US3927594A - Piano action - Google Patents

Piano action Download PDF

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Publication number
US3927594A
US3927594A US516218A US51621874A US3927594A US 3927594 A US3927594 A US 3927594A US 516218 A US516218 A US 516218A US 51621874 A US51621874 A US 51621874A US 3927594 A US3927594 A US 3927594A
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United States
Prior art keywords
striking
key
end portion
restraining
jack
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US516218A
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English (en)
Inventor
Masanori Morita
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Roland Corp
Original Assignee
Roland Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP12112773A external-priority patent/JPS553720B2/ja
Priority claimed from JP49090118A external-priority patent/JPS5117426A/ja
Application filed by Roland Corp filed Critical Roland Corp
Application granted granted Critical
Publication of US3927594A publication Critical patent/US3927594A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10H—ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
    • G10H1/00—Details of electrophonic musical instruments
    • G10H1/02—Means for controlling the tone frequencies, e.g. attack or decay; Means for producing special musical effects, e.g. vibratos or glissandos
    • G10H1/04—Means for controlling the tone frequencies, e.g. attack or decay; Means for producing special musical effects, e.g. vibratos or glissandos by additional modulation
    • G10H1/053—Means for controlling the tone frequencies, e.g. attack or decay; Means for producing special musical effects, e.g. vibratos or glissandos by additional modulation during execution only
    • G10H1/055—Means for controlling the tone frequencies, e.g. attack or decay; Means for producing special musical effects, e.g. vibratos or glissandos by additional modulation during execution only by switches with variable impedance elements
    • G10H1/0556—Means for controlling the tone frequencies, e.g. attack or decay; Means for producing special musical effects, e.g. vibratos or glissandos by additional modulation during execution only by switches with variable impedance elements using piezoelectric means
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10C—PIANOS, HARPSICHORDS, SPINETS OR SIMILAR STRINGED MUSICAL INSTRUMENTS WITH ONE OR MORE KEYBOARDS
    • G10C3/00—Details or accessories
    • G10C3/16—Actions
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10H—ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
    • G10H1/00—Details of electrophonic musical instruments
    • G10H1/32—Constructional details
    • G10H1/34—Switch arrangements, e.g. keyboards or mechanical switches specially adapted for electrophonic musical instruments
    • G10H1/344—Structural association with individual keys

