Abstract: An eccentric gear pump for use in pumping a variety of fluids. The pump has conventional plungers reciprocably positioned in a cylinder and includes a drive case with a rotatable drive shaft therein. The driven shaft is connected eccentrically to drive gears in a plurality of gear assemblies. Each gear assembly also includes a driven gear which has a yoke assembly eccentrically connected thereto. The yoke assembly is connected to a corresponding plunger. Rotation of the drive gear results in rotation of the driven gear which in turn causes reciprocation of the yoke assembly and plunger. Cam rollers are attached to opposite sides of the driven gear, and the cam rollers ride closely within a cam groove in a cam track on opposite sides of each driven gear. The interaction of the cam roller and the cam groove limits movement of the yoke assembly and piston to substantially purely reciprocal motion with respect to the drive case. Each gear assembly includes a pressure lubricated gear case.

Abstract: A drive for overlapping wipers includes a pair of wiper shafts offset to different sides of a drive shaft, each driven by a spatial mechanism, which, by virtue of the offset from the drive shaft, creates a position and speed differential between the wipers that prevents them from colliding at inner wipe.

Abstract: A polishing apparatus comprising a support base on which is mounted a power source to drive a swash plate, and an extension member connecting the power source and the swash plate to a remote polishing member. The polishing member comprises a gripping portion for the operator and a receiving member adapted to accept a polishing stone. The extension member comprises a hollow outer tube having a movable inner core to transmit the reciprocating motion of the swash plate to the receiving member of the remote polishing member in order to reciprocate the polishing stone at high speed.

Abstract: This application relates to a device which is mounted onto a threadless shaft and which converts the rotary motion of the shaft into linear translation of the device. The device includes two blocks which have an axial bore therethrough and a plurality of roller bearings, four of which are disposed on the block called the adjusting block and two of which are disposed on the block called the mounting block. The adjusting block carries the tensioning devices which generate the friction between the bearings and the shaft. The mounting block is the component to which both the driven load and the adjusting block are secured. Pins are provided so that the blocks will always be assembled in the same orientation as they were when they were machined.

Abstract: Arrangement for damping linear movements intended for use on a safety valve. An arrangement for damping linear movements of the valve spindle (10) of a safety valve of small amplitude and high frequency comprises two counter-rotatable damping parts (18, 36) with intermeshing wall (22, 24, 32) which delimit narrow working gaps (44, 46) containing a high-viscosity silicone grease. The linear intake movement is converted by a threaded drive (12, 40) into a rotary movement during which the silicone grease (47) in the working gaps (44, 46) is subjected to shear forces and eliminates the unwanted energy by virtue of its internal friction.

Abstract: A mechanism for generating oscillatory motion omnidirectionally transforms rotating motion in which the rotating member is continuously rotated unidirectionally into any number of simultaneous arcuate motions intersecting at predetermined angles. This mechanism includes a disk-shaped body rotatably mounted and swept in a circle so that it completes two periods of rotation over the course of one period of sweep. The altitude of the disk-shaped body always intersects a point on an imaginary line, regardless of the angle of inclination of the disk-shaped body. This imaginary line is perpendicular to the circularly swept path of the disk-shaped body at the center of the circularly swept path. Points on the circumferential edge of the disk-shaped body describe an infinite number of arcs as they move around the circularly swept path. These arcs intersect at a common point from an infinite number of angles.

Abstract: A high speed short stroke saw for cutting plaster casts, bone and the like, is constructed to operate with minimal noise from the mechanism. The motor driven rotary shaft and the oscillating saw blade shaft are mounted in bearing support structures in a casing. The rotary motion of the motor shaft is translated to the oscillating motor of the saw blade by a bearing mounted cam that fits within a drive rod and receives the motor shaft. The drive rod is connected to a bearing mounted crank which receives the saw blade shaft. This entire mechanism is sealed in oil.

Abstract: Disclosed is an exercise device providing mechanical actions for independent or simultaneous exercise of the upper and lower body of a human user. Each action incorporates a mechanical movement converting output of the user to rotational motion and thereby powering one of two electrical generators. An exercise controller selects loads to be applied to the generators. The loads are coupled by the mechanical movements back to the user to provide resistance to the exercise effort. The exercise controller drives an electronic display which informs the user of his or her intensity of effort as well as the proportion of that effort being met through exercise of the upper body and the part being met through exercise of the lower body.

