US3339582A

US3339582A - Chromatographic switching valves

Info

Publication number: US3339582A
Application number: US474354A
Authority: US
Inventors: Edwin L Karas
Original assignee: Foxboro Co
Current assignee: Schneider Electric Systems USA Inc
Priority date: 1965-07-23
Filing date: 1965-07-23
Publication date: 1967-09-05
Anticipated expiration: 1984-09-05
Also published as: GB1094968A

Description

Sept. 5, E L. KARAS CHROMATOGRAPHIC' SWITCHING VALVES Filed July 25, 1965 2 Sheets-Sheet 2 INVENTOR. EDWIN L. KARAS DOM 2% ATTORNEY "of the invention; and

United States Patent 3,339,582 CHROMATOGRAPHIC SWITCHING VALVES Edwin L. Karas, Sharon, Mass., assignor to The Foxboro Company, Foxboro, Mass., a corporation of Massachusetts Filed July 23, 1965, Ser. No. 474,354

Claims. (Cl. 137624.13)

ABSTRACT OF THE DISCLOSURE A chromatographic switching valve employs a rotatable cylinder with a compression spring therein each end of which urges respective combinations including a resilient body and rotatable member against abutting faces of respective stationary members so that channels in each rotatable member selectively bridge passages in said respective stationary members.

This invention relates to valves and, more particularly, to actuated valves suitable for switching chromatographic columns.

The present invention provides means for chromatographic column switching having necessary characteristics of precision, durability, as well as being failsafe. The illustrated embodiment employs a group of four switched passages; alternate adjacent passages are inter-connected in turn by rotary switching means. The invention may be adapted to switch fewer or more passages by employing the means thereof.

It is an object of this invention to provide a rotary chromatographic switch having a simple actuating means capable of long-term operation without losing count or nus-switching.

It is another object of this invention to provide a rotary switch actuated directly by electrical and mechanical means.

:1 "It is another object of this invention to provide a rotary switching means having provision for wear compensation jdis mantled for inspection or repair, without tools and 1 without uncoupling tube connections.

It is another object of this invention to provide a chromatographic switching valve having minimum side -capacity for fluids.

It another object of this invention to provide a chromatographic switching valve which may alternatively .be utilized as a vapor sampling valve.

It is another object of this invention to provide explosion-proof chromatographic switching means capable vof operation in all types of environments.

These and other features of the invention will become apparent-from the following detailed description thereof,

ftak'en 'in conjunction with the several figures in the drawing, in which:

FIGURE 1 is a cross-sectionalview of an embodiment FIGURE 2 is a view of the invention at right angles to the plan of FIGURE 1, showing some of the operating elements in an exposed depiction thereof.

Referring now to FIGURE 1, valve body 10 is fitted at opposing parts thereof with bearings 11 and 12 having Patented Sept. 5, 1967

balls

15 and 16, thereby exerting force on said

balls

15 and 16, tending to increase the spacing between them.

Metal balls

15 and 16, in turn, are centered in

washers

17 and 18 disposed at right angles to the axis of cylinder 13, thereby causing pressure to be exerted through

washers

17 and 18, against rubber discs 19 and 20, adjacent thereto. Rubber discs 19 and 20 tend to exert an equalized pressure over the contacting surfaces thereto of Teflon

glands

21 and 22.

Teflon glands

21 and 22 are locked in the direction of rotation of valve cylinder 13 by means of locking alignment clips 9, the latter shown in FIGURE 2. In this manner, the combination stack of compression spring 14,

balls

15 and 16,

washers

17 and 18, rubber discs 19 and 20, and Teflon

glands

21 and 22 are actually axially disposed within the interior of valve cylinder 13, rotating in alignment with the body of valve cylinder 13. Thereby, rotation of the

glands

21 and 22 produces relative movement of passages 21a and 21b in gland 21 and passages 22a and 22b in gland 22.

Valve seat 23 is compressed against the outwardly disposed surface of gland 22 by means of screw cap 24,

coupling onto threads of valve body 10. Valve seat 23 contains four ports, 23A, B, C, D, brought therethrough to its face compressed against gland 22. These ports 23A, B, C, D connect to passages 25A, C, D, which exit from valve seat 23 through a center hole 24A, provided for exit means in the center of screw cap 24. Valve seat 23 is aligned with valve body 10' by means of locating pin 26, in order to obtain the desired correspondence between ports 23 and passages 22A and 223 in gland 22.

