US1664459A - Control mechanism - Google Patents

Description

C. T. MASON CONTROL MECHANISM April 3, 1928. 1,664,459

INVENTOR Cfiages Maw/7' ATTORNEY vide a control mechanism that tuated in response to a relatively slight slip movement or lost motion between driving and driven members and a novel means for 'tions against Patented Apr. 3, 1928.

1,664,459 NITED STATES PATENT OFFICE.

CHARLES THOMAS MASON, or SUMTEB, sou'rn caaomna CONTROL MECHANISM.

Application filed March 28, 1922. Serial No. 547,594.

My invention relates to control mechanisms and particularly to mechanisms for controlling electrically-operated refrigerating machines.

, One object of my invention is to provide a device of the above indicated character that shall be simple and durable in construction and effective in operation.

Another object of my invention is to provide a control mechanism which shall be so actuated by a relatively powerful moving member and controlled by a comparatively delicate thermo-responsive or other mechanism as to ensure greater reliability and more positive action than is usual with many delicate thermo-responsive control devices. Another object ofmy invention is to proutilizing such" movement.

Another object of my invention is to provide a mecahnism for member that shall be of positions and biased in different direcits latched positions by a single means. I

lVith such objects in view, as Well as other advantages whichniay be incident to the utilization of the improvements, the invention consists in the parts and combinations thereof hereinafter set forth and claimed,

with the understanding that the several'nee type comprises condensing and expansion chambers, known as the high and low pressure sides of the machine. In a refrigerator of the rotary compressor type, a compressor, driven by an electric motor, is adapted,

to draw off evaporated refrigerant from the expansion chamber and to deliver the same to the condensing chamber in a state of high compression. lVater conducting coollVhen this shall be acoperating a controlf latched in a plurality operated refrigerating machine will be in the compressed refrigerant g tubes, in the condensing chamber, cause to so condense as to form a body of refrigerating liquid.

liquid reaches afloat valve releases some of it to the expansion chamber, pansion absorbs heat from medium.

It is desirable, machines, to have tomatically responsive to certain level. a for conduction wherein its exthe surrounding in certain refrigerating the operation thereof aucertain high and low temperature limits but, as is also known to those versed in the art, temperature respnsive mechaisms are usually delicate and not adapted to directly positively actuate Pother relatively heavy, mechanisms or parts with accuracy and precision.

It is my aim to nism that shall be provide a control mechaaccurately responsive to precise temperature limits, that shall be effeetive to operate relativelyheavy moving parts and that shall be of such simple and economical construction as to conserve space, ensure continued service and-to render more effective the operation of the machine or device controlledthereby;

In practicing ing and driven members, and compressor shafts, of a machine, as above described.

my invention, I provide a 'slip or lost motion connection between drivsuch as the motor 7 refrigerating Thedost or slip motion of this connection is utilized in the starting and stopping of the motor, to operate a switch in the motor circuit and to operate certain valves for controlling the operation of a refrigerator or other device. The operation of the switch is controlled by nism which is,

temperature changes occur.

a delicate latching mechain turn, controlled by a thermo-i-esponsive device disposed in a refrigera-tor or adjacent to other means wherein Thus, through the medium of a delicately actuated device,

a relatively heavy member may with suflicient tively actuate the same.

be supplied force to accurately and posi- In order to make the invention more clearly understood, means are shown in the accompanying drawings for carrying the same into practical effect, without limiting the improvements,

in their useful applcations, to the particular constructions, which for the purpose of explanation, are made the subject of illustration.

7 Figure 1, of the accompanying drawings, 1

r ameans 15, such as full is a semi.rdiagrammatic structural view'of a control mechanism embodying my invention, showing, structurally, the adjacent ends of driving and driven members or shafts and the lost or slip-mot-ion mechanism thereof and showing, diagrammatically, the cooperating switch, valves and thei no-responsive device therefor.

Fig. 2 is a view, partially in section and partially in elevation of the structural parts of Fig. 1, with a portion of a motor for the driving shaft shown diagrammatically,

3 is a view taken along the line Ill III of Fig. 2 and i Fig. 4: is an end view of the device shown in Fig. 2, as viewed in the direction of the arrow IV.

