US3555966A

US3555966A - Air cylinder with pilot valve in head

Info

Publication number: US3555966A
Authority: US
Inventors: Ignazio James Coniglio
Original assignee: Mead Specialties Co Inc
Current assignee: Mead Specialties Co Inc
Priority date: 1969-12-08
Filing date: 1969-12-08
Publication date: 1971-01-19
Anticipated expiration: 1988-01-19

Abstract

A fluid control arrangement including a cylinder having a pair of spaced heads joined by a hollow body in which a piston is mounted for reciprocal movement. A valve unit is provided in a valve bore integrally formed within at least one of the heads of the cylinder. The valve unit includes a spring-biased reciprocable valve member having a valve operator integrally formed therewith and extending into the hollow body so as to be in actuatable relation with the piston. A pair of conduit openings extend into the valve bore, and, depending upon the positioning of the valve member in the bore due to the operation of the piston, communicate with or are blocked from each other.

Description

United States Patent [72} Inventor Ignazio James Coniglio Chicago, Ill.

[2l] Appl. No. 880,468

[22] Filed Dec. 8, 1969 [45] Patented Jan. 19, 1971 [73] Assignee [54] AIR CYLINDER WITH PILOT VALVE IN HEAD f 5 Claims, 5 Drawing Figs. U [52] U.S. Cl 91/306, 137/6256, l37/624.14 [51] Int. Cl F011 25/06 [50] Field of Search 91;306;305/04001970; 137/(lnquired), 625.69

[56] References Cited UNITED STATES PATENTS 2,296,647 9/1942 McCormick 91/306 3,162,093 12/1964 Zoller 91/306 3,352,324 11/1967 Stryker l37/625.69

Primary ExaminerPaul E. Maslousky Attorney-Olson, Trexler, Wolters & Bushnell ABSTRACT: A fluid control arrangement including a cylinder having a pair of spaced heads joined by a-hollow body in which a piston is mounted for reciprocal movement. A valve unit is provided in a valve bore integrally formed within at least one of the heads of the cylinder. The valve unit includes a springbiased reciprocable valve member having a valve operator integrally formed therewith and extending into the hollow body so as to be in actuatable relation with the piston. A pair of conduit openings extend into the valve bore, and, depending upon the positioning of the valve member in the bore due to the operation of the piston, communicate with or are blocked from each other.

AIR CYLINDER WITH PILOT VALVE IN HEAD This application is a continuation of application Ser. No; 750,998 filed July I8, 1968, now abandoned, which in turn was, also, a continuation of application Ser. No. 570,075, filed Aug. 3, 1966, now abandoned. y

This invention relates generally to pneumatic control circuitry and more particularly to pneumatic control circuitry which incorporates a pneumatic or hydraulic cylinder jack and pneumatic pilot valve.

The movement of a pneumatically operated piston has heretofore been employed to actuate pneumatic pilot valve. However, in the prior art arrangements, the pilot valves have been mounted outside of the piston cylinder to be actuated, for example, by a radial projection on the exposed piston rod. Such arrangements have proved costly to install and to maintain, have resulted in congested work areas around piston rods, and have presented reliability problems. 7

An important object of the present invention is therefore to provide a pneumatic control arrangement which overcomes the foregoing limitations of the prior art.

Another object of the invention is to provide a pneumatic control system wherein one or more pilot valves are arranged to be actuated directly by the pneumatically operated piston.

Still another object of the invention is to provide a pneumatic control arrangement in which pilot valves are integrally incorporated in a pneumatic cylinder, thereby eliminating bulky appendages.

These and other objects and features of the invention will become more apparent from aconsideration of the following descriptions.

A pneumatic control arrangement in'accord with the invention includes acylinder having spaced heads and a hollow body connecting the heads. One of the heads of the cylinder is fashioned with a valve bore and with spaced pneumatic conduits opening into the bore. A reciprocable piston issituated in the cylinder, and a valve unit is located in the head having the valve bore. The valve unit itself includes a valve operator that projects from the valve bore through an inner wall portion of the corresponding head into actuatable relationship with the piston, and a reciprocable valve member is arranged in the bore to move with the valve operator (preferably being integral therewith), the valve member being provided with flow control passageway means for selectively connecting the pneumatic conduits.

