US2390139A

US2390139A - Lead wire threading machine

Info

Publication number: US2390139A
Application number: US448742A
Authority: US
Inventors: Anthony J Vasselli
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1942-06-27
Filing date: 1942-06-27
Publication date: 1945-12-04
Anticipated expiration: 1962-12-04

Description

Dec. 4, 1945. J V ELL. 2,390,139

LEAD WIRE THREADING MACHINE Filed June 27, 1942 2 Sheets-Sheet 1 9 INVENTOR.

Anthony J Vasselh;

Dec. 4, 1945. A J VASSELU 2,390,139

LEAD WIRE THREADING MACHINE Fiiea June 27, 1942 2 Sheets-Sheet 2 INVE TOR.

Anfhorzy d. assellb.

ATT E] R NEYI Patented Dec. 4, 1945 LEAD WIRE THREADING MACHINE Anthony J. Vasselli, Newark, N. J., assignor to Radio Corporation of America, a corporation of Delaware Application June 27, 1942, Serial No. 448,742

14 Claims.

My invention relates to machines for threading or guiding lead-in conductors. or wires of the envelope of radio tubes and the. like into hollow contact pins on the base of the envelope.

The final operation in the manufacture of many electrical devices having a number of lead-in conductors connected to contact pins on a base element,'such as radio tubes, comprises threading the conductors into and through the center of the tubular contact pins, and soldering the outer ends of the pins and conductors. Because the conductors are usually long, slender and quite springy, it has heretofore not been feasible to thread the conductors into the pins by machine, and threading has been performed by hand. In hand threading, one lead at a time is straightened and guided into its pin.

An object of my invention is a machinev that will guide lead-in wires into contact pins on the base of the envelope of radio tubes and the like.

Another object of my invention is an improved method of threading lead-in wires into contact plIlS.

The characteristic features of my invention are defined in the appended. claims and one embodiment thereof is described. in the following specification and shown in the accompany drawings in which Figure 1 is a plan view, partly in section, of my improved base threading machine,

Figure 2 is a sectional view of my machine taken along line 2-2 of Figure 1,

Figures 3, 4, 5, 7 and 9 are end views of an envelope and show essential, successive steps in the threading of a base on my improved machine.

Figures 6 and 8 are side views, respectively, of Figures and 7,

Figure 10 is a cross sectional view of the tube guiding means and is taken along line Ill-I0 of Figure 2, and

Figure 11 is a schematic view of the wire straightening means of my invention.

The particular envelope l and base 2 chosen for illustrating my improved base threading machine and its.operation, is for the so-called' allmetal tube and comprises an insulating wafer or disc carrying a number of parallel hollow contact pins 3, preferably arranged in a circle. The envelope is cylindrical and the lead-in conductors or wires 4 pass through a glass header 5. in one end of the envelope. The points at which the wires enter the header preferably lie in a circle, which in the particular tube illustrated is concentric with and slightly smaller in diameter than the circle in which the contact pins are arranged. It is a comparatively simple operation to pull kinks out of the wires and cut them to a uniform length, but because of the length and slenderness of the wires they cannot be made to stand perpendicular to the header, and the outer ends of the wires will move to random positions. Automatic machines have not as yet been devised for finding the ends of the wires and guiding them into the small openings in the contact pins. The only point on the lead, which is predetermined and which can be "found is at the base of the wire where it is molded into the header. According to my invention each of the wires is first engaged near its base by a hook'li. Each hook is carried on radially slidable fingers 1, and is moved outwardly to give the wires a set at an angle approximately 30 with the axis of the tube, so that when the finger is then moved inwardly it must work against the natural springiness caused by the set in the wire. A crotch or V slot 8 is made in the finger opposite the hook 6. After the wires are given an outward set, the tube is moved lengthwise, away from the fingers, to bring the fingers near the ends of the wire, whereupon the fingers are moved radially inward to bring the crotch 8. exactly to the base pin circle on which the contact pins are arranged. Wires lying in the crotches, hence, are effectively held on the pin circle, and by simple rotational orientation of the base over the ends of the wires. the wires can all be shoved simultaneously into the pins.

