US2996941A

US2996941A - Keyboard construction

Info

Publication number: US2996941A
Application number: US768102A
Authority: US
Inventors: Stiles Gene Anbrey
Original assignee: PRATT READ AND CO Inc
Current assignee: PRATT READ AND CO Inc
Priority date: 1958-10-20
Filing date: 1958-10-20
Publication date: 1961-08-22
Anticipated expiration: 1978-08-22

Description

Aug. 22, 1961 G. A. STILES KEYBOARD CONSTRUCTION 2 Sheets-Sheet 1 Filed Oct. 20, 1958 Aug. 22, 1961 G. A. STILES 6,

KEYBOARD CONSTRUCTION Filed Oct. 20, 1958 2 Sheets-Sheet 2 i1 nited States Patent 2,996,941 KEYBOARD CONSTRUCTION Gene Aubrey Stiles, Westbrook, Conn., assignor to Pratt,

Read & Co., Incorporated, Ivoryton, Conn., a corporation of Connecticut Filed Oct. 20, 1958, Ser. No. 768,102 11 Claims. (Cl. 84-440) This invention relates generally to keyboards of the type used in organs and like musical instruments, and more particularly to a new and improved keyboard construction including an adjustable device for regulating the keys.

The manufacture of keyboards involves several precise regulating operations, such as key leveling to align the playing surface of the keys, key tensioning to give the keys a desired touch, and adjusting the stops which limit the movement of the keys. The regulation of known keyboard constructions is a rather precise job which requires skillful manipulation, and this involves considerable time and requires that the task be assigned to trained and experienced workers, all of which increases costs.

Accordingly, an object of the present invention is to provide a keyboard construction including a regulating device which may be adjusted easily by relatively unskilled persons.

A further object is to provide a single adjustable device for regulating both the level and touch of the keys of a keyboard, and which also serves as an up-stop therefor.

Another object is to provide a keyboard unit having pre-leveled and pre-tensioned keys so that the unit may be readily assembled in a musical instrument.

Another object of the invention is to provide a keyboard regulating device of simple and inexpensive construction, and yet one which provides accurate leveling, tensioning and up-stop adjustments.

A feature of the invention is the provision of a keyboard construction wherein the keys extend on opposite sides of a fulcrum or balance point, which includes a regulating device having a stiff portion on one side of the fulcrum for providing a rigid up-stop, and having a resilient portion on the other side of the fulcrum for applying spring tension to the key to bias it against the up-stop.

Another feature of the invention is the provision of a regulating device for organ keys including a horizontal spring device supported above the fulcrum of each key and having one adjusting screw engaging the key behind the fulcrum to control the resilient pressure applied thereto by the spring and to provide an adjustment of the touch of the key, and having another adjusting screw engaging the key in front of the fulcrum which serves as an up-stop and affords an adjustment for accurately leveling the keys.

A further feature is the provision of a regulating device for organ keys including a spring having special fastening portions which slip on and grip balance and guide pins for the keys so that the device can be readily mounted and dismounted and individual keys are readily removable. The keyboard with the regulating devices attached and pre-adjusted may be provided economically as a separate unit.

Certain embodiments of the invention are illustrated by way of example in the accompanying drawings in which:

FIG. 1 is a perspective view of :an organ with one end cut away to show the keyboard construction;

FIG. 2 is an enlarged fragmentary perspective view of a keyboard showing the regulating devices which provide tensioning, leveling and up-stop control;

FIG. 3 is an exploded view of the key assembly of FIG. 1;

FIG. 4 is an enlarged cross sectional view of one of the regulating devices of FIG. 2;

"ice

FIG. 5 is an enlarged side view showing the detailed construction of the spring device included in FIGS. l-3;

FIG. 6 is an enlarged top view showing the detailed construction of the spring device included in FIGS. 1-3;

FIG. 7 is a fragmentary view showing a modification of the spring device of FIGS. 5 and 6;

FIG. 8 shows an enlarged top view of an alternate construction of the spring device; and

FIG. 9 shows an enlarged side view of an alternate construction of the spring device.

