US2247710A - Mechanism for pianos - Google Patents

Description

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MECHANISM FOR PIANOS Filed Dec. 13, 1937 I5 F'|c.1

I NVENTO RS Patented July I, 1941 MECHANISM FOR PIANOS Arthur H. Morse, Cincinnati, Ohio, and Charles Pieper, South Fort Mitchell, Ky., assignors to The Baldwin Company, Cincinnati, Ohio Application December 13, 1937, Serial No. 179,424

6 Claims.

Our invention has reference to upright pianos of the type in which the striking and damping mechanism, usually called the action, is wholly or at least partly below the level of the keyboard. In pianos of this type special means must be employed for connecting the keys to the action. The present invention has reference to an improvement in these means, and more particularly to improvements on the invention disclosed in United States patent application No. 125,771 now pending, filed on February 15, 1937, by Arthur H. Morse, one of the present applicants, for a Piano key and action connection and assigned to The Baldwin Company, the instant assignee.

One of the objects of the present invention is to provide means, in keeping with many of the advantages disclosed in the aforesaid application, whereby a conventional upright piano action bracket may be employed. In attaining this object we effect an economy and standardization, of advantage to a piano manufacturer who makes upright pianos of several types.

Another object is to provide a flexibility in aligning the keys with the action in pianos of the type mentioned, which hitherto could not be attained.

Still another object is to provide a key-to-action connecting link which can be made by manufacturing operations now current in piano action making.

The manner in which these objects are attained, and the attainment of other objects which are within the spirit and scope of the invention, we shall now describe specifically. For clearness, reference is made to the accompanying drawing wherein:

Figure 1 shows a cross-sectional side elevation of the key and action mechanism of a piano employing the invention;

Figure 2 is a perspective view of a wippen, modified to adapt it to the invention;

Figure 3 is a fragmentary perspective view of a guide rail; and

Figure 4 is a perspective view of a guide rail support bracket.

With reference to Figure 1 an upright piano includes a horizontal keybed l on which are supported a series of playing keys such as 2 at the rear end of each of which is attached a vertically extending regulating screw 3, which may be a capstan screw. In the rear of the keybed and keys is a piano action 4, and as the present invention is for pianos of the compressed type the action is partly below the level of the keys. Behind the action is the usual string supporting framework 5, supporting a plurality of tensioned strings such as 6. The action 4 includes for each note an upright hammer l for striking a string 6, of which there may be three per note as is well known to piano makers. The action 4, as

an assembly for all the notes of the piano is an integral unit on rails held together in proper relation by a number of brackets as 8, according to a usual practice of construction. In general, four of the brackets 8 are employed in an upright piano, one at each end of the instrument and two intermediately spaced. The two intermediately spaced brackets are at positions known as breaks, one between the highest pitched bass note and the lowest pitched treble note, the other at a convenient place in the treble section, and at keyboard positions adjacent these breaks are spaces between the rear ends of corresponding keys.

Now it will be noted that according to the organization disclosed in Figure 1, the bracket 8 may be an ordinary, conventional upright piano action bracket (devoid'of special extension elements), held at the top to the piano framework by a usual bracket bolt 9 and supported at the usual place in the bottom by a vertically extending socket screw I0.

In conventional upright pianos the screw It would be attached to a keybed; but in our construction, because of the nature of the instrument with which the invention is concerned, it rises from a cantilever bracket H, attached to the underside of the keybed to extend downwardly-rearwardly therefrom to the screw H1. The screw [0, operable on a thread in the bracket H, is adjustable in height to align the action vertically, and to accommodate this alignment the top of bracket 8 has a vertical slot in which the bolt 9 is placed. A look nut is provided for the screw l 0.

At the bottom of the action is a forwardly extending wippen l2 for each note, rearwardly pivoted as shown and located below the keyboard level. The wippen is the prime motivating lever of the action and the particular means employed for connecting it to the corresponding key is a member l3 extending nearly vertically between the key 2 and the action 4. This member l3 has near its top a forwardly extending shelf M to be impelled by the key through the capstan screw 3, and at its bottom has a rearwardly extending arm l5 whereby it is pivotally attached to the wippen, as shown. Pressed into the top of the member I3 is an upwardly extending guide rod l6 which is slidably guided in a rail ll.

The rail I1 is supported on a number of vertically extending L shaped brackets l8 which are attached to the upper side of the piano keybed I at the locations corresponding to the above mentioned breaks, and at each end of the keyboard.

It will be seen that the operation of the mechanism for any one note of the piano to produce a tone consists in manually moving the front end of a key downward, the rear end of the key thus rising and with it the member l3, through the medium of the capstan screw 3 and the projecting shelf [4 which bears against it. The motion of the member I3 is materially guided by the rod l6 operating through the rail [1, and as the member (3 rises its rearwardly projecting lower arm l rotatively lifts the wippen l2, thus operating the action and hammer to strike the strings.

