US2831649A

US2831649A - Pallet valves

Info

Publication number: US2831649A
Application number: US156407A
Authority: US
Inventors: Lamar E Hayslett
Original assignee: Wurlitzer Co
Current assignee: Wurlitzer Co
Priority date: 1950-04-17
Filing date: 1950-04-17
Publication date: 1958-04-22
Anticipated expiration: 1975-04-22

Description

April 22, 1958 L. E. HAYsLETT w PALLET VALVES Filed April 17, 1950 w 2 Sheets-Sheet 1 JNVENTOR.

April 22, 1958 L. E. HAYsLEfT PALLET VALVES Filed April 17, 1950 2 Sheets-Shet 2 :gali

/ INVENTOR.

BYA m =netic path of extremely low reluctance.

taken in| conjunction which: t

United VStates ,Patent O PALLET vALvEs Application April 17, 19s0,s`eria1 No. 156,407

' 7 ciaims. (cl. 251-86) f This invention relates generally to theoperation of air actuated electric organs and more particularly to the operation and mounting ofvalves in such an organ.

In a preferred type of electric organ a metal reed spaced from a pickup element is used as a tone generator as described by Hoschke in his Patent N0.`2,015,014. A potential is applied across each reed and itsassociated pickup element or elements, so that the reed and its pickup act as the plates of a capacitor. The capacitauce of each of said capacitors is varied by vibrating the reed by an air blast Vand the electrical oscillation set up is amplified and applied to some transducing means such as a loud speaker. An electric organ utilizing such tone generators is provided with either a pressure or a vacuum air chest and a pallet valve is provided for each reed or for a group of reeds. This invention is primarily concerned with electromagnetic means for controlling pallet valves in electric organs. I v

Electromagnets for controlling pallet valves could be mounted individually, but this would be cumbersome and expensive and wiring would be dfiicult.

An object of thisV invention is a provision of structure for mounting a plurality of pallet valve actuating electromagnets.

A further object of this invention is the provision of structure as set -forth in the foregoing object, said structure being of electrically conductive material to provide a common connection to a plurality of electromagnets.

A magnetic field is the strongest when it is Vprovided with a complete path of low reluctance. Specifically, in an electromagnet havingan armature, the armature is actuated most efliciently when the total air gap between one end of the magnetcore, the armature, and the other end of the magnet core is very small. To preclude interaction and improper operation of Vadjacent electromagnets, it is imperative that stray flux from each magnet should be precludedin so far as possible i `An important object of this invention is' the provisio of a pallet valve actuating electromagnet having a mag- A specific object of this invention is the provision of a mounting structure for a plurality of pallet valve actuating electromagnets which provides areas of high reluctance between adjacent magnets to afford a distinctive magnetic path for each electromagnet to preclude interaction among electromagnets. 1

Energization of pallet valve actuating magncts causes transient Vdisturbances which may be picked up inadvertentlyV and magnified to cause-clicks or other annoying noises to appear in the output of an electric organ.

VAnother' object of this invention is the provision of electromagnetic valve actuating means and mounting structure for eliminating transient disturbances.

Other and further objects and advantages of the present invention will appear from the following description when with the accompanying drawings in lFig. l is a plan view of a magnet group assembly; I

"ice

frame; i

`Fig. 3 is a section of one of the magnets as taken along the line 3 3 of Fig. 1; 1 f 1 Fig. 4 is'a perspective view of one of the magnets; y Fig. 5 is a perspective view of a magnet armature; Fig. 6 is a perspective view of a grounding tab; Fig.7 is a perspective view of an improvedform of magnet group frame showing amagnet in place thereon; Fig. 8 is a side view showing the modification of Fig. 7; Fig. 9 is aV perspective view showing a frame of Fig.` 7; f 1 1 Fig. 10 is a plan view of a magnetic tab; andV 1 Fig. ll is a'side view similar to the sectionalcview of Fig. 3 showing a modfied structure.

