US2209216A - Control device - Google Patents

Description

CONTROL DEVICE Filed Aug. 22, 1936 INVENTOR 99M ,5 my

M A 'TTORNEY Patented July 23, 1940 UNITED STATES CONTROL DEVICE Daniel D: Wile, Detroit, Mich., assignor tt Detroit Lubricator Company, Detroit, Mich., a corporation of Michigan Application August 22, 1936, Serial No. 97,364

10 Claims.

My invention relates generally to control devices and more particularly to expansion valves. It is an object of my invention to provide an expansion valve control device having a new and improved, sectionally constructed casing.

Another object of my invention is to provide an expansion valve having a sectionally constructed casing of a character such that expansion of certain of the sections in response to temperature changes, and resultant loose connections between the sections, is prevented.

Another object of my invention is to-provide an expansion valve having a new and improved arrangement of the operating parts thereof.

Another object of my invention is to provide new and improved means for dampening vibration and resultant noise in an expansion valve control device.

These and other objects of my invention will.

be apparent from a reading of the following description taken in connection with the accompanying drawing which form .a part of this specification, and in which drawing Figure 1 is a view shown in central longitudinal cross section of an expansion valve embodying features of my invention, and

Fig. 2 is a view shown in elevation of the expansion valve of Fig. 1, having parts broken away to show certain structure.

Referring to the drawing, there is shown. an expansion valve having a sectionally constructed casing including a metallic body I having an inlet 2 and an outlet 3 for refrigerant. In the present construction the body I is formed having a tubular wall portion 4 that is integral with and projects upwardly within the body I from the bottom wall thereof, as seen on the drawing, and the tubular portion 4 defines a valve chamber 5. An internal wall or partition 6, integral with the body I, surrounds the inlet 2 and joins the side wall and the wall portion 4, dividing the interior of the body into an inlet or high pressure chamber 1, and an outlet or low pressure chamber 8. An aperture 9-is provided in the portion of the tubular wall 4 that is disposed between the valve chamber 5 and the inlet chamber 1, communicating with and connecting the chambers at a point preferably adjacent the upper end of the valve chamber 5.

50 The upper end of the tubular portion 4 is open,

and the tubular portion 4 has an upper end portion of reduced diameter that is preferably internally threaded for receiving an externally threaded, removable, tubular-shaped valve seat member Ill. The tubular-shaped member ID has a head H that abuts the underside, or top wall of chamber 5, and in the underside of head H there is provided a recess in which is soldered a valve seat member 12. The valve seat member l2 has a centrally disposed aperture [3 there- 5 through providing a downwardly facing seat for cooperation with the conical face [4 of a reciprocal valve member 15 to control flow of refrigerant through aperture or passage IS. A valve carrier member I1 is disposed for reciprocal movement within valve chamber 5 and has a recessed bore opening through its upper end for loosely receiving the valve member l5. At its upper end the valve carrier member I1 is preferably f'ormedhaving an external annular flange l8, the outer periphery of which slidably engages the inner wall of the valve chamber 5 for guiding the valve carrier member. The lower end portion, as at I9, of the valve'carrier member I! may be of reduced diameter for slidably engaging in a tubular guide member 20 for guiding the carrier member I1. Surrounding the carrier member l1 and guide member 20 there is a helical coil spring 2|, one end of which abuts the underside of flange I8, the spring being under compression urging valve member 15 toward its seat.

The valve body I is formed at its upper end having an extended tubular portion or hollow boss 22, and spaced from and below the upper end of the boss 22 the body is preferably formed having an external, upwardly facing annular shoulder or seating surface 23. Mounted on the upper end of the body I there is an open-ended, tubular extension orspacer member 25 that is formed of a material having low heat conductivity, which may be Bakelite or any other suitable material. The spacer member 25 preferably has a lower end portion internally threaded, and the tubular boss 22 is preferably externally threaded for screw threading into the tubular spacer member to connect the parts together, one end of the spacer member 25 preferably seating on the upwardly facing shoulder or seating surface 23. In the past, in the construction of expansion valves, it has beend-ifiicult to obtain an entirely satisfactory fluid-tight connection between a heat insulating spacer member and a metallic valve body because of the tendency of the spacer member to become distorted. Spacer members of 50 plastic material, having low heat conductivity, tend to expand peripherally in response to changes in atmospheric conditions, causing the connection between the spacer member and valve body to become loosened and permitting 66 of the tubular boss 22.