The invention provides a new and improved keyboard construction including a simple and inexpensive regulating device which may be easily and quickly adjusted by relatively unskilled workers. The keyboard with regulating devices attached may be provided as a separate unit for use in an organ, or the unit may be provided as a practice keyboard or training device, or for any other key operated apparatus. In a specific embodiment of the invention, an elongated spring arm is mounted on the balance and guide pins for the key and extends horizontally above the key on both sides of the balance point. A portion of the spring arm is stiff and is provided with keyhole apertures which slip over the pins and fit into grooves provided therein so that the spring may be mounted and detached very easily. A vertical adjusting screw is provided at each end of the spring arm, and thus the screws engage the key on opposite sides of its fulcrum and provide a very simple and accurate means of leveling and tensioning the key. The screw located in front of the fulcrum is carried by the stiff portion of the spring arm, and provides a solid upstop which may be adjusted to move the front of the key up or down and level it with the other keys. The screw which is back of the fulcrum is carried in a resilient portion of the spring arm and controls the pressure which the spring applies to the key. This screw may be adjusted to set the touch of the key. The ends of the spring arm may be resilient and U-shaped with an aperture in one leg which may be forced down on the screw to grip the threads under spring tension and hold them against rotation so that the regulating settings are maintained.

In FIG. 1 there is shown an organ 10 having two manuals 11 and 12. The keys 13 are constructed from three

pieces

16, 17 and :18, and they are supported on the two key frames 19. Each of the keys 13 is provided with a regulating device 14 located over the inner piece 18.

The regulating devices 14 and their relationship to the keys may be seen more clearly in FIGS. 2 and 3. It may be noted that the keyboard construction shown in FIG. 2 has keys 13 which are relatively straight and a key frame 19 which is somewhat simpler than the construction shown in FIGS. 1 and 3, and this illustrates that the regulating devices 14 may be used with keys and frames of various configurations. The regulating devices shown in these figures are all identical.

The regulating devices 14 each include a spring arm 21 having a portion 22 which is relatively stiff and a portion 23 which is resiliently bendable. The

ends

24 and 25 of the spring arm 21 are U-shaped and support the two inverted

screws

26 and 27 which are adjusted to regulate the keys. The regulating devices -14 are supported horizontally over the rear or keytail portion of the keys 13 by the guide pin 28 and the balance pin 29 which are secured to the keyframe 19 and extend vertically upward through openings in the keys. Another guide pin 30 extends into the front of the key, and the

pins

29, 30 together guide the movement of the key. A switch actuator 20 is operated when the key is depressed to throw the switches which energize the tone generator of the organ.

The key pivots on the felt 31 at the base of the balance pin 29, so the felt 31 is the fulcrum of the key. The heads of the two adjusting

screws

26 and 27 engage the

felts

34 and 35 which are located on opposite sides of the balance pin 29. Since the portion 22 of arm 21 is stiif, the screw 26 limits the upward movement of the front of the key and thus forms an up-stop. When the key is depressed, the keytail pushes on the screw 27 and this bends the resilient portion 23 of the spring 21 so that it supplies the force which returns the key when it is released. The spring portion 23 is slightly bent when the key abuts against the up-stop screw 26, and thus the spring applies suificient biasing force to hold the key up.

When the screw 26 is turned, the upper position of the key is changed, so this screw may be adjusted to level any one key with the others. For any given setting of the screw 26, the other screw 27 may be adjusted to change the initial bend of portion 23 thus varying the biasing force applied to the rear of the key. Therefore, the screw 27 provides a convenient means of adjusting the touch or feel of the keys. The tops of

screws

26 and 27 may be turned down and flattened so as to accommodate a conventional adjusting wrench, and since the devices 14 are supported above the keys, the

screws

26 and 27 are readily accessible for adjustment.

