US3601730A

US3601730A - Magnetic-detenting control

Info

Publication number: US3601730A
Application number: US16107A
Authority: US
Inventors: Jack C Cookerly; George Robert Hall
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-03-03
Filing date: 1970-03-03
Publication date: 1971-08-24
Anticipated expiration: 1988-08-24

Abstract

Magnetic-detenting control for resistance strip, switches, valves or other devices in which it is required that the control be in increments and that there be a pause at each increment. The positions of the control are indexed by a series of magnets mounted on a base and alternately arranged in opposite polarity. A manually operable slider is guided for movement along the magnets and forms a support for a detenting magnet. The detenting magnet is arranged with its magnetic field flowing in the direction of movement of the slider. As the detenting magnet is moved along the series of stationary magnets, a dwell occurs as opposite poles come into registry with each other. The points at which the detent actions or swells take place can thus be relatively closely spaced and calibrated. The position of the slider can readily be determined visually, and the detent actions can be determined by feel.

Description

United States Patent Appl. No. Filed Patented MAGNETIC-DETENTING CONTROL Primary ExaminerG. Harris Attorney-Hill, Sherman, Meroni, Gross & Simpson ABSTRACT: Magnetic-detenting control for resistance strip, switches, valves or other devices in which it is required that the control be in increments and that there be a pause at each increment. The positions of the control are indexed by a series of magnets mounted on a base and alternately arranged in opposite polarity. A manually operable slider is guided for movement along the magnets and forms a support for a detenting lo m l 5- magnet. The detenting magnet is arranged with its magnetic field flowing in the direction of movement of the slider. As the US. detenting magnet is moved along the series of stationary mag- 335/207 338/183 nets, a dwell occurs as opposite poles come into registry with each other. The points at which the detent actions or swells Int. Cl. H011 7/02 take place can thus be relatively closely spaced and calibrated. Field of Search 335/205, The position of the slider can readily be determined visually, 206, 207, 306; 338/183 and the detent actions can be determined by feel.

7 I 0 ll I I} ill, ,//Z I 2 I 1 l r g a! 2 a 2 I l MAGNETIC-DETENTIN G CONTROL This application is a continuation-in-part of our application, Ser. No. 662,628, filed Aug. 23, 1967.

SUMMARY AND OBJECTS OF THE INVENTION In carrying out the present invention, we locate a series of magnets along a base in side-by-side relation with respect to each other, in which the magnetic fields of the magnets run along the short axes of the magnets, and provide a slider movable along the magnets and carrying a detenting magnet in which the direction of magnetic field flows in the direction of movement of the slider, to effect a dwell in movement of the slider each time unlike poles on the detenting magnet move into registry with unlike poles of the series of magnets.

A principal object of the present invention is to provide a novel and improved form of sliding detent relatively free from friction.

Another object of the invention is to provide a simplified form of magnetic detent in which vibration and friction caused by physical contact are reduced to a minimum.

Another object of the invention is to provide a simplified form of detenting control free from noise and vibration and adapted to positively detent the steps of a control device operated and controlled thereby.

A still further object of the invention is to provide a simplified form of magnetic detenting control, so arranged as to give a visible indication of the position of the control, which may be determined at a glance, and capable of readily calibrating the points at which the detenting action takes place.

Still another object of the invention is to provide a friction free magnetic detent, in which a detenting action is attained by relative movement between two magnets.

Other objects, features and advantages of the invention will be readily apparent from the following description of certain preferred embodiments thereof, taken in conjunction with the accompanying drawings, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic top plan view of a magnetic detent constructed in accordance with the principles of the present invention, diagrammatically showing the detent in a control for varying the resistance of a resistor;

FIG. 2 is a transverse sectional view taken through the detent shown in FIG. 1;

FIG. 3 is a plan view of a modified form of the detent showing the slider of the detent having a connector leading therefrom for connection with a device to be operated in accordance with the position of the slider along its slides; and

FIG. 4 is a schematic plan view showing the principles of the present invention applied to an annular arrangement of magnets.

DESCRIPTION OF PREFERRED EMBODIMENTS OF INVENTION In FIGS. 1 and 2 of the drawings, we have shown a detenting controller including an elongated base 11 having upright arms l2. 12 at opposite ends thereof forming a support for a slide bar 13, extending between said arms. The slide bar 13 has a nonmagnetic slider 15 mounted thereon for slidable movement therealong in accordance with a desired position of the control to be operated by said slider.

