US2655811A - Device for limiting rotary motion - Google Patents

Description

Oct. 20, 1953 w, BEHRENS 2,655,811

DEVICE FOR LIMITING ROTARY MOTION Filed Feb. 16, 1952 2 Sheets-Sheet 1 IN VEN TOR. m; L AM If. 17105:

Oct. 20, 1953 w. H. BEHRENS DEVICE FOR LIMITING ROTARY MOTION 2 Sheets-Sheet 2 Filed Feb. 16, 1952 Arramvrr Patented Oct. 20, 1953 I 2.655.811 DEVICE FOR LIMITING ROTARY MOTION William H. Behrens, Postville, Iowa, assignor to Collins Radio Company, Cedar Rapids, Iowa, a corporation of Iowa Application February 16, 1952, Serial No. 271,965

4 Claims.

This. invention relates in general to motion limiting means and in particular to a pair of rotatably supported dials wherein the limits of rotation of one of the dials are varied in accordance with the position of the other dial.

It is oftentimes desirable to mount a pair of concentric dials so that one dial indicates a portion of the setting and the other dial indicates the remaining portion of the setting. Suppose, for example, that in a radio receiver it is desired to cover the tuning range from 40.6 to 46.9 megacycles. If the outer dial is calibrated from 40 to 46 megacycles, rotation of it would automatically set up the megacycle position. To obtain the one-tenth setting a second dial may be mounted concentric with the first dial and calibrated from zero to nine. However, if it is desired to remain in the 40.6 to the 54.9-range, means must be provided so that when the outer dial is in the 40 megacycle position the inner dial will not go below six. When the outer dial is moved to 41 megacycles or any other setting, the inner dial must be free to move over the entire range.

It is an object of this invention therefore, to I provide a motion limiting device.

Another object of this invention is to provide a pair of improved control dials.

Further objects, features and advantages of this invention will become apparent from the following description and claims when read in view of the drawings, in which:

Figure l is a disassembled view showing the relative space relationship of the various parts;

Figure 2 is a top view of the control device of this invention with the inner dial in the locked position;

Figure 3 is a top view of this device with the inner dial in the unlocked position;

Figure 4 is a sectional view illustrating the device in the locked position;

Figure 5 is a sectional view illustrating the device in the unlocked position,

Figure 6 is a front view of the device, and;

Figure '7 is an enlarged detail view of the spring 25.

Figure 1 illustrates an indicator dial l0 which is formed with an outer knurled edge II and which has a center sleeve portion [2 that is connected to the outer portion by an extension IS.

A second indicator dial I4 is formed with an internal opening [6 of a size just large enough to fit over the portion 12 and has an outside diameter just small enough to fit within a circular opening 11 formed in the member H]. A handle 18 is attached to the member I4. A generally arcuate slot i9 is formed in the member [4 and a central opening 2| is formed substantially through the member [4. A link member 22 has apivot opening 23 formed at one end and a locking pin 24 is attached to the other end.

As best shown in Figure 2, the members I0, 14 and 22 are assembled together and mounted 'on a base plate 26. The link member 22 is pivotally supported on the base plate 26 by a pin 21 that passes through the opening 23. A spring 25 biases the link 22 away from the center of member ID.

A hollow shaft 28 passes through an opening formed in the plate 26 and is attached to the portion I2 by a set screw 29 receivable in an Opening 3|. This is best shown in Figure 4.

A second shaft 32 is rotatably mounted within the hollow shaft 28 and has its end connected to the member l4 bya set screw 33.

The member H! has a portion 34 which has cam portions 36 and 31 at either end thereof.

The cam portion 36 is adaptable to engage the pin 24 and cam it into the opening ll. This cannot be accomplished, however, unless the opening iii of the member I4 is adjacent the pin 24. When this occurs, the pin 24 may move within the confines of the opening l9 and will limit the movement of the member l4 an amount equal to the angle of the opening l9.

Figures 2 and 4 illustrate the top view and a sectional view of the locked position with the pin 24 in the opening l9.

Figures 3 and 5 illustrate the unlocked position wherein the member I4 is free to rotate as desired.

The indicator dial l6 might, for example, be calibrated from 40-46 as shown in Figures 2 and 3 and the dial I4 may be calibrated from 0.1 to 0.9. Suppose, for example, that it is desired to tune from 40.6 to 46.9. The inner dial l4 must be able to rotate over the entire range from 1 to 9 for every position of the dial I0 except the one corresponding to 40. When the dial [0 is set to 40, inner dial l4 must be locked so that it will not move below 6. The present apparatus prevents the outer dial in from being moved into the 40 setting unless a unit larger than 5 is adjacent the Pin 24.

The spring biasing means 25 urges the link 22 outwardly from the dial l4 so that it is cammed into engagement with the dial l4 only when it engages the cam portions 36 and 31.

It is to be realized that the upper as well as the lower unit may be regulated and an example of a lower limit is given for illustrative purposes only.

Although this invention has been described with respect to a particular embodiment thereof, it is not to be so limited as changes and modifications may be made therein which are within the full intended scope of the invention as defined by the appended claims.

I claim: V

1. Apparatus for limiting the relative motion between a pair of dials comprising, an outer dial, an inner dial, a generally arcuate slot formed in the inner dial, cam means formed in the outer dial, a base plate, a first hollow .shaft rotataabl supported by said base plate and attached to said outer dial, a shaft received with-insaid hol low shaft and attached to said inner dial, a link member pivotally supported on said plate, a locking pin attached to said member and-extending transversely thereof betweenuthe .outer and inner dials, and said locking pin engageable with the cam portion of the outer dial.

'2. Motion limiting means comprising outer and inner dials, a first hollow shaft attached to the outer dial, a second shaft passing rotatably through the second shaft and attached to the inner dial, a plate rotatably supporting the first and second shafts, a link member pivotally supported on said plate, a generally arcuate opening formed in said outer dial with cam surfaces formed at either end thereof, an arcuate slot formed in the inner dial, and a locking pin attached to said link member and received in said arcuate opening and into-the said arcuate slo to limit the motion of the inner dial.

3.- Motion limiting apparatus for a pair of dia mounted concentrically with respect to each other comprising, a plate, an outer and inner dial-,a first hollow shaft rotatably supported by said plate and attached to said outer dial, a second shaft rotatably supported within said hollow shaft and attached to said inner dial, a generally crescent shaped opening formed in said outer dial, a link member pivotally supported by said plate, a locking pin attached to one end of said link member and received in said crescent shaped opening, and a locking slot formed in said inner dial and engageable with saidiqlqcking pin when it is cammed into the end position by said outer dial 4. A motion limiting means for limiting the motion ;ofan 'innemdial with respect to an outer dial when the outer dial is in a certain position comprising-aninnerdial, an outer dial, a plate,

'ahhollow shaft rotatably supported by said plate,

said outer dial connected to said hollow shaft, asecond shafttreceived through said hollow shaft and connected to said inner dial, a circular opening formed substantially through said outer dial and said inner dial received therein, a center sleeve portion attached to said outer diaLalink member pivotally supported by said plate, and received within the confines of said outer dial. spring biasing means normally biasing said link member radially outward from said inner dial, a cam portion formed on said outer dial and engageable with said link member to cam it in toward said inner dial, and said inner dial formed with an arcuate slotinto which the link member is received'whencammed therein.

I-I. BEHRENS.

Number Name Date K 1,599,548 Baggott, .Septnll, 1926 Butler Sept. 3, 1929

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