US3475719A - Electrical connector - Google Patents

Description

ELECTRICAL CONNECTOR 2 Sheets-Sheet 1 Original Filed Jan. 19, 1965 EDGAR A. BONGORT m 5 0m K WA v T G L N U L E 6 m w 2 H 7/! ///////////W////// lf/{l/l/f/l/ll/l/ il/ll/l/ I/l/l/l/ Ill/l/ll/ f 2 K0 3 2 8 8 2 4 3 5 5 6 w 4 O 4 3L l III III mtff 11- L w. T. AKIN ET AL 3,475,719

ELECTRICAL CONNECTOR Oct. 28, 1969 2 Sheets-Shet 2 Iriginal Filed Jan. 19, 1.965

ii vd hv I T mR w N 0 TB GA a A G D WE United States Patent 3,475,719 ELECTRICAL CONNECTOR Welling T. Akin, Birmingham, and Edgar A. Bongort,

Southfield, Mich., assignors to B/W Controller Corporation, Birmingham, Mich., a corporation of Michigan Original application Jan. 19, 1965, Ser. No. 426,522, now Patent No. 3,313,902, dated Apr. 11, 1967. Divided and this application Mar. 23, 1967, Ser. No. 625,522 Int. Cl. Hillr 13/50, 9/08 US. Cl. 339-182 1 Claim ABSTRACT OF THE DISCLOSURE This disclosure relates to a socket type electrical connector for effecting connection between a plurality of electric wires and a coaxial arrangement of conducting surfaces such as the exposed ends of an electrode assembly useful in liquid level control devices.

In our copending application, Ser. No. 426,522 filed Jan. 19, 1965, now US. Patent 3,313,902 issued Apr. 11, 1967 of which this application is a division, we disclose an electrode assembly useful in liquid level control devices, and an electrical connector of the socket type which is adapted to be pressed over the projecting end of the electrode assembly to effect connections of electric leads therewith. The connector is of such construction that it tightly grips the end of the electrode assembly to avoid accidental dislodgment, and when in place on the electrode assembly substantially prevents the entry of moisture or foreign matter into the electrical connection.

This disclosure shows a female electrical connector for connecting a plurality of conductors to a male member having a plurality of axially spaced conductive end portions in which the connector is molded of resilient electrically non-conductive material in which there are a plurality of electrically conductive helical wire coils embedded in the connector for limited radial expansion upon mounting of the connector on the male member to engage the electrically conductive portions thereof and effect electrical connection between the conductors and said portions of the male member.

In the drawings:

FIGURE 1 is a vertical sectional view of a liquid carbonating tank showing an electrode assembly embodying the invention mounted therein and comprising an electrode unit and our improved electrical connector mounted thereon;

FIGURE 2 is a side elevation, partly in section, of the electrode assembly and the electrical connector shown in FIGURE 1;

FIGURE 3 is a cross-sectional view taken along line 33 of FIGURE 1;

FIGURE 4 is an exploded view, partly in section of a slip connector for the electrodes showing clip means for securing the connector to an electric conductor; and

FIGURE 5 is a perspective view of the parts of FIG- URE 4 shown in assembled condition.

In FIGURE 1 there is shown a liquid carbonating tank 20 having a cylindrical side wall 22 and a curved bottom wall 24 integrally secured together as by welding. The top of the tank is hermetically closed by a closure plate 26 havin apertures through which project the parts described herebelow.

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A liquid inlet fitting 28 having a check valve therein is threadedly received in a suitable aperture in plate 26, and includes an inlet passage 30 opening into the tank 20 and a liquid supply pipe 32 connected to a pump or the like (not shown) to supply water or other liquid to the tank 20. There is also a second fitting (not shown) threaded into plate 26 for the introduction of carbonic gas under pressure. Such may be identical to fitting 28 and adapted for connection through suitable pressure control devices to a cylinder of liquefied carbon dioxide in a well-known manner. Plate 26 also exhibits an unthreaded aperture 34 within which there is secured as by welding a liquid outlet fitting 36, the upper end of which is threaded as at 37 for connection to a pipe or hose. A liquid discharge tube 38 projects into the tank 20 from fitting 36 and terminates in an inwardly curved portion 40 having its open end adjacent the bottom tank wall 24 approximately at the centerline of the tank. Those parts of the carbonator described hereinabove are conventional in the art and form no part of the instant invention.

