US1100755A - Dictaphone. - Google Patents

Description

T. H. MACDONALD, DEGD.

S. B- MACDONALD, EXEUUTRIX.

DIGTAPHONE.

APPLICATION FILED NOV. 4, 1912.

Patented June 23, 1914.

m M Z UNITED STATES PATENT OFFICE.

THOMAS H. MACDONALD, DECEASED, LTE OF IBRIDGELPORT, CONNECTICUT, BY'SOPHIE B. MACDONALD, EXECUTRIX,- OF BR IDGEPORT, CONNECTICUT, ASSIGNOR T0 AMERI- CAN GRALPHOIHONE COMPANY, OF BRIDGEPOBT, CONNECTICUT, ACOBPOBATION OF WEST VIRGINIA.

DICTAPHON E.

Application filed November 4, 1912. Serial No. 729,449.

To all whom'z't may concern:

.Beit known that THOMAS H. MACDONALD, deceased, late of Bridgeport, Connecticut, has invented a new and useful Improvement in Dictaphones, which is fully set forth in the following specification.

This invention relates to graphophones or talking-machines, primarily the type intended for both recording and reproducing and commonly known as 'dictaphones or commercial machines, which type employs a single diaphragmwith two styli (one for recording and the other for reproducing).

Heretofore it has been supposed that a reproducer should bear upon the record-tablet with a pressure greater than that necessary or desirable in a recorder; therefore, with this end in view, various means have been provided whereby additional weight may be applied when thereproducing-stylus is in operative engagement with the recordgroove, and removed when the recordingstylus is in operative relation with the "record-tablet.

One feature of the present invention is the elimination of this additional weight or pressure. w

Another feature is the provision of improved means for preventing lateral play during the recording-operation, while permitting lateral play during the reproducingoperation.

The invention consists of the construction and arrangement of the parts hereinafter set forth and claimed, and will be best understood by reference to the accompanying drawing, in which the figure is an end view, partly in vertical section, of a dictation graphophone equipped with a preferred embodiment of the present invention.

ln the drawing, 1 indicates the cylindrical sound-record, or the blank cylinder, carried on the usual rotating mandrel.

2 is the usual carriage-sleeve surrounding the feed-screw, driven by the usual water (not shown) which likewise serves to rotate the mandrel.

3 is the usual controlling-lever, having at its lower end the ring which encircles the sleeve 2 and has two cut-away portions 4 and 5 with the intermediate nose 6,the parts 4-6-5 constituting the usual camsurface'ada'pted to co-act with the partial feed-nnt (not shown). I

7 is the casing or frame of the carriage, having at itsrear the tubular extension 8 with the reduced nipple 9, which latter is adapted to carry the mouth-piece or listening-tuhe. This extension 8 is detach-ably se cured to carriage 7, as by screw 10.

11 is a telescoping tube located in the extension 8; and 12 is a link connecting the forward end of this telescoping-tube 11 with the nose 6 on controllingdever 3.

13 is a sleeve pivoted in the inner vor rear end of telescoping-tube 11, by the transverse pivot 14 (located in a. vertical plane), to permit lateral play of the sleeve.

15 is the usual speaker or head, having the tubular neck 16, the rear of which latter is secured in the sleeve 13 upon an extended horizontal axis, so as to permit ver tical play of the head 15. The diaphragm of head 15 carries the usual recording-stylus IT and the usual reproducing-stylus 18 in the same vertical plane. the parts in the reproducing position, reproducing-stylus 18 being in operative engagement with the sound-record.

By the construct-ion thus far set forth, it is seen that the head, with its two styli 17 and 18, is free to swing in a vertical plane, by reason of the horizontal pivoting of the neck 16; that it can swing laterally, by reason of the transverse play of the sleeve 13 upon its pivot 14; and that the two styli can be shifted transversely with respect to The drawing shows the cylindrical record or blank 1, by means The dispensing with this additional weight, I

which is one of the main objects of the present invention, is based upon the discovery that if, during the recording-operation, the recording-stylus beheld absolutely locked against any lateral play Whatever, so

