FR2641408A1 - ROTARY ELECTRIC SWITCH, IN PARTICULAR WITH MANUAL CONTROL - Google Patents

Abstract

The invention relates to a rotary electric switch, in particular manually operated. The switch is characterized in that its housing 1 has a substantially cylindrical shape, coaxially surrounds its rotary assembly and carries on one of its internal end faces fixed contact elements 15, 16, that the rotary assembly 2 comprises a member 30 the front surface of which is located axially opposite said front face 18 of the housing carries the rotary electrical contact element 35, and in that the removable locking means of the rotary assembly 2 in the angular closed positions and d The opening of the electrical contacts are formed by recessed 23, 48 and protruding parts 21, 49, 51 of complementary shape, provided on facing surfaces respectively of the rotary assembly 2 and of the housing 1. The invention is notably usable for small household appliances.

Description

The present invention relates to a rotary electrical switch

  in particular with manual control, of the type comprising a rotary assembly carrying at least one electrical contact element enclosed in a housing carrying a fixed electrical contact device having at least one set of external connection terminals and internal contact elements capable of being electrically connected or isolated depending on whether the rotary contact element is in a predetermined angular position for closing or opening the fixed contacts. Known switches of this type have the disadvantage of being bulky, which excludes their use in relatively small electrical appliances of relatively small dimensions such as for example coffee machines. Because of the size of known rotary switches, these devices and machines are currently equipped with toggle-type switches. However, in the measure o to manipulate these switches must exert a pressure force by a finger of one hand, which may move the device on its support surface, it is advisable to use the other hand to hold the device, especially when it is relatively light or the support surface

relatively smooth.

  Consequently, the use of toggle switches is not a satisfactory solution to the problem of manual control of small household electrical appliances and / or

of low weight.

  The present invention aims to provide a rotary switch which is perfectly adapted to equip these household electrical appliances,

  without the aforementioned disadvantages.

  To achieve this objective, a rotary switch according to the invention is characterized in that the casing has a substantially cylindrical shape, coaxially surrounds the rotary assembly and bears on one of its inner end faces said fixed contact elements, that the assembly rotary device comprises a member whose front surface is located axially opposite said end face of the casing and carries the rotary electrical contact element and in that the means for releasably locking the rotary assembly in said predetermined angular positions are formed by complementary recessed and protruding parts provided on surfaces facing respectively from

the rotating assembly and the boot.

  According to an advantageous characteristic of the invention, the detachable locking means are formed by surface portions in recessed and protruding inclined slope, complementary shape, front surfaces axially facing the rotating assembly and the boot and sliding one on the other during the

  rotation of the rotating assembly in the casing.

  According to yet another advantageous characteristic of the invention, the carrier member of the rotary contact element is axially movable in said casing and the fixed contact elements to be electrically connected by it are separated by walls made of a material electrically insulating, arcuate, projecting axially towards said member, from the inner end face of the housing carrying said fixed contact elements, the end surfaces of these walls form ramp surfaces on which slides rotating contact element during the rotation of the rotary assembly and have inclined slopes on either side of a fixed contact element to form removable locking recesses of the rotary assembly in the closed position of the

  electrical contacts of the switch.

  According to yet another advantageous characteristic of the invention, the rotary assembly comprises inside the casing, facing the other internal front face of the latter another axially movable member in the casing, that the front faces facing of this member and the casing have complementary shaped recessed and protruding parts, which are arranged so that the projections of one face engage in recesses of the other when the rotating assembly

  found in an open position of the switch.

  According to yet another advantageous characteristic of the invention, the rotary assembly comprises an axis housed in the housing, which carries at an axially projecting end of the casing an actuating knob and on which are fitted, in a rotationally fixed manner, the two members and in that the compression spring is axially interposed between these two members by bearing on the inner end faces facing them, the free end of the axis advantageously having a smaller diameter tip housed in a hollow practiced inside the

  corresponding internal frontal face of the casing.