Abstract: An improved gate valve having a body with a gate positioned therein to reciprocate between positions opening and closing flow through the body, a pressure responsive actuator connected to move the gate stem, a manual override stem and an overriding drive connection connecting both the actuator and the manual override stem to the gate stem so that the gate stem and gate are moved by both the actuator and by the manual override stem independently of the actuator. A modified form of the invention is provided for directly connecting to an extension of an actuator stem for operating a valve manually. In another modified form, camming element and a camming extension are provided to increase the forces providing release of the paddles from within a groove on the interior of the housing so that the locking action of the paddles do not prevent proper operation of the mechanism.

Abstract: The herein proposed invention relates to mechanical engineering. The essence of the invention resides in the fact that a contrivance for setting the table position includes two disks provided with drives for moving the table in a horizontal plane and disposed eccentrically one above the other as to be free to rotate about their pivot pins, the upper disk being rotatably mounted with respect to the pivot pin of the lower disk. The pivot pin of the lower disk mounts one device for reading the length of table movement in a horizontal plane along one of the coordinate axes, and a pin is fixed in position on the upper disk a distance from its axis equal to the amount of eccentricity between the pivot pins, the pin being movably associated with the table so as to carry another device for reading the length of table movement in a horizontal plane along the other of the coordinate axes.

Abstract: A contact lens cleaning device provides a mechanical apparatus for the thorough agitation and cleaning of contact lenses immersed in a disinfecting solution. The device comprises a base portion bearing a reservoir for containing a measured amount of disinfecting solution, and a main housing portion including a lens holder portion for releasable capture of the contact lenses to be cleaned. The lens holder is connected to rotating crankshafts by connecting rods, and the crankshafts are connected to a knob on the outside of the main housing, so that rotary motion of the crankshafts is translated to reciprocating motion of the lens holder.

Abstract: A motion conversion apparatus 10 for converting continuous rotary motion into oscillatory, wide angle scanning motion is disclosed herein. The motion conversion apparatus 10 of the present invention includes a link 40 disposed to pivot about a pair of pivot points 33 and 35. The link 40 induces oscillation about a first axis of a member 11 coupled thereto thereby providing output oscillatory scanning motion. The apparatus 10 of the present invention further includes flywheel means 20 and 30 adapted to rotate about a second axis for causing the link 40 to pivot about the pivot points 33 and 35. A shaft 14 operatively coupled to the flywheel means 30 supplies input rotary motion.

Abstract: In a serial printer wherein a bi-directionally operating motor drives a carriage in an oscillatory motion between two end points, an improvement for minimizing the time for direction reversal of the carriage. There is a ballistic rebound device for transferring energy of the moving carriage in one direction into a resilient member and for retransmitting energy absorbed by the resilient member back into the carriage in a direction opposite the one direction. There is also an electrically operated brake for selectively coupling the ballistic rebound device to the carriage. Sensing apparatus is provided for sensing the position of the carriage with respect to the two ends.

Abstract: The nut structure (3) of a screw jack has ball bearing units (4, 5, 6) the middle one (5) of which engages from one side and the two outer ball bearing units (4, 6) engage from the opposite side on the same plane of action into the thread (2). Thus the nut structure (3) is supported against the screw shaft (1) without tilting moments so that no neck bearing is needed. As a result the screw jack works with extremely little friction and with extremely little tendency to vibrate.

Abstract: In a control device, especially for heating and ventilation systems in mo vehicles, comprising a rotatable control knob and a linearly movable setting member, a lever is provided for coupling the knob and member and converting rotational motion of the knob into linear movement of the setting member. To achieve this, the control knob 2 is provided with a guide slope extending at an acute angle to the axis of rotation. A shorter arm portion of the lever is controlled by the guide slope. A longer arm portion of the lever is actuated by movement of the shorter arm portion against the guide slope and acts upon a coupled setting member in a linear manner.

Abstract: A device for interconverting rectilinear and rotary motion is designed so as to reduce side thrust exerted on a frame by a slide as the slide reciprocates linearly relative to the frame and such rectilinear motion is converted into the rotary motion of a crank or vice versa. More particularly, an elongated opening, which receives a crankpin of the crank such that the crankpin moves back and forth along the elongated opening, is provided in a swing mounted for oscillatory movement relative to the slide. At least one arm is pivotally attached to the frame and to the swing so as to effect the oscillatory motion of the swing relative to the slide as the slide reciprocates relative to the frame. As the slide reciprocates relative to the frame, the orientation of the elongated opening relative to the slide is constantly varied.

