MXPA96004734A - Automatic return mechanism for valves of a quarter of vue - Google Patents

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 rod connected to the valve and having an outer portion accessible from the exterior of the valve body, the return mechanism has an elongate housing defining an elongated chamber, a drive shaft rotatably mounted in the housing and having one end connected in operation to the portion outer end of the valve stem, an intermediate portion disposed in the chamber and carrying a differential pinion, 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 camera pair reciprocal movement in directions longitudinally opposite and having teeth engagement with diametrically opposed sectors of the pinion teeth and a spring disposed between one end of each of the rack members and an end wall of the chamber for deflecting the rack members to an open position or closed, after the valve member has been moved from its original position with the handle, by release of the handle, the springs return the rack members to their original positions, causing rotation of the differential pinion to return to the valve member to its original position

Description

AUTOMATIC RETURN MECHANISM FOR A ROUND FOURTH VALVES BACKGROUND OF THE INVENTION 5 This invention relates to automatic return mechanisms for valves, such as quarter-turn valves, which automatically return the valve member to either of the two positions, fully open or fully closed, by the occurrence of a certain event such as release of an operation handle. Quarter-turn valves, + ales such as ball valves, butterfly valves and plug valves, typically include a handle that is connected in operation to a rod that carries the valve member and is rotated 90 ° to move the valve. 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 (1 closed or normally open + o) and is moved by one operator to the other position for only a short time. hand-operated, manually operated quartz + return valves commonly used for sampling purposes in procedures. For the procedures in which samples are routinely taken from a liquid undergoing treatment for analysis, the valve is normally closed and it is opened by an operator only long enough to remove an appropriate frequency of a liquid for a particular analysis In such applications, it is highly desirable that the valve include a return mechanism that automatically returns the valve member to the fully closed position when the operator releases the handle, rather than relying solely on the operator to ensure that the valve h has returned to the proper position. A conventional automatic return mechanism for manually operated valves includes an extension spring located inside a tubular handle with an end connected to the valve body at a radially spaced location from the axis of rotation of the rod. This spring is stretched when an operator moves the handle from any of the two positions, closed or open, and returns the handle to its original position when the operator releases the handle. Since the force of the spring is compensated from the axis of rotation of the rod, it imposes a lateral load on the rod which can displace the rod of its lining and cause leakage. An advantage of most manually operated quarter-turn valves is that the position of the handle can be used as an indication in the valve position., E or is, when the handle st pair-wing To the flow, the valve is open and when it is 90 ° from the flow, it is closed, the handles that use the return of the anterior spring are located at the flow when the valve is open or closed, making it impossible to determine the valve position from the position of the handle. Also to increase the closing torque, the length of the handle must be increased to accommodate larger springs at the point where the handle may become difficult to handle in some applications. Another conventional automatic return mechanism for manually operated valves includes a clock spring located in a housing at one end connected to the valve stem. The spring / housing unit is very expensive to manufacture and very bulky, 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 at higher proportions than the compression or extension springs. A reliable and relatively inexpensive automatic return mechanism is highly desirable for quarter-turn valves that do not impart a lateral force on the valve stem and / or do not have at least some of the other defects of the prior conventional ones. .

