US 2686450 A
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Description (OCR text may contain errors)
g- 17, 1954 E. SANDER 2,686,450
PAD SPRING FOR WIND INSTRUMENTS Filed April 9, 1951 fldif. f/aZ.
2 V 2 5 -15. lo 22 54 IN V EN TOR.
A TTOENE Y5.
Patented Aug. 17, 1954 UNITED STATES PATENT OFFICE 3 Claims.
This invention relates to a pad spring for wind instruments, and particularly to pad springs for wind instruments of the type wherein a key controlled rock shaft mounts pad carriers and the spring serves as a means to bias the shaft and position the valve pads in selected relation to tone holes in the tubular body of the instrument, that is, to bias the valve pads to either open or closed position as desired. Examples of instruments upon which this pad spring unit may be mounted are clarinets, bassoons, oboes and saxophones, but it will be understood that this list of instruments is illustrative and is not intended to be limiting.
The conventional practice in the manufacture of wind instruments as it respects the provision of a spring to control a tone pad, has been to provide a needle type of spring mounted upon a post which supports or journals one end of the rock shaft, which needle spring extends adjacent to and substantially longitudinally of the rock shaft and bears against a stop projecting from the shaft. Such needle type springs tend to crystallize and break after usage, the life of the needle spring before breakage usually being comparatively short. When the needle spring breaks, it is necessary to disassemble the instrument and either apply a totally new post carrying a new spring unit, or to withdraw from the post the broken remnant of the spring and to replace it with a new needle spring. The replacing of a needle spring in this manner is a difiicult and time-consuming operation.
Another disadvantage of the needle type of spring shaft commonly used has been that it tends to impose upon the post which mounts it a rotative stress. The continued application of such stress with resultant rotation of the post can be avoided only by keying the post to the body of the instrument in a manner to prevent rotation. If a post is not keyed and is permitted to rotate even slightly, the result is a binding of the rock shaft in the socket of the post which mounts or journals it. Such binding of a rock shaft interferes with the proper manipulation of the instrument to play it and also causes sticking of the keys and the pads.
It is the primary object of this invention to provide a pad spring so constructed as to avoid the disadvantages of the needle type of spring heretofore employed.
Other objects of the invention are to provide a pad spring which is easy to mount and assemble in the instrument, which can be adjusted rapidly and easily to vary the spring tension exerted thereby, which can be made of material which possesses long life and resists breakage, which can be reused repeatedly after overhauling of the instrument, and which avoids the imposition upon the instrument of any stress of a character which would tend to bind the posts or vary the feel or touch of the pad keys in their operation.
Other objects will be apparent from the following specification.
In the drawing:
Fig. l is a side view illustrating a portion of a body of a clarinet having my improved pad spring applied thereto.
Fig. 2 is a transverse sectional View taken on line 22 of Fig. 4.
Fig. 3 is a transverse sectional view taken on line 3-3 of Fig. 4.
Fig. 4 is an enlarged sectional view taken on line 4-4 of Fig. 3 with the set screw and spring end oriented in slightly differen relation than shown in Fig. 3.
Fig. 5 is a fragmentary perspective view of an instrument illustrating a modified embodiment of the invention.
Referring to the drawing which illustrates the preferred embodiment of the invention, the numeral I0 designates a tubular body member forming a part of a clarinet and adapted to be assembled with other parts to complete the clarinet body. Thus, at one end, the body part In may be provided with a reduced dimension neck portion l2 adapted to be inserted in an enlarged bore portion at the end of another body section, and at its opposite end the body part I0 is provided with an enlarged bore portion (not shown) and is encircled by a ferrule or ring member l4 adapted to reinforce the body section It at the part at which another body unit (not shown) has its neck inserted therein. The body portion I0 is provided with a plurality of tone holes (not shown) formed therein at selected points and being of selected size. These tone holes are adapted to be closed or spanned by pad members i8 constituting valves. The body will be provide: at each tone hole with a valve or pad seat so that when the pads bear upon the seat, the tone hole is closed. It will be understood, however, that the pads may constitute ring members which reduce the efiective area of the tone holes when seated without completely closing said tone holes.
