US2211246A - Control switch - Google Patents

Description

Aug. 13, 1940. B. E. SHAW 2,211,246

CONTROL SWITCH Filed Aug. 7, 1939 2 Sheets-Sheet l 6 jmmr.-

Aug. 13, 1940. B. E. SHAW 2,211,246

CONTROL SWITCH Filed Aug. '7, 1939 2 Sheets-Sheet 2 ll-mn I nnnnnnnnnnn Patented Aug. 13, 19,40

, CONTROL SWITCH Burton E. Shaw, Bristol,.Ind., assis-nor to Penn Electric Switch Co., tion of Iowa Goshen, Ind., a corpora- Application August 7, 1939, Serial No. 288,836

17 Claims.

One of' the objectsl contemplated. for my present invention is the provision of a simple and inexpensive control switch particularly designed for operation as a water pump switch, inasmuch as switches of this character do not require a close differential for their operation.

Another object is to provide a switch structure in which (l) Bouncing of the contacts is eliminated;

(2) The contacts are quickly thrown to a wide open position for quenching an arc between them, particularly when the switch is used on direct current;

.(3) 'I'he wide open contacts are brought slowly toward each other as the switch operating mechanism moves in a switch closing direction and when they are quite close then they are snapped the rest of the way to closed position, and

(4) The differential adjustment for the switch is designed in a novel manner to limit the minimum and maximum differential in a very simple and inexpensive manner.

A further object is to provide a combination of toggle spring and V over-roller connection between a switch actuating lever andthe switch contacts whereby the elimination of contact bounce and the securing of quick wide opening of the switch is made possible, as will hereinafter be described in detail.

Still a further object is to provide a toggle mechanism so cooperating with a V over-roller mechanism that the usual variations in switch contact pressure caused by increase and decrease of the usual V over-roller spring at various points in the operation of the V over-roller mechanism is eliminated.

Still another object is to provide a novel means for operatively connecting a pressure responsive diaphragm with a switch actuating lever, the partsbeing easily and quickly assembled and being retained in assembled position after a pivot shaft for the switch actuating arm is placed in position, without the necessity of other fastening means.

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 Inorefullyv set forth, pointed out in my claims and illustrated in the accompanying drawings. Although the invention is susceptible of a variety of embodiments, it is unnecessary to fully describe and illustrate more than one in orderto give a full understanding of the invention both from its structural and functional standpoints. Accordingly, Ihave illustrated a preferred and desirable embodiment of (Cl. 20G-83) the invention in the accompanying drawings, in which Figure 1 is an end elevation of avcontrol switch embodying` my invention;

Figure 2 isa vertical sectional view thereof on the line 2-2 of Figure l;

Figure 3 is a horizonal sectional view on the line 3 3 of Figure 1 and shows the mechanism inside the casing in plan view;

Figure 4 is an enlarged vertical sectional view on the line 4 4 of Figure 3 showing particularly the yrange and differentialadjusting springs;

Figure 5 is an exploded perspective view of two connecting elements used in my switch structure;

Figure 6 is a sectional View similar to Figure 2, with the casing omitted and the parts enlarged lto the scale shown in Figure 4, the elements of the control device being shown in a different position from that in Figure 2;

Figures 7, 8 and 9 are still other positions of the and Figure l is a perspective View of a pivot lug for a toggle switch arm of my control switch.

' On the accompanying drawings, I have used the reference numeral Ill to indicate a pipe for supplying any fluid under pressure to my control switch. The pipe I0 is threaded into a boss I2 of a diaphragm chamber. I3. A diaphragm I4 is interposed between the chamber I3 and acasing bottom member I5. Screws I6 are used for holding the parts relative to each other and for compressing the marginal edge of the diaphragm so that a fiuid-tight connection is provided. A restricted orifice plug I'I may be provided in the boss I2 to prevent surging of the diaphragm.

A cover I8 is' provided and secured in position relative to the casing bottom I as by screws I9 whereby the two elements I5 and I8 cooperate to form a closed casing for the switch operating mechanism which will now be described.