that the record-groove will not stagger from side to side, then there will be no appreciable tendency forthe reproducingstylus to chatter or to jump from one groove to the next; and that it is those. tendencies engage conical seats in the rear end of the neck 16. And, in the second place, in order to lock both sleeve and speaker against lateral play, the preferred embodiment comprises a spring-pressed member carried by one of the parts (as the stationary casing 8) and co-acting with a corresponding guidegroove carried by the other member (as the telescoping-tube 11). More specifically, along the top of extension 8 is secured the flat spring 19, preferably counter-sunk to lie flush with, or below the surface of, the extension 8; and from the free end of this spring depends a plunger 20,.which passes freely through a suitable opening in the wall of extension 8, and also through a longitudinal slot in telescoping-tube 11,the lower end or tip of this plunger being tapered as shown. Along the upper side of sleeve 13 is a longitudinal groove or slot 21, having flared sidewalls, adapted to engage snugly the tapered tip of plunger 20. The length of sleeve 13 and its slot 21, and the relative location of plunger 20, are such that in the reproducing position (shown in the drawing) the plunger does not engage the slot, and the sleeve 13 (with the speaker and its reproducing-stylus 18) is capable ofdateral play; but when the partshave been=drawn forward, by handle 3 and link 12, into the recording position (where recording-stylus 17 engages the cylinder 1), then the longitudinal slot 21 of the sleeve 13 engages snugly with plunger 20 anclis thereby locked against lateral play. Preferably the adjustmentis such that the flaring side-Walls of this slot 21 slightly lift plunger 20 against the tension of spring19, so that the latter serves to hold the parts securely in close engagement, andzthereby the sleeve (with the speaker) is firmly held locked against any lateralplay whatever.

The advantages of the present invention are more fully realized by the employment of styli of smaller diameter'than heretofore customary, because, within limits, the smaller the diameter of the recording-stylus, the deeper the record-groove (and the less the tendency of the recording-stylus to stagger from side to side), and because the reproducingrstylus (which is customarily of smaller diameter than the recording-stylus) is less. liable to skip out of the deeper groove, and therefore will more faithfully track the proper course. For example, in the present construction, excellent results have been attained, both in recording and in reproducing, by the employment of a recordingstylus having a diameter of about eighteen one-thousandths (0.018) of an inch, and a reproducing-stylus of somewhat less diameter.

It is to be understood that the invention is not limited to the precise constructions and arrangements above set forth, as they can be varied considerably without losing the benefit of the novel improvements herein disclosed. For example, it is not essential (although it is preferable) that the styli be of. the small dimensions indicated; the spring-pressed plunger or its equivalent might be located in one of the telescoping parts, with the guide-groove in the stationary casing; or the guide-groove might be located in the neck or other part of the speaker, instead of in the sleeve 13, in which case precision of the pivoting of the neck within the sleeve may be dispensed with; and other transpositions of parts or other changes of construction and arrangement of details may be employed, without in any case'departing from the spirit of the invention.

Having thus described the invention, the following is claimed:

1. In a talking-machine, a member having lateral as well as vertical play and carrying a diaphragm provided with a recordingstylus and a reproducing-stylus, means for shifting said member'rectilinearly to bring either stylus into operative position to the exclusion of the other, a stud, and a groove caused to engage therewith by the shifting into position of said recording-stylus, whereby the latter is locked against lateral play.

2. In a graphophone, the combination of a telescoping-member, means for drawing the same in and out, a longitudinally-slotted sleeve pivoted in said member to swing laterally, a speaker pivoted in said sleeve to swing vertically and having a recordingstylus and a reproducing-stylus, and a spring-pressed plunger co-acting with the slotaforesaid to lock said speaker against lateral play during the recording-operation. 3. In a graphophone, the combination of a telescoping-member, means for drawing the same in and out, a longitudinallyslotted sleeve pivoted therein to swing laterally, a speaker pivoted in said sleeve to swing verllw a reproducing-styluaand means for shifting either stylus into operative position reproducing-stylus, and a studadapte'd to be "engaged by the slot aforesaid to lock said speaker against lateral play during the recording-operation.

4. In a recorder-reproducer for graphophones, the combination with a collar pivoted to swingilaterally, a head pivoted to swing vertically in said collar and having-a diaphragm carrying a recording-stylus andwithout change of pressure, of a springpressed plunger adapted to co-act with a head against lateral play when recording. 7

In testimony whereof I, as said executrix,

have signed this specification in the presence of two subscribing witnesses.

SOPHIE B. MACDONALD Ewec'wtm'w of the estate of Thomas H. Maedonald, deceased. o I Witnesses:

' J. S. GRIFFITH,

L. S. EASTMAN.

groove in said collar to lock said collar and 15

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