Abstract: An aircraft seat may include a seat back coupled to a shell of one or more passenger compartment shell sections of a passenger compartment installed within an aircraft cabin. The aircraft seat may include a seat pan coupled to a floor of the aircraft cabin proximate to an ottoman installed within the passenger compartment. The seat back may be in contact with a surface of the seat pan when the aircraft seat is in a first position. The seat back may be separated from the surface of the seat pan when the aircraft seat is in a second position. The seat back may be configured to move independently of the seat pan when the aircraft seat transitions between the first position and the second position.

Abstract: A volumetrically efficient mechanism for raising and lowering sitting assemblies to provide ready access below them. A scissors assembly is selectively moved from a collapsible to an extended (raised) configuration by an electric motor with a telescopic arm that acts on hingedly mounted U-shape frames. The distal ends of the frames include wheels that ride over a lower support assembly. The telescopic arm is mounted to one of the distal upper member of the frames and the motor is rigidly mounted to the upper end of the other U-shape frame or to the lower support assembly causing them to selectively move between the two extreme configurations.

Abstract: The invention relates to a vehicle seat comprising a vehicle seat upper part and a vehicle seat lower part, which are spaced apart from one another along a height axis Z and are connected to one another by means of a scissor frame arrangement, wherein at least two damping elements are provided between the vehicle seat upper part and the vehicle seat lower part, the at least two damping elements each extending, inclined at an angle of attack ?, relative to a first axis parallel to the height axis.

Abstract: A chair equipped with a pendant controller to help a person rise from a setting position to a standing position with the assistance of arm rests for stability. The chair allows the rear of the seat to be lifted by an electric lifting device mounted directly under the rear of the seat. The front of the seat is hinged to the front frame of the chair allowing the rear of the seat to be moved up to allow the user to reach a height that allows them to exit the chair. The arm rest allows the person to maintain stability during the process.

Abstract: A method for adjusting a vehicle seat includes moving each of a set of first valves respectively associated with ones of a group of first bladders into an open position allowing the receipt of air into and fluidic communication among the group of first bladders, inflating the first group of bladders to a predetermined pressure, and closing each of the set of first valves to maintain an inflation level of each of the first bladders.

Abstract: A seat comprising a seat support for receiving and bracing a seat plate, which comprises a rear region and a front region, the rear region, which receives the ischial bones (os ischii), being arranged lower than the front region and the seat support supporting the rear region, wherein the front region of the seat plate is formed resiliently as a flexible zone without direct supports.

Abstract: A pump assembly for a vehicle seatback includes a plurality of air bladders defining a lumbar support. A valve body has an inlet and a plurality of outlets that are coupled with the associated plurality of air bladders. A selection device is operably coupled with the valve body for engaging a select one of the plurality of air bladders with the inlet. A manually compressible air chamber is coupled with the inlet for inflating the select one.

Abstract: An article of furniture is disclosed. The article of furniture comprises a stool configured to be used on a generally horizontal surface such as a floor. The stool comprises a seat and a base comprising a rounded bottom surface configured to rest upon the floor. A mass is positioned beneath the seat so that the base is at equilibrium in a first tilted orientation relative to the floor. The base can be tilted to second tilted orientation relative to the floor by tilting the rounded bottom surface of the base relative to the floor.

Abstract: The invention relates to a vehicle seat which may be adjusted forward and back along a seat rail arranged on both sides, and in which both the inclination of a seat surface and a back surface and a height thereof may be adjusted. Such a vehicle seat is intended to be adapted very easily and in an uncomplicated manner to the different body sizes of drivers. This is achieved in that a common adjustment mechanism is provided for all seat adjustment sequences, which coordinates the individual adjustment sequences, in that the coordination of the adjustment sequences produces seat adjustments in which the seating position of the respective driver is optimized irrespective of body size.

Abstract: A suspension system for a seat assembly of a machine includes an upper support member and a lower support member. A plurality of vertically aligned guide pins interconnect the upper and lower support members, and are telescopically movable to adjust a distance between the upper and lower support members. A plurality of suspension devices are operatively connected to the upper and lower support members for biasing the upper support member away from the lower support member.