In order thatthe principles of the invention may be readily understood, two embodiments thereof, but to which the application is not to be restricted, are shown in the accompanying drawing wherein:

FIG. 1 is a perspective view of a pneumatic control arrangement constructed in compliance with the invention, a portion of the piston housing being broken away to show internal details;

FIG. 2 is an enlarged, fragmentary view taken substantially along the line 2-2 of FIG. 1;

FIG. 3 is a further enlarged view taken substantially along the line 3-3 of FIG. 2;

FIG. 4 is a view similar to the showing of FIG. 3 but illustrating a modified form of the invention, differing from the arrangement of FIGS. l-3 in details of the valve unit; and

FIG. 5 is a view taken substantially along the line 55 of FIG. 4. i

In the examples of the invention hereinafter set forth the term pneumatic" is exemplary; hydraulic mechanisms and circuits are also contemplated. Referring now in detail to the drawing, specifically to FIG. I, a pneumatic control arrangement indicated generally by the numeral is seen to comprise a pneumatic cylinder I2 and

pneumatic pilot valves

14 and 16. The cylinder I2 includes a pair of spaced

heads

18 and 20 of blocklike construction which are connected by a hollow cylindrical tube or body 22 in defining a housing for a reciprocable piston 24. The piston 24 is secured on a piston rod 26 by means of a radially projectingflange 28, which may be defined by a washer, and a nut 30 which turns on a threaded inner end 32 of the piston rod 26. On its external end, the piston rod 26 carries a threaded attachment site 34 or other means for coupling the piston rod to an element which it is desired to drive. The introduction and exhaust of pressurized fluid for moving the piston 24 are achieved by

pipes

36 and 38 which are threaded into or otherwise suitably connected with the heads I8 and 20 respectively. The

pipes

36 and 38 are connected by passageways 40 into the hollow body 22. Radially outwardly of the external wall of the body 22, the

heads

18 and 20 are held rigidly against the hollow cylindrical body 22 by cylindrical rods 97.

In compliance with the features of the present invention, the

pilot valves

14 and 16 are incorporated directly in the as

sociated heads

18 and 20 to be integral therewith; and turning to a consideration of FIGS. 2 and 3, valve unit 16 comprises a valve operator 44 integral with a reciprocable valve member '46, a flow directing arrangement 48 and a biasing spring 50.

The valve operator 44 projects through a reduced diameter end portion 52 of a valve bore 53, bore 53 being fashioned in head 20 and operator 44 extending through an inner wall portion 54 of head 20 into actuatable relationship with the piston 24. In addition to the valve bore 53, the head 20 is fashioned with

pneumatic conduits

56 and 58 which open radially into the bore 53. It will be'apparent from an inspection of FIG. 3, that the

pneumatic conduits

56 and 58 are spaced longitudinally of the axis of bore 53. Conveniently, an inlet fltting 60 is mounted in communication with conduit 58, and an outlet fitting 62 is secured in communication with the conduit 56. An exhaust conduit 64 may also be arranged to open into the valve bore 53 at a different longitudinal position than either the conduit 56 or the conduit 58.

Although various means may be employed to provide ap propriate connection between the valve operator 44 and the reciprocable valve member 46, it has proved convenient and preferable to form them integrally. The valve member 46 is in the nature of a spool valve member including a cylindrical portion 66 and a spaced follower portion 68 connected thereto by a reduced diameter or necked-down region 70, region 70 forming an annular flow control passageway for selectively connecting the

pneumatic conduits

56 and 58. The valve member 46 also blocks fluid communication between the pilot valve and the main cylinder, as will be apparent hereinafter. Advantageously, the valve member 46 is drilled with a bore 72 that defines a retainer for one end of spring 50. Being a compression spring, spring 72 requires an opposing abutment, and this latter function is supplied by a plug 74 which is turned into a threaded bore 76 that is formed coaxially with the valve bore 53. Means of sealing cap 74 and head 20 to prevent fluid from escaping from valve bore 53 is pro vided.

