Showing papers on "Pulley published in 1989"

Compact cable transmission with cable differential

Abstract: A pretensioned cable transmits power along a first support member (link) from a rotary actuator to a rotating output joint, typically an output pulley fixed to a second link arm but rotatable in a coupling between the first and second links. A reducer, typically two sets of coupled idler pulleys of different diameter, is mounted at a point removed from the actuator, and preferably as close as possible to the output joint. An axially split spool mounted on the actuator output wraps the outgoing and returning cable sections on different halves of the spool in opposite directions to provide pretensioning of the cable in the entire cable circuit at one point. To form a differential, a pretensioned cable carried on paired pulleys having smooth outer surfaces parallel to the axis of rotation couples the pulleys. The pulleys have axes of rotation that can intersect and their cable carrying surfaces are closely spaced, preferably by less than half the width of the cable. The outer surfaces can be stepped to accommodate two or more cables for bi-directional operation, or to create a conventional differential with a spider. The links and pulleys of the transmission are long and narrow. This high aspect ratio provides a compact configuration that is conducive to whole arm manipulations where any exterior surface of the links can engage an object. A low inertia, low friction brushless D.C. motor operating under the control of a pulse width modulated controller responsive to the current drawn by the motor, in combination with the cable transmission of this invention, provide excellent force control.

Anatomy of the flexor tendon sheath and pulley system: A current review

Abstract: The flexor tendon sheath in the fingers is a synovial-lined, fibroosseous tunnel with segmental condensations of fibrous tissue. These fibrous bands or pulleys are: (1) the palmar aponeurosis pulley (formed by the transverse fibers of the palmar aponeurosis), (2) five annular pulleys, and (3) three cruciform pulleys. The second and fourth annular pulleys are the largest, thickest, and most constant in form and incidence. The first, third, and fifth annular pulleys are less constant in shape and incidence as are the cruciform pulleys. No other pulleys have been identified in this study.

Exercise apparatus having high durability mechanism for user energy transmission

Abstract: An exercising apparatus is disclosed which simulates stair-climbing. In order to reduce breakage problems in the force-transmitting structure between each pedal and a one-way rotating drive shaft, a pair of pulley wheels, each associated with a pair of cables, are used. Each pulley wheel rotates the drive shaft, and is pulled in one direction of rotation by a pedal-connected cable, and in the other direction of rotation by a cable connected to a return spring. Each cable on each pulley wheel reels into and out of helical grooves formed in the periphery of the pulley wheel.

Biomechanical analysis of finger flexor pulley reconstruction

Abstract: Fifty cadaver digits were used to study the mechanical properties of five different methods of pulley reconstruction and the effectiveness of three different pulley reconstructive arrangements in restoring a normal relationship between tendon excursion and joint motion All reconstructed pulleys showed less stiffness and more displacement before failure than normal intact pulleys Although reconstruction using a length of another tendon woven through the remaining fibrous rim of the pulley and both double and triple tendon graft loops around bone absorbed more energy to failure than a normal pulley, only the triple loop around bone could withstand as much load before failure as a normal pulley No reconstruction restored a normal tendon excursion/joint motion relationship, but reconstruction of the A2 and A4 pulleys restored a more normal relationship than either the “belt loop” reconstruction or a combination belt loop, A2 and A4 reconstruction

Exercise bicycle for exercising arms and legs

Abstract: An exercise bicycle includes a frame, a crank shaft journalled on the rear portion of the frame, and a wheel axle journalled on the front portion of the frame. Two crank arms are secured to two ends of the crank shaft and carry two pedals. Two swing wheels are secured to two ends of the wheel axle and carry two crank pins on which two sheaves are sleeved rotatably. Two swing levers are mounted pivotally on the front portion of the frame at the lower ends thereof and have lengthwise extending slide slots in which the sheaves are received slidably. A rear driving pulley and a rear driven pulley are sleeved rigidly on a sleeve which is sleeved rotatably on the crank shaft. A mechanism is provided between the crank shaft and the sleeve so as to interlock them when the pedals rotate in a predetermined direction. A front driving pulley is sleeved rigidly on the wheel axle. A front driven pulley and a wheel are sleeved rigidly on a wheel hub which is sleeved rotatably on the wheel axle. The front and rear driven pulleys are rotated by the rear and front driving pulleys through belts. The swinging movement of the swing levers and/or the rotation of the pedals can be converted into the rotation of the wheel.

