US3699630A - System for ordered dispensing of wire and the like - Google Patents

[52] US. Cl ..29/203 MW [51] ..

H05k

3/32 [58] Field of Search.....29/203 MW, 203 B, 203 R, 203

35 Claims, 8 Drawing Figures

PATENTEDum

24

I972 SHEET

3 BF 4 SYSTEM FOR ORDERED DISPENSING OF WIRE AND THE LIKE BACKGROUND OF THE INVENTION Automatic assembly of electronic equipment has progressed substantially with technology advancements in microelectronics including integrated circuit systems. Several types of automatic wiring machines have been developed and are in extensive use to provide circuit interconnections between circuits, e.g., printed circuit boards, mounted on circuit panel boards. These interconnections are made between rows of terminal pins projecting from one side of the panel board to provide power and signal distribution to circuits mounted on the other side of the panel board. Because of the greater efficiency and accuracy of these machines over other methods of making extensive wire interconnections required for complex electronic equipment, these wiring machines provide a substantial advantage in production of electronic equipment.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, FIG. 1 shows the system of the preferred embodiment of the invention comprising a dual arrangement of wire dispensing heads 10 mounted on opposite ends of ahead positioning

carriage

13 including a

boom

14 which is made operative to move the heads 10 to automatically dispense

individual wires

16 along separate paths of a wire harness pattern defined by

wire retainers

17 and

wire termination sites

15 on wire

harness form boards

18.

Positioning and movement of the wire dispensing heads 10 relative to the

form boards

18 are provided by a numerically programmed control system to produce incremental positioning of the heads 10 in accordance with a discrete signal program, for example, or other numerical or computer controlled systems providing for controlled movements from point to point or along continuous paths. In this connection, illustrative reference is made for the first-mentioned system described in U. S. Pat. Nos. 3,252,147 and'3,2'62,l05. A positioning control system found in machine tool control is described wherein movable platens or tables, spindles, and workpiece are positioned in one or several axes in accordance with programs defined by a numerical code in individually programmed blocks of a punched tape or by other suitable information input.

As shown in FIG. 1 by arrows X and Y, operational movements of heads 10 parallel to the

form boards

18 provides concurrent and selective dispensing of

wires

16 by heads 10 along individually programmed wire paths between

termination sites

15 which pass about projecting arms of

retainers

17 to produce-a

wire harness

20, for example. The wire

harness form boards

18 are mounted on work tables 19 by suitably positioned fixtures or

clamps

19a which provide for positioning individual boards uniformly on tables 19 for ordered wire dispensing operations. In addition to providing for control of movement of the heads 10 over the

form boards

18, the preferred numerically controlled system controls certain auxiliary and preparatory functions for internal operations of heads 10 including wire selection, pay-out and feed intervals of selected wires, wire cutting, and operating levels of

feed tubes

22 in a manner described more fully hereinafter.

Considering now the. details of construction of the wire dispensing heads 10, a wire supply is shown in FIG. 1 to comprise groups of precoded spools 11 disposed above platforms 10a for respective ones of wire dispensing heads 10.

Wires

16 are selectively supplied from spools 11 to corresponding

capstans

25 and then to feed

tubes

22, for example, feed

tube

22a. As provided for each of the dispensing heads 10,

wires

16 from the respective group of spools 11 are guided to the feed tubes by peripheral channels in

guide rollers

26 and in the

capstans

25. The capstan drive assemblies of the respective heads 10 provide individual operating modes including a positive payout mode in which the capstans selectively pay out one or more of the

wires

16 into

corresponding feed tube

22a, and'a regulated feed mode in which the capstan assembly regulates the tension of the selected wires 16being dispensed along individual wire paths of

harnesses

20.

DETAILED DESCRIPTION OF A TYPICAL WIRE DISPENSING HEAD Referring now to FIGS. 2 and 3 for a more detailed description of the structure of a typical one of the wire dispensing heads 10, FIG. 2 is a front view which shows the internal construction with the

feed tubes

22 in their retracted position prior to wire dispensing operations, and FIG. 3 shows the wire dispensing head in payout operating mode securing a selected wire 16a at a selected location at a wire group termination site at the beginning of a layout run. A

frame

30 supports cooperating members of the wire dispensing head 10 to guide the

wires

16 laterally from the supply spools 1 Ito respective channels 27 of the

guide roller

26, andvertically to

respective channels

29 of the

capstan

25 to be fed through respective

wire mark sensors

60 and guide tubes 39'of a

cutter bar assembly

32. The ends of the

wires

16 in guide tubes 39 are thus disposed to be fed into

feed tubes

22 which are coaxially disposed along the axes of respective guide tubes 39. In the preferred embodiment therefore, provision is made in each head 10 for guiding six

wires

16 from the supply spools 11 to the

capstan

25, maintaining uniform separation of the

wires

16 by guiding the wires 16in annular channels 27 of the

guide roller

26. The spools 11 on respective spindles are constructed to provide drag during pay-out and wire feed intervals. Each of the

