Patent Publication Number: US-7718872-B2

Title: Repetition action mechanism for an upright piano

Description:
BACKGROUND OF THE INVENTION 
   The invention relates to an improved mechanism for achieving the so-called magic touch effect during double repetition in an upright piano. 
   As is well known, upright pianos are not suitable to musically reproduce the so-called magic touch which, in actual practice, requires to provide a high level of energy as required to compact the harmonics of in the sounds produced by the piano strings when they are transitorily struck. 
   Prior approaches to achieve the above mentioned compactness have not been found as satisfactory, since they are very complex from a mechanic standpoint and unsuitable to produce the required harmonic characteristics. 
   SUMMARY OF THE INVENTION 
   Accordingly, the aim of the present invention is to overcome the above mentioned problem, by providing a device adapted to achieve the double-repetition magic touch effect in an upright piano, which is structurally very simple, and comprises a very small number, of component elements of simple and reliable configuration and construction. 
   Within the scope of the above mentioned aim, a main object of the present invention is to provide such a device which is mechanically very efficient and which, moreover, being specifically designed for upright pianos, is adapted to allow an easy adjustment of its two escapements, without generating large-size or interference problems. 
   Another object of the present invention is to provide such a device which, owing to its peculiar constructional features, is very reliable and safe in operation. 
   Yet another object of the present invention is to provide such a device which is very competitive from a mere economic standpoint. 
   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 an improved device specifically designed for providing the so-called magic touch effect during a double repetition in an upright piano, characterized in that said device comprises a plurality of keys, said keys being swingably mounted on a keyboard frame and supporting, each, a drive element interconnected with a slanted swinging arm, in turn pivoted to a main swinging bridge assembly, said main swinging bridge assembly being operatively coupled to a hammer butt roller pivoted to a first pillar element and supporting a plurality of adjusting buttons for adjusting a first and second escapements, a second pillar element being coupled to said main swinging bridge assembly, to said second pillar element being pivoted a lever of said second escapement supporting an adjusting button element for adjusting the operating angle thereof, said adjusting button element cooperating with a lever of said first escapement supporting a further adjusting button element. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further characteristics and advantages of the present invention will become more apparent hereinafter from the following detailed disclosures of a preferred, though not exclusive, embodiment of the invention, which is illustrated, by way of an indicative, but not limitative example, in the accompanying drawings, where: 
       FIG. 1  schematically shows the operating mechanism according to the present invention, in a rest position thereof, with the rod damping device and frame in a separated condition; 
       FIG. 2  schematically shows the device with a key thereof in a driven or operated condition; and 
       FIG. 3  is a view similar to the preceding figures, but illustrating the inventive device in a further simplified embodiment thereof. 
       FIG. 4  is a further version of the device. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   With reference to the number references of the above mentioned figures, the improved device, specifically designed to provide the so-called magic touch effect during a double repetition in an upright piano, according to the present invention, comprises a plurality of keys  1  which, at a free end portion thereof, comprise a slot operating as a key guiding element, owing to the engagement thereof with an oval tip  3 ; as shown, at the bottom of said oval tip  3  a pad element  4  for damping or cushioning the key  1  depression stroke is provided. 
   The oval tip  3  and pad element  4  are coupled to the keyboard frame  5 , which also supports a further pad element  6 , associated with a second oval tip  7 , said further pad element engaging in a guide slot  8  and being arranged on a black key  9  of the keyboard. 
   Said keys  1  and  9  are pivoted, through a guide slot  10 , to a fixed round tip  11 , operating as a pivot pin or fulcrum for allowing the keys to swing, said fixed round tip  11  also projecting from said keyboard frame  5 . 
   As shown, the keys  1  are further cushioned, at a rest condition thereof, by a further pad element  12 , also applied to the keyboard frame  5 . 
   The key  1 , at its opposite end portion, supports a metal drive element  14 , suitably anti-clockwise slanted, which can be screw adjusted, and having, at the top thereof, a cylindric configuration with an ogival end portion to transmit driving power to a slanted swinging arm  15 . 
   The latter practically provides a knee-joint lever, which can be considered as a continuous energy or power escapement lever, the angle of which varies to control acceleration and deceleration of key depression. 
   Said lever is provided, at the bottom thereof, with a concave contour, housing therein a small cushioning pad or felt  16 , operating to cushion the drive element  14  engagement. 
