US3012459A

US3012459A - Drop action

Info

Publication number: US3012459A
Application number: US683345A
Authority: US
Inventors: Orville T Wood; Jr Julius E Underwood
Original assignee: PRATT READ AND CO Inc
Current assignee: PRATT READ AND CO Inc
Priority date: 1957-09-11
Filing date: 1957-09-11
Publication date: 1961-12-12
Anticipated expiration: 1978-12-12

Description

Dec. 12, 1961 o. T. WOOD ET AL DROP ACTION 2 Sheets-Sheet 1 Filed Sept. 11, 1957 wgwmw uwwr 1 INVENTOR o 077/12162 ll/oad Q 5 JzLZL'usEUnder wit/F; s M 1 45 Dec. 12, 1961 o. T. WOOD ETAL DROP ACTION 2 Sheets-Sheet 2 Filed Sept. 11, 1957 3,012,459 DROP ACTION Orville T. Wood and Julius E. Underwood, Jr., Essex, Coun., assignc-rs to Pratt, Read & Co., Incorporated, Ivoryton, ComL, a corporation of Connecticut Filed Sept. 11, 1957, Ser. No. 683,345 2 Claims. (Cl. 84-240) This invention relates to a piano action and more particularly to an action of the drop-type for low upright pianos.

It is desired that the elements of a piano action be arranged so that when assembling the piano during the manufacturing stage and when servicing the piano throughout its useful life, the various parts are easily accessible. Many of the actions previously used in low upright pianos do not satisfy this standard. These actions are of the drop-type and have an abstract member which is connected between the rear of the key and the whippen for transmitting movement of the key to the action. The abstract has commonly been pivotally mounted on the whippen and detachably connected to the key. Consequently, the abstract has been freely swingable when not connected to the key, and during assembly and servicing operations, these freely swingable abstracts fall forward into the key zone thus interfering with operations on the action. Although guiding elements have been included in some piano actions to prevent the abstracts from falling forward, these do not completely solve the assembly and servicing problems because the abstracts are retained in a position where they obstruct the operation. Furthermore, the guiding structure itself has been somewhat complicated and expensive.

Accordingly, an object of this invention is to facilitate the assembly and servicing operations associated with low upright pianos by providing a drop-type piano action with an improved abstract.

Another object of'the invention is to provide an improved abstract guiding structure for a drop-type piano action, with the guiding structure being laterally adjustable to withdraw and retain all the abstracts in a position where they are out of the Way during assembly and servicing operations.

A further object of the invention is to provide improved abstract and guiding elements for a drop action in which all of the abstracts may be retained in a rearward position and in which the individual abstracts may be readily disconnected and removed from the piano.

A still further object of the invention is to provide improved abstract and guiding means for a piano action which may be economically manufactured and readily assembled into actions having ditferent dimensions.

A feature of the invention is the provision of an improved drop action with an abstract guiding structure so that the abstracts are supported in a first position by the guiding structure during operation of the piano, and the abstracts are movable to a second position by adjusting the guiding structure.

Another feature of the invention is the provision of an improved drop-type piano action for a low upright piano, including an abstract guide rail supported by laterally adjustable supporting arms and which retains associated abstract members in a first position for playing the piano and in a second position for facilitating assembly and servicing operations. The adjustability of the supporting arms may be provided by a slotted connection or a pivotal linkage.

A further feature of the invention is the provision of improved guiding structure for the abstracts of a drop action, the guiding structure including an elongated strip of relatively stiif resilient material which is supported States Patent G along its length by a pair of elongated tubular ferrules, with the material having openings to receive portions of the abstracts.

Referring now to the drawings:

FIG. 1 is a view, partly in section, of a piano action and key assembly showing in particular an abstract guiding structure in accordance with the invention;

FIG. 2 is an enlarged exploded view showing in detail the guiding structure of FIG. 1;

FIG. 3 is an enlarged detail view which illustrates the manner of connecting the abstract to the whip as used in the action of FIG. 1;

FIG. 4 is an enlarged detail view of a modified form of guide rail supporting structure;

FIG. 5 is a view, partly in section, of another embodiment of the invention; and

FIG. 6 is a view, partly in section, showing a piano action provided with a modified form of the rail supporting arm of FIG. 5.

In practicing the invention there is provided a piano of the low upright type having a piano action including hammers, whips, and associated structure of substantially standard construction. Abstract members of an elongated shape are pivotally connected to the whip, and stand in substantially upright position. Each abstract includes a head portion which extends over the rear end of a key and is engaged by the key for transmitting movement of the key to the whip. Each abstract has an elongated pin extending axially therefrom. A guide rail is provided which is adjustably mounted on rail supporting arms connected to the action bracket. The guide rail includes elongated ferrules holding a strip with a series of apertures therein which receive the pins on the abstracts. The apertures are of a size to permit the pins to slide axially without binding. The rail supporting arm is adjustably connected to the action bracket by a clamping device or a pivotal linkage so that upon disconnecting the abstracts from the keys, they may be moved to a rearward position where they will be out of the way. The abstracts may be provided with a slot at the point where they are connected to the whips so they may be individually disconnected from the whips and readily moved from the piano.