Abstract: An application for an assist chair includes a mechanism for interfacing the assist chair to a floor such as a base and stand and a mechanism for supporting a user of the assist chair such as a seat, seat back and optionally a seat-height adjustment and adjustable seat arms. The assist chair includes one or more devices that capture energy from a user sitting on the mechanism for supporting the user. The device(s) for capturing the energy release the energy when the user transitions from a sitting position on the assist chair to a standing position, thereby assisting the user in attaining the standing position.

Abstract: A raiser seat for assisting a person from a sitting to a standing position is described. The seat comprises: a seat frame (4); a seat (10) supported for movement relative to the seat frame between a lowered position and a raised position; and a movement mechanism for moving the seat between the lowered and the raised positions. The movement mechanism comprises at least one cam (104) and the seat rests on the at least one cam such that rotation of the at least one cam results in movement of the seat relative to the seat frame.

Abstract: The portable seat is positioned on the two seat rail tubes of a standard wheelchair with brackets. The seat has a lower frame and an upper frame having four pivoted legs slidably mounted in channels. A horizontal arm connects the two front legs at the lower part thereof and has a pivoting and threaded drive nut. Another horizontal arm connects the two rear legs at the lower part thereof and has a pivoting and threaded drive nut, being oppositely threaded. A drive screw is mounted to both drive nuts and when rotated the legs are pushed together to raise the seat thereon. As an additional feature, a tilt seat section may be attached to the upper frame causing the seat to tilt forward allowing the user too more easily dismount. This feature may be activated when the seat is or is not elevated. Appropriate electronics operates the portable seat.

Abstract: A foldable vehicle seat assembly includes a pivotable seat back that is can be positioned into an upright position and a folded position. The pivotable seat back may optional also be able to be positioned in one or more additional positions thereby allowing a reclining or forward positioning of the seat back. The seat bottom cushion subassembly is positioned over the seat bottom reinforcement member. The pivotable seat bottom reinforcement member provides structural support to a forward section of seat bottom cushion subassembly when this section is raised during seat repositioning.

Abstract: A raiser seat for assisting a person from a sitting to a standing position is described. The seat comprises: a seat frame (4); a seat (10) supported for movement relative to the seat frame between a lowered position and a raised position; and a movement mechanism for moving the seat between the lowered and the raised positions. The movement mechanism comprises at least one cam (104) and the seat rests on the at least one cam such that rotation of the at least one cam results in movement of the seat relative to the seat frame.

Abstract: A lift chair is provided which includes a frame having four legs and a back rest portion. A seat has a front portion pivotally attached to the frame and has a rear portion which can be lifted upwardly. The seat movable from a first generally horizontal sitting position to a second angled lift position where the rear portion of said seat is lifted upwardly. Arm rests members are movably attached to opposite sides of the frame. Each arm rest member has a generally horizontal arm rest portion and a vertical activating rod member. The arm rests are movable from a first upper vertical position to a second lower vertical position. A rope and pulley system is provided which includes a pulley attached to a lower end of each activating rod and additional pulleys are attached to the frame. A rope is attached to the rear portion of the seat and extends around the pulleys.

Abstract: A safety seat for vehicles, including a seat portion having a tubular frame for a textile sitting surface. The seat portion is secured to a strap framework secured to a vehicle via two vertical support straps. A shoulder harness secures an occupant and has two strap portions in the vicinity of the occupant's back, each strap portion extending vertically between a releasable securement on a vehicle roof and a rear end of the seat portion. The two strap portions are deflected at the rear end and are then guided in a crossed manner beneath the sitting surface of the seat portion to securements disposed near the front edge of the seat portion. The shoulder harness has two shoulder straps held on the strap portions and extending to releasable securements near the front edge of the seat portion. The shoulder straps have a releasable cross connection for their interconnection over an applicant's chest.

Abstract: An adjustable bicycle seat assembly includes an adjusting unit which includes a top end member connected to the seat post and an adjusting tube is connected to a lower end of the top end member. An inner space is defined in the adjusting tube and an outer space is defined between the adjusting tube and the seat post. A path is defined between the adjusting tube and the top end member so as to communicate with the inner space and the outer space. An axle is movably received in the path and removably seals the path. An anti-rotation device is located between the seat post and the seat tube so as to prevent the seat post from rotating relative to the seat tube.