- objectionable.

moisture to enter the casing which is, of course, In general, spacer members formed of a material of low heat conductivity having little or no coeificient of expansion are unsuitable, for usually such spacer members are insufficiently strong and tend to split or.crack. In order to obviate the above mentioned objection, -I provide a metallic band 21 that is preferably arranged around or encircles the outer periphery of the spacer member 25 where the spacer member is threaded onto the body to prevent peripheral expansion of the spacer member, or splitting of the spacer member, and resultant leakage of moisture into the casing. Preferably a lower 'end portion of the spacer member 25 is of reduced diameter, and the reenforcing band 21 tightly press-fitted onto said 'reducedportion with the outer surface of the band being substantially flush with the outer wall surface of the spacer member. If desired, instead of the reenforcing band 21 being fitted over the spacer member 25, it may be molded in the wall of the spacer member.

1 Adjacent its upper end the tubular boss 22 of the valve body I has an upwardly facing, internal annular shoulder 28 on which a closure member or wall means 29 seats and closes the interior of the valve body from the interior of the tubular spacer member 25. Preferably the wall means 29 has an upturned annular flange 30 that engages and fits tightly with the inner wall surface hermetically securing and sealing the wall means 29 to the valve body I. Adjacent its upper end the tubular spacer member 25 is provided with a transverse wall 33, and immediately beneath the wall 33 there is a metallic bellows member 34 that may have one end, or its lower end, hermetically secured and sealed around its periphery to the outturned flange 3| of wall means 29. Theother, or free end of the bellows 34 may be hermetically secured and sealed around its periphery to a movable wall 35 which is preferably cup- -.shaped having a centrally disposed, downwardly projecting tubular portion 36 that extends centrally through the bellows 34 substantially in axial alignment with the valve member ,|5. The bellows 34 and closure member or wall means 29 cooperate to provide a closed expansible pressure chamber 36 i Theupper or conical-shaped end of the valve member I5 is preferably truncated, as shown, the valve member having a bored recess 31 that opens through the upper end of the valve member and extends axially with-the longitudinal axis of'the valve member. Extending into the recess 31 there is a connecting or push rod 38, one end of which abuts the recessed wall of the valve memchamber 8, The deflector member 40 is prefer-' by a tube or conduit 52.

ably secured to the underside of the closure plate ,ing the rod 38. Carried by the cup-shaped, free end Wall 36 there is a connecting member or collar 4| that has an annular slot in which the inner end of wall 35 is clamped and rigidly secured to the connecting member. Preferably the connecting member 4| has a recess 42 in its lower face for receiving the upper end of the push rod 38, the upper end of the push rod bearingagainst the recessed wall. The connecting member 4| projects upwardly and has an internally threaded, bored recess for receiving one end of a connecting or push rod 43 which screw threads thereinto.

Movable with the bellows movable end wall 36 there is a pair of spaced spring-fingers which, in the present instance, are joined by a base portion 45. The base portion has an aperture therethrough for receiving an upper end portion of the connecting member 4|', the connecting member preferably having an external annular flange on the upper surface of which the base 45 seats. Screw threaded onto the push rod 43 there is a tubular shaped nut 46, the lower end of which abuts the upper face of base 45 to 4|. The spring fingers 44 project upwardly from the base 45 into an aperture 41 in the transverse The upturned annular wall 33 and are held under tension in engagefiange 30 preferably has an outturned annular ment with the, wall defining the aperture 41. Preferably upper end portions of the spring fingers 44 are rounded or curled inwardly, as at 48, and the convex surfaces of the portions 48 disposed in contact with the wall or aperture 41 to reduce friction therebetween. The spring fingers 44 frictionally engaging the wall or aperture 41 serve to dampen vibratory action of the valve member and associated parts to provide a smooth reciprocal motion and prevent so-called chattering of the valve caused by overtravel and resultant impact of the valve against its seat.

