Abstract: The tool comprises a handle pivotally connected to a head that comprises a tightener composed of a split ring having a diameter sufficiently large to encompass the cap. The handle has a cam arrangement that acts on the ring to contract it when the handle is pivoted, thereby tightening the cap on the bottle. The head also has one or more lips that catch underneath the cap to remove the latter when opening the bottle.

Abstract: Headstock and tailstock chucking apparatus for crankshaft machine tools, such as lathes and grinders, utilizing a centering hole defined in the crankshaft workpiece end for axially locating the workpiece relative to the machine, and the machining tools. The stock spindle chucks utilize a center engaging a previously located and dimensioned workpiece center to axially position the workpiece, which is biased into firm engagement with the center prior to chucking. The chuck center and workpiece is axially located and spindle motors reciprocate chuck actuating mechanism sequentially producing axial locking and radial chucking of the workpiece. Further, automatic limit switch positioning apparatus is employed to automatically position machine limit switch controls in accordance with workpiece dimensions and quill location.

Abstract: Continuously cast plastic strip has interspaced marks or defects with lengths of unmarked usable strip therebetween. To obtain a maximum possible yield of sheets from such strip, the lengths of the portions between the marks or defects are measured and cut into sheets of two or more different lengths, the cutting being such as to produce the maximum yield of sheets of either or all lengths, singly or in combination, which can be obtained from the length cut. This procedure reduces the loss or waste due to the marks or defects, to a minimum. A special system is provided for this practice and for cutting out the marks or defects between the unmarked strip portions free from defects, with a minimum of loss or waste. Other features are involved.

Abstract: This invention relates to a method of making reinforcements for concrete, in which a band material of a thin steel plate which has a certain thickness and a certain width and or which both ends are bent is fed until it contacts with a rotating cutter wheel having edges which height is approximately same as the thickness of the said plate, and the said material is cut so that reinforcements of a certain dimension are continuously made; and an apparatus therefor comprising a cutter wheel, a pushing plate and a supporter which constitute a cutting part, and some couples of belt pulleys to continuously feed the material, or further having an equipment to bend both ends of the said material.

Abstract: A machine for automatically producing a bib apron and for affixing a narrow strip thereto to form both the neck loop and tie elements for the apron. The machine includes a cutting mechanism having a skewed roller carrying a cutting blade which makes point contact with a second roller to divide a continuous web of nonwoven fibrous material into separate rectangular sheets. The material for the strip is folded longitudinally and is then advanced across each sheet by a feed mechanism including a capstan drive and a clamping mechanism for holding the strip in juxtaposition with the sheet. Thereafter, the strip is contacted by a pull member which draws the center of the strip in a downstream direction to form a "V". The forward corners of the sheet are then folded over the legs of the V and are adhesively secured to the body of the sheet to hold the strip in place.

Abstract: A touch sensitive device is associated with at least one key of an electronic musical instrument such as an electronic organ, includes a layer of a pressure responsive, variable conductance material, and exhibits a switching action when subjected to pressure beyond a threshold pressure, any increase in pressure thereafter providing an increase in conductance up to a saturation pressure. The device may be used either as a combined switch and amplitude control or may be used in associated with one or more capacitors to provide either a high pass or low pass touch-control audio filter. In a totally polyphonic instrument a tone generator and touch-control filter are respectively associated with and responsive to each key depression, the output signal from each activated filter being coupled preferably to audio mixer circuitry.

Abstract: A circuit is shown for changing the frequency of a basic keyed oscillator by controlling the amount of keying voltage reaching the oscillator and the circuit used for vibrato. The purpose of this circuit is the achievement of true "pipe organ celeste" effect without using an added rank or set of oscillators. Circuits are described wherein the harmonic structure of the signal resulting from this modification of a basic keyed oscillator can be made to change by means of controlling the amount of keying voltage reaching the oscillator for the purpose of achieving the desired harmonic structure of the rank when operated in the "non-celeste" mode as opposed to the "celeste" mode. A circuit is also described for amplitude modulation and harmonic structure modulation at the vibrato rate to enhance the vibrato.

