FR2645341A1 - ELECTRICAL LIMIT SWITCH WITH STATE SIGNALING - Google Patents

Abstract

Elastic means 3 suddenly actuate a contact holder 9 upwards when a push button 1 reaches, from a rest position R, an arming position E. In the event of a blockage preventing this sudden movement, a lever 24 forces the movement when the push-button 1 continues its movement to a forced actuation position A. The push-button carries colored areas 101, 102. The contact carrier bears a colored area 104. According to the relative position of these areas , observed through a window of the box 100, the user can adjust the positioning of the switch with respect to a moving body which must actuate it, so that the two phases of the actuation take place at the appointed point. The user can also know whether the contact carrier moves under the action of the elastic means or under that of the lever. Use to facilitate the installation of the switch and the detection of damage.

Description

The present invention relates to a switch

  limit switch with state signaling.

  FR-A-2,596,197 discloses an electric switch mounted in a box and in which a driven crew carrying contacts is abruptly moved in one direction by the expansion of elastic means which are previously armed by the movement of a driving crew (control pusher) that moves parallel to this direction. Transmission means driven by the lead crew forcibly move the lead crew during an additional race of the lead crew when the resilient means have not been effective in moving the led crew to the lead. from the initial race of

the leading crew.

  Switches of this nature can be used in installations where the safety of operation or that of the personnel is conditioned by the opening of an electrical circuit. The elastic means, by their sudden expansion, open the electrical circuit in optimal conditions (absence of arcing between the contacts). By cons, said elastic means may be unable to ensure the opening in case of rupture of the elastic means, jamming, or welding contacts long remained in the closed state. In this case, the transmission means force the crew to carry out its displacement when the leading crew performs its

extra race.

  When installing such switches it is often necessary to adjust the relative position of the switch and the mobile that must act on the driving crew. This mobile is for example a cam fixed to a machine or apparatus member, which cam must actuate the switch when the member reaches a

certain position.

  It is rather difficult to give the mobile a position such that, on the one hand, it can cause the normal actuation of the switch so that the mobile stops at a set position and that, on the other hand, it be able to give the crew leading an additional calibrated run intended for the forced actuation of the led crew of the switch, a race which will be carried out only if the mobile has not stopped at its

setpoint position.

  Until now, the latter adjustment was done by trial and error listening for example the sound of the trigger caused during the sudden relaxation of the elastic means and giving the mobile a slight additional displacement. In other cases, it was placed between the mobile and the driven crew in maximum driving position, a shim selected by estimating that the normal operation of the switch would occur

  well for the desired setpoint position.

  Of course, there is known a sudden-action limit switch and positive safety control which includes a visualization of the position of the driven crew. This does not make it possible to verify that the adjustment made enables the driving crew to perform the additional travel required for forced actuation.

  in case of failure of the elastic means of

  is lying. The present invention proposes to equip a switch of the kind indicated at the beginning, with simple signaling means which provide sufficient information to the installer to allow him to adjust accurately and without risk of error the relative position of the switch and the mobile when mounting, and check the operation of the switch once mounted. According to the invention, the electric switch limit state signal comprising: - a driving crew capable of movement between a rest position and a forced actuation position through an arming position; - a led crew carrying contacts, and

  able to move between two positions of

  tation; - Elastic means that are armed by the movement of the crew from its rest position to its cocking position and adapted to relax abruptly to cause the crew conducted its aforementioned displacement when the leading crew is in arming position; - Transmission means driven by the driving crew to subject the crew conducted its aforementioned displacement when the leading crew exceeds the cocking position without the elastic means have produced said displacement of the led crew; means for visualizing the displacement of the driven crew, is characterized in that the display means are designed to further visualize the displacement of the driving crew and to allow the simultaneous examination of the

movements of both crews.

  It is thus possible to detect the following states: switch at rest; driven crew actuated "normally" by elastic means; crew leading to the forced actuation position. This makes it possible to precisely adjust the relative positioning of the switch and the moving part which actuates it so that the switch has for each position of the mobile the state

respectively desirable.

