Abstract: An apparatus to cap in succession containers transported in serial order on a conveyor belt. The apparatus comprises a cap dispensing station operating in a timed-relationship with the container feed rate to loosely apply on each container a screw-type cap in thread alignment with the threads on the container neck. The cap dispensing station includes a cap relase passage at least partially closed by a resilient lip preventing a cap to travel through the passage under the effect of gravity. A selectively actuatable cap ejector drives the cap out of the passage against the resiliency of the lip, freeing the cap which is deposited on a container underneath. During the cap movement through the passage, the resilient lip frictionally engages the cap, guiding same, to allow precise positioning of the cap on the container. A cap tightening station is provided downstream of the cap dispensing station to rotatably engage the caps loosely applied to the containers to tighten same.

Abstract: A method and apparatus for applying closures to containers, and capable of applying stake-on caps having generally rectangular cross-sectional exterior surfaces to container whose bodies are also of the same general cross-section, the parts being delivered in random orientation, and each cap being applied to a container in such a manner that it is in proper orientation with respect to the container when finally assembled. The apparatus includes a turret (54) provided with a non-rotatable cam (108), an interrupted drive gear (114), and an alternate continuous drive gear (124). Mounted on the turret (54) for rotation about the centerline of the turret are a plurality of spindle assemblies (90). When applying a rectangular closure (14) to a container (12) designed to receive the closure in only one position of orientation a novel chuck assembly (130) is employed which has an engagement portion which may be held in one of two detent positions spaced 180.degree. apart.

Abstract: Improved bottle capping chucks are disclosed which are compatible with existing bottle capping machines especially screw capping machines. The chucks define frusto-conical throat surfaces with specially selected taper angles which directly contact and grip the bottle cap. The chucks are designed to assure that no slippage occurs even when twisting torque is applied in screwing a cap onto a bottle at high speed operation. The chucks are of one-piece construction with no moving parts and provide excellent wear and deterioration resistance. The chuck will also accommodate screw caps with upward extending applicator type spouts. A range of chucks of various dimensions will accommodate a range of cap diameters. In a second embodiment of the invention a combination chuck is disclosed which defines a plurality of concentric frusto-conical throat surfaces of successively smaller diameters. This combination chuck can accommodate a wide range of cap diameters and cap and bottle shapes.

Abstract: Apparatus for applying closures to containers held by grippers and moving in a row on a conveyor. The closures are fed from a supply into pockets on a star wheel which delivers them to closure carriers mounted to an applicator wheel which rotates in a plane parallel to and above the closure path of movement, about an axis perpendicular to that of the star wheel. Rotation of the closures carried by the carriers on the applicator wheel is synchronized with the rate of movement of the containers, and the closures are brought into converging alignment with the containers. The applicator wheel has optional means for pressing the closure partially or wholly to a final applied position on the containers, and/or for rotating them while still carried by the carriers to desired torque level.

Abstract: A method and apparatus for applying threaded plastic closures to the necks of containers wherein the containers are moved successively in an upright position and threaded plastic caps are successively applied in loose engagement with the neck of the container and wherein successive independent hold-down forces are provided by independently mounted plates in overlying relation to the path of the containers being transferred to the capping machine and substantially simultaneously a friction force is applied to the sides of the threaded closures by a spring preloaded rail while the successive hold-down forces are applied to rotate the closures and partially thread the closure on the neck of the containers.

Abstract: Apparatus for gripping a container when being capped in a container filling and capping machine is provided and consists of at least two adjustable container gripper belt assemblies oppositely suspended on a table top between a conveyor. The assemblies will grip the container during its travel therealong and prevent rotation of the container when the cap is applied onto a bottle neck of the container by a capping mechanism.

Abstract: Apparatus for applying closures to containers, comprising a first rotating conveyor adapted to move containers to be closed to a second rotating conveyor, and a third rotating conveyor adapted to remove the closed containers from the second conveyor. The second conveyor comprises a rotating supporting element adapted to receive and transfer containers in succession, and grip elements which overlie the supporting element and are adapted to receive in succession closures which are downwardly provided with a tube for extracting the liquid contained in the containers and to screw the closures on the containers after the tubes have entered the containers. The apparatus furthermore comprises grip elements which are adapted to grip the upper portion of the tubes before they are inserted in the containers and to slide toward the lower end of the tubes so as to straighten the tubes and allow them to correctly enter the containers.

