Patent Abstract:
This invention is an improvement to be applied to certain known bottle openers, called automatic bottle openers, in which, in order for the extraction to take place it is essential that the closure offers sufficient friction on the worm. Otherwise, once the worm has penetrated the closure, at the point of extraction, it can unthread itself from the closure by means of an anti-clockwise rotary movement and the perforated closure remains inside the neck of the bottle. The invention solves the disadvantage and is characterised in that; if the friction of the closure on the worm is not sufficient, a mechanical system takes over automatically that stops the worm only in anti-clockwise rotary motion during the single extraction stage to then, in the process of the same upward movement, allow the restoration to anti-clockwise rotation so that that the worm can be released from the closure.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a continuation of pending International patent application PCT/EP2006/007807 filed on Aug. 7, 2006 which designates the United States and claims priority from Italian patent application UD2005A000132 filed on Aug. 10, 2005, the content of which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention is applied to particular bottle openers, called automatic bottle openers, of the type already known and it consists of an innovation, an improvement on the said openers that in general are able to open wine bottles. 
         [0003]    In particular the invention is useful when the bottles, rather than being closed with the normal cork closures, are closed with another type of closure called synthetic closures. 
         [0004]    These closures are made from plastic material, silicone etc. and are usually more viscid and more slippery than cork. 
         [0005]    In the type of bottle openers that are to be considered and where the invention has an application, the worm-screw (screw), during the extraction stage of the closure from the bottle neck in an anti-clockwise rotation motion, does not dispose of any stop other than that represented by the friction that the closure offers on the bottle neck. 
         [0006]    If this friction is not sufficient, the worm-screw, once it has penetrated the closure in the bottle neck and then been pushed upwards in order to carry out the extraction, can be unthreaded with an anti-clockwise rotary movement and the opening does not take place. 
         [0007]    The aim of the invention is to obviate this disadvantage. 
       BACKGROUND OF THE INVENTION 
       [0008]    Automatic bottle openers are know that are applied to a wall or to a table or are also directly placed on the neck of the bottle and are held there tight during the opening operation. Allen. U.S. Pat. No. 4,253,351. 
         [0009]    In this type of bottle opener, the worm-screw does not penetrate the closure due to the pushing effect and the rotary movement produced by the operator&#39;s hand but rather because it is pushed to penetrate with only a downward axial movement and the rotation is imposed as it is constrained, during this movement, to cross a nut or nut screw, that forces it to rotate. 
         [0010]    With this type of bottle opener, it is possible to distinguish two families; in the first, as that described by Allen U.S. Pat. No. 4,253,351, it is the worm-screw itself that crosses the nut to assume the rotary movement; in the second family, the one that we shall be considering, the worm-screw has the sole function of penetrating the closure in order to extract it and the rotary movement is assumed by means of a complementary helicoidal screw integral with the worm, positioned on the same axis. 
         [0011]    In the bottle openers where the worm crosses the nut (Allen), to complete the opening operation and release the worm from the closure, two complete movements are necessary from the top downwards and vice-versa. 
         [0012]    Instead, in the type of bottle openers that are to be considered and described and where the invention will find an application, the worm makes a single movement, first downwards to penetrate the closure, then upwards, with a single operation to extract said closure and proceeding in the same movement to release it after from the closure. 
         [0013]    This second method allows a faster operation that is safer, less complex, with less breakages and improved simplicity of construction, however it presents the disadvantage, as already mentioned and until now unresolved, that if in the extraction stage the closure does not offer sufficient friction on the worm, the worm is unthreaded from the closure that remains perforated in the bottle. 
         [0014]    Said friction is necessary with respect to the worm, in the prolongation of its upward axis, it is fixed to a movable support by means of an idle system, a bearing, two flanges etc. that do not offer any type of stop to the rotation of the worm. 
         [0015]    The need for the worm-screw to be free to rotate in both directions derives from the fact that first, when it is pushed into the closure it must rotate clockwise to penetrate it and then once the closure has been extracted from the neck of the bottle it must still be free to rotate in the opposite direction, namely anti-clockwise, to be able to release itself from the closure itself. 
         [0016]    As long as it concerns cork closures, the extraction operation is generally successful. However, in the last few years, new types of closures have appeared on the market, namely synthetic closures: (Silicone plastic material etc.). These closures offer the advantage of being odourless and not having unpleasant flavours, they generally cost less and their use is increasingly widespread. 
