CA2179851A1 - Automatic return mechanism for quarter turn valves - Google Patents
Automatic return mechanism for quarter turn valvesInfo
- Publication number
- CA2179851A1 CA2179851A1 CA 2179851 CA2179851A CA2179851A1 CA 2179851 A1 CA2179851 A1 CA 2179851A1 CA 2179851 CA2179851 CA 2179851 CA 2179851 A CA2179851 A CA 2179851A CA 2179851 A1 CA2179851 A1 CA 2179851A1
- Authority
- CA
- Canada
- Prior art keywords
- valve
- end portion
- rack
- chamber
- housing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Landscapes
- Mechanically-Actuated Valves (AREA)
- Valve Device For Special Equipments (AREA)
- Non-Deflectable Wheels, Steering Of Trailers, Or Other Steering (AREA)
Abstract
An automatic return mechanism for valves, such as quarter turn valves, including a body having a flow passage, a valve member rotatably mounted in the flow passage and movable between open and closed positions and a stem connected to the valve and having an outer portion accessible from the exterior of the valve body.
The return mechanism has an elongated housing defining an elongated chamber, a drive shaft rotatably mounted in the housing and having one end operably connected to the outer end portion of the valve stem, an intermediate portion disposed in the chamber and carrying a pinion gear, an outer end portion extending outwardly from the housing, a manually-operated handle connected to the outer end portion of the drive shaft, a pair of rack members mounted inside the chamber for reciprocative movement in opposite longitudinal directions and having teeth mesh with diametrically opposed sectors of the pinion teeth and a spring disposed between one end of each rack member and an end wall of the chamber for biasing the rack members toward an open or closed position. After the valve member has been moved from its original position with the handle, upon releasing the handle, the springs return the rack members to their original positions, causing rotation of the pinion gear to return to valve member to its original position.
The return mechanism has an elongated housing defining an elongated chamber, a drive shaft rotatably mounted in the housing and having one end operably connected to the outer end portion of the valve stem, an intermediate portion disposed in the chamber and carrying a pinion gear, an outer end portion extending outwardly from the housing, a manually-operated handle connected to the outer end portion of the drive shaft, a pair of rack members mounted inside the chamber for reciprocative movement in opposite longitudinal directions and having teeth mesh with diametrically opposed sectors of the pinion teeth and a spring disposed between one end of each rack member and an end wall of the chamber for biasing the rack members toward an open or closed position. After the valve member has been moved from its original position with the handle, upon releasing the handle, the springs return the rack members to their original positions, causing rotation of the pinion gear to return to valve member to its original position.
Description
2179~Sl R:\XF\CLIENT\66043\9342\MBC1040.W52 AUTOMATIC RETURN MECHANISM FOR QUARTER TURN VALVES
BACKGROUND OF THE INVENTION
This invention relates to automatic return mechanisms for valves, such as quarter turn valves, which automatically return the valve member to either the fully open or fully closed position upon the occurrence of a certain event, such as releasing an operating handle.
Quarter turn valves, such as ball valves, butterfly valves and plug valves, typically include a handle which is operably connected to a stem carrying the valve member and is rotated 90 to move the valve member between fully open and fully closed positions.
Manually-operated quarter turn valves are used in applications where the valve member is either normally closed or normally open and is moved by an operator to the other position for only a short time. For example, manually-operated quarter turn valves commonly are used for sampling purposes in petrochemical processes and other processes where samples of a process liquid are routinely taken for analysis. The valve is normally closed and is opened by an operator only long enough to withdraw an appropriate amount of a liquid for a particular analysis. In such applications, it is highly desirable for the valve to include a return mechanism which automatically returns the valve member to the fully closed position when the operator releases the handle, rather than relying solely on the operator to insure that the valve has been returned to the proper position.
One conventional automatic return mechanism for manually operated valves includes an extension spring located inside a tubular handle with one end connected to the valve body at a location radially spaced from the rotational axis of the stem. This spring is stretched when an operator moves the handle from either the closed or open position and returns the handle to --2-- R:\XE\CLIENT\66043\9342\MBC1040.W52 its original position when the operator releases the handle. Since the spring force is offset from the rotational axis of the stem, it imposes a side load on the stem which can displace the stem from its packing and cause leaking. One advantage of most manually-operated quarter turn valves is that the handle position can be used as an indication of the valve position. That is, when the handle is parallel to flow, the valve is open and when at 90 to flow, it is closed. Handles employing the above spring return are located at 45 to flow when the valve is either open or closed, making it impossible to determine valve position from the handle position. Also, to increase the closing torque, the length of the handle must be increased to accommodate longer springs to the point of where the handle can become unwieldy in some applications.
Another conventional automatic return mechanism for manually operated valves includes a clock spring located in a housing with one end connected to the valve stem. The spring/housing unit is quite expensive to manufacture and quite massive, particularly when larger springs are required to provide the desired amount of return torque. If the clock spring fails, special tools are required to wind the replacement spring. The clock spring is under continuous stress which tends to result in failure rates higher than compression or extension springs.
A compact, relatively inexpensive and reliable automatic return mechanism for quarter turn valves which does not impart a side force on the valve stem and/or does not have at least some of the other shortcomings of the above conventional ones is highly desirable.
SUMMARY OF THE INVENTION
A principal object of the invention is to provide a reliable, relatively inexpensive automatic return -- 2~qg8~1 _3_ R: \XE\CLIENT\66043\9342\MBC1040 .W52 mechanism for valves, such as manually-operated quarter turn valves, which does not impose a side load on the valve stem.
Another principal object of the invention is to provide such an automatic return mechanism which can be conveniently retrofitted on existing valves.
A further principal object of the invention is to provide such an automatic return mechanism including a housing which can be conveniently opened to inspect or replace parts inside the housing.
A still further principal object of the invention is to provide such automatic return mechanism requiring a reduced torque for moving the valve member from its normal position.
Other objects, aspects and advantages of the invention will become apparent to those skilled in the art upon reading the following detailed description, the drawings and the appended claims.
The invention provides an automatic return mechanism for valves including a body, a valve member disposed inside the valve body and rotatable between an open position to permit flow and a closed position to prevent flow and a stem rotatably mounted in the body and having an internal portion connected to the valve member and an operating portion accessible from the exterior of the valve body. The automatic return mechanism is operatively connected to the operating portion of the valve stem for moving the valve member between the open and closed positions. The return mechanism includes an elongated housing having an elongated internal chamber, a drive shaft rotatably mounted in the housing and having an intermediate portion disposed in the chamber, a first end portion operably connected to the operating portion of the valve stem and a second end portion accessible from the exterior of the housing. An operating means, such as a manually-operated handle, is operably connected to the second end of the drive shaft for moving the valve 2:1798Sl _4_ R:\XF\CLIENT\66043\9342\MBC1040.W52 member from one position to the other, a pinion gear having teeth is carried on the intermediate portion of the drive shaft, a first elongated rack member is slidably mounted in the chamber for reciprocative movement therein and including one end portion having a drive portion including teeth which mesh with a first sector of the pinion gear, a second elongated rack member is slidably mounted in the chamber for reciprocative movement therein and including one end portion having a drive section including teeth which mesh with a second sector of the pinion gear generally diametrically opposed to the first sector. A first biasing means biases the first rack member in a first longitudinal direction and a second biasing means biases the second rack member in a second longitudinal direction opposite to the first longitudinal direction whereby, when the operating means is operated to move the valve from either the open position or the closed position, rotation of the pinion gear causes the two rack members to be moved longitudinally against the biasing force of the respective biasing means and, when the operating means is released, the biasing means cause the two rack members to move in opposite longitudinal directions and rotate the pinion gear to return the valve member to its original position.
