US2924105A - Control apparatus for use with an element having both axial and rotary motion - Google Patents

Description

. R. A. GRAHAM 2, CONTROL APPARATUS FOR USE WITH AN ELEMENT IAL AND ROTARY MOTION June 27, 1957 Feb. 9, 1960 HAVING BOTH AX Filed FIG. 2

FBG. I

INVENTOR RICHARD A. GRAHAM M JM 0 1% CONTROL APPARATUS FOR USE WITH AN ELEMENT HAVING BOTH AXIAL AND ROTARY MOTION Richard A. Graham, Mequon, Wis.

Application June 27, 1957, Serial No. 668,451

4 Claims. (CI. 74-22) This invention relates to an apparatus for controlling the movement of a movable element adapted to move with both axial and rotary motion, and more particularly to a control apparatus supported by the movable element and including a feed-back mechanism adapted to establish a signal in response to movement of the element.

The present invention is directed to a control apparatus to be supported by the movable element, such as a valve stem or the like, and includes a base or frame which is carried by the valve stem of a valve to be controlled. The frame supports a servo motor and the drive shaft of the motor is connected through suitable reduction gearing to a sleeve which is journaled within the frame. The sleeve in turn is secured to the valve stem so that rotation of the drive shaft is transmitted to the valve stem to rotate the same and control the valve.

. ted S ates Patent The motor is connected in a control circuit and is operated in either a forward or reverse direction by manual or automatic closing of the circuit to open or close the valve.

The feed-back mechanism comprises a signaling device which is supported by the frame and is connected in the same or a second control circuit. Rotation of the drive mechanism is fed back through a gear system to the signaling device to thereby establish an operating signal in the second control circuit.

According to one embodiment of the invention, the upper end of the valve stem is slidably secured within the sleeve so that the valve stem may move axially in relation to the sleeve. In this form of the invention, the frame is fixed and the valve stem moves axially with respect to the frame.

In a modified form of the invention, the upper end of the valve stem or other movable element is fixed within the sleeve so that the frame is moved in accordance with the axial movement of the valve stem. In this construction, a flexible connection is provided between the frame and an outside object by a guide rod which is slidably received in the frame.

To compensate for nonconcentricity of the rotatable element, such as the valve stem, the frame may be resiliently connected through a torque arm to an outside object.

The present invention provides a simple and inexpensive control apparatus which is readily adaptable for use with both new and existing elements to be controlled. The apparatus is extremely compact with the motor, gearing and feed-back mechanism all contained within the housing and supported by the controlled element.

Other objects and advantages will appear in the course of the following description.

The drawings illustrate the best mode presently contemplated of carrying out the invention.

In the drawings:

Figure 1 is a vertical section of the apparatus .of the invention;

2,924,105 Patented Feb. a, race "ice Fig. 2 is a transverse section taken along line 22 of Fig. l;

Fig. 3 is a view taken along line 33 of Fig. 1;

Fig. 4 is a side elevation of a modified form of the invention with parts broken away in section; and

Fig. 5 is a transverse section taken along line 55 of Fig. 4.

The drawings illustrate a control device 1 for use with a movable element having both rotary and axial movement and which includes a built-in feed-back mechanism adapted to establish a signal in response to movement of the element.

For purposes of illustration, the control apparatus 1 shown in the drawings is associated with a valve stem 2 of a conventional rising stem gate valve 3 which is adapted to control the flow of fluid passing through a pipe line or conduit 4. However, it is contemplated that the control apparatus can be employed with other elements which are adapted to have both axial and rotary motion in operation.

The control apparatus 1 comprises a generally circular base 5 which is provided with a central recess 6. A series of columns 7 are mounted on the base 5 and extend upwardly therefrom and carry a pair of spaced plates 8 and 9.

The drive mechanism for rotating the valve stem 2 comprises a conventional servo motor 10 which is mounted on the upper plate 8, and the drive shaft 11 of motor 10 extends through a suitable opening in plate 8 and is journaled therein.

Rotation of drive shaft 11 is transmitted through suitable reduction gearing to the valve stem 2 to thereby rotate the valve stem in accordance with rotation of drive shaft 11. To this end the drive shaft 11 carries a gear 12 which meshes with a gear 13 secured to shaft 14. The shaft 14 is suitably journaled between the spaced plates 8 and 9.

