US2260335A - Piano action - Google Patents

Description

@CL 23 19M K J. c. Pom/VIN Q PIANO ACTION Filed Nov. 28, 1940 Patented Oct. 28, 1941 PIANO ACTION Julian C. Potwin, Ivoryton, Conn., assignor to Pratt, Read & Company, Ivoryton, Conn., a corporation of Connecticut Application November 28, 1940, Serial No. 367,603

12 Claims. (Cl. 84-240) This invention relates in general to piano actions and in particular to improvements in a drop-type action for a low upright piano,-

A general object of this invention is to provide an improved drop-type action for a low upright piano.

Another object of this invention is torprovide improved means for guiding the playing movement of an abstract for a drop-type action.

Yet another object of this invention is to provide an improved guide means for the abstracts of a piano action which is removably mounted on the key supporting means and movable to move all of the abstracts at one time to a rest Further objects, features and advantages of this invention will become apparent from the following description when taken in connection with the accompanying drawing in which:

Fig. 1 is an elevation partly in cross section of one of the units of a complete piano action showing the improved abstract and abstract guide means of this invention in normal assembled position in a piano;

Fig, 2 is a View illustrated similarly to Fig. l showing the piano action and guide means in a position of rest ready for disassembly from the piano;

Fig. 3 is a fragmentary view of abstract, guide position adjacent said action, so that the abmeans, and key in a position intermediate the stracts and remaining portions of the action can assembled and disassembled POSOD 0f FigS l be handled together as a unit for assembly and and 2, respectively; I shipping purposes, Fig. 4 is a sectional View as seen along the A stili further object of this invention is to line 4 4 in Fig. 2 showing the Connection of the provide an improved abstract and abstract guide abstract lifter rod or body portion to the abstract means for a piano action which is of simple and head DOFOII. rugged construction, and of a standard design Fig. 5 iS 21 fragmentary detailed plan view of for a plurality of stock-size pianos, whereby to the abStlaCi? guide means a'S Seen aio-11g the line reduce manufacturing costs to a minimum. 5 5 in-Figl; and

A feature of this invention is found in the Fig. 6 is a fragmentary sectional view of a provision of abstract guide means which is removably mounted on the key bed and vadapted to support the piano keys when theyare in a rest position, as Well as provide means for kguiding the abstracts in their normal playing movement.

Another feature of this invention is found in the provision of an abstract having a head portion which extends over the rear end of the corresponding key and is of a form such that the head portion slides over the capstan screw mounted on the rear end of the key coincident with a relative movement of all of the abstracts and keys to their nal assembled positions. All of the keys and abstracts .are thus connected and disconnected at one time regardless of Whether the abstracts are moved away from the keys, or the keys away from the abstracts so that the usual time and inconvenience encountered in connecting and disconnecting the abstracts and keys individually is entirely eliminated.

A further feature of this invention is the provision of an abstract in which the lifter rod portion is formed with a U-shaped hook at each end thereof, with the hooks extending in opposite directions. These hooks are rigidly connected with the head and foot portions of the abstracts and serve both to positively align these portions in a direction from front tol back ofthe piano, and to provide for a substantially unit'construction of the abstract.

modification of the abstract guide means portion of the invention.

In practicing my invention I provide a droptype piano action having a plurality of abstracts, all simultaneously connectble, or disconnectible with corresponding piano keys as an incident to the assembly or disassembly, respectively, of the action and piano keys. The abstracts are each axially or pivotally connected at their lower portion into the remainder of the `piano action, and such action includes supporting brackets for mounting the action in a piano case rearwardly of thme keys. The abstracts are vguided in an upright path during the normal playing movement thereof by means of stationary guide means which includes a rail common to all of the abstracts, and a plurality of individual apertured flanges thereon. Each abstract is operatively connected with its corresponding stationary flange by riding in the aperture of the flange over a portion of the abstract intermediate the top and bottom thereof. The guide means is supported on theV key supporting means ofthe piano case and is entirely independent of the piano action frame or brackets except that it may be swung `with the abstracts into a position of rest adjacent the remainder of the action to provide a compact unit assembly for transporting in any manner desired. `'Iheguide means is positioned beneath the top level of the keys and is out of the way when working on the assembled action and keys, and substantially entirely out of sight so far a-s the top of the keys and action is concerned in the assembled condition of the piano.

