US1233588A - Electrical switching apparatus. - Google Patents

Description

F; B. LITTLE.

ELECTRICAL SWITCHING APPARATUS.

APPLICATION FILED FEB. 25. 1915.

' Patent'd July 17, 1917,

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v F. B. LITTLE.

ELECTRICAL SWITCHING APPARATUS.

, APPLICATION FILED FEB. 25, 1916.

1,233,588. Patented July 17-, 1917.

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wk/a. Y% %Z UNITED STATES PATENT OFFICE.

FREDERICK B. LITTLE, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO

J. C. DEAGAN MUSICAL BELLS,

or CHICAGO, ILLINOIS,

A CORPORATION OF ILLINOIS.

ELECTRICAL SWITCHING APPARATUS.

Application filed February 25, 1916.

To all 207mm it may concern:

Be it known that I, FREDERICK B. LITTLE, citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Electrical Switching Apparatus, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to electrical switching apparatus and is of particular service in connection with musical instruments which employ manually operated keys arranged in banks. I combine such an instrument with a bank of switches that are adapted to effect the operation of responsive devices, such as sound producing elements supplied in addi-- tion to the keyboard musical instrument, this bank of switches being so arranged and proportioned as to permit of the manual operation of the keys while the keys are in controlling relation to the switches which are located above the keys and at the rear ends of the revealed portions thereof.

I will explain my invention more fully by reference to the accompanying drawings which show the invention embodied in a piano, though the invention is not to be lim ited to such a keyboard instrument. In the drawings Figure 1 is a front elevation of a piano associated with a switching mechanism; Fig. 2 is a plan view of the structure shown in Fig. 1; Fig. 3 is a sectional elevation of the upper portion of the instrument on line 3 3 of Fig. 1, the circuit controlled by one of the switches overlying one of the keys being diagrammatically illustrated; Fig. 4 is a side view, partially in section, showing one switch in two alternative positions, one position being indicated by full lines and the other position by dotted lines, the switch when occupying the position shown by full lines opening the circuit controlled thereby and when occupying the position shown by dotted lines closing the circuit controlled thereby; and Fig. 5 is a front view illustrating two switches,- one in as sociation with a white key and the other in association with a black key.

Like parts are indicated by similar characters of reference throughout the different figures.

The keyboard instrument illustrated 1s a Specification of Letters Patent.

Patented July 17, 1917. Serial No. 80,326.

piano with strings and inasmuch as any such keyboard instrument may enter into embodiments of my invention, a detail description of the piano need not be furnished.

The keyboard of the instrument includes a key bed 1 carrying a fulcrum bar 2 and a riser 3 between which and the key bed the white keys 4 and the black keys 5 pass, these keys being held in place by the pivot pins 6 projecting upwardly from the fulcrum bar 2. The rear or inner ends of the keys are associated, in any usual or suitable way, with the action 7, of suitable construction, and which serves directly to set the piano strings or other sound producing elements 8 into vibration.

As is usual, the ends of the key bed 1 are built up or thickened, as indicated at 8 so as to project materially above the part of the key bed which underlies the keys, these key bed enlargements 8 being desirably carried upwardly to have their top faces in about the same plane with the top faces of the black keys 5. These key bed enlargements 8 desirably support the switching equipment which is inclusive of pedestal blocks 9 adapted to rest upon the key bed enlargements 8 or other conveniently arranged supports, these pedestal blocks being fixedly connected by a pipe 10 and a bar continuation 11 of the pipe, the structure 10, 11 being supported by the pedestal blocks materially above the level of the keys. In order to adapt the switching attachment to keyboards of varying lengths the pedestals, or at least one of them (that shown at the left) is adjustably attached to the structure 10, 11 so as to be adjustable lengthwise thereof. Bolt and slot connection 12 may be the means for effecting the adjustable connection between the pedestal support 9 at one end of the instrument. The pipe 10 constitutes the conduit for the wires that lead to the switches which are supported by the pipe, the switching attachment being thus bodily separable from the keyboard of the piano when it is not desired to have the switching mechanism in sight. The switches employed desirably include each a blade 13 adapted to enter between the leaf contacts 14 when permitted by the associate piano key. The stem 15 supporting each blade 13 is pivoted at 16 to an ear projecting from the pipe 10, the portion of the stem between the pivot 16 and the piano key (.4 or 5) engaging the stem being of arc-shape with a curvature suflicient to permit the blade 13 to engage the associate contacts 14 when the key underlying the stem is depressed. A leaf spring 17 is attached to each stem 15 and bears upon the pipe 10 in a manner to keep the stem 15 and the underlying piano key in constant engagement the spring 17 thus forcing the engagement between the blade 13 and the complemental contacts 14 when ever the key underlying the stem 15 is depressed sufiiciently to operate the piano action individual to this key. When such key is released the piano action will elevate it, as is well known by those skilled in the art of pianos, the elevated key lifting the stem 15 and withdrawing the blade 13 from between the contacts 14 previously engaged thereby. The position to which a released piano key restores the blade 13 is indicated by full lines in Fig. 4. I prefer to employ a pair of metallic contact leaves 14 for each contact blade 13 to avoid noise and in order to avoid noise that might result consequent upon the mutual separation and the. resultant mutual approach of the stem 15 and the underlying piano key, I face the bottom of this stem with felt 18 where the key is engaged.

