Abstract: In one embodiment, a fluid delivery system includes a motor assembly and a fluid pump assembly. The fluid pump assembly is spaced apart from the motor assembly, and at least one of the motor assembly or the fluid pump assembly is movable to change a distance between the motor assembly and the fluid pump assembly. The fluid delivery system includes a flexible linkage that couples the motor assembly to the fluid pump assembly, and is configured to transfer motion from the motor assembly to the fluid pump assembly. Further, the fluid delivery system comprises a linkage tightening mechanism configured to generate a tightening force on the linkage by biasing at least one of the motor assembly or the fluid pump assembly in a direction that increases the distance between the motor assembly and the fluid pump assembly.

Abstract: A bicycle rear derailleur has a base member mountable to a bicycle frame, a movable member movably coupled to the base member, a chain guide assembly rotatably connected to the movable member for rotation about a rotational axis, a biasing element configured and arranged to bias the chain guide assembly for rotation in a first rotational direction with respect to the movable member, and a fluid damper having a fluid cavity containing a volume of fluid. The fluid damper is operatively disposed between the chain guide assembly and the movable member to apply a damping force to the chain guide assembly when the chain guide assembly rotates in a second rotational direction opposite to the first rotational direction. The fluid damper has a compensation device in fluid communication with the fluid cavity and is configured to accommodate a change in the volume of fluid in the fluid cavity.

Abstract: A rotary piston pump equipped with a motor having two counter-rotating rotary pistons. The two rotary pistons are housed in an oval pump housing. The two rotary pistons are arranged on a first output shaft and a second output shaft. The first output shaft and the second output shaft are driven and synchronized via at least one elastic element.

Abstract: A tensioning assembly having a drive pulley, a tension pulley and a tension adjustment system is provided. The drive pulley has a first drive pulley channel and a second drive pulley channel. The tension pulley has a first tension pulley channel and a second tension pulley channel. The second tension pulley channel is aligned with the first drive pulley channel. The first drive pulley channel and the second drive pulley channel of the drive pulley and the first tension pulley channel and a second tension pulley channel of the tension pulley are configured and arranged to engage and route an endless looped member. The tension adjustment system is coupled to adjust the distance between the drive pulley and the tension pulley to adjust the tension in the endless looped member in relation to the drive pulley.

Abstract: A motor support has a slidable carriage that includes a pair of elongated tubes slidably encompassing parallel elongated fixed cylindrical rails on a stationary base bed with bearing sleeves press fitted in the end portions of the glider tubes. The bearing sleeves support the guide tubes on the rails and transfer the motor load on the glider tubes to the rails with a reservoir of a viscous lubricant within the center portions of the glider tubes. A spring commands the strength of the movement of the slidable carriage and is sealed in a spring housing using one or more gusset plates.

Abstract: An engine includes an engine structure defining a plurality of cylinders. A crankshaft is rotatably mounted to the engine structure and a plurality of pistons are each disposed in a corresponding one of the plurality of cylinders and drivingly connected to the crankshaft. A drive pulley is drivingly connected to the crankshaft. An accessory is mounted to the engine structure and includes a driven pulley connected to the drive pulley by a belt. The belt has a load direction extending through an axis of rotation of the drive pulley and the driven pulley. The accessory includes a housing having two slots extending generally parallel to the load direction of the belt and each receiving a fastener therein. A tensioner bolt is located between the two slots and extends generally parallel to the load direction to apply a tension force on the housing in the load direction.

Abstract: A tensioner may be part of a power system to tension an endless power transmitting element. The tensioner includes an arm having an arm arbor with a slot therethrough that is rotatable about a first axis, a bushing having a sleeve that includes a cut-out and a removable sleeve-segment that has a protrusion thereon, the sleeve-segment being receivable in the cut-out with the protrusion in the slot, and a spring coupled to the arm for rotation of the arm about the first axis into tensioning engagement with a power transmitting element. The spring is positioned where it can radially expand into contact with the protrusion of the bushing, at least the protrusion on the sleeve-segment, as the arm is rotated in a direction opposite the direction of tensioning engagement such that the bushing is urged radially outward relative to the arm arbor to provide frictional damping.

