Abstract: A stem nut for driving a valve stem is coaxially rotatable within a drive collar which is offset from the axis of a nutating drive motor. The drive motor and the drive shaft are coupled together for rotation by means of readily interchangeable sprockets driven by a roller chain. The coaxial stem nut and the drive collar are releasably locked together by removable pins. When the pins are removed, the stem nut permits the valve stem to be directly operated with a wrench or the like. The stem nut is readily removable from the offset drive assembly by releasing a snap ring.

Abstract: An extremely accurate and inexpensive true sidereal rate drive assembly for an astronomical telescope, the telescope including a base having a driven gear rotatable about the polar axis of the telescope, and the drive assembly including a housing mounted on one side of the base, a single low speed synchronous drive motor mounted in the housing, and a worm gear mounted on the drive shaft of the motor for directly coupling the motor to the driven gear. In addition, a thumbwheel may be provided which is coupled to the motor shaft through appropriate reduction gearing, and which serves as a fine adjustment control for the telescope.

Abstract: A motor vehicle roof arrangement having a cover that can be slid and/or tilted out with respect to an opening in the roof. The cover is movable by means of an electric motor through at least one incompressible driving cable. The electric motor is mounted at a front side of the opening in the roof on a stationary part of the roof, and by means of a secondary drive wheel of an intermediate drive, drives a pinion that is engaged in the driving cable. The pinion is arranged in a front rain groove of a roof frame essentially on the center longitudinal axis of the roof of the motor vehicle. The intermediate drive is located in a gear housing to which the electric motor is flanged to form a drive unit. A secondary drive gear of the intermediate drive is detachably connected with a shaft of the pinion by mating internal and external gear elements.

Abstract: A device for varying fluid pressure in increments in order to vary the position of a mechanism in a remote location such as a valve wherein the output pressure of the fluid may be controlled through an automatic system which may be manually overridden without disengaging the automatic control system.

Abstract: An actuator with a positive centrifugal clutch has a clutch drum loosely rotated relative to a rotary drive shaft and is provided with large inner diameter portions and engaging protuberances inwardly projecting from the large inner diameter portions; a clutch body loosely fitted within the clutch drum and driven by the rotary drive shaft, and provided with a retaining hole opening radially from the center thereof toward the inner wall of the clutch drum; and an engaging permanent magnet loosely movably retained in the retaining hole of the clutch body. When the clutch body is in a standstill state, the engaging permanent magnet provides a magnetic attraction between itself and the rotary drive shaft and thereby is accommodated within the retaining hole. When the clutch body continues its rotation, centrifugal force is generated.

Abstract: This auxiliary control device for manually and rotatably driving, for example in case of failure of the current supply system, a motor and reduction gear unit kinematically connected for example to a winding door or grille, a sectional door, or the like, comprises a pulley adapted when rotated to cause the axial movement of a sliding member through the medium of a cam device disposed across the pulley and the sliding member. This sliding member comprises on the one hand a set of dogs of a first half-coupling which are adapted to engage the dogs of another set rigid with the main driven shaft, and on the other hand noses adapted to engage guiding projections formed on a rotary braking member disposed coaxially to the pulley. When the dogs of the two sets engage each other the noses are fully disengaged from the guiding projections and thus the rotary braking member does not exert any antagonistic torque likely to counteract the actuation of the auxiliary control device.

Abstract: A hydraulic choking device for use in controlling fluid flow from an oil or gas well, having an improved valve chamber and valve design to reduce parts' wear and facilitate repairs, wherein the chamber is provided with a cavity within the chamber passageway sidewall to which the fluids are initially directed and wherein a ball nose plug is utilized as the valve gate to seal the valve.

Abstract: In a window lifter drive for motor vehicles a base member contains a cable drum to which a manual crank handle drive or a motor drive can be selectively secured. The base member includes a housing enclosing the cable driven with an opening on one side for a pinion on the crank handle drive. The housing has an opening on the opposite side for a driving claw part of the motor drive. Each of the pinion and the driving claw part can act directly on the cable drum.

