Showing papers on "Pulley published in 1990"

Force reflecting hand controller

Abstract: A universal input device for interfacing a human operator with a slave machine such as a robot or the like includes a plurality of serially connected mechanical links extending from a base. A handgrip is connected to the mechanical links distal from the base such that a human operator may grasp the handgrip and control the position thereof relative to the base through the mechanical links. A plurality of rotary joints is arranged to connect the mechanical links together to provide at least three translational degrees of freedom and at least three rotational degrees of freedom of motion of the handgrip relative to the base. A cable and pulley assembly for each joint is connected to a corresponding motor for transmitting forces from the slave machine to the handgrip to provide kinesthetic feedback to the operator and for producing control signals that may be transmitted from the handgrip to the slave machine. The device gives excellent kinesthetic feedback, high-fidelity force/torque feedback, a kinematically simple structure, mechanically decoupled motion in all six degrees of freedom, and zero backlash. The device also has a much larger work envelope, greater stiffness and responsiveness, smaller stowage volume, and better overlap of the human operator's range of motion than previous designs.

Mechanical properties of human pulleys.

Abstract: In order to determine the mechanical properties of the fibro-osseous pulleys in the hand, the diaphyseal annular pulleys, the volar plate annular pulleys and the cruciate or condensable portions were tested. A custom-made loading device provided proper fit of the soft tissues for a uniform distribution of the pulley load during testing. The A2 pulley was found to be the strongest of the pulleys; the A1 and A4 were the next strongest. The A3 pulley was nearly equal in mean breaking strength to the other annular pulleys, but in absolute breaking load was considerably weaker because of its shortness. The A4 was the least compliant of the pulleys. We concluded that the fibro-osseous A2 and A4 were mechanically stronger and stiffer pulleys than the A1, A3, A5 (volar plate) pulleys. In testing one type of pulley reconstruction, we found that the "belt loop" technique of Karev nearly matched the annular pulleys in strength and energy absorption.

Rotary closure for a sports shoe

Abstract: Separable parts of a sports shoe are movable toward and away from one another by means of a traction cable which can be wound on and off a cable pulley which is rotatably mounted in a housing, has an engaging projection, and cooperates with a stationary stop and with a stop construction which is rotatably mounted coaxially with the pulley. The stop construction has two rotatable stop arms which enable up to almost three turns of the cable pulley between extreme positions. In this way the rotary closure is on the one hand constructed for a relatively large adjustment of length and on the other hand is secured against overstreching of the traction cable.

Orthogonal two-axis moving apparatus

Abstract: A technique of this invention discloses an orthogonal two-axis moving apparatus basically adapted to move in horizontal and vertical directions. In one embodiment the apparatus includes a vertical block, a horizontal moving member movably supported on the vertical block, and a driving mechanism for moving the horizontal moving member, a driving pulley, a driven pulley, and a belt for transmitting a driving force.

Constant force compensation for power spring weight balance

Abstract: An apparatus for offsetting a constant force over a range of movement, includes a power spring or clock spring, defined by a length of resilient material wound in a spiral, the opposite ends of which are attached relative to one of the force and a fixed point, and to a pulley. The pulley is substantially coaxial with the spring and has a rounded outer contour defining a progressively varying slope proceeding axially along the pulley. A flexible cord wraps around the pulley and leads to the other of the force and the fixed point. The opposite (inner and outer) ends of the spring can be mounted such that the inner end of the spring is fixed relative to the fixed point and the outer end of the spring is attached to the pulley. The constant force can be the weight of a window sash, movable vertically in a frame. The rounded outer contour of the pulley defines a curve corresponding to an increase in torque of the spring with displacement, due to decrease in radius of the spring and decrease in active length of the spring with binding of inner wraps of the spiral.

Turn-lock fastener for sports shoe

Abstract: In this turn-lock fastener for a sports shoe according to the invention, a pull-cable arrangement, which pulls together the shoe- closing flaps, can be wound onto and unwound from a rotary cable pulley. The pull-cable arrangement consists in this connection of a single pull-cable, and a stop element is provided coaxially with the cable pulley and rotatably mounted in such a manner that the cable pulley can only perform a maximum of up to approximately two rotations in one direction of rotation. A particularly space-saving turn-lock fastener is thus produced, with reliable safety as far as overturning of the pulley cable is concerned. … …

