EP1052664A1 - Sealed position detection device with abrupt opening - Google Patents

Abstract

The system uses spring biased levers acting on switches to guarantee rapid switch change when movement is detected. The position detector includes a pushbutton (3) on which a coaxial spring (7) exerts a repulsive force. The pushbutton acts the control elements (600) for switches (60,61) inside the casing (2). The system includes a biased vertical lever (5) solidly attached to a shaft (51) mounted to rotate about a horizontal axis, and coupled to further independent horizontal levers (52,53) co-operating with a hairpin spring (55). In the normal state, the switches (60,61) are operated by the horizontal levers (52,53) When an object is detected by the pushbutton movement, the pushbutton acts on the system of levers and the switches change to th rest position at the correct fast speed.

Description

The invention relates to a sealed position detection device with abrupt opening.

The invention relates more particularly to such a device operating in harsh environment, i.e. for applications where the amplitude of shock and / or the operating speed of the device are high. The shocks relate both to the object position detection member, which is fitted with the detection device, that the internal organs of the device, in particular the switch or switches actuated by the position detection member.

The device, as just indicated, can include one or two switches or more.

Conventionally, position detection devices are provided with a control member provided with a telescopic element in the extension a switch button, which allows a large stroke and facilitates adjustment

Figure 1 appended to this description illustrates an example of embodiment of position device 1a according to known art, which will be described succinctly.

The position detection device 1a, of axis of symmetry A (which is suppose vertical to fix ideas) includes a box 2a enclosing one or several switches 6a arranged in its lower part, for example the switch 60a. The latter is actuated by a push button 600a, or a similar organ, acting on internal contact blades (not visible on the figure 1).

In the top of the housing 2a, there has been shown an operating member constituted by a push button 3a. it is the latter which will detect the position of an object or any external organ (not shown) moving according to the Δ axis. At the end of the race, it will strike the top of the push button 3a which then sinks inside the housing 2a. The push button 3a causes its turn a so-called telescopic member 5a whose body, for example cylindrical, supports on a control member 51 has push buttons 600a, for example of the switch 60a (or of the set 6a of switches, if there are several).

Finally the switch (s) 6a are normally arranged horizontally, so that the actuator 5a can act on the push buttons 600a via the control member 51a by the top.

The wires 9a, for connection with external circuits (not shown) emerge from below the housing 2a, in the example described.

The structure of the position detection device 1a which has just been recalled briefly has several drawbacks.

In particular, this structure has the harmful effect of transmitting directly the attack speed of the operating member 3a to the assembly 6a switches. When the maneuvering speed is high and / or the shocks of large amplitude, typically resulting in a force greater than 500 gf, this may have the effect of damaging the switch (s), or even their destruction. In all cases, this translates into a shorter lifespan of these.

The invention aims to overcome the drawbacks of the devices of the known art, and some of which have just been recalled.

The object of the invention is in particular to make the speed independent of attack of the operating member of the proper operating speed of the position sensing device switch (or switches, if any includes several).

To do this, unlike the known art, a coupling is provided indirect mechanics between the control member of the position, generally of the "push button" type, and the control member the switch, generally also of the "push button" type or equivalent. The The above mechanical coupling is obtained by means of a lever assembly. which induces a mode of operation which can be called "inverted". Indeed, in a so-called working state, the control member of the switch or switches is under pressure. When the operating device of the position detection is activated (so-called "go" movement), it allows release of the control member of the switch (s), which returns to its own speed, at a position that can be called rest. When the organ of maneuver is released (so-called "return" movement), the control member of the switches is again subjected to the aforementioned pressing force. However this force can be much weaker than the driving force at which is subject to the operating member. Indeed, it must be of an amplitude sufficient to overcome friction, due to the bodies ensuring the sealing of the limp of the position detection device, and return the push button to its initial position. By these provisions, we obtain an autonomy of operation between the operating members of the detection device position and the operated switch (s).