Abstract: An electric piano, using only one string per note and no soundboard, employs special mechanical and electrical means capable of controlling all of its various characteristics in order to duplicate the sound and other characteristics of a conventional piano. A floating bridge, floating on the strings and supported solely thereby, is used not for the pickup or transfer of string vibrations to any other device, but to control the characteristics of the string vibrations. Magnetic pickups consisting of a series of coils with adjustable permanent-magnet cores are arranged in special positions along the active lengths of corresponding strings and, in conjunction with frequency responsive capacitor circuitry, convert the vibration of each string into an electrical signal, shape the signal, and provide a composite signal output containing all the tone characteristics needed to produce a true piano sound.

Abstract: A device for continous pitch variation has rotary support means which connect the extension piece of the neck flexibly with the body of the instrument. A string holder is mounted on one rotary support lever and has adjustable holding elements for each string. A system of levers transmits the tension of the strings over an adjustable point of force transmission to a tension spring. The tension spring has an adjustable seat.

Abstract: A supporting and pivot device for use in a keyboard of a musical instrument. The device is preferably made of plastic and is wedge-shaped having a pair of adjacent slots, one of said slots being adapted to securely receive a pin by virtue of the resilient deflection of one wall of the receiving slot towards the other slot. The lever of the keyboard is pivotably secured to the support frame through the device and secured pin.

Abstract: The present invention provides a spreadable anchor assembly comprising a plural leg flange nut with a perforated cap carrying a driven spreader, the cap being made of thick paper and having centrally a perforated circular line inside the top opening of the flange nut, the top of the spreader adhering to the lower side of the cap.

Abstract: Apparatus for controlling the flow of exhaust gases between a plurality of rocket storage chambers, launch tubes or the like (herein referred to as chambers), and a common manifold for ducting rocket exhaust gases to a discharging location comprises a plurality of chamber-to-manifold flow transition sections, each having disposed within vertical portions thereof a pair of flow control doors. The flow control doors, pivotably mounted at upper portions in opposing relationship, are configured and counterbalanced to hang, in static conditions and under the force of gravity alone, in a fully or nearly fully closed condition. Alternatively, un-counterbalanced doors may be configured to hang, under static conditions, at least slightly inwardly inclined towards the vertical axis of the transition portion in which they are hung.

Abstract: A conveyor mechanism comprises a sprocket having a plurality of concave cutouts and receiving an endless chain of elements, each element having a convex surface, each of said cutouts having a supplemental indexing cutout associated therewith and each of said elements having a supplemental indexing projection thereon, said indexing cutouts and projections mutually interfitting and precluding rotation of each element in the respective sprocket cutout.

Abstract: A milling attachment for a lathe or the like having a base supported vertical column including a vertical dovetail slot, a block having a dovetail slidably received in the dovetail slot and a vertical adjusting screw rotatably secured to the column and passing through the block to thereby raise and lower same. The block carries a spindle having a horizontal axis of rotation extending along one side of the supporting column and further carries an electric motor which is positioned adjacent the supporting column and has an axis of rotation which is horizontal and extends perpendicularly to the spindle axis. The block, spindle and motor are locked at a selected vertical position by means of a hand screw which extends through the vertical column dovetail slot into the dovetail wherein it is threaded to a T-nut slidably received within a vertical slot.

Abstract: A function generator is provided which establishes an output signal according to a functional relationship determined by the preformed contour of an easily precut cam member. The function generator includes a variable gain controller section coupled to a proximity sensing motion balance servomechanism which varies the gain of the controller according to the sensed proximity of the servomechanism to the edge of the cam member without physical contact therewith. The cam member's position is in turn determined by an input signal which may be related to the controller input signals or may be an independent signal from a remote source. The gain and consequently the output of the controller is varied according to the functional relationship determined by the precut contour of the cam member.

Abstract: An electrohydraulic proportional actuator for converting an electrical input signal to proportional mechanical output. Fluid power may be derived from pressurized fuel or lubricating oil of an associated engine. The actuator may be used to drive any engine function requiring modulated control. The mechanical output is proportional to the electrical input. The actuator includes mechanical feedback to linearize the response function, thus eliminating the need for closed loop operation of the system in which the actuator is used. Both linear and rotary actuators are disclosed in various embodiments. Each type is capable of operation with either a proportional solenoid and valve or a force rebalance solenoid and valve.

Abstract: Hydraulic control apparatus for controlling the rate of flow of a fluent plastic from an injection nozzle of an injection molding machine wherein an injection ram is connected to a hydraulic piston in a hydraulic cylinder. The control apparatus controls the pressure exerted by a hydraulic fluid in the cylinder by means of a main hydraulic circuit including the cylinder, a valve and a pump connected in series and a main line pressure valve connecting in parallel a plurality of pilot pressure control valves having different pressure set points to the main line. The pilot pressure control valves are operated in sequence by an electrical relay and timer circuit, or a combination of such circuit and limit switches.

