US2966330A

US2966330A - Magnetic control means

Info

Publication number: US2966330A
Authority: US
Inventors: Benjamin L Binford
Original assignee: Magnetrol Inc
Current assignee: Magnetrol Inc
Priority date: 1959-06-29
Filing date: 1959-06-29
Publication date: 1960-12-27
Anticipated expiration: 1977-12-27

Description

Dec. 27, 1960 B. L. BINFORD 2,966,330

MAGNETIC CONTROL. MEANS Filed June 29, 1959 &

" I Nl/gNTOR @W W/M ATTORNEYS nite States 2,966,330 MAGNETIC CONTROL MEANS Filed June 29, 1959, Ser. No. 823,699

7 Claims (Cl. 251-6 This invention relates to magnetic control means and more particularly to magnetically operated actuating means for a fluid control valve.

Magnetic control devices in which operated devices, such as electrical switches for fluid control valves, are operated by movement of a magnet in response to the positioning of a magnetic armature have been known and used successfully for many years. One problem encountered in use is the construction of such a device to provide a high initial or break-away force to move the operated device when the magnet is initially attracted, this being particularly acute when the operated device is a fluid control valve. It is also highly desirable that such devices be constructed to operate the operated device in either or both directions of movement of the magnetic armature.

It is one of the objects of the present invention to provide magnetic control means which produces a high mechanical advantage between the movable magnet and the operated device during initial movement of the magnet and a lower mechanical advantage during subsequent movement of the magnet to provide the desired amount of travel of the operated device without requiring excessive magnet movement.

According to a feature of the invention, the operated device is moved by a pivoted lever turning successively about spaced pivotal axes as it moves in a direction to actuate the operated device.

Another object of the invention is to provide magnetic control means in which the operated device is actuated by movement of the magnetic armature from neutral in either or both directions.

According to another feature of the invention, a pair of magnets are spaced longitudinally of the path of travel of the magnetic armature supported on a pivoted carriage which also carries actuating members to engage a lever through which the operated device is actuated and turn it in the same direction regardless of the di rection of turning of the carriage. The actuating members are preferably spaced different distances from the pivotal axis of the carriage having the same ratio to each other as the distance of the respective actuating members from the lever axis so that the same mechanical advantage is produced between the carriage and the operated device regardless of the direction of turning of the carriage.

The above and other objects and features of the invention will be more readily apparent from the following description when read in connection with the accompanying drawings, in which:

Figure 1 is a top plan view with parts in section of magnetic control means embodying the invention;

Figure 2 is a section on the line 2-2 of Figure 1; and

Figure 3 is a section on the line 3-3 of Figure 1 with parts in elevation.

The device, as shown, comprises a base which may be formed of cast metal or other suitable similar material for mounting adjacent to a tank whose level is to tet i 2,95%,330 Patented Dec. 27, 1960 be measured or controlled or adjacent to -a similar-mechanism or part whose condition is to be measured or controlled. The base 10 carries a tube 11 of non-magnetic material projecting vertically upward therefrom and pref erably closed at its upper end. A magnetic armature 12 is movable in the tube 11 and may be moved by an op erating rod 13 connected to a float or other condition sensing means. The float may enter the tube from either its upper or lower end, but normally enters from its lower end, as shown, with the upper end of the tube being closed. Normally when installed a cover member, not shown, is secured to the base and encloses the tube and the other operating parts of the unit.

Movement of the armature 12 is sensed by the control means of the invention and is utilized to actuate an operated device, such as an electrical switch or a fluid control valve. The control means, as shown, comprises a supporting frame 14 which is preferably recessed at one side to fit partially over the tube 11 and which carries a clamping arm 15 secured thereto by screws to be drawn up closely against the tube 11 to clamp the frame 14 securely thereto. It will be seen in this way that the entire controlling means may be simply secured to the tube in any desired position thereon. The frame 14 pivotally supports a carriage 16 which is mounted on a pivotal axis 17 on the frame to tilt about the axis. The carriage carries a pair of magnets 18 and 19 at its upper and lower ends, respectively, and is so proportioned that when one of the magnets moves toward the tube 11 the other moves away from it. When the armature is in a lower position, as shown in dotted lines in Figure 2, the lower magnet will be attracted to it and will turn the carriage clockwise from the neutral position illustrated. Similarly, when the armature moves upwardly into the field of the upper magnet, it will attract the upper magnet to rock the carriage counterclockwise. Preferably the armature is of such a length as to substantially span the distance between the magnets so that when it moves into the field of one magnet it moves out of the field of the other and the carriage will be turned relatively quickly with a positive action and will remain in the position it occupies until the armature hasmoved an appreciable distance in the opposite direction.