With reference to the drawing, there is shown in Fig. 1 a piano action which is supported principally on a rail i6 which in turn is mounted on a plurality of mounting brackets II. A whip I2 is pivotally connected to the rail I and in turn pivotally supports a jack or ily I3. As the whip I2 is raised the jack I3 engages, in the usual manner, the butt I6 of a hammer I4, this motion being transmitted through the jack to pivot the hammer into striking engagement with a corresponding piano string. A back-check I1 and bridle strap wire I8 are both supported on the whip. The foot portion I9 of an abstract 2I is pivotally connected by a pin 22 to the whip I2, the abstract head 23 being in abutting engagement with the capstan screw 24 which is mounted at the rear end of a piano key 26. The abstract head 23 and foot portion I9 are connected together by a lifter rod 21 which is illustrated as being made of wire, but which may be provided also in wood, plastic, or like material. Each end of the lifter rod is integrally formed with a hook 28, which extend in opposite directions from the body portion of the lifter rod.

In connecting the upper end of the lifter rod and the abstract head 23 together, the body portion of the lifter rod opposite the free end 29 of the hook is snugly tted into a vertically extending open slot 3I which is formed at the rear end of the abstract head and substantially centrally thereof (Fig. 4) A cavity or bore 32 laterally aligned with the slot 3| and spaced inwardly therefrom, is adapted to receive in driven engagement the hook end 29. As is clearly shown in Fig. 4, the hook end 29 is formed with flutes,

undercut portions, or other means to obtain a entire length, and a positive alignmentA in a direction from front to back of the piano is obtained between the foot and head portions of the abstract. Because of the double engagement of the lifter rod with each of the head and foot y portions this alignment is maintained during subsequent use of the action so that a better playing action is assured throughout the life of the piano. In many of the wire and wood abstracts of the prior art the abstract head is formed with a depending neck portion extending along the body of the lifter rod while the abstract foot portion is formed with a similarly upwardly extending neck portion to provide for adequate rigidity between the substantially right-angled sections of the abstract, when the lifter rod is driven or screwed into a corresponding cavity in the head and foot portions. The abstract of the present invention eliminates these additional neck portions while increasing the strength and rigidity of the abstract, thus providing not only an improved construction but also a saving in the cost of the wood required for making the abstract head and foot portions.

The abstract 2| is shown in Fig. l in its playing position, the lifter rod being in a substantially upright position and the capstan 24 being in abutting engagement with a felt bushing 33 on the lower side of the head portion 23. When the abstractu is operated for playing, therefore,

it moves in a substantially vertical or straightline direction while the capstan is moved along a small arcuate path so that only a slight rocking action occurs between the head 23 and the capstan 24. As a result, there is little or no friction due to relative travel between the capstan and the abstract head so that the wear on the felt bushing 33 is practically eliminated thus reducing repair and servicing costs to a minimum. This lack of relative travel and friction between the abstract and capstan screw also permits a fast recovery of the abstract after each playing stroke of the key 26, so that the action is capable of efficient operation and fast repetition.

From the above description and consideration of Fig. 1, it is seen that the abstract 2I is of substantially integral or unit construction and connected at its lower portion by pin 22 to the whip I2 while its top portion is entirely free of the remainder of the action and in abutting engagement only with the capstan screw 24. Thus although the abstract head and foot portions are in positive alignment with each other, as previously explained, the abstract must be properly guided during its playing movement to efliciently transmit the playing stroke of the key 26 to the action. This guiding is accomplished in the present invention by guide means designated generally by the reference character 34 and supported when in final assembled position, entirely independently of the piano action and on the means for supporting the piano keys 26. For the purposes of illustration the key supporting means may be more specifically described as including a key bed 36 which is within the piano case and rigidly secured to the piano, and a key frame 31 mounted on the key bed and supporting the keys 26 thereon.

