US2787313A - Connector installation control - Google Patents

Description

April 2, 1957 G. CHERNACK CONNECTOR INSTALLATION CONTROL Filed March 14, 1956 INVENTOR.

A TTOR/VEY United States Patent CONNECTOR INSTALLATION CONTROL Gilbert Chernack, New York, N. Y., assignor to Burndy Engineering Co. Inc., a corporation of New York Application March 14, 1956, Serial No. 571,457

6 Claims. (Cl. 153-1) My invention relates to connector installation by compression, and to the control thereof, to insure continuous high quality connections.

Such connections are made, for example, by inserting a wire into a terminal and placing the assembly into a die. The indentor on the ram of the compression equipment is then forced into the terminal, swaging it to provide an electrical and mechanical bond between the connector and the conductor. The depth to which the indenting member penetrates into the terminal is the most critical factor. It determines both the electrical and the mechanical characteristics of the resultant connection. The compression equipment usually provides for changing dies to accommodate a variety of connector sizes. Damage will result if the ram is allowed to descend when a die is improperly placed in the press.

Accordingly, the principal object of the present invention is to provide a control mechanism designed for use with pneumatic and/or hydraulic press equipment for insuring that an electrical connector has been properly installed to a conductor by signalling an improper installation; and which prevents the operation of the press unless the compression dies have been properly positioned.

I accomplish these and other objects and obtain my new results as will be apparent from the device described in the following specification, particularly pointed out in the claims, and illustrated in the accompanying drawing in which:

Fig. l is a side elevation of the press pump, connections and control mechanism, the pump and control mechanism shown mounted on a platform.

Fig. 2-is a top plan view of the pump and control mechanism.

Fig. 3 is a diagrammatic representation of the wiring circuit.

The. complete equipment, Fig. 1 comprises a press 10, a control means contained in the control box 12, and a pump 14.

The press, which is illustrated in Fig. l, as an example, may be of the type shown and described in co-pending application Serial No. 351,882, filed April 29, 1953, now abandoned. It comprises a C-shaped frame 16, containing a fluid driven spring loaded indentor 18, a die rack 20 containing various sized dies 22, and a rack knob 24 for locking the die rack in proper position for each die setting.

The fluid pressure for operating the indentor is supplied to the press through oil hose 26 from the pump 14. In the latter device is a free piston within a cylinder. Air from the hose 2% leading from the control box, is admitted to one end of the cylinder at an operating pressure of between 75 and 125 pounds per square inch. The other side of the cylinder is filled with hydraulic fluid, which may be built up to a maximum pressure of 6000 pounds per square inch by virtue of the difference in the cross-sectional areas of the air and oil sides of the pump piston. An oil accumulator tank 27 is connected to the oil side 29 of the cylinder of pump 14. The hydraulic fluid is used to actuate the indentor in the compression tool or press 10.

Each individual operation of the press is controlled by means of a solenoid and valve contained in the control box 12, which controls the air from the supply air line to the pump through hose 28. The solenoid and valve are indicated by reference numeral 30 in the circuit diagram of Fig. 3. When the solenoid is energized, air is admitted to the pump, causing the ram and indentor to descend. When a faulty connector installation has been made due to an incomplete ram'stroke, the solenoid is tie-energized, and air is cut off to the pump. This relieves the hydraulic pressure, allowing the spring-loaded ram-to which the indentor is mounted, to rise to its rest position.

The press 10 is preferably mounted to a special base 32 by means of bolts 34. A butt switch is used to warn the operator and prevent further operation ofthe press should the indentor be stopped by some condition from reaching the maximum penetration required for a proper bond. When the press is secured in position on the base, the butting switch arm 36 extends from a butt switch 38 contained in the control box (shown in the circuit diagram of Fig. 3), and is positioned with respect to the die 22 so that the arm will be depressed by the indentor 18 when the indentor butts the die to complete the stroke. This arm is released by the indentor when the pressure is released and the ram returns to its starting position.

Dam-age will result if the ram is allowed to descend when the die rack is improperly placed. To prevent this, there is installed a limit switch which is closed only when the rack, and selected die, are exactly in place. A rack knob switch arm 4-0 extends from a limit switch 41 in the control box (and shown in the circuit diagram), and is positioned alongside the rack knob 24 to indicate the proper position of the rack knob when locking the rack in proper position for using the dies. As was explained in the patent application for the press, Serial No. 351,882, the rack knob terminates in a tapered pin which is positioned in a recess on the rack for each position of use of the various dies. if the pin is not seated properly in one of the recesses, the knob will protrude and engage the switch arm 40.

The wiring circuit is shown diagrammatically in Fig. 3. The power source 42 is connected to various parallel branches, each containing elements in series.

One parallel series branch 44 contains a time-delay relay 46, hereinafter explained, in series with the butt switch 38 and a parallel connection of foot switch 48 and relay contact 50. Butt switch 38 is normally closed and its purpose is to reset the time-delay relay 46, when a good installation is made by opening this circuit. Foot switch 48 (shown diagrammatically in Fig. 3), normally open, is operated by the actuating lever 52 of the pump 14. Relay contact 50 is located on the time-delay relay and closes instantaneously when the relay is energized by closing of the foot switch.

The next parallel branch contains the limit switch 41 in series with several parallel branches. One of these branches has a relay contact 54 in series with a parallel combination of the solenoid 30 and a green signal light 56. A second branch has a relay contact 58 in series with a parallel combination of a red light 59, a trans former 60 and a buzzer '62 working olf the transformer. Another branch has another relay 64 in series with a counter 68.

