US1617477A - Spring jack - Google Patents

Description

1,617,477, Feb. 15,l927. RACLARKE SPRING JACK Filed Jan. 14, 1924 posed for easy connection into a circuit, has no insulating member subject to Wear, has

1,617,477 as i oeei ca RALPH ALBERTO CLARKE, or s1. ALBANS, VERMONT, ASSIGNOR TO FRANKLIN [RADIO 7 COMPANY, or 'sr. ALBANS, VERMONT, Acoitr-oaATioN-oii VERMONT:

SPRING JACK.

Application filed January 14, 1924. Serial 'No. 686,094.

This invention relates to certain new and.

useful improvements in spring jacks which are particularly adapted for'usewith radiocommunication circuits and apparatus. Parit is necessary toreducethe capacitive effects between the conductive portions of the'apparatus. Such apparatus often have one or more stages ofamplification, and it'is custornary to couplethe reproducing instrument to the apparatus proper by the use of a springqack for eachstage, to receive a plug member connected to the reproducer; and to provide contact'members in the jack to control the circuits in the apparatus. Owing to tlie'large areas and short distances used in currently manufactured jacks, a high capacitive'eii'ect exists, to the serious impairment of'the selectivity of theapparatus.

It is therefore an object of thisinvention to so design'and arrange the elements of the spring-jack as to produce anflarticle' which occupies slight space,"is cheap in manufacture and easy to mount, has its terminals disits several elements spaced apart and having relatively small capacitive surfaces, is'readily adapted to the Various circuits, and is shielded against body-capacity effects.

In the accompanying drawings are shown several modifications of theapplication' of circuits. Fig. l'is an open circuit jack.

Fig. 9. is a double circuit jack. F 3 is a jack similar to that of Fig. 2 butwith an additional auxiliary blade. F i'gs. 4and 5 are respectively a cross-section on line i-t of Fig.2, and aside view of the jack with the panel in section. 7

My improved spring 'jack comprises a metal supporting member 1 with an insulating base block 2 thereon to receive and main tain electrically insulated from each other the various blade and terminal elements. A threaded aperture 3 through these members serves toreceive the threaded plug sleeve 4, which passes through the customary panel board 5 of bakelite or the like, tohold-the member 1 in place by clamping it tightly to the panel board. A screw 6 may likewise be used for this purpose.

Mounted on this insulating block 2 and this jack consti'uctionfor usewith various fastened thereto bindin'g'posts and screws 7 and 8 are the various spring blades 9,10, 11, 12 of the several figures: Binding post screws? are insulated from and recessedin aperti'ires 13 ofthe metal plate 1; while screw 8' is in electrical connection with the spring blade 10 which'niakes contact-with the plug sleeve element, and with the metal plate'l. The blades may be easily manufactured by punching substantially L shaped blanks from" sheet metal and then bending them to the proper form. The attachingfoot 14 is formed'byb'ending one leg of the blank outof its plane; andfthe other leg or major portion of the spring bladehas itsmaj'or axis disposed chordally with regard toxthe circular base, and substantially radial with re blades intended to come into c ntact with 'the to the major axis'fand"extending? into the path offthe plug; and are adapted to be e'ngard 'to the plug sleeve 4. The 'on'tereiids of j gaged and'niox' edlaterally thereby,".thus

moving the blade in'aplane' parallel-to the base. These cam surfaces 15, 16 are disposed at different planes with regard to the base,lso one ofthem makes contactwitlrthe ball-'point'and' the otherwith tliesleeve on the plug. In order to assure the plug against accidental withdrawal and toaflford a proper contact, a ridged? or18 respectively is provided to engage thegroove of are plug.

To cooperate with these" spring blades are. provided terminal inembers'19'whic'h' are similarly" cutout and formed by PlIHClTil'ig operations; They are each'provid'ed with a small projection or contact point 20 oftun'gsten or the like to'assure regularcontact with the blade element. The ends of the terminal elements are bent and fastened' to tlie insulating base block 2 by means of binding posts and screws 21 which are insulated from the metal plate and recessed in apertures similar to 13.

'The wires used to connect the jack in the circuit or circuits are clamped in the binding posts at 7, 8, and 21. It will be noted that these posts may be set at any angle to avoid bends in the wires.

Only a very small area of the terminal member and of the spring blade are'opposite each other, which assures a very low ca acity when the jack opens the circuit upon t e insertion of the plug. The spring blades tend introduced;

to bend for their whole length in a plane.

parallel 'totlie base, instead of bending only at the line of contact with the base, which assures a long life and full flexibility.

The various figures show theapplicability of the construction of various types of jacks. In Fig. 1 is a so-cal lcd single circuit jack. The plug has but a single contact member which cooperates with the spring blade 9. This blade opens a circuit by moving away from'the contact point- 20 when the plug is In Figs. 2, 4t and 5 is a more complex type,

with two'inoving blades to make contact respective'ly with the ball-tip and the sleeve of a standardplug, as shown in Fig. 5.

In this case each blade opens a circuit upon the iiitroductioii of the plug. The system allows a wide separation of the, spring blades and the terminal members.

Fig. 3 shows a still more complex type, in-

dicating the possibilities of assembly on a base ofa single size. In this case the two right-hand spring blades function as in Fig. 2. but in addition to this, an insulating pillar 22 added, between the spring blade 11 and I Lthe auxiliary springblade 12. This latter spring blade has 'no direct electrical or V mechanical connection Withthe other blades orthe plug except by this pillar; it controls two circuits, one being open when the plug 1 is in the jack, and the other being open when the plug is Withdrawn. As before a wide. space is presented between the blades and terminal members.

. These modificationsof the a plicatio of 1 the new, principle of construction indicate its adaptability to the various types of jacks which are required for various circuit comb nations. V

I claim:

1. In a spring jack, a base and a spring blade held substantially at right angles to "said base and having an integral laterally OfiSGt supporting portion with a bent foot secured to said base, said blade having a plug receiving {portion and adapted to be bent by suchplug upon insertion into the jack in a direction substantially parallelto the plane of said base.

2. In a spring jack, a base, a spring conltact blade held substantially at right angles angles to its plane, and a plurality of spring blades each held substantially at right angles to said base and having an integral laterally offset supporting portion with a bent foot secured to said base, each of said blades having a plug receiving portion and adapted to be bent by such plug upon insertion into the jack in a direction substantially parallel to the plane of the said base, said blades being insulated from each other and converging from their respective securing points to present their respective plug receiving portions opposite said aperture at different distances from the plane of said base.

4. In a spring jack, an insu'latingbase member having a plug sleeve eccentrically mounted therein, a spring blade mounted on said base and extending chordally across said base and presenting its free end opposite said sleeve and being adapted to move in a plane substantially at right angles to the axis of said sleeve.

5. In a'spring jack, an insulating base member having a plug sleeve mounted there- 111,3I1Cl a plurality of spring blades mounted for resiliency in a plane sbustai tially parallelto said base and converging towards said sleeve.

6. In a spring jack, an insulating base, a plug sleeve mounted in said base, a plurality of insulated spring blades mounted by lateral feet on said base, and having cam vsurfaces thereon opposite said sleeve, the

cam surfaces on said blades being disposed in different planes substantially parallel to said base, and said blades beingdisposed for resiliency in said planes.

In testimony whereof, I'aflix my signature.

RALPH ALBERTO CLARKE.

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