The guide means 34 is located entirely below the keys 26 and includes a rest rail 38 which is common to all of the abstracts 2| and is arranged forwardly and transversely thereof. Rail 38 is of substantially L-shaped form with a horizontal leg portion thereof resting on top of the key bed 36 and a vertical leg portion extending beyond the rear end of the key bed and downwardly from thehorizontal portion, so that the square shoulder formed by the L-shaped configuration of the rail is in abutting engagement with the top square corner of the rear end of the key bed. By virtue of this square engagement of the rail with the key bed the rail is both firmly mounted on the key bed, and in case of its removal is more readily returned to the same position thereon; screws 39 serving to hold the rail in its sup- I ported position. The top of the vertical portion longitudinally of the rail 38 is cut away to form a shoulder 4I having a longitudinally extending rib or projection 42 on the top thereof. The top of the horizontal leg portion is covered with a bushing 43 of` suitable material and supports the rear end of the keys 26 when they are in their rest position shown in Fig. l. This utilization of the rail 38 as a support for the keys serves to reduce the width of the key frame 31, since the key frame need only be of a size suiiicient to provide a firm support for the key fulcrum 44. Since the amount of wood in the rail 38 is considerably less than the amount required in a key frame to fill the space from the end of the key frame 31, as shown in Fig. l, to the end of the key bed 36 so that the keys may rest thereon, this construction provides for an appreciable saving in the cost of the key frame.

Supported on the shoulder 4I and projecting rearwardly therefrom are guide arms or members 46V for each of the abstracts 2| which are secured to the rail 38 by screws 41. Each arm 46 is formed on the bottom thereof with a groove or recess corresponding to the rib 42, the mating engagement therebetween preventing any rotation of the arms relative to their support. The free end of each flange 46 is formed with an aperture 48 of a size to guidably receive therein the body or lifter rod portion of its corresponding abstract, the rib 42 serving to align the flange 46 withv the abstract head and foot portions and the shoulder 4| being such as to support each member at substantially right angles relative to the abstract lifter rods. Each abstract is thus guidably supported intermediate its loot portion I9 and its head portion 23 ina stationary arm or flange 46 and specifically at the aperture 48 therein. Because of the extension of the lifter rod 21, through a corresponding aperture 48, it is contemplated that the arm 46 be connected to the abstract prior to the connection of at least one of the abstract end portions to the lifter rod. With the assembly of the guide means 34 entirely below the abstract heads 23 and forwardly of the abstracts, the top of the action rearwardly of the abstracts is completely open and free of any supporting structure for the abstract so that ready access is had to the remaining portions of the action after connection of the abstracts with the keys 26.

In the adjustment of the guide means 34 to properly guide the abstracts 2| for playing operation in a substantially vertical or straight-line directions the rail 38 may be adjusted vertically, laterally and longitudinally of the key bed by endwise movement of the rail or by shimming the rail either at the rear end, or top of the key bed, the shims being glued to the key bed so as to yform an integral part thereof. Also the individual arm members 46 may be pared by a knife or chisel in a manner such that the arm may be moved to a desired position relative to the abstract lifter rod 21. A plurality of adjustments are thus possible so that the structure is quickly adjusted to the most frictionless position for properly guiding the playing movement of the abstracts 2|. Since these adjustments are of a somewhat permanent nature for a particular piano, any subsequent removal of the rail 38 from the key bed 33 does not require a readjusting of the guide means on a return of the rail on the key bed; the screws 39 serving to always return the rail to the same position.

With the abstracts supported in their playing positions by the guide means 34, as shown in Fig. l, the keys 26 may be easily connected with, or disconnected from the abstracts by simply moving the key frame 31 either forwardly or rearwardly of the key bed 36. To facilitate the connection of the keys with the abstracts the forward end of each abstract head 23 is bevelled downwardly and rearwardly, to permit insertion of the capstan screw 24 thereunder for engagement with the covering 33 of suitable material. I

Complete removal or assembly of the entire keyboard may thus be accomplished without in any way touching or handling the abstracts.

However, a preferred method of assembly of the action and keys comprises mounting the action and abstract guide means in the Diano case as shown in Fig. 2. The keys and key frame are mounted on the key bed 36. The guide means 34 is then brought forwardly and the abstracts, of course, move with such means. In a position ofv thevguide means immediately ahead, in point of time assembly, of that illustrated in Fig. 8, the bevelled front edge B of the rail 38 engages the bevelled under-edge K of the rear end of the key andvraises the key to the position shown in Fig. 3. As the guide means is swung forward toward the position of Fig. -1, the capstan screw 24 engages the bevelled extension H on the abstract head, to raise the head and abstract. In the nal movement to the position of Fig. 1, the key and capstan screw snap intothe position of Fig. 1, and the guide means, the abstracts, and keys are all in playing position. The rail 38 is then securely connected to the keybed by the screws 39.