A frame 2U of inverted U shape (see Figure 4l is provided with a pair of base flanges 2|. The flanges 2| are secured in position on the casing bottom I5 by some of the screws I6. The frame carriesa pivot pin 22 on which is pivoted a switch actuating lever 23. The lever 23 is bent to the 'shape shown in Figure 4 with a pair of flanges 23a pivoted on the pin 22 and a connecting portion 23h spanning the flanges 23a. l

The" diaphragm I4 is operatively connected with the switch actuating lever 23 by means of a. diaphragm follower plate 24 and a cap member 25. The follower plate 24 has a V blade 26 extending upwardly therefrom, kwhich blade may -be riveted org otherwise suitably secured to the plate.'y The cap member 25, as shown in Figure 5,

consists of .a stamping having a central V seatv portion 25a formed therein and a surrounding flange 25h. The V seat portion 2l extends plate 20a.

through a rectangular opening 21 in the connecting plate 23h of the switchactuating lever 23, Awhile the iiange 25h contacts with the bottom of the plate. The rectangular opening prevents the cap member 25 from undesirable rotation and the V seat 25a in turn prevents the V blade 26 and follower plate 25 fron.. undesired rotation.

A range spring 28 of the tension type is connected with the plate 23h in alignment with a diierential spring 29 shown in Figure 2, so that the range spring. tends to rotate the switch actuating lever clockwise. The upper end of the range spring has therein a threaded washer 30 into which is threaded a range adjusting .screw 3I The head of the screw 3I is supported by a connecting plate 20a of the frame 20.

The differential adjusting spring 29 is of the compression type and interposed between a rivetlike member 32 and a spring follower 33. Threaded in the follower 33 is a differential adjusting screw 34. The screw 34 has a shoulder as at 35 and a washer 36 is positioned thereon to prevent upward movement of the screw 34 relative to the The follower plate 33 has a pair of arms 31 which act as a limit stop for the differential adjusting lscrew 34 in one direction, as shown in Figure 9. It will be noted that the upper ends of the arms 31 engage the plate 20a in this ligure. To limit thevadjustment of the screw 34 in the other direction, itsl threads are limited and the lower end of the screw is provided with a reduced portion 34a, as shown in Figure 4. In this 'gure the maximum compression of the spring 29 has been secured and the follower plate 33 has run oi the lower ends of the threads and the reduced portion 34a keeps it in position for subsequent coaction with the threads when the screw is rotated in the other direction. 1

A block of insulation 38 is mounted on the frame 20 and carries a plurality of stationary contacts 39. Movable contacts 49 of the bridging type, as shown in Figure 3, are provided for coaction therewith. There are two sets of the contacts 39 and a bridging contact 48 for each offset.

Each bridging contact is carried by a bracket 4I slidably mounted in a plate of insulation 42 which forms an extension of a toggle switch arm 43. Hairpin keepers 44 retain the bridging contacts 40 and the brackets 4I in assembled relation to the extension 42 and limit the sliding movement of the brackets in one direction rela-v tive thereto. Leaf springs 45 are interposed between the extension 42 and the contacts 48 for biasing the contacts toward said limit of movement.

'I'he toggle switch arm 43 is provided with knife edges 46 for coacting with V seats 41 formed by substantially triangular shaped openings in the sides of the frame 20. A toggle or over-center spring 48 is connected with the lower end of the toggle switch arm 43 and has its upper end connected with a V over-roller link 49. The link 49 is connected to a bracket 58 of the frame 20 by pivoted links 5I and pins 52 and 53. The pin 53 is limited in its movement by shoulders 54 and 55 formed on the bracket 59. The V portion of the link 49 is indicated at 49a. It coacts with a roller 56 connected by a pin 51 to the switch actuating arm 23.

The actuating arm 23 has a switch closing extension 58 adapted to engage the toggle switch arm extension 42, as shown in Figure 9, and also has a stop extension59 engageable with a vdownturned ilange 29h of the frame plate 20a.

Practical operation extension 59 engaging the iiange 20h. The toggle spring 48 is on the left side of a center line passing through the knife edge 46 and the V seat 41 and therefore the contacts 40 are held in engagement with the contacts 39 by the tension in the spring 48.