The stifi portion 22 of each spring 21 is provided with two apertures of a special configuration which fit over the

pins

28 and 29 and into grooves in the pins so that the arms may be assembled in place very easily. An advantage of this construction is that any individual spring may be easily removed from the

pins

28 and 29, and the key may then he slipped olt the pins and removed from the keyboard. Thus, a damaged key may be readily removed for repair or replacement with a new key without disturbing any of the other keys and without marring the appearance of the musical instrument or training device. The settings of the

adjustment screws

26 and 27 are not disturbed when the spring arm 21 is removed, so the key and spring may be put back in place without requiring any readjustment of the leveling, or touch settings.

The construction of the spring arm 21 of FIGS. 1-3 is shown in greater detail in FIGS. 4, and 6. The arm 21 is made stiff at the portion 22 by bending down the sides 37 to form a channel-shape. The

apertures

32 and 33 which fit over the

pins

28 and 29 are located in this stifl? channel portion and have a keyhole configuration which facilitates mounting the arm 21 on the

pins

28 and 29. The diameter of the semicircular portion of the

apertures

32 and 33 is slightly larger than the diameter of

pins

23 and 29 so that the semicircular edge will fit down over the pins. The keyway edges 38 and 39 are then aligned with the grooves 36 in

pins

28 and 29, and when the arm 21 is moved longitudinally, the

edges

38 and 39 slide into the grooves. The quarter-circle edge 40 of aperture 32 abuts against the pin 28 when the arm. is properly located. The

edges

33 and 39 of aperture 32 are preferably shorter than the corresponding edges of aperture 33, so the arm 21 is located by edge 40 and guide pin 28 and is not located from the balance pin because it may be rapped forward, backward or sideways during spacing of the keys. The semicircular portion of aperture 32 is slightly elongated so that the pins will fit into the

apertures

32 and 33 even though the spacing between the pins will vary slightly from one key to another because of the rapping. The extended quartercircle edges '41 permit the key-way edges 39 to be bent down slightly as shown in PEG. 4, and edge 39 engages the lower surface of the groove 36 whereas edge 38 engages the upper surface to provide a tight fit. The bent edge 39 of hole 32 is on one side of arm 21 and edge of hole 33 is on the other side so that the arm 21 is twisted very slightly when mounted in place to make sure the

edges

38 and 39 grip firmly on the top and bottom surfaces respectively of the groove 36.

The U-shaped end portions 24 and are resilient and each has an aperture 42 in the lower leg in alignment with an aperture in the upper or free leg. The apertures 42 are formed to provide a thread for receiving the adjusting screws 26 and 27, and the apertures '43 are about the same diameter as the outside diameter of the screw thread. Thus, the screws may be advanced in the apertures 42 to extend through the apertures 43, and the edge of apertures 43 will be in semi-engagement with the screw thread. When the

screws

26 and 27 have been properly adjusted, the upper or free legs may be forced down, and the edges of apertures 43 will engage the screw thread under spring tension supplied by the resilient U-shaped end portions, thereby preventing rotation of the screws and securing them in the desired positions.

FIG. 7 shows a modification of the U-shaped end portions of the spring arms. The upper or free leg of the

end portions

24 and 25 is at a slight angle with respect to the lower leg, and the extreme ends 53 of the free legs are bent on the center line of the holes 43. This in eifect makes the holes 43 slightly elliptical so that the edges thereof will grip the adjusting screws 26 and 27 tightly.

FIGS. 8 and 9 show another construction for the arm 21. The construction is generally quite similar, but the configuration of the

keyholes

32 and 33 is different and the ends of the arm are not U-shaped. The edges 48 and the bent edges 49 which fit into the grooves 36 on the

pins

28 and 29 have the same relationship as discussed in connection with FIGS. 5 and 6, but an extension 51, which is centrally located and rectangular, is provided to permit bending edges 49 down. The keyhole apertures 32 and 33 are located in the channel-shaped portion 22 of the arm as previously explained, and the flat portion 23 supplies the spring action for tensioning the keys. The up-stop and leveling screw 26 is received in the threaded aperture 42 at end 24, and the tension adjusting screw 27 is received in the threaded aperture 42 at end 25.