Each of the pad members is mounted by means of an elongated arm or lever 20 upon a rock shaft 22. The rock shaft is journaled at its opposite ends by means of posts 24 carried by the body I 0 and provided with sockets (not shown) of a character to journal the end portions of the rock shaft. Each rock shaft mounts a key 26, which keys project laterally from the rock shafts which mount them and are conveniently grouped for selective manipulation by the fingers. It will be understood that the construction thus described is conventional and the arrangement is such that the musician may manually depress a selected key 25 during playing for the purpose of indi vidually rocking shafts 22 as desired, thus moving the pads l8 toward and from the body portion It to shift the pads away from their normal position, usually spring biased to close the tone hole associated therewith.
My invention pertains to the spring means for positioning or biasing the rock shafts as desired. One embodiment of the invention is illustrated in Figs. 2, 3 and 4 and entails the use of a cupshaped member or sheath having an end portion 39 and a skirt portion 32. The end portion or Wall to is preferably of substantial thickness and approximate circular shape and has a central aperture therein substantially coaxial with the skirt portion 32 and of smaller size than the inner diameter of said skirt portion. The size of the aperture 3 3 is preferably such that it will fit freely and rotatably upon the rock shaft 22. The end wall 3c is preferably provided with a substantially radial screw-threaded bore 35 for the reception of an anchor member, here illustrated as a set screw 38. The anchor member or set screw bears against the rock shaft 22 and, when effectively tightened, serves to anchor the sheath member 32?, 32 in selected position upon the rock shaft 22. Thus the sheath 8t, 32 is secured fixedly to the shaft in a manner to prevent axial sliding of the sheath along the shaft and also to prevent rotation of the sheath upon the shaft.
A coil spring 453, preferably consisting of a plurality of convolutions, is adapted to encircle the rock shaft 22 and to be received with clearance within the bore of the skirt portion 32. in other words, the diameter of the wire of which the spring is formed is less than the clearance between the inner surface of the skirt portion 32 and the surface of the rod 22. The sheath 3G, 32 is preferably provided with a passage 52 communicating with the interior or bore portion of the skirt 32 adjacent its inner end. As here illustrated, the bore or passage 32 extends substantially longitudinally through the end wall Si; in spaced relation to the axial bore 3 1. The bore portion i2 is of a diameter preferably slightly larger than the diameter of the wire of which the coil spring at is formed, and is adapted to receive an end portion i t of the coil spring The coil spring is preferably of such a length or dimension that the opposite end thereof is adjacent to or projects from the mouth at the open end of the skirt 32 and a terminal portion it: extends tangentially from the coil spring at and is adapted to engage the body it preferably substantially tangentially, as seen in 2 and 3. The coil spring is so wound that the tension exerted thereby and transmitted by the terminal portion and the sheath 3%], 32 to the rock shaft 22 biases said shaft rotatively in the desired direction, for example, in a direction to hold the pads 58 seated upon the body at the valve seats around the tone holes.
The device may constitute a pie-assembled unit, that is, the spring 36 may be held within the sheath 3%, 32 'by the mounting of its end or terminal portion lin the socket d2 of the shaft so that the parts can be manipulated as a unit. This unit can be applied to the rock shaft and the instrument very easily, usually being applied while the rock shaft is disassembled or removed from the instrument. The application of the spring to the rock shaft is done by simply passing the rock shaft through the aperture 3d and through the coil spring, the interior dimension of which coil spring is preferably greater than the diameter of the shaft 22 so that a circumferential clearance between the parts 22 and 40 exists. After the rock shaft has been journaled at its ends by means of the posts 24, the sheath 3G, 32 may be rotated in a direction to bias the spring it to the extent desired, and thereupon the anchor member 38 may be brought into play to lock the sheath in the desired spring biasing position. the event it is desired to change the tension exerted by the spring, that can be done by simply releasing the anchor member 38 and rotating the sheath member in the proper direction and then re-securing the anchor member 38. In the usual arrangement, for the purpose of rendering the device inconspicuous and also for the purpose of insuring against disengagement of the spring from the sheath, the sheath will be positioned adjacent to one of the ends of the shaft and to one of the posts 24 with the mouth of the bore of the skirt 32 confronting the post 24 or one of the lever arms 23. By this means the coil spring is held against withdrawal from the sheath in the event any tendency for such withdrawal exists incident to usage. Positive means to anchor the spring to the shaft may be provided if desired, but usually a snug fit of the terminal portion it in the bore 32 will be sufficient to hold the spring, especially if the bore :52 is somewhat inclined relative to the axis .of the shaft 22 so that the withdrawal of the spring from the sheath would require distortion of the spring. it is desirable that the spring shall be readily removable from its sheath to facilitate replacement should the spring break or be damaged. One of the advantages of the device, however, is that a tough and long-wearing spring can be provided. Thus coil springs made of material such as Phosphor bronze or stainless steel wire can be used in the device, and the advantage of the long life and the resistance to breakage of such materials can be secured.