Abstract: A hydraulic engine of the type working between a high pressure and a low pressure and comprising working chambers and mobile elements movable in said working chambers, wherein means are provided for connecting said working chambers in turn with the low pressure source.

Abstract: A high pressure plunger and a method of making for use in piston-cylinder like apparatus which are used for the high pressure compression of gases up to, for example, approximately 40,000 p.s.i. A high pressure plunger of the present invention comprises a tubular member of hard wear resistant material whose opposing ends are abuttingly engaged by steel end caps with the steel end caps being interconnected internally of the tubular section with a tension member so as to hold the tubular member in compression.

Abstract: The invention relates to a process and apparatus for pre-folding and unfolding of a closure on a folding box of rectangular cross-section, which closure is formed of the creased unslotted end portion of the walls of the box of which two opposite closure panels are each provided with a pair of creases running from the corners and converging toward the center of the margin so as to form triangular pockets upon folding. The device comprises two pairs of folding tools at 90.degree. to one another and means for displacing them. One of the pairs corresponding to the creased panels each is bifurcated with a folding tine which engages its panel at substantially one location during folding while the other tine in inactive and an unfolding tine which engages the opposite face of the same panel during unfolding while the folding tine is inactive.

Abstract: A machine is disclosed for erecting cases stored in upright, flattened positions in storage magazines. The machine includes means for extracting end member cases from the magazines, for dropping the extracted cases into drop chutes, for urging the cases in a generally horizontal direction out of the drop chutes, for opening the flattened cases by spreading the case sides apart, for tucking in lower case end flaps, for folding one case bottom panel in under the tucked end flaps, for applying adhesive to the bottom surface of the folded bottom panel, for folding another bottom panel in under the bottom panel having adhesive thereon, and for compressing the two bottom panels together.

Abstract: Apparatus for folding the panels of a bulk box blank into a tube. Such apparatus is particularly suited to fold the panels of extremely large heavy-weight blanks which are resistant to folding and therefore difficult to fold manually. The apparatus includes a vacuum hold down unit to hold and register the blank in position, folding arm assemblies to successively fold down the outer panels of the blank into a tube, and a hold-down device to restrain the folded panels from springing upward as the folded blank is moved into a compression unit.

Abstract: Apparatus for producing composite filter plugs for cigarettes or other smokers' products has two sets of conveyors which feed filter rod sections of different types to the flutes of a rotary assembly conveyor. The latter assembles the sections into groups each having a section of first and second type and moves the groups to an auxiliary conveyor which transports the groups sideways to successive pneumatic holders of a transfer conveyor. The transfer conveyor has two carriers which rotate about parallel axes and are coupled to each other by linkages, one for each holder. The linkages cause the holders to rotate relative to that carrier which supports the holders so that the orientation of holders remains unchanged during travel through 90.degree. or 270.degree. when the groups are taken over by successive increments of a web which is moved lengthwise and is draped around the resulting rod-like filler to form therewith a rod.

Abstract: An automatic toaster for continuously toasting bread slices one at a time, from the bottom of a generally vertical stack of bread slices. The bread toaster includes a housing having a discharge opening at one end and a hopper at the other end for receiving a vertical stack of bread slices. A conveyor feeds the bread slices one at a time between a pair of heating elements whereafter the bread is ejected through the discharge opening in the housing. The pair of heating elements are mounted above and below the conveyor and are movable toward and away from the conveyor so the amount of toasting on each bread slice can be determined according to the preference of the user. An automatic counter is connected to the conveyor for counting the number of slices being toasted and for turning off the toaster after a predetermined number of slices of toast have been made.

Abstract: A process for the production of a semi-moist food product having an appearance of meat being marbled throughout with fat and a system capable of performing such a process is disclosed. The process comprises mixing separate and distinct batches of dough and cooking the dough in separate swept surface heat exchangers before combining the doughs to form a food product having a meat-like appearance.

Abstract: A milk containing liquid is fed at a controlled rate into a tank having rotatable blades defining scoops at an upper portion thereof. In one process, the milk containing liquid precipitates to form ricotta cheese. The precipitation rises in the tank and is scooped into a funnel by the rotating blades. The scooped precipitation flows through the funnel to an exit port in the vessel sidewall. In another process, the milk containing liquid coagulates to form curd and whey which is severed into cubes by the rotating blades and is scooped into the funnel.

