US1939697A

US1939697A - Float switch

Info

Publication number: US1939697A
Application number: US444201A
Authority: US
Inventors: Malcolm E Henning
Original assignee: Penn Electric Switch Co
Current assignee: Penn Electric Switch Co
Priority date: 1930-04-14
Filing date: 1930-04-14
Publication date: 1933-12-19
Anticipated expiration: 1950-12-19

Description

M. E. HENNING Dec. 19, 1933.

FLOAT SWITCH Filed April 14, 1950 daveulo'r -J7Zalcahll 2': Hex 2121 1 Patented Dec. 19, 1933 PATENT OFFICE FLOAT SWITCH Malcolm E. Henning, Des Moines, Iowa, assignor to Penn Electric Switch 00., Des Moines, Iowa,

a corporation of Iowa Application April 14, 1930. Serial No. 444,201

9 Claims.

The object of my invention is to provide a float switch which is simple, durable and comparatively inexpensive to manufacture.

A further object of my present invention is to provide a float switch consisting of a casing with a pair of electrical contact prongs extending therefrom to which a plug may be applied for connecting the switch in an electric circuit.

Still a further object is to provide a switch l0 within the casing and means operated from a float outside of the casing for actuating the switch therein.

Still another object is to provide in the casing a switch structure having an armature arm with a spring acting thereon to pull it in one direction and a magnet to pull it in an opposite direction, the space provided for the throw of the armature arm being such thatthe arm will normally remain adjacent the magnet when moved to such position and will remain spaced from the magnet when moved to such position.

Still a further object is to provide an operative connection extending through .a bearing bushing and connected with the switch on the inside of the casing and with a float on the outside of the casing, the bearing bushing extending through an opening in the wall of the casing.

With these and other objects in view my invention consists in the construction, arrangement and combination of the various parts of my device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawing, in which:

Figure 1 is an end elevation of the float switch structure showing it applied to a liquid tank, the tank being shown in section and afloat being 11- lustrated in connection with the switch structure; the switch structure being connected with a pump which is shown diagrammatically.

Figure 2 is a side elevation of the switch structure with the cover thereof removed,

Figure 3 is a sectional view on the line 3-3 of Figure 2.

Figure 4 is a sectional view on the line 4-4 of Figure 3.

Figure 5 is a. sectional view on the line 5-5 of Figure 2 and Figure 6 is an enlarged sectional view on the '60 Mali-801M034.

0n the accompanying drawing I have used the reference numeral 10 to indicate a liquid tank or the like. A float switch structure A is mounted thereon and includes a casing 12 provided with a 65 cover member 14. Screws or the like 18 may be used for connecting the casing 12 with the tank 10. A bearing sleeve 18 is mounted through an opening 20 in one end of the casing 12 and retained in position by a nut 22. A shaft 24 extends rotatably through the sleeve 18. A float 1 arm 26 is connected with the shaft 24 and terminates in an eye 28. A float 30 is attached to a float rod 32 which extends through the eye 28. Lock nuts 34 are provided on the float rod 32 above and below the eye 28 for adjusting the operation of the switch A relative to the high and low levels of the liquid 36 within the tank 10. An opening 38 is provided in the tank 10 for the float rod 32 and a bracket 40 is provided to guide the float rod.

Within the casing 12 a pintle 42 is suitably supported and a switch arm 44 is pivoted thereon. The switch arm is provided with a resilient leaf spring arm 48 which is operativelyconnected by a link 50 to an arm 52 on the shaft 24. A clamp screw 54 is provided for clamping the arm 52 on 1 3;; the shaft 24, the arm being split as best shown in Figure 4.

A magnet 56 acts upon the arm 44 to pull it in a circuit closing direction. A spring 58 acts in opposition to the magnet 56. The spring 58 has one end connected with a cotter pin which forms the pivotal connection between the upper end of the link 50 and the arm 52.

Its opposite end embraces a sleeve 60 which may be adjusted toward or away from the upper wall of the casing 12 by rotating a screw 62 which is screw threadedly mounted in the sleeve 60. Thus the tension of the spring 58 may be adjusted. A lock nut 64 is provided for the screw 62.

A flexible lead 66 extends from the switch arm 44 to a contact prong 68 (see Figure 5). A second contact prong 70 is electrically connected through a screw '72, spring 74 and nut 76 with a contact plate 78. A stationary contact 80 is 5. carried by the plate 78 and coacts with a contact 82 extending through an opening in the arm 44 and connected with a leaf spring 84, all as clearly set forth in my co-pending application, Serial No. 426,677, filed January 27, 1930.