Abstract: A tensioner (1) for a belt drive comprises a base(2, 3) defining an axis (A), a mobile element (4) hinged onto axis (A) and defining a guiding surface (22), an elastic helical element (18) having a square or rectangular cross section for actuating the mobile element (4) and an idle pulley (5) surrounding the guiding surface (22). The tensioner (1) further comprises a journal bearing (4, 29, 32, 33) for supporting the pulley (5) on the guiding surface (22).

Abstract: In a hydraulic tensioner having a coiled plunger-biasing spring, the volume of the high pressure oil chamber is reduced by incorporating a bar inside the spring. One of both ends of the spring are formed to block passage of the bar, so that the bar and spring can be installed as a pre-assembled unit, and dropping of the bar out of the spring can be avoided.

Abstract: A tension device for a drive chain of a bicycle including a first pulley having a first rotational axis swingable around a swing center, and a second pulley having a second rotational axis movable along a movable direction to change a distance between the first rotational axis and the second rotational axis. The first pulley is arranged to be forced around the swing center to apply tension to the drive chain, and the second pulley is arranged to be forced along the moving direction to apply tension to the drive chain.

Abstract: An electric power steering apparatus includes a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism includes an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other, and a belt tension adjuster.

Abstract: A belt tensioning system for a motor and a belt-driven blower each secured inside an air handling unit. The blower rotatably carries a first shaft, a first sheave and a bladed arrangement being secured to the first shaft. A second sheave secured to a second shaft is rotatably carried by the motor. A belt engaging the periphery of the first sheave and the second sheave urges the first sheave to rotate about the first shaft in response to the motor urging the second sheave to rotate about the second shaft. An adjuster having adjustment means is secured to the structure. Actuating the adjustment means in a direction urges the motor either toward the adjuster or away from the adjuster to vary the distance between the first sheave and the second sheave to vary the tension in the belt.

Abstract: A drive system for an imaging device of the type having a curved arm. The drive system includes a carrier that engages and supports the curved arm such that the curved arm can be moved along the carrier. The drive system includes a belt extending through the carrier and secured about the periphery of the curved arm. The drive system receives and drives the belt to move the curved arm relative to the carrier. The drive system includes a tensioning mechanism configured to move in such a direction relative to the carrier in order to increase the tension on the belt and to move in such a direction relative to the carrier in order to decrease the tension on the belt.

Abstract: A belt tensioning device for shifting a pulley such that a belt passed around the pulley is tightened to a predetermined tension. The device includes a rod coupled to the pulley, a member coupled to and movable along the rod, and a spring that exerts a reactive force against the member when the member is moved in a first direction along the rod. The device further includes a spacer which engages the member to limit the advancement of the member in the first direction.

Abstract: A pulley fixing apparatus of an office machine having a pulley fixing part rotatably fixing a driven pulley on a frame, a sliding part movably supporting the pulley fixing part on the frame, and an automatic tension adjusting part elastically urging the pulley fixing part in a direction such that the driven pulley imparts a predetermined tension to a power-transmitting belt. The pulley fixing apparatus readily enables mounting and dismounting of the power-transmitting belt and the driven pulley and control of the power-transmitting belt tension by simplifying structure and assembly. Further, the pulley fixing apparatus reduces manufacturing cost and assembly time by decreasing the number of parts.

Abstract: A belt or chain tensioner comprises a plunger that is slidably received in a chamber of the tensioner housing. The plunger is biased by a spring to project out of the housing and into contact with a tensioning shoe by which tension is applied to the chain or belt. The chamber is supplied with hydraulic fluid to damp movement of the plunger within the housing. The spring is captively connected between the plunger and housing and located outside of the housing. The tensioner is simple to install and remove from an internal combustion engine as the plunger and housing are held together by the spring.

Abstract: The invention is an improved belt drive system of the type having an automatic belt tensioner, an automatic belt tensioner pulley, a crankshaft pulley, an accessory pulley, and a power transmission belt trained about the automatic belt tensioner pulley, the crankshaft pulley, and the accessory pulley. It is improved by the inclusion of an initial tensioner.

Abstract: Apparatus and method for monitoring chain pull of a conveyor drive that includes a conveyor drive having a fixed frame, a moveable frame, a spring assembly and a sensor assembly. The moveable frame supports a motor and is biased against the fixed frame by the spring assembly to oppose a force generated by the conveyor drive chain pull. The sensor assembly can be installed or removed without disassembly of the spring assembly and preferably without substantial interruption to the operation of the conveyor drive.

