US3460230A

US3460230A - Electrical contact attachment apparatus

Info

Publication number: US3460230A
Application number: US627983A
Authority: US
Inventors: Norbert L Moulin
Original assignee: Hughes Aircraft Co
Current assignee: Raytheon Co
Priority date: 1967-04-03
Filing date: 1967-04-03
Publication date: 1969-08-12
Anticipated expiration: 1986-08-12

Description

Aug. 12, 1969 N. 1.. MOULIN ELECTRICAL CONTACT ATTACHMENT APPARATUS 4 Sheets-Sheet '1 Filed April 3. 1967 Norbert L. Moulin,

INVENTOR.

rime- ATTORNELV Aug. 12, 1969 N. 1.. MOULIN 3 I ELECTRICAL CONTACT ATTACHMENT APPARATUS I Filed April 5. 19s? 4 Sheets-Sheet 2 Fig. 2.

Norbert L. Moulin,

INVENTOR I ATToRMEY.

IIIII/l/IMIII Aug. 12, 1969 I N. L. MOULIN 3,460,230

ELECTRICAL CONTACT ATTACHMENT APPARATUS Filed April 3, 1967 4 Sheets-Sheet 5 I a N 0 g V I 5g Norbert L. Moulin, r' INVENTOR,

mum-M ATTORNEY.

S'- 12, 1969 N. L. MOULIN 3,460, 30

ELECTRICAL CONTACT ATTACHMENT APPARATUS Filed April 3, 1967 4 Sheets-Sheet 4.

Fig. 5.

Norbert L. Moulin,

INVENTOR.

IL- 'M ATTORNEY.

United States Patent 3,460,230 ELECTRICAL CONTACT ATTACHh/IENT APPARATUS Norbert L. Mouiiu, Placentia, Calif assignor to Hughes Aircraft Company, Culver City, Caliil, a corporation of Delaware Filed Apr. 3, 1967, Ser. No. 627,983 Int. Cl. B21d 37/00 U.S. Cl. 29-203 4 Claims ABSTRACT OF THE DISCLOSURE This disclosure describes an apparatus for semi-automatic crimping of electrical contacts to electrical conductors. The apparatus includes electro-mechanical elements which are controlled to operate a crimping tool to attach one electrical contact to a conductor during each cycle of operation of the machine. The cyclic control is achieved through a motor-driven cam driving a mechanical linkage for operating the crimping tool and an electrical timing mechanism for controlling the rotation of the motor.

This invention relates to an apparatus for attaching an electrical contact to the end of an electrical conductor and more particularly to a semi-automatic device for crimping electrical contacts to electrical conductors.

Complex electronic equipment requires many thousands and often tens of thousands of electrical conductors to inter-connect the various electrical components. Since many of these conductors are connected to connectors or terminal boards, a necessity has arisen for the development of fast operating, reliable equipment for attaching electrical connectors to such conductors. This attachment requirement becomes critical when the conductors and contacts are small in size because of the extreme difiiculties in handling such conductors and using hand-operated devices for their attachment.

One method of attaching a small contact to an electrical conductor and perhaps for most operations, a preferred method, is to crimp the barrel of the contact so that it grips the metallic portion of an electrical conductor.

Therefore, it is an object of the present invention to provide an improved machine for semi-automatically attaching an electrical contact to an electrical conductor.

It is a further object of the present invention to provide a preferred embodiment wherein the barrel of the electrical contact is crimped to an electrical conductor in a semi-automatic fashion.

A still further object of the present invention is to provide in a semi-automatic contact crimping apparatus a control for maintaining a storage of electrical contacts. This control is operative only for a predetermined time interval sufficient to maintain the storage of such contacts at a predetermined level.

The above and other objects of this invention are accomplished in a preferred embodiment which comprises the general elements for storing a large number of electrical contacts and dispensing them into an orientation so that each may be automatically positioned to receive an electrical conductor and to be crimped thereto. This storage, positioning, and crimping operation is achieved through an electro-mechanical structure which comprises a vibratory hopper and track assembly, an electric motor and cam, and a crimping tool which is positioned to receive a contact from the track and to be activated by the motor and cam mechanism as part of the cyclic operation of the machine. A capacity level control is associated with the track assembly so that the vibratory hopper is activated only when it is necessary to bring the quantity of the contact stored in the track assembly to a predetermined maximum number.