In a preferred embodiment, the housing chamber has a cross sectional shape including generally semicircular side portions having an inner surface and each rack member includes an outer surface facing the inner surface of the side portions and has a shape generally corresponding to that of the inner surfaces of the side portions. The housing preferably includes a pair of generally semicylindrical halves which are assembled together and cooperate to define at least part of the chamber. The housing preferably also has removable end caps which define the opposite ends of the chamber and threadable members, such as set screws, are adjustably mounted in the opposite end caps, extend _5_ R:\XF\CLIENT\66043\9342\MBC1040.W52 into the chamber and engage the opposite ends of a rack member to limit movement of the valve member between the open and closed positions.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view of a ball valve including an automatic return mechanism of the invention shown with the handle in the open position.
Fig. 2 is a partially sectioned, elevational view of the ball valve illustrated in Fig. 1.
Fig. 3 is a sectional view taken generally along line 3-3 in Fig. 1.
Fig. 4 is a sectional view taken generally along line 4-4 in Fig. 3.
Fig. 5 is a fragmentary view of the return mechanism with the top half of the housing removed.
Fig. 6 is an enlarged, partially fragmentary and exploded view of the coupling between return mechanism and the valve stem.
Fig. 7 is a fragmentary sectional view of an alternate embodiment employing a non-metallic raised portion in the vicinity of the pinion gear.
Fig. 8 is a view similar to Fig. 3 of an alternate embodiment employing extension springs in place of compression springs.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The automatic return mechanism of the invention can be used for a wide variety of valves and similar controls including a rotatable control shaft carrying a control means and a manually-operated operating means connected to the control shaft for rotating the control means between different positions. It is adaptable for quarter turn valves, such as ball valves, butterfly valves and plug valves, which are normally held in either the fully open or fully closed position. It is particularly adaptable for manually-operated ball ~17~851 --6-- R:\XP\CLIENT\66043\9342\MBC1040.W52 valves and will be described in connection with that specific application.
Illustrated in the drawings is a ball valve 10 including a body 12 defining an internal flow passage 14 extending therethrough and an external boss 16. The opposite ends 18 and 20 of the body 12 are internally threaded for connection in a piping system (not illustrated).
Disposed inside the body 12 is a rotatable valve member consisting of a ball 22 having a central opening 24. The ball 22 is mounted on valve seats 26 for rotational movement between an open position wherein the opening 24 is aligned with a flow passage 14 as illustrated in Fig. 2 and a closed position wherein the opening 24 is rotated 90 to the position illustrated in Fig. 2 and the ball 22 blocks flow through the passage 14.
A stem 28 is journalled in the boss 16 via a bearing sleeve 30 held in place by a threaded retainer 33 surrounding the stem 28 and threaded into the boss 16. The retainer 33 is tightened sufficiently to compress packing (not shown) surrounding the stem 28 into the sealing engagement with the stem 28. The stem 28 is rotatable about a first rotational or stem axis 34 and has an internal end portion 35 connected to the ball 22 and an external end portion 36 which is accessible from the exterior of the valve body 16. In the specific embodiment illustrated, the external end portion 36 projects outwardly from the boss 16 and has a terminal part 38.
The ball 22 is moved between full opened and full closed positions by rotating the stem 28 90 back and forth about the stem axis 34 with a manually-operated, automatic return mechanism 40 embodying the invention mounted on the valve body 16 and operably connected to the valve stem 28.
The return mechanism 40 has a housing 42 which is fastened to a mounting bracket 44 which in turn is 2~7985~
_7_ R: \XE\CLIENT\ 6 6 043\93 4 2\1D~C 1040 . W52 mounted on the valve body 16. In the specific embodiment illustrated, the valve body 16 has a pair of laterally protruding ears 46 (one shown in Fig. 2) including threaded apertures 48, the mounting bracket 44 has an inner flange 50 adapted to fit against the ears 46 and including a pair of apertures 52 alignable with the ear apertures 48 and the mounting bracket 44 is fastened to the valve body 16 by bolts 54 extending through the flange apertures 52 and threaded into the ear apertures 48.
The mounting bracket 44 includes an outer flange 56 which is spaced outwardly from and connected to the inner flange 50 by a pair of web sections 58 and has a plurality, e.g., 4, apertures 60. The housing 42 has a like number of threaded apertures 62 alignable with the outer flange apertures 60 and is fastened to the outer flange 56 by bolts 64 extending through the apertures 60 in the outer flange 56 and threaded into the housing apertures 62. The housing 42 has an internal chamber 66 defined in part by opposed end walls in the form of removably mounted end caps 68 and 70 described in more detail below.
The return mechanism 40 has a drive shaft 72 mounted in the housing 42 for rotation about a second rotational or drive shaft axis 74 which preferably is coaxial with the stem axis 32. The drive shaft 72 has a first end portion 76 journalled in the housing 42 via a low friction bushing 78 and operably connected to the valve stem 28,` an intermediate portion 80 disposed in the chamber 66 and carrying a pinion gear 82 and a second end portion 84 journalled in the housing 42 via a low friction bushing 86 and accessible from the exterior of the housing 42.
In the specific embodiment illustrated, the ball valve 10 is an existing one of conventional design and the return mechanism 40 is designed to fit onto the existing valve without modifying it. More specifically, the external end portion 36 of the stem 21793~
--8-- R:\XP\CLIENT\66043\9342\MBC1040.W52 28 projects outwardly from the boss 16 and the terminal part 38 is threaded. The valve normally has an elongated handle (not shown) extending generally perpendicularly to the stem axis 32 and including a gripping portion and an inner end portion connected to the terminal part 38 of the stem 28. The terminal part 38 of the stem 28 has opposed flat surfaces for receiving a generally rectangular slot in the inner end portion of the handle and the handle is held in place on the valve stem by a nut (not shown) threaded on to the terminal part 38. An operator can rotate the ball 22 90 between full opened and full closed positions by rotating the handle.
In place of the handle, the first end 76 of the drive shaft 72 is drivingly connected to the terminal part 38 of the valve stem 28 via a sleeve or coupling 90 (Figs. 2 and 6). One end 92 of the coupling 90 has a slotted opening 94 for receiving the terminal part 38 of the valve stem 28 and the opposite end has a rectangular extension 96 which fits into a socket 98 on the first end 76 of the drive shaft 72. The coupling extension 96 and socket 98 can be of any complementary shape. For example, when the coupling extension 96 is rectangular as shown, the socket 98 also can have a rectangular shape or it can have an octagonal shape so that the rotational orientation of the drive shaft 72 relative to the valve stem 28 can be adjusted during assembly.
The pinion gear 82 can be a separate geared part suitably mounted on the intermediate portion 80 of the drive shaft 72 and made from a material different from the drive shaft, e.g., a suitable synthetic thermoplastic or thermosetting material, such as Delrin, an acetal resin marketed by DuPont de Nemours.
In the specific embodiment illustrated, the pinion gear 82 is a spline section 98 formed as an integral part of the drive shaft 72 and including gear-like teeth 100.
~ ~1798~ 1 _ 9 _ R:\XE\CLIENT\66043\9342\MBC1040.W52 While the housing 42 and the chamber 66 can have various suitable configurations, including rectangular or other polygonal cross sections, in the specific embodiment illustrated, the housing 42 includes a pair of generally semicylindrical shells or halves 102 and 104 including an elongated body 106, opposed side edges having out turned flanges 108 extending along the length of the opposite edges. The housing halves 102 and 104 are removably fastened together by a plurality of longitudinally spaced bolts 110 or the like interconnecting the flanges 102 and 104 as best shown in Fig. 1.
The end caps 68 and 70 mentioned above are removably mounted on the opposite ends 112 and 114 of the assembled housing halves 102 and 104 by bolts 116 or the like and cooperate therewith to define the chamber 66. In the specific embodiment illustrated, the chamber 66 has a generally cylindrical shape and an oblong cross section having generally semicircular opposed side portions 118 and 120 having inner walls 122 as best shown in Fig. 4.
The housing halves 102 and 104 can be formed from a suitable metal, such as aluminum, or a suitable non-metallic synthetic thermoplastic or thermosetting material, such as Delrin.