Abstract: A transmission for a self-propelled engine includes an endless transmission (1) with a belt (2) between a driving pulley (3) and a driven pulley (4) carried by the input shaft (5) of a clutch engaging mechanism (7) whose output shaft (6) is coupled to the wheels (20) of the machine. The clutch engaging mechanism (7) is a toothed clutch engagement disposed within a housing (19) mounted oscillably about the output shaft (6) of the clutch engaging mechanism (7) in the direction of tensioning or respectively relaxing the belt (2) of the endless transmission, at least under the action of a control mechanism (13), whose operation is subject to the control member (10) of the clutch engaging mechanism so as to give rise to the passage to the clutch engaged condition of the clutch engaging mechanism (7) and then the tensioning of the belt (2).

Abstract: A quiet drive device for motor vehicle sliding sunroofs is proposed capable of withstanding even strong drive forces and permitting an equal, that is to say, smooth displacement of a cover of the motor vehicle sliding sunroofs. The drive device comprises a toothed belt, which is guided so that two parallel line sections are formed on the toothed belt. On the running line sections the toothed belt, with an external toothing extending without interruption over its outer circumference, is in meshing engagement with two drive cables for a cover. An internal toothing extending without interruption over the inner surface of the toothed belt is in meshing engagement with a toothed pinion that can be driven to rotate in both directions and is partially wrapped by the toothed belt.

Abstract: A device is designed to press the transmission belt of an electric cart and is formed of a pivot set, a first swiveling member, a second swiveling member, a first wheel set, a second wheel set, and an elastic element. The first and the second swiveling members are pivoted with the pivot set such that they are located at two sides of the transmission belt. The first and the second wheel sets are provided with one or more rollers which are pivoted to the first and the second swiveling members. The rollers come in contact with the transmission belt to enhance the transmission effect of the transmission belt. The elastic element provides the first and the second swiveling members with a spring force enabling them to swivel toward the transmission belt.

Abstract: A device for tensioning a drive belt extending between a vehicle power source and its driven attachment is provided. The device includes first and second members slideably coupled together and adapted to extend between and operably engage a first powered shaft member and a second shaft member carried on the attachment. A compression spring is coupled with the slideable members for urging them apart and tensioning a belt entrained around pulleys carried on the two shaft members. An overcenter locking structure is provided to secure the spring in its compressed configuration or release the compression and retract the slideable members for removal, adjustment and/or installation. Adjustable stops abutting the ends of the spring permit the level of spring force to be selected for a variety of applications.

Abstract: A belt tensioning device includes a first element having a threaded opening and a first pulley supported on the first element. The device further includes a second element having an opening in substantial alignment with the threaded opening of the first element and a second pulley supported on the second element. A belt is secured around and between the first and second pulleys. The belt tensioning device also includes an element for applying a tension force to the belt. In one preferred embodiment the element for applying a tension force to the belt includes a rotatable screw extending between the first and second support elements. The screw has a first end including a threaded portion adapted for threadably engaging the threaded opening of the first element and a second end remote therefrom adapted for extending into the opening of the second support element. The element for applying a tension force also includes a shoulder fixed to the screw, between the first and second ends thereof.

Abstract: To provide a belt-drive mechanism wherein the tension degradation of the circular belt and slips of the dviving pulley are prevented, and a precise tension adjustment of the circular belt is enabled aw well, a belt-drive mechanism, having a fixed pulley (24), an adjust pulley (26), a circular belt (25), and an adjustment assembly (41) for adjusting distance between the fixed pulley (24) and the adjust pulley (26) by shifting position of the adjust pulley (26), comprises a pair of fastening members (32) for fixing the distance after the distance is adjusted. The adjustment assembly (41) comprises: a coupling member (31) having a screw hole (30); a pair of elastic members (32) for tensioning the shaft (27) outward of the circular belt (25); and an adjusting screw (29) set through a hole of another supporting face (28) to be screwed into the screw hole (30) of the coupling member.

Abstract: A belt tensioner of the Zed type with a pivot-arm, a pulley attached to the pivot-arm for receiving a belt load, a pivot, a base, and a torsion spring operatively connected between the pivot-arm and base and wherein damping of the pivot-arm is primarily provided by a pivot bushing in response to the belt load and a force generated by the spring.

