US2086030A - Driving mechanism for valves - Google Patents

Description

July 6, 1937. H. E. HODGSON ET AL DRIVING MECHANISM FOR VALVES Filed Feb. 29, 1936 3 Sheets-Sheet l 'wwmwma July 6, 1937. H. E. HODGSON ET AL DRIVING MECHANISM FOR VALVES Filed Feb. 29, 1956 "s Sheets-Sheet 2 July 6, 1937. H. E. HODGSON ET AL DRIVING MECHANISM FOR VALVES 3 Sheets-Sheet 5 Filed Feb. 29, 1936 Patented July 6, 1937 UNITED STATES DRIVING MECHANISM FOR VALVES Howard E. Hodgson, Wauwatosa, and John L.

Defandorf, Shorewood', Wis., assignors to Cutler-Hammer, Inc., Milwaukee, Wis., a corporation of Delaware Application February 29, 1936, Serial No. 66,502

Claims. (01. 172--239) This invention relates to driving mechanisms for valves and other devices and is particularly applicable to motor driven valve operating mechanisms of the unit type.

Motor driven valve operating mechanisms have heretofore been provided with torque limit switching means for controlling valve closing operation of the motor and position limit switching means for controlling valve opening operation thereofl, Such' mechanisms are commonly provided with reduction gearing including a driving worm which is displaceable axially against the action of a spring to operate the torque limit switching means when the torque applied to the valve operating spindle exceeds a given value and the position limit switching means is usually operated from the valve operating shaft through the medium of an interposed reduction gearing.

The present invention relates to motor driven valve operating mechanisms of the aforesaid character and has among its objects to provide an improved torque limit switchingmechanism for such mechanisms.

Another object is to provide improved electrical control means for valve operating units of the aforesaid character.

Another object is to provide a valve operating unit of the aforesaid character having improved means associated therewith for effecting manual operation thereof.

Various other objects and advantages of the invention will hereinafter appear.

The accompanyingdrawings illustrate an embodiment of the invention which will now be described, it being understood that the embodiment illustrated is susceptible of modification without departing from the spirit and scope of the appended claims.

In the drawings,

Figure 1 is a schematic and diagrammatic view of a valve operating mechanism and control means therefor, embodying. the invention;

Fig. 2 is a sectional view of a valve operating unit embodying the operating mechanism shown in Fig. l;

Figs. 3' and 4 are side elevational views of the valve operating unit shown in Fig. 2;

Fig. 5 is a sectional view taken substantially on lines 5--5 of Fig. 2;

Figs. 6 and 7 are sectional views taken substantially on lines 6-6 of Fig. 2 illustrating certain adjustable parts of the valve operating unit in different positions, and

Figs. 8 and 9 are side views partly in section corresponding to Figs. 6 and 7, respectively.

Referring to Fig. 1, the invention is shown in connection with a valve operating mechanism including speed reduction gearing of the character disclosed in the patent to P. P. Dean, No. 1,708,- 941, issued April 16, 1929. Such mechanism includes a valve operating shaft I, a driving shaft 2, a planetary speed reducing gear 3 for establishing a driving connection between said shafts and a motor M operatively connected to shaft 2 through the medium of a worm wheel 4 and a worm 5. The planetary gear 3 includes a pinion 3 fixed to the driving shaft 2, a plurality of pinions 3 carried by a member 6 fixed to the valve operating shaft I and an internally toothed ring gear 3, the pinions 3 being arranged between and in mesh with the pinion 3- and ring ring gear 3. The ring gear 3 is revolubly mounted, and as is apparent restraint of said ring gear renders the planetary gear effective as a driving connection between the driving shaft 2 and valve operating shaft l, whereas release ,of said ring gear permits rotation thereof for release of said driving. shaft from said driven shaft.