A control mechanism of my invention comprises, in general, a driving member or shaft 2, such as the shaft of an electric motor 5, a driven member or shaft 3, as of rotary compressor, a flexible coupling 1- for joinins the shafts 2 and 3 through a slip connection device 6 that convertstorsional slip movement between the shafts 2 V and 3 into longitudinal or axial movement with respect to the shafts, means comprisa main operating lever 7 responsive to rotative movement of the driving and driven members 2 and 3, respectively through the device 6, plurality of control devices or valves9 connected tothe lever 7, a control device or SWllLCl1111GCllfl11lSln 10, a latch device 12, a thermoresponsive device 14 and the refrigerating chamher or brine tanlr of a refrigerating device. for actuating the thermo-responsive device 14:.

oil

The movement-converting device 8 comprises a collar or ring 17 secured tothe driving shaft 2, as by a screw 18, and a collar 20 that is turnable relative to tie shaft 2 about the axis thereof. 7 H

The collars 17 and 20 are provided-in the adjacent transverse engaging surfaces thereof, with av plurality of longitudinally oppositely registering pockets or recesses 21. These pockets, being similar, are all shown only in connection with the collar 20, as more clearly illustrated in Fig. 3. Each oppositely registering pair 'of the pockets 21 adapted to so receive a ball 22 therein as to closely encompass the same when the shafts 2 and 3 are-stationary. as shown in the drawings. Each slot 21, also, slopes for a certain distance, in a direction around the shaft 2, from one end of the slot which is of a depth substantially equal to a radius of the ball 22 therein. to the surface of the ring 17 or 20 in which it is disposed. The direction of slope is determined by the .direction of rotation of the shafts and is also such, in the pockets of each pa r, that, when the shafts 2 and turn relatively, the ball therein will move toward the adjacent surfaces of the collars 17 and 20. Thus, in response to such relative turning movement, the collar 20 is moved away fromthe collar 17 along the shaft 2 until it engages a ring or plate 24 constituting a part of the flexible coupling l. 'lhe distance of movement of the collar 20 is less than the diameterof the halls 22 to prevent the latter escaping from the pockets 21. The coupling 4 further comprises a plate25 secured to the shaft 3, as

by a set screw 26 in a sleeve portion 27 thereof, and is provided with diametrically 0pposite openings 28 therethrough. A flexible disk or plate 30 disposed between the plates 24; and 25, is secured to the plate at by bolts 31 that extend, at one end, into the openings 23. The latter are sufliciently larger than the heads of the bolts 31 to permit a slight torsional movement between the plates 25 and 30. The plate 24: is provided with dianietriCally-opposite openings, not shown, similar to the openings-28 that are angularly displaced 90 from the openings 28 and in which the plates 30 and 25, are disposed.

lhe collar 20 is provided with an annular or perimetral groove or channel 33, inits outer surface and has an annular recess 34 and an annular shoulder 35 therein. A helical spring 36 surrounds the shaft 2, inthe recess 3%,and presses oppositely against the shoulder 35 and the [collar 24 to move the collar 20 against the collar 17 when the devic. comes to rest. The plate 24, turnably mounted on the shaft 2, has an annular portion 38, constituting a shoulder, which bears on the shaft 2, and a central opening in which a ring 39 is disposed. The latter, constituting an outer ball race in which balls 40 are disposed, hears against the shoulder 38 to hold he plate 2st. in position. The ring 39 and the balls lOare in turn held in position by a ring 4-11,

constituting an inner ball race, and headed screw 42 extendingcentrally into the end of the shaft 2. V

Longitudinally extending pins 44, secured. to the plate 2 project into openings 4:5 in the collar 20 that are symmetrically disposed about the shaft'2 between the groove 33 and the recess 34. V

The main operating lever 7 comprises a yoke portion 4L7 having pins 48 extending into the channel 33, on diametrically opposite sides of the collar 20, and is pivoted on a pin 49; Ehe lever 7 further comprises an arm 50 that is pivotally connected. By pins '52 and 53, to oppositely longitudinally extending links 54 and 55, respectively. The linlr is connected to operating arms or levers 56 of the control devices or valves 9. The latter, while merely illustrative of any control device that may be operated by he lever 7 may be utilized to control the water supply of a refrigerator condensing heads of bolts 32, joining the llll) chamber, to open and close the suction line between the expansion chamber and the compressor and to start and stop the flow of refrigerant from the condensing to the expansion chambers thereof.