A single action unit, one of several in the complete action for a piano, is illustrated in FIG. 1 along with a key and supporting structure for the keyboard. A key 10 in the complete keyboard is mounted in the usual manner upon a keybed or frame 11 shown in section.

When the key is depressed, its movement is transmitted to an action including a hammer 16 which strikes the string 17 of the piano. The movement is applied to the harm mer by fiyjack 15 which is pivotally supported on whip 13 which in turn is pivotally mounted on the action rail 14 shown in section. Additional conventional supporting rails 14a and 14!; are provided, and these are also shown in section. The abstract 18 directly transmits movement of the key to the action, being pivotally connected to the whip 13 at point 20, and including a body portion 21 extending upwardly to a point above the level of the key 10. The body portion may be of wood and may have a wooden head 22 secured thereto at the upper end thereof. Alternatively the body and mounting portions may be a metal rod, preferably of aluminum, and a wooden head member may be connected thereto. A lip portion 24 of the head member 22 extends over the rear end of the key 10.

. A screw 25, which may be a standard capstan, is threadably connected to the rear end of the piano key and extends upwardly from the key to abut against a felt pad 26 which is secured to the lip portion 24 in alignment with the screw. The arcuate head of screw 25 facilitates a slight rocking action at the pad '26 when the key is 3 pivoted and the abstract lifted in normal playing operation. Relative alignment between the felt pad 26 and the screw is maintained during the playing operation by the guide rail 28 which is connected to a mounting arm 29 supported by an extension of theaction bracket 12.

The guiding structure of this embodiment of the invention is illustrated in detail in FIG. 2. The guide rail comprises an elongated strip 31 with a length equal to that of the piano action and composed of felt or other material having a sufiiciently great density to be relatively stiff and yet sufiiciently resilient to act as a bushing material. The strip should be of sufiicient crosssection to provide inherent rigidity, and it has been found that a heavy felt strip .100 inch thick by .75 inch wide possesses the desired properties. Alternatively, silicone rubber or the material marketed under the trademark Teflon may be used as the material for the strip. The strip 31 is provided with a plurality of holes 32 extending through its thickness, each of which receives a pin 34 which is carried by the head. member 24 of the abstract 18. The "guide pin 34 is preferably made of metal and has a circular cross-section along its length and is upset to form a head portion 35 of a slightly larger diameter at the end remote from the head member 24. Each hole 32 has a .diameter greater than the body of guide pin 34 but smaller than the head portion 35 so that the head portion will restrain the abstract 18 from falling when it is detached from the whip 13. Since the strip 31 is resilient, however, and since the head end 35 is only slightly larger than holes 32, an abstract which has been detached from the whip may be removed from the action by forcing the head portion through-the hole. During operation of the piano, the abstracts 18 are loosely guided by the edges of the strip at the holes 32 which surround the pins and prevent lateral deviation in their movement.

A pair of elongated ferrules of a length equal to that of strip 31 and having a c-shaped cross-section are slipped over the opposite longitudinal edges of the strip and then crimped tight to grip the strip. The ferrules may be of metal, plastic or other material which will support the strip so that it will not bend along its length. The strip is so constructed that its inherent stiffness will prevent bending across its width. The rail supporting arm 29 has a channel shape, and the parallel channel walls include a mounting portion 36 which is shaped to conform to the upper surface'of the guide rail 28. The rail supporting arm is also provided with a lip portion 37 with a hole therein which is adapted to receive a screw 39 which may be of a self-tapping type. A rail clamp 48, which conforms to the shape of the lower surface of the guide rail, is also provided with a hole 41 to receive screw 39 so that the rail clamp may be drawn tightly against the guide rail to hold the latter firmly against the rail supporting arm 29. The strip 31 has a hole 42 through which screw 39 extends, and this hole has an elongated shape to permit slight longitudinal adjustment of guide rail 28 when aligning holes 32 with pins 34.

The end of the rail supporting arm 29 remote from the guide rail is attached to bracket 12. A threaded stud 44 may be permanently afiixed to the bracket with a portion extending upwardly. An elongated slot 46 is provided in the rail supporting arm 29 so that the arm will rest on the bracket with stud 44 passing through the slot 46. A knurled nut 45 may be screwed onto the stud to hold the guide arm securely in position. 'The position of the rail supporting arm, and therefore the position of the abstracts, may be changed by loosening nut 45 and sliding the arm along the bracket between the limits determined by the length of slot 46. In this manner, all of the abstracts may be moved from their forward operating position to a rearward position. The abstracts may be retained in the rearward position during assembly, disassembly, and repair and adjusting operations whenever desired by carrying out the very simple adjusting steps described above.

