Abstract: A conveyance element (20) for a conveyor (1), in particular for a people conveyor such as a moving walkway (2), is configured for being moved in a conveying direction and comprises an outer side (20a) configured for accommodating and supporting passengers; and an opposing inner side (20b) facing away from the outer side (20a). At least a portion of the inner side (20b) is a concave portion (32) having a concave shape along the conveying direction.

Abstract: An escalator is described that is designed in an installation space-saving manner and can be operated with low wear. The escalator has a plurality of treads and a guide-rail assembly to guide the treads during a return run. Each tread front intermeshing structure and a rear intermeshing structure that are complementarily configured in such a manner that they can meshably engage into one another in the forward run. The escalator is configured such that at least in a central region of the return run moving at an incline, the intermeshing structures of adjacent treads are meshably arranged with each other. As a result, the dimensions of the escalator can be reduced and adjacent treads can mutually guide each other through the meshing engagement.

Abstract: A chain drive (10) for a people conveyor (1) having a plurality of conveyance elements (4) comprises a drive chain (12) which is configured for driving the conveyance elements (4). The drive chain (12) includes a plurality of drive chain links (16) traveling along a closed path including a conveyance portion (5) and a return portion (7). The drive chain (12) further includes a plurality of linkages (42). Each linkage (42) is configured for coupling the drive chain (12) with one of the plurality of conveyance elements (4). The length of each linkage (42) along the path of the drive chain (12) is variable.

Abstract: Example drive systems for handrails of walkways and moving stairs may comprise a plurality of carriages. In some examples, each carriage may comprise a body with several leading rollers that roll along a guide that defines a handrail path. The carriage may further comprise a locking/release mechanism for selectively coupling the carriage to a drive chain of the handrail. The locking/release mechanism may comprise a hook configured to move between an engagement position wherein the carriage is coupled to the drive chain and a disengagement position wherein the carriage is uncoupled from the drive chain. In some cases, a position of the hook may be controlled by a wheel that travels along a cam profile.

Abstract: The invention provides a manufacturing system for processing a web, the system comprising a rigid frame with a plurality of processing stations; an endless belt which is movable relative to the frame; a track for guiding the endless belt between the processing stations; and a drive structure for advancing the belt along the track, To enable more flexible processing time at each processing station and to make better use of the space along the track, the system facilitates movement of a web at different speed at different locations along the track.

Abstract: A transporting apparatus serves for transporting containers in a container-handling installation, which has a first container-handling arrangement for handling containers, and a second container-handling arrangement, which is arranged downstream of the first handling arrangement and serves for handling the containers once they have been handled by the first container-handling arrangement. The transporting apparatus includes a transporting path, which has its entire length arranged between the first and second container-handling arrangement and along which the containers can be transported from the first container-handling arrangement to the second container-handling arrangement. The apparatus includes at least one transporting element, which is mounted in a movable manner on the transporting path and is intended for retaining and transporting a container.

Abstract: Disk-shaped pulleys 6 arranged on entrance side IN and exit side OUT and rotated around a horizontal axis, an expansion link chain 8 endlessly wound between the disk-shaped pulleys, and a flexible handrail belt member 10 connected outside the expansion link chain and extendable/retractable in a traveling direction are provided. The expansion link chain comprises expansion links 82 connected in series. The expansion link is flexibly extendable/retractable in length direction and has a pivot 84. An acceleration/deceleration device 12 accelerates/decelerates the pivot, and has a first track chain 122 endlessly guided along a predetermined first track and a first pressing fitting 128 having a rod shape extending outwards swingably attached to the first track chain. A tip of the first pressing fitting is detachably engaged with the pivot to accelerate/decelerate the pivot by continuously changing distance between the pivots by change of swing angle of the first pressing fitting.

Abstract: An acceleration and deceleration device includes: a chain 19 that is endlessly guided along a predetermined first track; a U-shaped member 40 of which a terminal end portion is attached to the chain 19 so as to be swingable and a part from an intermediate portion to a front end portion is formed as two parallel members and which has a long and narrow U-shaped groove between the parallel members; and a subject moving body 102 that has a driving shaft sliding inside the U-shaped groove of the U-shaped member 40, wherein the driving shaft of the subject moving body 102 is rotatable with respect to the U-shaped member 40 within a predetermined range in the U-shaped groove of the U-shaped member 40 and the driving shaft of the subject moving body is slidable with respect to the U-shaped member in the U-shaped groove of the U-shaped member 40.