Definitions

  • a key extension member pivoted about a fulcrum on a base has a first end portion connected to the key and a second end portion carrying a pin for pivotally mounting a hammer which has a striking portion for striking a sensor element, and a free end portion. The free end is retained by a jack mounted on the base, causing the hammer to rotate and strike the sensor when the pin moves up during depression of the key.
  • This invention relates to a keyboard device for keyed instruments as, for example, electronic pianos, and particularly to such a device having a lesser number of elements for performing the necessary functions of such an instrument as compared to those of the prior art.
  • the force with which the string is struck should be proportional to the force with which the key is struck
  • the device according to this invention successfully satisfies the above requirements.
  • FIG. 1 is a general sectional view of a first embodiment of the key mechanism or action according to this invention
  • FIG. 2 is a plan view of the mechanism shown in FIG.
  • FIG. 3 is a perspective view of the key extension member shown view in FIG. 1
  • FIGS. 4, 5 and 6 are illustrations of the sequence of operation of the device shown in FIG. 1,
  • FIG. 7 is a circuit diagram showing a preferred embodiment of the electronic circuitry interacting with the key mechanism according to this invention.
  • FIG. 8 are wave form diagrams for the circuit of FIG.
  • FIG. 9 is a general sectional view of a second preferred embodiment of this invention.
  • FIG. I is perspective view illustrating the operation of the device of FIG. 9;
  • FIG. 11 shows a conventional electronic circuit including a switch coupled to the key mechanism
  • FIG. 12 is a diagram for illustrating the principle of operation of the device in FIG. 11;
  • FIG. 13 shows the construction of the well known key operated switch
  • FIG. 14 is a diagram of the electric circuit for the embodiment shown in FIG. 9.
  • a key extension member I with flat sides disposed vertically is connected to a key 2 at its front (first end portion), said member 1 having a notch 3 at the middle bottom portion thereof.
  • the entirety of the member 1 is supported on a fulcrum 6, with the notch 3 fitted on said fulcrum 6 at the front side of the vertical portion of an L-guide disposed on a base plate 4, the member 1 being kept in a state wherein it is pushed to the fulcrum 6 by means of a spring 7.
  • a lateral shift of the member I as would be produced when a finger strikes the key 2 is prevented by a guide 8 provided on the base plate 4.
  • a receiver block 9 for the key 2 is also disposed on said base plate 4.
  • a hammer pin 10 On which a hammer I1 is rotatably pivoted.
  • An inverted T-jack 12 (one embodiment of restraining means) having a hook 13 at the upper end thereof is rotatably pivoted on a pin 14 positioned in a rear portion of the base plate 4, and a spring 15 is provided to give a clock-wise torque to said jack around the pin 14, whereby the tip 16 of the hammer 11 receives a soft clockwise thrust.
  • a jack operating plate 17 consisting of a horizontally bent lug in the rear portion of the member 1 is disposed against a downward protrusion 19 at the right end of the horizontal base 18 of jack 12.
  • a back check pin 20 is provided on the bottom of the member 1 at the rear side of notch 3.
  • a back check 21 is pivotally supported at the bottom on said back check pin 20.
  • the back check 21 has a C shaped portion 23 at the rear side of the pin 20, and the tip of the back check driving plate 24 is made to enter into the cut-out 22 of the C-portion, said driving plate 24 being a portion of the base plate 4 bent to form a horizontal ledge thereof.
  • a damper switch 25 is provided at the rear of base plate 4. Damper switch 25 is adapted to be operated by the left end portion 26 of horizontal base 18 of T-jack 12 as the jack swings around pin 14. Damper switch 25 is interconnected with the electronic circuitry of the piano.
  • the damper switch 25 may also be disposed so as to be driven by an upper supporter bar 30.
  • a mechanicalelectrical transducer includes a sensor element 27 which is, for example, a piezo-electric element. The mechanical-electric transducer is adapted to generate an output voltage corresponding to the intensity of the force with which the sensor element is struck. The sensor of course is struck by hammer 11 when the corresponding key is depressed.
  • a damper cushion 28 secured to a supporter bar 30 is normally in contact with sensor element 27 for gently damping its vibration. When the keyboard is struck, damper cushion 28 is removed from contact with sensor 27, allowing the latter to vibrate freely. (as shown in dashed lines in FIG. I and FIG. 5). Thus the damper cushion 28 is adapted to prevent or to release the vibration of the sensor 27 in accordance with the up and down motion of the key 2 when the same is struck.
  • FIGS. 4, 5 and 6 show aspects of key operation, FIG. 4 showing the mutual relation of parts before the key is struck.
  • the back check 21 will, swing clockwise (along arrow e in FIG. 6) when the key 2 moves up (along arrow d in FIG. 6). Accordingly, hammer 11 will be released and restored to the position shown in FIG. 4.
  • the damper switch 25 will also be restored to the closed state, and the damper cushion 28 will give a soft thrust onto the sensor 27. Further, the damper switch 25 will be opened while key 2 is pushed down after having been struck, but it will be closed when the finger tip has left the keyboard, whereby a damper effect will be obtained by means of an electronic circuit incorporated into the electronic keyboard instrument.
  • FIG. 7 An example of such an electronic circuit is illustrated in FIG. 7, wherein reference numbets 1, 2, 6, 10, ll, 25, 27, and 31 indicate the same members as shown in FIG. 1.
  • Reference number 32 refers to a mechanical electrical transducer circuit, 33 a gate circuit, 34 a musical scale signal oscillator, 35 an amplifier, and 36 a speaker.