On a new torque sensor for tendon drive fingers

Abstract: A new type of torque sensor is proposed for finger actuation with N actuators and tendons per N external degrees of freedom. The finger joint around a drive pulley is proportional to the tension difference on both ends of the pulley. Using a coupling mechanism between tendons, this tension difference can be measured directly without sensing individual tendon tensions. On the basis of this idea, a tension differential-type torque (TDT) sensor is proposed. With a single body of small size and fewer signal lines, the TDT sensor has several advantages over the conventional approach, which obtains the torque by attaching two tension sensors at both ends of the drive pulley and feeding sensor signals to a differential circuit. The basic principle of the TDT sensor is described, together with the design orientation. The dynamic and static characteristics are examined with the introduction of equivalent rotational stiffness, which is useful for examining system stability. The specially designed TDT sensors were implemented in a two-fingered robot hand, and the effectiveness of the sensor was confirmed. >

Vibratory pile driver

Abstract: A vibratory pile driver having means for clamping onto a pile or similar structure to be driven or extracted substantially linearly, eg vertically, includes a hydraulic gear motor having two oppositely rotatable shafts and a pair of semicircular weights aligned in the same vertical plane Each weight is rotatably secured to a shaft parallel to the motor shafts Means, in the form of drive and driven pulleys, sprockets or the like connected by toothed timing belts, chains or the like, respectively, are provided for driving the weights from the motor shafts Since the gears of the hydraulic gear motor operate in synchronization, the weights are driven synchronously to provide substantially linear, eg vertical, forces Such an arrangement combines the synchronizing gears and the power source and makes it possible to eliminate relatively large gears, to use larger diameter weights and to achieve, under certain designs, a smaller overall machine width adjacent the pile to be driven

Package handling conveyor system

Abstract: An apparatus for handling and conveying packages includes a conveyor frame for housing a combination roller-slider bed and a belt mounted on the combination roller-slider bed to define a package-supporting conveyor surface The conveyor drive includes a drive pulley in contact with the belt, a gearbox coupled directly to the drive pulley and an electric motor coupled directly to the gearbox The shaft of the drive pulley is designed to fit within the output shaft of the gearbox The motor and gearbox are mounted adjacent to but outside of the conveyor frame Electrical or mechanical system associated with the apparatus controls the speed and acceleration of the belt

Strength Characteristics and Failure Modes of Locking‐Loop and Three‐Loop Pulley Suture Patterns in Equine Tendons

Abstract: Size 3-0 polydioxanone was used as a single strand, single braid (3 strands), or double braid (6 strands) to create six suture material-pattern combinations for equine tenorrhaphy: single-strand locking loop, single-braid locking loop, double-braid locking loop, single-strand three-loop pulley, single-braid three-loop pulley, and double-braid three-loop pulley. Maximum load to failure for the single-strand locking loop (46.1 +/- 2.9 newtons [N]) was less than for all other sutures (range, 103-155 N). The load required to form a 2 mm gap between tendon ends was greater for the single-braid three-loop pulley (66.7 +/- 6.9 N) and double-braid three-loop pulley (85.4 +/- 17.7 N) than any other sutures. The load required to produce a 10 mm gap was least for the single-strand locking loop (34.3 +/- 3.9 N) and greatest for the double-braid three-loop pulley (131.5 +/- 27.5 N). Gap between tendon ends at maximum load was greater for the single-braid (18.1 +/- 0.9 mm) and double-braid (19.2 +/- 2.2 mm) locking loops than for any other sutures. Suture material broke in 53% of the locking-loop tests but in only 17% of the three-loop pulley tests. Tendon matrix disruption accounted for 43% of the locking-loop failures and 77% of the three-loop pulley failures. The three-loop pulley pattern provided more support, less tendon distraction, and less tendon matrix constriction and distortion than the locking-loop pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

Cable tensioning device

Abstract: The cable tensioner has a pair of elongated platforms mounted side-by-side on a base with each having drive and driven geared pulleys with geared idler pulleys therebetween arranged along the edge of the platform confronting the other platform. A geared endless belt encircles the pulleys on each platform and has a grooved exterior machined to match the cable being handled. The drive and driven pulleys are adjusted to tension the associated belts and the idler pulleys are pressed towards the idlers on the adjacent platform. The base is mounted to permit sideways motion plus pivoting, tilting and rising and falling as a unit.