Abstract: A retrofit height adjustable seat for a chair having a support frame having a base for connection to the support frame and a top seat frame include a displacement mechanism movably interconnecting the base, a rack operably connected to one of the base and top seat frame and pinion operably connected to the rack. The displacement mechanism includes a pair of interconnected scissor arms which in a retracted mode are in a generally parallel position relative to one another rendering the top seat frame seat adjacent the base and when in an extended mode are in a generally nonparallel position relative to one another rendering the top seat frame seat displaced away from the base.

Abstract: A modular standing frame is described herein. The modular standing frame has a chair module adapted to raise and lower a user between sitting and standing postures without inducing shear between the user and the seat and seat back of the chair module. The chair module may be selectively coupled to one of a glider module adapted to provide walking-type exercise to a standing user, a workstation module that provides a work surface for a sitting or standing user, and a mobility module that allows the standing frame to be moved about by a user much like a wheel chair.

Abstract: A raiser seat for assisting a person from a sitting to a standing position is described. The seat comprises: a seat frame (4); a seat (10) supported for movement relative to the seat frame between a lowered position and a raised position; and a movement mechanism for moving the seat between the lowered and the raised positions. The movement mechanism comprises at least one cam (104) and the seat rests on the at least one cam such that rotation of the at least one cam results in movement of the seat relative to the seat frame.

Abstract: The present invention is an improved seat to be attached to standard wheelchairs and scooters with or without the original seat thereon. It further may be used as a standalone seat in regular chairs where additional assistance is needed to elevate and/or tilt the seat. In the preferred embodiment, a portable inflatable seat is positioned to the two seat rail tubes with brackets. Upon the top of a lower frame is stack mounted a plurality of box-like inflatable seat bags. An air pump unit with battery is removably attached to the back of the wheelchair. A control unit is also removably to the wheelchair and a control box is attached to the armrest and to the control unit. When turned on, the air pump unit will inflate the seat bags. The user will be elevated to a height of about 6 inches or so. As an additional feature, a tilt seat bag is attached to the top of the highest inflatable seat bag. Its inflation will cause the seat to tilt forward allowing the user to more easily dismount.

Abstract: An object of the present invention is to provide a compact base for a seat with a suspension for a vehicle driver, for use in buses, heavy vehicles or special use vehicles, including excavation vehicles or foresting equipment, in which the operator or driver is subject to vibrations. The present invention provides total independence of the suspension properties, including stiffness, damping and range of travel, with height adjustment. In order to accomplish this, the compact base for the seat is divided into parts including a suspension and a seat height adjustment mechanism. These parts have no common component including balloons, dampers or guiding systems. In this manner, the suspension properties of the seat are not affected by the seat height adjustment. Moreover, the invention provides a compact seat base through the use of structures and balloons that fit one within the other.

Abstract: A combination chair and seat pivoting mechanism includes a frame and a seat section pivotally connected to a front end of the frame. The seat section is pivotal along a fulcrum axis defined along a front end thereof. The front end remains contiguously abutted with the frame during pivoting motions. Pulleys are connected to spaced portions of the frame and are registered along a single plane. A weight member is coupled to the pulleys and positioned subjacent to the seat section. A cable is tethered to the frame and the weight member. A pneumatic piston has a stationary portion coupled to the frame, and a linear piston coupled to the seat section. The pneumatic piston and weight member cooperate in tandem for resisting an operating force directed on the seat section during sitting and standing procedures.

Abstract: An Occupant Retraction System (ORS) retracts a partially exposed occupant into a vehicle. The system responds to a trigger, wherein an occupant support retracts and actively pulls the occupant into the vehicle interior. The triggering event may be initiated by a manual switch, a rollover sensor, a crash sensor, a hostile ordnance sensor, or the like. A belt, harness, or foot strap may be connected to the occupant support to pull the occupant into the vehicle interior. A forcing means may be provided by a spring, hydraulic, pneumatic, or electro-mechanical actuator. The system further includes a damper for limiting acceleration to a safe maximum.

Abstract: An apparatus—which could be a chair (10), but could also be an apparatus that supports a person in other than a seated position—comprising a moveable platform (including a seat (12) in case of a chair) urged always toward a neutral position when a person is seated or otherwise positioned on the apparatus (10). The motion of the platform/seat (12) toward and away from the neutral position is constrained so that the platform/seat (12) remains at least approximately horizontal in its orientation relative to the floor on which the apparatus/chair (10) is positioned even when traveling along a path not horizontal to the floor, i.e. e.g. along a path inclined to the floor. A method is also provided in which the apparatus/chair (10) is used to provide lower-back therapy.

