USRE26405E

USRE26405E - Molded in place rubber seat butterfly valve

Info

Publication number: USRE26405E
Authority: US
Publication date: 1968-06-11

Description

H. R. KILLIAN Re. 26,405

MOLDED IN PLACE RUBBER SEAT BUTTERFLY VALVE `lune 11, 1968 5 Sheets-Sheet l Original Filed Aug. 28, 1959 www June 1 1, 1968 H. R, K|L L |AN Re. 26,405

MOLDED IN PLACE RUBBER SEAT BUTTERFLY VALVE Original Filed Aug. 28. 1959 5 Sheets-5heet FNET June 11, 1968 H R K|| L|AN Re. 26,405

MOLDED IN PLACE RUBBER SEAT BUTTERFLY VALVE Original Filed Aug. 28. 1959 5 Sheets-Sheet 4 wxv QN. Rh,

June 11, 1968 H. R. KILLIAN MOLDED IN PLACE RUBBER SEAT BUTTERFLY VALVE 5 Sheets-Sheet 5 Original Filed Aug. 28, 1959 FNLM United States Patent O 26.405 MLDED IN PLACE RUBBER SEAT BUTTERFLY VALVE Henry R. Killian, Naperville, Ill.. assigner to Henry Pratt Company, a corporation of Illinois Original No. 3,122,353, dated Feb. 25, 1964, Ser. No. 110,165, May 1S, 196i, which is a division of Ser. No. 836.710, Aug. 23, 1959. Application for reissue Aug. 30, 1965, Ser. No. 485.676

7 Claims. (Cl. 251-306) Matter enclosed in heavy brackets [l appears in the origina! patent but forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.

This invention relates to valve structures, and a new and improved butterfly valve structure. The present application is a division of rny oopending application, Serial No. 836,710, filed August 28, 1959, now Patent No. 3,050,781, issued August 28, 1962.

Water distribution systems throughout the United States use a great many valves. Many valves are used only for the purpose of closing oft a section of distribution water main in order to make repairs or to attach additional lines to the main. Such valves are generally buried in the ground and may be operated only occasionally, sometimes years passing between the times the valve is operated, In other installations, the valves may be operated daily such as in water filtration plants. These valves have traditionally been gate valves primarily because butterily valves have not been competitively priced. It is believed that the cost of making butterfly valves, has in the past been significantly higher than the cost of making gate valves, a situation which is reversed with the present invention.

It is the primary object of this invention to make a new and improved butterfly valve structure.

Another object of the present invention is to provide means for substantially lowering the cost of manufacturing butieriiy valve structures.

Another object of the invention is to provide a novel valve structure having a resilient seat for the valve closure disc, which seat may have an increased life and effectiveness through the life ofthe Valve.

Other objects, features and advantages of the present invention will be apparent from the following description of the method and a preferred embodiment of the valve of this invention illustrated in the accompanying drawings. in which:

FIGURE l is a fragmentary elevational view of a valve made in accordance with the present invention;

FIGURE 2 is a top plan view partly in section of the valve taken substantially along the line 2 2 in FIG- URE l;

FIGURE 3 is a vertical sectional view through the valve partially broken away and enlarged, and taken substantially along the line 3-3 in FIGURE l;

FIGURE 4 is a horizontal sectional view through one of the trunnions of the valve, taken substantially along line 4-4 in FIGURE 3',

FIGURE 5 is a plan view of the valve body as prepared for receiving the resilient seat',

FIGURE 6 is a medial sectional view through the body taken substantially along the line 6-6 in FIG- URE 5;

FIGURE 7 is an end elevational view of the body shown in FIGURE 5;

FIGURE 8 is an exploded central sectional view through the mold parts and valve body preparatory to Re. 26,405 Ressued June 1l, 1968 assembly thereof for forming the resilient seat in the valve body;

FIGURE 9 is a fragmentary central sectional view through the assembly of valve body and mold parts with the press of the molding machine removed for clarity of illustration and showing the molding of the resilient seat in the valve body;

FIGURE 10 is a plan view of the assembly shown in FIGURE 9 with the top mold part removed, the gure showing the cavity for receiving the resilient material; and

FIGURE ll is a finished valve body with the resilient seat therein as removed from the mold.

The valve chosen to illustrate the invention is one intended for water service in the 150 lb. class, such valves being tested at several times 150 lbs. per square inch. The particular valve chosen is a wafer-type butterfly valve which may be inserted between flanged pipe sections which are bolted together around the annulus of the valve body. The methods employed for placing a resilient seat in the valve chosen for illustration may be followed in making butterfly valves having different types of bodies so as to be useable with pipes having different standard means of connection to the valve. For example, some pipe lines use bolted flanges, others use bell and spigot connections as well as other known connections between pipe sections into which valves may be inserted.

