US2262503A - Guard for phonograph needles - Google Patents

Description

Nov. 11, 1941. w. E. KIERULFF GUARD FOR PHONOGRAPH NEEDLES 2 Sheets-Sheet 1 Filed June 30, 1939 Nov. 11, 1941. I w. E. KIERULFF 2,262,503

GUARD FOR PHONCGRAPH NEEDLES Filed June 30, 1939 2 Sheets-Sheet 2 Patented Nov. 11, 1941 UNITED STATES PATENT OFFICE GUARD FOR PHONOGRAPH NEEDLES William E. Kierulfl, Fort Wayne, Ind., assignor to The Magnavox Company, Incorporated, Fort Wayne, Ind., a corporation of Indiana Application June so, 1939, Serial No. 282,043

3 Claims.

The present invention relates to a guard for a phonograph needle, particularly desirable for a costly, fragile needle such as a sapphire needle used in connection with an electric sound device.

It is an object of the present invention to provide a guard for a phonograph needle which will protect both the needle and the record from breakage due to strain imposed thereon under different conditions of use. An important object is to provide such a guard which is entirely automatic in operation, which will automatically swing into protective position upon removal of the tone arm from playing position on the record, and which will remain in such position until after the tone arm has been placed upon a record and the record has started rotating for reproducing the inscribed sound.

Another object is to provide a device that will automatically lower the needle gently on the record thereby preventing possibility of damage to either the needle or record by too forceful placement of the needle on the record and which will assist the needle in the support of the tone arm.

The novel device also serves as a lead member which tends to carry the tone arm across the record and minimize the steady horizontal component which is on the needle. This permits the use of a lower needle point impedance and a more flexible reproducing head than could be used if the needle head was to carry the tone arm across the record by itself.

A still further object is to provide a guard that will clean or dust off the record while it is being played.

The above and other features, advantages and capabilities will become apparent from a detailed description of the accompanying drawings in which I have illustrated one form of my invention but the construction there shown is to be understood as illustrative only and not as defining the limits of my invention.

In the drawings:

Fig. 1 is a fragmentary view in side elevation of the end of the tone arm in position upon the record and turntable prior to playing of the record.

Fig. 2 is a front elevational view thereof.

Fig. 3 is a view similar to Fig. 1, but with the needle in position for playing the record.

Fig. 4 is a fragmentary side elevational view of a modification of the device shown in Fig. 1.

Fig. 5 is a front elevational view partly in cross section of the device shown in Fig. 4.

Fig. 6 is atop plan view of another modification of the device shown in Fig. 1.

Fig. 7 is a fragmentary side elevational view of the device shown in Fig. 6.

Fig. 8 is a front elevational view of the device shown in Figs. 6 and 7.

Fig. 9 is a side elevational view of still another modification of the device shown in Fig. 1.

Fig. 10 is a front elevational view of the device shown in Fig. 9.

Referring to the disclosure in Figs. 1-3 of the drawings the novel guard I is shown as pivotally attached to tone arm 2 of a phonograph or other sound reproducing device (not shown) by means of bolt 3 in the side of the tone arm. Needle t is fixed in the lower front portion of the tone arm by means of set screw 5 in a manner well known to the art. The guard I comprises an arm or plate of metal or other suitable material having an arcuate base with itscenter spaced from the pivot 3 of the arm or plate and with an inwardly turned flange attached to or integral therewith. On the under side of this flange is suitably attached a layer 1 of felt, a brush or other soft, durable material which will take up the shock of a fall thereagainst, and will frictionally engage the surface of a record.

When the tone arm 2 is removed from the record 8 on the turntable 9 the guard I, being freely rotatable on the bolts 3, will drop to vertical position, as shown in Figs. 1 and 2, with the flange 6 well below the point of the needle 4 so that should the tone arm be accidentally dropped it will fall with the flange contacting the surface, such as a record, on which the tone arm falls and hence protecting the needle and also the record, the base being soft.

The flange will also be in this position when the tone arm is placed on the record, but when the turntable and record are rotated (in the direction shown by the arrow) the friction of the record against the felt base I will cause the guard to rotate and, because of the eccentric arrangement of the base, gradually lower the needle into gentle contact with the record as shown in Fig. 3. The base of the guard remains in contact with the record to assist the needle in supporting the tone arm, thus permitting the use of a more fragile needle and a more flexible tone arm and to sweep dust or other dirt accumulation from the record.

Figs. 3 and 4 show a modified form of guard comprising a disc-like plate 10 being a segment of a circle more than a semicircle and pivotally mounted above the tone arm 2 by means of triangularly shaped bracket ii, the base of which is fixed to the tone arm 2 as by screws l2 and the apex is provided with bolt ii on which the, plate It is pivoted-at a point spaced from its center. Coiled spring I4 is connected to the plate and bolt head to normally maintain the plate in the position shown in the flgures by. forcing lug II thereon against an edge or the bracket II. The plate I is provided on its circular edges with flange l6 indented at H to form a seat for the base ll of felt or other suitable material aiilxed thereon by suitable means.

The operation of the modifled form is similar to that of the form-shown in Figs. 1 to 8, but the lowering of the needle is more gradual and consequently gentler contact is made with the record I and the return or the guard to protective podtion is faster and more certain due to the action of the spring.

Figs. 6, 7 and 8 show a still further modification in which the guard comprises brackets i! and 20 rotatably mounted on bolts 2| on either side of the tone arm 2 and connected at their lower arcuate edges by base plate 22 provided with groove 23 and on the under side oi which is covering 24 of felt or the like. Spring 25 is Placed around one of the bolts and attached to the ton arm 2 and bracket i! to normally retain the guard in protective position as shown. Movement of the turntable in the direction or the arrow will rotate the guard in the same direction permitting the needle to slowly pass through the groove 28 and gently contact the record.

In Figs. 9 and are shown another modification in which the guard comprises elongated flanged plate 28 on the lower side of which is a brush or the like 21. This plate is pivotally attached by pins or other suitable means to spaced arms 28 and29 pivoted to the tone arm 2 by bolts ill or the like, a spring 3| being placed between the arm 29 and the plate 28 to normally retain projection or lug 32 on the arm 29 against the underside of shoulder 33 on the tone arm. This arrangement permits suflicient movement of the guard in the direction or the arrow, upon movement of the turntable in that direction, to gently place the needle on the record and insures a quick return of the guard to'protective position upon raising the tone arm from the record.

It is apparent that the invention provides an eflicient guard for a needle for a phonograph, or the like, that will be in operative position at all times, except during the playing or the rec- 0rd, that will gently place the needle on the record automatically and will clean the record during the playing thereof. It is also apparent the disclosed guards will automatically return to protective position by gravity and that they may be'used with or without the springs as desired, the springs, however, providing quick, positive return to such position.

Having thus described my invention, I claim:

1. A guard for the needle of a phonograph having a tonearm comprising spaced arms pivoted to the tone arm, a plate having pivots adjacent its ends, and said arms being pivotally connected at said pivots to said plate.

2. A guard for the needle of a phonograph having a tone arm comprising spaced arms 'pivoted to the tone arm, a plate having pivots adjacent its ends, and said arms being pivotally connected at said pivots to said plate, and spring means having one of its ends connected to said plate and its opposite end connected to one of said arms.

3. A guard for the needle of a phonograph having a tone arm comprising spaced arms pivoted to the tone arm, a flanged plate having pivots adjacent its ends, and said arms being pivota'liy connected at said pivots to said plate.

WILLIAM E. KIERULFF.

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