Abstract: A lifting chair, having a seat which is pivoted upward, being hinged along its front edge to help lift an individual who has trouble rising from an ordinary chair, also has arms which move upward during this pivoting process. Similarly, the seat and arms are moved downward to help the individual sit down. The linkage preferably is a parallelogram type preventing rotation of the arms as they are moved upward and downward along arcuate paths.

Abstract: A chair includes a support having one or more vertical rails to slidably receive one or more brackets, each bracket includes an opening formed between two ears, a seat plate includes one or more cams disposed in the opening of the bracket and rotatably secured to the ears of the bracket with a shaft, to allow the seat plate to be rotated relative to the bracket and the support. The cam may engage with the rail to support the seat plate in a folding position when the seat plate is parallel to the support, and may also to engage with the rail to support the seat plate in an open and working position when the seat plate is perpendicular to the support.

Abstract: A locomotion device for physically disabled persons, comprising: a chassis (10) mounted onto a pair of rear wheels (11) and a pair of front swiveling wheels (12); a seat frame (20) frontally articulated to the chassis (10), so as to be displaced between a substantially horizontal first position and a second raised position that is markedly downwardly forwardly inclined; a backrest frame (30), which is interiorly articulated to a rear portion of the seat frame (20) and to the chassis (10), in order to be displaced between a first position, which is substantially orthogonal to the seat frame (20), and a second position, which is substantially coplanar to said seat frame (20); an impelling means (40), which is operatively coupled to the chassis (10) and to the seat frame (20), in order to provide the selective displacement of the latter between the first position and the second position; a movement locking means (50), which is mounted to the chassis (10) to allow the selective locking of the rear wheels (11); an

Abstract: A seat elevating mechanism for chair particularly designed for old men and patients having weak legs mainly includes a seat that can be elevated or lowered using a power-actuated telescopic lifter. The seat is maintained in a horizontal position while being elevated or lowered, so that a user may stably sit thereon until the seat is fully elevated or lowered to enable the user to get up or sit down effortlessly.

Abstract: A folding chair has a height adjustable seat whose height is controlled by a pneumatic cylinder having locking springs is seated inside each of the two tubular front legs of the chair. A trigger mechanism allows the user to release the locking aspect of the springs, adjusting the height of the seat before locking the spring length again. The chair is supported by a pair of cylindrical sleeves that move up and down the front legs and that are connected by a seat stop bar that maintains the seat in a position ready for use because it is contacted by the straight rear edge of a pair of gussets connected to the sides of the seat. The chair seat pivots upward into a storage position through a pair of hollow pins connected to fittings at the top of the pneumatic cylinders and that move up and down the front legs within an elongated slot cut into each front leg.

Abstract: A chair includes a seat frame, a seat movably mounted on the seat frame, a backrest pivoted to the seat frame, a reciprocating mechanism mounted under the seat frame to cause the seat to engage in a series of repeated up-and-down motions, and a reclining mechanism mounted under the seat frame to enable the backrest to be adjusted for reclining. The reciprocating mechanism has a transmission member which is driven by a motor and is provided with a contact portion in contact with the underside of the seat. The reclining mechanism includes a control lever for regulating the position of an actuation pin in a triangular hole of a position control plate such that the actuation pin serves to activate or deactivate a pressure release knob of a cylinder which is fastened at one end with the backrest.

Abstract: A portable patient transfer assist system for improving the mobility and independence of persons with limited range of motion. The portable patient transfer assist system includes a base assembly is designed for resting upon a horizontal support surface, a lift assembly operationally coupled to the base assembly having a stored position and an extended position and being fully adjustable between the stored and the extended positions, a seat assembly operationally coupled to a top end of the lift assembly designed for being sat upon by the user.

Abstract: An adjustable height automotive seat (10) is provided, including a backrest portion (12) and a seat portion (14), the seat portion (14) capable of being vertically displaced in relation to the backrest portion (12) and thereby accommodating shorter passengers.