he responsive devices which the switches 13, 14 control may be of any suitable nature, the responsive device illustrated in Fig. 3 as being individual to one piano key being a sound-producing responsive device. The various keys of the piano or those keys which are at the higher end of the keyboard may each have a responsive device individual thereto and when these responsive devices are sound-producing responsive devices they may be arranged to produce tones occupying the same places in the musical scale which are occupied by the tones produced by the operation of the corresponding piano keys. In Fig. 3 I have shown one form of sound producing device including a resonating bar 19 located before a resonating. tube 20, a hammer 21 being operable to strike the bar 19 when the magnet 22'controlling this hammer has its circuit closed at the contacts 13, 14 individual thereto when the piano key individual to such contacts is depressed. After the magnet 22 is energized the contact actuator 23 is moved by the armature that carries the hammer to separate the contact 24 from the contact complemental thereto to open the magnet circuit, this arrangement being illustrated and claimed in my co-pending. application Serial No. 80,328, filed Feb. 25, 1916. The source of current is illustrated as a battery 25, though any suitable source of current, properly adjusted, may be employed. The switch blades 13 belonging to each of the switches are commonly connected with one side of the battery through a main switch 26 common to all of the key switches, the switch 26 being employed to throw all of the key switches out of service when it is desired to play the piano alone. The other side of the battery is connected with as many conductors 27 as there are switches 13, 14, each magnet 22 being included in such conductor 27. A contact 24 and its complement are also included in each conductor 27 each such conductor terminating in a pair of contact leaves 14. The conductors 27 are led through the pipe 10, each being passed through a side thereof where connection with the associate leaves 14 is to be efifected.

By reason of the shape of the switch stems 15 the required range of movement of the switch blade 13 is afforded although the switches engage the piano keys close to the pivotal points of the latter. The required range of movement of the switches is thus effected or permitted by the piano keys while these keys are properly accessible to the fingers of a player whereby the piano may be manually played with the accompaniment furnished by the electro-magnetically oper ated sounding devices. The switchingmechanism desirably extends over the upper half of the keyboard leaving the lower half of the keyboard free so that the part of the piano pertainin to the lower-portion of the keyboard may be played without the accompaniment. Whenever it is desired temporarily to throw the switching mechanism out of circuit the switch 26 may be thrown to open the common conductorleading from the battery 25 to the switch blades 13. When the switching mechanism is to be permanently disassociated from the piano keys the elements 10 and 11 are lifted together with the pedestals 9 attached thereto, these pedestals merely resting upon the supports 8 In order that the structure may be strengthened the pipe 1O is paralleled by the pipe 10 that is connected with the pipe 10 by means of bracing 10 this structure fixedly defining the positions of the switch blades 13, the leaf contacts 14 with respect to the pipe 10 and the pedestals 9 and inasmuch as the pedestals 9 are snugly received between the end pieces 9 the switch stems 15 are quickly and accurately located in proper relation to the piano keys to which these stems are individual.

While I have herein shown and particularly described the preferred embodiment of my invention I do not wish to be limited to the precise details of construction shown as changes may readily be made without departing from the spirit of my invention, but having thus described my invention I claim as new and desire to secure by Letters Patent the following 1. The combination with a key; of a switch individual to the key and including cooperating contacts one movable toward the CII other, the movable contact being provided with a pivotally mounted stem of arc shape engageable by the key, and a spring for substantially maintaining said stem in engagement with the key; and a separably mounted support for the switch disposed to locate the switch over a revealed portion of the key close to the key mounting whereby the portion of the key between the switch and the front end of the key is rendered accessible for operation while the switch is adapted for operation.

2. The combination with .a key; of a switch individual to the key and including cooperating contacts one movable toward the other, the movable contact being provided with a pivotally mounted stem of arc shape engageable by the key, and a spring for substantially maintaining said stem in engagement with the key; and a support for the switch disposed to locate the switch over a revealed portion of the key close to the key mounting whereby the portion of the key between the switch and the front end of the key is rendered accessible for operation while the switch is adapted for operation.

In witness whereof, I hereunto subscribe my name this 17th day of February A. D., 1916.

FREDERICK B. LITTLE.

WVitnesses:

G. L. ORAGG, ETTA L. WHITE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.

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