Aug. 14, 1934. M. H. LOUGHRIDGE 1969,895 PHONOGRAPH RECORD AND METHOD OF PLAYING SAME Filed Nov. 10, 1930 2. Sheets-Sheet l

237N Aug. 14, 1934. M. H. LOUGHRIDGE 1,969,895 PHONOGRAPH RECORD AND METHOD OF PLAYING SAME Filed Nov. 10, 1930 2. Sheets-Sheet 2

466 NVENTOR. Patented Aug. 14, 1934 1969,895

UNITED STATES PATENT OFFICE

1969,895 PHONOGRAPE RECORD AND METHOD OF PLAYING SAME Matthew H. Loughridge, Bogota, N. J. 2. Application November 10, 1930, Serial No. 494.63 10 Claims. (CI. 24-42) This invention relates to phonograph records standard records. The purpose of the present and to the method of recording and playing the invention is to provide an attachment to phono same and has for an object to prevent the un grapins of the standard type which puts a char authorized use of phonograph records and to acteristic into the record relative to the sound 5 introduce a certain degree of Secrecy in trans grooves when it is being recorded which prac- 60 mitting and using the Subject matter recorded tically prevents this record being reproduced on on the record. Another object of the invention any inachine except those provided with a cor is to enable phonograph records to be recorded responding attachment. By restricting the use of on standard machines with a particular chair these attachments it is possible to make the 0 acteristic that prevents their reproduction. On Subject of a record practically a secret from un- 65. standard machines; another object of the inven authorized persons. is tion is to record records according to a code key In making a record according to standard prac and which are reproduceable Only by a COrre tice the record blank is centered through a cen sponding code key; another object of the inven tral aperture on the stem of the turntable, and 15 tion is to provide records of sheet stock which are the Spiral is inscribed on the record by a feeding o - grooved to increase their rigidity; other objects mechanism carrying the stylus over the record. of the invention will appear from the following When the record is to be reproduced it is cen specification and the accompanying diaWings, in tered in a similar manner on the stem of the which, turntable and the stylus is fed by following the 20 Fig. 1 is a plan view of a turntable with a grooves of the record in a free tone arm type of 75 record and an attachment for recording or play mechanism, or by a feeding mechanism similar to . ing the record according to this invention; that used in recording the spiral. - Fig. 2 is a side elevation corresponding to If the aperture in the record fitting over the Fig. i. With the record and attaching device in stem of the turntable is materially larger than 25 Section; the stem there is considerable difficulty in finding so. Fig. 3 is a transverse section of the record or in positioning the record so that the spiral is shown in Fig. 1 in the reverse position; concentric with the stem of the turntable and Figs. 4, 5, 6, and 7 are details, partly Sectioned, with the centre of rotation. If the spiral is not showing the relation of the record to the stem properly centered the stylus is subject to a trans 30 of the turntable; verse movement equal to the degree of eccentric 85 Fig. 8 is a plan view, partly Sectioned, show ity which effects the results obtained from the ing the attaching device for positioning the record record, and, when an eccentrically mounted rec in the turntable stem; ord is running there is considerable difficulty in Fig. 9 is a detail of the base part of the at placing the stylus of the pick-up head in the first 35 taching device with the stem Sectioned; groove of the record. 90. Fig. 10 is a side elevation of one form of In the present invention the record is purposely the attaching device complete; off-centered from the stem of the turntable when Fig. 11 is a view from the bottom of a modi it is being inscribed with the result that it can only fied form of attaching device; be reproduced when correspondingly centered on. 40 In the ordinary construction of phonographs, the turntable of a reproducing machine. In 95. it is the intention that records shall be inter practice this is obtained by providing in the changeable so that they may be played on dif centre of the record blank a comparatively large. ferent machines. This is desirable for musical circular opening. In this opening an adapter is and ordinary commercial records, but it is not placed which is a comparatively close fit and 45 desirable in records that are used for dicta which is provided with an aperture to receive the OO phone and similar purposes. In fact, the value stem of the turntable. This aperture is off-cen of such records in many cases would be con tered relative to the centre of the opening in the siderably enhanced if they were So constructed record so that the record and the sound grooves that they could not be played. On the Ordinary thereon are correspondingly off-centered rela 50 phonograph. It is desirable, however, to embody tive to the opening in the record and it is apparent 105. in, or provide attachments to, the standard type that a record so made can be reproduced only of phonograph that will enable these machines when it is placed on a turntable and the central. to be used for making dictaphone records Or for opening is correspondingly off-centered relative reproducing such records, without however in to the stem of the turntable. This gives the cen 55 pairing their intended use in the playing of tral