Abstract:
The invention concerns a chronograph-type watch provided with a movement ( 29 ) comprising: current time display means, measured time display means, a time base designed to regulate said display means, a control device ( 34, 40 ) for starting and stopping the measured time display means, a reset device for resetting the measured time display means when time measurement is over. The watch is provided with a case ( 10 ) for housing the movement ( 29 ) and comprising at least one slide ( 24 ) for controlling the control and reset devices. Said watch further comprises a locking device ( 32, 52 ) designed to co-operate with the control device ( 34, 40 ) to enable or disable it, and an actuating member ( 28, 44 ) designed to de accessible outside the case ( 10 ), for controlling the locking device ( 32, 52 ).

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention concerns chronograph-type watches. Such watches allow a period of time to be measured from a given moment, control being carried out by an application of pressure on one or more push-buttons. It relates more specifically to a watch provided with a movement comprising: 
        current time display means,     measured time display means,     a time base arranged for adjusting both the current time and measured time display means,     a control device for starting and stopping the measured time display means, and     a reset device for resetting the measured time display means when a measurement is finished.        
 
         [0007]     This watch further comprises a case acting as a housing for the movement and including at least one push-button for controlling the control and reset devices. Some of these watches comprise only one push-button for controlling both devices, others, more commonly, comprise two distinct push-buttons.  
         [0008]     Such watches are liable to inadvertent manoeuvres. Thus, a shock on one of the push-buttons can suddenly stop a measurement that is being carried out. Such a situation can also occurring during diving, when the water pressure acts on the start-stop push-button and can interrupt a measurement that is being carried out, which may, at the very least, be detrimental.  
         [0009]     Moreover, it is possible to make watches that comprise a single hand capable of displaying several pieces of information, like for example the minutes of the current time and the minutes of the measured time. One such watch is disclosed in EP Patent No. 02022505.8. In order to avoid any uncertainty as to the information being displayed, it is desirable for the passage from one function to another to occur clearly. This can be achieved by locking the chronograph mechanism while the hand with a dual display function is indicating information other than that relating to the measured time.  
       SUMMARY OF THE INVENTION  
       [0010]     It is an object of the present invention to overcome these drawbacks. Thus, the watch according to the invention is characterized in that it further comprises a locking device, arranged for cooperating with the control device, and capable of occupying first and second positions in which the control device can or cannot be activated, and an activating member that can be accessed from outside the case to control the locking device. Owing to this locking device, it is thus possible to prevent any accidental manipulation.  
         [0011]     Of course, chronograph-type watches are known wherein the push-buttons can be screwed onto the middle part, so as to improve water resistance. It is quite clear that a screwed-in push-button becomes inoperative. Such an operation requires however certain care, each push-button having to be locked by itself. If there is a control member accessible from the outside of the case, which controls the locking member, it is possible to lock the two push-buttons simultaneously. The control member can either be a push-button or a crown, depending upon the desired purpose.  
         [0012]     When the measured time display means also allow other information to be displayed, it is desirable for the control device to be inactive while the measured time display means are displaying this other information. For this purpose, the locking device is arranged such that it can only act on the control device when the measured time display means are at zero or are displaying information other than the measured time. Consequently, while the measured time display means display information other than the measured time, any action on the control member, and thereby on the locking device, enables the control device and resets the dual display hand to zero. In this case, the control member is advantageously a push-button.  
         [0013]     During some measurements, it is desirable to be able to keep the information until it can be noted down or used. In order to allow information to be saved, the locking device is designed so as to enable or disable the reset device.  
         [0014]     The locking device advantageously comprises a locking part which acts on the push-button in order to immobilise it. Consequently, the push-button cannot be accidentally moved, either by a movement of the user, or by water pressure during a dive.  
         [0015]     In a variant, the locking device includes a mobile connecting part arranged such that, depending upon the position that it occupies, an application on the push-button either is or is not transmitted to the control mechanism.  
         [0016]     It is also possible to combine the presence of a mobile connecting part with locking the push-button. In this case, during the locking operation, the push-button can be moved, so as to place its sealing gasket under stress and thus reinforce water resistance.  
