FR2528939A1 - GAS VALVE COUPLED TO A PIEZOELECTRIC SYSTEM AND GAS APPLIANCES INCORPORATING SUCH A FAUCET - Google Patents

Abstract

THE PIEZO-ELECTRIC SYSTEM 8 IS PROVIDED ON THE SUPPORT 9 MOUNTED FREELY IN ROTATION ON THE TAP CONTROL AXIS 14, BETWEEN THE TAP BODY 15 AND THE OPERATION BUTTON 17; A PART 13 ARRANGED BETWEEN THE SUPPORT AND THE BUTTON ALLOWS SYSTEM 8 TO BE ACTIVATED IN THE DIRECTION OF THE TAP OPENING, AND TO KEEP THE LATTER AT REST, IN THE DIRECTION OF THE TAP CLOSING. THE INVENTION APPLIES MORE PARTICULARLY TO VALVES WITH AXIAL ADJUSTMENT SCREW.

Description

2528939 '

  The present invention relates to gas valves coupled to piezoelectric ignition systems of a gas burner, for which the rotation of the operating knob in the opening direction of the valve

  activates and triggers the piezoelectric system.

  According to the French patent 75 34369 in the name of the present Applicant, it has already been proposed a gas valve coupled to a piezoelectric system, constituted by at least said valve comprising a body, a rotary control shaft constituted by a set screw axial, having at its free end an operating knob; said piezoelectric system arranged in a fixed manner with respect to the valve body, and perpendicularly with respect to

  the control axis; this system itself comprises a parallelepiped box

  dique, a piezoelectric element contained in the latter, a striker movable in the casing relative to the piezoelectric element, an actuating pin of the mobile striker, a spring or elastic means disposed in the casing; this system is actuated from its rest position, by means of the lug, by loading the spring, then projecting the striker against the piezoelectric element, under the effect of the loaded spring;

  an intermediate piece of actuation of the piezo system

  electric, consisting of a gear wheel; this intermediate piece is mounted coaxially with respect to the rotary control axis, and more specifically around a hub belonging to the operating knob,

  between the valve body and said knob; she is free in transla-

  relative to the control shaft, and each tooth around the perimeter of

  the wheel is capable of actuating the striker of the piezo-electric system

  than; means for coupling in rotation the rotary control shaft and the intermediate actuating part, in the opening direction of the valve, the piezoelectric system remaining or returning to its rest position, during the rotation of the the axis of

  control in the closing direction of the valve.

  In the case of the French patent 75 34369, the latter means is obtained in the following manner: the toothed wheel is locked in rotation on the hub of the operating knob, both in the closing direction and in the opening direction of the valve ; the toothed wheel is pushed in translation, against an axially fixed stop relative to the valve body, by a spring disposed between said wheel and the operating knob; in the closing direction of the valve, each tooth of the wheel is pushed by the pin of the piezoelectric system, and the wheel moves backwards against the spring, each time a tooth passes against the ergot, while returning against the stop between two teeth; in this way the piezoelectric system remains in the

  rest position, when closing the valve.

  According to the French patent 75 34369, the rotary control shaft moves axially, since it is a setting screw. The piezoelectric system being fixed, the intermediate actuating piece must be axially fixed while being driven. in rotation (in the direction of opening of the tap) by the control leaxe, whatever the axial position of the latter; this allows, on the one hand the freedom in translation of the toothed wheel with respect to the control axis, and on the other hand the support of the same wheel against an abutment axially

  fixed, under the effect of the compressed spring by the operating knob.

  The present invention aims to find another solution

  the same technical problem, namely to operate a piezo-electric system

  that thanks to the rotation of a control shaft of a gas valve, mobile

  in translation with respect to the same tap.

  In a general manner, according to the invention, provision is made for a separate and independent support for the valve body and the operating knob, mounted therebetween coaxially with respect to the rotary control axis, and totally free in rotation with respect to this latest; the piezoelectric system is mounted on this support, and at least one means is provided for stopping the rotation of said support, at least in the direction

  opening of the valve, under the effect of the rotation of the

  intermediate actuation of the piezoelectric system.

  An axial abutment is provided on the rotary axis and the support is disposed between the stop and the operating knob, so as to

  move axially with the control shaft.