The expansion valve includes a thermostatic power element which comprises in general a temperature responsive bulb element 50 and an expansible chamber 5| communicatively connected When in operative posi; tion the bulb 50 is arranged in heat transfer relation with a refrigerant evaporator (not shown) andpreferably at the outlet end thereof. The bulb, expansible chamber and conduit may be charged with a suitable expansible-contractible fluid for exerting a force in chamber 5| inaccordance with the temperature of an evaporator at the location of the bulb 50." The preferable fluid employed, as is Well known, depends upon the kind of refrigerant mediumthat is used in the refrigerating system employing the valve. The expansible chamber 5| is defined by cooperating parts including a cap-or casing'53 that is mounted on the upper end of the tubular spacer mem ber 25: The cap 53 may be formed of sheet metal and an annular portion-of its lower end is preferably outwardly offset, as at 54, providing a downwardly facing annular shoulder or seating surface '55 for seating on the upper'end of spacer member 25. An upper end portion of the tubular spacer member 25 may be externally threaded to receive the annular ofiset portion 54 which is internally threaded for screw threading'the parts together. Disposed within the cap 53 there is a wall means in the form of a plate 56 which is disposed substantially transverse to the side wall of the cap 53, adjacent the upper end of the spacer member 25. The transverse wall 58 has an upturned annular flange 51' around its outer periphery that fits tightly against the inner wall surface of the cap 53,- and preferably the transverse wall 56 is hermetically secured and sealed at its flange 51 to the side wall of the cap 53. The transverse wall 56 has a centrally disposed aperture therethrough and hermetically secured and sealed to a border portion around said aperture is one end of a metallic bellows member 58 that is preferably smaller than bellows 34. The other, or free end of the bellows 58 is hermetically secured and sealed to a cup-shaped movable end wall 60 disposed in chamber 5|. The cup-shaped member 80 has a central portion that extends from the free end of the bellows 58 downwardly and centrally therethrough and has an inner end wall 6| provided with a centrally located aperture therethrough. Carried by and concentric with the end wall 6| there is a connecting member or collar 62 that extends through the aperture in the end wall BI and projects upwardly toward the top wall of cap- 53. In the present instance the end wall 6! of the cup-shaped'member 80 has a border portion around its aperture which is clamped and soldered in anextemal annular recess in theconnecting member 62 to rigidly connect the parts together in a fluid-tight manner. The connecting member 62 and the rod 43 are preferably loosely connected in a manner such that the thermostatic power element can be readily removed, and to this end the rod 43 may have a pointed upper end for seating in a conical recess provided in the inner end wall of a bored recess 52" that opens through thelower end of the connecting member 62.

Secured to and depending from the undersid of the top wall of cap 53 there is a stop member 53 of tubular form having a lower end wall 64 provided with an aperture for receiving a reduced upper end portion 65 of the connecting member 62. At its upper end the connecting member 62 preferably has an annular flange or head 61 positioned for longitudinal movement within the tubular stop member 63, the head 61 being adapted to engage with the lower inner wall of the tubular member 83 to limit compression movement of the bellows 58. However, this stop means 61 does not function as such during the operation of the device, for the movable end wall 42 of the bellows isadapted to engage wall 29 to limit compression movement of both bellows and valve in a valve opening direction before the member 67 engages its stop. The head 61 and stop 63 cooperate to limit compression movement of.the

is not operatively associated with the other parts of the expansion valve. A helical coil spring 68 surrounds the connecting member 62 and tubular stop member 63, having its upper end abutting the top wall of the cap 53 and its lower end abutting the end wall Gl, the spring 68 being under compression acting to compress the bellows 58.

The expansible pressure chamber 36 is to be connected in communication with a refrigerant evaporator (not shown) such as by means of a conduit or tube 69. The conduit 69 may have one end connected to one end of a threaded fitting 10 that may thread into an aperture in a wall of body I and have an inner end portion projecting through an aperture in wall 29 into the expansible chamber 36. The conduit 59 may be suitably connected to the fitting I0 by a nipple H. The other end of conduit 69 is preferably connected to a refrigerant evaporator at a point adjacent the location of the temperature responsive bulb 5. so that the pressure in chamber 36 substantially corresponds to the temperature to which bulb 50 is subjected at the outlet end of a refrigerant evaporator.