BRIEF DESCRIPTION OF THE INVENTION A principal object of the invention is to provide a relatively inexpensive reliable automatic return mechanism for valves, such as manually operated four-turn valves, which does not impose a lateral load on the valve stem. Another main object of the invention is to provide such an automatic return mechanism that can be conveniently retrofitted on existing valves. A further main object of the invention is to provide an automatic return mechanism that includes a housing that can be conveniently opened to inspect or replace parts within the housing. Still a further main object of the invention is to provide an automatic return mechanism that requires a low torque to move the valve member from its normal position. Other objects, aspects and advantages of the invention will be made clear to those skilled in the art by reading the following description of the above, the drawings and the appended claims. The invention provides an automatic return mechanism for valves which includes a body, a valve member disposed within the interior of the valve body and pivoted between an open position to allow the flow and a closed position to prevent the flow, and a rod rotated in the body and has a portion connected to the valve member and a portion of o? e? It is accessible from outside the body of the valve. The automatic return mechanism is operatively connected to the operating portion of the valve stem by moving the valve member between the open and closed positions. The return mechanism includes an elongate 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 connected in operation to the operating portion of the valve stem. and a second end portion accessible from the outside- of the housing. An operating means, such as a manually operated handle, is operatively connected to the second end of the drive shaft to move the valve member from one position to the other, a differential pinion having teeth is carried on the intermediate portion of the valve member. the drive shaft, a first rack member is slidably mounted in the chamber for reciprocating movement therein and includes an end portion having a drive portion having teeth that mesh with a first sector- of the differential pinion, a second rack member The elongate is slidably mounted in the chamber for reciprocal movement therein and includes an end portion having a driving section that includes teeth that mesh with a second sector of the differential gear generally in a diagonally opposite manner to the first sector. . A first diverter member deflects the first member (rack) in a first longitudinal direction and a second diverter member biases the second rack member in a second longitudinal direction opposite to the first longitudinal direction whereby, when the operating means operates to move the valve from either of the two positions, open or closed, the rotation of the differential pinion causes the two rack members to move longitudinally against the diverting force of the respective diverting means and, when the operating means is released, the The diverter means causes the two rack members to move in opposite longitudinal directions and rotate the pinion to return the valve member to its original position In a preferred embodiment, the housing chamber has a cross sectional shape that includes generally semicircular lateral portions that have a surface and interior and each rack member includes an outer surface facing the interior surface of the side portions and has a shape generally corresponding to that of the interior surfaces of the side portions. The housing preferably includes a pair of halves generally is icil? Ndr-? They are armed together and cooperate to define at least part of the camera. Preferably, the housing also has removable end heads which define the opposite ends of the chamber and threaded members, such as screw-in, of pressure, are easily mounted on the opposite ex erting heads, extend towards the chamber and mesh with each other. opposite ends of a rack member to limit the movement of the valve member between the open and closed positions.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 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. Figure 2 is a partially sectioned elevation view of the ball valve illustrated in Figure 1. Figure 3 is a sectional view taken generally along line 3-3 in Figure 1. Figure 4 is a view sectional view taken generally along line 4-4 in figure 3. Figure 5 is a fragmentary view of the r-egress mechanism with half of the upper part of the housing removed. Figure 6 is an elongated, partially fragmented and exploded view of the coupling between the return mechanism and the valve stem. Figure 7 is a fragmentary sectional view of an alternate embodiment employing a non-metallic raised portion in the vicinity of the differential pinion. Figure 8 is a view similar to Figure 3 of an alternative embodiment employing extension springs > There are compression springs instead.