The control mechanism or switch device 10 comprises movable and stationary contact members 58 and 59, respectively, that are connected in the circuit of the motor 5 for driving the shaft 2 or to other device.

The movable contact member 58 is preferably mounted, through a resilient arm or strip 60 and an insulating member 61, on a lever 62 that is pivoted on a pin 63. The lever 62 is provided, at one end, with oppositely inclined cam surfaces 65 and 66 and is adapted to move between stationary pins 67 and 68 adjacent to its other end.

The latch device 12 comprises a pair of pawls or dogs 70 and 71, pivotally mounted on a pin 72, that have spaced parallel arms 73 and 74 and latching arms 75 and 76, re-

spectively. The arms 75 and 76 extend, in directions,

opposite IBliItlWB overlapping from the pin 72, to positions adjacent to the limiting positions of the lever 62, to engage and latch the latter in said positions. A roller 78, mounted at the outer end of the link 54 by a pin 79, is biased against one end of the lever 62 by a spring 80 that extends between a stationary pin 81 and a pin 82 on the link 54 and constitutes energystoring means for actuating the lever '62.

The thermo-responsive device 14 comprises a container or bulb 84 disposedin a refrigerator 85 and connected, by a tube 86, to a fixed or stationary end 87 of a bellows device 88.

The bulb 84, the tube 86 and the bellows 88 constitute a closed system that is charged with methyl chloride or other suitable inaterial having a vapor pressure sensitively responsive to ten'iperature changes. A rod 90 is connected, at one end, to the longi tudinally movable end 91 of the bellows device 88 and,.at its other end, by a pin 92, to one arm 93 of a bell crank lever 94 that is pivoted to a. fixed pivot pin 96 and hasits other arm 97 screw threaded or otherwise constructed to receive an adjustable weight member 98.

In operation, the parts assume the positions shown in the drawings, when the shaft 2 is at rest. Under this condition, in a refrigerating machine, the temperature in the refrigerating chamber or brine tank 85 gradually rises and the vapor pressure of the methyl chloride increases to expand the bellows device 88. During this expansion, the rod 90 is moved to the right, and, in turn, moves the bell crank lever 94, in counterclockwise direction, against the action of the weight member 98. The latter may be adjusted along the arm 97 to cause the proper movement of the lever 94 in response to any the roller 78 to move along the cam surface 66 and to thereby move the lever 62 in the clockwise direction to engage the contact 'members 58 and 59 and to start the motor of the shaft 2. During this movement, the lever 62 engages and is latched by, the arm 75, of the pawl 70. lVhen the shaft 2 lo tates, the sloping surfaces of the pockets 21, in the collars 17 and 20, move oppositely with respect to the balls 22 and the latter force the collar 20 along the shaft 2 against the action of the spring 36. This movement causes the pin 48 in the channel 33 to move the lever 7 clockwise about its pivot pin 49 to operate the valves 9 and to move the roller 78 downwardly along the cam surface 66 and around the end of the lever 62 to position opposite the cam surface 65 thereof.

When the temperature in the bulb 84 falls to a predetermined point, the bellows device 88 contracts to move the. arm 90 to the left. This action causes the arm 93 to engage the arm 7 3 of the pawl 70 and to disengage the arm 75 from the end of the lever 62. Thus released, the lever 62 is moved counter-clockwise by the roller 78 which is moved -up Wardly, by the spring 80, against the cam surface 65.

Counter-clockwise movement of the lever 62 disengages the contact members 58 and 59 to stop the motor and to thus, cause the collar 20 to move to the left, when the shaft 2 ceases to rotate. The above actions cause the lever 62 to become again latched by the arm 76, in its left-hand position, and to move the roller 7 8 to the right, into the position shown in the drawings. The above cycle of operation may be repeated automatically in response to rise and fall of the temperature of the bulb 84.

The control mechanism of my invention is extremely simple in construction and operation, economical to i'naintain and very positive and accurate in its response to specific temperature values.

I claim as my invention:

1. In a control mechanism, the combination with driving and driven members having a slip connection therebetween, of control means, means responsive to ,relative movement of the driving and driven members for actuating said control means to operative and inoperative positions, and automatically-releasable means for locking said control means in said positions.