The disconnection of the action and keys is substantially thev reverse of the above process. However, 'on disconnection of the abstracts from the keys 26 and key supporting means, the abstracts are free to fall forwardly away from the action, it being apparent that the guide means 34 will also fall forwardly with the abstracts. Any possibility of this happening is overcome in the present invention by the provision of means for `retaining all of the abstracts in a substantially upright position adjacent the remainder of the piano action on their separation from their associated keys and the key supporting means, so that the complete action and guide means can be handled as a compact unit. Such means includes a mounting arm 5| located at each end of the complete action, the upper end of each arm being secured to the rail 38 at the shoulder 4| and the lower end thereof being pivctally connected to the rail l0. Since any slight lifting or tipping of the rail 38 frictionally binds 4the guide means 34 in a set position on the abstracts, the abstracts are all pivotally and simultaneously movable by the guide means about their pivot points at the pins 22 (Fig, 2). To facilitate the pivotal moving of the abstracts and guide means 34, the lower ends of the arms 5| are slotted so that the arms may be moved relative to their pivotal connection at the rail I0. The hinges or arms 5|, therefore, are both pivotally and radially movable to concurrently move all of the abstracts relative to the action, the rail 38 (Fig. 2) functioning as a rest rail for abstracts during this movement. Retention of the abstracts in a substantially upright position adjacent the piano action is accomplished by suitable latches or hooks 52 which are rotatably mounted on the hammer rest rail 53 and engageable with certain ones of the abstract lifter rods. Because of the tendency of the flanges 46 to frictionally engage the abstract lifter rods on tipping of the guide means 34, from a hori- Zontal position from end to end, it is obvious that the hinges or arms 5| may be eliminated so far as any support they might furnish for the rail 3B is concerned, and the abstracts pivotally moved rearwardly adjacent the remainder of the piano action by a direct manual movement of the rail 33 to be latched as previously described.

The rail 38 in its supported position on the keybed 35 thus provides a mounting for the guiding members'46 and a rest support for the keys 26, and when removed from the key supporting means serves as a rest rail for the abstracts 2|, the rail on its removal from the keybed being adapted to concurrently and pivotally move all of the abstracts toward the action and into a rest position adjacent thereto.

,Low upright pianos are usually manufactured in three or four different stock sizes. Application of the piano action and abstract guide means of this invention to all of these sizes is readily accomplished by substituting in the action abstracts having lifter rods 21 of diierent lengths. inasmuch as one of the most important advantages of a low upright piano is its low cost, it is desirable that the elements of the action and its associated parts be standardized whenever possible. Since the guide means 34 is engageable with the abstracts only at the lifter rod 21, and since this engagement may be made along the length of the abstract between the abstract head 23 and the foot portion I9 which will remain the same irrespective of the length of the abstract, the same guide means may be used in any of the low uprights of stock size.

A modification of the guide means is illustrated in a fragmentary manner in Fig. 6. A rail E6 common to all of the abstracts in the same manner as the rail 38 is removably mounted at the rear end of the key bed 36 and a key frame 51, so that the top portion thereof corresponds in position exactly with the position of the top or the portion 4l for the rail 38. The flanges :i5 are rigidly secured to the top of the rail 56 exactly in the manner previously described with reference to the rail 38. A rest rail 58 for the rear ends of the keys is rigidly secured to the top of the key frame 51, and a bushing 43 of suitable material is mounted on top of the rail 58.

The rails 56 and 58 are not of integral construction, and the rail 56 is secured to the key supporting means by means of brackets 59 provided across the entire action at the breaks between the sets of keys where they are pointed in dif- I:

ferent directions in the customary manner. The body 21 of each abstract rides in a bushed aperture 6B in each flange in the same manner as previously described.

The abstracts and keys are connected and disconnected in substantially the same manner as discussed above, except that the rail 56 is now disconnected from the key bed 36 or connected thereto, by means of the brackets 59 fitting over the key rest rail and frame as shown in Fig. 6. Screws Si at the rear of the brackets rigidly secure the bracket to the key supporting means. It is understood that the abstract and key constructions for the modication of Fig. 6 are identical with those illustrated in Figs, 1 to 5.