DESCRIPTION OF THE PREFERRED MODALITIES The automatic return mechanism of the invention can be used for a wide variety of valves and similar controls that include a rotary control shaft carrying a control means and a manually operated operating means connected to the control shaft to rotate the control shaft. means of control between different positions. It is adaptable for quarter-turn valves, such as ball valves, butterfly valves and plug valves, which are normally kept either fully open or fully closed. It is particularly adaptable for manually operated ball valves and will be described in relation to that specific application. Illustrated in the drawings is a ball valve 10 which includes a body 12 which defines an internal flow passage 14 which extends therethrough and an external protrusion 16. The opposite ends 18 and 20 of the body 12 are internally threaded for connection to a pipe system (not shown) - Arranged inside the. body 12 is a rotary valve member consisting of a ball 22 having a central opening. ?4. The ball 22 is mounted on the valve seat 25 for rotational movement between an open popping where the opening 24 is aligned with a flow passage 14 as illustrated in Figure 2, and a closed position where the opening 24 is rotated 90 ° towards the position illustrated in Fig. 2 and the ball 22 blocks the flow through the passage 14. A rod 28 is rotatably supported on the protrusion 15 through a bearing liner 30 held in place. ? place by a threaded retainer 33 that surrounds the rod 28 and threaded into the protrusion 15. The retainer 33 is threaded sufficiently to compress the packing (not shown) surrounding the rod 28 towards the sealing gear with the rod 28. The rod 28 ee rotatable about d? N first axis of rotation or rod 34 and has an inner end portion connected to the ball 22 and an outer end portion 36 which is accessible from the outside of the body of the valve 16. In The specific modality illustrated, the external extreme portion 36 projects outwardly from the protrusion 16 and has a terminal portion 38. The ball 22 moves between fully open and fully closed positions by rotating 90 ° ei. rod 28 back and forth around the axis of the. shank 34 with a manually operated automatic return mechanism 40 embodying the invention, mounted on the valve body 16 and connected in operation to the valve rod 28. The return mechanism 40 has a housing 42 LO which is secured to a mounting bracket 44 that its e? it is mounted on the valve body 16. In the specific embodiment illustrated, the valve body 16 has a pair of projecting lugs 45 (one shown in Figure 2) including threaded openings 48, the mounting bracket 44 has an inner flange 50 adapted to fit against the ears 46 and includes a pair of openings 52 alignable with the openings of the ears 48 and the mounting bracket 44 is secured to the body of the valve 16 by p >cheeks 44 extend through openings in flange 52 and are screwed into openings of ears 48. mounting bracket 44 includes an outer flange 56 which is spaced outwardly and connected to flange. 50 inside a pair of reinforcement sections 58 and has a plurality of, for example 4, openings 60. housing 42 has a similar number of threaded openings 62 alignable with openings of outer flange 60 and is attached to flange. outer 56 by bolts 64 that extend through openings 60 in outer flange 56 and threaded towards openings in housing 62. housing 42 has an internal chamber 66 defined in part by opposite end walls in form of mounted end heads. rernovibl cemente 68 and 70 described in more detail immediately. return mechanism 40 has a drive arrow h2 mounted in housing 42 for rotation about a second rotation ee or drive shaft 64 which is preferably coaxial with axis of rod 32. drive shaft 72 has a first end portion 76 rotatably supported in housing 42 through a low friction bushing 78 and connected in operation to rod of valve 28, an intermediate portion 80 disposed in chamber 66 and which carries a differential pinion 82 and a second end portion 84 rotatably supported in housing 42 through friction bucket 86 and accessible from outside of housing 42. In specific embodiment illustrated, ball valve 10 is? of conventional design and r-egress mechanism 40 is designed to fit over existing valve without modifying it. More specifically, external end portion 36 of rod 28 projects externally from protrusion 16 and terminal portion 38 is threaded. valve normally has an elongated handle (not shown) that extends generally perpendicular to stem axis 32 and includes a handle portion and an inner extrusion portion connected to end portion 38 < rod 28. end portion 38 of rod 28 has opposed flat surfaces to receive a generally rectangular groove in extreme portion of handle and handle is held in place on valve stem with a nut (not shown) screwed on terminal part 38. An operator can rotate 90 ° ball 22 in re positions fully open and fully closed by turning handle. Instead of handle, first end 76 of driving shaft 72 is connected in drive to terminal flange 38 of valve stem 28 through a sleeve or coupling 90 (figures 2 and 6). One end 92 of coupling 90 has a slotted opening 94 for receiving terminal portion 38 of valve stem 28 and opposite end has a rectangular extension 96 which fits in a bushing 98 on first end 76 of drive shaft 72. coupling extension 96 and casing 98 can be of any complementary configuration. For example, when coupling extension 96 is rectangular as shown, casing 98 may also have a rectangular confi guration or may have an octagonal configuration so that rotational orientation of drive shaft 72 relative to rod of valve 28 can be adjusted during assembly. differential pinion 82 may be a separate too portion, suitably mounted in intermediate portion BO of drive shaft 72 and made of a material o than drive shaft, for example a synic moplastic or mal setting material, such as Delpn, an acetal resin commercialized by D? Pont. In illustrated specific embodiment, idler gear 82 is a grooved section ') () formed as an integral part of drive shaft? < •• includes teeth ti or gear LOO.