Abstract: A linkage apparatus comprised of two interconnected levers extending between a valve actuator for a rotatable valve and a rotatable operating shaft of the valve. The relative position of the interconnection between the levers is presettably adjustable so as to enable varied operation in the rotational displacement of the operating shaft. Effecting the adjustment is independent of the actuator operation.

Abstract: A valve operator powered selectively either by an electric motor or by a manually operable handwheel, the driving connections from both the motor and the handwheel to the valve including one or more planetary gear sets each having a central pinion rotatable by the motor, a ring gear surrounding the pinion, and planet gears interposed between and meshed with the pinion and the ring gear, the planet gears being rotatable about their own axes and mounted eccentrically on a spider member rotatable about the gear axis, the spider member being operable by its rotation to transmit operating power to the valve being controlled. The ring gears of all of the gear sets are fixed in a rotatable gear case which is turned by the handwheel. A pair of non-reversing torque control devices, disposed respectively between the gear set and the motor, and between the gear set and the handwheel, prevent rotation of the motor by operation of the handwheel, and rotation of the handwheel by operation of the motor.

Abstract: A device for transmitting simultaneously to two parallel rods a motion with a single degree of freedom as a longitudinal translational motion from a sleeve surrounding the rods and which is itself subject to first and second degrees of freedom, a translational and a rotary motion, which includes a plate interconnecting the ends of the parallel rods, the plate lying perpendicularly to the axis of translational motion of the rods, and a connecting mechanism between the plate and the sleeve such that the connecting mechanism is adapted for transmitting only the translational motion to the plate.

Abstract: A driving arrangement for a pump, especially a liquid metering pump, includes a pump tappet mounted on a support for displacement in and opposite to a predetermined direction during a pumping and a return stroke thereof, respectively. A restoring spring member urges the pump tappet opposite to the predetermined direction. There is further provided a mechanical energy storage device which includes a storage tappet mounted on the support spaced from the pump tappet for displacement in and opposite to the predetermined direction, and an elastically yieldable storage member urging the storage tappet in the predetermined direction.

Abstract: This invention provides the provision of a motor, whose output shaft is fixed to a pinion gear, meshed with two mutually opposed driven pinion gears, each carrying a respective cam roller, which alternatively enter and exit a cam surface on a cam follower, which is fixed to a second shaft, to oscillate said follower and said second shaft, and a first sector gear which is fixed to said second shaft and meshed with a second gear, which is axially fixed to the rocking lever in the drive linkage of a machine gun. Alternatively, the first sector gear is meshed with a second sector gear formed on the rocking lever.

Abstract: A threadless linear actuator apparatus comprising a sealed actuator unit with a sealed housing for a set of spool-shaped roller bearings. The roller bearing set includes at least one variable pitch loading roller and two fixed pitch rollers arranged in a skewed relationship about a cylindrical drive shaft. A variable moment is applied to the apparatus through a moment applied about an axis which is perpendicular to and intersects the drive shaft axis which, when applied, varies the pitch of the pivotable loading roller.

Abstract: A power drive and lift-and-carry mechanism in which a rotary input drives a mechanical system to produce a relatively long dwell stage and, in combination with a crank drive mechanism, produces a transfer motion with a substantially straight lift and lower motion coupled with a horizontal component in a smooth transfer motion for work parts.

Abstract: A cable or tape window regulator apparatus and method is provided with a dual camming action. The dual camming action allows the glass to have relative movement with respect to the drive member of the window regulator. Therefore, the glass will have a total vertical travel which is greater than the vertical travel of the cable or tape.

Abstract: An apparatus for converting rotary motion to translatory motion. The apparatus contains shaped rollers located therein so that the longitudinal axis of the rollers forms an acute angle with the longitudinal axis of a shaft passing through the apparatus. The rollers are contained in a cylindrical housing having end pieces. The rollers are shaped to have maximum contact with the shaft. Roller race means and spring means contained within the housing retain the rollers and provide a load to maintain tight shaft to roller contact. Rotation of the apparatus about a shaft causes a shaft to move in a longitudinal direction, while rotation of the shaft within the apparatus causes the apparatus to move in a longitudinal direction.