Abstract: An adjustment drive apparatus particularly for motor vehicles having coaxial rotatably supported driving and driven members with a helical spring which is braced against the inner circumferential surface of a hollow cylindrical element coaxial with these members operating to effect drive transmission therebetween. One of the members has a first claw or driver connection member rigidly affixed thereto, the claw member pressing against one of the ends of the helical spring to effect an extension or enlargement of the spring when relative rotation occurs between the spring and the claw member. The hollow cylindrical element within which the helical spring is located is affixed for rotation with the other of the driving and driven members. An auxiliary driving member is provided which, when activated, will cause the spring to be disengaged so that the driven member may be rotated through the auxiliary driving member.

Abstract: A two mode operable piston pump has a cam lock with a shaft biased into the drive axial passage of a cam shaft to lock the cam shaft to a lever body, a lock edge on the lever body engaging a flat on a head portion of the cam lock. Inserting a power tool into the drive axial passage opposite the head pushes the shaft up and releases the cam shaft for operation of the pump in a power mode.

Abstract: Means are provided for coupling at will a driven shaft (2), intended more particularly for adjusting the orientation of the blades of a boat propellor, either to the output shaft (1) of a motor or to a hand operable member (3). To this end there are provided three coaxial inwardly splined ring-wheels juxtaposed axially and integral respectively, the first two (13,14) with the two shafts and the third one (16) with said member, an outwardly splined hub (15), a tangent wheel (22) integral with said member and coacting with an endless screw (23) operable by means of a crank and screw means actuated by the rotation of a crank mounted on a head (28) and arranged so as to control the axial sliding of the hub by means of thrust bearings (32) and springs (33).

Abstract: A microtome actuable both manually and by a motor, with a single coupling element, whereby rotation of the hand wheel when the motor drive is engaged and thus the risk of injury by the manual grip are excluded. The coupling element is located in the hand wheel and is capable of locking in two positions by means of pulling and rotating, the respective positions establishing the manual or motor drive mode. The drive mode is made readily apparent from the outside by means of symbols. In the hand wheel, an equalizing weight for the object carriage is provided.

Abstract: A valve operator has a de-clutch mechanism for automatically shifting the clutch out of handwheel drive and into electric motor drive upon actuation of the electric motor. The motor drive sleeve 23 has an annular step 25 which has a flat 26. The clutch 50 is biased by spring 55 toward the motor drive sleeve 23 but is prevented from moving in the direction of the motor drive sleeve by the clutch fork 40 which has extending therefrom two latch arms 71,72 one of which 71 is longer than the other 72. The longer latch arm 71 abuts against the step 25 on the motor drive sleeve. When the electric motor M is energized, the motor drive sleeve rotates and the flat 26 comes into alignment first with the longer latch arm 71 and later with the shorter latch arm 72, thereby releasing in two steps the clutch fork 40 and allowing the clutch 50 to shift out of handwheel drive and into electric motor drive.

Abstract: An improved closure operator as for example for a garage door opener wherein a motor is coupled to the drive shaft of the door at one end thereof to drive pull-up and pull-down pulleys and a clutch mechanism is provided between the drive motor and the drive shaft which can be decoupled by moving a lever arm so as to disconnect the motor from the drive shaft to allow the door to be manually opened or closed as, for example, in the event of power failure. The unit results in a substantial simplification over prior art garage door operators which require a rail and trolley mechanism for opening and closing the door.

Abstract: A vehicle includes a hydraulically operated multi-speed transmission controlled by a rotary pilot valve and pilot-operated shift valves. An electronic control unit generates electrical control signals for automatically controlling the transmission. A manually movable lever generates mechanical transmission control signals. An interface mechanism includes a sector gear which rotates the rotary valve in response to movement of the lever. A stepping motor rotates the sector gear via a torque-multiplying gear train in response to the electrical control signals. A rotary gear ratio encoder is rotatably cooupled to the rotary pilot valve and generates signals indicative of the actual gear ratio of the transmission.

Abstract: A mechanical override is provided for use with electromechanical linear actuators used in the control of lever operated valves. A pair of telescoping tubes are supported in a fixed relationship to the valve. One tube provides a mounting location for the linear actuator while the other tube is stationary. A lead screw will be manually rotated to move one tube relative to the other. The linear actuator will travel with the moving tube to adjust the valve position.

Abstract: A manual actuator which enables manual operation of a valve, damper or other controlled element upon loss of hydraulic pressure in an associated electrohydraulic actuator assembly. The apparatus preferably includes nut segments which are automatically moved into engagement with a coacting threaded shaft upon loss of hydraulic pressure in the electrohydraulic device and which function when so engaged with the shaft to render a manual operating element effective to move the controlled part.

