US3228277A - Drop type piano action - Google Patents

Description

Jan. 11, 1966 P. J. ROEHRIG DROP TYPE PIANO ACTION Filed Jan. 16, 1959 w i WW O wan m w 11 NM 8 N; @r m W 34. De. L W ,3

United States Patent 3,228,277 DROP TYPE PIANO ACTEON Phillip J. Roehrig, Rockford, Ill., assignor, by meant: as-

signments, to Aurora Corporation of Illinois, Chicago, 111., a corporation of Illinois Filed Jan. 16, 1959, Ser. No. 787,230 6 Claims. (Cl. 84-240) This invention relates to a piano action of the type in which the action proper is dropped well below the level of the keys and the actuating motion of the latter is transmitted through an upright pull link pivotally joined at opposite ends to the rear end of the key lever and the free end of the whip.

The general object of the invention is to greatly reduce the cost of piano actions of the above character through the use of metal parts in the pull link and its connection with the key lever while at the same time avoiding any possibility of metal to metal contact.

Another object is to provide a new and improved connection between the pull link and the key lever of a drop piano action which, as compared to prior constructions, permits the use of a substantially narrower piano case and facilitates the repair of the keys and individual actions in service use.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which FIGURE 1 is a fragmentary side elevational view of a drop type piano action and its actuating key incorporating a pull link embodying the novel features of the present invention.

FIG. 2 is a perspective view of a part of the key.

FIG. 3 is an enlarged fragmentary section taken along the line 33 of FIG. 1.

FIG. 4 is a fragmentary plan view of several keys and their associated pull links.

In the piano action shown in the drawings for purposes of illustration, the improved pull link indicated generally at is arranged to transmit the actuating or upward movement of the rear end of a key 11 to the whip lever 12 of a so-called upright action 14 for throwing a hammer 15 against a piano string 16. The key is fulcrumed in the usual way intermediate its ends on a balance rail 17 and its rear end normally rests on a pad 18 extending along the rear edge of the key bed 19.

The link 10 is straight and composed of two alined parts the lower one of which is a rod 20 preferably composed of wood, The lower end projects into the forked end of the whip and is joined to the latter by a suitable pivot pin 21.

In accordance with the present invention, the upper part of the link comprises a metal screw 22 having an elongated shank 23 and a head 24 thereon coupled in a unique manner to the end of a bar 25 lying along and clamped against the top of the key and projecting a short distance beyond the rear end thereof. The screw is threaded at its lower end 26 and screwed into a hole in the upper end of the rod 20 in axial alinement therewith.

The underside of the head 24 is fiat and abuts against the top of a ring 27 composed of firm but nevertheless somewhat pliable material such as a standard rubber grommet somewhat larger in diameter than the screw head and having a center hole 28 loosely receiving the screw shank 23. Around its periphery the ring is formed with an outwardly opening square bottomed groove 29 disposed intermediate the ends of the ring between axially spaced flanges which define the substantially parallel side walls 30. The groove is of substantial depth, about of an inch in the present instance, and its bottom is somewhat larger in diameter than the head of the screw. (See FIG. 3.)

The bar 25 for coupling the link to the key is a rigid sheet metal stamping substantially equal in thickness to the width of the groove 29 and having a hole 32 punched therein near one end for receiving a screw 33 driven into the top of the key to clamp the bar solidly against the key with the other end of the bar projecting a substantial distance beyond the key end. This other end of the bar is notched at 34 to provide two legs 35 spaced apart a distance slightly less than the diameter of the bottom of the groove so as to compress the ring 27 radially as it is forced edgewise into the notch. At the inner end, the notch is enlarged to provide a circular wall 36 slightly larger than the bottom of the groove 29 and disposed outwardly beyond the end of the key. By making the outer end of the notch narrower than the ring, the latter is normally held in the hole 36 but may, by edgewise compression of the ring, be withdrawn from the notch whenever it is desired to disconnect the link from the key.

To provide full contact between the washer and the underside of the screw head the projecting end portion of the bar 25 is bent up about a transverse line 37 enough to dispose the bar end perpendicular to the screw shank 23 in the final assembly. Thus, the actuating force derived from the depression of a key is distributed uniformly around the washer and acts along a line closely coinciding with the axis of the link. By virtue of the yieldability of the rubber of the ring 27 and the looseness of the fit of the latter in the hole 36, the connection the washer provides between the screw and the key easily accommodates the change in the angular relation which occurs between the screw and the key in the short actuating movement of the latter. At the same time, the motion of the key is transmitted directly to the screw and pull link without substantial yielding because of the firmness of the rubber and the substantially equal sizing of the hole 36 and the screw head 24. On the other hand, the grommet avoids any possible contact between the metal parts and is sufiiciently yieldable to constitute an effective shock absorber or cushion.

If desired, the screw shank 23 may be enlarged immediately below the ring 27 so as to resist sliding of the washer down the shank. This may be accomplished by forming ribs 38 on the shank.