Abstract: A nut sheller which embodies a base having a lower nut holder on which a nut to be shelled may be positioned, a spring operated hammer operable upwardly to strike the nut holder, an opposing inertia anvil operable from a remote nut loading position to a lowered position into engagement with the nut to be shelled, and a lever adapted to be manually moved to bring the inertia anvil down and then automatically cause the hammer to operate, the lever being operably connected to cock the hammer against its spring as the lever is moved back to its remote nut loading position. Shielding means are provided, moved under the control of the operating lever so that the shell fragments fall into a nut bowl arranged below and around the nut holder. Thus the entire nut shelling operation may be accomplished by one hand, merely by moving the lever in one direction and then returning it.

Abstract: A system for the handling of solid waste involving multiple solid waste handling stations. Each station has a hopper unit for receiving waste, a storage unit, and a compactor unit for transferring and compacting the waste. Each station is provided with detector means for detecting a packed storage unit. Adjoining stations are operatively interconnected by station selector means. The station selector means responds to the detector means to deactivate a station having a packed storage unit and to activate an adjoining station having an empty storage unit.

Abstract: A magazine type printing head for a printing machine having at least one two part chamber with a stack of typeface carrying slugs in each part. The head has means which move an upper slug from a stack in one part of the chamber to the second part and then moves a lower slug in the second part to a printing position in the first part of the chamber. The printing head has particular application in a hot stamping machine where means to heat the slugs are provided. A dye carrying foil is conveyed adjacent the typeface of the slug or slugs in the printing position. A movable support retains an article to be stamped and presses the article together with the foil against the typeface.

Abstract: The attachment device is adapted to be mounted to the delivery end of an offset duplicating machine and includes: a frame; an impression cylinder rotatably mounted to the sidewalls of the frame; a gripper bar device which is also rotatably mounted to the sidewalls of the frame and which is disposed between the duplicating machine and the impression cylinder, the gripper bar device including a gear wheel in meshing engagement with a gear wheel of the duplicating machine and with a gear wheel on the impression cylinder, the gripper bar device further including a series of members for gripping a sheet received from the duplicating machine and for conveying it to gripping elements on the impression cylinder; and character printing means mounted to the frame, including a gear wheel in meshing engagement with the gear wheel of the impression cylinder and a character numbering device rotatably mounted to contact successive sheets conveyed on the impression cylinder so as to print consecutive characters thereon.

Abstract: A machine for printing on thin-walled frusto-conical containers having little resistance to transverse deformation is provided with rotatable mandrels for holding and centering the containers during printing. Each mandrel has a rotatable body provided with two axially spaced centering rings adapted to engage the walls of the container and centralize the container relative to the axis of the mandrel upon axial movement of the container on to the mandrel. The centering rings make sealing engagement with the walls of the container and subdivide the space enclosed between the container and the mandrel body into an end chamber between the base of the container and the outer end of the mandrel, and an annular chamber between the side wall of the container and the mandrel body.

Abstract: A hammer mechanism which undergoes reciprocating motion across platen-supported paper webs in a dot matrix printer effects printing by momentarily energizing coils associated with selected resilient hammer elements mounted on a common magnetic structure to neutralize a magnetic field from the common magnetic structure and release the hammer elements from a retracted position. Each end of the common magnetic structure extends to define dummy hammer positions adjacent the first hammer element on each end, providing uniform magnetic field strength to the end hammer elements and to all hammer elements in between. The hammer elements are fabricated and mounted as individual elements of resilient magnetic material with mounting of the elements being accomplished in pairs using a common plate for each pair and screws which have a portion of reduced diameter directly behind the head thereof to provide easy access to the shaft of the screw in the event of breakage during installation.

Abstract: This invention relates to a device for releasably mounting thin walled cylindrical members in a machine involving rotary working operations, such as rotary screens used in rotary printing presses. The device comprises cylindrical end members adapted to be mounted on the rotary machine and adapted to fit within and engage inner peripheral flanges at the ends of the cylinder. The end members comprise an annular slot which contains a ring member expandible by suitable pressure means. Each ring member contains an outer annular groove adapted to engage the inner flange at each end of the cylinder upon expansion of the ring member thereby securing the ends of the cylinder on each end member. The ring member can be a steel band expandable by the action of a pressurized air tube mounted in the annular slot, or alternatively, the ring member can be an outer wedge ring disposed in the annular slot with an inner wedge ring in the slot which can be axially moved and thus radially moving the outer wedge ring.