  The appended drawing, given by way of example, will provide a better understanding of the invention, the characteristics it has and the advantages it is likely to provide:

  Fig 1 is a longitudinal section of a piezo system

electric type simplified.

  Fig 2 shows in perspective with tearing off a system

  piezoelectric self-operating.

2528939- '

  FIG. 3 illustrates the use of a piezoelectric system such as that of FIG. 1, associated with an actuating part fastened to the rotary axis of a gas cock, FIG. 4 is a partial cutaway view, showing the connection between the actuating part and the rotary axis of the valve. FIG. 5 is an exploded view of the actuating part illustrated in FIGS. 3 and 4 and of its exhaust coupling means.

with the rotary axis.

  Fig 6 shows in perspective a gas valve established according to the invention and whose piezoelectric system is

  completely enclosed in a crankcase.

  FIG. 7 illustrates an exhaust actuating part intended to act on a piezoelectric system such as that illustrated.

enfig 2.

  FIG. 8 shows how the actuating part of the piezoelectric system is uncoupled from the operating knob of the valve,

during the closing of it.

  FIG. 9 is a view similar to that of FIG. 7, but illustrating an alternative embodiment of the actuating piece of FIG.

piezoelectric system.

  Fig 10 is an exploded view of the intermediate piece

  actuator and the end of the valve operating knob.

  FIGS. 11 and 12 show the operation of a device according to the invention, the intermediate part of which actuates the piezoelectric system is carried out according to the variant of FIGS. 9 and 10. FIG. 13 illustrates in perspective another way of

  make the intermediate part of actuation of the piezoelectric system

than.

  Fig 14 shows a gas valve coupled to a piezo system

  by means of an intermediate actuating part such as

that illustrated in fig 13.

  FIGS. 15 to 22 are diagrams which illustrate the operation of the intermediate operating part illustrated in FIG.

  combination with a knob.

  The piezoelectric system illustrated in FIG. 1 comprises, in the known manner, an elongated casing 8 at the end of which a piezoelectric element 2 is fixed, against which is projected a firing pin 3 moved by a thrust member 4 against In the opposite direction of an elastic means 5 As is well known, the firing pin pushed by the thrust member is released, so that under the reaction of the spring 5 it comes to strike the element.

  piezoelectric by causing it to produce an electrical voltage.

  FIG. 2 illustrates a more sophisticated system whose piezoelectric element 2 is always retained at one end of the casing or casing 1, but the striker 3 is associated with a pushing member 6 which can be telescopically displaced by relative to the envelope 1 This member is recalled to its rest position by a spring 7 We will not return to the operation of such a piezoelectric system which is well known in the art It will be recalled simply that from its rest position, the displacement of the thrust member towards the casing 1 allows to load the springs 5 and 7, then to project the striker against the piezoelectric element, the return to the rest position of the push member being effected under the sole effect of the spring 7, all thanks to ramps judiciously arranged on the thrust member, as described in the patent

  French 80 26988 of the present Applicant.

  In FIGS. 3, 4, 5 and 6, a piezoelectric system such as that shown in FIG. 1 is used. In these figures, the casing of the piezoelectric system is realized in one-piece form with the support 9, itself comprising an elongated body 9a and two lateral cheeks 9b defining between them a certain space below which the side wall of the body 9a is cut to form a slot 9c Inside the body 9a is placed the piezoelectric element electrical 2 held in place by a threaded metal plug referenced 10 with which cooperates an output conductor 11 held against the plug 10 by means of an insulating capsule 12 An inner groove 12 has the capsule 12 snaps into place with a cord 9 D provided for this purpose at the periphery of the body 9 a Similarly, a second capsule 12 is secured to the other end of said body to serve as a stop at one end & u spring 5 actuation of the percu tor, whose opposite end bears on the latter or more exactly at the bottom of a depression 3a thereof An intermediate actuating piece 13 placed between the cheeks 9b is rotatably mounted around the rotary axis 14 of a gas valve 15 with axial adjustment screw The periphery of the intermediate actuating part 13 is provided with teeth 13a intended to cooperate with the front face 3b of the striker 3 in order to retract it against the reaction of the spring 5 It is easily understood that the rotation of the intermediate actuating piece causes the recoil of the striker and its release so that it can hit the element 2 The resulting electric charge is routed to the burner, on the one hand by the electric wire it, and on the other hand by the striker 3, the wheel 13, the axis 14 and the body 1-5 of the tap, if

  necessary with an electric arc between striker 3 and wheel 13.