Abstract: A belt-drive tensioning system for a motor drive positioning system, especially for X-Y digital plotters. The tensioning system employs spring-loading involving motion along only one translational direction to accurately preset and maintain constant the desired belt tension. Preferred embodiments to provide a self-contained modular unit include a dual plate assembly in roller-bearing relationship, and the use of V-shaped mounting springs.

Abstract: In a tensioner in which a tension rod advances from the casing to apply a tension to a chain or timing belt, the advancement of the rod is locked by inserting a pin into a penetrated hole formed at the drawing out portion of the rod. The penetrated hole is sealed to prevent the loss of lubricating oil when the pin is removed.

Abstract: A belt tensioning device for use in a copying machine. The tension device includes two pairs of levers each lever having a first and second arm. A pair of floating rollers are provided to tension the belt by formation of loops in front of and behind, respectively, of an intermittent contact point between the belt and a pressure element moving at a different speed. Each floating roller is suspended in the ends of the first arms of the respective levers. The end of other arms of one pair of levers is connected to the end of the corresponding second arm of the other pair of levers by a tension spring system. One pair of levers has a larger transmission ratio than the other, so that the floating rollers return to their old positions after contact between the belt and pressure element.

Abstract: An endless belt driven wood lathe or the like is disclosed as having an endless belt tension adjustment device for a motor driven belt pulley and associated endless belt. The belt pulley is driven by a generally horizontal shaft extending from a motor that is pivotally mounted to a motor housing. The motor is pivotally mounted to the motor housing along a shaft that is generally parallel to the motor shaft about which the belt pulley is journalled. An endless belt adjustment device is connected to the motor through adjustable slot means in the motor housing to cause the motor to be pivoted relative to the motor housing while predetermined spring tension force is applied to the motor, including the motor shaft journalled belt pulley and endless belt entrained thereabout. The belt pulley preferably includes a series of stepped pulley sections each having an outer surface which is configured to engage a poly-V endless belt in a compact and efficient construction.

Abstract: A novel spring and dual pulley construction wherein the pulley includes a pair of co-axial grooves, one of the grooves having a constant diameter that accepts a powered cable acting in one direction, while the other groove has a varying radius of curvature that accepts a second cable connected to one end of the tension spring and with the other end of the spring fixedly mounted. This arrangement maintains a constant spring force on a member moving along a slide in a reciprocating fashion and having one side thereof connected to said powered cable for movement in one direction and the other side connected to the second cable for movement in the opposite direction activated by a constant spring force regardless of the extension of the spring.

Abstract: An apparatus is disclosed for driving a pair of friction rollers arranged adjacent one another forming a wedge-shaped yarn-forming gap. A common drive belt is run along the surfaces of both rollers and the shaft of an electric motor. The motor is displaceably mounted in a guide which maintains the motor shaft in an essentially parallel relation to the friction roller shafts. The motor shaft can thereby be displaced for the purpose of increasing or decreasing the tension of the drive belt.

Abstract: A tensioner for a power transmission belt that is adapted to be operated in an endless path and a method of making the same are provided, the tensioner comprising a support unit for being fixed relative to the belt, a belt engaging unit carried by the support unit and being movable relative thereto, a mechanical spring unit operatively associated with the support unit and the belt engaging unit for urging the belt engaging unit relative to the support unit and against the belt with force to tension the belt, and a dampening unit operatively associated with the support unit and the belt engaging unit to dampen the movement of the belt engaging unit relative to the support unit, the dampening support unit comprising a shaft. The dampening unit and the spring unit are coaxially spaced apart and coaxially aligned on the shaft with the belt engaging unit having a portion thereof disposed between the dampening unit and the spring unit and being rotatably carried by the shaft.

Abstract: An automatic compaction assembly for compacting samples of asphaltic or bituminous materials is disclosed. A slide hammer is carried for vertical motion along a guide rod which has a compaction foot at a lower end. A drive chain is driven along a generally triangular path by a suitable drive motor and has weight engaging and raising lugs. An upper chain sprocket shuttle and a lower chain sprocket shuttle are slideably carried in a main frame of the compactor and cooperate with a drive sprocket on the drive motor to define the triangular path of chain travel. A horizontal overarm is formed as a portion of the upper shuttle and receives the upper end of the guide rod. As the guide rod moves downwardly, the release point defined by the upper shuttle also moves down thereby maintaining a constant weight drop distance during sample compaction. The slide weight, after being released from the drive chain continues to move upwardly along the guide rod until its upward travel is halted by gravity.