The guide for moving the envelope along the center line of the envelope and perpendicular to the base preferably comprises a bracket 9 attached to the bottom of the frame of the machine and having V ways. l0 extending perpendicular to the plane of the fingers. A step II in the ways accommodates the large flange at the end of the envelope andv conveniently serves as a lower stop for the envelope to measure the length of the wires and insure engagement of the fingers with the ends ofthe wires.

The successive. positions of one of the fingers with its crotch and hook are shown respectively inv Figures 3 to 9, inclusive. The envelope, with the wires standing in random positions about the exhaust tube, is placed against its guide and moved to the upper or dotted line position shown in Figures 2 and 3. The fingers are then moved inwardly and the tube rotated slightly to engage the lower ends of the wires with the fingers as shown in Figure 4. The fingers then move outwardly as shown in Figures 5 and 6 to bend the wire through a sufficiently large angle to workharden and set the wire. Soft or annealed held in a circle equal in diameter to the diameter of the base pin circle. Shoulders 12 on the fingers in this position are, as shown in broken lines in Figure 2, so made as to guide the base over the envelope and center the contact pin circle over the circle of the ends of the wires. The base may be rotated slightly to bring the pins and wires into alignment or registry, the particular rotational position of the base being determined visually with index marks or mechanically by notches and the like. While the base is held down the tube is pushed up and lead wires enter and pass through the base pin holes. A slight outward movement of the fingers accompanied by a slight turn of the envelope disengages the hooks from the lead wires so that the fingers may be retracted and the threaded tube and base re-- moved.

The fingers I preferably travel on a line extending through the center line of the envelope, but could. if desired. be made to move along lines tan ential to the pincircle or to a circle larger or smal er than the pin ircle. As shown in Figure 1, the fingers are radia ly slidable in grooves in a metal annulus l3. The fin ers are biased inwardly by sprin s M and their movement is conveniently controlled in unison by a cam rin l5 having inclined cam s ots l6 enga ing pins I! on the fin ers. As the cam ring rotates the pins move inwardly or outwardly in synchronism. The cam slots may, if desired, have a step [8 upon which the pin I! may rest to position the fingers in the wire threading position-of Figure 6. The cam ring is biased in one direction by a spring l9 attached at one end to a bracket on the annulus I3 and attached at its other end by a screw to the cam ring. The bias is preferably applied to normally ho d the fingers in their outermost position as shown in Figure 1. A foot treadle may be connected to the cam ring through a pull chain 2i to rotate the cam ring and move the fingers inwardly.

The envelo e usual y arrives at the base threading stage with leads badly twisted, matted,

kinked and bent, and before threading can begin I the leads must be straightened and cut to the proper length. Various mechanical fingers and combs for untangling and straightening the wires have been unsuccessfully tried.

I propose, according to another feature of my invention, to slidably grip the ends of the wires between the toothed drums of a wringer and pull them straight. While the wires are tautened they all may be cut to length by shears. As shown in the Figure 11 the leads are passed through the Opening 29 in the face plate 2|, between the cutting blades 22 and 23 and into the rounded teeth 24 on the two drums 25 and 26. The teeth are widely spaced and the circle of rotation of the teeth overlap only enough to slidably grip the wires between the points of the teeth. As the teeth pull the wires the envelope is drawn against the face plate with considerable force and moves the plate against the stop 21. The drums are geared together at their ends so that the teeth of the two drums run in spaced relation, and one of the drums is eccentrically journalled so that it may be moved toward or away from the other drum. The spacing between the teeth of the two drums is easily adjusted with relation to the thickness and stifiness of the wires, so that the wires will be pulled straight without breaking. When the drums are driven at a speed of-say 350 R. P. M., the wires inserted through the face plate are caught by the teeth and straightened almost instantaneously. The cut-off shears for the wires may be manually operated or may be automatically actuated as by the magnet 28. The magnet winding is energized from the source 29 connected by a switch 30 which is closed by the face plate. The operator picks up an envelope with say her left hand, bunches the wires so they will pass through the face plate hole and into the drums. The wires are straightened and cut off, whereupon the envelope with the straightened wires is placed against the guide I0 and threading of the base proceeds as explained above.