Abstract: The disclosure is directed to an angle adjusting arrangement for mirror for use in a motor vehicle and the like, which is free from variations due to atmospheric temperatures, in the state of magnetic coupling between driving mechanisms and the mirror so as to achieve a predetermined coupled state for positive operations at all times, and is also capable of manual adjustments as desired, without a possibility of any damage to the arrangement.

Abstract: Drive mechanism for a feed screw or threaded spindle for tool machines. The threaded spindle is drivable both by a drive motor and also by a handwheel which can be coupled by an axial shifting movement of a control rod. The drive connection between the drive motor and the threaded spindle is released through an axial movement of the handwheel, so that the output shaft on the motor on the one hand is not moved in response to a rotational movement of the handwheel and, on the other hand, cannot drive the threaded spindle in the case of an unintended start.

Abstract: Control system which may be manually operable without disengaging, automatically or otherwise, the automatic features of the control system.

Abstract: A stem nut for driving a valve stem is coaxially rotatable within a drive collar which is offset from the axis of a nutating drive motor. The drive motor and the drive shaft are coupled together for rotation by means of readily interchangeable sprockets driven by a roller chain. The coaxial stem nut and the drive collar are releasably locked together by removable pins. When the pins are removed, the stem nut permits the valve stem to be directly operated with a wrench or the like. The stem nut is readily removable from the offset drive assembly by releasing a snap ring.

Abstract: A valve operator (10) which includes a ball screw (28) in constant engagement with the output shaft (24) of an air cylinder for automatic operation of the valve, and which includes a manual drive means (20) engageable with the ball screw (28) in any position thereof. The manual drive means (20) includes a ball nut (30) engaged with the ball screw (28), a clutch output member (34) attached to the ball nut (30), a clutch input member (38) which is rotatable by a handwheel (56) through a worm gear train (49, 52), and a manually actuatable clutch actuating assembly (42) which is operable to engage the clutch input member (38) with the clutch output member (34).

Abstract: A drive shifting apparatus for a valve control and the like is provided with a source of power for motor operation, a separate source of power for hand operation and a shifting means shiftable between the hand power and motor power sources. The shifting means may be a spring loaded clutch normally connecting the motor power source with the valve control, a latch means to hold the clutch in the hand power position against the spring pressure and a cam on the motor automatically releasing the latch when the motor is energized.

Abstract: An actuator device is disclosed for opening a sliding door comprises a casing or box in which a driven shaft is rotatably carried, wherewith are in rigid rotatory relationship a pinion gear meshing with a rack mounted on the sliding door and a helical gear wheel meshing with a worm screw keyed to a driveshaft driven by an electric motor housed in the casing and including a rotor carried on the driveshaft and arranged between a pair of plates one whereof is rigid with the driveshaft and the other whereof is rotatively coupled to but axially movable with respect to the driveshaft by means of a torque limiter.

Abstract: A coupling device, located between the drive part and the cycle part of a moped, wherein the crank drive is provided with a stationary double pinion, connected by an endless chain to the free-wheel pinion, which is secured to the back wheel of the moped, for driving the back wheel by either pedaling or by engine power. The axle of the crank drive passes through the hub of a trapezoidically grooved pulley which is connected by an endless belt to the drive pulley, which is driven by an engine. A mechanism, carried by the grooved pulley, makes it possible to optionally connect or disconnect the grooved pulley, and its associated double pinion, from the engine drive. This mechanism constitutes a double lever having a bent projecting nose, which lever is controlled by a pivotable control button to move the lever between a locked and unlocked position, as desired. When the engine drive is uncoupled from the rear wheel of the moped the moped can be powered by pedalling or by free wheeling.

Abstract: A rotary actuator having an output drive rod mounted within an output sleeve that is rotated by a drive motor. A driving mechanism for coupling the torque of the drive motor to the output sleeve includes a worm wheel that is mounted on the output sleeve so as to be freely rotatable relative to the output sleeve and a driving portion for transmitting power from the worm wheel to the output sleeve. A clutch also is mounted on the output sleeve for rotation with axial movement along the output sleeve. The clutch is normally biased into its first position for engagement with the drive portion of the drive mechanism for coupling it to the output sleeve for transmitting rotational force. A declutch mechanism causes the clutch to be moved of engagement with the drive portion, if the drive portion ceases to operate and the output sleeve is to be rotated by a hand wheel.

