FR2580425A1 - ELECTRICAL SWITCH, IN PARTICULAR FOR A GAS VALVE ASSEMBLY - Google Patents

Abstract

THE INVENTION CONCERNS AN ELECTRICAL SWITCH 10 CONSISTS OF TWO BOXES 12 and 20. A FIRST BOX 12 INCLUDES A PORT 14 FOR RECEIVING A SHAFT. THE SWITCH INCLUDES AN ACTUATION ELEMENT 16 THAT CAN BE MOVED AXIALLY OR IN ROTATION WITH RESPECT TO PORT 14, THE ACTUATION ELEMENT BEING RECEIVED IN A PORT 18 OF THE SECOND BOX. THE TWO BOXES ARE FIXED TOGETHER BY ULTRASONIC WELDING AROUND THE MAJOR PART OF THE PERIPHERIES OF THE PORTS 14, 18 TO RETAIN AT LEAST PART 22 OF THE ACTUATOR 16 BETWEEN THE TWO BOXES, THE SWITCH ALSO INCLUDING ONE MOBILE SWITCHES AT LEAST PART IS RETAINED BETWEEN THE FIRST AND THE SECOND BOXES AND WHICH ESTABLISH AN ELECTRICAL CONTACT AT LEAST OF THE ACTUATOR 16 WITH FIXED CONTACTS 26. APPLICATION IN PARTICULAR TO A GAS VALVE ASSEMBLY.

Description

The present invention relates to switching

  electric motors which are suitable in particular, but not exclusively, for use in conjunction with a spindle or shaft of a gas valve assembly for igniting or re-igniting gas supplied thereby;

  to a domestic appliance such as a stove.

  Examples of electrical switches

  known for this purpose are disclosed in the British patents.

  N 1 469 931 and N 1 490 995 to which we are invited

  to refer to for other basic information.

  An object of the present invention is to improve

  the above examples of electrical switches allowing them to be of a much smaller dimension

  and to be easier to assemble.

  An electrical switch according to the present

  invention comprises a first boot comprising a first

  extending axially to receive a pin or an axis, an actuating means mounted to move axially and / or rotatably with respect to the orifice, a second casing having an axially extending orifice receiving the actuating element, the first and second housings being secured to one another by ultrasonic welding around a substantial portion of the peripheries of said orifices

  to retain at least part of the element of

  between the first and second bootmakers, and

  mobile tacts having at least one portion retained between the first and second booties, all of which

  axial and / or rotary movement of the action element

  to make electrical contact with fixed contacts.

  Mobile contacts do not need to be

  blink a contact with the fixed contacts by a snap action. It should be noted that by ultrasonically welding the first and second sheaths together, it is possible to reduce the overall dimension, to avoid the use

  screws, rivets and adhesives that are difficult to handle

  ler and to assemble by an automatic machinery. Preferably, the movable contacts are represented by a stress blade contact which may comprise two external bridge contacts separated by a flexible central portion intended to abut against the actuating element. The assembly may be such that during the operation of the actuating element, the external contacts remain fixed, while the central part is deflected by the actuating element until

  the external contacts and the central part

  together relative to a fixed part of the constraint blade contact mounted between the first and second casings. Preferably, the fixed contacts comprise two fixed terminals which are in the paths of

  movement of the external contacts of the blade contact with

constraint.

  The advantage of the preferred features of the movable and stationary contacts is that undesired curvature of the external contacts of the stress blade contact can be avoided even if operation of the actuating element continues after the external contacts.

  were brought to abut against the fixed terminals.

  In one embodiment, the actuating member is axially movable and has a projecting portion extending through a gap of said ultrasonic weld around a substantial portion of the peripheries of the orifices of the first and second housings, so as to abut against the central portion of the stress blade contact. In another embodiment in which the actuating element is also axially movable, the central portion of the stress blade contact extends through a gap of the ultrasonic weld around a substantial portion of the peripheries of the orifices of the first and the second

  casings, so as to abut the actuating element

  is lying. In both of these embodiments, rather than relying solely on the elasticity of the blade contact

  constrained to bring about the return of the

  in a non-functional initial position, mechanical return elements may be provided which may take the form of a spring such as a spring

helicoldal compression.

  As indicated above, it is also possible for the actuating member to be rotatable and, in this case, the central portion of the stress blade contact can extend through a gap of the ultrasonic weld around the a large part of the peripheries of the orifices in the first and second bootcases, so as to abut against a cam presented

by the actuating element.

