US3158777A - Grid for electron tubes - Google Patents

Grid for electron tubes Download PDF

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Publication number
US3158777A
US3158777A US31360A US3136060A US3158777A US 3158777 A US3158777 A US 3158777A US 31360 A US31360 A US 31360A US 3136060 A US3136060 A US 3136060A US 3158777 A US3158777 A US 3158777A
Authority
US
United States
Prior art keywords
grid
notches
stay
rods
turns
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US31360A
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English (en)
Inventor
Stecker Albert
Hildebrandt Hartmut
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
US Philips Corp
North American Philips Co Inc
Original Assignee
US Philips Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by US Philips Corp filed Critical US Philips Corp
Application granted granted Critical
Publication of US3158777A publication Critical patent/US3158777A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J19/00—Details of vacuum tubes of the types covered by group H01J21/00
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2893/00—Discharge tubes and lamps
    • H01J2893/0001—Electrodes and electrode systems suitable for discharge tubes or lamps
    • H01J2893/0012—Constructional arrangements
    • H01J2893/0019—Chemical composition and manufacture
    • H01J2893/0022—Manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2893/00—Discharge tubes and lamps
    • H01J2893/0001—Electrodes and electrode systems suitable for discharge tubes or lamps
    • H01J2893/0012—Constructional arrangements
    • H01J2893/0019—Chemical composition and manufacture
    • H01J2893/0022—Manufacture
    • H01J2893/0025—Manufacture by winding wire upon a support

Definitions

  • Vibrations or shocks may cause electrodes of electron tubes to vibrate mechanically and this mechanical vibration produces disturbances referred to as microphony.
  • the amplitude of the oscillations is determined by the structure and the material of the electrodes, the mechanical natural frequency, the damping and by the resulting electrode movement.
  • the cathodes and anodes of electron tubes are generally robust; they are heavily damped and have a high natural frequency causing no inconvenience. Hence they substantially do not give rise to direct microphonic phenomenon.
  • the grids of electron tubes are built from thin support rods and grid wires the degree of damping of which is slight and the low natural frequency of which gives rise to microphonic disturbances.
  • the grid support rods of normal grids are comparatively slender and at their low natural frequency are subjected to large displacements which are transmitted in phase to all the grid windings. All the grid windings move in accordance with the vibrating grid stays at right angles to the grid plane and change the electrode spacings. These spacing variations produce inter alia variations in the mutual conductance and the capacitance of a tube.
  • FIGS. 1 and 2 show a portion of a grid made in accordance with the prior art
  • FIG. 3 shows a portion of a grid in accordance with the invention
  • FIG. 4 shows a detail of a grid stay rod in accordance with the invention in a notch of which a grid wire is arranged
  • FIG. 5 shows the same detail after the grid Wire has been secured by pressing.
  • this grid structure provides a self-supporting grid
  • the individual turns can still be slightly twisted in the notches.
  • an insufficient mechanical bond between the grid turns and the support rods is produced. It has been found that the turns and support rods of such grids are damped only slightly, have a low natural frequency and vibrate strongly.
  • the stay rods of which are provided with notches in which at least part of the turns of grid wires are pressed, in order to reduce mechanical grid vibrations, in particular support rod vibrations, the grid wires are deformed in the notches.
  • the deformation of the grid wire which usually consists of molybdenum, is enabled by the use of grid stays made of a suitable copper chrome alloy.
  • the deformed grid wires completely fill the notches so that the maximum high natural vibration at which the stay rods oscillate in the absence of notches is retained. Furthermore the deformation, which substantially consists in a flattening of the wires at the areas at which they engage the notch sides, is so considerable that the wires cannot move or twist in the notches. This provides intimate bonds between the windings and the stay rods which ensure a stable grid the natural frequency of which substantially is a maximum.
  • the mechanically rigid bonds between the stay rods and the turns produce a satisfactory heat conduction from the turns to the rods and hence a satisfactory heat exchange.
  • the rigid bonds produce considerable damping of the grids; this is due to the fact that the stay rod displacements, which are small already owing to their high natural oscillation are further reduced because the grid turns joined to the rods counteract the vibration thereof.
  • the grid turns are arranged in known manner in the form of a cross winding in which each disengaged curved part of a turn at least once crosses the disengaged part of another turn so as to engage it, the grid turns damp one another already at the slightest movement of the stay rods and thus increase the resistance of the grid to microphony.
  • Grid wires 3 are wound with different pitches on two stay rods 1 shown in FIG. 3. Each pair of turns 5 of the two grid wires 3 cross midway between the stay rods 1 so as to engage one another at points 6.
  • the stay rods 1 are provided with notches 2 (FIG. 4) along the lines along which ahey are engaged by the grid wires 3. It is sufiicient, however, for the notches 2 to be provided only in the sides of the rods 1 on both sides of the grid plane.
  • FIG. 4 shows an enlarged detail of a grid support-rod 1 made of a copper-chrome alloy and provided with notches 2.
  • the sides of the notches are at an angle of about 25 to one another and the depth of the notches is about of the diameter of the rod 1. This may be 0.75 mm.
  • molybdenum grid wires 3 having a diameter of for example 0.08 mm., which are softer than the rods 1 and, owing to the fact that the angle between the notch sides exceeds that of the known grid constructions, have a wider contact area.
  • the grid wires are not entirely received in'the notches but about 25 to 35% of their diameter projects beyond the undeformed rod parts.
  • the former are pressed into the latter by means of pressure rollers which act directly upon the wire since these project beyond the rods.
  • the grid wires are deformed at the areas at which they are engaged by the rollers and at the areas at which they are pressed against the hard sides 7 of the notches.
  • the deformation' substantially consists in the wires being flattened at the contact areas.
  • the grid-wires 2 rolled into the notches are intimately joined to the rods 1 and cannot be twisted therein. In order to prevent these bonds from being loosened again in the subsequent process of straightening the grids, the final stretching is performed at a low ate'mper'ature as possible.
  • the appreciable mechanical strength and'damping of thegrids in accordance with the invention is further increased by turns of the grid wires crossing and engaging one another between the rods.
  • the crossing wires3 are'joined to one'another at the joints of contact,
  • a sufiicient damping is also obtained with'a normal arrangement ofthe turns so that the use of cross winding may be dispensed with.
  • a grid'for an electron discharge tube comprising a stay rod provided with'notch'es the sides ofwhich form an angle of about 25 in which a wire, softer than the material of the stay-rod, is pressed and deformed to accommodate the sides'of the notch and filling the notch, said notches having a depth which is about one-tenth the diametergof the support rod.
  • a grid for an electron'discharge tube comprising a plurality of turns of wire wound on a plurality of stayrods each having notches the sides of which form an angle of about 25 and in which wire softer than the material of the stay-rod is pressed and deformed to acchommodate the sides of the notch and filling the notch, said notches having a depth which is about one-tenth the diameter of the support rod, said turns of wire engaging one another between the stay-rods.
  • a grid for an electron discharge tube comprising a plurality of turns of wire wound on a'plurality of stayrods each having notches the sides of which form an angle of -about2 5 and in which 'wir'e s'ofte'r than the material of the stay-rod is pressed and-deforme'clto accommodate the sides of the notch and filling the notch, 'said'tnrns of Wire engaging one another between the stay-rods and being joined together at the points of engagement.