Cooperating with the annular chamber or groove that is defined by necked-down region 70, the flow directing arrangement 48 comprises a system of alternating resilient sealing means 78, conveniently rubber O-rings, and respectively labeled from left to right as 78b, 78c and 78d, and spacing means or'ring spacers 80. Each of the spacing means or ring spacers 80 is formed with a generally U-shaped cross section with the closed end thereof disposed generally radially inwardly. In addition, each of the spacers 80 is perforated with a series of arcuate ports 82 in the floor or inner collar thereof. Thus, each of the spacers defines a radially outwardly opening groove which is communicated in the radially inward direction by means of the ports 82. In order to direct flow between the

several conduits

56, 58 and 64, one of the spacers 80 is aligned radially with each of these conduits, as is well shown in FIG. 3. Cooperatively, the axial extent or length of the necked-down region 70 is arranged to span the radial distance between immediately adjacent spacers-80.

At one extremity of its travel, piston 24 will forcibly engage the valve operator 44 to drive the same inwardly and against the compression spring 50. As the valve operator 44 moves inwardly, the necked-down region 70 moves from the position shown in FIG. 3 until its axial length spans the radial distance between the conduit 56 and the conduit 58. A fluid path will thus be formed permitting a pressurized fluid to flow, for example, from conduit 58 through the ports 82 in the spacer 80 aligned therewith, into the annular chamber defined by the necked-down region 70 and the resilient seal 78 and thence through the ports 82 in the spacer 80 aligned with conduit 56 and ultimately into the latter conduit. In this position portion 66 of the valve member engages resilient seal 780 which in turn engages bore 53, blocking flow of pressurized fluid to conduit 64. Upon retreat of the piston 24, the valve operator 44 will be released to the action of spring 50 and/or the force exerted by pressurized air on theequivalent area of the.follower portion 68 and the valve member 46 will be returned to its normal outward position shown in FIG. 3 where the necked-down region 70 communicates conduit 56 with exhaust conduit 64 and where follower portion 68 engages resilient seal 78d which in turn engages bore 53, blocking flow of pressurized air from conduit 58 to conduits 56 and/or 64. In these movements of the valve member 46, the several resilient seals 78b, 78c and 78d provide a sealing action against both the walls of valve bore 53 and the radially outwardmost surfaces of valve member 46, specifically portions 66 and 68 thereof. Cylindrical portion 66 always engages seal 7812, thereby blocking fluid communication between the pilot valve and the main cylinder. It should be recognized that the movements of piston 24 may thus be employed, through the resultant manipulations of pneumatic valve 16, to control the actuation of some other device, such as for example a related pneumatic cylinder, valve, or other device, or it may be employed in a servomechanism sense to provide information about the position of piston 24.

In accordance with a feature of the invention, the conduit 58 comprises a pressure inlet conduit as has been described hereinabove; and in further accord with the invention, the conduit 56 comprises a pressure outlet conduit between the pressure inlet conduit 58 and the inner wall portion 54 of head 20. With the pressure inlets and outlets and the exhaust conduit positioned as shown, fluid pressure from the inlet conduit 58 cooperates with the bias established by spring 50 in resisting pressurized fluid forces imposed on the valve operator 44 and the valve member 46 from within the hollow body of the cylinder 12, thus preventing movement of operator 44 from its outward position by these pressurized fluid forces.

The valve unit 14 is constructed like the valve unit 16 and operates in a similar manner.

Positioning of the

pilot valves

14 and 16 within the cylinder heads 18 and 20 profoundly simplifies the installation of a pneumatic control arrangement incorporating a pneumatic cylinder and one or more pneumatic valves. The expensive and time-consuming job of designing and installing the mounting facilities for the pneumatic valves is entirely eliminated, and the effort involved in locating a suitable place to mount a pneumatic valve is completely avoided. Furthermore, there is no need for concern over the possibility of trip points shifting due to wear or mishap, Because the entire operating mechanism of the pneumatic valve is safely housed within a cylinder head, the risk of contamination from dirt, grit and chips is virtually eliminated. Moreover, there are no complicated actuating mechanisms to wear out or deform from fatigue; the actuating force is in exact axial alignment with the movement of the valve operator; and finally, costly electrical wiring is not required. Hence, the chance of explosion or fire resulting from spark hazard is nonexistent.

