U.S. patent number 3,804,130 [Application Number 05/274,158] was granted by the patent office on 1974-04-16 for form board for receiving and removably retaining strand material.
This patent grant is currently assigned to Hughes Aircraft Company. Invention is credited to Rodolfo Castro, Walter E. Hinds, John W. Tarbox.
United States Patent |
3,804,130 |
Tarbox , et al. |
April 16, 1974 |
FORM BOARD FOR RECEIVING AND REMOVABLY RETAINING STRAND
MATERIAL
Abstract
A wire dispensing system provides for ordered dispensing and
forming of wires along predetermined paths to produce cables and
including automating the production of cable harnesses. A wire
dispensing head is controlled to selectively dispense wires from a
group of supply spools, laying the wire along predetermined paths
according to the desired harness pattern configuration, cutting the
wires to conform to the individual path lengths, and securing the
wires at respective termination sites. The wire dispensing head
includes feed tubes selectively actuated to secure the wires at the
termination sites wherein movements of the dispensing head are
controlled to accurately move the selected feed tubes along the
paths determined by the harness pattern configuration. The desired
length of an individual precoded wire is determined by optically
sensing the configuration of a wire mark which controls wire
pay-out by a rotatable capstan while the feed rate tension of the
wires is regulated by the same capstan at a low level capable of
accurately locating the wires along the wire layout paths of the
cable harness wherein the tension is regulated so as not to exceed
the level of wire retention at the termination sites. The
termination sites include openings having resilient retaining means
comprising a slit pattern in neopreme at each opening for receiving
the end portion of a feed tube and retaining wires on withdrawal of
the feed tube.
Inventors: |
Tarbox; John W. (Malibu,
CA), Hinds; Walter E. (Los Angeles, CA), Castro;
Rodolfo (La Palma, CA) |
Assignee: |
Hughes Aircraft Company (Culver
City, CA)
|
Family
ID: |
26800217 |
Appl.
No.: |
05/274,158 |
Filed: |
July 24, 1972 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
103233 |
Dec 31, 1970 |
3699630 |
|
|
|
Current U.S.
Class: |
140/92.1; 29/755;
140/93R; 29/760 |
Current CPC
Class: |
H01B
13/01245 (20130101); Y10T 29/53243 (20150115); Y10T
29/53265 (20150115) |
Current International
Class: |
H01B
13/012 (20060101); H01B 13/00 (20060101); B21f
027/00 () |
Field of
Search: |
;140/92.1,93
;29/23B,23J,241 ;317/119,122 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Larson; Lowell A.
Attorney, Agent or Firm: MacAllister; W. H. Rengel; Richard
J.
Parent Case Text
This is a continuation, of application Ser. No. 103,233, filed Dec.
31, 1970.
Claims
What is claimed is:
1. In combination with a strand dispensing head, form means for
receiving and retaining said strand material in a predetermined
configuration, said form means comprising:
support means for supporting said strand material; and
means associated with said support means for removably retaining
said strand material, said means including resilient means disposed
in openings in said support means for removably retaining said
strand material in said opening.
2. The combination according to claim 1 in which said resilient
means comprises a sheet of resilient material including a slit
pattern formed in said material.
3. The combination according to claim 2 in which said sheet of
resilient material is secured to said support means.
4. The combination according to claim 3 in which said strand
dispensing head includes a feed tube having an end portion and the
opening in the support means and the slit pattern in said sheet of
material is constructed and arranged to receive said end portion
including strand material projecting therefrom so that the
projecting strand material is removably retained by said resilient
material in said slit pattern.
5. The combination according to claim 4 in which sheet of resilient
material consists of neoprene having a thickness of approximately
one-eighth to one-quarter inch and a shore hardness of
approximately on the order of 40 and the slit pattern includes a
plurality of radial sections formed in said opening.
6. In a form board providing for receiving and removably retaining
strand material in a predetermined configuration including common
trunk and branch paths leading to terminal areas, a termination
site in a terminal area for receiving and removably retaining
terminal portions of said strand material comprising:
a form board area having a plurality of apertures formed therein
for passing terminal portions of the strand material;
retaining means disposed about at least one of the apertures, said
retaining means engaging the terminal portion of the strand
material placed in the aperture so that the terminal portion is
removably secured thereby to provide a level of holding force on
the engaged strand material to resist removal for up to a
predetermined level of tension exerted on the strand material.