Another object which the invention sets itself is to eliminate the shocks induced by the switch control member, for example of the button type, on the contact blades with which it is provided, or at the very least attenuate them. Indeed, these shocks increase the travel of these blades by inertia, which has for effect of reducing the life of the switch.

To do this, according to a preferred embodiment, one positions the switch (or switches, if there are several) perpendicularly relative to the operating member of the position detection device, so that the switch control member acts on the blade (s) contact in a direction perpendicular to the direction of movement of the organ maneuver. The shocks result in forces exerted according to a longitudinal direction with respect to the general direction of the contact blades. The orthogonal component is then nonexistent, or at least not significant, which eliminates the aforementioned drawback.

When a position sensing device has two switches or more, there is an additional problem. Indeed, the characteristics mechanical components are dispersed from one switch to another. Now, we have to ability to ensure that even in the presence of extreme dispersions of characteristics of the switches mounted inside the housing, all switches must respond to the actuation of the operating member of the position detection device.

According to the invention, and in a preferred embodiment also, the problem is solved by providing a unique means exerting a force of pressure on the control elements of the switches. This unique means can advantageously be constituted by a spring of the so-called "hairpin" type, but acting on independent levers, one for each switch.

In a further variant of this embodiment, provision is made means allowing a temporal sequencing of the operation of various switches constituting the position detection device.

The subject of the invention is therefore a device for detecting a position determined in the space of a mobile object comprising a box provided with a detection member capable of reversibly moving, according to a determined axis, from a first spatial position, in a state called rest, to a second spatial position, in a so-called detection state, when said mobile object comes to bear against him and drives him, at a first speed depending on the speed of movement of this object, from said first position to said second position, said housing comprising at least one electrical switch provided with at least one control unit delivering an electrical signal during said detection, characterized in that it comprises first elastic means exerting a force on said detection member, driving it towards said first position, and mechanical coupling means of said control members of each of said switches with said detection member, sensitive to movements of the latter, in that said switches having a first state said to be working and a second state said to be at rest, said coupling means mechanically cooperate with second elastic means so as to exert a pressing force on said control means so that each of said switches either in said working state when said detection member is in said rest state, in that said mechanical coupling means release said bearing force on said control means when said detection member goes from said rest state to said detection state, so that each switch goes from said working state to said resting state, at a speed which is clean, independent of said first speed, and in that said means mechanical coupling, driven by said second elastic means, again exert said bearing force on said control means when said object ceases to train said detection member and the latter returns from said detection position to said rest position under the action of said first elastic means, and that each of said switches returns at said working position.

• la figure 1 illustre schématiquement un exemple de dispositif de détection de position selon l'art connu, représenté en perspective et en écorché ;
• la figure 2 illustre un exemple de dispositif de détection de position selon un mode de réalisation préféré de l'invention ; et
• les figure 3A et 3B illustrent le fonctionnement d'un tel dispositif de détection de position.

The invention will now be described in more detail with reference to the accompanying drawings, among which:

• Figure 1 schematically illustrates an example of position detection device according to the prior art, shown in perspective and cut away;
• FIG. 2 illustrates an example of a position detection device according to a preferred embodiment of the invention; and
• FIGS. 3A and 3B illustrate the operation of such a position detection device.

We will now describe an example of a device for detecting position 1, according to a preferred embodiment of the invention, with reference to the Figure 2. This illustrates this position detection device 1, in perspective and skinned.

It comprises a protective housing 2, itself comprising a substantially cylindrical lower main body 20, a priori metallic, with an axis of symmetry Δ. The main body is crimped, by its lower part 203, on a support 8, of substantially circular section. The main body 20 is surmounted by a neck or barrel 21, also substantially cylindrical. This barrel 21 contains a sleeve or guide barrel 22 comprising a pierced cylindrical part 220 and a lower flange 221, also pierced. The lower flange 221 is inserted between the upper inner wall 200 of the main body 20 and a stop segment or crimping 24, so as to block the guide barrel 3 in a fixed position relative to the upper wall 200 of the housing 2. The stop segment 24 is inserted into a peripheral groove 23 hollowed out in an upper zone of the side wall 201 of the main body 20. The barrel 21 is also provided, in an upper zone, with an internal peripheral stop 210.