         [0017]     In order to allow the user to know which state the chronograph mechanism is in, the locking device further includes a display member visible on the watch dial, for indicating the position occupied by the locking device, and consequently, whether or not the control device can be activated.  
         [0018]     The activating member can be formed of a crown pivotably mounted on the case. It can also be formed of a push-button.  
         [0019]     In a particularly simple embodiment, the locking device includes: 
        a stem arranged through the case and for carrying the crown comprised in the control member, and a pinion at its end inside the case,     a ring surrounding the movement and provided with a toothing over one portion of its edge adjacent to the pinion, and capable of occupying two positions, the passage from one position to the other occurring via a movement of rotation, and     an interposed member, secured to the ring and cooperating with the push-button so that it can or cannot act on the control device.        
 
         [0023]     Other features and advantages of the invention will appear from the following description, made with reference to the annexed drawing. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]      FIG. 1  shows a watch provided with a mechanism according to the invention,  
         [0025]      FIGS. 2   a  and  2   b  illustrate a chronograph mechanism provided with a member for locking the single “start-stop” function, fitted to the watch of  FIG. 1 ,  
         [0026]     FIGS.  3  to  3   d  concern a device for making the “start-stop” and “reset” push-buttons inactive by locking them,  
         [0027]     FIGS.  4  to  4   d  show a device for uncoupling the “start-stop” and “reset” push-buttons, making them inoperative. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0028]     The watch shown in  FIG. 1  is of the chronograph type. It includes, in a conventional manner, a case  10  acting as a housing for a movement, which carries a dial  12 , current time hour hand  14 , current time and measured time minute hand  16  and measured time second hand  20 .  
         [0029]     Display of the current time is corrected by means of a time setting crown  22 , connected to the members of the movement by a time setting stem that is not visible in the drawing.  
         [0030]     The timing functions are carried out by three push-buttons  24 ,  26  and  28  respectively arranged at two o&#39;clock, four o&#39;clock and eight o&#39;clock. Push-button  24  controls the starting and stopping of a measured time measurement, whereas push-button  26  resets hands  16  and  20  when a measured time measurement has been interrupted. Finally, push-button  28  allows the chronograph mechanism to pass from a first state, in which it is locked, into a second state in which it is unlocked.  
         [0031]     When the chronograph mechanism is locked, hand  16  displays the minutes of the current time, whereas, when it is unlocked, it indicates the measured time. In the locked state, push-buttons  24  and  26  are inactive. In order to pass from one of these states to the other, the mechanism includes a locking device which will be described in more detail hereinafter and which has the effect of making push-button  24  inoperative when the mechanism is locked, whereas push-button  28  is inactive when a measurement is being made.  
         [0032]     This mechanism forms part of a movement that comprises, in a conventional manner that is not visible in the drawing, an energy source, such as a barrel, a time base such as a sprung balance, a going train, of which only one mobile  29  is visible in  FIG. 2   a , and an escapement connecting the going train to the balance in order to maintain the latter, as well as time setting and chronograph mechanisms. The various components of the movement are arranged on a frame  30 , formed of a plate and bridges, which assures the relative positioning of the various mobile parts.  
         [0033]     As explained hereinbefore, the chronograph mechanism shown in  FIGS. 2   a  and  2   b , which is described in more detail in EP Patent Application No. 02022505.8, displays the minutes of the measured time and of the current time with a single hand  16 . The part of the mechanism relating to the “start-stop and “reset” controls could easily be replaced by any other existing chronograph mechanism.  
         [0034]     The mechanism shown in the drawing essentially comprises locking, control and reset devices, whose component parts are identified by the first two numbers of their reference, starting respectively with 32, 34 and 36. The springs included in this mechanism are schematically represented by arrows identified by the letter “F” followed by the number corresponding to the reference of the part on which it acts. The arrow is oriented, approximately, in the direction in which the spring exerts its force.  
