EP0019141B1 - Cam switch - Google Patents

Abstract

The electric switching apparatus assembled of a plurality of consecutively arranged modular units, includes snap action arresting means integrally formed on opposite side walls of each unit. The arresting means includes frame-shaped resilient arresting pieces leveled with the upper surface of the assigned side wall and being at one edge thereof integrally connected thereto and cooperating with matching arresting points on the adjoining unit.

Description

The invention relates to a cam switch, consisting of a drive, a latching chamber adjacent to it and one or more switching chambers arranged one behind the other and connected to the latching chamber, the drive having an axis of rotation on which a ratchet wheel of the latching chamber is seated and which up to one for all control chambers common control roller protrudes, such that the drive, index wheel and control roller are connected in a rotationally fixed manner, furthermore in the locking chamber for the purpose of changing the switching angle, spring-loaded, movable balls parallel to the axis of rotation are provided which cooperate with the index wheel, also in each switching chamber an electrical contact device with fixed contact rails, movable contact bridges, contact pressure springs and plungers interacting with the control roller is provided.

A cam switch of this type is known from the article by L. L'hoest in the magazine »Elektro-Anzeiger«, 7/77, pages 46 and 47. In the known cam switch, the individual components, namely drive, latching chamber and switching chambers, are held together by axially parallel screw bolts, so that, for. B. for a change or extension of the switching program not only remove the cam switch from the mounting wall, but must also take it apart by loosening these bolts, so that the cam switch falls apart into its individual parts. After that, the individual components have to be assembled again with great difficulty. If the number of switching chambers is changed, you have to replace longer or shorter new bolts with the earlier ones. In such work on the cam switch, it can happen that one or the other switching chamber is incorrectly inserted, for example rotated by 180 °, so that the switching program is no longer correct, because inside the switching chambers the contacts can be prepared either as openers or closers, so that there are program changes in connection with the control roller. Finally, the switching chambers in the known cam switch are essentially cylindrical, so that the contacts inside the switching chambers are arranged in a circle around the roller. Accordingly, the contact rails with the contact terminal screws are distributed in rows and at a distance from one another on the circumference of the essentially cylindrical switching chambers.

Furthermore, from DE-A-2 554 177 a snap connection with a frame and approximately triangular locking points in longitudinal section is known. However, this snap connection only serves to attach two plates of each individual switching element. However, the connection of the various switching elements to each other takes place by connecting rods which have screw threads at both ends, one screw thread being screwed into a plate and one nut sitting on the other end. Since the known switching elements each have two plates, there is a special internal structure, because each switching element requires its own camshaft. These camshafts each engage in recesses in the adjacent camshaft via projections. This results in a play of movement from switching element to switching element and thus inexact switching. Otherwise, this prior art is not a cam switch, but rather only a series of switching elements.

FR-A-1 591 978 describes a multiple rotary switch in which any number of switch parts can be assembled using resilient tongues and locking points.

A command switch is known from the "Siemens-Zeitschrift" 48 (1974), number 4, pages 310 and 311, which essentially consists of a drive and a block of similar switching elements. The switching elements of the same type are held together by two longitudinal bolts which pass through bores in the switching elements. The drive has a U-shaped plate, wherein a tab is formed in the upper bent leg of the plate, which is bent upwards at its end. At the end of the switching element block facing the drive, a plate with an upper bent leg is also attached, which has a recess. The command switch is installed in such a way that the drive is inserted into the hole in the mounting plate from the front and then the mounting bracket is screwed in from the rear with a ring nut. The switch insert, i.e. H. the switching element block is then hung with the said recess on the bracket of the drive and then fastened by a screw in the front bearing plate.

In the case of the invention, the cam switch explained at the beginning has been assumed. In a cam switch constructed in this way, forces are introduced from the drive which are not inconsiderable spring forces, namely spring forces which run essentially axially in the latching chamber and essentially radially in the switching chambers. In the case of a cam switch, it is important that precise, sudden switching of a possibly large switching program takes place. On the one hand, the spring forces counteract the drive are, on the other hand, must be caught by the housings of the interrupters or the latching chamber. The problem in the locking chamber is that the balls under spring pressure roll on the flanks of the locking projections of the locking wheel and that certain torsional forces are generated. In the interrupters there are by no means always symmetrical spring loads; rather, depending on the arrangement of the contact bridges to form openers or closers, one-sided radial spring forces can occur, which thus press on one or more interrupters. In addition, cam switches must not have any play from the switch chamber to the switch chamber even when the rotary movement is transmitted, because this could result in an inexact switching process of the entire switching program.