Abstract: An acceleration and deceleration device includes: a chain 19 that is endlessly guided along a predetermined first track; a U-shaped member 40 of which a terminal end portion is attached to the chain 19 so as to be swingable and a part from an intermediate portion to a front end portion is formed as two parallel members and which has a long and narrow U-shaped groove between the parallel members; and a subject moving body 102 that has a driving shaft sliding inside the U-shaped groove of the U-shaped member 40, wherein the driving shaft of the subject moving body 102 is rotatable with respect to the U-shaped member 40 within a predetermined range in the U-shaped groove of the U-shaped member 40 and the driving shaft of the subject moving body is slidable with respect to the U-shaped member in the U-shaped groove of the U-shaped member 40.

Abstract: This invention is related to a Passengers' Transportation System and refers to a system of two mechanisms that allows the transportation of passengers without stopping to drop or incorporate them. They are: a Covered Linear Transporting Floor mechanism and a Uniformly Varied Movement Mechanism. This system includes a covered linear transporting floor that moves at a constant speed which is equivalent to the average speed of vehicles in a city. The Covered Linear Transporting Floor Mechanism connects different points on a given route while the other one with the Uniformly Varied Movement Mechanism allows passengers get on and off of the Covered Linear Transporting Floor Mechanism by themselves. The gradual change in speed is achieved by having the floor of the Uniformly Varied Movement Mechanism, made of sliding steps that slide one on top of the other, at different speed ranges, guided by a set of rails and speed variation systems that could be mechanical, electro-mechanic or electromagnetic.

Abstract: A drive control system for conveyor utilizes a dynamic chain pull calculation program that is integrated with a PLC, which communicates to a plurality of controllers. The controllers in turn automatically adjust their associated drive motors so as to maximize efficiency at moving material on a conveyor system. Sensing devices provide continuous load parameters to a PLC that in turn, processes the data and adjusts the system's operation based upon desired conditions.

Abstract: A transport system for the movement of passengers/goods formed by a moving endless belt having: a series of pallet assemblies; drive equipment for transmitting a drive movement from actuating equipment to the pallet assemblies in a low speed section located in an embarking/disembarking area of the endless belt; drive equipment for transmitting a drive movement from actuating equipment to the pallet assemblies in a high speed section located in a middle area of the endless belt; and drive equipment for transmitting a drive movement from actuation equipment (400?) to the pallet assemblies in a transitional speed section located between the embarking/disembarking area and the middle area of the endless belt.

Abstract: Auxiliary drag mechanism at variable speed, consisting of a variable pitch worm being geared with connection means of the components to be moved, at least during part of their path of travel, at variable speed. The worm is mounted between two end supports (8) and at least one intermediate support (9), whose supports leave free the gearing area between the connection means and the worm, along said worm.

Abstract: A travelator system for conveying a passenger, comprising a main conveyor and a branch conveyor. The main conveyor includes a first plurality of shafts each having a first plurality of belt pulleys disposed side by side thereon. The main conveyor also includes a plurality of mutually parallel endless belt loops which define a moving conveying surface of the main conveyor, each belt loop being passed over a belt pulley on two different shafts. Adjacent belt loops on the same common shaft are passed over different belt pulleys such that a first belt loop is passed over a belt pulley on a previous shaft relative to the common shaft in a transport direction of the main conveyor, while a second belt loop is passed over a belt pulley on a following shaft relative to the common shaft in a transport direction of the main conveyor.

Abstract: The conveyor of a travelator comprises a number of shafts and a number of mutually parallel endless belts. The conveyor comprises a number of conveyor modules successively connected to each other with a connecting section between them. The belts in the connecting section are arranged to be loosenable so that at least one shaft over which the belts to be loosened are passed is detachable so as to allow the conveyor modules to be released from each other. To release a conveyor module, at least one shaft on which the belt loops in the connecting section turn over is moved in relation to another shaft to slacken the belt loops. The shaft over which the loosened belt loops are passed is detached and removed from the belt loops. The detached conveyor module is removed for maintenance and/or replaced.

Abstract: Auxiliary drag mechanism at variable speed, consisting of a variable pitch worm being geared with connection means of the components to be moved, at least during part of their path of travel, at variable speed. The worm is mounted between two end supports (8) and at least one intermediate support (9), whose supports leave free the gearing area between the connection means and the worm, along said worm.