Self-jamming safety device for a rope

Abstract: A self-jamming safety device for a rope comprises two pulleys, one of which is fixed on a base flange, and the other on a support plate capable of pivoting on an articulation spindle. The pulley is provided with a first braking surface, against which the rope is pressed by a boss of the pulley when the support plate is driven by the tension of the rope to a first jamming position. The pulley is equipped with a second braking surface operating in conjunction with the first surface following continued pivoting movement of the support plate to a second jamming position. Switching between the two jamming positions takes place after the tension of the rope has exceeded a preset threshold.

Self-jamming descender for a rope with two jamming positions

Abstract: A self-jamming descender for a rope comprises a first base flange equipped with an articulation spindle and a first fixed pulley, a mobile support plate with an operating lever pivotally mounted on the spindle, and a second pulley securedly united to the support plate and eccentric with respect to the spindle. The second pulley comprises a boss cooperating with a first braking surface of the first pulley when the lever is in a first jamming position. The pivoting support plate is provide with a jamming cleat, separated from the second pulley by a space through which the rope passes, and cooperating with a second braking surface when the handle is moved to a second jamming position. Unjamming of the descender takes place in an intermediate position of the operating lever.

Stair climbing exercise apparatus

Abstract: A frame structure mounts two side-by-side steps which are pivotally connected to the frame structure for up-and-down motion. The first step is connected, via a strap, to a first pulley, the strap being wrapped around the pulley. The second step is connected by a second strap to the second pulley and the second strap is wrapped around the second pulley. A shaft extends between the first and second pulleys and the first pulley is connected to the shaft when the pulley rotates in one direction but is not connected to the shaft when it rotates in the other direction. The second pulley is, likewise, connected to the shaft when it rotates in the same one direction but is not connected to the shaft when the pulley rotates in the other direction. The resistance element of the apparatus is an electromagnetic brake which includes a rotatable armature, and the rotary motion of the shaft is transmitted to the armature by a planetary gear arrangement.

Belt construction, rotatable pulley and combination thereof and methods of making the same

Abstract: An endless power transmission belt construction, a rotatable pulley therefor, a combination of the belt construction and pulley and methods of making the same are provided, the belt construction having opposed side edges and having an inner surface defining a plurality of longitudinally disposed and alternately spaced apart like projections and grooves for meshing with an outer peripheral ribbed surface of a rotatable pulley, each projection of the belt construction having a generally V-shaped transverse cross-sectional configuration defined by tow substantially straight side edges that converge from the respective apexes of the grooves of the belt construction that are on opposite sides of that projection to an apex of that projection, the side edges of each projection of the belt construction defining an angle of approximately 60° therebetween with the thickness of the belt construction being substantially the same as the thickness of a similar belt construction wherein the angle is approximately 40° and with the distance between the center lines of the grooves of the belt construction that are on opposite sides of that projection being larger than such distance of the similar belt construction.

Sheet conveying apparatus

Abstract: Apparatus for conveying one or more sheets of paper. The apparatus includes a supporting housing; a first, upstream pulley and a second, downstream pulley rotatably mounted on the housing; a lower, endless, elastic belt mounted on the first and second pulleys, the belt having an upper and a lower reach, the reaches being substantially horizontal; a third, downstream pulley rotatably mounted on the housing above the lower belt; a fourth, upstream pulley rotatably mounted on the housing above the lower belt, the fourth pulley biased toward the lower belt; and an upper, endless, elastic belt mounted on the third and fourth pulleys, whereby the fourth pulley can move away from the lower belt when the thickness of the sheets being conveyed requires a larger gap to engage the upper belt.

Roll-up door construction

Abstract: A roll-up door for enclosing a doorway in a building. The door comprises a horizontal rotatable drum mounted above the doorway and a flexible door panel is wound on the drum. A pair of first pulleys are secured to opposite ends of the drum and one end of a flat belt is secured to each first pulley, while the opposite end of each belt is dead-ended on a fixed object. A counterbalancing weight is attached to the belt intermediate its ends and exerts a counterbalancing force to wind door panel on the drum. A pair of second pulleys are secured to opposite ends of the drum and located adjacent the first pulleys. One end of a second flat belt is secured to each second pulley, while the opposite end of each second belt is connected to the lower end of the door panel. A drive member, such as a hydraulic motor, is operably connected to the drum and operation of the motor in one direction will unwind the door panel from the drum and move the door to a closed position, while operation of the motor in the opposite direction will wind the door panel on the drum to move the door panel to an open position. A resilient member of spring is connected to the second belt intermediate its ends and exerts a biasing force to stretch the door panel.

