US2752461A

US2752461A - Switch assembly

Info

Publication number: US2752461A
Application number: US406258A
Authority: US
Inventors: George M Euler
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1954-01-26
Filing date: 1954-01-26
Publication date: 1956-06-26
Anticipated expiration: 1973-06-26

Description

June 26, 1956 G. M. EULER SWITCH ASSEMBLY Filed Jan. 26, 1954 1 .Pllill llllll [r2 ven tar". George M Eu/er', by

/7/ls Attorney United States Patent SWITCH ASSEMBLY George M. Euler, Morrison, Ill., assignor to General Electric Company, a corporation of New York Application January 26, 1954, Serial No. 406,258

3 Claims. (Cl. 200153) This invention relates to switch assemblies and more particularly to the combination of a switch and actuating means therefore.

There are frequent applications which require the actuation of a switch in response to physical movement of some other device. For example, in a sump pump installation, it is necessary to actuate a switch to start the pump motor when the water level in the sump rises to a predetermined upper level and to again actuate the switch to shut off the motor when the water level has fallen to a predetermined lower level. Floats or displacement weights are conventionally used to detect the water level and the switch must thus be actuated by physical movement of the associated float or displacement Weight. It is desirable that this switch actuating mechanism be simple, reliable, and inexpensive, and it is further desirable that it be usable with a commercially available switch.

It is therefore an object of this invention to provide an improved switch assembly incorporating the desirable features set forth above.

Further objects and advantages of this invention will become apparent by reference to the following description and the accompanying drawing, and the features of novelty which characterize this invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

This invention in its broadest aspects provides a switch including an actuating member having a first normal position and a second position. A spring is provided which engages the switch actuating member and another pivoted actuating member is provided which engages the spring. The other actuating member is movable under the influence of an external force to deflect the spring member thereby permitting the switch actuating member to move to its normal position.

In the drawing,

Fig. l is an elevational view showing a sump pump and motor equipped with the improved switch assembly of this invention;

Fig. 2 is a side elevational view, partly in section, illustrating the improved switch assembly of this invention and taken along the line 22 of Fig. 3; and

Fig. 3 is atop view, partly broken away, of the improved switch assembly of Fig. 2.

Referring now to Fig. 1, there is shown a sump pump 1 arranged in sump 2 and being driven by a suitable elec tric motor 3. It will be readily understood that the sump pump 1 and motor 3 as shown here do not form a part of this invention and that any desired combination of motor and pump may be used. The improved switch assembly of this invention is shown generally at 4 and is used to respectively start and stop pump motor 3 in response to predetermined changes in the level 5 of the liquid and the sump 2. In the arrangement shown, a pair of displacement weights 6 are suspended by means of a flexible wire '7 from actuating member 8 of switch 4. Weights 6 are heavier than the fluid in the sump 2 and in accordance with well known physical principles, their 2,752,461 Patented June 26, 1956 apparent weight changes when they are immersed in fluid. Thus, as the level 5 of the fluid in sump 2 rises above weights 6, their apparent weight is lessened thus lowering the downward force applied to actuating member 8 and in turn actuating switch 9, as will be hereinafter more fully described. Actuation of switch 9 which is connected in circuit with motor 3, starts the motor which operates sump pump 1 to pump fluid out of sump 2 through discharge pipe 10. When the level 5 of the fluid in sump 2 falls to a predetermined lower level so that weights 6 are substantially above the level 5, their apparent increase in weight exerts a greater downward force on actuating member 8 thus actuating switch 9 to turn off motor 3.

Referring now to Fig. 2, switch assembly 4 includes a small snap acting switch 9, which may be the type shown in Patent No. 2,332,911 to George M. Hausler issued October 26, 1943 and assigned to the assignee of' the present application. Switch 9 is secured to the upper surface of a mounting member 11, as by means of screws 12, which has an opening 13 formed therein through which actuating button 14 of switch 9 projects. A spring mounting member 15 is provided having one end 16 secured to the side of switch mounting member 11 opposite from switch 9 in any suitable manner, as by the same screws 12 which secure switch 9 to the mounting member 11. A cantilever spring 17 is provided having its end 18 secured to spring mounting member 15 adjacent its free end 19 in any suitable manner, as by riveting at 2h. Spring 17 engages actuating button 14 of switch 9 which has a normal position as shown in dashed lines and a second position as shown in solid lines in Fig. 2. In the embodiment shown in Fig. 2, spring 17 serves normally to bias switch actuating button 14 into its second position as shown.

In order to provide for adjusting the force applied to switch actuating button 14 by spring 17, a projection 21 is formed on one end of switch mounting member 11 and a screw 22 connects projection 21 and end 19 of spring mounting member 15. It will be readily seen that by turning screw 22 in one direction, end 19 of spring mounting member 15 will be moved toward projection 21 of switch mounting member 11 thus lessening the pressure applied to switch actuating button 14 by cantilever spring 17 and, conversely, turning the screw 22 in the opposite direction will move end 19 of spring mounting member 15 away from projection 21 thus increasing the pressure which the spring 17 applies to switch actuating button 14.

