US1946581A - Phonograph record cutter and playback combination - Google Patents

Description

PHONOGRAPH RECORD CUTTER AND PLAYBACK COMBINATION Filed Aug. 6, 1929 2 Sheets-Sheet 1 INVENTOR ROBERT HEAD [ATTORNEYS Feb. 13, 1934. R HE y 1,946,581

PHONOGRAPH RECORD CUTTER AND PLAYBACK COMBINATION Filed Aug. 6, 1929 2 Sheets-Sheet 2 INVENTOR ROBERT HEAD ATTORN EYS Patented Feb. 13, 1%34 UNE'FFEE STTES {PATENT QFFHCE Robert Head, Yonkers, N. Y., assignor, by mesne assignments, to United Research Gorporatlon, Long Island @ity, N. Y., a corporation of Delaware Application August 6, 1929. serial No. 383,801 2 Claims. (Cl. 2274-28) This invention relates to the art of phonographic recording and reproducing and more especially is directed toward improvement in recording machines of the disc record'type wherein such machines may be adapted to reproduce as well as record acoustical vibrations.

An object of the invention is to associate a reproducer with a recording machine of the above type in such manner that the mechanism which drives the record against the cutting stylus during recording is identically operable during reproduction to guide the reproducer stylus in the sound groove thus formed substantially inde pendent of any reaction from said sound groove and with consequent minimization of injury thereto.

It is customary in the commercial preparation of phonographic records to play over or reproduce a record as soon as the recording is complete, in order to determine while the artists are assembled if the result is satisfactory or whether the program must be repeated and a new record prepared. It is desirable that this reproduction be accomplished without disturbing the position of the record on the recording machine since the record is not centered before cutting so that it would be difilcult to center it quickly upon a difierent machine for purposes of reproduction.

For the above reasons it will be seen that the playback of a record upon completion is best obtained by suitably associating a reproducer with the recording machine. One method of accomplishing this is to mount the reproducer on an arm pivoted in such manner as to permit the reproducer stylus to traverse an approximately radial path from the perimeter to the center of the record after the manner in almost universal use for phonographs of the disc record tpye.

With such an arrangement the record bearing turntable is merely rotated during reproduction, the sound groove being depended upon to guide the reproducer stylus for causing the reproducer to move from the perimeter to the center of the record in accordance with the helical path traced thereon by the stylus. In order that the reproducer stylus follow the sound groove in this fashion, it is necessary that the stylus has a sharp point and be held against the record by an appreciable force. As contrasted with these requirements, it is necessary that the record he of a relatively soft material such as wax in order that the recording stylus may trace a sound groove in accordance with the acoustical vibrations being recorded.

It will be seen that the above contrasting requirements are of such nature that reproduction in accordance with the procedure outlined causes some degree of permanent injury to the record. This results from the fact that the sharp reproducer stylus point bearing appreciably upon the sound groove in order to be guided thereby, cuts into the relatively soft structure thereof and thereby changes to some extent the shape of the sound groove with resultant distortion for all subsequent reproductions therefrom.

In order to overcome this disadvantage it is proposed in the present disclosure to so associate the reproducer with the recording machine that the same mechanism which guides the recording stylus during recording is identically operable to guide the reproducer stylus'in the sound groove upon subsequent reproduction. With such an arrangement the sound groove efiects substantially no guiding action on the reproducer stylus in accordance with the helical curvature of the groove, but merely vibrates the stylus in accordance with the acoustical impressions formed in the groove. As a result of this arrangement, satisfactory reproduction is obtainable with the reproducer stylus bearing so lightly upon the record as to cause substantially no injury to the same.

In order to explain in detail the manner in which the novel results of the present disclosure are obtained, reference is had to the drawings of which--- Fig. 1 shows in perspective a portion of a record cutting machine of the disc record type with the recorder in position for cutting a record. and 'with a reproducer associated with the recorder supporting member in such manner as to be maintained out of operative relationship to a record.

Fig. 2 shows in perspective a view similar to that of Fig. l but with the reproducer in operative engagement with a record and with the recorder removed from the supporting member in order to disclose more fully the method of mounting the reproducer element.

Fig. 3 shows a detail of the structure disclosed in Fig. l for placing the recorder element in or out of operative engagement with a record.

Fig. 4 shows an assembly view partly in section and partly in side elevation of a record cutting machine of the type referred to herein, this view being adapted to disclose the manner of mounting the recorder and. reproducer elements as well as the arrangement for rotating and advancing the record relative to the cutter or reproducer element.

Referring to Fig. 1, a portion of a wax record 1 partly in section and partly in perspective is shown in position on the turntable 2 of a record cutting machine. The turntable 2 is mounted, as explained below, in such manner as to be rotated and simultaneously advanced radially in the direction indicated by the arrow X for recording purposes. A recorder 4 of a well known electrically operated type is shown with the cutportion passing thru a lug 12 formed on member 7 in such manner as to be rotatable with respect thereto. Screw-threaded thru nut 11 is a bolt 13, the lower end of which fits into a hole drilled thru a lug 9 formed on member 6. The bolt 13 is affixed to lug 9 by means of a pin 10 which prevents the bolt from rotating. As a result of this arrangement any rotation of the nut 11 will cause the member 6 to be raised or lowered with respect to member 7 in accordance with the direction of rotation of the nut.

