US 3553475 A
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Description (OCR text may contain errors)
United States Patent Inventor Richard A. Fee  Field of Search 307/18, 25, Stratford, Conn. 29, 10; 62/237Cons. Exam., 239, 243; ZOO/51.09 Appl. No. 800,302 Filed Nov, 27 9  References Cited Patented Jan. 5, 1971 UNITED STATES PATENTS Assignee Harvey Hubbell Incorporated 3,431,428 3/1969 Van Valer 307/10 f c la lz t iofzl zonnecticut FOREIGN PATENTS rpo 1,343,143 12/1963 France ZOO/51.09
ELECTRICAL CIRCUIT WITI-I POWER INLET CONTROL 2 Claims, 3 Drawing Figs.
US. Cl 307/18, 307/10, 62/237, 307/29 Int. Cl. H02] 1/10 P/(IHIIR Y Division of Ser. No. 597,160, Nov. 25, 1966, Patent No. 3,452,167.
Assistant Examiner-H. J. l-lohauser CIRCUIT Attorney-Wooster, Davis & Cifelli Primary ExaminerRobert K. Schaefer ABSTRACT: This disclosure relates to a primary circuit supplied with electrical power by a power inlet and an auxiliary circuit controlled by the power inlet. The power inlet carries an auxiliary circuit controlling switch which is actuated by the connecting and disconnecting of the power inlet with a mating electrical connector device to complete the primary circuit.
PATENTH] JAN 5197i 355K475 INVENTOR.
BY fwie mym w ELECTRICAL CIRCUIT WITH POWER INLET CONTROL This application is a division of my copending patent application Ser. No. 597,160, filed Nov. 25, 1966, now U.S. Pat. No. 3,452,167, entitled Power Inlet With Auxiliary Circuit Controlling Switch.
This invention relates to a locking electrical connector and, more particularly, to an improved locking electrical connector wired in a primary circuit wherein the connection and disconnection of the connector parts actuates a switch controlling an auxiliary circuit.
It is known to supply a temporary source of electrical power to an electrical system or device on a mobile unit through a separable locking electrical cable connector. For example, to supply electrical power from a supply cable connector body to a power inlet on a refrigeration unit of a truck or to the electrical system of a yacht. Of course, when the electrical requirements of the mobile unit are satisfied, the connected connector parts, i.e. power inlet and connector body, are disconnected and the mobile unit is ready to be moved. However, problems arise in practice when the mobile unit, for example, a refrigerator truck or a moored yacht, is inadvertently moved away from a dock without disconnecting the connector body from the power inlet. This usually results in destruction of the electrical power cable and/or connector, and subsequent expensive repairs and down time of the power supply dock.
Accordingly, it is a primary object of the present invention to provide an improved electrical connector wired in a primary circuit which incorporates a switching means arranged to be connected in an auxiliary electrical circuit to be controlled, for example, the ignition circuit of a truck or yacht, to control the auxiliary circuit in a desired manner, for example, to prevent the engine of the truck or yacht from being started while the power cable is connected to its power inlet.
Another object is to provide in combination a power circuit and an auxiliary circuit'wherein the condition of the power circuit controls the condition of the auxiliary circuit.
To accomplish these objects, in one form, a power inlet and connector body are provided wherein a main source of electrical power is conducted through said body and inlet to supply a primary circuit, and a switching means is incorporated into said power inlet and arranged to control an auxiliary circuit in response to the connection and disconnection of said power inlet and connector body.
Other objects and further details of that which I believe to be novel and my invention will be clear from the following description and claims taken with .the accompany drawing, wherein:
FIG. 1 is a wiring diagram showing a representative circuit including a primary circuit, an improved connector therefor, and a secondary circuit controlled by the connector;
FIG. 2 is a side elevational view of a separated connector body and power inlet constructed in accordance with the present invention; and
FIG. 3 is an enlarged side elevational view of the FIG. 1 connector body and power inlet shown in position during their connection prior to full connection, with portions of the power inlet broken away and shown in section to illustrate the auxiliary circuit switch in the power inlet.
With particular reference to the drawing there is illustrated a connector body connected to a source of electrical power through a usual electrical power supply cable C. The connector body 10 is constructed to be selectively connected to the flanged power inlet 12 which is secured to the wall W of a mobile unit, for example, a refrigeration truck or the like. The power inlet 12 is, in turn, electrically connected in a primary electrical circuit of the mobile unit, such as the refrigeration circuit shown in FIG. 1, by means of another electrical cable C. An auxiliary circuit switch assembly 14 including a switch 30 is connected in an auxiliary circuit to be controlled, such as the ignition circuit for the engine of the mobile unit, as shown in FIG. I. The switch 30 is designed to be normally closed allowing the ignition circuit to be actuated; however, when the primary circuit power supply connector parts 10 and 12 are connected, as a result of their construction the switch 30 is opened, thus preventing the actuation of the ignition circuit.
The power inlet 12 is provided with a flanged metal shell 16, insulation body member 18 and contact blades 20, one of which may be formed to function as a key and be a grounding contact. The leads of cable C are wired to the terminals of contact blades 20. The insulation body member 18 includes a bore 22 and a counterbored seat 24, arranged to accept the auxiliary circuit switch assembly 14. The connector body 10 may be of known construction and need not be specifically described; it does contain internally disposed receptacle contacts 21 arranged to receive contact blades 20, and includes an insulation body member having a substantially flat face 11.
