US2192360A

US2192360A - Automatic and other gramophones

Info

Publication number: US2192360A
Application number: US231082A
Authority: US
Inventors: Mann George Stanley
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-09-29
Filing date: 1938-09-21
Publication date: 1940-03-05
Anticipated expiration: 1957-03-05

Description

March 5, 1940. s, MANN 2,192,360

AUTOMATIC AND OTHER GRAMOPHONES Filed Sept. 21, 1938 Inventor 57-5. WVA/M ttqrneys Patented Mar. 5, 1940 UNITED STATES PATENT OFFICE AUTOMATIC AND OTHER GRAMOPHONES George Stanley Mann, Ipswich, England Application September 21, 1938, Serial No. 231,082 I In'Great Britain September 29, 1937 8 Claims.

This invention relates to gramcphones ally but particularly to so -called automatic magazine grarnophones in which a number of records, stored in'a magazine or pile, are transferred in succession to a turntable for playing, the pick-up or tone-arm being automatically raised from a record upon termination of the playing thereof and, after being swung over to the starting position, lowered on to the next record to be played.

The primary object of the present invention is to provide improved and simplified means for automatically raising the piclvup or tone-arm at the requiredmoment and for allowing it to descend when a fresh record has: been deposited upon the turntable.

A further object of the invention is to provide means for giving a controlled gradual lifting and lowering movement to the pick-up or tone-arm.

According to the invention a gramophone pickup or tone-arm mechanism is characterised by the incorporation of electro-magnetic means for auton'iatically raising the said arm under the control of electrical switch means adapted to be operated by the horizontal movement of the said arm.

According to preferred embodiments of the invention the pick-up or tone-arm has-associated therewith a vertically movable rod which is adapted by its movements to raise and lower the arm, said rod having associated therewith an electric-magnetic means for imparting a vertically rising movement thereto in order to efiect the raising of the pick-up or tone-arm. When the arm has been swung over to the starting position the electro-magnetic means is de-energised in order to allow the rod and the pick-up or tone-arm to descend.

According to a further feature of the invention and in order that the pick-up or tone-arm shall rise and fall with a gradual controlled movement, it is associated with a damping means, for example a dash-pot device. hereinbefore mentioned rod associated with the pick-up or tone-arm may carry a piston member adapted to work in a cylinder against a fluid resistance.

In order that the invention can be fully appreciated one preferred embodiment thereof will now be described with reference to the accompanying drawing wherein the single figure shows a vertical sectional elevation of a gramophone pick-up arm mechanism. 1

The pick-up arm I is pivoted at 2, for movement in a vertical plane, upon a rotatable bracket 3 supported upon the top board 4 of a gramo- For this purpose the is coupled with the upper end of a vertical rod t'formed of magnetic metal and disposed coaxially with the rotatable bracket 3 and. its

bearing. Said rod 5 is guided for vertical movement and also turning movement within a guide sleeve 6.

The coupling between the pick-up arm I and the rod 5 is such thatsaid rod turns with the arm.

At a position below the top board l the rod 5 is provided with an enlarged portion 1 which constitutes a core for an electro-magnet 8 of hollow or so-called pot form. It should be noted that this electro-magnet 3 is connected through the intermediary of the sleeve *5 with the rotatable bracket 3 and therefore said magnet turns with the pick-up arm l and vertical rod -5.

The said rod 5 is also provided with another A enlargement 9 which constitutes an armature for co-operating with the electro-magnet 8 and below this armature the rod 5 carries an arm lit-provided. at its outer end with a stud I! adapted to is such that, when the pick-up reaches the usual run-01f groove of the record on completion of its playing, the arm I0 is oscillated in a horizontal plane to effect energization of the electro-magnet 8 and thus bring about an upward movement of the rod 5 and the consequential raising of the pick-up arm I to lift the needle l2 from the record indicated in dotted lines at l3.

De-energization of magnet 8 following deposition of a fresh record on the turntable and return of the pick-up arm to its starting position allows the pick-up arm to fall, thus to bring the needle I! into contact with this fresh record. I

According to another feature of the invention and in order that the pick-up arm I shallrise and also fall with a gradual movement instead of .being caused to rise sharply by the action of the electro-magnet 8 and to fall suddenly by its own weight, means are provided for effecting a dashpot controlled movement.