Located inside the housing chamber 66 and in the side portions 118 and 120 thereof is a pair of identical elongated first and second rack members 122 and 124, each including a drive portion 126 having teeth 128 which mesh with generally diametrically opposed sectors of the teeth 110 on the spline portion 98 of the drive shaft 72. The rack members 122 and 124 are slidably disposed in the chamber 66 for reciprocative movement in opposite longitudinal directions relative to the chamber side portions 118 and 120. More specifically, the first rack member 122 moves along a longitudinal axis 130 which is generally perpendicular to and radially spaced from the drive ~179851 .
- 1 0 - R:\XE\CLIENT\66043\9342\MBC1040.W52 shaft axis 74 and the second rack member 124 moves along a second longitudinal axis 132 which is generally parallel to the first longitudinal axis 130 and generally perpendicular to and radially spaced from the drive shaft axis 74.
The outer surface 134 of the rack members 122 and 124 opposite to the teeth 128 preferably has a generally semicircular cross sectional shape generally corresponding to that of the chamber side portions 118 and 120. The rack members 122 and 124 can be made from a suitable metal, such as aluminum, or a suitable low friction non-metallic material, for example, a synthetic thermoplastic or thermosetting material, such as Delrin. If the rack members 122 and 124 are fabricated from a metal, either the outer surface 134 of the rack members 122 and 124 or a portion of the housing inner walls 123 along which the rack members 122 and 124 slide is coated with a low friction material. In the specific embodiment illustrated, the rack members 122 and 124 are fabricated from aluminum and the outer surfaces 134 are coated with Teflon or a similar fluorocarbon polymer. If the rack members 122 and 124 are fabricated from a low friction non-metallic material, such a coating is not required.
The inner wall 123 of the housing 42 includes a raised portion 136 in the vicinity of the spline section 98 over which the rack members 122 and 124 slide during reciprocative movement between the open and closed positions of the valve 10. The rack members 122 and 124 are effectively clamped between the spline section 98 and the raised portion 136 and this can be the sole means for guiding the rack members 122 and 124 and holding them in place. Since less than the entire length of the rack members 122 and 124 are in contact with the raised portion 136 at any one time, the surface area of contact between the rack members 122 and 124 and the housing 42 is reduced, resulting in a 21~8~1 .~
- 1 1 - R:\XE\CLIENT\66043\9342\M3C1040.W52 reduction in the torque required to open and close the valve.
The raised portion 136 can be formed as an integral part of the housing halves as shown in Figs. 2 and 8 or be in the form of a sleeve 138 of low friction material, such as Teflon and Delrin, and fitted into an annular recess 140 in the housing 42 as shown in Fig.
7. To further reduce friction between the rack members 122 and 124 and the inner wall 123 of the housing 42, a suitable lubricant, such as mineral oil or silicone, can be applied to the outer surface 134 of the rack members 122 and 124 and/or the inner surface of the raised portion 136. If the rack members 122 and 124 slide along the inside surfaces of the semicircular side portions 118 and 120 of the chamber 66, such a lubricant can be applied to those structures.
The ball 22 can be moved from a full closed to a full open position or vice versa by manually actuating an operating means operably connected to the second end portion 84 of the drive shaft 72. In the particular embodiment illustrated, the second end portion 84 of the drive shaft 72 projects outwardly from the housing 42 and has a terminal part 140 which is threaded and has opposed flat surfaces (Figs. 1 and 2). The operating means is in the form of an elongated, manually-operated handle 142 including a gripping portion 144 and an inner end portion 146 having a slot (not shown) which fits over the terminal part 140 of the drive shaft 72. The handle 142 is held in place on the drive shaft 72 by a nut 148 threaded over the terminal part 140.
Suitable biasing means are provided for biasing the rack members 122 and 124 in opposite longitudinal directions to rotate the drive shaft 72, via the spline section g8, to a rotational position corresponding to the full closed or full open position of the ball 22 and releasably holding the drive shaft 72 in that position. While various suitable means can be used for '~1798~ 1 --12-- R:\X~\CLIENT\66043\9342\MBC1040.W52 this purpose, in the specific embodiment illustrated in Figs. 1, 3 and 5, the biasing means includes a compression spring 150 located between each rack member 122 and 124 and a spring retainer inside the housing chamber 66. More specifically, the end portion 152 of each rack member 122 and 124 opposite to the drive section 126 is enlarged to provide a bearing surface 154 for one end of a spring 150 and the inside surfaces 156 of the housing end caps 68 and 70 act as a bearing surface for the opposite end of a spring 150. The end portions 152 of the rack members 122 and 124 and the inside surfaces 156 of the end caps 68 and 70 preferably include generally cylindrical, longitudinally extending bosses 158 and 160, respectively, which fit into the opposite ends of the springs 150 to hold them in place. The bosses 160 have been omitted from Fig. 5 for the sake of clarity.
Fig. 3 illustrates the position of the rack members 122 and 124 and the compressed state of the springs 150 when the return mechanism 40 is adapted to hold the ball 22 in the full closed position and the ball 22 has been moved to the full open position by rotating the handle 142 90. As viewed in Fig. 3, when an operator releases the handle 142, the springs 150 simultaneously move the rack members 122 and 124 to the left and the right, respectively, causing the drive shaft 72, and thus the ball 22, to be rotated counterclockwise from the full open position to the full closed position. When an operator re-opens the valve by rotating the handle 142 90 clockwise as viewed in Fig. 3, the rack members 122 and 124 are simultaneously moved to the right and left, respectively, in response to clockwise rotation of the spline section 98 on the drive shaft 72 and the springs 150 are compressed as illustrated.
In both the illustrated embodiments, the rack members 122 and 124 are arranged so that the ball is turned clockwise to open. In the valve trade, the - 21798~1 --13-- R:\XE\CLIENT\66043\9342\MBC1040.1~52 standard practice is for the ball to turn clockwise to close.
To prevent a potential air lock which could increase the amount of torque required to open and close the valve the end caps 68 and 70 preferably include a vent 160 for venting the chamber 66 to the atmosphere. When the valve is in a hazardous environment, the vents 160 can include a pressure relief sealing mechanism to prevent the ingress of deleterious gases, flames, etc.
Other conventional type springs can be used to perform the same function as the compression springs 150. For example, as illustrated in Fig. 8, the compression springs 150 can be replaced by extension springs 162 suitably connected between the drive portion 126 of the rack members 122 and 124 and the end caps 68 and 70, respectively. With such an arrangement, the extension springs 162 are stretched, instead of being compressed, when the drive shaft 72 is rotated to the position illustrated in Fig. 3, and pull the rack members 122 and 124 to the left and right, respectively, causing the drive shaft 72 to be rotated counterclockwise back to a full closed position when an operator releases the handle 142.
The return mechanism 40 preferably includes external means for adjusting the stop position for the ball 22 in the open and closed position. In the specific embodiment illustrated in Figs. 1-7, such means comprises a pair of threaded members, such as set screws 166 and 168, threaded into each end cap 68 and 70 and extending into the chamber 66. One set screw 166 is for limiting the open position and extends through the spring-retaining boss 160 on an end cap and engages the spring-retaining boss 158 on a rack member when the rack member as in the open position. The other set screw 168 is for limiting the closed position and engages the end 170 of the drive section 126 of a - ~1798~1 --14-- R:\XP\CLIENT\66043\9342\MBC1040.W52 rack member when the rack member has been returned to the closed position.
For assembly of the return mechanism 40, one end of the drive shaft 72 can be installed in a first housing half 104, the rack members 122 and 124 installed in that housing half, the second housing half 102 slipped over the opposite end of the drive shaft 72 and moved into place with the flanges 108 abutting and the housing halves fastened together. The end caps 68 and 70 are moved into place after the outer ends of the springs 150 have been slipped over the bosses 158 on the end caps, and mounted on the assembled housing halves. The bracket 44 can be mounted on either the housing 42 or the valve body 12 first and then mounted on the other. In either case, the coupling 96 preferably is installed on the terminal part 38 of the valve stem 28 prior to final mounting and the drive shaft socket 98 slipped over the coupling extension 96 as the return mechanism or the return mechanism/bracket is moved into place.