  Preferably, the first casing is in the form of a base to which are attached, both the movable contacts and the fixed contacts, and the second casing is in the form of a cover. There may be a slot in the movable contacts to allow sliding contact with a T-shaped guide of the base. If the movable contacts are represented by the stressed blade contact mentioned above, the slot is formed in the fixed part with respect to which

  the external contacts and the central part can

  Med. There may initially be at least one energy steering element in the form of a rib of the base or lid or both of these elements to assist

  to perform ultrasonic welding on the lid.

  Preferably, there are several ribs of this type of which

  35.they continually extends around an important part of

  aunt from the periphery of the orifice of the base.

  The base may have mounting members for use involving attachment of the base to a support. It may be more appropriate in any given application that the assembly is in the form of a detachable element having at least two tongues to resist any unwanted rotation of the base relative to the support. The detachable element may be an annular washer having a notch in its inner periphery so as to cooperate with a lug on the base, the annular washer being sandwiched between the base and the support, and the tongues being located on each side. 'a bolt or other part of the support. Alternatively, the mounting member may be in the form of an integral member of the base having at least two flutes used to resist undesired rotation of the base relative to the support. The splines can receive two bolts as mentioned above or other parts of the support. If several pairs of keys are provided, then the orientation of the base can be adjusted

to the support.

  The fixed contacts can be plugged in position but preferably they have a structure

  with barbs allowing pressure mounting.

  In addition, the fixed contacts may have a flat blade structure extending centrally from a cavity to receive a suitable external conductor, but preferably the fixed contacts may be used

  with external conductors of the driving type.

  In order to comply with official regulations, resources

  such as a cam may be provided in association with the preferred driving form of

fixed contacts.

  Naturally, the support is preferably in the form of a gas valve assembly comprising a pin or shaft which extends through the orifice of the

  first boot and which is functionally attached to the

  actuation. The operation of the latter brings the movable contacts into electrical contact with

  fixed contacts so as to cause the operation

  of a conventional electric ignition or re-ignition circuit. It may be appropriate, depending on the details of the gas valve assembly, that the actuating element is retained in its operative position as long as gas is supplied in the event that the ignition is re-ignited.

this gas would be needed.

  Several electrical switches according to the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a plan view of the first electrical switch omitting the cover; Figure 2 is a sectional view along the line II-II of Figure 1 comprising the cover; Figure 3 is a sectional view along the line III-III of Figure 1 comprising the cover; Figures 4, 5 and 6 are, respectively, bottom, end and side views of the lid; Figure 7 is an end view of the base taken in the direction of the arrow VII of Figure 2, and half section on the line III-III of Figure 1 before depression on a fixed contact; Fig. 8 is a bottom view of the base showing only the fluted portion of the base; Figure 9 is a view of the forced blade contact of the left end of Figure 2; Fig. 10 is a view of the stress blade contact of the right-hand end of Fig. 2 with omission of the external contacts; Figures 11 and 12 are, respectively, plan and sectional views of a second electrical switch corresponding to Figures 1 and 2; Fig. 13 is a sectional view of the actuating element for illustrating the cam; Figures 14 and 15 are, respectively, plan and sectional views of a third electrical switch corresponding to Figures 1 and 2; Figures 16 and 17 are, respectively,

  bottom and end views of the element

chable;

  Fig. 18 is a plan view of a modification

  cation applicable to each of the switches of the figures

1 to 17;

  Figures 19 and 20 are, respectively, side and plan views of the fixed contact of Figure 18; FIGS. 21 and 22 are respectively fragmentary plan and sectional views, the latter being taken on the broken line XXII-XXII of FIG. 21, concerning another modification applicable to each of the switches of FIGS. 1 to 17, or their modification of Figures 18 to 20; and Fig. 23 is a perspective view of

fixed contact of Figures 21 and 22.

  A first electrical switch 10 according to the present invention is illustrated in the appended figures 1 to 10. The switch 10 comprises a first housing in the form of a base 12 integrally molded in plastic material having axially a through orifice 14, so as to receive a pin or shaft (not shown) of a gas valve assembly. An actuator element 16 also integrally molded of plastic is mounted to move axially relative to the orifice 14 and the actuating element 16 is received in a suitable orifice 18 extending axially through the second housing . The latter is in the form of a lid 20, molded integrally with plastic and

  attached to the base 12 by ultrasonic welding. It is important

  both from the point of view of the resistance to the liquid inlet, for example due to splashing that the ultrasonic welding extends around a large part of the peripheries of the orifices 14 and 18. It will also be noted that the ultrasonic welding acts to retain at least a portion 22 of the actuating member 16 between the base 12 and the cover 20. A movable contact means 24 is also retained between the base 12 and the cover 20 and operates by movement axial axis of the part 22 of the actuating element 16 to establish

  an electrical contact with the fixed contacts 26.

