US2873332A - Adjustable differential switch actuator - Google Patents

Description

W. J. WILLIAMS ADJUSTABLE DIFFERENTIAL SWITCH ACTUATOR Feb. 10, 1959 4 Sheets-Sheet 1 Filed Feb. 1, 1956 m Mm 1. WW d m w w ATTQRNEY Feb. 10, 1959 w. J. WILLIAMS 2,873,332

ADJUSTABLE DIFFERENTIAL SWITCH ACTUATOR Filed Feb. 1, 1956 4 Sheets-Sheet 2 INVENTOR. W////'am VWY/iams BY g ATTORNEY Feb. 10, 1959 w. J. WILLIAMS 2,873,332 ADJUSTABLE DIFFERENTIAL SWITCH ACTUATOR Filed Feb. 1, 1956 4 Sheets-Sheet 3 v 2? FUN 32 iii; G x F151. i 115K. VIM/1am d 14 17/1007.

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ATTOINY V United States Patent ADJUSTABLE DIFFERENTIAL SWITCH ACTUATOR 7 William J. Williams, Wilmette, Ill. Application February 1, 1956, Serial No. 562,849

7 Claims. (Cl. 200-166) This invention relates to an adjustable mechanism for operating switches or switching mechanism with precision accuracy for making and breaking or controlling switch operations at ditferent speeds or under diiierent conditions, controlling such operations together with differentials between the making and breaking, or changing of electrical circuits by such switch or switching mechanism.

More specifically, I provide by this invention adjustable switch operating mechanisms comprising a compound lever linkage and special operating arrangement adjustable to precision accuracy for making and breaking or controlling the switch operations for different conditions under control of suitable mechanisms responsive to such conditions or changes thereof. By my invention I can accurately determine the differentials between the making and breaking, or changing of electrical circuits effected by such switches or switching mechanisms.

Further objects and advantages are within the scope of this invention such as relate to the arrangement, operation and function of the related elements of the structure, to various details of construction and to combinations of parts, elements per se, and to economies of manufacture and numerous other features as will be apparent from a consideration of the specification and drawings of a form of the invention, which may be preferred, in which:

Figure I is an elevation partly in section showing a pressure operated device in operative relation with a switch using my means of actuating the adjustable diiIer-' ential switch operating mechanism.

Figure II is a partial elevation of a temperature responsive means for my switch operating mechanism.

Figure III is a sectional elevation of a modification of my invention using a speed responsive controlling device. I

Figure 1V is an end elevation of the form of my invention shown in Figure I.

Figure V is a section taken substantially on the lines V--V of Figures I and III.'

Figure VI is a section taken substantially on the line VI-VI of Figure I.

Figure VII is an enlarged perspective view of one of the levers of my invention.

Figure VIII is a section taken substantially on the lines VIII-VIII of Figure I.

Figure IX is a section taken lines IX-IX of Figure III.

Figure X is a section taken substantially on the lines X--X of Figure III.

Figure XI is a diagrammatic showing of the action of the form of my invention shown in Figure III, under various operating conditions.

Referring to the drawings, in Figure I, I show an assubstantially on the sembly of my invention usinga self returning or snap switch unit indicated at 10 having a depending operating pin 11, and a double lever adjusting and operating mechanism 12 (see Fig. I) having an actuating pin 14 adapted to be moved by a plunger 15 which moves upwardly and pin 11 and actuates the same.

downwardly according, in this particular instance, to a pressure responsive device 16. In the .embodiment illustrated of my precision and accurately adjustable mechanism 12 for controlling the action of switch pin 11 from the plunger 15, I provide an L-shaped support 20 to the upper part 21 of which the switch unit 10 may be secured as by the screws 22 (see Figure IV), the lower part 23 of the L-shaped support is secured to the top of the condition responsive device as shown.

The upper L portion 21 of the support carries at opposite sides bearings, the one 24 at the righthand and the other, 25 at the left side for carrying the transverse screw threaded lever supporting shaft 27, said shaft being free to rotate in said bearings and having the head 28 for adjustment purposes, the other end being provided with a pair of locking nuts 29.

My operating and adjustable mechanism includes two cooperating levers, one of said levers3t) pivoted at the left side in Figure I to a pivotal stud 31 (see Figure VIII) carried by the bearing 25 as shown, said pin and bearing 25 being fixed as shown at 32 to part 21 on support 20. This lever 30 carries a slider element 34 having a contacting button 34' for actuating the switch pin 11. For different installations I change the position of the slider 34 as may be required or desirable-friction retaining the slider in fixed position.

