US3123989A

US3123989A - Air conditioning control switch

Info

Publication number: US3123989A
Authority: US
Publication date: 1964-03-10
Anticipated expiration: 1981-03-10

Description

March 10, 1964 T. A. WRIGHT 3,123,989

AIR CONDITIONING CONTROL SWITCH Filed Dec. 20, 1961 2 Sheets-Sheet 1 FIG. I

FIG. 6

)5 so I: 2 64 as O 2 7 INVENTOR. 7| 8 TIMOTHY A. WRIGHT.

FIG. 5 M M ATTORNEY.

March 10, 1964 T. A. WRIGHT AIR CONDITIONING CONTROL SWITCH 2 Sheets-Sheet 2 Filed Dec. 20, 1961 INVENTOR. TIMOTHY A. WRIGHT FIG. 4

ATTORNEY.

United States Patent m 3 123 989 AIR coNnmoNiNo CONTROL SWITCH Timothy A. Wright, Chittenango, N.Y., assignor to Carrier Corporation, Syracuse, N.Y., a corporation of Delaware Filed Dec. 20, 1961, Ser. No. 160,819 Claims. (Cl. 62427) The present invention relates to air conditioning apparatus of the self-contained room type and more particularly to a self-contained room air conditioner having an improved control therefor.

Room air conditioners today are required to perform a plurality of functions in addition to merely cooling the air. For example, at times it is desirable to render the refrigeration system inoperative and to circulate air through the room air conditioner by operating only the fan means therein. It is also desirable to operate the room air conditioner so as to cool the area to be treated, yet at the same time remove stale air from the room and discharge it to the ambient. At other times it may be desirable to draw ventilation air from outdoors into the room to be treated. The controls for self-contained room air conditions are rather complex, when the conditioners are required to perform the varied functions abovedescribed as well as others.

An object of this invention is to provide a self-contained room air conditioner having controls which obviate the deficiencies and disadvantages of prior constructions.

Another object of this invention is to provide an air conditioning apparatus having a single mechanism for controlling operation of the refrigeration system and the fan means, as well as opening and closing dampers for regulating the flow of fresh air and stale air'through the air conditioning apparatus.

Yet another object of this invention is to provide a room air conditioner with a single rotatable control having a shaft for operating control switches and flexible cable means secured to the shaft for actuating separate ventilation air and exhaust air dampers in a coordinated sequence, so as to sequentially cool and dehumidify the air, circulate room air without cooling, supply fresh air to the area to be treated, or exhaust stale air from the area to be treated to the ambient.

A further object is to provide a room air conditioner with a control arrangement which is simple, compact and economical to manufacture. These and other objects of the invention will become more apparent hereafter.

This invention relates to a room air conditioner comprising a casing having a refrigeration system therein. The refrigeration system includes a motor-driven compressor, a first heat exchange coil, expansion means and a second heat exchange coil. Partition means are provided within the casing to form a first compartment and a second compartment. Within the casing are fan means for circulating air over the heat exchange coils. The partition means has first and second openings therein. Secured to the partition means are dampers for closing each opening. Switch means are provided for controlling operation of the compressor motor and the fan means. The switch means are actuated by a rotatable control. A pair of flexible cables are connected to the rotatable control, one for operating each damper. Lost motion means connect each cable to a respective damper. Upon rotation of the rotatable control to different predetermined positions, the

Patented Mar. 16, 1964 switch means will be selectively actuated to control operation of the compressor motor and the fan means and the cables will be actuated to operate the dampers.

The attached drawings illustrate a preferred embodiment of the present invention, in which like numerals designate like elements in each of the several views, and in which:

FIGURE 1 is a perspective view of a room air conditioner embodying the present invention;

FIGURE 2 is a perspective view of the room air conditioner of FIGURE 1 with parts broken away to more clearly illustrate the control for actuating the dampers;

FIGURE 3 is a perspective view illustrating the relationship of the elements of the control of the present invention;

FIGURE 4 is a sectional view of the control switch of FIGURE 3 on an enlarged scale showing the control shaft positioning means;

FIGURE 5 is a sectional view of the control switch of FIGURE 3 on an enlarged scale showing the switches and the cam actuators therefor; and

FIGURE 6 is a schematic wiring diagram of the electric control for the air conditioner illustrated in FIGURE 1.