wires

16 is wrapped one or more times around the

capstan

25 in

respective channels

29 to provide pay-out of the

wires

16 and regulate the feed rate thereof. For example, any selected wire 16a is paid-out by actuation of a cor responding pinch roller 34 and frictional engagement of the wire 16a with the rotating

capstan

25 as shown more clearly in FIG. 3. Subsequently, the driving force transmitted to the wire 16a, during regulated feed while laying of the wire along paths of the wire harness is determined by the degree of frictional engagement of the wire 16a and the annular surface formed by the

bottom of'the channel

29 for translation of the rotary motion of a capstan to linear movement of the wire 16a through the

feed tube

22a to regulate the tension during layout of the selected wire 16a. In actual operation of the preferred embodiment, by way of example, the feed tension of wire 16a is regulated to a constant low level of 2 pounds for 14-16 gauge insulated wire. By regulation of feed tension, i.e., frictional engagement without pressure of an engaged pinch roller 34,

wires

16 in the

harness

20 will be maintained taut during wire feed from

feed tubes

22 to assure that the wires will precisely follow along the layout paths to produce the programmed wire harness. Concurrently, the tension of the wires during feeding is regulated by the capstan driveto prevent excessive tension and possible damage thereto as they are passed out of tapered openings at the lower ends of the

feed tubes

22 to be disposed about

retainers

17 on the

form board

18. Further, the regulation of wire tension to a low level assures retention by

gripholes

40 in individual positions at the

wire termination sites

15 of the wire harness form board 18 (FIG. 3).

In FIG. 2, the

capstan drive assembly

24 is shown to comprise a continuously rotating

capstan

25 driven by a

motor

31 via a belt drive including a belt 31a and pulleys 31b which couple the drive shaft of the

motor

31 to the drive shaft of the

capstan

25.. The

motor

31 drives the

capstan

25 continuously at a speed corresponding to the desired rate of pay-out of the selected wire 16a. As shown more clearly in FIG. 3, the selected wire 16a is driven down by the

capstan

25 into

feed tube

22a, e. g., during a pay-out interval. In the preferred embodiment of the control arrangement, which is described in detail in the description of FIG. 3, the selected wire 16a is paid out in sections before and after lowering of the selected

feed tube

22a; In general, the length of wire paid out must project out of the

feed tube

22a for securing an end portion thereof in the slit pattern of the selectedgriphole 40 at the

wire termination site

15, as shown in FIG. 3.

At the beginning of pay-out interval, the end of selected wire 16a is movedfrom its position at shearing

edge

33 of the

cutter bar assembly

32 throughthe lower section of guide tube 34 and into the selected

guide'tube

22a. After the

feed tube

22a is lowered to plunge into

griphole

40, an additional length of wire l6a'is paid outto provide an exposed end position which is retained by the

layer

53 as the

tube

22a is withdrawn from the griphole 40 as will be explained in detail later.

The pay-out interval occurs at the beginning of each wire dispensing cycle in the process of forming a

wire harness

20, and is followed by a wire feed interval in which the

capstan

25 maintains a constant feed tension on the selected wire 16a during traversal of the harness layout pattern. During the pay-out interval, a positive drive is applied to the wire 16a as a result of engagement and pressure applied by pinch roller 34 as shown in FIG. 3. An individually actuated pinch roller 34 is provided for each of the six

wires

16, and only the pinch roller 34 corresponding to the selected wire 16a, for example, is energized to engage wire 16a by entering the corresponding groove in the

capstan

25. As the pinch roller 34 engages wire 16a, it forces the selected wire 16a into frictional engagement with the bottom of the groove of the constantly rotating

capstan

25 to payout wire 16a.

In the pay-out interval, the selected wire 16a must be paid out past the

cutter assembly

32 and into the

corresponding feed tube

22a to provide a length of wire projecting from the end of the selected

feed tube

22a which is retained by the

griphole

40. Accordingly, at the beginning of each dispensing cycle, the pinch roller 34 shown in FIG. 3, which corresponds to the selected wire 16a, is moved laterally by actuation of the

corresponding linkage

34a coupled to a

pneumatic actuator

35a. As shown in FIG. 2, six

pneumatic actuators

35 are individually connected to a regulated air supply and electromagnetically actuated to selectively control the supply of air to individual ones of the

actuators

35 for corresponding pinch rollers 34.

The

cutter bar assembly

32, shown in FIGS. 2 and 3, is disposed below the

capstan assembly

24 and consists of a stationary lower section secured to a laterally projection 41 of the

frame

30; and a slidable upper section disposed on the lower section to form a

wire cutting edge

33. A cutter actuating solenoid 42 is mounted on the opposing wall of

frame

30. The armature of solenoid 42 is connected to the movable upper section of the wire cutter assembly 32' by an

arm

47a. The solenoid is energized to produce relative movement of the upper section to cut the wire 16a, for example, at a predetermined point approximately 10 inches from the end of the layout run which is at a predetermined one of termination sites for the selected wire 16a.