Other objects, features, and advantages of this invention will become apparent from reading the following detailed description of one embodiment of this invention and referring to the accompanying drawings in which:

FIGURE 1 is a plan view of an improved electrical contact attachment apparatus construction in accordance with the principles of the present invention and with the cover removed for clarity.

FIG. 2 is a side elevational view taken from the right side of the apparatus shown in FIG. 1. The mounting blocks for the control switches have been cut away to show the cam surfaces, and the crimping tool has been removed for clarity.

FIG. 3 is a plan view of the track assembly and the light sensitive switch members shown in FIG. 1 with the guide bushing shown in FIG. 4 removed for clarity of illustration.

FIG. 4 is a sectional view taken along the line 44 of FIG. 3 but showing the guide bushing attached to the track assembly and aligned with the slot.

FIG. 5 is a sectional view of the track assembly, one light sensitive switch member and the corresponding light source and mirror.

FIG. 6 is a schematic drawing showing the control switches and the cam surfaces of the cam mechanism.

Referring now to FIG. 1, the principles of the present invention are embodied in a preferred embodiment which includes the general structural elements of a feeder bowl or hopper '10 for storing or dispensing in a predetermined orientation, a plurality of relatively small elongated contacts 12, such as a conventional crimp type removable contact. The hopper 1G is typically a vibrating device, such as a Model SA-VFC manufactured by Automation Devices, Inc., Erie, Pa., and includes a helical ramp 18 around the periphery of the bowl. The use of such a device as this is conventional in the handling of small objects such as contacts since it can readily handle a small object in a predetermined orientation. As each contact 12 reaches the top of the ramp 18, it drops into a groove 20 in a plate or platform 21. The groove 20 is of a width and depth sufiicient to permit each contact 12 to be oriented with the barrel thereof extending upwardly, or away from the groove 20. Near the end of groove 20, from that nearest the top of the ramp 18, is a return tray 22. The tray 22 receives misaligned or misoriented contacts and returns them to the hopper 10 through a slot (not shown) in the wall of the bowl.

A track member or guide device 14 is positioned near the hopper 10 at the end of the groove 20 with one end raised so that the contacts 12 may be dispensed from the hopper it into the track. Positioned near the other end of the track 14 is a crimping tool 16 such as a Model MS3l914 manufactured by Daniels Manufacturing Corp, Pontiac, Mich. Thus, as the contacts 12 are dispensed from the hopper 10 they move down the track 141 under the force of gravity into a predetermined location relative to the crimping tool 16. Associated with the crimping tool 16 is an electro-mechanical mechanism which positions each contact and operates the jaws of the crimping tool 16. For convenience, these elements and components are packaged in a relatively compact enclosure 23 which includes a cover 17, FIG. 2, along with appropriate indicators and control instrumentation to provide operative equipment.

In FIGS. 2, 3, and 4 is shown in detail the electromechanical mechanism utilized to develop the cyclic operation of the apparatus. Referring primarily to those figures, the track assembly 14 comprises an elongated structure having two halves 24, 2% which are spaced a predetermined distance apart and are flanged to define a groove 28. As the contacts are dispensed each is supported by the flanges with a portion of the contact below the flange in the groove 28. Near one end of the track assembly 14 is a track relief or slot 30 of a diameter slightly larger than that of the electrical contact to be handled by the track. In association with the slot 30 is an escapement mechanism 32 carrying a bearing mounted plunger 34 movable in the slot 30 and in a guide bushing or member 36 attached to the track assembly 14 and aligned with the slot 30. Secured to one side of the track assembly 14 are a pair of light

sensitive switch members

38a, 38b and a solenoid plunger mechanism 40. The light sensitive switch members function to control the actuation of the vibratory hopper and will be described in more detail in relationship to a description of FIG. 5. The solenoid mechanism 40 functions to separate the contacts, to make sure that only one moves into the slot 30 at a time, and to assist the alignment of the contact 12, in the slot 30. This mechanism is timed as part of the sequence of each cycle; thus, as one of the contacts moves to the edge of the slot 30, the solenoid is activated and a plunger (not shown) advances to separate and locate the contact from any adjacent contact to which it may have inadvertently become attached and to push it into the slot 30.

