IE80610B1

IE80610B1 - A switch

Info

Publication number: IE80610B1
Application number: IE940050A
Authority: IE
Inventors: Desmond Regan; Shay Lavelle; Thomas O'carroll
Original assignee: Square D Co
Priority date: 1994-01-21
Filing date: 1994-01-21
Publication date: 1998-10-21
Also published as: IE940050A1; GB2285888B; GB2285888A; GB9419929D0

Abstract

A switch such as a circuit breaker comprises a base and cover 1 which cooperate on assembly to form an enclosure for the various components of the switch. The base has locating means defined by a slot 51 closed at a lower end 52 and open at an enlarged lead-in portion at an upper end 53. The cover has an end stop 55 which extends downwardly for engagement on assembly with the slot 51 to retain a conductor 50 in position between the base and cover. The base and cover have step means 58, 59 which also interengage on assembly. Because the conductor 50 is located and retained in this way there is no risk of an attached braid being sandwiched between the base and cover on assembly. The conductor is also particularly well insulated.

Description

The invention relates to switches in general, especially circuit breakers and in particular to miniature circuit breakers having a movable contact connected by a line or input conductor and a stationary contact connected by a load terminal to an electrical source.

More particularly the invention relates to a switch such as a circuit breaker of the type comprising a housing defined by a base, and a cover, the base and cover having a rear wall portion, a front wall portion, and upper and lower side wall portions extending between the front and rear wall portions, the switch including a conductor, the conductor being retained between the base and cover, on assembly.

The load terminal is usually connected by means of a pigtail or braid to a coil and the line conductor is usually connected by means of a pigtail or braid to a bimetal, the other side of the bimetal being connected to the movable contact.

In conventional constructions, the line conductor is relatively loosely confined between the base and cover on assembly. Therefore, on assembly care must be taken to avoid the associated pigtail from becoming trapped between the base and cover.

This invention is directed towards providing a switch with an improved mounting arrangement for a conductor which will overcome these difficulties.

The invention is characterised in that the base includes an elongated slot closed at a lower end thereof and open at an upper end to receive and locate the conductor, and the cover includes an end stop for engagement with the elongated slot to retain the conductor within the slot. 8061 0 -2This arrangement eliminates the problem of a braid or pigtail being sandwiched between the base and cover on assembly. In addition, it contributes to the insulation in the area of the live incoming connector components. The provision of an elongate slot facilitates assembly and also provides particularly good electrical insulation. The end stop arrangement facilitates positive location and retention of the line conductor within the slot. The slot may have a lead-in portion.

In a preferred embodiment of the invention, the base and cover side wall portions include step means which inter-engage on assembly of the base and cover to closely align and retain the base and cover side wall portions in the region of the conductor. This arrangement facilitates assembly, retention of the line or input conductor in position and contributes to the insulation in the area of the conductor.

The invention will be more clearly understood from the following description thereof given by way of example only with reference to the accompanying drawings in which:Fig. 1 is a view of a circuit breaker according to the invention with a cover removed; Fig. 2 is a perspective view of a base part of the circuit breaker; Fig. 3 is a perspective view of a cover part of the circuit breaker; Fig. 4 is an exploded perspective view of a conductor and a conductor retaining portion of the circuit breaker; -3Fig. 5 is a perspective view of the conductor and conductor retaining portion of Fig. 4; and Fig. 6 is an enlarged view of portion of the base of the circuit breaker, with a conductor in position.

Referring to the drawings, there is illustrated a switch which in this case comprises a circuit breaker 1 including a line terminal 2 for coupling to a source of electricity and a load terminal 3 for coupling to a load. The load terminal 3 is connected by means of a pigtail or braid (not shown) to a coil 5 connected to a fixed contact. The line conductor 2 is connected by a pigtail or braid to one side of a bimetal 10, the other side of which is connected to a movable contact. The bimetal is adjusted by a calibration screw 12.

The circuit breaker 1 comprises a base 20 and a cover 21. The base 20 and cover 21 both have rear wall portions 22a, 22b respectively, front wall portions 23a, 23b, upper side wall portions 24a, 24b and lower side wall portions 25a, 25b respectively which cooperate on assembly of the base 20 and cover 21 to form an enclosure for the various components of the circuit breaker.

As will be particularly apparent from Fig. 4 a line conductor 2, portion 50 of which is illustrated is retained between the base 20 and cover 21 on assembly of the housing of the circuit breaker. In this case, for ease of assembly the base 20 has locating means defined by a slot 51 closed at a lower end 52 and open at an upper end 53 to receive and locate the line conductor 50. The cover 21 includes an end stop 55 extending downwardly therefrom for engagement on assembly with the line conductor locating slot 51 of the base to retain the line conductor 50 in position. The upper end 53 of the slot in this case has a lead-in portion.

It will be noted that the base and cover are provided with step means 58, 59, respectively which inter-engage on assembly of the base 20 and cover 21 and closely align and retain the base and cover side wall portions in the region of the line conductor 50. 5 The advantage of locating the line conductor or input connector 50 in the manner described above is in eliminating any difficulty of the braid being sandwiched between the base 20 and cover 21 on assembly. Further, and more importantly, the line conductor is particularly well insulated against electrical shock. This is especially important in humid environments with incomplete insulation. 10 It will he appreciated that while the invention has been described with reference to a miniature circuit breaker, it may be applied to any type of circuit breaker and indeed to switches in general. 15 The invention is not limited to the embodiments hereinbefore described which may be varied in construction and detail. *

Claims

1. Claims;

1. A switch comprising a housing defined by a base, and a cover, the base and 5 cover having a rear wall portion, a front wall portion, upper and lower side wall portions extending between the front and rear wall portions, the switch including a conductor, the conductor being retained between the base and cover on assembly, characterised in that the base includes an 10 elongated slot closed at a lower end thereof and open at an upper end to receive and locate the conductor, and the cover includes an end stop for engagement with the elongated slot to retain the conductor within the slot.

2. A switch as claimed in claim 1 wherein the elongate slot includes a lead-in portion 15

3. A switch as claimed in claim 1 or 2 wherein the base and cover side wall portions include step means which inter-engage on assembly of the base and cover to closely align and retain the base and cover side wall portions in the region of the conductor. 20

4. A switch substantially as hereinbefore described with reference to the accompanying drawings.

5. A switch as claimed in any preceding claim wherein the switch is a circuit breaker. 8061 0