Good results have been obtained in threading the lead wires into the base pins of so-called all-metal radio tubes of which the types commercially known as the 6K7 or the 6J7 are common. These tubes have an envelope about one inch in diameter and have eight copper leads about .015 inch in diameter andtwo inches long extending from the header of the tube. An operator can consistently thread the bases of 450 to 500 tubes per hour with my base threading machine, whereas the same operator can thread no more than 300 per hour by hand. My improved base threading machine is inexpensive to make and is easy to operate.

The feature disclosed in. this application of straightening the wires by pulling them by means of toothed drums is claimed in an application in the name of Anthony J. Vasselli, entitled Lead. wire straightening machine, Serial No. 612,163, filed August 23, 1945, as a continuation-in-part of this application.

I claim:

. l. The method of threading a plurality of lead wires of an envelope into hollow contact pins circularly arranged on a base of the envelope, comprising straightening the lead wires, hooking each wire near its end adjacent the envelope and bending the wires radially outward at an angle to the plane of the envelope from which the wires emerge, then pushing the wires adjacent their outer ends int a position in registry with the hollow contact pins and finally moving said envelope and base together to pass the wires into the pins.

2. The method of threading a plurality of lead-in wires of an envelope into hollow contact pins arranged on a base for the envelope, comprising stretching the wires to straighten the wires, hooking simultaneously each wire adjacent the envelope and bending each wire adjacent the envelope, then reverse bending each wire by pushing its outerend into a position in registry with the opening of its contact pin, and pushing the wires into the pins.

3. The method of threading a plurality of lead-in wires of an envelope into hollow contact pins arranged on a base for the envelope, comprising guiding the envelope along a line parallel to the center line of the envelope and parallel to the. holes in the pins to be threaded, engaging each wire near the envelope and bending the wire outwardly at an angle to the center line of the envelope, said bend being sufficient to workaaoonaa Q push the wires into the pins.

4; A machine for threading a plurality'oileadin wires of an envelope into hollow contact pins on a base for the envelope comprising an annulus, a plurality of radially slidable fingers in said annulus, means for simultaneously moving all of said fingers radially, a blade at the inner ends of each finger, each blade having a hook and an opposed crotch, and a guide-for holding said envelope n a line normal to the'pl'ane'of said blades.

5, The method of threading into a pluralitycf definitely spaced apertures in a base a plurality of lead wires of an electrical device having an end member from which the lead wires project in definite spaced relation different from the spacing of the apertures in the base which comprises bending the lead wires near the end member to work harden and set the lead wires with their ends spaced differently than the spacing of the apertures of the base, bending the set wires back to positions where the spaced relation of the outer ends of the lead wires corresponds to the spaced relation of the apertures in the base, and moving the base and the electrical device relatively to each other to insert the lead wires in the a ertures of the base.

6. The method of threading a plurality of lead wires of an electrical device having a fiat end member with lead wires projecting alongside an axis perpendicular to said end member through a base having a fiat portion with a plurality of apertures in spaced relation which comprises engaging the lead wires near the end member and bending them away from said axis intopositions wherev the spacing of the ends of the leads is greater than the spacing of the apertures in the base, engaging the lead wires at points more remote from said end member and pushing them back to positions where the spaced relation of the outer ends of the lead wires corresponds to the spaced relation of the apertures in the base, and moving the base and the electrical device toward each other to insert each lead wire in a corresponding aperture of the base.

7. The method of threading into parallel hollow contact pins arranged in a circle on a base, a plurality of lead wires of an electrical device having an end member in which the lead wires are arranged in a smaller circle and projectin from said end member which comprises bending the lead wires outwardly from the center of said smaller circle and near the end member sufficiently to work harden and set the lead wires, positioning the outer ends of the lead wires in spaced relation corresponding to the spaced relation of the hollow contacts of the base, aligning the spaced outer ends of the lead wireswith the corresponding hollow contacts of the base, and moving the base and the electrical device toward each other lengthwise of the set lead wires to insert the lead wires in the hollow contacts.