Due to the flexibility of the pivotal connection provided by the yieldable ring between the pull link and the key, precise longitudinal alinement of the key and the bar 25 is not necessary. The latter may, by swinging about the shank of the screw 33 as an axis, be disposed at an angle relative to the key as illustrated in FIG. 4. By such edgewise adjustment of the bars, any slight unevenness in the spacing of the keys may be corrected in the 1 initial assembly.

After the proper angular positions of the diiferent action units relative to their actuating keys has been established in the initial assembly of a complete action, the screws 33 are tightened down to clamp the bar solidly against the top of the key. As an incident to this, a depending lug 40 struck out of the inner end of the bar 25 is forced into the wood of the key and thus becomes effective in holding the bar against turning relative to a key thus establishing and maintaining a fixed angular relation between the bar and the key. Preferably in the formation of the bar, opposite ends are bent slightly relative to each other about a line 41 thereby raising the area adjacent the screw hole 32. As the screw is tightened down, this raised portion is straightened slightly and the resulting stressing of the bar is utilized to advantage in holding the lug 40 embedded in the wood of the key. This insures maintenance of the locked relation 3 of the bar and the key throughout the service life of the action.

It Will be apparent that the parts of the pivotal connection between the pull link and the key are either standard elements such as the grommet 27 or may be made by high speed automatic machinery. In addition to lower material costs, the assembly of these parts is greatly facilitated thereby further reducing the overall cost of the action. The improved pull link arranged as above described also permits a substantially closer horizontal spacing of key bed and the action proper than is possible with prior constructions. A wider latitude is thus allowed in the design of the piano case.

I claim as my invention:

1. Mechanism for actuating a piano action comprising a manually operable key lever fulcrumed intermediate its ends, an elongated endwise reciprocable link having a head thereon, a ring composed of yieldable material on said link and abutting the underside of said head, said ring having axially spaced flanges defining a groove around its periphery opening outwardly in the plane of the ring, and a projection having a forked end projecting beyond the end of said key lever with the legs of the fork straddling said ring and seated in said groove whereby to position the ring axially relative to said key lever While permitting relative angular displacement between the lever and said link during swinging of the lever and endwise movement of the link thereby.

2. In a piano action, the combination defined in claim 1 in which the ends of the legs of said fork are spaced closer together than the diameter of the bottom of said groove whereby to confine said ring in said notch while permitting edgewise shifting out of the notch by compression of said yieldable material.

3. In a piano action as defined in claim 2 in which 35 the legs of said fork define a notch enlarged at its inner end substantially to the size of the bottom of said groove.

4. In a piano action as defined in claim 1 in which said projection comprises a bar lying against the top of said key lever and secured to the latter by means including a screw entered through a hole in the bar, and means locking the bar against edgewise swiveling relative to the lever about the axis of said screw.

5. In a piano action as defined by claim 4 in which said locking means includes a lug spaced from said screw and embedded in said key lever.

6. In a piano action of the drop type, the combination of, a manually operable key lever fulcrumed intermediate its ends, an elongated endwise reciprocable link having a head thereon, a ring of resiliently yieldable material on said link and having a flange at the upper end abutting against the underside of said head, and a fork rigid with and projecting from the rear end of said key and having a rearwardly opening notch with the legs thereof straddling said ring and abutting the underside of said flange, the edges of said fork legs defining a generally circular hole at the closed end of said notch and a narrower slot at the outer end thereof, and said ring being held in said hole but being compressible to permit shifting of the ring edgewise out of said notch through said slot.

References Cited by the Examiner UNITED STATES PATENTS 1,342,029 6/ 1920 Ong 84-24O X 2,061,154 11/1936 Heitzmann. 2,227,741 1/1941 Betz. 2,270,426 1/1942 Farny 84-240 2,291,430 7/1942 Ingersall.

2,312,516 3/ 1943 A-lldredge 28785 2,419,071 4/1947 Hall 287-85 X FOREIGN PATENTS 2/1928 France. 7/1937 Great Britain.

C. W. ROBINSON, Examiner.

Claims (1)

1. 6. IN A PIANO ACTION OF THE DROP TYPE, THE COMBINATION OF, A MANUALLY OPERABLE KEY LEVER FULCRUMED INTERMEDIATE ITS ENDS, AN ELONGATED ENDWISE RECIPROCABLE LINK HAVING A HEAD THEREON, A RING OF RESILIENTLY YIELDABLE MATERIAL ON SAID LINK AND HAVING A FLANGE AT THE UPPER END ABUTTING AGAINST THE UNDERSIDE OF SAID HEAD, AND A FORK RIGID WITH AND PROJECTING FROM THE REAR END OF SAID KEY AND HAVING A REARWARDLY OPENING NOTCH WITH THE LEGS THEREOF STRADDLING SAID RING AND ABUTTING THE UNDERSIDE OF SAID FLANGE, THE EDGES OF SAID FORK LEGS DEFINING A GENERALLY CIRCULAR HOLE AT THE CLOSED END OF SAID NOTCH AND A NARROWER SLOT AT THE OUTER END THEREOF, AND SAID RING BEING HELD IN SAID HOLE BUT BEING COMPRESSIBLE TO PERMIT SHIFTING OF THE RING EDGEWISE OUT OF SAID NOTCH THROUGH SAID SLOT.

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