Referring particularly to FIGURES 1 through 4, a completed valve according to the present invention is shown. The valve body generally designated 12 is annular in form with a pair of

trunnion bosses

13 and 14 at diametrically opposite sides of the body. A central rib 15 extends around the body between the trunnion bosses. At the upper portion of FIGURES 1 and 3 there is shown the bottom of a valve operator 16 having a plate 17 resting directly upon the upper end of the trunnion boss 13. Such an operator connects directly with the valve shaft 18 extending through the trunnions, through the valve body 12 for connection with the valve disc 19 centered within the housing. Taper pins 20 are ordinarily used to secure the disc 19 to the shaft 18 so that turning of the shaft will cause the disc to turn therewith. The disc is substantially round with a relatively narrow peripheral portion except at the hubs of the disc which surround the shaft 1S. At the hubs the disc is enlarged by the

bosses

21 and 22, as shown in FIGURES l and 3. so as to accommodate the shaft 18. Each side of the disc is somewhat bowed outwardly so that the center of the disc is substantially wider or thicker than the shaft, the shaft passing through the center portion of the disc.

'the disc of the valve sealingly engages a resilient seat in the valve body. In FIGURE l the outer periphery 23 of the disc is shown in Contact with a rubber seat 24. The seat extends through the valve body and over the sides thereof to form a gasket 25 on one face 26 of the valve body and, as shown in FIGURE 3, there is a similar gasket 27 on the opposite face 28. The hubs of the disc ride against the rubber seat which is slightly flattened at

surfaces

29 and 30, respectively (FIGURE l), so that the hub contacts the seat material, as shown in FIG- URE 3.

The shaft 18 passes through the trunnions provided and are surrounded by a

sleeve bearing

31 and 32 at opposite ends of the shaft. Each sleeve bearing is preferably formed of nylon sheet material, approximately .030 inch (.762 mm.) thick. Beyond the sleeve bearings at each end of the shaft is a

pressure seal

33 and 34. At the upper end of the valve, the shaft 18 extends through the presusre seal to engage an operator for the valve and at the opposite end, a cap plate 36 is bolted by the bolts 37 to the trunnion boss 14 to enclose the end of the shaft.

In operation, the valve disc 19 rests directly upon the rubber seat 24 and its weight is carried by the seat, there being no thrust bearing on the shaft 18. The plate '36 has a vent 38 to prevent any pressure building up at the end of the valve shaft beyond the pressure seal 34. The valve opens and closes with about 90 of movement. The disc is turned between a position engaging the rubber seat throughout 360 wherein the valve is closed, to an open position 90 displaced therefrom. The periphery of the disc sweeps into and out of contact with the rubber' seat, the hubs of the disc remaining in contact with the seat at all times.

One of the advantages of the present invention is that a very accurate seat may be formed centrally in the valve body so that an accurately round valve disc will have cornplete contact throughout its periphery with the seat material. In the past, seats of a resilient character have generally been separately made and either mechanically or adhesively secured in a machine valve body. Shims and similar procedures and devices were used to fit the seat to the valve disc. The necessity of such fitting of each valve is avoided in the present invention.

Referring particularly to FIGURES through 7, the valve body for the valve chosen for illustrating the invention is shown as prepared to receive the resilient seat. The body 12 is a cast iron, or other material, member which has very little machining on its surfaces. The casting, as it comes from the mold, may have a cored hole through each

trunnion

13 and 14. These cored holes are reamed to provide a smooth bore 40 through the trunnion 13 and a similar smooth bore 41 through the trunnion 14, both bores being accurately centered on a center line through the valve body. Each bore is provided with a

counterbore

42, 43, respectively, for receiving the pressure seals about the valve shaft. The face 44 of the valve body is ground flat, its face being uppermost in FIGURE 6. The opposite face 45 is machined with the ground face on a platen so that the machining operation will result in forming a valve body of a given thickness within a relatively close tolerance. Both faces 44 and 45 may be machined to reach the same result. The trunnions are given drilled and tapped openings 46 for the reception of the plate 36 and the valve operator. The described operations are all the machining operations required on the valve body to prepare it for receiving the resilient seat. In addition, the surfaces to which the rubber material is to be bonded are appropriately cleaned to provide a good bond between the rubber and metal. The circular interior surface 47 of the valve is generally a rough cast surface which can and often contains considerable irregularities. The surface is generally cylindrical in form but may vary therefrom due to the casting procedures. 'Ihese variations will not affect the accuracy of the seat to be formed. The last operation in preparing the valve body is the drilling of a locating hole 48 in the face 46 specifically in the boss 13 extension of that face.

