US2513191A - Piano action - Google Patents

Description

June 27, 1950 M MARTIN 2,513,191

PIANO ACTION Filed May 28, 1948 3 Sheets-Sheet l June 1950 L. M. MARTIN PIANO ACTION 3 Sheets- 2 Filed May 1948 L. M. MARTIN June 27, 1950 PIANO ACTION 3 Sheets-Sheet 3 Filed May 28, 1948 Patented June 27, 1950 UNITED STATES PATENT OFFICE PIANO ACTION Lloyd M. Martin, San Francisco, Calif.

Application May 28, 1948, Serial N 0. 29,839

(Cl. 8 i249) 16 Claims.

This invention relates to piano actions, and more particularly to a piano action of the upright, type and is eminently suitable for employment in the small or spinet variety of this type of piano in which an economy of space is required, necessitating that the action shall be compact and of a minimum number of moving parts.

This invention embodies the basic invention of my prior United States Letters Patent No. 2,266,690 in which the jack is pivotally mounted in the. abstract and constitutes an improvement.

thereon.

Itis one object of this invention to provide inanupright action of the type described, a repetitive spring affording repetition in all respectsequalto that obtainable in piano actions of the grand piano type.

Itis a further object of this invention to provide: a piano action. in which the functions of thejack, the. back check, and the bridle strap are combined in a single unitary element.

It is a further object of this invention to provide a piano action of the type described in whi'ch the jack strikes forward on the operation ofthe let-01f.

It is a further object and feature of this invention that the jack on its forward motion as above described locks the hammer butt.

It is a further object and feature of this invention to provide in the unitary jack, back check and bridle strap a bridle strap element which not only pulls the hammer back if it fails to return sufiiciently but also performs the function oftying the action together and positioning the abstract on removal of the action.

It is a further object and feature of this inventionthat byreason of the manner of pivot-- ingthe jack in the abstract and by reason of the fact that the jack is a forward striking jack the jack let-off button ma be positioned in the whippen.

If is a further object and feature of this invention to. provide a piano action of the type decribed inv which the hammer butt is given a preferred shape which allows the jack to slide forward along the hammer butt during the letoff and permits the back check element of the jack to contact the catcher stem. element of the hammer butt, thereby interlocking the hammer butt in two places.

It is a further feature of this invention to employ an abstract formed of aluminum or other suitable: metal having an encirclement on its upper-- end which completely surrounds the cap- 2 stan on the offset portion of the forward end of the key.

These and other objects and advantages will be apparent from the annexed specification in which:

Figure l is a side elevation of a piano action and key embodying the present invention shown in the normal or nonstriking position of the key and hammer.

Figure 2 is an elevation similar to Figure 1 showing the action in the struck position.

Figure 3 is an elevation similar to Figure 1 showing the piano action in the repetition position.

Figure 4 is a cross section through the offset end of the key showing the formation of the capstan and abstract encirclement.

Figure 5 is a plan View of the capstan and encirclement.

Figure 6 is a perspective elevation of an alternative form of an upper end of an abstract and the offset section of the key.

Referring now more particularly to the drawings, there is showna piano action comprising a key bed I0 formed as indicated in two pieces ll, I2 upon the latter of which is mounted a balance rail l3 and a front guide rail M'. A key I5 is provided pivotally mounted on the balance rail as at It and the guide rail as at H in the conventional manner. The inner end of the key [5 has an olfset portion 18 upon which is mounted a capstan If). The capstan I9 is adapted to be positioned in the encirclement 253 of the abstract 2!.

An action flange rail 22 is provided in the customar manner on which is mounted a whippen flange 23 from which a whippen 24 is pivoted as at 25. The whippen 24 has a straight portion 26 and a substantially half circular portion 21, and on the upper side thereof adjacent the junction of the straight portion 28 and the curved portion 21, a, lu 28 is .formed adapted to receive the lower end of the abstract 2! and pivotally mount the same as at 29. Adjacent the upper end of the curved portion 2'! of the whippen 24, a jack let-off button 36 is adjustably mounted as by means of the regulating screw 3|, as indicated. The let-off button 39 has a tapering configuration, as indicated, so that turning of the screw 3| performs the regulating function.

