US1580037A - Phonograph - Google Patents

Description

C. I.HALL

PHONOGRAPH A il 6, 1926.

Filed Jan. 1922 Inventor: Chester I. Hall His Attorney.

Patented Apr. 6, 1926. i

UNITED STATES 1,580,037 PATENT OFFICE.

CHESTER I. HALL, OF FORT'WAYNE, INDIANA, ASS IGNOR T0 GENERAL ELECTRIC COM- PANY, A. CORPORATION OF NEW YORK.

PHONOGRAPH.

Application filed January 20, 1922. Serial No. 530,679.

To all whom, it may concern:

Be it known that I, CHESTER I. HALL, a citizen of the United States, residing at Fort Vayne, in the county of Allen, State of Indiana, have invented certain new and useful Improvements in Phonographs, of which the following is a specification.

My invention relates to 'disc type sound reproducing machines and has for its principal object to provide such a machine in which all the parts are supported in a cylindrical casing the cover of which constitutes therecord turn-table. A further object is to simplify the construction and decrease: the number of necessary parts for phonograph machines in general Without sacrificing the reliability to the end that a high grade, inexpensive machine may be provided." A further object is to adapt my improved machine to electric drive. Other advantages of my improved machine will appear as the de-' scription proceeds.

The features which I believe to be novel are pointed out in the claim appended hereto. The details of construction and operation will be understood from the following description taken in connection with the accompanyingdrawings in which Fig. 1 shows a top view of my machine with the tone arm omitted, and Fig. 2 shows a vertical section taken on line AA of Fig.- 1.

Referring now to the drawings, in which like parts are designated by like numerals, 1 indicates a cup-shaped casing constituting the cabinet of the phonograph. This casing is preferably an iron casting but may be made of other material such as aluminum, and may if desired be stamped from sheet metal. Centrall located in the bottom of this cup is a hu 2 which supports a vertical record spindle 3. A hard steel ball is provided in the bottom of the central opening of the hub forming a step bearing for the spindle. 3. The spindle is guided near its upper end by means of a bearing 4 which bearing is supported from the floor of the casing by the leg members 5 and 6. The bearing housing 4 and the legs 5 and 6 are preferably cast in one piece which may be fastened to the floor of the casing by screws, or when the casing is a casting, may be integral therewith. Near the top of the spindle, above the bearing 4, a collar 7 is provided which has a flat upper surface of sufiicient diameter to concentrically support the record supporting disc 8 in a horizontal position. The disc 8 is provided with a central opening through which the upper end of the spindle 3 extends to cooperate with the central opening in the usual disc phonograph record. The outer edge 9 of the disc 8 is turned down ust outside the upper edge of the cylindrical casing 1. The upper edge of the casing 1 is machined oii' smooth so that the disc 8 forms a rather closely fitting cover for the casing 1, the two being out of contact a sutficientamount to allow free rotation of the disc 8 without scraping.

In the present illustration I have shown the revolving parts of the machine driven by an electric motor of the induction type. The rotor of this motor comprises a band 10 of conducting material such as copper depending from the under side of the disc cover 8 and concentric therewith. In the present illustration I have shown the band 7 11 and secure the band 10 to the disc 8 where the two meet in any suitable manner, andwhere the machine is driven by a different type of motor the band 10 may be omitted altogether.

The stationary parts of the motor consist of current coils 13 and a potential-coil 14 displaced in phase relation with respect to each other and mounted on opposite sides of the band 10 on magnetic cores l5 and 16 respectively. A circular air gap is provided between the magnetic core pieces into which the band 10 extends and is caused to rotate by the currents produced therein by the out of phase magnetic flux across the air gap. This type of motor is well known and its operation need not be further explained. The stationary parts of the motor are sup, ported in the casing by the lug 18 and standards 17 extending from the side and bottom of the casing respectively. This arrangement of the motor produces a minimum of side thrust on the vertical spindle 3; however, other arrangements of the motor and casing-1.

spindle of an ordinary centrifugal governor through the sliding member 30 to thead 'justin screw 31 threaded through the wall other types of motors may be used Without departing from the scope of my invention.

The legs 5 and 6 of the hearing t are spaced apart to make room for a worm gear 19 secured on the spindle 3 between the bearings 2 and 4. The gear 19 cooperates with a worm 20 on a horizontal shaft 21. The shaft 21 is carried in bearings 22' and 23 contained in supporting standards 24 and 25 respectively, rising from the floor of the The shaft 21 constitutes the 26 fastened to the shaft at 27 and having its movable end secured to a collar 28. which is adapted to slide back and forth on the shaft 21 due to the centrifugal action of'the overnor. Coo erating with the sliding colar 28 is a friction pad 29, which pad is adjustable towards andaway from the collar 28 by reason of its being connected of easing 1 and terminating on the outside in the milled head 32. It will be understood that the governor is'driven through the disc 11, spindle 3, inverted worm gear 19, 20 and shaft 21, at a speed proportional to the speed of the'record supporting disc, and that the governor will regulate the speed and keep it uniform by reason of the friction between the collar 28 and the friction pad 29. The normal speed may be adjusted by turning screw 32 to move the friction pad 29 toward or away from the collar 28.

It will be apparent from the foregoing description that the cover disc 8, together with the disc 11 and armature band 10, if these latter parts are provided, maybe readily lifted off the vertical sindlefl 3 which operation will expose allo the parts contained within the casing facilitating their inspection, oiling and adjustment. Feet 33 provided with felt pads 34 are formed on the bottom of the'casing to support the same in a level position on any flat surface such as a table top. Casing 1 is provided with an external bracket arm 35 upon which the usual diaphragm arm (not shown) may be pivotally supported. The casing 1, together with the supporting pieces 5, 6, 17, 24 and 25, lug 18, bearing hub 2, projections 33 and bracket 35, may be cast in one piece, whichwill require very little machining to make. it ready to receive the few operating parts. The parts are rugged in construction and easily assembled, and although the machine is inexpensively built, is entirely reliable.

The usual electrically driven phonograph machine has a spindle hearing through the top of the casing and there is a short rigid mechanical connection through the top of the casing between this bearing and the magnetic circuit of the motor through which mechanical vibrations are conveyed to the record table and phonograph record. The magnetic vibrations are detrimental and the constructions shown in the present application damps out those vibrations to some extent because of the long and somewhat restricted path through which such vibrations musttravel in order to reach the record supporting disc 8. The electric circuit of the motor has not been shown but it will be understood that the usual circuit connections are made and a switch provided for turning the motor on and off. 7

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means.

WVhat I claim as new and desire to secure by Letters Patent of the United States, is

A phonograph comprising a cylindrical cup-shaped cabinet, a cover therefor constituting the record turn-table, said cover having a turned-over edge adapted to fit loosely over the top of said cabinet, a central vertical spindle for said turn-table entirely rotatably supported from the floor of said cabinet and an induction motor for driving said phonograph comprising a stationary core member supported from the inner wall of said cabinet and a movable armature member constituting a cylindrical band of conducting material of less diameter than the cabinet depending from the under side of said cover.

In witness whereof, I have hereunto set my hand this 16 day of Jan. 1922.

CHESTER I. HALL.

Images