  The invention will be better understood, and other purposes, features, details and advantages thereof

  will appear more clearly during the description

  explanatory text which will follow with reference to the appended schematic drawings given solely by way of example illustrating an embodiment of the invention, and in

which: -

  - Figure 1 is an exploded perspective view of a rotary switch according to the present invention;

264 1,408

  - Figure 2 is an axial sectional view of the switch according to Figure 1 and illustrates it in its open position of the electrical contacts; - Figure 3 is an axial sectional view towards the line III-III of Figure 2; - Figure 4 is a sectional view along the line IV-IV of Figure 3; Fig. 5 is a sectional view along the line V-V of Fig. 2 but showing the rotary contact element as a whole; and - Figure 6 is an axial sectional view of the switch according to Figures 1 to 5, but showing it in its closed position of the electrical contacts. The rotary electrical switch shown in the figures, by way of example, comprises a casing 1 of generally cylindrical shape and a rotary assembly 2 comprising an arrangement 3 enclosed in the casing i and

  an external operating knob 4.

  The box i of an electrically insulating material consists of two parts 5, 6 axially aligned and assembled by fitting. The part 5 has at its free end an annular widening in the form of a flange 7 which engages in a cylindrical cavity 8 in a flange portion 9 of the

  button and thus serves as a means of guiding the latter.

  Part 6 of the casing i in the form of a cylindrical cup carries the fixed electrical contact device of the switch. This device essentially comprises, in the example shown of a unipolar switch, two lugs 12, 13 of external electrical connection which pass through the front wall 14 of the casing part 6 and are formed inside thereof in elements. internal contact contact 15 and 16 each carrying a contact pad indicated at 17. These contact elements 15 and 16 are plated on the inner surface 18 of the bottom end wall 14. The contact elements 15 and 16 are diametrically opposed by relative to the XX axis of the switch. The front wall 14 carries on its inner surface 18, near its periphery, between the two contact elements 15, 16, and diametrically opposite, two walls 20 each substantially in the form of a circular arc, which project axially towards the outside. inside the boot. The height of these walls is substantially constant in their median part 21 and decreases progressively 22 towards the contact elements 15 and 16. In the radial direction, the front surfaces extend perpendicularly to the axis XX and form ramps. sliding for a movable contact element of the rotating assembly, as will be explained later. It is found that the peripheral ramp formed by the two walls 20 forms a recess 23 at each contact element 15, 16. The elements are located closer

of the X-X axis as the walls 20.

  The rotary assembly 2 comprises an axis 25 whose cross section is non-circular and has a flat shape. This axis carries at its end 26 which passes through the flange 7 of the casing 1 the operating knob 4 and has at its opposite end a cylindrical end 27 through which it is housed in a housing 28 of appropriately cylindrical shape formed in the bottom wall 14

boot maker.

  The internal arrangement 3 of the rotary assembly 2 comprises a first member in the form of a ring 30 and second member in the form of a washer 31 which are integral in rotation with the axis 25 but axially mobile thereon. These two members are fitted on the shaft 25 and respectively pushed towards the opposite inner end walls of the casing, namely the surface 18 which carries the fixed electrical contacts 15 and 16 and the inner face of the flange 7 indicated at 32, under the effect of the force of a compression spring 33 which is supported by these ends on appropriate surface portions of the inner surfaces facing the members

and 31.

  The ring-shaped member 30 bears on its end face opposite the inner end face 18 of the casing the aforementioned movable contact element which has been assigned the reference number 35. This element 35 is cut from a plate of oblong shape so as to have a central portion in the form of washer 36 pierced with a circular hole 37 with two excrescences 38 diametrically opposed, while the ends 39 are shaped in pads whose parallel side edges are folded from the plane of the plate in

  opposite direction of the fixed contact elements 15 and 16.

  In order to be able to receive the contact element 35, the front surface of the ring 30 has a raised structure which protrudes axially towards the fixed contact elements and has a shape corresponding to that of the element 35. This part comprises a circular central zone 43 corresponding to that of the washer 36 of the element 35 and, diametrically opposed bars 44 whose width corresponds to the flat portion of the sliding pads 39 of the element 35 and whose side faces 45 are inclined d a way corresponding to the inclination of the flanges 40 of the element 35. The raised portion 42 further has axial protuberances which engage in the protrusions 38 of the element 35. Due to this conformation of the ring 30 and the element 35, it is immobilized in rotation on the ring and occupies substantially the entire front surface of the body of the ring 30. There is furthermore on the cylindrical surface p peripheral of this ring the presence of an annular shoulder 46 forming a bearing surface for the

spring 33.

