US3002413A - Key mounting for musical instruments - Google Patents

Description

Oct. 3, 1961 sc R 3,002,413

KEY MOUNTING FOR MUSICAL INSTRUMENTS Filed July 8, 1959 2 Sheets-Sheet 1 mmvnm Kn-Z J'd eke/- Oct. 3, 1961 K. SCHERER 3,002,413

KEY MOUNTING FOR MUSICAL INSTRUMENTS Filed July 8, 1959 2 Sheets-Sheet 2 mmvron K2 Z JJ. exer- 4 I/% f m United States Patent" Claims priority, application Germany July 15, 1958 Claims. (Cl. 84-423) The present invention relates to a key mounting,

especially for a musical instrument in which each key is pivotably mounted on a shaft by being provided at the lower side opposite to the actual keyboard surface with a slot which is slipped over the shaft, and by being removably secured on the shaft by suitable retaining means.

It is an object of the present invention to provide a key bearing of the above mentioned type consisting of a slot in the key near the rear end thereof and having an opening toward the lower side and a shaft upon which the slotted portion of the key is slipped so that the inner end of the slot forms the main bearing surface for pivoting the key on the shaft; and it is ayfurther object'of the invention to close the mentioned slot underneath the shaft by means of a removable locking member in such a manner that the latter will also act upon the shaft to maintain the same in engagement with the mentioned bearing surface at the innerend of the slot. Still another object of the invention consists in providing such a locking member of a very simple and inexpensive construction and adapted to be easily operated for locking the key to the shaft and for unlocking it therefrom to permit the key to be removed.

In prior key constructions, these objects were not adequately attained since the key, which was likewise provided with a downwardly open slot for the insertion of the shaft, was clamped into a bushing of a U-shaped cross section which was pivotable on the shaft. Each of the two arms of this bushing had a small inwardly projecting nose whichfwhen the key was clamped into the bushing, engaged into a. corresponding recess in the key. Such a bearing had, however, the disadvantages that each individual bushing hadto be slipped separately upon the shaft while the latter was inserted into its bearings, and that, after the keys were clamped to the bushings, there was no assurance that the individual bushings were in positive engagement with the closed ends of the slots. Furthermore,,the connection between the bushing and the key merely by the small projections on the bushing and the corresponding recesses in the key was so unreliable that the key. could be easilylifted off its bearing accidentally.

According to the present invention, however, the key bearing is designed so that the retaining member consists ofa locking strip which is slidable within at least one groove or channel which is provided within the key and traverses the slot in which the shaft is seated. This locking strip securely closes the seating slot, positively engages with the shaft and forms a part of the bearing surface on which the key is pivotable about the shaft,

' and prevents any accidental removal of the key from the shaft. 7 V

A further, object of the invention is to design the locking stripso as'to engage at a certain resilient tension with the shaft so that the latter will always be in a proper engagement withits bearing surface on the key slot. For thispurpose as well as for preventing an accidental withdrawal of the locking strip from the shaft, either the locking strip or'the channel into which it is inserted, or both, may be slightly curved in the longitudinal direction. If desired, the bearingsurface in the slot may also be covered with a suitable resilient material.

According to a preferred embodiment of the invention, the channel within the key into which the locking strip is inserted is made in the form of two opposite grooves extending longitudinally in lateral surfaces of the key,

and the locking strip is made of a bifurcated shape and the two arms thereof are slidable within these grooves.

In this case, the shaft will be in engagement with the key and the locking strip at three different points, whereby the key will be prevented from tilting in a lateral direction.

Since the locking strip preferably engages with the shaft under tension, it is advisable to enlarge the width of the channel or grooves at least at one side, but preferably atboth sides of the slot and at the side of the locking strip which is not in engagement with the shaft.

Another important'feature of the invention consists in the provision of either one or two symmetrically opposite stop surfaces on the locking strip which are adapted to engage with a stop member on the key when the locking strip is being withdrawn from the shaft so as to prevent the locking strip from being pulled out entirely from the key or from falling out accidentally after it is withfor pulling the locking strip out more easily.