In the construction shown, movement of the carriage and armature is adapted to control a fluid control valve indicated generally at 21 and shown in section in Figure 3. The control valve comprises a hollow body having an upper inlet passage 22 communicating with a passage 23 for the supply of air or similar fluid under pressure. Preferably a filter 24' is interposed in the passage 23 to filter any foreign particles therefrom before the fluid reaches the valve. The passage 23 communicates with a supply connection 24 in the base 10 and is preferably sealed by drawing the base plate of the support 14 tightly against the base 10 by means of screws 25 with a suitably perforated gasket'2 6 interposed therebetween.

The valve controls communication with an outlet passage 27 which communicates with an outlet connection 28 in the base 10. Communication and sealing are established between the outlet connection 28 and outlet passage 27 through the gasket 26 and sealing pressure exerted by the screws 25 in the same manner as for the inlet passage. The outlet passage may be connected to a pressure operated control valve or other control or indicating instrumentality to indicate or to correct changes in the condition sensed by the float or othersensing means which moves the armature.

The control valve itself comprises a double poppet valve member 29 adapted to seat at its upper end against the opening of the supply port 22 and its lower end in an atmospheric exhaust port formed in a closure plug for the valve casing. A stem 32 secured to the valve 29 extends downward through the closure plug and is adapted to he engaged and moved to actuate the valve.

The stem 32 is adapted to be engaged and moved upward by one end of a lever 33 which is pivoted intermediate its ends on a double pivot member 34, as best seen in Figure 2. As shown, the lever is formed in its bottom .with a notch receiving the pivot member 34 which has an appreciable length lengthwise of the lever to provide two pivot edges spaced lengthwise of the lever. The purpose of this construction will appear more fully hereinafter. At its upper surface, the lever carries a spring strip 35 secured at one end to the lever by rivets 36 and at its opposite end extending over the end of the lever. .The end of the strip 35 carries an adjusting screw 37 ;which may be turned into engagement with the end of the lever to move the strip 35 more or less away from the upper surface of the lever. This adjustment not only adjusts the initial clearance between the lever and the valve stem 32, but also provides resilience to prevent exertion of excessive pressure on the valve stem. A spring 38 connected to the end of the lever normally swings the lever counterclockwise to substantially the position shown.

The lever is turned by turning of the carriage and can be turned by movement of the carriage in either direction from its neutral position or only by movement in a selected direction from its neutral position. For this purpose, the carriage carries a pair of actuating screws 39 and 41 spaced lengthwise of the lever on opposite sides of the pivotal axis 17. With this construction regardless of the direction in which the carriage turns one or the other of the screws will engage the lever and turn it clockwise about the pivot 34 to move the valve stem 32 upward and actuate the valve. When it is desired to actuate the valve in response to turning of the carriage in one direction only one of the screws 39 or 41 may be backed off so that it will not engage the lever under any conditions at which time the lever will be turned only when the carriage turns in one direction.

As the lever initially turns from its initial position it will pivot about the left edge of the pivot member 34 which provides a relatively long lever arm between the lever pivotal axis and the actuating member 39 or 41 and a short lever arm between the lever pivotal axis and the valve stem 32. Thus a high mechanical advantage will be provided between the carriage and the valve stem to provide maximum multiplication of the force exerted by the carriage on the lever. This produces a high initial or break-away force on the valve stem to direct it away from its normal position, as shown in Figure 3, in which the valve member is seated on the exhaust port. After a small initial movement, the lever will turn about the right-hand edge of the pivot member 34 which provides a lesser mechanical advantage to a greater degree of movement. Therefore, the valve can be given the desired amount of pressure without requiring excessive movement of the magnets and carriage.