Abstract: A device for applying and removing threaded caps to and from threaded filler necks of containers includes a centering device, a rotatable grasping member mounted within the centering device for grasping a cap and turning the cap to thread it relative to the filler neck, a driver within the centering device for rotating the grasping member, and a resilient arrangement in a frame to resiliently hold the centering device relative to the frame and permit the centering device to move axially and radially relative to the frame. The frame and the centering device have sufficient clearance between them to permit axial and radial movement of the entering device relative to frame.

Abstract: Method and apparatus are disclosed for preventing rotation of bottles in a capping machine while caps are screwed onto bottle necks with capper heads which develop slight axial forces. An especially configured stationary guide member develops an off-center, mechanical force on the shoulder of the bottle which produces an anti-rotation frictional force at the bottle base while wedging the bottle into frictional engagement with an especially configured neck pocket in the capper star wheel. The guide and neck pocket are shaped to maintain the bottle in axial alignment with the capper head while the cap is started onto the bottle neck which support is removed when the cap is tightened so that the aforedescribed pocket frictional engagement can occur.

Abstract: A method and apparatus for transferring sample holders to and from workstations positioned along a transfer path, including an entrance support having a first transfer for supplying the sample holders to the transfer path, an exit support for receiving the sample holders from the transfer path, a second transfer for transferring the sample holders along the transfer path past the workstations and a controller for coordinating the actuation of the first and second transfers and the workstations.

Abstract: A closure applying apparatus (1) suitable for use in capping machines for placing, on a container (B) having a threaded neck portion (26) and an annular collar (30) below said neck portion, a tamper-evident screw-type capsule (A) made of rigid plastic material and having a lower skirt portion (27) which is connected by a plurality of thin frangible bridge portions (28) to an upper internally threaded skirt portion (22) and is provided with an inwardly projecting bead (29) for snap engaging beneath said annular collar (30) as a result of screwing of the capsule (a) on the container (B). The apparatus comprises a rotary, vertically reciprocable capping chuck having a plurality of jaws (4) for gripping the capsule (A), each jaw (4) being provided at its lower end with an inner flange (14) which engages from below the edge of the lower skirt portion (27).

Abstract: A machine for threadably engaging a supply of screw caps onto the threaded neck of a supply of containers, comprising in combination: said intermediate turret plate including at least one pocket for receiving the container; means for sequentially infeeding the containers into said container pocket of said intermediate turret plate; at least one chuck spindle mounted relative to said upper turret plate in concentric alignment with said container pocket of said intermediate turret plate, said chuck spindle including a rotatable, non-reciprocable shaft journaled relative to said bracket and a cap chuck rigidly secured to a lower end of said shaft in concentric alignment with said container pocket and said chuck spindle; means for rotating said shaft of said chuck spindle; means for sequentially infeeding the screw caps into said chuck; at least one container platform positioned concentrically below said container pocket of said intermediate turret plate to provide seating for said container; means for vertically

Abstract: A capping machine in which open containers are successively brought to a capping station where a respective container is held against rotation to permit closing of the open container by rotating movement of a cap fed from a reservoir to a pick-up station; a head frame assembly of the machine includes a spindle assembly carrying a chuck at the lower spindle end and drivingly connected by way of an adjustable clutch and by way of a positive drive connection with a driving motor; additionally, the spindle assembly includes a double-acting pneumatic cylinder to cause reciprocation of the spindle in its axial direction; the various components of the head frame assembly are balanced about a pivot shaft on which they are mounted for pivot movement in unison so that the actuating force for pivoting the head frame assembly can be kept relatively small; in operation, the head frame assembly is pivoted from a capping position where the chuck is in alignment with the open end of the container, into a pick-up position whe

Abstract: A container capper is provided which includes a container clamping mechanism for clamping previously-filled containers at a capping station that is positioned at a point along a container conveying means. The capper also includes an adjustable speed rotary motor which drives a capper head having a plurality of radially movable, cap-grasper jaws supported therein for grasping caps and rotating them relative to the containers. Motor speed adjustability and torque sensing are provided to give precise control of the amount of torque with which caps are applied to containers. The capper head is vertically movable from an upper, cycle start, position to an intermediate position, at which the jaws thereof may be loaded with a cap, and to a lower position, at which the loaded cap is placed onto the top of a clamped container and is rotated thereon until a predetermined torque is reached. The capper head is moved between its upper, intermediate and lower positions by means of a camming mechanism.

