GB2121546A

GB2121546A - An explosion-or flame-proof cam-operated ganged switch

Info

Publication number: GB2121546A
Application number: GB08315335A
Authority: GB
Inventors: Gerhard Schwarz
Original assignee: Brown Boveri und Cie AG Germany; BBC Brown Boveri France SA
Current assignee: BBC Brown Boveri AG Germany; BBC Brown Boveri France SA
Priority date: 1982-06-03
Filing date: 1983-06-03
Publication date: 1983-12-21
Also published as: GB8315335D0; FR2528229A1; DE3220914A1; GB2121546B; DE3220914C2

Abstract

Mechanical or electronic switching elements (22) e.g. Hall plates, are arranged in at least one housing element (10, 12), and are actuated by a switch latch (13) at one end of the switch by way of a selector shaft (42), which actuates the individual switching elements (22) by means of cam discs. A cup-like housing element (10, 12) for accommodating electronic components (16, 18) comprises, in a manner known per se, a circular elevation surrounding a central bore in the central region, thus forming a recess in which a ring (28) is inserted and held in a stationary manner, which ring (28) bears means (30) e.g. permanent magnets for influencing the electronic elements (22) arranged in the housing element. A cover plate, which is connected to the selector shaft (42) and can rotate with the latter, is arranged between the ring 28 and the base of the recess and is formed such that, when the selector shaft (42) is rotated, a lug of the cover plate can be moved between the means (30) and the element (22) and vice versa, e.g. so as to act as a magnetic shield. <IMAGE>

Description

SPECIFICATION An explosion- or flame-proof cam-operated ganged switch The invention relates to a cam-operated ganged switch according to the classifying part of Claim 1.

There are electrical cam-operated ganged switches which are enclosed so as to be pressure-resistant and which comprise not only mechanical switching elements, but also electronic switching elements. A cam-operated ganged switch of this type is illustrated in the British Patent Specifiation No. 1 579 561, in which Hall generators are integrally cast in the housing element on both sides of a guide pin extending into the element and permanent magnets are arranged on the actual guide pin and, according to the position of the guide pin, influenced by the cam disc, either influence or do not influence the Hall generators.

The object of the invention is to disclose a solution which is an improvement on the known one.

This object is solved according to the invention in that the cup-like housing element for accommodating the electronic components comprises, in a manner known per se, a circular elevation, surrounding the central bore, in the central region, thus forming a recess in which a ring is inserted and held in a stationary manner, which ring bears means for influencing electronic components arranged in the housing element, and that a cover plate, which is connected to the selector shaft and can be rotated with the latter, is arranged between the ring and the base of the recess and is formed such that, when the selector shaft is rotated, a lug of the cover plate can be moved between the means and the element and vice versa.

A further embodiment of the invention is disclosed in further claims.

An embodiment of the invention and further advantages and improvements thereof are illustrated and described in detail with reference to the drawings, in which: Figure lisa sectional view through a camoperated ganged switch with electronic components; Figure 2 is a sectional view through a housing element for accommodating the electronic components, which are not shown, with a ring inserted therein and a cover plate; Figure 3 is a view of a cover plate; and Figure 4 is a view of the ring with inserted permanent magnets in the direction of the arrow F.

According to Figure 1, the cam-operated ganged switch of the invention is formed from housing parts 10 and 12 which, as can be be seen from Figure 2, comprise a chamber 14 which is open at one side and in which electronic components 16, secured to a printed circuit board 18, are integrally cast by means of casting resin 20. A Hall generator 22 is also secured to the printed circuit board 18. A connecting lug 24 projects from the casting resin and is led by means of connecting parts 26 to a connecting lug which is not shown, which connecting lug corresponds to our copending Patent Application No -8314963 (corresponding to West German Patent Appliction P 32 20 915.0, Our Ref: P9595). A ring 28, which bears two permanent magnets 30, is provided to actuate the Hall generator.The ring 28 is inserted in a recess 31 in the base 32 of the housing element 14 and held therein in a stationary manner. The base 34 of the recess comprises a further stepped structure 36, in which a cover plate 38 is inserted. The ring 28 is formed in the manner of a cup and comprises in its centre a through-bore 40 through which a selector shaft 42 (see Figure 1) can extend. This bore 40 is in alignment with a recess 41 in the housing element 10, 12, which recess 41 is surrounded by a tubular collar 44 which, together with the side walls 46, form the chamber 14for accommodating the electronic components. The Hall generator 22 is in each case mounted on the annular surface 35, formed by the recess 31 inside the chamber 14, on both sides with respect to the central axis.