Between the upright arms l2, 12 of the base 11 are a series of

permanent magnets

16 and 17 arranged along said base from one end thereof to the other, with the poles of said magnets alternately arranged. As for example, the south poles of the permanent magnets 16 all face upwardly while the north poles face the base. The north poles of the permanent magnets 17 face upwardly while the south poles thereof face the base 11.

The

permanent magnets

16 and 17 may be ceramic magnets, and preferably are made from a thermoplastic material impregnated with barium ferrite, and are commonly termed ceramic magnets. The magnetic fields of the

magnets

16 and 17 run across the short axes of the magnets. With such ceramic permanent magnets, the magnetic fields of the magnets can run across the short axes of the magnets. The particular magnetic material used, therefore, has a distinct advantage, in that it may be magnetized along its short axis and will stay magnetized indefinitely, and will not be demagnetized by alternating current.

A further advantage of the magnets made from a thermoplastic material impregnated with barium ferrite is that the magnets may be in one continuous strip having magnetized sections and demagnetized sections, which may be of equal or unequal lengths in accordance with the control function to be attained by the detenting control of the present invention.

The

magnets

16 and 17, therefore, may be made from one relatively long bar magnetized in sections along the short axis of the bar, or may be made from individual ceramic magnets placed along the base 11 in side-by-side relation with respect to each other as shown in FIG. 2 of the drawings.

The slider 15 has a downwardly opening generally U-shaped recessed portion 18 having a detenting magnet 19 recessed therein and extending across the base 11 and

magnets

16 and 17. The detenting magnet 19 may be secured to the slider 15 by an adhesive or by any other suitable securing means and may also be a ceramic or plastic magnet, with the magnetic field of the magnet running along the short axis thereof, in the direction of travel of the slider 15 along the slide 13.

As for example, the north pole of the magnet 19 is on one side of the magnet while the south pole of the magnet 19 is on the opposite side of the magnet. The two poles of the magnet 19 thus face in the direction of travel of the slider along the slide 13 and each time a north pole of the detenting magnet 19 comes over a south pole of a magnet 16 there will be a dwell in movement of the slider 15 along the slide 13, due to the attraction between the opposed poles of the magnets. A similar dwell will take place each time a south pole of the magnet 19 comes into the magnetic field of a north pole of a magnet 17.

The slider 15 and detenting magnet 19 are thus movable along the slide rod 13 with a series of dwells which take place each time unlike magnetic fields of the detenting magnet 19 come into the opposed magnetic fields of the

magnets

16 and 17 throughout the length of travel of the slider 15 along the slide rod 13.

A relatively fine detenting action thus takes place, providing a plurality of dwells for the slider 15 along the slide bar 13, determined by feel as said slider is pushed along said slide bar.

The present detenting control is of particular advantage in controlling'the resistance through a resistance strip, in that movement of the control is silent and the points at which the detenting action takes place can be calibrated in db., s, ohms, volts, etc. and the position of the slider can readily be determined at a glance. The visual position of the slider 15 thus gives a graphic display of the resistance, and there is always a feel with respect to the distance traveled by the slider from zero to a full on position, which is not present in other controls, particularly in the form of one or more rotary controls, in positions where the operator cannot continually look at the control. In the present control the operator can determine the position of the control by counting the detent positions as the slider passes into the respective detenting positions.

In FIG. I we have shown a resistance rod 21 mounted on the arms 12, to one side of the slider 15 and extending parallel to the slide rod 13. The resistor 21 may be a carbon rod or a wire wound resistance, and may be insulated from the base 11 and

magnets

16 and 17 and be connected with a suitable source of power.

The slider 15 may have a contact 23 extending therefrom and electrically connected with a power line or one terminal of a device to be energized, in a manner which need not herein. be shown or described, since it forms no part of the present invention. The contact 23 is thus engaged with the resistor rod to increase or cut out the resistance of said rod and there is no physical connection between the slider and detenting magnet 19 and the cooperating

magnets

16 and 17 spaced along the base 11 between the upright arms 12. The resistor rod 21 may also be replaced by multiple contacts engaged by the contact 23 as the slider 15 moves along the slide bar 13, to provide a multiple contact switch.