Although the housing 42 and the chamber 66 may have several suitable configurations, including rectangular cross sections or other polygon, in the specific illustrated mode, the housing 42 includes a pair of generally semi-cylindrical shells or halves 102 and 104 that include a body elongate 106, opposite side edges having petagne outwardly turned 108 extending along the length of the opposite edges. The housing halves 102 and 104 are removably secured therein if by a plurality of longitudinally spaced bolts 110 or the like which interconnect the flanges 102 and 104 as shown best in FIG. 1. The above-mentioned end heads 68 and 70 before they are removably mounted on the opposite ends 112 and 114 of the assembled Lenten halves 102 and 104 with bolts 116 or the like and cooperate therewith to define the chamber 66. In the specific embodiment illustrated, the chamber 66 it generally has a cylindrical shape and a transverse or oblong section having opposed generally semicircular side portions 118 and 120 having inner walls 122 as best shown in Figure 4. The halves of the housing 102 and 104 can be formed from a suitable metal, such < Like aluminum, or a matepa! Suitable non-synthetic metal ther oplast j for thermal setting, such as Deiim located within the housing m m a 66 and in L4 The side portions 118 and 120 thereof are a pair of a first and a second identical elongated creel members 122 and L24, each including an actuation portion 5 having teeth 128 that mesh with diagonal sectors. generally opposed to the teeth 110 on the ribbed portion 98 of the drive shaft 72. The rack members 122 and 124 are slidably disposed in the chamber 66 for reciprocal movement in opposite longitudinal directions relative to the side portions of the chamber 118. and 120. fias specifically, the first rack member 122 moves along a longitudinal axis 130 which is generally perpendicular to, and spaced radially from, the drive shaft 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 spaced radially from, the eed and the drive shaft 74. The outer surface 134 of the rack members 122 and 124 opposite the teeth 128 preferably have a generally semicircular cross-sectional shape corresponding to that of the side portions of the chamber 118 and L20. The rack members 122 and 124 can be made of a suitable metal, such as aluminum, or a suitable low-friction non-metallic material, for example, a synthetic thermoplastic or thermal fr-watering material such as Delr-in. 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 interior portions of the housing 123 along which it is formed. slide the rack members 122 and 124, is coated with a low friction material. In the illustrated specific embodiment, the rack members 122 and 124 are made of aluminum and the outer surfaces 134 are coated with Teflon or a similar fluorocarbon polymer. Such a coating is required if the cremalier members 122 and 124 are made of a non-metallic low friction material. The inner wall 123 of the housing 42 includes a raised portion 135 in the vicinity of the grooved section 98 on which the rack members 122 and 124 slide against each other reciprocal movement between the open and closed positions of the housing. the valve 10. The rack members 122 and 124 are effectively spliced between the grooved section 98 and the raised portion 136 and this may be the only means for guiding the rack members 122 and 124 and retaining them in place. Since less than the total length of the rack members 122 and 124 is in contact with the raised portion 136 at any time, the contact surface area between the rack members 122 and 124 and the housing 142 is reduced, resulting in a reduction in torque required to open and close the valve. The raised portion 136 can be bluntly formed part L6 integral of the housing halves as shown in Figures 2 and 8, or be in the form of a sleeve L38 the low friction material, such as Teflon and LOelrin, and fitted into an annular recess-140 in the housing 42 as is shown in Figure 7. To further reduce the 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, may be applied to the outer surface 134 between the members. zipper 122 and 124 and / or the inner surface of the raised portion 136. If the rack members 122 and 124 slide along the interior surfaces of the semicircular side portions 118 and 120 of the chamber 65, such lubricant may apply to these structures. The ball 22 can be moved from a fully closed position to a fully open position or vice versa by manually operating an operation means connected in operation 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 that is coiled and has opposite planar surfaces (Figures 1 and 2). The operating means is in the form of a manually operated elongate handle 142 which includes a rake-holder portion 144 and an inner end portion 146 having a groove (not shown) which fits over the base I? terminal 140 of the drive shaft 72. The handle 142 is held in place on the drive shaft 72 by a threaded nut L48 on the end portion 140. Suitable derailleur means are provided to divert the zipper member 122 and 124 in directions opposing longitudinals to rotate the drive shaft 72 