US2852973A - Key and key bar - Google Patents

Description

Sept 23, 1958 M. J. coRBET-r, JR 2,852,973

KEY AND KEY BAR Filed June 30, 1953 SPt- 23 1958 M. J. coRBE'r-r, JR 2,852,973

l KEY AND KEY BAR Filed June 30. 1953 n S@ E;

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. Jare/Jf- Sept 23, 1958 M. J. coRBE'r-r, JR 2,852,973 n KEY AND KEY BAR 3 Sheets-Sheet 3 Filed June 30. 1953 l www mmv/mw E INVENTOR.

KEY AND KEY BAR Michael l'. Corbett, Jr., North Tonawanda, N. Y., assignor to rEhe Rudolph Wurlitzer Company, North Tonawanda, N. Y., a corporation of Ollio Application June 30, 1953, Serial No. 365,108

\ Claims. (Cl. 84-423) This invention is concerned generally with an electronic organ, and more specifically with a key and key bar for mounting the same.

This invention is concerned with the provision of a key for an electronic organ. The key is molded of plastic in a one piece construction and is aflixed to a metal member for mounting the key in position in a keyboard. The plastic key and the metal member or key bar to which it is attached have different coeiiicients of thermal expansion, and care must be taken to avoid bowing or cracking of the parts. The keys must be precisely positioned in the keyboard for a neat appearance and for proper engagement by an organists lingers. The keys must be mounted only for vertical pivoting motion free from side sway or twisting which would disturb an organists touch and would hinder proper operation.

It is an object of this invention to provide simplified means for mounting a key and key bar in an electronic organ.

Another object of this invention is to provide an improved adjustment between an electronic organ key and key bar and the mechanism actuated thereby.

Another object of this invention is to provide new or improved means for aiiixing an electronic organ key to a key bar to compensate for different coefficients of thermal expansion of the key and key bar.

More specifically, it is an object of this invention to provide means for attaching an electro-nic organ key to a. key bar at spaced` apart points in different planes to allow relative movement between the key and key bar with different thermal changes in dimensions.

Yet another object of this invention is to provide improved means for positioning an electronic organ key and key bar in a keyboard and for guiding the key and key bar against twisting or lateral movement.

Another object of this invention is to provide electronic organ key and key bar guiding means having an improved, smooth action.

A further object of this invention is to provide means for mounting electronic organ keys and key bars so that they are individually removable from the organ without the necessity of ydisassembling any part of the organ.

Other and further objects and advantages of the present invention will be apparent from the following description when taken in connection with the accompanying drawings, wherein- Fig. 1 is a fragmentary perspective view of a portion of an electronic organ embodying the principles of the invention;

Fig. 2 is an end view of the organ on a slightly enlarged scale;

Fig. 3 is a perspective View of an organ key and key bar and the parts cooperable therewith on a greatly enlarged scale;

Fig. 4 is a vertical sectional view through the key and key bar as taken along the line 4-4 of Fig. 3;

Fig. 5 is a vertical sectional view taken along the line 5--5 of Fig. 4;

2,852,973 Patented Sept. 23, 1958 ice Fig. 6 is a perspective View of the key taken from below the key;

Fig. 7 is a perspective view of the key bar taken from beneath the key bar;

Fig. 8 is a top view showing the attachment of the key bar to a fixed part of the organ as taken along the line 8 8 of Fig. 4;

Fig. 9 is a horizontal view partly in section looking up along the line 9 9 of Fig. 4;

Fig. 10 is a vertical sectional view similar to Fig. 4 showing a modified key and key bar;

Fig. 11 is a horizontal sectional view along the line 1li-11 of Fig. 10;

Fig. 12 is a perspective view of the key guide device shown in Fig. 10;

Fig. 13 is a vertical view partly in section along the.

line 13-13 of Fig. 12;

Fig. 14 is a vertical sectional view along the line 14-14 of Fig. 12; and

Fig. 15 is a fragmentary sectional view similar to a portion o-f Fig. 10 showing the manner in which the key and key bar are removable from the organ.

Referring now in greater particularity to the figures, wherein similar numerals are used to identify like parts throughout, an electronic organ Ztl embodying the principles of the invention is shown in general in Figs. 1 and 2. The organ comprises a cabinet 22 having a pair of keyboards 24, a pedal manual 26, and a Volume control pedal 28. A reed box 30 is suitably supported within the organ cabinet and comprises a plurality of vibratile reed sound generators, and a blower and closed air circuit for vibrating the same. The vibratile reed sound generators are of the type disclosed in Hoschke No. 2,015,016 wherein a pickup element spaced from each reed forms a capacitor therewith. The capacity of each such capaciL tor depends on the spacing between the reed and pickup element, and therefore varies with vibration of the reed. When a D. C. potential is impressed across each reed and associated pickup element, and A. C. potential is generated which is a function of the vibration of the reed. The electrical oscillations so generated are amplified by suitable electronic amplifying means 32, and the amplitied oscillations are applied to a loundspeaker 34 for translating the oscillations into audible organ tones.