   The mentioned slanted swinging arm  15 , in turn, is pivoted, through a pivot pin  17 , to a first pillar element  18 , supporting a further bearing pad or felt for bearing thereon the slanted swinging arm  15 . 
   The pillar element  18  is rigidly coupled, for example by glue, to a main swinging bridge assembly  19 , which can swing with respect to a fork element  20 , on a horizontal pivot pin  21 , rigid with the rod NK coupled, by a screw, to the framework of the device. 
   The main bridge assembly  19  defines an angle W having a different ratio between the axis (A) of the bridge assembly  19  and the axis joining the two pivot pins  21  and  36 . 
   Said main bridge assembly supports moreover a metal rod  22  which, at the top free end portion thereof comprises a first hammer abutment or catcher  23 , cooperating with a second hammer abutment or catcher  24 , which is applied, through a metal rod  25 , to the catcher shank  26  of a hammer assembly, generally indicated by the reference number  27 . 
   The butt element of the hammer  27  is pivoted on a pivot pin  28  which is coupled to a second pillar element  29 , which is coupled, through a coupling screw  30 , to the metal frame  31  in turn coupled to the framework of the mechanism  32 . 
   Through said second pillar element  29 , a throughgoing opening  33  is provided, in which is engaged the metal rod supporting, at its bottom end portion, a first adjusting button  34 , for adjusting the first escapement, the lever  35  of which is pivoted through a pivot pin  36  to said main bridge element  19 . 
   Said lever  35  is provided, in turn, with a tail portion  37 , adapted to abut against a cushioning pad or felt  38 , coupled to the button  34  of the first escapement. 
   With reference to  FIG. 2 , as the key, in its rotary movement, transmits power or energy, the lever or jack  35  is caused to disengage from a roller  40  driving a hammer felt  41 , thereby ending its anti-clockwise stroke, whereas the pin  36  does not reach a horizontal line in alignment with the pivot pin of the bridge assembly  19 , and will remain at large distance above the level of the horizontal line of the pivot pin  21 . 
   As shown, the roller  40  is linked to the connecting butt  27 , through a coupling pin  42  of the hammer  27 , at its butt point  43 . 
   In particular, said hammer butt point  43  supports the rod  44  of the hammer felt  41  which, in turn, is supported the hammer molding  45 . 
   The hammer rod, or shank  44 , after having struck and rebounded off the piano strings, can perform a swinging movement and, at an end of stroke or limit portion thereof is braked by a braking felt or pad  46  which is applied to a hammer bearing bar  47 , fixed to the point  48  of the framework. 
   It should be pointed out that the device further comprises a second pillar element  49 , arranged at a middle portion of the main bridge assembly  19  and including a V-shape spring  50  which is connected at an attachment point  51 , provided on the pillar element  49  and having the end portions thereof affecting the lever  52  of the second escapement and the lever  35  of the first escapement. 
   More specifically, the lever  52  of the second escapement is pivoted to the pillar element  49  through a pivot pin  53  which also horizontally extends. 
   The spring  50  clockwise urges the levers  35  and  52  respectively, of the first and second escapements. 
   Said levers  35  and  52  comprises button elements  54  and  55  which are supported by adjusting screws  56  and  57 . 
   The device according to the in invention comprises moreover a swinging movement cushioning element, indicated by the reference number  58 , comprising a crank lever  59 , pivoted on a pivot pin  69 , and being applied to a bar or rod  61 . 
   The pedal  62  of the cushioning or damping elements is coupled to the metal body  63  of the damping or cushioning lever  67 . 
   Said lever  59  comprises, at an end portion thereof, a metal spoon element  64  cooperating with an end portion of the key  1  and abutting on a pad or felt  65  supported by said key. 
   The lever  59  is constantly urged in abutment on the felt or pad  68  of the spring  60 . 
   A second spoon element  66  cooperates with the bottom end portion of a damping lever  67 , including a cushioning felt or pad  68  and being adapted to swing about a swinging pin  58 . 
   The damping lever  67  supports, at its other end portion, a metal arm  70  bearing a felt or pad  71 , through a support element  72 , urged by the urging spring  74  against the piano string  73  providing the harmonic sound. 