The condition of the springs, the rack members and other internal parts can be inspected, broken springs replaced and/or larger gauge springs for providing a higher closing torque installed by removing and replacing the end caps.
The construction of the return mechanism 40 has been described in connection with a conventional manually-operated ball valve. With such an arrangement, existing manually-operated ball valves can be converted to one with an automatic return capability by simply installing a return mechanism of the invention in place of the operating handle during assembly or retrofitting assembled valves by removing the handle and replacing it with a return mechanism of the invention.
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of the invention and, without departing from the spirit ~17985 1 --15-- R:\X~\CLIENT\66043\9342\M3C1040.W52 and scope thereof, make various changes and modifications to adapt it to various usages.
BACKGROUND OF THE INVENTION
This invention relates to automatic return mechanisms for valves, such as quarter turn valves, which automatically return the valve member to either the fully open or fully closed position upon the occurrence of a certain event, such as releasing an operating handle.
Quarter turn valves, such as ball valves, butterfly valves and plug valves, typically include a handle which is operably connected to a stem carrying the valve member and is rotated 90 to move the valve member between fully open and fully closed positions.
Manually-operated quarter turn valves are used in applications where the valve member is either normally closed or normally open and is moved by an operator to the other position for only a short time. For example, manually-operated quarter turn valves commonly are used for sampling purposes in petrochemical processes and other processes where samples of a process liquid are routinely taken for analysis. The valve is normally closed and is opened by an operator only long enough to withdraw an appropriate amount of a liquid for a particular analysis. In such applications, it is highly desirable for the valve to include a return mechanism which automatically returns the valve member to the fully closed position when the operator releases the handle, rather than relying solely on the operator to insure that the valve has been returned to the proper position.
One conventional automatic return mechanism for manually operated valves includes an extension spring located inside a tubular handle with one end connected to the valve body at a location radially spaced from the rotational axis of the stem. This spring is stretched when an operator moves the handle from either the closed or open position and returns the handle to --2-- R:\XE\CLIENT\66043\9342\MBC1040.W52 its original position when the operator releases the handle. Since the spring force is offset from the rotational axis of the stem, it imposes a side load on the stem which can displace the stem from its packing and cause leaking. One advantage of most manually-operated quarter turn valves is that the handle position can be used as an indication of the valve position. That is, when the handle is parallel to flow, the valve is open and when at 90 to flow, it is closed. Handles employing the above spring return are located at 45 to flow when the valve is either open or closed, making it impossible to determine valve position from the handle position. Also, to increase the closing torque, the length of the handle must be increased to accommodate longer springs to the point of where the handle can become unwieldy in some applications.
Another conventional automatic return mechanism for manually operated valves includes a clock spring located in a housing with one end connected to the valve stem. The spring/housing unit is quite expensive to manufacture and quite massive, particularly when larger springs are required to provide the desired amount of return torque. If the clock spring fails, special tools are required to wind the replacement spring. The clock spring is under continuous stress which tends to result in failure rates higher than compression or extension springs.
A compact, relatively inexpensive and reliable automatic return mechanism for quarter turn valves which does not impart a side force on the valve stem and/or does not have at least some of the other shortcomings of the above conventional ones is highly desirable.
SUMMARY OF THE INVENTION
A principal object of the invention is to provide a reliable, relatively inexpensive automatic return -- 2~qg8~1 _3_ R: \XE\CLIENT\66043\9342\MBC1040 .W52 mechanism for valves, such as manually-operated quarter turn valves, which does not impose a side load on the valve stem.
Another principal object of the invention is to provide such an automatic return mechanism which can be conveniently retrofitted on existing valves.
A further principal object of the invention is to provide such an automatic return mechanism including a housing which can be conveniently opened to inspect or replace parts inside the housing.
A still further principal object of the invention is to provide such automatic return mechanism requiring a reduced torque for moving the valve member from its normal position.
Other objects, aspects and advantages of the invention will become apparent to those skilled in the art upon reading the following detailed description, the drawings and the appended claims.
The invention provides an automatic return mechanism for valves including a body, a valve member disposed inside the valve body and rotatable between an open position to permit flow and a closed position to prevent flow and a stem rotatably mounted in the body and having an internal portion connected to the valve member and an operating portion accessible from the exterior of the valve body. The automatic return mechanism is operatively connected to the operating portion of the valve stem for moving the valve member between the open and closed positions. The return mechanism includes an elongated housing having an elongated internal chamber, a drive shaft rotatably mounted in the housing and having an intermediate portion disposed in the chamber, a first end portion operably connected to the operating portion of the valve stem and a second end portion accessible from the exterior of the housing. An operating means, such as a manually-operated handle, is operably connected to the second end of the drive shaft for moving the valve 2:1798Sl _4_ R:\XF\CLIENT\66043\9342\MBC1040.W52 member from one position to the other, a pinion gear having teeth is carried on the intermediate portion of the drive shaft, a first elongated rack member is slidably mounted in the chamber for reciprocative movement therein and including one end portion having a drive portion including teeth which mesh with a first sector of the pinion gear, a second elongated rack member is slidably mounted in the chamber for reciprocative movement therein and including one end portion having a drive section including teeth which mesh with a second sector of the pinion gear generally diametrically opposed to the first sector. A first biasing means biases the first rack member in a first longitudinal direction and a second biasing means biases the second rack member in a second longitudinal direction opposite to the first longitudinal direction whereby, when the operating means is operated to move the valve from either the open position or the closed position, rotation of the pinion gear causes the two rack members to be moved longitudinally against the biasing force of the respective biasing means and, when the operating means is released, the biasing means cause the two rack members to move in opposite longitudinal directions and rotate the pinion gear to return the valve member to its original position.
In a preferred embodiment, the housing chamber has a cross sectional shape including generally semicircular side portions having an inner surface and each rack member includes an outer surface facing the inner surface of the side portions and has a shape generally corresponding to that of the inner surfaces of the side portions. The housing preferably includes a pair of generally semicylindrical halves which are assembled together and cooperate to define at least part of the chamber. The housing preferably also has removable end caps which define the opposite ends of the chamber and threadable members, such as set screws, are adjustably mounted in the opposite end caps, extend _5_ R:\XF\CLIENT\66043\9342\MBC1040.W52 into the chamber and engage the opposite ends of a rack member to limit movement of the valve member between the open and closed positions.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view of a ball valve including an automatic return mechanism of the invention shown with the handle in the open position.
Fig. 2 is a partially sectioned, elevational view of the ball valve illustrated in Fig. 1.
Fig. 3 is a sectional view taken generally along line 3-3 in Fig. 1.
Fig. 4 is a sectional view taken generally along line 4-4 in Fig. 3.
Fig. 5 is a fragmentary view of the return mechanism with the top half of the housing removed.
Fig. 6 is an enlarged, partially fragmentary and exploded view of the coupling between return mechanism and the valve stem.
Fig. 7 is a fragmentary sectional view of an alternate embodiment employing a non-metallic raised portion in the vicinity of the pinion gear.
Fig. 8 is a view similar to Fig. 3 of an alternate embodiment employing extension springs in place of compression springs.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The automatic return mechanism of the invention can be used for a wide variety of valves and similar controls including a rotatable control shaft carrying a control means and a manually-operated operating means connected to the control shaft for rotating the control means between different positions. It is adaptable for quarter turn valves, such as ball valves, butterfly valves and plug valves, which are normally held in either the fully open or fully closed position. It is particularly adaptable for manually-operated ball ~17~851 --6-- R:\XP\CLIENT\66043\9342\MBC1040.W52 valves and will be described in connection with that specific application.
