US3306152A

US3306152A - Keyboard

Info

Publication number: US3306152A
Application number: US375780A
Authority: US
Inventors: Paul A Klann
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-06-17
Filing date: 1964-06-17
Publication date: 1967-02-28
Anticipated expiration: 1984-02-28

Description

P. A. KLANN Feb. 28, 1967 KEYBOARD 2 Sheets-Sheet 1 Filed June 17, 1964 INVENTOR. PAUL A. KLANN A TIURNEYJ Feb. 28, 1967 P. A. KLANN KEYBOARD Filed June 17, 1964 2 Sheetsfiheet 2 3O INVENTOR.

PAUL A. KLANN BY mawmmafi h 7 United States Pate 3,306,152 KEYBOARD Paul A. Klann, P.0. Bx'2398, Waynesboro, Va. 22980 Filed June 17, 1964, Ser. No. 375,780 11 Claims. (Cl. 84423) This invention relates to improvements in keyboards of the type used in musical instruments.

Keyboards of the type used in musical instruments have conventionally been constructed with individual natural keys of ivory covered wood and flat keys of ebony Wood. Such key construction is quite expensive and various endeavors have been directed toward making keyboards with plastic keys. However, these endeavors to make plastic keys and keyboards have not been entirely successful due to the fact that they do not provide a musician the proper feel equivalent to wood. Also, when molding plastic keys the plastic sometimes shrinks providing hollows in the top of keys and eliminating the feel of a good wood keyboard. It is an object of this invention to provide a keyboard with inexpensive, all plastic hollow keys which is comparable in touch to wood base solid keys.

The base or supports for keys and keyboards have commonly been constructed of wood even though it has been apparent that a metal support could be more quickly and easily fabricated and would be much less expensive than wood. However, the use of a metal support for keys in a keyboard creates the problem of noise with the key contacting the metal. It is an object of this invention to provide a keyboard with a metal base or support which in-' cludes means for eliminating undesirable noise.

It is further desirable that keys in a keyboard construction are guided for vertical movement only about a pivotal connection with side play eliminated and that the keys are stopped at the limits of their travel in a common plane. It is a further object of this invention to provide a unique pivotal support and key stopping means in a keyboard in which the keys are constructed of hollow molded plastic and the support base is constructed of metal.

In a keyboard construction, it is disadvantageous-if, upon lifting the keys for any reason, they come loose from their fulcrum. The keyboard of this invention provides a unique fulcrum arrangement at the rear end of the key so that lifting of the keys will not cause disengagement of the fulcrum or pivot for each key.

It is another object of this invention to provide a simple and unique arrangement for adjusting the tension of a spring means which returns the key to its usual position. This spring means also acts in a direction to keep the pivot point of each key engaged with its fulcrum.

Other objects of the invention will'be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode which has been contemplated of applying that principle.

In the drawings:

FIG. 1 is a top plan view of a portion of a keyboard constructed in accordance with this invention with one key shown partly in section and several keys removed from the support for the sake of clarity and illustration.

FIG. 2 is an end elevation view of the keyboard of this invention again witha portion of a hollow plastic key broken away and shown in section for the sake of clarity.

FIG. 3 is a detailed sectional view through the rear end and pivotal support of one key of this keyboard taken along line 3-3 of FIG. 1.

FIG. 4 is a detailed sectional view taken along line 4-4 of FIG. 3.

t flfice slots 32 and the horizontal abutment 3,306,152 Patented Feb. 28, 1967 FIG. 5 is a detailed sectional view taken along line 5-5 of FIG. 2.

FIG. 6 is a bottom FIG. 2.

FIG. 7 is a detailed 7-7 of FIG. 2.

Referring to the drawings, the keyboard is indicated generally at 10 and includes hollow plastic keys 12 such as the usual naturals and flats 14.

A base or support for the keys of the keyboard is indicated generally at 16 and this base and support together with the keys include guide and stop means indicated generally at 18 as well as pivot means indicated generally at 20 in FIG. 2. Spring means 22 are provided for biasing each key against the stop means to define its usual position prior to being played.

The individual keys are molded of plastic and are hollow and therefore quite light and inexpensive in construction. In ordinary plastic molding, however, if the hollow tops of the naturals 12 were not supported from below they would shrink in the molding process creating a depression which is undesirable to a musician. This invention provides means for overcoming such a drawback by molding within each hollow key ribs 24 and 26 in the wide portion of the key and extending generally parallel to the edges of the key at the playing surface end of each key.

The keys are not only hollow plastic but include a rear open end 28 of each key for removal of molding cores.