The invention is accordingly an object of the invention to provide a cam switch composed of individual assemblies in which the internal forces effective between the assemblies, which are due to the numerous, differently directed springs, are absorbed so that in practice there is no risk that the cam switch opens at any point when actuated, at the same time ensuring simple manufacture of the individual parts, simple assembly of the assemblies, furthermore a simple possibility of changing the circuit program and finally a simple, clearly arranged possibility of attaching the wiring.

The object is achieved according to the invention in that the cam switch has an essentially square cross-section, that both the successive switching chambers with one another and the latching chamber with the switching chamber adjacent to it as well as the drive with the latching chamber are located on two opposing longitudinal sides of the cam switch, externally visible and actuatable, resiliently elastic components which can be locked in latching points are releasably connected to one another in such a way that the resiliently elastic components provided on the switchgear chambers consist of flat elastic frames which are known per se and which project from the outside via projections of the rest points of adjacent switchgear chambers and the latching chamber engage that the effective between the drive and locking chamber, resiliently elastic components are formed by outwardly angled projections of a mounting plate which engage in the bracket of the locking chamber, the B efestigungsplatte is connected on the one hand to the other components of the drive and on the other hand rests against the end face of the latching chamber, that the switching chambers are designed asymmetrically and can be arranged in a rotationally secure manner with respect to one another, and that the fixed contact rails of the switching chambers with their contact connection screws are led out to the two longitudinal sides of the cam switch, which are not with the elastic frame are provided. In this way it is achieved that the spring forces of the contact pressure springs on the housing inner walls are always directed so that the elastic frame can not detach from the projections of the locking points even with asymmetrical loading and that the axial spring forces and torsional forces between the drive and key chamber are absorbed . Another advantage is that changes can be made to the cam switch without this having to be removed from the mounting plate and disassembled into its individual parts.

Advantageous embodiments of the invention result from the dependent claims.

• Fig. 1 eine perspektivische Ansicht eines Nockenschalters mit mehreren Bauelementen, die mit Abstand voneinander gezeichnet sind und den Aufbau des Nockenschalters verdeutlichen,
• Fig. 2 eine perspektivische Ansicht eines zusammengesetzten Nockenschalters,
• Fig. 3 eine Ansicht auf die Unterseite eines Nockenschalters entsprechend Fig. 2 in vereinfachter Darstellung,
• Fig. 4 eine Vorderansicht auf einen Teil des Nockenschalters gemäß Fig. 2, wobei eine Schaltkammer von den anderen abgetrennt und die Steuerwalze herausgezogen gezeichnet ist,
• Fig. 5 eine Draufsicht zu Fig. 4,
• Fig. 6 eine Ansicht in Richtung der Pfeile VI-VI,
• Fig. 7 eine Ansicht in Richtung des Pfeils VII-VII in Fig. 4,
• Fig. 8 eine Einzelheit in vergrößertem Maßstab,
• Fig. 9 eine Ansicht in Richtung der Pfeile IX-IX in Fig. 1,
• Fig. 10 eine Ansicht gemäß den Pfeilen X-X in Fig. 1 und
• Fig. 11 eine Ansicht in Richtung des Pfeils XI in Fig. 1.

In the drawing, exemplary embodiments of the invention are shown in the diagram, and that shows

• 1 is a perspective view of a cam switch with several components, which are drawn at a distance from one another and illustrate the structure of the cam switch,
• 2 is a perspective view of an assembled cam switch,
• 3 is a view of the underside of a cam switch corresponding to FIG. 2 in a simplified representation,
• 4 shows a front view of part of the cam switch according to FIG. 2, one switching chamber being separated from the other and the control roller being drawn out,
• 5 is a plan view of FIG. 4,
• 6 is a view in the direction of arrows VI-VI,
• 7 is a view in the direction of arrow VII-VII in Fig. 4,
• 8 shows a detail on an enlarged scale,
• 9 is a view in the direction of arrows IX-IX in Fig. 1,
• Fig. 10 is a view according to the arrows XX in Fig. 1 and
• 11 is a view in the direction of arrow XI in FIG. 1st

Fig. 1 illustrates the structure of a cam switch according to the invention, which consists of several interconnectable components, namely a drive, a latching chamber and one or more switching chambers. The drive 1 is designed here as a manually rotatable switch button 1a, to which a marking plate 2, a grid plate 3, a cover plate 4 and a fastening plate 5 are connected. This entire unit is held together, for example, by the fact that the switch button 1a is fastened on an axis of rotation 25, which in turn is located at the other end in a ratchet wheel 7 and can optionally be extended such that the control rollers of the switching chambers described below are also located on the axis of rotation.