aperture of the record a characteristic rela-10 2 1,969,895 tive to the sound grooves When the record is in The adapter may be constructed of a solid Scribed which must be matched When the record is piece of metal having a spring engagement with reproduced. the turntable stem, an eccentric suitably arranged The adapter, called an eccentric, which fits the thereon to engage the record aperture and with 5 aperture of the record is provided With latching tabs corresponding to 32 arranged as desired. In 80 means whereby the record may be secured to this FigS. 2 and 10 the adapter is inade adjustable so eccentric in a particular position and thereby the that it can be used to make records having differ degree of eccentricity of the Sound grooves is de ent locking positions on the eccentric and to cor termined, making it necessary to establish the respondingly reproduce such records. This con 10 same degree of eccentricity in the record when it prises the base 22 having formed integral there 85 is being played and thus a variety of combina With the eccentric 23 and the hollow split stem tions may be obtained in which records may be 31. The collar or ring 25 is mounted on the selectively used and may be effectively prevented eccentric 23 and rotates on top of base 22 about from otherwise being used. W this eccentric. The base 22 is provided with aper. 5 This invention is intended to be practiced with tures as indicated at 33, 34, 35, and 36 and the 90 Standard phonograph mechanisms which are or collar 25 is provided with one or more depending dinarily used with standard records and for this stems 26 which register with the apertures in 22 purpose the adapter is provided which is applied and engage the record in the position desired by a Spring clutch to the stem of the turntable relative to the centre of stem 31. Fig.11 indicates 20 and is readily replaceable. The adapter may be a modified form of this device in which the eccen 95 formed to take specific sizes of records or it may tric is increased in diameter at 23a and two lock be made adjustable to take different sizes of rec ing members 37 and 33 are arranged to engage ords and, in this Way, by controlling the use of the the record. adapter, the use of the records is controlled. The record as indicated in Fig. 2 is preferably 25 In the drawings, 11 is the turntable mounted on made from sheet Stock Such as aluminuin or cellu the stem 16 of the phonograph mechanism 17. 12 loid and is provided with annular ridges at 14 is the record or record blank with the sound and 15 between which the sound grooves are grooves 13 and provided With an annular ridge at placed. These ridges stiffen the stock and pre 14 and another annular ridge at 15 leaving a sur vent buckling. It will be observed in Fig. 2 that 30 face between these ridges for the spiral of the the Surface of the record slopes downwardly to 105 sound groove. It should be understood that these Ward the Outer edge and when reversed, as in ridges are optional and their use largely de Fig. 3, the Surface slopes in the opposite direc pends upon the class of material out of which the tion. In addition to stiffening the stock of the record is made. records the ridges help to reduce the adhesion 35. The adapter 21 slides over the stem of the between the turntable and the record which 210 turntable 16 which grips by a spring action and ordinarily obtains on a felt covered turntable with engages the central portion 24 of the record by the result that if the record is placed on the turn the eccentric 23, thereby de-centering the record table Without Some securing means it will slip in On the turntable to the extent indicated in Fig. 1. operation and Will automatically become de 40. The adapter 23 is provided with a stem 30 en centered. - 115 closing the turntable stem 16 and securing the top In considering the operation of this invention flange 21 in place. This flange engages the coil the usual pick-up head, preferably of the mag spring 29 bearing upon the washer 28 which en netic type, is used to control the stylus which is gages the ring 25, mounted on the eccentric 23. mounted on an arm substantially tangent to the 45 Aplunger 26 depends from the ring 25 and enters movement of the Sound grooves. The record 120 an aperture in the base 22 to engage an aperture blank is mounted on the eccentric of the adapter in the record as indicated at 26 so that the record and the Sound grooves are thus inscribed eccen and adapter are locked together in this position tric to the aperture in the record through which and rotated by the turntable. The plunger 26 the turntable stem projects although these sound 50 may be released from the record by means of a grooves are concentric with the stem of the turn- 125 latch 27. table in this position. The degree of eccentricity between the aperture When the record is removed and applied to an Of the record and the turntable stem will be other turntable there is not only the difficulty of understood from Figs. 4, 5, 6, and 7 in which line finding a centre in the comparatively large open 55 b passes through the centre of the aperture while ing through which the turntable stem projects, 30 line a passes through the centre of the stem and but the playing centre of the sound grooves is the degree of eccentricity is represented by the displaced from the centre of this opening to an distance between lines a and b. The tab 32 indi extent that may be varied as well and hence this Cates One position of the record on the eccentric centre cannot be found except by a great deal of 60 23 in Fig. 4 and the tab 32 which locks the record experimentation. However, when the record is 135 14 to the eccentric 23 in Fig. 5, indicates another mounted on an adapter having the same degree position of the record with a different degree of of eccentricity as the adapter on which it was eccentricity relative to the stem of the turntable. Originally made, the playing centre is thereby It is apparent that a record locked to the eccen established. 