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US31360A 1959-06-16 1960-05-24 Grid for electron tubes Expired - Lifetime US3158777A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE3158777X 1959-06-16

Publications (1)

Publication Number Publication Date
US3158777A true US3158777A (en) 1964-11-24

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US31360A Expired - Lifetime US3158777A (en) 1959-06-16 1960-05-24 Grid for electron tubes

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Country Link
US (1) US3158777A (da)
AT (1) AT222768B (da)
DK (1) DK97142C (da)
GB (1) GB878238A (da)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070217557A1 (en) * 2004-09-23 2007-09-20 Dotomi Inc. Secured identities collaboration system and method

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1570265A (en) * 1923-07-05 1926-01-19 Philips Nv Electrode for discharge tubes
US1792219A (en) * 1926-02-27 1931-02-10 Siemens Ag Method of securing grid wires
US2829298A (en) * 1954-04-14 1958-04-01 Philips Corp Grid for use in electric discharge tubes

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1570265A (en) * 1923-07-05 1926-01-19 Philips Nv Electrode for discharge tubes
US1792219A (en) * 1926-02-27 1931-02-10 Siemens Ag Method of securing grid wires
US2829298A (en) * 1954-04-14 1958-04-01 Philips Corp Grid for use in electric discharge tubes

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070217557A1 (en) * 2004-09-23 2007-09-20 Dotomi Inc. Secured identities collaboration system and method
US8954486B2 (en) 2004-09-23 2015-02-10 Dotomi, Llc Secured identities collaboration system and method

Also Published As

Publication number Publication date
AT222768B (de) 1962-08-10
GB878238A (en) 1961-09-27
DK97142C (da) 1963-10-21

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