US2562673A

US2562673A - Mounting for switch assemblies

Info

Publication number: US2562673A
Application number: US146101A
Authority: US
Inventors: Merwin J Larsen
Original assignee: CENTRAL COMMERCIAL IND Inc
Current assignee: CENTRAL COMMERCIAL IND Inc; CENTRAL COMMERCIAL INDUSTRIES Inc
Priority date: 1950-02-24
Filing date: 1950-02-24
Publication date: 1951-07-31
Anticipated expiration: 1968-07-31

Description

.Euiy 3i, 1951 Filed Feb. 24, 1950 M. J. LARSEN MOUNTING FOR SWITCH ASSEMBLIES s Sheets-Sheet 1 I 7 wkrwzkrjzarjerz Q; om haw .5

y 31, 1951 J. LARSEN 2,562,673

MOUNTING FOR SWITCH ASSEMBLIES Filed Feb. 24, 1950 3 Sheets-Sheet 2 a. 5 m A fife/z Z021 777060): 4271 0115672).

y 1951 M. J. LARSEN MOUNTING FOR SWITCH ASSEMBLIES 3 Sheets-Sheet 3 Filed. Feb. 24, 1950 151/2 Ward/Z12 raZ o r-f 724215 e1 Patented July 31, 1 951 MOUNTING FOR SWITCH ASSEMBLIES Merwin J. Larsen, Villa Park, 111.,

assignor, by

mesne assignments, to Central Commercial In= dustries, Inc., Chicago, Ill.,

Delaware a corporation of Application February 24, 1950, Serial No. 145,101 12 Claims. (01. 84-423) This invention relates to switch mountings and more particularly to a mounting for use with keyboard musical instruments of the class disclosed in United States Letters Patent Nos. 2,250,065 and 2,487,977 wherein mechanisms are employed for selectively translating audio tone signals into audible sounds for musical expression in response to depression of the playing keys of a piano or other keyboard instrument.

, The herein disclosed invention makes use of an assembly of electric switches in which each individual switch is preferably of the same form as the switch disclosed in said Patent No. 2,487,977 and an object of the invention is the provision of a mounting for facilitating attachment of the assembly to and removal of same from the keyboard of a musical instrument.

v 'A further object is the provision of a mounting of the class and for the purpose set forth, the form and-constructionof which insures applicationof a key switch assembly to a piano or other keyboard musical instrument withavoidance of injury to any part of the instrument, which mounting when attached will hold the key switch assembly at a fixed elevation above the keyboard and correctly correlate the individual switches of said assembly with respective playing keys thereof.

Other and further objects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which:

Figure l is a view in front elevation of a piano showing the invention applied thereto; 1 Figure 2 is a-section taken substantially on line 2 -2 of Figure 1 with parts in full lines;

' Figure 3 is a section taken on line 3--3 of Figure 2;

Figure 4 is a section taken 4-4 of Figure 3; g

Figure 5 is a view in side elevation of one of substantially on line the end jacks;

Figure 6 is a perspective view of one of the end jacks, the various parts of which are disassembled forthe sake of olearness; and

Figure 7 is a vertical section through the switch supporting rail showing a trio switch for use with the invention.