Referring to FIGURE 2, valve cylinder 13 has four index pins, 27A, B, C, D, axially aligned and alfixed to its exterior, providing means for lip 28A of plunger hook 28 to catch, where-by plunger hook 28 is enabled to cause valve cylinder 13 to turn with the movement of hook 28. Plunger hook 28 is flexibly fastened to solenoid 29 by screw 30. Washer 31 and positioning spring 32 operate to tend to position plunger hook 28 parallel to the direc- 50 tion of solenoid 29 movement. By this means, each stroke of solenoid 29 pulls hook 28 flexibly attached thereto and pin 27A of valve cylinder 13 taut in lip 28A of hook 28, thus turning valve-cylinder 13 a, quarter turn. As noted,

valve glands

21 and 22 turn in synchronism with the body of valve cylinder 13. Upon magnetic release of solenoid 29, the return spring 33 pushes solenoid 29 back toward its non-actuated position and hook 28 is permitted by its flexible connecting washer 31, and positioning spring 32 to flex over the body of valve cylinder 13, riding away from pin 27A to apoint where hook 28 has its lip 28A reach past the next pin 27B in sequence, catching pin27B by the constraining action of positioning spring 32. The next successive actuation of solenoid 29 then causes valve cylinder 13 to rotate another one-quarter turn, repeating the sequence of plunger actuation and release.

Gland 22 contains passages 22A and B, having dimensions calculated to bridge the distance between two adjacent ports in Valve seat 23. If the ports are numbered in rotational sequence, 23A, B, C, D, passage 28A bridges 23A and 23B while

passage 22B bridges

23C and 23D. Upon a quarter-turn rotation of gland 22, the passages are moved in a rotational direction relative to ports 23 and thereafter bridge ports 23B and 23C in one pair and also

bridging ports

23D and 23A in another pair. The next quarter-turn rotation of gland 22 and its passages therein next bridges ports 23A and 23B by means of passage 22B and

bridges ports

23C and 23D by means of passage 22A. In this manner, each successive quarter turn of gland 22 bridges pairs of ports not bridged the previous quarter turn cycle, alternating the pairs of :ports connected together each operation of the solenoid 29.

Gland 22 is made of Teflon, which conforms to the face of valve seat 23 under the pressure exerted upon it by rubber disc 20. The rubber disc 20 acts like a fluid in transmitting pressure from washer 18 to gland 22 and thereby tends to uniformly deform gland 22 in the direction of the valve seat 23 face. In this manner, the Teflon surface against the valve seat 23 face is sealalbly conformed thereto over the entire contacting surface. Any wear or deformity otherwise tending to contribute to a misfit and loss of seal between gland 22 and valve seat 23 is compensated by the distributed pressure against gland 22 deforming it to a complete seal throughout each point of contact with seat 23.

Valve body is held to the solenoid body 34 by means of retaining ring 35 and coupling ring 36. The plunger 29 is actuated by solenoid coil 37, having leads 38A and 38B thereto, leading from the base aperture 39 of solenoid body 'base 34A. Plunger 29 runs in collar 40 and solenoid subassembly 41, which are mated together by exterior threads thereon at the interior of solenoid body 34. Rubber gasket 42 prevents vibrational unthreading of subassembly 41.

The assembly consisting of solenoid body 34, solenoid body base 34A, coil 37, and gasket 42 may be threaded into suitable mating threads in an explosion-proof housing (not shown) so that leads 38 emerge inside said housing. Said assembly then serves as an explosion-proof seal, enclosing the solenoid coil 37 and leads 38 within said explosion-proof housing, while the remainder of the valve may be exposed to combustible atmospheres without danger of causing ignition of said atmosphere. The valve body assembly including the components located within valve body 10 and caps 24 may be removed from the solenoid body 34 by means of unfastening coupling ring 36. This removal allows plunger 29 to be withdrawn. In this removed condition, the solenoid body assembly is retained in explosion-tight seal with said explosion-proof housing, permitting valve maintenance without the delay caused by observing safety regulations pertaining to the opening of said explosion-proof housing.

By uncoupling caps 24 and removing valve seats 23, said removal of the valve body assembly may be accomplished without uncoupling the tubing connection (not shown) attached to passages 25. This procedure allows inspection or replacement of said lvalve body assembly or parts therein without the use of tools.