In FIG. 1 the main cylinder conduits or

pipes

36 and 38 are shown schematically as extending to an external master valve 92 receiving inlet pressure as indicated. The valve is capable of alternately supplying pneumatic pressure to the ends of the main cylinder, and venting to atmosphere the nonpressurized end. The pilot valve outlets 62 also extend to the valve 92 for controlling the position thereof. This arrangement causes the piston 24 to reciprocate continuously. Although this feature is believed to be novel, it is clearly to be understood that pneumatic connections other than through the valve 92 are contemplated.

While a particular embodiment of the invention has been thus far shown and described, it will be appreciated that many modifications may be made. Therefore, and in order to enhance the understanding of the invention, a modified form thereof is shown in FIGS. 4 and 5. The form of the invention shown in FIGS. 4 and 5 is similar in some respects to the cmbodiment of H65. l--3 inclusive. Accordingly, like numerals have been used to designate like parts with the suffix letter being employed to distinguish those elements associated with the embodiment of FIGS. 4 and 5.

The valve arrangement 16a, shown in FIGS. 4 and 5, is particularly characterized by the use of a tubular sleeve 84 as a flow directing means and as a spacer for the resilient seals 78a, sleeve 84 being fixed in the valve bore 53a in stationary position. The sleeve 84 is specially provided with a precise longitudinal bore 86 as exemplified by a lapped bore. cooperatively, the valve spool operator member 460 is fashioned with similarly precise surfaces 88, typically lapped with the bore. In addition, the sleeve 84 is provided with radially opening, annular, axially spaced seal grooves 90 which receive the resilient seals 78a; and flow passage grooves 92 are alternated with the gasket grooves 90. Each of the flow passage grooves 90 includes means to effect flow from the central bore of sleeve 84 to the respective, flow passage groove 92, specifically a plurality of radial apertures 93. Furthermore, the sleeve 84 includes awall formation 94 between each of the gasket grooves 90 and the longitudinal bore 86. Desirably, an internal, annular groove 96 communicates the apertures 93 in each flow control groove radially outwardly of the cylinder of bore 86.

The resilient seals 78:: are confined compressibly between the wall of bore 53a and the walls of the gasket grooves 90, the gasket grooves being arranged to permit slight freedom of movement of the sealing means for facility in assembling the pilot valve 161: in the head 20a. The cooperating precisely

machined surfaces

86 and 88 effectuate a seal at the interface of the sleeve 84 and the outside circumference of the spool operator or valve member 46a. To preserve and promote the useful life of these precise surfaces, they are suitably hardened in manufacture.

Operation of the valve unit 16a is similar to that of the

valves

14 and 16. The spool operator configurations are identical. The spool lands 98b, 98c, and 98d correspond to the inner sealing portions of the resilient seals 78b, 78c, and 78d.

The specific examples herein shown and described are to be considered as being primarily illustrative, Various changes in structure will, no doubt, occur to those skilled in the art; and such changes are to be understood as forming a part of this invention insofar as they fall within the spirit and scope of the appended claims.

I claim:

1. A pneumatic control arrangement comprising: a housing including spaced heads of blocklike construction having mutually perpendicular faces and a hollow, cylindrically shaped body connecting said heads at first faces thereof, a reciprocable piston in said hollow body, each of said heads having a threaded bore extending thereinto from a second face opposite said first face thereof, with a complementarily threaded imperforate access plug extending into said threaded bore and closing the same to provide an internal imperforate abutment surface, and a valve bore integrally formed in said head in coaxial relation and accessible communication with said threaded bore and closed by the plug seated therein, with spaced openings each extending through certain ones of said remaining perpendicular faces at right angles to the planes thereof into said valve bore and each of said openings receiving therein a conduit for transporting air under pressure therethrough, a pilot valve unit in each of said valve bores and including annular flow directing means in a position of confinement between one end of the valve bore and an adjacent portion of the plug at the'opposite end thereof and a valve member reciprocable with said annular flow directing means, said valve member having integrally formed therewith a valve operator projecting from said valve bore through a reduced diameter end portion thereof in an inner wall portion of said head into actuable relation with said piston, said valve member being spool-shaped and including a cylindrical portion and a spaced follower portion toward the plugend of said valve bore and connected to said cylindrical portion by a reduced, necked-down portion forming an annular flow passageway for selectively connecting said conduit openings, said valve member having a central boreat least through said follower portion and compression spring means within said valve bore and said central bore, contacting said valve member at one end and said plug abutment surface at the other end thereof, said spring normally biasing said valve member in a position whereby saidvalve operator extends into said hollow body, certain ones of said conduit openings being normally blocked from each otherwhereby'upon the actuation of said valve operator by the movement of said piston within said hollow body into engagement with the former said valve member is moved correspondingly within said annular flow directing means to position said necked'down portion into communication with said certain ones of said conduit openings, thereby to allow for a flow of fluid therebetween.