Abstract: The invention relates to a carriage for driving handrails of walkways and moving stairs, comprising a body (6) in the form of a vertical plate in which leading rollers (7) are assembled; two swinging locking pawls (12-13) for locking with a drive chain; a free turning wheel (24) intended to be supported against a cam profile in order to cause the pawls (12-13) to swing between an operative vertical position and an inoperative horizontal position; and an arm (8) intended to engage with the variable pitch screws.

Abstract: A transportation device with steps or pallets arranged in the form of an endless transporter. The transportation device has two or more advance guide rails which are arranged in an advance area of the transportation device, and two return guide rails which are arranged in a return area of the transportation device. Each step or pallet has sliding elements fastened to it have an advance sliding surface and a return sliding surface. In the advance area each step or pallet is oriented with the advance sliding surfaces of the two respective sliding elements on the advance guide rails and slides along the advance guide rails.

Abstract: A buffer conveyor (12) for conveying conformable work products (66) includes a collapsible conveyor belt (13) having an infeed section (14), a collapsible intermediate section (16) and an outfeed section (18). The infeed section (14) may be driven at a non-continuous speed, and the outfeed section may also be driven at a uniform, or non-continuous, speed, but the average speed of both the infeed and outfeed sections is the same. The intermediate section of the conveyor is driven at a non-uniform speed that is slower than, but proportional to, the speed of the infeed section.

Abstract: A mountainous or valley-shaped curved part 13 is provided in a part of a footstep guide rail 3 for guiding a movement of footstep rollers 5 linked by a footstep chain 7, the part being positioned in the vicinity of a drive sprocket 9. Consequently, owing to meshing of the footstep rollers 5 with the drive sprocket 9, an unevenness in velocity of the footstep rollers 5 is absorbed by the curved part 13, so that a moving velocity of the footstep rollers 5 moving on the downstream of the curved part 13 is maintained constantly, suppressing vibrating of the footsteps 4.

Abstract: The invention relates to a transport system for the movement of passengers/goods formed by a moving endless belt having: a series of pallet assemblies (100, 101); drive equipment (300, 320, 321, 310, 311) for transmitting a drive movement from actuating equipment (400) to the pallet belt (100, 101) in a low speed section located in an embarking/disembarking area of the endless belt; drive equipment (300?, 310?, 311?) for transmitting a drive movement from actuating equipment (400?) to the pallet belt (100, 101) in a high speed section located in a middle area of the endless belt; drive equipment (300?) for transmitting a drive movement from actuation equipment (400?) to the pallet belt (100, 101) in a transitional speed section located between the embarking/disembarking area and the middle area of the endless belt.

Abstract: A drive system for escalators having steps or moving walkways having pallets includes at least one drive motor. A drive chain is driven by the drive motor and is comprised of a plate link chain. The drive chain has such a pitch that a maximum of two links are used for each step or pallet. A mechanism for minimizing a polygon effect which occurs during entry and reversing of the chain at a reversing element includes at least one device for actuating one of the drive motor, the reversing elements or the drive chain with a non-constant rotational speed or velocity.

Abstract: A travelator and method for transporting passengers on a travelator. The travelator includes a plurality of successive conveyors arranged to form an acceleration section, a constant speed section including at least one conveyor having a constant transport speed, and a deceleration section. The acceleration section includes successive conveyors having constant speeds stepwise increasing in the transport direction for accelerating a passenger. The deceleration section includes successive conveyors having constant speeds stepwise decreasing in the transport direction for decelerating the passenger. The speeds of the conveyors in the acceleration section and the deceleration section are arranged such that the average acceleration experienced by the passenger over the entire length of the acceleration and deceleration sections is constant.

Abstract: An escalator with a high speed inclined section, includes link mechanisms, each of which has a first link with a first end rotatably connected to a step link roller shaft, and a second link, a first end of which is rotatably connected to a middle portion of the first link and a second end of which is rotatably connected to a step link roller shaft of an adjacent step. A rotatable auxiliary roller is located at a second end of the first link.

Abstract: In an escalator having a high-speed inclined portion, shape of an auxiliary track in a speed-changing region for steps is determined by finding a positional relationship between step link roller shafts of at least one of the steps and an adjacent step from a step speed profile representing speed of the step link roller shafts as a function of time. The shape of a riser is determined such that the riser aligns with a relative movement locus of the adjacent step by finding a relative positional relationship between the step and the adjacent step from the step speed profile.

