US2623963A - Pressure switch - Google Patents

Description

Dec. 30, 1952 H. H. WOLFE ET AL 2,623,963

PRESSURE SWITCH Filed April 27, 1948 3 Sheets-Sheet l l I l 10 fP/Nvswoes H. H/X MJLFE EDWARD w. HAAS VJ."- ,5 9mm,- ATTORNEYS Dec. 30, 1952 H H. WOLFE ETAL PRESSURE SWITCH 3 Sheets-Sheet 2 Filed April 27, 1948 5.. 5 Y 5 A REA 0W5 mm mm. i AA/AaA ANA-AKI m w m I i WM 2 h /...m. 1 mm m. m \w n ll v M uv 3 Q Mnh I 9 9n on an fl m j 3 w mu A: mAQAA/ AQ m a e 6... 3 V 7 V 3 i mm 7 7 mm be 1 av d Q Ma 3 T E 3, 3 3 n 8 8 K +9 "a w v n a w UP 2 a m mw an 3 Dec. 30, 1952 H. H. WOLFE ETAL PRESSURE SWITCH 3 Sheets-Sheet 5 Filed April 27, 1948 EDWARD W. HIMS INVENTOES H.HIX WOLFE ATTORNEYS Patented Dec. 30, 1952 PRESSURE SWITCH H. Hix Wolfe and Edward W. Haas, Dayton, Ohio,

assignors to The Dayton Pump & Manufacturing Company, Dayton, Ohio, a corporation of Ohio Application April 2'7, 1948, Serial No. 23,536

2 Claims. 1

This invention relates to pressure switches and to improvements therein, and is particularly concerned with the types of pressure switches which are used on water pumping systems and the like.

The usual type pressure switch for use with water systems, such as domestic systems, is quite complex and is often difficult to adjust and repair due to a plurality of small parts and to the arrangement of these parts in the switch. It is desirable, and particularly with switches for domestic installation, to simplify the structure of such a switch to reduce the chance that it will become inoperative and render the system it controls useless for a long period of time.

Furthermore, such pressure switches generally have rollers and cams and similar mechanisms which have an inherent amount of friction that materially detracts from the accuracy with which the switch can be adjusted to open or close at any predetermined pressure.

The primary object of the present invention is to provide an improved pressure switch of the type referred to above and which overcomes the objectionable features of the ordinary type pressure switch.

It is another object of this invention to provide an improved pressure switch constructed of a relatively few number of parts and being substantially free of frictional engagement of the moving parts with each other.

A still further object is the provision of an improved contact arrangement for a pressure operated switch simple to construct and which can readily be assembled and disassembled from the switch.

These and other objects and advantages will become more apparent upon reference to the following description taken in connection with the accompanying drawings in which:

Figure 1 is a vertical section taken through the switch of this invention and showing it with the contacts in open position;

Figure 2 is a view similar to Figure l but showing the contacts of the switch in closed position;

Figure 3 is a View similar to Figure 2 but with the contact portion of the switch removed in order better to show the pressure responsive actuator for the switch;

Figure 4 is a plan view looking down on the w actuator mechanism shown in Figure 3;

Figure 5 is a plan view looking down on the switch and terminal block;

Figure 6 is a vertical section indicated by the line 6--6 on Figure 5;

Figure 'I is a view similar to Figure 6 and in dicated by the line 1'l on Figure 5:

Figure 8 is a section view indicated by the line 8-8 on Figure 1;

Figure 9 is a perspective view of the actuator mechanism; and

Figure 10 is a perspective view showing the member which transmits thrust from the pressure diaphragm to the actuator mechanism.

Referring to the drawings, the switch according to this invention generally comprises a part indicated at H), which is the pressure responsive portion of the assembly, a part indicated at l2, which is the actuator portion of the assembly,

and a portion indicated at H. which is the terminal block and contact assembly.

These several parts are assembled together and are then enclosed with a casing l6 which includes the removable cover 18. The entire assembly is then ready to be connected to the electric lines to be controlled by the switch and the pressure part I!) and can be connected with the source of pressure which is to eiiect the said control.

Referring to the aforementioned pressure part Hi, this will be seen tocomprise a bottom or base part 20 having a threaded opening 22 that receives a pressure pipe, as, for example, the pressure line leading from a pump to the reservoir.

The upper portion of the cast part 20 has a machined peripheral flange and against this flange there is the flexible diaphragm 24. The diaphragm 24 is retained in position by the screws 26 which extend through the member 29 and the periphery of the flange and into engagement with a plate 28.

The lower portion of the casing 16 is turned in as indicated at 30 and is clamped between the periphery of the plate and the marginal portion of the diaphragm 24. Resting on top of the diaphragm 24 is an actuator plate 32 which has arms 34 extending upwardly from each side thereof and extending through the openings 35 in the plate 28. The member 32 and the arms 34 are for the purpose of transmitting thrust from the diaphragm 24 to the switch actuator mechanism at l2.

Referring to the actuating mechanism, this will be seen to comprise a bracket member 38 mounted on the plate 28 by the rivets 39 and having the spaced upstanding arms Ail at one end and the more widely spaced upstanding arms 42 at the other end.

The said arms are notched on their inside edges as indicated at M and a pair of bifurcated or U-shaped plates are arranged to have their legs engaged by the said notches. As shown, a first plate 4% is arranged so that the ends of its legs 33 are engaged by the notches M in the upstanding arms 40. Similarly, a second plate 56 is arranged to have the ends of its legs 52 engaged by the notches in the upstanding arms 42.

