Abstract:
A machine is herein disclosed for automatically applying buttons or other metal fittings in general on a support, of a type comprising loader elements, guide and load rods for feeding parts of the buttons or metal fittings to the support, and punches, respectively a top and a bottom punch, for clamping the button or metal fitting parts on the support, the machine further comprising a telescopic rod for operating the top punch and to hold constant, at the button applying point, a preset pressure value, independently from the presence of possible enlarged thickness portions at the button applying point.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to a machine for automatically applying buttons or other metal fittings in general on a support, such as a fabric support, the machine including a mechanism for controlling or compensating for the excessive pressure or pushing force due to the presence of enlarged thickness portions.  
         [0002]     More specifically, the field of the invention is that of the machine used for applying buttons (for example pressure buttons) and other metal fittings in general on a support such as a fabric support or other sheet material support in general.  
         [0003]     As is known, prior machines for applying buttons on a fabric piece or sheet conventionally comprise a bottom punch element and a top punch element, the punch elements being driven in different driving directions, so as to mutually clamp, on respective faces of the fabric support, the two parts forming the button to be applied.  
         [0004]     Said machines usually comprise moreover load or loading rods entraining respective portions of the buttons to be applied to the driving axis of the punches, said punches in turn operating for pressure crushing the button parts on the fabric support, to clamp said parts on the latter.  
         [0005]     A drawback of the above mentioned machines is that the driving means or mechanism included therein for driving or operating the top punch element, are not adapted to provide a reliable holding, on the button parts which must be coupled to one another, of the pressure necessary for closing said button parts, and this, in particular, if the thickness of the support fabric is changed with respect to a rated fixed thickness value based on which the machine is calibrated.  
         [0006]     Moreover, in prior machines of the above mentioned type, the load or loading rods are usually driven by a specifically designed servo-mechanism, which is separated from the punch element driving systems.  
         [0007]     Such prior solution has the drawback that the machine construction is very complex thereby the machine cannot operate in a reliable manner and must be frequently switched off to repair possible jammings occurring therein.  
       SUMMARY OF THE INVENTION  
       [0008]     Accordingly, the aim of the present invention is to provide a novel machine for automatically applying buttons and other metal fittings in general, which, with respect to prior like machines, is very simple construction wise and very reliable in operation.  
         [0009]     Within the scope of the above mentioned aim, a main object of the present invention is to provide such a machine which is adapted to provide a desired closing force on the punch elements, at the point at which the button is applied to the fabric support, independently from the thickness both of the fabric support and of the parts forming said buttons.  
         [0010]     Yet another object of the present invention is to provide such a machine which is further adapted to indicate possible failures in applying the button or metal fittings to the fabric support.  
         [0011]     According to one aspect of the present invention, the above mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by the machine as claimed in claim  1 .  
         [0012]     Preferred embodiments of the inventive machine are defined in the dependent claims.  
         [0013]     Owing to the provision of a driving mechanism including a telescopic system for controlling the displacement of the top punch element, the inventive machine allows to hold a constant pressure on the button being applied, independently from the thickness of the button and the fabric support therefor.  
         [0014]     With respect to the prior art in this field, and owing to the unified or standardized mechanism for driving both the punch elements and loading rods, the inventive machine provides moreover the advantage that it is much more simple construction wise and reliable in operation.  
         [0015]     Finally, the provision in the system of a load cell allows to indicate possible failures in applying the buttons or metal fittings on the fabric support.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     The above mentioned and further advantages, objects and features will become more apparent hereinafter from the following detailed disclosure of a preferred embodiment of the invention which is illustrated by way of a non limitative example, in the accompanying drawings, where:  
         [0017]      FIG. 1  is a general outlay of the machine according to the present invention;  
         [0018]      FIG. 2  is a side elevation view illustrating a detail of the driving mechanisms for driving the punch elements and loading rods, as included in the machine shown in  FIG. 1 ;  
         [0019]      FIG. 3  is a schematic view illustrating the conditions of the mechanisms of  FIG. 2 , as the button parts are loaded toward the button applying region;  
         [0020]      FIG. 4  illustrates the details shown in  FIG. 3 , in a button applying condition;  
         [0021]      FIG. 5  illustrates the details of  FIG. 3 , as a button is applied on a support having an increased thickness;  
         [0022]      FIG. 6  is an exploded view illustrating the detail of the top punch element driving system;  
         [0023]      FIG. 7  illustrates a further detail of a cam system for adjusting the position of the bottom punch element. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]     The inventive machine has been generally indicated by the reference number  1  in  FIG. 1 .  
         [0025]     Said machine essentially comprises two loaders  2  and  3  for feeding button parts or components, as respectively indicated by the reference numbers  4  and  5 , at a button applying axis  6  for applying said button to a support  7  (for example a support fabric, see  FIG. 3 ).  
         [0026]     Said button parts  4  and  5  are moreover driven toward their applying region, thereat operate a top punch element  8  and bottom punch element  9 , through respective guides  10  and  11 .  
         [0027]     As is clearly shown in  FIG. 2 , the inventive machine  1  comprises moreover a standardized driving mechanism for driving the bottom punch element  9  and loading rods  12 ,  13  for loading said button parts  4 ,  5 , said driving mechanism including a control lever  14  driven by a driving cam  15 .  