Jointed bicycle-simulation device for isometric exercise

Abstract: A bicycle-simulation exercise device for convalescing and handicapped persons having foot pedals and hand grips which all swing in an orderly fashion in directions not to place undue strain on the person's joints. The lower end of a first upwardly inclined leg-activated bar is pivotally connected to the lower end of a first upwardly inclined arm-activated bar. Adjacent these bars, second leg-activated and arm-activated bars are identically coupled. The two pivot points of the bars are attached to opposed ends of an elastomeric band which is trained about a pulley. In this manner, each of the four bars is mechanically coupled to the remaining bars. Two degrees of operating difficulty are provided by selective insertion of a rod into the pulley. With the rod removed from the pulley, the pulley is allowed to rotate with movement of the elastomeric band to make operation of the exercise device relatively easy. However, insertion of the rod into the pulley aperture locks the pulley and the frictional force created at the elastomeric band-to-pulley interface produces a greater resistance to bar movement.

Shape memory alloy rotary actuator

Abstract: A rotary actuator which provides a differential pulley pair having a shape memory alloy wire The shape memory alloy wire is thermally cycled through its phase change transition temperature and contracts Tension forces applied by the ends of the wires to opposite sides of the pulley pair result in a net torque which causes relative rotation between the pulley pair and a reference base The large mechanical advantage of the differential pulley converts a large force working through a small distance into a relatively large angular rotation

Remotely controlled lawn mower

Abstract: A lawn mower that is remotely controlled and self-propelled. The lawn mower is propelled by battery powered electric motors that drive a set of wheels that are fixed in relation to the frame. Steering is accomplished through a belt and pulley system generally aligned with the forwardly mounted steering wheels. A battery powered electric motor rotates a center pulley, that in turn rotates pulleys for positioning the steering wheels in relation to the frame. Direction and speed of the mower may be controlled with a two channel radio. Frustro-conical wheel projections may be provided to help cross uneven terrain. Cutting height adjusters for the wheels may also be provided.

Electric motor powered skateboard with integral brakes

Abstract: An electrically driven brake controlled skateboard employing an electric motor and associated battery mounted on the bottom of its foot supporting board employs a pulley arrangement whereby the initial slipping of its belt acts as a clutch for transferring rotational power from the motor to a U-grooved drive wheel of the skateboard. The U-groove is low cut so that the drive belt is partially exposed to the road surface. A dual purpose tether mounted brake control and on/off switch is used to control the braking of the skateboard and the energization of the drive motor.

Feeder for shape unstable articles

Abstract: A feeder for shape unstable articles such as pads for absorbing body fluids has an upright hopper having top and bottom openings for receiving and discharging pads. First and second rotationally driven upper pulleys having a plurality of round belt receiving grooves in their peripheries are mounted adjacent the bottom opening of the hopper on opposite sides of the vertical center line of the hopper. Third and fourth idler pulleys are arranged in laterally spaced apart relationship and symmetrical to the center line of the hopper at a lower level than the first and second pulleys. Because the lower pulleys are closer to each other than the upper pulleys, the belts converge toward each other such that articles which settle out of the hopper finally become wedged between the belts proximate to the lower pulleys. A stepping motor is energized to drive the pulleys and translate the belts so that the lowermost article in the stack is dispensed from between the lower pair of pulleys by reason of being frictionally engaged at its edges by the belts on the grooved pulleys. The stepping motor is started at the moment a pad should be dispensed and is stopped in response to the pad dropping across the beam of a photosensor so the feeder is self-timing. Thus, the feeder is self-adjusting for each individual article ranging from a short feed time for a compressed article to a longer feed time for the next article which may not be compressed and, hence, thicker.

Endless power transmission belt construction and method of making the same

Abstract: An endless power transmission belt construction and method 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 projections and grooves for meshing with a ribbed surface of a rotatable pulley or the like and defining a plurality of transversely disposed and alternately spaced apart projections and grooves that respectively extend between and to the opposed side edges, the longitudinal spacings between the transverse grooves or/and the depths of the transverse grooves being staggered so as to tend to reduce noise during normal operation of the belt construction with the pulley or the like.

A mechanical study of six digital pulley reconstruction techniques: Part I. Mechanical effectiveness.

