US2250274A - Control apparatus - Google Patents

Description

y 1941- E. c. RANEY 2,250,274 I CONTROL APPARATUS v Filed March 1, 1938 3 Sheets-Sheet 1 I 4 5L; 3 194 179 15 1;?

sariin gig/g INVEINTOR.

ATTORNEY.

y 1941- E. c. RANEY 2,250,274

CONTROL APPARATUS Filed March 1. 1938 3 Sheets-Sheet 2 INVENTOR July 22, 1941, E. c. RANEY 2,250,274

GONTROL'APPARATUS Filed March 1, 1938 3 Sheets-Sheet 1 4 2 2 1 l 1 as O 1 5 0 O 7 F/g ll 5 8\ s a 1 a '56 0 4 8 5 so 62- 10 1 as 5 4 8 1 is 1 6 8 I 1 1 s- I 18 ATTORNEY Patented July. 22, 1941 CONTROL APPARATUS Estel C. Raney, Columbus, Ohio, assignor to Ranco Incorporated, Columbus, Ohio, a corporation of Ohio Application March 1, 1938, Serial No. 193,324

4 Claims.

This invention relates to control apparatus, and particularly to temperature control apparatus for household refrigerators.

An object of the invention is to provide a temperature responsive device for control apparatus comprising an expansible member having a tube attached thereto, the tube and member being filled with a temperature responsive fluid, and a section of the tube being wound in a helix with another section of the tube, whereby the adjacent convolutions of the resulting helix are of different sections of the tube so that a relatively lengthy portion of the capillary tube may be placed in a relatively short clamp, attached to the part of an apparatus controlled by the control device,

and the helix will be resistant to axial stresses.

Other and further objects and advantages will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred form of embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 is an enlarged view of the control apparatus taken on line I--I of Fig.

Fig. 2 is a view of the apparatus taken on line 2-2 of Fig. 1;

Fig. 3 is a view of the apparatus taken on line 3-3 of Fig. 1;

Fig. 4 is a front view of the apparatus taken on line 44 of Fig. 1;

Fig. 5 is a rear view of the apparatus;

Fig. 6 is a view of the insulating block. showing the fixed contact member and the toggle switch pivoting member mounted on the block;

Fig. '7 is a side view of Fig. 6;

b Fig. 8 is a view of the switch actuating mem- Fig. 9 is a partial view of the member shown in Fig. 8;

Fig. 10 is a view taken on line I0--I0 of Fig. 3; I Fig. 11 is a partial view taken on line IIII of Fig. 2;

Fig. 12 is a side view of the frame member, with the insulating block in position, and,

Fig. 13 is a view taken on line I3-I3 of Fig. 8.

A control apparatus similar to that described and claimed in my copending application Serial Number 351,009, filed August 3, 1940, and indicated generally at 8, comprises a frame I0 preferably of a single section of sheet metal formed in a U shape, forming a front wall I4 and side walls I6 for supporting and inclosing the control mechanism. The side walls I6 each have a laterally extending flange I8, which is provided with two openings 22, at either end thereof, for connecting a power element 24 to the frame.

The power element 24, in the present form of disclosure, consists of a metal bellows 20 enclosed within a shell 26 and having a closed tube 2t connected thereto. ihe bellows and tube are filled with a thermal responsive fluid, such as methyl chloride, so that the fluid pressure will cause variations in pressure within the bellows according to the variations of temperatures to which a part of the tube is subjected. A section of the tube 2| adjacent the end thereof is reversed as at H and the doubled tube then formed into a closely wound helix as shown at I9.

The helix I0 may then be secured to the evaporator of a refrigerator apparatus by a thermal conducting clamping device (not shown) at tached to the evaporator. Such clamping devices are cylindrical in form and tightly embrace the helix so that the temperature of the helix will correspond to the temperature of the evaporator. The helix provides means for presenting a lengthy section of tube for contact with the clamp so that a relatively large volume of the enclosed fluid will be affected by the temperatures in the evaporator. It will be noted that every other convolution of the helix is formed of the reversed section of the tube, thereby reenforcing the helix against axial stress which may be caused by accidental pulling of the tube.