The means employed for restraining the ring gear 3 includes a pivoted latch 1 adapted to co-' operate with the stop 8 fixed to said ring gear. Latch l is biased to move out of engagement with stopB by a spring 9 and is movable into engagement with said stop by a toggle l0 having an operating magnet ll associated therewith. Magnet H is connected to the supply circuit of motor M to provide for engagement of latch fl with stop 8 upon energization of the motor and rection switches l4 and IS, the former switch being provided with normally open auxiliary contacts l4 and l4 and the latter with normally open auxiliary contacts l5 As hereinafter set forth, switch l5 provides for operation of motor M in a direction to effect closure of the valve while switch l5 provides for operation of motor M in a direction to effect opening of the valve. The control means for the direction switches l4 and i5 includes a pair of position limit switches l6 and ll and a torque limit switch l8.

The position limit switches l6 and I! are biased to open position and are provided with operating cams W and H which are mounted upon a shaft l9 driven from the valve operating shaft I through the medium of reduction gearing 26. The reduction gearing 29 may be of the epicyclic type such a given limit while cam l'l is arranged to per mit opening of switch I! when said shaft is driven in an opposite direction into a given limit.

directions.

series connected switches I8 and IB and is op-v eratively connected to the worm 5 through the medium of a torque responsive device 2|. .As hereinafter set forth, the torque responsive device 2| has a. spring associated therewith for yieldingly holding worm 5 against axial movement in either direction out of a given normal position and the same is adjustable to positively lock said worm against movement out of normal position in either direction selectively and to permit axial movement of said worm in an opposite direction upon transmission of apredetermined torque. Movement of worm 5 in one direction out of normal position effects opening of switch I8, and movement thereof in an opposite direction out of normal position effects opening of switch IS.

The control means for the direction switches I4 and I5 also includes a pair of normally open start push buttons 22 and 23, a normally closed stop push button 24 and a normally closed switch 25 which is associated with a mechanism for effecting manual operation of the valve.

To provide for manual operation of the valve the member 6 which carries the pinions 3 is provided with bevel gear teeth 6 to be engaged by a pinion 6 fixed to a shaft 26 having an operating hand wheel 21 associated therewith. /Pinion 6 is normally held out of engagement with the bevel gear 6 and the shaft 26 is movable axially by hand wheel 2? to move said pinion into mesh with said bevel gear for establishment of a driving connection between said hand wheel The switch 25 and the valve operating shaft I. is associated with the shaft 26 and is adapted to be opened prior to engagement of pinion Ii into mesh with bevel gear 6 The function and operation of the aforedescribed system will now be more fully set forth. As is apparent, the switches I4 and I5 are connected to selectively establish connections between lines L L and L and the motor M which provide for operation of the motor in opposite However, such connections are always arranged so that switch I4 provides for operation of motor M in the direction required to eifect closure of the valve, and switch I5 provides for operation of said motor in the direction required to effect opening of the valve. Also the torque responsive device 2| is adjusted to suit the direction of operation required to effect closure of the valve. If worm 5 tends to move in the direction of arrow A during closure of the valve, the torque responsive device 2| is adjusted to positively lock the same against movement out of normal position in the direction of arrow B, whereas if worm 5 tends to move in the direction of arrow B during closure of the valve said tgrque responsive device is adjusted to positively lock the same against movement out of normal position in the direction of arrow A. In the system illustrated it is assumed that limit switch I6 opens prior to seating of the valve, and that limit. switch I! opens at the instant the valve moves into full open position.

