US2478474A

US2478474A - Piano key mounting

Info

Publication number: US2478474A
Application number: US659776A
Authority: US
Inventors: Harry A Felder
Original assignee: Wurlitzer Co
Current assignee: Wurlitzer Co
Priority date: 1946-04-05
Filing date: 1946-04-05
Publication date: 1949-08-09
Anticipated expiration: 1966-08-09

Description

Aug- 9, 1949 H. A. FELDER 2,473,474

PIANO KEY MOUNTING Filed April 5, 194e O N N INVENTOR.

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@a/af@ Patented Aug. 9, Y1949 UNITED PIANO KEY MOUNTING Harry A. Felder, De Kalb, Ill., asslgnor to The Rudolph Wurlitzer Company, Chicago, Ill., a

corporation Application April 5, 1946, Serial N0. 659,776

9 Claims. l

This invention relates to a piano key mounting applicable for use in piano key assemblies for pianos, and also applicable to piano accordions, particularly as to the bearing and bearing guides therefor on the balance rail of the key bed.

The purpose of this invention is to provide a bearing assembly embodying a wide support for the keys on the balance rail such as to prevent cooking or tilting of the keys sidewise, particularly wherein the key rods extend angularly from the keys to the point of lift. By means of such bearing structure each key is provided with a bearing support directly in line with its point of applied pressure and its point of lift.

Another feature of the invention resides in the bearing support for the key-s such as may be readily removed and replaced with respect to the balance rail.

A further feature of the invention resides in the knife edge bearing support such as to minimize friction and improve the touch accordingly.

Still a further feature of the invention resides in a simplified construction which will permit of a wood guide rail replacing the usual metal guide rail, and reduce manufacturing` costs. This is accomplished by providing a retaining bar common to a plurality of bearing elements removably mounted for retaining them in their bearing relation with the balance railwhile permitting their hinging action with a minimum of friction.

A further feature ofthe invention resides in the provision of spaced knife edge tapers formed along the lower edge of the retaining bar at such intervals as to receive and interlock with the respective hinge bearing elements to maintain them in their proper spaced relation.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims:

Fig, 1 is a plan view of a key assembly with parts broken away.

Fig. 2 is a side elevation thereof.

Fig. 3 is a perspective view enlarged and partly in section, showing the interlocking hinge relation of the retaining bar, hinge bearing element and guide rail.

Fig. 4 is an enlarged side elevation of the retaining bar, showing two adjacent hinge elements, and with bearing plate and balance rail shown in section.

In the drawings there is illustrated a key bed shown herein as being particularly applicable for use with a piano action, but which is also applicable with variations to a piano accordion action. Said key bed includes a key bed support Ii) having a front molding Il, guide rail I2 for the natural keys, and guide rail I3 for the sharp keys. Said key bed also includes the natural keys I4 and sharp keys I5. Each of said natural keys includes an extension comprising a key rod IS, and each of the sharp keys includes a similar extension Il. To accommodate the keys to the action, said rods may be bent as at IB so as to extend at an angle from their bearing point to a point of lift indicated at I9. Said key rods terminate at the point of lift in a flattened biiurfcated portion Ita, for suitable connection with the piano or accordion action.

For hingedly supporting the several keys at their fulcrum point, there is mounted upon the key bed support I@ to extend transversely thereof a balance rail 2D. Said balance rail is formed with a, longitudinally extending groove 2l in which the natural keys have their bearing, and a corresponding groove 22 slightly offset rearwardly thereof in which the sharp keys have their bearing. Said balance rail is preferably constructed of wood, but each of said grooves has its bearing surface lined with a strip of felt 23, said grooves being substantially Vshape in cross section.

Each of said keys with its respective rod is hingedly supported on the balance rail by a removable hinge bearing element. The hinge bearing element 24 is preferably formed of sheet metal having a pair of V-shaped bearing members 25, 25a spaced apart but joined by a laterally hanged supporting plate 26. Said supporting plate is provided at one end with an upstanding hinge pin 2l extending through the key extensions IS, I1 for securing them to their respective bearing elements 24. A corresponding bearing element 28, having hinge pins 29, is provided for supporting certain of the keys in reverse relation to the bearing elements 24, as shown in Fig. 4, wherein two natural keys lli lie adjacent each other, as do keys a and b. The extension of key a is supported by the bearing element 24, whereas the extension of key b is hingedly supported by the bearing element 28. By reason of their close proximity, said bearing elements are reversed and so related that their spaced bearing members overlap and interlock one between the other.

For retaining the bearing elements on the guide rail and in their spaced relation, there are provided retaining bars 32 and Sila. The bar Si) is provided for each series of bearing elements supported in groove 2l, and the other said bar a is provided for that series of elements supported in groove 22. The lower edge of said bars is of normal thickness as indicated at 3l in Fig. 4, but is beveled to a knife edge 32 at spaced intervals for retaining engagement with the bearing members 25, 25a of the

hinge bearing elements

24, 28. The upper edge of each bar is provided at intervals with an apertured lug 33 for receiving a locating pin 34. Said locating pin is provided with a head for retaining a compre-ssion spring 35 between said head and lug 33 such as to hold the bar in its retaining position under spring tension.

It will be noted that the bearing plate 23 is formed with its walls extending at a greater relative angle to each other than the walls of the bearing members 25, 25a mounted therein'. Thus, the bearing members are permitted to freely oscillate to a limited extent within the bearing plate. Similarly, the knife edge or beveled portions 32 of the retaining bars are formed with their walls extending at an angle oi less degree than the adjacent inner walls of the bearing members, as shown in Fig. 3. This permits of similar freedom of hinge movement between the bearing members and the fixed retaining bar. It will, therefore, be observed that somewhat of a knife edge bearing support is provided for the hinge bearing element-s which are retained in bearing position and in their proper spaced relation by a retaining bar which similarly has a knife edge bearing contact therewith such as to minimize friction.