         [0028]     Said lever  14  is pivoted on a pivot pin  16  and presents end portions  17 ,  18  which respectively operate on the cam  15  and a middle lever  19  for controlling the movement of the bottom punch element  9 .  
         [0029]     On said lever  14  a pawl  20  is moreover provided, which, as it is engaged inside a corresponding fork element  21 , drives said loading rods  12  and  13  through a rigid bush assembly  22 , rigid with the fork element  21  and designed for sliding on a guide rod  23  and small plate  24  in turn clamped to corresponding end portions of said loading rods  12  and  13 .  
         [0030]     The front end portions of said loading rods push said respective button parts  4 ,  5  into corresponding guides  25  and  26 , so as to drive them to their applying axis  6 .  
         [0031]     At a middle position between said lever  14  and bottom punch element  9 , a further lever  19  is arranged, said further lever  19  being pivoted on a pivot pin  27  and having an end portion  28  abutting against the roller  18  of the lever  14 , whereas the end portion  29  drives the bottom punch element  9 .  
         [0032]     More specifically, the pivot pin  27  of the lever  19  is of a cam or eccentric pivot pin, including a drive disc element  30  (see  FIG. 7 ) having a cylindric portion  31  on the same axis as that of the drive disc, and a further cylindric portion  32  eccentrically arranged with respect to said cylindric portion  31 .  
         [0033]     Due to the above construction, the vertical position of the lever  19  can be modified by causing the drive disc  30  to turn with respect to the machine body or frame.  
         [0034]     On said cam  15 , which is driven by a suitable geared unit (not shown), is pivoted an end portion  33  of a telescopic rod  34 , the other end portion  35  of which will drive the top punch element  8  through knee joint  36  in turn pivoted to the machine body at its pivot pin  37 .  
         [0035]     As is clearly shown in  FIG. 6 , the telescopic rod  34  comprises a bottom arm  38  to be clamped, on a side, to a crank pin  39  of the cam  15  and, at the other side, to the telescopic rod cylinder  40 .  
         [0036]     Inside said cylinder  40  are moreover arranged, in succession, a loading cell  41 , a cup spring pack  42  and a spacer element  43 .  
         [0037]     This assembly is held in a set position, by pressurizing the spring pack  42 , and engaging the threaded bar  44 , also arranged inside the cylinder  40 , by a nut  45 .  
         [0038]     A firm connection of the rod construction  34  is made by engaging the arm  38  on a corresponding end portion of the cylinder  40  (in the shown embodiment by engaging a pin, not shown, in respective engaging holes, as shown).  
         [0039]     The threaded bar  44  is in turn rigid with the top arm  46  of the rod  34 , said top arm  46  being pivoted at  47  on the articulated or knee joint  36  (see  FIG. 2 ).  
         [0040]     The preloading condition of the cup spring pack  42  is obtained by screwing on the nut  45  on the threaded bar  44 , and being sensed or measured by a loading cell  41 .  
         [0041]     Thus, as the cam  15  is rotatively driven (according to the arrow F 1  of  FIG. 3 ) the following occurs:  
         [0042]     the telescopic rod  34  will be driven in the direction of the arrow F 2 ;  
         [0043]     the knee joint  36  will be opened by causing it to turn about its pivot pin  37  (arrow F 3 );  
         [0044]     the top punch element  8  will be lowered (arrow F 4 ) in the direction of the button piece or part  4  supported by a respective button grip (not shown);  
         [0045]     the lever  14  will be turned about its pivot pin  16  (arrow F 5 );  
         [0046]     the loading rods  12 ,  13  will be moved away or withdrawn from the button applying region (arrow F 6 );  
         [0047]     the middle lever  19  will be rotatively driven about its pivot pin  27  (arrow F 7 ) by abutting the end portion  18  of the lever  14  against the corresponding portion of the lever  19  (arrow F 8 );  
         [0048]     the bottom punch element  9  will be raised toward the respective button part or piece  5  (arrow F 9 ).  
         [0049]     Thus, owing to the above disclosed movements, the button will be brought to its closure or applying condition clearly shown in  FIG. 4 .  
         [0050]     If, in such a closing or closure position, the thickness encountered by the punch elements  8 ,  9  is larger than the above disclosed one, then the status of the machine will be that shown in  FIG. 5 .  
         [0051]     As is herein shown, in particular, the knee joint  36  has an opening angle f          larger than that shown in  FIG. 4  and the telescopic rod  34  will have its cylindric part  40  slightly removed or displaced away from the corresponding bearing point  48  of the arm  46 , by driving that same cylinder  40  in the direction of the arrow F 10  of  FIG. 5 .  
         [0052]     This displacement of the cylinder  40  will transfer to the cup spring pack  42 , the excess pushing due to the movement of the cam  15  toward its limit position, thereby preventing such excessive pushing from affecting the end portion of the top punch element  8 , thereby holding, at the button applying point, a preset pressure value.  
         [0053]     The load cell  41 , in particular, operates to indicate to an operator a possible excessive or insufficient pushing of the spring, with respect to a present pushing range, which would indicate a failure in the button applying operation.  
         [0054]     The machine as disclosed is susceptible to several modifications and variations, all of which will come within the scope of the following claims.  
         [0055]     Thus, for example, the telescopic rod  34  can be replaced by a cylinder (either of a pneumatic or of a hydraulic type), the piston of which will affect the knee joint  36  and the pushing force of which would be controlled by a central control unit.