An element, hereinafter referred to generally as the jack 32, is provided, but which in fact performs the function of a jack, of a back check, and a bridle strap. The jack 32 is pivoted as 3 at 33 on the abstract 2| and is provided with an outstanding portion or let-off heel 34 adapted to contact the let-oiT button 3|] as indicated. The let-off heel 34 is provided with a felt contact strip 35 for the usual purpose.

The jack 32 has 3. depending arm 36 on which is mounted a boss 3'5, and a similar boss 38 is formed on the whippen as indicated. A coil spring 39, hereinafter referred to as a jack spring, but which in fact also performs the function of a repetitive spring, is mounted upon the bosses 31 and 38.

The lower end of the arm 36 of the jack 32 is provided on its inner side with a felt stop 4|! adapted to engage the forward side of the abstract 2| adjacent its lower end and thus hold the jack in the nonstriking position properly placed for an ensuing strike.

The upper end of the jack 32 is provided with an upwardly and inwardly, extending arm 4| and a second upwardly and inwardly extending arm 42, the arm 42 being shown herein as having a substantially semi-circular rib. The upper end of the arm 4| forms the jack proper, while the arm 42 has a back check pad 43 thereon, as well as a bridle strap pad 44.

The flange rail 22 on its upper edge is provided with a hammer butt flange in which is pivotally mounted as at 5| a hammer butt 52. Mounted in the hammer butt 52 is a hammer shank 53 carrying on its upper end a hammer 54 formed in the conventional manner. The hammer butt 52 in accordance with this invention is formed with a portion 55 on which is mounted the knuckle leather 55 and with a portion 51 on which is mounted the catcher stem leather 58. v

The inner end of the whippen 24 is provided with an upstanding spoon 55, which spoon is ofiset to one side of the inner end of the whippen and has a leg 6| bent horizontally and positioned in the hole 62. The fit between the leg 5| and the hole 62 is a tight fit holding the spoon 60 in position but permitting adjustment by a spoon adjustor. v

A damper flange 53 is provided upon the flange rail 22 mounting the damper 64 in the conventional manner. A'bracket T5 is provided on which are mounted the flange rail 22, the hammer rail 1| and the hammer butt spring rail 12. A hammer butt spring i3 is mounted in the rail 12, as shown, and has-a curved lower end I4 adapted to ride in the hammer button spring pad 15.

Referring now to Figure 4, there is shown a section through the capstan l9 and the encirclement 25. The capstan I9 is formed of a screw having a flange 85, a tapered sleeve 8!, a felt pad upon the flange and a regulating screw head 82 by means of which lost motion may be removed from the abstract. It will further be noted that the encirclement 25 of the abstract 2| is flared outwardly at the bottom and is adapted to substantially surround the capstan l9, thus assuring a firm seat and firm retention on the capstan. Further, the encirclement is provided with a large slot 85 permitting the retraction of the encirclement toward the keyboard on removing the action.

Referring now more particularly to Figure 6, there is shown an alternative embodiment of the offset [3 and the upper end of the abstract 2|. In the embodiment as' shown, the offset 18' has a groove extendinglongitudinally of the offset and a second groove 9| extending transversely of the offset. A felt 92 is placed thereon and the abstract 2| has a bending point 93, a generally horizontal portion 94, a second bending point 85, and a lip 96, as shown. The horizontal portion 94 is adapted to ride in the groove 9| the bending point 95 to ride over the shoulder 97, and the lip 95 to ride in the groove 5|, thus, in effect, hanging the end of the abstract over the end of the offset.

The operation of the piano action is as follows: Assuming the action to be in the nonstriking position as shown in Figure 1, the jack 32 is positioned, by reason of the manner in which it is mounted, with the jack proper 4| engaging the knuckle 56 so that on striking of the key the jack will give the desired stroke to the hammer butt 52 and cause the hammer 54, released from the jack by the let-off button 35, under its own momentum to strike the striking line 16. Referring now to Figure 2, wherein the action is shown in the struck position, it will be noted that the jack proper 4| has slid along the knuckle leather 55 of the hammer button 52, in a socalled let-off, permitting the back check 43 to engage the catcher stem leather 58. Further, the let-off button 35 is in engagement with the heel 34. and in the process of striking has forced the jack proper 4| from its initial position as shown in Figure 1, engaged under the knuckle leather 55 to its position as shown in Figure 2.