through the grooved section 98 to a rotational position corresponding to the fully closed or fully open position of the ball 22 and releasably retaining the drive shaft 72 in that position. Although different means suitable for this purpose may be used, in the specific embodiment illustrated in Figures 1, 3 and 5, the diverting means includes a compression spring 150 located between each rack member 122 and .124 and a spring retainer within the receiving chamber 66. More specifically, the end portion 152 of each rack member 122 and 124 opposite the drive section 126 is elongated to provide a bearing surface 154 for one end of a spring 150, and the inner surfaces 156 of the end heads of the housing 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 1.24 and the inner surfaces 155 of the end heads 6fl and 70 include preferably protuberances generally cylindrical extending longitudinally 158 and 160, respectively, Which fit within the former tremo '', opposites of springs 150 to hold them in place. The protuberances 160 have been omitted from Figure 5 for reasons of clarity. Figure 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 retain the ball 22 in the fully closed position and the ball 22 has been moved to the position fully open by rotating 90 ° handle 142. As seen in figure 3, when an operator releases handle 142, springs 150 move simultaneously with rack members 122 and 124 to the left and right, respectively, causing the driving arrow 72, and therefore the ball 22, rotate in a levorotatory fashion from the fully open position to the fully closed position. When an operator reopens the valve by rotating 90 ° the handle 142 in a clockwise direction as shown in Figure 3, the rack members 122 and 124 move simultaneously to the right and to the left, respectively, in response to the clockwise rotation of the grooved section 98 of the drive shaft 72 and the r-ports 150 are compressed as illustrated. In both illustrated embodiments, the rack members 122 and 124 are arranged so that the ball rotates in the same manner as it will open. In the field of valves, the normal practice is that the ball will rotate dexterously to ce rr-ar.

To avoid potential air entrapment which could increase the amount of torque required to open and close the valve, the end heads 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 may include a pressure relief sealing mechanism to prevent the ingress of noxious gases, flames, etc. Another type of conventional 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 relocated by extension springs 162 suitably connected between the drive portion 126. of the rack members 122 and 124 and the end cap 68 and 70, respectively. With such an arrangement, the extension springs 162 are extended instead of being compressed, when the drive shaft 72 is rotated towards the position illustrated in FIG. 3, and pulls the rack members 122 and 124 to the left and right, respectively, causing the drive shaft 72 to rotate in a left-handed manner to a fully closed position when an operator 11 bera l manij 14. The return mechanism 40 preferably includes external means to adjust the stopping position for the ball 22 in the open and closed position. In the specific embodiment illustrated in Figures L-7, such means comprise a p =? R of threaded members, such as set screws 166 and 168, threaded into each end head 68 and 70, and extending toward chamber 66. A screw of pressure 166 is to limit the open position and extends through the spring retaining protrusion 160 on an end head and engages the spring retention protrusion 158 on a rack member when the rack member is in the open position. The other pressure screw 168 is for limiting the closed position and engages the end 160 of the driving section 126 of a rack member when the rack member has returned to the closed position. For the assembly of the r-egress mechanism 40, one end of the drive shaft 72 may be installed in a first housing half 104, the cremaler members 122 and 124 installed in that housing half, de-ally the second housing half. 102 on the opposite end of the driving shaft 72 and moved towards the place with the flanges 108 adjoining and securing the halves of the housing together. The end heads 68 and 70 move to the place after the outer ends of the springs 150 have been slid over the protuberances 158 on the end heads, and mounted on the assembled housing halves. The bracket 44 can be mounted first either in the housing 42 or in the valve body 12 and then ontai or in the other. In any case, the coupling 96 is preferably installed on the terminal part 38 of the valve stem 28 before the final assembly, and the bushing of the drive shaft 98 slides on the coupling extension 96 as the mechanism of movement moves to the place. return or the mechanism / r-egress bracket. The condition of springs, rack members and other internal parts can be inspected, broken springs replaced and / or large springs calibrated to provide a higher closing torque installed by removing and replacing the end springs. The construction of the return mechanism 40 in relation to a conventional manually operated ball valve has been described. With such an arrangement, existing manually operated ball valves can be converted into valves with automatic regr-it capability by simply installing a return mechanism of the invention in place of the operating handle during assembly, or by re-fitting the assembled valves by removing the handle and replacing it with a return mechanism of the invention. From the foregoing description, a person skilled in the art can easily determine the essential characteristics of the invention and, without departing from the spirit and scope thereof, make various paths and modifications to adapt it to various uses.