The key switch assembly comprises a horizontal U-shaped bar I which supports a plu-' rality of longitudinally spaced apart switches l i, such that there isa switch for and individual to a'respective playing key K of the keyboard of the piano P. Each individual switch is preferably of the form disclosed in' United" States Letters Patent No. 2,487,977 and in order that the full preferred type of elec-' purpose of the invention shall be clearly understood by persons skilled in the art, said switch is herein shown to comprise at least an output terminal i 2 and a movable contactor [3. The contactor is actuable in response to motion of an associated playing key and eifectively makes electric engagement with said terminal 12 when the key is depressed. This is accomplished by forming the contactor with a coil M, the lower terminal of which is attached to a vertical strip l5 of insulating material contained in the channel of bar it. The contactor is connected to a nut it which is free to slide vertically in said strip, the coil i4 functioning as a retractile spring for urging the nut in a downward direction when the playing key K is depressed against the action of its customary elevating spring S. Passing through the nut and adjustable vertically therein is a playing key controlled plunger [1. Said plunger passes through the lower flange F of said U bar Ill, and, as shown, it bears lightly against the upper surface of said playing key. When the playing key is elevated pressure in an upward direction is exerted against the plunger by the normal upward urge of spring S so as to dis-- No claim is made herein to any of the above named characterizing elements, except in combination with my invention. The key switch supporting rail IE} is a straight bar of metal of such dimensions as to be accommodated in a space of minimum proportions above the playing keys and at the extreme back ends thereof and disposed in a horizontal position above the keyboard. As shown, the length of said bar is approximately equal to'thatof a keyboard having eighty-eight playing keys. However, this may vary according to the octave range of the keyboard with which the invention is used.

The essential feature of the invention consists in providing end mounting jacks which are apends of the aforemen-' plicable to the opposite tioned key switch supporting bar It for quick and convenient application of the bar to or removal of same from the keyboard. To this isadded the feature for fixedly supporting the bar at any predetermined elevation above the keyboard and withsaid output tor-v consisting of unique meansout disabling any of the playing keys and whereby and with like ease and convenience the bar can be detached from said keyboard as and when desired.

The above referred to jacks are shown at 2B and 2| at- Figure 1'. Said jacks-are substantially identical except that they are formed as rights and lefts for a purpose which will be manifest as the description proceeds. structurally and functionally alike except in the respect just mentioned, a description of one of them will suffice for the other. Referring now to Figure 6 in which the component parts of jack 2| are shown disassembled, the jack comprises four

complementary parts

22, 23, 24 and 25.

Part 22 of said jack 2| consists of an L-shaped strip of thin gauge steel providing a vertically disposed long leg or portion 29 and a horizontally disposed short leg or portion 21, the latter formed on its lower edge with a longitudinal series ofdepending V-shaped teeth 28. The leg. or portion 26 is formed with a vertical slot 29.

At; one side of and suitably secured to said leg 26; is a casing 30 having a vertically disposed adjusting screw 3| therein, the upper end of which is swiveled to the upper closed end of said casing as at 32 and formed exteriorly of the casing with a hand knob 33.

Part 23 of said jack is also L-shaped' and formed of thin gauge-steel and provided with a vertical leg or portion 34 and a horizontal leg or portion 35 at the lower end of said vertical leg, said horizontal leg having at its upper edge a longitudinal series of upwardly projecting V- shaped teeth 36. Secured at 31 to the upper end of leg 34 is a metal stamping 38 consisting ofa vertically disposed substantially rectangular portion 39, a horizontal arm 49 at the base thereof and a vertical upwardly extending bracket extension 4| which is rectangular in crosssection. At one side of portion 39 is a guidestrip 42 which is spaced apart from one edge of leg 34, a distance suificientto receive the vertical leg 26 of part 22 of said jack so that when the complementary parts of the jack are assembled the

legs

26 and 34 of parts 22 and 23- are in free edge to edge relation and whereby thei-horizontalleg 35 of part 23 is disposed above the horizontal leg 21 of part 22 and in the same general plane therewith. Said

horizontal legs

35 and 23 are planar and of such thin gauge as to enable their insertion into the case of the piano via the space between an endmost playing key and'the adjacent'cheek block of the case of the piano.

