US2137510A - Gramophone record - Google Patents

Gramophone record Download PDF

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Publication number
US2137510A
US2137510A US94509A US9450936A US2137510A US 2137510 A US2137510 A US 2137510A US 94509 A US94509 A US 94509A US 9450936 A US9450936 A US 9450936A US 2137510 A US2137510 A US 2137510A
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US
United States
Prior art keywords
groove
grooves
width
ridge
records
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
US94509A
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English (en)
Inventor
Severin Edwin
Brunnert Otto
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.)
Telefunken AG
Original Assignee
Telefunken AG
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 Telefunken AG filed Critical Telefunken AG
Application granted granted Critical
Publication of US2137510A publication Critical patent/US2137510A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B3/00—Recording by mechanical cutting, deforming or pressing, e.g. of grooves or pits; Reproducing by mechanical sensing; Record carriers therefor
    • G11B3/68—Record carriers
    • G11B3/72—Groove formations, e.g. run-in groove, run-out groove
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B3/00—Recording by mechanical cutting, deforming or pressing, e.g. of grooves or pits; Reproducing by mechanical sensing; Record carriers therefor

Definitions

  • the invention relates to gramophone records, its object being the production of long-playing records.
  • the gramophone records hitherto usually made, which generally turn at a speed of 78 revolutions per minute, have playing duration of about 4 minutes with a groovewidth of ISO-180a, or microns, a. maximum amplitude of 60p. and a diameter of 30 cm.
  • the playing duration of the records may be increased by somewhat more than double the duration.
  • the introduction of such discs is prevented by the fact that most driving devices have a speed of '78 revolutions per minute and can only be adapted for use with discs having a low number of revolutions by re-buildlng or interposition of special intermediate gears.
  • the ridge generally lying between two grooves is cut away in the case of a maximum amplitude having to be cut so 10 that the grooves abut against one. another or partially intersect each other.
  • pick-ups of small weight and small moment of inertia of the moved mass which have no resonances, such as the rattle" resonances is occurring.
  • the pick-up in the transmission frequency range, it has been found that in the case of maximum amplitudes the pick-up is still safely guided on a record according to the invention.
  • the dimensions of the grooves may be altered according to a further feature of the invention.
  • the 30 width of the grooves and the width of the ridge lying between two grooves are, according to the invention, each reduced to about iii-50 the pitch or spacing of the grooves amounting to about 80-100 35
  • the width of the groove amounts to about 160-180 ,'and the ridge between two grooves to 110 vIf required, the width of the grooves and of the ridges may be further reduced.
  • the depth 40 of the groove amounts only to about 2511. as compared with about 85,; in the hitherto known records.
  • the usual maximum amplitude of with about 200 cycles per second is reduced to approximately 30-35 with 200 cycles 45 per second, it having been found advantageous to make the groove width approximately equal to the maximum useful amplitude. It is now also possible with half the usual maximum amplitude to reduce the speed to about 33%; revolu- 60 tions per minute, so that the same cutting and reproducing conditions in relation to the angle of relief are obtained as with the records turning at 78 revolutions per minute of the type hitherto usually employed. The rise of the groove then lies approximately within the order of magnitude of the rise of the known records with '78 revolutions per minute.
  • the cutting profile in the case of a long-playing record according to the invention is altered.
  • a front angle of about 45 is adopted, in order that with the aforesaid groove width a suflicient groove depth may be obtained, which is necessary owing to the unavoidable striking of the wax disc.
  • Figure 1 represents a section through one of the hitherto usual gramophone records
  • Figure 2 is a section through a record according to 0 the invention. Only a part of the records, on which the sound grooves. are recorded laterally, is shown in diagrammatic form. In the case of the record l,'on which sound grooves, in this case idle running sound grooves, are only shown on one side, the average groove width 3 amounts to about 160-180; while the ridge 4 between two grooves is approximately 1101:. The depth 5 of the grooves amounts to about 85 1.
  • the average groove width I amounts to about 40-50
  • the ridge width 8 also amounts to about 40-50;.
  • Either the modulated grooves may abut against one another, as shown in the centre of the figure, or the grooves may even intersect each other at the upper edges, as will be seen at the right-hand side, so that in the case of a maximum amplitude on the upper surface no complete ridge is present.
  • the depth 9 of the grooves amounts to about 25;.
  • a gramophone record comprising a disk having a spiral acoustic groove of the lateral undulatory type, the width of the groove being approximately equal to its maximum amplitude, and the pitch of the groove being sorelated to the groove width and amplitude that adjacent groove' Figure 2 shows the groove profile for a long-.
  • vsections intersect each other at points where they are modulated maximum amplitude.
  • a gramophone record comprising a disk having a spiral acoustic groove of the lateral undulatory type, in which the maximum amplitude of undulation is at least approximately as great as the groove width, and in which the pitch, groove width, and maximum am plitude bear such a relation to each other that the contour of the record material between adjacent groove sections varies from that of a flat topped ridge to that of an inverted V the altitude of which at any point depends on the sum of the modulation amplitudes or the adjacent groove sections at such point.
  • a gramophone record comprising record material containing a spiral groove of constant pitch and width, said groove being laterally undulated due to sound, the
  • roove width and maximum ampiitude of undulation being approximately equal and being so related to the pitch that the pitch minus the width is at least as great as the maximum amplitude and is at most 1.7 times the maximum amplitude.
  • a gramophone record of the lateral undulatory type comprising a flat disk'having a spiral groove on one face thereof and a ridge in- $0 to 50 microns, and the said groove being from 40 maximum amplitude of to 50 microns, whereby "at points where adjacent groove sections are modulated to as much as two-thirds of their maximum amplitude the normal flat top of the intervening ridge is entirely cut away and the grooves intersect each other.
  • a gramophone record of the lateral undulatory type comprising a flat disk having a spiral groove on one face thereof and a ridge intervening between adjacent has a flat-top at points modulated by less than a groove sections which where the grooves are predetermined amount and an inverted V-shaped top at points where the grooves are modulated by more than said predetermined amount, the width of said groove being from 40 to groove being from to having a maximum width the maximum amplitude from 40 to 50 microns.

Landscapes

  • Toys (AREA)
  • Shaping Of Tube Ends By Bending Or Straightening (AREA)
  • Mechanical Operated Clutches (AREA)
US94509A 1935-08-17 1936-08-06 Gramophone record Expired - Lifetime US2137510A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DET2246A DE896123C (de) 1935-08-17 1935-08-17 Schallplatte

Publications (1)

Publication Number Publication Date
US2137510A true US2137510A (en) 1938-11-22

Family

ID=7543745

Family Applications (1)

Application Number Title Priority Date Filing Date
US94509A Expired - Lifetime US2137510A (en) 1935-08-17 1936-08-06 Gramophone record

Country Status (3)

Country Link
US (1) US2137510A (sv)
DE (1) DE896123C (sv)
SE (1) SE93790C1 (sv)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1278734B (de) * 1963-09-07 1968-09-26 Eberhard Buecheler Verfahren zur Herstellung eines Isolierrohres
DE1297885B (de) * 1968-03-27 1969-06-19 Rabe Erich Verfahren und Vorrichtung zum Schneiden von Schallplatten

Also Published As

Publication number Publication date
SE93790C1 (sv) 1938-12-14
DE896123C (de) 1953-11-09

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