         [0017]    In general, these closures are viscid, slippery and impose less friction on the worm-screw than that normally imposed by cork, therefore during the opening operations, the worm penetrates the closure but when the movement is inversed and pushed upwards in order to achieve extraction, the worm, not disposing of any other way of stopping in rotation can be unthreaded with the anti-clockwise rotary movement and the closure remains perforated but in the neck of the bottle and therefore opening does not take place. 
       SUMMARY OF THE INVENTION 
       [0018]    The aim of this invention is to avoid this disadvantage and for this reason, during the single extraction stage, a mechanical system is made to take over automatically that substitutes the lack of friction and keeps the worm blocked in rotation so as to as allow the extraction and then in the process of the same upward movement, still to leave it free in the anti-clockwise rotation, so that the worm can release itself from the closure. This also allows all types of closures to be extracted and without almost greater cost or greater effort. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a side view of a bottle opener in accordance with the invention. 
           [0020]      FIG. 2  is a partially cross-sectional, front elevational view of the bottle opener of  FIG. 1 . 
           [0021]      FIG. 3  is a partially cross-sectional, side view of the bottle opener of  FIG. 2  without the lever. 
           [0022]      FIG. 4  is a cross-sectional top view of the bottle opener of  FIG. 3  along line A-A. 
           [0023]      FIG. 5  is an exposed side view of the top of the bottle opener of  FIG. 3 . 
           [0024]      FIG. 6  is a cross-sectional top view of the bottle opener of  FIG. 3  along line B-B. 
           [0025]      FIG. 7  is a cross-sectional top view of the bottle opener of  FIG. 3  along line C-C. 
           [0026]      FIG. 8  is a cross-sectional top view of the bottle opener of  FIG. 3  along line D-D. 
           [0027]      FIG. 9  is a partially cross-sectional, side view of the bottle opener of  FIG. 3  when in the first working stage. 
           [0028]      FIG. 10  is an exposed side view of the top of the bottle opener of  FIG. 5  when one of the pins strikes the head of one of the ribs. 
           [0029]      FIG. 11  is a partially cross-sectional, side view of the bottle opener of  FIG. 3  when the small block has achieved the lower dead center. 
           [0030]      FIG. 12  is a cross-sectional top view of the bottle opener of  FIG. 3  along line A-A during the penetration stage of the worm in the closure. 
           [0031]      FIG. 13  is a partially cross-sectional, side view of the bottle opener of  FIG. 3  during the extraction of the closure from the neck of the bottle. 
           [0032]      FIG. 14  is a cross-sectional top view of the bottle opener of  FIG. 3  along line A-A when the upper movement of the closure does not offer sufficient friction on the worm. 
           [0033]      FIG. 15  is a partially cross-sectional, side view of the bottle opener of  FIG. 3  when the nut screw has stricken the stops. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0034]    This description that is intended as illustrative and not limitative will be provided with a series of drawings that give an improved understanding of the invention. 
         [0035]    In the field of bottle openers that we will be considering, the assembly that has the worm-screw to carry out the opening and release of the closure only executes one movement from the top downwards and only one subsequent inverse movement. 
         [0036]    In this process, we can distinguish four different work stages. 
         [0037]    Starting from the rest position, the sequences will have the following order. 
         [0038]    First stage=Approach of the worm to the closure 
         [0039]    Second stage=Penetration in the closure 
         [0040]    Third stage=Extraction of the closure from the neck of the bottle 
         [0041]    Fourth stage=It is the stage in which the worm is released from the closure. 
         [0042]      FIG. 1  shows a general view of one of these bottle openers, called automatic, in which the worm  16  assumes the rotary movement since a helicoidal screw  15  integral to it and placed on the same axis is forced to cross a nut screw  17  that in the downward and upward movements will force said worm to rotate. 
         [0043]    As set out in  FIG. 1 , the bottle opener is in the resting position and is seen from the side. 
         [0044]    The number  1  indicates the external tubular casing, with  2  a support base on a table to which will it be locked by means of a clamp  2   a.    
         [0045]    The numbers  11  and  3  indicate a lever that in the lower part  3  extends in a U-shape to encompass the casing. 