Claims (2)

NOVELTY OF THE INVENTION CLAIMS

1. A valve including, a valve body having a flow passage extending therethrough; a valve member disposed in said flow passage and movable therein an open position to allow flow through said flow passage and a closed position to prevent flow through said flow passage; A valve stem mounted on said valve body for rotation about a first axis of rotation and having an inner portion connected to said valve member and a portion of op > arm accessible from outside of said valve body; and an automatic return mechanism connected in operation to the operating portion of said valve stem to move said valve member between the open and closed positions, said regashing mechanism including, an elongate housing having an elongated internal chamber; a drive shaft mounted on said housing for rotation about a second axis of rotation and having an intermediate portion disposed in said chamber, a single external portion connected in operation to the operating portion of said shaft valve and a second end portion accessible from the outside of said housing; operative means connected in operation to the second end portion of said driving arrow for moving said valve member from one of said positions, open and closed, to the other; a differential pinion having teeth driven by the intermediate portion of said driving arrow for common rotation together with the; a first elongated rack member slidably mounted in said chamber for reciprocal movement along a first longitudinal axis generally perpendicular to, and radially spaced from, said second axis of rotation, an end portion of said first rack member having a portion of drive that includes teeth q? e mesh with a first sector of the teeth on a side of said differential pinion; a second elongated rack member slidably mounted in said chamber for reciprocal movement along a second longitudinal axis generally parallel to said first longitudinal ee and generally perpendicular to, and radially spaced from, said second axis of rotation, an end portion said second rack member has a drive section including teeth that mesh with a second sector of the teeth in said differential pinion, generally in a form dianetrically opposed to said first sector; first diverter means providing a diverting force for deflecting said first zipper member in a first longitudinal direction, and second diverter member providing a diverting force for diverting said second zipper member in the second longitudinal direction, opposite said first long-distance direction, whereby, when said operating means operate to move said valve member from one of said positions, closed and closed, to the other, the rotation of said differential pin causes said first and second rack members move longitudinally against the diverting force of the respective diverting means and, when said operating means are released, the first and second diverter means cause the first and second rack members to move in opposite longitudinal directions and rotate said differential pinion to regress said valve member to said position. 2.- A valve in accordance with the claim 1, further characterized in that said operating means comprises a manually operated handle connected to the second end portion of said driving shaft. 3.- A valve in accordance with the claim 2, further characterized in that said chamber has a transverse shape including generally semicircular opposite side portions having an inner surface; and each of said zipper members includes an outer surface facing the inner surface of said side portions and has a shape generally corresponding to that of the interior surfaces of said portions 1 at e \\ 1 e. 4.- A valve in accordance with the claim 1, further characterized in that said housing includes a \ - > The halves are generally semi-solid, which are assembled together and cooperate to define at least one part of said chamber. 5. A valve according to claim 3, further characterized in that said housing has a raised portion that extends internally radially from the inner surface of said side portions in the vicinity of said differential pinion and has an inner surface, said rack means sliding along the interior surface of said raised portion during movement between the open and closed positions. 6. A valve according to claim 2, further characterized in that said housing has opposite ends defining said chamber in part; and said first and second diverter means comprise a spring disposed between one end of each of said cream members! parrot and one of those extreme walls. 