Each of the

feed tubes

22 is slidably disposed for vertical movement to different plunging and operating levels for inserting a respective one of the

wires

16 in

gripholes

40 and for operational layout movements over the wire

harness form board

18 at different operating levels, e.g., wire laying levels Nos. 1, 2 and 3, as shown in FIG. 3. Selective vertical movement and positioning of

feed tubes

22 at these levels is provided by an

actuator bar

36. Tube guides a formed in the lower section 43 of the

frame

30 guide the lower sections of

feed tubes

22 which are biased upwardly by

helical springs

38 having lower sections seating on the lower section 43 of

frame

30.

Springs

38 bias

respective feed tubes

22 into

respective seats

46 formed in an opposing lower surface of upper frame section 41.

Annular end sections

37 of

feed tubes

22 are secured to the upper ends of the tubing and

sections

37 are formed to pass through respective tapered

openings

45 in the

actuator bar

36 to pass all but selected

feed tubes

22. As shown in FIG. 3, the selected feed tube 224i is positioned in griphole of one of the

termination sites

15 by energization of the corresponding one of the

solenoids

46 which positions the end of

plunger

47 in an

annular channel

48a in the

end section

37 of

feed tube

22a. As a result, when the

actuator bar

36 is lowered, only one selected

feed tube

22a, for example, is lowered to plunge the end thereof into

griphole

40.

Thus, a selected one of the

feed tubes

22a is lowered along with the

actuator bar

36 in the bars movement from the upper position, indicated by dashed

line

36, to the lower position as shown in FIG. 3. In a wire layout cycle, the feed tube selection is made prior to lowering

actuator bar

36. Accordingly, only the selected

feed tube

22a is lowered and the remaining

feed tubes

22 remain seated in'their

respective seats

46 by the bias of the helical springs 38.

As noted, the selected

feed tube

22a is positioned by

actuator bar

36 to locate the mouth thereof at any one of several operating levels during XY movements, indicated as wire laying levels Nos. 1, 2, 3 in FIG. 3 and also a lower-most position in which the mouth of the

feed tube

22a is located in

griphole

40 for securing the selected wire 16a at the desired

termination site

15.

Positioning of the

actuator bar

36 to a desired level is controlled by pneumatically actuated positioners or other suitable positioning devices (not shown) coupled to

cables

48. In a preferred arrangement the positioners for

actuator bar

36 comprise a primary pneumatically operated positioner (not shown) which when actuated applies tension to the

lower cable

48 to move the

actuator bar

36 down from the top position 36' to plunge the selected

feed tube

22a into

griphole

40. Additional positioners are subsequently energized to return the primary positioner in increments to position the selected

feed tube

22a to the desired operating level and at the endof the cycle to return the

feed tube 22a actuator bar

36 to the initial position 36'. As evident from the showing, the position of

feed tube

22a and

actuator bar

36 corresponds to the location of the primar'y positioner. I

In FIGS. 2 and 3,

actuator bar

36 is shown secured to guide

tubes

49 for limited vertical travel on guide posts 50. As shown in FIG. 3, the downward travel of the actuator is limited by engagement of

guide tubes

49 with shoulders on the guide posts 50. Cam operated switches 51 and 52 (FIG. 2) disposed on either side of the

actuator bar

36 are operated by respective cam surfaces to provide an indication'of the extreme positions of the actuator bar 36.-Those positions are the return position as shown in FIG. 2 and the plunged position in which the mouth of the selected

feed tube

22a is positioned in the

griphole

40 as shown in FIG. 3.

Switches

51, 52 provide signals for the logic circuits for determining the location of the feed tubes prior to layout travel, for example. In this instance, switch 52 being operated, the logic signal would inhibit travel in the layout run because the feed tube has not been raised.

TERMINATION SITES Referring to FIGS. 4 and 4a for a more detailed description of the

termination sites

15 and

gripholes

40, a plurality of

gripholes

40 are located at each of the

wire termination sites

15 of the wire

harness form board

18. As described in connection with FIG. 1, the wire

harness form board

18 includes a plurality of

wire termination blocks

15a located at

respective termination sites

15, a typical one of these blocks is shown in FIG. 5.

A

wire termination block

15a comprises a

metal plate

52 which is secured to a

baseboard

54 to firmly and uniformly seat the entire area of a

layer

53 of resilient material, such as neoprene, against the opposing area of

baseboard

54. A uniform array'of openings is provided in the

plate

52 for

gripholes

40 including a -slit pattern formed in the

resilient layer

53 and located coaxially over openings in the

baseboard

54 as shown in FIGS. 4 and 4a. In the preferred embodiment as shown, the wire termination block is spaced from the work table 19, as indicated in FIG. 3, to accommodate the length of wire 16a which is paid out through the mouth of the

feed tube

22a after insertion thereof into the

griphole

40. 7

An important feature of the present invention is the provision of the

wire termination sites

15 having

gripholes

40, each of which is capable of receiving the end of a feed tube and retaining the end of the wire 16a upon withdrawal of the feed tube and against the force of tension applied to the wire during the layout between

sites

15. In the feed time period regulation of feed to maintain constant low wire tension is provided by frictional engagement of the wire 16a and the

capstan

25 due to the tension exerted on the wire 16a during head movement in the layout of wire 16a in the harness pattern. Various parameters such as size and diameter of the

wires

16, type of insulating material on the wire and composition of the material of the