         [0035]     Locking device  32  includes: 
        a switching member  321 , comprising: 
            a bird-shaped body  321   a , with a head  321   b  provided with a hole  321   c  in which there is engaged a stem passing right through frame  30  and carrying a finger  321   d  visible in  FIG. 2   b , a beak  321   e , two wings  321   f  and  321   g , wing  321   g  being provided with a pin  321   h , and a tail  321   j , head  321   b  being arranged on the centre side of the movement and tail  321   j  at the periphery, in proximity to 7 o&#39;clock,     a lever  321   k  pivotably mounted on tail  321   j  and extending over the periphery of the movement from 7 to 9 o&#39;clock, provided with a pin  321   m  disposed so that it is or is not located on the path travelled by push-button  28 , and a stop member  321   n  placed at its free end,     a pawl or click  321   p  pivotably mounted on lever  321   k  and limited in its movement by stop member  321   n,      
            a switching cam, for example a column wheel  322 , schematically shown, controlled in rotation by pawl  321   p , rotating on frame  30  at  322   a,       an interlocking lever  324 , comprising a body of elongated shape  324   a , pivotably mounted on frame  30  in its median part, and one of whose ends is provided with a nose  324   b  arranged for cooperating with the columns of wheel  322 , whereas the other end comprises a first oblong hole  324   c  in which a stud  325  is mounted to slide, for cooperating with control device  34 , and a second oblong hole  324   d , in which a pin  326  with a head is housed, itself secured to frame  30 , for positioning lever  324  in the plane of the movement.        
 
         [0042]     The constituent parts of locking device  32  are positioned by springs schematically represented by an arrow, and more particularly: 
        body  321   a  by spring F 321   a,       lever  321   k  by spring F 321   k  which tends to return it when pressure has been applied to push-button  28 ,     pawl  321   p  by spring F 321   p  which holds it pressed against pin  321   n,       body  324   a  by spring F 324   a , which tends to apply nose  324   b  against wheel  322 , and     stud  325  by spring F 325 , which tends to press it on the external side of oblong hole  324   c.          
 
         [0048]     Control device  34 , more particularly visible in  FIG. 2   b  comprises in particular: 
        a control lever  341  comprising: 
            a body  341   a  arranged at the periphery of the movement from 2 to 7 o&#39;clock, which pivots at  341   b  on frame  30  slightly below 4 o&#39;clock, and which is provided, at one of its ends, with a bent portion  341   c  extending into the thickness of stud  325 , and     a pawl  341   d , pivotably mounted on the other end of body  341   a , whose function will be specified hereinafter,    
            a cam  342 , for example of the column wheel type, driven by pawl  341   d , which controls the coupling of the chronograph, not shown in the drawing, and positions switching member  321  by its finger  321   d.          
 
         [0053]     The constituent parts of control device  34  are positioned by springs and more particularly: 
        body  341   a , by spring F 341   a  which tends to return it when pressure has been applied to push-button  24 , and     pawl  341   d , by spring F 341   d , which applies it against cam  342 .        
 
         [0056]     Reset device  36  is formed in particular by a lever  361  and a hammer  362 .  
         [0057]     Lever  361  is provided with a pin  361   a  arranged opposite push-button  26  and a groove  361   b  placed so that it can act as a housing for pin  321   h  when finger  321   d  is abutting against a column of cam  342 . A spring F 361  tends to push lever  361  back against the push-button. The hammer is also subjected to an elastic force by a spring F 362  holding it pressed against wheel  322 .  
         [0058]     Hammer  362  will not be described in more detail. It is designed to cooperate with cams carried by the mobiles of the chronograph gear train carrying the hands, in order to reset them. Such devices are well known to those skilled in the art.  
         [0059]     In the mechanism thus described, push-button  24  acts on lever  341  via stud  325 , which abuts against bent portion  341   c . Thus, when stud  325  is not inserted between bent portion  341   c  and push-button  24 , an application of pressure on the latter has no effect.  
         [0060]     When the chronograph mechanism is locked, nose  324   b  is abutting against a column of cam  322 . In this position, stud  325  is drawn back from push-button  24 , which is thus inactive.  
