US2802996A

US2802996A - Holders for thermionic valves

Info

Publication number: US2802996A
Application number: US404118A
Authority: US
Inventors: Deakin Stanley Thomas
Original assignee: Edison Swan Electric Co Ltd
Current assignee: Edison Swan Electric Co Ltd
Priority date: 1953-01-19
Filing date: 1954-01-14
Publication date: 1957-08-13
Anticipated expiration: 1974-08-13

Description

1957 s. T. DEAKlN 2,802,996

HOLDERS FOR THERMIONIC VALVES Filed Jan. 14, 1954 3 Sheets-Sheet l .NVENTOQ ATTOR NEYS Aug. 13, 1957 s. T. DEAKIN HOLDERS FOR THERMIONIC VALVES 3 Sheets-Sheet 2 Filed Jan. 14, 1954 \NVENTOR MA TM M ATTORNEYS Aug. 13, 1957 s. T. DEAKlN 2,302,995

HOLDERS FOR THERMIONIC VALVES Filed Jan. 14, 1954 3 Sheets-Sheet, 3

ATTORNEYS United States HOLDERS FOR THERMIONIC VALVES Stanley Thomas Deakin, Ewell West, England, assignor to The Edison Swan Electric Company Limited, London, England, a British company Application January 14, 1954, Serial No. 404,118

Claims priority, application Great Britain January 19, 1953 2 Claims. (Cl. 339-90) especially when used for portable apparatus, it is important to prevent the anode lead from becoming disconnected from the anode terminal and this normally means that the lead must be supported from the valve holder. In the case, however, of a high anode voltage terminal, such a support is liable to give rise to leakage in the form of flash over tracking or corona from the high voltage terminal and, moreover, means must be made for ventilation to avoid over-heating of the valve. It is also important to retain the valve in position under conditions of shock or vibration, such, for example, as may occur in vehicles or aircraft.

The main object of the present invention is to provide an improved valve holder which avoids these drawbacks.

According to the present invention, a holder assembly for a thermionic valve of the kind referred to comprises a resilient anode contact projecting downwards from an insulating cap mounted on the upper end of a cylindrical insulating shield adapted to surround the valve, which shield is detachably secured at its lower end to the valve socket member, the said shield being radially spaced from the valve envelope and having side apertures to provide for ventilation of the valve.

Preferably the shield is attached to the base by mengaging formations which may be disengaged by partially rotating the shield.

The terms top and bottom as used herein, refer to positions when the valve is upright and do not preclude the use of the holder in positions other than an upright position of the valve.

In order that the invention may be more clearly understood, reference Will now be made to the accompanying drawings, in which:

Fig. 1 is a side elevation of the holder;

Fig. 2 is a vertical cross-section of the holder shown in Fig. I viewed in the same direction;

Fig. 3 is a horizontal cross-section on the line III-III of Figs. 1 or 2;

Fig. 4 is an underneath plan view of the cap, whilst Fig. 5 is a perspective view from the side of the cap, and

Figs. 6, 6a, and 6b are perspective views of the anode contact assembly.

Referring first to Figs. 1 and 2, the reference 1 indicates the valve socket member, 2 the insulating shield, and 3 is the cap, whilst 4 indicates the valve. The socket 1 in the form shown is of a type suitable for plug-in valves of the kind it is proposed to employ and is formed with an upstanding cylindrical rim 5 from the external surface of which lugs 6 project radially outwards; in the actual arrangement shown, there are four such lugs.

The shield member 2 is formed with a cylindrical part at its upper end, from which ribs 7 extend downwards to a ring portion 8 at the bottom end. Intermediate the ribs 7 are internal lugs 9 (Figs. 2 and 3), projecting radially inwards and adapted to underly the lugs 6 on the rim 5 of the socket. In order to remove the shield it is necessary only to rotate itpartially until the lugs 9 are spaced between the lugs 6 and it can then be lifted upwards. As shown more clearly in Fig. 1, the internal lugs 9 on the shield are located in the ventilating openings between the ribs 7 and extending inwardly, whilst their mid parts are recessed downwardly seen in Fig. l as of a V- or U-shape so that the lugs 6 which are also of V- or U-shapcd formation will rest in the recesses in lugs 9; as shown this will tend to resist rotation of the shield, it being appreciated that the shield 2 is spring pressed upwards in a manner which will be described.