resilient layer

52 determine the level of holding force of the

griphole

40. In general, the diameter of the wires, including the insulation, varies from 0.1 to 0.3 inches and the coefficient of friction between a

neoprene layer

53 and the insulating plastic of a

wires

16 should be adequate to retain the wires in the

gripholes

40 when the feed tension is regulated to approximately 2 pounds or in the range of approximately I to 3 pounds, for example. The preferred s'lit pattern in the

layer

53 is shown in FIG. 4a and provides for deflection of the radial sections thereof during plunging of the end of

feed tubes

22 therein, and return of these sections during withdrawal of the end of

feed tubes

22 to engage the plastic insulation of the

wires

16. The radial sections of

layer

53 retain the end of the wires against the force of the tension applied to the

wires

16 during feed and layout thereof in the harness pattern.

In the preferred embodiment, gripholes 40 were pro- .vided for insertion of a 0.125 inch diameter insulated wire (l6-gauge) for example, by a

feed tube

22a.

Feed tubes

22 have an outside diameter of 0.250 inch and an internal diameter of 0.187 inch wherein the mouths of the feed tubes are tapered internally and externally to accommodate frictional engagement with the wires and

layer

53. In order to accommodate the plunging of the end of the feed tube into the gripholes, and provide for retaining the

wires

16 upon withdrawal of the

feed tubes

22, the griphole openings are made substantially larger than the

feed tubes

22a relying upon the thickness and the shore of the

neoprene layer

53 to retain the

wires

16 in the

gripholes

40 by the radial sections of the slit patterns in the respective gripholes.

Accordingly, for feed tubes having a 0.250 inch outside diameter, one-half inch diameter openings are provided in an

aluminum plate

52 and

baseboard

54, and the slit pattern is located coaxially with respective concentric openings in the

plate

52 and

baseboard

54. The diameter of the cut in the slit patterncan vary from the size of the openings to a lesser diameter of approximately 75 percent of the opening, and in a particular structural embodiment, the cuts of the slit patterns extended substantially across the openings of the

respective gripholes

40. The thickness and the hardness of the

neoprene layer

53, as well as the extent of the slit diameter, determine in part the gripping force produced on the

wires

16. The limitation on the retaining force provided by the gripholes to the

wires

16 is primarily due to the need for insertion of the

feed tubes

22 into the gripholes without damaging or bending the feed tubes, and preferably to facilitate ease of insertion and removal thereof while providing sufficient frictional force on the

wires

16.

The preferred slit pattern of

gripholes

40 is shown in FIG. 4a which consists of six radial sections formed by three cross cuts passing through the center of the

gripholes

40. Other

suitable gripholes

40 have been formed by an H grid pattern, for example, in the

neoprene layer

53 in which the cross bar of the H projects across the center of the griphole opening. The H pattern can be modified to provide a grid pattern H-H having additional cuts normal to the cross bar to facilitate passage of the end of

feed tube

22a allowing for deflection of the individual sections of the grid pattern according to the location and diameter of the feed tube projecting into particular sections.

In general, the thickness of the

neoprene layer

53 varied from one-eighth to one-quarter inch in thickness having a shore hardness of 40. A

resilient layer

53 on

wires

16. In the testing of the griphole construction, it was found that with larger diameters of

wire

16, having the same insulation material, the larger the holding force for the same griphole construction. Also, it was found that with increasing thickness of a

resilient layer

53 of neoprene, and the higher hardness or shore, the greater is the holding force, while the shape of the slit or grid pattern did not produce any significant change on the wire holding force value which varied from two to four pounds for smaller range of wire sizes, i.e., 0.125 inch or less in diameter. I Further it was found that a force of four pounds is required to plunge the end of

feed tube

22a into

griphole

40, in a manner as shown in FIG. 3, in which the layer had a one-quarter inch thickness and a shore hardness of 40. At a shore hardness of 70, the force increased from four pounds to within the range of 6 to 8 pounds with a radial slit pattern diameter of threeeights inch in a one-half inch opening having a pattern as shown in FIG. 4a.

Further, it should be noted that the retaining force of the griphole 40 on the wire 16a does not vary with direction in which the wire is being fed, i.e., a pull exerted coaxiallywith the griphole or in a direction normal thereto, such as produced in movements of withdrawal of the

feed tube

22 from a gripholeor during travel parallel to. the surface of the

board

18. Thus,

the retention by the resilient material of

layer

53 is 'suming these latter conditions are satisfied, the maximum feed tension on a selected wire 16a while retaining the wire in the

griphole

40 is independent of the amount of wire passed through the griphole, i.e., only sufficient wire need be passed through the pattern in

layer

53 to provide engagement of the wire 16a with the engaging edges or surfaces of the material in the

layer

53 in the pattern.