Referring to FIGURE 1 there is shown an air conditioning unit embodying the present invention. The unit It} comprises a casing 11 having an inlet 12 and an outlet 13 in the front thereof. Mounted in the front of air conditioning unit It) are selector switch knob 14 and thermostat knob 15. It will be understood by those versed in the art that the casing may be placed in a window or through a wall such that inlet 12 and outlet 13 are in communication with the room or area to be treated and the opposite end of the casing is in communication with the ambient.

In FIGURE 2 it can be seen that within casing 11 there is provided a refrigeration system comprising compressor 18, condenser 19, expansion means 20 and evaporator 21, interconnected by suitable piping (not shown). It will be readily understood that the expansion means may be a capillary tube as shown or, if desired, a thermal expansion valve may be used.

Partition panel assembly 22 separates the casing 11 into indoor compartment 23 and outdoor compartment 24. Secured to the partition panel assembly is double-ended motor 25. Mounted on the ends of the shafts of motor 25 are evaporator fan 26 and condenser fan 27. It can be seen that the compressor, condenser, and condenser fan are disposed in the outdoor compartment and that the evaporator and evaporator fan are disposed in the indoor compartment. Fan motor 25 (not shown in FIGURE 2) is in outdoor compartment 24.

Evaporator fan 26 draws air into casing 11 through inlet 12 in the face thereof, through filter 29 through evaporator 21, and discharges the air upwardly through opening 28 in partition panel assembly 22 and outwardly into the area to be treated through outlet 13 in the front of casing 11.

Condenser fan 27 draws air into the casing through condenser 19 and discharges it through outlet 30 in the rear of casing 11. Deflector 31 may be provided within the casing to minimize mixing of the air being drawn into the casing in the rear thereof with the air being discharged from the rear of casing 11.

Means for exhausting stale room air are provided in the air conditioning unit. Such means comprise duct 32 and damper means for controlling the passage of air through the duct. Duct 312 communicates at one end with opening 33 in vertical wall 34 of the partition panel assembly and at the other end with opening 35 in condenser housing 36. As a result of the pressure differential between housing 36 and compartment 23, when the damper means is open, air moves from indoor compartment 23 to condenser housing 36, outdoor compartment 24 and the ambient. The passage of air through duct 32 is controlled by exhaust damper 37. Damper 37 is secured to shaft 358 which is journaled at its ends in support members 3? and 40. The damper is biased to the closed position by coil spring 41. The means for open ing damper door 3'7 includes flexible Bowden cable 42 secured to the door by lost motion means 43. Lost motion means 43 comprise the L-shaped end of the cable which extends through hole 44 in exhaust damper 37. Cable 42 extends through and is movable within sheathing 45 afiixed in place by bracket 46. The opposite end of cable 42 is secured to the control switch as will hereafter he more fully explained.

The means for providing ventilation air to the area to be treated comprise ventilation damper 42 regulating the passage of air through opening 47 in wall 52. Damper 48 is aflixed to shaft 49. Vertically disposed shaft 49 is pivotally supported by support members 51 connected to wall 5.2 of partition panel assembly 22. Spring 53 may be used to bias ventilation damper 48 closed. Such spring may be of the coil type (as shown) or may be of another type, for example, a leaf spring. The means for opening the ventilation damper door comprise flexible Bowden cable 54 suitably connected at one end to the control switch and at its opposite end to 'lost motion means 55. Lost motion means 55, provided between the end of cable 54 and damper 48, include the offset or L-shaped end of cable 54 which extends through and is movable with respect to hole 48' in damper 48. The relationship of the elements of the control is more clearly illustrated in FIGURE 3. It is apparent that

Bowden cables

42 and 54 are secured to a single operator. Cable 54 extends through sheathing 56 which is suitably secured to bracket 57.