An alternate and presently preferred method of forming the valve body is to give the inner surface 47 a rough machining to insure that the surface is circular cylindrical within a tolerance of the order of plus or minus .010 inch` lf this is done, the rubber seat material to be placed in the valve housing may have a more uniform thickness in turn causing a more uniform hardness due to the curing of the rubber along with more uniform shrinkage of the rubber material and a dimensional stability of the seat measured between any diametrically opposite points. If the valve body, as cast, has an inner surface 47 which is circular cylindrical and centered within the body within the tolerances which would be obtained with a machined surface 47, machining operation may be omitted and the advantages thereof will still be obtained.

The placement of the seat material in the valve body is accomplished by using the valve as part of a transfer mold. Referring particularly to FIGURES 8 and 9, the prepared valve body 12a forms a part of a mold, including a lower mold part 50 and an upper mold part 5l. A locating pin 52 in mold part 50 is received in the locating hole 48 in the valve body. At the location of the pin, the valve body will be properly positioned on the lower mold 5l). Complete orientation of the valve body relative to the mold is obtained by using the reamed

openings

40 and 41 in the valve body, inserting

plugs

56 and 57 therein, to close the same and provide the desired configuration for the seat material around the valve shaft openings. The assembly of the valve body and mold parts results in the formation of a cavity which may be filled with rubber or rubber-like material to forni the valve seat.

In the description of the valve, the seat materia] has a gasket on either face and the space for the gaskets is provided by annular recesses, such as 58 and 59, in the respective mold parts. The

plugs

56 and 57 have a

smaller diameter portion

56a and 57a, respectively, which enters the enlarged portions 54a of the cross bore in the lower mold part in order to form a ring 60 of rubber material in the bores of the trunnions of the valve. This ring 60 will form a seal against the valve shaft when the shaft is inserted within the ring as assembled and illustrated in FIGURE 3. As illustrated in FIGURE 9, the assembly may be completed by threaded rod 61 which holds the plugs bottomed against the lower mold part, and the inner part of the plugs in the mold part accurately centers the valve body relative t0 the mold parts. The upper mold part 51 closes the cavity for receiving the rubber and a ring 62 thereon with bronze bearing rings 62a and 62b is intended to enter the space above the seat cavity to transfer an accurately measured amount of rubber into the cavity. The lower surface 63 is shaped to form the one side of the seat as illustrated. The mold parts contact with the valve body in metal-to-rnetal contact at the extremities of the cavity formed for the rubber material. The cavity being lled with the rubber material forms a homogeneous valve seat within the valve body.

The techniques of transferring a rubber material into a mold cavity and curing (vulcanized) the same under heat and pressure are known. In the present invention, the mold parts are treated so that the rubber material will not adhere thereto. The rubber is vulcanized in the mold, it being understood that suitable presses are used to apply pressure to the assembly of mold parts and mold body. Once the rubber material is vulcanized, the mold is disassembled and the valve body removed, the metal and rubber portions being unitary at this time. As the curing of the rubber continues in the mold, the rubber has a natural inherent shrinkage tendency. Thus, all parts df the rubber in the area of Contact with the metal valve housing produce tension n the rubber a! such interfaces.

Referring particularly to FIGURE 10, the central upstanding portion 53 of the lower mold is shown as having its smooth outer surface 55 slightly flattened at 64 and 65 to provide the flat areas for the hubs of the valve discs. The cavity C between the valve body and upstanding portion 53 of the mold is also visible. Pins 66 received in upstanding standards 71 on the lower mold part hold an upper ring plate 67 in proper position relative to the upper and lower mold portions. The raw rubber is placed between the upstanding central part 53 of the lower mold part and the ring plate 67 just prior to transfer into the cavity C. In assembly, the valve body is placed in position after which the rubber is inserted followed by the upper mold part.

The finished valve housing ready to receive the disc, valve shaft, bearings and seals, is illustrated in FIGURE ll, The inner surface 70 of the valve scat 24 is perfectly smooth and corresponds in contour to the surface 55 of the mold. It is accurately centered within the valve housing irrespective of any irregularities or roughness or variations in the rough cast valve body. The thickness of the valve seat measured radially will be non-uniform, because the outer Surface of the valve seat intimately follows the rough cast housing and is bonded thereto. The inner working surface, however, is quite smooth so that an accurately formed disc will have sealing contact with the seat throughout 360.

Referring again to FIGURE 3, the assembly is made by simply inserting a sleeve of nylon sheet or other bearing material to form the

sleeve bearings

31 and 32, the disc placed in the valve after which the shaft is inserted and pinned to the disc. The pressure seals may be of various forms and are thereafter inserted at the ends of the shaft after which the plate 36 and valve operator 16 are assembled on the ends of the housing.