In an alternate arrangement of the present invention, the wire dispensing head 10 pays-out a length of wire out of the feed tube before plunging the end of any selected

feed tube

22a into the griphole, and as a result,

a loop of wire is retained by the pattern in the griphole 40 with the end of the wire 16a remaining above the

form board

18. Thus, if it is desired to provide for ends of

wires

16 remaining above the board, pay-out of

wire

16 past the end of the

feed tube

22a precedes plunging of the end of the

feed tube

22a into the

griphole

40. It should be noted that a loop of

wire

16 is formed at the end of each run of

wire

16 of the wire harness formed by either arrangement of the system of the present invention as described and illustrated by the preferred embodiment. Avoidance of loops of

wire

16 at theend of layout runs is readily provided by more precisely cutting the

wires

16 or providing for deeper penetration of the

gripholes

40 at the end of each run to pull the end of the wires through the

gripholes

40, or both. No need presently exists for elimination of wire loops at

gripholes

40 and accordingly, the preferred embodiment actually constructed produced wire loops at gripholes located at the end of layout paths of the harness pattern.

WIRE MARK SENSORS Referring to FIGS. 6 and 7 for a detailed description of the wire detection arrangement of the system of the present invention, each wire dispensing head 10 includes wire-

mark sensors

60 for each of the six

wires

16 as shown by the top view of FIG. 7 and by the front view of the head assembly of FIG. 2. Referring to FIG. 6 for a detailed description of the wire-

mark sensors

60, the wire detection arrangement is indicated in the drawing by the plurality of

differential amplifiers

62 coupled to a driver amplifier 64 (including a rectifier to provide a unidirectional output) and a typical one of six wire-

mark sensing chambers

66. The wire-

mark sensors

60 perform two functions in the detection of the difference in output of upper and

lower photodetectors

65 and 67 which are illuminated by a

light source

68 located on the opposite side of the

sensing chamber

66. Each of the wire-

mark sensors

60 detects a wire-mark 63 which consists of adjacent flattened areas of thewire 16a disposed normal to one another which produces a difference in light intensity at the

photodetectors

65 and 67 when the mark passes

photodetectors

65, 67. Also each of the

sensors

60 detects the end of a wire passing these

photodetectors

65, 67.

In operation, a difference in output of

photodetectors

65 and 67 in sensing

chamber

66, in response to a wire mark 63 on wire 16a, for example, will be detected by

differential amplifier

62 having an output connected 08 from timing circuit 0830 which input is present during the mark detection period to trigger a timing circuit 0815 at input as Circuits 088, 0815, OS and 0831, i.e., one-shot timing circuits, define the pay-out interval at the beginning of each wire dispensing cycle wherein circuit 088 is triggered by a signal g57 upon selection of a

feed tube

22 and prior to plunging thereof to pay-out an 8-inch length of wire 16a into

feed tube

22, for example. The length of wire paid out during the period of circuit 088 is less than the length of

feed tube

22 but greater than the maximum downward travel of

feed tube

22 to maintain the wire 16a threaded in

feed tube

22a, for example.

After the end of the

feed tube

22a is inserted into the

griphole

40, as shown in FIG. 3, timing circuit 0830 is triggered to define a mark sensing interval in which an additional length of wire 16a is paid-out. The time period of 0830 provides for a maximum pay-out of 30 inches of wire 16a, for example, but circuit 0830 is reset when the wire-mark 63 is sensed and circuit 0815 is triggered to payout a maximum of 15 inches of wire from the time circuit 0815 is triggered.

Timing circuit

0515 is triggered by mark pulse MS passed by a gate 69 enabled by the (true) output 08 During the time period of circuit OS15, wire 16a is paid out to assure that an end portion of sufficient length projects out of the mouth of

feed tube

22a for gripping by the

layer

53 at

griphole

40. To provide for variances in location of wire-mark 63, i.e., located in the length of wire paid out during the time period of 088, a flip-flop M2 is provided to store the mark pulse MS for later triggering of the circuit OS15, i.e., after the 088 time period. Accordingly, a gate 69b, enabled by output 08 provides for passing pulse MS for storage by flip-flop M2 which is reset by output 08 The OR

gate

690 passes pulse MS or the output of AND gate 69a to trigger the timing circuit 0815. The flip-flop circuits M1 and M2 and timing

circuits

058, 0515, 0830 and 0831 are triggered by the leading edge of the signal coupled to the set or reset inputs. Thus, upon detection of the mark pulse MS, an output OS is produced which extends the payout interval for a period sufficient to allow 15 inches, for example, of wire 16a to be paid out of the

feed tube

22a after detection of the wire mark 63.

In order to detect the absence of a mark pulse MS during the maximum pay-out interval and the end of the wire 16a,

logic circuit

70a is provided to interrupt the wire dispensing operations. In the event that the predetermined pay-out interval is passed for mark sensing, flip-flop M1 is set to provide a true output M which interrupts operation of the wire dispensing head and system.

In addition, the gates 73, 73a are provided to detect an output from

amplifier

64 indicating the end of wire 16a, for example, passing through the

sensing chamber

66, i.e., a wire-mark 63 is not expected outside the mark sensing interval defined by output 08 (and 08 As indicated previously,

timing circuit

0515 defines the pay-out interval after wire-mark 63 is detected and a pulse output from

amplifier

64 during this period of 0515 indicates the end of the wire, or a second wire-mark 63 has occurred erroneously. Preferably, the output 08 in response to a mark pulse MS, is delayed to avoid detection of an extended or double pulse output from amplifiers 63 when a single wire mark passes

photodetectors

65 and 67. Outputs of AND gate 73, 73a are passed by

OR gate

72 to trigger flip-flop M1 to produce an output M to terminate the wire dispensing operations. Thus, flip-flop M1 is sent by outputs of

gates

71, 73, or 73a to terminate wire dispensing operations due to the absence of a wiremark during the sensing period or due to the end of the wire passing through the sensing chamber 63.