Assuming that the valve is in open position, closure of push button 22 establishes an energizing circuit for switch I4 extending from line L through stop push button 24, through switc 25 and push button 22, to and through the oper I ating winding I4 by conductor 30 through lim't switch I6 and by conductor 3| to. line L Up n closure of switch I4, motor Misenergized to operate in a direction to eifect closure of the valve, and immediately upon energization of the motor 'the valve operating shaft I.

magnet II is energized to move pawl 1 into engagement with the stop -8 on ring gear 3 to establish a driving connection between shaft 2 and Upon response of switch I4 the auxiliary contacts I4 thereof close and establish a shunt circuit around the start push button 22 whereby the operating winding H is maintained energized upon release of push button 22. Also upon response of switch I4 a second maintaining circuit therefor is established extending from line L through stop push button 24, switch 25 and auxiliary contacts I4 to and through the operating winding I4 by conductor 32 through the torque limit switch I8 and by conductor 33 through auxiliary contacts I4 to line L As hereinbefore stated, limit switch I6 opens prior to seating of the valve and. upon opening thereof switch I4 is maintained energized by the aforedescribed maintaining circuit extending through the torque limit switch I8. Upon seating of the valve the torque transmitted to the valve operating shaft I increases and upon transmission of a given torque, worm 5 moves against the action of the torque responsive device 2| in the direction of arrow A or arrow B, as the case may be, to open one of the sets of contacts of the torque switch I8. The aforedescribed maintaining circuit for switch I4 exit should be noted that the aforedescribed malntaihing circuit for switch I4 extending through 7 said switch is not reclosed due to opening of the auxiliary contacts I4 .and I4. Also since the position limit switch I6 is in open position the energizing circuit for switch I4 cannot be reestablished by push button 22. Thus upon seating of the valve, motor M cannot be restarted in its closing direction.

Assuming that the valve is in closed position,

"depression of push button 23 establishes an energizing circuit for switch I5 extending from line L through stop push button 24, through switch 25, through push button 23 to and through the operating winding I5, by conductor 34, through limit switch I! which is now in closed position, and by conductor 3| to line L Upon closure of switch I5 motor M is energized to operate in a direction to efiect opening of the valve and magnet I I is energized to move pawl I into engagement with stop 8 toestablish the driving connection between driven shaft 2 and the valve operating shaft I. As hereinbefore stated, the torque responsive device 2| is adjusted to positively lock worm 5 against movement out of normal position during opening of the valve, and a positive drive is therefore provided between motor M and the valve operating shaft I to insure unseating of the valve under the action of the hammer blow which is imparted tothe valve operating shaft upon engagement of latch I with stop 8 on ring gear 3. Upon closure of switch I5 the auxiliary contacts I5 thereof shunt the push button 23 to ma ntain the aforedescribed energizing circuit for the Winding I5 upon release of said push button. Upon movement of the valve into open position limit switch l1 opens to interrupt the aforedescribed energizing circuit for winding I5. Switch I then drops out to deenergize motor M and to also deenergize the magnet II for substantially instantaneous interruption of the driving connection between shafts 2 and I.

In the system illustrated it is assumed that limit switch l6 opens prior to seating of the valve,

I! is adjusted to open prior to seating of the' valve and limit switch I 6 is adjusted to open when the valve moves-into full open position. Also conductor 30 is connected to limit switch I! and 1 conductor 34 is connected to limit switch l6 to provide for control of switch l4 by limit switch 11 and for control of switch l5 by limit switch l6.

In connection with the foregoing it should be noted that opening of push button 24 or switch 25 disconnects the operating windings of both of the direction switches I4 and I5 from line L Thus push button 24 provides for stopping of the driving motor at any time during valve opening or closing operations and the switch 25 prevents operation of the driving motor upon movement of pinion 6 into mesh with bevel gear 6 for establishment of the driving connection between hand wheel 21 and the valve operating shaft I.

It should also be noted that since latch 1 is released from ring gear 3 when motor M is deenergized, the driw'ng connection between shaft 2 and the valve operating shaft I .will be interrupted during manual operations;

Referring now to Fig. 2, the same illustrates a theworm gear 4 and speedreduction gearing termediate the ends of a shaft 31 and said shaft is supported adjacent opposite ends of said worm by roller-bearings 3B and 39 mounted within openings in walls 40'and 4| within casing 36. The roller bearings 38 and 39 are of a type permitting axial movement of the shaft 31 in opposite directions out of the normal position shown in Fig. 1 a'ndthe right hand end of said shaft is connected to the shaft of motor M by a slidable coupling 42. Coupling 42 includes an internally splined sleeve 43 and a pair of toothed members 44 and 45engaging the splines within said sleeve, the former member being fixed to shaft 31 and the latter being fixed to the shaft of motor M.

