GB2237683A

GB2237683A - A switch

Info

Publication number: GB2237683A
Application number: GB9023037A
Authority: GB
Inventors: Klaus Kreimendahl
Original assignee: Schupa Elektro & Co KG GmbH
Current assignee: Schupa Elektro & Co KG GmbH
Priority date: 1989-11-03
Filing date: 1990-10-23
Publication date: 1991-05-08
Anticipated expiration: 2010-10-23
Also published as: GB2237683B; GB9023037D0; DE3936610A1; DE8913003U1; IT9021840A0; DE3936610C2; IT9021840A1; NL194252C; FR2654253B1; BE1005375A0; FR2654253A1; NL9001885A; IT1244800B; DK217890D0; ATA165490A; DK217890A; AT403227B; NL194252B; CH681184A5

Abstract

A switch with contact levers 10 (also Figs 2, 3) moved abruptly to a switched-on position upon actuation comprises rocker member 1 for switching on using a toggle-lever mechanism, a drive spindle 3, a loosely mounted push rod 4 having abutment surface 5 at one end and at the other end resilient member 6 bearing on side wall 7 of recess 7' in the casing and a double-sided extension 9 acting on spring-loaded contact levers 10, motion of rocker member 1 continuing (Fig. 5) until drive spindle 3, as a result of the kinetic energy continuously acting on it, leaves abutment surface 5 of push rod 4 (Fig. 6) whereby contact levers 10 held by springs 12 and by extensions 9 of push rod 4, abruptly take up the switched-on position. Reference is included to a circuit-breaker. <IMAGE>

Description

- -7 C- A switch The present invention relates to a switch having novably

mounted contact levers which are moved to a switched-on position abruptly when the switch is actuated, especially but not exclusively a double-pole protective switch for protection against f ault currents, the contact levers being held in a switched-of f position by pressure springs and holding-down elements, and a rocker member for switching the switch on, using a toggle-lever mechanism which via a drive spindle in or on the rocker member acts on a switching shaft, with the contact levers being disposed in a bottom part of the switch casing.

Such a switch is described in DE-33 35 887 C 2. It may be used as a circuit-breaker, and during the switching-on process it pivots a lever via a contact lever until a pin abuts a catch and temporarily locks the contact lever. During the rest of the switching-on process, the lever continues to pivot and a shoulder thereof comes against an abutment surface of a control lever and pivots it clockwise. This disengages the pin from the catch, and the contact lever suddenly moves from the locked 'position towards a fixed contact, which it touches in an abrupt fashion.

An aim of the present invention is to develop simple compact means which can be inserted in a conventional mechanism f or operating protective switches against fault currents, without the need for substantial alteration to the conventional movement sequences of the levers therein.

Accordingly the present invention is directed to a switch as set out in the opening paragraph of the present specification, in which a push rod acting on the movable pre s sure- spr ing-1 oaded contact levers has an abutment surface at one end and at its other end comprises a resilient member which bears on a side wall of a recess in the bottom part of the casing, and a double-sided extension on the push rod acts on the movable contact levers when the rocker member used for switching turns on its pivot and, via its drive spindle, acts on the push rod, both via the toggle-lever mechanism and via a projecting end of the drive spindle, and continues to act on the contact levers in the switched-on position during the subsequent motion of the rocker member until the drive spindle, as a result of the kinetic energy continuously acting on it, leaves the abutment surface of the push rod, as a result of which the contact levers, which are held by pressure springs and by the extensions of the push rod, abruptly take up the switched-on position.

Preferably the push rod, which bears via a resilient end member on the side wall of a recess in the bottom part of the casing, can be loosely moved laterally via an integral ly- formed pin in an aperture and via an integral ly- formed projection in a slot in a vertical wall of the bottom part of the casing, and can also be moved substantially vertically.

An example of a switch made in accordance with the present invention is shown in the accompanying 5 drawings in which:

Figure 1 shows a longitudinal cross-section through such a switch; Figure 2 shows a side elevational, partsectional view of the switch shown in Figure 1 in the plane A-B; Figure 3 shows a plan view of the switch shown in Figure 1 from the plane C-D; Figure 4 is a diagrammatic elevational view of the switch in a switched- off position; Figure 5 is a diagrammatic elevational view of the switch in an actuating phase; and Figure 6 is a diagrammatic elevational view of the switch in a switched- on position.

A double-pole protective switch for protection against fault currents, is shown in Figures 1 to 3. it combines a push- rod for abrupt switching-on with a previously proposed toggle-lever mechanism which, via a switching shaft, acts on pivotably movable contact levers, which are held in the switched-off position by pressure springs and holding-down elements.

Actuating means in the form of a rocking element 1 is mounted on a pivot 2 inside the switch casing 1 and, offset from the pivot 2, has a drive spindle 3 which extends right through the rocking element 1. The spindle 3 projects from the middle of the rocking element 1 and is non-positively connected to a previously proposed toggle5 lever mechanism between itself and a control shaft 19. The control shaft 19 and pivotable contact levers 10 are mounted in a bottom part 8 of the casing. The levers 10 are held in the switched-off position by respective pressure springs 12 which bear against the base of the part 8 and the underside of the contact levers 10. The contact levers 10 are forked at their ends opposite to those on which are mounted the switch contacts 20. By means of a fork 21, the pressure-spring loaded contact levers 10 are secured in position against a holding-down element 22 and an abutment 23,- by which they are vertically guided when actuated.