While there has been shown what is considered to be a preferred embodiment of the invention, it will be manifest that many changes and modifications may be made therein without departing from the essential spirit of the invention. It is intended, therefore, in the annexed claims, to cover all such changes and modifications as fall within the true scope of the invention.

What is claimed is:

1. A rotary switching valve comprising:

a stationary member having a working face with passages extending therethrough and terminating at the surface of said working face,

a rotatable member having a complementary face adapted to sealably abut against said working face and having at least one channel therein bridging selected portions of said complementary face so that relative rotation of said complementary face to said working face in the plane of the abutting faces periodically form a bridging connection of a pair of said passages by a said channel,

a resilient body bearing against said rotatable member at portions thereof opposed to said complementary face,

pressure means consisting of a compression spring urging said resilient body against said rotatable member thereby obtaining a uniform seal between said abutting faces,

holding means being a cylindrical member enclosing said rotatable member and said resilient body and said spring for axially aligning said resilient body and said rotatable member,

means for keying said rotatable member to said holding means in angular alignment so that rotation of said holding means results in rotation of said resilient body and said rotatable member, and

actuation means for periodically rotating by a predetermined amount said holding means thereby causing said rotatable member to turn its complementary face relative to said working face of said stationary member.

2. The rotary switching valve of claim- 1 wherein said rotatable member consists essentially of a fluorocarbon resin and said resilient body is comprised essentially of an elastomer.

3. The rotary switching valve of claim 1 wherein a first end of said spring urges a first resilient body against its respective first rotatable member and the opposite end of said spring urges a second resilient body against its respective second rotatable member with keying of said first and second rotatable members to said cylindrical member for rotation therewith, whereby said spring is held compressed within said cylindrical member between said first and second resilient bodies.

4. The rotary switching valve of claim 1 wherein said holding means is a cylindrical member having a set of catches axially aligned therewith about the circumference of said cylinder, and

wherein said acutating means includes a solenoid operated hook having its lip adapted to engage each of said catches in turn said hook being flexibly mounted to the solenoid body so that said lip may flexibly ride over and engage one said catch upon solenoid de-activation and said lip may pull said catch thus turning said cylinder a predetermined amount upon solenoid activation whereby said passages and said channels are positioned in predetermined relationships.

5. A rotary switching valve comprising:

a valve body rigidly mounted to a valve mount having a substantially planar working face with passages extending through said valve body and terminating at the surface of said working face,

a rotatable valve gland consisting essentially of a fluorocarbon resin having a substantially planar complementary face adapted to sealably abut against said working face and having at least one channel therein bridging a portion of said complementary face so that relative rotation of said complementary face to said working face in the plane of the abutting faces periodically forms a bridging connection of a pair of said passages by a said channel,

a resilient body consisting essentially of an elastomer bearing against said rotatable valve gland over a surface opposite said complementary face thereof,

pressure-transmitting means for urging said resilient member against said rotatable valve gland so that pressure is uniformly distributed over said surface opposite said complementary face of said valve gland,

a member having opposed convex ends one end contacting the center of said pressure-transmitting means,

a helical spring having one end cupping the other convex end of said member thereby urging said member against said pressure-transmitting means,

a hollow cyl nder rotatably mounted to said valve mount for holding said valve gland and said resilient body and said pressure-transmitting means and said member and said spring in series axial alignment within said cylinder,

and keying means angularly aligning said valve gland with said cylinder whereby rotation of said cylinder results in rotation of said complementary face of said valve gland relative to said working face'of said valve body.

6. The rotary switching valve of claim 5- wherein said valve gland consists essentially of a fluorocarbon resin and said resilient body consists essentially of an elastomer.

7. The rotary switching valve of claim 5 wherein said valve gland consists partly of a fluorocarbon resin and partly a filler therefor.

8. The rotary switching valve of claim 5 with actuation means for periodically rotating said cylinder at predetermined amount including a solenoid operator having a hook extension adapted to engage in turn each of a set of protuberances disposed about said cylinder said hook being flexibly mounted to the solenoid operator so that it flexes over a said protuberance upon solenoid de-activation thereby being in an engaging position for pulling a said protuberance a predetermined amount upon solenoid activation, said protuberance being disposed to result in selective angular registration of said abutting faces.