It will also be noted that in the position shown in Figure 2' the hammer butt 5| is locked in two places, to wit, the engagement of the back check 53 and the catcher stem 58 as well as the engagement of a jack proper and the knuckle 56, thus positively holding the hammer in the position shown in Figure 2 as long as the key remains in the struck position. Progressing from the position shown in Figure 2 to the position shown in Figure 3, the piano player has permitted the key I5 to rise a very shore distance. In practice, is sufficient. This permits the back check 43 to disengage slightly from the catcher stem 58 so that under the force of the jack spring 39, which at this point becomes greater than the force of the hammer butt spring 13, the jack proper 4| is forced back into its engaging position under the knuckle 55 ready for a repetitive stroke, giving an action similar to the repetition of a grand piano action.

It will be noted that were it not for the fact that the jack or repetitive spring 39 overcomes the force of the hammer butt spring 13, the hammer butt would be forced all the way to the full back position prior to the reengagement of the jack proper 4| under the knuckle 56.

The let-01f button 30 in the position shown in Figure 3 is in contact with the heel 34 so that immediately following a repetitive stroke of the key I5 the jack proper 4| will be forced to slide along the undersurface of the knuckle 56, rapidly letting off and giving a very rapid repetitive action to the hammer 54.

On complete release of the key l5 to permit the key to return to its position shown in Figure 1,

in the event the hammer 54 fails to return fully,

the bridle strap pad 44 formed upon the upper end of the arm 52 of the jack will contact the catcher stem 58 and will draw the hammer to the desired position. Further, on removing the action; or if the key I5 is removed from the piano, the capstan l9 being disengaged from the encirclement 2|]; the bridle strap 44 will remain hooked over the catcher stem 58 by virtue of the pressure of the spring 39 onthe jack, thus main- '5 taming-the component parts of the actionfirmly associated for readyremoval of the entire action.

It will be apparent fromthe foregoing description that by reason of the very short abstract 2| shown in the present embodiment. in combination with a key having an offset .|8,.the pianoaction can be employedin either36, 38 or- 40"-pianos without the necessity of having a separate'design of action for each. type piano. This is accomplished by reason of the fact that if the key I5 is taken to represent a '36 piano, 2. 38"piano may be employed with the-sameactionhaving a, shorter-but similar ofisetg. and with a 40 :piano the key will require no .oflset, the capstan being formed'directly upon the end of the keyiand the abstract connecting therewith.

It will further be apparent that the-piano action of this inventiongembodies anew form of combination jack, back check and bridle formed of one unit performing all three functions.

It will be further observed that the working stroke of the jack of this invention is forward and that by virtue of the fact that the jack is pivoted in the abstract and that the abstract is-in' turn pivoted in the whippen itis possible toplace the regulator or let-off button-in the whippen, as indicated.

While there has been described what is to be considered the preferred embodiment of the invention, it will'be apparent to those skilled in the art that various changes andmodifications may be made therein Withoutdepartingfrom the ,essence of the invention,. and it is intendedto cover herein all such changes and modifications as come within the true spiritand scopeof. the aped to engage the inner end of said key; .a .jack pivotally mounted on said abstract;,.a .hammerbutt on said hammer adapted to be. engaged by said jack; 2. let-,oii heel mounted. on the rearside of said jack; a let-oh button mounted on said whippen and adapted to engage said let-ofi a heel on strikingof said key to force. the upper end of said jack forwardly out otengagement with said hammerebutt.

2. Inapiano. action of the type in which a pivotally mounted hammer isadaptedrto strikea vertically disposed piano string upon the stroke of a key; the combination ofra hammer flange rail; a whippen pivotally mounted on .said hammer flange rail; an abstractpivotally. mounted on said whippen and having its upper end adapted to engage the inner end of said key; a jack pivotally mounted on said abstract at a point intermediate the extremities of said jack; a hammerbutt on said hammer adapted to be engaged by said jack: a let-off heel mounted on the rear side of said jack; and a let-ofi" button mounted on whippen and adapted to engage said let-01f heel on striking of said key to force the-upper end of said ,iack forwardly out of engagement with said hammer butt.