The abstract 18 may be constructed as illustrated in FIG. 1 and FIG. 3. In this form, the abstract 18 is an elongated, substantially flat member, preferably made of metal such as aluminum. The abstract 18 may be readily connected to a head member with pins as previously described. The whip 13, to which abstract 18 is pivotally connected, is provided with a slot 47 at the end intermediate its parallel vertical surfaces and extending longitudinally. A pin 20 extends through the whip transversely of its lengthand bridges the two end portions 48 across the slot. The abstract18 is provided with a cavity 19 which extends diagonally of its length from the edge 51 to the center line 52. The cavity is enlarged somewhat at the center line to form a seat for the pin '20. The pin is wnapped with a bushings? of felt or other suitable material so that it fits snugly in'the enlarged portion 54 of the cavity 19. The narrower portion of the cavity is of a size which will compress the bushing and allow passage ofthe pin when the abstract is drawn down and away from the whip. Thus, the abstract may be readily connected to or disconnected from the whip.

Abstracts of difierent lengths may be required in different piano actions and the arm 29 need be modified only slightly to accommodate longer or shorter abstracts. A modified form of the invention is illustrated in FIG. 4 where the abstract is shorter than the abstract 18 of FIG. 1. Rail supporting arm 66 of FIG. 4 is a stepdown construction having a vertically extending portion 50 which may be made of various lengths depending upon the length of the abstract.

Another embodiment of the invention is illustrated in FIG. 5. The rail supporting arm 55 in this embodiment is preferably made of wood and is pivotally connected to bracket 70 at a point 56. The point 56 is located below the key 71 and near point 72 so that the guide arm 55 extends upwardly in a substantially parallel relation with the abstract73 to a point above the head element 74 of the abstract. An angle member 62 is attached to the end portion 57 of the arm 55. The upper leg of the angle member 62 contacts the lower surface of the ferrules 75 of the guide rail 63 which receives the pins 78 connected to the head 74 of the abstract 73. The upper leg of the angle member 62 is provided with a hole to receive a screw 76 which may be self-tapping. The rail clamp 77, which is constructed as shown in FIGS. 1 and 2, is seated on the upper surface of the guide rail 63 and holds the same against the angle member 62 when screw 76 is tightened.

Linkage 60 is pivotally connected to bracket 70 at .point 58 and is likewise pivotally connected to the rail supporting arm 55 at point 61. Linkage 60 comprises a pair of arms 84 and 81 pivotally connected together at their ends. The

arms

80 and 81 are held extended by the weight of the rail supporting arms and abstract members, and pivotal movement of the

linkage arms

80 and 81 in relation to one another islim-ited in the downward direction by the ear 59 which is an integral part of member 81 and extends over an edge of the member 82. The linkage members are free to pivot upwardly, however, so that as illustrated in FIG. 6 by the dotted lines, the guide arm, the guide rail 63 and all of the abstracts 73 .may be withdrawn to a rearward position. They are retained in this position by their own weight which then is distributed predominately on the rearward side of pivot points 72 and 56. I

It is apparent from a comparison of FIGS. 5 and 6 that this embodiment of the invention particularly lends itself to use with abstracts of different lengths. The length of rail supporting arm 55, which is a simple wooden stick, is merely changed as illustrated where the arm of FIG. 6 is shorter than. the arm of 'FIG. 5. This simple modification greatly extends the range of applica tion of the invention without adding burdensome manufacturing costs. 1

The action of the invention is improved in that manufactu'ring and servicing operations may be carried out Without interference from the abstract. All of the abstracts, one for each key, may be simultaneously withdrawn from their playing position. Adjustments may then be made to regulate the relative position of the abstract and key, and the adjustment operation will not be interrupted by falling abstracts nor hampered by the limited access avaialble in prior actions. Individual abstracts may be completely Withdrawn and replaced in a simple manner in which the abstract may be detached from the whippen and withdrawn from the guide rail. The improved guide rail is of a simple construction which is readily and inexpensively manufactured and which at the same time gives satisfactory guiding results. The rail supporting arm may be modified at low cost to accommodate abstracts having different lengths.

What is claimed is:

1. In a piano action including bracket means for supporting the same in a piano rearward of the keys, the combination of a pivotally mounted abstract member having a guiding portion, a guide rail structure comprising a pair of elongated tubular members having a longitudinal slot therein and an elongated substantially flat strip of resilient relatively .stifi material having a hole therein with the edge at the hole receiving and surrounding said guiding portion of said abstract member, said strip being supported along the longitudinal edges thereof by said tubular members, and rail supporting arms means movably mounted on the bracket means and secured to said tubular members for connecting said guide rail structure to said bracket means, said rail supporting arm means having means for holding said guide rail structure and abstract member in a first position where said abstract member engages one ofthe piano keys for transmitting movement thereof into the action and in a second position rearward of the keys.

2. A guide rail structure for use in a piano action, said structure including a pair of elongated tubular members having a longitudinal slot therein forming substantially parallel longitudinal edges, and an elongated substantially fiat strip of resilient relatively stiff material having openings therein extending transversely of the length thereof, said strip being supported along its longtudioal edges by the longitudinal edges of said tubular members.

References Cited in the file of this patent UNITED STATES PATENTS