9. A rotary switching valve comprising:

valve mounting means,

a hollow cylinder rotatably attached to said mounting means,

a helical compression spring within said cylinder axially aligned therewith and substantially centered therein,

generally spherical members within said cylinder located either end of said helical spring each having a portion in cupped contact with a said end,

pressure-transmitting discs having a diameter slightly smaller than the bore of said cylinder each having a centered indentation respectively contacting and cupping said spherical members at portions thereof op posite said portions cupped by said spring,

elastomer discs within said cylinder having a diameter slightly smaller than said cylinder bore respectively contacting said pressure-transmitting discs at surfaces thereof opposite surfaces contacting said spherical members,

substantially round and disk-shaped valve glands within said cylinder having a diameter slightly smaller than said cylinder bore respectively contacting said elastomer discs at surfaces thereof opposite surfaces contacting said pressure-transmitting discs and having planar faces disposed opposite said elastomer discs,

valve bodies each having a planar working face contacting said planar faces of valve glands fixed to said valve mounting means so that said spring is held in compression by said valve glands and said elastomer discs and said pressure-transmitting discs and said spherical members in series and the face of each said valve gland sealably abuts the face of a respective valve body, and

keying means to align said valve glands angularly with said cylinder so that rotation of said cylinder causes rotation of said planar faces of said valve glands against said planar working faces of said valve bodies.

10. The rotary switching valve of claim 9 with actuation means for periodically rotating said cylinder a predetermined amount including a solenoid operatotr having a hook extension adapted to engage each of a set of protuberances disposed about said cylinder said hook being flexibly mounted to the solenoid operator so that it flexes over a said protuberance upon solenoid de-activation thereby being in an engaging position for pulling a said protuberance a predetermined amount upon solenoid activation,

said protuberances being disposed to result in selective angular registration of said abutting faces.

References Cited UNITED STATES PATENTS 802,948 10/ 1905 Waterman 251--230 X 2,233,192 2/1941 Armington 137625.46 X 3,131,706 5/1964 Harban 137-62546 X 3,203,249 8/1965 Jentzsch 251 X 3,223,123 12/1965 Young 137625.46 3,286,730 11/1966 Beck 137-625.21

ALAN COI-IAN, Primary Examiner.

Claims

1. A ROTARY SWITCHING VALVE COMPRISING: A STATIONARY MEMBER HAVING A WORKING FACE WITH PASSAGES EXTENDING THERETHROUGH AND TERMINATING AT THE SURFACE OF SAID WORKING FACE, A ROTATABLE MEMBER HAVING A COMPLEMENTARY FACE ADAPTED TO SEALABLY ABUT AGAINST SAID WORKING FACE AND HAVING AT LEAST ONE CHANNEL THEREIN BRIDGING SELECTED PORTIONS OF SAID COMPLEMENTARY FACE SO THAT RELATIVE ROTATION OF SAID COMPLEMENTARY FACE TO SAID WORKING FACE IN THE PLANE OF THE ABUTTING FACES PERIODICALLY FORM A BRIDGING CONNECTION OF A PAIR OF SAID PASSAGES BY A SAID CHANNEL, A RESILIENT BODY BEARING AGAINST SAID ROTATABLE MEMBER AT PORTIONS THEREOF OPPOSED TO SAID COMPLEMENTARY FACE, PRESSURE MEANS CONSISTING OF A COMPRESSION SPRING URGING SAID RESILIENT BODY AGAINST SAID ROTATABLE MEMBER THEREBY OBTAINING A UNIFORM SEAL BETWEEN SAID ABUTTING FACE, HOLDING MEANS BEING A CYLINDRICAL MEMBER ENCLOSING SAID ROTATABLE MEMBER AND SAID RESILIENT BODY AND SAID SPRING FOR AXIALLY ALIGNING SAID RESILIENT BODY AND SAID ROTATABLE MEMBER, MEANS FOR KEYING SAID ROTATABLE MEMBER TO SAID HOLDING MEANS IN ANGULAR ALIGNMENT SO THAT ROTATION OF SAID HOLDING MEANS RESULTS IN ROTATION OF SAID RESILIENT BODY AND SAID ROTATABLE MEMBER, AND ACTUATION MEANS FOR PERIODICALLY ROTATING BY A PREDETERMINED AMOUNT SAID HOLDING MEANS THEREBY CAUSING SAID ROTATABLE MEMBER TO TURN ITS COMPLEMENTARY FACE RELATIVE TO SAID WORKING FACE OF SAID STATIONARY MEMBER.