Where care has been exercised in the manufacture of the valve housing so that the rubber seat has a substantially uniform thickness and hardness, the valve disc may be separately manufactured so as to have a minimum interference with the seat surface. The uniformity of the seat permits much less interference than would otherwise be possible. The immediate advantage is that the amount of torque needed to turn the disc in the valve -is much less because of the less interference, yet complete 360 of sealing between the disc is obtained with each valve coming from the assembly line.

The valve is then ready for shipment and requires no tting or handwork to insure proper operation under working pressures. It has been found that the valve of the present invention may be manufactured in the manner outlined so that the valve is fully competitive with gate valves and other valves used extensively in water service.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations are to be understood therefrom for some modifications will be obvious to those skilled in the art.

I claim:

1. A buttery valve, comprising:

a unitary valve body of unitized portions including an outer annular metal portion having a generally cylindrical centered opening therethrough, the walls of which with an inner portion of vulcanized rubber material bonded thereto form a passage fo-r uid;

the metal portion having a pair of opposite trunnions on a common center line extending across the valve body,

the walls of said valve body metal portion forming said central opening having irregularities therein;

the vulcanized rubber material having a smooth inner surface accurately centered in said metal portion in relation to said trunnions and forming a valve seating surface, said rubber material extending longitudinally of the unitary valve body in the direction of flow and substantially normal to the common center line of the trunnions so that said trunnion center line passes through the seating surface portion,

the outer portion of said rubber seat material bonded to said irregular walls and being united with said walls so as to be combined therewith throughout the contiguous area of the seat material and said metal body portion,

said seat material having a non-uniform thickness between said smooth inner surface and irregular walls due to its following said irregularities, said rubber seat material consisting of a mass of molded in place rubber material maintained in said relative position to the trunnions in said valve body metal portion;

a valve disc in said valve body having an outer edge cooperating with said valve seating surface to close the valve, and a valve shaft in said trunnions secured to said disc.

2. A butterfly valve as specified in claim 1 wherein said mass of molded in place rubber material extends into each trunnion providing a ring of resilient material integral with said mass between said shaft and the valve body in sealing contact with the shaft.

3. A butterfly valve, comprising:

a unitary valve body of unitized portions including an outer annular metal portion having a generally cylindrical centered opening therethrough, the walls of which with an inner portion of vulcanized rubber material bonded thereto form a passage for fluid;

the vulcanized rubber material having a smooth inner surface accurately centered in said metal portion in relation to said trunnions and forming a valve seating surface, said rubber material extending longitudinally of the unitary valve body in the direction of flow, said seating surface being generally circular in a plane transverse the direction of flow and located relative to said trunnions with its axis intersecting said common center line centrally between the trunnions,

4. A butterfly valve as specified in claim 3 wherein said mass of molded in place rubber material is homogeneous and extends into each trunnion `forming a ring of seat material in each trunnion, said ring being in sealing engagement with said valve shaft and `being united with said metal portion forming a part of said unitary valve body.

5. A butterfly valve as specified in claim 3 wherein said mass of molded in place rubber material and said metal portion are of wafer-like shape with portions of said mass extending over each side ofthe metal portion providing a ypair of spaced annular gaskets, one on either side of the valve body, said gasket portions having been united with said metal portion simultaneously with the rest of said molded in place seat material providing said unitary valve body.

6. A butterfly valve, comprising:

a rigid housing having a valve cavity therein,

a valve closure mounted in the housing,

means associated with the housing for fixing the position of a rubber valve seat in the valve cavity,

and a rubber valve seat vulcanized in place in the cavity in contact with the housing and adapted to receive a valve closure in predetermined position with reference to the housing,

said rubber valve seat being in tension with respect to the housing at substantially all areas in Contact with the housing.

7. A butterfly valve, comprising:

a rigid housing having a valve cavity therein,

a valve closure mounted in the housing,

means associated with the housing for fxing the position of a rubber valve seal in the valve cavity,

and a rubber valve seat vulcanized in place in [he cavily in contact with the housing and adapted to receive a valve closure in predetermined position with reference to the housing,

said rubber valve seat being in tension with respect to the housing at all areas in Contact with the housing patent.

References Cited 5 The following references, cited by the Examiner, are of `record in the patented file of this patent or the original UNITED STATES PATENTS Huntting 251-357 X 10 Phillips 251-306 Perry.

Voss 251-368 Fawkes 251-306 Alger 251-314 X Anderson et al 251-172 Saar 251-306 Young et al 251-368 Ramsey 251-306 Bennett 277-207 FOREIGN PATENTS 6/1955 Great Britain.

A. ROSENTHAL, Primary Examiner. M. CARY NELSON, Examiner.