         [0046]    Said lever is connected to the support base  2  by means of a pin  4 . 
         [0047]    From the two prolongations of the U-shaped lever  3  originate two arms  5  connected to said lever by two pins  7   a - 7   b  and on the opposite side, said arms connect to a small cylindrical block  6  placed in the casing  1  by means of two pins  7   c - 7   d.    
         [0048]    At the base, the casing  1  comprises a receptacle  9  where the neck of the bottle  28  will be placed in abutment and immediately above, comprising an empty sector  10 , face downwards to allow the closure to exit once extracted from the neck of the bottle. 
         [0049]    The casing  1  also comprises, laterally on both sides, two openings  8  that will allow the two pins  7   c - 7   d  and therefore the small cylindrical block  6  to make the downward and upward movement during the work stages. 
         [0050]      FIG. 2  is a section seen from the front of the same bottle opener in  FIG. 1  made to rotate clockwise at 45[deg.]. In this Figure it is to be noted how the two arms  5  that originate from the lever  3  are connected with the small cylindrical block  6  by means of the two pins  7   c - 7   d . These two pins are locked on the said small block  6  with a screw system. 
         [0051]    The small cylindrical block  6  is longitudinally perforated in the centre along its entire its length and on the upper part said perforation extends to make a seat with a bearing  12  that is locked here and that will have a thrust bearing function. 
         [0052]    Said small block  6 , is free in the casing to scroll from above to below and vice-versa, but cannot rotate. 
         [0053]    A pin  13  passes in said central perforation of the small block  6 , said pin is free to rotate in the small block and in the upper part it is fixed to the central ring of the bearing  12 . Said pin  13  continues upwards with an appendix  14  with a smaller diameter. 
         [0054]    On the pin  13 , proceeding downwards and under the small block  6 , a helicoidal screw  15  is obtained for a section of 7-9 cm. and at the base of said screw the worm-screw  16  is connected integrally. 
         [0055]    The screw of said worm  16  will have the same pitch as the helicoidal screw  15 . 
         [0056]    The helicoidal screw  15  crosses a small cylindrical block  17 , said small block has a nut screw function. Said nut screw  17  can scroll axially in the casing but cannot rotate and is blocked in the upward movement by a series of stops  18   a - 18   b  secured on the casing itself  1 . 
         [0057]    Still on the casing  1 , towards the bottom and at the height where the point of the worm reaches  16  in the resting position, a flange  19  is secured, perforated in the centre in order to allow the passage of the worm  16  and the helicoidal screw  15 . 
         [0058]    From said flange  19 , a series of relieves or ribs  20  that will be better seen in another drawing, extend upwards in contact and fixed on the inside wall of the casing  1 . 
         [0059]    After having described a large part of the details, attention is now drawn to the pin  14 . It is on this pin that the novelty regarding the invention is found. On said pin  14 , a small cylindrical block  21  is inserted held over by a stop  22 . 
         [0060]    Said small block  21  is perforated in the centre and can rotate on the pin  14 . 
         [0061]    The small block  21  includes in the lower part a free wheel with HF.23 type rollers. 
         [0062]    Said free wheel is fixed on the small block  21  and is suitable for working on the pin  14 ; this is directed so that the pin  14 , the pin  13 , the helicoidal screw  15  and therefore eventually also the worm-screw  16  can freely rotate in the clockwise direction even if the small block  21  and free wheel  23  included, do not rotate. 
         [0063]    However, in the anti-clockwise rotary motion, the pin  14  and eventually also the worm  16 , cannot rotate if the free wheel  23  and the small block  21  do not also rotate with them. 
         [0064]    Said small block  21 , includes on its exterior, a series of projections  24 . 
         [0065]    The particulars will be seen in more detail in the following Figures. 
         [0066]      FIG. 3  is something of a repetition of  FIG. 2  but as seen from the side and namely made to rotate with respect to this in the anti-clockwise direction at 45[deg.]. 
         [0067]    Due to a question of space, the drawing of levers  11 - 3 - 5  is not repeated as the movement and the working of the invention can equally be understood. 
         [0068]    Moreover, it is not that these levers are always necessary as the downward and upward movement essential to obtaining opening can also be obtained by the force of a small electric motor that, for example, in the movement downward can make the screw-worm rotate in order to make it penetrate the closure. 