Abstract: A finger assembly for a rotatable screwcapping head which is capable of gripping and screwing a screw closure onto a prethreaded container. The finger assembly includes a guide member which retains at least two fingers pivotally positioned thereon. The fingers have a concave surface which is capable of gripping the screw closure as the fingers are moved to a closed position. A pair of C-shaped retaining rings encompasses both the guide member and the fingers and serves to secure them to the rotatable screwcapping head. The finger assembly also includes an actuator for pivoting the fingers between a closed position wherein the fingers grip the screw closure and an open position wherein the fingers release the screw closure.

Abstract: A screwcapping head for applying prethreaded closures onto prethreaded containers is disclosed having a hysteresis clutch. The screwcapping head includes a housing adapted to be secured to a rotatable drive spindle and a quill mounted in the housing for free rotation thereto. The screwcapping head also includes a hysteresis clutch having a pair of permanent magnetic rings secured to the housing and a disc of hysteresis material secured to the quill and sandwiched between the pair of permanent magnetic rings. The clutch is capable of slipping after the application of a prethreaded closure onto a prethreaded container at a desired torque value while eliminating the torque reversal feature inherent in synchronous clutches.

Abstract: Apparatus for applying container caps of different sizes to containers includes a main housing arranged for rotation by a driving spindle, an upwardly biased cam rod coaxially disposed relative to the spindle and movable reciprocably, a releasable holding device normally restraining the cam rod against upward movement, a transverse cam follower shaft mounted in a transverse passage formed in the cam rod and having outwardly projecting ends, on which a pair of cam followers are rotatable, a main cam fixed in position relative to the main housing and disposed about the cam rod and having opposed vertical cam tracks in which the outwardly projecting cam followers are disposed, a helix cam arranged for limited angular movement and disposed about the cam rod and within the main cam and having opposed helical cam tracks in which the outwardly projecting ends of the transverse cam followers are disposed whereby limited angular movement is imparted to the helix cam by the biasing means upon release of the cam rod by

Abstract: A capping machine for applying plastic screw-on caps (10) having a tamper evident band 38 to flexible sided round containers (12) having a neck provided with a radially extending flange (24) adjacent the open top of the container. The capping machine includes a portion (114) rotatable about a stationary portion (58), the rotatable portion including a plurality of operating stations (116). Each operating station has a chuck (118) and a novel gripping structure (120) capable of firmly engaging the flange (24) on the container to prevent the container from rotating when a cap is being screwed onto the container. The chucks and gripping structures are each provided with cam followers (122, 124) which engage cams (126, 128) and, as the rotatable portion (116) rotates about the stationary portion (58), the chucks and gripping structures will be shifted vertically in time with each other.

Abstract: A thermoplastic fastener having a slight taper, is friction welded to a thermoplastic workpiece. A system for friction welding the fastener includes a way of automatically stopping rotation of the fastener while contact pressure between the fastener and the workpiece is maintained.

Abstract: A capping head for screwing a prethreaded closure onto a container provided with a screw thread. The capping head includes a housing adapted to be secured to a rotatable drive spindle and having a bore formed therein which is open at one end. A quill is mounted in the housing for free rotation therewith. The quill contains two radial bores which house a pair of poppet valves. The capping head also includes a torque-dependent clutch having a drive plate secured to the housing and a driven plate secured to the quill. The clutch is constructed such that it will stop screwing a prethreaded closure onto a container once a desired, predetermined torque value is reached. A chuck is attached to the driven plate and is fluidly activated between an open and closed position by the poppet valves.

Abstract: A method and apparatus for restraining containers against rotation when being moved through operation stations of a cap application process. In the embodiment shown a resilient belt is supported on a star wheel so that a section of the belt subtends an arc of each container receiving pocket in the star wheel. In response to the reception of a container in a pocket the belt section conforms to and wraps around the contour of the container. The belt surface contacting the container exerts a frictional force that is greater than the frictional force applied to the container by guide rails as the star wheel moves the container past the guide rails. The container is thus restrained against rotation within the pocket during the cap application process.

