US3076371A

US3076371A - Keyfork arrangement

Info

Publication number: US3076371A
Application number: US118341A
Authority: US
Inventors: Clifford W Andersen
Original assignee: Wurlitzer Co
Current assignee: Wurlitzer Co
Priority date: 1961-06-20
Filing date: 1961-06-20
Publication date: 1963-02-05
Anticipated expiration: 1980-02-05

Description

Feb. 5, 1963 c. w. ANDERSEN KEYFORK ARRANGEMENT Filed June 2o. 1961 lll!! 3a-29@ w; @Z2/22270 @-w/ MMM@ 5% United States Filed June 20, 1961, Ser. No. 118,341 6 Claims. (Cl. Sli-240) rthis invention relates generally to pianos and more particularly to arrangements for connecting a piano action to its operating key.

In the past, individual piano actions .have been connected to their respective operating keys in compliance with a variety of schemes. The connections in droptype actions have been commonly made, for example, by providing a lbore in the rear of the key. After the 'free end of a lifter rod has been passed through this bore, a nut or similar element is secured to the end of the rod over the top of the key. More recently, this scheme has been supplanted by assembling a fork to the end of a key and by securing a rubber gromrnet to the end of the lifter rod, the rod being releasably secured to the key by inserting the grommet in a keyhole-shaped notch opening from the end of the fork. This arrangement, while affording a certain facility in assembly and disassembly of the lifter rod and'the key, has proved susceptible of incurring objectionable play or looseness in the voverall connection. l

Therefore, an important object of the present invention is to provide an arrangement which positively interconnects a piano actionlift'er rod and its operating key.

A more general object of the invention is to provide a new and improved connection for a piano action and its operating key lever.

Another object of the invention is to provide a keyfork arrangement that ensures positive transmission of key lever motion to a cooperating piano action.

Additional objects and features of the invention pertain to the particular structure and arrangements whereby the above objects are attained.

atent A structure in accord with the invention includes a 'l key lever arrangedrfor rockable movement; an endwise reciprocable link having a grip-assisting formation adjacent one end; a connecting element on the `link adjacent the rear end of lthe key lever, the connecting element having a constricted portion situated transversely of the link in radial alignment with a portion of the grip-assisting formation;` a-fork rigid with and projecting 4rearwardly from the key lever including tines spaced apart to define a stright-sided slot for receiving the constricted portion of the connecting element, the' tines compressing the constricted portion into gripping engagement with the grip-assisting formation; and tip means on each of the tines for restraining the connecting element against movement in the plane of the fork in a direction away from the end of the key lever.

The invention, both to its structure and mode of operation, Will be better understood by reference to the following disclosure and drawing forming la part thereof, where- 1n:

FIG. l is a perspective view of a keyfork arrangement constructed in accordance with the invention;

FIG. 2 is an enlarged plan view of a keyfork blank shown prior to ultimate formation of the tips of the tines;

FIG. 3 is a view of the keyfork of FIG. 2 after completion and showing the keyfork receiving and retaining a connecting, nubber grommet;

FIG. 4 is a front elevational view of FIG. 3; and

FIG. 5 is an enlarged view taken through the section 5-5 of FIG. 3.

of the arrangement 3,076,371 Patented Feb. 5, 1.963

Referring now in detail to the drawing, especially to FIG. l, a keyfork indicated generally by the numeral it) will be seen rigidly mounted to the rear end of a conventional piano key lever 12. The keyfork it) includes a tongue portion 14 which is driven directly into the end of the key lever 12, preferably at a slight angle, the tongue 14 being advantageously coated with rosin in order to achieve better attachment.

In accordance With conventional practice, the piano key lever 12 is arranged for rockable movement by being fulcrumed on a balance rail pin to pivot about a balance rail. In further accord with conventional practice, manual depression of the outer end of key lever 12 is arranged to result in the striking of a corresponding piano string through a piano action; and in order to receive the key lever motion, the piano action includes an abstract, sticker or lifter rod 16. The abstract 16 is pivotally connected to the operating elements of the piano action at one end and is coupled to the piano key lever 12 at the other end by means of the keyfork 10 and a connecting element 18 taking the form of a rubber grommet.