         [0069]      FIG. 3  highlights the two relieves or ribs  20   a - 20   b  that originate from the flange  19  and extend over a well defined section upward and in the case described here, until penetrating a few millimetres into the base of the small block  6  in two lateral grooves  26  on said small block made over its entire length. 
         [0070]      FIG. 4  shows in plan view the section A-A of the small block  21 . This small block, on its upper part, above the free wheel  23 , presents three equidistant grooves, hollowed as a trench, FIG.  5 - 0 -in each one of these grooves a spring  25  is positioned which, on one side towards the centre of the small block  21 , is fixed on this and on the other part towards the exterior a small pin  24  is positioned that projects to the exterior. 
         [0071]    The small pin  24  can be a screw that for a small section is screwed on the spring.  25 . 
         [0072]      FIG. 5 , is a front elevation of the small block  21 , made to rotate 45[deg.] anticlockwise with respect to  FIG. 3 . The trench groove  0  on the upper part is highlighted. These grooves will act as a counter shoulder to the small pins  24  when they strike the ribs  20 . 
         [0073]      FIG. 6 , is a plan view of the section B-B. This section is practically the lower part of the small cylindrical block  6 . 
         [0074]    It is noted how this small block  6  past the central hole, comprises for the entirety of its length, various lateral grooves. Of these, two  26   a - 26   b  will serve to allow the passage of the two ribs  20   a - 20   b  the other four  26  will serve to allow the small block  6 , in the movement downwards, to go past the stops  18  placed in a fixed way further below on the casing  1 . 
         [0075]      FIG. 7 , is a plan view of the section C-C that corresponds to the upper part of the nut screw  17 . 
         [0076]    The four stops  18  are highlighted that originating in a secured way from the casing  1 , project for a few millimetre from the interior of the casing in order to block the upward movement of the nut screw  17 , moreover the two grooves  27  are highlighted that are obtained laterally on the same nut screw so that the latter can scroll longitudinally along the two ribs  20   a - 20   b  but not rotate. 
         [0077]      FIG. 8 , shows in plan view the section D-D that corresponds to the upper part of the flange  19 . 
         [0078]    The flange  19  is highlighted from where the two ribs  20  extend upwards. 
         [0079]    The flange  19  is perforated in the centre and the point of the worm  16  is highlighted. 
         [0080]    This flange  19 , is secured in a fixed way to the casing  1  as are also the relieves or ribs  20 . 
         [0081]    After having described the various components that form the bottle opener, the four stages and the movements for understanding working will now be described. 
         [0082]    In the first working stage,  FIG. 9 , from the rest position seen in the previous  FIG. 1 , by lowering the lever  11  the movement of the arms  5  is also obtained and therefore also the movement downwards of the small cylindrical block  6  and therefore also of the whole assembly that is connected to this small block  6  by means of the bearing  12 . 
         [0083]    Therefore the movement downwards of the entire apparatus will take place and the point of the worm  16  will approach the top of the neck of the bottle  28  and the closure  29 , placed under the base  9  of the bottle opener. 
         [0084]    Also the nut screw  17 , not encountering obstacles, will move downwards together with the helicoidal screw  15  until striking the upper part of the flange  19 . 
         [0085]    This first stage, defined as transfer, is idle and there is no rotation. 
         [0086]    Together with the entire assembly, the small block  21  will also be lowered, placed higher up on the pin  14  and the small pins  24 , when the nut screw  17  is in abutment on the flange  19 , will be positioned near the highest point of the ribs  20 . 
         [0087]      FIG. 10  shows what could occur if one of the small pins  24  in the process of the movement downwards, should strike the head of one of the ribs  20 . 
         [0088]    In this case, the spring  25  to which the small pin is connected, will allow said pin to take a position so as not to obstruct the assembly in the process of the movement downwards, which could occur if the small pin  24  were fixed on the small block  21 . 
         [0089]    The case represented with  FIG. 10 , is extreme and normally does not occur because even if the small pin  24  struck the head, at the top of the rib  20 , said pin, aided by the flexibility of the spring and by the fact that the small block  21  can rotate, will position itself immediately at one side or the other of the ribs  20 . 
         [0090]    It is to be noted that the small pin  24  can assume that position only in the movement from above downwards while in the opposite movement, namely upwards, it will remain blocked between the trench groove  0  and it will behave as if it were fixed on the small block  21 . 