Abstract: A capping apparatus includes a turn table which is supported to be rotatable and provided with a plurality of container holders for temporarily holding the containers securely, a plurality of cap holders for releasably holding caps to be screwed onto the mouth portion of the containers, a plurality of torque motors individually provided for rotating the corresponding cap holders and a microcomputer for controlling the level of torque applied to the cap holders by the torque motors. The torque applied to the cap holder during the screwing operation is set to be higher in level during the first revolution of the cap and lower in level during the remaining rotation of the cap than the torque applied upon completion of the screwing operation so that the caps can be screwed onto the threaded mouth portions of the containers all at the same tightening level.

Abstract: An automatic tightening method comprises the steps of transferring a torque, generated in a driving section for a screw cap through a power transmission joint section to a container, thereby screw-tightening the screw cap in a tightening apparatus for screw-tightening the screw cap by a rotational torque from the driving section, detecting a tightening torque applied to the container, adjusting the driving section or the power transmission joint section when the tightening torque reaches a predetermined tightening torque, and holding the predetermined tightening torque for a predetermined period of time, thereby obtaining the predetermined tightening torque irrespective of the transmitted rotation torque. Also, an apparatus for carrying out the method is disclosed herein.

Abstract: A capping machine for applying removable closures to bottles, jars or other containers has a capping head cantilevered (without other support) from a post rising from the machine base, the capping head height being infinitely variable by simple adjustment. The side belts which engage the containers are also infinitely variable for height, being carried by a parallelogram structure pivoted on the capping head body and adjustable by means of a single nut. The cap chute has a pair of retractable rollers to locate the closures at the pick-up point, these rollers being mounted on tension-spring biased cranked levers so pivoted that their lever arm, for movement of the roller axes, makes only a small acute angle with the path of the closures. The sealing shoe is suspended in the capping head by a pair of levers which permit the shoe to rock in a vertical plane.

Abstract: A screwcapping machine for screwing a screw closure onto a prethreaded container. The screwcapping machine includes a housing fixed to a stationary support shaft and has a pair of drive motors for independently rotating the turret and the spindles about their own axis. The housing also has a cam which is traversed by a cam follower attached to each spindle which causes the respective spindle to reciprocate. The screwcapping machine further includes a positioning means for selectively orienting the screw closure relative to one of the screwcapping heads when the respective spindle is in a predetermined position and control means for actuating the screwcapping heads to enable the head to grasp the screw closure and tighten it onto the container.

Abstract: For placing prethreaded closure caps on the mouths of screw threaded bottles and effecting preliminary engagement of the caps with the threads of the bottles, the caps are withdrawn successively from a feed chute and supplied to suction pick-up members, which are individually supported by brackets, turning about the center of a star wheel. The brackets are supported by a cam track which raises and lowers the suction pick-up members, which carry the caps on their lower surface. The caps are thus lowered onto the bottles in a level condition and are held level by the pick-up members during preliminary engagement of the caps with the bottle threads. The caps are conveniently rotated by rotating the pick-up members in their brackets through contact with a stationary friction or rack member.

Abstract: This relates to a capper for applying closures to containers. In a packer's plant there is frequently a necessity to modify a capper so as to apply closures to containers of different diameters and different heights with the closures also being different in diameters, thicknesses, etc. In the past, the cappers have been provided with change parts and are in a certain degree adjustable so that a capper can be modified to accept a range of container diameters and heights and closure sizes. However, shut-down time has continued to be an important factor. Further, final adjustment of the capper after modification has been a problem. There has been provided a universal capper which is provided with height and width adjustments for both containers and closures and all of these adjustments may be made while the machine is operating so as to obtain minute adjustments. The changeover time is no longer a factor with the universal capper.

Abstract: A rotary application head for applying a screw-threaded closure to a container includes a collet 26 for gripping the closure, the collet being secured to a drive member 31 having an external flange 36 disposed between a thrust bearing 37 supported by the main body 10 and a friction clutch plate 38 backed by a pressure plate 40 which is driven by the body through pins 42. A piston 17 disposed in a pneumatic cylinder 16 in the body acts through push rods 19 to apply a predetermined axial loading between the pressure plate 40, friction clutch plate 30 and the flange 36. When the closure reaches a predetermined tightness, the reaction torque causes the collet and drive member to slip relative to the pressure plate and body, preventing over-tightening of the closure. External axial forces applied to the collet cause the piston 17 to be displaced axially to compensate for these forces without altering the torque at which slipping occurs.