3. In a piano action of the type in which a i butt on said hammer adapted to-be engaged by said'jack; ,a let-off heel mounted on the rear side, of said jack; a let-off button mounted on saidwhippen and adapted to engage said let-off heelonstrikingof said key to force the upper end of said jackv forwardly out of engagement with said hammer-butt; and a coil spring :mounted between said whippen and the lower end of said jack biasing said jack rearwardly towards reengagement position with said hammer- =butt whereby said jack is positioned for repetition.

4.-In:-a pianoiaction of the type in which a pivotally mounted hammer is adapted to strike avertically; disposed piano string upon the stroke of .akey; the combination of a hammer flange rail; a-whippen pivotally mounted on said ham- 'mer flange rail; an abstract pivotally mounted on :said whippenand having its upper end adapted to engage the inner end of said key; a jack pivotally';mounted on said abstract at a point intermediate the extremities of said jack; a-hammerbutton said hammer-adapted to be engaged by said jack; a let-off heel :mounted on the rear side of said jack; a let-01f button mounted on said whippen and-adapted to engage said let-off heel ont-striking of said key to force the upper end of said jack forwardly out of engagement with said hammer-butt; an upwardly and forwardly extending arm on said jack; a catcher stem formed on said-hammer-butt; anda back check formedon said upwardly extending arm adapted to engage said catcher stem.

5. In apiano action of the type in which a pivotally mounted hammer is adapted to strike a vertically disposed piano string upon the stroke ofrakey; the combination of a hammer flange railya' whippen pivotally mounted on said hammerjjflangerail; an abstract pivotally mounted on saidtwhi'ppen and having its upper end adapted to engage the inner, end of said key; a jack pivotally. mounted on said abstract at a point intermediate the extremities of said jack; a hammerbutton said hammer adapted to be engaged by said jack; a let-01f heel mounted on the rear side of said jack; a let-off button mounted on said whippen and adapted to engage said let-off heel on striking of said key to force the upper end of said jack forwardly out of engagement with said hammer-:butt; an upwardly and forwardly expivotally mounted hammer is adapted to strike a vertically disposed piano string upon the stroke of ,aikeyy'the combination of a hammer flange rail; a whippen pivotally mounted on said hammer flange rail; an abstract pivotally mounted on said whippen and having itsupper end adapted to engagethe inner end of said key; a jack pivotally. mounted on saidabstract at a point intermediate the extremities of said jack; a hammerbutt on said hammer adapted to be engaged by said jack; a let-off heel mounted on the rear siderof said jack; a let-off button mounted on said whippen and adapted to engage said let-oi? ;heel on-striking of said key to force the upper end of said jack forwardly out of engagement withfsaid hammer-butt; an'upwardly and forwardly extending arm on said jack; a catcher stem formed on said hammer-butt; a back check formed on said upwardly extending arm adapted to engage said catcher stem; and a coil spring mounted between said whippen and the lower end of said jack biasing said jack rearwardly towards re-engagement position withsaid hammerbutt whereby said jack is positioned for repetition.

7. In a piano action of the type in which a pivotally mounted hammer is adapted to strike a vertically disposed piano string upon the stroke of a key; the combination of a hammer flange rail; a whippen pivotally mounted on said hammer flange rail; an abstract pivotally mounted on said whippen and having its upper end adapted to engage the inner end of said key; a jack pivotally mounted on said abstract at a point intermediate the extremities of said jack; a hammerbutt on said hammer adapted to be engaged by said jack; a let-off heel mounted on the rear side of said jack; a let-ofi button mounted on said whippen and adapted to engage said let-off heel on striking of said keyto force the upper end of said jack forwardly out of engagement with said hammer-butt; an upwardly and forwardly extending arm on said jack; a catcher stem formed on said hammer-butt; a back check formed on said upwardly extending arm adapted to engage said catcher stem; a bridle-strap pad formed on said arm adapted to engage said catcher-stem and return said hammer on release of the key; and a coil spring mounted between said whippen and the lower end of said jack biasing said jack rearwardly towards re-engagement position with said hammer-butt whereby said jack is positioned for repetition.