Abstract: A body-mimicking system ergonomically integrates a user with a work station while promoting active sitting and proactive positioning. Particularly, cooperative structures are provided to timely promote healthy and productive postures in task seating operations through the maintenance of ergonomic access and reach to a work station at all times. The system enables a user to effortlessly and dynamically shift from a conventional seating position to a lean/stand posture, and any health posture in between, without disrupting the task at hand. When viewed in its cooperative aspects of clinically preferred human postures and its anticipation of the next best posture in relation to a specific user the system operates as a synergistic biomechanical system.

Abstract: The operator adjustable workstation facilitates adjustments ranging from a seated work level to a standing work level with an infinite number of health posture arrangements and work surface levels in between. Two trigger controlled height and angle adjustment body support actuators and a foot controlled lower leg and lower leg support pivot actuator, provide the operator with independent control to quickly lock into place and/or release each health posture and work surface at any level within the adjustment range. The workstation includes a base structure, a body support area, a work surface area, and lift arm. The work surface area incorporates two substantially planar work surfaces. The body support area incorporates seat, back, lower leg and lower leg support components. The body support and work areas incorporate two separate lift arms. The lift arms have first ends and second ends.

Abstract: A lift seat specifically suited for assisting an individual from a seated to a standing position or from a standing to a seated position. The lift seat has a hinged seat platform that is pivotally coupled with a base platform and a lift link assembly coupled to a wheeled carriage. The wheeled carriage is driven linearly by a motor powered lead screw that operates in either direction of rotation to advance the position of the carriage. The movement of the carriage in one direction causes the lift link assembly to raise the seat platform while the movement in the opposite direction causes the platform to lower.

Abstract: An adjustable height work station is adjustable between a seated work level and a lifted work level. The work station includes a base structure, a work area, and a lift arm. The work area incorporates a substantially planar surface. The lift arm has a first end and a second end. The first end is pivotally secured to the base structure while the second end is pivotally secured to the work area. Tie first end and second end are pivotable through a range of motion to raise and lower the work area between the seated work level and the lifted work level while maintaining the planar surface of the work area in a substantially horizontal position through the range of motion.

Abstract: A height adjustable wheelchair apparatus for allowing users to be able to move more easily in and out of the wheelchair. The height adjustable wheelchair apparatus includes a frame, a wheel assembly upon which the frame is mounted, a seat member being mounted to the frame and being adapted to be raised and lowered, a backrest being mounted to the frame, an armrest assembly being removably mounted to the frame; and further includes a lift assembly being mounted to the frame and being adapted to raise and lower the seat member.

Abstract: A seated walker has a frame that includes pair of inverted U-shaped side members and a cross bar. A seat is pivotally affixed to the frame and is movable between an upper position where the seat is generally vertical and out of the way of the user and a lower position where the seat is generally horizontal and can be utilized by the user to sit down. An elastic cord is affixed to the frame of the seated walker and encircles the seat so that the seat is biased toward its upper position. By use of the elastic cord, a user can disable the biasing function by hand to remove the elastic cord from encircling the seat and, engage the biasing. Thus, the user can use or not use the biasing function as desired. As a further feature, the seat can be pivotally affixed to a front cross bar and is supported by a pair of generally L-shaped members extending outwardly from the underside of the seat and which rest upon pair of side braces that are positioned lower on the frame than the front cross bar.

Abstract: A chair composed of a seat adapted to be adjusted in height and depth, and a chair body, on which at least one rack rail extending in the direction of vertical adjustment is arranged, which is associated with the seat on which a vertically adjustable holding element runs, which is associated with the seat, the rack rail meshing with a gear wheel mounted on the holding element, and on which a drive element able to be rotated by the gear wheel is arranged. The holding element constitutes a projecting seat holding portion, on which a seat carrying part runs for movement in the direction of depth adjustment.

Abstract: A manual uplift apparatus comprising a structural frame unit, a mechanical uplift assembly unit, and a power translating mechanism connecting the two units to allow the user to more easily obtain a standing position from a previously seated position. A second use for the apparatus may be as an exercise product for exercising upper body muscle groups. The structural frame unit is used to support and guide the mechanical uplift assembly unit. The mechanical uplift assembly unit has two sections that can independently move vertically with respect to the structural frame unit. One section has a seat, the other has rails or hand engagement handles. When downward force is applied to the hand engagement handles, the section having the handles move vertically downward and produces an upward force in the section having the seat through the power translating mechanism.