Reference should first be had to Fig. 2 Vwherein a mag-V net mounting frame 12 made of iron, steel, or other material of high magnetic permeability is illustrated. vThe frame 12 is provided with a rearwardly directed flange 14 at Vits lower edge having a plurality of. apertures 16 through which screws or other fastening elements may be placed to secure the frame at a convenient point on'an electric organ. The frame is provided with rectangular spaced slots or apertures 18 for receiving magnet cores 20 (Fig. 3). The magnet cores are constructed withrectangular cross'sections so that the magnets may be spaced closer than they could be with the usual round cores and so that the cores can be fabricated from flat stock without the necessity of grinding the forward'extremity or armature attracting surface of the core to the Shape shown.` The core is reduced in cross sectional dimension to form a shoulder 22 which abuts against a spring contact 24 as lwill be explained later and has a'neck 26 extending through the aperture 18. The core'may be'secured to the frame by welding or by peening over the end of the neck 26 or by any other desirable means. Directly below each slot or aperture 18 Vin the framel 12 is a'slot 28, each of which has a shoulder 30 and a forwardly projecting tongue 32. A large transverse slotV 34 is placed substantially midway between each pair of slots 18 and extends transversely of the frame a distanc'e at least as great as the extreme transverse lirnits of the slots 18, 28 as will be apparent hereinafter.

Referring next to Figs. 3 and 4, each magnet coil 36 is Wound on an insulated form 38, the inside dimensions of which fit snugly over the armature core'20. vEach form 38 has end sections 40 of insulating materialfor retaining the coil windings thereon. The end'section at the rear of each coil form has two upwardly projecting

lugs

42 and 44 thereon, the former extending upwardly a greater distance than the latter. The leads of the coil Winding are wrapped around small necks adjacent the upper extremity'of each of these lugs. The grounding tab 24 previously referred to is shown in perspective in Fig. 6 and conforms in shape generally to the rear end [piece 40 having an upstanding finger 46 similar to the lug 42, but having no structure comparable to the lug 144. The tab is formed from a thin sheet of phosphor bronze or other switch material and as previously noted with Irespect to Fig. 3 is held against the frame 12 by the :side of which isspaced 'an upwardly directed ear 52.

The rear section 54 of the armature is provided with an aperture 56 and a slot 58, the purposeof which Will be disclosed later. The forward end 60 of the armature is displaced upwardly so that it maycooperate with the portion of the 3v magnet core as seen in Fig. 3. The armature is mounted in the slot 28 in a vertical plane and is then twisted into a horizontal plane with the neck 50 of the armature resting on the shoulder 30. The lower edge of the angularly disposed tongue 32 provides a knife-edged bearing for the upper surface of the neck 50. i

A curved frame section 62 extends rearwardly from di-rectly .above each slot or aperture ^18 and has a corrugatedupper surface. A tension spring 64 fits over the :section 62 and is connected to the end section 54 of the armature 48. Spring tension is adjusted by moving the spring from one to another of the corrugations on the upper surface of the section 62. The aperture 56 and slot V58 prevent rotation of the spring and consequent change in spring tension. The forward end of the core 20 is substantially arcuate in shape as is the cooperating portion at thetp 66 of the forward end 60 of the armature. The tip 66 is provided with a shoulder 68 in order that the tip 66 will align itself directly With the core 20 When the magnet is energized.

In Fig. 3 the frame 12 is shown secured to a mounting surface 70 of `an electric organ with an aperture 72 in this surface which is to be understood as being an air passage to or from a vibratile reed. The armature 48 is provided near its forward end with an aperture 74 within which is removably secured a rubber grommet 76 having at its lower extremity a socket 78 provided for retaining the pallet member 80 of the valve. The pallet includes a thin section 82 of rigid plastic having a ball 84 fitting within the socket 78. A surface layer 86 of felt or leather is secured to the lower surface of the plastic section 82 as by an adhesive to seal the aperture or port 72 and to eliminate mechanical noise. In the position :shown in Fig. 3 wherein the magnet is deenergized, the resiliency of the rubber grommet 76 and the ball and socket action insures that the pallet 86 will be fiat against the surface 70 to seal the port 72 under the action of spring 64. When the magnet is energized, the section 66 quickly aligns with the armature 20 and tends to stop without overshooting due to the shoulder 68 restricting the magnetic path and also due to the top of the grommet 76 abutting against the magnet. It may be seen that the magnetic path through the core 20, armature 48 and frame v12 is of very low reluctance as each of these is of magnetic material and the air gap between the core 20 and section 66 is short. The slots 34 in the frame provide areas of high reluctance between adjacent magnets and prevent undesirable interaction. An integral strip 88 joins the extremities of the curved sections 62 of the frame 12 and a projection 90 is provided on the strip 88 adjacent each section 62 to provide a mounting lug for a resistor 92 which is also connected to the lead Wire of the magnet coil which is wrapped around the lug 44. These resistors are provided to reduce transient voltages developed upon energization and deenergization of the magnets.

