US2033729A

US2033729A - Phonographic construction

Info

Publication number: US2033729A
Application number: US751602A
Authority: US
Inventors: Monfort Noel
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-11-05
Filing date: 1934-11-05
Publication date: 1936-03-10
Anticipated expiration: 1953-03-10

Description

arch l0, gg. YN, MONFQRT PHONOGHAPHIC CONSTRUCTION Filed NOV. 5, 1934 INVENTOR we@ Wfor,

ATTORN Fys WITNESSA Patented Mar. 10, 1936 UNITED sTA'rss orner.

My invention relates to improvements in phonographic constructions, and it consists in the combinations, arrangements and constructions herein described and claimed.

An object of my invention is to provide a phonograph which is intended especially for use in automobiles, sound trucks, boats or other places where there is abnormal vibration.

A further object of the invention is to provide a phonograph having a pivoted tone arm to swing in a horizontal direction, but which is prevented from swinging in a vertical plane.

A further object of the invention is to provide means for counteracting the effect of sudden jolts or jars while at the same time permitting a free movement ofthe needle across the disk as the latter is turned.

A further object of the invention is to provide a device of relatively simple construction by means of which the above mentioned advantages are attained.

Other objects and advantages will appear in the following specication and the novel features of the invention will be particularly pointed out in. the appended claims. l

My invention is illustrated in the accompanying drawing forming part of this application, in which: Y

Figure 1 is a side elevation of a tone arm and a counter-weight used in connection therewith, certain portions of the gure being in section, and,

Figure 2 is a plan view of a portion of a phonograph disk showing my invention as applied thereto.

In the drawing, the upper portion of the cabinet which contains the motor, not shown, is indicated at 3. The central shaft 4 bears the turntable 5 upon which the record disk 6 is mounted. The construction thus far described is ordinary and forms no part of the present invention except as it lcooperates with the novel features hereinafter described.

As will be seen from the drawing the tone arm 'I is bent at 8 and has a portion 9 which eX- tends into a sleeve I0. It is adjustable vertically Y in this sleeve and is held in adjusted position by means of a set screw II.

The latter is pivotally mounted on a. suspension arm I8 between collars I9 or in any other suitable manner. Slidably disposed on the rod I1 is a cylindrical weight 2D which is adjustable along the rod and may be retained in adjusted position by a set screw 2l. The arm I terminates in a yoke 22, between the arms of which is pivotally mounted a sound box 23. The latter bears the usual needle 24. One of the trunnions 25 of the sound box is extended and there is an arm 26 which is rigidly attached to the trunnion. A spring 21 is secured to one end of this arm and has its other end attached to a screw eye 28, the shank of which extends, through a bracket 29 secured to the tone arm, and is provided with an adjusting nut 30.

From the foregoing description of the various parts of the device the operation thereof may be readily' understood. The tone arm 1 may swing about the central axis of the sleeve, the ball-bearing set holding the sleeve from vertical displacement and at the same time permitting the rotation of the sleeve. The needle is placed on the outer groove of the record disk 6 and when the latter is turned it travels inwardly toward the center, being held in the grooves of the diskv by means of the spring 21, the tension of which may be adjusted by rotating the adjusting nut 33.

As the tone arm moves, the gear I5 will be turned, and hence the arm I9, bearing the weight 20. The latter has inertia, so that the eect of a sudden jolt will be dissipated by the inertia of the weight, thus preventing the swinging of the tone arm laterally and hence preventing the jumping of the needle from one groove to another. A sudden vertical movement will have very little effect, since the tone arm is rigid as far as a vertical movement is concerned, and the spring 2l will keep the needle in the groove.

I claim:

1. A phonograph construction comprising a rigid tone arm disposed horizontally and having a vertically bent portion, a sleeve for mounting the vertically bent portion to rotate about a vertical axis, a sound box pivotally carried by the tone arm at the opposite end thereof, and being provided with a reproducing needle, a spring for holding the needle in contact with the disk, means connected with the vertically bent portion for dissipating abnormal shocks tending to swing the tone arm, said means comprising a pivoted arm, a gear segment secured thereto, an adjustable weight on said arm, and a gear on said sleeve and arranged to mesh with said segment.

2. A phonograph construction comprising a cabinet top, a rigid tone arm disposed parallel to the top and having a bent portion, a sleeve for mounting the bent portion to rotate about an axis perpendicular to the top, a sound box pivotally carried by the tone arm at the opposite end thereof and being provided with a reproducing needle, a suspension bar carried by the top and projecting downwardly, an arm pivotally mounted on said suspension bar in parallel relation with the top and being provided with a gear segment, a gear carried by said sleeve and in 5 engagement with said segment, and a weight adjustably secured to the arm.

NOEL MONFORT.