Multistage transmission and shifting process therefor

Abstract: A multistage transmission has a plurality of gear stages and an additional gear stage which may be engaged to transmit part of the input shaft torque before disengagement of an engaged gear stage. A friction clutch is used to engage the additional stage. Alternatively, a variable-ratio pulley connection may be used for the additional stage. Synchronization of the transmission input shaft with a gear stage to be engaged is attained by controlling the change in input shaft speed in accordance with a selected speed gradient.

Transmission provided with a driving belt and V-shaped pulleys

Abstract: Transmission provided with a driving belt and V-shaped pulleys. The side faces of the transverse elements or the contacting surfaces of pulleys in a variable transmission are provided with enlarged straight or oblique grooves between ridges in order to improve the efficiency and to reduce the wear of the transmission.

Multi-paddlewheel system for generating electricity from water canal

Abstract: A generator for electricity, utilizing one or two groups (29A and 29B) of separately placed water-driven paddlewheels (31) placed side by side in man-made canal. Each group is coupled together by a belt (41A and 41B) embracing a plurality of drive pulleys (43) which deliver power to central assembly pulleys (70A and 70B) on a single shaft (67). The central assembly pulleys each incorporate a centrifugal clutch (75 and 75') which transmits power to flywheel device (71A) which monitors rotational speed, thereby building up angular momemtum. A pulley (72) delivers the power via a belt (90) to a power-take-off pulley (104), then through a centrifugal clutch (92) to a shaft (91) and then to a generator (82).

System and method for monitoring drill bit depth

Abstract: Methods and apparatus for accurately determining drill bit depth are provided. A hook load is sampled at a rate of at least 4 Hz and is compared to a load threshold to establish a slips-in condition. A determination is made retroactively that the drill string stopped moving when the hook load passed through a high dynamic threshold. On the slips-out procedure, the identical high threshold is used, with movement established when the hook load exceeds the high threshold. The high dynamic threshold corresponds to the points at which the drill string actually stops and starts moving in the slips-in and slips-out procedures. The apparatus provided is a drawworks encoder mounting assembly which retrofits an auxiliary brake section of the drawworks or the rotary seal air coupler of a drawworks clutch. A split ring gear fits around and is secured to the rotating cylinder of the rotary seal air coupler. The split ring gear is part of a pulley having another gear and a drive belt, such that rotation of the drum and rotorseal air coupler cylinder is translated to a shaft of an encoder coupled to the second gear. The encoder thereby tracks the rotational movement of the drawworks drum. At desired times, also provided is a second encoder which is part of a calibrator which, via a calibrator wire, precisely measures the location of the travelling block relative to a known vertical location. The first and second encoder readings are compared continuously and are used to provide excellent calibrations between the drum rotation and the travelling block movement.

Wire tensioner for a wire handling machine

Abstract: A wire tensioner, for feeding wire from a wire source to a wire handling machine such as a coil winding machine, comprising a tension pulley coupled with an output shaft of a motor via a clutch such as an electromagnetic powder clutch with a variable torque transmission capability. Wire is passed around the tension pulley which is turned by the motor in the direction opposite to the feeding direction of the wire. By controlling the torque transmission ratio of the clutch, the tension of the wire is controlled with a fast response. This tensioner can be advantageously used for a motor coil winding machine to removing any slacking in the coil wire and improving the wire density of the motor coils.

Alternator-starter with automatic coupling device

Abstract: The invention relates to electrical machines which operate as an alternator and starter through a coupling device. The invention resides in the fact that the coupling device comprises at least one train epicyclodal single shot to satellites 14 wherein the ring 21 is connected to the frame 23 by a first free wheel 24 and planet carrier by a second free wheel 22. by this arrangement, the output shaft 13 of the alternator causes the engine when starting with a suitable gear ratio. For against, when the engine is running, it drives the output shaft 13 with a ratio defined by the ratio of the connection between the motor and the input pulley of the alternator-starter. The invention is applicable to motor vehicles.

Opening/closing mechanism for the use in circular-arc shaped sliding doors

Abstract: An opening/closing mechanism for use in a circular-arc shaped sliding door including a transverse frame having a circular-arc horizontal sectional shape and mounted on the upper parts of a pair of left and right door bodies; a drive pulley and a driven pulley mounted on the circumferentially one end of the transverse frame and on the other end thereof, respectively; and an endless belt wound between and around the drive pulley and a driven pulley, the pair of door bodies being connected in place to the endless belt so that they may be slidably moved in opposite directions to each other along a pair of left and right guide rails, respectively, each of which is bent in a circular-arc shape concentric with the center of the circular-arc of the transverse door frame.