As can be seen from Figure 2, the ring 28 is also in the shape of a cup and comprises diametrically opposite pockets 50 and 52, in which the permanent magnets 30 and 33 are inserted.

The cover disc 38 comprises a central opening 60, which is formed by two rectangles or squares offset by 45", so that the recess 60 is in the form of a star.

The cover plate 38 comprises cut-out sections 66 and 68, so that lugs 70 and 72 are thus formed. The cut-out sections 66 and 68 are disposed diametrically opposite one another, so are the lugs 70 and 72.

As can be seen from Figure 1, when in the assembled state, i.e. when the cover plate 38 and, disposed thereupon, the ring 28, are inserted in the recess, the Hall generator(s) 22 can be switched in that, by rotating the cover plate 38, either the cut-out sections 66 and 68 or the lugs 70 and 72 are disposed "between" the permanent magnets 30,33 and the Hall generators 22 such that, when the lugs 70 and 72 are disposed between the permanent magnet and the Hall generator, the influence of the magnetic field on the Hall generator(s) is prevented.

Helical springs 80 and 82, respectively, are provided in order to retain the rings inside the recess, the helical spring 80 acting on the ring of the plane 12 under the effect of the plane 10 and the helial spring 82 acting on the ring of the plane 10 under the effect of the cover 11. Hollow-type screwed rivet connections 84 are provided to connect the cover 11, to which, as illustrated in our copending Patent Application No 8314963 the connecting terminals are attached, and the base 13, in which the switch latch for actuating the selector shaft 42 is arranged, and the individual planes disposed therebetween.

1. An explosion- or flame-proof cam-operated ganged switch, comprising mechanical or electronic switching elements lying in at least one plate and disposed in at least one housing element, a switch latch at one end of the switch and a cover at the other end, a selector shaft which extends from the switch latch to the cover, projects beyond the latter, is disposed in a central recess and actuates the individual switching elements by way of cam discs,