8. A machine for threading through a base having a plurality of definitely spaced apertures a plurality of lead wires of an electrical device having an end member from which the lead wires project in definite spaced relation comprising guiding means for holding the device coaxial with and slidable along the longitudinal axis of the guiding means, wire setting mechanism comprising a finger mounted to reciprocate transverselyof the longitudinalaxis of saidguid ing means and having an undercut sideslot wider than a lead wire, actuating" mechanism for moving' the finger in one-direction to-place said slot further from the-axis'of the guiding means than the corresponding aperture of the base in said holder and in the other direction to substantially align the end of said slot with the corresponding aperture in the base, and a stop on said guiding means for-positioning at will a device in said guiding means with the end portion of a leadwi're-in-theplane of movement of said finger.

9-. A machine for threadingthrough a base having a plurality of definitely'spaced apertures a; plurality" of lead wires of an electrical device having an end member from which the lead wires project in definite spaced relation comprising a guide for holding the device with the lead wires projecting in the direction of the longitudinal axis of the guide, wire setting mechanism comprising a plurality of fingers mounted to reciprocate transversely of the longitudinal axis of said guide, each of said fingers having means for engaging a lead wire, and actuating mechanism for moving the fingers outwardly and away from the .axis of said guide a distance greater than the spacing of the leads in said end member and inwardly and toward each other to space the ends of said slots to correspond to the spacing of the apertures in the base.

10. Means for threading the lead wires of an electrical device having an envelope'with lead wires extending from an end member thereof into a base having spaced apertures comprising an envelope guide for slidably supporting the envelope with the lead wires projecting lengthwise of said guide, base guiding means for positioning a base in substantial alignment with an envelope in said envelope guide, fingers movable transversely of the lead wires for engaging the lead wires and bending them back and forth transversely of the envelope by movement of said fingers, and actuating means for moving said fingers to bend said lead wires outwardly and then bending them back to set them with their free ends in registry with the apertures in the base.

11. Apparatus for positioning in predetermined spaced relation a plurality of lead-in wires which project side by side from the wall of an envelope comprising a guide for holding the envelope with its leading-in wires extending in the same direction as the longitudinal axis of said guide, means for engaging each wire at a point adjacent the envelope in said guide and bending the wire away from said axis of said guide in one direction sufiiciently to work harden the wire adjacent the envelope, and means for pushing the outer ends of the wires in the opposite direction toward said axis of said guide to set the ends of said wires in a space relation corresponding to the spaced arrangement of contact pins on a base for the envelope.

12. A machine for threading into spaced hollow contact pins a plurality of lead-in wires projecting side by side from the wall of an envelope comprising a guide for holding an envelope with its projecting lead wires substantially parallel to the longitudinal axis of said guide, means for bending the wires of an envelope in said guide away from said axis of said guide into a position at a suificient angle to said axis to work harden said wires at the bends and means for moving the outer ends of said wires back into a spaced relation corresponding to the spaced relation of said contact pins for insertion of said wires into said hollow contact pins. y l

13. Means for positioning lead wires of a bulb for insertion into symmetrically spaced contacts comprising a guide for supporting a bulb with its. lead wires projecting alongside the longitudinal axis of said guide, wire positioning members movable back and forth transversely of the longitudinal axis of said guide for engaging said wires near the wall of a bulb in said guide, and actuating means for moving said members back and forth to work'harden said wires by bendingsaid wires back and forth near the wall of the bulb, and to position said wires with their free ends in spaced relation corresponding to the spaced relation of said contacts.

14. A machine for threading a plurality of lead-in wires of an envelope into hollow contact pins arranged in a circle on a base for the envelope, comprising a way for slidabl guiding the envelope along its longitudinal center line and parallel to the holes in the pins to be threaded, a finger slidable perpendicularly to said line and having a hook for engaging one ofsaid wires near the envelope, actuating means for moving said finger with its hook engaged wire laterally away from said line to outwardly bend and set the wire and for also moving said finger with its hook inwardly against the set of the wire to push the wire into an upstanding the endsvof the wires in a circle corresponding to the circle in which the hollow contact pins are arranged, and means for guiding the base to bring the hollow ends of the pins into registry with the ends of the wires.

ANTHONY J. VASSELLI.