  To do this, it suffices that the intermediate actuating piece is integral with the rotary axis 14 in the direction of the opening of the

tap 15.

  However, it is necessary to disengage this intermediate piece

  actuator and the axis 14 when closing the valve.

  For this purpose, the face of the piece 13 which is oriented opposite the valve 15 is provided with four ramps 13b (Fig 5) ending with rises 13c Against the face in question of the piece 13, comes carry an open washer 16 surrounding the axis 14 and one of the end 16 suitably arched cooperates with the ramps 13 b as will be explained further further The opposite end of the

  washer 16 is deformed to form a tab 16b perpendicular to

  This tab 16b enters a slot 17a of the operating knob 17 of the axis 14, so that the rotation of this button in the opening direction causes that of the actuating part. 13, by abutting the end 16a of the washer 16 against the teeth 13c In the opposite direction, the washer 16 rubs against the slopes 13b without driving Of course, the operating knob 17 is force-fitted or overmolded on the corrugated end 14a of the axis 14 The support 9 being placed transversely relative to and on the axis 14, the rotation of the intermediate piece 13 could lead if it had a heel 9 e which cooperates with tap

to wedge it angularly.

  It is observed that the axis 14 comprises a collar 14b against which the outer face of one of the cheeks 9b-of the support 9 bears, the inner face of this cheek forming a stop for the actuating part 13, against which support with operating clearance the end of a hub 17b provided on the operating knob 17, itself passing through the other cheek 9b of the support 9 Thus, the latter

  is it linked longitudinally with respect to the axis 14.

  Thus, it is possible to use the piezoelectric device and its drive as just described, whether the valve 15 is of the plug or needle type, that is to say that its rotary axis can

  longitudinal translation, without influencing its function-

  ment. In the embodiment illustrated in FIG. 6, the entire case of the piezoelectric system and the support are assembled in the form of a casing 18 made of plastics material comprising a heel 18 which can cooperate with the valve body 15 in order to avoid its rotation The casing in question comprises a perforation through which passes the conductor 11 intended to allow the formation of a

  spark at a burner or the like.

  In the embodiments illustrated below, we are no longer dealing with a piezoelectric system according to FIG. 1, but on the contrary with a system such as that illustrated in FIG.

  parallel to the rotary control axis of the valve.

  In the example shown in FIGS. 7 and 8, the casing 8 of the piezoelectric system is contained, parallel to the axis 14, in a support made in the form of a carcass 19 resting against a face 15a of the valve 15 This carcass is extended by a side tab 19a through which the rotary axis 14 passes, the end branch 19b of said tab being folded to cooperate with a second face 15b of the valve 15

  parallel to that 15a The side tab 19a is

  born between the flange 14b of the rotary shaft 14 and a piece inter-

  intermediate actuation 20 on which acts, as will be described better

  further, the operating knob 17 of the tap 15.

  The actuating part 20 comprises at least one ramp 20 with rising part 20a in the direction of opening of the valve, followed by a step 20b which ends either at the origin of the single ramp or the origin of a ramp following the first etc. In a preferred embodiment, it is expected to place three ramps 20 has successive so that the centering of the actuating part 20 is the best possible, it is expected to make it spin on the hub 17b of the button 17 whose diameter is very much greater than that of

the axis 14.

  On the face of the part 20 opposite the ramp 20 is noted the presence of a toothing 20c which cooperates with lying teeth 17c formed on the corresponding face of the button 17, that is to say of its

  transverse face from which the hub 17b.

  It is observed that the distance separating the face of the button 17 provided with the teeth 17 c of the lateral leg 19 of the carcass 19 is greater than the overall spacing of the intermediate actuating piece.

  when its toothing is engaged in the teeth of the button 17 (fig 7).

  When opening the valve 15, that is to say when the button 17 is rotated in the direction of the arrow F in the figure, the teeth 17c drive the actuating part 20 whose ramps are supported on the pushing member 6 of the piezoelectric system

  illustrated in fig 2, so as to burst a spark at the end.

  For this purpose, it is arranged that the bursting of the spark occurs just before the end of the cooperation of the rising portion 20a and the organ 6, then it comes to the right of the redan 20 b corresponding, so that it returns to its initial rest position in which-the mechanism of the piezoelectric system

  is re-engaged for the production of a subsequent spark.