         [0061]     If the user exerts pressure on push-button  28 , the latter pushes pin  321   m , which controls lever  321   k . The latter drives pawl  321   p  which rotates column wheel  322 .  
         [0062]     One of the columns of wheel  322  releases nose  324   b  which falls between two columns via the effect of spring F 324   a , such that stud  325  is placed between push-button  24  and bent portion  341   c.    
         [0063]     Another application of pressure on push-button  28  causes column wheel  322  to rotate through one step, such that nose  324   b  is lifted up and stud  325  moves away from push-button  24 , which becomes inactive again.  
         [0064]     When push-button  24  is active, an application of pressure on the latter causes a measurement to start, in accordance with the usual operation of chronograph mechanisms and pivots lever  341  which drives pawl  341   d  and, with it, cam  342 . Finger  321   d  is raised by a column of cam  342 . Pin  321   h  is then engaged in housing  361   b . Moreover, lever  321   k  is driven by body  321   a  such that pin  321   m  is shifted with respect to push-button  28 . Consequently, as soon as the chronograph mechanism is started, push-button  28  becomes inactive. In this state, push-button  26  is also inactive. Of course, lever  361  pivots via the effect of an application of pressure on push-button  26 , but his movement has no influence on the other parts of the mechanism.  
         [0065]     Another application of pressure on push-button  24  stops the measurement and causes cam  342  to rotate through one step. Finger  321   d  is then between two columns of the cam. It is not fall however, despite the action of spring F 321   a , because of pin  321   h  held in housing  361   b . Push-button  28  thus remains inactive.  
         [0066]     If push-button  24  is again subject to an application of pressure, the measurement starts again and finger  321   d  abuts against a column.  
         [0067]     If an application of pressure is exerted on push-button  26  when the measurement is interrupted, i.e. when finger  321   d  is between two columns of cam  342 , lever  361  tips and releases pin  321   h . Body  321   a  tips via the effect of spring F 321   a , and with it lever  321   k . Pin  321   m  is then again opposite push-button  28  which becomes active again. The movement of body  321  also releases hammer  362  which resets the measured time minute hands to zero.  
         [0068]     Pressing on push-button  28  causes the chronograph mechanism to return to its locked state and minute hand  16  passes from zero to displaying the current time, as was explained hereinbefore.  
         [0069]      FIG. 3  shows a watch whose case  10 , time setting crown  22  and two push buttons  24  and  26  can be seen.  FIG. 3   a  also shows dial  12 .  
         [0070]     Crown  22  is used for setting information relating to the current time, push-button  24  for controlling the starting and stopping of a chronograph mechanism, and push-button  26  for resetting it. This watch is shown in  FIG. 3   a  in cross-section along a plane A-A perpendicular to the drawing and in  FIGS. 3   b   1  and  3   b   2  in cross-section along a plane B-B that is also perpendicular, in the locked position of push-button  24  at  3   b   1  and the released position at  3   b   2 .  FIGS. 3   c  and  3   d  show, seen from the side as indicated by arrows C and D, a part of the watch with the push-buttons respectively in the locked position and released position.  
         [0071]     In these Figures, the chronograph mechanism is only shown schematically, by a portion of control lever  40  and reset lever  42 , these portions respectively cooperating with push-buttons  24  and  26 . This mechanism can be of any type controlled by two push-buttons.  
         [0072]     Case  10  further carries, at 8 o&#39;clock, a second crown  44  which, as can be seen in  FIG. 3   a , is secured to a stem  46  passing through the wall of case  10 . Stem  46  is provided with a pinion  48  mounted on a square  46   a  of stem  46  and held by a screw  50  engaged in a threading made in stem  46 .  
         [0073]     The watch is also fitted with a ring  52  disposed inside case  10 , adjacent to the inner wall of the middle part and to dial  12 , which forms with crown  44 , stem  46  and pinion  48 , a device for locking push-buttons  24  and  26 .  
         [0074]     Ring  52  is provided, in its portion close to crown  44 , with a sector of contrate toothing  52   a , which meshes with the toothing of pinion  48 , thus allowing it to be driven in rotation, over a limited angle. As will be explained hereinafter, ring  52  is used for locking push-buttons  24  and  26 .  
