US3105691A

US3105691A - Pick-up for use with record players

Info

Publication number: US3105691A
Application number: US7572A
Authority: US
Inventors: Dragt Jan Cornelis Willem
Original assignee: US Philips Corp
Current assignee: US Philips Corp; North American Philips Co Inc
Priority date: 1959-03-26
Filing date: 1960-02-09
Publication date: 1963-10-01
Anticipated expiration: 1980-10-01
Also published as: BE588997A; GB947056A; ES256751A1; CH381877A; FR1251910A

Description

J. C. W. DRAGT Filed Feb.

PICK-UP FOR USE WITH RECORD PLAYERS Oct. 1, 1963 INVENTOR 1m c.w.ORAGT AGENT United States Patent 3,105,691 PICKUP FOR USE WKTH RECGRD PLAYERS Tan tlornelis Wiilem Dragt, Eindhoven, Netheriands,

assignor to North American Phiiips Company, Inc.,

New York, N,Y., a corporation of Delaware Filed Feb. 9, 1960, Ser. No. 7,572 Claims priority, app-iication Netheriands Mar. 26, 1%9 3 *Claims. (iii. 274-65) The invention relates to a pick-up for use in a record player, this pick-up comprising a pick-up unit housed in an envelope with two diametrically opposite needles, which can be moved into the working position by turning them about the longitudinal axis of the unit in one direction and in the other direction respectively.

Pick-ups of this kind are generally known and used in practice. The turn of 180 to be performed by the pick-up unit to go over the working position of one needle to the working position of the other is limited, in these known devices, as a rule in both directions by stationary rabbet.

The invention is based on the recognition of the fact that the adjustment of the needle in its working position with stereophonic record players is extremely critical, since the cross-talk factor from one sound channel to the other becomes considerably more unfavourable even when the pick-up occupies only a slightly oblique position. With a deviation of not more than 2", for example, this factor amounts already to 2.

The invention consists in that the turn of the pick-up unit is limited on both sides by a stop, of which stops at least one is accurately adjustable. less important for the other stop, if it is associated with the working position of a needle not used for stereophonic reproduction.

The accompanying drawing shows a longitudinal sectional view of one embodiment of a pick-up according to the invention.

In a housing 1 of light material is arranged a pick-up unit 2 so as to be rotatable on gudgeons 3, which fit in round openings of a frame 4, secured in the housing. The pick-up unit comprises two diametrically opposite needles 5 and 6, of which the latter is to be used for stereophonic reproduction and must therefore be movable This adjustability is' into its working position with great accuracy and be held therein. This position is shown in the FIGURE.

The unit 2 can be turned about the gudgeons 3 with "ice the aid of a tag 7, which is at right angles to the plane of the drawing and which projects, as shown in the drawing, downwardly below the housing 1, and which is secured to the unit by a rivet 8.

A flat spring 9, secured to the frame 4, co-operates with a lug-shaped part it) of the unit 2, which part is provided to this end with two opposite flat surfaces, of which the surface 11, shown in contact with the spring, is to some extent oblique to the plane of the drawing, so that the unit 2, if it were free, would turn slightly beyond the correct position of the needle 6 under the action of the spring pressure. However, this additional turn is prevented by a screw-bolt 12, located below the unit 2, as shown in the drawing; this bolt has a fine screwthread. The point of this bolt abuts against the stationary stop 13 of the frame 4- as soon as the needle 6 arrives at its correct position. Small deviations from this position may always be corrected by means of the bolt 12.

What is claimed is:

l. A phonograph cartridge comprising a housing, a pick-up unit rotatably mounted in said housing and .having two spaced, alternately operating needles therein, said pick-up unit being rotatable about its longitudinal axis to bring the selected needle into record-engaging position, and at least two stops for limiting the rotation of said pick-up, one of said stops being provided with means for adjusting the same whereby the selected needle is located in the correct record-engaging position.

2. A phonograph cartridge comprising a housing, a pick-up unit rota-tably mounted in said housing and having two spaced, alternately operating needles therein, said pick-up unit being rotatable about its longitudinal axis to bring the selected needle into record-engaging position, and at least two stops for limiting the rotation of said ick-up, said pick-up unit having a relatively fiat, lugshaped part, a spring secured at one end to said housing and the free end thereof contacting said lug-shaped part when one of said stops engages said rotated pick-up unit.

3. A phonograph cartridge as claimed in claim 1 wherein said means for adjusting one of said stops is a screw bolt abutting against the other of said stops.

References Qited in the file of this patent UNITED STATES PATENTS

Claims

1. A PHONOGRAPH CARTRIDGE COMPRISING A HOUSING, A PICK-UP UNIT ROTATABLY MOUNTED IN SAID HOUSING AND HAVING TWO SPACED, ALTERNATELY OPERATING NEEDLES THEREIN, SAID PICK-UP UNIT BEING ROTATABLE ABOUT ITS LONGITUDINAL AXIS TO BRING THE SELECTED NEEDLE INTO RECORD-ENGAGING POSITION, AND AT LEAST TWO STOPS FOR LIMITING THE ROTATION OF SAID PICK-UP, ONE OF SAID STOPS BEING PROVIDED WITH MEANS FOR ADJUSTING THE SAME WHEREBY THE SELECTED NEEDLE IS LOCATED IN THE CORRECT RECORD-ENGAGING POSITION.