Illustrated in the drawings is a ball valve 10 including a body 12 defining an internal flow passage 14 extending therethrough and an external boss 16. The opposite ends 18 and 20 of the body 12 are internally threaded for connection in a piping system (not illustrated).
Disposed inside the body 12 is a rotatable valve member consisting of a ball 22 having a central opening 24. The ball 22 is mounted on valve seats 26 for rotational movement between an open position wherein the opening 24 is aligned with a flow passage 14 as illustrated in Fig. 2 and a closed position wherein the opening 24 is rotated 90 to the position illustrated in Fig. 2 and the ball 22 blocks flow through the passage 14.
A stem 28 is journalled in the boss 16 via a bearing sleeve 30 held in place by a threaded retainer 33 surrounding the stem 28 and threaded into the boss 16. The retainer 33 is tightened sufficiently to compress packing (not shown) surrounding the stem 28 into the sealing engagement with the stem 28. The stem 28 is rotatable about a first rotational or stem axis 34 and has an internal end portion 35 connected to the ball 22 and an external end portion 36 which is accessible from the exterior of the valve body 16. In the specific embodiment illustrated, the external end portion 36 projects outwardly from the boss 16 and has a terminal part 38.
The ball 22 is moved between full opened and full closed positions by rotating the stem 28 90 back and forth about the stem axis 34 with a manually-operated, automatic return mechanism 40 embodying the invention mounted on the valve body 16 and operably connected to the valve stem 28.
The return mechanism 40 has a housing 42 which is fastened to a mounting bracket 44 which in turn is 2~7985~
_7_ R: \XE\CLIENT\ 6 6 043\93 4 2\1D~C 1040 . W52 mounted on the valve body 16. In the specific embodiment illustrated, the valve body 16 has a pair of laterally protruding ears 46 (one shown in Fig. 2) including threaded apertures 48, the mounting bracket 44 has an inner flange 50 adapted to fit against the ears 46 and including a pair of apertures 52 alignable with the ear apertures 48 and the mounting bracket 44 is fastened to the valve body 16 by bolts 54 extending through the flange apertures 52 and threaded into the ear apertures 48.
The mounting bracket 44 includes an outer flange 56 which is spaced outwardly from and connected to the inner flange 50 by a pair of web sections 58 and has a plurality, e.g., 4, apertures 60. The housing 42 has a like number of threaded apertures 62 alignable with the outer flange apertures 60 and is fastened to the outer flange 56 by bolts 64 extending through the apertures 60 in the outer flange 56 and threaded into the housing apertures 62. The housing 42 has an internal chamber 66 defined in part by opposed end walls in the form of removably mounted end caps 68 and 70 described in more detail below.
The return mechanism 40 has a drive shaft 72 mounted in the housing 42 for rotation about a second rotational or drive shaft axis 74 which preferably is coaxial with the stem axis 32. The drive shaft 72 has a first end portion 76 journalled in the housing 42 via a low friction bushing 78 and operably connected to the valve stem 28,` an intermediate portion 80 disposed in the chamber 66 and carrying a pinion gear 82 and a second end portion 84 journalled in the housing 42 via a low friction bushing 86 and accessible from the exterior of the housing 42.
In the specific embodiment illustrated, the ball valve 10 is an existing one of conventional design and the return mechanism 40 is designed to fit onto the existing valve without modifying it. More specifically, the external end portion 36 of the stem 21793~
--8-- R:\XP\CLIENT\66043\9342\MBC1040.W52 28 projects outwardly from the boss 16 and the terminal part 38 is threaded. The valve normally has an elongated handle (not shown) extending generally perpendicularly to the stem axis 32 and including a gripping portion and an inner end portion connected to the terminal part 38 of the stem 28. The terminal part 38 of the stem 28 has opposed flat surfaces for receiving a generally rectangular slot in the inner end portion of the handle and the handle is held in place on the valve stem by a nut (not shown) threaded on to the terminal part 38. An operator can rotate the ball 22 90 between full opened and full closed positions by rotating the handle.
In place of the handle, the first end 76 of the drive shaft 72 is drivingly connected to the terminal part 38 of the valve stem 28 via a sleeve or coupling 90 (Figs. 2 and 6). One end 92 of the coupling 90 has a slotted opening 94 for receiving the terminal part 38 of the valve stem 28 and the opposite end has a rectangular extension 96 which fits into a socket 98 on the first end 76 of the drive shaft 72. The coupling extension 96 and socket 98 can be of any complementary shape. For example, when the coupling extension 96 is rectangular as shown, the socket 98 also can have a rectangular shape or it can have an octagonal shape so that the rotational orientation of the drive shaft 72 relative to the valve stem 28 can be adjusted during assembly.
The pinion gear 82 can be a separate geared part suitably mounted on the intermediate portion 80 of the drive shaft 72 and made from a material different from the drive shaft, e.g., a suitable synthetic thermoplastic or thermosetting material, such as Delrin, an acetal resin marketed by DuPont de Nemours.
In the specific embodiment illustrated, the pinion gear 82 is a spline section 98 formed as an integral part of the drive shaft 72 and including gear-like teeth 100.
~ ~1798~ 1 _ 9 _ R:\XE\CLIENT\66043\9342\MBC1040.W52 While the housing 42 and the chamber 66 can have various suitable configurations, including rectangular or other polygonal cross sections, in the specific embodiment illustrated, the housing 42 includes a pair of generally semicylindrical shells or halves 102 and 104 including an elongated body 106, opposed side edges having out turned flanges 108 extending along the length of the opposite edges. The housing halves 102 and 104 are removably fastened together by a plurality of longitudinally spaced bolts 110 or the like interconnecting the flanges 102 and 104 as best shown in Fig. 1.
The end caps 68 and 70 mentioned above are removably mounted on the opposite ends 112 and 114 of the assembled housing halves 102 and 104 by bolts 116 or the like and cooperate therewith to define the chamber 66. In the specific embodiment illustrated, the chamber 66 has a generally cylindrical shape and an oblong cross section having generally semicircular opposed side portions 118 and 120 having inner walls 122 as best shown in Fig. 4.
The housing halves 102 and 104 can be formed from a suitable metal, such as aluminum, or a suitable non-metallic synthetic thermoplastic or thermosetting material, such as Delrin.
Located inside the housing chamber 66 and in the side portions 118 and 120 thereof is a pair of identical elongated first and second rack members 122 and 124, each including a drive portion 126 having teeth 128 which mesh with generally diametrically opposed sectors of the teeth 110 on the spline portion 98 of the drive shaft 72. The rack members 122 and 124 are slidably disposed in the chamber 66 for reciprocative movement in opposite longitudinal directions relative to the chamber side portions 118 and 120. More specifically, the first rack member 122 moves along a longitudinal axis 130 which is generally perpendicular to and radially spaced from the drive ~179851 .
- 1 0 - R:\XE\CLIENT\66043\9342\MBC1040.W52 shaft axis 74 and the second rack member 124 moves along a second longitudinal axis 132 which is generally parallel to the first longitudinal axis 130 and generally perpendicular to and radially spaced from the drive shaft axis 74.
The outer surface 134 of the rack members 122 and 124 opposite to the teeth 128 preferably has a generally semicircular cross sectional shape generally corresponding to that of the chamber side portions 118 and 120. The rack members 122 and 124 can be made from a suitable metal, such as aluminum, or a suitable low friction non-metallic material, for example, a synthetic thermoplastic or thermosetting material, such as Delrin. If the rack members 122 and 124 are fabricated from a metal, either the outer surface 134 of the rack members 122 and 124 or a portion of the housing inner walls 123 along which the rack members 122 and 124 slide is coated with a low friction material. In the specific embodiment illustrated, the rack members 122 and 124 are fabricated from aluminum and the outer surfaces 134 are coated with Teflon or a similar fluorocarbon polymer. If the rack members 122 and 124 are fabricated from a low friction non-metallic material, such a coating is not required.