These and other additional objects, features, and advantages of the present invention will become further apparent from the following detailed description thereof, particularly when read with reference to the accompanying drawings, in which- FIGURE} shows a perspective view of a key bearing unit;

FIGURE 2 shows a side view of a full-tone key without a locking strip on an enlarged scale;

FIGURE 2a is a side view showing an enlarged view of a part of a full-tone key with a locking striprinserted therein;

FIGURE 3 is a cross section taken on line 3-3 of FIG. 2 in the direction of the arrows;

FIGURE 4 is a cross section taken on line 4-4 of FIG. 2 in the direction of the arrows; FIGURE 5 shows a side view of a half-tone key;

FIGURE 6 is a cross section on an enlarged scale taken on line 66 of FIG. 5 in the direction of the arrows;

FIGURE 7 is a cross section on an enlarged scale taken on line 7-7 of FIG. 5 in the direction of the arrows; while FIGURE 8 shows an enlarged cross section of the rear part of a modified key with a locking strip thereon.

A base plate B carries a row of small adjacent bearing brackets 1 for pivotably mounting the full-tone keys 2 and half tone keys 3 on acommon shaft 5 extending through bores 4 in brackets 1. Preferably, however, as shown in FIGURES 5 to 7, each key 2 and 3 may be composed of a key body 14a and a cover 14b forming the actual keyboard or playing surface.

The full-tone key 2 as illustrated in FIGURES 2, 2a, 3, and 4, is in the conventional manner provided with a slot-shaped bearing aperture 6 which extends from its openend at the lower side of the key at an upwardly in clined direction. Key 2 is mounted on shaft 5 by sliding it downwardly over theshaft so that the latter will enter into slot 6 and come to rest on the arcuate bottom 6c hereof. Itis then locked in position on shaft 5 nine manner as illustrated particularly in FIGURE 2a by slid- Patented Oct. 3, 1961 l '3 ing a locking strip 7 into a slot 8 which extends into the key from the rear end thereof and crosses slot 6 at a point so closely underneath shaft that locking strip 7 will engage at a slight tension against shaft 5.

In order to prevent locking strip 7 from sliding out of slot 8 or from being accidentally withdrawn therefrom to such an extent as to disengage from shaft 5 and unlock key 2, either the locking strip or slot 8 or both may be slightly curved longitudinally. If both the locking strip and slot 8 are curved, the degree or direction of the curvatures should differ from each other.

Slot 8 may extend transversely through key 2, or more preferably it is made in the form of two opposite grooves 8 and 8" in the lateral outer surfaces of the key, as shown in FIGURES 3 and 4. In this case, locking strip 7 is made of a bifurcated shape, as shown particularly in FIGURE 8, so that its two arms 7' and 7" may be inserted into grooves 8' and 8", respectively, and the upper surfaces of these two arms will thenengage with the lower surface of shaft 5.

Slot 8 or one or both of grooves 8' and 8" may be enlarged in width at the lower side thereof at 9 adjacent to one or both sides of slot 6 so as to permit locking strip 5 to flex away from shaft 5 if it engages at too great a tension with the shaft.

In order to prevent locking strip 7 from sliding out or being accidentally withdrawn entirely from slot 8 or grooves 8' and 8" when moved to the unlocking position, it may be provided with at least one stop surface 15. If locking strip 7 is made of a bifurcated shape and its two arms 7 and 7" are resiliently movable relative to each other, the free end of each arm may have such a stop surface in the form of a projecting nose 10 which is adapted to engage with a stop member 11 on key 2, for example, a pin which passes transversely through the key and the two ends of which are slidable along the bottoms of grooves 8 and 8" until they engage with the projecting noses 1t) and thus prevent key 2 from being further withdrawn, except by force.

Slot 8 or grooves 8 and 8" preferably extend inwardly 7 from the end of key 2 opposite to the visible front end 12 thereof. Locking strip 7 has an end portion which projects outwardly of slot 8 or grooves 8,,8 and is preferably provided with suitable means, for example, a hole 13, for applying a tool to facilitate the withdrawal of strip 7 from shaft 5 when key 2 is to be removed.