  • a capacitive type pick up is shown; that is, mechanical displacement of sensor 27 causes a corresponding variation in its capacity.
  • This variation in capacity is applied to the mechanical electrical transducer circuit 32, causing a voltage proportional to the variation of capacity to be applied to the gate circuit 33.
  • a musical scale signal as shown in FIG. 8a which is furnished by the musical scale signal generating circuit 34 to the gate circuit 33 will be controlled by this voltage which corresponds to the force with which the key was struck and, after amplification in amplifier 35, will cause a musical sound having an amplitude and attenuation characteristic corresponding to the keyboard beating (as shown in FIG. 8b) to be furnished by speaker 36, following amplification in amplifier 35. If the finger tip is removed from the keyboard at time I in FIG.
  • FIG. 7 may further be found resistors RI-RS, transistors Trl, Tr2 and Tr3, condenser Co, diode D, power source E, E, Collector voltage Co of Transistor Tr3 and a damper pedal switch D.P.S.
  • a piezoelectric element or a capacitive pick-up is utilized as the sensor 27, but it may be replaced by a mechanical vibrator like a sensor string or a reed, which may readily be utilized as an action member for a general keyboard instrument other than an electronic instrument.
  • FIG. 9 shows the constitution of the second embodiment of this invention in a sectional view, wherein, instead of a piezo-electric element 27 or other mechanical vibrator (string, reed or the like), is provided a lever switch S in a space above the member 1 in the vicinity of the hammer pin 10.
  • a lever switch S in a space above the member 1 in the vicinity of the hammer pin 10.
  • FIG. 11 an electric circuit for making a touch sense by detecting a charged potential of a time constant circuit consisting of a condenser C and a resistor R9, wherein an output signal from a musical signal source V is controlled by a gate circuit G, the output voltage of a transistor 0 being utilized as the controlling signal.
  • the lever switch S is coupled with the key, whereby it will be switched over from contact A to contact B by the striking of a key.
  • the time necessary for above switch-over substantially corresponds to the force with which the key was struck.
  • the switch lever will be transferred from contact A to contact B in a short time and before the potential across the condenser C, which is discharging, has been lowered substantially so that contact B will be supplied with a relatively high potential.
  • said transference of the switch will take considerably longer, thereby lowering the potential across the condenser C, so that contact 8 will be supplied with a relatively low potential.
  • FIG. I2 is a graph showing the relation between condenser potential and discharge time.
  • the hammer would be accelerated in accordance with the force with which the key is struck, so that the force striking the string would also be acceleratingly increased.
  • the speed of the transference of the switch would merely be proportioned to the speed of keyboard striking, and no accent due to the accerelation of the hammer of and piano keyboard is, therefore, represented.
  • the purpose of this invention is to provide a keyboard switch for an electronic piano, that may be made at low cost, and that will operate reliably with an excellent touch sense.
  • the operation of the electric circuit of FIG. 14 will be explained, when utilizing the key arrangement shown in FIG. 9.
  • the emitter electrode of a transistor Q as shown in FIG. 11 is connected through the resistor R and a diode D1 to one terminal of the damper switch 25, the other terminal of which is connected through the damper pedal switch D.P.S. to ground potential.
  • Transistor Q is switched to the conductive state charging condenser C, when lever 38 makes contact with contact B.
  • the switching of lever 38 from contact A to contact B takes place when striking of the key causes hammer 11 to pivot, thereby causing projection 37 to strike lever 38.
  • the striking of the key also causes jack 12 to pivot, opening damper switch 25.
  • the potential across condenser C when transistor 0 becomes conductive varies, as described above, with the time required for lever 38 to travel from contact A to contact B.
  • the corresponding voltage at the emitter of transistor 0, i.e. the voltage controlling gate circuit G, is substantially the same as that across condenser C while transistor 0 is conductive and switch 25 is open.
  • damper switch 25 closes.
  • the remaining charge on the condenser C] will be discharged within a short interval through the resistor R10, diode D1, damper switch 25, and damper pedal switch D.P.S., whereby a damping effect will be produced.
  • the key frame I is further provided with a jump preventer 39 which will effectively prevent any jump of the hammer 11, as would be produced when it makes an upward swing.
  • the keyboard device wherein the hammer pin 10 is integrally pivoted on the key extension member 1 and the back check 21 of the hammer is pivoted swingably thereon 1, may be simply manufactured by punching out a single metallic plate and by press-forming as shown in FIG. 3 to successfully perform any necessary function of a keyboard instrument as stated above, so that it may be utilized for a wide field of keyboard instruments including the electronic piano.
  • the vibration of the sensor 27 due to the action of key member I is mechanically damped by means of the damper cushion 28, and is also electrically 6 damped through the damper switch 25, so that a perfect damping effect is attained.
  • the sensor 27 of the first embodiment (FIG. I) is replaced by the lever switch S provided in the vicinity of the pivotal pin 10 of the hammer 11, whereby the force of the hammer striking the lever switch consists of the motion of the key due to keyboard striking added to an acceleration due to the swinging motion of the hammer around the pin 10, so that there may be obtained any loud or soft tones corresponding to to the variation of tone strength resulting from the striking of the key in a conventional piano.