The mounting member 5 is slidably dove-tailed into the member 6 in such manner as to be horizontally adjustable in an approximately radial direction relative to the axis of the turntable 2. The adjustment is accomplished by means of a force exerted upon the handle 13' affixed to the vertical portion 14 of the member 5. The handle 5 with its vertical portion- 14 and handle 13' constitute a horizontally adjustable crossbar on which the recorder 4 and reproducer 33 are mounted.

The recorder 4 is pivotally mounted at one end of an arm 15, which latter has passing therethru and affixed thereto at an intermediate point a spindle 16 bevelled to a point at each end for mounting the same between the bearings 17 and 18. The opposite end of the arm 15 is tapered to the form of a cylindrical rodfor receiving a weight 19 slidably engaging the same and having associated therewith a screw 20 for clamping the weight in any position on the arm 15. The weight 19 is adapted to partially counterbalance the weight of the recorder 4 in order to regulate the pressure exerted .by the recording stylus 3 upon the record 1. 'This counterbalancing effect is adjusted to a desired magnitude by shifting the weight 19 along to a proper point and then clamping the same in position by means of screw 20. The center 'of gravity of the recorder 4 is below the point of support so that the stylus thereof is maintained in an approximately ver tical position at all times.

the boss 21 and rigidly affixed thereto is a pin 29'- positioned eccentrically on the boss in such manner that when the handle 27 is elevated the pin is out of engagement with the member 15, but when the handle 2'7 is depressed the pin engages the shoulder of the arm 15 thereby rotating the arm in a counterclockwise direction as viewed from the left in Fig. 1, which causes the recorder 4 to be elevated out of operative engagement to the record 1. The boss, due to its frictional contact with member 14, maintains the position to which it is thus rotated, as explained above, and thus effectively clamps the arm 15 in such position until the handle 27 is subsequently raised again.

The vertical adjustment between members 6 and '7 is provided to raise and lower the support of the recorder 4 to care for records of varying degrees ofthickness. During recording, member 5 which slidably engages member 6 is clamped in position for maintaining the recorder in operative relationship to the turntable 2 by means of the clamping arrangement comprising the indentation 28 formed in member 5 cooperating with a ball bearing 29 resting upon the upper surface of member 5 and retained in 'a hole 30 formed in the horizontal portion of member 6 by means of a spring clip 31 having one end thereof rigidly affixed to member 6 by means of the screw 32, and the other end resiliently bearing upon the upper portion of the ball 29 after the manner indicated. The indentation 28 is, of course, in the line of adjustment with the hole 30 so that as member 5 is'adjusted with respeot to member -6, the ball 29 will ultimately be urged into the indentation 28 by means of the resilient action of the spring clip 31 with the resultant clamping action between members 5 and 6.

Associated with the recorder supporting member 5 is a reproducer 33 of the electrically operated type. This reproducer is pivotally mounted as indicated at 34 in a supporting frame 35 which latter is aflixed to the underside of member 5 as indicated by the dotted lines. The reproducer is pivotally supported by frame 35 in such manner that the front and rear portions approximately balance each other so that the stylus 36 engages the sound groove of the record with a light pressure.

In order that the reproducer be placed in or out of operative engagement 'with a record, as desired, means are provided for locking the same in an elevated position. This means comprises a lever 37 pivotally affixed to member 14 by means of a screw 38 passing thru a hole in member 37 and screw-threaded into member 14. The lever 37 has formed in the end thereof a V-shaped notch 39 adapted to engage a pinm afllxed to the reproducer 33. A handle 41 is affixed to the lever at the point of support for elevating or lowering the same. As the handle 41 is lowered the lever 3''! is correspondingly elevated thereby causing the notch 39 to engage pin 40 and thus rotate the reproducer for raising the'stylus 36 thereof out of operative engagement with the record. In order to lock the reproducer in such elevated position, the handle 41 is adapted to resiliently engage a wedge-shaped lug 42 formed on member 14, thus forcing the handle 41 away from the member 14 until it passes beyond the lower portion of the lug 42 whence the resilient tension thereon draws it against the member 14 in a looking position under the shoulder formed by the wedge 42. A pin 43 protrudes from the member 14 below the wedge in order to limit the down-- ward motion of the handle 41. With the handle 41 in' the elevated position shown, the V-shaped notch 39 cooperating with the pin 40 provides a centering action for the reproducer which prevents excessive transverse motion thereof.

During reproduction the reproducer 33 is maintained in operative relationship to the turntable 2 as shown in Fig. 2, by means of the above mentioned clamping arrangement associated with members 5 and 6, comprising elements 29 and 30 cooperating with a suitably positioned indentation 45 formed in member 5. The member 5 is adjusted tothe clamping position of Fig. 1 or to that of.Fig. 2 by means of a force exerted upon handle 13.