An adjoining the drive Latching chamber 9 essentially contains the ratchet wheel 7 with stop pin 6 and ratchet springs 8 with balls which cooperate with the raster wheel 7.

The locking chamber 9 is followed by one or more switching chambers 11 which are equipped with control rollers 10 and an electrical contact device. The control roller 10 actuates glass balls 12, which can also be replaced by suitably designed plastic plungers with a spherical end surface. When glass balls 12 are used, special plungers 13 are present, which in turn actuate contact bridges 16 which are supported by contact pressure springs 17 and interact with contact rails 15. An end cover 14 forms the end of the switching device.

The above-described essential components (drive 1, latching chamber 9, switching chambers 11) of the cam switch are releasably connected to one another by lateral, externally visible and actuatable, resiliently elastic webs 19 and brackets 22 interacting with latching points 18, 23.

As particularly illustrated in FIG. 2, the resiliently elastic components consist of two mutually opposite, essentially flat webs 19 which engage from outside via the locking points 18 of the component to be connected. Advantageously, these resilient webs 19 are frame-shaped, as shown in the drawing. The locking points 18 are then designed as projections which engage in the recesses of the said frame-shaped webs. The projections of the locking points 18 can advantageously, seen in longitudinal section, be triangular, in such a way that the frame-shaped webs 19 are spread outwards when the individual components are pushed together by the action of the outward-sloping surface of the triangular projections and become inherent Set the spring force behind the triangular protrusions when pushing completely together.

To detach the components from one another, depressions 24 (FIG. 2) are provided, which are intended for the use of a screwdriver-like tool.

It is also of particular advantage that the components (drive 1, latching chamber 9, switching chambers 11) are designed such that they are asymmetrical in relation to one another, that is to say they are secured against rotation. that is, the components can only be connected to one another in a very specific position by simply plugging them together.

The connection between the drive unit described with a mounting plate 5 with the adjoining latching chamber 9 takes place in such a way that a resilient bracket 22 with two recesses is provided on one outside of the latching chamber, which has two outwardly angled projections (latching points 23) Mounting plate engages. On the other opposite outside of the locking chamber 9, a rigid bracket 21 is arranged, in which two further, outwardly angled projections 20 of the mounting plate 5 can be used. In practice, the latter projections 20 are first brought into engagement in the rigid bracket 21, and then, by pivoting the drive toward the latching chamber, the angled projections (latching points 23) are brought into engagement in the resilient bracket 22, the fastening plate 5 being tight on the corresponding end face of the locking chamber 9 is present.

The following is to be explained regarding the overall construction of the above-described cam switch.

In electrical control systems, the wiring of cam switches was previously problematic because of the radial arrangement of their connections within crowded device arrangements and often could only be carried out with the aid of additional connection brackets on all terminals. The inventive design of the cam switch, on the other hand, offered the possibility of providing all the connection screws for the wiring on the two opposite sides of the components, which are not provided with the webs 19 and locking points 18 described. The result is a switch block which is composed of one or more components and which has a substantially rectangular, preferably square cross-section, the connecting terminals being staggered. This means that all connections, no matter how tightly the device is installed, are freely accessible to the wiring, and additional connection angles are saved.

As illustrated in FIG. 3, a stable screwdriver guide on each terminal leads the screwdriver exactly to the connection screw and centers it when wiring, even when using so-called electric or pneumatic screwdrivers. Slipping of the screwdriver, damage and unsafe connections are avoided. In practice, this results in a significant reduction in the wiring time required.

Resilient clamping disks with additional clamping ribs are advantageously provided, which ensure a secure conductor connection. The switching chambers are completely closed and thus offer protection against the ingress of dust, insulation or foreign parts and prevent lines from being accidentally inserted into the internal contact space.