The guide and stop means 18 include a horizontal guide and stop flange 30 which is part of the base 16 and is slotted with a plurality of slots 32 which are opened in a vertical plane as shown in'FIG. 1. Each key in turn has a vertical rib 34 and'a horizontal abutment 36. The

plan view taken along line 66 of sectional view taken along line bottom of the hollow key is flat as indicated at 35 in FIG. stop. The keys are- 7 andthis flat surface also serves as a positioned such that the vertical ribs 34 extend into the slots 32 and the horizontal abutments 36 are beneath the bar or flange 30. In this manner, each key is guided for pivotal movement in a vertical plane only by ribs 34 in the bottom side of flange bar 30 defines the top of each key when it is not played and the-top of each key will be in the same plane. Similarly, surface 35 and abutment flange 30 define the extent of travel of each key. In order to keep noise at a minimum, due to the hollow plastic key and the metal support base, each side of the flange bar 30 is lined with a felt cover such as top felt cover 38 and lower felt cover 40. These felt covers are slotted, such as slot 42 in felt cover 38, and the slots are not quite as large as the slots 32 in the flange bar 30 so that the felt overlies the edges of the slot and aids in keeping noise to a minimum.

The pivot means 20 at the rear end of each key includes a fulcrum bar 44 extending toward the front edge of the keyboard as a flange from the base 16 and having its forward edge covered by a plastic covering 46 of anti-friction soft plastic such as Teflon or'the like. The forward edge of fulcrum bar 44 cooperates with a recess 48 in the rear edge of each key to define the pivotal support for each key.

The spring means 22 includes a coil spring 50 for each key. Each coil spring 50 is anchored upon a spring tab 52 which is a portion of the stationary base 16 while the other end of each spring 50 is hooked around an adjusting screw 54 as shown best in FIG. 3. The adjusting screw 54 is rotatably but non-threadedly mounted through each key and includes a non-threaded portion 56 extending through a hole 58 in the top of the key while the tip of the screw 60 is similarly mounted for rotation. The spring 50 has a hooked end 51 which cooperates with the threads 55 of the screw and upon rotating the screw 36 abutting against the tip 51 will move downwardly or upwardly creating more or less tension in the spring 50 and therefore more or less bias of the key which is overcome by a musician pressing downwardly on the forward end of the key.

Thus, adjusting screw 54 controls the touch of each key and each key may be individually adjusted by means of the individual screw 54 carried thereby.

For actuating music producing instrumentalities by means of the key, there is provided a removable actuator plate 64 which may cooperate with switches or other instrumentalities (not shown) as are known in the art. The actuator plate 62 is slotted at 64 for straddling the adjusting nut 54 and has tongues 66 along opposite side edges thereof. These tongues slide into complementary grooves 68 molded into the inside of the key. The actuator plate 62 may be slid in from the rear open end 28 of the key as shown in FIGS. 3 and 4.

As can be seen from the foregoing, applicant has provided a unique keyboard constructed substantially entirely of plastic and metal thus providing a construction which is simple to manufacture, inexpensive and easy to assemble. Furthermore, a unique adjustment for the touch of each key is provided and the construction is such that noise produced by operation of the keys is minimized. The keys pivot about a fulcrum and cannot ordinarily be lifted out of the fulcrum by raising the front end of the keys vertically. To remove an individual key it is pulled forwardly with sufficient force to overcome the force of spring 50. A further feature of the invention is the means for guiding each key in a vertical plane and preventing side play while also defining a common horizontal plane for all the keys by means of a stop surface on the keys cooperating with a guide'bar.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to the preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

I claim:

1. A keyboard comprising: a plurality of hollow molded plastic keys, a stationary metal base for supporting the plurality of keys, stop and guide means including spaced parallel slots in a horizontal flange portion of the base,- the slots open in a vertical plane, and a vertical rib and horizontal abutment on each key, the ribs being guided in the slots and the abutments abutting against the bottom of the flange to define a common horizontal plane for all the keys, a pivot means for each key including a portion of the base and a portion of the rear end of each key cooperating 'to provide a pivotal support for each key, and a spring means connected to the base and to each of the keys in such a manner as to bias each key toward the pivotal support.

2. A keyboard as defined in claim 1 wherein at least some of the hollow molded plastic keys have longitudinally extending supporting inner ribs therein under the playing surface thereof.