The abstract 16 includes a wooden rod 2i) and a Screw element 22 which threadedly engages the free end of rod 2i). The element 22 comprises a threaded tip 24 for entering an axial hole bored in the rod 2o or for direct, progressive engagement With the rod. Screw element 22 is also provided with a slotted head 26 and a grip-assisting formation 28. In accordance with an important feature of the invention, the formation 2S takes the form 'f of a diamond-patterned knurl extending an appreciable distance along the shank of element 22 and into close proximity with the head 26. A portion of the formation 28 is particularly disposed in radial alignment with a central, constricted portion of the element 18, which constricted portion defines an endless circumferential groove 30.

' As is shown in FIGS. 2 and 3, the keyfork 10 includes a pair of tines 32 which are spaced apart in parallel relationship to define a straight-sided slot 33 for receiving the element 18 at the groove 30 thereof. The connecting element 18 is advantageously fashioned from a suitable, tough, elastomeric material; and when the element 1S is so fabricated, the tines 32 can be spaced apart by a distance somewhat less than the normal root diameter ofthe groove 30. So arranged, the tines 32 compress the constricted` portion of the connecting element into gripping engagement with the formation 28 which is disposed in the central vertical bore of the connecting element in radial alignment with the circumferential groove 30. This arrangement eectively restrains the connecting eiement against longitudinal movement relative the abstract 16 for positively transmitting key lever motion to the piano action. While the head 26 cooperates in this function, the principal purpose of the head 26 in the present arrangement is to provide means for readily regulating the position of the connecting element 18 relative to the free end of the wooden rod 2o.

Returning to FIG. 2, the straight-sided slot 33 will be seen fashioned with a curved bottom or end 34; and this end 34 is adapted to mesh with the oor of groove 30 for restraining the connecting element 18 against move- Iment in the plane of the keyfork in a direction toward the end of the key lever 12. In compliance with an important feature of the invention, means are also provided for restraining movement of the connecting element in the opposite direction. Specifically, the tines 32 are provided with enlarged tip portions 36 which are right angularly formed as is shown in FIG. 3. Thus, the tines are provided with tips of greater dimension transversely of the principal plane of the keyfork than either the body of the tines or the constricted portion of the connecting element.

In assembling the connecting element 1S to the keyfork, the resilient nature of the materialfrom which the element is fabricated permitsdistortion of the sidewalls f ,groove 30 a1lowins passage 0f the enlarged tips 36- In the course of normal use, forces Sufficient to distort the connecting element 18 are not encountered. Aocordingly, the right angularly for-med tips 36 restrain the connecting element 18 against movement in the plane of the keyfork in a direction away from the end of the key lever 12. Positive transmission of key lever motion to the cooperating piano action is thus ensured.

It is to be recognized that the keyfork 1) is provided with two planes of substantial symmetry. One plane y of actual symmetry bisects the slot 33 at right angles to the plane lof tongue 14, and one plane of substantial symmetry is disposed generally coplanarly with the tongue 14 and the principal portions of the ktines 32.. This symmetrical arrangement of the keyfork 10 facilitates handling of numbers of thekeyforks in assembly and precludes the problem of properly orienting each keyfork in automatic feed equipment.

The tip portions 36 are fashioned withflattened ends 38 as shown in PIG. 2. The fairly considerable surfaces aiforded by these flattened ends provides purchase for facilitating the driving of the keyfork into the end of the piano key lever.

While a particular embodimentof the. invention has been showr1, it is to` be understood, of course, that the invention is not limited thereto since many modica.- tions may be made. It is, therefore, contemplated to cover by the appended claims any such modifications as fall within the tnue spirit and scope ,of the; invention.