In order to maintain alignment of wire 16a in the sensing chamber 63, a wire guide assembly is shown in FIG. 6 to comprise a

flanged guide tube

74 seated in an opening in the top of the enclosure of the

sensing chamber

66. The upper, radial surface of the

guide tube

74 is beveled at an angle of 20 relative to the radius for coaxial seating of a

diaphragm

76 formed of a resilient material, such as neoprene, to provide resilient, frictional engagement with the wire 16a, as it passes through the

guide tube

74 and into the

wire sensing chamber

66. A

ferrule

75, formed of nylon, for

example, is retained in the position shown by a

cap

77 having an annular channel for receiving the periphery of the

ferrule

75 to maintain the

rubber diaphragm

76 deformed between opposing beveled radial surfaces of the

guide tube

74 and

ferrule

75. A coaxial passageway is formed in the wire guide by center apertures including a protruding edge of the

diaphragm

76 which frictional engages the periphery of wire 16a as the wire passes through this wire guide. The aperture of

diaphragm

76 is cut at an angle of 30 relative to the axis thereof before deflection and the aperture formed therein has a minimum diameter of approximately 20 percent less than the outer diameter of the wire passing through the guide tube. This wire guide assembly provides for accurately aligning wire 16a in the interior of the

sensor chamber

66 to position the wire 16a precisely along the longitudinal axis of the chamber to be centrally located along this axis which passes between the

photodetectors

65, 67 and the

light source

68.

The frictional engagement of the

diaphragm

76 with the periphery of the wire 16a passing therethrough is slight in the direction of the wire movement into the

sensing chamber

66 while inhibiting reverse movement or backlash of the wire 16a to provide uniform movement of the wire coaxially through the

sensing chamber

66. As a result, the wire-mark sensor for wire 16a is not subjected to lateral movements or deflections of the wire 16a along the length of the wire in the chamber which would otherwise tend to produce undesired differences in outputs of the

photodetector

65 and 67 due to deflections of the wire 16a from the axis of the sensing chamber while passing opposite these detectors.

FIG. 7 is a top view of the six wire-

mark sensors

60 for the six

wires

16 for the wire dispensing head 10 shown in FIG. 2 and 3, a typical wire guide'assembly having been described and shown in FIG. 6. In the preferred embodiment of the-invention, the wire guide assemblies for

sensors

60 are removable and interchangeable to accommodate different ranges in sizes of

wires

16 where

thediaphragm

76 is approximately 20 percent smaller in diameter than the midrange diameter wire in aparticular range. In the present arrangement, two sets of wire guide assemblies were found adequate for accommodating different wire sizes for all wire harnesses in a particular industrial application wherein the most common wire size is 0.125 inch diameter including insulation for No. 16 gauge wire. The preferred shore of the

neoprene diaphragm

76 is 60 although neoprene in the range of 40 to 80 shore was found to provide many of the advantages of the invention for wire guiding in the assembly. The thickness of the

diaphragm

76 is approximately 0.125 inch, i.e., including the range of thicknesses from 0.10 to 0.156 inches, for example. Another less common wire size in a smaller range of sizes is a No. 26 gauge wire having an outside diameter of 0.025 inch including insulation. In this smaller range of sizes, the diameter of wirewas more common in the range of 0.025 to 0.30 inch.

The

wires

16 can be either a stranded or solid conductors of copper, aluminum or other electrically conductive material capable of being formed in the harness pattern. The insulation most common is a uniform thickness of solid plastic although woven glass threads or other insulating threads forming a woven insulation is suitable. A common insulation which provides the advantage of tolerance to heat is tetrafluoroethylene.

OPERATION In operation, wire dispensing by the system arrangement of the present invention to form a cable harness, comprising a group of wires formed to a desired layout pattern, is preceded by loading respective heads from spools 11 of

precoded wires

16 and threading the wires from these spools to the

cutting edge

33 of the

cutter bar assembly

32. Individual wires are passed through channels in the

roller guide

26 and the

capstan

25 including one or more loops around the capstan by each wire. After the

wires

16 have been loaded in the respective heads 10 and the wire

harness form boards

18 have been properly positioned on respective tables 19, as shown in FIG. l, the heads 10 are positioned to locate the

respective feed tubes

22a for-the selected wires 16a above the first gripholes programmed in the harness layout. Initial positioning of the heads 10 and selected

feed tubes

22 is programmed according to the tape or other record provided by the numerical or computer programmed control system. Assuming the tape or other record has been properly loaded into the control for system, the operator need only to press a start button which moves the tape to read the first block of the program. After the heads have been positioned over the

first gripholes

40 of the programmed layout the tape is moved to read the next block of the program which includes selection of

feed tubes

22a, for example, by actuation of the corresponding

solenoids

46 as shown in FIG. 3 for one of the heads 10. Prior to movement of the

feed tube

22a downwardly into the griphole I 40 for the head 10 shown in FIG. 3, wire 16a is paid-out into

feed tube

22a by energizatiori of

pneumatic actuator

35 which positions pinch roller 34'to engage and press wire l6a into

channel

29 and against the continuously rotating

capstan

25.