A modification of my invention is shown in Figs. 7-10 wherein parts similar to those heretofore described are identified by like numerals with the addition of the subscript a. The frame member 12a is made in this embodiment of non-magnetic material which, for example, may be aluminum, brass or plastic. The frame member 12a is provided with a rearwardly directed mounting fiange 14a having apertures 16a therein for receiving screws or other fasteners. Apertures 18a are provided for receiving the armature cores 20a, and apertures 28a having shoulders a are spaced therebelow for receiving the armatures. In this modification the upper bearing surface for the armature is not struck forward to form a tongue as disclosed in the earlier form. Sections 62a extend to the rear of the frame for receiving armature biasing Springs 64a which are connected to armatures 48a which may be identical with the armatures 48. In this modification the

spool end pieces

94 and 96 are made of metal or other conductive material and have upstanding offset

arms

98 and 100 respectively. Each of the arms is notched at .4 the top as at 102 and 104 and is provided with a

lower notch

106 and 108 respectively. Additionally, each arm is provided with an aperture 110 and 112, respectively, and with

lateral notches

114 and 116 between the upper and lower notches. The insulating coil form 38a is provided with tabs at the forward end which have ears 117 which may be bent outwardly to secure the spool end 94 in place. The ends of the coil winding are brought out at opposite ends of the magnet and wound about the

notches

114 and 116 of the metallic spool ends, and soldered to provide a good electrical connection. A resistor 92a is provided to suppress clicks as explained with regard to the earlier form of the invention and is connected directly between the spool ends. The end of the resistor connected to the rear spool end 96 preferably) has its lead placed through the aperture 112 and bent over the top notch 104 to form a good mechanical connection prior to soldering. The lead from the other end of the resistor could be placed through the hole 110, but for simplicity of mounting it is preferable to wrap it around the top of the arm through the notches 106 and 102, and soldered.

A tab 118 of magnetic material (Fig. 10) is provided with an aperture 120 similar in size and shape to the aperture 18a and has a notch 122 extending upwardly from its bottom and with the top of the notch spaced from the aperture 120 the same distance as the distance lbetween the bottom of the aperture 18a and the top of the slot 28a. An ear 124 extends upwardly from the top of the body of the tab 118 and is integral therewith. As may be seen in Figs. 7 and 8, the tab 118 is inserted against the front of the frame 12a with the aperture 120 and notch 122 aligned with the aperture 18a and the slot 28a respectively and is held in place by a shoulder 22a of the core 20a impinging against it, the extending neck 26a of the core being peened over, welded, or otherwise suitably secured to the frame 12a to clamp the tab 118 to the frame. The magnetic path in this embodiment is completed through the core 20a, the short air gap between the core and the armature 48a, the armature 48a, and through the magnetic tab 118 back to the core 20a. The non-magnetic character of the frame 12a precludes undesired interaction between the magnets. The ear 124 of the magnetic tab 118 engages with the arm 100 and associated Wire connections to form a good electrical connection therewith so that both the resistor and the magnet coil may be grounded through the frame 12a. In the event the frame 12a is made of plastic, additional grounding connections may be required as will be understood. As seen in Fig. 8 the frame and magnet are mounted 'similarly to the construction previously described on a mounting board 70a with the pallet 80a covering a port 72a.

Another form of my invention which is substantially a combination of the two forms previously described is shown in Fig. 11, the frame being of magnetic material and the individual tabs, such as tabs 118 of Fig. 10 being eliminated.l More particularly, frame 12b is made of magnetic material such as iron or steel and is provided with a mounting flange 14b having mounting apertures 16h. Rearwardly curved sections 62b having scalloped upper edges are provided for adjustably securing annature biasing springs 64b which are attached to armatures 48b which may be identical with the armature 48a previously described. The spool end pieces 94b and 96b are made of sheet metal and may be identical with the

end pieces

94 and 96. The end piece 94h may be secured by ears 117b and a resistor 92b may be secured betweenthe upstanding arms 98b and 100b of the end pieces.

