July 6, 1954 R. M. JENSEN ET AL TUNING DIAL ASSEMBLY FOR ELECTRICAL APPARATUS Filed Dec. 27, 1951 .R. M JENSEN INVENTORS- C. SAMEK A TTORNEV Patented July 6, 1954 UNITED orFl-ce APPARATUS Rhineliardt M.- Jensen and Charles T. Samek,
Berkeley: Heights; N. J phone.- Laboratories, Incorporated, New York,,. Nell a-colzporation-of N ew Y orkx Application Decemlier27, 1951, Serial No. 263,667
2: Glai'ms; (Cl. 116-1241) 1. This invention relates to tuning dial assemblies andJnore particularly to such. assembliesrw-herein a. longitudinal reciprocal" tuningv elementrmay be selectively. moved to accurately predetermined positions.
An object of this invention the provision of a dial assembly for use with adjustable elec-,
trical apparatus wherein reciprocal axial motion, imparted to an operating shaft by a central knob, is converted to a calibrated circular motion.
In the preferred embodiment of our invention, the dial assembly comprises a sleeve member, having a longitudinally extending central bore therein, fixedly secured to and projecting from the face of a suitable apparatus panel. The central bore of the sleeve, at its free end, is of reduced diameter and is internally threaded, and the outer surface thereof is provided with a helical groove having a substantially long lead, which extends the length of the sleeve. Positioned in the central bore of the sleeve, and having its outer endin threaded engagement with the outer end of the sleeve, is an operating shaft which is operatively connected to suitable apparatus mounted on the rear of the panel.
Rotatably mounted on the sleeve and having an internally extending pin in engagement with the groove on the outer surface of the sleeve, is a shouldered hub member which has secured to its inner end an indicating dial plate. Mounted on the reduced diameter portion of the hub member, bearing against the shoulder and secured, as by a press fit, is a suitable bearing which is secured, also as by a press fit, in a recess in the rear of a knob member which is positioned on the outer threaded end of the shaft, and is secured thereto by a suitable nut located in a recess in the outer face of the knob.
In operation, when the control knob is rotated, either clockwise or counter-clockwise, the shaft will move axially With a reciprocating motion. Since the indicating dial is secured to the hub member, which, in turn, is rotatably mounted on the sleeve and in engagement with the groove therein which has a long lead, and since the shaft will travel in the fine threads in the sleeve, the knob will complete several revolutions to a single revolution of the dial depending on the pitch of the groove on the sleeve, thereby causing the apparatus attached to the shaft to reciprocate and be finely adjusted.
Other objects and advantages of this invention will be apparent from the following detailed description when read in connection with the following drawings wherein:
assignors to Bell Tele Fig. 1 is a side elevational view, partly irrsection of an assembly'constructed' in accordance: with this invention, and illustrates the contrcl knob at the end of'its outward travel;-
Fig; 2 is aview similar to Fig. 1 but shows the control knob-at theend of itsinward travel;- and Fig. 3 is a front elevational view, to a reduced scale, of the knob and indicating dial.
As shown in the drawings, there is mounted on the face of the apparatus panel I0, a shouldered sleeve member I I, which is secured in position in a suitable aperture in the panel by abutting the shoulder against the panel and spinning into contact with the panel the extending portion of the sleeve. The sleeve l I is provided with a central bore I2 which has a reduced diameter portion I3 at its outer end and is provided with the fine internal threads I4. Theouter surface of the sleeve I I is provided with a helical groove I5 which has a long lead and extends substantially the full length of the sleeve H.
Rotatably mounted in the central bore I2 of the sleeve II, and having its threaded outer end I 6 in engagement with the threads I 4 on the sleeve I I, is the operating shaft I I which is operatively connected to the adjustable member [8 of the capacitor l-9 which is enclosed in the housing 20 mounted on the rear of the panel l0.
Journaled on the sleeve II and having an internally extending pin 2 I, in engagement with the groove I5 on the sleeve II, is a shouldered hub member 22 which has secured to its inner end, by means of screws 23, an indicating dial plate 24, provided with suitable indicia, as shown in Fig. 3, arranged to register with the index pin 25 located on the panel I0.
Secured on the reduced diameter portion of the hub 22, against the shoulder, by means of a press fit, is the ball bearing 26 which is also secured by a press fit, in the recess 21 located in the rear of the knob 28. The knob 28 is in threaded engagement with the outer threaded end IB of the shaft I1, is secured thereto, and locked in position by means of the jam nut 29 located in the recess 30 in the front face of the knob 28. A suitable collar 3| is secured on the shaft IT to limit the outward movement of the shaft and its associated elements.
When the control knob 28 is rotated, either clockwise or counter-clockwise, the shaft I! will move axially due to the engagement of the threaded end J 6 with the fine internal threads I4 in the front end of the sleeve II. Since the dial plate 24 is secured to the hub 22, which is rotatably mounted on the sleeve II with its pin 2| in engagement with the groove l5, which has a substantially long lead, and the shaft I! will travel in the fine thread ll of the sleeve H, the knob 28 will complete several revolutions to .a single revolution of the dial plate 24, the number depending upon the ratio of the pitch of the thread 14 to the itch of the groove Hi.
It will thus be observed that the movable element 18 of the capacitor l9, attached to the shaft I1, will be caused to reciprocate and the capacitance will be finely controlled. A wide range of adjustment is indicatable by the dial because of the limited rotation of the latter relative to the knob.
Although we have shown and described a preferred embodiment of our invention it is to be understood that various modifications may be made therein without departing from the scope and spirit of the invention.
What is claimed is:
1. A tuning dial for electrical apparatus comprising a support, a sleeve having a fine internal thread and an external helical groove secured to said support, a shaft in engagement with said internal thread, a hub rotatably mounted on said 25 sleeve and in operative engagement with said external helical groove, a knob rotatably mounted on said hub and secured to said shaft for causing the rotation thereof and a dial plate secured to said hub.
2. A tuning dial for electrical apparatus comprising a support, a sleeve having a fine internal thread and a coarse external helical groove, secured to said support, a shaft in engagement with said fine internal thread, a hub rotatably mounted in said sleeve and having an internally extending pin in engagement with said external helical groove, a bearing secured on said hub, a knob mounted on said bearing for rotatably supporting said knob, said knob having one end I of said shaft secured therein for causing the rotation thereof and a dial plate secured to said hub.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,622,389 Miessner Mar. 29, 1927 1,725,639 Herman Aug. 20, 1929 1,733,337 Deutscher Oct. 29, 1929 1,836,583 Elliott Dec. 15, 1931