Abstract: A drive system for an escalator or a moving walkway includes at least one drive motor, at least one drive chain and a reversing element for the drive chain. A device for modifying the speed of the drive chain is arranged in at least an entry or exit area of the reversing element.

Abstract: A variable speed handrail for a passenger moving walkway system, comprising a flexible profile comprised of a plurality of fixed blocks each having a grooved structure and circulating along the walkway or escalator and moving with a constant speed. A plurality of handgrips coupled on the flexible profile which move at a substantially identical speed. The handgrips have for their dragging first and second connection devices respectively connected to a constant speed and a variable speed drag mechanism.

Abstract: A conveyor for transporting articles is disclosed. The conveyor is for transporting articles having an initial pitch, wherein the initial pitch of the articles is subsequently decreased and/or increased. After the subsequent increase and/or decrease in pitch, the initial pitch can then be restored or a different pitch obtained.

Abstract: In an escalator with a high speed inclined section, steps are coupled in an endless manner and circulate. Driving roller shafts of the steps adjacent to each other are coupled with each other by a link mechanism. An interval between the driving roller shafts is changed as the link mechanism is transformed. An outer peripheral length change absorbing mechanism is provided in a reversing section of a circulation path of the steps. The outer peripheral length change absorbing mechanism absorbs a change in an outer peripheral length of a polygon, formed by connecting axes of the driving rollers with straight lines, while guiding movement of the driving rollers in the reversing section.

Abstract: In an escalator with a high speed inclined section, shape of an auxiliary rail is set, in a section between a forward path side horizontal section and a forward path side constant inclined section of a circulation path, such that, of steps adjacent to each other, a moving track of a relative position of a step on a lower step side with respect to a step on an upper step side is the same as surface shape of a riser of the step on the upper step side.

Abstract: The device includes a protection and safety assembly which covers the downstream end of said device and which, in said decelerated safety zone, includes a moving member disposed above said handrail elements and adapted to be entrained by a foreign body itself entrained by said handrail elements in the same direction as and at the same speed as said handrail elements along a substantially horizontal path, and detector means adapted to detect predetermined displacement of said member in said direction, and to cause at least said device to stop.

Abstract: In the escalator with a high speed inclined section, a shape of an auxiliary rail is set in a section between a forward path side horizontal section and a forward path side constant inclined section of a circulation path such that, of steps adjacent to each other, a moving track of a relative position of a step on a lower step side with respect to a step on an upper step side is the same as a surface shape of a riser of the step on the upper step side.

Abstract: An accelerated walkway having a moving surface made up of sets of treadboards of variable length which are mounted between lateral traction chains. A drive mechanism is related with the lateral traction chains. Each set of treadboards has a front treadboard and a rear treadboard that are grooved and mutually articulated along an axis perpendicular to the direction of movement. The rear treadboard of each set of treadboards is mounted on the lateral traction chains and on lateral guidance rails. The front treadboard of each set of treadboards rests on and is displaceable over the rear treadboard of a next set of treadboards in the direction of movement by guide elements.

Abstract: There is provided an escalator with a high speed inclined section, including a plurality of link mechanisms each of which has a first link with one end portion thereof rotatably connected to a step link roller shaft and a second link one end portion of which is rotatably connected to a middle portion of the first link and the other end portion of which is rotatably connected to a step link roller shaft of an adjacent step. In the other end of the first link, a rotatable auxiliary roller is provided.

Abstract: In an escalator with a high speed inclined section, assuming that an upper-step-side end of a tread is the origin of a coordinate system when a step is seen from a side with the tread being horizontal and on an upper side, a riser passes a point whose horizontal and vertical coordinates can be expressed as (kr cos &agr;m, −kr sin &agr;m) (where k is a speed change ratio; r is a distance between the step link roller shafts of steps adjacent to each other in upper and lower landing sections; and &agr;m is an inclination angle of an intermediate inclined section).