  The second washer-shaped member, of the internal arrangement 3 of the rotary assembly, has on its external front surface oriented towards the inner surface 32 of the casing i all around its periphery a crown comprising a raised pattern having parts hollow 48 and radially projecting portions 49. In the lateral view, this relief is in the form of a series of isosceles triangles. This raised pattern forms a ramp having a front surface which constitutes a sliding path cooperating with a raised pattern provided on the internal face facing the casing. This last pattern presents, angularly regularly distributed over a circle about the axis XX of the switch, four projections 51 in the form of a prism with triangular cross-sections whose top edge 52 extends radially and which project axially inwards. 31. These prismatic projections 51 are arranged to be located axially opposite the hollow pattern 48 and

with projections 49 of the washer 31.

  It can be seen that the protruding parts 49 of the washer 31 and the prismatic projections 51 on the inner surface 32 of the casing are angularly arranged, on the one hand, with respect to each other and, on the other hand, with respect to the elements fixed contact 15, 16 and the ramp 20 separating them, so that the prismatic projections 51 is engaged by their crown edges 52 in the center of a recess 48 of the raised pattern of the washer 31, when the element movable contact 35 of the rotary assembly rests on the substantially horizontal portion 21 of the ramp of the fixed electrical contact device, that is to say when it occupies its open position of the electrical contacts of the switch. The closing position of the electrical contacts is determined by the engagement of the movable contact element 35 in the recesses 23 formed by the ramp 20, where are the fixed electrical contacts and 16. In this position the pads 39 of the element are applied under the effect of the pressure force of the spring 33 on these fixed contact elements 15, 16 thereby shortcicuitant electrically.

  To complete the description, we note

  still the presence of an O-ring 54 interposed between the flange 7 of the housing and an annular shoulder 55 integral with the axis 25 to make the switch tight in its front part. In addition, to facilitate assembly of the two parts of casing 5 and 6, the portion 5 has at its free end elastic locking tabs 56 which engage in appropriate recesses 57 pévus in the wall of the party

boot maker 6.

  The operation of the switch according to

  the invention is evident from the description of the

  structure that has just been made. Indeed, Figures 2 and 3 show the switch in its stable and well defined position of the opening of the electrical contacts of the switch. As indicated above, in this position the prismatic projections 51 are engaged in the recesses 48 of the raised pattern of the washer 31 of the rotary assembly 2, while the movable contact element 35 rests on top of the ramp portions 21 of the fixed contact device. When the rotary assembly is rotated about the axis XX, by actuating the operating knob 4, the apex edge 52 of the prismatic projections 51 slide on the upwardly sloping surfaces of the washer 31; which requires the application of a force on the operating knob and causes the sliding of the movable contact element 35 on the ramps 20, in the direction of the fixed contact elements 15, 16. During this printed rotational movement of outside the washer 31 is pushed axially towards the inside of the casing 1, while

26 4 1 4 0 8

  first alone by compressing the spring 33, and then with the ring 30 as soon as the movable contact element 35 engages the downward portion 22 of the ramps 20. The stable position of closure of the electrical contacts is reached when the element 35 rests on the fixed contacts 15 and 16 by shortcuitienting them. In this position of the rotary assembly 2, the vertices 52 of the prismatic projections 51 are in contact with the tops of the projecting parts 49 of the washer 31, as illustrated in FIG. 6. To change the position of the switch, it is necessary again to exert a force on the operating knob so that the movable contact element 35 can rise, against the force produced by the spring 33, the rising faces 22 of the ramps 20 of the contact device fixed. This sliding movement of the shoes 39 of the element 35 is facilitated by

the inclination of the flanges 40.