Programming is carried out by a solid, easily replaceable control roller, which can be designed for all switching chambers together or individually for each switching chamber and which works together with actuating balls or plungers. The switching bridge of each switch is forced to operate via this continuous, one-piece cylindrical control roller rotatable inside the interrupters. The control roller has holes arranged on its circumference in accordance with the switch program.

Each switching bridge is assigned an actuating ball or a plunger with a spherical front end, which can be inserted into the corresponding hole to close the spring-loaded switching bridge when the control drum rotates, but which are pushed out of the hole to open the switching bridge. The balls are guided in a cage so that they form a unit with the switching bridge and cannot fall out even when the control roller is removed. In this way, each switching chamber represents a self-contained functional unit.

This has several advantages. On the one hand, the switchgear can be assembled by a layperson. Even complicated switching programs can be done in a simple manner, e.g. B. created by a control engineer, because it is only necessary to provide the solid control roller according to the given processing or the existing circuit diagram with holes at the appropriate points. Due to the massive control roller, displacements and twists as with the use of conventional cam wheels are excluded.

The locking chamber with the locking wheel is also very simple as a structural unit. Here steel balls work with a plastic ratchet wheel, as has been described in relation to FIG. 1, in such a way that the switching angle can be changed by simply repositioning these balls. The switching programs to be achieved are therefore extremely versatile and comprehensive. Mechanical wear is largely avoided.

4 to 11 serve for better clarification and illustration of the embodiment of FIGS. 3 to 3. Therefore, the same reference numerals have been used for the same parts.

First of all, FIGS. 4 and 5 make it particularly clear that the switching chambers 11 are divided in the axial direction into two halves 11a, 11b. However, the switching chambers are made from a single piece, e.g. B. made by pressing. These two halves are shifted against each other in the axial direction according to FIG. In addition, the frame-shaped components (webs 19) with the two switching chamber halves are displaced in the axial direction. The frame-shaped components (webs 19) are designed as flat spring tabs and are each attached to the outer sides of the two switching chamber halves. According to the design of these spring tabs, the locking points 18 on the adjacent switching chambers are shifted asymmetrically.

Fig. 4 further illustrates that the contact terminal screws 26 with the fixed contact rails 27 and the screwdriver guides 28 are arranged inclined so that a screwdriver can be applied obliquely in the direction of the dash-dotted lines 29 and can thus be worked without hindrance.

The switching chambers 11 have intermediate webs 35, 36 and 37 or guides on one axially open end face, which form certain open spaces on the end face for the loose insertion of movable contact pieces 30, furthermore of contact pressure springs 31, plungers 32 and contact connecting bars 33 with fixed contact pieces 34. On the other face of the switching chamber, which is open on the face side, and on an end cover 14, further intermediate webs and guides are provided, as is particularly illustrated in FIG. 7, due to the different viewing direction, the reverse of FIG. 6. In cooperation with the intermediate webs and guides of an adjacent switching chamber, the loose parts become loose used contact parts, that is, both the movable contact pieces 30 in their range of motion and the contact pressure springs 31 as well as the plunger 32 and finally the contact connecting rails 33 are held captive with fixed contact pieces 34.

This has the essential advantage that on the one hand a small amount of production and time is required when inserting these contact parts, but on the other hand in the assembled state of the electrical switching device the control roller can be pulled out of the device without any electrical parts of the interrupters can fall out.

FIG. 11 illustrates in connection with FIGS. 9, 10 and 1 that the components for the connection between the drive 1 on the one hand and the locking chamber 9 on the other hand are designed such that they transmit effective forces axially and / or tangentially in the locking chamber 9 can. The axial forces come from the axially parallel detent springs 8 with their balls, which cooperate with the detent wheel 7. The tangential forces come from the rotation of the axis of rotation 25.

A further advantageous embodiment of the switching chambers results from the fact that the end webs 35, 36 and 37 or guides explained above are connected to an intermediate wall 38 running perpendicular to the axis of rotation of the control roller. This intermediate wall has a circular opening 39 for the passage of the control roller 10.