Attachedby screws that it is slidably Its upper end is which said and to'stamping 43 by means of said 46 and part 2-5and so that parts'23, 24* and 25 arezmovable vertically as a. unit when said screw:

3| is turned in one direction; Itfollows from the above that the toothed thus to form coactive jaws of a clamp for securingbar'lli in a fixed position of vertical ade justmentx above the-' keyboard;

As the jacks are- 38a to one side of portion 39 of part 23' of said'jackis a metallic stamping:

lug 44 providing a nut Slidable in the slot 29 is a plate Said plate is attached to said portion 39- the" arrangement of the parts being such that portion 39 is interposedbetween plate;

planar horizontally; disposed legs 21 and-35' of parts 22' and 23 arecapable of adjustment relative to each other;

" against the extensions with 48. The open side of the channel bar Ill is closed by a removable cover 49. The front or closed side of said channel bar is provided with a removable cover 59. The upper and lower flanges FI and F of said channel bar are formed with vertically aligned elongated slots 5|.

As previously stated, the end jacks 29 and 2| are identical except that they are formed as rights and lefts', i. e., the vertical arm 4| of jack 2| extends to the left whereas the corresponding vertical arm of jack 29 extends to the right. This is appreciated on reference to Figure l which shows the switch assembly operatively mounted so that the lower ends of the key actuated plungers of the respective electric switches on bar I!) are in operating relation to the respective playing keys of the keyboard.

When attaching the switch assembly to the instrument the horizontal legs of.

parts

22 and 23 of jack 2| are placed edgewise as a unit iii the space between end playing key K and the right hand cheek block C of the piano so that said legs extend into the case, the-leg 35 ofpart" 23' extending rearwardly and disposed beneath the-lower edges of-the horizontal boar-d" P ofthel case and leg 21. extending downwardly and dis-- posed in the same general vertical" plane as-le'g 35. The screw- 3| isthen turned so as to mov said legs away from each other, the teeth 36. of: leg- 35 being firmly imbedded in the under surface of said board. The teeth28vof leg 21'of said" part 22 are similarly imbedded in theupper'surfiface of the key bed mounting? board B; In this? manner the jack is firmly clamped to the p'iano so as to dispose the extension 4| in a rigid vertical positionat the front of the fall board of t the case of the piano at one end of the keyboard.-

" on the jacks by passing the extensions 4| rip-- war-dly through their coactive-slots 5|-5| at the;

respective ends of said bar. Said extensions-are disposed in back of the aforementioned clamp plates 48 andthe latter are thenpressed firmly resultant clamping. engagement ofthe extensions against adjacent vertical walls of said slots. clamp cover plate- 59. Said plates 48- are each thereof urged to a released-position by springs 48w sothat whenthe screws areturned-inan opposite direction bar I0 is released and can be either;

completely removed, from the keyboard or adjusted vertically and horizontally to properly correlate the plungersof the individual keyactuated switches with their respective playing. keys.

The gist o fthe herein-disclosedinvention finds expression in theform, shape andconstruction, of the component parts of jacks, each jackcone sisting of-- complementary parts, planar portions ofwhich are freely insertable into the case: ofthe piano or sin'iilar-keyboardv musical instruement from exteriorly thereof and via the spaces between the extreme end keys of V the keyboard. and the adjacent cheekblocks of the case otthez piano, whereby and by virtue of the coactive

toothed legs

21 and 35 the jacksare rigidly secured in a position. A further feature of the invention is the herein stated use ofcomple mentary elements-of a clamp in which the-coac This is effected by screws 5| which are mounted on the outer? tive superposed toothed clamping portions thereof be in the same vertical plane with each other and are of planar form and of the same gauge so as to be readily received in the space between said extreme end keys of the keyboard and said adjacent cheek blocks.

What is claimed is:

l. The combination with a musical instrument including a case having a keyboard and a plurality of longitudinally spaced apart electric switches for and actuable by respective playingkeys of said keyboard; of mounting means for supporting said switches above said keyboard for actuation thereof by said playing-keys, said mounting means comprising devices having clamping portions insertable in and removable from said case from exteriorly thereof and adapted for clamping engagement with surfaces of the case interiorly of the latter and at the respective ends of said keyboard and serving when in clamped engagement with said surfaces to support said switches at the back ends of the effective playing surfaces of said playing-keys for free fingering of any selected ones of said keys when playing a musical score.