By reason of the spaced bearing members 25, 25a a bearing support for each key is provided of much greater width than the key and extending laterally therefrom, such as to stabilize it against cocking movement, a portion of the bearing support being in line with the point of pres- Vsure applied to the key and its point of lift I9.

By removing the locating pins Se, the retaining bar -may be withdrawn to thereby release and permit removal of the key bearings. Furthermore, the keys are maintained in proper alignment in the key bed by reason of the relatively wide stabilizing character of the hinge bearing elements and their nesting association with the bearing plate 23 and retaining bar 3i).

The invention Vclaimed is:

1. A piano key mounting including a key bed support for a plurality of piano keys, a transversely extending balance rail support on said key bed support, a bearing surface on said rail, a hingerbearing element secured to each key bearing engagement with said bearing surface, and a retaining bar common to the respective said bearing elements mounted in engagement therewith for retaining said elements in their bearing engagement with said surface.

2. A piano key mounting including a key bed support for a plurality of piano keys, a transversely extending balance rail supported on said key bed support, said balance rail having a groove extending longitudinally thereof, a hinge bearing element secured to each of said piano keys having a' pocket forming bearing portion seated in said groove, and a retaining member secured to said balance rail engageable with the pocket portion of the respective said elements for retaining them in bearing engagement with said balance rail while permitting pivotal movement relative thereto.

3. A piano key mounting including a key bed support for a plurality of piano keys, a transversely extending balance rail supportedon said support for a plurality of piano keys, a transversely extending balance rail -supported on said key bed support, said balance rail having a groove extending longitudinally thereof, a hinge bearing element secured to each of said keys having a V-shaped bearing portion seatable in said groove, and a retaining bar having a V-shaped portion seatable in the V-shaped portion of said bearing element for holding each of said bearing elements in seated relation to said groove while permitting oscillatory movement relative to said balance'rail and retaining bar.

5. A pianokey-mounting including a key bed support for a plurality of piano keys, a transversely extending balance rail supported on said keybed support, a bearing plate mounted in and conforming to said groove, a hinge bearing element secured to each of said keys having a vshaped bearing portion in bearing engagement with said plate, and a retaining member for each of said bearing elements secured to said rail, said retaining member having a V-shaped edge in engagement with the V-shaped bearing portion of said element with its side walls spaced therefrom to permit said element to rock relative to said plate and member.

6. A piano key mounting including a key bed support for a plurality of piano keys, a transverselyfextending balance rail supported on said key 'bed support, a V-shaped bearing plate extending longitudinally of said rail, a hinge bearing element secured to each of said keys, a V- shaped bearing member formed at a sharper angle than said plate for rocking bearing engagement therein, a retaining member having a V- shaped edge of sharper'form than said bearing member forseating engagement thereon, and means for securing -said retaining member to said vrail for retaining said bearing element on said bearing plate while permitting rocking movement thereof relative to said plate and retaining member,

7. A piano key mounting including a key bed support for a plurality of piano keys, a transversely extending balance rail supported on said key bed support, a V-shaped bearing plate extending longitudially of said rail, a hinge bearing element secured to each of said keys to extend laterally thereof and longitudinally of said rail having a pair of spaced V-shaped bearing members, a retaining bar for retaining them on said bearing plate, said bar having its retaining edge forme-d with spaced V-shaped portions corresponding to and in registry with the spaced bearing members of each bearing element t0 lie therein and of sharper contour to permit rocking movement of said members relative thereto and to said bearing plate, the portion of said retaining bar intermediate said V-shaned pertions thereof providing end thrust bearing Yshoulders for said bearing-members, and means for positioning and securing saidiretaining bar on said rail to hold said elements in bearing relation therewith and maintain them-in predetermined spaced relation to each other for key alignment.

8. A piano key mounting including a key bed support for a plurality of piano keys, a transversely extending balance rail supported on said key bed support, a V-shaped bearing plate extending longitudinally of said rail, a hinge bearing element secured to each of said keys to extend laterally thereof and longitudinally of said rail having a pair of spaced V-shaped bearing members, a retaining bar for retaining them on said bearing plate, said bar having its retaining edge formed with spaced V-shaped portions corresponding to and in registry with the spaced bearing members of each bearing element to lie therein and of sharper contour to permit rocking movement of said members relative thereto and to said bearing plate, the portion of said retaining bar intermediate said V-shaped portions thereof providing end thrust bearing shoulders for said bearing members, removable locating pins for locating said retaining bar on said rail to thereby locate and retain said bearing elements in lateral spaced relation for key alignment, and a spring on each of said pins for yieldingly retaining said bar and members in bearing relation with said rail while permitting said members to rock relative thereto.

9. A piano key mounting including a key bed support for a plurality of piano keys, a transversely extending balance rail supported on said key bed support, a bearing plate mounted on said rail extending longitudinally thereof, a bearing element secured to each of said keys having a V- shaped bearing member for bearing engagement With said plate, a retaining Ibar extending longitudinally of said rail common to said bearing elements for retaining engagement therewith, said retaining bar having spaced V-shaped portions conforming to and in registry with the bearing member of said bearing elements respectively, the intermediate portion of said bar forming spacing shoulders therebetween for retaining said bearing elements in spaced relation for key alignment, and yielding means for securing said bar to said guide rail.

HARRY A. FELDER.

REFERENCES CITED The following reierenlces are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,246,998 Pickard et al Nov. 20, 1917 1,561,100 Mills Nov. 10, 1925 1,667,089 Umbriaco Apr. 24, 1928 2,257,060 Moilliet Sept. 23, 1941