Abstract: A variable-stroke, constant-compression, reversible radial pump, the stroke of which may be infinitely adjusted by means of a variable-throw eccentric from a normal-cycle maximum through zero to a reverse-cycle maximum, and the compression of which is maintained constant through the use of a variable-geometry cylinder-head assembly. The cylinder geometry varies when the cylinder head is raised and lowered by means of a synchronized screw arrangement which is coupled through a gear set to the variable-throw eccentric. The variable throw-eccentric comprises a hollow input shaft which is drilled and threaded diametrically. A threaded, splined adjustment shaft is screwed into the threaded diametric hole in the input shaft. Each end of the adjustment shaft is mounted in bearing races which are anchored at diametrically opposed points in a connecting-rod journal.

Abstract: A bicycle having pedal bars pivoted on the frame near the rear wheel, with a pedal sprocket positioned above the rear wheel. A connection member couples the rear end of each of the pedal bars to the pedal sprocket and further includes conversion mechanism whereby up and down movement of the push bars induces rotative movement of the pedal sprocket. Foot pedals are mounted on the front end of the pedal bars. Downward pressure by a rider on the foot pedals (alternately applied) forces upper movement of the connection members and corresponding rotation of the pedal sprocket for driving the bicycle.

Abstract: An improved cam sleeve operator for use primarily with valves of the plug type in which a tapered plug is raised to unseat associated slips and then rotated to a valve open position during opening of the valve and is rotated to a valve close position and lowered to seat the associated slips for closing the valve. The operator comprises a cylindrical housing having an inverted L-shape configuration, a cam sleeve which controls the position of the valve trunnion in response to the prime mover, and a pin connecting the valve trunnion to the operator for effecting sequential vertical and rotational motion of the valve trunnion in response to unitary continuous motion of the prime mover.

Abstract: A headlight adjuster gear assembly (100) is provided having a pair of angularly oriented intermeshed gear members comprising a driven gear member (4) adapted to be rotated and cause rotation of a driving gear member (4) which is operable upon rotation to adjust a vehicular headlight. Gear members (2, 4) are enclosed by a pair of housing members (80, 90) that are hinged together at one end and fastened at an opposite end by pins (28) or other suitable means to prevent loss of either or both housing members (80, 90) upon their detachment as well as provide improved resistance to their separation from torque arising during the adjusting process.

Abstract: A drive mechanism for transmitting bidirectional drive to two or more rotary actuator spindles, having a disc driven by an input shaft. Each spindle carries a spur gear which engages alternately with inner and outer tooth sections formed at different positions around a respective track in the disc. To accommodate several gears, tracks are provided at two different radii and three tracks of different width are nested together. The spur gears and tooth sections can be replaced by cams and tracks or shaped levers and pegs. The disc can be moulded and enables standard valves to be used in a complex operational sequence.

Abstract: A valve actuation system is disclosed having a spur wheel which meshes with a crown-wheel segment attached to the valve. For linear increase or decrease in the flow cross section, the toothing of the crown-wheel segment is arranged to produce a multiplication ratio which decreases and/or increases in the direction of opening, i.e., which produces valve opening rates which become smaller and/or larger.

Abstract: The improved positive pullback synchro valve actuator of the present invention comprises a universal cam assembly having a frame supporting a deformable cam strip which is operatively connected to a plurality of contour adjustment screws and which may be adjusted to form the desired shape of the cam. The cam strip is further operatively connected to a plunger which is disposed for movement transversely of the cam strip and in the longitudinal direction. The apparatus is positive in its pullback, as the plunger is linked to the universal cam assembly, such that when the operator turns the universal cam assembly, there is assurance that the associated valve is closed. In some applications, the plunger may be connected to a shaft yoke which is disposed transversely of the plunger for converting the longitudinal movement into limited reciprocal rotational movement. In these embodiments, the shaft yoke engages a valve shaft which is urged by such yoke into limited reciprocal rotational movement.

Abstract: A shutoff valve includes a pivotably displaceable flap shaped cutoff part mounted in a flow passageway through a housing. The flap shaped cutoff part is relatively thin so that in the fully open position it does not appreciable reduce the flow passageway cross-section. The cutoff part is pivotably supported at one point in the housing wall and at a diagonally opposite it is supported by a combination of a guide pin and a sliding guide. An actuator located outside the flow passageway is connected to the cutoff part for displacing it between the closed and opened positions. The actuator includes a piston cylinder unit connected to a shifter rod. The shifter rod effects the movement of the guide pin in the sliding guide so that the cutoff part is pivoted about an axis extending transversely of the axis of the flow passageway between the closed and opened positions.