2. In a control mechanism, the combination with driving and driven members hav- All ing a slip connection therebetween, of control means, means responsive to relative movement of the driving and driven members for storing potential energy, and means for releasing said energy to actuate said control means. 1

A control mechanism for a refrigerating machine, con'iprising a motor shaft, a compressor shaft driven thereby, said shafts being disposed in end-to-end axial alignment having limited relative angular movement, means for controlling one of the operations of the machine, and means responsive to relative movement between the motor and compressorshafts for actuating said control means.

A control mechanism for a refrigerating machine, comprising a movable motor element, a member driven thereby having limited movement relative thereto, a switch for controlling the operation of themotor element, a latch mechanism for said switch, means responsive to relative movement between he motor and the driven member for storin energy to actuate said switch, and temperature-responsive means for releasing said latch mechanism.

5. In a control mechanism, the combination with driving and driven members having a slip connection. therebetween, of a control device, means responsive to relative movement of the driving and driven mem' bers for storing energy to actuate the control device, means for holding the control device against said sponsive means for releasing said holding means. 7

6. In a control mechanism, the combination with driving and driven members having a slip connnection therebetween, of a control device, means responsive to relative movement of the driving and driven memhers for storing energy to actuate the con trol device, means for holding the control device against said energy-storing means in a plurality of positions, and thermo-responsive means for releasing said holding means from said positions.

7. In a control mcchanisn'i, the combination with a-Xiallyaligned driving and driven shaft members having limited relative movement therebetween, of a control device, potential energy-storing means including a spring for actuating the control device, and means connected between the driving and driven members and responsive to relative movement thereof for storing energy in said storing means.

8. In a control mechanism, the combination with driving and driven members having a slip connection therebetween, of a control device, energy-storing means responsive to relative movement of the driving and driven members for actuating the control device, and thermo-responsive means for restored energy, and thermo-releasing said energy to actuate the control device.

9. In a control mechanism, the combination with driving and driven members having a slip connection therebetween, of a con trol device, means responsive to relative movement of the driving and driven mem bers for storing energy to actuate the control device, means for holding the control device against actuation by the energy-storing means, and thermo-responsive means for releasing the holding means.

10. A control mechanism for a refrigerating machine, comprising a movable motor element, a member driven thereby having limited movement relative thereto, a switch for controlling the operation of the motor element, a latch mechanism for holding said switch in its open and closed positions, means responsive to relative movement be tween the motor element and the driven member for storing energy to open and close said switch, and temperature-responsive means for releasing said latch mechanism.

11. A mechanism for controlling operation of a refrigerating machine, comprising a control member movable in reverse directions between open and closed positions means for latching the same in each of said positions, a motor and means actuated thereby for biasing the control member away from each of its latchedpositions.

12. A mechanism for controlling operation of a refrigerating machine, comprising a control member movable in reverse directions between open and closed positions, means for latching the same in each of said positions, a motor, means actuated thereby for biasing the control member away from each of its latched positions and thermoresponsive means for actuating the latching means to release the control member from each of its latched positions. I

13. In a control mechanism for a refrigerating machine, the combination with a driving motor element and a member driven thereby having limited movement relative thereto and means responsive to relative movement thereof, of a control device for direct actuation by said means, and a control device yieldably connected thereto.

14%. In a control mechanism, the combination with driving and driven members having a slip connection therebetween and a member responsive to relative movement thereof, of a control device yieldably connected to said responsive member to be alternately biased thereby in a plurality of directions, means for latching the control device in aplurality of positions, and thermo-responsive means. for releasing the latching means.

15. In a control mechanism, the combination with driving and driven members, having a slip connection therebetween and a member actuated in response to relative movement thereof, of a pivoted control arm having opposite cam surfaces, a latch device for holding the control arm in two positions, a yieldable member connected to said responsive member and adapted to engage said cam surfaces to bias the control arm away from its latched positions, and thermoresponsive means for releasing the latch de- 10 vice.

16.A control mechanism comprising a pivoted control arm having opposite cam surfaces, a double latch mechanism for l1olding the arm in two positions, means for biasing the arm away from its latched positions including a portion adapted to alternately engage said cam surfaces and thermoresponsive means for releasing the latch mechanism.

In testimony whereof, I have hereunto subscribed my name this 13th day of March, 1922.

CHARLES THOMAS MASON.

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