US 3378045 A
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Description (OCR text may contain errors)
April 15, 1i968 P. E. THURMAN 3,378,045
APPARATUS FOR PRODUCING HELICAL COILS Filed March 17, 1966 *razrl 2 INVENTOR.
United States Patent O 3,378,045 APPARATUS FOR PRODUCING HELICAL COILS Paul E. Thurman, Detroit, Mich., assignor to Hans Sickinger Co., West Bloomfield Township, Mich., a corporation of Michigan Filed Mar. 17, 1966, Ser. No. 535,155 7 Claims. (Cl. 14092.94)
This invention relates to the production of helical wire coils for binding together the sheets of writing pads, pamphlets, books or the like which are perforated along one edge of the sheets and covers.
It is an object of the invention to provide a novel and improved method and apparatus for producing such coils, which will enable the user to make various pitches of spirals with a single tool assembly. Thus it will be much less expensive for the manufacturer of spiral bound books and pamphlets to provide himself with equipment for making different types and sizes of binders.
It is another object to provide an apparatus of this character which is of a relatively simple and inexpensive nature, and is compatible with existing equipment for the manufacture of spiral binders.
The manner of accomplishing the foregoing objects and other objects and features of this invetnion will become apparent from the following description of embodiments of the invention when read with reference to the accompanying drawings, in which:
FIGURE 1 is a cross-sectional view in elevation of a supporting head for the tool, showing the tool in position and with the mandrel and wire therein;
FIGURE 2 is an enlarged view in elevation of the tool and mandrel, the mandrel being partly broken away from purposes of clarity, and
FIGURE 3 is a perspective view of the tool, the mandrel being removed.
Briey, the illustrated embodiment of the invention comprises a coiling tool of elongated shape having a mounting ange at one end. The main portion of the tool is roughly of semicylindrical shape, having a dat side with a recess extending therealong, and a convex side. The recess is flared, and adapted to receive a flared mandrel which is rotatably driven during use. The tool is also provided with a series of slots extending in from the at side thereof and deep enough to go beyond the bottom of the recess. These slots are parallel to each other and disposed at an angle equal to the average pitch of the coils to be produced. The width of the slots is considerably greater than the wire thickness.
In use, the wire will be threaded through the slots and around the mandrel, and the mandrel will then be rotated. This will cause the wire to be driven through successive slots, the wire passing around the mandrel on its open side. By varying the angle at which the wire enters the first slot, a considerable variation in the pitch of the coil can be produced.
It has -been found that the variations in pitch which can be produced with this construction, in which the mandrel is exposed and the wire unguarded around a substantial portion thereof, will be very much greater than the pitch variations which could be obtained with conventional tools, such as that shown in Patent No. 3,101,750, dated Aug. 27, 1963 and entitled Apparatus for Producing Helical Coils. The exact reason for this unexpected difference is not at present known to me but is believed to have something to do with the extent to which the wire is worked or deformed in the initial phases of its passage around the mandrel and through the slots of the tool.
lReferring more particularly to the drawings, the coiling tool is generally indicated at 11 and is adapted to ICC be mounted on one end of a stationary housing 12 of cylindrical shape. A pair of ball bearings 13 ad 14 are mounted within housing 12, and rotatably support a shaft 15 which is driven by means not shown. A mandrel 16 has a tapered end 17 mountable within a complementary recess 18 in shaft 15. :Mandrel 16 is removable from shaft 15 so as to be replaced by a mandrel of different size, and is ared in a forward direction. The purpose of this are is to insure proper release of the coiled wire from the mandrel in case it hits an obstruction, as described more fully in the aforementioned patent.
Tool 11 comprises a mounting portion 19 and a coiling portion 21, as seen in FIGURE 2. The coiling portion is of generally semicylindrical shape, with the mounting portion flaring outwardly therefrom at one end. Both portions have in common a at surface 22 which is interrupted by a forwardly ared concave recess 23 extending axially along the coiling portion 21, and a sharper rearwardly flared concave recess 24 in mounting portion 19, the latter recess terminating in a semicylindrical recess 25. A flange 26 extends outwardly from the convex side of mounting portion 19, and is adapted to be gripped by a fastening nut 27 threadably mounted on the outer end of housing 12, as seen at FIG. l.