Abstract: A device for rolling up onto a core a stencil or ink screen being removed from a duplicator, in which means alongside the or a duplicator cylinder for supporting a core and for driving it at a peripheral speed in excess of the peripheral speed of the duplicator so that a stencil or ink screen from the duplicator may be unrolled from the cylinder and onto the core with tension in the stencil or ink screen maintained by virtue of slipping drive to the core.

Abstract: A duplicating apparatus is equipped with a photoconductive modulator screen cylinder for making reproductions of a graphic original on a dielectric receiving medium utilizing aperture-controlled electrostatic printing techniques. Means is provided for creating a charge distribution system on the surface of the modulator corresponding to an image to be reproduced from the graphic original. The apparatus also comprises charging means for projecting gas ions against the modulator screen cylinder, electrode means for collecting the gas ions selectively transmitted by the modulator screen cylinder on the dielectric receiving medium and means for developing the dielectric receiving medium to create a visible image.

Abstract: A printing machine, especially an office offset printing machine, in which a master before being wrapped around the master cylinder is pre-curved by sliding over an edge of one pivotable part of a bipartite table which part is tilted manually during the mounting of the master to expose said edge against which the master is guided by a roller positioned above the table and by a guiding and operating member arranged between the two parts of the table. The curvature may be preadjusted in accordance with the characteristics of the master by adjusting the relative end positions of said roller and said table edge. The end of the movable table part closest to the master cylinder forms together with a guiding plate a slot which guides the master until it is gripped by the master cylinder. By actuating a handle and thereby raising one end of the movable table part the other end is lowered and thus said slot facing the master cylinder is opened to avoid straightening of the pre-curved master.

Abstract: Dampening unit for an offset printing machine includes at least one dampening unit roller, a container for dampening medium and a rotatable sprinkler roller disposed mutually adjacent one another, the sprinkler roller includes a shaft, a pair of discs disposed at opposite ends of the shaft and an envelope wettable by dampening medium from the containers and formed of a plurality of means displaceable in a rotary path for throwing onto the dampening-unit roller from a region of an edge of the envelope extending along the length of the sprinkler roller droplets of dampening medium withdrawn from the container, the plurality of throwing means being stressed in tension between the discs and extending parallel to the shaft, and traverse means carrying a plurality of fingers disposed adjacent to and spaced from the discs and having respective edges projecting into the rotary path of the plurality of throwing means.

Abstract: Dampening rolls receive spray from a multi-nozzle spray member having a spray path extending beyond the ends of the rolls. Overspray preventing shields are mounted at opposite ends of the spray path and have free dripping lower portions positioned over the dampening rolls. An oscillating roll runs against a dampening roll to spread the moisture film and a wet form roll provides contact between the oscillating roll and the plate cylinder. Preferably, the spray member oscillates transversely along the dampening rolls and separate shields are mounted on the spray member and fixed with respect to the press frame.

Abstract: This invention relates to a printing device of the type having a carriage which supports a printing roll. In order to perform the printing operation, the carriage is pivotally and slidably mounted on a slide rod. An arm of the carriage is mounted in a housing and is provided with a guide roller that is located in the same vertical plane as the printing roll. The guide roller cooperates with a guide means that extends parallel to the slide rod to keep the printing roll in engagement with a printing anvil and to enable the printing roll to swing upwardly into a raised position when arriving at one of the ends of the slide rod.

Abstract: A printing mechanism comprises a housing, providing a print head carrying a flat type face, and a platen for supporting a forwardly moving sheet that is interposed between the platen and the type face. The platen includes an extended planar portion adjacent the sheet and movable parallel with it. Means are provided for bodily rotating the print head relative to the housing around an axis that is substantially parallel to the plane of the sheet, and in a path lying in a plane that is substantially perpendicular to the plane of the sheet so as to bring the type face into printing contact with the sheet against the platen planar portion; the planar portion is moved parallel with the sheet and at the same linear speed during the printing contact.