Abstract: A rotary type capping apparatus for screwing caps onto the mouths of containers includes a turn table provided with a plurality of container holders fixedly mounted along the periphery thereof, a main motor for rotating the turn table in a predetermined direction and a capping head assembly including a plurality of cap holders, each of which is disposed above the corresponding one of the plurality of container holders, so as to be movable closer to or away from the turn table. In one aspect of the present invention, the capping apparatus includes at least one motor exclusively used for rotating the cap holders for causing the caps held by the cap holders to be screwed onto the mouths of containers. In another aspect of the present invention, the capping apparatus is so structured to increase the torque applied to a cap until it has reached a predetermined level during the cap screwing operation thereby insuring that all caps may be screwed on as tightly as desired.

Abstract: A container capping apparatus having a generally vertical tubular spindle carrying a cap holding chuck assembly is rotatable about its axis to apply a screw cap to a container with predetermined force. A control rod is vertically movable within the spindle against an actuator spring to release the applied cap from the chuck. An axle carried by the control rod projects through vertically elongated slots in opposite sides of the spindle, and is received in a control collar slidable on the spindle. A cam follower is carried by a yoke vertically slidable on the spindle and an external adjusting nut is carried by the yoke for movement therewith in operative engagement with the collar. The vertical position of the nut relative to the yoke is selectively adjustable, thereby to adjust the position of the control rod relative to the cam follower.

Abstract: This invention provides a pre-tightening mechanism for effecting the initial application of a threaded closure on a threaded bottle neck. The pre-tightening mechanism includes a friction rail for effecting a turning movement of the closure relative to the bottle neck and a spring biased cap hold-down plate which maintains a substantially constant pressure on the closure and maintains the closure panel horizontal during the pre-tightening operation.

Abstract: A sealing machine is disclosed of the type which applies closure caps to containers at extremely high speeds by moving filled containers successively through a cap feeding station, a cap applying station, and a cap sealing station. The machine is characterized by improvements in its several sections which permit it to operate effectively at increased speeds, and at the same time provide for an improved adjustability for differing package sizes. The adjustability provides for independently operable adjustments for the sealing chamber height and for the width and height of the side belts which move the containers through the sealing chamber. Additionally, an improved cap feed is described with a cap feeding star wheel and improved container guiding side belts are also disclosed.

Abstract: An improved sealing machine cap pickup is disclosed. The cap pickup is mounted on a sealing machine to feed closure caps onto filled containers being carried through the machine and to lightly turn the caps onto the containers. The pickup includes an improved universally mounted cap guide which directs the caps to a cap applying means such as spaced resiliently mounted and relatively deep cap applying belts or cap rotating friction shoes. Pressure backup plates are positioned above the cap rotating means for urging the caps downwardly at the correct rate as they are turned onto the moving containers.

Abstract: Apparatus wherein a body includes a passageway having one end adapted to receive the neck of a container and the other end in communication with a closure magazine, and a roller mounted in the body generally tangential to the passageway for rolling engagement with a closure, the roller being configured with a reduced region for passing a closure into generally tangential relation, roller rotation in opposite directions serving to tangentially rotate a closure to closed and opened relation upon opposite directional roller rotation, respectively.

Abstract: A capping machine turret has a number of circumferentially spaced screw-cap applying spindles with a cap engaging chuck at the lower end of each spindle. Each screw cap applying spindle of the capping machine is rotated by means which frictionally applies an accurately predetermined torque to the spindle and therefore to the cap engaging chuck at the lower end of the spindle. This is accomplished by providing a pair of pinions which are rotatably mounted on each spindle and are continuously rotated by drive means associated with the turret generally. Drive washers are provided at the outer radial faces of the two pinions and between the pinions and these drive washers have internal spline formations which interfit with external spline formations on the spindle.

Abstract: A method and means are described for improving the feeding of closures and containers to a sealing machine. Sealing machines utilize container controlled trips for controlling the stop and start of the closure feed to the sealing section to synchronize the container and closure feeds. Means is provided for compensating the action of the container controlled trip in accordance with the operating speed of the sealing machine. This permits changes in the machine speed to occur or to be made while retaining the necessary synchronization of the cap and the container feeds.