The other end of shaft 27 carries the other lever 37 pivoted at one end to an adjustable pivot 38 which as shown in Figure VI may be formed of a stud 39 extending forwardly of a block 40 screw threaded on shaft 27. The underside of lever 37 contacts the pressure operated pin 14 to be actuated therefrom (see Figure I).

To operate the first lever 30 from the second adjustable lever 37, I provide on said lever 37 a sliding contact button 42 adapted to be frictionally held in place on said lever, the details of this mounting being a sliding clamp 43 which may be moved to various positions on lever 37-see Figure VII.

Thus it will be seen that I can adjust the button 42 on the adjustable or second lever 37 to approximately a desired position and then by turning screw shaft 27 by its slotted head 28, the pivotal bearing 38 for the second lever 37 may be accurately adjusted to vary the effective length thereof. This simultaneously adjusts the effective length of the first lever 30 since it varies the position at which the button 42 of lever 37 contacts the first lever 30.

In operation the variable pressure responsive plunger 15 actuates pin 14, swinging lever 37 about its pivot 38 whereupon the button 42 also swings the first lever 30 about its pivot 31. Thereupon button 34' contacts switch Since the break away inertia of the snap switch 10 is greater than that required to hold the switch in its changed position, upon reversal of plunger 15 (due to a drop in pressure) the switch pin 11 will not be lowered until the pressure on plunger drops somewhat below that required to move the pin upwardly. This gives a differential between the first operation of switch 10 and its reversal.

In Figure II, I shows a similar arrangement to Figure I except that in Figure II the plunger 15 is operated lever 30 carries a flat leaf spring 36 fixed thereto at its pivotal end as shown at 35, said spring 36 contacting the switch pin 11 and having a curled free end resting on lever 30 and slidable thereon. For different installations to obtain different make and break speeds for the switch operation I change the size, thickness and flexibility of the spring 36 as may be required or desirable. The other parts of. my two lever switch actuating mechanism arethe same as in Figure I. In Figure III the plunger 15 is operated by a speed responsive device or governor 17'. In this form of my invention the plunger 15 uponin creasing speeds, actuatcs pin 14, swinging lever 37 about its pivot 38, whereupon the button 42 also swings the In Figure XI, the operation of the embodiment of,

first lever 30' about its pivot 31.

Figure III is diagrammatically illustrated showing that as the lever 30 carryingspring 36 moves upward itcompresses orifiattens said spring 36 until the potential energy stored in spring 36 is sufficient to overcome the resistance of theswitch unit 10 and the-spring contacting theswitch pin 11 thereupon moves the snap. switch 10 to close its:- contacts. This action is predetermined by the speed of the governor 17 according to the settingof the adjustablelever mechanism and the resiliency of the. particular spring 36 used. At-this point the pressure required to holdthe switch in contact (see'second diagram from left Figure XI) is very small compared to the operating pres sure, just described, consequently, the stored energy-or build-upof spring 36 readily holds the switch in contact or closed position. Moreover, the mechanism will not only hold the switch closed at said predetermined speedsor greater, but also over a large range of reduced speeds 1 therefrom as shown in the diagram the third from the left in Figure XI. Then when the speed of the governor is thereafter reducedto a predetermined lower point, the

switch pin 11 recedes to a point where the inherent action of. the snap switch 10 overcomes the greatly reduced holding power value of spring 36 at which time the switch 10 will reset with a snap action due to the inherent construction of the switch itself. This action is illustrated in the extreme right-hand diagram of Figure XI.

For various installations, as desired, different springs 3may be used so that with springs with differentresiliency will, efiect in conjunction with the lever andpendent on a predetermined condition and the openingof 'said: switch dependent upon different conditions, the

combination of a pair of cooperating movable levers; means to pivotally support in fixed position of'adjustment both said levers, one of said levers adapted to operate the switch, theother lever arranged for operating said first mentioned lever, the effective operative relation of the fulcrums of said levers being adjustable; and means controlled by said responsive device to actuate said second lever.

'2. In an adjustable switch operating mechanism,

adapted to be operated by a device responsive to varying I conditions to make and break a switch upon occurrence of different conditions, the combination of a pair of movablelevers; means to pivotally support, in fixed position of'adjustment said levers, said means including a longitudinal screw threaded shaft, one of said levers arranged to operate the switch; adjustable means carried by the other lever for actuating said first lever, said last mentioned lever having a screw threaded pivotal'bearing mounted on said screw threaded sha'ft'for adjustably sup porting the pivotal end of said second lever, means controlled-by-the condition-responsive device to operate said second lever to cause said first lever to operatesaid switch. and means to lock said threaded shaft in various positions of adjustment.