In FIG. 3 we have schematically shown in plan view a detenting control similar to that shown in FIGS. 1 and 2 in which a pair of

parallel slide bars

24, 24 extend between the

upright arms

12, 12 of the base 11 and form a slidable support for a slider 25. The slider 25 may be a nonmagnetic slider like the slider 15 and serves as a movable support for a magnet 26, like the magnet 19, and also has a control rod 27 extending parallel to the

slide bars

24, 24 and secured to said slider for movement therewith. The control rod 27 is shown as slidably guided in an upright arm 12 in a suitable manner and as extending from said arm. Said slider may have connection with a device to be operated, which may be in the form of a switch or series of switches, a resistor, or a series of stops to determine the positions of the stops, or to any other devices to be operated into preselected control positions, in which the positions of the devices may visually be determined by a glance at the slider or by feel, by counting the detent positions as moving the slider along the

slide rods

24, 24, as previously mentioned.

ln FIG. 4, we have shown

magnets

27 and 29 similar to the

magnets

16 and 17, but arranged in the form of an annulus. The

magnets

27 and 29 have alternately arranged poles, that is, the north poles of the magnets 27 face outwardly while the south poles of said magnets face inwardlyHThe south poles of the magnets 29 face outwardly and the north poles face inwardly.

As diagrammatically shown in FIG. 4, an arm 30 is suitably mounted for rotation about the axis of a shaft 31, coaxial with the center of the annulus formed by the

permanent magnets

27 and 29. The arm 30 has a knob 32 in its outer end. A permanent magnet 33 is shown as extending inwardly of said knob 32 and as depending from the arm 30, and extending along the outer sides of the

magnets

27 and 29.

The detenting magnet 33 is thus moved along the altemately arranged

magnets

27 and 29 by grasping the knob 32 with the fingers, and moving the arm 30 about the axis of the shaft 31, to detent the various positions of said arm. The arm 30 may have connection with a device to be operated in any suitable manner, with the

magnets

27 and 29 so arranged as to provide a plurality of closely spaced detenting positions, indicating the positions of the device to be operated by feel, or by visually glancing at said arm and control knob.

The

magnets

27 and 29 like the

magnets

16 and 17 may be made from separate pieces of thermoplastic material impregnated with barium ferrite or from a single piece of thermoplastic material impregnated with barium ferrite- Where the magnets arevformed from a singlepiece of thermoplastic material impregnated with barium ferrite, the material may be magnetized along spaced short axes of the material, to conform to a series of desired stops. Furthermore, parts of the annulus may be magnetized while other parts may be demagnetized and the polarity of the magnetic fields of the magnetized parts of the annular strip of material may run in opposite directions or in the same directions.

We claim as our invention:

1. A magnetic-detenting control comprising in combination,

a. a base,

b. a series of permanent magnets spaced along said base arranged to provide a series of alternately arranged poles of opposite polarity,

c. a detenting magnet mounted for movement along said series of magnets and adapted to have connection with a device to be controlled, the magnetic field of said detenting magnet running in the direction of travel of said magnet along said series of magnets, whereby the opposed fields of said series of magnets will alternately retard movement of said detenting magnet along said series of magnets and provide a series of detenting stops.

2. The magnetic-detenting control of claim 1, wherein said series of magnets and said detenting magnet are made from thermoplastic materials impregnated with barium ferrite, and are all magnetized along the short axes of the materials.

3. The magnetic-detenting control of claim 2, wherein the series of magnets are arranged along said base in a straight line and the poles thereof face said detenting magnet including,

a. means for mounting said detenting magnet for movement along said series of magnets, in a relatively friction-free path.

4. The magnetic-detenting control of claim 1, wherein the series of magnets are arranged in a straight line and including,

a. a slide bar mounted on said base and extending along said series of magnets,

b. a slider mounted on said slide bar for movement therealong, and

c. means mounting said detenting magnet on said slide bar for movement along said series of magnets.