Although the manner of mounting and locking the keys has only been particularly described with reference to the full-tone keys 2, the same also applies to the half-tone keys 14, as illustrated in FIGURES 5 to 7.

Although my invention has been illustrated and described with reference to the preferred embodiment thereof, I wish to have it understood that it is in no way limited to the details of such embodiment, but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed my invention, what I claim is:

1. In a musical instrument having a plurality of keys, means for pivotably mounting said keys adjacent to each other comprising a base, a shaft, means connected to said base and adapted to mount said shaft on said base in a spaced relation thereto, each of said keys having a slot in its lower side near one end thereof extending in its entire length transversely of said key and adapted to receive said shaft when said key is placed thereon, so that said shaft is then engaging with the arcuate inner end of said slot, each of said keys further having at least one elongated recess therein extending substantially in the longitudinal direction of said key from the rear end thereof and transversing said slot at a certain distance from said arcuate inner end of said slot, and a locking member adapted to be inserted into said recess from the open rear end thereof and then to traverse said slot so as to:

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close the same in the downward direction and to maintain said key in a pivotable position on said shaft but in a locked position relative to said shaft.

2. A musical instrument as defined in claim 1, wherein said elongated recess is disposed at a plane substantially coinciding with the plane of the lower surface of said sha-ft when the upper surface of the shaft engages with said arcuate inner end of said slot so as to lock said shaft to remain in engagement with said arcuate inner end without affecting the free pivotability of said key about said shaft.

3. A musical instrument as defined in claim 1, wherein at least said elongated recess is curved in the longitudinal direction. 7

4. A musical instrument as defined in claim 1, wherein at least said locking member is curved in the longitudinal direction.

5. A musical instrument as defined in claim 1, wherein said elongated recess and said locking member therein are curved in the longitudinal direction but have different degrees of curvature.

6. A musical instrument as defined in claim 1, where in said recess is enlarged in width, as seen in the vertical direction of said key, at an area adjacent to said slot and at least at one side thereof.

7. A musical instrument as defined in claim 1, wherein said recess comprises a pair of opposite grooves in the lateral outer surfaces of said key extending from the rear end thereof to a point beyond said slot, said locking member being bifurcated and having two arms adapted to engage into said grooves and to be slidable therein in the longitudinal direction of said key relative to said slot and underneath and in engagement with said shaft.

8. A musical instrument as defined in claim 1, wherein said recess comprises a pair of opposite grooves in the lateral outer surfaces of said key extending from the rear end thereof to a point beyond said slot, said locking member being bifurcated and having two arms adapted to engage into said grooves and to be slidable thereinin the longitudinal direction of said key relative to said slot and underneath and in engagement with said shaft, and wherein said arms of said locking member are resilient relative to each other, .at least one of said arms having a projection thereon, said key also having a projection thereon, said two projections being adapted to engage with each other after said locking member is partially withdrawn from said slot to prevent said locking member from being accidentally withdrawn entirely from said recess.

9. A musical instrument as defined in claim 1, wherein said locking member and said key have associated means thereon adapted to interengage after said locking member is partially withdrawn from said recess to prevent said locking member from being accidentally withdrawn entirely from said recess.

10. A musical instrument as defined in claim 1, wherein said locking member has an end portion projecting from the rear end of said recess when said locking member is fully inserted into said recess, said end portion being adapted to serve as a handle for manipulating said locking member.

References Cited in the file of this patent UNITED STATES PATENTS 2,495,913 Ahern et al. Jan. 31, 1950 2,514,978 Terlinde July 11, 1950 2,565,239 Kostka Aug. 21, 1951 2,816,470 dorio Dec. 17, 1957 2,826,953 Scherer Mar. 18, 1958 2,836,094 Amberg May 27, 1958 FOREIGN PATENTS 928,750 Germany June 10, 1955

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