The operation of the expansion valve in connection with a refrigerating system is as follows: When the refrigerant evaporator is relatively warm, such as for example after the defrosting period, the-fluid in bulb 50, and consequently in the chamber 5|, will have expanded and will exert a force against the bellows 58 therein corresponding to the temperature of the evaporator at the location of the bulb 50. Also, in chamber 36 the expanded gas in the evaporator will exert a force against the bellows 34 in accordance with the pressure of the refrigerant in the evaporator. Theforces acting on the bellows 58 and 34 oppose each other, the bellows 58 being expansible in a direction tending to open the valve while the bellows 34 is expansible under pressure in chamber 36 in a valveclosing direction. During the shut down period the pressure exerted by the gases in chambers 5| and 36 are substantially equal, but due to. the difference in the areas of the bellows there is a differential between the opposing forces acting on the bellows, and there may also be a differential between the opposing forces exerted by the springs 2i and 68 such that the valve is held closed during the shut-down period. When the refrigerant compressor is started, gaseous refrigerant is withdrawn from the evaporator and from the pressure chamber 36 reducing the pressure in the evaporator and chamber 35'. When the pressure in chamber 36- is decreased such that the force acting against the bellows 34 plus the force exerted by spring 2|, becomes less 'than the sum of the opposing forces exerted by appreciated that I have provided a new and im- 1 proved thermostatic expansion valve. By providing a metallic band around the insulating, tubular spacer member 25, the spacer member will not expand peripherally and the screw-threaded connection or other type of connection that may be employed between the spacer member and the valve body will remain tight, preventing the entrance of moisture into the casing. Furthermore, I have provided a new and improved articulated push rod structure connecting the valve and valve actuating means, and carrying spring fingers engaging an inner wall of the tubular spacer member to dampen vibration of the operating parts. In addition, it will be appreciated that the assembly of my expansion valve is facilitated by reason of the structural relation between the spring fingers, bellows and closure member that seals one end of the bellows, for these parts and the other parts associated therewith may be assembled as a sub-assembly before assembling heat conductivity-having one end disposed toward said opening and connected to said body, said spacer member having a transverse wall provided with an aperture therethrough, a thermostatic power element mounted on the other end of said spacer member and operable to actuate said valve member, a bellows member in said spacer member and operable in response to pressure for actuating said valve member, means operatively connecting said bellows member and said valve member, a rod having one end connected to said power element, a connecting member secured to the movable end of said bellows member and having screw-threaded connection with the other end of said rod, a pair of spaced spring fingers for engaging the wall defining said aperture for dampening vibration, said spring fingers having a base seatingonsaid connecting member, and a tubular nut threaded onto said rod and abutting said base to tightly clamp said fingers to said connecting member. 1

2. In an expansion valve control device, a body an open end disposed toward said opening and' connectedto said body, a closure member closing said opening and having a' central aperture, a bellows member in said spacer member and acted on by pressure to aid said first-named means to 1 ,move said valve memberin said one direction,

said bellows member being carried by and having one end sealed and secured to said closure member, a thermostatic power element mountedon the other end of said spacer member for moving said valve member in the opposite direction, means operatively connecting said bellows member and said valve member and reciprocally guided in said aperture, and a connecting member carried by the free end of said bellows member and having a loose connection with said thermostatic power element.

3. Injla control device, a body having a passage for fiuidetherethrough including a valve port and having an opening in a wall thereof, a resiliently mounted valve member controlling said port, an open ended spacer member connected at one end thereof to said body and overlying said opening, a thermostatic power element mounted on the other end of'said spacer member, movable pressure responsivemeans disposed within said spacer member, connecting means secured to said pressure responsive means and having a seat portion, said connecting means operatively connecting said pressure responsive means and said power element with said valve member for movement of said valve member, a plurality of spring fingers engaging an internal wall of said spacer member to dampen vibration of said valve member, said spring fingers having an apertured base portion received by said connecting means and seating thereon, and means to secure-said base portion to said connecting means.

4. In an expansion valve," a body having a passage therethrough for a refrigerant medium including a valve port, said body having an opening in a wall thereof, a valve. member controlling said port, an open ended spacer member having ,one end disposed toward said opening and] connected to said body, said spacer member having an internal transverse wall provided with an aperture therethrough, a thermostatic power element mounted on the other end of said spacer member, pressure responsive movable means disposed within said spacer member and operatively connected to said valve member, a connecting member connected at one end thereof to said power element, a connecting member connecting said pressure responsive means and said first-'- named connecting member, a plurality of spaced spring fingers engaging the wall defining said aperture to dampenpvibration, said spring fingers having a base portion seating on one of said connecting members, and means cooperable with the other of said connecting members to secure said base and said one connecting member together.