The inner wall 123 of the housing 42 includes a raised portion 136 in the vicinity of the spline section 98 over which the rack members 122 and 124 slide during reciprocative movement between the open and closed positions of the valve 10. The rack members 122 and 124 are effectively clamped between the spline section 98 and the raised portion 136 and this can be the sole means for guiding the rack members 122 and 124 and holding them in place. Since less than the entire length of the rack members 122 and 124 are in contact with the raised portion 136 at any one time, the surface area of contact between the rack members 122 and 124 and the housing 42 is reduced, resulting in a 21~8~1 .~
- 1 1 - R:\XE\CLIENT\66043\9342\M3C1040.W52 reduction in the torque required to open and close the valve.
The raised portion 136 can be formed as an integral part of the housing halves as shown in Figs. 2 and 8 or be in the form of a sleeve 138 of low friction material, such as Teflon and Delrin, and fitted into an annular recess 140 in the housing 42 as shown in Fig.
7. To further reduce friction between the rack members 122 and 124 and the inner wall 123 of the housing 42, a suitable lubricant, such as mineral oil or silicone, can be applied to the outer surface 134 of the rack members 122 and 124 and/or the inner surface of the raised portion 136. If the rack members 122 and 124 slide along the inside surfaces of the semicircular side portions 118 and 120 of the chamber 66, such a lubricant can be applied to those structures.
The ball 22 can be moved from a full closed to a full open position or vice versa by manually actuating an operating means operably connected to the second end portion 84 of the drive shaft 72. In the particular embodiment illustrated, the second end portion 84 of the drive shaft 72 projects outwardly from the housing 42 and has a terminal part 140 which is threaded and has opposed flat surfaces (Figs. 1 and 2). The operating means is in the form of an elongated, manually-operated handle 142 including a gripping portion 144 and an inner end portion 146 having a slot (not shown) which fits over the terminal part 140 of the drive shaft 72. The handle 142 is held in place on the drive shaft 72 by a nut 148 threaded over the terminal part 140.
Suitable biasing means are provided for biasing the rack members 122 and 124 in opposite longitudinal directions to rotate the drive shaft 72, via the spline section g8, to a rotational position corresponding to the full closed or full open position of the ball 22 and releasably holding the drive shaft 72 in that position. While various suitable means can be used for '~1798~ 1 --12-- R:\X~\CLIENT\66043\9342\MBC1040.W52 this purpose, in the specific embodiment illustrated in Figs. 1, 3 and 5, the biasing means includes a compression spring 150 located between each rack member 122 and 124 and a spring retainer inside the housing chamber 66. More specifically, the end portion 152 of each rack member 122 and 124 opposite to the drive section 126 is enlarged to provide a bearing surface 154 for one end of a spring 150 and the inside surfaces 156 of the housing end caps 68 and 70 act as a bearing surface for the opposite end of a spring 150. The end portions 152 of the rack members 122 and 124 and the inside surfaces 156 of the end caps 68 and 70 preferably include generally cylindrical, longitudinally extending bosses 158 and 160, respectively, which fit into the opposite ends of the springs 150 to hold them in place. The bosses 160 have been omitted from Fig. 5 for the sake of clarity.
Fig. 3 illustrates the position of the rack members 122 and 124 and the compressed state of the springs 150 when the return mechanism 40 is adapted to hold the ball 22 in the full closed position and the ball 22 has been moved to the full open position by rotating the handle 142 90. As viewed in Fig. 3, when an operator releases the handle 142, the springs 150 simultaneously move the rack members 122 and 124 to the left and the right, respectively, causing the drive shaft 72, and thus the ball 22, to be rotated counterclockwise from the full open position to the full closed position. When an operator re-opens the valve by rotating the handle 142 90 clockwise as viewed in Fig. 3, the rack members 122 and 124 are simultaneously moved to the right and left, respectively, in response to clockwise rotation of the spline section 98 on the drive shaft 72 and the springs 150 are compressed as illustrated.
In both the illustrated embodiments, the rack members 122 and 124 are arranged so that the ball is turned clockwise to open. In the valve trade, the - 21798~1 --13-- R:\XE\CLIENT\66043\9342\MBC1040.1~52 standard practice is for the ball to turn clockwise to close.
To prevent a potential air lock which could increase the amount of torque required to open and close the valve the end caps 68 and 70 preferably include a vent 160 for venting the chamber 66 to the atmosphere. When the valve is in a hazardous environment, the vents 160 can include a pressure relief sealing mechanism to prevent the ingress of deleterious gases, flames, etc.
Other conventional type springs can be used to perform the same function as the compression springs 150. For example, as illustrated in Fig. 8, the compression springs 150 can be replaced by extension springs 162 suitably connected between the drive portion 126 of the rack members 122 and 124 and the end caps 68 and 70, respectively. With such an arrangement, the extension springs 162 are stretched, instead of being compressed, when the drive shaft 72 is rotated to the position illustrated in Fig. 3, and pull the rack members 122 and 124 to the left and right, respectively, causing the drive shaft 72 to be rotated counterclockwise back to a full closed position when an operator releases the handle 142.
The return mechanism 40 preferably includes external means for adjusting the stop position for the ball 22 in the open and closed position. In the specific embodiment illustrated in Figs. 1-7, such means comprises a pair of threaded members, such as set screws 166 and 168, threaded into each end cap 68 and 70 and extending into the chamber 66. One set screw 166 is for limiting the open position and extends through the spring-retaining boss 160 on an end cap and engages the spring-retaining boss 158 on a rack member when the rack member as in the open position. The other set screw 168 is for limiting the closed position and engages the end 170 of the drive section 126 of a - ~1798~1 --14-- R:\XP\CLIENT\66043\9342\MBC1040.W52 rack member when the rack member has been returned to the closed position.
For assembly of the return mechanism 40, one end of the drive shaft 72 can be installed in a first housing half 104, the rack members 122 and 124 installed in that housing half, the second housing half 102 slipped over the opposite end of the drive shaft 72 and moved into place with the flanges 108 abutting and the housing halves fastened together. The end caps 68 and 70 are moved into place after the outer ends of the springs 150 have been slipped over the bosses 158 on the end caps, and mounted on the assembled housing halves. The bracket 44 can be mounted on either the housing 42 or the valve body 12 first and then mounted on the other. In either case, the coupling 96 preferably is installed on the terminal part 38 of the valve stem 28 prior to final mounting and the drive shaft socket 98 slipped over the coupling extension 96 as the return mechanism or the return mechanism/bracket is moved into place.
The condition of the springs, the rack members and other internal parts can be inspected, broken springs replaced and/or larger gauge springs for providing a higher closing torque installed by removing and replacing the end caps.
The construction of the return mechanism 40 has been described in connection with a conventional manually-operated ball valve. With such an arrangement, existing manually-operated ball valves can be converted to one with an automatic return capability by simply installing a return mechanism of the invention in place of the operating handle during assembly or retrofitting assembled valves by removing the handle and replacing it with a return mechanism of the invention.
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of the invention and, without departing from the spirit ~17985 1 --15-- R:\X~\CLIENT\66043\9342\M3C1040.W52 and scope thereof, make various changes and modifications to adapt it to various usages.