The auxiliary circuit switch assembly 14 comprises a spring biased plunger 26 of electrical insulation material mounted for sliding movement in a central opening in bushing 42 of electrical insulating material mounted in one end of a tubular member 28, and a switch 30, which 'may be a miniature switch or other suitable switch means, mounted at the other end of the member 28. The tubular member 28 is open at both ends and includes an external threaded portion 32, a first internal threaded portion 34 and a second smaller diameter internal threaded portion 36. Member 28 is positioned in the bore 22 of the power inlet body member 18 and held in place by the clamping action of the lock nut 38 (threadedly mounted on threaded portion 32 and spaced from the body member 18 by the fiber washer 40) and the annular flange 46 of bushing 42 which has an external threaded portion 44 threadedly engaged with the first internal threaded portion 34 to mount it in the member 28. The flange 46 limits engagement of thebushing 42 with the tubular member 28 and also is mounted in the counterbored seat 24 to secure the tubular member 28 in the bore 22.
The spring biased plunger 26 comprises a tubular member including a closed normal wall 48 at one end and a circumferential flange 50 at its other end. The flange 50 is normally biased against the internal rim about the central opening 43 of bushing 42 by the operating coil spring 52 within which is mounted guide drive rod 54. One end of the spring 52 bears against the inner side of wall 48 and the other end biased against the head of rod 54 which, in turn, is biased against the switch actuating button 56 of the switch 30. The switch 30 has a threaded mounting hub 55 secured in the tubular member 28 in threaded engagement with the smaller diameter threaded portion 36. The switch 30.is constructed in a known manner, and in one form is commercially available as a MICRO switch and, therefore, will not be described in detail. It includes internal contacts (not shown) and terminals 30' for securing leads of the auxiliary circuit, and it is constructed to have its contacts engaged normally when the switch button 56 projects to its outermost position and to have its contacts disengaged when the switch button is depressed.
The operation of the improved power inlet should be readily apparent. The separable rotatably locking electrical connector parts 10 and 12 are electrically wired in the primary circuit in the normal manner, while the switch 30 is wired in the auxiliary circuit. When the connector body 10 is connected to the power inlet 12, and before electrical contact is made between the contact blades 20 and receptacle contacts 21 of the power inlet 12 and connector body 10, respectively, the connector body face 11 engages and pressure is exerted on the plunger 26. As the plunger 26 is forced axially into the switch assembly, on further movement of the connector body relative to the power inlet, the operating spring52 is compressed and the spring force is transmitted to the head of the operating rod 54, thereby depressing the switch button 56 of switch 30 which remains depressed until the connector body 10 is removed. Depression of the switch button results in opening the contacts of switch 30 and breaking the auxiliary circuit. The total travel of the plunger 26 required to actuate the switch is very small compared to the total length of travel of the plunger and occurs at the initial movement of the plunger before the primary circuit is closed. The amount of travel needed can be increased or decreased by adjustment of the spring tension which is effected by the position of securing means 38 and 42 on the tubular member 28.
Referring to the schematic wiring diagram shown in FIG. 1, there is illustrated a primary circuit denoted as a refrigeration circuit which is a part of an electrical system on a mobile unit, such as a truck, requiring electrical power. This primary circuit receives electrical power through the power inlet 12 when the connector body is connected to it. As is readily apparent, connection of the connector parts causes elements of the auxiliary circuit switch assembly 14 to be actuated mechanically, thereby opening the switch 30 and breaking the auxiliary circuit which is denoted as an ignition circuit, which may be that of the truck. This prevents inadvertent operation of the vehicle while the connector parts are connected and thus protects the primary electrical supply cable and its connector.
The switch of the power inlet may contain normally closed contacts, normally open contacts or both to control plural auxiliary circuits. lf normally closed contacts are used, the power inlet will inactivate the auxiliary circuit. Conversely, the auxiliary circuit will be activated if normally open contacts used. Should the switch contain both normally open and normally closed contacts, it then becomes possible to control two auxiliary circuits with a single device and open one and close the other. a
It is understood that the present disclosure has been made only by way of example, and that numerous changes in details of construction and the combination and arrangement of parts may be resorted to without departing from the true spirit and the scope of the invention.
1. The combination of a primary circuit and a secondary circuit wherein the completion of said primary circuit changes the state of said secondary circuit, comprising: a main power source; a connector device; conductive means connecting said power source to said connector device; a power inlet means arranged to be selectively detachably connected to said connector device; conductive means connecting said power inlet means to said primary circuit so that said primary circuit may be energized;.a power source for said secondary circuit; a switch in said secondary circuit in series with said secondary cir'cuit power source and switch actuating means carried by said power inlet means and responsive to the connecting and disconnecting of said power inlet means with said connector device to open and close said switch.
2. The circuits as defined in claim 1 wherein said switch actuating means comprises a reciprocable plunger carried by said inlet means in position to extend beyond the front wall of said inlet means when said inlet means is disconnected from said connector device and arranged to be depressed when said power inlet'means'and said connector device are connected, whereby the contacts of said switch may be engaged and disengaged by the extension and retraction of said plunger.