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION An explosion- or flame-proof cam-operated ganged switch The invention relates to a cam-operated ganged switch according to the classifying part of Claim 1. There are electrical cam-operated ganged switches which are enclosed so as to be pressure-resistant and which comprise not only mechanical switching elements, but also electronic switching elements. A cam-operated ganged switch of this type is illustrated in the British Patent Specifiation No. 1 579 561, in which Hall generators are integrally cast in the housing element on both sides of a guide pin extending into the element and permanent magnets are arranged on the actual guide pin and, according to the position of the guide pin, influenced by the cam disc, either influence or do not influence the Hall generators. The object of the invention is to disclose a solution which is an improvement on the known one. This object is solved according to the invention in that the cup-like housing element for accommodating the electronic components comprises, in a manner known per se, a circular elevation, surrounding the central bore, in the central region, thus forming a recess in which a ring is inserted and held in a stationary manner, which ring bears means for influencing electronic components arranged in the housing element, and that a cover plate, which is connected to the selector shaft and can be rotated with the latter, is arranged between the ring and the base of the recess and is formed such that, when the selector shaft is rotated, a lug of the cover plate can be moved between the means and the element and vice versa. A further embodiment of the invention is disclosed in further claims. An embodiment of the invention and further advantages and improvements thereof are illustrated and described in detail with reference to the drawings, in which: Figure lisa sectional view through a camoperated ganged switch with electronic components; Figure 2 is a sectional view through a housing element for accommodating the electronic components, which are not shown, with a ring inserted therein and a cover plate; Figure 3 is a view of a cover plate; and Figure 4 is a view of the ring with inserted permanent magnets in the direction of the arrow F. According to Figure 1, the cam-operated ganged switch of the invention is formed from housing parts 10 and 12 which, as can be be seen from Figure 2, comprise a chamber 14 which is open at one side and in which electronic components 16, secured to a printed circuit board 18, are integrally cast by means of casting resin 20. A Hall generator 22 is also secured to the printed circuit board 18. A connecting lug 24 projects from the casting resin and is led by means of connecting parts 26 to a connecting lug which is not shown, which connecting lug corresponds to our copending Patent Application No -8314963 (corresponding to West German Patent Appliction P 32 20 915.0, Our Ref: P9595). A ring 28, which bears two permanent magnets 30, is provided to actuate the Hall generator.The ring 28 is inserted in a recess 31 in the base 32 of the housing element 14 and held therein in a stationary manner. The base 34 of the recess comprises a further stepped structure 36, in which a cover plate 38 is inserted. The ring 28 is formed in the manner of a cup and comprises in its centre a through-bore 40 through which a selector shaft 42 (see Figure 1) can extend. This bore 40 is in alignment with a recess 41 in the housing element 10, 12, which recess 41 is surrounded by a tubular collar 44 which, together with the side walls 46, form the chamber 14for accommodating the electronic components. The Hall generator 22 is in each case mounted on the annular surface 35, formed by the recess 31 inside the chamber 14, on both sides with respect to the central axis. As can be seen from Figure 2, the ring 28 is also in the shape of a cup and comprises diametrically opposite pockets 50 and 52, in which the permanent magnets 30 and 33 are inserted. The cover disc 38 comprises a central opening 60, which is formed by two rectangles or squares offset by 45", so that the recess 60 is in the form of a star. The cover plate 38 comprises cut-out sections 66 and 68, so that lugs 70 and 72 are thus formed. The cut-out sections 66 and 68 are disposed diametrically opposite one another, so are the lugs 70 and 72. As can be seen from Figure 1, when in the assembled state, i.e. when the cover plate 38 and, disposed thereupon, the ring 28, are inserted in the recess, the Hall generator(s) 22 can be switched in that, by rotating the cover plate 38, either the cut-out sections 66 and 68 or the lugs 70 and 72 are disposed "between" the permanent magnets 30,33 and the Hall generators 22 such that, when the lugs 70 and 72 are disposed between the permanent magnet and the Hall generator, the influence of the magnetic field on the Hall generator(s) is prevented. Helical springs 80 and 82, respectively, are provided in order to retain the rings inside the recess, the helical spring 80 acting on the ring of the plane 12 under the effect of the plane 10 and the helial spring 82 acting on the ring of the plane 10 under the effect of the cover 11. Hollow-type screwed rivet connections 84 are provided to connect the cover 11, to which, as illustrated in our copending Patent Application No 8314963 the connecting terminals are attached, and the base 13, in which the switch latch for actuating the selector shaft 42 is arranged, and the individual planes disposed therebetween. CLAIMS

1. An explosion- or flame-proof cam-operated ganged switch, comprising mechanical or electronic switching elements lying in at least one plate and disposed in at least one housing element, a switch latch at one end of the switch and a cover at the other end, a selector shaft which extends from the switch latch to the cover, projects beyond the latter, is disposed in a central recess and actuates the individual switching elements by way of cam discs, and connecting terminals, characterised in that the cup-like housing element (10, 12) for accommodating the electronic components (16) comprises, in a manner known per se, a circular elevation (35,44), surrounding the central bore (41), in the central region, thus forming a recess (31) at the outer surface of the base, in which recess (31) a ring (28) is inserted and held in a stationary manner, which ring (28) bears means (30, 33) for influencing electronic components arranged in the housing element, and that a cover plate (38), which is connected to the selector shaft and can rotate with the latter, is arranged between the ring and the base of the recess (31) and is formed such that, when the selector shaft is rotated, a lug (70,72) of the cover plate can be moved between the means and the element and vice versa.

2. A switch according to Claim 1, characterised in that the ring comprises two diametrically opposite box-like chambers (50, 52), in which a cubic permanent magnet (30, 33) is in each case inserted, which permanent magnets influence the electronic components.

3. Aswitch according to Claim 2, characterised in that the cover plate is formed from a sheet and comprises two diametrically opposite segment-like cut-out sections (66, 68), the radial dimensions of which correspond to the dimensions of the permanent magnets.

4. An explosion- or flame-proof cam operated gang switch, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.