Although only the preferred embodiments of the invention have been illustrated and described herein, it is to be understood that modications and alterations therein can be made which are within the full intended scope of this invention as dened by the appended claims.

claim:

l. In piano mechanism for a piano having keys and key supporting means, the combination of a plurality of abstracts operatively connected with the keys, each of which abstracts is movable in an upright direction when operated for playing, and means for guiding the playing .movement of said abstracts, including a rail member supported on said key supporting means extending transversely of said abstracts and positioned forwardly thereof, said rail member having a shoulder portion projecting rearwardly of said key supporting means, and a stationary guide member individual to each of said abstracts mounted at one end on said shoulder portion and operatively connected at the other end with its corresponding abstract, each of said guide members having an aperture at the other end thereof receiving therein a portion of its corresponding abstract intermediate the top and the bottom thereof, with said guide means being positioned entirely below the point of connection of said abstracts and said keys.

2. In piano mechanism for a piano having key supporting means, the combination of an action including a plurality of abstracts, with each of said abstracts being operatively connected at one end to said action and free of the action at its other end, and operated for playing in a substantially upright direction, means for guiding the playing movement of said abstracts including a rail member common to said abstracts and arranged forwardly and transversely thereof, said rail member being removably mounted on said key supporting means near the rear end thereof, and an apertured guiding arm for each of said abstracts connected to said rail member and having the aperture thereof in guiding connection with a corresponding abstract intermediate the ends of said abstract, said guiding means on removal of the rail member from said key supporting means being movable with said abstracts to move said abstracts simultaneously to a rest position substantially within the confines of said action.

3. In piano mechanism for a piano having key supporting means, the combination of an action including a plurality of pivotally mounted whips, a plurality of abstracts having upper and lower ends, axis means pivotally connecting each abstract at its lower end to a corresponding whip, means for guiding the abstracts in their playing movement positioned entirely below the upper ends of said abstracts, rail means removably supported on said key supporting means forwardly of the abstracts and common to all of said abstracts, and a plurality of stationary guide anges on said rail means, with a ange individual to each abstract, each flange having an end extending toward its corresponding abstract and an opening at said end for slidably receiving therein a portion of the abstract intermediate the upper and lower ends thereof, with said rail means being removable from said key supporting means and carrying all of said abstracts therewith to a rest position spaced from said key supporting means.

4. The combination with a piano action for a piano having keys and key frame means, said action including an abstract for each of said keys having a foot portion pivotally connected into said action and a head portion free of the action, with a lifter rod portion connecting said two portions together in relatively fixed positions, of means for guiding the playing movement of said abstracts positioned entirely below said head portions and forwardly of said abstracts so that the space intermediate said head portions and the remainder of said action is entirely open, said guiding means including a rail member common to said abstracts and arranged transversely thereof, said rail member being removably mounted on said key frame means at the rear end thereof and having a shoulder portion cxtending rearwardly beyond said key frame means, and a stationary guiding arm for each of said abstracts supported on said shoulder portion having an opening at one end thereof in guiding connection with the lifter rod portion of a corresponding abstract intermediate said head and foot portions, said guiding means on removal of the rail member from said key frame means being movable with said abstracts to pivotally move all of said abstracts at one time to a rest position adjacent the remainder of said action, and means for retaining said abstracts in said rest position.

5.' In piano mechanism for a piano having key supporting means and a plurality of keys with a capstan mounted near the rear end of each of said keys, the combination of an action including a plurality of pivoted abstracts corresponding in number to said keys, with each of said abstracts including a foot portion pivotally connected to said action and a head portion free of said action and extending over the rear end of a corresponding key for operative engagement with a corresponding capstan, said two portions being connected together by a lifter rod portion arranged therebetween and movable in an upright direction when the abstract is operated for playing, means guidably supporting said lifter rod portions for guiding the operating movement of said abstracts, said guiding means being located forwardly of said abstracts and entirely below said head portions and including a rail member removably supported on said key supporting means and arranged transversely of said abstracts, said rail member having one portion thereof supported on the top of said key supporting means and another portion extending downwardly from said one portion and engaging the rear end of said key supporting means, and a guide member for each of said abstracts mounted on said other portion and having an end thereof projecting rearwardly from said other portion for guiding cononection with a corresponding lifter rod portion, said guiding means on disconnection of said rail member from said key supporting means being movable with said abstracts to p-ivotally move said abstracts out of engagement with said capstans and to a rest position within the connes of said action.