Abstract: An apparatus for capping and uncapping containers includes a framework for storing screw-on caps in a number of stacked columns. A guide for aligning containers, such as bottles or vials held in a standard holder, consists of two members movable with respect to one another and defining a number of openings of adjustable size into which the containers are to project so as to become aligned with the stacked caps. An endless, cogged belt is operatively positioned within grooves formed on longitudinal surfaces of the members, portions of the cogged belt projecting into the openings defined by the members into which the containers are to project. This cogged belt in operation contacts the exterior surface of screw-on caps and turns them with respect to the threaded necks of the containers on to which they are to be placed or from which they are to be removed. The two members can be moved apart relative to one another in order to allow the necks of the containers and the caps to be positioned within the openings.

Abstract: An apparatus for directing and seating a closure having abutments disposed about its interior periphery, with a container having mating grooves for receiving such closure. The preferred embodiment employs an overhead adjustable belt for correctly positioning and guiding the closure onto a moving container by applying a continuous downward force across the top of the closure once it comes to rest upon the container. The container in turn is caused to be contacted at its periphery by a rotating belt and a back-up stationary surface. The resultant torque imparted thereto urges, the container to turn and positively engage and lock with the closure abutments.An alternate embodiment, employs a knurled roller disposed along the container-closure line of travel for initially positioning the closure on the container by engagement with the closure at its periphery. A frictional pawl further upstream, contacts the already positioned closure to cause initial locking between the closure abutments and container grooves.

Abstract: This invention relates to an apparatus for moving a plurality of two-piece canning jar-type lids in series to a feed mechanism in the form of a magazine which will single-line the caps and maintain them in assembled position. The single-lining mechanism is designed to feed lids into the path of movement of a plurality of containers, also moving in series on their sides with their axes horizontal. The caps or lids are carried at an angle to the path of movement of the finish of the jars such as that the finish of the jars or containers will each individually remove a cap from the supply of caps. The caps are then retained on the finish of the jar and are moved with the jar, in a linear path, with the caps being rotated by frictional engagement and thereby threaded onto the finish of the containers.

Abstract: This disclosure relates to a capping machine for applying caps to containers, such as jars. The capping machine is provided with a simple automatic cap feed wherein the caps are gravity fed through an orienting chute which directs the caps towards a cap locating station with which there is aligned a capping chuck. The caps are primarily advanced by gravity and as they approach the cap locating station, fluid jets, preferably steam, are directed against the caps to advance them to their positions in alignment with the capping chuck. Means are also provided for directing jets of steam into the top of a container to which a cap is to be applied to displace air between the container neck and the cap and thus create a partial vacuum within the sealed container.

Abstract: An automatic stoppering apparatus for bottles and the like having threaded necks with matching threaded stoppers is adapted upon feed of the bottles into the apparatus wherein they are carried on and by a generally vertically disposed rotating drum to screw the stoppers into sealing engagement with the bottles during rotation of the drum and before discharge of the bottles by means of associated rotatably and vertically movable stopper grasping and attaching heads that cooperate with the rotating drum in operation of the apparatus.

Abstract: A housing that is continuously rotatable on a vertical axis has an opening in its bottom and contains a central vertical shaft rotatable a limited number of degrees relative to the housing. This shaft is connected through the housing opening with a chuck that contains means for gripping a screw cap to screw it onto a container. Valve means connect a source of air pressure with the gripping means to cause such means to grip a screw cap. Secured to the housing is a valve member provided with a bleed passage through it, the inlet of which is connected with the air pressure source and the outlet of which normally is closed by a closure member. Projecting from the side of the shaft is a torque arm that is pressed by compressible means carried by the housing to cause stop means projecting from the side of the shaft to move the closure member away from the bleed passage a certain distance.

Abstract: An apparatus for capping a flexible container having a predetermined amount of fluid therein wherein a member is provided for engaging and compressing an area of said flexible container during the capping operation. The member, in compressing said container, causes the liquid to be raised or elevated in the container and held closer to the top thereof while the cap or closure is being tightened upon the container. The seal of the cap or closure member is such that air cannot reenter the container and the liquid will remain at the elevated position within the container.

Abstract: This invention provides a pre-tightening mechanism for effecting the initial application of a threaded closure on a threaded bottle neck. The pre-tightening mechanism includes a friction rail for effecting a turning movement of the closure relative to the bottle neck and a spring biased cap hold-down plate which maintains a substantially constant pressure on the closure and maintains the closure panel horizontal during the pre-tightening operation.