Abstract: An operable chair includes a seat which is pivotally connected to a support arm, the support arm being operably mounted on an upright frame for selective vertical movement along the frame. The seat is mounted for selective and adjustable tilting so that an operator may lean forward from the chair at a desired angle. A footrest is operably mounted to the upright support for selective vertical movement there along, independent of the seat. The footrest includes a foot platform which is selectively pivotable as well. A body restraining harness is provided for an operator seated in the seat, and includes an adjustable length cable connected to a bracket operably mounted on the upright support, to adjustably restrain the upper torso of a person seated in the seat, with the upper torso leaning forwardly over a desired work site.

Abstract: A full floating device of a rear seat cushion for an automobile comprises a fixed frame fixed on a floor panel of the automobile, a pivot frame to which the end of the supporting bracket is linked by a pivot pin and on which a seat cushion is mounted, and an angle adjusting means pivoting the rear end of the pivot frame about the pivot pin in order to adjust the inclination of the seat cushion mounted on the pivot frame. The device in accordance with the present invention can adjust the angle of the rear seat cushion of the automobile according to the condition of the passenger, and the passenger can be comfortable.

Abstract: A chair includes a base and a seat each having two side tracks and a front track. Three pairs of pivotal bars have upper ends coupled to the tracks of the seat and have lower ends coupled to the tracks of the base. The bars may expand and fold when the seat moves up and down relative to the base. A tube is extended in the base, the seat includes a downward extending rod slidably engaging in the tube and threaded with a bolt. A motor is coupled to the bolt for driving the bolt and for moving the seat up and down relative to the base to adjust the height of the seat relative to the base.

Abstract: A seat mechanism for mounting in a shower or bathtub has a telescoping lift column that raises and lowers the seat. The column has mutually interacting elements that have two end elements and at least one middle element between them. The at least one middle element and at least a first of the end elements have external threads. The at least one middle element and a second of the end elements have internal threads. A drive is arranged to rotate one of the two end elements.

Abstract: A portable device is provided for assisting persons with the acts of sitting down and rising from a seated position. The device comprises a base a seat, an inflatable air chamber and a battery powered air compressor. The air chamber, the compressor and the battery are self-contained within the base and seat, which fit together to form a case. The device further comprises three stabilizing scissor-braces which support and stabilize the side edges and the rear edge of the seat throughout its range of travel. The air chamber is preferably fashioned of non-stretch material. The device may also include a cable and spring mechanism to urge the seat into a closed position from a raised open position.

Abstract: A vehicle seat, the seat cushion of which is divided into front and rear cushions in a fore-and-aft direction. The front cushion is rotatably mounted at its front-side lower end on a front end of a cushion frame of the vehicle seat to be tilted forward or backward. The rear cushion is placed behind the front cushion and supported by a lift mechanism mounted on a rear portion of the cushion frame. The lift mechanism is interlocked with the front cushion to raise the rear cushion to an upper position when the front cushion is tilted forward and to lower the rear cushion and place it behind the front cushion on the cushion frame in a horizontal condition when the front cushion is tilted backward and placed on the cushion frame.

Abstract: A vehicle seat suspension system is provided which includes, in a seat support comprising an upper housing and a lower housing and a scissors linkage support apparatus, a spring fixed to the upper housing and a cable attached to the spring and wrapping around a pulley attached to the upper housing and downwardly to an arcuate or eccentric pulley attached at the scissors linkage axis pivot and an actuator knob which allows a seat occupant to tighten or loosen the cable and raise or lower the seat to provide a vehicle seat suspension system. The present invention provides a suspension system which can be discreetly and infinitely adjustable and which allows a user to adjust the suspension curve characteristics of the seat by utilizing a non-circular drive pulley which is movably adjustable.

Abstract: A vehicle seat suspension system is provided which includes, in a seat support comprising an upper housing and a lower housing and a scissors linkage support apparatus, a spring fixed to the upper housing and a cable attached to the spring and wrapping around a pulley attached to the upper housing and downwardly to an arcuate or eccentric pulley attached at the scissors linkage axis pivot and an actuator knob which allows a seat occupant to tighten or loosen the cable and raise or lower the seat to provide a vehicle seat suspension system. The present invention provides a suspension system which can be discreetly and infinitely adjustable and which allows a user to adjust the suspension curve characteristics of the seat by utilizing a non-circular drive pulley which is movably adjustable.