Upon an increase in pressure against the lower side of the diaphragm I4, the switch actuating.

arm 23 will be moved about its pivot 22 in a counterclockwise direction, as shown in Figure 6, wherein the V portion 49a of the V over-roller link 49 has just passed center relative to the roller 56. The tension in the spring 48 now tends to move the links 49 and 5I toward the right, and due to thelost motion between the shoulders 55 and 54 such movement will occur as shown in Figure '1. This movement causes the spring 48 to swing to the right side of center relative to toggle switch arm 43, thus causing the switch arm to swing in a counterclockwise direction. First of all, the extension 42 will take up the space between its left hand surface and the keeper 44 with the leaf springs 45 keeping the contacts 40 engaged with the contacts 39 and the momentum gained by the extension 42 will serve as a hammer action to quickly separate the contacts.

'I'he roller 51 now on the left' side of the V portion 49a will be impelled toward the left by the pull of the spring 48, as s hown in Figure 8, thus swinging the lever 23 to its left hand limit and permitting the contacts to separate widely, as shown in Figure 8. Thus theY contacts are quickly and Widely separated so as to extinguish any arc that forms between them and this is particularly necessary in connection with D. C. work.

When the pressure again recedes in the diaphragm chamber I3, the lever 23 will swing slowly toward the right, as in Figure 9, causing the extension 58 to engage the extension 42 and slowly propel the switch contacts toward engagement with each other. When they have gone most of the way, as shown in Figure 9, and movement continues a slight distance further, the V portion 49a of the V over-roller link. 49 will pass center relative to the roller 51 and the link 49 will swing to its opposite position, as shown in Figure 2, thus causing the spring 48 to again pass center and' close the switch. Due to the short distance` circuit.

The differential adjusting spring 29 is effective only during a portion of the throw of the lever 23. As the lever approaches open position, as shown in Figure 8, the rivet-like pin 32 engages the casing bottom I5 so that the spring 29 is effective on only one limit of movement of the switch. Thus, changing of the diierential effects only one linut of the range of the switch, whereas the` opposite limit remains xed Vat whatever position the range adjusting screw 3I is located.

I have used an over-center spring 48 to serve both as a toggle connection for the switch arm 43 and as a means for causing operation of, and

keeping the V portion and the roller in engage- 75 ment with each other and'iinally serving as an operative connection between the toggle switch arm and the V over-roller mechanism. 'I'his arrangement reduces thelnumber of parts considerably and utilizes both the V over-roller mechanism and the toggle spring mechanism to eilect the desired quick and wide opening of the switch contacts. The switch arm is not actuated until the V over-roller mechanism has eected movement of the toggle spring, whereupon the toggle spring then acts upon the toggle switch arm to swing it' from one position to the other. This combination arrangement of the two mechanisms also eliminates variation in the switch contact pressure during the movement of the switch from one position to the other.

My invention has been described in the foregoing specilcation and illustrated in the drawings more or less precisely as to details. It ,is to be understood, however, that changes may be made in the arrangement and proportions or" parts and equivalents may be substituted without departing from the spirit and scope of the invention as set forth in the appended claims.

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

l. In a control switch, a frame, a switch actuating lever pivoted relative thereto, a toggle switch arm also pivoted relative thereto, a toggle spring for actuating said toggle switch arm, a V link loosely connected with said frame, a roller carried by said switch actuating lever, the V portion of said V link coacting therewith and being retained in such coaction by said toggle spring and means on said switch actuating lever for engaging said toggle switch arm and moving it the major portion of itstravel toward switch closing position, said roller passing the V portion of said V link when the toggle switch arm is closely adjacent said switch closing position.

2. In a control switch, a. frame, a switch actuating lever and a toggle switch arm pivotecl thereto, a toggle spring for actuating said toggle switch arm, a V link., a link connection between one end of said V link and said frame, means for limiting movement of said V link and saidV link connection, a roller carried by said switch actuating lever, the V portion of said V link coacting, therewith and being retained in such coaction by said toggle spring, such coaction eiecting V over-roller operation by toggle spring operation to move said toggle switch arm to-open circuit position' and means on said switch actuating lever for engaging said toggle switch arm and moving it the major portion of its travel toward closed circuit position, said roller passing the V portion of said V link when the toggle arm is closely adjacent said closed circuit position.