Abstract: A gas-operated valve actuator having a gas operated motor, a mechanism for disengaging the valve's manual operation apparatus, and a device for quickly shutting off the actuator when the valve's drive shaft reaches its travel limit.

Abstract: This invention relates to a motorized actuator in which the motor shaft is drivably connected with the output shaft through an intermediate shaft assembly.The motor shaft assembly includes a worm and wormwheel which is formed with cut-outs each drivably receiving the extended ends of some of the teeth of a pinion which forms part of the intermediate shaft assembly. The pinion is at all times in driving engagement with a gear on the output shaft and is axially movable by a lever to disengage the motor drive so as to allow independent manual operation of the pinion and thereby the output shaft by a handwheel mounted on a shaft. The shaft is drivably coupled with a wormwheel which is in driving engagement with the pinion by means of the driving lugs.

Abstract: An electrical window lift drive especially for use in a motor vehicle, includes a drive housing, an electric motor attached to the housing having a shaft extending into the interior of the housing. A worm gear is mounted on the motor shaft for rotation thereby. A worm wheel is mounted for independent rotation coaxially with respect to a first portion of a bearing shaft inside the housing on a member intermediate the bearing shaft and the wheel. The bearing shaft is supported in the housing on both sides of the worm wheel and extends transversely of the motor shaft. The worm wheel meshes with and is driven by the worm gear. A drive member is mounted coaxially with respect to a second portion of the bearing shaft, and means are provided intermediate the worm gear and the drive member for transferring rotary motion of the worm gear to the drive member.

Abstract: An apparatus for feeding a workpiece to a machine is provided which may be driven by either a handcrank or an electric motor. The handcrank and the motor are each coupled to the apparatus by a clutch. The clutch for the handcrank is spring biased to a disengaged condition. A selector lever for engaging the clutch associated with the motor and for actuating the motor is also provided. The selector lever and the handcrank are oriented such that only one of them may be in driving relationship with the apparatus at any one given time.

Abstract: A support structure (10), preferably a rotatable bed, pivotable between a generally horizontal use position and a generally vertical storage position is disclosed. A counterbalancing mechanism (20) which reduces the amount of force needed to rotate the support structure (10) is operatively connected to the support structure (10). A drive arm (70) driven by a motor mechanism (64) in a linear direction is also operatively connected to the support structure (10). The drive arm (70) is connected to the support structure (10) through a linkage apparatus. The linkage apparatus has linkage plates (82) pivotably connected to drive arm (70) and connecting plates (92) extending from the support structure (10). A T-shaped rod mechanism (102) is engaged by latch (116), rotatably connected to the linkage plates (82), and extends through a hole in frame member (14) of support structure (10) where a coil spring (124) is received about the rod mechanism (102).

Abstract: A manual override drive apparatus for use with normally powered driving assemblies, such as valve actuators, is disclosed which has a body having an axial bore therethrough, a shaft movable axially but not rotatably extending through the bore and having screw threads thereon, a cage in the body rotatably disposed about the shaft having elongate circumferentially arranged pockets and restrained against axial movement by thrust bearings, a plurality of elongated gear segments movably disposed in the pockets having screw threads which mate with the threads on the shaft, cam means operable to move the gear segments toward and away from the shaft for engagement and disengagement of the screw threads on the shaft and the gear segments, and means operable to rotate the cage and thus the gear segments thereby driving the shaft axially when the gear segments are in threaded engagement with the shaft.

Abstract: A manual override control for use with a double-acting hydraulic or electric powered valve actuator provides means for selectively moving the actuator rod between its extended and retracted positions in the event of a failure of the primary actuator control means. The override control includes a generally cylindrical housing having an axial passage throughout its length, means for connecting one end of the passage to an actuator housing, a threaded drive nut rotatably mounted in the other end of the passage, a threaded member having a socket portion at one end thereof for releasably connecting it to an actuator rod, and means for rotating the drive nut to move the threaded member, and thus the actuator rod, in an axial direction. When functional operation of the primary actuator control means is restored, the override control can be quickly disconnected from the actuator rod and/or normal operation of the actuator can be resumed.