The torque responsive device 2| is associated withthe left hand end of shaft 31 and is mounted within a hollow cylindrical projection 46 on casing 36. The left hand end of shaft 31 has a ball bearing 41 mounted thereon, the inner race of .said bearing being fixed to said shaft and the outer race thereof having thrust collars 48 and 49 fixed thereto. Said thrust collars are held in assembled relation on the outer race of ball bearing 41 by rivets 50 and the same are formed to hereinafter described. The thrust collars 48 and 49 are located between two stop members 52 and 53, the former stop member being fixed to the right hand end of a cylindrical sleeve 54 and the latter being slidable within said sleeve. The left hand end of sleeve 54 is internally threaded to receive a screw adjusting cap 55 and said sleeve contains a helical spring 56 which is held under compression betweensaid cap and the stop member 53. The outer end of casing projection 46 is internally threaded to receive a threaded ring member 51 and the left hand end of sleeve 54 is slidably mounted within the opening in said ring member while the right hand end thereof is slidably mounted within a bored opening in an inwardly extending flange 58 on the interior of casing projection 46.

As shown in Figs. 6 and '7, stop member 53 is provided with oppositely disposed stop projections 59-59 which extend outwardly through oppositely disposed slots 6060 in sleeve 54 and normally engage the left hand face of flange 58.

'The sleeve 54 is provided with an outwardly projecting flange 6| and the left hand face of said flange normally engages ring member 51 while the right hand face thereof is provided with oppositely disposed recesses 62-432 which are in alignment with the stop projections 59. The stop projections 59 and flange 6| also cooperate with a pair of oppositely disposed inwardly extending stop projections 63-63 on the interior of casing projection 46.

Sleeve 54 is rotatable within casing projection 46 and is adapted to be locked in different angular positions within said casing projection by a removable round headed screw 64 threaded into ring member 51. As shown in Fig. 4, the outer surface of sleeve 54 is provided with grooves 65 and 66 and the head of screw 64 is adapted to engage within either of said grooves to lock said sleeve in different angular positions corresponding to lines C and CC.

With sleeve 54 locked in the angular position corresponding to line C, (Fig. 4) the recesses 62 in flange 6i and the stop projections 59 on stop member 53 are angularly aligned with the stops 63 on casing projection 46 as shown in Figs. 6 and 8. The stop projections 59 on stop member 53 are then located between the right hand face of flange 58 and the left hand faces on stop projections 63. Stop member 53 is thus locked against axial movement in eitherdirection out of normal position and since recesses 62 are aligned with stop projections 63 the sleeve 54 is movable out of normal position towards the right with respect to stop member 53 against the action of spring 56. The worm 5 is thus positively locked against axial movement towards the left out of normal position by engagement of thrust collar 48 with stop member 53. However. when worm 5 tends to move towards the right, thrust collar 49 engages stop member 52 and tends to move sleeve 54 towards the right against the action of spring 56. Spring 56 normally holds sleeve 54 in the position shown in Fig. 2, but upon transmission of a given torque said sleeve and worm move out of normal position against the action of said spring.

With the sleeve 54 locked in the angular position corresponding to line C-CpFig. 4, the stop projections 59 on member 53 and the recesses 62 in flange 6| are out of alignment with the stop projections 63 on casing projection 46 as shown in Fig. 7. As is apparent from Fig. 9, sleeve 54 is then looked against axial movement out of normal position towards the leftbyring member 55 and towards the right by the stops 63. However,.the stop member 53 is movable towards the left against the action'of spring 56. The worm 5 is thus positively locked against movement to: wards the right out of normal position by engagement of thrust collar 49 with the stop 52.