  With particular reference to Figures 2, 7 and 8, the base 12 is illustrated as having

  below the mounting elements as part of

  grante formed as an element 28 having eight grooves

  30. When the base 12 is mounted on the valve assembly

  net to gas, two vertical bolts of this set can be received by opposite grooves 30. A wall

  cylindrical inner 32 on the base 12 not only defined

  orifice 14, but also

  coidal compression 34 which pushes the element of action-

  16 to its inactive position as illustrated in the figures. Two lugs 36 on the base 12 can be used

  to drive in position conventionally two con

  Fixed, brass-ported contacts 38 forming the fixed contacts 26. A T-shaped guide 40 on the base 12 may be slidably touched by the movable contacts 24 in the manner explained below. Four ribs 42 in total, each having a pointed apex to allow their use as an energy directing element during ultrasonic welding, are formed on outer walls 44 of the base 12o. These comprise a short end wall 44 by the T-shaped guide 40, two side walls 44 extending parallel to the fixed contacts 38 and a curved end wall 44, which is an integral part of the two side walls 44, has portions extending transversely to the base 12 towards piece 22 of the item

  16 and is concentric with the cylindrical wall

  32. The ribs 42 are melted during the assembly.

  Two locating holes 46 receive two complementary lugs 46 'of the lid 20. With reference in particular to FIGS. 4 and 6, it can be seen that in addition to the lugs 46', the lid has two walls 48 shaped Parts extending transversely of the walls 48 are located in the assembly opposite two similar walls 48 'extending transversely on the base 12 so as to provide slots therebetween. The brass contacts 38 extend through the slots in the middle of respective generally rectangular cavities, each being defined between a bottom wall 50 of the base 12, the cover 20, one of the side walls 44 of

  the base 12 and an inner wall 52 adjacent and longitudinal

  of the base 12. A locating pin 54 of the cover

  key 20 further helps to retain the movable contacts 24 in engagement with the T-shaped guide 40 of the base 12. A somewhat longer lug 56 of the cover 20 helps to maintain the movable contact means 24 in a condition of prior stress wherein there is a known gap between the moving contacts 24 and

the neighboring contacts 38 brass.

  With reference in particular to FIGS. 1, 2, 9 and 10, it can be seen that the movable contacts 24 are

  in the form of a blade contact 58 with a metallic stress

  integrally formed and comprising two outer bridge contacts 60 separated by a flexible central portion 62. The outer contacts 60 and the central portion 62 are formed at the free end of the arm 64 which extends at an angle to relative to the other arm 66 forming a fixed mounting piece of the stress blade contact 58. A slot 68 in the arm 66 allows the stress-relieved blade contact 58 to be inserted into the groove 40.

  T-shape of the base 12. The free ends of the

  External tacts 60 may be shaped to have a curved appearance. The central portion 62 of the stress blade contact 58 extends out of the plane of the contacts

  60 and to part 22 of the actuating element

  16. The portion 22 of the actuating member 16 passes through an interval of the ultrasonic weld.

  around a large part of the peripheries of the ori-

  14 and 18 of the base 12 and the cover 20. An axle or spindle (not shown) can be fixed

  at an orifice 70 of the actuating element 16.

  In operation, as the actuating member is moved axially downward, as shown in FIG. 2, the workpiece 22 pushes against the central workpiece 62 of the stress blade contact 58 and makes the central workpiece 62 deviates, while the external contacts 60 remain fixed. Finally, the arm 64 comprising the external contacts 60 and the central portion 62 is caused to deviate relative to the arm 66 which remains fixed to the base 12. The external contacts are thus brought into contact with the adjacent brass contacts 38 constituting the fixed contacts. 26. When

  the actuating element 16 is released, the helicoidal spring

  Compression dal 34 returns the actuating element

  16 to its initial inactive position.

  A second electrical switch 1oa is shown in FIGS. 11 to 13. The components of the second switch that correspond to components of the first switch have the same reference numbers with the addition of the suffix a. It is therefore necessary to indicate

  only that the actuating element 16a can move

  cer rotation relative to the orifice 14a of the base 12a. The central piece 62a of the constrained blade contact

  58a passes through the indicated range of ultrasonic welding

  around a substantial portion of the orifice 14a.

