US2422292A - Control device for switches or the like - Google Patents

Description

June 17, 1947. DILLMA.N ET AL CONTROL DEVICE FOR SWITCHES OR THE LIKE Filed Feb. 28, 1944 INVENTORS N 2 3% A BY 4M ATTORNEY Patented June 17, 1947 CONTROL DEVICE FOR SWITCHES OR THE LIKE Earnest J. Dillman and Jack E. Fleury, Detroit,

Mich, assignors to Detroit Lubricator Company, Detroit, Mich., a corporation of Michigan Application February 28, 1944, Serial No. 524,228

1 Claim. 1

This invention relates to new and useful improvements in devices for actuating and for determining the actuation of a reciprocated control device, such as a switch or the like.

An object of the invention is to provide an actuating device which will automatically function to lock or hold the control device in actuated position upon operation thereof.

Another object is to provide an actuating device which dominates the operation of a control device by its normally actuating operating means.

The invention consists in the improved construction and combination of parts to be more fully described hereinafter and the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawing to be taken as a part of this specification, there is fully and clearly illustrated a preferred embodiment of the invention, in which drawings:

Figure 1 is a view of the control device partially diagrammatic and in section and operatively related to the actuating device which is shown in vertical section on the line of Fig. 2.

Fig. 2 is a view in section on the line 22 of Fig. 1;

Fig, 3 is a detail view also in section on the line of Fig. 2 but showing the actuating device in locked position, and

Fig. 4 is a detail view on the line 4-4 of Fig. 3 and also showing the actuating device in locked position.

Referring to the drawings by characters of reference, designates generally a. supporting structure or casing which contains and supports the reciprocated control device 2 such as a snap-acting electric switch having a fixed contact 3 and a movable contact carried by an overcenter switch arm 4 which is pivotally supported, as at 5. Coop-erable with the arm 4 there is a toggle spring 8 for quick and snap action movement of the arm 4 which is reciprocated by a rod 1 which may be of electric insulating material and has in its rear face or side opposed knife edges 8 providing a vertical slot through which extends a normally rigid resilient switch operating blade 9, carried by bell crank type operating lever Ill. The blade 9 is adjustably held under tension by an adjustment screw so that the resistance of the blade 9 to movement relative to the lever I!) may be determined. The lever I is pivotally supported, as at and has its arm l3 movable between spaced. stop members I4, I5. The lever ID is urged toward switch open position by a spring I6 held under compression by the structure I and acting against the lever arm l3, normally tending to hold the arm I3 against the stop member M. The switch 2 is moved to closed position by a power element operable by temperature or pressure and comprising an expansible, collapsible member l8, such as a metal bellows, having a thrust member l9 engaging and acting on the lever arm |3 against the force of the spring l6.

Mounted on the casing I, there is a housing member 20 containing a bell crank type lever 2| journalled on a shaft 22 extending between the side walls 23, 24 of the housing member. The lever 2| has an operating arm 25 which extends into the casing I through a wall slot 26 and into spaced opposing relation to the free end portion of the blade 9. The lever 2| has a horizontal arm 21 to which is anchored one end of a helical coil spring 28 having its one end adjustably supported by an adjustment screw 23 carried by and extending downward through an aperture in the top wall 33 of the housing member 23. The spring 28 urges the lever arm 21 into engagement with a longitudinally reciprocal shaft 3| supported by and extending between the casing side walls 23, 24 and extending through apertures 32, 33 respectively in said walls. The shaft 3| limits the m0vement of the lever 2| by the spring 28 and determines the force of the spring which opposes movement of the lever arm toward the switch operating blade 9. The top casing wall 30 carries an automatic operating means 34 having a cup-like casing 35 which is closed by a movable wall member 36 such as a, metal bellows facing the lever arm 2'! and providing a pressure chamber 3! having an inlet connection 38 for connecting the chamber 31 to a source of fluid pressure which, for example, might be the high side or condenser pressure of a refrigerating apparatus. Secured to the head or end wall of the bellows 36 there is a thrust member or push rod 39 having a conical free end portion seating in a conical recess 40 of a socket member 4| rigidly mounted on the lever arm 21.