An improved electrode assembly embodying the invention is indicated generally by the numeral 42 in FIG- URES 1 and 2, and comprises an electrode unit and an electrical connector 80. The electrode unit comprises telescopically connected inner and outer electrodes 44 and 46 electrically insulated from each other by an intervening dielectric sleeve 50, with opposite ends of the electrodes being exposed for purposes hereinafter explained. A coupling or bushing 54 is telescoped over the electrode unit with an intervening dielectric sleeve 52 separating the outer electrode 46 from the coupling. Improved sealing means are provided for sealing the electrodes, sleeves and coupling against leakage of fluid pressure axially thereof. A cylindrical or tubular splash shield 66 may be provided which is supported on the electrode assembly and defines a chamber about the exposed end 46b of the outer electrode to prevent false liquid level sensing. The electrode unit is shown disposed vertically in the tank 20. Electrode 44 projects below electrode 46, and is provided with a threaded lower end to receive an enlarged tip 48 of carbon or graphite in accordance with common practice in the art.

More specifically there is interposed between the electrode rod 44 and the electrode tube 46 an insulating sleeve or tube 50 made of a suitable deformable dielectric material such as plastic or the like, polyvinyl chloride being suitable for this purpose, the opposite end portions of which project beyond the ends of tube 46 and grippingly encircle the rod 44, leaving however, the upper end 44a of the rod and the carbon tip 48 exposed, as shown in FIGURE 2. A second insulating sleeve or tube 52 of the same material as sleeve 50 snugly encircles electrode tube 46 terminating intermediate opposite ends of the tube to leave the ends exposed, as at 46a and 46b. An axially bored fitting or coupling member 54 is received over sleeve 52, and is provided with an externally threaded length 56 for reception within a threaded aperture 58 in the closure plate 26 of tank 20.

As shown in FIGURES 2 and 9, inner electrode rod 44 exhibits a circumferential groove 60 spaced from the outer end thereof. An elastomeric O-ring 61 encircles tube 50 radially opposite such groove. Outer electrode tube 46 has its upper ned counterbored as at 47 to form a lip 62 which is inwardly rolled or swaged radially opposite the groove 60 on the rod to compress the O-ring and force the sleeve or tube 50 into the groove 60 to the position shown in FIGURE 2. The contraction of the O-ring by the swaging or rolling of the lip places'the O-ring under compression and the inward circumferential force of the O-ring under the influence of the lip 62 displaces the tube 50 forcibly into groove 60, forming a fluid-tight seal between the rod 44 and tube 46 and in addition preventing relative axial movement therebetween.

The upper end of bushing 54 is counterbored similar to that of electrode tube 46 as shown in FIGURE 9. A circumferential groove 64 is machined in electrode 46 spaced from the upper end thereof. An elastomeric O- ring 65 is slipped over tube or sleeve 52 and positioned radially opposite groove 64. The lip 54a at the upper end of the fitting is then swaged or rolled over the O-ring to compress it radially and cause it to contract about insulating sleeve 52, in turn forcing the sleeve into the groove 64 to effect a fluid-tight seal between the fitting 54 and the outer electrode tube 46. This squeezing of the O-ring and sleeve 52 also locks the electrode unit in the fitting against displacement.

The elastomer selected for the manufacture of the O- rings 61 and 65 may be that normally used for fluid pressure sealing O-rings. In any event it should be of suflicient elasticity so that it will continuously urge the underlying sleeve forcibly into the respective grooves 60 and 64 despite tendency of the underlying sleeve to thin out slightly with cold flow. It will be noted that the O-rings are entrapped on three sides by the overlying swaged lip. The end of the lip is disposed adjacent the sleeve immediately above the O-ring to prevent extrusion of the O-ring.

In swaging or rolling the lip 62 and the lip 54a the respective O-rings are contracted about the sleeve as aforesaid. This contraction may arise from either or both of two actions of the lip. As shown in FIGURE 9 the O-ring is somewhat flattened in cross section prior to swaging of the lip. When the lip is swaged or flared over an axial loading is imposed on the O-ring tending to increase its cross-sectional radial dimension and forcing its inside surface against the sleeve to in turn press the sleeve tightly into the groove. This axial compression of the O-ring therefore serves to load the O-ring and contribute to the sealing action. During the rolling or swaging of the overlying circumferential lip the ring is also radially compressed and this too contributes to loading of the ring and establishment of the seal.

The electrode assembly 42 functions to control the level of liquid within tank 20. As stated above, a pump is provided to pump water or other liquid into the tank through passage 30 in fitting 28. When the liquid level in tank 20 falls below the lower end 48 of electrode 44, the pump is started to supply water to the tank. When the level of the water in the tank reaches the bottom of the upper electrode 46 the pump is automatically stopped. Thus the liquid level in tank 20 is maintained between the lower ends of the two electrodes 44 and 46.