Switch mounting member 11 has a pair of downwardly extending portions 23 formed on each side thereof and a base member 24 is attached thereto. Base member 24 has an opening 25 formed therein for a purpose now to be described. Actuating member 8 is provided having its end 27 pivoted in openings 28 in mounting member portions 23, as by means of a transverse portion 29. A notch 30 is formed in the end 31 in which the end 32 of cantilever springs 17 is seated. Actuating member 8 has a portion 26 extending from its end 31 and through opening 25 in base 24. Wire 7 which supports displacement weights 6 is attached to the end of extension 26 of actuating member 8.

In operation, assuming that the water level 5 in sump 2 has fallen sufliciently to substantially expose displacement weights 6, the resultant downward force exerted by wire 7 on actuating member 8 will cause it to move to the position as shown by the dashed lines 33 in Fig. 2 thus moving cantilever spring 17 to the position shown in dashed lines and allowing actuating button 14 of switch 9 to move to its normal position in which its contacts are open and the motor 3 is deenergized. When the level 5 of the fluid in sump 2 rises to a predetermined level, the

downward force exerted by wire 7 on actuating member 8 will be overcome by the upward force exerted by cantilever spring 17 thus moving actuating member 8 to the position shown in solid lines in Fig. 2 and moving actuator button 14 of switch 9 to its second or contacts closed position to energize motor 3. It will be readily seen that the water level at which actuator 8 moves to its solid line position as shown in Fig. 2 thereby to permit cantilever spring 17 to move switch actuator button 14 to its second or contacts closed position is determined by adjustment of screw 22 which adjusts the upward force exerted by cantilever spring 17. The lower level at which the actuator member 8 moves to its dashed line position 33 as shown in Fig. 2 is determined by the spacing of the upper weight from the lower weight.

While the improved switch assembly of this invention has been shown in connection with a sump pump, it will be readily understood that it is usable in other installations which require actuation of the switch in response to an external force. It will also be readily apparent that this invention provides an improved and simplified switch assembly which adapts a small commercially available snap acting switch to a wide variety of uses.

While I have shown and described a particular embodiment of this invention, further modifications and improvements will occur to those skilled in the art. I desire that it be understood therefore that this invention is not limited to the forms shown and I intend in the appended claims to cover all modifications which do not depart from the spirit and scope of this invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A switch assembly comprising a snap acting switch including an actuating button having a first normal position and a second position, a mounting member having an opening formed therein, said switch being secured to one side of said mounting member with said actuating button extending through said opening, a spring mounting member having one end secured to said first named mounting member, a cantilever spring member having one end secured to said spring mounting member adjacent the other end thereof and engaging said switch actuating button, said first named mounting member having an extension formed on one end thereof, screw means engaging said mounting member extension and said other end of said spring mounting member for adjusting the pressure applied on said switch actuating button by said spring, said first named mounting member having a pair of projections extending on either side thereof away from said switch, a base member secured to said projections, and another actuating member engaging the other end of said spring member and having its other end pivoted, said base member having an opening formed therein, said other actuating member having an extension extending through said base member opening, said other actuating member extension being adapted to be moved to a first position under the influence of an external force to deflect said spring member and thereby permitting said switch actuating button to move said normal position.

2. A switch assembly comprising a switch including an actuating member having a first normal position and a second postion, a mounting member for said switch, a cantilever spring member having one end secured to said mounting member and engaging said switch actuating member and normally biasing the same to said second position, a base member spaced from said mounting member, and another actuating member having one end engaging the other end of said spring member positioned intermediate said mounting member and said base memher and having its other end pivoted, said base member having an opening formed therein, said other actuating member having an extension formed on said one end thereof and extending through said base member opening, said other actuating member extension being adapted to be moved t a first position under the influence of an external. force to deflect said spring member thereby permitting said switch actuating member to move to said normal position, said spring member returning said other actuating member to a normal position and moving said switch actuating member to said second position when said force is removed from said other actuating member extension.

3. A switch assembly comprising a snap acting switch including an actuating button having a first normal position and a second position, a mounting member having an opening formed therein, said switch being secured to one side of said mounting member with said actuating button extending through said opening, a spring mounting member having one end secured to said first named mounting member, a cantilever spring member having one end secured to said spring mounting member adjacent the other end thereof and engaging said switch actuating button and normally biasing the same to said secend position, said first named mounting member having an extension formed on one end thereof, screw means engaging said mounting member extension and said other end of said spring mounting member for adjusting the pressure applied on said switch actuating button by said spring, said first named mounting member having a pair of projections extending on either side thereof away from said switch, a base member secured to said projections, and another actuating member having one end engaging the other end of said spring member positioned intermediate said first named mounting member and said base member and having its other end pivoted to said projections, said base member having an opening formed therein, said other actuating member having an extension formed on said one end thereof and extending through said base member opening, said other actuating member extension being adapted to be moved to a first position under the influence of an external force to deflect said spring member thereby permitting said switch actuating button to move to said normal position, said spring member returning said other actuating member to a normal position and moving said switch actuating button to said second position when said force is removed from said other actuating member or extension.

References Cited in the file of this patent UNITED STATES PATENTS 842,554 Johnson Jan. 29, 1907 2,302,923 Zimarik Nov. 24, 1942 2,338,365 Thorp et a1. Jan. 4, 1944 2,547,765 Lund Apr. 3, 1951 2,612,368 Ransome Sept. 30, 1952 FOREIGN PATENTS 200,810 Switzerland Jan. 16, 1939