- 3. In a control switch, a frame, a switch actuating lever and a toggle switch arm pivoted thereto, a toggle spring for actuating said toggle switch arm, a V link loosely connected with said frame, a roller carried by said switch actuating lever, the V portion of said V link coacting therewith for effecting V over-roller operation followed by toggle spring operation to move said toggle switch arm to open circuit position and means on said switch actuating lever for engaging said toggle switch arm and moving it the major portion of its travel toward switch closing position,

said roller passing the V portion of said V link when the toggle switch arm is closely adjacent said switch closing position.

4. In a control switch, a pressure responsive switch actuating lever, a toggle switch arm pivotally mounted, a toggle spring therefor and means ior connecting said toggle spring with said switch actuating lever comprising a V over-roller mechanism, said toggle lever being operable from one of its positions to the other as a resultant of movement of said V over-roller mechanism from one of its positions to the other.

5. In a control switch, a frame, an actuating lever and a toggle arm pivoted relative thereto,

f a toggleY spring for actuating said toggle arm, a

link loosely connected with said frame for limitedmovement` relative thereto, a roller and V cam connection between said link and said'actuating lever, said toggle spring being connected with said link and eecting past center operation of said toggle arm as a result of. movement thereof from one of its limits to the other one by said roller and V cam connection and means on said actuating lever for engaging'said toggle arm and moving it the major portion oiits travel toward one of its positions, said roller passing the crest of the V cam when the toggle arm is closely adjacent said position.

6. In a control switch, a frame, an actuating lever'and a toggle arm pivoted relative thereto, atoggle spring for actuating said toggle arm, a link loosely connected with said frame ionlimited movement relative thereto, a roller and V cam connection between said link and said actuating lever, said toggle spring being connected with said link and eiecting past center operation of said toggle arm as a result of movement thereof from one of its limits to the. other one by said roller and V cam connection. l

'7. In a control switch of the character described, a switch actuating lever, a stationary contact, a switch arm, a contact carried thereby and` adapted for engagement with said stationary contact 'and means for operatively connecting said switch arm with said switch actuating lever comprising. V over-roller mechanism and toggle spring mechanism connected in series with each other and at their free ends with said switch arm and switch actuating lever respectively whereby operation of one of said mechanisms effects operation of the other one and the other one then effects movement of the switch arm to one of its positions as the switch actuating lever is moved in one direction and reverse operation of said one of said mechanisms eects operation of said other one and said other one then eiects movement of the switch arm to the other of its positions as the switch actuating lever is moved in the opposite direction.

8. In a control switch, a switch actuating lever, a switch arm, and means for operatively connecting said switch arm with said switch actuating llever comprising V over-roller mechanism and toggle spring mechanism connected in series with each other and having their terminal ends connected with said arm and lever respectively ywhereby operation of one of said mechanisms effects operation of the other one and the other one then effects movement of the switch arm to switch open position as the switch actuating lever is moved in one direction and operation of said one of said mechanisms eil'ects operation of said other one and said other one then effects movement of the switch arm to switch closed position as the switch actuating lever is moved inthe opposite direction. f

9. In a control switch of the characterl described, a switch actuating lever, a switch arm, and means yfor operatively connectingsaid arm with said lever comprising V over-roller mechanism and toggle spring mechanism arranged in tandem and connected at their free ends with the arm and lever respectively so that operation of one of said mechanisms eiects operation of the other one and the other one then eects movement of the switch arm as the switch actuating4 lever is moved.

10. A control device of the kind disclosed comprising a frame, a switch actuating lever pivotally mounted thereon, a range spring biasing said switch actuating lever to move in one direction, pressure responsive means to move said lever in the other direction against the bias of said range spring upon a pressure increase, a toggle switch arm, artoggle spring foractuating said switch arm, a stationary contact carried by said frame, a movable contact on said toggle switch arm and movable relative thereto, the amount of such movement being limited, spring means urging said movable contact toward said stationary contact to a position limited by said limiting means when the contacts are out of engagement with relation to each other and means for operating said toggle spring comprising V over-roller mechanism effecting a connection of said toggle spring with said switch actuating arm, said V over-roller` mechanism including la lost motion connection permitting said toggle spring to move across center relative to said toggle switch arm after said V over-roller mechanism changes positions before the toggle switch arm is moved to its other position.