In a carbonator of the character shown, the liquid is delivered to the tank through passage 30 in a jet stream under pressure, and the carbon dioxide is also delivered under pressure, causing vigorous agitation of the liquid in the tank. As the liquid may splash against the lower end of electrode 46 when the actual level is much lower, giving a false reading and thus stopping the pump, the electrode 46 is provided with a tubular shield 66 having a lower skirt 68 spaced from the electrode and extending downwardly therebeyond as shown in FIGURE 2. Shield 66 is provided with a vent hole 70 on opposite sides thereof. The upper end of the shield is inwardly tapered as at 72 for slidable reception between tube 46 and sleeve 52 to be gripped therebetween, with a head 74 assisting to hold the parts assembled. The lower end of sleeve 52 abuts against a shoulder 76 on the shield, which serves as a stop to prevent the shield from being improperly positioned. When thus assembled the liquid must rise in the shield 66 to contact the electrode tube 46, insuring against agitated liquid splashing up on the electrode to stop the pump prematurely.

The electrode assembly 42 is coupled to an electrical control device such as a relay (not shown) through a cable 78 which is releasably coupled to the upper ends of the electrodes 44 and 46 and coupling 54 by means of the receptacle 80 shown in FIGURE 2. The receptacle 80 includes a cap or connector body 82 of molded plastic material such as polyvinyl chloride or the like, and a plurality of electrically conductive slip connectors 84, 86 and 88 embedded in the plastic. Each of these slip connectors is in the form of a helical wire coil which is secured to a respective end of one of the conductors 90, 92 and 94 of cable 78 by a clip 96 as shown most clearly in FIGS. 4 and 5.

Each slip connector, such as the connector 84 of FIG- URE 4, is formed with a projecting end portion 98 for insertion into the clip 96, which is suitably formed of sheet metal or the like to accommodate the connector end and the wire 90. Once the connector end 98 and wire end are inserted into the passages in the clip 96, the clip is crimped about the wires as shown in FIGURE 5 to provide a secure connection therebetween. In making the receptacle 80, the slip connectors 84, 86 and 88 are first connected to the wires 90, 92 and 94 respectively by the crimp connectors 96, and the slip connectors then mounted on a dummy core pin similar in dimension to the upper end of the electrode assembly 42, and the plastic material molded about the connectors and wires to form the cap 82. When the plastic has cured, the dummy core pin is removed, leaving a stepped cylindrical cavity therein corresponding substantially to the configuration of the upper end of electrode assembly 42. Preferably the slip connectors are placed under slight tension, so that upon completion of the receptacle they will contract to an inside diameter slightly less than the outside diameter of the upper ends of the electrode rod 44, the electrode tube 46 and the coupling 54. Thus when the electrode assembly 42 is inserted into the receptacle 80, the connectors 84, 86 and 88 will releasably grip the respective portions of the electrode assembly, preventing accidental disengagement. In addition to providing a convenient releasable connection between the electrode assembly 42 and the electrical cable 78, the receptacle 80 may be positioned on the electrodes in any desired position of rotation, or may be rotated while coupled to the electrodes.

The electrically conductive wall 22 of tank 20, coupling 54, slip connector 88 and wire 94 provide a path for the flow of electricity which is common to both of the electrode circuits for controlling the pump supplying water or other liquid to the tank. One circuit includes electrode tip 48, electrode 44, connector 84 and conductor 90. The second circuit includes electrode 46, connector 86, and conductor 92. As the liquid in the tank is electrically conductive, when its level falls below tip 48, the electrical connection between the tip and tank wall 22 is broken, operating a suitable control to start the pump. Also, when the liquid rises to contact the lower end of electrode 46, a circuit is completed to a control operable to stop the pump. Thus the liquid level in the tank is maintained between limits determined by the positions of the electrode tip 48 and the lower end of electrode tube 46.

What is claimed is:

1. A female electrical connector for engagement with a male member having a plurality of axially spaced electrically conductive end portions, comprising: a connector body molded of resilient electrically non-conductive material having a hollow cylindrical portion opening through one face of the body and adapted to releasably gn'ppingly engage the projecting end portions of said male member; a plurality of electrically conductive helical wire coils embedded in said connector body for limited radial expansion and encircling said cylindrical portion in axially spaced-apart relation with the inner surfaces of each coil exposed to said opening in the body, each helical wire coil exhibiting an end portion projecting away from said helical coil; and an electrical cable defining a plurality of insulated conductors extending through a face of said connector body remote from said cylindrical portion with each conductor having an exposed end portion; means permanently electrically connecting the exposed end portion of one of said wire coils with one of said exposed ends of said conductors, said molded connector body incapsulating said connected end portions to form an hermetically sealed structure; and each of said helical wire coils being resistingly expandible to releasably grippingly hold the end portions of said male member against accidental dislodgment from the connector body.

References Cited UNITED STATES PATENTS 2,690,541 9/1954 Elliott 339-26 2,857,580 10/1958 Raetsch 339183 3,193,636 7/1965 Daniels 339-182 X 10 RICHARD E. MOORE, Primary Examiner US. Cl. X.R.

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