  In addition, once the switch is installed and

  operation, it is possible to see if the crew led.

  moves under the action of the elastic means before the driving crew reaches its position of forced actuation or otherwise under the action of the means of

  transmission after the leading crew has passed the -

  intermediate position of arming. In the second case, the switch is defective, and the invention therefore has the advantage of allowing easy detection of such a defect. Other peculiarities and advantages of

  the invention will become apparent from the following description

  BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the moving parts of a switch according to the invention, in which the movements of the driving and the driven crew are of opposite senses; - the. FIGS. 2 to 5 are elevational views of the switch according to the invention in three states that the state signaling means can assume, when the switch does not show any damage, and respectively in a state resulting from damage; FIG. 6 is a partial perspective view of a second embodiment of the signaling means, where one of the colored surfaces is stationary; FIG. 7 is a partial perspective view of signaling means using inversion means; - Figure 8 is a schematic sectional view 30. of a snap switch and positive opening in which the movements of the two crews are the same direction; and FIG. 9 is a sectional view of a mode of

  preferred embodiment of the switch according to the invention.

  The switch of the apparatus according to the invention comprises in a housing 100, shown in phantom, made of a body and a lid not detailed, a switch having its own casing 31, generally represented by dashed lines. One end 32 of a driving unit 1 of the switch passes through an upper opening 33 of the casing 31 and receives, from an actuating pusher 107 of the switch, longitudinal displacements of direction F and G and axis XX 'which bring it from a rest position R to a forced actuation position A, or conversely by compressing or relaxing a return spring 26 placed between a bottom 34 of the casing 31 and the opposite end 35 of the crew

leading 1.

  First transverse support members such as 2 which are carried by the crew driving symmetrically

  relative to a central and longitudinal plane PP 'of that

  ci, transmit compressions to ends of devices such as 3, one of whose lines of action is shown in phantom; these devices which are well known per se, and can take various forms such as a spring cylinder, all have the property of I relax suddenly by restoring the energy they have accumulated in a spring during a compression unstable prior. The supports 2 can then be constituted by parallel edges which receive notches provided at one of the ends of the devices 3 so that each support 2 constitutes a pivot for the

device 3 associated.

  Second support members 4 such as parallel ridges, which receive opposite ends of these devices, and which are arranged symmetrically with respect to the plane PP ', are part of a driven crew 9 comprising a C-shaped cage comprising a partition 5 parallel to XX 'and perpendicular to the plane PP' and two parallel wings 6, 7 perpendicular to the axis XX 'and terminated by returns 8a, 8b directed toward one another in the same plane, which form open housing adapted to each receive a conductive contact bridge 10, respectively 11. The partition 5 is enlarged to carry the members 4 on its dorsal face opposite the wings 6 and 7. Each bridge carries at its ends pellets

  of contact that are directed opposite the other bridge.

  The wafers of the bridge 10 can abut against two fixed contact surfaces placed in a plane Q. When the wafers of the bridge 10 are spaced apart from the plane Q, the wafers of the bridge 11 can lean against two other fixed contact surfaces, one of which is represented with the reference 90, placed in a plane U. These two plans

  parallel are perpendicular to XX '.

  Insulating intermediate pieces 12, 13 which are applied against the contact bridges in the opposite direction F and G and which are guided along the cage (for example along the returns 8a, 8b), communicate to the bridges pushes in opposite directions. developed by one and the same

  compression spring 14 placed between them.

  The driven crew 9 can move parallel to XX 'in a plane T, between a stable lower position

  rest and a stable upper working position.

  Thanks to the presence of the bistable devices 3 these displacements are operated abruptly in direction G and F. when the pusher moves, even progressively, in direction F and respectively G of the position R to the position A and vice versa; in the direction F corresponding to the depression of the crew leading from the rest position, the sudden displacement occurs for a particular position E of the driving crew, said cocking position which is intermediate between the extreme positions A and R. At the end of these displacements, the contact bridges 11 and 10 are applied against the fixed contacts for the rest and working positions of the driven crew 9, which are themselves determined when the latter encounters fixed stops 28,

respectively 27 of the housing 31.

  If the movable contacts of the contact bridge 11 are welded against the corresponding fixed contact pads 90 when the driven crew is in its lower rest position, the abrupt movement movement of the crew in the direction G does not occur. could occur when the leading crew reaches the arming position E, for which the alignment of the projections or edges 2 and 4 has just been exceeded in direction F; this impossibility results from the fact that the elastic devices 3 can not themselves develop

  sufficient forces to break the weld points.