Compound bow with adjustable cable length

Abstract: A compound bow utilizes tension cables and bowstring cables acting on grooved cam pulley assemblies. The tension cables are not continuous to the bowstring cables but are individually anchored at each end. Looped ends of the bowstring cable are transfixed by a rigid cross pin which can be selectively lodged in one of a plurality of cross slots intersecting a diametrical groove in a side surface of a pulley. The bowstring is captured in a groove as it enters the pulley by a segment of a tension cable pulley.

Electro-hydraulic control system for a dual-pass continuously variable transmission

Abstract: A control system for controlling hydraulic pressure in a dual pass continuously variable transmission includes a pump to provide primary and secondary hydraulic pressures for regulating the pulley ratio and belt tension. A minicomputer regulates the primary and secondary pressures, and a transition mechanism alternates the paths of the primary and secondary pressures between first and second pulleys of the transmission so that the primary pressure is fed to the drive pulley and the secondary pressure is fed to the driven pulley.

Belt drive comprising a toothed belt and a toothed pulley

Abstract: A belt drive comprising a toothed belt and a toothed pulley. The belt is provided with a guide rib that extends in the longitudinal direction of the belt and traverses the teeth thereof. To provide lateral guidance of the belt on a toothed pulley, the guide rib engages an annular groove on the periphery of the pulley. Disposed on the base of the annular groove of the pulley is an insert that is made of a material that has a softer resilience than does the material of the belt. The radial height of the insert is such that when the toothed belt runs up onto the toothed pulley, the guide rib of the belt first contacts the soft-elastic insert, and only after radial compression of the insert do the belt teeth rest upon the corresponding surfaces of the toothed pulley.

Apparatus for controlling the tension of a wire fed to a winding machine

Abstract: An apparatus having a drive pulley around which the wire is rolled, driven by a motor coupled to a speed control element. The pulley is provided with a tachometer which generates a signal proportional to the speed of movement of the wire. An extensometer, coupled to the wire, generates a signal, representative of a predetermined, ideal tension in the wire, which is compared with a set value. The resulting signal is superimposed on the tachometer signal to generate a signal to control the control element. The apparatus may also be provided with a spring biased oscillating arm located after the extensometer that has a pulley on one end, over which the wire passes. Also, a coding wheel may be provided after the oscillating arm assembly which generates a signal proportional to the speed of the wire. The coding wheel signal is converted to a signal representative of a variation in tension of the wire. The preset ideal value is established by subtracting the converted signal from a second set value, corresponding to an ideal variation in the tension of the wire.

Front and rear wheel drive motorcycle

Abstract: A front and rear wheel drive motorcycle includes an engine unit including a cylinder assembly and a crank shaft and first and second speed change belt mechanisms mounted to one end of the crank shaft for driving the front and rear wheels, respectively. The first and second speed change belt mechanisms are operatively connected to first and second speed change gear mechanisms through first and second speed change gear mechanisms through first and second driven pulleys respectively provided to the first and second change belt mechanism. To one end of the crank shaft is mounted a driving pulley means operated in common with the first and second speed change belt mechanisms. The driving pulley means comprises a stationary driving pulley mounted to one end of the crank shaft and operated in common with the first and second speed change belt mechanisms and a pair of movable driving pulleys mounted to one end of the crank shaft with the stationary driving pulley interposed therebetween. The cylinder assembly of the engine is directed substantially horizontally forward towards the front wheel or rearward towards the rear wheel with respect to the motorcycle body for effectively utilizing the space for the location of the respective elements or units of the motorcycle.

Hydraulic transmission control system

Abstract: A hydraulic control system for a steplessly variable transmission, having primary and secondary pulley assemblies, controls a line pressure for complementarily varying effective diameters of the primary and secondary pulley assemblies so as to steplessly vary a transmission ratio of the steplessly variable transmission. The line pressure is changed according to an engine output transmitted to the primary pulley assembly from an engine and a transmission ratio of the steplessly variable transmission. A decrease of pressure is caused in the line pressure according to a thrust exerted on either one of the primary and secondary pulley assemblies caused by centrifugal force.