Abstract: A rolling nut in combination with a smooth shaft includes a plurality of bearing-like roller cages surrounding the shaft and having internal surfaces in contact with portions of the outer surface of the shaft and is operative for transforming a rotary movement of the shaft into thrust movement of the rolling nut. The rolling nut is open and is provided with a base plate formed with a plurality of pocket-shaped recesses in which the roller cages are partially inserted. The base plate is formed with similar recesses at both sides thereof so that the roller cages can be repositioned on either side of the plate to selectively adjust the roller cages to the left hand thread of the shaft or the right hand thread of the shaft.

Abstract: A device for tracking a movable body along a linear path parallel to a plane includes a linear motor for driving the body along the linear path. The body is mounted, as by rollers, for movement along a guide, such as a pair of parallel guide rails, supported on a base which also supports the motor. To enhance stability of the body during tracking movement, the rollers or other mounts for the body are urged against the guide by the magnetic action of a flux which is separate from the principal flux used to generate thrust for the linear motor and which provides an attractive force against preferably a pair of members, such as steel plates, of high magnetic permeability fixed to the movable body.

Abstract: A damper controls fluid flow and includes a frame with an opening through which the fluid is intended to flow when the damper is open, and a closure cap movable between a first position in which it blocks the opening and a second position in which the opening is unblocked. In the second position, the closure cap is rotated with respect to its first position, so as to minimize interference with fluid flow through the opening. A mechanism controls the movement of the closure cap, and includes a first and second bracket fixed with respect to the frame and the closure cap, respectively. An elongate guideway is defined in one bracket and a pin on the other bracket is captive within the elongate guideway.

Abstract: The apparatus comprises a disk shaped shut-off flap located in the passage of a main body. The shut-off flap is mounted such to a rocking shaft that the flap can be lifted off its seat during one phase of movement of the rocking shaft and may be rotated into an open position during a further phase of movement of the rocking shaft. The operating means comprises a linear drive in the shape of a control rod including a control groove. A follower and driving means engages the control groove and the shut-off flap. Accordingly the shut-off flap is guided for above lift off and rotating movements. This linear drive allows an impeccable sealing between the inner space of the shut-off apparatus and the environment.

Abstract: The rolling nut for transforming a rotary movement of a smooth shaft into a thrust movement of the nut comprises a tubular housing in which a number of roller cages defining a center passage for the shaft and engaging an arcuate surface portion of the shaft are arranged. The roller cages are inclined to the axis of the shaft and to each other. Wedge-shaped distance rings are arranged between the neighboring roller cages and laterally of the end roller cages. The roller cages and the distance rings are interchangeable within the housing so that the direction of the angle of inclination of each roller cage within the housing can be varied.

Abstract: A sterile intravenous flow valve includes in-line valve mechanism which is maintained sterile in all of its positions. The valve also includes an adjustment member and a locking mechanism for selectively locking the adjustment member in place to thereby assure accurate flow rate settings. Sterility is achieved by providing a sealed chamber formed by a snap-fit engagement between the adjustment member and the main body member of the valve.

Abstract: A valve for use in a domestic water installation such as a shower is moveable between open and closed positions by an operating mechanism. The mechanism includes a ratchet that provides intermittent unidirectional drive to the valve member from a manual operator. Successive repetitive movements of the operator moves the valve between open and closed positions. The valve includes a seat and a poppet the disposition of which is controlled by cams that ensure that pressure of water in the conduit assists in moving the valve between open and closed positions.

Abstract: A handle arrangement for a hot water tap or faucet which requires an axial and rotational movement of the handle in order to turn the tap "on" or a rotational movement only, in order to turn the tap "off". When applied to a hot water tap the handle arrangement provides a safety device against rotation by young children as the combination of movements is difficult or impossible for young children to overcome. The arrangement comprises a spindle member 11 which is attached to an existing tap spindle 18 by grub screws 19 and co-operates with a drive member 13 fixed to the handle to provide a ratchet arrangement between a drive member 13 and spindle member 11. The ratchet arrangement allows the tap to be turned off merely by rotation of the handle but does not engage when the tap is rotated in the direction to turn the tap on. A hexagonal protrusion 14 inside the handle co-operates with the handle member 11 to cause rotation of the handle when the handle is depressed axially inwardly.

Abstract: A flying cutoff system for tubing and the like wherein a cutting die mechanism (46) is driven by a threadless shaft (36) and traveler assembly (44) powered by a reversible DC motor (40). Die set position relative to the press is accurately monitored even in the presence of slip in the drive.