7. The terminal site according to claim 6 in which said strand
material consists of insulated wire.
8. The terminal site according to claim 7 in which said retaining
means comprises resilient material providing a predetermined
coefficient of friction with the insulating material of the wire
for removably securing the engaged terminal portion of the
wire.
9. The terminal site according to claim 6 in which said retaining
means comprises a layer of resilient material having a slit pattern
formed therein for removably securing the terminal portion of the
strand material passed through the aperture and the slit
portion.
10. The termination site according to claim 6 in which said strand
material is dispensed by a feed tube and said aperture including
said retaining means is constructed and arranged so that the feed
tube is removably received therein in order to dispose the terminal
portion of the strand material in the aperture to be removably
secured by said retaining means upon withdrawal of said feed tube
from said aperture.
11. The terminal site according to claim 10 in which said retaining
means comprises resilient material having a portion which consists
of a slit pattern formed in the layer of resilient material and
constructed and arranged to removably receive the open end of the
feed tube including the terminal portion of the strand material and
resiliently secure the terminal portion upon withdrawal of the feed
tube.
12. The terminal site according to claim 11 in which the said
resilient material consists of a layer of resilient material
extending over the plurality of apertures and having a slit pattern
located at a plurality of apertures.
13. The terminal site of claim 12 which further comprises a layer
of rigid material disposed over said layer of resilient material to
provide a multilayer structure at said terminal area.
14. The termination site according to claim 13 in which said layer
of resilient material comprises neoprene and said strand material
includes an outer plastic layer so that the holding force is direct
tension on the engaged strand in the range of 1 to 4 pounds exerted
on the strand material.
15. The termination site according to claim 14 in which said strand
material consists of insulated wire in which the insulating
material and neoprene provides a coefficient of friction for
producing the holding force.
16. The termination site according to claim 12 in which the slit
pattern extends a substantial distance across the aperture to pass
the open end of the feed tube and retain the wire upon withdrawal
of the feed tube.
17. The termination site according to claim 12 in which the slit
pattern for a plurality of apertures consists of radial sections
projecting across the respective apertures to be deflected to the
feed tube and resiliently return to frictionally engage the
terminal portion of the strand material to secure the strand
material in the apertures.
18. The termination site according to claim 12 in which said strand
material comprises insulated wire and the feed tubes are tapered to
deflect the resilient material in the apertures.
19. The termination site according to claim 12 in which the slit
pattern consists of an H pattern.
20. The termination site according to claim 12 in which the slit
pattern consists of a grid pattern.
21. The termination site according to claim 12 in which said layer
of resilient material is neoprene having a thickness of
approximately in the range of 1/8 to 1/4 inch in thickness.
22. The termination site according to claim 21 in which said layer
has shore hardness of 40, the slit pattern is formed by cuts
extending approximately in the range of 75 to 100 percent across
the respective apertures, the apertures are approximately 1/2 inch
in diameter and the feed tube is approximately 1/4 inch in
diameter.
Description
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.
Despite the successful operation and use of these automatic wire
machines in wiring of circuit panel boards, many other types of
circuit interconnections are being made manually. One of these
latter types of interconnection commonly in use in electrical or
electronic equipment is the cable harness which provides power and
signal distribution internally between circuit board panels of
subassemblies and between individual units including distant units
of electronic or electrical equipment.
Automatic assembly of these latter types of interconnections has
not progressed due to the many difficult problems encountered in
providing a system arrangement or machine which is versatile, i.e.,
a machine capable of accommodating diverse requirements of the
electrical and electronic industry without the complexity of
foregoing wire wrapping machines. In this field, there is little
standardization in wire use including color coding, multiple wire
colors and gauges which has resulted in difficult problems of wire
manipulation, and particularly in those instances where long cables
are required for interconnection of distant terminals. Further, a
machine for automatic assembly of cable harnesses, for example,
must also provide a high degree of reliability in providing the
proper interconnections to multiple terminal sites.