There is in the barrel 21 an operating member 3 of the position detection, usually of the push button type. This last comprises a cylindrical body comprising upper parts 30 and lower 32, separated by a peripheral cylindrical collar 31. The part lower 32 is inserted into the upper part 220 of the guide barrel 22. The outside diameter of the lower part 32 of the push button 3 is equal to or slightly smaller than the inside diameter of the upper part 220 of the barrel guide, so as to allow back and forth movements of the button pusher 3, along the axis Δ. The amplitude of the translational movement as well authorized is limited above by stop 210 and below from above guide bush 22.

A coaxial spring 7, of the strand type, is inserted between the inner wall 211 of the barrel 21 and the outer wall 2200 of the upper part 220 of the barrel guide. This spring 7 is thus disposed between the bottom of the collar 31 and the top of the collar 221. It therefore pushes the collar 31 upwardly that it comes into contact, in a state called "normal", with the stop 210. The upper part 30 of the push button 3 is therefore also pushed towards the up and out of the position detection device 1 as much as possible (position which is will call "rest").

The position detection device 1 being assumed to be of the waterproof type, there is on the periphery of the upper part 230 of the push button 3, and in a upper area of the barrel 21, various conventional elements (joint sealing, etc.) performing this function, elements shown under the reference general 4. These elements, in themselves common to known art, are well known to the Man of the Trade and it is useless to describe them further.

If an external member Obj (shown in dotted lines), whose position along the axis Δ must be detected, exerts pressure on the upper part 30 of the push button 3, it will sink inside the housing 2, more precisely inside the barrel 21 (position which will be called "pressed" or "retracted", or even "working"). The sealing elements 4, in order to be effective, usually exert significant frictional forces on the wall of the upper part 30 of the press button 3. When the force which has caused the push button 3 to depress ceases, it is necessary for the spring 7 exerts a large restoring force so that the push button returns to its initial or "rest" position.

Also, according to a first important characteristic of the invention, and this unlike the devices of the known art, the operating member, constituted by a push button 3 in the example described, does not act directly as an organ for controlling switches 6 (or via a telescopic member). We assumed, in the example of figure 2, to fix the ideas, that the device for detecting position 1 included two separate switches 60 and 61.

Indeed, under the lower part 32 of the push button 3, there is a vertical lever 5, or an equivalent member, integral with a shaft 51, rotating around a horizontal axis Δ _H , orthogonal to the axis Δ, that we assume vertical. More generally, the lever 5 is included in a plane parallel to the axis Δ. The upper part 50 of the main body of this lever 5 is in contact with the bottom of the push button 3. The lower part 54 of the lever 5 is in contact with additional horizontal levers, 52 and 53, which may be constituted by folds at 90 degrees from the lower part 54 of the lever 5. However, in a preferred embodiment, as will be shown below, when the position detection device 1 comprises two or more switches (for example 60 and 61), several horizontal levers 52 and 53 are provided, separated from the vertical lever 5, one for each switch.

The horizontal shaft 51 is mounted on the internal wall of a support included in the housing 2, (and which will be described below under the reference 203), for example by providing holes (not shown) in the thickness of the wall of this support. A “pin” type spring 55 is wound around the shaft 51. The rear single branch 550 of the spring 55 is supported on the wall 202. The one or more front arms, two in this case, 551 and 552, exert a force of pressure on the horizontal levers 52 and 53 and push them towards the inside of the box 20, in the direction of the push buttons, for example 600, which are provided the switches, 60 and 61.

Although this provision is not mandatory, provision is made in a preferred embodiment, to place the switches, 60 and 61, vertically. This should be understood to mean that they are arranged in the housing 2 of such that the push buttons (only one is visible in figure 2: 600 for the switch 60) with which they are provided, or any equivalent actuating member internal contact blades (not visible in figure 2), are actuated according to a horizontal direction (therefore orthogonal to the driving direction of the push button 3: axis Δ). This provision, as noted, minimizes the influence of shocks on the contact blades, the resulting forces (longitudinal) being substantially parallel to these.