Abstract: A V-belt stretching mechanism to adjust the tension of the V-belt in an internal combustion engine wherein a spring plate has two arms with ends staggered in the longitudinal direction of an adjust bolt. A slide cam has hooks which engage with the arms. Engagement and disengagement of the cam with the arms of the spring plate makes it possible to automatically adjust the tension in the V-belt.

Abstract: A safety interlock system for mounting on the support assembly of a row-crop harvester is provided to protect against damage from a loose or broken gathering member being drawn into the chopper of the harvester. Specifically, the system includes a guide sprocket mounted on an idler arm that is urged by spring means to tension the gathering member. If the gathering member is loose or breaks, the idler arm swings forward under the force of the spring. A linkage, connected to the idler arm, moves in response thereto and interacts with a finger lever to activate a switch. Activation of the switch energizes an interrupter means, such as an electronic clutch, that interrupts the drive to the gathering member. The switch is protected from damage, dirt and debris by being mounted away from the gathering member within a compartment in the support assembly.

Abstract: A treadmill exercising apparatus comprising a generally planar frame equipped with a planar slider bed and head and tail rollers journalled respectively at the head and tail ends of the frame, over which an endless nylon belt is trained. The treadmill frame at its head end is equipped with a cross member that pivotally mounts a motor assembly including an electric drive motor and shaft driven by same that is keyed to a stepping pulley aligned with a stepping pulley keyed to the head roller, and between which a drive pulley belt is tensioned by a tensioning device that subjects the motor assembly to uniform spring biasing action about the pivotal mounting of the motor assembly for uniformly tensioning the pulley belt into drive transmitting relation with the respective pulleys, and with the motor assembly including a hand crank arrangement for manually relieving the pulley belt tension for changing of the pulley belt with respect to the stepping pulleys for convenient speed changing of the treadmill belt.

Abstract: A belt tensioning adjustment assembly for a powered unit including a operating lever and a rotably supported wheel over which a cable passes and friction locking means is provided for fixing the rotated position of the wheel thereby to effect selective non-incremental adjustment of the cable length. The non-incremental adjustment of the cable length allows a drive belt tensioning lever to effect deflection of a belt drive and to effect driving engagement of a motor shaft to a work attachment unit.

Abstract: A tensioner for a power transmission belt that is adapted to be operated in an endless path and a method of making the same are provided, the tensioner comprising a support unit for being fixed relative to the belt, a belt engaging unit carried by the support unit and being movable relative thereto, a mechanical spring unit operatively associated with the support unit and the belt engaging unit for urging the belt engaging unit relative to the support unit and against the belt with a force to tension the belt, and a fluid dampening unit operatively associated with the support unit and the belt engaging unit to dampen the movement of the belt engaging unit relative to the support unit in at least one direction of movement thereof, the fluid dampening unit comprising a rotary dampening unit. The rotary dampening unit and the spring unit are coaxially aligned. The support unit has an opening passing therethrough for receiving a fastening member that will fasten the support unit to a vehicle bracket or the like.

Abstract: A door operator mechanism which has a motive power source and drive and a manual drive for use with a manual source of power. A mechanism is included which by the simple expedient of pulling a chain or cable disconnects the power source and associated driver and connects the manual drive for use of a manual source of power. Release of the cable causes the reverse.

Abstract: A livestock feeding apparatus having an endless belt supported on an elongated table above a feed bunk by a plurality of stands. The stands are laterally and vertically adjustable to level the apparatus and accommodate different sized bunks. The belt has an upper run that rides on a wood deck secured to the support. An idler pulley and drive pulley engages one end of the belt opposite ends. The belt is retained in driving engagement with the drive pulley by a driven roller engageable with the lower run of the belt adjacent the drive pulley. A motor drives the roller at a speed so that the surface speed of the roller is greater than the linear speed of the belt to maintain the lower portion of the run of the belt between the roller and the drive pulley under tension. A sweep assembly slidably mounted on the wood deck operates to move the material off of the side of the top run of the belt into the bunk.