5. In an expansion valve control device, a body having an inlet and an outlet for fluid, a reciprocal valve member in said body for controlling an operating'member having one end operatively connected to said power element, a connecting member secured to the movable end. of said bellows member, said operating member being adjustably secured to said connecting member so that the effective length of said operating member may be varied, and a pair of spaced spring 6. In an expansion valve control device, a body, I

a valve means in said body controlling flow therethrough, said body having an opening in a wall thereof, wall means substantially closing said opening and having a central aperture therethrough, a tubular spacer member having an open end disposed toward said wall means and connected to said body, a thermostatic power element mounted on the other end of said tubular spacer member, a bellows. member above said wall means and sealing said opening and being disposed within said tubular spacer member and sealed to said wall means, means operatively connecting said valve means to said bellows member, and means external of said body and operatively connecting together said thermostatic power element said bellows member and said firstnamed connecting means, said first-named connecting means extending through and substan-' tially closing said central aperture.

'7. In an expansion valve, a casing having passageway therethrough and having an opening through one wall thereof communicating with the passageway, a rigid plate means separate from said casing and positioned within the open- -of the casing opening, said rigid means having an aperture therethrough, a reentrant plate member sealed to the other end of and extending within said bellows member, said plate member and said rigid means cooperating to form stops to 7 limit the collapsing movement of said bellows member, a valve means Controlling flow through the passageway, a rod member connecting said plate member and said valve means and extending through and closingsaid rigid means aperture, a spacer member having a passagewaytherethrough and having one end portion surrounding said bellows member, said spacer member overlying the wall opening and having said end portion secured to said casing, a temperature responsive power element on the other end of said spacer member, and means connecting said power element to said plate member.

8. In an expansion valve control device, a body having an inlet and an outlet, a reciprocal valve member in said body controlling flow therethrough, means acting to move said valve member in one direction, said body having an opening in a wall thereof, a tubular spacer member having an open end disposed toward said opening and connected to said body,'a closure member closing said opening and having an aperture, a bellows member sealing said opening and acted on by pressure to aid said first-named means to move said valve member in said one direction,

said bellows member being carried by and having one end sealed and secured to said closure member, a cap member carried by said spacer member, an annular ring member sealed within to the end portion of said cap member adjacent to said spacer member, a second bellows member within said cap member and having one end sealed to said ring member, a cup-shaped closure member, an annular flange extending outward from said closure member and having the other end of said second-named bellows member sealed thereto, a thimble member having a pair of abutments in one end portion, said thimble member beingsealed to and extending through the bottom portion of said closure member with said one end portion toward said cap member, said cap member said ring member said second bellows member said closure member and said thimble member forming a sealed pressure responsive chamber, a cup-shaped stop member having its lip portions secured to the end wall of said cap member and having an aperture through the bottom wall, said end portion extending through the stop member aperture and having one of the abutments within said stop member, said stop member and said thimble member abutments serving as limiting members limiting expansion and contraction of said responsive chamber, means operatively connecting said thimble member and said. valve member and reciprocally guided in said aperture, and a connecting member carried by the free end of said thimble member and having a loose connection with said thimble member.

9. In an apparatus of the character described, a casing having a passageway therethrough, wall means separating said passageway into an inlet and an outlet chamber, said wall means having a valve port therethrough connecting said chambers for flow of fluid, said casing having an aperture through a wall of said casing and opening into said outlet chamber and overlying said port, a valve member within said casing and controlling flow of fluid through said port, a plate member secured to and sealing said well aperture and spaced from said wall means, said plate member having an aperture therethrough, a pressure T sensitive member overlying said plate member and cooperating therewith to form a pressure sensitive chamber, thrust means operatively connecting said sensitive member and said valve member and extending through and substantially closing said plate member aperture, and means for supplying pressure to said sensitive chamber.

10L In an'apparatus of the character described, a casing having a passageway therethrough, wall means closing said passageway to flow of fluid, said wall means having a valve port therethrough for flow of fluid, said casing having an aperture through a wall of said casing and opening into said passageway and spaced from said wall means,

' a valve member within said casing and controlling flow of fluid through said port, a plate member secured to and sealing said wall aperture and spaced from said wall means, said plate member having an aperture therethrough, a bellows member overlying said aperture and having one end sealed and secured to said plate member, a plate member secured and sealed to the other end of said bellows member, said bellows member and said plate members cooperating to form a pressure sensitive chamber, thrust means operatively connecting said last-named member and said valve member and extending through and substantially closing said plate member aperture, and means for supplying pressure to said sensitive chamber.

' DANIEL D. WILE.

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