The physical configuration of the various organ keys in the keyboards 24 varies from key to key, but the variations in configuration do not form a part of the subject matter of this invention. Accordingly, only a single key is illustrated by way of example in Figs. 349, this key being identified generally by the numeral 36. The key 36 is of a one piece molded construction having a iiat upper surface 38 for contact by an organists inger. The key is provided with longitudinal and transverse reinforcing flanges 46 on its under surface and is provided at its rear or inner end with a depressed or downwardly oifset flange or wall 42. The key further is provided near its outer end with a depending skirt or apron 44 having internal shoulders at 46 and having a recess 48 for receiving a screw head as will be more apparent hereinafter.

A key bar generally designated by the numeral 50 and shown more clearly in Fig. 7 comprises a channel-shaped body portion 52 having flanges along its longitudinal edges. The key bar 50 is provided at its outer or free end with a depending arm 54 having a reversely bent end or tip 56. T he longitudinal flanges of the body portion 52 are terminated short of the depending arm 54 as at 58 to impart a certain degree of resilience to the key bar as will be apparent shortly.

The key 36 is aiiixed to the key bar 5t) at spaced apart points located in different planes. Specifically, a screw 61B is countersunk in the depressed Wall or flange 42 and is threaded into an aperture 62 in the body 52 of the key bar 50. A second screw 64 extends through the apron 44 ofthe key with the head of the screw 48 positioned in the recess 58 and with the shank of the screw threaded into an aperture 66 inl the depending arm/ 54 of the key bar. It will be understood that the screws 60 and 64 cany be sheet metal screws fitting into unthreaded apertures as illustrated in Fig. 4, or they can be machine screws received in threaded apertures, or they can be machine screws extending through unthreaded apertures and held in place by nuts. The screw 64 holds the depending arm S4 against the internal shoulders 46, but does not hold the arm too snugly against these shoulders at the top of the arm. Therefore, when the key bar 50 is elongated relativey to the key 36 by thermal changes in dimension due to the different expansion characteristics of the material of the key and of the. bar,` the upper portionk of the arm 54 merely seats more firmly against the shoulders 46 without causing damage to the key or key bar. Similarly, when the key bar contracts relative to the key, the upper portion of the arm 54 pulls away from the shoulders 46 slightly without causing damage to the key or key bar. It will be apparent that the junction between the key bar body and the depending arm flexes slightly during such relative expansion and contraction, and it is for this purpose that the longitudinal flanges on the body of the key bar are terminated short of the junction as at 58.

A leaf spring member 68 is aflixed to the inner end ofthe key bar 50. The leaf spring member 68 includes a flat central portion 70y held tightly against the top surface of the key bar by fasteners such as rivets 72. One end 74 of the leaf spring member extends outwardly beyond the end of the key bar and is preset upwardly for proper initial positioning of the key and key bar as will be apparent hereinafter. The opposite end 76 of the leaf sprmg member 68 likewise is defiected upwardly and is provided with an elongated opening 78. A screw 8.0 passes through the opening 78 and is threaded into a suitable hole in the body of the key bar. The clamping surface of the screw head bears against the upwardly deflected spring end 76 which maintains tension and thereby holds the screw 80 in adjusted position.

The outwardly extending end 74 of the` spring member 68 associated with each key 38 is apertured for receipt of a screw 82 which is threaded into a horizontal flange 84 of a mounting plate 86 which may extend the entire width of one of the keyboards 24, or which may be formed in sections to makev up this length. The horizontal flange 84 is vertically offset from the major portion of the plate 86 as may be seen in the drawings. Preferably the flange 84 is provided with struck out fingers 88 extending angularly upwardly on opposite sides of the end 74 of the leaf spring member 68 to prevent pivoting of the key and key bar about the screw 82.

An insulating block 90 is vertically mounted beneath the plate 86 for each key 38 and carries a plurality of flexible wires 92 forming key switch contacts. Insulating rods 94 are positioned beneath the free ends of the wires 92 and carry longitudinally extending conductive inserts 96. The rods 94 are under control of organ stop switches so that the rods can be rotated to position the conductive inserts 96 for engagement by the wires 92 when it is desired for certain stops to be played. An actuator 98 in the form of an insulating strip is mounted in vertical position beneath the plate 86 and is provided with suitable apertures for receiving the wires 92. It will be understood that there is an actuator 98 and a set of wires 92 for each key. The actuator 98 is provided with a reduced neck portion 100 etxending upwardly through a suitable aperture in the plate 86 and carrying a rubber cap or bumper 102 positioned for engagement by the screw 80. When the key 3,8 is depressed, the screw 80`pushes down on the rubber cap 102 to lower the actuator 98 and thereby to deflect the wires 92 into contact with the 4 insulating rods 94 or conductive inserts 96 carried thereby to complete a circuit to the reeds.