   Thus, the component elements of the inventive device will cooperate to apply a constant percussion intensity on the piano strings, regardless of the dynamic pressure applied on the key  1 , even if several rapid key pressures are made consecutively. 
   The slanted swinging arm  15  is so designed and arranged as to provide, with the lever  35 , a suitable angle adapted to provide the subject mechanism with a high mechanical efficiency, to the benefit of the hammer mechanism  27 . 
     FIG. 3  shows a modified embodiment of the device which has been further simplified, mainly with respect to the bar or rod  94  supporting the double fork pillar element  29 , to allow the hammer  44  rigid with the coupling butt pivoted on the pivot pin  28  of the pillar element  29  to swing; this clamping mechanism being formed by the plate  75  clamped to the butt element  43  by the clamping screw  76 . 
   The hammer butt supports, at a side end portion thereof, and by glue, the tail portion of the hammer  26  which is suitably upward clockwise slanted, and comprises a hammer catcher  24 , having its bottom end portion downward extending and rigid with the tail portion  26  through a metal arm  25 . 
   The damping device  67 , pivoted to the pivot pin  58  of the pillar element  29  is driven, during the movement, by a sliding wheel  87  pivoted to the pivot pin of the metal fork  86  which, in the movement portion, operates on a wedge element  88  fixed to the bottom end portion of the damper  67 , which can be adjusted by the adjusting screw  89 . 
   When energy is transmitted by depressing the key, the slanted swinging arm  15 , by urging the main bridge assembly  19 , affects, through the lever, the first escapement  35  and second escapement  53  below the roller of the hammer butt  43 . 
   The operating stroke of the lever of the second escapement is locked by a small button element  95  coupled to the pillar element  29 , thereby providing a downward directed angular movement which, by operating on the spoon element  85 , disengages the lever  35  of the first escapement in a clockwise direction, thereby allowing the hammer  44  to back rebound, after having struck the piano strings, and thus impacting the catcher  24  cooperating with the catcher  25 , as it has been broadly disclosed with reference to  FIGS. 1 and 2 . 
   The slanted swinging arm  15 , at a middle portion thereof, comprises an adjusting metal screw, the top end portion thereof is engaged in the portion pivoted with the pivot pin  93 , which screw, as it is anticlockwise turned, will transmit an upward directed urging force. 
   At its bottom end portion engaged in the portion pivoted to the pivot pin  78 , said screw, in its anticlockwise movement, will transmit its force downward, thereby causing a quick expansion of the parts in the opposite direction. 
   The pillar element  80 , rigid with the bridge assembly  19 , comprises a wide slot for allowing the spring  81  pivoted to the pivot pin  51  of the lever  54  of the second escapement to pass therethrough. 
   Thus, the spring will urge the lever  35  of the first escapement in an anticlockwise direction, thereby abutting against the felt or pad element  93 , which is suitably engaged in the slot  91  of the lever of the second escapement, which is clockwise urged and locked by the adjusting button  53 . 
   The bridge assembly  19  comprises, at a middle portion thereof, a slot  90  for allowing the spring  81  to pass therethrough in the underlying part of the bridge assembly so as to provide an increase elasticity in the movement of the lever of the first and second escapements. 
   The screw  84  operates as an adjustment screw for adjusting the force of the spring  81 . 
   The lever  35  of the first escapement supports, at its bottom end portion, a spoon element  85 , cooperating with the button  55  clamped near the pivot point of the lever  51  of the second escapement. 
   As the button  55  is lowered or depressed it affects said lever  51 , and causes the lever  35  to clockwise disengage, thereby allowing the hammer  44  to freely transmit its energy against the piano string. 
   From the above disclosure, it should be apparent that the invention fully achieves the intended aim and objects. 
   In particular, it is to be pointed out that the specifically designed inventive constructional features allow to provide a very simplified device, together with a great operating reliability. 
   The invention, as disclosed, is susceptible to several modifications and variations, all of which will come within the scope of the invention. 
   For example, it would be possible to design an embodiment of the device adapted to also operate above the horizontal line, in an upward direction. 
   Moreover, all the constructional details can be replaced by other technically equivalent elements. 
   Furthermore, it would be also possible to design a further modified embodiment of the device, adapted to operate with a movable fulcrum arrangement including springs of the well-known HERARD system. 
   In practicing the invention, the used materials, as well as the contingent size and shape, can be any, according to requirements and the status of the art.