Abstract: Apparatus for electrically controlling the application and release of aircraft brakes. In one embodiment, the invention includes a slurry clutch controlling a reciprocating member which is operatively connected to the pressure plate. In another embodiment of the invention, a torque motor is adapted to have an armature which comprises a ball screw, the ball screw being in engagement with a longitudinal drive ring communicating with the pressure plate. Rotation of the armature causes the drive ring to move the pressure plate into forceful engagement with the brake disk stack or to retract the same. In yet another embodiment of the invention, a plurality of torque motors are interconnected with a bull gear which is operative for driving the pressure plate.

Abstract: An improved threadless feed screw mechanism includes elongated concentric inner and outer races radially spaced apart from each other with a cage positioned between the races. The cage includes a plurality of rollers each positioned in a slot, the slots having axes inclined relative to the axes of the races. The rollers are normally in contact with the facing surfaces of the inner and outer races. A portion of at least one of the facing surfaces is recessed providing a clearance for the rollers. As the rollers and cage move, the rollers advance along the slot relative to the cage. As each roller moves into the recessed area a cam member returns the roller to the opposite end of the slot.

Abstract: A metal detector assembly consisting of a metal detector box component and a supporting shaft has a spring-loaded hinge-support interconnecting the box component and the head shaft component. The hinge-support comprises a frame attachment member and a pivotally connected shaft attachment member. A coiled spring surrounds the pivot connection and is biased between shoulders on each of the two members to permit a flexing action and cause a desirable smooth horizontal arcuate swinging action of the head component of the metal detector. The device exaggerates a slight wrist movement initiated by the user and continues to swing as the user walks about thereby reducing arm fatigue and facilitating a more efficient and reliable sweeping action of the metal detector head. Alternatively, the device may further contain a spring-loaded detent mechanism in the pivot connection to optionally hold the shaft in a rigid relation to the hand held box component when desired.

Abstract: A fail-safe actuator of the type which permits cycling of a control member during normal operation without encumbrance from a return mechanism includes a link having a slot. A pin secured to a crankshaft coupled to the controlled member is slidably disposed within the slot. The slot permits rotation of the crankshaft within a range defined by the slot length. Upon system failure, a fluid pressure is moved to a predetermined position by a biasing spring to force the crankshaft to a fail-safe position.

Abstract: An energy absorber strut includes a pair of elongated drive nuts threaded internally to mate with a drive screw having high lead threads on opposite ends so that outward movement of the nuts on the screw rotates the screw in one direction and inward movement rotates the screw in the opposite direction. A mandrel mounted to rotate with the screw is restrained from rotation by a capstan spring which surrounds and grips it. Prestressed torsion springs connected to the ends of the capstan spring permit it to unwind slightly and drag with respect to the mandrel when the torsion springs are subjected to a predetermined torque.

Abstract: A valve actuator for a dosing pump for a paint toning machine, wherein the dosing pumps (3) are mounted in a sled movable with respect to the frame of the machine and a dosing mechanism (21-24) displacing the pistons (4) of the dosing pumps and an actuator rotating the valves (8) of the dosing pumps are mounted in the frame. The actuator comprises a crank (13) mounted rotatably in the frame and two cam rods (15, 16) which are mounted pivotally in the frame and of which one (15) is located in the path of movement of the crank and the other (16) is provided with a transfer mechanism (26) for transferring the cam rod optionally into and out of the path of movement of the crank.

Abstract: The linear feed device is suitable for extremely slow feed rates or extremely small feed steps. It works with two motors (M.sub.1, M.sub.2) which drive a nut (16) and a screw spindle (2) via an intermediate drive (12-15; 22-25). The intermediate drives have slightly different transmission ratios, e.g., 1:0.340909 and 1:0.3414634.With a thread pitch of 2 mm of the spindle, this results, with the same direction of rotation of the motors, in about 0.0013 mm advance per revolution of the motor shafts. With the help of step motors, therefore, extremely small advance steps can be achieved.

Abstract: An improved, motorized Lunkenheimer valve is provided having two independently actuated drive means for operating the valve, one of which moves the valve stem and disc longitudinally along the axis of the stem and the other of which rotates the stem and disc about the longitudinal axis of the stem. The two drive means can be operated concurrently to effect more rapid opening or closing, and countercurrently to provide a continuous grinding operation when the valve is in the closed position.