The drive spindle 3 for the toggle-lever mechanism has an end 11 which projects sideways from the rocking element 1. The projecting end 11 of the spindle 3 acts on the push rod 4 when the rocking element 1 is actuated. The push rod 4 is a separate part which is loosely incorporated in the switching mechanism and is used for abruptly ending the process of switching on the _switch without the normal undesirable partial contacts (known as "billing or kissing") and the resulting burning of the contacts.

The push rod 4 is loosely incorporated in the 1 switching mechanism by means of a pin 14 and a projection 16. The pin 14 of the push rod 4 is horizontally and vertically movable in an aperture 15 in a wall 18 of the bottom part 8 of the casing. The projection 16 guides the push rod 4 in a slot 17. in the wall 18, mainly in the vertical direction. The push rod 4 also has a doublesided extension 9 for acting on the contact levers 10. A resilient end member 6 of the push rod 4 abuts against a recess 7' in the bottom part 8 of the casing, whereas at its opposite end the push rod has an abutment surface 5 which is acted upon by the end 11 of the drive spindle 3 when the rocking element 1 is actuated.

Figures 4 to 6 are diagrams of the switched-off position, a moment in the movement phase, and the switched-on position, respectively.

As shown in Figures 4 to 6, the switching-on process is as follows:

In Figure 4, the switching contact 20 of a contact lever 10 is in the switched-off position. The rocking element 1 is actuated in the direction of the arrow (Figures 4 to 6), thus pressing the drive spindle 3 of element 1 against the abutment surface 5 of the push rod 4 (Figure 5). As a result, the actuating force exerted by the rocking element 1 on the push rod 4 is transmitted by the extension 9 to the contact lever 10., A moment in this phase of motion is shown in Figure 5. As can be seen, the drive spindle 3 is still touching the abutment surface 5. The pin 14 comes against a side wall 151 in the aperture 15, and the projection 16 abuts a side wall 17 - of slot 17. In the process the resilient end member 6 of the push rod 4 slides with friction against the side wall 7 of the recess 71. The pressure spring 12 is now additionally compressed and the fork 21 of the contact lever 10 is pushed away from the abutment 23 of the element 22 by the same amount as the switching contact 20 of the lever 10 approaches the fixed contact 13 in the bottom part 8 of the casing. During this phase of notion, the drive spindle 3 leaves the abutment surface 5 of the push rod 4. The energy of the pressure spring 12 is thus released, resulting in an abrupt switching- on. In Figure 6, the switching-on process is completed, and the switching contact 20 and fixed contact 13 are in the switched-on position. When the switched-off position is brought about by moving the rocking element 1 in the opposite direction, the switch is prepared for further switching-on.

Thus it will be appreciated that, in the illustrated switch, the movably mounted contact levers 10 may be held in position during a switching-off process and abruptly released only after the necessary contact pressure has been reached.

il 4

Claims

1. A switch having movably mounted contact levers which are moved to a switched-on position abruptly when the switch is actuated, especially but not exclusively a double-pole protective switch for protection against fault currents, the contact levers being held in a switched off position by pressure springs and holding-down elements, and a rocker member for switching the switch on, using a toggle-lever mechanism which, via a drive spindle in or on the rocker member acts on a switching shaft, with the contact levers being disposed in a bottom part of the switch casing, in which a push rod acting on the movable pressure-spring-loaded contact levers has an abutment surface at one end and at its other end comprises a resilient member which bears on a side wall of a recess in the bottom part of the casing, and a double-sided extension on the push rod acts on the movable contact levers when the rocker member used for switching turns on its pivot and, via its drive spindle, acts on the push rod,, both via the toggle-lever mechanism and via a projecting end of the drive spindle, and continues to act on the contact levers in the switched-on position during the subsequent motion of the rocker member until the drive spindle, as a result of the kinetic energy continuously acting on it, leaves the abutment surface of the push rod, as a result of which the contact levers, which are held by pressure springs and by the extensions of the push rod, abrupty take up the switched-on position.

2. A switch according to claim 1, in which the push rod, which bears via a resilient end member on the side wall of a recess in the bottom part of the casing, can be loosely moved laterally via an integral ly-f ormed pin in an aperture and via an integral ly- formed projection in a slot in a vertical wall of the bottom part of the casing, and can also be moved substantially vertically.

3. A switch, substantially as described herein with reference to and as shown in the accompanying drawings.

i i 1 Published 1991 atThe Patent Office. State House. 66/71 High Holborn. LondonWCIR47?. Further copies may be obtained from Saks Branch. Unit 6. Nine Mile Point Cunnfelinfacb. Cross Keys, Newport. NPI 7HZ. Printed by Multiplex techniques lid. St Mary Cray, Kent