65 tric 23 in the position shown in Fig. 4 would not If an attempt is made to reproduce these rec be properly centered if applied to another eccen ords With the Sound grooves out of centre, this will tric locked to the record in the position shown in cause a transverse movement of the stylus rela Fig. 5, hence a Selective effect is secured in the tive to the turntable which makes the stylus point use of the adapters which further increases the follow a line which experiments indicate to be an 70 element of Secrecy in the application of the in ellipse. If the record is played at a comparatively 45 vention. In Figs. 6 and 7 an additional tab is high Speed this ellipse, by the centrifugal force, indicated at 32d on the eccentric 23 for the pur Such force, for instance, as throws a loose object pose of making the adapters specific to the use from a rotating turntable at a tangent, will throw of a particular type of record having apertures the stylus off the sound grooves and this action 5 registering With these tabs. is somewhat facilitated by the downwardly slop- 150 1,969,895 3 ing surface of the record towards the outer edge having a stem, with a device engaging said stem as indicated in Fig. 2. On the other hand, if the for Selectively positioning a record on said turn record is played at a slow speed it is possible that table having an aperture larger than said stem. in records of the Ordinary type the Stylus head 6. The combination of a phonograph turntable Will hold the Sound grooves but the articulation is having a stem. With a device engaging said stem 80 very much impaired. For secrecy in reproduc for positioning a record having an aperture larger tion, high speed recording is to be preferred as far than Said stem on said turntable and means emi as the application of this invention at the present bodied in said device for adjustably engaging the is known. reCOrd. 0 it is apparent that if an attempt is made to 7. The combination of a phonograph turntable 85 reproduce records which are de-centered on a having a stem with a device engaging said stem machine having a Screw fed mechanism, that it for positioning a record on the turntable having is impossible for this mechanism to carry the an aperture eccentric to the Sound grooves of the stylus over the Sound grooves moving in an eccen record, Said device having a portion eccentric to 5 tric and keep the stylus tracking in the groove. Said Sten for engaging the record. 90 Having thus described my invention, I claim; 8. A phonograph record comprising a record 1. A phonograph record of the disc type hav blank with Sound grooves having a central aper ing a circular aperture for mounting on the stem ture therein for placing on the stem of a phono of a turntable, but of Substantially greater diame graph turntable, the aperture being substantially 20 ter than the stem of Said turntable and sound larger than the stem, said sound grooves being 95 grOOves on Said record eccentric to Said record disc located eccentric to said aperture and having and having their centre within said aperture. their centre within said aperture and means for 2. A phonograph record of the disc type hav centering said Sound grooves on said stem. ing a circular aperture for Inounting on the stem 9. A phonograph record comprising a disc of 25 of a turntable but Substantially larger than said Sheet Stock With annular grooves on the active 100 Stern and Sound grooves On Said record eccentric Surface thereof and a circular aperture for mount to Said record disc but having their centre With ing On the stem of a turntable and substantially in Said aperture. larger than the stem of the turntable, said aper 3. The combination of a phonograph turnta ture being eccentric to the sound grooves of the 30 ble having a stem. With a device engaging said record and means for centering the sound grooves 105 stem for clamping a record on said turntable, said On Said Stem. device having a portion eccentric to said stem en 10. A phonograph record comprising a disc of gaging an aperture in the record which aperture sheet stock having a central circular aperture is eccentric to the sound grooves of the record. for the Stern of a turntable and substantially arg 35 4. The combination of a phonograph turntable er than the Stem of the turntable, an annular sur 10 having a stem, a device engaging said stem for face on said record for receiving sound grooves, positioning a record having an aperture larger Said Surface being inclined relative to the face than Said Stein. On Said turntable, said device hav of the turntable and Said sound grooves being ing a locking engagement with said record to cen eccentric relative to the central aperture of the 40 tre the Sound grooves of the record about the turntable and having their centre located within 115 turntable Stem. Said aperture, 5. The combination of a phonograph turntable MATHEW H. LOUGHRIDGE.

45 20

50 125

55 130

60 35

65 140

70 45

5 50