6. In piano mechanism for a piano having keys and key frame means, the combination of an action movable as a single unit in and out of the piano including a plurality of abstracts, each of said abstracts being operatively connected at one end in to said action, with the other end in operative engagement with a corresponding key and entirely free of said action, an abstract rest rail member arranged forwardly of said abstracts and extending transversely thereof, said rail being removably supported on said key frame means near the rear end thereof, and a guide member on said rail member, with one of said members having a projection thereon and the other member having a corresponding portion fitting over the projection to position them relatively, additional guide members on said rail member with all of said guide members operatively connected with corresponding abstracts for guiding the playing movement of each of said abstracts, with said rest rail and guiding members on removal of said rail member from said key frame means being movable with said abstracts to move the abstracts to a rest position adjacent said action, and said entire action including said rail member being transportable as a unit.

7. In a piano action including a plurality of pivoted whips for a piano having key frame means and keys, and a capstan portion at the rear end of each of said keys, the combination of an abstract operatively associated with a corresponding whip and key having a lower end and a head portion, axis means pivotally connecting said lower end with a corresponding whip, said head portion being free of the remainder of the action and extending over the rear end of a corresponding key and directly above a capstan portion, and stationary means located entirely belowsaid head portions having a plurality of openings corresponding in number to said abstracts with an opening guidably supporting an abstract in the playing movement thereof, means for mounting said stationary means on said key `frame means near the rear end thereof, each of said .capstan portions being operatively engageable with the lower side of a corresponding head portion when the abstracts are in a playing position, with said lower side having a bevelled contourI such that the capstan portion and head portion are readily connectible incident to movement of one of said portions to an assembled position relative to the other in the piano.

8. An abstract for a piano action having opposite end portions, one of said portions having a groove formed in one end thereof extending in a direction up and down of said action and a cavity in one side thereof in alignment with said groove in a direction from front to back of said action, and a body member connected at each end to one of said end portions, said body member being of hooked shape at one of its ends, with the free end of said hook shaped end inserted in the cavity of said one portion and with the side opposite the free end engaged within said groove to retain said one end `portion in a xed position relative to said other end portion.

9. An abstract for a piano action having opposite end portions, one of said portions having a groove formed in one end thereof in a `direction up and down of said piano action, and a body member connected at each end to one of said end portions, said member being of hooked shape at one of its ends, with the end of said hook shaped end driven in said one end portion so as to be in alignment with said groove in a direction from front to back of said piano action and the side opposite said free end being engaged within said groove to retain said one end portion in a fixed position relative to said other end portion.

10. In piano mechanism for a piano having key frame means, with said mechanism including an action having a plurality of abstracts movable in a substantially upright direction when operated for playing, the combination of means for guiding the playing movement of said abstracts including a rail member common to all of said abstracts, said rail member being supported on a rear end portion of said key frame means forwardly of said abstracts, and having a shoulder formed along the bottom at the forward side thereof engaging a corresponding shoulder on said rear end portion, and stationary flange members supported on the top of said rail member, with a flange member being individual to each of said abstracts and having an end thereof extending rearwardly from said rail member for slidable connection with a corresponding abstract to guide the playing movement thereof.

11. In piano mechanism for a piano having key frame means, the combination of an action having a plurality of pivoted abstracts movable in a substantially upright direction when operated for playing, means for guiding the playing movement of said abstracts including a pair of rail members common to all of said abstracts and arranged forwardly of said abstracts, one of said rail members being mounted on said key frame means near the rear end thereof, means removably supporting the other rail member on said key frame means in a predetermined position relative to said one rail member, and stato one end of the Wire lifter having side faces with a groove therein opening from one of said faces and extending in said face in the direction n of the Wire lifter when it is secured to said end member, and said end member having an aperture therein, with said Wire lifter having a hook portion on the secured end projecting into the aperture of the end member and frctionally secured therein, and having a second portion disj'c posed in said groove in said end member.

JULIAN C. POTWIN.

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