The plate 86 is provided along its front edge with a downturned flange 104 to which is affixed by suitable means such as screws or welding a vertically upstanding flange 106 of a key control plate 108. This plate is provided with a substantially Z-saped bracket 110 extending substantially from edge to edge of the plate 108. The bracket 110 has an upper, horizontal flange 112 parallel tothe plate 108, and the flange 112 and plate 108 are provided with aligned slots 114. These slots receive the depending stem or leg 116 of a T-shaped guide member 118. The transverse arms 120 of the guide member are secured within the channel-shaped body portion 52 of the key bar 50 near the outer end thereof and are secured thereto by means such as welding or rivets 122. Strips 124 of polyethylene plastic are secured along the upper surfaces of the flange 112 and the plate 108 in the vicinity of the apertures 114 and are held in place by means such as screws or rivets. rIhe polyethylene strips are provided with apertures 126 forming relatively snug fits with the stern or shank 116 of the guide 118, the apertures 114 being large enough so that the stem or shank 116 does: not contact the metal of the bracket 110 or the plate 108. The fitting of the stem 116 through the spaced apart guide apertures in the polyethylene strips guides the key 38 for movement without lateral shifting or twisting, while the engagement of the metal of the guide 1178 against the polyethylene strips provides a smooth action and a vpleasant touch to the organist.

The extreme outer edge of the plate 108 is turned up to form a right angle flange 128. A felt strip 130, is secured to the upper surface of the plate 108 adjacent the flange 128 and is engageable by the apron 44 of the key 36 to limit downward movement of the key. A similarfelt strip 132 is secured on the undersurface of. a right angle bracket 134 affixed to the underside of the plate 108. The depending arm 54 of the key bar 50 projects through a suitable aperture 136 in the plate 108 with the horizontally disposed tip 56 underlying the felt strip 132 which limits upward movement of the key.

The upward inclination of the outer end 74 of the leaf spring member places a slight initial tension on the leaf spring member to maintain the key in its uppermost position with the tip 56 against the upstop. Downward pressure on the key causes the leaf spring member 68 to flex until the apron 44 engages the downstop to prevent further depression of the key. -It will be apparent that the guide 118 as well as the upwardly struck sections 88 prevents pivoting of the key and key har about the mounting screw 82.

A modified structure is shown in Figs. 1.0-15. Many of the parts of the modified structure are similar to those previously disclosed, and such parts will be identified by similar numerals with the addition of the sufiix a. The key 36a is identical with that previously disclosed, being of one piece molded construction and having an upper surface 38a and a depending skirt or apron 44a with a screw head recess 48a and internal. shoulders 46a. The key bar 50a is in part similar to that previously described and has a channel-shaped body portion 52a with a depending arm 54a. The key 36a is held on the key bar 50a.

by screws 60a and 64a in different planes as previously described. The key is pivotally mounted in the same manner previously set forth by means of a leaf spring,

member 68a having a central body portion 70a riveted to the key bar as at 72a. The leaf spring member 68a is provided with upwardly deflected ends 74a and 76a for the purposes previously described.

Improvement in the structure of Fig. 10 is found in the guiding means and the limit stops for limiting up and down movement of the key. A key guide 138 takes the form of a metal channel 140 lying on its side. The horizontal flanges 142 of this channel are maintained in proper spaced apart relation by a plurality of cylindrical spacers 144. Screws 146 pass through suitable apertures in the sheet metal channel 140 and are threaded into the ends of the spacers 144. The guide 138 is provided with a plurality of vertical slots or guideways 148 extending across the web 150 of the channel and partway into the flanges 140. The web and adjacent portions of the flanges are coated inside and out with layers 152 and 154 of polyethylene plastic with the plastic covering the edges of the slots 148. As will be understood, the polyethylene plastic may be cast directly on the sheet metal channel member, thereby obviating the need for fasteners to secure the plastic in position as it will be held by the plastic sections fitting through the slots 148. It further will be understood that-the plastic could be fo-rmed in one or more sheets which would be attached to the metal channel by means such as screws or rivets.