2. A pneumatic control arrangementasclaimed in claim 1, wherein said annular flow directing means includes spacer means locating annular sealing rings insaid valve bore in predetermined spaced positions relative to said spaced openings and with an inner portion of the plug in proximate position ofconfinement relative to adjacent spacer means portions.

3. A pneumatic control arrangement as claimed in claim 2, wherein the plug abutment surface is within an inwardly directed annular flange thereon with the inner edge thereof in proximate position of confinement relative to adjacent Spacer means portions.

4. A pneumatic control arrangement as claimed in claim 1, wherein said annular flow directing means includes spacer means locating annular sealing rings in said valve bore in predetermined spaced positions relative to said spaced openings, and wherein the plug abutment surface is within an inwardly directed annular flange thereon with adjacent spacer means portions within said flange in the position of confinement.

5. A fluid control arrangement as claimed in claim 1, wherein first one of said conduit openings comprises an inlet and a second one of said conduit openings comprises an outlet, and wherein said valve bore further includes an exhaust opening extending thereinto and being spaced from said fluid conduit openings, said exhaust opening,through said neckeddown portion of said valve member, communicating with said outlet when said valve member is in the normal position, and being blocked from said outlet when said valve member is actuated by said piston.

Claims

1. A pneumatic control arrangement comprising: a housing including spaced heads of blocklike construction having mutually perpendicular faces and a hollow, cylindrically shaped body connecting said heads at first faces thereof, a reciprocable piston in said hollow body, each of said heads having a threaded bore extending thereinto from a second face opposite said first face thereof, with a complementarily threaded imperforate access plug extending into said threaded bore and closing the same to provide an internal imperforate abutment surface, and a valve bore integrally formed in said head in coaxial relation and accessible communication with said threaded bore and closed by the plug seated therein, with spaced openings each extending through certain ones of said remaining perpendicular faces at right angles to the planes thereof into said valve bore and each of said openings receiving therein a conduit for transporting air under pressure therethrough, a pilot valve unit in each of said valve bores and including annular flow directing means in a position of confinement between one end of the valve bore and an adjacent portion of the plug at the opposite end thereof and a valve member reciprocable with said annular flow directing means, said valve member having integrally formed therewith a valve operator projecting from said valve bore through a reduced diameter end portion thereof in an inner wall portion of said head into actuable relation with said piston, said valve member being spool-shaped and including a cylindrical portion and a spaced follower portion toward the plug end of said valve bore and connected to said cylindrical portion by a reduced, neckeddown portion forming an annular flow passageway for selectively connecting said conduit openings, said valve member having a central bore at least through said follower portion and compression spring means within said valve bore and said central bore, contacting said valve member at one end and said plug abutment surface at the other end thereof, said spring normally biasing said valve member in a position whereby said valve operator extends into said hollow body, certain ones of said conduit openings being normally blocked from each other whereby upon the actuation of said valve operator by the movement of said piston within said hollow body into engagement with the former said valve member is moved correspondingly within said annular flow directing means to position said necked-down portion into communication with said certain ones of said conduit openings, thereby to allow for a flow of fluid therebetween.

2. A pneumatic control arrangement as claimed in claim 1, wherein said annular flow directing means includes spacer means locating annular sealing rings in said valve bore in predetermined spaced positions relative to said spaced openings and with an inner portion of the plug in proximate position of confinement relative to adjacent spacer means portions.

5. A fluid control arrangement as claimed in claim 1, wherein first one of said conduit openings comprises an inlet and a second one of said conduit openings comprises an outlet, and wherein said valve bore further includes an exhaust opening extending thereinto and being spaced from said fluid conduit openings, said exhaust opening, through said necked-down portion of said valve member, communicating with said outlet when said valve member is in the normal position, and being blocked from said outlet when said valve member is actuated by said piston.