A second gear 15 is secured to the shaft 14 and meshes with a gear 16 carried on shaft 17. The shaft 17 is suitably journaled between the plates 8 and 9 and the lower end of shaft 17 extends downwardly through a suitable opening in plate 9 and is received Within an axial recess formed in the upper end of sleeve coupling 18. The shaft 17 is secured within the recess in sleeve 18 by set screws 19.

The lower end of sleeve 18 has a hexagonal-shaped enlargement 20 and is provided with an axial recess 21 which slidably receives the upper end of valve stem 2. The valve stem is slidably secured within the recess 21 by a key 22 which moves within a longitudinal keyway 23 formed in the periphery of the valve stem 2. With this construction, the valve stem 2 moves in and out of the recess 21 as the valve stem is rotated by the drive mechanism. In this construction shown in Fig. 1, the control apparatus itself is fixed and the valve stem 2 moves axially in relation to the apparatus.

The lower end of valve stem 2 is connected through a suitable swivel connection to valve disc 24 of gate valve 3. The valve 3 is of conventional construction and is provided with a slotted seat 25 which receives the disc.

Rotation of the drive shaft 11 is transmitted through the gearing arrangement to the shaft 17, and the shaft 17 is connected through the sleeve 18 to the valve stem 2 so that the valve stem 2 will be rotated in accordance with rotation of drive shaft 11 and shaft 17. Rotation of valve stem 2 moves valve disc 24 within the slot 25 to either open or close the valve. The number and size of the gears in the gear train will determine the ratio of turns between the drive shaft 11 and the valve stem 2 with the specific ratio of rotation between these'members being determined by the particular apparatus to which the rotatable, element, such as valve stem l, is connected.

The control apparatus of the invention includes a builtin feed-back mechanism, similar to that disclosed in the co-pending application of Charles E. Jordan, .Serial No. 665,521 filed lune 13, 1957, which is adapted to establish a control signal in response to movement of the drive mechanism. The feed-back mechanism includes a gear 26 which is secured to sleeve 18, and the gear; 26 meshes with agear 27 carried by a shaft 28.

The shaft 28 is journaled within a plate 29 which, is secured to base 5, and the lower end of shaft 28 is operably connected to, a potentiometer 30 or other variable impedance device or to a digital signal conversion device, which is disposed within recess 6 of base 5. 'With this structure, rotation of sleeve 18 is transmittedthrough the gears 26 and 27 to vary the resistance of the potentiometer 30 and thereby establish an electrical control signal. i

To resiliently support the apparatusl, the inner end of a torque arm 31 is connected by a suitablescrew to the undersurface of base5. The outer end of the torque arm 31 is resiliently connected by means of a rubber or plastic grommet 32 to the upper horizontal flange 33 of a split ring bracket 34 by a bolt 35. The spli ring bracket 31 is attached to the conduit 4 or other outside or fixed object. The resilient connection between .the apparatus and outside object, such as conduit 4, compensates for nonconcentricity in the valve stem or other element to be controlled. This connection, in effect, compensates for run-out of the shaft and permits the unit to Work.

The drive and feed-back mechanism of the apparatus are enclosed by a cup-shaped cap 36 which is suitably secured within a recess formed in the periphery of base 5.

Electrical energy is supplied to the unit by the. electrical leads, not shown, which are connected to the motor 10 and potentiometer 30 andpass through an opening in the cap 36 and through an aligned opening 37 in an angle-shaped bracket 38 which is secured to base 5. The leads are connected to the terminals on a control panel 39 supported by plate 8, and other suitable leads, not shown, connect the terminals to the motor and potentiometer respectively.

As shown in the drawings, the control apparatus is used in conjunction with the valve 3 to control the flow of fluid passing within conduit 4. In this situation, the motor is energized, either by manual actuation of a switch or by the automatic closing of a control circuit in which the motor is connected,,to open and close the valve. Rotation ofthe drive mechanism is transmitted through the feed-back mechanism to establish a signal which can be used to indicate the rate ofjflow of the iiuid in conduit-4 or to control the operation of the motor to automatically open and close the valve.