Accordingly, the present invention is directed to a system
providing ordered dispensing of wire along predetermined paths to
produce cables interconnecting a plurality of terminal sites
according to a stored program including data for locating the wire
between terminal sites.
SUMMARY OF THE INVENTION
The system arrangement provides, in response to a digital stored
program including data for termination points and the paths
therebetween, for selectively dispensing of individual wires by
wire dispensing heads movably disposed on the carriage of a
controlled positioning device disposed above respective cable
harness forms, each harness form including a plurality of
termination sites having openings for retaining terminal portions
of individual wires laid along predetermined paths between
designated sites to form the cable harness. The common paths for
individual wires form the branches and main trunks and the branches
lead to termination sites where the individual wires are separated
and retained. Selection of individual wires is provided by system
control of wire pay-out and feed tubes threaded from a precoded
wire supply wherein the length of individual ones of the wires is
designated by marks which are detected prior to securing the
lead-ends of the wires at the beginning of respective wire paths to
form a cable harness having each wire coded and located according
to the code identification. In dispensing an individual wire of a
harness in a wire dispensing cycle of the system, the wire is
removably secured in a selected one of a plurality of wire
retention positions of a termination site and the tension on the
wire during movement along a predetermined path to another
termination site is regulated by a capstan drive in order to
accurately place the length of wire along the path while not
exceeding the retention capability at the initial termination
site.
In a cycle of operation, one of a plurality of wires supplied to
each dispensing head is paid-out by the capstan into a
corresponding feed tube aligned with the wire feed position on the
capstan. The feed tube is lowered to secure the lead-end of the
wire at the termination site, then raised to the proper wire laying
level whereupon the dispensing head is moved along the layout path
to the desired termination site for securing the other end of the
wire. The tension of wire is regulated during layout by the capstan
operating in a feed mode and the wire is cut upon approaching the
termination site whereby the end of the wire is drawn from the feed
tube to be secured at the latter site.
The cable harness pattern of the preferred embodiment comprises a
form board disposed on a work table of the machine and this board
includes wire retainers and termination sites located at the end of
branches of the cable harness, each site comprises a plurality of
openings for receiving the end of a feed tube and a resilient layer
having slit patterns coaxially disposed in the respective openings.
The slit pattern provides for passing the end of a feed tube while
retaining the wire projecting therefrom upon feed tube withdrawal.
After the wires of cable harness have been dispensed, the cable
harness can be removed from the board for assembly of other cable
harnesses. Preferably, any additional processing of the cable
harness desired is performed prior to removal from the board. For
example, when the wire retainers are fixed to the board and are not
removed with the cable harness formed, the wires are tied or
otherwise secured to maintain the desired configuration required
for use including branch separation and orientation in two or more
axes on individual configurations desired.
Individual wires are precoded to identify each wire and the length
thereof. Accordingly mark sensors provide for detection of the
beginning of each wire length by the physical configuration of a
wire-mark. The absence of a wire-mark, or the exhausting of a
supply of wire selected to be dispensed, is also detected to
interrupt wire dispensing operations for the selected wire.
While the system of the present invention, as described herein, is
directed to wire dispensing, strand material including fibers,
fiber optical strands and tubing, other corresponding elongated
materials which are capable of being dispensed between points by
the system are intended to be included in the present invention.
Further, the term cable harness, as used herein, refers to strand
material dispensed to form interconnections between termination
sites in which common paths between these sites form branches of
the cable harness.
Accordingly, it is an object of the present invention to provide a
system for ordered dispensing of wire or other strand material and
the like, having the foregoing features and advantages.
Another object of the invention is the provision of an improved
system for automatic dispensing of strand material and the like to
form a desired cable harness configuration of individual
strands.
A further object of the present invention is to provide a system
arrangement for dispensing strand material about strand retainers
according to a stored program which controls the dispensing
operations to dispense the strand material about the retainers in
order to locate the strand material in the desired cable harness
configuration.
Another object is to produce a cable harness or the like by
dispensing a length of strand material in a pattern which is
determined, in combination, by the path of strand dispensing and
retainers on a forming board providing for layout and removal of
the strand material.