The upper and lower surfaces, 28 and 29 respectively, of coiling portion 21 are ilat. A series of -transverse slots 29 are formed in coiling portion 21 of the tool, these slots being equidistantly spaced and parallel to each other, and penetrating surface 22 to a depth greater than the depth of recess 23. The inclination of slots 29 is equal to the average inclination of the coils to be formed by the tool. The width of slots 31, and their depth beyond the bottom of recess 23, are substantially greater than the thickness of the wire 32 which is to be formed into the spiral coil, for example, about three times greater. The bottoms of slots 31 are flat and parallel to surface 22. The distance between the slots is such that when wire 32 is coiled around mandrel 16, it will, with constant pitch, leave the bottom of each slot rand enter the top of the next slot, as seen in FIGURE 2.
Although the plane of surface 22 is a diametral one, ythat is, passing through the axis .of recess 23, this need not be so to accomplish the purposes of the invention. In other words, the portion of mandrel 16 which is surrounded by tool 11 could be slightly more or less than The flare angle of recess 23 is preferably the same as that of mandrel 16. The forward face 33 of tool 11 is at the same angle as slots 29. The intersections 34 of slots 31 with surface 22 are beveled, as seen best in FIG- URE 3.
In operation, :a guide indicated partially at 35 will be provided above tool 11 so that the lead angle of wire 32 may be varied. This guide may be shifted to the left or right as indicated by the double-ended arrow 36 in FIG- URE l, thereby shifting the feed angle of the wire as shown by the solid and dot-dash lines in FIGURE 2. The wire will be first manually threaded through slots 31 and around mandrel 16 until it is passed through all the slots.
Mandrel 16 will then be rotatably driven by shaft 15 in the direction of arrow 37 of FIGURE 2, the wire being formed into a spiral by its contact with the walls of slots 31. The spiral wire will be fed outwardly from tool 11 and through the perforations 38 in a pack of sheets 39.
By adjusting the position of guide 35, it will be possible to obtain various pitches of spirals without changing tool 11 on mandrel 16. In a typical example, it has been found that a tool body 11 with a slot pitch of five slots per inch can be used to produce a spiral with anywhere from four turns to six turns per inch. To produce live turns per inch, the wire would be fed at approximately the angle 3 shown in solid lines in FIGURE 2. To produce a coarser pitch, say four turns per inch, the angle of feed would be indicated by dot-dash position 32 of wire 32. On the other hand, .a production of a finer spiral pitch, for eX- arnple, six turns per inch, can be achieved by the feed angle indicated at 32".
While it will be apparent that the embodiment of the invention herein disclosed is well calculated to fulfill the Objects of the invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.
What is claimed is:
1. In a coiling tool construction for the production of spiral Wire binders, an elongated body having a coiling portion of generally semicylindrical shape, a mounting portion extending outwardly from one end of said coiling portion, a concave recess on one side of said body extending the entire length thereof, a rotatable mandrel Within said recess, the side of the mandrel facing away from said recess being exposed, and a series of parallel inclined slots in the coiling portion of said body extending inwardly from the side thereof having said recess and having a depth substantially greater than the depth of said recess, the width of said slots being substantially greater than the width of a wire to be formed into a spiral coil by said tool.
2. The combination according to claim 1, the side of said coiling tool with said recess having a surface in a diametral plane interrupted by the recess and said slots.
3. The combination according to claim 1, the said concave recess being outwardly flared toward the forward end of said coiling portion, said mandrel being provided with a corresponding flare.
4. The combination according to claim 2, said coiling portion having parallel sides at right angles to said surface, the intersections of said surface with said slots being beveled.
S. The combination according to claim 1, further provided with a guide adjacent said coiling tool and adjustable in the direction of the coiling tool axis, said Wire passing through said guide before entering the first slot of said coiling tool, whereby the angle of feed of said wire may be varied.
6. The combination according to claim 1, the distance between said slots being such that a spiral wire of constant pitch may leave the bottom of one slot and enter the top of the next slot adjacent said mandrel.
7. The combination according to claim 2, the bottoms of said slots being at and parallel to said diametral plane.
References Cited UNITED STATES PATENTS 3,101,750 8/1963 Pfae 14C-92.3
CHARLES W. LANHAM, Primary Examiner.
L. A. LARSON, Assistant Examiner.