Control shaft 59, to which an end of each

flexible cable

42 and 54 is secured, not only controls the actuation of the ventilation and exhaust dampers, but also controls the functioning of selector switch 60. Shaft '59 is journaled in switch 60 which is secured to bracket 61. tintegrally formed on the end of shaft 59 is crank arm 62. Stub shaft 63 is connected to crank arm 62. The ends of

Bowden cables

42 and 54 are suitably secured to stub shaft 63. Control shaft 59 is connected to switch shaft 65 by suitable means as, for example, pin 66.

Referring now to FIGURE 4, there is seen casing 63 for selector switch 60. Extending from the casing are four

terminals

69, 70, 71 and '72, by means of which the switch may be electrically connected to the other components. Provided within casing 68 are positioning means for retaining

shafts

59 and 65 in a predetermined selected position. It will be noted that when switch shaft 65 is maintained in a predetermined selected position,

control cables

42 and 54 and, therefore,

dampers

37 and 48 will also be maintained in selected position. The positioning means

comprise leaf springs

74 and 75 and positioning spring 76. The positioning spring contacts cam 77 and restrains the movement of cam 77. Cam 77, which is secured on shaft 65, may have a varying number of sides dependent upon the desired number of switch positions. For example, the presently preferred cam is pentagonal and the switch has five positions.

Referring to 'FTGURE 5 there is shown another view of selector switch 60 more clearly illustrating the switch means therein. Secured on switch shaft 65 are a pair of cams 78 and 79 for actuating arms 8t} and 81.

Contacts

82 and 82 on arm 8t} are adapted to engage

contacts

84 and 85 respectively, on terminals 70 and 71, respectively.

Contact 83 on arm 81 is adapted to engage contact 86 on terminal 72.

Considering now the wiring diagrams of FIGURE 6, it is seen that power is supplied from a suitable source through leads L1 and L2. Selector switch knob 14 is rotated to properly position selector switch 60. Cams 7% and 79 are rotated when knob 14 is turned to position

arms

81 and 81.

Thermostat 88 is regulated by thermostat knob 15 on the face of casing 11. The thermostat comprises arm 89 movable from the off position shown in solid line to the on position shown in dotted line and arm X) movable into engagement with either high contact 91 or with low contact 92. The thermostat is adjustable from the high position to the low position to suitably regulate the speed of the two-speed fan motor 25.

Fan motor 25 is of the permanent split-capacitor type and includes run winding 95 and start winding 96. A conventional overload protector 97 may be provided in the motor circuit to protect against excessive temperature in the motor windings or against excessive current. The fan motor circuit is provided with capacitor 98.

Electric motor 99 for operating compressor 18 is preferably of the permanent split-capacitor type and comprises run winding 100 and start winding 101. Provided within the motor is an overload protector 102. To produce the necessary phase change required at startup, a capacitor 103 is provided.

OPERATION The operation of my improved air conditioning unit may best be understood by reference to the following chart in which are set forth the positions of the ventilation and exhaust dampers and the operating conditions of the compressor motor and fan motor for each setting of the selector switch knob.

The purpose of each of the operations of the air conditioning unit determined by the setting of selector switch knob 14 is as follows:

(1) 0fi.-The ventilation damper and exhaust damper are closed and the compressor motor and the fan motor are inoperative so that no conditioning effect is applied to the room.

(2) Power Vent.The fan motor is operative and the ventilation damper is open to change the air within the room by permitting fresh outdoor air to enter without any conditioning effect being applied thereto.

(3) Circulate.-The ventilation damper and exhaust damper are closed and the fan motor is operative to recirculate room air without conditioning the same.

(4) Cool Vent.The compressor motor and fan motor are operative and the exhaust damper is open to remove some of the room air while at the same time cooling the air supply to the room.