An electric motor 41 is supported by a bulkhead 43 forming part of the structure of the housing 23 and includes a pinion gear 42 attached to its output shaft which drives a bevel gear 44. The bevel gear 44 is attached to one end of a shaft 45 which contains at its other end a crank member 46 and intermediate thereof a cam member 48. A connecting rod or rocker arm 50 is pivotally mounted to a spacer (not numbered) attached to the bulkhead 43 and at one end contains a roller 52 which rides in engagement with a first cam surface 54 of the cam member 48 and at the other end a U-shaped finger contact 56 which engages the plunger 34 of the escape ment mechanism 32. The connector rod 50 is springloaded by a spring 57 hearing against the bulkhead 43 so that after each cycle it returns to a predetermined starting position. The cam member 48 also contains a second cam surface 58 around the periphery of the member 48 near the end thereof opposite from that containing the first cam surface 54.

Referring to FIG. 1, as well as FIG. 2, attached to the crank 46 is a roller bearing 60 which rides in a notch 62 in a first lever arm 64 of the crimp tool operating mechanism. The first lever arm 64 is pivotally attached to the bulkhead 43 at a point 70 and includes a connecting linkage 66 afiixed to it as well as to a second pivotal lever arm 68. The second lever arm 68 is pivotally indirectly attached to the bulkhead 43 at a point 72 and includes at the other end a roller 74 which is in engagement with one of the arms 76 of a crimping tool 16. The point 72 of pivot of the second lever arm 68 is adjustable to accommodate different crimping tools with varying size arms by mounting the pivot point 72 on a disc 78 which is rotatable in a dent in the bulkhead 43 and once rotated is held securely by a lock nut 80.

A counter-clockwise movement of the crank shaft, as shown by an arrow 82 (FIG. 1), causes the levers to move in such a fashion that the second lever arm 68 rotates clockwise; thus, moving the movable arm 76 of the crimp tool 16 toward a stationary arm 84 to radially move the jaws (not shown) of the crimping tool 16. To facilitate the insertion of the end of the electrical conductor into the barrel end of the contact when it is positioned in the jaws of the crimping tool, a disked plate 86 having a central bore 88 is mounted on the top of the crimping tool 16 and secured by a bent spring 90.

A desirable feature for any automatic or semi-automatic apparatus is to provide controls to deactivate parts of the apparatus when they are not needed. In the present invention the vibratory hopper 10 needs to be activated only when it is necessary to feed contacts in the track assembly 14. One of the pair of light sensitive switch members 38a is used to deactivate the vibratory hopper 10 when a predetermined maximum number of contacts are stored in the track 14 and the other light sensitive switch member 38b is used to activate the hopper 10 when the number of contacts in the track is below a predetermined minimum number. Referring to FIGS. 1 and 5, this control is accomplished by mounting a light source 92, such as a light bulb, on the other side of the track assembly 14 from each of the light

sensitive members

38a, 38b which may be a conventional photo relay, such as a Model 8RCO1A, manufactured by Sigma Instruments, Inc., Braintree, Mass, and coupling the light energy to the photo relay by a mirror 93 and a chamber 94 extending across the track assembly 14. When a contact is aligned with th chamber 94, insufiicient light falls upon the photo relay to deactivate it. Thus, when the track 14 contains contacts sufficient to align a contact with the chamber associated with the light sensitive member 38a, nearest the hopper 10, the hopper will be deactivated; however, when sufiicient contacts have been removed from the track so that one is not aligned with the chamber associated with light sensitive member 38b, nearest the tool, the vibratory hopper is again activated so that additional contacts can be dispensed and stored in the track 14.

