Gripall Wiring Socket

• alternative name: JR

The Gripall Wiring Socket is a compact two‑terminal bakelite extension fitting intended for making fixed connection points for loud‑speakers, headphones, or similar accessories. It was designed as an improvement over general‑purpose electrical fittings, providing a secure and reliable contact for ordinary pin tags used in wireless apparatus.

The unit consists of a small rectangular brown bakelite moulding with lugs drilled for fixing screws. Two external terminals connect internally to a pair of spring‑loaded contact sockets of distinctive construction.

Construction

• Body: brown bakelite moulding, approx. 1½″ square × ⅝″ deep
• Mounting: two lugs for screw fixing
• Internal contact system:
  • Brass tube with two opposed metal balls mounted in drilled holes
  • Balls pressed together by phosphor‑bronze springs
  • Pin tag inserted between the balls, ensuring firm contact
• Terminals: two external screw terminals connected to the internal spring sockets

Purpose and performance
The socket was intended to eliminate loose trailing wires and provide a neat, fixed extension point for domestic wireless installations. The spring‑ball contact system ensured positive electrical contact with standard pin tags used on loud‑speakers and telephones.

Note: The Wireless World article uses Gripall, while other advertisements and articles  use Grippall for the same brand.

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Elenco delle radio e altri apparecchi della J.R. (Brand) Jean Rigaut, Grippall Electrical Products, Ltd.; London