It is apparent from the foregoing description that the keyboard construction and regulating device of the in vention requires relatively few component parts, and all of these parts may be fabricated comparatively inexpensively. The regulating device can be adjusted easily and accurately and this eliminates much of the manipulation which has been previously required in order to get the keys properly leveled and adjusted to have the desired touch. Although the invention is described herein in connection with a musical instrument, it is appareat that it may be used to provide a practice keyboard, or keyboard consoles of various other types.

I claim:

1. A keyboard including in combination, a key support having a pivot point, a key pivotally mounted on said support and having first and second portions on opposite sides of the pivot point, an elongated arm supported adjacent said key at the pivot point, said arm having a stifi portion mechanically coupled to said first portion of said key and providing a rigid stop for limiting the movement of said key, and said arm having a spring portion mechanically coupled to said second portion of said key and applying spring tension thereto for urging said key against said stop.

2. In a musical instrument keyboard, the combination including, a keyframe having a pivot point, a key pivotally mounted on said keyframe and having forward and rear portions on opposite sides of the pivot point, an elongated spring arm supported adjacent and substantially parallel to said key above the pivot point, said spring arm having a stiff portion overlying said forward portion of said key and providing a rigid up-stop for limiting the upward movement of said forward portion of said key, and said spring arm having a resilient bendable pontion overlying said rear portion of said key and applying spring pressure thereto for urging said forward portion of said key toward said stop.

3. A keyboard including in combination, a keyframe having a pivot point, a key pivotally mounted on said keyframe and having first and second portions on opposite sides of the pivot point, first and second adjustable means respectively overlying said first and second portions of said key, a support member including a stiff portion supporting said first adjustable means and a resilient spring portion supporting said second adjustable means, said first adjustable means being movable in a direction substantially perpendicular to said key for leveling the same and for providing a rigid up-stop therefor, said second adjustable means applying the. spring tension of said resilient spring portion of said member to said second portion of said key and normally urging said first portion of said key against said first adjustable means, and said second adjust-able means being adjustable to vary the spring tension of said resilient portion for controlling the touch of said key.

4. A keyboard including in combination, a keyframe, a key pivotally mounted on said keyframe and having forward and rear portions on opposite sides of the pivot point, an elongated spring arm supported adjacent and substantially parallel to said key above the pivot point thereof, said spring arm having a stiff portion overlying said forward portion of said key and a resilient bendable portion overlying said rear portion of said key, a first adjustment screw supported by said stiff portion of said spring arm and engaging said forward portion of said key for leveling the same and for providing an adjustable up-stop, and a second adjustment screw supported by said bendable portion of said spring arm and engaging said rear portion of said key for applying thereto spring pressure supplied by said resilient portion for urging said first portion of said key against said first adjustment screw, said second adjustment screw being adjustable to vary the tension of said resilient portion for controlling the touch of said key.

5. A regulating device for use with a keyboard which includes pivotal keys having portions on opposite sides of the pivot point, said device including in combination, an elongated spring arm including a stitf portion and a resiliently bendable spring portion, a first adjustment screw threaded through said arm and supported by said stiff portion thereof, and a second adjustment screw threaded through said arm and supported by said spring portion thereof, said first and second screws bieng movable transversely of said arm upon rotation thereof, whereby said regulating device is adapted to be mounted adjacent a key of the keyboard with said first and second screws engaging said key on opposite sides of the pivot point so that said first screw provides an adjustable upstop and said second screw applies spring tension to said key and controls the touch thereof.

6. A keyboard including in combination, a keyframe, a balance pin and a guide pin supported adjacent each other on said keyframe, a key mounted on said keyframe "having openings for receiving said pins and being pivotal about said balance pin, said key having forward and rear portions on opposite sides of said balance pin, an elongated spring arm, said spring arm and said pins including cooperating means for detachably fastening said spring arm to said pins for supporting the same above and substantially parallel to said key, said spring arm having a stiff portion overlying said forward portion of said key and providing a rigid up-stop for limiting the upward movement of said forward portion of said key, and said spring arm having a resilient portion overlying said rear portion of said key and applying spring pressure thereto for urging said forward portion of said key toward said stop.