Practical operation In the operation of my device,' the parts to be in the position illustrated in Figure 2, the switch is in clam circuit position so that electric current will flow through the pump motor 86 shown diagrammatically in Figure 1. This operates the liquid pump 88 for pumping liquid into the tank 10. The rising liquid raises the float 30 until the lower lock nuts 34 engage the 1 eye 28 and swing the arm 26 upwardly. Such upward swinging of the arm 26 will raise the left hand end of the resilient arm 48 (see Figure 2) until it has been bent to such an extent to overcome the magnetic influence of the magnet 56 to hold the arm 44 in closed circuit position. The arm will then move towards open circuit position picking up the spring 48 as it does so whereupon the

contacts

80 and 82 will become quickly separated.

Another thing hastening separation is that the arm 44 immediately upon moving away from the magnet 56 is in a weaker magnetic field. The

spring 58 will then retain the switch arm in open position until the level of the liquid 36 lowers to a predetermined point whereupon'the upper lock nuts'34 will engage the eye 28 for swinging the arm 26 downwardly, closing the switch and again starting the pump 88.

The magnet 56, as the arm 44 moves towards it, acts with ever increasing influence on the arm while as the arm moves in an opposite direction the influences of both the magnet and the spring 58 decrease but the magnetic influence decreases in greater proportion than' the spring influence. The result is a switch in which the arm 44 will stay in either of the positions to which it is moved and the two-way-resilient arm 48 always insures that the switch arm will quickly move from one position to another. The tension of the spring 58 may be varied to insure the operation just described, it being adjusted to compensate for the weight of the

arms

26 and 52. The switch is illustrated on the drawing as being in connection with a float merely by way of illustration. A

Other'control devices may be made for the switch and the switch may be reversely arranged whereby toopen a circuit when the level of the liquid lowers if desired without departing from the real spirit and purpose of my invention, and

it is my intentionte cover by my claims, any

modified .forms' of structure or use of mechanical equivalents, which may be reasonably included within their scope. D

I claim as my invention:

1. In a switch structure, a movable switch arm,

a movable actuating member, a link connection between said actuatin member and said switch arm, said switch arm being arranged to normally stay in either closed or open circuit position when moved to assume said position and a spring counterbalancing the weight of said actuating member so that such weight does not move the switch arm from one of its assumed positions to the other one.

2. In a switch structure, a switch casing, a stationary contact therein, a pivoted switch arm, a contact carried thereby for coaction with said stationary contact, amovable actuating member, a spring counterbalancing the weight of said member and a leaf spring having one end secured to said switch arm and its other end operatively connected with said member.

3. In a switch structure, a stationary contact,

4. In a switch structure, a movable switch arm,

a magnet adjacent said switch arm and'tending to exert a pull in an upward direction thereon to retain said switch arm in raised position but not sufficient to raise it when in lowered position, a movable actuating member connected with said switch arm and a spring tending to counterbal- I ance the weight of said actuating member so that it, when free, will permit said switch arm to ree main in either'of said positions. 5. In a switch structure, a movable switch arm, a magnet adjacent said switch arm and tending to exert an upward pull thereon, a two .po'sition actuating member connected with said switch arm and a spring connected with said actuating member and tending to move the same in a direction to counterbalance the weight of said actuating member so that when said switch arm is moved to either its raised or its lowered position it will remain therein until moved by the actuating member to its other position.

6. In a switch structure, a stationary contact, a movable switch arm having a contact for coaction therewith, a magnet adjacent said switch arm and tending to exert a pull thereon to engage said contacts with each other, a movable actuating member, adjustable spring means to counterbalance the weight of said member and a leaf spring having one end connected with said nected with said member.

'7. In a switch structure, a pivoted switch arm, a movable actuating member, a spring counterbalancing the weight of said member, a lever seswitch arm and its other end operatively conv c'ured to said control shaft and a leaf spring having one end secured. to said switch arm and its other end operatively connected with said memher.

8. In a switch structure, a movable switch arm, magnetic means tending to cause movement thereof in one direction, a movable actuating member, a leaf spring having one end connected to said switch arm, a link connection between the other end of said leaf spring and said member and a spring counterbalancing the weight of said actuating member.

9. In a switch structure,- a movable switch arm, a magnet adjacent said switch arm and tending to exert a pull thereon in one direction, a movable actuating member, adjustable spring means to counterbalance the weight of said actuating member and a leaf spring having one end connected with said switch arm and its other end operatively connected with said actuating member. I

MALCCLM E. HENNING.