7. A valve according to claim 6, further characterized in that said housing has a main body that includes a hollow interior and opposite ends; and said end walls comprise an end cap removably mounted on each of the ends of said housing body and cooperating with the same or to define said c-love. 8.- A valve in accordance with the rei indication 1, further characterized in that each of said rack members has a first end portion that includes a first flanged support surface; said end heads have an inner wall that includes a second bearing surface; and said spring means comprises a compression spring having opposite ends and disposed between said second end portion of a rack member and said end wall with the end edges resting against the first and second bearing surfaces. 9. A valve according to claim 8, further characterized in that said compression spring is an elongated spiral spring having opposite ends; said first support surface includes an outwardly extending protrusion which fits within one end of said spring; and said second support surface includes a protrusion extending outwardly - which fits inside another end of said spring. 10.- A valve in accordance with the claim 8, further characterized in that each of said rack members has a first end portion including said teeth and a second opposite 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 said ex-pair. 11. A valve in accordance with the claim 7, further characterized in that each of said rack members has a first end portion including said teeth and a second opposite end portion; and said valve includes adjustable stop means for limiting the open and closed position of said valve member comprising, a first elongate stop member mounted on at least one of said end heads for adjustable longitudinal movement relative to said end head, said first stop member includes an external portion accessible from the outside of said end head and an inner portion extending in said chamber towards the second end portion of a rack member and engageable therewith to limit the open position of said valve member; and a second elongated stop member mounted on said end-torque-adjustable longitudinal end head relative to said end head, the second stop member having an external portion accessible from the outside of said extr-emo head and an internal portion that is extends in said chamber towards the first end portion of a rack member and engageable therewith to limit the closing position of said valve member. 1

2. A valve according to claim 2, further characterized in that said differential pinion is a grooved section formed co or an integral part of said drive shaft. 13.- A valve in accordance with the claim ? , further characterized in that the operating portion of said valve stem extends outwardly from said valve body and has a terminal part; the first extrusion portion of said driving arrow includes a female lug; and said return mechanism includes a coupling having a first end connected in operation to the terminal part of said valve rod and a second end which fits in the bushing on said driving shaft. 14. A valve according to claim 2, further characterized in that said valve is a quarter-turn valve. 15. A valve according to claim 14, further characterized in that 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 movable flow passage between an open position to allow the flow through said flow passage and a closed position will prevent the flow through said flow passage; a valve rod mounted on said valve body for rotation about a first axis of rotation and having an inner portion connected to said valve member and an operating in-line extending outwardly from said valve body;; and an automatic return mechanism connected in operation to the operating portion of said valve stem to move said valve member in the positions of the valve. open and closed, said return mechanism including an elongated housing having an elongated internal chamber, a drive shaft mounted on said housing will rotate about an axis of rotation coaxial with said first rotation ee and having a p > intermediate orc disposed in said chamber, a first end connected in operation to the operating portion of said valve stem and a second end portion accessible from the outside of said housing, a manually operated handle connected in operation to the second end portion of said driving arrow to move said valve member from one of said positions, open and closed, to the other; a differential pinion having teeth which are carried by the intermediate portion of said drive shaft for common rotation together with the first elongated rack member slidably mounted in said chamber for reciprocal movement along a first longitudinal axis generally perpendicular to, and radially spaced from, said second axis of rotation, an end portion of said first rack member has a drive portion that includes teeth that mesh with a first of the teeth on one side of said differential pinion. , a second flared rack member slidably mounted in said chamber pair reciprocally movement along a second longitudinal axis generally par-allele to said