According to another feature of the invention, the actuating members 39 and 41 are spaced different distances from the carriage axis 17, having the same ratio to each other as the distances from the lever pivotal axis to the actuating members 39 and 41. Thus the actuating member 39 is closer to the pivot 34 and is also closer to the pivot 17, the proportions being such that the same amount of turning torque on the carriage in either direction will produce the same mechanical advantage on the valve stem and the same movement of the valve stem. The mechanism therefore operates in precisely the same way regardless of which direction of turning of the carriage is utilized to move the valve or whether the valve is moved in response to movement of the carriage in either direction.

In normal use, with the carriage in its neutral position,

as shown in Figure 2, or if it is turned in one direction and the actuating screw which would normally engage the lever in that direction has been backed off, the lever will be out of engagement with the valve and the valve will move down onto the exhaust port to open the inlet port to the outlet passage 27. When the lever is turned clockwise, as seen in Figure 2, it will move the valve upward away from the exhaust port and will cause it to seat against the inlet port 22 to vent the outlet passage 27 and to close otf the supply of fluid. This operation can be used to control pressure responsive valves or other similar pressure operated devices.

While one embodiment of the invention has been shown and described herein, it will be understood that it is illustrative only and not to be taken as a definition of the scope of the invention, reference being had for this purpose to the appended claims.

What is claimed is:

1. Magnetic control means comprising an elongated pivoted lever, an operated device including an actuating .rod engaged by the lever at a predetermined distance from its pivot and moved by the lever as it is rocked in one direction about its pivot, a pivoted carriage adjacent to the lever, magnetic means to turn the carriage in either direction about its pivot, and a pair of actuating members carried by the carriage spaced on opposite sides of its axis and respectively engageable with the lever at spaced points in its length to rock the lever in said one direction about its pivot as the carriage is rocked in either direction about its pivot.

2. The magnetic control means of claim 1 in which the actuating members are spaced different distances from the carriage pivot to maintain the same mechanical advantage between the carriage and the operated device regardless of the direction of rocking of the carriage.

3. Magnetic control means comprising an elongated tube of non-magnetic material, a magnetic element movable in the tube, a carriage pivoted on an axis adjacent and transverse to the tube, magnets on the carriage on opposite sides of its axis and spaced lengthwise of the tube to be selectively attracted by the magnetic element as it moves in the tube, a lever pivoted intermediate its ends on a pivot parallel to and spaced from the carriage axis, a pair of actuating members on the carriage on opposite sides of its axis and spaced lengthwise of the lever selectively to engage the lever and rock it in one direction as the carriage is turned in one direct on or the other about its axis, and an operated device engaged and operated by the lever as it is turned in said one direction.

4. The magentic control means of claim 3 in which the actuating members are spaced different distances from the carriage axis in the same ratio to each other as the distances of the actuating members from the lever pivot to provide the same mechanical advantage between the carriage and the operated device regardless of the direction of turning of the carriage.

5. Magnetic control means comprising an elongated tube of non-magnetic material, a magnetic element movable in the tube, a carriage pivoted on an axis adjacent and transverse to the tube, magnets on the carriage on opposite sides of its axis and spaced lengthwise of the tube to be selectively attracted by the magnetic element as it moves in the tube, a lever pivoted intermediate its ends on a pivot parallel to and spaced from the carriage axis, a pair of actuating membrs on the carriage on opposite sides of its axis and spaced lengthwise of the lever selectively to engage the lever and rock it in one direction as the carriage is turned in one direction or the other about its axis, and a poppet type valve mounted adjacent to the lever and having an actuating rod engageable by the lever when it is rocked in said one direction to actuate the valve.

6. The magnetic control means of claim 5 in which the actuating members are spaced different distances trom the carriage axis in the same ratio to each other as the distances of the actuating members from the lever pivot to provide the same mechanical advantage between the carriage and the valve regardless of the direction of rotation of the carriage.

7. The magnetic control means of claim 6 in which the lever pivot provides two spaced pivotal axes about 5 which the lever pivots successively as the lever turns in said one direction to provide a high initial mechanical References Cited in the file of this patent UNITED STATES PATENTS Long June 2, 1942 Bogue Feb. 21, 1956