Actuator

35 retracts the pinch roller 34 after wire 16a is paid-out into

feed tube

22a a sufficient distance to be retained therein when lowered to plunging position, e.g., 8 inches, in accordance with the prior description of control by the logic shown in FIG. 6.

Continuing the description of the operation of only the dispensing head 10 shown in FIGS. 2 and 3, the

actuator bar

36 is then moved downwardly carrying the selected

feed tube

22a to its lowermost position in which the lower end of this feed tube is positioned in

griphole

40, as shown in FIG. 3. Wire 16a is again paid out until a wire-mark 63, shown in FIG. 6, is detected by the corresponding wire-

mark sensor

60, or until the end of the wire-mark sensing time period, as discussed more fully in the discussion of the wire-mark sensor in FIG. 6 supra. Assuming the wire-mark 63 is sensed, wire 16a is again paid out for a predetermined time period, corresponding to a length of approximately 15 inches, for example, which assures that the end of the wire 16 a extends beyond the end of the

feed tube

22a and into the

griphole

40. The

feed tube

22a is then withdrawn to any selected one of the wire laying levels, Nos. 1, 2, 3, as shown in FIG. 3 for example, by positioning of the

actuator bar

36 by

cables

48 connected to a primary positioner (not shown).

After the selected

feed tube

22a: has been positioned at the proper one of the operating levels Nos. 1, 2 or 3,

depending upon the amount of clearance needed to pass over previously laid wires, if any, the wire dispensing headis moved along the desired path towards a termination site laying the selected

wire

16 along the programmed path of the wire harness pattern. For example, as shown in FIG. 1, the movement of the head 10 parallel to the wire

harness form board

18 follows a path from a

termination site

15 to lay the wire 16a via the

retainers

17 and then to the

wire terminating griphole

40 at one of the

termination sites

15 at the other end of the board. Accordingly, wire dispensing head 10 is controlled to be moved at the selected wire laying level from point to point or along a contour in order to follow a predetermined path between termination sites 15 (and gripholes 40) for the selected wire 16a. 1

Also, during the feed interval, the wire dispensing heads 10 are controlled to maintain a feed tension at a level which does not exceed the retentive force of

gripholes

40. Further, the regulated tension is maintained sufficiently low to insure that no damage occurs as the wires 16a passes out of the rounded or tapered mouths of the

feed tubes

22a. Regulation of feed tension at a constant. level is maintained by wire-wraps around the

rotating capstans

25 of the respective heads 10. If the feed tension exceeds the desired level, the wire-wraps around the capstans become taut engaging the knurled surface in the bottom of

channels

29 of

capstans

25 to produce positive feed to assist movement of the wires from the capstans into the

feed tubes

22a. It is important to note that the capstans operate in the feed mode when the wires are being positively fed during the feed interval as contrasted with the pay-out interval in which the pinch rollers 34 are moved into actuated position to produce engagement of the selected

wires

160 with the respective knurled surfaces of the capstans during the pay-out interval at the beginning of the wire dispensing cycle. Further, the knurled surface is only one form of providing sufficient frictional engagement of the wire 16a with the

capstan

25 to provide the positive feed or pay-out of the wire 16a to provide pay-out or regulation of tension at a constant desired level of tension. Other surfaces providing frictional engagement and capable of withstanding a high degree of abrasion or wear over long periods of time under these conditions are suitable.

At the end of each individual wire dispensing cycle of wire 16a, for example, feed

tube

22a is again inserted into a griphole 40 at the end of the

run termination site

15 to secure the end of the wire 16a in the

latter griphole

40 for retaining both the end of the wire and the length of the wire and in the wire harness pattern.

After insertion of the wire 16a in the

latter griphole

40,

the

feed tube

22a is retracted by

actuator bar

36 to the tions of the present invention are contemplated and will be apparent to those skilled in the art without departing from the spirit and scope of the invention. For example, it is anticipated in accordance with the foregoing description that dual dispensing heads 10 are operated concurrently and in parallel to produce two cable harnesses in a single cycle. Alternatively, the program for the individual cable harnesses can be employed to set up

form boards

18 by substituting a tool on one end of the

boom

14 for a dispensing head and forming openings for

gripholes

40 and also for placement of

retainers

17 on the

board

18. Since the location of the

gripholes

40 is recorded on the programmed tape,

boards

18 can be readily set up on the same work tables and control equipment. Further, it is contemplated that the cable harness be formed in three dimensions by providing control of movement in three axes or five axes, although such need rarely exists due to the flexibility of cables for electronic and electrical equipment. For heavy donductors for high power transmission in interconnections is uncommon and forming in three dimensions can usually be accumulated more readily by forming after planar layout. These and other variationsof the preferred embodiment of the invention are readily apparent in view of the foregoing disclosure. Further, it is readily apparent that the invention is not limited to dispensing of wire but is equally capable of dispensing strand materials including, but not limited to fibers, fiber optic material, tubing, and other strand materials or variations thereof.