Figures 4 and show a second modified form of the invention in which the control apparatus moves with the axial movement of the valve stem rather than having the valve stem move axially in relation to the unit as inthe first embodiment.

In the embodiment shown in Figures i and 5,,the rotation of the shaft 17 is transmitted to the valvestem 2 and rotation of' the valve stem moves the same axially and correspondingly movesthe entire unit in theaxial direction; To connect the shaft 17 and valvestem 2, the valve stem is secured within an axial recess 40 formed in the lower end of sleeve coupling 41, which corresponds generally tosleeve coupling 18 of the first embodiment, by set' screw 42. "The shaft is secured within an axial opening in the upper end of coupling 41, asin the first embodiment. 7

To provide a resilient connection for-the unit, a pair of posts. 43 are secured to valve Sand are-slidably re- .ceived withinopcnings 44 formed in therecessed. portion. 6,015 base; 5. The posts .43 serve tolguide the, in-

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viding a resilient connection between the unit and a fixed object such as valve 3.

While the present disclosure is directed to the use of the control apparatus associated with a vertically disposed valve stem, it is contemplated that the unit may be applied to any rotating and linear moving element to control the action of the same. Similarly, the unit may be disposed horizontally or at any desired angle which will correspond to theposition of the element to be controlled. i

The present control device is a simple and compact unit in which the. drive mechanism and the feed-back mechanism are.both containedwithin a single housing and supported by the controlled element.

Various modes of. carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I-claim: v M

l. A control apparatus for use with a rotatablemembar with said member adapted to move axially as the same isrotated, comprising a base adaptedto be supported on the rotatable rnember, a motor carried by the base and having a drive shaft, a sle evejoiirnaled within an openingin the base, gear means connecting said drive shaft and said sleeve, means connecting said sleeve and saidrotatable. memberfortransrnitting rotation of said sleeve to the rotatable member, and means for prov iding relative axial movement between said rotatable membet and, said sleevet o permit said rotatable member to move, axially of said sleeve as said member is rotated.

2. A control apparatus for use with a rotatable member with said member adapted to move axially as the same is rotated, comprisinga base adapted to be supported on the rotatable member, amotor carried'by the base and having a drive shaft, a sleeve journaled within an opening in the base, gear means connecting said drive shaft and said sleeve, key means connecting said sleeve and said rotatable member for transmitting rotation of said sleeve to the rotatable member and'for providing relative axial movement between said rotatable member and said sleeve, an arm extending outwardly from the base, and means for resiliently securing said arm to an outsideobjectto permit movement of said apparatus with respect to said object due to non-concentricities in said rotatable member.

3. A control apparatus for use with a rotatable member with said member adapted to move axially'as the same is rotated, comprising a fixed basedisposed to be supported by'the rotatable member, a motor carried by the base and having a drive shaft, 'mea ns'for connecting the base to a fixed outside object, a sleeve journaled within an openinggin the base, gear means connecting said drive shaft and said sleeve, and key means to key the rotatable member to the-sleeve totherebytransmit the rotation of said sleeve to the 'rotatablemember and to permit axial movement of said rotatable member with respect to the sleeve. I

4. A control apparatus, comprising a frame, a rotatable member disposed to be connected to an article to be controlled with rotation of said rotatable member providing a change in condition of said article, said to tatable member; disposed to advance axially as the same is rotated, drive shaft means supported by theframe and adapted to rotate inUacc ordance with a given signal, a sleeve j o urnaled withirr an opening in the frame and having an axial opening therein disposed to slidably receive the outer end of said rotatablemember, gear. means connecting said drive shaft means and. said sleeve, and means for securing the. rotatable member Within; said axial opening in said sleeveto therebvtransmit.therotation of said drive shaft means to the rotatable. member, whereby .,.said rotatable-member will rotatein accordance with ro- 6 tation of said drive shaft means and will advance axially 1,528,594 Artrip Mar. 3, 19 25 in relation to said sleeve. 1,698,174 Sauter Jan. 8, 1929 1,990,090 Packard Feb. 5, 1935 References Cited in the file of this patent 2,005,891 Elberty June 25, 1935 UNITED STATES PATENTS 3 2,598,052 Krecan May 27, 1952 865,556 Anderson Sept. 10, 1907

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