  On the other hand, when the user wishes to close the tap 15, he turns the control knob in the opposite direction, that is to say in that of the arrow F 1 of FIG. 8 because of the action of the member 6 on the intermediate piece 20, the latter is locked in rotation by abutment of the member 6 in a recess 20b, so that the recumbent portions of the teeth 17 c of the button 17 push the teeth 20 c of the workpiece actuation that advances against the return spring of the organ

  6, as well illustrated in fig 8 Thus during all the closure

  re tap the intermediate piece 20 is not actuated.

  If one is dealing with a ball valve, the axis 14 does not undergo

  longitudinal displacement, both during the opening operation and

  during the closing, so that the carcass 19 remains in the same position relative to the tap 15 On the contrary, sil'on

  when dealing with a needle valve, the axis 14 carries out a translation-

  longitudinal direction which causes a displacement of the carcass 19 with respect to the tap 15 However, because this carcass bears against the faces 15a and 15b of the valve 15, oriented parallel to the axis 14,

  whatever the type of valve, no rotation of the piezoelectric system

  can not be carried out under the force applied to the piezoelectric system.

  than by the ramps of the actuating member 20.

  In addition, the presence of the toothing 20 c and teeth 17 c allows during the wear of the needle or the valve seat to catch this game by rotation of the operating knob 17 Indeed, if there is wear of the seat of the valve, the rotation of the button 17 will have to be greater than before to obtain the complete closure of the valve, and the closed position materialized by the coincidence of the toothing cl and the 17 cl will automatically evolve to a new position materialized by the coincidence of the same toothing 20 cl with the next tooth 17 c 2 (in the direction Fl), thanks to the possibility of rotation of the

  button 17 relative to the piece 20.

  In the embodiment shown in FIG. 9, the intermediate actuating piece no longer acts directly on the piezoelectric element pushing member 6, but it is in contact with an element of FIG.

  21, intended to act on the thrust member 6 of the system-

  piezoelectric element This control element 21 comprises a ring 21 has ramps and redans identical to those of the intermediate actuating part 20 and a finger 21b whose end penetrates into the carcass 19, in order to act on the pushing member 6 Of course the length of the finger 21b is calculated so that its curved end remains steadily inside the carcass 19 even when the valve is fully open It is observed that in the mode embodiment illustrated in FIG 9, the side lug 19 of the carcass 19 is provided with one or two wings 19 c which surround one or two flats 15 c formed in the valve body 15 to protect the periphery of the part actuating intermediate 20 and the control element 21, the control knob 17 is advantageously extended by a tubular sleeve 17 d surrounding at least partially said periphery. As illustrated in FIG. 11, when the operating knob 17 is unscrewed (arrow F), the toothing 20 c of the part 20 is driven by the

  17 c teeth of this button, so that the part in question-turns.

  As the control element 21 is stationary in rotation as a result of the cooperation of its finger 21b with the interior of the carcass 19, the ramps 20 of the workpiece 20 act on those of the element 21 to make it move axially in the direction of the valve, that is to say the piezoelectric system The finger 21 b pushes the thrust member 6 into the envelope 1 of the system considered that works to produce a spark When the redans of the 20 and the control element 21 are in facing relation, the latter returns in its place as shown in FIG 12, then the button 17 continues to rotate

  other actuations of said piezoelectric system occur.

  On the other hand, when the user wishes to close the tap, he turns the operating knob in the opposite direction (arrow F1 in FIG. 2). The control element 21 is angularly fixed and retains the intermediate piece 20 In these conditions, the rotation considered of the knob 17 leads to a clearance L of the toothing 2 e) c of the part 20 relative to the teeth 17 c of the button, by axial displacement of the whole part. 20 and the element 21 it enconltre the reaction ioltotd spring (the return of the thrust member 6 Thus, the closing of the valve is effected without actuating the piezoelectric system Again the release of the toothing 20 e and teeth 17 c allows the catching of the wear of the needle

or the seat of the faucet.

  In the embodiment of FIGS. 13 and 14, the intermediate actuating piece 20 comprises only a ramp 20a which develops from a

  low point at a high point on either side of a tongue 20 d.