5. A magnetic-detenting control in accordance with claim 1,

including,

a. upright brackets at opposite ends of said base,

b. a slide bar extending between said brackets and mounted thereon,

c. a slider slidably mounted on said slide bar for movement therealong and forming a movable support for said detenting magnet and positioning said detenting magnet in close proximity to said series of magnets for movement therealong.

6. The magnetic-detenting control of claim 5, wherein said series of magnets are made from a single strip of thermoplastic material impregnated with barium ferrite, and oppositely magnetized in increments throughout thelength of said strip.

7. The magnetic-detentingcontrol of claim 5, including,

a. a resistor extending along one side of said base, and

b. a contact arm on said slider having contact with said resistor to vary the resistance thereof.

8. The magnetic-detenting control of claim 2, including,

a. upright brackets at opposite ends of said base,

b'. a slide mounted between said brackets,

c. a slider slidably mounted on said slide for movement therealong and along said series of magnets, and

d. means mounting said detenting magnet on said slide to depend therefrom in juxtaposition to said series of magnets.

9. The magnetic-detenting control of claim 1, including,

a. means arranging the series of magnets in the form of an annulus,

b. means mounting said movable magnet for movement along said series of magnets in juxtaposition thereto, whereby the alternately arranged magnetic fields of said series of magnets in cooperation with the magnetic field of said detenting magnet will effect detenting dwells in travel of said detenting magnet along said series of magnets.

10. The magnetic-detenting control of claim 9, wherein the means mounting said movable magnet for movement along said series of magnets. comprises,

an arm pivoted for movement about the center of said annulus and extending radially therefrom, and

a supporting connection between said arm and said detenting magnet positioning said detenting magnet in juxtaposition to said series of magnets.

Claims

1. A magnetic-detenting control comprising in combination, a. a base, b. a series of permanent magnets spaced along said base arranged to provide a series of alternately arranged poles of opposite polarity, c. a detenting magnet mounted for movement along said series of magnets and adapted to have connection with a device to be controlled, the magnetic field of said detenting magnet running in the direction of travel of said magnet along said series of magnets, whereby the opposed fields of said series of magnets will alternately retard movement of said detenting magnet along said series of magnets and provide a series of detenting stops.

3. The magnetic-detenting control of claim 2, wherein the series of magnets are arranged along said base in a straight line and the poles thereof face said detenting magnet including, a. means for mounting said detenting magnet for movement along said series of magnets, in a relatively friction-free path.

4. The magnetic-detenting control of claim 1, wherein the series of magnets are arranged in a straight line and including, a. a slide bar mounted on said base and extending along said series of magnets, b. a slider mounted on said slide bar for movement therealong, and c. means mounting said detenting magnet on said slide bar for movement along said series of magnets.

5. A magnetic-detenting control in accordance with claim 1, including, a. upright brackets at opposite ends of said base, b. a slide bar extending between said brackets and mounted thereon, c. a slider slidably mounted on said slide bar for movement therealong and forming a movable support for said detenting magnet and positioning said detenting magnet in close proximity to said series of magnets for movement therealong.

6. The magnetic-detenting control of claim 5, wherein said series of magnets are made from a single strip of thermoplastic material impregnated with barium ferrite, and oppositely magnetized in increments throughout the length of said strip.

7. The magnetic-detenting control of claim 5, including, a. a resistor extending along one side of said base, and b. a contact arm on said slider having contact with said resistor to vary the resistance thereof.

8. The magnetic-detenting control of claim 2, including, a. upright brackets at opposite ends of said base, b. a slide mounted between said brackets, c. a slider slidably mounted on said slide for movement therealong and along said series of magnets, and d. means mounting said detenting magnet on said slide to depend therefrom in juxtaposition to said series of magnets.

9. The magnetic-detenting control of claim 1, including, a. means arranging the series of magnets in the form of an annulus, b. means mounting said movable magnet for movement along said series of magnets in juxtaposition thereto, whereby the alternately arranged magnetic fields of said series of magnets in cooperation with the magnetic field of said detenting magnet will effect detenting dwells in travel of said detenting magnet along said series of magnets.

10. The magnetic-detenting control of claim 9, wherein the means mounting said movable magnet for movement along said series of magnets comprises, an arm pivoted for movement about the center of said annulus and extending radially therefrom, and a supporting connection between said arm and said detenting magnet positioning said detenting magnet in juxtaposition to said series of magnets.