However, when worm 5 tends to move towards the left, thrust collar 48 engages thrust member 53 and tends to move said stop member towards the left against the action of spring 56. The spring 56 normally holds stop member 53 in the position shown in Fig. 2 but upon transmission of a given torque worm 5 and stop member 53 move towards the left out of normal position against the action of said spring.

As shown in Fig. 3, thetorque limit switch I8 and the position limit switches I6 and H are mounted upon a wall 65 associated with casing 36. Each of the switches 18 and I8 shown in Fig. 1 includes a movable contact 66 and a pair of cooperating stationary contacts 61 and 68. The two pairs of stationary contacts 61 and 68 are mounted upon opposite sides of an insulating base 69 fixed to the wall 65 and the movable con-.

tacts 65 are yieldingly mounted upon opposite sides of an insulating base having its upper of the torque limit switch are normally in en-,

gagement with their copperating stationary contacts B1 and 68. However, upon movement of worm 5 out of normal-position towards the right under the action of a predetermined torque the thrust collar 48 engages pin "I3 on lever 12 and shaft II and the insulating base 10 are then rotated in a counter-clockwise direction to disengage the right hand movable contact 66 from its cooperating stationary contacts. On the other hand, upon movement of worm 5 towards the left out of normal position the collar 49 engages pin 13 on lever 12, and shaft II and insulating base 10 are then rotated in a clockwise direction to disengage the left hand movable contact 66 from its cooperating stationary contacts.

What we claim as new and desire to secure by Letters Patent is:

1. In a valve operating system, in combination, a valve drive shaft, a driving motor therefor, driving connectionsbetween said motor and said shaft including a part yieldingly held in a given normal position and movable out of such position in response to a predetermined torque during operation of said motor in a direction jo efiect closure of the, valve, means for starting said motor in opposite directions selectively, a torque upon operation of said valve drive shaft into a given limit in its valve closing direction and to also prevent restarting of said motor in valve closing direction.

driven thereby, a driving connection between said motor and said member including an element tending to move in one direction out of a given normal position upon operation of said motor in one direction, and in an opposite direction out of said normal position upon operation of said motor in an opposite direction, a spring associated with said element, a mechanism adjustable to selectively lock said element against movement in either direction out of normal position and to render said spring operative to oppose movement of said element in an opposite direction out of normal position, and control means for said motor including a limit switch operable upon movement of said element out of normal position to effect stopping of said motor..

3. In a power transmission mechanism, in combination, a reversible motor, a member to be driven thereby, gearing interposed between said motor andsaid member including a worm driven by said motor, and torque responsive means associated with said worm for effecting stopping of said motor, said means including an adjustable "mechanism for locking said -worm against movement out of a given normal position in opposite directions selectively, and a single spring associated with said mechanism for yieldingly holding said worm against axial movement in either direction out of normal position upon looking thereof against movement in an opposite direction out of normal position.

4. In a valve operating device, in combination,

a reversible motor, a valve operating shaft, gearmeans for biasing said stop members to yield-' ingly hold said worm in normal position, and control means for said motor including means for stopping the same upon movement of said worm out of normal position against the action of said spring means.

5. In a valve operating device, in combination,

a reversible, motor, a valve operating shaft, gearing interposed betweensaid motor and said shaft including a worm driven by said motor, an enclosing casing for said gearing, an adjustable torque responsive device interlocked with said casing, said device being adjustable with respect to said casing to lock said worm against axial movement out of a given normal position in opposite directions selectively, and having a spring associated therewith whichacts upon locking of said worm against axial movement in either direction out of normal position to oppose movement of said worm in an opposite direction out of normal'position, and a switch associated with said torque responsive device for stopping said motor upon axial movement of said worm out of normal position in either direction against the action of saidspring.

HOWARD E. HODGSON.

JOHN L. DEFANDORF.

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