US2552199A - Pickup support apparatus for phonographs - Google Patents

Description

May 8, 1951 c. METCALFE ETAL 2,552,199

PICKUP SUPPORT APPARATUS FOR PHONOGRAPHS Filed Oct. 50, 1946 0340787025 (2)7022? A amZ/e l A/ammarfimarfle rra/ewiy Patented May 8, 1951 PICKUP SUPPORT APPARATUS FOR PHONOGRAPHS Clifford Metcalfe, Ruislip, and Alexander James Rae, Southall, England, assignors to Electric & Musical Industries Limited, Hayes, Middlesex, England, a company of Great Britain Application October 30, 1946, Serial No. 706,611

In Great Britain October 31, 1945 This invention relates to apparatus for playing phonograph records in which the pickup arm or tone arm is automatically applied to a record.

In apparatus of this type the pickup arm or tone arm, hereinafter referred to as the pickup arm, is fed to a position adjacent the record so that when lowered the needle engages the smooth outer edge of the record and some form of mechanism is usually provided for feeding the pickup arm inwardly so that the needle engages the first groove of the record.

The object of the present invention is to provide an improved and simplified form of mechanism for causing the needle to engage the first groove of the record.

According to the invention there is provided mechanism for feeding the pickup arm to cause the needle to engage the first groove of the record which comprises a first member carried by an angularly movable post supporting the pickup arm, said member being adapted to be engaged at appropriate times after the needle is in contact with the record by a second memher which wipes past said first member to cause the needle to engage a groove in the record, one of said members being a leaf spring adapted to yield when said groove is reached so that further feeding movement of said needle is prevented.

In order that the said invention may be clearly understood and readily carried into efifect the same will now be more fully described with reference to the accompanying drawing, in which:

Figure l is a view in part sectional elevation of part of a pickup arm operating mechanism, and

Figure 2 is a detail view looking in the direction of the arrow in Figure 1.

The invention is shown as applied by way of example to the pickup arm support of automatic phonograph mechanisms. The pickup arm (not shown) is mounted in a support I carried by an angularly movable post 2, there being provided a rod 3 passing through said post 2 and actuated by a face cam 4 mounted for rotational movement beneath said rod 3 and in a plane normal to said post 2, said rod 3 under the action of said face cam 4 being raised and lowered so as to cause the pickup to be raised and lowered from the record at appropriate times. Said post 2 is also arranged to be angularly 2 Claims. (01. 274-13) moved under the action of a roller 5 mounted cam 4 is carried by a gear wheel 8 which is arranged to be operated at appropriate times so that when the pickup reaches the end of the playing period and after the pickup has been lifted from the record said post 2 is angularly moved so as to swing the pickup arm outwardly and after a fresh record has been fed to the turntable the sequence of operations is such that the pickup is again swung inwardly and when said rod 3 is lowered under the action of said face cam 4 the pickup arm is lowered so as to cause the needle to land on the smooth edge of the record. In order to feed the needle into the first playing groove of the record a leaf spring 9 is secured to the lower end of said post 2 and said gear wheel 8 is provided with a bracket i0 which supports an eccentrically mounted disc Ii which during rotational move-'- ment of said gear wheel 8, is adapted to wipe past said leaf spring after the needle is in engagement with the smooth edge of the record, said disc H, due to its frictional engagement with said leaf spring 9 causing the pickup arm to be fed inwardly until a groove in the record is reached when the spring 9 yields so that further feeding movement of the needle into the record grooves is prevented. Said leaf spring 9 is preferably of bowed form in longitudinal section with the apex of the bowed portion presented to said disc II. The disc II is eccentrically mounted so as to be capable of adjustment whereby the frictional engagement of said disc with said leaf spring can be adjusted, and for this purpose the disc is carried by a vertically-extending arm of the aforesaid bracket If] so that the periphery of the disc H is presented to the apex of said leaf spring and may be supported on said arm by a captive nut l2 carried by said arm and by a screw 13 which passes through said disc H and into engagement with said captive nut 12. The disc II is eccentrically disposed with respect to said screw l3 so that when the screw is loosened the disc can be rotated for adjustment purposes.

Although the invention has been described with particularity, it is to be understood that the particular details and arrangements shown are by way of illustration only and not by way of limitation. Various modifications will suggest themselves to those skilled in the art, and are to be considered as falling within the spirit of the invention.

We claim:

1. Pickup support apparatus for phonographs comprising, in combination, a post adapted to support a pickup arm, a support for said post, said post being mounted in said support so as to permit oscillating movement of said post about its axis, a rotary cam adjacent said post, said rotary cam being provided with a cam track, a cam follower mounted on said post and coacting with said cam track to produce oscillatory movement of said post, said cam track being arranged to cause said post to rotate about its axis in one direction through a predetermined angle and to then reverse its direction of rotation through a predetermined smaller angle and then release said cam follower from engagement with said cam track, an auxiliary cam mounted in fixed relationship to said rotary cam and arranged for rotary movement therewith, a resilient member mounted on said post and arranged to be irictionally engaged by said auxiliary cam, the position of said auxiliary cam relative to said rotary cam being such that said frictional engagement occurs only when said cam follower is unengaged with said cam track, the relative positions of said resilient member and said auxiliary cam being such that after engagement therebetween further rotation 4 of said auxiliary cam tends to cause continued rotation of said post in said reverse direction, and means for adjusting the degree of frictional engagement between said resilient member and said auxiliary cam.

2. Pickup support apparatus in accordance with claim 1 in which the means for adjusting the frictional engagement between said resilient member and said auxiliary cam comprises an eccentric mounting for said auxiliary cam whereby the distance between the resilient member and the auxiliary cam surface is variable.

CLIFFORD METC'ALFE. ALEXANDER JAMES RAE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,289,357 Green July 14, 1942 2,366,358 Knox et al. Jan. 9, 1945 2,424,132 Alexandersson July 15, 1947

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