11. A control device comprising a frame, a'

switch actuating lever pivotally mounted thereon, pressure responsive means to 'move said lever, a

vswitch arm, a stationary contact carried by said frame, a movable contact onsaid switch arm and movable relative thereto, the amount of such movement being vlimited, spring means urging said movable contact toward said stationary contact to a position limited by said limitingmeans when the contacts are out of engagement with relation to each other and means for operating said' switch arm from said actuating lever comprising V over-roller mechanism and toggle spring mechanism connected in tandem between the two.

12. A control device of the kind disclosed comprising a frame, a switch actuating lever and a toggle switch arm pivoted thereto,'a toggle spring for actuating said switch arm, a stationary contact carried by saidvframe, a contact on said switch arm for engagement with said stationary contact and means for operating .said toggle spring comprising V over-roller mechanism efecting a connection of said toggle spring with said switch actuating arm.

1'3. In a control device of the kind described, a frame, a switch actuating lever pivoted relative thereto, a range spring biasing said lever to move in one direction, pressure responsive means to move said lever in the other direction against the bias ofsaid range spring 'and as a result of pressure increase, a differential spring engaging said switch actuating lever during the portion of its movement between one of its limits of movement and a position intermediate its limits of movement, a spring follower for said differential spring and having a threaded opening, an adjusting sci'ew coacting with the threads of said spring follower, means engaging said spring follower to limit the adjustment of said adjusting screw in one direction, said adjusting screw effecting disassociation of its threads from the threads of the spring follower to llimit adjustment oi the adjusting screw in the other direction, a toggle switch arm, a toggle spring for actuating said switch arm, switch contacts controlled by said switch arm as to opening and closing a circuit in opposite positions of the switch arm and means for operating said switch arm through said toggle spring comprising V over-roller mechanism connecting said toggle spring with said switchactuating lever.

14. In a control device, a frame, an actuating lever pivoted relative thereto, a differential spring engaging said actuating lever during the portion of its movement between one of its limits of movement and a position intermediate its limits of movement, a spring follower for said differential spring and having a threaded opening, an adjusting screw coacting wtih the threads of said spring follower, said adjusting screw eiecting disassociation of its threads from the threads of the spring follower to limit the adjustment of the adjusting screw in one direction, a switch arm and toggle spring and V over-roller mechanisms arranged in tandem and operatively connected at their free ends with said switch arm and said switch actuating lever.

15. In a control device, a frame, an actuating lever pivoted relative thereto, a dierential spring engaging said actuating lever during the portion of its movement between one of its limits of movement anda position intermediate its limits of movement, a spring follower for said differential spring and having a threaded opening, an adjusting screw coacting with the threads of said spring follower, means engaging said spring follower to limitV the adjustment. of said adjusting screw in one direction, a switch arm, a toggle spring for actuating said switch arm, switch contacts controlled by said swsch arm asA to opening and closing a circuit in opposite positions of the switch arm and means for operating said switch arm through said toggle spring comprising V over-roller mechanism connecting said toggle springA with said switch actuating lever;

16. In a control switch, a switch actuating lever, a pressure responsive diaphragm operatively connected therewith, the operative connection including a follower plate against the diaphragm and having a V blade projecting therefro`ma cap member thereon having a V seat, said switch actuating lever having a rectangular opening receiving the V seat portion of vsaid cap member, said cap member having a flange surrounding the V seat portion and engaging the switch actuating lever surrounding the opening therein, a toggle switch arm pivotally mounted, a toggle spring therefor and means for connecting said toggle spring with said switch actuating lever comprising a V over-roller mechamsm.

17.5In a control switch, a switch actuating lever, a' pressure responsive diaphragm operatively connected therewith, the operative connection including a follower plate against the diaphragm and having a V blade projecting therefrom, a cap member having a V `seat coacting therewith, said switch actuating lever having an opening receiving the V seat portion of said cap member, a toggle switch arm pivotally mounted, a toggle spring having one end connected therewith and means for connecting the other end of said toggle spring with said switch actuating lever comprising a V over-roller mechanism interposed between said other end and said lever.

BURTON E. SEAW.

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