         [0091]    The reason for which the projections  24  of the small block  21  are connected with it by means of a flexible system  25  can now be understood. 
         [0092]    Here, the first stage is completed. 
         [0093]    Proceeding in the downward movement, the second stage will begin  FIG. 11  that consists in the penetration of the worm  16  in the closure  29 . 
         [0094]    In this second stage, since the nut screw  17  has struck the upper part of the flange  19  and is blocked here in the movement downwards and is still blocked in the rotary motion by the ribs  20 , the helicoidal screw  15  in order to be able to proceed in the movement will be forced to rotate clockwise and thus the worm  16  that is pushed downwards and rotating will penetrate the closure  29 . 
         [0095]    This rotation is possible because the entire movable assembly that starts from the pin  13 , is fixed on the central ring of the bearing  12  that has a thrust bearing function and allows therefore the entire assembly connected with it to rotate freely both in the anti-clockwise and clockwise direction. 
         [0096]      FIG. 11  shows the position that the various components come to assume when the small block  6  in the downward movement has achieved the lower dead centre. 
         [0097]    Now we will examine what occurred and how the small block  21  behaved. 
         [0098]    When the helicoidal screw  15 , pushed downwards started to rotate, the pin  13  and the pin  14  also followed that movement. 
         [0099]    The small block  21 , positioned on pin  14  where the free wheel  23  operates, by means of inertia, will begin a rotary movement together with the pin  14  and this will continue until one of the small pins  24  strikes one of the ribs  20 . 
         [0100]    At this point, the small block  21 , will be obstructed in the rotary motion and will proceed downwards without rotating. This fact will not prevent, however, the rotation of the pin  14  since, in that clockwise rotation direction, thanks to the free wheel, it is free to rotate even if the small block  21  and said free wheel  23  do not rotate. 
         [0101]    Proceeding in the movement, it is understood therefore that the small pin  24   a  in contact with the rib  20   a    FIG. 12  will follow the movement of the assembly downwards, sliding and touching the wall of the rib  20   a  until it reaches the lower dead centre. 
         [0102]      FIG. 12  shows in plan view, the position that the small pins  24   a - 24   b - 24   c  will have taken with respect to the ribs  20   a - 20   b  during the penetration stage of the worm in the closure. 
         [0103]    The small pin  24   a  will be in contact with the rib  20   a  while the other two small pins  24   b ,  24   c  will be free in the space between the casing  1 , the small block  21  and at a certain distance from the rib  20   b.    
         [0104]    Here the second stage is completed, the one that we call penetration. 
         [0105]    The following third stage  FIG. 13  will be that in which the extraction of the closure from the neck of the bottle takes place and it is in this stage that the invention finds its application. 
         [0106]    In order for the operation to be carried out, it is necessary to invert the force on the small block  6  to push the assembly upwards. We repeat that in this stage, it is essential that the worm only has upward axial movement and is not rotated. 
         [0107]    Pushing upwards, the entire system will move away from the top of the neck of the bottle and if the closure  29  offers sufficient grip and friction on the worm  16  the opening will take place. 
         [0108]    In this case, the friction offered by the closure being sufficient to keep the worm blocked, there is no anti-clockwise rotation of said closure and eventually, also the pin  14  and the small block  21  that includes the free wheel  23 , will move upwards with only the axial movement and with the small block  21  the small pin  24  will also follow the movement, maintaining the position, with respect to the ribs  20 , assumed during the previous penetration stage. 
         [0109]    In this case therefore the invention that is presented here does not intervene and the opening will be carried out according to the traditional system. 
         [0110]    Instead the behaviour of the worm will be different and as a result of the axis that supports it, until reaching the pin  14  where the small block  21  is positioned with the respective free wheel, if the closure does not offer sufficient grip and friction on the worm. 
         [0111]    In this case, as the closure  29  is tightly held in the neck  28  and offers a certain resistance to extraction and considering the fact that it does not offer sufficient friction, the worm, free in rotary motion when the upwards movement begins, rather than operate the extraction will prefer to attempt to unthread itself from this closure by starting an anti-clockwise rotary movement. 