A further object of the invention is to provide a feed arrangement
for regulating the tension of strand material being dispensed.
Still another object is to provide a system arrangement for
facilitating the securing of strands at termination sites during
automatic strand dispensing.
Another object is the provision of strand dispensing arrangement
providing for selection, pay-out and regulated feed of any strand
of a group being selectively dispensed.
Other objects and features of the invention will become apparent to
those skilled in the art as the disclosure is made in the following
detailed description of the preferred embodiment of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing the wire dispensing system
arrangement of the preferred embodiment of the invention for
ordered dispensing of wires to form wire harnesses;
FIG. 2 is a front view of one of the wire dispensing heads shown in
the system of FIG. 1, having covers removed to show the structural
arrangement thereof and partly broken away to show a typical feed
tube assembly;
FIG. 3 is a sectional view of the dispensing head shown in FIG. 2
taken along a sectional line 3--3 and showing a selected one of the
feed tubes lowered into position for securing a wire at a
termination site;
FIG. 4 is an enlarged detailed view of a section of a termination
block of the site shown in FIG. 3 for showing certain details in
the securing of a wire at the termination site;
FIG. 4a is a detailed view of the preferred radial pattern for
securing the end of the wire in the termination block shown in
FIGS. 3 and 4;
FIG. 5 is a top view of the termination block;
FIG. 6 is a schematic diagram for the wire-mark sensors of the wire
guide-sensor assembly including a sectional view of a typical
sensor and the logical circuit diagram therefor;
FIG. 7 is a top view of the wire guide-sensor assembly including
six wire-mark sensors for individual wires for each wire dispensing
head.
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 a head
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. No. 3,252,147 and No. 3,262,105. 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 22 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 16 being 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 10
in pay-out operating mode securing a selected wire 16a at a
selected location at a wire group termination site 15 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 11 to respective channels 27 of
the guide roller 26, and vertically 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 16 in 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 corresponding 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 20 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 25 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 two 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 drive to 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 selected
griphole 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 moved from its position at shearing edge 33 of the cutter bar
assembly 32 through the 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 16a is paid
out to 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 15
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 No. 1, No. 2 and No. 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 30a 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 22a is positioned in griphole 40 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 bar's 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 X-Y movements, indicated as wire laying levels No. 1,
No. 2, No. 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 plunger 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 end of 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 primary positioner.
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. These
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.
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 two pounds or in the range of
approximately one to three pounds, for example. The preferred slit
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 provided for
insertion of a 0.125 inch diameter insulated wire (16-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 .250 inch outside diameter,
1/2 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 pattern can 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 1/8
to 1/4 inch in thickness having a shore hardness of 40. A resilient
layer 53 formed of neoprene of 1/8 inch thickness and having a
shore hardness of 40 was preferred to provide for ease in insertion
and withdrawal of the feed tubes 22 while providing more than
adequate retaining force on wires 16. In the testing of the
griphole construction, it was found that the 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 the 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 charge 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.
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 1/4 thickness and a shore
hardness of 40. At a shore hardness of 70, the force increased from
four pounds to within the range of six to eight pounds with a
radial slit pattern diameter of 3/8 inch in a 1/2 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 coaxially with the
griphole or in a direction normal thereto, such as produced in
movements of withdrawal of the feed tube 22 from a griphole or
during travel parallel to the surface of the board 18. Thus, the
retention by the resilient material of layer 53 is directly related
to the elasticity of the material and the coefficient of friction
between the material of layer 53 and insulating plastic of the wire
16a. Preferably, the gripholes 40 are formed by an opening of
minimum diameter suitable to accommodate the outside diameter of
feed tubes 22 and tolerances required for positioning of the feed
tubes coaxially with the opening. Assuming 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 the end 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 sensor 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 the wire
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 the wire passing these photo-detectors 65, 67.