         [0075]      FIGS. 3   b   1  and  3   b   2  show push-button  24  in cross-section, engaged in case  10 , respectively in the locked and free positions. A tube  54 , driven into a hole in case  10 , acts as a housing for push-button  24 . The latter is formed of an external button  24   a , on which the user presses, and a stem  24   b  screwed onto button  24   a  and engaged in tube  54 . A sealing gasket  24   c  is housed on stem  24   b  and abuts against the inner end of button  24   a , whereas a helical spring  55  surrounds stem  24   b  and is supported on the one hand in the bottom of tube  54 , and on the other hand, against sealing gasket  24   c  returning push-button  24  when it is subject to pressure. A washer can advantageously be inserted between spring  55  and sealing gasket  24   c.    
         [0076]     Push-button  24  is held in case  10  by means of a screw  56  engaged in a threaded hole of stem  24   b , which is not visible in the drawing. This screw is provided with a head  56   a , which cooperates with lever  40  to control the chronograph mechanism. Head  56   a  has a groove  56   b  extending radially into its cylindrical portion.  
         [0077]     In order to lock push-button  24 , ring  52  comprises a cylindrical portion  52   b , whose inner and external diameter and height are such that the portion can be engaged in groove  56   b , as shown in  FIG. 3   c.    
         [0078]     Portion  52   b  is provided with a rounded cut out portion  52   c , disposed such that, when it is aligned on push-button  24 , the groove is released, which makes the movement of push-button  24  possible.  
         [0079]     When ring  52  is in one of its end positions, cut out portion  52   c  is aligned on axis B-B, such that push-button  24  can be activated. In the other position, ring  52  is engaged in groove  56   b , thus locking push-button  24 .  
         [0080]     Push-button  26 , which has the same structure as push-button  24  cooperates with ring  52  in an identical manner to the latter. A detailed description would thus add nothing further to comprehension of the device.  
         [0081]     In an advantageous manner, the two end positions of ring  52  can be defined by a jumper spring which has not been shown in the drawing, which would have the advantage of clearly marking these two positions. Moreover, in order to allow the user to know whether or not the mechanism is operating, ring  52  is provided with a display zone  52   c  comprising two marks, for example of different colours  52   d  and  52   e , one or other of which appears, in an aperture  12   a  of dial  12 , thus showing which position ring  52  is occupying and, consequently, whether the mechanism is operating or locked.  
         [0082]     The variant shown in FIGS.  4  to  4   d  differs from that of FIGS.  3  to  3   d  in that ring  52  does not lock push-buttons  24  and  26  but makes them active or inactive via the insertion of an elastic member. In this variant, the same parts bear the same references as in FIGS.  3  to  3   d.    
         [0083]     In this variant, ring  52  is made of elastic material, for example steel or beryllium bronze. It also includes a cylindrical portion  52   b , but into which strips  52   f  are cut, secured to the cylindrical portion at one of their ends, and free and forming, by bending, a finger  52   g  at the other end. This finger  52   g  is at the same level as screw head  56   a . Consequently, if strip  52   f  is opposite screw head  56   a , an action on push-button  24  makes screw head  56   a  abut against strip  52   f , finger  52   g  pushing lever  40 . In proximity to bent portion  52   g , the cylindrical portion is interrupted, such that, if the ring is rotated to bring it into the second position, the strip is no longer opposite screw head  56   a , the movement of push-button  24  then occurring in the void.  
         [0084]     The various embodiments described hereinbefore can be subject to numerous variants. It is thus possible to fit the locking device with means for placing gaskets  24   c  under stress, in order to reinforce the water resistance of the watch.  
         [0085]     The function of the control member could also be performed by a time setting crown  22  in its pushed-in position, especially if the movement includes a quartz time base and an electrical energy source.  
         [0086]     Thus, owing to the various embodiments of the device described hereinbefore, it is possible to propose chronograph-type watches offering improved operating reliability.