(5) Power C00I.The compressor motor and fan motor are operative to condition and circulate room air.

Considering FIGURE 6, it will be seen that leads L1 and L2 are adapted to be connected to a source of power, for example, a 220-volt power source. Selector switch knob 14 may be set to a predetermined condition, for example, Power Cool. Arm 8% would be positioned in engagement with contact 85 and arm 81 would be positioned as shown in dotted line.

Thermostat 88 is appropriately set by turning thermostat knob 15. Arm 89 would be moved to the on position shown in the dotted line and arm 90 would be moved in accordance with the desired temperature condition into engagement with either high contact 91 or low contact 92. Assume for purposes of illustration that low speed of fan motor 25 is desired. Arm 90 is in engagement with low contact 92.

In these positions of the selector switch and the thermostat, fan motor 25 would be operative on low speed and the compressor motor would also be operative.

It will be noted that when selector switch control knob 14 was rotated to the Power Cool position, crank arm 62 was moved to properly position the

dampers

37 and 48. In this instance, springs 41 and 53 would bias the doors to the closed position. Room air would be drawn in inlet 12 in the face of casing 11 and through evaporator 21 by evaporator fan 26 and then discharged upwardly through opening 28 in partition panel assembly 22 and outwardly into the room through outlet 13 in the face of casing 11. At the same time, outdoor air would be drawn over condenser 19 by condenser fan 27. The air would then be discharged through outlet 30 in the rear of casing 11.

The refrigeration system functions in its normal fashion, that is compressor 13 forwards high pressure vaporous refrigerant to condenser 19 wherein the refrigerant may be condensed by the cool air passing over the condenser. The condensed refrigerant passes through expansion means 20 wherein it is appropriately metered. The expanding vaporous refrigerant in evaporator 21 cools the room air passing thereover. When thermostat 88 is set in the low position, fan motor 25 operates on low speed and thorough dehumidification of the air may be obtained. For top capacity operation and rapid cooling, thermostat 83 may be set in the high position.

Control shaft 59 and switch shaft 65 are maintained or restrained in the selected position by the spring means shown in FIGURE 4. Pentagonal cam 77 provided on shaft 65 engages within a recess in positioning spring 76. Leaf spring 75 bears upon positioning spring 76 and leaf spring 74 bears upon the opposite side of cam 77. Thus, in each selected position of selector switch knob 14, the spring means function to restrain movement of switch shaft 65. Inasmuch as control shaft 59 is secured to shaft 65 and thus also restrained from motion, crank arm 62 and

cables

42 and 54 connected thereto are maintained inoperative.

Assume now that selector switch knob 14 is positioned in the Cool Vent position. Arm 80 would be in engagement with contact 84 and arm 81 would be in the dotted line position. Thermostat arm 9t] would be in engagement with either contact 91 or contact 92. Thus, in operation both compressor motor 99 and fan motor 25 are operative. When selector switch shaft 65 was rotated, crank arm 62 was moved to open exhaust damper 37. Cable 42 pulled damper 37 against the force of spring 41 to open the damper door. Cable 54 rode freely through lost motion means 55 so that spring 53 maintained ventilation damper 48 closed. Evaporator fan 26 pushes stale air into duct 32 and condenser fan 27 pulls stale air from the duct and forces such air from casing 11 through outlet 30.

If selector switch knob 14 is moved to the Circulate position, arm 89 would be in engagement with contact 85 and arm 81 would be in the position shown in solid line. Compressor motor 99 will be inoperative and only fan motor 25 will be operative. Both ventilation damper 48 and exhaust damper 37 are closed, inasmuch as the ends of

cables

42 and 54 are inoperative through lost motion means 43 and 55.