To lock the switches in the aforementioned position, suitable conventional type housings, for example holding members lower 81, in the base 8, and upper 203, bearing on the internal wall 202 of the body 20 of the housing 2. In the example of FIG. 2, provision has also been made horizontal holding rods 62 inserted in the wall of the body 20 of the housing 2. The bodies of the switches 60 and 61 are threaded on these axes, by their parts back. It has in fact been assumed that these bodies have channels provided for this purpose. effect, for example 601.

Insulated conducting wires 9, forming connections between the blades contacts of switches 60 and 61 and external electrical circuits or electronics (not shown), leave the housing 2, in the example described, by a lateral orifice 80 produced in the base 8. We could just as easily provide a axial outlet orifice, under the base 8. A good seal is obtained, conventionally, using resin including the outlet of the conducting wires 9.

We will now describe schematically, with reference to FIGS. 3A and 3B, the operation of the position detection device 1 of FIG. 2. The common elements in Figure 2 have the same references and will not re-described as necessary.

FIGS. 3A and 3B show only the main organs strictly necessary for the proper understanding of the invention.

FIG. 3A illustrates the state taken by the position detection device 1 as shown in FIG. 2, state referenced I. In this initial state, or in rest state, the push button 3 is in the high position, and exits at the maximum of the barrel (figure 2: 21) of the case (figure 2: 2). It is in fact driven in this position by the spring 7 which exerts a vertical pushing force f ₁ on the flange 31, from bottom to top, and pushes it until it is pressed against the stop 210. The spring hairpin 7, is supported on the wall 202 by its rear branch 550 and exerts, by its front forms, for example 551, a horizontal thrust force f ₂ (to the left in the example of FIG. 3A) on the horizontal levers, for example 52. It follows that the push buttons, for example 600, are in the depressed position. The push buttons 600 therefore actuate the internal contact blades of the switches (so-called "working" position). The lower part 54 of the vertical lever 5 is also driven by the horizontal levers, for example 52. The vertical lever 5 rotates around the axis Δ _H and its upper part 50 comes into contact with the bottom of the lower part 32 of the button pusher 3.

When an object or an organ or any object Obj , whose position in space must be detected (for example a so-called end position, during a movement along the axis Δ) comes into contact with the part upper 30 of the push button 3 and exerts a pushing force F , from top to bottom, along the axis Δ, the push button 3 sinks into the barrel (Figure 2: 21). The state obtained, or state referenced II, is illustrated in FIG. 3B. The lower part 32 of the push button 3 crushes the spring 7 which compresses, until the flange 32 abuts on the top of the upper part 220 of the guide barrel 21.

The vertical lever 5, by its high portion 50, tends to disappear and is rotated around the _H axis Δ. Its lower part 54 in turn drives the horizontal levers, for example 52, which themselves exercise lead the front branches of the spring 55, for example 551, and compress it. It follows that the latter releases the horizontal pushing force f ₂ (FIG. 3A) previously exerted on the push buttons, for example 600. The internal contact blades are no longer pressurized and relax, which usually results in an electrical circuit break, the connection being assumed to be established in the working state (state I). The new force exerted f ′ ₂ can moreover become zero depending on the amplitude of the retraction movement of the horizontal levers, for example 600.