Abstract: A laboratory study on fresh-frozen human cadaver limbs compared six types of flexor tendon pulley reconstruction in the fingers. The reconstructions used were those described by (1) Bunnell, (2) Karev, (3) Weilby, and (4) Lister, and two types developed by us that have not been previously described. The pulleys were studied in specific configurations to determine their effectiveness in transforming tendon excursion into finger flexion. In each finger, comparison was made between the amount of tendon excursion required for full flexion with an intact pulley system versus the various types of reconstructed pulleys. The ratio of these two values was defined as the mechanical effectiveness of the pulley reconstruction. The Karev reconstruction was most effective at 108.2%, which was significantly different from the other five reconstructions ( p

Belt grinder attachment for powered rotary tools

Abstract: A belt grinder attachment for powered rotary tools mounts an abrasive belt for movement transverse to the axis of the tool for ease of alignment of the belt on a work piece. The attachment body member can either be threaded onto the tool housing or be clamped thereon. An arm extends from the body member and is radially adjustable for tensioning the belt. A driven pulley assembly is mounted on the free end of the arm and provides for the belt to run either directly on opposite sides of the arm or to one side only. The normal chuck of the tool is replaced by a drive pulley and the belt extends around both the drive and driven pulleys.

Power transmission belt

Abstract: PURPOSE:To conform with the contact surface of a pulley all the time and form a proper oil film as well as to abate the extent of running noise by fitting each spherical projection at both ends of a pin in spherical cavities of a friction material, and installing each cavity on the content surface with the V-pulley of the friction material. CONSTITUTION:Spherical cavities 7, 7' are installed on each inner surface of friction materials 1, 1', while each spherical projection 4a is installed at both ends of pins 4 being opposed, fitting it therein shiftably free motion, and cavity parts A, A' heading for the inside are installed on an opposed contact surface with a V-pulley of the friction materials 1, 1'. In consequence, at the time of belt driving, a V angle made by each side of these friction materials 1, 1' in the pulley is freely followed and thereby it is always accorded with a frictional surface with the pulley. In addition, the cavities A, A' on each contact surface of these friction materials 1, 1' come to an oil sump for lubrication to be given to a belt during its running, especially at the time of high speed running, a proper oil film is formed in a gap with the frictional surface of the V-pulley, and in combination with the action, a running noise is thus abatable.

Resistance weight kit

Abstract: A resistance weight kit which may be readily installed in a door frame. The resistance weight kit includes an extendable screw threaded support bar assembly (22) having rubber feet (28) at either end which may engage the sides of a door frame in an elevated position. Mounted on the support bar assembly are two radiallly outwardly extending eyes (52). A first pulley block (14) may be secured to one of the eyes (52) by a quick connector (60). A second pulley block (16) is provided and intermediate portions (74, 76) of a primary rope (18) engage the sheaves (58) of each of the pulley blocks. The ends of the rope are formed into eyes and one end (80) may be connected to the other radially outwardly extending eye (52) by another quick connector (60). A weight holder (12) is connected to an eye (56) on the second pulley block (16) by another quick connector (60). An engagement device is connected to the eye (78 ) on the other end of the rope by another quick connector (60). The engagement device may be a baseball (88) with an extension length of rope (86). Alternatively, it may be a cross bar (110) or ankle band (122). The kit may further include a platform (20) having a third pulley block (114) mounted thereon, another extension length of rope (116) passing through the pulley block and having eyes at either end, the platform mounted extension length of rope also being quickly connectable. The kit may be used for physical therapy and rehabilitation after injury or surgery, and also for physical training, such as for example in instructiong a baseball player in the proper overhand throwing technique.

A mechanical study of six digital pulley reconstruction techniques: Part II. Strength of individual reconstructions

Abstract: A laboratory study was done on fresh-frozen human cadaver limbs, using six types of pulley reconstructions about the flexor tendons of the fingers. The reconstructions used were those described by (1) Bunnell, (2) Karev, (3) Weilby, and (4) Lister, and two types developed by us that have not been previously described. The pulleys were tested at constant strain rate to failure with the peak force recorded as the breaking strength. A total of 385 reconstructed pulleys were tested and the results were analyzed statistically. A new "loop and one half" pulley reconstruction was significantly stronger than the other five reconstructions (p less than 0.01) with an average load to failure of 22.5 kilograms-force. The other pulley reconstructions varied in average breaking strength from 2.8 kilograms-force to 18.4 kilograms-force.

Continuously variable transmission using planetary gearing with regenerative torque transfer and employing belt slip to measure and control pulley torque

Abstract: A continuously variable, regenerative transmission is disclosed in which a continuously variable transmission assembly is employed in conjunction with a regenerative gear assembly incorporating high and low clutches and situated intermediate a prime mover, such as a vehicle engine, and an output, such as the drive train to vehicle wheels. By monitoring certain system conditions (such as the rate and direction of rotation desired for the output, the rate of rotation of the engine and belt slip) while simultaneously controlling the engine speed, a control subsystem adjusts the effective diameters of input and output pulleys of the continuously variable transmission assembly to obtain a pulley torque versus belt tension that gives a belt slip value which results in rotation of the output in the desired direction at a rate according to a predetermined ratio schedule of the rate of rotation of the engine with respect to the rate of rotation of the output under the measured instantaneous conditions and in view of the output speed desired.