8. 'In a piano action of the type in which a pivotally mounted hammer is adapted to strike a vertically disposed iano string upon the stroke of a key; the combination of a hammer flange rail; a whippen pivotally mounted on said hammer flange rail; an abstract pivotally mounted on said whippen and having its upper end adapted to engage the inner end of said key; a jack pivotally mounted on said abstract at a point intermediate the extremities of said jack; a hammer-butt on said hammer adapted to be engaged by said jack; a hammer-butt spring rail; a hammer butt spring mounted on said spring rail and biasing said hammer rearwardly; a let-ofi heel mounted on the rear side of said jack; a'let-off button mounted on said whippen and adapted to engage said let-01f heel on striking of said key to force the upper end of said jack forwardly out of engagement with said hammer-butt; and a coil spring mounted between said whippen and the lower end of said jack biasing said jack rearwardly towards re-engagement position with said hammer-butt whereby said jack is positioned for repetition, said coil spring having sufficient force to overcome the force of said hammer butt spring during said positioning of said jack for repetition.

9. In a piano action of the type in which a pivotally mounted hammer is adapted to strike a vertically disposed piano string upon the stroke of a key; the combination of a hammer flange rail; a whippen pivotally mounted on said hammer flange rail; an abstract pivotally mounted on said whippen and having its upper end adapted to engage the inner end of said key; a jack pivotally mounted on said abstract at a point intermediate the extremities of said jack; a hammer-butt on said hammer adapted to be engaged by said jack; 2;, hammer-butt spring rail; a hammer butt spring mounted on said spring rail and biasing aid hammer rearwardly; a let-ofi heel mounted on the rear side of said jack; a let-off button mounted on said whippen and adapted to engage said let-off heel on striking of said key to force the upper end of said jack forwardly out of engagement with said hammer butt; an upwardly and forwardly extending arm on said jack; a catcher stem formed on said hammer butt; a back check formed on said upwardly extending arm adapted to engage said catcher stem; and a coil spring mounted between said whippen and the lower end of said jack biasing said jack rearwardly towards reengagement position with said hammer-butt whereby said jack is positioned for repetition, said coil spring having sufficient force to overcome the force of said hammer butt spring during said positioning of said jack for repetition.

10. In a piano action of the type in which a pivotally mounted hammer is adapted to strike a vertically disposed piano string upon the stroke of a key; the combination of a hammer flange rail; a whippen pivotally mounted on said hammer flange rail; an abstract pivotally mounted on said whippen and having its upper end adapted to engage the inner" end of said key; a jack pivotally mounted on said abstract at a point engage said let-off heel on striking of said key to force the upper end of said jack forwardly out of engagement with said hammer butt; an upwardly and forwardly extending arm on said jack; a catcher stem formed on said hammer butt; a back check formed on said upwardly extending arm adapted to engage said catcher stem, and a bridle-strap pad formed on said arm adapted to engage said catcher-stem and return said hammer on release of the key; and a coil spring mounted between said whippen and the lower end of said jack biasing said jack rearwardly towards re-engagement position with said hammer-butt whereby said jack ispositioned for repetition, said coil spring having suflicient force to overcome the force of said hammer butt spring during said positioning of said jack for repetition.

11. In a piano action of the type in which a pivotally mounted hammer is adapted to strike a vertically disposed piano string upon the stroke of a key, the combination of a hammer flange rail; a whippen pivotally mounted on said hammer flange rail in a substantially horizontal position and having its rear end extending upwardly; an abstract pivoted from a mid-portion of said whippen and having an upper end adapted to engage the inner end of said key; a jack pivotally mounted on said abstract at a point intermediate the extremities of said jack and above said whippen; a hammer butt on said hammer; said jack being bifurcated at its upper end forming a pair of arms; a knuckle on said hammerbutt; one of said arms being adapted to engage said knuckle; a catcher stem on said hammerbutt; a back check on the other of said arms adapted to engage said catcher-stem; a, let-ofi heel mounted on the rear side of said jack; and

a let-off button mounted on said upwardly extending end of said whippen and adapted to engage said let-01f heel on striking of the key to force said first mentioned jack arm forwardly out of engagement with said knuckle.