When the force F ceases its effects, the reverse process starts and we pass again from state II to state I. But it should be noted that, unlike the known art device (for example the one illustrated by FIG. 1), there is autonomy of the proper operations of the operating member part proper of the position detection device 1, that is to say the push button 3 (and the forces exerted on it ) and the control member part of the switch or switches, 60 and 61. In particular the force f ₂ may be much less than the force f ₁ , and a fortiori at the force f ' ₁ . Indeed the latter, maximum since the spring 7 is compressed, must be sufficient to overcome the friction forces due to the sealing members (Figure 2: 4). This is obtained by the provisions specific to the invention, in particular the presence of the assembly constituted by the vertical 5 and horizontal 52 levers, as well as the hairpin spring 55, which is interposed between the two main parts of the detection device position 1 and which allows an operation which has been called "reverse". When detecting the position of the object Obj, which results in a significant shock: force F , the latter is not transmitted to the control members of the switch or switches, 60 and 61. The contact blades are released at their own speed, entirely independent of the speed at which the push button 3 is pressed in. Furthermore, according to the preferred embodiment, they can be sensitive to vibrations, thanks to the particular (vertical) arrangement of the body of the switches 6, by example 60, in the housing (figure 2: 2). It should also be noted that the amplitude of the shocks is attenuated by the fact that the latter are subject to the housing by holding members (FIG. 2: 81 and 203) generally made of relatively flexible material, composed of plastic and resin.

We will now describe an additional variant of the position detection according to the invention.

If we consider again Figure 2, as indicated and in a preferred embodiment, when there are two or more switches, 60 and 61, we provides two independent horizontal levers, 52 and 53, one per switch. Of this fact, it is possible to obtain non-simultaneous operation of the switches, according to a pre-established time sequence, while guaranteeing a correct functioning of these despite the presence of possible disparities in their characteristics. It suffices to provide a spatial offset between the horizontal levers. This offset can be obtained simply: presence of a boss on one or more levers, etc. By way of nonlimiting example, when the push button 3 is pressed, push button 600 of switch 60 can be released before that (not visible) of switch 61.

On reading the above, it can easily be seen that the invention achieves the goals it has set for itself.

In particular, it makes it possible to make the speed of operation of the operating speed switch (s) the main operating member.

It also removes, or at least attenuates very strongly the shocks undergone by the contact blades of the switches. It should be clear, however, that the invention is not limited to only examples of achievements explicitly described, in particular in relation to Figures 2 to 3B.

In particular, numerical values, for example the number switches, have been specified only to fix ideas. They depend essentially of the precise application targeted.

Likewise, the springs can be replaced by members similar offering an elastic effect.

Finally, the notions of vertical or horizontal are purely arbitrary. he must be clear that even if the longitudinal axis of symmetry Δ of the position detection was assumed to be vertical, to fix ideas, the position detection can be placed in any way in space. It is not no more necessary than the external object or organ, at least one of which particular position in space must be detected, moves along the axis of symmetry Δ above. As a nonlimiting example, it could move perpendicular to the Δ axis, on either side of it, a detection occurring each time the object intersects the axis Δ in its movement, which results in the push button 3 being pressed.

Claims (12)