A push rod 23 is connected to the movable end of the bellows 20 and engages a switch actuating member 50 for actuating the switch by the expansion and contraction of the bellows 20, as will be described later. The shell 26 is provided with a flange 28, having squared corners thereon which register with the corners of the flanges I8. Openings are provided adjacent each corner of the flange, which register with the openings 22 in the flanges I8, and the shell 26 is connected to the frame I0 by rivets 32. Thus the power element 24 provides a rigid reinforcing base for maintaining the side walls rigid.

A toggle switch mechanism is mounted on a block I02 preferably formed of a dielectric material, such as Bakelite, and the block is attached to the frame I0 between the side walls IS. The block I02 is formed with two oppositely disposed side walls I50 which are adapted to fit between the side walls I6 of the frame I0, and maintain the walls rigidly spaced from one another. A pair of bosses I48 are formed on the side walls I50 and are adapted to engage the edges of the side walls I6 for locating the block with respect to the edges of the walls.

The side walls are formed ears which, after tlle block W2 is inserted in position, are turned to conform to the curved corners of walls I46, formed on the insulating block. When the ears I52 are turned, the inside edges engage shoulders I44 formed at each corner of the block I02. Thus the block is locked in engagement with the side walls I6 of the frame it. The bosses I46 are adapted to engage in a shallow offset I49, formed in the edge of the side walls I6 to prevent movement of the block with respect to the upper and lower edges of the side walls. Thus the insulating block I02, carrying the switch mechanism may be easily and securely attached to the frame, further reenforcing the walls and forming a closing wall for the control apparatus.

A U shaped bracket I04 is secured to the insulating block I02 by rivet I03 extending through the yoke and block. The legs of the U shaped bracket I04 are provided with two pairs of V shaped notches or pivots I06 and N1 for pivoting the ends of a pair of toggle members therein. The pivots I06 are oifset with respect to the pivots I01 and are disposed closer to the block I02 for reasons which will appear hereinafter. The moving parts of the switch mechanism comprises two U shaped toggle members I06 and H0, which are preferably formed of sheet metal stampings and reenforced by the upturned edges III and I I2 respectively. The ends of the legs of each of the members I08 and H are adapted to engage in the pivots I06 and I0! respectively, and are yieldingly retained in their respective pivots by a tension spring I09, connected in holes II3 formed in the yoke of the members, and carried between the legs thereof. The ends of the legs of the members are beveled to form knife edged bearings. The yoke of the member I08 has a semicylindrical section I I6 formed therein for reenforcing the member and to allow space for the spring I 09 to move between the legs thereof. The member H0 is adapted to carry an insulating member or strip 6, preferably of fiber, on the free end thereof. The strip H6 is connected to the member IIO by three ears I22, formed on the member IIO, two of which are crimped over the side edges of the strip and the third of which extends through an opening in the strip and is crimped over the surface of the strip adjacent the opening. A contact bar I I6 is secured on the end of the strip H6 and is adapted to bridge a pair of fixed contacts I32 mounted on the insulating block I02. A T shaped opening II! is provided in the strip I I 6 through which a part of the contact bar II8 extends. preferably formed of a copper sheet having the eneral shape of a triangle, having 9. lug I2I formed at the apex and a similar lug I23 formed at the center of the base thereof. The sheet is loosely formed over the end of the member II6 as shown in Fig. 1, and the lug I 23 is turned to extend into one end of the opening II! for holding the contact member H6 in place on the strip. A pair of contacts I20 are riveted to the wide part of the contact member I I6, and are spaced to enage the fixed contacts I32 when the switch is closed. The contacts I32 are suitablymounted each on one of a pair of terminal bars I30 riveted to the block. The circuit wires for the device to be controlled may be connected to the terminal members I30, by terminal screws I34 threaded in the terminal members from the opposite side of the insulating block through suitable openings in theblock. A chamber I36 is formed in the block I02 by walls I46 for accommodating the The contact bar H6 is wire leads from the circuit. A plate i333, preferably of insulating material, is provided for inclosing the chamber. The plate H8 is secured over the chamber opening by screws 562, which are threaded in a pair of bushings 540, formed integral with the insulating block 502. The bushn s I40 serve as supports for. the cover. The plate I30 i provided with an opening Hi to admit the line wires to the chamber I36. Thus the switch mechanism may be completely assembled on the insulating block I02, and the block then secured to the walls of the frame, as a unit.

