US2605735A

US2605735A - Spiral tuning dial

Info

Publication number: US2605735A
Application number: US15549A
Authority: US
Inventors: Ware Paul
Original assignee: Allen B du Mont Laboratories Inc
Current assignee: Allen B du Mont Laboratories Inc
Priority date: 1948-03-18
Filing date: 1948-03-18
Publication date: 1952-08-05
Anticipated expiration: 1969-08-05

Description

Aug. 5, 1952 P. WARE 1 2,605,735

SPIRAL TUNING DIAL Filed March 18, 1948 2 SHEETS-SHEET 1 FIG.1

INVENTOR UFMWM ATTQRHEY Aug. 5, 1952 I P. WARE 05,7

SPIRAL TUNING DIAL Y I" Filed March 18, 1948 Y I 2 SPEETS-rSHEET/ INVENTOR. PAUL WARE ATTORNEYS Patented Aug. 5, 1952 Allen N. 1., a corporation of Delaware B. Du Mont Laboratories, Inc Passaic,-

2 Claims. (01. 118-1242) This invention relates to an indicating device that is provided with a dial on which markings or calibration points are arranged in the form of a spiral. It will be particularly described and illustrated as it is used as a high frequency radio tuning dial. It is not restricted to this use, however, being particularly suited for any use where it is desirable toindicate the position of a shaft which may turn a plurality of times between stops.

The invention may be understood from the description in connection with the accompanying drawings in which:

Fig. 1 is a side View of an illustrative embodiment of the invention.

Fig. 2 isa section along the line A-A of Fig. 1.

Fig. 3 is a plan view of the spiral selector gear.

Fig. 4 is a section along the line 4-4 of Fig. 3.

Fig. 5 shows an illustrative layout of the dial,

and

gear.

Reference character I indicates diagrammatically a support for a tuner or other mechanism of the known sort that is provided with a tuning shaft 2 which is to be rotated. This shaft is turned by means of a knob 3. A gear 4, which may, for instance, be made of fibre is secured to the shaft 2 by holder 5. I

Gear 4 meshes with a gear 6 which is attached to a disc 8 which has a spiral groove 8' in one side thereof. Gear 6 and disc 8 are so connected that they rotate together on a shaft?! thatis fixed in position. A dial 1, which is preferably of material such as Lucite or other light transmitting plastic material that can be adapted for edge-lighting, is mounted in front of the gear 6, so that it turns with this gear.

An arm I is supported on shaft l I. This arm ID has a bend l0 in it so that it does not strike shaft 2 before it is turned sufficiently on shaft H. A pin l3 carrying a roller I3, is mounted on the arm l0 near the opposite end of this arm from shaft II. This pin and roller extend into the spiral groove 8' in disc 8. A spring l2 keeps tension on arm Ill so that the roller constantly rolls along the outer edge of the groove 8 in the disc 8.

A block I4 which supports a frame I is mounted on arm Ill. This frame I5 is made of lightweight material and is shaped so as to extend upwardly across the face of the dial 1. The end of frame I5 is formed into a loop or ring l6,

through which the numerals and markings on the dial 1 may be observed. This loop I6 has radially extending points 11.

An illustrative marked dial is shown in Fig. 5. This particular dial is for use on a television receiver tuning assembly, and shows the numbered television channels as well as frequency in megacycles for tuning in frequency modulated stations, etc.

Fig. 6 shows a portion, greatly enlarged, of the spiral groove 8' of disc 8 in which pin l3 carrying roller I3 is caused by the action of spring [2 to be tensioned against the outer edge of the groove 8'. A V-shaped notch l8 may be provided into which the roller l3 will'fall, thus causing a noticeable detent action at each of several predetermined points which may correspond to the numbered television channels shown on the illustrative dial of Fig. 5.

The device is operated by turning the knob 3. When this knob 3 is turned, the dial 1 is turned at a slower rate. As this dial and disc 8 are turned, the pin I3 is moved along the spiral groove 8' of disc 8, thus causing the arm [0 to move on shaft H as a-pivot. As the arm Ill. moves it carries the frame [5 with it. The loop or ring I6 which is carried. by this frame is thus caused to move substantially horizontally across the face of the dial 1. Thus the successive portions of this dial that are visible through the loop 16 are in the form of a spiral. Each time a numbered channel appears behind the loop, a detent is felt on the knob, and a click is heard as the roller falls into notch on the spinal groove. A suitable enclosure, notfshown, with a slightly arcuate horizontal slot therein, may be used to prevent viewing at one time any of the dial except that portion that is seen through the loop l6. The points I! aid in reading the positions of the dial. The end of the frame l5 may be rectangularly shaped with a small rectangular openingtherethroughso as to obscure all of the dial except that which is behind this open- What is claimed is:

1. A radio tuning indicator comprising a rotatable dial rigidly affixed to a rotatable disc in back-to-back relationship, said dial having parallel planar surfaces and being light conducting uninterruptedly throughout and to all outer surfaces thereof and having a scale on one surface thereof, said disc having a spiral groove in the surface thereof, said scale being formed in a spiral corresponding to said groove, a viewing frame having an opening therein adjacent 3 said scale and being pivotally mounted to move substantially parallel and radially with respect to the parallel surfaces of said dial. and a guide member engaging said spiral groove and rigidly attached to said frame to guide said opening in alignment with said scale, said rigidly connected frame and guide member forming a rigid combination which: extends around the edges of said dial and disc.

2. The tuning indicator of claim 1 in which said guide member comprises a pin havinga roller mounted on an arm and bearing -on.--theside of said groove, said groove having notches in the side thereof on which saidrollerbear's,

said notches acting as detents and being-aligned.

with markings of said scale, said armbeing spring biased against said side PAULWARE.

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

UNITED STATES PATENTS Number Name Date 1,387,551 Meitner g. Aug. 6, 1921 1,694,384 Herman Dec. 11, 1928 1,975,675 Antelme- Oct. 2, 1934 2,083,924 Scantlebury July 15, 1937 2,144,325 Buchardt Jan. 17, 1939 2,218,987 Johannesson et a1. Oct. 22, 1940 2,333,787 I-Iofiman Nov. 9, 1943 2,400,553 Howar'd May 21, 1946