It will be noted that the plate 59 is substantially larger than the plate 66 and extending completely around the upstanding arms 40, and that each of the legs 52 thereof have the V-shaped recesses therein and which are positioned to be engaged by the V-shaped upper ends of the arms 3d upstanding from the plate 32.

Having its head positioned beneath the plate 23 and extending upwardly through an aperture 56 in the closed end of the plate 59 is a bolt 58. A spring fill surrounds the bolt and bears at its lower end on the top of the plate 50 and at its Turning now to the contact and terminal block I M of the switch, this will be seen in Figures 1, 2 and 5 through 8 to comprise a block ill of insulating material and which has extending therein from one side a pair of recesses .12. The recesses 12 are substantially rectangular and extending into each end of each of the recesses is a stationary contact plate it. Each of the contact plates 74 is connected with a rod 16 which extends transversely through the block it to the side 78. The screw i8 is for the purpose of connecting the electric leads 8% to the said rods, and as will be noted in Figure 5 the leads are brought into the ends of the rods through grooves or slots 82 in the adjacent side of the block ll).

Disposed in each of the recesses 12 between the bottom thereof and the stationary contact plate M are the movable contact plates 8d. These plates are adapted for bridging the stationary contact plates when in their Figure 2 position and for interrupting the electrical connection between the plates when in their Figure 1 position.

The movable contact plates are guided and actuated by the blades 85 of insulating material which extend through the plates 84 and intothe recesses 88 of the block it. A spring 9!! surrounds each of the blades 8d and continuously urges the associated movable contact plate toward its contact making position.

Each of the blades 55$ is shouldered as at 92 and thus when moved upwardly engages the associated movable contact plate and lifts it from its contact making position. The blades 85 extend beyond the limits of the block ii and there is a cover plate 9 which closes the recess 12 and also retains the blades 85 in position.

The block 78 together with its contacts, contact actuating blades, and cover plate at, is mounted in position on the actuator I2 by means of the screws 95 which extend through the said block and cover plate and into the turned back tabs 98 and I05) which are integral with the bracket 38.

In Figures 5, 6 and 7 it will be noted that there is an adjustable screw I02 extending outwardly from the block H; on the actuator side thereof.

This screw is adjustable by means of a socket head therein from the top of the block and serves as a stop for limiting the maximum upward movement of the plate 66, as will be seen in Figure 1 wherein the plate and screw are shown in engagement.

The screw also serves to adjust the pressure diiierential within which the switch operates, because the closer the screw stops the plate "55 to a horizontal position the smaller the drop in pressure required beneath the diaphragm 24' to allow the said plate to return to its Figure 2 position.

In operation, the switch can be assumed nor mally to have all of its parts shown in the Figure 2 position. At that time the pressure at which the switch will operate is set by means of the nut 55. Thereafter the switch will remain in its Figure 2 position until pressure builds up beneath the diaphragm 24 and moves the plate 32 upwardly and the arms 35 cause the plate 58 to rotate clockwise about its pivotal connection with the upstanding arms 42.

The setting of the spring 60 determines the amount of pressure required to so move the plate 50. When the plate '50 is moved upwardly until the line of action of the spring 66 is above the engagement of the legs 48 of the plate 46 of the upstanding arms 44, the said plate 46 will snap upwardly to its Figure 1 position and bring about a quick opening of the switch contacts. Thereafter the switch will remain open until the pressure beneath the diaphragm drops to the point where the plate 50 will move downwardly and again snap the plate 46 downwardly.

As mentioned before, the pressure at which the switch will open can be adjusted by the nut 64 and the pressure differential, that is, the amount which the pressure must drop beneath the diaopposite the recesses therein and receives a screw phragm 24 before the switch again closes, can

be adjusted by the screw I02. Both the nut and screw are available from the top of the switch merely by removing the cover member l8.

It will be apparent that the switch has substantially no friction due to the pivotal arrangement of the plates 46 and 50 and thus can be adjusted as to operating pressure very accurately. Furthermore, a minimum of assembling operations are necessary because the switch part I 4 is merely assembled and then is retained in assembled position by the same means which secures it in place on the bracket of the actuator. Similarly, in the actuator the two plates 46 and 50 are retained in position by the same spring which causes the plate 46 to snap over center.

It will be apparent that the construction of the switch is inexpensive and that the assembly thereof is quite simple, and servicing and repair of the switch can easily be done at any time.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions and, accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

We claim:

1. In a pressure switch including a switch casing cover; a terminal block unit of insulating material demountable from the switch mechanism upon removal of switch casing cover, a plurality of bores extending from one side to the other of said block, recesses in said one side adjacent said bores, notches in the said one side connecting said recess with a pair of said bores, contact means comprising rods extending through said 5 bores and plates fastened to said rods and extending along said notches to overlie said recesses, and a cover plate of insulating material on said one side closing said recesses and thereby enclosing said contact means in position.

2. In a pressure switch including a switch casing cover; a terminal block unit of insulating material demountable from the switch mechanism upon removal of switch casing cover, a plurality of bores extending from one side to the other of said block, recesses in said one side adjacent said bores, notches in the said one side connecting said recess with a pair of said bores, contact means comprising rods extending through said bores and plates fastened to said rods and extending along said notches to overlie said recesses, a cover plate of insulating material on said one side closing said recesses and thereby enclosing said contact means in position, blades extending through said cover plate and recesses into said block and having shoulders thereon adapted for contact with the inside of said cover plate, and movable contact means in said recesses spring urged toward the fixed contacts and adapted for engagement with the shoulders on said blades whereby actuation of said blades will separate the movable and fixed contacts.

H. HIX WOLFE.

EDW. W. HAAS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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