We have given considerable attention to the manner of connecting the arm l5 to the wippen l2 and into the gear of this arm we have out a forwardly extending slot I9 and have driven a transverse pin into the rear part of the arm and across the slot. We have then modified that under part of the wippen which is usually known as the capstan block and have cut into its under surface an Omega shaped slot 2|. It will thus be seen that by this arrangement the member 13 may be securely pivoted to the I wippen l2 for all purposes of operating the piano, by the pivot formed by the pin 20 in the slot 2|; but that if so desired the member l3 may be readily engaged or disengaged from the instrument. in the construction of the piano the action may be first installed in the instrument and the hammers conveniently attached thereto in proper positions. The keys may then be added to the piano, the brackets 18 then installed, the rail I! attached, and finally the members l3 added. The bracket [8 has a unique advantage. For, in the placing of the keys 2 in pianos ordinarily, there may be an occasional inaccuracy such that the rear ends of the keys may not be properly aligned so as to be at an exact position desired. We therefore slot one of the holes 22 for holding the bracket l8 to the keybed, and when the bracket is attached to the bed by means of a wood screw placed through this slot, the position of the bracket can be adjusted forwardly and rearwardly so that the rear ends of the keys and more particularly the capstan screws 3 bear against the members [3 at the proper places. Having done this, the bracket I8 can be securely fastened by means of another screw placed in the forward hole 23 of the bracket.

We find it advantageous to construct the member I3 mostly of wood. Thus its vertical shaft, the shelf I4, and arm l5 we preferably make of maple and have provided a type of joint for uniting these parts comprising a glued mortise and tenon construction at 24 and 25.

For quiet operation and for resiliency the Omega shaped slot 2| is lined with bush cloth 25 and the guide holes 21 in the rail l! are hushed.

It will be seen that many of the advantages disclosed in the above mentioned application No. 125,771, obtain in the present invention. Thus, for instance, conventional keys and action may be employed, conventional regulating screws may be used at the rear ends of the keys and any key may be as easily removed or installed as in a conventional upright piano. In removing the action from the instrument, we find it convenient to unfasten the rail I! and to tie it by cord say to one of the action rails.

Having thus described our invention, we claim:

1. The combination in a piano of a key bed, keys pivoted on said bed, an action located beyond said keys and having wippens located below the level of said keys, means for transmitting the The advantages of this are that motion of said keys to said wippens comprising a series of rod-like members each having thereon a rigid arm rigidly attached thereto and extending over the end of a key, said arms having bearings on said keys at points interspaced from the axes of said rod-like members, connections between said rod-like members and said wippens, brackets attached to said key bed and guide means for said rod-like members attached to said brackets and operating to guide said rod-like members above said keys in their up and down movement.

2. Apparatus as claimed in claim 1, in which said piano has a string frame, brackets for said action, means for connecting said brackets to said string frame, a second set of brackets attached to said key bed and extending downwardly therefrom, and means for supporting said action brackets on said last mentioned brackets.

3. Apparatus as claimed in claim 1 wherein said motion transmitting members are formed of elongated wooden rods, said arms being wooden bars mortised into said rods, said rods having cylindrical metallic members of small diameter projecting upwardly from their upper ends for guiding as aforesaid.

4. Apparatus as claimed in claim 1 wherein said motion transmitting members are formed of elongated wooden rods, said arms being wooden bars mortised into said rods, said rods having cylindrical metallic members of small diameter projecting upwardly from their upper ends for guiding as aforesaid, and in which said members are connected to said wippens by rigid wooden arms mortised to said members and pivotally attached to said wippens.

5. In combination in a. piano, a key bed, keys pivoted thereon, an action located beyond said keys and having wippens located below the level of said keys, means for transmitting the motion of said keys to said wippens, comprising substantially vertically extending members connected to said wippens and extending substantially above said keys, each of said members having a rigid arm rigidly attached thereto, extending over said keys, and having a bearing on said keys at a point interspaced from the axis of said members, means above said keys for guiding the upper ends of said members for up and down motion, and brackets mounted on said key bed for supporting said guiding means on said bed, said brackets having means for adjustment whereby said motion transmitting means as a whole may be adjusted with respect to said keys without disturbing the position of said action.

6. The combination in a piano of a key bed, keys pivoted on said bed, an action located beyond said keys and having wippens located below the level of said keys, means for transmitting the motion of said keys to said wippens comprising a series of rod-like members each having thereon a rigid arm rigidly attached thereto and extending over the end of a key, said arms having bearings on said keys at points interspaced from the axes of said rod-like members, connections between said rod-like members and said wippens, brackets attached to said key bed, and guide means for said rod-like members mounted on said brackets and operating to guide said rod-like members in their up and down movements.

ARTHUR H. MORSE. CHARLES PIEPE'R.

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