3. In a compound adjustable lever mechanism for operating a snap switch from a variable condition responsive device, said mechanism including a transverse screw threaded shaft, a combinedsupport and pivot for a first lever atone end ofsaidshaft, said. supportadapted to be fixed to the frame of said mechanism; a first lever mounted on said pivot and adapted for contacting the actuating pin of the switch; a support for the other end of said shaft; means to rotate said second lever around saidpivot,

' actuated from saidcondition responsive device; a second a said support adapted to be fixed to the frame of said lever having a screw threaded pivot carried by said shaft; means to prevent said pivot from turning; a slider carried by said second lever; means on said slider for operating said first lever; and means to rotate said screw threaded shaftto adjust said pivot and simultaneously change-the effective fulcrum lengths" of both said levers.

4. In a compound adjustable lever mechanisrn'for op erating a snap switch from a variable condition responsivedevice, said mechanism including a transverse shaft provided with screw threads, a combined support and pivot for a first lever atone end of said'shaft, said support adapted to be fixed to the frame ofsaid mechanism; a first lever on said pivot, actuated from'said condition responsive'de/ vice; means to prevent said pivot from turning; a slider carried bysa-id second lever; means on said slider for operating said first lever; means to rotate said shaft to' adjust said pivot and change the efiective fulcrum lengths of said levers; and" means to lock said shaft in fixed position of adjustment. I

5. In a compound adjustable lever mechanism for operating a snap switch from a variable condition responsivedevicesaid mechanism including a transverse shaftprovided with two screw threaded portions, a combined support and pivot for a first lever at one end of said shaft,

mechanism; a first lever on said pivot for contacting the actuating pin" of the switch; a bearing support for theother end'of said shaft permitting free rotation of said shaft L therein; a second lever having a screw threaded pivot carried by said shaft at one set of two screw threaded portions; means to rotate said second lever aroundsaid pivot, actuated from saidcondition responsive device; means-to'prevent said pivot from turning; a slider carried;

by said second lever; means on said slider for operating" said firstlever; means to rotate said shafttoadjust said 6. In a compound adjustable lever mechanism for operating a snap switch for a variable condition responsive device, said mechanism including a transverse shaft pro-' vided with two screw threaded portions, a combined sup port and pivot for a first lever at one endof said shaft,

said support adapted to be fixedto the frameof said mechanism; a first leveron said pivot for contacting the actuating pin of the switch; a bearingsupport for the.

other-end of; said shaft permitting'free.rotation ofnsaid shafttherein; a second: lever. having a screw threaded pivot carried by said shaft at one set of said two sets of said" second lever; 'a substantially hemispherical button carried'by said slider, said button adapted to contact'said' first lever to operate the same; and means to rotate said shaft to-very accurately position saidpivot and'change" the effective fulcrum lengths of said levers after said slider has been approximately positioned.

7. In a compound adjustable lever mechanism for operating a snap switch from a variable condition responsive device, said mechanism including a transverse shaft provided with two screw threaded portions, -a combined support and pivot for a first lever at one end of said shaft, said support adapted to be fixed to the frame of said mechanism; a first lever on said pivot for contacting the actuating pin of the switch; a bearing support for the other end of said shaft permitting free rotation of said shaft therein by providing relatively smooth cylindricalv portions between said shaft and the opening in said support for carrying said shaft; a second lever having a screw threaded pivot carried by said shaft at one of said two sets of screw threaded portions; means to prevent said pivot from turning; an approximately settable slider carried by said second lever; an operating button adapted to contact said first lever to operate the same; means to rotate said shaft to very accurately position said pivot and change the effective fulcrum lengths of said levers after said slider has been approximately positioned; and screw threaded locking means on the first mentioned screw threaded portion of said shaft adapted to lock said shaft in adjusted position by contact thereof with said first mentioned combined support and pivot.

References Cited in the file of this patent UNITED STATES PATENTS 2,268,340 Loomis Dec. 30, 1941 2,314,211 Hausler Mar. 16, 1943 2,389,436 Kearney Nov. 20, 1945 2,412,347 Mardis Dec. 10, 1946 2,562,385 Marcellus July 31, 1951 2,720,563 Williams Oct. 11, 1955

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