first longitudinal axis and generally in a perpendicular fashion to- and radially spaced from said second axis of rotation, a end portion of said second ramp member that has a drive section that? it includes teeth engaging with a second sector of the teeth in said differential pinion generally diametrically opposite to said first sector-, first spring means providing a diverting force for deflecting the first rack in a first longitudinal direction, and second spring means providing a diverting force for deflecting said second zipper in the second longitudinal direction opposite 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, the rotation of said differential pinion causes the first and second rack members to move longitudinally against the deviating force of the respective spring means and, when said handle is released, the first and second spring means cause the first and second rack means to move in opposite longitudinal directions and rotate the directional pinion to return the valve member to said position. 17. A valve according to claim 16, further characterized in that said housing includes a far- halve generally parallel moieties having opposite emo1 ', which are assembled together and cooperate to define p? I how much does a part e? said chamber having a transverse ridge which generally includes opposite semicircular side portions having an inner surface; removable end heads mounted on opposite ends d-1 the assembled housing halves and forming the opposite outer walls of said housing; said rack members include an exterior surface facing the inner surface of the side portions and having a shape generally corresponding to that of the interior surfaces of the side portions; and said spring means are disposed between one end of each of said rack members and one of said end heads. 18. A valve according to claim 17, further characterized in that each of said rack members has a first end portion including teeth and an opposite second end portion that includes a first elongate bearing surface; said ex-spindle heads have an inner wall including a second bearing surface; and said spring means comprise a compression spring having opposite ends and disposed between the second end portion of the rack member and an end head with the opposite ends of the supports contiguous with said first and second bearing surfaces. 19. A valve in accordance with the rei indication L7, further characterized in that each of the members d: cremaller-a have a p i or r-a extrusion that includes said teeth and a second portion ext rows opposite; and said spring means comprise an extension spring that rests opposite ends with one end connected to the first end portion of the rack member and the opposite end connected to one of said end heads. 20. A valve according to claim 18, further characterized in that said valve includes adjustable stop means for limiting the open and closed positions of said valve member, comprising, a first elongate stop member mounted at least one of said end heads for adjustable longitudinal movement relative to said end head, said first stop member includes an external portion accessible from the outside of said end head and an inner portion extending said chamber toward the second end portion of said the rack member and engages with the same pair to limit the open position of said valve member; and a second elongated stop member mounted on said extr-emo head for longitudinal movement adjustable in relation to said head, end, the second stop member having an external portion accessible from the outside of said head, end and an internal portion q? and extends in said chamber towards the first end portion of said rack member and engaged therewith to limit the closing position of said valve. 21. A valve according to claim 20, further characterized in that said valve is a ball valve "13 SUMMARY OF THE INVENTION 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 connected rod to the valve and having an outer portion accessible from the outside of the valve body; the return mechanism 0 has an elongate housing defining an elongated chamber, a drive shaft rotatably mounted in the housing and having one end connected in operation to the outer end portion of the valve stem, an intermediate portion disposed in the chamber and having a differential pinion, an outer end portion extending externally from the elevator, a manually operated handle connected to the outer end portion of the drive shaft, a pair of rack members mounted within the interior of the camera. a reciprocal movement in longitudinal or opposite directions and having teeth meshing with sector-diainetral is opposite of the pinion teeth and a spring disposed on one end of each of the members, of a rack and a par-ed The end of the chamber for deflecting the rack members to an open or closed position; r ~ > after the valve member has been moved < \ e < -u original position with the handle, by releasing the handle, the springs return the rack members to their original positions, causing rotation of the differential pinion to return the valve member to its original position. EA / crm * cpm * ieoh *