The switch mechanism is adapted to be operated by the power element 24 through the switch actuating member 60. The member 60 is preferably formed of heavy sheet metal and comprises a base 62 and an arm 64 formed integral therewith, and is pivotally supported between the side walls I6 by a pin 66. The pin 66 is tightly pressed in holes 61 and 66, formed in an upturned ear 60 of the base 62 and at the base of the arm 64, respectively, so that the pin 66 is substantially an integral part of the actuating member 60. The length of the Pin 66 is such that a relatively short section of the pin will extend beyond either side of the member 60 when the pin is in place. The side walls I6 each have a circular indentation 62, formed therein, each of which is provided with a bearing 63 for receiving an end of the pin 66. The bearings 63 are formed by lancing a circular opening in the indented part of the wall so that the metal adjacent the opening is extended to present a substantial bearing surface. Thus the ends of the pin 66 may extend through the bearings 63, without extending beyond the plane of the surface of the side walls I6. In the assembly of the control device, the actuating member 60 is secured in position between the walls of the fr .2 I0 prior to the connection of the power element 24 to the frame so that the walls may be spread and the ends of the pin 66 slipped into the bearing 63. When the power element is attached to the frame, the walls are then held rigid, and the pin 66 will be locked in the bearings. The arm 64 is provided with fingers 64 and 61 formed at the end thereof. The fingers are provided with 9. lug 66 and an engaging screw 66 which engage the toggle member I08 when the switch is oper ated. The screw 66 is adapted to be held between a member 66, riveted to the arm 64, and the finger 64. The member 66 and the finger 64 are each formed with curved portions I0 and TI respectively for receiving the adjusting screw 66. The member 66 is preferably formed of resilient material so that the screw 66 will be pressed in the curved sections I0 and II for preventing change in the adjustment of the screw. The arm 64 is provided with 0. lug 6I formed thereon for engaging the switch member IIO for limiting the opening movement of the switch member. The base 62 of the member 60,-has one end upturned, as at I2, which is formed with a neck 14 and shoulders 16. A washer I6, having an opening 11 of substantially the same shape as the cross section of the neck I4, is loosely carried on the shoulders I6, and held on the neck I4 by mutilations I6 at the top of the neck. The washer 16 has a circular embossed part 60 for centering a compression spring I60 thereon. A screw 64 having an indented part (not shown) in one end thereof for receiving the end of the thrust rod 23, is threaded in a lanced opening 62, formed in the base 62. The screw 84 is locked in position by a lock washer 66 after it is once adjusted to a proper operating position with respect to the push rod 23. An arm 90, formed on the member 50 extends at substantially right angles with the arm 54, and is adapted to move in a rectangular opening 92, formed in the front wall I4 for limiting the movement of the actuatin member 50 within a definite range to prevent distortion of the parts of the control apparatus if the helix I9 should be subjected to warm atmospheric temper- I atures.

When the block I02 with the toggle switch mechan'sm assembled thereon is attached to the frame 0, the yoke of the toggle member I06 is first slid between the fingers 64 and 61 of the arm 54 and the block N2 is then secured to the side walls I6 as described above. Thus the actuating member 50 is adapted to engage the member I08 and move it about its pivot to operate the switch, as will be described hereinafter.

The top of, the frame is closed, after the block I02 is attached thereto, by a cover I90 having one end of the cover turned at right angles and the end edge of the turned portion shaped to conform with the top side of the block I02 toefiectively enclose the switch apparatus in the frame. v The cover I90 is formed with turned edges I9I, which fit over the ends of the frame walls, and detents I93 are provided in the edges I9I, which engage with similar detents I94 formed in the side walls I6 adjacent the top thereof for frictionally holding the cover on the frame.

The spring I60 is provided for controlling the temperatures at which the switch is operated. One end of the spring I60 is adapted to engage the washer 16, as described above, and thereby transmit a load on the bellows through the member 50. The other end of the spring is engaged by a plate I62, having a circular centering boss I63 and a threaded hole I64 through the center thereof for receiving a screw I66. The plate is formed with a pair of ears I65, which engage the wall of a slide or member I68, to prevent rotation of the plate. The plate is connected to the slide I 68 by the screw I66, which is threaded in the hole I64, and supported on a bracket I61 formed on the slide. The bracket I61 is provided with a hole through which the screw I66 is extended and rigidly fixed thereto by a nut I10 and washer I1I. Thus the spring I60 may be adjusted at the factory by turning the screw I66 one way or the other to change the distance of the end of the spring I60 from the bracket I61 and establish the proper adjusting range of the control apparatus by the user thereof.