The depending arm 54a of the key bar is provided with a right angle ange 152 which is adapted to fit into one of the slots 148 and to form contact with the polyethylene therein. The flange 152 is formed of metal, and the engagement of the metal flange with the polyethylene in the guide slots 148 provides a smooth action and a pleasant feel to the organist. Since the flange 152 forms a right angle construction with the depending arm 54a, a rigid structure is presented. Thus, the sliding of the ange 52 within the polyethylene coated slots 154 provides an even more positive guiding action preventing lateral deflection or twisting of the key. Further improved positioning is afforded by this construction by virtue of the fact that the flange 152 is located immediately adjacent the screw 64a holding the key on the key bar.

The lower end of the depending arm 46a is provided with a tip 156 which is rearwardly deeced at right angles to the arm, thus being exactly opposite to the tip 56. A strip 158 extends the length of the keyboard and is mounted in fixed position. The strip 158 is provided on its upper surface with a felt layer 160, and on its lower surface with a felt layer 162. The apron 44a is engageable with the upper felt strip 162 to limit downward movement of the key, while upward movement of the key is limited =by engagement of the tip 156 with the lower felt strip 162. It readily will be seen that only a single member thus is necessary to provide both an upstop and a downstop, whereas two such members were necessary in the first construction disclosed.

A further novel feature is found in connection with the structure of the last discussed modification. By removing the screw holding the upwardly deflected spring arm 68a, the key and key bar may be pivoted loosely about the limit stops 158-162 as a fulcrum. Such pivoting movement is illustrated in Fig. 15. It will be seen that the key and key bar thus can be readily easily removed and replaced without the necessity of disassembling any part of the organ.

It will be apparent that the spring mount for the key and key bar affords a positive, yet effective connection ofthe key and key bar to the stationary part of the organ. The location of the screws holding the key onto the key bar in spaced apart planes compensates for differences in thermal expansion. The double guide formed by the spaced slots in the bracket 110 and iby the elongated recesses or slots in the channel 140 positively prevents lateral displacement or twisting of the keys, thus at all times presenting a neat appearance and avoiding unwanted motion. The entire structure obviously is simplified, and the engagement of the metal portions of the key bar with the polyethylene plastic provides a smooth action. The upstop and downstop are readily and conveniently assembled and prevent operation of the key beyond its desired range. In addition, the keys are individually removable as just discussed and as shown in Fig. 15.

lt will be understood that the specific examples of the invention shown and described are by way of illustration only and by way of limitation. Structural modifications can be made and form a part of the current invention in so far as they fall within the spirit and scope of the appended claims.

The invention is hereby claimed as follows:

1. A key for a musical instrument including a key bar affixed to said key, a fixed support, a leaf spring afiixed to said support and to said key bar, said spring having an end portion along said key bar extending at an acute angle therefrom, an adjusting screw extending through said spring end portion and said bar, and a tone producing actuator in contact with said screw, said screw being locked in adjusted position by said spring end portion.

2. A key for a musical instrument as set forth in claim 1 wherein the end of the leaf spring opposite to the end with the adjusting screw is provided with a single mounting hole, wherein the fixed support is provided with a corresponding hole, a fastener extending through the holes in the spring end and in the support for mounting the key on lthe support, and wherein the support is provided with struck up projections on opposite sides of the hole therein and engageable with the edges of the spring to prevent pivoting of the spring about the fastener.

3. A key for a musical instrument as set forth in claim 1 and further including a depending strip projecting below said key, and guide means having a pair of spaced apart members which are spaced different distances from said key, said members having slots therein receiving said depending strip for guiding said key and preventing twisting thereof.

4. A key yfor a musical instrument as set for-th in claim 1 wherein the key bar has a depending member thereon, said key bar and depending member having a predetermined coefiicient of expansion, said key having a different coefficient of expansion and having a depending portion adjacent the depending member on said key bar, means for securing a horizontal partof said key to a horizontal part of said key bar, and means for securing the depending member on said key bar to the depending portion of said key, the securing means being in different planes to allow slight bending of said key and key bar to compensate for the different coefiicients of expansion.

5. A key for a musical instrument as set forth in claim 4 wherein the depending key portion has a vertical seat receiving the depending member on the key bar.

References Cited in the file of this patent UNITED STATES PATENTS 1,840,712 Grant Jan. 12, 1932 2,253,782 Hammond et al Aug. 26, 1941 2,260,412 Stephens Oct. 28, 1941 2,340,050 Gano Jan. 25, 1944 2,495,913 Ahern et al Jan. 31, 1950 2,514,978 Terlinde July 11, 1950 2,558,659 Mork June 26, 1951 2,567,870 Bozak et a1 Sept. l1, 1951 2,612,812 Greenleaf et al. Oct. 7, 1952 2,630,503 Larsen et al. Mar. 3, 1953

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