  It can be seen that the parts through which the pads 38 slide on the ramp walls 20 are not those which cooperate with the fixed contact elements, 16. Thanks to this measure it is possible to prevent the contact parts of the pads from being contaminated by the plastics material.

  walls 20 and the wear of these parts.

  It follows from the preceding description that the

  two closed positions of the electrical contacts and

  of the opening of these are perfectly defined.

  Thanks to the cooperation of the axially raised parts, provided on the rotating assembly 2 and the casing provide locking of the rotary assembly in each of the two positions. Any change of position involves the engagement of an outside force through

operating knob 4.

Claims (7)

REVEND I CTIONS   1. Rotary electric switch including manual control, of the type comprising a rotating assembly carrying at least one electrical contact element and a casing enclosing said assembly and carrying a fixed electrical contact device having at least one set of terminals. external connection and of internal contact elements that can be electrically connected or isolated from one another according to whether the rotary contact element is in a predetermined angular position for closing or opening the electrical connection of the fixed contacts, as well as means for releasably locking the rotary assembly in said predetermined angular positions, characterized in that the casing (1) has a substantially cylindrical shape, coaxially surrounds the rotary assembly (2) and bears on one of its internal end faces (18) said fixed contact elements (15, 16), that the rotary assembly (2) comprises a member (30) the front surface which is situated axially facing said end face (18) of the casing carries the rotary electrical contact element (35), and in that the means for releasably locking the rotary assembly (2) in said positions predetermined angles are formed by complementary-shaped recessed (23, 48) and projecting portions (21, 49, 51) provided on facing surfaces respectively of the rotating assembly (2) and the boot maker (1).   2. Switch according to claim 1, characterized in that the removable locking means are formed by recessed surface portions (26, 48) and projections (21, 49, 51) with inclined slopes, of complementary shape, front surfaces axially in view of the rotating assembly (2) and the casing (1), and sliding on each other during the rotation of   the rotating assembly in the housing.   3. Switch according to one of the claims   1 or 2, characterized in that the member (30) carrying the rotary contact element (35) is axially movable in said casing and the fixed contact elements (15, 16) to be electrically connected by it are separated by walls (20) of an electrically insulating material, in the form of arcs, which project axially towards said member (30) from the inner end face (18) of the casing (1), carrying said elements fixed contact surfaces (15, 16), the end surfaces of these walls (20) form ramp surfaces on which the rotary contact element (35) slides during the rotation of the rotary assembly (2) and exhibit inclined slopes on either side of a fixed contact element (15, 16) to form recesses (23) for removable locking of the rotary assembly   in the aforementioned closing position.   4. Switch according to claim 3, characterized in that the contact element (35) is formed by a metal washer (36) carrying at its periphery, diametrically opposite two pads (39) whose lateral flanges (40) are- advantageously taken in the direction of inclination of the ramp surfaces (20) on which they slide and which have a width less than the recesses (23) delimited by said ramp (20) and allowing them to bear on the   fixed contact elements (15 and 16).   Switch according to one of the claims   3 or 4, characterized in that the rotary assembly (2) comprises inside the casing (1), facing the other end face (32) of the latter, another member (31) axially movable in the case, that the front faces facing this body and the boot 2 6 4 1 4 0 8   has complementary shaped recesses (48) and projections (49, 51) which are arranged so that the projections (51) of one face engage with the recesses (48) of the other when the rotating assembly (2) is in the aforementioned opening position of the switch. 6. Switch according to claim 5, characterized in that the rotary assembly (2) comprises an axis (25) housed in the casing (1), which carries at an axially projecting end of the housing an operating knob (4). and on which are fitted, integrally in rotation, the two aforementioned members (30, 31) and in that a compression spring (33) is axially interposed between these two members by resting on the internal facing end surfaces. of these, the free end of the shaft (25) advantageously having a cylindrical end (27) housed in a recess (28) formed inside the front face   internal (18) corresponding housing.   Switch according to 3 to 6, characterized in that the stationary contact elements (15, 16) are located closer to the axis (XX) of the switch than the sliding ramp walls (20), so that that the parts through which the movable contact elements (35) slide on the ramp are not those which   come into contact with the elements (15, 16).