         [0112]    This fact will also cause the rotation of the pin  14  and also the small block  21  that now, due to the effect of the free wheel  23  is integral with said small block. This start of rotation will last until one of the small pins  24  strikes against one of the ribs  20 . 
         [0113]      FIG. 14  shows in plan view, the position that the small pins  24  are to assume when in the movement upwards the closure does not offer sufficient friction on the worm. In this case, the small pin  24   a  will be moved away from the rib  20   a  until the small pin  24   b  strikes against the rib  20   b.    
         [0114]    The way in which the small pins  24  are arranged with respect to the ribs  20  will determine the width of the rotation angle that the small block  21  can carry out before one of the small pins  24  goes against one of the ribs  20  and in conclusion before the invention takes effect. 
         [0115]    This rotation angle, with the closure blocked between the neck of the bottle and the worm in this, must be as small as possible in order not to lose the opening effect. 
         [0116]    In an attempt to reduce the space between the small pins and the ribs, these have been arranged according to the drawing in  FIGS. 12 and 14 . 
         [0117]    At this point, proceeding in the upward movement, the small pin  24   b , will follow that axial movement, sliding while supported and rubbing along the wall of the rib  20   b  thus preventing the rotation to the small block  21  and therefore also to the axis that starts from the pin  14  to the worm  16  and namely until the extraction of the closure is not possible. 
         [0118]    The lower the friction offered by the closure  29  on the worm  16 , the greater will be the rubbing force of the pin  24   b  on the rib  20   b.    
         [0119]    In this case, the small pin  24   b  is practically placed to replace and compensate the low friction offered by the closure. 
         [0120]    In this third stage, the nut screw  17 , already when the upward movement begins, not encountering any obstacles, and being included in the helicoidal screw  15  that does not rotate, must follow the upward movement until it goes against the stops  18 . 
         [0121]    The fact that the pin  24  does not allow the rotation of the pin  14 , together with the fact that the nut screw  17  moves upwards following the axial movement of the helicoidal screw  15 , will be the motive for which the entire axis, including the worm that is now found within the closure, moves upwards without rotating. 
         [0122]    When the nut screw  17  is in abutment on the stops  18 , the worm  16  will have passed upwards, making a sufficient space to extract the closure and the opening will take place. 
         [0123]    The fourth stage will begin in which the worm is released from the closure. 
         [0124]      FIG. 15 , shows the position that the various components have come to assume when the nut screw  17 , in its upward movement, has struck the stops  18 . 
         [0125]    The closure  29  extracted from the neck of the bottle  28  is seen placed towards the lower part of the flange  19  and with the worm  16  inside. 
         [0126]    The most important aspect now is that it is fundamentally important in the end to obtain the result that the invention intended to achieve as well as that of observing the position the small pins  24  have taken in this moment. They have now overcome the highest part of ribs  20  and are in a position in which, in the process of the upward movement, not encountering obstacles in the casing, are free to rotate together with the small block  21 , the pin  14  and eventually therefore also with the worm  16 . 
         [0127]    At this point, continuing in movement, the nut screw  17  being blocked both in the rotary motion (the ribs  20 ), as well as in axial movement (the stops  18 ), the helicoidal screw  15 , in order to be able to proceed upwards, is forced into anti-clockwise rotation and in that direction will make the entire axis rotate including the worm  16 . 
         [0128]    The closure  29 , included in the worm  16  will be in abutment at the base of the flange  19  and here will remain blocked without the possibility of rotating, as a result, the upward movement and the contemporary anti-clockwise rotation of the worm  16 , will make the worm release itself from the closure  29  for the lower part of the flange  19  to disappear further. 
         [0129]    The closure released in this way can exit the bottle opener across the perforation  10  of the casing  1 . 
         [0130]    The upward movement can occur until the top dead centre has been reached that coincides with the rest stage ( FIG. 1 ). 
         [0131]    At this point the opening has taken place, the closure has been expelled by the bottle opener and the assembly is ready to start a new operation. 
         [0132]    The importance and the function of the ribs  20  that together with the free wheel  21  with the small pins  24 , allow the realization of the invention is now understandable. 
         [0133]    It is important to establish the point that the ribs  20  can reach in their upward extension. This point will must always be below that reached by the small pins  24  at the moment in which the nut screw  17  is in abutment against the stops  18  because this is the moment in which the rotary motion begins.

Technology Classification (CPC): 1