  • the shock transmitted to the switch by the hammer is very small, so that there is no danger of damage of the switch, and the finger feels but a very slight shock when striking a key.
  • a key action comprising, in combination, a base; a key extension member pivotally supported on said base and having a first end portion connected to said key whereby said key extension member moves in correspondence to the movement of said key, a projecting portion, and a second end portion; striking means pivotally mounted on said second end portion and having a free end portion adari ed to receive a restraining force and a striking portion adapted to rotate from a rest position to a striking position striking said sensor means upon movement of said second end portion of said key extension member while said free end portion is acted upon by said restraining force; and restraining means mounted on said base and having a restraining portion for applying said restraining forces to said free end portion of said striking means while said key moves from said first to said second position, and an activating portion adapted to cooperate with said projecting portion of said
  • said restraining means comprise an inverted T-jack having an upper end portion for receiving said free end portion of said striking means and applying said restraining forces thereto, and having a horizontal base having a first horizontal end portion positioned relative to said projecting portion of said key extension member in such a manner that said projecting portion exerts a force on said first horizontal end portion following the striking of said sensor means by said striking means, said inverted T-jack further having a second horizontal end portion, said restraining means further comprising means for pivotally mounting said inverted T-jack on said base in such a manner that application of said force to said first horizontal end portion causes said inverted T-jack to rotate from an original position wherein said restraining force is applied to said striking means to a release position wherein said upper end portion is disengaged from said free end portion of said striking means, and spring means connected between said base and said inverted T-jack for returning said inverted T-jack to said original position following disengagement of said horizontal portion of said key extension member from
  • said back check means comprise a back check pin forming an integral part of said key extension member, a back check plate forming part of said base, and a back check pivotally mounted on said pin and having a C shaped portion for receiving at least a part of said back check plate, said back check being mounted relative to said striking means in such a manner that said back check pivots from a first position disengaged from said striking means to a second position preventing the movement of said striking means while said key moves from said first to said second position.
  • said sensor means include a sensor element adapted to be struck by said striking means; further comprising damping means for damping the movement of said sensor element when in contact therewith, and means for mechanically coupling said damping means to said key extension element in such a manner that said damping means is in contact with said sensor element only when said key is in said first position.
  • said sensor element is a capacitive pick-up having a capacitance varying as a function of force applied thereto; and wherein said sensor means further comprise first circuit means connected to said capacitive pick-up for furnishing an output voltage having an amplitude varying as a function of said capacitance tone signal furnishing means for furnishing a tone signal having a predetermined frequency, and gate circuit means having a signal input connected to said tone signal furnishing means, a gating input connected to said first circuit means and an output, for furnishing a gated tone signal at said output, said gated tone signal having a frequency corresponding to said predetermined frequency and an amplitude corresponding to said amplitude of said output voltage, and electroacoustic transducer means connected to said output of said gate circuit means for furnishing an audible tone corresponding to said gated tone signal.
  • said sensor means comprises a sensor element adapted to be struck by said striking means and furnishing an output signal corresponding to the magnitude of the force applied thereto, and transducer means connected to said sensor means for converting said output signal into a corresponding audible tone; further comprising a damper switch electrically connected to said transducer means and mounted on said base in operative proximity to said second horizontal end portion of said horizontal base of said inverted T-jack in such a manner that said second horizontal end portion operates said damper switch to a state preventing production of said audible tone when said restraining means is in said original position and operates said damper switch to a state permitting said furnishing of said audible tone when said restraining means moves from said original to said release position.
  • said striking means comprise a hammer adapted to pivot about said pin and having a striking portion positioned in close proximity to said pin; and wherein said sensor means comprise a selector switch having a selector arm moving from a first to a second position under action of said striking means, and transducer means connected to said selector switch for furnishing an audible tone having an amplitude varying as a function of the time required for said selector arm to move from said first to said second position.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Electrophonic Musical Instruments (AREA)
US516218A 1973-10-26 1974-10-21 Piano action Expired - Lifetime US3927594A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP12112773A JPS553720B2 (nl) 1973-10-26 1973-10-26
JP49090118A JPS5117426A (nl) 1974-08-05 1974-08-05