The apparatus is controlled so as it performs one crimping operation each time a foot switch or other control 95 is depressed or placed in an activating condition. Such control is accomplished through a conventional capacitor relay circuit (not shown) which is coupled between a source of electrical energy 97, such as volts AC, and the motor 41. In FIG. 6 the control device is shown in a condition before the motor is activated, that is the foot switch is not activated. However, when the foot switch is activated in a conventional fashion a charged capacitor discharges to close a relay through a first normally closed limit switch 98 which is held closed by a first portion 103 of the second cam surface 58 of the cam member 48. This locks the relay closed for approximately of motor rotation at which time the relay opens. However, a second normally closed limit switch 100 is activated at a point approximately 165 from the starting position of the motor rotation and this operates the motor for the additional rotation since both of the

switches

98, 100 are in parallel between the power source 97 and the motor 41 at which time the switch 100 opens stopping the motor. A slight overlap of motor control occurs, the first switch 98 controlling the motor relay from 0 to 179 of rotation with the second switch 100 closed starting at 166 and although the first switch 98 opens at 179, the second switch 100 remains closed until one revolution is completed. At any time the foot switch is depressed, it may be released and the machine will complete one cycle or if the foot pedal remains depressed the machine will complete one cycle. A third limit switch 101 is operated by a second portion 105 of the cam surface 58 and is coupled in series between the power source 97 and the solenoid 40 to provide a pulse to the solenoid during every cycle of operation. Shown in dashed representation in FIG. 1, the limit switches are mounted on blocks (not numbered) on opposite sides of the second cam surface 58 at heights to enable each to be operated by the appropriate cam surrface with the second switch 100 and the third switch 101 on adjacent steps in the same block (not numbered).

As the machine makes one operation, it crimps a contact, ejects it, and positions a new contact for crimping. Starting with a contact in position for crimping, the following events takes place. The operator inserts the end of the conductor into the wire barrel of the contact beneath the aperture 88 and between the jaws of the crimping tool 16 and trips the foot switch 95. The motor 41 starts powering the crank 46 and the first lever 64 whereupon the second lever 68 draws the movable crimping arms 76 toward the fixed arm 84 which radially moves the jaws of the crimping tool 16 to crimp the contact on to the wire. As the crimping tool 16 is closing, the plunger 34 in the escapement mechanism 32 moves down by means of the connecting rod or rocker arm 50 and allows the next contact in the track assembly 14 to slide down into the slot 30 where the plunger 34 on its way up pushes this contact through the guide bushing 36, ejecting the previously crimped contact out of the aperture 88 and locates the next contact in the proper position for crimping. To clarify this operation, the plunger 34 may not move down until the indentors or jaws (not shown) of the crimping tool 16 are applying pressure on the contact being crimped. When this occurs the plunger 34 moves down to pick up a new contact as the crimping tool 16 continues to close. As the plunger 34 reaches the bottom of its stroke, it pauses allowing time for one of the stored contacts in the track assembl 14 to fall intO the slot 30 with the assistance of the solenoid and plunger 40 into a position where the plunger 34 picks it up on the upward stroke pushing it through the guide bushing 36, ejecting the crimped contact out of the crimping head which has released the contact it has just crimped and positions the new contact for crimping. The timing for this operation is controlled by the contour and position of the first cam surface 54 and the second cam surface 58 of the cam member 48.

To insur the reliability of the crimp and to prevent the user from having doubt of the machines reliability, the crimping head in this present embodiment is a standard production hand crimp which includes a ratchet mechanism that insures a complete cycle before a contact can be released from the tool. The crimping machine powers this hand crimp tool; thus, any failure of the machine to complete a full cycle would prevent further operation of the machine and also prevent removal of a contact with an incomplete crimp.

To remove the crimping tool 16 from the machine, or to clean out the track assembly, or to purge the machine of contacts without crimping them, no tools are required. To remove crimping tool 16 or clean out the track assem bly 14, deflect wire spring 90 and remove guide plate 86, the hand crimp may now be removed. Further access to the track assembly 14 can be obtained by removing the guide bushing 36 and a track cover 104. To purge the machine of contacts without crimping them, an ejector spring can be provided adjacent to the slot 30 (not shown). Such a spring would not be accessible unless the crimping tool were removed so as to further insure that a, person who might purge the machine to change contact size would be reminded to adjust the hand crimp tool to the correct setting for that specific contact.