Engine unit for motor vehicle

Abstract: A motor vehicle power unit (19) comprised of a transversely disposed in-line cylinder block (21) inclined rearwardly. A crankshaft (28) is contained within a dry sump crankcase (29) positioned between the cylinder block (24) and drives and output shaft through an intermediate gear. The output shaft and crankshaft define a plane that intersects a plane defined by the cylinder bores and crankshaft. A dry sump oil reservoir (29) is positioned between these planes and the output shaft has a pulley that drives a plurality of engine accessories that lie forwardly of and over the cylinder block (24).

Counterbalanced coordinate-measuring instrument

Abstract: A coordinate-measuring instrument has a purely mechanical device (14) to compensate for the weight of a vertically displaceable spindle (9). The compensation device consists of a helical-coil spring having a working range which is small as compared with its length in relaxed condition, and a belt transmission interposed between the spring and the spindle (9). The belt transmission is preferably developed in the manner of a block and tackle. A first or drive pulley engages and drives the belt for Z-axis positioning of the spindle, and a second or belt-tension pulley applies weight-compensating tension to the belt.

Self adjusting timing belt tensioner

Abstract: Apparatus for applying an optimum tensioning force to an endless belt or the like, including a first pivot axis, a belt engaging pulley eccentrically supported for rotation about a second axis displaced from the first pivot axis, a torsional biasing spring for urging the belt-engaging pulley into belt-tensioning engagement with the belt and for automatically maintaining the tension force applied to belt. The torsion spring is disposed about the first axis within the eccentric pulley, which includes further springs for releaseably gripping the pivot to adjustably limit the applied tensioning force in a first direction and in a second direction, whereby the tension in the belt is optimally maintained throughout the engine operating temperature cycle.

Drive control for walk-behind mower with hydrostatic transmission

Abstract: A self-propelled lawn mower employs a hydrostatic transmission and differential to power rear drive wheels which are situated behind a forward mowing deck. The hydrostatic drive has infinitely variable adjustment of speed from reverse, through neutral, to a maximum forward speed. There are independent disc brakes for the drive wheels, with right and left brake levers situated adjacent the operator hand grips. An engine has its center of gravity behind the drive wheel shaft to balance the weight of the mowing deck. Left and right thumb-operated control levers are rockably mounted on the handle bar assembly, adjacent the inboard side of the right and left hand grips. This arrangement permits one-hand control of the transmission speed with either hand, while actuating the respective brake lever with the same hand, making one-hand brake-turning of the mower possible. The engine output shaft has a pulley connected by belt drives to the blades and to the hydrostatic drive.

Riding type mower

Abstract: PURPOSE:To suppress sinking of engine accompanying variation in belt tension, by connecting at least on side of a pulley set between an engine output shaft and a blade shaft to an engine through a rocking arm and a rod CONSTITUTION:A pulley 19 is rotatably attached with a shaft 25 to a rocking arm 23, whose middle part is connected to a front part of an engine 7 through a rod 26 One end of the rocking arm 23 is rockingly pivoted on a shaft 24 to the lower end part of a bracket 22, which is fixed to a front end face of a frame 6 Sinking of the engine 7 accompanying a variation in tension of a belt 17 driving a cutter device 13 is suppressed and thus propagation of an engine vibration to the frame can be prevented

Belt drive continuously variable speed transmission

Abstract: A continuously variable belt transmission of the type comprising: primary and secondary pulleys, each of which comprises a pair of axially opposed sheaves supported on a shaft, one of the sheaves being movable and the other being fixed; a belt wound around these pulleys; a pressure adjusting mechanism for imparting to at least one of these pulleys an axial force which corresponds to torque transmitted; and mechanical actuators for axially shifting the movable sheaves of these pulleys, wherein: first thrust bearings are respectively interposed between the backsides of the movable sheaves and one ends of the mechanical actuators; a first automatic aligning mechanism is provided for supporting at least one of the races of each the first thrust bearing; and axial forces occurring at the pulleys are carried by the shafts directly, or via the first thrust bearings, the first automatic aligning mechanisms and the mechanical actuators, or via the pressure adjusting mechanism. Further, adjustable intermediate members are provided which abut against the other ends of the mechanical actuators and are radially supported on shoulders of a casing, the adjustable intermediate members being adapted to rotatably support the shafts, and wherein second thrust bearings are interposed between the backsides of the adjustable intermediate members and a flange formed on one end of the shaft, at least one of the races of each the second bearing being supported by a second automatic aligning mechanism.

