Belden Mfg. Co. v. Glade, 6092.

• Decision Date: 03 June 1937
• Docket Number: No. 6092.,6092.
• Citation: 90 F.2d 317
• Parties: BELDEN MFG. CO. v. GLADE et al.
• Court: U.S. Court of Appeals — Seventh Circuit

90 F.2d 317 (1937)

BELDEN MFG. CO. v. GLADE et al.

No. 6092.

Circuit Court of Appeals, Seventh Circuit.

June 3, 1937.

Cyril A. Soans and Paul J. Glaister, both of Chicago, Ill., for appellant.

George Bayard Jones, of Chicago, Ill., for appellees.

Before SPARKS and MAJOR, Circuit Judges, and LINDLEY, District Judge.

SPARKS, Circuit Judge.

This appeal is from a decree of the District Court holding United States patent No. 1,858,196 to Wermine, assigned by him to appellant, not infringed. This patent was issued May 10, 1932, on an application filed March 28, 1927. The accused device was covered by appellees' United States patent to Glade, No. 1,988,725, issued January 22, 1935, on an application filed August 5, 1929. The answer was non-infringement and invalidity, and the court did not pass on the question of validity.

The Wermine patent relates to electric plug connectors of the type used for connecting an electric device to an electric supply current, a suitable socket connected to the line being provided for receiving the plug. The stated objects of the invention were to provide a practically unbreakable, weatherproof plug connector, easy to manufacture, of reasonably low cost, and capable of being easily and quickly connected.

Appellant relied upon claims 11, 12, 13, 26 and 27. The first three claims are specific as to certain features of the plug, of which claim 12 is typical,¹ and the last two claims are directed more broadly to the basic four-element combination, of which claim 27² is typical.

The patented plug connector comprises a body portion of resilient material preferably rubber, which is provided with an axial aperture extending therethrough. The body portion is preferably round in cross section and is shaped so as to facilitate gripping thereof when inserting or withdrawing from the socket.

The axial aperture is preferably round in cross section to accommodate an end portion of the cable, which comprises a pair of relatively insulated conductor members enclosed in a sheath of insulating material such as rubber.

The body portion is recessed at opposite sides of the axial aperture to receive inner end portions of contact prongs. These prongs are made of stiff metal, and each is provided with a lug punched outwardly therefrom and adapted to receive a bared portion of the respective conductors between the lug and the strip proper. The bared portion of the conductor may be soldered to the strip and the lug bent inwardly, so as to clamp the conductor in place and to some extent relieve the soldered connection of strain. Such connection of the conductors to the prongs results in an abutment means, extending laterally from the prongs, which is adapted to engage a portion of the plug so that the prongs cannot readily be pulled endwise from the plug.

In order to maintain the prongs in properly spaced relation, a plug is provided which is adapted to be seated in the aperture at the end of the body from which the prongs project. It is provided with recesses for receiving the prongs, and also with recesses in its inner portion for receiving the extreme inner end portions of the conductors. The plug is also provided with an intermediate portion of reduced diameter, and the aperture in the body is provided with an end portion of enlarged diameter, which is provided with an intermediate portion of reduced diameter to correspond to the diameter of the reduced portion of the plug. The body being of resilient material such as rubber, and the plug which may be of rubber also, may be forced into the axial aperture, so that the reduced portion of the aperture engages the reduced portion of the plug, thereby locking it in place.

Optional means for preventing sharp bending of the cable next to the plug is provided by a sleeve of rubber, or other material of which the plug is made, integral with the plug and extending a distance sufficient to reinforce and protect the cable.

A modified construction provides a body portion similar to the one above referred to, together with a cap member, either or both of which may be of resilient material such as rubber and provided with a dovetail interlocking connection whereby the two members are adapted to be locked together. In this form the body portion is provided with an axial aperture for receiving the cable, and the cap member is apertured for permitting passage therethrough of a pair of prongs which are seated in the body portion by means of recesses. The conductors of the cable may be connected to the respective prongs, as hereinbefore described, and the cap member may conveniently be provided with a separating boss for spreading the extreme inner end portions of the conductors. An upstanding head or edge portion of resilient material may be provided on the outer body portion, which is adapted to engage the face of the socket, which is effective to produce a substantially waterproof joint.

The accused device of the Glade patent relates to the same subject as that of the Wermine patent. Its objects were to produce a terminal cap consisting of few parts, simple design, and sturdy construction; one that permits the conductor ends to be connected therewith in a secure and reliable manner, and whose prongs or blades will be substantially and reliably connected with the cap members. A further object was to produce a plug and cord connection, having such a secure fastening therebetween, and between the wires and the blades, that the cable may be grasped either adjacent the cap or a greater distance therefrom, for removing the plug from the socket, without damage to the cap, cable, wires or blades.

Appellees' device or cap comprises a core, a collet, a cable, and two blades or prongs. The blades are parallel and extend from the cap to connect with the socket. The cable consists of two wires which transmit the current, and the ends of the wires are bared for contact with the blades. In these respects the blades and cable are identical with all prior art in this field. It was common practice to mount the blades to a cap member by merely bending them in such manner as to allow a rivet or screw to be passed through the bent portion, thus securing it to the cap body. This constituted a faulty and fragile connection, and no doubt caused the disclosures of both Wermine and Glade to come into existence.

Wermine corrected that defect in the manner hereinbefore set forth. Glade corrected it by forming the blades so as to interlock with grooves and indentations formed on the outer surface of the core, which are held in position by a collet whose interior surface is serrated and which is forced on the core and held in place thereon by friction. Each blade is bent and the portion between these bends forms right angles with both the upward protruding portion and the downward portion, which latter portion continues downward in a plane parallel to the protruding portion. A further right angle bend at the base of the downward continuing portion provides means for locking the blade against displacement, thus forming a hook at the base of the blade. A notch is formed in the end of this hook to accommodate one of the conductor wires.

The core has peripheral grooves for accommodating the portions of the blades, and end grooves to accommodate the bends in the blades, and also sockets at the lower ends of peripheral grooves for the purpose of receiving the hook portions of the blades. The cable wires after being introduced through the...