  It is the same for the control element 21 which is provided with a single ramp 21c whose high and low points are located on either side of a stop 21 d As the control element remains angularly fixed, the tongue 20 d is locked during the rotation of the part 20 on the side of the low point F of the ramp 21 c in the closed position of the valve, and the side of the point O of the same ramp 21 c in its position opening It is observed that the ramps 20a and 21c of the part 20 and the element 21 each comprise a neutral zone 20 e respectively 21 e placed at the low point of each ramp and another neutral zone 20 f, 21 f placed at the top of each ramp The areas in question are in

  reality of flats whose role will be better explained later.

  It will be noted that the ends of the tongue 20 d and of the stop 21 d are respectively in abutment against the ramp 21c and that 20a, when said part 20 and the control element 21 bear against each other.

the other.

  The operation of the gas valve comprising an actuating mechanism of the piezoelectric system according to FIGS. 13 and 14 follows from the foregoing explanations:

  Fig 15 is a developed view of both ramps 20a and 21a.

  When the valve is closed, these two ramps are in contact with each other except for the neutral zones 20 f and 21 f of each of them It is observed that the end of the finger 21 b bears against that the pushing element 6 of the piezoelectric system, such that the depression of this member inside the carcass 19 in no case causes the triggering of the piezoelectric system As illustrated in FIG. reference 22 placed on the operating knob 17 is in front of a sign 23 indicating the closing of the valve If the knob 17 is rotated in the opposite direction of that of the clockwise, so in the sense of opening of the tap, in the exudmi t of Lsa / itgute Lle 2 L (1 pushes the éelieni L of coliimmande _L in the direction of the tap, so that the finger 21 b of this -élément ac't int 1 Mu 1 Piezo-61 organism, and it is necessary to make a spark burst, for example mple when the mark 22 is at an index 24 (see Fig 17 and 18) At this time, the end of the tab 20 d just at the beginning of the flat range 21 f of the ramp 21 c Thus, from this position, it is possible to continue to open the valve in order to complete the adjustment of the gas outlet, without action on the thrust member 6, that is to say we can adjust i O the valve at an angle "without acting on the piezoelectric system (cf fig 19 and 20) It is observed that in the open position of the valve the thrust member 6 remains depressed beyond the position in which

  it caused the projection of the striker against the piezoelectric element.

  In case the ignition does not occur, it is of course necessary to return to the initial position of figs 15 and 16 and to

repeat the operation.

  As illustrated in FIGS. 21 and 22, the movement of the intermediate piece 20 in the closing direction causes, as in the other embodiments, the disengagement of the teeth 17 c of the operating knob relative to the teeth 20 c of the part 20, this one and

  the element 21 moving alternately axially to the encon-

  the reaction of the return means of the thrust member 6.

  When a gas appliance incorporates a tap coupled to a piezoelectric system, as previously described in these various

  variants, the support of the piezoelectric system is also inde-

  in the frame of the apparatus, and the rotational stop means of the support may consist of a surface belonging to said support, taking support

against the frame of the device.

  It must also be understood that the foregoing description

  has been given only as an example and that it does not limit the field of the invention, of which one would not go out by replacing the

  Execution details described by all other equivalents.

Claims (10)