it will be observed that the only force which is exerted by this spring upon the rock shaft or the other parts of the device acts to rotate the rock shaft about its axis. In other words, there is no force comparable to that normally exerted by the conventional needle spring which tends to turn the mounting posts 25 in a manner to disalign the shaft receiving sockets or to produce a binding of the rock shaft.
A modified embodiment of the invention is illustrated in Fig. 5. In this construction the roclr shaft 22 is provided with a lateral projection 59 which preferably has a bore passing therethrough. A coil spring 52 encircles the rock shaft 22 and has an end portion at adapted to be anchored to the lateral projection as by passing through a socket in said lateral projection. The opposite end of the coil spring terminates in a portion 58 extending substantially tangentially from the coil spring and bearing against the tubular instrument body Hi. This construction serves to act in the same manner as the preferred device and is somewhat simpler and less expensive. However, this embodiment of the invention does not possess the advantage of a ready and. easy adjustment of the amount of spring tension which can be accomplished where the sheath is provided, and also tends to be somewhat less attractive than the form which employs the sheath.
It will be understood that, while two embodiments of the invention have been illustrated herein, changes in the construction may be made within the scope of the appended claims without departing from the spirit of the invention.
1. A pad spring for a musical instrument having a tubular body provided with a tone hole and mounting a rock shaft carrying a pad to close said hole and a finger piece, comprising a substantially cup-shaped member having an end wall and annular skirt portion, said end wall having an axial opening for rotatably receiving said shaft and a second opening spaced from said first opening and communicating with the interior space between said shaft and skirt portion, a set screw carried by said member for anchoring engagement with said rock shaft, and a coil spring encircling said shaft and fitting within the space between said shaft and skirt portion, said spring including a longitudinally projecting end portion received in said second opening and an opposite substantially tangential end portion extending clear of the end of said skirt portion for engagement with said tubular body.
2. A pad spring for a musical instrument having a body mounting a pad-supporting rock shaft, comprising a sheath adapted to rotatably encircle said shaft in radial spaced relation thereto, an anchor member carried by said sheath and adapted to lock said sheath on said shaft, and a coil spring encircling said shaft and having its convolutions disposed in said sheath, one end of said coil spring projecting from said sheath for engagement with said body, the other end of said coil spring being detachably anchored to said sheath.
3. In a musical instrument a tubular body, a rock shaft, a lever carried by said shaft, means carried by said body spaced from said lever for journaling said shaft, said body and means forming a fixed assembly, a coil spring encircling said rock shaft between said lever and journal means and having an end portion projecting into engagement with said fixed assembly, a member carried by said rock shaft spaced from said arm, said spring having a second end portion interlocked with said member, and an annular skirt portion carried by said member encircling said shaft and coil spring.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 885,880 Stahl Apr. 28, 1908 1,319,625 Sciarra Oct. 21, 1919 1,817,024 Voos 1. Aug. 4, 1931 2,394,143 Brockman Feb. 5, 1946 2,514,394 Irving July 11, 1950 2,533,388 Meyers Dec. 12, 1950 FOREIGN PATENTS Number Country Date 172,103 Italy Feb. 16, 1935