Device for detecting a determined position in the space of a mobile object comprising a box provided with a detection member capable of reversibly moving, along a determined axis, from a first spatial position, in a so-called state of rest, at a second spatial position, in a state known as detection, when said movable object comes to bear against it and drives it, at a first speed dependent on the speed of movement of this object, from said first position to said second position, said housing comprising at least one electrical switch provided with at least one control member delivering an electrical signal during said detection, characterized in that it comprises first elastic means (7) exerting a force ( f ₁ ) on said detection member (3), driving it towards said first position, and mechanical coupling means (5, 50-54) of said control members (600) of each of said interrupts pteurs (60, 61) with said detection member (3), sensitive to the movements of the latter, in that, said switches (60, 61) having a first state known as working and a second state known as rest, said means mechanical coupling (5, 50-54) cooperate with second elastic means (55) so as to exert a bearing force ( f ₂ ) on said control means (600) so that each of said switches (60, 61) either in said working state when said detection member (3) is in said resting state, in that said mechanical coupling means (5, 50-54) release said bearing force ( f ₂ ) on said means of control (600) when said detection member (3) changes from said rest state to said detection state, so that each switch (60, 61) changes from said working state to said rest state, at a speed which its own, independent of said first speed, and in that said mechanical coupling means (5 , 50-54), driven by said second elastic means (55), again exert said bearing force ( f ₂ ) on said control means (600) when said object ( Obj ) ceases to drive said detection member (3) and that it returns from said detection position to said rest position under the action of said first elastic means (7), and that each of said switches (60, 61) returns to said working position. Device according to claim 1, characterized in that said housing (2) has a narrowed end region (21) with an internal sleeve guide (22) held in place by a pierced lower flange (221) between a lower stop segment (23), integral with an internal wall (201) of said housing (2), and the bottom (200) of said narrowed end region (21), and in that said detection member consists of a push button (3) capable of translational movements inside said guide sleeve (22) between said first and second positions, along said determined axis (Δ), said push button (3) being pushed back by said first elastic means (7) towards said first spatial position. Device according to claim 2, characterized in that said button pusher (3) includes a peripheral flange (31) in an area median, separating a so-called lower region (32) of the push button (3) from a so-called upper region (30), in that said housing (2), in said region narrowed end (21), is provided with a peripheral stop (210) on a wall internal (211), in that said first elastic means are constituted by a coil type spring (7), coaxial with said lower region (32) of said push button (3), arranged, on the one hand, between said lower flange (221) said guide sleeve (22) and said middle peripheral flange (31) of said push button (3), so as to push it towards said stop peripheral (210), and, on the other hand between an external wall (2200) of said guide sleeve (22) and an inner wall (211) of said region narrowed end (21), and in that this peripheral stop (210) defines said first spatial position and the top of said guide sleeve (22) defines said second spatial position. Device according to any one of Claims 2 to 3, characterized in that the said mechanical coupling means comprise a first lever (5), included in a plane parallel to the said determined axis (Δ) and mounted on a movable shaft (51) in rotation about an axis (Δ _H ) orthogonal to said determined axis (Δ), in that the end of said lower region (32) of said push button (3) is supported on one of the ends (50) of this lever (5), called upper, and transmits to it the movements of the push button (3), in that a second end (54) of said lever (5), called lower, drives at least one second lever (52, 53) acting on each of said switch control members (600), and in that said second elastic means (55) exert said bearing force ( f ₂ ) on each of said switch control members (600) by through each of said second levers (52, 53), when said push button (3) is in said state of rest and releasing this force ( f ₂ ) when it is in said state of detection. Device according to Claim 4, characterized in that the said second elastic means consist of a spring (55), of the pin type, comprising a central region wound around the said shaft (51), a so-called rear branch (550) resting on an inner wall (202) of said housing (2) and at least one branch (551, 552) said before exerting said bearing force ( f ₂ ) on one of said second levers (52, 53). Device according to claim 5, characterized in that said housing (2) comprising several switches (60, 61), a second lever (52, 53) by switch (60, 61), all said second levers (52, 53). actuated by said first lever (5) and said hairpin spring (55) comprising as many front branches (550, 551) as there are second levers (52, 53), each of said front branches (550, 551) being associated with one of said second levers (52, 53). Device according to claim 6, characterized in that said second levers (52, 53) are spatially offset, so that said switches (60, 61) pass from said working state to said resting state according to a predetermined time sequence. Device according to any one of Claims 2 to 7, characterized in that that said switches (60, 61) comprising contact blades electric arranged in a so-called longitudinal direction and said means of controls being constituted by push buttons (600) actuating these blades in a direction orthogonal to the longitudinal direction, each of said switches is arranged inside said housing so that that said longitudinal direction is parallel to said determined axis (Δ). Device according to any one of Claims 2 to 8, characterized in that that the housing (2) is of substantially cylindrical shape open on the end opposite said narrowed region (21), and in that it is crimped on a base circular (8). Device according to any one of Claims 3 to 9, characterized in that that said device being of the waterproof type, means (4) are provided ensuring said seal between said upper region (30) of said push button (3) and an inner wall of said narrowed region. Device according to claims 9 or 10, characterized in that, lines electrical connections connecting each of said switches to circuits electric or electronic external to said housing, said base comprises a opening allowing lateral passage. Device according to claims 9 to 10, characterized in that, rows of electrical connections connecting each of said switches to circuits electric or electronic external to said housing, said base comprises a opening allowing passage through a so-called rear face of the housing, according to a direction parallel to said determined axis.

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