In operation, a difference in output of photo-detectors 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 to the driver 64. The signal output of
amplifier 64, in response to the difference signal at its input is
represented in FIG. 6 by a pulse MS which is coupled to the logical
circuitry 70 shown in the lower portion of FIG. 6. The mark pulse
MS is passed by an OR gate 69c via AND gate 69 which is enabled by
a logical input OS.sub.30 from timing circuit OS30 which input is
present during the mark detection period to trigger a timing
circuit OS15 at input os.sub.15. Circuits OS8, OS15, OS30 and OS31,
i.e., one-shot timing circuits, define the pay-out interval at the
beginning of each wire dispensing cycle wherein circuit OS8 is
triggered by a signal g57 upon selection of a feed tube 22 and
prior to plunging thereof to pay-out an eight-inch length of wire
16a into feed tube 22, for example. The length of wire paid out
during the period of circuit OS8 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 OS30 is triggered to define
a mark sensing interval in which an additional length of wire 16a
is paid-out. The time period of OS30 provides for a maximum pay-out
of 30 inches of wire 16a, for example, but circuit OS30 is reset
when the wire-mark 63 is sensed and circuit OS15 is triggered to
payout a maximum of 15 inches of wire from the time circuit OS15 is
triggered. Timing circuit OS15 is triggered by mark pulse MS passed
by a gate 69 enabled by the (true) output OS.sub.30. 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 OS8, a flip-flop
M2 is provided to store the mark pulse MS for later triggering of
the circuit OS15, i.e., after the OS8 time period. Accordingly, a
gate 69b, enabled by output OS.sub.8, provides for passing pulse MS
for storage by flip-flop M2 which is reset by output OS.sub.15. The
OR gate 69c passes pulse MS or the output of AND gate 69a to
trigger the timing circuit OS15. The flip-flop circuits M1 and M2
and timing circuits OS8, OS15, OS30 and OS31 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.sub.15 is
produced which extends the pay-out 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.sub.1 which
interrupts operation of the wire dispensing head and system.
The maximum time period for wire-mark sensing is determined by
timing circuit OS30 and at the end of the sensing period, circuit
OS30 times out to produce output OS.sub.30 '. In the absence of a
wire-mark pulse MS, outputs OS.sub.15 ' and OS.sub.31 gate the
output OS.sub.30 ' to trigger flip-flop M1. A timing circuit OS31
provides an overlap in the mark sensing time period for gating
output OS.sub.30 ' and is triggered along with circuit OS30 by
control signal g58 at the beginning of the wire sensing period.
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
OS.sub.30 (and OS.sub.8). As indicated previously, timing circuit
OS15 defines the pay-out interval after wire-mark 63 is detected
and a pulse output from amplifier 64 during this period of OS15
indicates the end of the wire, or a second wire-mark 63 has
occurred erroneously. Preferably, the output OS.sub.15, 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.sub.1 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
wire-mark 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.degree. 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.degree. relative to the axis thereof before deflection and the
aperture formed therein has a minimum diameter of approcimately 20%
less than the outer diameter of the wire passing through the guide
tube. This wire guide asembly 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 FIGS. 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 the
diaphragm 76 is approximately 20 percent smaller in diameter than
the midrange diameter wire in a particular 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 wire was 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 10 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. 1, 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 40 for the head 10 shown in FIG 3,
wire 16a is paid-out into feed tube 22a by energization of
pneumatic acutator 35 which positions pinch roller 34 to engage and
press wire 16a 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., eight
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 16ais 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 60 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 16a 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, No.
1, No. 2, No. 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 No. 1, No. 2, or No. 3, depending upon
the amount of clearance needed to pass over previously laid wires,
if any; the wire dispensing head 10 is moved along the desired path
towards a termination site 15 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.
Also, during the feed interval, the wire diepensing 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 16a
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 16awith 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 the wire
16a, for example, feed tube 22ais 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 16ain the latter griphole 40,
the feed tube 22a is retracted by actuator bar 36 to the position
shown in FIG. 3 by dashed line 36'. Solenoid 46 is then
de-energized to complete the wire dispensing cycle. The wire
dispensing head 10 is then moved to the next griphole 40 and the
next selected feed tube 22 is positioned in the following
programmed griphole 40 to dispense the desired wire 16 in the wire
harness layout pattern.
In the light of the above teachings of the preferred embodiment
disclosed, various modifications and variations 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 variations of 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.
* * * * *