  In order to effect a forced lifting of the driven crew 9, and therefore a break of these possible welds, a levi-r 24 receives from the end 35 of the leading crew 1 a thrust that communicates in the proper direction the driven crew if the latter has remained stationary when the driving crew has crossed the cocking position E towards the forced-actuation position A. Two journals 21, 22 of the lever are received in bearings 29, 29 'of axis YY' parallel to / and adjacent to the plane U, integral with the housing 31. The lever 24 comprises a central control arm 19 which is engaged between two parallel wings 35 'of the end 35 and which has two bosses opposed transverse cylinders 17, 18 coupled with two transverse drive grooves

parallel 15, 16 of the wings 35 '.

  The lever 24 further comprises opposite the arm 19 a central lifting arm 20 which has an active surface or edge 23 placed opposite the face

lower 38 of the cage.

  The driving line 1 has in a region 105 a beach 101 having a recognizable appearance, for example a black color, followed in the direction of the arrow F (direction of the depression) a bottom range 102,

for example of white color.

  The driven crew 9 has on an upper region of the cage 5, 6, 7, 8 adjacent to the region 105 for an observer whose line of sight is ZZ ', a range 104 having a recognizable appearance different from that of the 101 range and the bottom range 102. In the example, the range 104 is red. The beach 104 is formed

  on the outside face of the return 8a of the cage 9.

  The observer can examine these areas through a sealed and transparent window 106 (FIGS. 2 to 5) of the casing 100, and through a sealed window and

  transparent, located next, the inner boot 31.

  When the driving crew 1 is in the rest position R and therefore (except for damage) the driven crew 9 is itself in the (resting) position, only the white background range 102 is visible through the two superimposed windows (Figure 2). When the actuator 107 outside the stacker, communicates its movement to the driving crew 1 on the race between the rest positions R and arming E, the white beach 102 runs behind the window until the moment led 9 performs a sudden upward movement in direction G. At the time of this sudden movement, the red range 104 occupies the lower half of the window, see Figure 3, the other half being still

  occupied by the bottom beach 102, white color.

  If the leading crew 1 is communicated with an additional movement in the direction F, the black area 101 gradually progresses to the white area 102 in the upper half of the window (FIG. 4). This additional movement is that corresponding to the safety stroke during which the lever 24 actuates the crew in the direction G if it has not already been

  made by the elastic devices 3.

  When it is necessary, the casing 100 being fixed on a frame or stationary support 109, to make a position adjustment of a cam 110 intended to actuate the operating member 107, it is arranged that, when the moving part 108 carrying the cam is at its desired stopping position M, firstly the driving crew is in arming position E (what the window indicates as shown in Figure 3) and secondly the cam still has the ability to drive the driving crew to the forced actuation position. In other words, it must be avoided that the actuating member 107 has already reached the end of the active ramp of the cam when the driving crew has reached the cocking position. For this, we place the mobile 108 in position M, we adjust the cam vertically downwards until

  the red age 104 comes to occupy the bottom of the window 106.

  Then, if the cam is adjustable parallel to the direction of movement of the moving part 108, it is verified that the black area 101 occupies the upper half of the window 106, when the mobile 108 is pushed beyond its desired stop position until 'at a limit position N. In the opposite case we adjust horizontally

the cam 110.

  In many cases, only the N position is defined that the moving part must not exceed, for safety reasons. The adjustment can then be simplified: it is sufficient to put the moving part 108 in position N and to adjust the cam 110 so that the tracks 101 and 104

  are both visible in the window.

  During normal operation, as soon as the red range appears, we are sure that the moving equipment has moved and we are entitled to wait for the contacts 11, 90 to separate to cause a stop in M. If this was not the case, the moving part 108 would continue its race to the limit position N. for which the leading crew would carry out its additional race and operate a forced opening of these contacts. In this case, we see appear gradually and approximately symmetrically the beaches 101 and 104 in the window 106 as shown in Figure 5, while the piece 108 advances from its position M to its position N. The staff of maintenance can thus realize that the switch is defective. In all cases, the black surface that is linked to the movement of the pusher appears next to the window when the race

  has been communicated is sufficient.

  The aims of the invention do not require the exclusive use of the means just described. As shown in FIG. 6, the white background range 102, the presence of which is desirable for contrast with the red beaches on the one hand, and black, on the other hand, could be carried by a stationary piece 112 relative to the casement of the apparatus and in front of which would move two flaps, one 101a carrying the black beach 101, the other 104a carrying the red beach 104, these two flaps being respectively connected to movable crews such as the leading extrusion 1 and

  the led crew 9 mentioned previously.