3. A keyboard comprising:

(a) a plurality of rear open ended molded hollow plastic keys, each key vertical rib, a horizontal abutment and inner supporting ribs in at least some keys,

' (b) a stationary metal base for supporting and guiding all the keys, the base including a lined horizontal flange with vertical guide slots therein for guiding the vertical rib of each key, the flat bottom surface having a flat bottom surface, a

and horizontal abutment of each key sandwiching the lined flange -to define stop positions for each key,

(c) a lined horizontal bar-like fulcrum cooperating with a recess in the rear end of each key to provide a pivot point for each key,

((1) a coil spring for each key having one end connected to a stationary support and the other end connected to the key in front of the fulcrum,

(e) a screw carried by each key and adjustably holding one end of the coil spring for adjusting the bias of the coil spring, and

(if) an actuator tab extending from the rear open end of each hollow plastic key.

4. A keyboard as defined in claim 1 wherein the pivot means comprises a generally horizontal bar-like fulcrum cooperating with a horizontally extending recess in the rear end of each key.

5. A keyboard as defined in claim 1 further comprising means carried by each key to adjust the bias of the spring means.

6. A keyboard as defined in claim 5 wherein the spring means includes a coil spring for each key, the base including a spring tab for holding one end of each spring and the key including a screw extending through the rear end thereof for adjustably holding the other end of the coil spring.

7. A keyboard as defined in claim 1 further comprising noise reducing linings on the top and bottom of the horizontal bar, the linings being slotted corresponding to the slots in the bar with the slots of lesser size so that the linings protrude over the slots in the bar.

8. A keyboard as defined in claim 4 further comprising a lining on the edge of the generally horizontal barlike fulcrum, the lining being of a plastic material.

9. A keyboard as defined in claim 8 wherein the plastic material is Teflon.

10. A keyboard as defined in claim 9 further comprising an actuator tab extending into a rear open end of each hollow key.

11. A keyboard comprising: a plurality of hollow molded plastic keys, a stationary metal base for supporting the plurality of keys, guide and stop means including a portion of the base and a portion of each key cooperating together to allow all the keys to move in parallel vertical planes and to define a position in a common horizontal plane for all the'keys, a horizontal pivot for each key including a pivotal support portion of the base positioned rearwardly of the keys and a portion of the rear end edge of each key cooperating to provide a pivotal support for each key, and a plurality of coil springs each spring connected to the base and to the rear end of one of the keys and extending longitudinally of the key so as to bias the key toward the pivotal support portion of the base and maintain constant tension on the key to apply a constant force to the rear end edge of each key cooperating with the pivotal support portion of the base.

References Cited by the Examiner UNITED STATES PATENTS 2,530,712 11/1950 Martin 84433 2,832,251 4/ 1958 Hayslett 84433 2,852,973 9/1958 Corbett 84-434 3,099,930 8/1963 Haviland 84-433 3,205,754 9/ 1965 Becwar 84-435 FOREIGN PATENTS 474,925 10/ 1962 Italy.

RICHARD B. WILKINSON, Primary Examiner,

Claims

3. A KEYBOARD COMPRISING: (A) A PLURALITY OF REAR OPEN ENDED MOLDED HOLLOW PLASTIC KEYS, EACH KEY HAVING A FLAT BOTTOM SURFACE, A VERTICAL RIB, A HORIZONTAL ABUTMENT AND INNER SUPPORTING RIBS IN AT LEAST SOME KEYS, (B) A STATIONARY METAL BASE FOR SUPPORTING AND GUIDING ALL THE KEYS, THE BASE INCLUDING A LINED HORIZONTAL FLANGE WITH VERTICAL GUIDE SLOTS THEREIN FOR GUIDING THE VERTICAL RIB OF EACH KEY, THE FLAT BOTTOM SURFACE AND HORIZONTAL ABUTMENT OF EACH KEY SANDWICHING THE LINED FLANGE TO DEFINE STOP POSITIONS FOR EACH KEY, (C) A LINED HORIZONTAL BAR-LIKE FULCRUM COOPERATING WITH A RECESS IN THE REAR END OF EACH KEY TO PROVIDE A PIVOT POINT FOR EACH KEY, (D) A COIL SPRING FOR EACH KEY HAVING ONE END CONNECTED TO A STATIONARY SUPPORT AND THE OTHER END CONNECTED TO THE KEY IN FRONT OF THE FULCRUM, (E) A SCREW CARRIED BY EACH KEY AND ADJUSTABLY HOLDING ONE END OF THE COIL SPRING FOR ADJUSTING THE BIAS OF THE COIL SPRING, AND (F) AN ACTUATOR TAB EXTENDING FROM THE REAR OPEN END OF EACH HOLLOW PLASTIC KEY.