7. A keyboard including in combination, a keyframe, a balance pin and a guide pin supported adjacent each other on said keyframe, a key mounted on said keyframe, said pins being pivotal about said balance pin, said key having forward and rear portions on opposite sides of said balance pin, said pins having grooved portions above said key, an elongated spring arm having a pair of keyhole apertures therein detachably fastening the same in said grooves of said pins for supporting the same above and substantially parallel to said key, said spring arm having a stiff portion overlying said forward portion of said key and providing a rigid up-stop for limiting the upward movement of said forward portion of said key, and said spring arm having a resilient bendable portion overlying said rear portion of said key and applying spring pressure thereto for urging said forward portion of said key towad said stop.

8. A keyboard including in combination, a keyframe, a balance pin and a guide pin supported adjacent each other on said keyframe, a key mounted on said keyframe, said key being pivotal about said balance pin, said key having forward and rear portions on opposite sides of said balance pin, said pins having grooved portions above said key, an elongated spring arm having a pair of keyhole apertures therein detachably fastening the same in said grooves of said pins for supporting the same above and substantially parallel to said key, said keyhole apertures having offset edge portions for resiliently engaging said grooves, said spring arm having a stiff portion overlying said forward portion of said key and providing a rigid up-stop for hmiting the upward movement of said forward portion of said key, and said spring arm having a resilient bendable portion overlying said rear portion of said key and applying spring pressure thereto for urging said forward portion of said key toward said stop.

9. A regulating construction for a keyboard including in combination, a keyframe, a balance pin and a guide pin supported adjacent each other on said keyframe, a key mounted on said keyframe with said pins extending therethrough and being pivotal about said balance pin, said key having forward and rear portions on opposite sides of said balance pin, an elongated arm. detachably fastened to said pins above said key, said arm having a stiff portion overlying said forward portion of said key and a bendable spring portion overlying said rear portion of said key, a first adjustment screw supported by said stiff portion of said arm and engaging said forward portion of said key for leveling the same and for providing an adjustable up-stop, and a second adjustment screw supported by said spring portion of said arm and engaging said rear portion of said key for applying thereto spring pressure supplied by said spring portion to urge said first portion of said key against said first adjustment screw, said second screw being adjustable to vary the tension of said spring portion for controlling the touch of said key.

10. A regulating device for use with a keyboard construction with includes keys having first and second portions on opposite sides of a pivot point and which also includes a balance pin and a guide pin extending through each key, said device including in combination, an elongated spring arm including a stiff portion and a resiliently bendable spring portion, said stiff portion including means for detachably fastening said spring arm to the pins, a first adjustment screw threaded through said arm and supported by said stiff portion thereof, and a second adjustment screw threaded through said arm and supported by said spring portion thereof, said first and second screws being movable transversely of said arm upon rotation of said screws, said spring arm including U-shaped spring portions at each end thereof having apertures therein with edge portions engageable with said screws for applying spring pressure to said screws to hold the same against rotation, whereby said device is adapted to be mounted on said pins with said first and second screws respectively engaging said first and second portions of said key to provide up-stop, leveling and tension adjustments for the key.

11. In a keyboard which includes individual pivotal keys having portions on opposite sides of a pivot point, apparatus for regulating individual ones of the keys including in combination, a guide pin and a balance pin extending through the key and having grooves therein above the key, an elongated arm including a stiff channel portion adjacent one end and a flat spring portion adjabeing adjustable to level the key and to set the touch cent the other end, said channel portion having a pair of thereof.

keyhole apertures therein for detachably fastening said arm to said grooves of said pins, a first adjustment screw References Cited 111 the file 0f thls Patent threaded through the end of said arm adjacent said chan- 5 nel portion and movable transversely of said arm, and a UNITED S1 ATES PATENTS second adjustment screw threaded through the end of 449,756 Egan Apr. 7, 1891 said arm adjacent said spring portion and movable trans- 2,607,257 Hadden Aug. 19, 1952 versely thereof, said first and second screws engaging the 2,764,907 Link 'Oct. 2, 1956 key on opposite sides of the pivot point and respectively 10