  This allows the free end of the central piece 62a to be below a cam 72 formed on the underside shown in Figure 12 of the piece 22a sandwiched between the base 12a and the cover a. A third electrical switch 10b is illustrated in FIGS. 14 to 17. The components of the third switch which correspond to the components of the first

  switch have the same reference numbers with the addi-

  suffix b. It is therefore necessary simply to indicate that, apart from some differences in size,

  the main difference from the first switch

  is that the third switch has elements

  different mounting. In particular, instead of one

  forming part 28-, with grooves

  there is a detachable element 74 having two lances

  spacers 76 which are on each side of a vertical bolt of the gas valve assembly. The tabs 76 thus resist any unwanted rotation of the

  base 12b with respect to the gas valve assembly. The the-

  detachable 74 may take the form of a washer

  ring whose inner periphery has a slot 78 cooperated with

  with a key 80 of the base 12b.

  A modification that can be applied to any of the switches described above is shown in FIGS. 18 to 20. The modification relates to the manner of fixing

  the fixed contacts at the base. A disadvantage of

  position of the fixed contacts in position by separating or pushing the free ends of two lugs formed on the base and passing through complementary orifices of the fixed contacts, is that the areas of the contacts are reduced

  which are available to establish electrical contact

  only with the free ends of the external contacts of the moving blade contact with stress. The modification overcomes this disadvantage by omitting the lugs of the base and the complementary orifices of the fixed contacts and, instead, provides barbs on the fixed contacts to allow their introduction into grooves.

complementary to the base.

  The components of this change that correspond to the components of the first switch have the same reference numbers with the addition of the suffix

"C."

  Each of the two brass fixed contacts 82 comprises, as in the switches described above,

  an elongate flat blade 84 extending substantially perpendicularly

  in particular relative to a vertical flange 86 which itself extends substantially perpendicular to a flat contact area 88. In this modification, however, there is no hole in the flat contact area 88 and provision is made for an inclined barb 90 opposite the vertical flange 86. The transverse portions of the curved end wall 44c of the base 12c are formed of two respective grooves 92 in which the barbs 90 are to be driven. When the vertical flange 86 of the fixed contact 82 abuts against the transverse wall 48'c of the base 12c and the flat contact area 88 of the fixed contact 82 abuts against the bottom wall 56 of the base 12c, the barb 90 is deflected elastically. inside the groove 92 to take a more vertical attitude, so that it acts to resist the release of the fixed contact 82 relative to the base 12c. Another modification that is applicable to one or the other of the switches described is shown in FIGS. 21 to 23. The other modification concerns the

  fixed contacts to external conductors

  nes. In some countries, it is

  external conductors as drivers of the type called

  The "push-in", or a bare end of a solid or strand wire conductor is simply pushed beyond

  a barbed contact that can be deflected

  to establish an acceptable electrical connection, but in Great Britain it is necessary to use a tool to positively fix and release the electrical connection. The purpose of the other modification is to provide fixed contacts for use with external contacts

  of the driving type, leaving the possibility

  to make these fixed contacts capable of being

born by a tool.

  Components of this other modification that correspond to the components of the first switch and the variation mentioned above have the same numbers

  reference with the addition of the suffix "d".

  A fixed brass contact 94 for use with one or two outer conductors 96 having exposed ends 98 includes a flat contact area 88d having an inclined barb 90d to provide contact

  elastically deflected inside a complete groove

  92d formed by the transverse portion of the curved end wall 44d of the base 12d. The edge of the flat contact area 88d extending along a side wall 44d of the base 12d includes a vertical flange 100 extending substantially at right angles to the flat contact area 88d. A slot 102

  is formed in the flange 100 to allow locating

  above the adjacent transverse wall 48'd which may itself comprise a slot 102 'to receive the flange 100, which helps to obtain a localization

  precise of the fixed contact 94 relative to the base 12d.

  Two elastically deflected barbs 104 extend from the flange 100 and initially occupy the free position shown in dotted line in FIG.

  position, the end or the bare ends 98 of the conductive

  or two conductors 96 may be pushed

  freely in the switch through additional holes

  formed in the side wall 44d. Notched end surfaces 106 of the barbs 104 can be

  move to establish an electrical connection with the former

  tremité or the exposed ends 98, namely the locked position shown in solid lines in Figure 21, rotating an eccentric cam 108 formed between two cylindrical end lugs 110. These lugs 110 are received

  so that it can rotate freely in complete holes

  formed in the base 12d and the lid (no

  shown). At least one of the end lugs 110

  carries a groove 112 into which a conventional blade screwdriver can be inserted to effect the rotation

of the cam 108.