  As can be seen in FIG. 7, it is also possible to have flaps 120, 121 carrying the tracks 101 and 104 and movable in the same direction G by means of a suitable mechanical inversion means in front of the fixed bottom or backlighting range 102, fixed or not. 122 of the movement of the leading crew 1 to actuate the flap 120. We then first appear in the lower part of the window the range 104 connected to the crew and then, in the upper part of the window 106 the beach 101 coming out of

behind the beach 104.

  An arrangement of the type described with reference to FIG. 7 may also be used to obtain ranges with opposite movements, as described with reference to FIGS. 1 to 5, in the case where the crews are movable in the same direction. In this case, as shown in FIG. 8, the driving equipment 1 first causes the armature of the force-accumulator member 3 to be activated in direction F and then releases the driven contact-carrying member 9 in the same direction abruptly. by raising a lock by means of a cam 132. The reminders of the crews leading i and led 9 in the rest position are here carried out by springs such as 26 acting on the driven crew and possibly 26 'acting on the lead crew , while the mobile colored beaches are carried by the driven crew 9 and the other by a flap associated with a motion reversal device as described in FIG.

reference to Figure 7.

  The transmission means 24 for forced opening is simply made in the form of a finger carried by the driving crew 1 and pressing the driven crew 9 when the driving crew 1 exceeds its arming position without that the crew did not jump

in active position.

  In a particular embodiment of a state indication switch device, visible in FIG. 9, and having the general constitution shown in FIG. 1, the cage of the driven crew 9 comprises a thin sleeve 140 surrounding the leading line 1 so as to have a flat surface 141 carrying for example a red beach 104, in the vicinity of a flat surface 142 of the pusher bearing the black beach 101 and the

  bottom range 102 of white color.

  These two surfaces 141 and 142 being close to one another, a porthole or magnifying optical device 143, advantageously secured to the housing 31 of the switch, can be placed facing the region 144

  o will move the beaches.

  This arrangement has the advantage of arranging the window 143 of the casing 31 and the window 145 of the casing 100 of the side of the appliance 146 to which access must be had to effect the electrical connection of terminals such as 147 by removing a cover 148 provided with the

aligned window 145.

  It should also be understood that the principles underlying the means described can be implemented using equivalent means; this is how the two mobile crews with colored surfaces can very well perform both or separately angular movements if they are

swiveling crews.

Claims (8)

  A state-of-travel limit switch comprising: - a driving unit (1) capable of movement between a rest position (R) and a forced operating position (A) through a position of armament (E); - A driven crew (9 to 13) carrying contacts (10, 11) and capable of movement between two switching positions; - Elastic means (3) which are armed by the movement of the driving crew (1) from its rest position to its cocking position and adapted to relax suddenly to subject the led crew (9) its aforementioned displacement when the driving crew (1) is in the cocking position (E); - transmission means (24) driven by the driving crew (1) for subjecting the driven crew (9) its aforementioned displacement when the driving crew exceeds the cocking position (E) without the elastic means (3) have produced said displacement of the driven crew (9); means (101, 102) for visualizing the displacement of the driven crew (9), characterized in that the viewing means are designed to further visualize the displacement of the driving crew (1) and to allow the Simultaneous examination of the movements of the two crews (1, 9). 2. Switch according to claim 1, characterized in that a casing (31, 100) of the apparatus comprises a window (106; 143, 145) through which appear selectively, depending on the positions occupied by the crews (1). , 9) two beaches (101, 104) of different appearance, each driven by one of the crews (1, 9).   3. Switch according to claim 2, characterized in that the two beaches (101, 104) more or less cover each part of a bottom range (102), still different appearance, connected to the housing (100).   4. Switch according to claim 2, characterized in that one (101) of the beaches is integral with a bottom range (102) which is more or less covered by the other range (104) depending on the position   relative of the two different appearance ranges (102, 104).   5. Switch according to one of claims 1   at 4, characterized in that one (104) of two different appearance ranges (101, 104) is carried by a sheath (140) integral with one (9) crews (1, 9) and surrounding the other crew (9) in the vicinity of the other range of different appearance (101), carried by the other crew (1).   6. Switch according to one of claims 1   to 4, characterized in that one (101) of the tracks is connected to the corresponding crew (1) via   motion transformation means (122).   7. Switch according to one of claims 1   at 4, characterized in that the two crews (1, 9) move in the same direction, and in that one (101) of the different appearance of the tracks is connected via a device of motion reversal (122) to   the crew (1) of which this range visualizes the displacement.   8. Switch according to one of claims 1   7, characterized in that the ranges (101, 102, 104) are colorful beaches.