The slide 866 is formed of sheet metal and comprises a wall part having a turned end which comprises the bracket I61. The bracket and wall part are reenforced by web parts E61 formed thereon. A lug I12 is riveted adjacent one end of the wall part of the slide I 68 and extends through a slit E15 formed in the wall M for enagernent with the periphery of a cam I16. The ing is cylindrical in shape and is provided with a flange 915 on the end thereof which engages the outside surface of the cam I16 to hold the adjusting member M8 against the wall It. The spring I60 yieldingly engages the lug I12 with the De" riphery of the cam. The width of the slide I68 is such that the sides thereof engage the walls I6 and when the slide is moved by the cam, the walls uide the member in a direction of the axis of the spring I60.

The cam I16 includes a hub I82 formed integral therewith which is adapted to be axially supported on a post I18 secured to the wall It, such as by extending a hollowed neck part on the post through a hole in the wall I4 and then rolling the neck outwardly and against the wall as indicated at i". A slot I19 is provided in the wall part of the slide I68 to accommodate the turned part I11 and permit the slide I68 to move against the inside surface of the wall I4. The hub I82 is square in cross section so that a knob I86 provided with a squared recess may be fitted on the hub whereby the cam can be rotated by the knob. Circular grooves are provided adjacent the end of the hub I82 and in the recess in the cap, so that a split ring spring I80 may be interposed between the two grooves and thereby hold the knob'on the shaft.

When the cam I16 is rotated by the knob, the periphery thereof is in engagement with the lug I12, and translates the slide I66 in a direction of the axis of the spring I60. The cam I16 is provided with detents I81 on the periphery thereof which are adapted to engage the lug I 12 and limit the rotation of the cam member in either direction. Thus when it is desirable to increase the pressures or temperatures at which the switch is operated the cam is rotated counterclockwise, as viewed in Fig. 4, which moves the slide I68 downwardly thereby compressing the spring I60, to increase load upon the bellows. When it is desired to decrease the pressures or temperatures at which the switch operates, the

cam is rotated clockwise which permits the spring I60 to raise the slide I68 upwardly and decrease the tension of the spring I60.

therein causes expansion of the bellows 20 to rotate the member 50' clockwise, as viewed in Fig. 1. The finger 64 is in engagement with the member I 08 and the lug 6| is in engagement with themember III), and these two members are moved to the right and about their pivots I06 and I01. The pivots I06 and I01 are offset from one another as described above, so that the center of the spring I09 will pass to the right of the pivot I01 prior to passing to the right of pivot I06, and in so doing will cause the member IEO to be snapped to the switch closing position, which causes the spring I09 to pass to the right of pivot I06 and snap the member E08 against the screw 66. The refrigerating apparatus is thus energized and the coil I9 will then be cooled and cause the gas pressure in the bellows 29 to decrease. The spring I60 will then cause the member 50 to be rotated counterclockwise and the finger 61 will move the member I08 and the spring N39 to the left of the pivot I86 and cause the member I68 to be snapped to the ing 65. The spring 508 is then carried to the left of the pivot I01 and snaps the member IIS against the stop M on the arm 5 3 to open the switch and deenergize the refrigerating apparatus.

The control apparatus may be attached to the refrigerator by a sheet metal bracket I19 secured.

post I16 extends. Holes are provided adjacent rature responsive element includng tube, a section of said upon itself and said reversed adjacent tube section being formed he ccnvolntions of the helix substaning one another.

'ecsnre responsive member; a tube connected neemizer, said tube having a section thereof reversed upon another section of the tube and having the two sections formed in a helix, the convolutions of the helix being relatively close to one another.

3. A temperature responsive device, including a pressure responsive member; a tube connected to the member, said tube having a. section thereof formed in a helix, and the convolutions of the said helix having another section of the tube interposed there between for reenforcing the said helix against axial stresses.

4. A temperature responsive device, including a pressure responsive member; a tube connected to the member, the said tube having a section hereof formed in a helix, and the convolutions of the helix having a helical formed member interposed therebetween for. reenforcing the said helix against axial stresses.

'E STEL C. RANEY.

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