Fig. 4 shows a view partly in section and partly in elevation for indicating the manner in which the record is simultaneously rotated and advanced radially against the cutter or reproducer element. The cutter head assembly comprising elements 5, 6 and 7 carrying the recorder 4 and the reproducer 33 is mounted on a supporting member affixed to the frame 51 of the recording machine. This mounting is accomplished by means of bolt 8 passing thru a hole suitably drilled in the member 50 and held in position by means of a nut 52 screw-threaded on the end of the bolt 8. In the view shown, the recorder 4 is in the cutting position on the record 1. The record bearing turntable 2 is mounted on a spindle 53 and is supported by the bearing 54 resting upon a movable carriage 55. The carriage 55 has formed on the lower side thereof lugs 56 adapted to slide in grooves formed in the pair of guide rails 57 (the second guide rail is behind and on line with that shown) which permits a longitudinal motion of the turntable towards and away from the cutter element. The guide rails 57 are in turn affixed at each end to the frame 51 of the recording machine. Affixed to the lower end of the spindle 53 is a bevelled gear 58 which meshes with a second bevelled gear 59 for purposes of rotating the turntable. The gear 59 is afiixed to sleeve 60 which latter is journalled thru at each end and supported by the bearing members 61 which latter are formed integral with the carriage 55. Extending thru the sleeve 60 is driving shaft 62 supported by bearing members afiixed to the frame of the machine at 63 and 64, respectively. The shaft 62 is of rectangular cross section in order to engage rollers 65 mounted within the sleeve 60 for purposes of rotating the gear 59.

This type of construction is required due to the fact that the turntable 2 must be advanced longitudinally at the same time that it is rotated. Hence, the gear 59 in order to remain in mesh with the gear 58 for purposes of rotating the turntable must be adapted to be rotated by the shaft 62 and'at the same time capable of sliding along the same as the carriage 55 is advanced towards the cutter element.

For purposes of advancing the carriage 55 longitudinally and consequently the turntable 2, the carriage has afiixed thereto a lug 66 having a formed on the lower portion thereof a screwthreaded nut adapted to engage a threaded shaft 67 which latter is journalled at each end thru the bearing supports 64 and 68 afiixed to the frame of the machine as indicated.

The operation of the mechanism is as follows: The motor 69 simultaneously rotates shafts 62 and 67 thru the trains of gears '70 and 71. The rotation of the threaded shaft 6'7 cooperating with the threaded nut on member 66 advances the carriage and with it the turntable 2 radially towards the cutter head. At the same time the rotation of shaft 62 due to its rectangular cross-section cooperating with the rollers 65 affixed to sleeve 60 rotates the gear 59 which in turn meshing with gear 58rotates the spindle 53 and hence-the turntable 2 and record 1. Since the gear 59 is mounted on sleeve 60 which in turn is joumalled thru the bearing members 61 affixed to the carriage 55, the advance of the carriage 55, of course, carries the bevelled gear 59 along with it, this longitudinal motion being accomplished by means of the rollers 65 riding on the shaft 62. A pawl and ratchet arrangement '72 is provided for returning the carriage to its initial position manually without rotating the turntable.

.It willbe seen from the description given in connection with Fig. 4 that during the recording process, the cutting stylus 3 of the recording element cuts a spiral sound groove in the record during the recording process. If now the carriage is returned to its initial position and the stylus of the reproducer element placed in the sound groove of the record and the motor 69 started once again, the record will be rotated and simultaneously advanced radially in such manner that the sound groove of the record exerts substantially no guiding action upon the stylus of the reproducer element, and the only guiding pressure exerted on the stylus of the reproducer will be that due to the undulatory impressions representing the acoustical vibrations. Consequently, there will be no permanent injury to the record as a result of the reproduction.

Iclaim:

1. In a phonograph recording and reproducing machine, the combination of a turntable for supporting a disc record, a recorder, a reproducer, a

support therefor radially adjustable relative to said turntable, means independently and adjustably mounting said recorder and said reproducer on said support, means for radially adjusting said support to a first locking position for placing said recorder in operative relation to said turntable and for adjusting said support to a second locking position for placing said reproducer in operative relation to said turntable, means independently operable to cause said recorder or said reproducer to operatively engage a record, and driving means operable to rotate and simultaneously advance said turntable in a radial direction relative to said support for purposes of both recording and reproducing.

2. In a phonograph recording and reproducing machine, the combination of a horizontally positioned turntable adapted to be uniformly and simultaneously rotated and advanced radially relative to a supporting member, said member comprising a fixed portion, a first and vertically adjustable member engaging the same, a second and horizontally adjustable member slidably engaging the first. said second member having formed therein in such slidably engaging portion a plurality of indentations adapted as said second member is adjusted to dependently and adjustably mounted on said second member in such manner that either may be caused to engage or disengage a record; said second member being adjustable to a first said clamping position for positioning said recorder in operative relation to said turntable, and to a second such position for similarly positioning said reproducer.

. ROBERT HEAD.

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