Abstract: An escalator with a high speed inclined section in which a position of a link connection point is determined by the following equations: XM=X1+L1 cos {&bgr;−&ggr;}, and YM=Y1+L1 sin {&bgr;−&ggr;} (where &bgr;=tan−1{(Y1−Y2)/(X1−X2)}; &ggr;=cos−1{(L12−L22+W2)/2L1W}; W={square root over ( )}{(X1−X2)+(Y1−Y2)}; XM: horizontal coordinate of the link connection point; YM: vertical coordinate of the link connection point; L1: a distance from axis of an upper-step-side step link roller shaft to the link connection point; and L2: a distance from axis of a lower-step-side step link roller shaft to the link connection point).

Abstract: A variable-speed moving walkway includes an array of support rollers (10) provided with a plurality of horizontal drive rollers (11), having upper surfaces arranged to be generally flush with each other and rotated about each axial center, and an endless belt (16), supported by the array of support rollers, for moving continuously by their rotation. An array of accelerating rollers (12), an array of high-speed rollers (13), and an array of decelerating rollers (14) constitute the array of support rollers, and allow rotational speeds of the horizontal drive rollers to gradually increase from a low speed, to be maintained at a constant high speed, and to gradually decrease to a low speed, respectively. In addition, the endless belt (16) readily extends or retracts in the direction of movement and barely extendable or retractable in the widthwise direction. The belt (16) extends and retracts in the direction of movement in response to the rotational speed of the horizontal drive rollers.

Abstract: A treadmill with at least one endless belt provided with a plurality of tread lamellae and guided around two deflection pulleys which are arranged one behind the other with parallel axes, the deflection pulleys being smooth in the area where they are in contact with the belt and at least one belt being implemented as a flat belt. Each tread lamella is provided with at least one engagement element projecting from the lower surface of the tread lamella. In addition, at least two stabilizers are provided, which are connected to the deflection pulley such that they are secured against rotation relative thereto, a stabilizer of this kind being in engagement with an engagement element on the lower surface of a tread lamella when the circumferential area of the deflection pulley, which rotates in synchronism with the stabilizer, is in contact with the at least one belt, and at least one stabilizer being always in engagement with the engagement element of a tread lamella.

Abstract: A moving walk for effecting transport in a longitudinal direction includes a series of belt modules with modules at a center portion running at a higher rate than modules at exit ends. Among the belt modules are at least first and second belt modules, each having a first end and a second end, a endless belt extending from the first end to the second end, and a drive circulating the endless belt. The first and second belt modules are disposed adjacent one another in the longitudinal direction with the second end of the first belt module opposing the first end of the second belt module. The second end of the first belt module is disposed higher that the first end of the second belt module when a passenger is transported from the first belt module to the second belt module to facilitate transition from module to module.

Abstract: The invention relates to a moving walk which can transport users in opposite two directions. A number of pallets 3 are arranged for rounding or circulation on annular rails 11 having two linear sectors 1A and 1B. Screw rods 16 are arranged on the linear sectors 1A and 1B of the rails 11. The adjacent pallets 3 are interconnected through string members 22. The pallets 3 are moved in opposite directions on the linear sectors 1A and 1B, respectively. Each pallet 3 is inserted at its front end under a read end of its preceding pallet 3 to provide a continuous walk surface so that many users are transported safely.

Abstract: A variable-speed passenger conveyer comprises: endless driving chains which disengage the pallets at an acceleration zone and high-speed zone; a screw shaft which has a pitch that changes step by step so as to accelerate or decelerate the palettes; high-speed driving chains which engage the palettes at the high-speed zone to transport the palettes at high speed; and a driving system.

Abstract: A speed-variable conveyor includes a belt-formed fibrous body deformable in a moving direction and a width direction, a plurality of rollers mounted on both ends in the width direction of the fibrous body, and a pair of guide rails for movably supporting the rollers and differing in spacing according to the moving speed of the fibrous body. The moving speed of the fibrous body is low where the width of the fibrous body is large, and high where the width is small. A support moving body contacting a lower surface of the fibrous body for driving the fibrous body is provided. This reduces a load applied to the fibrous body.

Abstract: A travelling walkway for conveying of persons, comprises sections with different speeds and with varying speeds, is formed from pivotably interconnected and driven carriers, wherein the length distances between the carriers are variable and step elements, which overlap one another in running direction of the travelling walkway and are displaceable relative to one another, are present on the carriers. Link chains, which are arranged parallel in longitudinal direction and which are transversely connected at the joints by means of step plates to form an articulated lattice variable in length and width, are used as carriers. Lateral guides and guide rollers produce the stretching and pushing together of the articulated lattice required by changes in width. Grooved and smooth drive belts move the articulated lattice at different speeds as necessary. The articulated lattice is horizontally deflected at both ends of the travelling walkway by means of a circulating device.

