US3114400A - Wire straightening apparatus - Google Patents

Description

Dec. 17, 1963 J. o. HINKLE IETAL 3,

WIRE STRAIGHTENING APPARATUS Filed June 30, 1961 2 Sheets-Sheet 1 W In Dec. 17, 1963 J. o. HINKLE. ETAL 3,114,400

v WIRE smrcnmumc APPARATUS Filed June 30, 1961 r 2 Sheets-Sheet 2 United States Patent York Filed June 30, 1961, Ser. No. 121,035 3 Claims. (Cl. 140147) This invention relates to the straightening of elongated objects, and more particularly to a novel apparatus for insuring thte straightness of fine wires eventually bent to an S configuration and used in point contact diodes.

Difficulty has been encountered with deviation of the fine tungsten wires used in point contact diodes, after the S bend has been formed therein, from the eye plane (a plane including the axis of the pin assembly upon which the wire is mounted, as by soldering), and thereason for such deviation has been determined to reside in deviation of the wire from a position coincident with the axis of the pin assembly prior to the formation of the S bend therein. Further, such deviation of the S bent wire from this eye plane has been discovered to promote skidding of the wire across the surface of the semi-conductor body against which one end of the wire bears in the completed diode assembly, resulting in undesirable scratching of such surface and attendant high reverse currents during test operation of the diode necessitating rejection thereof as unsatisfactory.

It is, accordingly, an object of this invention to effect the straightening of elongated objects, such as fine tungsten wires, in the manner more fully set forth hereinbelow.

Another object of the invention is to enable the straightening of such objects to be achieved rapidly and automatically and as an integrated step in the operation of a diode wire soldering and S bend machine.

A further object of the invention is to eliminate the above-mentioned undesirable high reverse currents in the performance of the completed diode by insuring the straightness of the fine tungsten wires prior to the formation of the S bend therein.

The invention generally comprises a straightening means which is automatically positioned into engagement with the wire, to deflect the wire to a slight degree, simultaneously with the automatic positioning of a rotating drive means into engagement with the rotatable holding means in which the pin assembly is supported, thus efiecting the rotation of the wire while in a slightly deflected position against the surface of such straightening means. Upon the automatic withdrawal of the straightening means and rotating drive means, the wire springs back to a straight position coincident with the axis of the pin assembly upon which same is mounted.

The invention and the advantages thereof may be more readily understood by reference to the accompanying drawings, wherein:

FIG. 1 is a side plan view, partially in section, showing the straightening apparatus of the present invention; and

FIG. 2 is an end view, partially broken away, showing the driving wheel.

Referring now to FIGS. 1 and 2, the spin station subassembly, generally indicated at 50, is seen to be positioned adjacent to the periphery and upper and lower faces of a rotatable work support table 1, which table is indexed to the various stations during operation of the wire soldering and S bend machine. Spindle housing 2 is mounted on the upper face of the work support table and secured thereto through mounting element 51 by bolt 52. A pin assembly holding spindle 53 is rotatably mounted in the spindle housing and includes a knurled, annular drive surface 54 formed at the lower end thereof.

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Diode pin assembly 3, which includes the tungsten wire 4, is fixedly supported within this rotatable spindle.

Mounted beneath the work support table on main frame member 5, almost directly below the spindle housing 2, a double acting air cylinder 6 having air inlets 7 and 8 and a piston rod extension 9.

Motor support plate 12 is connected to the end of the piston rod extension and movable therewith, and to this efiect is slidably mounted within support members 11 and 15 in the manner shown at 13 in FIG. 2. Electric motor 16 is mounted on the support plate 12 and secured thereto by bolts 18. Straightening finger support members 19, 21, and 22 and guard 23 are mounted on the motor in the manner depicted. Straightening finger 24 is mounted atop straightening support member 22 and attached thereto by bolts 26.

Electric motor 16 is seen to further comprise power transmission means housing 27 from which projects power shaft 30. Driving wheel 28 is mounted upon such shaft as shown and secured thereto by pin 29. Rubber 0 ring 31 is positioned around the periphery of the driving wheel and secured thereto in any convenient manner, as for example, by a stretch fit or adhesive bond.

Operation Upon the completion of the wire soldering step at a previous station, the work support table 1 is automatically indexed to the position depicted in FIGS. 1 and 2. Once the table has assumed such position, control means, not shown, eifect the supply of compressed air to air cylinder inlet 8, thus shifting the motor 16 and'straightening finger 24 to the position depicted in FIG. 1 wherein the rubber O ring 31 is seen to be in frictional driving engagement with the knurled spindle drive surface 54 and the straightening finger in engagement with tungsten wire 4.