Abstract: There is disclosed a printing apparatus having a print head and an inking mechanism for inking the print head. The inking mechanism comprises an ink roller, an inker body or carrier for the ink roller and structure for movably mounting the inker body. The ink roller is rotatably mounted to the inker body by mounting means including a pair of mounting members. The inker body has a pair of undercut slots and the mounting members have respective flanges received in the slots. Each mounting member is shown to have a resilient member or finger engageable with a respective shoulder on the inker body to lock the mounting member to the inker body. The inking mechanism has means for preventing its disconnection from the printing apparatus while the inking mechanism is in cooperation with the print head, but the inking mechanism can be removed and replaced with a new inking mechanism having a new ink roller while the inking mechanism is out of cooperation with the print head.

Abstract: A printing cylinder for printing machines comprising a shaft, a sleeve adapted to support a printing block and mounted on the shaft with radial clearance, and an adjusting mechanism provided at each end of the sleeve. Each adjusting mechanism comprises a guide ring and a clamping ring having cooperating conical guide surfaces. A fit between the shaft and the guide ring is so easy that the guide ring may be somewhat tilted relative to a plane at right angles to the longitudinal axis of the shaft, and the clamping ring comprises radial, adjustable securing means and axial adjusting means, whereby it is possible to center the sleeve very precisely relative to the shaft.

Abstract: A shatter resistant armor-piercing military projectile is disclosed. The struction comprises a plurality of high strength metallic lamellae interconnected with a high ductility alloy selected to provide an impact energy management system capable of maintaining the projectile's structural integrity during adverse operating conditions, such as oblique impact on spaced or solid armor targets.

Abstract: A weapon system comprises a fuze and a transmitter, said transmitter transmitting an RF coded pulse signal whose pulse repetition frequency presets the time base of the fuze and whose pulse combination code presets the mode of operation of the fuze, the fuze having an RF detector for receiving and detecting said signal, a logic circuit for reading said signal with respect to time base and mode of operation, and a timing circuit for enabling said detection for a predetermined time period at a predetermined time in flight.

Abstract: A detonator control circuit, principally for use for setting off an explosive charge, but other applications include, e.g., setting off a burglar alarm. The circuit includes a D.C. source, a first thyristor connected in series with the source and a detonator or alarm bell, etc. and a second thyristor connected in a triggering circuit. The control circuit is primed by causing the second thyristor to conduct and thereafter is kept in a state of readiness for allowing the first thyristor to conduct when required and detonate an explosion or ring the bell, etc.Preferably an indicator lamp shows that priming is taking place successfully and when it goes out the circuit is ready.

Abstract: An ignition current generator for an electrical projectile fuze comprising a soft iron ring which, viewed in the direction of the projectile, is secured at the rear end face of a substantially ring-shaped permanent magnet which is axially displaceable. The permanent magnet, in a first position thereof, surrounding an induction coil and bearing with its front end face or surface against a flange of a soft iron core. This soft iron core is provided at its outer circumference with a groove in which there is located the induction coil. The stroke of the permanent magnet is of a size such that in a second position of the permanent magnet the induction coil is located externally of the magnetic field produced by the permanent magnet, and the permanent magnet also in its second position is located upon the soft iron core.

Abstract: 1.

Abstract: A projectile for dispensing an aerosol of lachrymating irritant material in which the aerosol material is ejected through a nozzle only after firing from a gun or weapon launcher and has imported within the target area. Safety means is provided to prevent premature discharge of the aerosol.

Abstract: A jacketless hunting projectile or bullet of the mushrooming-tip, high cutting-type has a projectile body including a solid cylindrical guide part and a hollow head tapering toward a point. The hollow head has a progressively increasing wall thickness toward the solid part of the bullet and defines a cylindrical hollow space which receives a filling of a spreading material forming the tip of the projectile. This material rolls back the head after splitting it along notches formed in the hollow wall with sharp edges.

Abstract: A vehicle conveyor is provided with an upper wheel engaging active track and a lower inactive track. Rollers can be moved up by a roller up guide into the active track to engage the wheel of a vehicle for moving the vehicle along a path. The length of the conveyor is reduced by providing a roller down guide which can remove a roller from the active track along the length of the conveyor and by cycling the rollers such that the first roller on the active track engages the front wheel of a vehicle until the rear wheel of the vehicle is beyond the roller up guide, then an additional roller is raised to the active track behind the rear wheel of the vehicle and the first active roller is removed from the active track. Consequently, the vehicle is first moved by engagement by its front wheel and subsequently moved by engagement with its rear wheel to reduce the length of the conveyor.