A plurality of upstandng lugs 126 are formed integral with the frame 12b, and each of the arms 100b impinges against one of these lugs to form an electrical connection for the associated coil and resistor. The frame is mounted on a mounting board 70b with the pallet 80b closing a port 721). As the frame 12h is made of magnetic material, slots similar to the slots 34 (Fig. 2) are provided to magnctically isolate each magnet.

It is apparent that I have herein presented an improved pallet valve actuating electromagnet and structure for mounting a plurality of such electromagnets in which a path of high magnetic permea'bility is provided through the magnet core, armature, and mounting structure with a very small air gap between the core and armature to insure rapid and certain operation with a minimum number of ampere turns of energization. Paths of high reluctance are interspersed between adjacent magnets to prevent interaction vtherebetween.

Although certain preferred embodirnents of my invention have been shown and described for illustrative purposes, it is to be understood that my invention is not to be limited thereby, but is to include all that which falls within the spirit and scope of the following claims.

I claim: e

1. An electromagnetic valve actuating mechanism comprising a pluralty of magnet cores, a magnet armature associated with each of said cores, and an elongated plate-like member for mounting a plurality of said magnets and their associated armatures, said plate-like member having substantially continuous free l'ongitudinal edges demarcating and terminating the main portion of said elongated plate-like member and including transverse portions of magnetic material between each magnet core and associated armature, and longitudinally spaced nonmagnetic portions extending transversely substantially the entire distance between said longitudinal edges, the nonmagnetic portions being positioned between adjacent magnet cores to prevent nteraction therebetween.

2. An electromagnetic valve actuating mechanism comprising a plurality of units, each including a magnet core and an armature including magnetic material actnatable towards said core, and means for mounting a plurality of said units, said means comprisng an elongated section having substantially continuous free longitudinal edges demarcating and terminating the main portion of said elongated section and including transverse portions of magnetic material between the core and armature of each ofsaid units and longitudnally spaced non-magnetic portions extending transversely substantially the entire distance between said longitudinal edges', the non-magnetic portions being positioned between adjacent units to prevent interaction therebetween.

3. An electromagnetic valve actuating mechanism comprising a mounting bracket, electromagnetic means carried by said mounting bracket, an armature carried by said bracket and actuatable towards said electromagnetic means, said armature having an aperture near its free end, and a valve closure member carried by said armature, said valve closure member including a resilient support member detachably snapable into the aperture in said armature, a pallet, and a universal connection between said pallet and said resilient mounting member.

4. In electromagnetic valve actuating mechanism, an elongated mounting bracket comprising a plate-like mounting surface, rearwardly directed meansproviding attaching structure adapted to be mounted ona supporting surface, said rearwardly directed means being integral with and extending substantially the entire length of said bracket, and a plurality of arms integral with and rearwardly bent from adjacent the top of said plate-like mounting surface and curving downwardly therefrom in a substantially continuous curve and having a plurality of means therein to provide spring anchors, the extremities of the arms being joined by a continuous longitudinal edge integral with the arms. 5. In electromagnetic valve actuating mechanism as set forth in claim 4, and further including a plurality of units mounted on said plate-like mounting surface and each including a magnet core and an armature including magnetic material associated with said core, said platelike mounting surface including transverse portions of magnetic material between each magnet core and associated armature, and longtudinally spaced non-magnetic portions between adjacent magnet cores to prevent magnetic interaction therebetween.

6. An electromagnetic valve actuating mechanism as set forth in claim 1, wherein the plate-like member is made of magnetic material and has slots forming the non-magnetic portions.

7. An electromagnetic valve actuating mechanism as set forth in claim 1 wherein the plate-like member is made of non-magnetic material, and the magnetic portions comprise inserts of magnetic material.

References Cited in the file of this patent V UNITED STATES PATENTS 1,311,830 Mohr July 29, 1919 1,724,924 Graham Aug. 20, 1929 1,736,684 Wiek Nov. 19, 1929 1,765,958 Wiek June 24, 1930 1,958,640 Reynolds May 15, 1934 2,061,920 Pifiath Nov. 24, 1936 2,089,332 Boner Aug. 10, 1937, 2,190,381 Merkel Feb. 13, 1940 2,207,572` Ayers July 9, 1940 2,375,100 Gibbon May 1, 1945 2,392,411 Reisner Ian. 8, 1946 2,493,885 Last Jan. 10, 1950 2,498,807 Hagenback Feb. 28, 1950 g FOREIGN PATENTS 695,555 Germany Aug. 1, 1940