1 7 2. The machine according to

claim

1 in which said means for producing relative movement is responsive to the control means to feed individual strands between successive ones of the receptacles so that an individual strand is located along paths determined by subsequent direction of relative movement of said dispensing means and the cable harness form.

3. The machine according to

claim

1 in which the control means includes means for storing a program and logic circuit means responsive to the program means for automatically forming a cable harness including controlling relative movement of said 4. The machine according to

claim

3 in which the program storage means comprises a digital recording of operations for automatically forming a cable harness including a plurality of successive points forming the paths of relative movement of the dispensing means and the cable harness form.

5. The machine according to

claim

1 in which said control means includes cyclic means for dispensing lengths of strand material in successive strand dispensing cycles for respective paths of the strand material according to any predetermined harness pattern and means for detecting and cutting the strand material in successive cycles, said latter means being responsive to marking of the individual lengths thereof.

9. The machine according to

claim

1 in which said means for feeding strand material includes a feed tube for guiding said strand material and having an open end for dispensing the strand material to be received by said retaining means.

14. The machine according to

claim

13 in which the control means includes means for operating the cutting means at a predetermined distance before positioning at one of each of the interconnected pairs of termination sites so that the cut lengths of strand material correspond to individual lengths of the paths between interconnected spaced termination sites.

15. The machine according to

claim

14 in which said strand material includes marking for designating sequential lengths thereof and said dispensing means includes sensing means responsive to said marking so that individual lengths of strand material are dispensed along corresponding paths of the cable harness.

17. The machine according to

claim

16 in which the restrictive means comprise resilient means for passing and frictionally engaging the open end of the feed tube through the apertures and removably retaining termination portions of said strand material dispensed through the aperture from the open end of the feed tube.

18. The machine according to

claim

17 in which said means for feeding strand material includes means for regulating the tension on said material during relative movement so that the tension on the material is less than the retention exerted bythe frictional engagement with said strand material.

20. The machine according to

clam

19 in which said control means includes a digital stored program of the relative movements of said machine for. automatically forming said cable harness.

21. The machine according to

claim

19 in which said feeding means comprises a pluralityof feed tubes having open dispensing ends and means for selectively positioning the feed tubes for feeding individual wires from the open ends thereof.

23. The machine according to

claim

22 in which said wire retaining means includes receptacles which project above said surface, and the control means includes feed regulating means comprising a capstan engaging said wire regulating the tension on the wire to provide for retention by said retaining means by lateral engagement with said receptacles due to tension of said wire and by said resilient means at termination sites.

24. The machine according to

claim

1 in which said means for producing relative movement includes means for dispensing the strand material at different strand dispensing levels along the harness paths and about the receptacles which project into planes corresponding to said dispensing levels.

25. The machine according to

claim

24 in which said receptacles are disposed on a surface of the form having at least x and y axes and the levels of dispensing are provided in the z axis to form a cable harness having an accumulation of strand material along common harness paths forming trunks and branches of the cable harness.

26. The machine according to

claim

1 in which said harness form includes a surface for supporting said strand material being dispensed along said harness paths and the means capable of retaining and receiving termination portions of the strand material comprises means for passing the termination portions through said surface.

27. The machine according to

claim

1 in which retaining means are provided at the termination sites comprising resilient means disposed in openings provided in the pattern form at said termination sites, said openings and resilient means disposed therein being constructed and arranged to receive the termination portions of said strandmaterial and the strand feeding means and retaining said termination portions upon withdrawal of the strand feedin means.

28. The machine according 0

claim

1 in which the machine includes a supply of strand material and the feeding means for the strand dispensing head includes means for selectively feeding strand material from said

pp y

29. The machine according to claim 28 in which the feeding means includes means individual to said strands in said supply for dispensing selected strand material from said supply. a I

30. The machine according to

claim

29 in which the individual feeding means comprises feed tubes and individual ones of said feed tubes are capable of being selectively moved to be positioned for cooperating with the strand retaining means during relative movement for forming said cable harness.

31. The machine according to

claim

1 in which the feeding means includes means for feeding individual strand material and driven capstan means for engaging said strand material.

32. The machine according to

claim

31 in which said driven capstan means includes respective means for individual strand material, said latter means being operable to cause the driven capstan means to selectively engage the strand material so that the selectively engaged strand material is paid-out.

33. The machine according to

claim

31 in which the feeding means includes feed tubes for respective ones of said strand material for individual feeding of any selected strand.

34. The machine according to

claim

8 in which said means for producing tension on the strand material comprises capstan means associated with said strand material for feeding so that frictional engagement with the strand material is produced as a function of tension on the strand material.

35. The machine according to

claim

8 in which the tension producing means comprises capstan means drivingly engaging said strand material to be responsive to tension exceeding a predetermined amount to drive said strand material so that the tension of strand material is regulated to a predetermined level.