When selector switch knob 14 is rotated to the Power Vent position, arm 80 would be in engagement with contact 84 and arm 81 would be in the solid line position. Compressor motor 99 is inoperative in this mode of operation. Control shaft 59 is positioned so that crank arm 62 moves control cable 54 against damper 48 to open the ventilation damper. Exhaust damper 37 is closed. Thus, fan motor 25 circulates room air and draws ventilation air from the outdoors into outdoor compartment 24, through opening in the partition panel assembly into indoor compartment 23, and through outlet 13 into the room to be treated.

If selector switch knob 14 is positioned in the Off position, there would be no contact made between arms and 31 and their respective contacts. Thus, compressor motor 99 and fan motor 25 are inoperative. Crank arm 62 is positioned so that both ventilation damper 48 and exhaust damper 37 may be biased to the closed position.

Thus, it will be seen that by the present invention there has been provided a simplified control for a room air conditioning unit. By movement of a single knob the electrical switch for controlling the compressor motor and fan motor may be properly positioned and at the same time the dampers for regulating the flow of air through the casing of the air conditioning unit may also be selectively positioned. Positioning means are provided in the electrical switch to maintain the control shaft in a predetermined selected position and as a result, the dampers are also maintained in the predetermined selected position. The linkages for effecting movement of the dampers are relatively simple and inexpensive to as semble. Thus, manufacture of the air conditioning unit is facilitated.

While I have shown a preferred embodiment of the present invention, it will be obvious that other modifications may be made without departing from the invention and I desire that my invention be limited only within the scope of the appended claims.

I claim:

1. A room air conditioner comprising a casing; a refrigeration system in said casing including a motor-driven compressor, a first heat exchange coil, expansion means and a second heat exchange coil; partition means forming a first compartment and a second compartment in said casing; fan means for circulating air over the heat exchange coils; said partition means having a first opening and a second opening therein; a damper for closing each opening; switch means for controlling operation of the compressor motor and fan means; a rotatable control for actuating the switch means; a pair of flexible cable means connected to the rotatable control, one for operating each damper; and lost motion means connecting each cable means to a damper, whereby rotation of the rotatable control to different predetermined positions will selectively actuate the switch means to control operation of the compressor motor and fan means and will actuate the cables to operate the dampers.

2. A room air conditioner as in claim 1 wherein each of said dampers are biased to the closed position by a spring.

3. A room air conditioner as in claim 1 wherein said rotatable control comprises a shaft having a crank arm secured thereto, the flexible cable means being secured to such crank arm.

4. A room air conditioner comprising a casing; a refrigeration system in said casing, said refrigeration system comprising a compressor, a condenser, expansion means and an evaporator; partition means defining an indoor compartment and an outdoor compartment in said casing; a housing for said condenser, a fan for drawing air through said condenser; a fan for drawing air through said evaporator; motor means for driving said fans; said partition means having first and second openings therein, said first opening communicating said indoor compartment with said outdoor compartment; duct means communicating said second opening with said condenser housing; a ventilation damper for closing said first opening; an exhaust damper for closing said second opening; switch means for controlling operation of the compressor and motor means; a rotatable control for actuating the switch means; a pair of flexible cable means connected to the rotatable control, one for operating the ventilation damper and the other for operating the exhaust damper; first lost motion means connecting said one cable means to the ventilation damper; and second lost motion means connecting said other cable means to the exhaust damper, whereby rotation of the rotatable control to different predetermined positions will selectively actuate the switch means to control operation of the compressor motor and fan means and will also selectively operate the ventilation damper and the exhaust damper.

5. A room air conditioner as in claim 4 including position restraining means cooperating with said rotatable control for releasably retaining the rotatable control in a References (Iited in the file of this patent UNITED STATES PATENTS 2,451,366 Terry Oct. 12, 1948 2,711,087 Jennings June 21, 1955 2,720,090 Ford Oct. 11, 1955 2,778,197 Legeza et al. Jan. 22, 1957 2,811,022 Lathrop Oct. 29, 1957 2,986,016 Giliham et a1. May 30, 1961 3,021,696 Spiegelhalter Feb. 20, 1962