There is a final parallel circuit containing a normally open position 41a of the limit switch 41 in series with a red signal light 59 and in parallel with the transformer 60 and buzzer 62. Thus, when the rack is properly positioned, the limit switch 41 keeps the circuit to the solenoid 30 closed and the circuit to the red light 59 open. Relay contact 54 is normally closed and is located on the timedelay relay 46. The contact 54 is timed open by relay 46, if a crimp has not been properly made. The green light 56 in parallel with the solenoid signals the operator that the press is ready for use. Relay contact 58 is normally open and is timed closed by the relay if a crimp has not been properly made, and controls the transformer 60 and warning buzzer 62 circuit and red light 59. Relay contact 64 is normally open and it is timed closed when an improper installation has been made, and closes the circuit to the counter 68 which records the improper installation.

To limit the time allowed for the indentor to butt against the die, the time-delay relay is energized when the circuit is closed. If the butt limit switch is not tripped within the allotted period, the time-delay relay acts to energize the warning device. Simultaneously, the solenoid valve is closed and a counter activated to record an incomplete operation.

When the control circuit is in the position as shown on the wiring diagram, the solenoid valve 30 is energized, thereby permitting air to flow to the pump 14 and the green light 56 is on, assuming the rack is properly positioned. To perform the installation, the operator presses the actuating lever 52 (and switch 48), thereby closing the circuit to the relay 46. This energizes the relay starting the installation cycle and closes contact 50, permitting the circuit to continue its operation if the operator releases the actuating lever and foot switch. The timedelay relay is adjusted to allow just enough time to perform the crimping operation. If we assume now that a good installation has been made by the indentor 18 butting on the rack die 22, then the butt switch 38 is depressed and opened by the indentor when it butts the die. This opens the circuit to the relay 46 and resets the relay, permitting further operation. If the indentor and die do not butt and thus fail to produce a satisfactory indent, the switch 38 is not opened. Relay contact 54 is then timed open by the relay 46 and opens the circuit to the solenoid 30, de-energizing the solenoid and cutting off the air supply to the pump 14. Also, the green light will go oh. At the same time, relay contact 58 will be closed when the time has expired, closing the circuit to the transformer 60 and the warning buzzer 62, and the red light 59 signalling the operator that the crimp is not satisfactory. At the same time, relay contact 64 is timed closed, closing the circuit to the counter 68 which records the bad installation.

Suppose now that the rack 20 is improperly positioned. In this case, the limit switch 41 is opened and closed in position 41a. The eifect of this is to de-energize the circuit to the solenoid and to the green light 56, deenergizing the solenoid, cutting oif the air supply, and shutting off the green light. The circuit to the red light is closed, causing the red light and the buzzer to signal the operator.

In place of the switch arm 36 and the butt switch 38, a hydraulic pressure switch 35, working olf oil hose 26, may be substituted. When the indentor has completed the installation to the proper depth, resulting in a build-up of oil pressure up to the maximum of 6000 pounds per square inch, the pre-calibrated hydraulic pressure switch is opened, like butt switch 38.

The control mechanism provides complete quality control and inspection of all connections made in the press. With the present apparatus, there is no need to depend upon the skill of the operator to determine whether the indentor has properly engaged the dies. By signalling 4 the operator when an unsatisfactory connection has been made, by preventing operation of the press, if the dies are not properly aligned, and by recording the improper installation of the connector, there is guaranteed continuous quality control of compression type connections, together with inspection of the most critical factor in any compression connector installation, the depth of indent.

I have thus described my invention, but I desire it understood that it is not confined to the particular forms or uses shown and described, the same being merely illustrative, and that the invention may be carried out in other ways without departing from the spirit of my invention, and, therefore, I claim broadly the right to employ all equivalent instrumentalities coming within the scope of the appended claims, and by means of which, objects of my invention are attained and new results accomplished, as it is obvious that the particular embodiments herein shown and described are only some of the many that can be employed to attain these objects and accomplish these results.

I claim:

1. A connector installing apparatus, comprising a press for indenting electrical connectors, having an indentor, a die for receiving the connector, a control mechanism comprising a circuit, a switch for keeping said circuit closed until the indentor has reached a predetermined position with respect to the die, and a limit switch for opening a circuit when the die is not in proper position for use with respect to the indentor, signal means for signalling the failure of the indentor to reach the predetermined position with respect to the die, and an operating means for moving the indentor to the starting position in the press when the indentor fails to reach the predetermined position with respect to the die.

2. The apparatus of claim 1 wherein a knob is provided for accurately positioning the die in the press, and the limit switch is provided with an arm positioned adja cent the knob to indicate its position.

3. The apparatus of claim 1 provided with a timedelay relay to limit the time allowed for each stroke of the indentor.

4. The apparatus of claim 3 wherein the time-delay relay is connected to the operating means to stop the operation of the press, if the time-delay relay operates to limit the time of the indentor stroke.

5. The apparatus of claim 3, wherein the time-delay relay is connected to the operating means to stop the operation of the press, if the limit switch fails to close.

6. The apparatus of claim 1 wherein the circuit includes the following elements: a source of power connected to a first group of parallel branches, one parallel branch containing a time-delay relay in series with a first switch and a parallel connection of an operating switch and a first relay contact; another parallel branch containing a limit switch with the open position of the limit switch in series with a first signal, and the closed position of the limit switch connected with a second group of parallel branches, one of the second group of branches containing a second relay contact in series with a parallel combination of a solenoid for controlling the operating means and a second signal; another of the second group of branches containing a third relay contact in series with a third signal; and still another of the second group of branches containing a fourth relay contact in series with a counter, with the various relay contacts located on the time-delay relay for opening and closing the circuits in accordance with the operation of the time-delay relay.

No references cited.

Images