the trailing end of each of the scrap strips Sr no longer have any support and such strip falls haphazardly to a position beneath the floor line F, as suggested in the dot-dash lines in FIG. 1. It will be appreciated that a workman will have a difficult time in bringing the trailing end of the strap strip up to the leading end of the scrap removed from a subsequent coil, for the purpose of attaching such trailing and leading ends.

My invention overcomes the difficulties above-noted and is diagrammatically illustrated in FIGS. 2 and 3. As before, the wide strip S is pulled through the slitter knives K, Kl and the trimmed strip St is wound on the mandrel of a recoiler R. The scrap strips Sr in this case pass around respective rolls 10, are guided laterally by pairs of spaced rolls 11--11 and then are wound on scrap winders Sw. FIG. 3 shows the scrap strips diverging in a direction away from the trimmed strip but this is only to show the various parts in uncovered relation. Actually, since the scrap strips Sr move downwardly from the trimmed strip St, there is sufficient clearance for the scrap strips to move parallel to the trimmed strip.

Just before the trailing end of the wide coil passes through the slitter knives, a shoe 12 is pressed against the roll 10 to clamp the scrap strip therebetween and thus halt any further longitudinal movement of the scrap strip. Then, when the trailing end of the wide coil finally passes through the slitter knives, the scrap strips will not fall into the pit 14 beneath the floor line F, but rather will be supported in an upright position by leaning against adjoining parts of the slitter housing, as shown in the dot-dash lines in FIG. 2, so that the ends of the scrap strips are positioned near the slitter rolls in handy position for connection to the leading end of the scrap strips from a subsequent wide coil, and ultimate stitch-weld connection thereto. The shoes 12 may thereafter be retracted from the respective rolls, and the slitter line restarted.

FIGS. 4 and 5 disclose a preferred form of structure for carrying out the improved method of my invention. A pair of vertical posts 15--15, which may be formed as steel tubing having a rectangular cross section, are firmly anchored to the factory foundation and/or fractory framework in spaced-apart relation, a spacing of about six feet (about twenty two centimeters) apart having been found suitable for most purposes.

A support pad 16 is secured to each post 15 to extend forwardly thereof, each pad supporting horizontally-extending upper and lower metal tubes 17 and 18. The posts, pads and tubes are preferably welded together to form a very rigid support structure. A pair of guide and clamp bodies 20 are mounted on the tubes 17 and 18 for horizontal movement therealong. Each body is a fabrication and includes a flat guide portion 21 having sliding engagement with a slide bar 22 which is fixed to the upper surface of the upper tube 17 and extends the length thereof. A gib 23 holds the guide portion 21 and slide 22 against vertical separation.

Each body 20 also includes a pair of spaced gusset plates 25--25 which are welded to the flat guide portion. The plates support a shaft 26 therebetween, on which is rotatably mounted a previously-mentioned roll 10. Each of the rolls 10 has a hardened portion to withstand wear caused by contact with the scrap strip Sr passing therearound.

Bars 27 are welded crosswise of the plates 25 to support bearings 28 in which the shafts of the spaced rolls 11--11 are supported. As shown in FIG. 5. the rolls are spaced a distance "x" which, for all practical purposes, is equal to three inches (about 7.6 centimeters). As will be evident from FIGS. 4 and 5, the scrap strip Sr extends downwardly from the slitter rolls and passes under the roll 10 and through the rolls 11--11 on its way to the scrap winder.

A flat slide bar 30 is fixed to the lower tube 18 and extends the length thereof. A slide plate 31 is welded across the gusset plates 25--25 and has a flat slide surface engaging a like surface on the bar 30. A gib 32 holds the bar 30 and slide plate 31 against lateral separation.

A shaft 33 is mounted between the outer extremities of the gusset plates. A boss 34 is rotatably mounted on the shaft 33 and a flat arm 35 is welded to and extends from the boss. As best seen in FIG. 4, the free end of the arm has a shoe 12 welded to it, the shoe having an arcuate surface complementary to the curvature of that portion of the scrap strip Sr which passes around the roll 10. The shoe 12 is also hardened to withstand wear.

Mounted on a platform 37 which is welded in position between the gusset plates 25--25 is an air bag 38 which is interposed between the platform 37 and the arm 35 and is operable, when air under pressure is admitted to the interior of the bag, to firmly press the shoe 12 against that portion of the scrap strip Sr at the roll 10, and thus clamp the strip against movement. The air bag may be of the type designated as Firestone Airstroke, Model 116. A valve (not shown) may be operated by a control on the operator's console, to cause air flow to the bag. The valve may also provide for exhaust of air from the bag, so that the latter will assume its unextended shape to cause withdrawal of the shoe 12 from engagement with the strip.

It will be appreciated that each of the bodies 20 may be slid lengthwise of the upper and lower tubes 17 and 18 to a selected horizontal position, the slide bars 22 and 30 providing for this movement. Secured to a longitudinal edge of the slide bar 22 is a gear rack 40 which extends for almost the entire length of the slide bar. A vertical shaft 41 is mounted in bearings carried by each body 20 and a gear 42 is fixed to the inner end of the shaft for meshing engagement with the rack 40. The outer end of the shaft 41 is squared, as shown at 43, to detachably receive a handle 44 (shown in dot-dash lines in FIG. 4).

To set up the apparatus for a slitting operation, a workman will move each of the bodies 20--20 horizontally along the tubes 17 and 18, to a position wherein the pass between the rolls 11--11 of each body will be lined up with the path of scrap movement. Movement of each body is effected by rotation of the handle 44 to rotate the gear 42 along the fixed rack 40. Wide strip S will then be fed into the slitter knives K, Kl. The leading end of the trimmed strip St will be secured to the arbor of the recoiler R and the leading ends of the scrap strips Sr will be threaded between a respective roll 10 and shoe 12, and then between the roll pairs 11--11 and thereafter attached to the arbor of the scrap winder.

When the trailing end of the wide strip nears the slitter knives, but has not yet passed through the knives, the machine operator actuates the valve control at his console to admit air under pressure to both air bags 38 so that the latter move their respective arms 35 to firmly press the shoes 12 against the scrap strip in the pass between the shoe and the roll 10 to firmly clamp that part of the scrap strip against linear movement. When the tail end of the wide strip S passes through the slitter knives, the tail end of both strips of scrap will remain in an upright position, such for example as shown in dot-dash lines in FIG. 2.

Thereafter, another coil of wide strip S may be placed on the uncoiler reel and threaded through the slitter knives. When sufficient strip has been trimmed by the slitter knives to provide a workable leading end of scrap strip, this leading end is clamped to the trailing end of the preceding scrap strip and the two ends are stitch-welded. Air is then exhausted from the air bags 38 to release the scrap strip and the slitting line is actuated for normal operation. It will be understood the leading end of the trimmed strip St will be attached to the arbor of the recoiler R (or in some cases to the trailing end of the strip already wound in the recoiler) before full slitting operation is resumed.