For this purpose the vertical rod 5 is extended below the switch arm l0 and at its lower end carries a piston l6 workingin a vertical cylinder l1 adapted to contain oil or other fluid.

During the upward movement of the rod 5 under the influence of the electro-magnet 8 the piston I6 is raised and fluid passes slowly to the under side of the piston through one or more restricted passageways such as that indicated at I8. Thus the rising movement of the pick-up arm I is retarded and proceeds gradually and smoothly Furthermore upon the de-energising of the electro-magnet 8 the rod 5 and the pick-up arm I will fall and in falling move the piston l6 downwardly against the resistance of the fluid so that the lowering of the pick-up arm is retarded and the needle l2 lowered on to the record smoothly and gradually in order to commence the playing thereof. 7 i

In order to limit the descent of the rod E and its associated magnetic core 1 and armature 9 an adjustablescrew means is is provided in the base of the dash-pot cylinder ll, the inner end of said screw means being adapted to form an abutment for the lower face of the piston it Although it is to be understood that any desired suitable switch mechanism may be provided and adapted for operation by means of the switch arm In, it is preferable that this switch mechanism be of the kind described in the specification of applicants co-pending British patent application No. 26383/37.'

The invention is not limited to the precise forms or details of construction described, as these may be varied to suit particular cases withoutdeparting from the scope of the appended claims.

What I claim and desire to secure by Letters Patent of the United States of America is:'

1. A gramophone pick-up or tone-arm mechanism comprising a bracket rotatable in a horizontal plane, a pivotal connection between said rotatable bracket and the tone-arm to allow the latter to be moved in a vertical plane, a hollow electro-magnet supported by and rotatable with the said bracket, a vertically movable rod extending through the bore of the hollow electro-magnet and concentric with the axis of rotation of the rotatable bracket, a connection betweensaid rod and the vertically movable arm and a magnetic core on the rod for cooperation with the electro-magnet so that upon energisation of said electro-magnet the rod is moved upwardly to lift the arm vertically about its pivotal connection with the bracket and, upon the termination of such energisation the vertical rod will move downwardly to return the arm to its lower position.

2. A gramophone pick-up or tone-arm mechanism, as claimed in claim 1, in which the vertically movable rod extends through a rotatable guide sleeve to which the bracket is secured.

3. A gramophone pick-up or tone-arm mech-. anism as claimed in claim 1, in which the tone arm is mounted for turning movement and the vertically movable rod is coupled by said lastnamed connection with the toneearm for turn ing movement therewith.

A gramophone pick-up or tone-arm mechanism as claimed in claim 1, in which the tonearm is mounted for turning movement, and the vertically movable rod is coupled by said lastnamed connection with the tone-arm for turning movable rod extends through a guide sleeve connected at one end to the electro-magnet and at its other end to the bracket whereby said'electromagnet turns with the pick-up arm and the rod.

5. A gramophone pick-up or tone-arm mechanism as claimed in claim 1, in combination with means for damping the upward and/or downward movement of the vertically movable rod.

6. A gramophone pick-up or tone-arm mechanism as claimed in claim 1, in; combination with means for damping the upward and/or downward movement of the vertically movable rod, said means comprising a piston element carried movement therewith, and in which the vertically I by said rod at the lower end thereof and a 00- operating cylinder containing a damping fluid.

7. A gramophone pick-up or tone-arm mechanism as claimed in claim 1, in combination with means for damping the upward and/or downward movement of the vertically movable rod,

and adjustable means for limiting the downward movement of the rod. 8. A gramophone pick-up or tone-arm mechanism as claimed in claim 1, in combination with means for damping the upward and/or downward movement of the vertically movable rod, said means comprising a piston element carried by said rod at the lower end thereof and a cooperating cylinder containing a damping fluid,

and adjustable means for limiting the downward movement of said piston element in said cylinder.

GEORGE STANLEY MANN.