Method of fitting a coil onto a bobbin
AssigneeCircuit Breaker Industries Limited
InventorsEdward Leet, Manuel F. V. Ribeiro
Life of this patent
Estimating the term…
Abstract
A method of fitting an overload coil for a circuit breaker onto a bobbin assembly. The overload coil is pre-formed into a helical coil with a pair of terminals and a coil sub-assembly is formed by attaching electrical leads to the terminals of the coil. Separate base and top halves of a split bobbin are assembled so that the pre-formed coil of the coil sub-assembly is held captive therebetween. A sensing tube is fitted through an aperture extending axially through the assembled split bobbin, and the sensing tube is mounted onto a magnetic cradle. Different top halves, such as a voltage coil top half and a high inrush top half may be fitted into a common base half. The invention extends to a bobbin assembly for a circuit breaker, as well as to an overload coil sub-assembly.
Claims15
A method of fitting an overload coil for a circuit breaker onto a bobbin assembly comprising the steps of:
- a) pre-forming the overload coil into a helical coil with a pair of terminals;
- b) forming a coil sub-assembly by attaching an electrical lead to at least one terminal of the coil;
- c) providing separate base and top halves of a split bobbin;
- d) assembling the base and top halves of the split bobbin so that the pre-formed coil of the coil sub-assembly is held captive therebetween;
- e) fitting a sensing tube through an aperture extending axially through the assembled split bobbin;
- and
- f) mounting the sensing tube onto a magnetic cradle.
A circuit breaker bobbin assembly comprising a pre-formed helical overload coil having a pair of terminals for receiving electrical leads, a split bobbin formed from separate base and top halves, the top half including a top flange and a tubular semi-hub extending therefrom, and the base half comprising a base flange and a tubular semi-hub extending axially therefrom, each of the semi-hubs terminating in complemental registering formations for preventing rotation of the semi-hubs when they are brought into alignment with one another, a passage being defined through the tubular hubs for accommodating a cylindrical sensing tube, the top and base halves in unassembled form being arranged to allow the pre-formed coil to be fitted therebetween, and in assembled form being arranged to hold the coil captive.
An overload coil sub-assembly for a circuit breaker comprising a pre-formed helical coil having a pair of terminals, a pair of leads connected to the respective pair of terminals, and at least one electromechanical component of a circuit breaker mechanism being attached to a free end of at least one of the leads, the coil being arranged to receive separate halves of a split bobbin.
Dependencies are inferred from the claim text.