The driving engagement between the rotating 0 ring and the rotatable spindle results in rotation of the latter with attendant rotation of the tungsten wire, in a deflected position, against the surface of the straightening finger. Upon the expiration of a predetermined period of time (approximately 1.5 seconds), control means, not shown, effect the supply of compressed air to air cylinder inlet 7 to shift the motor 16 and straightening finger 24 to the right in FIG. 1 to remove the rubber O ring from engagement with the spindle drive surface and the straightening finger from engagement with the wire.

It is to be noted that if the wire is straight prior to the operation of the instant device, he deflection occasioned by contact with the straightening finger will be within the elastic range, that is to say the wire will be deflected slightly but spring back to its original straight position once the straightening finger has been withdrawn. If, however, the wire is not straight originally, as is the more probable circumstance, the deflection occasioned by the contact with the straightening finger will extend the wire past the elastic limit into the plastic range so that some measure of permanent deformation (that necessary to substantial straightness of the wire) will occur thus insuring that the wire springs back to a straight position, which straight position is, of course, different from that which it occupied prior to the deflection by the straightening finger.

Various changes and modifications may obviously be made in the disclosed embodiment without departing from the spirit and scope of the invention.

What is claimed is:

1. In an apparatus for straightening an elongated object, a work support table, a holding chuck rotatably mounted upon said work support table for holding the object, a motor assembly including friction drive means and a straightening finger mounted adjacent said rotata- Patented Dec. 17, 1963.

e") ble holding chuck, said straightening finger comprising a deflecting surface of significantly lesser extent than the object as measured along the axis of the latter and said motor assembly being slidable in a direction substantially perpendicular to said axis to at least two positions in one of which the friction drive means are in driving engagement with the holding chuck to effect rotation of the object about its longitudinal axis and the deflecting surface is in engagement with the elongated object to effect deflection thereof and in the other of which no such engagements occur, and positioning means connected to the motor assembly and operative to selectively position the said assembly in either of the two said positions.

2. A device for straightening elongated objects comprising a rotatable holder including a chuck for holding an elongated object to be straightened and having a driven member connected thereto, an assembly mounted adjacent the holder and including a straightening finger for deflecting the elongated object and a driving member for drivingly engaging the driven member, and means for causing relative movement between the assembly and the holder in one direction to cause the finger to engage the elongated object and effect the deflection thereof while simultaneously causing the engagement of the driven and driving members to effect the rotation of the elongated object and in the opposite direction to move the finger away from the elongated object causing disengagement of the driving and driven members.

3. A device for straightening elongated objects comprising a rotatable holder including a chuck at one end thereof for holding a wire to be straightened and a circular driven member connected to the chuck at the opposite end thereof, a slidable assembly mounted adjacent the holder and including a straightening finger for deflecting the wire and a circular friction driving member for drivingly engaging the driven member, and means for sliding the assembly in one direction to cause the finger to engage the wire and effect the deflection thereof and simultaneously cause the engagement of the driven and driving members to effect the rotation of the wire and for sliding the assembly in the opposite direction to move the finger away from the wire and to cause disengagement of the driving and driven members.

References Cited in the file of this patent UNITED STATES PATENTS 331,386 Eames Dec. 1, 1885 934,429 Davies Sept. 21, 1909 2,120,877 Uber June 14, 1938 2,389,885 Anderson Nov. 27, 1945 2,505,924 Varga May 2, 1950 2,964,087 Riese Dec. 13, 1960

Claims (1)

1. 2. A DEVICE FOR STRAIGHTENING ELONGATED OBJECTS COMPRISING A ROTATABLE HOLDER INCLUDING A CHUCK FOR HOLDING AN ELONGATED OBJECT TO BE STRAIGHTENED AND HAVING A DRIVEN MEMBER CONNECTED THERETO, AN ASSEMBLY MOUNTED ADJACENT THE HOLDER AND INCLUDING A STRAIGHTENING FINGER FOR DEFLECTING THE ELONGATED OBJECT AND A DRIVING MEMBER FOR DRIVINGLY ENGAGING THE DRIVEN MEMBER, AND MEANS FOR CAUSING RELATIVE MOVEMENT BETWEEN THE ASSEMBLY AND THE HOLDER IN ONE DIRECTION TO CAUSE THE FINGER TO ENGAGE THE ELONGATED OBJECT AND EFFECT THE DEFLECTION THEREOF WHILE SIMULTANEOUSLY CAUSING THE ENGAGEMENT OF THE DRIVEN AND DRIVING MEMBERS TO EFFECT THE ROTATION OF THE ELONGATED OBJECT AND IN THE OPPOSITE DIRECTION TO MOVE THE FINGER AWAY FROM THE ELONGATED OBJECT CAUSING DISENGAGEMENT OF THE DRIVING AND DRIVEN MEMBERS.

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