System for controlling hydraulic fluid pressure for V-belt type automatic transmission

Abstract: An automatic transmission includes a gear power train and a V-belt type continuously variable power train which are connected in parallel between input and output shafts. A relatively low hydraulic fluid pressure is supplied to a follower pulley cylinder chamber when the V-belt type continuously variable power train is rendered inoperable, whereas a sufficiently high hydraulic fluid pressure is supplied to the follower pulley cylinder chamber when the V-belt type continuously variable power train is rendered operable, inducing a sufficiently high force which the follower pulley grips the V-belt with.

Cone pulley transmission with controlled quantity of pressure medium

Abstract: The invention relates to an infinitely adjustable cone pulley transmission, to which pressure medium is fed by one or more pumps by way of a hydraulic control unit in order to adjust the transmission ratio These transmissions are generally driven by an internal combustion engine at rotational speeds of between 1000 6000 min , resulting in a quantity of pressure medium proportional to the speed, which quantity is not sufficient for the functioning of the cone pulley transmission under widely varying operating conditions and considerably impairs the overall efficiency By means of the invention, the quantity of pressure medium is controlled as required by means of sensors, an electronic processing unit and a solenoid valve according to the instantaneous operating states (engine speed, accelerator pedal position, etc)

Unassisted lower torso strengthening and stretching device

Abstract: A device for stretching and strengthening the muscles of the lower back and legs of a person in a supine position. The device includes a board with straps to restrain the pelvis of the person. A rope and pulley system, operated by the person by pulling and releasing extends between the feet and to a support above the head. The rope is pulled by the user to raise the legs, and additional mechanical advantage is employed as the rope is gradually released to lower the legs.

Wind-drag type climber

Abstract: A wind-drag type climber includes a base frame, a suspended wheel, a handlebar assembly, two swing arms each carrying a pedal thereon, a driving shaft, and a speed-increasing mechanism interconnecting the wheel and the driving shaft so as to rotate the wheel at a speed greater than that of the driving shaft. The wheel has a plurality of generally radially extending wheel blades which create air impedance to the rotation of the wheel. A drawing member is fastened to the free ends of the swing arms at two ends thereof and has two chain-like sections engaged with the two sprockets of the driving shaft, and a cable-like section extending around two aligned lower pulleys. The sprockets are sleeved rotatably on the driving shaft by unidirectional bearings. Each of the bearings locks the corresponding sprocket on the driving shaft only when the corresponding sprocket rotates in a predetermined direction. A flexible reciprocating element extends around an upper pulley and is fastened to the free ends of the swing arms at two ends thereof.

Ultrasonic transducer probe

Abstract: A belt driven pulley mounting a transducer in a probe system used for ultrasonic medical diagnostic imaging. The location of the sector scanned by the transducer is varied by changing the angular relationship beween the drive pulley of the system and the driven pulley.

Arrangement and method to detect physical parameters of an elevator

Abstract: The invention relates to a method of detecting physical parameters, in particular motion parameters, of a goods and/or passenger lift, whose car is suspended on a cable pull driven by a driving pulley. It is the object of the invention to propose a test method for such lifts in which there is a reduction in the amount of work by contrast with previously known test methods, while the test quality is simultaneously increased. According to the invention, this object is achieved when the physical parameters of the lift are determined by connecting at least one displacement sensor to the cable pull and/or the driving pulley in order to generate displacement signals, by connecting the displacement sensors to an evaluation unit which contains a time generator, in order to feed the displacement signals to the evaluation unit, and by connecting the evaluation unit to switching points of the control circuit, at which signals are present which control the sequence of motions of the lift, in order to determine physical parameters from the displacement signals and the control signals. The method can be used advantageously to check the drivability of the driving pulley.

Bending control apparatus for endoscope

Abstract: A control wire which is secured at one end thereof to a bendable portion of the insert part of an endoscope is wound on a pulley which is rotatably provided in a control part, and a manual control device is provided outside the control part so as to be rotatable about a position which is offset from the axis of rotation of the pulley by a distance a. The rotational motion of the manual control device is transmitted to the pulley by a rotational motion transmitting device at a position which satisfies the conditions of c>a and c>b, wherein b is the distance from the transmitting device to the axis of rotation of the pulley and c is the distance from the transmitting device to the axis of rotation of the manual control device.