2. The combination according to claim 1 wherein said devices are each provided with means located exteriorly of said case for adjusting the clamping portions thereof to cause effective clamped engagement thereof with and release of same from said surfaces.

3. The combination according to claim 1 wherein the aforementioned clamping portions of each of said devices consist of planar metallic stampings of like thin gauge.

4. The combination according to claim 1 wherein the aforementioned clamping portions of each of said devices are horizontally disposed and lie in the same general vertical plane and consist of thin gauge planar metallic stampings.

5. The combination with a musical instrument including a case having a keyboard and a plurality of longitudinally spaced apart electric switches for and actuable by respective playing-keys of said keyboard; of mounting means for supporting said switches above said keyboard for actuation thereof by said playing-keys, said mounting means comprising devices having horizontal clamping portions disposed in the same vertical plane and consisting of thin gauge planar metallic stampings insertable in and removable from said case from exteriorly thereof and adapted for clamping engagement with surfaces of the case interiorly of the latter, the upper edge of one clamping portion of each separate mounting device and the lower edge of the other clamping portion thereof having teeth for penetrating said surfaces.

6. A device of the class described comprising a pair of planar L-shaped, slidably connected, metallic members of substantially the same thin gauge; said members disposed edge to edge and respectively provided with coactive superposed and spaced apart clamping portions lying in the same general vertical plane; and means embodied in said device for causing relative sliding motion of said members to varying the spacing of said clamping portions.

7. A device according to claim 6 wherein said means for causing relative sliding motion of said members comprises a nut on one of said members and a screw swiveled to the other member and coacting with said nut to move said members as aforestated in response to rotation of said screw.

8. A mounting for use with a keyboard musical instrument employing a case and a switch assembly adapted to be disposed above said keyboard exteriorly of said case and provided with a plurality of spaced apart electric switches for actuation by respective playing keys of said keyboard, said mounting comprising similar devices for clamping engagement with interior structural parts of said case; and means on said devices for removably supporting said switch assembly above and in fixed horizontal relation to said keyboard with the switches of said assembly in coactive relation to said respective playing keys at the back ends of the effective playing surfaces thereof.

9. A mounting for use with a keyboard musical instrument employing a case and a switch assembly adapted to be disposed above said keyboard exteriorly of said case and provided with a plurality of spaced apart electric switches for actuation by respective playing keys of said keyboard, said mounting comprising similar devices for clamping engagement with interior structural parts of said case at the respective ends of said keyboard, and means on said devices for removably supporting said switch assembly above and in fixed horizontal relation to said keyboard with the switches of said assembly in coactive relation to said respective playing keys at the back ends of the effective playing surfaces thereof.

10. The combination with a keyboard musical instrument employing a case and a key switch assembly disposed above said keyboard at the back ends of the effective playing surfaces of the playing-keys thereof, of means for removably mounting said switch assembly on said case, said means comprising clamps at the respective ends of said assembly for clamping engagement with the case interiorly thereof, said clamps each comprising a pair of coactive clamping portions insertable as a unit between a respective end key and an adjacent end portion of the case.

11. The combination with a keyboard musical instrument including a case and a switch assembly disposed above said keyboard exteriorly of the case and at the back ends of the effective playing surfaces of the playing-keys of said keyboard, of a pair of jacks detachably connected with said switch assembly at the respective ends thereof, each of said jacks comprising a pair of coactive portions for clamping engagement with horizontally disposed spaced apart portions of said case interiorly of the latter.

12. A combined switch organization and mounting for use with a case having a horizontally disposed keyboard, said organization and mounting comprising a rigid rectilinear member, a plurality of longitudinally spaced apart electric switches carried by said member, and means coactive with said case from within the latter for fixedly supporting said member at any selected elevation above and in parallel relation to said keyboard and for disposing said switches for actuation by respective playing keys of said keyboard.

MERWIN J. LARSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,300,878 Reynolds Apr. 15, 1919 2,505,608 Edwards Apr. 25, 1950