Abstract: The coupling means can be mounted over a rotatable shaft of existing motors and employs a lining sleeve which is disposed about or within the shaft and a helical spring which is disposed between the sleeve and shaft. Various types of couplings are used to secure a hand wheel to one or both ends of the spring such that rotation of the hand wheel causes the spring to bind about the shaft and cause turning of the shaft. In some embodiments, rotation of the hand wheel causes the opposite end of the spring to bind about the shaft to turn the shaft with the hand wheel.

Abstract: A valve assembly for regulating the amount or pressure of hydraulic fluid supplied to a hydraulically operated machine system comprises a progressively movable valve member, especially a rectilinearly-moving valve spool controlling ports in a ported valve sleeve, a motive power unit, such as an electric stepper motor, disengageable speed-reducing coupling means, including a worm and worm wheel, to convert the rotary output motion of the motor into valve motion, a valve member position feedback transducer, and an electrical controller controlling the motor in response to input command signals and the feedback signal. A manual override control lever is provided for moving the valve member when the power drive is disengaged.

Abstract: A portable drive unit for a valve actuator includes a portable two-cycle or four-cycle gasoline engine and a gear reducer. The gasoline engine is bolted, through vibration damper means, to the housing or gear box of the gear reducer. The gear box is clamped to the valve actuator through an annular clamp and clamp-receiving adapter structure which also includes vibration damper means. A flexible sleeve coupling in the bore of the annular clamp and clamp-receiving adapter couples the output shaft of the gear reducer to the handwheel input shaft of the valve actuator.

Abstract: A manual and power motivated drive apparatus, wherein a web is advanced by a drive means, such as a motor comprises; a driven means mounted on an output shaft coupled to the drive means; a manually rotatable input shaft; a first motion transmission means mounted on the input shaft; and a second intermediate motion transmission means engaging the first transmission means and rockable about the input shaft upon the rotation of the first transmission means. The second transmission means is rocked about the input shaft upon rotation thereof in a manner to be brought into engagement with the driven means, whereby the driving force of the input shaft is transmitted by way of the first and second transmission means and the driven means to the output shaft.

Abstract: A remote control steering attachment for a steering wheel wherein a driving motor is releasably attached to the steering wheel by means of a cross member adjustably bolted to the steering wheel. A clutch is interposed between the driving motor and the steering wheel so that the steering wheel can be operated when the unit is declutched and the driving motor is not being used. A remote control is used for controlling the driving motor and thus turning the steering wheel from a location distant from the steering wheel.

Abstract: There is disclosed herein an automotive window regulator and drive mechanism which includes a rotatable flexible drive shaft to transmit rotational forces from the regulator arm to a worm gear supported on a lower edge of the window. The worm gear engages a rack secured to a portion of the vehicle so as to vary the position of the window. In one embodiment, both electric motor drive and manual crank drive means are provided either of which may be selectively engaged to drive the rotatable flexible shaft. The regulator end of the flexible drive shaft may be supported in meshing engagement with a portion of the regulator drive gear by means of a pinion pivot arm which arm includes indexing gears to enable the flexible cable to track the worm gear thereby reducing the flexing of the flexible drive shaft.

Abstract: Valve operating system which is particularly suitable for use in the remote control of valves such as the function control valves of a crane or loading apparatus. The system includes output shafts for connection to the operating levers of the valves and input shafts disposed telescopically of the output shafts. A drive motor is connected to the input shafts for moving the same in unison along their axes, the detent means are provided for selectively locking the input and output shafts in each pair together. The detent means are operated by electrically energized solenoids which can be controlled remotely, e.g. from a hand held control unit connected to the remainder of the system by a cable.

Abstract: A valve spindle drive is disclosed in which the travel of the spindle is limited by a locking mechanism. The spindle is driven by a gearing system on which locking rings are provided. Each locking ring permits rotation in one direction. Arms resiliently mounted on the valve housing carry a second pair of locking rings for mating with the rings on the gearing system. Deflection of the arms during travel of the spindle actuates switches for controlling a spindle motor drive. Movement of the spindle and gearing relative to the second pair of locking elements provides for engagement of a pair of respective locking rings to prevent further spindle travel. The other pair of rings is prevented from coupling by a cam device carried by the gearing.