  If necessary, an abutment indicated at 114 on the base 12d may be provided to sandwich the barbs 104 between the cam 108 and the abutment 114 and thereby reduce any unwanted bending of the barbs 104 when in their position. locked position. One or more stops such as bumps or other protuberances may be formed on the cam 108 to limit the rotational movement of the cam 108 relative to the base 12d. We do not need two

258.0425

  barbs 104 if only one driver of the recess type 96 is required. If the cam 108 is returned to its initial position so as to release the driver

  or the outer conductors 96, the barbs 104 return-

  are elastically at their initial free position shown in dashed lines in FIG. 21. Note that the fixed contact 94 to be used with the other side wall 44d of FIG.

  switch is a mirror image of the one shown.

  In some countries it may be possible to omit the eccentric cam 108 and in this case the barbs 104 will be designed to initially extend into the position shown at the dot and dash line of Fig. 21, so that the insertion of a bare end 98 of an outer conductor 96 pushes the associated barb 104 to the locked position noted above

  and shown in full line in Figure 21.

Claims (17)

  1. Electrical switch (10, 10a, 0lob), characterized in that it comprises a first housing (12) having an orifice (14) extending axially therethrough for receiving a pin or an axis, an actuating element (16) mounted to move axially and / or in rotation with respect to the orifice (14), a second casing (20) having an orifice (18) passing through it axially so as to receive the actuating element (16), the   first and second casings (12, 20) being secured together   ultrasonic welding around an important part of   the periphery of the orifices (14, 18) for retaining at least a portion (22) of the actuating element   (16) between the first and second shoemakers, and   mobile tacts (24) having at least a portion   is also retained between the first and the second bot-   third and which can operate by the axial and / or rotary movement of the actuating element so as to make electrical contact with fixed contacts (26, 82, 94) ..   2. Electrical switch according to the claim   1, characterized in that the movable contact is a stressed blade contact (58) having two external bridge contacts (60) separated by a central portion   flexible (62) abuts with the actuating element.   3. Electrical switch according to the claim   2, characterized in that it is axially movable and comprises a projecting portion (22, 22b) which passes through an interval of the ultrasonic weld around a large part of the peripheries of the orifices of the first and second boot housings, so as to abut the party   central contact blade constraint.   4. Electrical switch according to the claim   2, characterized in that the actuating element is axially movable and the central portion of the stress blade contact passes through a gap of the weld   ultrasound around a large part of the peripheral   holes of the first and second   way to abut against the actuating element.   5. An electric switch according to claim 3 or claim 4, characterized in that a mechanical return element (34, 34b) is provided for   the actuating element in the form of a coil spring colidal compression.   6. Electrical switch according to the claim   2, characterized in that the actuating element is rotatable and the central portion (62a) of the stress blade contact passes through a gap of the ultrasonic weld around a substantial portion of the peripheries of the orifices of the first and second the second boot to abut against a cam (72) presented by the actuating element.   7. Electrical switch according to any one   than the preceding claims, characterized in that   that the first boot is in the form of a base to which are attached the movable contacts and the contacts   fixed, the second stacker being in the form of a vercle.   8. Electrical switch according to the claim   7, characterized in that a slot (68) is provided   in the movable contacts to allow sliding contact   with a T-shaped guide (40) on the base.   9. Electrical switch according to the claim   7 or 8, characterized in that there is initially at least one energy director (42) in the form of a rib on the base or the lid or both at once to assist ultrasonic welding.   10. Electrical switch according to any one   as in claims 7 to 9, characterized in that   base has mounting elements (28, 74) to be used to fix the base to a support.   11. Electrical switch according to the claim   10, characterized in that the mounting elements are in the form of a detachable part (74) having at least two lugs (76) used to resist any   unwanted rotation of the base relative to the support.   12. Electrical switch according to the claim   10, characterized in that the mounting member is in the form of a member (28) integral with the base having at least two flutes (30) used to resist any unwanted rotation of the base by report to the support.   13. Electrical switch according to any one   than the preceding claims, characterized in that   that the fixed contacts (82, 94) have a structure of   barb type for mounting by pressure.   14. Electrical switch according to any one   than the preceding claims, characterized in that   the fixed contacts (82) have a flat blade-like structure extending in the center of a cavity for receiving an appropriate external conductor.   15. Electrical switch according to any one   as in claims 1 to 13, characterized in that   fixed contacts (94) allow use with   external conductors of the recess type.   16. Electrical switch according to the claim   15, characterized in that tool-operated elements (108, 110, 112) are provided in association with the fixed contacts (94) for positively securing   and release the electrical connection type-de-embedding.   17. Electrical switch according to any one   than the preceding claims, characterized in that   it is combined with a support in the form of a gas valve assembly having an axis or a spindle 258Q425   which runs through the hole of the first boot and which is   operatively attached to the actuating element.