Carried by the shaft 3! and rigidly secured thereto, there is a cylindrical abutment member 42 mounted on one end of the shaft 3| and positioned in the aperture 33 for supporting its shaft end. The member 42 is provided with an abutment flange 43 engageable with the outside face of the wall 24 to limit inward movement of the abutment member 42 into the housing 20. The

other end portion of the shaft 3| extends through a cup-like retainer and guide member 44 secured to the outside face of the wall 23 and having an p r ure through its bottom wall aligned with the aperture 32. Secured on the end of the shaft 3| within and projecting from the member 44 there is a cylindrical button reciprocally guided in the member and which seats inward against a helical coil spring 45 positioned within the member i i. The spring 46 tends to urge the shaft 3i forwardly to bring the abutment mem ber 42 into overlying relation to the lever arm 21 and urges the end face 6'! of the abutment member 42 into endwise engagement with the side face or edge of the arm 21.

The height of the base of the socket 49 in the thrust receiving or socket member 4! above the lever fulcrum or shaft 22 is such relative to the resistances of the spring 23 and bellows 36 and to the lengths of th lever arms through which the spring 28 and rod .59 act on the lever 2i when the mechanism is in inactive position, Fig. 1, that the increasing lever arm of rod 39 upon its downward movement serves to overcompensate for the resulting increase in the resistance to and caused by its downward movement. The compensation, is also suflicient to take up or overcome the resistance of the leaf spring 9 and the overcenter spring 5 so that the pressure in chamber 3'5 which will initiate movement of the lever 2i against the resisting forces will cause a complete movement of the lever through its range of travel Which will open the switch 2 and position the arm 2! below the plane of the abutment member 42. Accordingly, the abutment face 4'! and the arm 2'; may have rounded marginal edges as would result from their formation by a bending operation and it is not necessary to have the fine adjustment of parts which would provide simultaneous lockin movement of abutment member 42 and overcenter or switch opening movement of arm 4. The overcompensated travel of lever 2i requires only that the abutment member 42 move into locking position after the lever 2| has opened the switch 2.

The operation of the actuating device is as follows: Assume for example that the power element 1 7 is connected say to the suction or return line of a refrigerating apparatus and the spring i6 is adjusted or set to determine the low side pressure at which operation of the refrigerating apparatus is to be started by closure of the switch 2 and that the power element or automatic operating means 3-, '5 connected as above noted to the system high side. The spring 28 is adjusted by the screw 29 to determine the pressure in the system high side at which the lever arm 25 will be moved to the position shown in Fig. 3 wherein the switch 2 will be moved to open position to stop operation or" the system. If for any reason the high side pressure, and therefore the pressure in the actuating device chamber 3! increases above the desired limit so that the lever 21 is moved to engage the blade 9 and flex it toward the right relative to lever I0 when facing Fig. 1,

then when the rod 1 has been moved sufficiently to move the switch arm 4 overcenter, the lever arm 2'. will be moved below the abutment member 42 so that the spring 46 will pull the abutment member 42 inward into overlying relation to the lever arm 21, as shown in Figs. 3 and 4. The flange 43 will engage the wall 24, thereby limiting the movement of the abutment member 42 by the spring 45. Accordingly, the lever 2| will be held and locked in its operated position, thereby holding the switch 9 in open position against any force of the power element l1 tending to move the switch 2 to closed position. Operation of the lever arm l3 by the power element ll will serve merely to flex the blade 9 Without any resulting movement of the rod 1. The refrigerating apparatus may be placed in operation by pushing inward on the button 45 to move the abutment member 42 out of overlying relation to the lever arm 2'. so that, assuming that the pressure has dropped to a pressure in the system high side, and therefore in the chamber 31 lower than the pressure at which element 34 initiated movement of the lever 2|, the spring 28 will pull the arm 2! up to its limit against the shaft 3 I.

What is claimed and is desired to be secured by Letters Patent of the United States is:

In a control device, a casing having spaced walls, a lever between and movable in a plane parallel to said walls, one of said walls having a cylindrical guide opening therethrough, a cylindrical abutment member reciprocally fitting in and projecting from both ends of said opening, said abutment member having its inner end engaging the side of said lever, means urging said abutment member against said lever, a stop flange at the outer end of said abutment member and engagcable with said one of said walls to limit inward movement of said abutment member by said urging means, the other of said walls having an aperture therethrough alined with said guide opening, a rod projecting from said abutment member and extending through said aperture, a spring urging said lever against said rod, and means to move said lever away from said rod and out of the path of movement of said abutment member so that said urging means can move said abutment member into the path of movement of said lever by said spring.

EARNEST J. DILLMAN. JACK E. FLEURY.

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

UNITED STATES PATENTS Number Name Date 2,262,205 Schachtner Nov. 11, 1941 2,292,214 Dillman Aug. 4, 1942

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