R E V E N D I C A T IO N S   1 Gas valve coupled to a piezoelectric system, consisting of by at least: -   said valve (15) comprising a body, a rotary control shaft (14) with an operating knob (17) at its free end, said piezoelectric system comprising at least one casing (8), a piezoelectric element (2) ) contained in the latter,   a moving striker (3) in the casing with respect to the piezo element   an elastic means (5) disposed in said casing, said system being actuated from its rest position by loading the elastic means and then projecting the striker against the element   piezoelectric under the effect of the loaded elastic means, -   an intermediate part (13/20) for actuating the piezoelectric system, coaxially mounted relative to the rotary control shaft (14), between the valve body (15) and the operating knob (17), free in translation with respect to said axis, comprising on its circumference at least one actuating member (13a, 20a) of the piezoelectric system, means (16, 17b-20c) for rotatingly coupling the rotary shaft (14) and the intermediate actuating piece (13-20), in the opening direction of the valve, the piezoelectric system remaining or returning to its rest position, during the rotation of the   the rotary control axis in the direction of closing the valve, characteris-   characterized in that it further comprises a support (9, 18, 19) independent of the valve body and the operating knob, mounted between them coaxially with respect to the rotary control axis, freely rotatable relative to said axis, on which the piezoelectric system is mounted, at least one means (9 e, 18 a, 19 b, 19 c) being provided to stop   the rotation of the support, at least in the direction of the opening of the valve.   2 tap according to claim 1, the rotary control shaft being an axial adjusting screw, characterized in that there is provided an axial stop (14 b) on the rotary shaft (14), the support being disposed between said stop and the operating knob, so as to move axially with the control shaft.   3 tap according to claim 1, characterized in that the   means of stopping the rotation of the support consists of a surface area   nant to said support, bearing against the valve body (15).   4 tap according to claim 1, characterized in that the axis   rotary control (14) and the main direction of the piezo   between them form an angle less than or equal to 90.   Valve according to claim 1, wherein the piezoelectric system has an elongate shape and aligns on one side the piezoelectric element (2) and on the other side the striker.   (3) pushed towards said element by the elastic means (5), an opening   re (9c) being provided in the casing for the actuation of the striker, characterized in that the piezoelectric system is positioned on the support (9), with respect to the intermediate actuating part (13), of such whereby, by rotation of the latter in the opening direction of the valve, the piezoelectric system is actuated through the opening of said system, the striker being urged in one direction by the actuating member (13a). , against the elastic means (5), then escaping said body to strike in the other   meaning the piezoelectric element (2) under the sole effect of the elastic means than loaded.   6 valve according to claim 1, wherein the piezoelectric system comprises a casing (8) consisting of a casing (1) and a thrust member (6) movable in translation on said casing, and a return means (7) to the rest position, said system being actuated from its rest position, by translating the envelope and the thrust member towards each other, this displacement for loading and the return means and the means for elastic striker, then projecting the latter against the piezoelectric element, the return to the rest position being effected under the sole effect of the return means, characterized in that, on the one hand the   actuating part (20) comprises a ramp (20 a) with rising part -   in the opening direction of the tap, and on the other hand the piezo   electrical device is positioned on the support (19), relative to the intermediate actuating part, so that, by rotation of   the latter in the direction of opening of the valve, the envelope (11) or.   the pushing member (6) of the piezoelectric system is moved under   the action of the rising part of the ramp, at least until   the firing pin (3) against the piezoelectric element (2).   7 tap according to claim 6, characterized in that, on the one hand the ramp comprises in the opening direction of the valve a rising portion (20 a) and a downward portion (20 b), and secondly the system piezoelectric is positioned on the support (19) relative to the ramp, so that, by rotation of the intermediate piece (20) in the opening direction of the valve, the casing (1) or the pushing member (6) of the piezoelectric system is moved under the action of the rising portion (20 a) of the ramp, then returns to its rest position through the descending portion (20 b) of said ramp.  8 valve according to claim 6, characterized in that a control element (21), mounted and movable in translation relative to the axis (14), is disposed between the piezoelectric system and the intermediate actuating piece (20), and comprises on one side a pusher (21b) located against the casing (1) or the thrust member (6) of the   piezoelectric system, and on the other side a counter-organ of   (21 a) in support against the ramp.   9 valve according to claim 6, wherein the piezoelectric system returns to its rest position, during the rotation of   the rotary control axis in the direction of closing the valve,   risé in that, on the one hand the ramp develops from a low point to a high point, located on either side of a tongue (20 d), and secondly there is provided a stop ( 21 d) angularly fixed relative to the rotary control axis against which the tab is locked, during the rotation of the intermediate actuating part (20), the side of the low point of the ramp in the closed position of the tap,   and the high point side in the tap open position.   Valve according to Claim 6, the rotary control shaft being an axial adjusting screw, characterized in that a means (16, 17c20c) is provided between the rotary control shaft (14) and the intermediate piece actuator (20), solidarisant the latter in the opening direction of the valve, but allowing, in the closing direction of the valve, a possible rotation of said rotary axis relative to said intermediate piece, locked in rotation in said direction of closing.   11 Gas appliance incorporating a gas valve coupled to a   piezoelectric system according to one of claims 1 to   , characterized in that the support (9, 18, 19) of the piezoelectric system   that is independent of the frame of the device.   12 Apparatus according to claim 11, characterized in that the means for stopping the rotation of the support (9, 18, 19) consists of a surface belonging to said support, bearing against the frame of the apparatus.