The invention` is claimed as follows:

1. In a piano,y the combination comprising: a key lever arranged for rockable movement;` an endwise reciprocable link having a grip-assisting formation adjacent one end; a connecting element on said link adjacent the rear endof said key lever, said element having a constricted. portion situated; transverselyy of. said link inradial alignment with a. portion ofsaid formationaal fork` rigid: with*I and projecting rearwardly from said .key leverincluding tines spaced apart to receive said constricted portion, said tines compressing; said constricted portion into` gripping engagement with said' formation; and tip means onveach of said, tines for .restraining'said element against move ment inthe. planeof saldi forkr in.` a ldirection away from said key lever.

2. In a piano, the:combinationvaccordingto claim l wherein saidv grip-assisting formation comprises afdiamondfpatterned knurl.v

3.- Ina piano, thecombination comprising: a key lever arranged for rockablev movement; anendwise reciprocable linkhaving a gripfassisting formation adjacent one end; a connecting Yclement of tough,- elastomeric material on; said link adjacent: theirear end of said key lever, said element having a constricted portion situated transversely of said link in radial alignment with a portion of said formation; a fork rigid with and projecting rearwardly from said key lever including tines spaced apart to define a straight-*sided slot for receiving said constricted portion, said tines compressing said constricted portion intogripping engagement with said formation; and tip means on each of said tines of greater dimension transversely of the principal plane of said .fork than either said tines or said constricted portion for restraining said element against movement in the plane of said fork in a direction away Yfrom the end of -said key lever.

4. In a piano, the combination comprising; a key lever arranged for rockable movement; an endwise reciprocable link having a grip-assisting formation adjacent one end; a connecting element of tough, elastomeric material on said link adjacent the rear Yend of said key lever, said element having a constricted portion defining an endless circumferential groove situated Atransversely of said link in radial alignment with a portion of said formation; and a .fork rigid with .and projecting rearwardly from said key lever including tines spaced apart to deline a straightsided slot for coupling to said element at lsaid groove, said tines compressing said constricted portion into gripping engagement with said formation, said tines having right angularly rformed tipportions extending beyond said element and havinggreater height than the width of said groove for restraining said connecting element against movement in the plane of saidgroovein ak direction away from the end of said key lever;

5. In a piano, the combination according to claim# wherein said grip-assisting formation. comprisesr al diamond-patterned knurl.

6. `In a piano, the combination comprising: a` key lever arranged for rockable movement;` an endwise reciprocable. link having a grip-assisting formation adjacent one end; a connecting element on saidlinkadjacent the rear end of said key lever, said element having a constricted portion situated transversely of said link in` radial alignment with a portion of said formation; and .a fork rigid with and projecting rearwardly from said key lever including tines spaced apart to receive-saidV constricted portion, said tines compressing vsaid constrictedv portion into gripping engagement with said formation.

ReerencesCited in the tile of `this patent- UNtTEDl STATES PATENTS FOREIGN PATENTS i 354,778 VGreat `Britain Augl 4, 1931v

Claims

1. IN A PIANO, THE COMBINATION COMPRISING: A KEY LEVER ARRANGED FOR ROCKABLE MOVEMENT; AN ENDWISE RECIPROCABLE LINK HAVING A GRIP-ASSISTING FORMATION ADJACENT ONE END; A CONNECTING ELEMENT ON SAID LINK ADJACENT THE REAR END OF SAID KEY LEVER, SAID ELEMENT HAVING A CONSTRICTED PORTION SITUATED TRANSVERSELY OF SAID LINK IN RADIAL ALIGNMENT WITH A PORTION OF SAID FORMATION; A FORK RIGID WITH AND PROJECTING REARWARDLY FROM SAID KEY LEVER INCLUDING TINES SPACED APART TO RECEIVE SAID CONSTRICTED PORTION, SAID TINES COMPRESSING SAID CONSTRICTED PORTION INTO GRIPPING ENGAGEMENT WITH SAID FORMATION; AND TIP MEANS ON EACH OF SAID TINES FOR RESTRAINING SAID ELEMENT AGAINST MOVEMENT IN THE PLANE OF SAID FORK IN A DIRECTION AWAY FROM SAID KEY LEVER.