Abstract: A device for maintaining a constant tension on an endless drive belt which supplies power to and drives the vehicle accessories. A mounting bracket is adapted to be mounted on an engine in a stationary position adjacent the drive belt and has an idler pulley rotatably mounted on an end of a lever. The lever is pivotally mounted on a shaft which extends outwardly from the mounting bracket. A torsional coil spring biases the idler pulley into tensioning engagement with the drive belt. The pulley is mounted on a stub shaft which extends parallel with the pivot shaft and is formed with an outer annular belt engaging surface. The pivot shaft is located within the periphery of the pulley belt engaging surface and the radial center line of said belt engaging surface intersects the bearing surface of the pivot shaft to provide a compact, low friction belt tensioner.

Abstract: The stationary drive station comprises a gear chain guided over three sprocket wheels. One sprocket wheel is driven by a drive motor. A tensioning wheel is rotatably journaled at a pivotably mounted lever acted upon by a tension spring. The tensioning wheel acts on the outer side of the gear chain and on the idle run thereof. The driving run of the gear chain extends at its outer side around part of the circumference of a further sprocket wheel. This further sprocket wheel is seated on a shaft carrying a winding core for winding-up printed products and other flat products. The shaft is journaled in a mobile frame which may be removed from the drive station. The driving connection between the gear chain and the further sprocket wheel can be released by upwardly pivoting a holding or holder structure about the axis of the one sprocket wheel driving the gear chain. The two remaining gear chain-sprocket wheels of the aforementioned three sprocket wheels are rotatably journaled at the holding structure.

Abstract: In a belt tensioning device of the type including a fixed structure, a pivoted structure mounted with respect to the fixed structure for pivotal movement about a first axis between first and second limiting positions, a belt engaging pulley rotatably carried by the pivoted structure for rotational movement about a second axis parallel with the first axis and a torsional coil spring acting between the fixed and pivoted structures for resiliently biasing the pivoted structure to move in a direction away from the first limiting position toward the second limiting position with a spring force which decreases as the pivoted structure is moved in a direction away from the first position toward the second position.

Abstract: An electric motor is supported at one end on a molded plastic electrically non-conducting housing which is slidably mounted on the metallic frame of a sewing machine at the base and which is biased toward the base of a compression spring to set tension in a belt through which the motor drives a pulley on the arm shaft of the sewing machine.

Abstract: In a motor support having a slidable carriage on which a motor with a pulley, carrying a belt connected to a pulley on a piece of machinery, is mounted, springs engage the carriage to provide a spring loading for the carriage and a fluid pressure arrangement is provided for moving the carriage initially to tighten the belt and then to compress the springs to the point that the force exerted by the springs on the carriage will be in equilibrium with the tension in the belt between the pulleys with such state of equilibrium being maintained solely by further compression of the springs under belt induced movement of the carriage as the load on the machinery may be increased.

Abstract: A belt drive system comprising a drive sheave, a driven sheave, a belt providing driving engagement between said sheaves and a clutch for engaging and disengaging said driving engagement. The clutch is engaged and disengaged by moving an idler pulley assembly toward and away from the belt and by moving the driven sheave away from and toward the drive sheave. The clutch further includes an actuator member for providing simultaneous coordinated movement of the idler pulley assembly and driven sheave for engagement and disengagement of the clutch.

Abstract: A door member such as a garage door is driven by a motor through a roller chain having a finite length to travel in the garage opening and closing directions. The roller chain is driven by a single drive sprocket driven by the motor to make its reciprocating movement along the same path while making rolling engagement at its roller portion with a guide rail constructed to support the roller portion of the roller chain from the opposite sides. A trolley connected to the door member by an arm is releasably coupled to the roller chain and is also guided along the guide rail while making sliding engagement therewith. A mechanism for detecting abutment of the door member with an obstruction present on the traveling path is provided to detect the above situation when a physical force is imparted to the roller chain due to the abutment. The opening and closing movement of the door member, stopping of rotation of the motor and detection of the presence of an obstruction are electrically controlled.

Abstract: A motor support has a carriage movably mounted by means of gliders, which are cross-sectionally square elongated tubes, that slidably encompass parallel elongated fixed rails on a stationary base bed with plastic or metal bearing sleeves press fitted in the end portions of the glider tubes to bearingly support them on the rails and transfer the motor load on the glider tubes to the rails in a friction free manner with a reservoir of a viscous lubricant within the center portions of the glider tubes.