Claims (21)
1. A valve including a valve body having a flow passage extending therethrough;
a valve member disposed in said flow passage and movable between an open position to permit flow through said flow passage and a closed position to prevent flow through said flow passage;
a valve stem mounted in said valve body for rotation about a first rotational axis and having an internal portion connected to said valve member and an operating portion accessible from the exterior of said valve body; and an automatic return mechanism operably connected to the operating portion of said valve stem for moving said valve member between the open and closed positions, said return mechanism including a elongated housing having an elongated internal chamber, a drive shaft mounted in said housing for rotation about a second rotational axis and having an intermediate portion disposed in said chamber, a first end portion operably connected to the operating portion of said valve stem and a second end portion accessible from the exterior of said housing, operating means operably connected to the second end portion of said drive shaft for moving said valve member from one of said open and closed positions to the other, a pinion gear having teeth carried by the intermediate portion of said drive shaft for common rotation therewith, a first elongated rack member slidably mounted in said chamber for reciprocative movement along a first longitudinal axis generally perpendicular to and radially spaced from said second rotational axis, one end portion of said first rack member having a drive portion including teeth which mesh with a first sector of the teeth on one side of said pinion gear, a second elongated rack member slidably mounted in said chamber for reciprocative movement along a second longitudinal axis generally parallel to said first longitudinal axis and generally perpendicularly to and radially spaced from said second rotational axis, one end portion of said second rack member having a drive section including teeth which mesh with a second sector of the teeth on said pinion gear generally diametrically opposed to said first sector, first biasing means providing a biasing force for biasing said first rack member in a first longitudinal direction, and second biasing means providing a biasing force for biasing said second rack member in second longitudinal direction opposite to said first longitudinal direction, whereby, when said operating means is operated to move said valve member from one of said open and closed positions to the other, rotation of said pinion gear causes said first and second rack members to be moved longitudinally against the biasing force of the respective biasing means and, when said operating means is released, said first and second biasing means cause said first and second rack members to be moved in opposite longitudinal directions and rotate said pinion gear to return said valve member to said one position.
a valve member disposed in said flow passage and movable between an open position to permit flow through said flow passage and a closed position to prevent flow through said flow passage;
a valve stem mounted in said valve body for rotation about a first rotational axis and having an internal portion connected to said valve member and an operating portion accessible from the exterior of said valve body; and an automatic return mechanism operably connected to the operating portion of said valve stem for moving said valve member between the open and closed positions, said return mechanism including a elongated housing having an elongated internal chamber, a drive shaft mounted in said housing for rotation about a second rotational axis and having an intermediate portion disposed in said chamber, a first end portion operably connected to the operating portion of said valve stem and a second end portion accessible from the exterior of said housing, operating means operably connected to the second end portion of said drive shaft for moving said valve member from one of said open and closed positions to the other, a pinion gear having teeth carried by the intermediate portion of said drive shaft for common rotation therewith, a first elongated rack member slidably mounted in said chamber for reciprocative movement along a first longitudinal axis generally perpendicular to and radially spaced from said second rotational axis, one end portion of said first rack member having a drive portion including teeth which mesh with a first sector of the teeth on one side of said pinion gear, a second elongated rack member slidably mounted in said chamber for reciprocative movement along a second longitudinal axis generally parallel to said first longitudinal axis and generally perpendicularly to and radially spaced from said second rotational axis, one end portion of said second rack member having a drive section including teeth which mesh with a second sector of the teeth on said pinion gear generally diametrically opposed to said first sector, first biasing means providing a biasing force for biasing said first rack member in a first longitudinal direction, and second biasing means providing a biasing force for biasing said second rack member in second longitudinal direction opposite to said first longitudinal direction, whereby, when said operating means is operated to move said valve member from one of said open and closed positions to the other, rotation of said pinion gear causes said first and second rack members to be moved longitudinally against the biasing force of the respective biasing means and, when said operating means is released, said first and second biasing means cause said first and second rack members to be moved in opposite longitudinal directions and rotate said pinion gear to return said valve member to said one position.
2. A valve according to Claim 1 wherein said operating means comprises a manually-operated handle connected to the second end portion of said drive shaft.
3. A valve according to Claim 2 wherein said chamber has a cross sectional shape including generally semicircular opposed side portions having an inner surface; and each of said rack members includes an outer surface facing the inner surface of said side portions and has a shape generally corresponding to that of the inner surfaces of said side portions.
4. A valve according to Claim 3 wherein said housing includes a pair of generally semicylindrical halves which are assembled together and cooperate to define at least a part of said chamber.
5. A valve according to Claim 3 wherein said housing has a raised portion extending radially inwardly from the inner surface of said side portions in the vicinity of said pinion gear and having an inner surface, said rack members sliding along the inner surface of said raised portion during movement between the open and closed positions.
6. A valve according to Claim 2 wherein said housing has opposed ends defining said chamber in part; and said first and second bias means comprises a spring disposed between one end of each of said rack members and one of said end walls.
7. A valve according to Claim 6 wherein said housing has a main body including a hollow interior and opposed ends; and said end walls comprise an end cap removably mounted on each of the ends of said housing body and cooperating therewith to define said chamber.
8. A valve according to Claim 7 wherein each of said rack members has a first end portion including said teeth and an opposed second end portion including an enlarged first bearing surface;
said end caps have an inner wall including a second bearing surface; and said spring means comprises a compression spring having opposite ends and disposed between said second end portion of a said rack member and a said end wall with the opposite ends bearing against said first and second bearing surfaces.
said end caps have an inner wall including a second bearing surface; and said spring means comprises a compression spring having opposite ends and disposed between said second end portion of a said rack member and a said end wall with the opposite ends bearing against said first and second bearing surfaces.
9. A valve according to Claim 8 wherein said compression spring is an elongated coil spring having opposite ends;
said first bearing surface includes an outwardly extending boss which fits inside one end of said spring; and said second bearing surface includes an outwardly extending boss which fits inside the other end of said spring.
said first bearing surface includes an outwardly extending boss which fits inside one end of said spring; and said second bearing surface includes an outwardly extending boss which fits inside the other end of said spring.
10. A valve according to Claim 8 wherein each of said rack members has a first end portion including said teeth and an opposite second end portion; and said spring means comprises an extension spring having opposite ends with one end connected to the first end portion of said rack member and the opposite end connected to a said end wall.
11. A valve according to Claim 7 wherein each of said rack members has a first end portion including said teeth and an opposite second end portion; and said valve includes adjustable stop means for limiting the open and closed position of said valve member comprising an elongated, first stop member mounted in at least one of said end caps for adjustable longitudinal movement relative to said end cap, said first stop member including an external portion accessible from the exterior of said end cap and an internal portion extending into said chamber toward the second end portion of a said rack member and engageable therewith to limit the open position of said valve member; and a second elongated stop member mounted in said one end caps for adjustable longitudinal movement relative to said end cap, said second stop member having an external portion accessible from the exterior of said one end cap and an internal portion extending into said chamber toward the first end portion of a said rack member and engageable therewith to limit the closing position of said valve member.
12. A valve according to Claim 2 wherein said pinion gear is a spline section formed as an integral part of said drive shaft.
13. A valve according to Claim 2 wherein the operating portion of said valve stem extends outwardly from said valve body and has a terminal part;
the first end portion of said drive shaft includes a female socket; and said return mechanism includes a coupling having a first end operably connected to the terminal part of said valve stem and a second end fitting into the socket on said drive shaft.
the first end portion of said drive shaft includes a female socket; and said return mechanism includes a coupling having a first end operably connected to the terminal part of said valve stem and a second end fitting into the socket on said drive shaft.