12. In a piano action of the type in which a pivotally mounted hammer is adapted to strike a vertically disposed piano string upon the stroke of a key, the combination of a hammer flange rail; a whippen pivotally mounted on said hammer flange rail in a substantially horizontal position and having its rear end extending upwardly; an abstract pivoted from a mid-portion of said whippen and having an upper end adapted to engage the inner end of said key; a jack pivotally mounted on said abstract at a point intermediate the extremities of said jack and above said whippen; a hammer butt on said hammer; said jack being bifurcated at its upper end forming a pair of arms; a knuckle on said hammerbutt; one of said arms being adapted to engage said knuckle; a catcher stem on said hammerbutt; a back check on the other of said arms adapted to engage said catcher-stem; a let-off heel mounted on the rear side of said jack; a let-01f button mounted on said upwardly extending end of said whippen and adapted to engage said let-off heel on striking of the key to force said first mentioned jack arm forwardly out of engagement with said knuckle; and a coil spring mounted between said upwardly extending end of said whippen and the lower end of said jack biasing said jack rearwardly towards re-engagement with said knuckle whereby said jack is positioned for repetition.

13. In a piano action of the type in which a pivotally mounted hammer is adapted to strike a vertically disposed piano string upon the stroke of a key, the combination of a hammer flange rail; a whippen pivotally mounted on said hammer flange rail in a substantially horizontal position and having its rear end extending upwardly; an abstract pivoted from a mid-portion of said whippen and having an upper end adapted to engage the inner end of said key; a jack pivotally mounted on said abstract at a point intermediate the extremities of said jack and above said whippen; a hammer butt on said hammer; said jack being bifurcated at its upper end forming a pair of arms; a knuckle on said hammerbutt; one of said arms being adapted to engage said knuckle; a catcher stem on said hammerbutt; a back check on the other of said arms adapted to engage said catcher-stem; a let-off heel mounted on the rear side of said jack; a let-ofi button mounted on said upwardly extending end of said whippen and adapted to engage said let-oif heel on striking of the key to force said first mentioned jack arm forwardly out of engagement with said knuckle; and a bridle strap pad on said other of said jack arms adapted to engage said catcher stem and return said hammer on release of the key.

14. In a piano action of the type in which a pivotally mounted hammer is adapted to strike a. vertically disposed piano string upon the stroke of a key, the combination of a hammer flange rail; a whippen pivotally mounted on said hammer flange rail in a substantially horizontal position and having its rear end extending upwardly; an abstract pivoted from a mid-portion of said whippen and having an upper end adapted to engage the inner end of said key; a jack pivotally mounted on said abstract at a point intermediate the extremities of said jack and above said whippen; a hammer butt on said hammer; said jack being bifurcated at its upper end forming a pair of arms; a knuckle on said hammerbutt; one of said arms being adapted to engage said knuckle; a catcher stem on said hammer-butt; a back check on the other of said arms adapted to engage said catcher-stem; a let-ofi heel mounted on the rear side of said jack; a let-off button mounted on said upwardly extending end of said whippen and adapted to engage said let-off heel on striking of the key to force said first mentioned jack arm forwardly out of engagement with said knuckle; a coil spring mounted between said upwardly extending end of said whippen and the lower end of said jack biasing said jack rearwardly towards re-engagement with said knuckle whereby said jack is positioned for repetition; and a bridle strap pad on said other of said jack arms adapted to engage said catcher stem and return said hammer on release of the key.

15. In a piano action of the upright piano type, a pivotally mounted whippen; an abstract pivoted on said whippen; a jack pivoted on said abstract; a pivotally mounted hammer; a hammer butt on said hammer; a let-01f button on said whippen; a let-01f heel on said jack; said whippen and jack each being so positioned as to cause said let-off button to contact said let-off heel and pivot said jack forwardly out of operating engagement with said hammer butt on stroking movement of said action.

16. In a piano action of the upright piano type, a pivotally mounted whippen; an abstract pivoted on said whippen; a jack pivoted on said abstract; a pivotally mounted hammer; a hammer butt on said hammer; a let-off button on said whippen; a let-off heel on said jack; said whippen and jack each being so positioned as to cause said let-oif button to contact said let-off heel and pivot said jack forwardly out of operating engagement with said hammer butt on stroking movement of said action; and a jack spring mounted between said jack and said whippen biasing said jack towards operating engagement with said hammer butt for repetition.

LLOYD M. MARTIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 629,362 Herrburger July 25, 1899 1,055,546 Maier Mar. 11, 1913 2,266,690 Martin Dec. 16, 1941 2,305,037 Schulze Dec. 15, 1942

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