The cap 3 is detachably secured to the upper end of the shield 2 and isshown more clearly in Figs. 4 and 5; it

consists of an inverted channel section 10 from which project side arms 11, the ends of the channel and of the side arms 11 are cut away so that these partsrest in slots in the upper edge of the shield. Fig. 6 shows the anode contact assembly and this comprises a terminal cap 12 intended to rest on the top of the valve anode terminal. The terminal cap is carried on the lower end of a coiled spring 13, the upper end of which is secured to opposite ends of a spring retaining strip 14. The mid part of the strip 14 is formed by the clamping jaws 15 for securing an insulated lead 16 (Fig. 2), the conductor of which is attached, preferably by soldering, whilst the sides of the strip 14 are formed with tongue portions 17 which are adapted to slide along horizontal grooves 18 formed in the inner surface of the two sides of the channel formed in the cap.

It will be appreciated that the strip 14 is readily detach able from the carrier cap by sliding the tongues 17 along the grooves 18 and this permits leads to be soldered to the strip 14 when the latter is separated from the cap and this avoids damage which might be caused to the cap by the heat necessary for soldering.

When the holder is fully assembled as shown more clearly in Figs. 1 and 2, the terminal cap 12 is pressed downwardly on the anode terminal of the valve by the spring 13 and the reaction in the cap lifts the shield and tends to hold the lugs 6 and 9 (Fig. l) in engagement. The cap is held in engagement with the shield 2 by the outward pressure on the two ends of the spring strip 14 against the inner surface of the shield.

Internal lugs may, if necessary, be provided in the shield to locate the spring clips. Normally, when it is desired to remove a valve, the shield 2, together with the cap and anode contact, would be lifted bodily off the valve socket.

It will also be appreciated that with this arrangement a relatively long leakage path is provided between the anode lead and the lead in connections at the base, and moreover, the high voltage leads are protected from danger to the operators by careless handling of the terminal.

In carrying out the invention the cap, the shield, and the socket may all be of any suitable insulating material such as a plastic material, one very suitable material being polychloro trifluor ethylene.

In cases where it is desirable to shield the valve electrostatically this may be effected by a metal shield around the insulating shield. The parts of the metal shield which extend over the openings between the arms 7 should be of mesh or perforated metal and the whole metal shield may conveniently be so formed.

Fig. 6a shows the spring strip 14 with the jaws 15 opened.

Fig. 6b shows an alternative method of securing the lead to the spring strip 14 according to which the jaws 15 embrace the insulation of the lead 16 and the conductor is soldered to the surface of the strip 14,

What I claim is:

1. A holder assembly for a thermionic valve of the type having lead-in wires through the base and a high voltage anode terminal on the opposite end thereof, comprising an insulating socket member, an insulating shield adapted to extend longitudinally substantially over the length of the valve and in spaced relationship thereto, means whereby said insulating shield is detachably secured to said socket member, an insulating cap detachably secured to an end of said shield, a connector for an external supply lead, lugs on said connector extending transversely of and slidable in slots in said cap so that the connector is detachably secured to said cap, resilient strips being formed at opposite ends of said connector, a helical spring carried by said strips and extending longitudinally Within said shield, and an anode terminal contact carried on an end of said spring, axial compression of the helical spring by pressure on said valve terminal acting to cause radial expansion of said resilient strips to grip the internal surface of the insulating shield.

2. A holder assembly for a thermionic valve of the 25 type having lead-in wires through the base and a high voltage anode terminal on the opposite end thereof, comprising an insulating socket member, an insulating shield adapted to extend longitudinally substantially over the length of the valve and in spaced relationship thereto, means for detachably securing the insulating shield to said socket member, an insulating cap detachably secured to an end of the shield, a connector for an external supply lead, lugs on said connector extending transversely of and adapted to slide in slots in said cap so that said connector is detachably secured to said cap, resilient strips being formed at opposite ends of said connector, a helical spring carried by said strips and extending longitudinally Within the shield, and an anode terminal contact carried on a free end of said spring, axial compression of the helical spring causing radial expansion of said resilient strips to grip the internal surface of the insulating shield.

ReferencesCited in the file of this patent UNITED STATES PATENTS 2,242,874 Usselman May 20, 1941 2,307,423 Savage Jan. 5, 194-3 2,716,224 Kruger Aug. 23, 1955 FOREIGN PATENTS 515,551 Great Britain Dec. 7, 1939