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US3927594A true US3927594A (en) 1975-12-23

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US516218A Expired - Lifetime US3927594A (en) 1973-10-26 1974-10-21 Piano action

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US (1) US3927594A (nl)
DE (1) DE2450855C3 (nl)
GB (1) GB1479177A (nl)
IT (1) IT1024690B (nl)
NL (1) NL7413568A (nl)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4129056A (en) * 1976-12-21 1978-12-12 Jensen Richard W Pedal control circuits for electronic piano
US4211141A (en) * 1978-03-17 1980-07-08 Jensen Richard W Pedal control circuits for electronic piano
US4562764A (en) * 1984-06-08 1986-01-07 Kurzweil Music Systems, Inc. Electronic musical performance
US5062342A (en) * 1988-12-28 1991-11-05 Casio Computer Co., Ltd. Piano action device for electronic keyboard musical instruments
US5249497A (en) * 1991-04-24 1993-10-05 Kabushiki Kaisha Kawai Gakki Seisakusho Keyborad apparatus for electronic musical instrument
US20030172714A1 (en) * 2002-03-12 2003-09-18 Tokai Rubber Industries, Ltd. Apparatus and method for evaluating damping performance of vibration-damping devices
US20030177885A1 (en) * 2002-03-25 2003-09-25 Pu Wenjun Upright keyboard instrument
US20180342230A1 (en) * 2016-11-17 2018-11-29 Sunland Information Technology Co., Ltd. System and method for recording user performance of keyboard instrument

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3342558C1 (de) * 1983-11-25 1984-09-13 Matth. Hohner Ag, 7218 Trossingen Anordnung bei einem elektronischen Tastenmusikinstrument

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US591887A (en) * 1897-10-19 Charles b
US2974555A (en) * 1955-03-18 1961-03-14 Wurlitzer Co Electronic piano
US3208326A (en) * 1963-07-12 1965-09-28 Wilfrid H Bendall Piano action
US3248470A (en) * 1963-04-24 1966-04-26 Allen Organ Co Electronic piano having means responsive to the velocity of the action
US3514522A (en) * 1967-11-06 1970-05-26 Charles E Mussulman Organ reed pickups with circuitry and lamp-photoresistor arrangement for percussive effects
US3516321A (en) * 1967-01-19 1970-06-23 Baldwin Co D H Electronic piano

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US591887A (en) * 1897-10-19 Charles b
US2974555A (en) * 1955-03-18 1961-03-14 Wurlitzer Co Electronic piano
US3248470A (en) * 1963-04-24 1966-04-26 Allen Organ Co Electronic piano having means responsive to the velocity of the action
US3208326A (en) * 1963-07-12 1965-09-28 Wilfrid H Bendall Piano action
US3516321A (en) * 1967-01-19 1970-06-23 Baldwin Co D H Electronic piano
US3514522A (en) * 1967-11-06 1970-05-26 Charles E Mussulman Organ reed pickups with circuitry and lamp-photoresistor arrangement for percussive effects

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4129056A (en) * 1976-12-21 1978-12-12 Jensen Richard W Pedal control circuits for electronic piano
US4211141A (en) * 1978-03-17 1980-07-08 Jensen Richard W Pedal control circuits for electronic piano
US4562764A (en) * 1984-06-08 1986-01-07 Kurzweil Music Systems, Inc. Electronic musical performance
US5062342A (en) * 1988-12-28 1991-11-05 Casio Computer Co., Ltd. Piano action device for electronic keyboard musical instruments
US5249497A (en) * 1991-04-24 1993-10-05 Kabushiki Kaisha Kawai Gakki Seisakusho Keyborad apparatus for electronic musical instrument
US20030172714A1 (en) * 2002-03-12 2003-09-18 Tokai Rubber Industries, Ltd. Apparatus and method for evaluating damping performance of vibration-damping devices
US6742381B2 (en) * 2002-03-12 2004-06-01 Tokai Rubber Industries, Ltd. Apparatus and method for evaluating damping performance of vibration-damping devices
US20030177885A1 (en) * 2002-03-25 2003-09-25 Pu Wenjun Upright keyboard instrument
US6965070B2 (en) * 2002-03-25 2005-11-15 Yamaha Corporation Upright keyboard instrument
US20180342230A1 (en) * 2016-11-17 2018-11-29 Sunland Information Technology Co., Ltd. System and method for recording user performance of keyboard instrument
US11087729B2 (en) * 2016-11-17 2021-08-10 Sunland Information Technology Co., Ltd. System and method for recording user performance of keyboard instrument

Also Published As

Publication number Publication date
DE2450855A1 (de) 1975-05-07
NL7413568A (nl) 1975-04-29
DE2450855C3 (de) 1980-05-08
GB1479177A (en) 1977-07-06
DE2450855B2 (de) 1979-08-16
IT1024690B (it) 1978-07-20

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