14. A valve according to Claim 2 wherein said valve is a quarter turn valve.
15. A valve according to Claim 14 wherein said quarter turn valve is a ball valve.
16. A quarter turn valve including a valve body having a flow passage extending therethrough, a valve member disposed in said flow passage movable between an open position to permit flow through the said flow passage and a closed position to prevent flow through said flow passage;
a valve stem mounted in said valve body for rotation about a first rotational axis and having an internal portion connected to said valve member and an operating portion extending outwardly from said valve body; and an automatic return mechanism operably connected to the operating portion of said valve stem for moving said valve member between the open and closed positions, said return mechanism including an elongated housing having an elongated internal chamber, a drive shaft mounted in said housing for rotation about a rotational axis coaxial with said first rotational axis and having an intermediate portion disposed in said chamber, a first end operably connected to the operating portion of said valve stem and a second end portion accessible from the exterior of said housing, a manually-operated handle operably connected to the second end portion of said drive shaft for moving said valve member from one of said open and closed positions to the other;
a pinion gear having teeth carried by the intermediate portion of said drive shaft for common rotation therewith, a first elongated rack member slidably mounted in said chamber for reciprocative movement along a first longitudinal axis generally perpendicular to and radially spaced from said second rotational axis, one end portion of said first rack member having a drive portion including teeth which mesh with a first of the teeth on one side of said pinion gear, a second elongated rack member slidably mounted in said chamber for reciprocative movement along a second longitudinal axis generally parallel to said first longitudinal axis and generally perpendicularly to and radially spaced from said second rotational axis, one end portion of said second ramp member having a drive section including teeth which mesh with a second sector of the teeth on said pinion gear generally diametrically opposed to said first sector, first spring means providing a biasing force for biasing first rack in a first longitudinal direction, and second spring means providing a biasing force for biasing said second rack in second longitudinal direction opposite to said first longitudinal direction, whereby, when said handle is operated to move said valve member from one of said open and closed positions to the other, rotation of said pinion gear causes said first and second rack members to be moved longitudinally against the biasing force of the respective spring means and, when said handle is released, said first and second spring means cause said first and second rack members to be moved in opposite longitudinal directions and rotate said pinion gear to return said valve member to said one position.
a valve stem mounted in said valve body for rotation about a first rotational axis and having an internal portion connected to said valve member and an operating portion extending outwardly from said valve body; and an automatic return mechanism operably connected to the operating portion of said valve stem for moving said valve member between the open and closed positions, said return mechanism including an elongated housing having an elongated internal chamber, a drive shaft mounted in said housing for rotation about a rotational axis coaxial with said first rotational axis and having an intermediate portion disposed in said chamber, a first end operably connected to the operating portion of said valve stem and a second end portion accessible from the exterior of said housing, a manually-operated handle operably connected to the second end portion of said drive shaft for moving said valve member from one of said open and closed positions to the other;
a pinion gear having teeth carried by the intermediate portion of said drive shaft for common rotation therewith, a first elongated rack member slidably mounted in said chamber for reciprocative movement along a first longitudinal axis generally perpendicular to and radially spaced from said second rotational axis, one end portion of said first rack member having a drive portion including teeth which mesh with a first of the teeth on one side of said pinion gear, a second elongated rack member slidably mounted in said chamber for reciprocative movement along a second longitudinal axis generally parallel to said first longitudinal axis and generally perpendicularly to and radially spaced from said second rotational axis, one end portion of said second ramp member having a drive section including teeth which mesh with a second sector of the teeth on said pinion gear generally diametrically opposed to said first sector, first spring means providing a biasing force for biasing first rack in a first longitudinal direction, and second spring means providing a biasing force for biasing said second rack in second longitudinal direction opposite to said first longitudinal direction, whereby, when said handle is operated to move said valve member from one of said open and closed positions to the other, rotation of said pinion gear causes said first and second rack members to be moved longitudinally against the biasing force of the respective spring means and, when said handle is released, said first and second spring means cause said first and second rack members to be moved in opposite longitudinal directions and rotate said pinion gear to return said valve member to said one position.
17. A valve according to Claim 16 wherein said housing includes a pair of generally semicylindrical halves having opposed ends which are assembled together and cooperate to define at least a part of said chamber with said chamber having a cross sectional shape including generally semicircular opposed side portions having an inner surface;
end caps removable mounted on the opposite ends of the assembled housing halves and forming the opposite end walls of said housing;
each of said rack members includes an outer surface facing the inner surface of said side portions and having a shape generally corresponding to that of the inner surfaces of said side portions; and said spring means are disposed between one end of each of said rack members and one of said end caps.
end caps removable mounted on the opposite ends of the assembled housing halves and forming the opposite end walls of said housing;
each of said rack members includes an outer surface facing the inner surface of said side portions and having a shape generally corresponding to that of the inner surfaces of said side portions; and said spring means are disposed between one end of each of said rack members and one of said end caps.
18. A valve according to Claim 17 wherein each of said rack members has a first end portion including said teeth and an opposed second end portion including an enlarged first bearing surface;
said end caps have an inner wall including a second bearing surface; and said spring means comprises a compression spring having opposite ends and disposed between the second end portion of a said rack member and a said end cap with the opposite ends of bearing against said first and second bearing surfaces.
said end caps have an inner wall including a second bearing surface; and said spring means comprises a compression spring having opposite ends and disposed between the second end portion of a said rack member and a said end cap with the opposite ends of bearing against said first and second bearing surfaces.
19. A valve according to Claim 17 wherein each of said rack members has a first end portion including said teeth and an opposite second end portion; and said spring means comprises an extension spring having opposite ends with one end connected to the first end portion of said rack member and the opposite end connected to a said end cap.
20. A valve according to Claim 18 wherein said valve includes adjustable stop means for limiting the open and closed positions of said valve member comprising an elongated first stop member mounted in at least one of said end caps for adjustable longitudinal movement relative to said end cap, said first stop member including an external portion accessible from the exterior of said end cap and an internal portion extending to said chamber toward the second end portion of said rack member and engageable therewith to limit the opened position of said valve member; and a second elongated stop member mounted in said one end cap for adjustable longitudinal movement relative to said end cap, said second stop member having an external portion accessible from the exterior of said end cap and an internal portion extending into said chamber toward the first end portion of said rack member and engageable therewith to limit the closing position of said valve.
21. A valve according to Claim 20 wherein said valve is a ball valve.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US54189295A | 1995-10-10 | 1995-10-10 | |
| US08/541,892 | 1995-10-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2179851A1 true CA2179851A1 (en) | 1997-04-11 |
Family
ID=24161529
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2179851 Abandoned CA2179851A1 (en) | 1995-10-10 | 1996-06-25 | Automatic return mechanism for quarter turn valves |
Country Status (3)
| Country | Link |
|---|---|
| CA (1) | CA2179851A1 (en) |
| IT (1) | IT1286342B1 (en) |
| MX (1) | MX9604734A (en) |
-
1996
- 1996-06-25 CA CA 2179851 patent/CA2179851A1/en not_active Abandoned
- 1996-10-09 MX MX9604734A patent/MX9604734A/en unknown
- 1996-10-10 IT IT96RM000690 patent/IT1286342B1/en active IP Right Grant
Also Published As
| Publication number | Publication date |
|---|---|
| ITRM960690A1 (en) | 1998-04-10 |
| IT1286342B1 (en) | 1998-07-08 |
| MX9604734A (en) | 1998-04-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4504038A (en) | Valve actuator | |
| US3877677A (en) | Valve operator for butterfly valves or the like | |
| US4783882A (en) | Door closer assembly | |
| US4678002A (en) | Faucet valve with adjustable stem tightener | |
| CA2051951C (en) | Travel stop assembly for valves | |
| US5417404A (en) | Geared ball valve | |
| US4911412A (en) | Valves with improved actuators | |
| WO1991014892A1 (en) | Hemi-wedge valve | |
| GB2073374A (en) | Valve assembly | |
| US4605199A (en) | Ball valve provided with a lock ring | |
| US4189950A (en) | Manual control apparatus | |
| US4164343A (en) | Eccentric ball type valve | |
| JPH03555B2 (en) | ||
| HU191941B (en) | Rapid-action valve | |
| US4080844A (en) | Manual control apparatus | |
| CA2179851A1 (en) | Automatic return mechanism for quarter turn valves | |
| WO2008043360A1 (en) | Flow adjustment valve | |
| WO1992014084A1 (en) | Bellows sealed rotary valve and seal assembly | |
| US5301708A (en) | Rotary plug valve actuator and associated rotary plug valve and associated method | |
| US6189561B1 (en) | Valve cartridge for lift valve having the closing pressure on the sealing limited | |
| EP0003687B1 (en) | Manual control apparatus | |
| MXPA96004734A (en) | Automatic return mechanism for valves of a quarter of vue | |
| USRE29253E (en) | Valve operator for butterfly valves or the like | |
| AU2004286001B2 (en) | Adjustable sealing means | |
| US6059262A (en) | Valve operator and method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |
Effective date: 19990625 |