Abstract: A conveyor belt (1) for persons includes several sections (2, 3, 4, 5, 6) with a first section (2) and a second section (3) forming an acceleration portion (7), in which the persons to be transported are accelerated from a low initial speed, which is unproblematic for stepping onto the conveyor belt (1) for persons, to a constant transport speed of a main portion (8) formed by a third section (4). Connected downstream of the main section (8) is a retardation portion (9), which is formed by means of a fourth section (5) and a fifth section (6) and in which the persons to be transported are retarded from the transport speed to a low final speed, which is unproblematic for departure from the conveyor belt (1) for persons. Arranged at each section transition is a respective transition device (10) having a roller (20, 20.11, 36, 37) by means of which the persons are guided free of risk from one section to the other.

Abstract: A speed variable moving sidewalk for conveying passengers includes an endless circulating path having inverting sections, a high-speed section and speed variable sections, and a large number of treadboards moving along the circulating path. Each treadboard can move independently as being guided by guide rails and has hooks on its underside which engage shafts of a driving chain for inverting section. The treadboard further has hooks on its underside which engage shafts of a rack chain in order to be driven in the high-speed section and a roller for transversely sliding relative to the neighboring treadboard. A handrail mechanism for the speed variable moving sidewalk includes: with the total length of the moving sidewalk being divided into plural portions, a multiple-number of independent moving handrail portions for allowing passengers to hold thereon, being arranged for the respective portions of the sidewalk while all of the moving handrail portions are arranged without overlapping with one another.

Abstract: A moving walkway comprising at least one flat slider belt (6) entrained around rollers (8) and a termination plate (2) at the discharge end of the belt (6). The termination plate (2) may be an end plate or a transfer plate. The configuration of the termination plate (2) is such in relation to the speed of the belt (6) and diameter of the end roller (8) that an object travelling at the speed of the belt and leaving the belt will strike the plate at a position downstream of the leading edge (4) of the plate. The leading edge (4) of the plate is so shaped that it defines with the adjacent portion of the belt (6) a nip (10) of small depth in a vertical direction and which permits easy removal of any material which might happen to become ingested into the gap between the leading edge (4) of the plate (2) and the belt (6).

Abstract: The variable-speed conveyor element applied to a handrail is made up of individual handles linked together by elements of variable length which themselves function like elements of the handrail. Each of these variable-length elements is formed from a continuous flexible link, such as a belt or cable, to which are fitted contiguous blocks which stop or limit the bending of the elements in one direction. The blocks have projections and recesses allowing them to mutually interlock and ensure the transmission of forces.

Abstract: A dual-speed escalator apparatus comprises a main frame defining an elongated sloped circulating path, a plurality of steps disposed along the circulating path and dual link assemblies each including a first and a second link. The first and second links each have one end pivotally connected to a front roller shaft on a step, and the other end of the first link has a link roller and is pivotally connected to the other end of the second link on a neighboring step. A front roller guide rail extends along the circulating path, a rear roller guide rail is disposed along the front roller guide rail for maintaining the steps in a predetermined position, and a folding rail is disposed along the front roller guide rail for guiding the link rollers on the dual link assembly and for folding the dual link assembly into a folded position at the end portions of the circulating path.

Abstract: A beltway comprised of at least one beltway section which has two spaced small diameter rollers which define the ends of the section, a drive unit and a thin flexible continuous slider belt which is adapted to pass over the rollers defining the ends of the section and to be driven by the drive unit. At junctions between two beltway sections a transfer plate is located. The transfer plate is formed to terminate close to the belt on either side thereof so that there is a smooth transition from the belt to the transfer plate and is of a width, in the direction of movement of the beltways, such that a user is in contact with the receiving beltway before losing contact with the delivery beltway.

Abstract: The steps of the escalator move along a curved path which has a fixed constant radius when viewed in plan. The step chain also follows the constant radius path and thus its effective length must vary at different locations along its path of travel in order to keep the step rollers on their constant radius tracks. The effective length of the step chain is varied using an eccentric pivot cam at chain link connections spaced along the chain whereby the degree of overlap of adjacent links can be changed by controlling the path along which cam actuating rollers travel. The cam actuating rollers control operation of the eccentric pivot cam link connections.