Abstract: The window in the door of an automotive vehicle is raised and lowered by means of an externally threaded, longitudinally moving cable. The drive arrangement for the cable includes a shell having first and second shell portions of which at least one is formed with an aperture. A pinion is rotatably secured between the shell portions and journaled in the aperture of apertures. A first group of fastening devices fastens the first shell portion to the second shell portion in a predetermined position, but may also fasten the shell portions to one another in each of a plurality of other positions angularly offset about the axis of pinion rotation from the predetermined position. The shell portions define therebetween respective passages through the shell in the several positions of the first shell portion, the passages being approximately tangential relative to the pinion and angularly offset from each other about the axis of the pinion.

Abstract: A reversible motor operated valve with a spring assist. The assist spring is provided to store energy therein as the motor actuates the valve from its closed to its open position. When the motor is reversed to actuate the valve back from its open to its closed position, the energy stored in the spring will be released to assist the motor in closing the valve.

Abstract: A choke suitable for use in the wellhead of a production well including a body having an inlet, an outlet and a seat, a valve member or gate adapted to move relative to said seat to restrict flow therethrough, a pressure responsive operator connected to move the gate with respect to the seat, a manual operator connected to said pressure responsive operator, means releasably connecting said manual operator to said gate to manually move said gate and for releasing said manual operator from said gate to allou said pressure responsive operator to move said gate and a control on the exterior of said manual operator connected to said releasable connecting means.

Abstract: A drive arrangement for sliding roofs, window panes, and other similar sliding members of motor vehicles is constructed for motorized operation and also for emergency manual operation. According to a preferred embodiment, the driving shaft of the drive arrangement has a first part of a clutch constrained from movement therewith and a second part displaceably mounted relative to the first part for interconnecting the drive motor with a drive pinion and for disengaging the drive pinion from the drive motor in a second relative position of the clutch parts. The driving force transmittable between the above-noted clutch parts is controlled by an adjustment member mounted on the driving shaft. The adjustment member can be connected to a manually operable handle for emergency operation of the sliding member by a handle through the use of a locking member which secures the adjustment member relative to the driving shaft in a plurality of positions.

Abstract: An electric regulating device, particularly for a speed control device for motor vehicles, with a servomotor and a rotatably mounted element which actuates the regulating member, the rotatable element particularly being a cable pulley which stands in operative connection with the servomotor via a gearing and a coupling device containing an electromagnet. At least one of the gears of the gearing is radially and at an angle or axially moveable mounted, and is connected indirectly or directly with an armature, which in turn cooperates with the electromagnet.

Abstract: Disclosed herein is a starter mechanism for an engine having a starter gear, which starter mechanism includes a rotatable starter shaft, a starter pinion rotatably mounted on the starter shaft for axial movement, in response to rotation of the starter shaft in one direction, to an engine starting position in driving engagement with the engine starter gear, and a drive member mounted for rotation coaxially with the starter shaft and drivingly connected to the starter shaft. Manual starting of the engine is selectively effected by rotating a circular member or rotor drivingly connected to the drive member through a first one-way clutch which, in response to rotation of the rotor in the one direction, affords common rotary movement of the rotor and the drive member and permits free wheeling of the drive member relative to the rotor in the same direction when the rotor is not operated.

Abstract: A circuit breaker having a spring operated closing mechanism for establishing contact between the moving contact and the stationary contact; a ratchet and pawl spring charging system in which the ratchet wheel is combined with the crank arm for the closing spring which in turn operates the moving contact arm toward closed position. The pawl carrier plates are mounted on and rotate on the outer periphery of the combined ratchet wheel and crank arm. A motor operated mechanism may also be connected through the same members.

Abstract: A mechanism which normally is driven by a motor, but which can be safely manually driven by a hand crank or the like in case of a power shortage or other emergency. The mechanism has a power-driven drive gear and a driven assembly which preferably includes a gear-like member, such as a worm, and a crank-receiving member, such as an internally splined hub. A disconnecting assembly which is responsive to engagement of the hand crank in the crank-receiving member is provided to disconnect the driven assembly from the power-driven drive gear.

Abstract: An electrically operated fail-safe valve actuator employs a spring which is wound to store energy during operation of the electric drive motor, an electric clutch operable to disengage the drive motor from the actuator output shaft in response to loss of power from the electrical supply whereby the spring drives the valve in the opposite direction.