Another feature the machine contains is a pair of conventional

digital counters

110, 112. One counter 110 can be set at any quantity of machine cycles and at that time, the predetermined counter turns off the machine and lights an indicator lamp 114 notifying the operator that the quality of the crimp must be verified and the other counter 112 can be used to indicate continuously the total number of cycles. Both of the

counters

110, 112 may be powered through one of the limit switches or other pulsing element of the control circuit. To reset the counter and start the machine, a key 116 for the specific purpose is required. This allows the crimping quality of the machine to be checked every so many predetermined cycles. Due to the ease with which the hand crimp tool can be removed from the machine a quality assurance person could at the time the machine has reached the predetermined count, remove the hand crimp tool and replace it with a calibrated tool, reset the counter and production could continue in a matter of seconds while the removed hand crimp tool is recalibrated. The machine is capable of crimping most crimp type removable contacts by changing the track assembly, hopper, guide plate, and hand crimp tool.

While the basic principles of this invention have been herein illustrated, it will be appreciated by those skilled in the art that variations in the disclosed arrangement both as to its details and as to the organization of such details may be made without departing from the spirit and scope thereof. Accordingly, it is intended that the foregoing disclosure and the showings made in the drawings will be considered only as illustrative of the principles of the invention and not construed in a limiting sense.

What is claimed is:

1. An apparatus for attaching an electrical contact to an electrical conductor comprising:

a hopper containing a plurality of electrical contacts and adapted to dispense said contacts from a predetermined location on the periphery of the hopper and at a predetermined rate;

a track assembly cooperating with said hopper and positioned adjacent to said predetermined location for receiving said contacts in an in-line fashion and in a predetermined orientation as they are dispensed from said hopper and including at one end a slot;

said track being inclined with its higher end nearest said hopper so that said contacts move along said track under the force of gravity and are in turn aligned with said slot near the lower end of said track;

a crimping tool juxtaposed with said track and including radially movable jaws having a centerline coaxial with the longitudinal centerline of said slot;

a plunger movable in said slot for moving, in turn, each of said contacts to a position where it may be contacted by the jaws of said crimping tool;

an electrical motor and a source of electrical energy coupled thereto;

a cylindrical cam member mechanically coupled to said motor for rotation thereby and having a first cam surface formed in one end and second cam surface formed in a portion of the periphery of said member near the other end thereof;

a plurality of electrical switches positioned adjacent to said cam member with the contact elements thereof engaging said second cam surface, said switches being electrically coupled between said motor and source of electrical energy to control as a function of the shape of said second cam surface the activation of said motor and correspondingly the rotation of said cam member;

a mechanical linkage coupled to said motor for rotation thereby and to said crimping tool for radially moving the jaws thereof;

a contacting rod having one end coupled to said plunger and the other end engaging said cam member so that said plunger moves in a reciprocating fashion as a function of the shape of the first cam surface;

whereby said first cam surface is of a shape permitting said switches to activate said motor sufiiciently to produce one revolution of said motor and said second cam surface is of a shape permitting said plunger to move through one cycle of reciprocating movement during each revolution of said motor.

2. The apparatus of claim 1 wherein the hopper is coupled to a source of electrical energy and is adapted to vibrate at a predetermined frequency.

3. The apparatus of claim 1 wherein the hopper is coupled to a source of electrical energy and is adapted to vibrate at a predetermined frequency, said apparatus also including a pair of light actuated switches positioned adjacent to said track and electrically coupled between said hopper and said source of electrical energy therefor, each of said switches being near a different end of said track and each including a light source on one side of said track and light sensitive element on the other side of said track and a chamber connecting each light source with the corresponding light sensi- 3,460,230 7 8 tive element so that when an electrical contact is 10- that said contacts move along said track under the force cated in said track and aligned with said chamber of gravity and are in turn aligned with said slot. insufiicient light falls on said light sensitive cell to activate said light switch; wherein References Cited one of said switches disconnects the electrical energy 5 UNITED STATES PATENTS from said hopper when said track contains a prede- 2 9 29,433 3/1960 Andren 29-630 termmed maximum number of contacts and said oth- 3,329,002 7/1967 Schwalm u 7 16 er switch connects said electrical energy to said hopper when said track contains a predetermined minimum number of contacts. 10 4. The apparatus of claim 1 wherein the track assemhly inclined with its higher end nearest said hopper, op- THOMAS EAGER Pnmary Exammer posite the slot in the lower end further comprises a soles CL noid plunger mechanism to separate the contacts, to make sure that only one contact moves into the slot at a time, 15 and to assist the alignment of the contact in the slot so 2,965,957 12/1960 Packard. 3,056,446 10/ 1902 Schmidt et a1.