Claims (8)

1. A cam-operated switch, consisting of a drive (1), a detent chamber (9), which is adjacent to the latter, als well as of one or several switch chambers (11), which adjoin the detent chamber (9) and are arranged one behind the other, the drive (1) having a rotary shaft (25), on which there sits a detent wheel (7) of the detent chamber (9) and which projects into a control drum (10) which is common to all the switch chambers (11), in such a way that the drive (1), the detent wheel (7) and the control drum (10) are connected so as to be secured against rotation, there being furthermore provided in the detent chamber (9), for the purpose of changing the switching angle, interchangeable balls which are subjected to spring pressure (8) and are movable parallel to the axis of rotation and which co-operate with the detent wheel (7), and there being furthermore provided in each switch chamber (11) an electric contact device with fixed contact bars (15; 27), movable contact bridges (16; 30), contact compression springs (17; 31) and tappets (13; 32) which co-operate with the control drum (10), characterised in that the cam-operated switch is substantially quadrilateral in cross-section, and in that there are detachably connected together both the respective successive switch chambers (11) to one another and the detent chamber (9) to the switch chamber (11) that is adjacent thereto and the drive (1) to the detent chamber (9) by means of resiliently elastic components (19, 20, 23) which are provided on respectively two opposite cam-operated-switch longitudinal sides and are visible and actuatable from the outside and can be detented in detent points, and in that the resiliently elastic components (19) which are provided on the switch chambers (11) consist of known »per se« elastic frames which have plane surfaces and which engage from the outside over projections (18) of the detent points of adjacent switch chambers (11) and of the detent chamber (9), and in that the resiliently elastic components which are active between the drive (1) and the detent chamber (9) are formed by outwardly angled projections (20, 23) of a fastening plate (5), which projections engage in stirrups (21, 22) of the detent chamber (9); the fastening plate (5), on the one hand, being connected to the other components of the drive and, on the other hand, bearing against the front end of the detent chamber (9), and in that the switch chambers (11) are designed so as to be joinable asymetrically and in a manner securing them against rotation relative to one another,. and in that the fixed contact bars (15; 27) of the switch chambers (11) are brought out with their contact connecting screws (26) in the direction of the two cam-operated-switch longitidunal sides which are not provided with the elastic frames.

2. A cam-operated switch as claimed in Claim 1, characterised in that the fixed contact bars (15; 27), with their contact connecting screws (26), are arranged so as to be laterally offset and staggered for the purpose of bringing about a free accessibility.

3. A cam-operated switch as claimed in Claim 1 or 2, characterised in that the stirrups (21, 22) of the detent chamber (9) are designed so as to be rigid on one of the cam-operated-switch longitudinal sides and so as to be resiliently elastic on the other cam-operated-switch longitudinal side.

4. A cam-operated switch as claimed in one of the preceding Claims, characterised by depressions which are provided adjacent to the detented elastic frames having plane surfaces.

5. A cam-operated switch as claimed in one of the preceding Claims, characterised in that the switch chambers (11) are displaced in two halves (11a, 11b) relative to each other in the axial direction, and in that the frame-shaped components (19) are designed as spring shackles having plane surfaces and are respectively fitted on the outsides of the two switch chamber halves and are displaced with them in the axial direction, and in that the projections (18) of the detent points are diplaced in a correspondingly asymmetrical manner.

6. A cam-operated switch as claimed in one of the preceding Claims, characterised in that the contact connecting screws (26), with the fixed contact bars (27) as well as screw driver guides (28), are inclinedly arranged towards the outside in such a way that an unhindered oblique application position (29) of a screw driver is rendered possible.

7. A cam-operated switch als claimed in one of the preceding Claims, characterised in that the switch chambers (11), at one axially open front end, have chambers, which are divided by intermediate webs (35, 36, 37) and guides, for the loose insertion of movable contact pieces (30), contact compression springs (31), tappets (32) and contact connecting bars (33) with fixed contact pieces (34), and in that, at the other open front end of the switch chambers (11) and on an end cover (14), there are provided further corresponding intermediate webs and guides, and in that the loosely inserted contact parts are held, so that they cannot be lost, by the intermediate webs and guides of two adjacent switch chambers or of one switch chamber and of the end cover (14), even when the control drum (10) is removed and re-inserted.

8. A cam-operated switch as claimed in Claim 7, characterised in that the front-end intermediate webs (35, 36, 37) and guides of the switch chambers (11) are connected to an intermediate wall (38) which extends vertically to the axis of rotation of the control drum (10), and in that the intermediate wall (38) has a circular opening (39) for the passage of the control drum (10).

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